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Sample records for chlorella virus deoxyuridine

  1. Structural organization of DNA in chlorella viruses.

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    Timo Wulfmeyer

    Full Text Available Chlorella viruses have icosahedral capsids with an internal membrane enclosing their large dsDNA genomes and associated proteins. Their genomes are packaged in the particles with a predicted DNA density of ca. 0.2 bp nm(-3. Occasionally infection of an algal cell by an individual particle fails and the viral DNA is dynamically ejected from the capsid. This shows that the release of the DNA generates a force, which can aid in the transfer of the genome into the host in a successful infection. Imaging of ejected viral DNA indicates that it is intimately associated with proteins in a periodic fashion. The bulk of the protein particles detected by atomic force microscopy have a size of ∼60 kDa and two proteins (A278L and A282L of about this size are among 6 basic putative DNA binding proteins found in a proteomic analysis of DNA binding proteins packaged in the virion. A combination of fluorescence images of ejected DNA and a bioinformatics analysis of the DNA reveal periodic patterns in the viral DNA. The periodic distribution of GC rich regions in the genome provides potential binding sites for basic proteins. This DNA/protein aggregation could be responsible for the periodic concentration of fluorescently labeled DNA observed in ejected viral DNA. Collectively the data indicate that the large chlorella viruses have a DNA packaging strategy that differs from bacteriophages; it involves proteins and share similarities to that of chromatin structure in eukaryotes.

  2. Association of Paramecium bursaria Chlorella viruses with Paramecium bursaria cells: ultrastructural studies.

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    Yashchenko, Varvara V; Gavrilova, Olga V; Rautian, Maria S; Jakobsen, Kjetill S

    2012-05-01

    Paramecium bursaria Chlorella viruses were observed by applying transmission electron microscopy in the native symbiotic system Paramecium bursaria (Ciliophora, Oligohymenophorea) and the green algae Chlorella (Chlorellaceae, Trebouxiophyceae). Virus particles were abundant and localized in the ciliary pits of the cortex and in the buccal cavity of P. bursaria. This was shown for two types of the symbiotic systems associated with two types of Chlorella viruses - Pbi or NC64A. A novel quantitative stereological approach was applied to test whether virus particles were distributed randomly on the Paramecium surface or preferentially occupied certain zones. The ability of the virus to form an association with the ciliate was investigated experimentally; virus particles were mixed with P. bursaria or with symbiont-free species P. caudatum. Our results confirmed that in the freshwater ecosystems two types of P. bursaria -Chlorella symbiotic systems exist, those without Chlorella viruses and those associated with a large amount of the viruses. The fate of Chlorella virus particles at the Paramecium surface was determined based on obtained statistical data and taking into account ciliate feeding currents and cortical reorganization during cell division. A life cycle of the viruses in the complete symbiotic system is proposed. Copyright © 2011 Elsevier GmbH. All rights reserved.

  3. Simple detection of hepatitis C virus using {sup 125}I-2'-deoxyuridine triphosphate and gamma counter

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    Lee, Soo Jin; Ahn, S. H.; Chung, W. S.; Woo, K. S.; Lim, S. J.; Choi, C. W.; Lim, S. M. [Korea Cancer Center Hospital, Seoul (Korea, Republic of)

    2000-07-01

    Hepatitis C Virus (HCV) is the major cause of post transfusion and sporadic non A, non B hepatitis. Current infection of HCV can be detected by PCR method. Using PCR, it has been possible to detect HCV viremia prior to immunological sero-conversion and to detect fluctuation of viremia in antibody-positive chronic HCV patients undergoing therapy with interferon. In this study, we established the simple method to detect HCV DNA by incorporation of {sup 125}I-deoxyuridine triphosphate(dUTP) into DNA during the PCR, and counted the radioactivity of PCR product by gamma counter. {sup 125}I-2'-deoxyuridine 5'-triphosphate was prepared, and incorporated into DNA during PCR. dUTP was radiolabeled by the iododemercuration of 5-mercuri intermediate. Iododemercuration labeling was completed with 98% yield and the obtained product was incorporated into DNA without further purification. After incorporation, covalently bonded radioiodine substituent was remained stable during PCR procedure HCV positive standard and positive patient sera in immunological assay were centrifuged. HCV RNA is isolated from by GTC(Guanidine Thiocyanate) and phenol/chloroform extraction method and synthesized complementary DNA by using reverse transcriptase. The '1{sup 25}I-dUTP was incorporated into HCV C DNA during PCR. PCR product purified by fiber matrix column and counted by gamma counter. PCR products were electrophoresized, and autoradiography image obtained. Amplified HCV DNA by {sup 125}I-dUTP PCR obtained the band on the gel by electrophoresis and autoradiography at the same position. In patient sera, radioactivity of HCV positive sample was 8 times higher than HCV negative viremia sample. We established HCV detection method using {sup 125}I-dUTP. {sup 125}I-dUTP PCR detection of HCV is convenient and reporducible.

  4. Metabolism of the carbocyclic analogue of (E)-5-(2-iodovinyl)-2'-deoxyuridine in herpes simplex virus-infected cells. Incorporation of C-IVDU into DNA

    International Nuclear Information System (INIS)

    De Clercq, E.; Bernaerts, R.; Balzarini, J.; Herdewijn, P.; Verbruggen, A.

    1985-01-01

    The carbocyclic analogues of (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU) and (E)-5-(2-iodovinyl)-2'-deoxyuridine (IVDU), in which the sugar moiety is replaced by a cyclopentane ring and which have been designated as C-BVDU and C-IVDU, respectively, are, like their parent compounds BVDU and IVDU, potent and selective inhibitors of herpes simplex virus type 1 (HSV-1) and, to a lesser extent, herpes simplex virus type 2 (HSV-2) replication. The authors have now synthesized the radiolabeled C-IVDU analogue, C-[ 125 I]IVDU, and determined its metabolism by HSV-infected and mock-infected Vero cells. C-[ 125 I]IVDU was effectively phosphorylated by HSV-1-infected cells and, to a lesser extent, HSV-2-infected cells. C-[ 125 I]IVDU was not phosphorylated to an appreciable extent by either mock-infected cells or cells that had been infected with a thymidine kinase-deficient mutant of HSV-1. Furthermore, C-[ 125 I]IVDU was incorporated into both viral and cellular DNA of HSV-1-infected Vero cells. This finding represents the first demonstration of the incorporation of a cyclopentylpyrimidine into DNA

  5. Sequence and annotation of the 314-kb MT325 and the 321-kb FR483 viruses that infect Chlorella Pbi.

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    Fitzgerald, Lisa A; Graves, Michael V; Li, Xiao; Feldblyum, Tamara; Hartigan, James; Van Etten, James L

    2007-02-20

    Viruses MT325 and FR483, members of the family Phycodnaviridae, genus Chlorovirus, infect the fresh water, unicellular, eukaryotic, chlorella-like green alga, Chlorella Pbi. The 314,335-bp genome of MT325 and the 321,240-bp genome of FR483 are the first viruses that infect Chlorella Pbi to have their genomes sequenced and annotated. Furthermore, these genomes are the two smallest chlorella virus genomes sequenced to date, MT325 has 331 putative protein-encoding and 10 tRNA-encoding genes and FR483 has 335 putative protein-encoding and 9 tRNA-encoding genes. The protein-encoding genes are almost evenly distributed on both strands, and intergenic space is minimal. Approximately 40% of the viral gene products resemble entries in public databases, including some that are the first of their kind to be detected in a virus. For example, these unique gene products include an aquaglyceroporin in MT325, a potassium ion transporter protein and an alkyl sulfatase in FR483, and a dTDP-glucose pyrophosphorylase in both viruses. Comparison of MT325 and FR483 protein-encoding genes with the prototype chlorella virus PBCV-1 indicates that approximately 82% of the genes are present in all three viruses.

  6. Virus-host interactions: insights from the replication cycle of the large Paramecium bursaria chlorella virus.

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    Milrot, Elad; Mutsafi, Yael; Fridmann-Sirkis, Yael; Shimoni, Eyal; Rechav, Katya; Gurnon, James R; Van Etten, James L; Minsky, Abraham

    2016-01-01

    The increasing interest in cytoplasmic factories generated by eukaryotic-infecting viruses stems from the realization that these highly ordered assemblies may contribute fundamental novel insights to the functional significance of order in cellular biology. Here, we report the formation process and structural features of the cytoplasmic factories of the large dsDNA virus Paramecium bursaria chlorella virus 1 (PBCV-1). By combining diverse imaging techniques, including scanning transmission electron microscopy tomography and focused ion beam technologies, we show that the architecture and mode of formation of PBCV-1 factories are significantly different from those generated by their evolutionary relatives Vaccinia and Mimivirus. Specifically, PBCV-1 factories consist of a network of single membrane bilayers acting as capsid templates in the central region, and viral genomes spread throughout the host cytoplasm but excluded from the membrane-containing sites. In sharp contrast, factories generated by Mimivirus have viral genomes in their core, with membrane biogenesis region located at their periphery. Yet, all viral factories appear to share structural features that are essential for their function. In addition, our studies support the notion that PBCV-1 infection, which was recently reported to result in significant pathological outcomes in humans and mice, proceeds through a bacteriophage-like infection pathway. © 2015 John Wiley & Sons Ltd.

  7. Focus formation and neoplastic transformation by herpes simplex virus type 2 inactivated intracellularly by 5-bromo-2'-deoxyuridine and near UV light

    International Nuclear Information System (INIS)

    Manak, M.M.; Aurelian, L.; Ts'o, P.O.

    1981-01-01

    The induction of focus formation in low serum and of neoplastic transformation of Syrian hamster embryo cells was examined after the expression of herpes simplex virus type 2 functions. Syrian hamster embryo cells infected at a high multiplicity (5 PFU/cell) with 5-bromo-2'-deoxyuridine-labeled herpes simplex virus type 2 (11% substitution of thymidine residues) were exposed to near UV light irradiation at various times postinfection. This procedure specifically inactivated the viral genome, while having little, if any, effect on the unlabeled cellular DNA. Focus formation in 1% serum and neoplastic transformation were observed in cells exposed to virus inactivated before infection, but the frequency was enhanced (15- to 27-fold) in cells in which the virus was inactivated at 4 to 8 h postinfection. Only 2 to 45 independently isolated foci were capable of establishing tumorigenic lines. The established lines exhibited phenotypic alterations characteristic of a transformed state, including reduced serum requirement, anchorage-independent growth, and tumorigenicity. They retained viral DNA sequences and, even at relatively late passage, expressed viral antigens, including ICP 10

  8. Quantitative uptake studies of 131I-labeled (E)-5-(2-iodovinyl)-2'-deoxyuridine in herpes simplex virus-infected cells in vitro

    International Nuclear Information System (INIS)

    Gill, M.J.; Samuel, J.; Wiebe, L.I.; Knaus, E.E.; Tyrrell, D.L.

    1984-01-01

    We have synthesized a 131 I-radiolabeled antiviral compound (E)-5-(2-iodovinyl)-2'-deoxyuridine (IVdU) and shown that this agent was selectively trapped within rabbit kidney cells, infected in vitro by thymidine kinase-positive (TK+) herpes simplex virus (HSV). The uptake of 131 I-labeled IVdU was specific, as it was not concentrated within either HSV (TK-) or mock-infected cells. In certain conditions, over 40% of the radiolabel was selectively trapped within HSV (TK+)-infected cells. This was a 20- to 30-fold increase over the uptake of 131 I-labeled IVdU by HSV (TK-) or mock-infected cells. The uptake of 131 I-labeled IVdU varied directly with (i) the dose of the virus used to infect the rabbit kidney cells; (ii) the concentration of radiolabeled IVdU added to the system; and (iii) the time of exposure of IVdU to infected cells. The ability of this agent to be trapped within HSV (TK+)-infected cells merits further evaluation in animal models as it has potential as a noninvasive, herpes-specific diagnostic test, in particular for HSV encephalitis

  9. Footprinting of Chlorella virus DNA ligase bound at a nick in duplex DNA.

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    Odell, M; Shuman, S

    1999-05-14

    The 298-amino acid ATP-dependent DNA ligase of Chlorella virus PBCV-1 is the smallest eukaryotic DNA ligase known. The enzyme has intrinsic specificity for binding to nicked duplex DNA. To delineate the ligase-DNA interface, we have footprinted the enzyme binding site on DNA and the DNA binding site on ligase. The size of the exonuclease III footprint of ligase bound a single nick in duplex DNA is 19-21 nucleotides. The footprint is asymmetric, extending 8-9 nucleotides on the 3'-OH side of the nick and 11-12 nucleotides on the 5'-phosphate side. The 5'-phosphate moiety is essential for the binding of Chlorella virus ligase to nicked DNA. Here we show that the 3'-OH moiety is not required for nick recognition. The Chlorella virus ligase binds to a nicked ligand containing 2',3'-dideoxy and 5'-phosphate termini, but cannot catalyze adenylation of the 5'-end. Hence, the 3'-OH is important for step 2 chemistry even though it is not itself chemically transformed during DNA-adenylate formation. A 2'-OH cannot substitute for the essential 3'-OH in adenylation at a nick or even in strand closure at a preadenylated nick. The protein side of the ligase-DNA interface was probed by limited proteolysis of ligase with trypsin and chymotrypsin in the presence and absence of nicked DNA. Protease accessible sites are clustered within a short segment from amino acids 210-225 located distal to conserved motif V. The ligase is protected from proteolysis by nicked DNA. Protease cleavage of the native enzyme prior to DNA addition results in loss of DNA binding. These results suggest a bipartite domain structure in which the interdomain segment either comprises part of the DNA binding site or undergoes a conformational change upon DNA binding. The domain structure of Chlorella virus ligase inferred from the solution experiments is consistent with the structure of T7 DNA ligase determined by x-ray crystallography.

  10. The Chlorella variabilis NC64A Genome Reveals Adaptation to Photosymbiosis, Coevolution with Viruses, and Cryptic Sex

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    Blanc, Guillaume; Duncan, Garry A.; Agarakova, Irina; Borodovsky, Mark; Gurnon, James; Kuo, Alan; Lindquist, Erika; Lucas, Susan; Pangailinan, Jasmyn; Polle, Juergen; Salamov, Asaf; Terry, Astrid; Yamada, Takashi; Dunigan, David D.; Grigoriev, Igor V.; Claverie, Jean-Michel; Etten, James L. Van

    2010-05-06

    Chlorella variabilis NC64A, a unicellular photosynthetic green alga (Trebouxiophyceae), is an intracellular photobiont of Paramecium bursaria and a model system for studying virus/algal interactions. We sequenced its 46-Mb nuclear genome, revealing an expansion of protein families that could have participated in adaptation to symbiosis. NC64A exhibits variations in GC content across its genome that correlate with global expression level, average intron size, and codon usage bias. Although Chlorella species have been assumed to be asexual and nonmotile, the NC64A genome encodes all the known meiosis-specific proteins and a subset of proteins found in flagella. We hypothesize that Chlorella might have retained a flagella-derived structure that could be involved in sexual reproduction. Furthermore, a survey of phytohormone pathways in chlorophyte algae identified algal orthologs of Arabidopsis thaliana genes involved in hormone biosynthesis and signaling, suggesting that these functions were established prior to the evolution of land plants. We show that the ability of Chlorella to produce chitinous cell walls likely resulted from the capture of metabolic genes by horizontal gene transfer from algal viruses, prokaryotes, or fungi. Analysis of the NC64A genome substantially advances our understanding of the green lineage evolution, including the genomic interplay with viruses and symbiosis between eukaryotes.

  11. Global analysis of Chlorella variabilis NC64A mRNA profiles during the early phase of Paramecium bursaria chlorella virus-1 infection.

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    Janet M Rowe

    Full Text Available The PBCV-1/Chlorella variabilis NC64A system is a model for studies on interactions between viruses and algae. Here we present the first global analyses of algal host transcripts during the early stages of infection, prior to virus replication. During the course of the experiment stretching over 1 hour, about a third of the host genes displayed significant changes in normalized mRNA abundance that either increased or decreased compared to uninfected levels. The population of genes with significant transcriptional changes gradually increased until stabilizing at 40 minutes post infection. Functional categories including cytoplasmic ribosomal proteins, jasmonic acid biosynthesis and anaphase promoting complex/cyclosomes had a significant excess in upregulated genes, whereas spliceosomal snRNP complexes and the shikimate pathway had significantly more down-regulated genes, suggesting that these pathways were activated or shut-down in response to the virus infection. Lastly, we examined the expression of C. varibilis RNA polymerase subunits, as PBCV-1 transcription depends on host RNA polymerases. Two subunits were up-regulated, RPB10 and RPC34, suggesting that they may function to support virus transcription. These results highlight genes and pathways, as well as overall trends, for further refinement of our understanding of the changes that take place during the early stages of viral infection.

  12. Efficient DNA ligation in DNA–RNA hybrid helices by Chlorella virus DNA ligase

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    Lohman, Gregory J. S.; Zhang, Yinhua; Zhelkovsky, Alexander M.; Cantor, Eric J.; Evans, Thomas C.

    2014-01-01

    Single-stranded DNA molecules (ssDNA) annealed to an RNA splint are notoriously poor substrates for DNA ligases. Herein we report the unexpectedly efficient ligation of RNA-splinted DNA by Chlorella virus DNA ligase (PBCV-1 DNA ligase). PBCV-1 DNA ligase ligated ssDNA splinted by RNA with kcat ≈ 8 x 10−3 s−1 and KM DNA ligase produced only 5′-adenylylated DNA with a 20-fold lower kcat and a KM ≈ 300 nM. The rate of ligation increased with addition of Mn2+, but was strongly inhibited by concentrations of NaCl >100 mM. Abortive adenylylation was suppressed at low ATP concentrations (8, leading to increased product yields. The ligation reaction was rapid for a broad range of substrate sequences, but was relatively slower for substrates with a 5′-phosphorylated dC or dG residue on the 3′ side of the ligation junction. Nevertheless, PBCV-1 DNA ligase ligated all sequences tested with 10-fold less enzyme and 15-fold shorter incubation times than required when using T4 DNA ligase. Furthermore, this ligase was used in a ligation-based detection assay system to show increased sensitivity over T4 DNA ligase in the specific detection of a target mRNA. PMID:24203707

  13. Response of Mammalian Macrophages to Challenge with the Chlorovirus Acanthocystis turfacea Chlorella Virus 1.

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    Petro, Thomas M; Agarkova, Irina V; Zhou, You; Yolken, Robert H; Van Etten, James L; Dunigan, David D

    2015-12-01

    It was recently reported that 44% of the oropharyngeal samples from the healthy humans in a study cohort had DNA sequences similar to that of the chlorovirus ATCV-1 (Acanthocystis turfacea chlorella virus 1, family Phycodnaviridae) and that these study subjects had decreases in visual processing and visual motor speed compared with individuals in whom no virus was detected. Moreover, mice inoculated orally with ATCV-1 developed immune responses to ATCV-1 proteins and had decreases in certain cognitive domains. Because heightened interleukin-6 (IL-6), nitric oxide (NO), and ERK mitogen-activated protein (MAP) kinase activation from macrophages are linked to cognitive impairments, we evaluated cellular responses and viral PFU counts in murine RAW264.7 cells and primary macrophages after exposure to ATCV-1 in vitro for up to 72 h after a virus challenge. Approximately 8% of the ATCV-1 inoculum was associated with macrophages after 1 h, and the percentage increased 2- to 3-fold over 72 h. Immunoblot assays with rabbit anti-ATCV-1 antibody detected a 55-kDa protein consistent with the viral capsid protein from 1 to 72 h and increasing de novo synthesis of a previously unidentified 17-kDa protein beginning at 24 h. Emergence of the 17-kDa protein did not occur and persistence of the 55-kDa protein declined over time when cells were exposed to heat-inactivated ATCV-1. Moreover, starting at 24 h, RAW264.7 cells exhibited cytopathic effects, annexin V staining, and cleaved caspase 3. Activation of ERK MAP kinases occurred in these cells by 30 min postchallenge, which preceded the expression of IL-6 and NO. Therefore, ATCV-1 persistence in and induction of inflammatory factors by these macrophages may contribute to declines in the cognitive abilities of mice and humans. Virus infections that persist in and stimulate inflammatory factors in macrophages contribute to pathologies in humans. A previous study showed that DNA sequences homologous to the chlorovirus ATCV-1 were

  14. Structure-function analysis of the OB and latch domains of chlorella virus DNA ligase.

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    Samai, Poulami; Shuman, Stewart

    2011-06-24

    Chlorella virus DNA ligase (ChVLig) is a minimized eukaryal ATP-dependent DNA sealing enzyme with an intrinsic nick-sensing function. ChVLig consists of three structural domains, nucleotidyltransferase (NTase), OB-fold, and latch, that envelop the nicked DNA as a C-shaped protein clamp. The OB domain engages the DNA minor groove on the face of the duplex behind the nick, and it makes contacts to amino acids in the NTase domain surrounding the ligase active site. The latch module occupies the DNA major groove flanking the nick. Residues at the tip of the latch contact the NTase domain to close the ligase clamp. Here we performed a structure-guided mutational analysis of the OB and latch domains. Alanine scanning defined seven individual amino acids as essential in vivo (Lys-274, Arg-285, Phe-286, and Val-288 in the OB domain; Asn-214, Phe-215, and Tyr-217 in the latch), after which structure-activity relations were clarified by conservative substitutions. Biochemical tests of the composite nick sealing reaction and of each of the three chemical steps of the ligation pathway highlighted the importance of Arg-285 and Phe-286 in the catalysis of the DNA adenylylation and phosphodiester synthesis reactions. Phe-286 interacts with the nick 5'-phosphate nucleotide and the 3'-OH base pair and distorts the DNA helical conformation at the nick. Arg-285 is a key component of the OB-NTase interface, where it forms a salt bridge to the essential Asp-29 side chain, which is imputed to coordinate divalent metal catalysts during the nick sealing steps.

  15. Functional Dissection of the DNA Interface of the Nucleotidyltransferase Domain of Chlorella Virus DNA Ligase*

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    Samai, Poulami; Shuman, Stewart

    2011-01-01

    Chlorella virus DNA ligase (ChVLig) has pluripotent biological activity and an intrinsic nick-sensing function. ChVLig consists of three structural modules that envelop nicked DNA as a C-shaped protein clamp: a nucleotidyltransferase (NTase) domain and an OB domain (these two are common to all DNA ligases) as well as a distinctive β-hairpin latch module. The NTase domain, which performs the chemical steps of ligation, binds the major groove flanking the nick and the minor groove on the 3′-OH side of the nick. Here we performed a structure-guided mutational analysis of the NTase domain, surveying the effects of 35 mutations in 19 residues on ChVLig activity in vivo and in vitro, including biochemical tests of the composite nick sealing reaction and of the three component steps of the ligation pathway (ligase adenylylation, DNA adenylylation, and phosphodiester synthesis). The results highlight (i) key contacts by Thr-84 and Lys-173 to the template DNA strand phosphates at the outer margins of the DNA ligase footprint; (ii) essential contacts of Ser-41, Arg-42, Met-83, and Phe-75 with the 3′-OH strand at the nick; (iii) Arg-176 phosphate contacts at the nick and with ATP during ligase adenylylation; (iv) the role of Phe-44 in forming the protein clamp around the nicked DNA substrate; and (v) the importance of adenine-binding residue Phe-98 in all three steps of ligation. Kinetic analysis of single-turnover nick sealing by ChVLig-AMP underscored the importance of Phe-75-mediated distortion of the nick 3′-OH nucleoside in the catalysis of DNA 5′-adenylylation (step 2) and phosphodiester synthesis (step 3). Induced fit of the nicked DNA into a distorted conformation when bound within the ligase clamp may account for the nick-sensing capacity of ChVLig. PMID:21335605

  16. Structure-Function Analysis of the OB and Latch Domains of Chlorella Virus DNA Ligase*

    Science.gov (United States)

    Samai, Poulami; Shuman, Stewart

    2011-01-01

    Chlorella virus DNA ligase (ChVLig) is a minimized eukaryal ATP-dependent DNA sealing enzyme with an intrinsic nick-sensing function. ChVLig consists of three structural domains, nucleotidyltransferase (NTase), OB-fold, and latch, that envelop the nicked DNA as a C-shaped protein clamp. The OB domain engages the DNA minor groove on the face of the duplex behind the nick, and it makes contacts to amino acids in the NTase domain surrounding the ligase active site. The latch module occupies the DNA major groove flanking the nick. Residues at the tip of the latch contact the NTase domain to close the ligase clamp. Here we performed a structure-guided mutational analysis of the OB and latch domains. Alanine scanning defined seven individual amino acids as essential in vivo (Lys-274, Arg-285, Phe-286, and Val-288 in the OB domain; Asn-214, Phe-215, and Tyr-217 in the latch), after which structure-activity relations were clarified by conservative substitutions. Biochemical tests of the composite nick sealing reaction and of each of the three chemical steps of the ligation pathway highlighted the importance of Arg-285 and Phe-286 in the catalysis of the DNA adenylylation and phosphodiester synthesis reactions. Phe-286 interacts with the nick 5′-phosphate nucleotide and the 3′-OH base pair and distorts the DNA helical conformation at the nick. Arg-285 is a key component of the OB-NTase interface, where it forms a salt bridge to the essential Asp-29 side chain, which is imputed to coordinate divalent metal catalysts during the nick sealing steps. PMID:21527793

  17. Functional dissection of the DNA interface of the nucleotidyltransferase domain of chlorella virus DNA ligase.

    Science.gov (United States)

    Samai, Poulami; Shuman, Stewart

    2011-04-15

    Chlorella virus DNA ligase (ChVLig) has pluripotent biological activity and an intrinsic nick-sensing function. ChVLig consists of three structural modules that envelop nicked DNA as a C-shaped protein clamp: a nucleotidyltransferase (NTase) domain and an OB domain (these two are common to all DNA ligases) as well as a distinctive β-hairpin latch module. The NTase domain, which performs the chemical steps of ligation, binds the major groove flanking the nick and the minor groove on the 3'-OH side of the nick. Here we performed a structure-guided mutational analysis of the NTase domain, surveying the effects of 35 mutations in 19 residues on ChVLig activity in vivo and in vitro, including biochemical tests of the composite nick sealing reaction and of the three component steps of the ligation pathway (ligase adenylylation, DNA adenylylation, and phosphodiester synthesis). The results highlight (i) key contacts by Thr-84 and Lys-173 to the template DNA strand phosphates at the outer margins of the DNA ligase footprint; (ii) essential contacts of Ser-41, Arg-42, Met-83, and Phe-75 with the 3'-OH strand at the nick; (iii) Arg-176 phosphate contacts at the nick and with ATP during ligase adenylylation; (iv) the role of Phe-44 in forming the protein clamp around the nicked DNA substrate; and (v) the importance of adenine-binding residue Phe-98 in all three steps of ligation. Kinetic analysis of single-turnover nick sealing by ChVLig-AMP underscored the importance of Phe-75-mediated distortion of the nick 3'-OH nucleoside in the catalysis of DNA 5'-adenylylation (step 2) and phosphodiester synthesis (step 3). Induced fit of the nicked DNA into a distorted conformation when bound within the ligase clamp may account for the nick-sensing capacity of ChVLig.

  18. Deep RNA sequencing reveals hidden features and dynamics of early gene transcription in Paramecium bursaria chlorella virus 1.

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    Guillaume Blanc

    Full Text Available Paramecium bursaria chlorella virus 1 (PBCV-1 is the prototype of the genus Chlorovirus (family Phycodnaviridae that infects the unicellular, eukaryotic green alga Chlorella variabilis NC64A. The 331-kb PBCV-1 genome contains 416 major open reading frames. A mRNA-seq approach was used to analyze PBCV-1 transcriptomes at 6 progressive times during the first hour of infection. The alignment of 17 million reads to the PBCV-1 genome allowed the construction of single-base transcriptome maps. Significant transcription was detected for a subset of 50 viral genes as soon as 7 min after infection. By 20 min post infection (p.i., transcripts were detected for most PBCV-1 genes and transcript levels continued to increase globally up to 60 min p.i., at which time 41% or the poly (A+-containing RNAs in the infected cells mapped to the PBCV-1 genome. For some viral genes, the number of transcripts in the latter time points (20 to 60 min p.i. was much higher than that of the most highly expressed host genes. RNA-seq data revealed putative polyadenylation signal sequences in PBCV-1 genes that were identical to the polyadenylation signal AAUAAA of green algae. Several transcripts have an RNA fragment excised. However, the frequency of excision and the resulting putative shortened protein products suggest that most of these excision events have no functional role but are probably the result of the activity of misled splicesomes.

  19. Structural studies demonstrating a bacteriophage-like replication cycle of the eukaryote-infecting Paramecium bursaria chlorella virus-1.

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    Elad Milrot

    2017-08-01

    Full Text Available A fundamental stage in viral infection is the internalization of viral genomes in host cells. Although extensively studied, the mechanisms and factors responsible for the genome internalization process remain poorly understood. Here we report our observations, derived from diverse imaging methods on genome internalization of the large dsDNA Paramecium bursaria chlorella virus-1 (PBCV-1. Our studies reveal that early infection stages of this eukaryotic-infecting virus occurs by a bacteriophage-like pathway, whereby PBCV-1 generates a hole in the host cell wall and ejects its dsDNA genome in a linear, base-pair-by-base-pair process, through a membrane tunnel generated by the fusion of the virus internal membrane with the host membrane. Furthermore, our results imply that PBCV-1 DNA condensation that occurs shortly after infection probably plays a role in genome internalization, as hypothesized for the infection of some bacteriophages. The subsequent perforation of the host photosynthetic membranes presumably enables trafficking of viral genomes towards host nuclei. Previous studies established that at late infection stages PBCV-1 generates cytoplasmic organelles, termed viral factories, where viral assembly takes place, a feature characteristic of many large dsDNA viruses that infect eukaryotic organisms. PBCV-1 thus appears to combine a bacteriophage-like mechanism during early infection stages with a eukaryotic-like infection pathway in its late replication cycle.

  20. Imaging of Herpes Simplex Virus Type 1 Thymidine Kinase Gene Expression with Radiolabeled 5-(2-iodovinyl)-2'-deoxyuridine (IVDU) in Liver by Hydrodynamic-based Procedure

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    Song, In Ho; Lee, Tae Sup; Kang, Joo Hyun; Lee, Yong Jin; Kim, Kwang Il; An, Gwang Il; Chung, Wee Sup; Cheon, Gi Jeong; Choi, Chang Woon; Lim, Sang Moo [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2009-10-15

    Hydrodynamic-based procedure is a simple and effective gene delivery method to lead a high gene expression in liver tissue. Non-invasive imaging reporter gene system has been used widely with herpes simplex virus type 1 thymidine kinase (HSV1-tk) and its various substrates. In the present study, we investigated to image the expression of HSV1-tk gene with 5-(2-iodovinyl)-2'-deoxyuridine (IVDU) in mouse liver by the hydrodynamicbased procedure. HSV1-tk or enhanced green fluorescence protein (EGFP) encoded plasmid DNA was transferred into the mouse liver by hydrodynamic injection. At 24 h post-injection, RT-PCR, biodistribution, fluorescence imaging, nuclear imaging and digital wholebody autoradiography (DWBA) were performed to confirm transferred gene expression. In RT-PCR assay using mRNA from the mouse liver, specific bands of HSV1-tk and EGFP gene were observed in HSV1-tk and EGFP expressing plasmid injected mouse, respectively. Higher uptake of radiolabeled IVDU was exhibited in liver of HSV1-tk gene transferred mouse by biodistribution study. In fluorescence imaging, the liver showed specific fluorescence signal in EGFP gene transferred mouse. Gamma-camera image and DWBA results showed that radiolabeled IVDU was accumulated in the liver of HSV1-tk gene transferred mouse. In this study, hydrodynamic-based procedure was effective in liver-specific gene delivery and it could be quantified with molecular imaging methods. Therefore, co-expression of HSV1-tk reporter gene and target gene by hydrodynamic-based procedure is expected to be a useful method for the evaluation of the target gene expression level with radiolabeled IVDU.

  1. Direct preparation of 14C-labelled 5-allyl- and 5-propyl-2'-deoxyuridine from [2-14C]2'-deoxyuridine

    International Nuclear Information System (INIS)

    Ruth, J.L.; White, S.K.; Bergstrom, D.E.

    1982-01-01

    [2- 14 C]5-Allyl-2'-deoxyuridine was synthesized directly from [2- 14 C]2'-deoxyuridine using mercury, palladium, and 3-chloropropene. [2- 14 C]5-Propyl-2'-deoxyuridine was obtained by hydrogenation of the [ 14 C]5-allyl-2'-deoxyuridine. Advantages of the synthetic method and its application to the preparation of other radiolabeled 5-alkyl/alkenyl-2'-deoxyuridines are discussed. (author)

  2. Synthesis and Cellular Uptake of Radioiodine labeled 2{sup '}-deoxyuridine derivatives with HSV1-TK

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Ah; Lee, Kyo Chul; Hong, Su Hee; Kim, Eun Jung; Lee, Jong Chan; An, Gwang Il; Choi, Tae Hyun; Cheon, Gi Jeong; Chun, Kwon Soo [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2006-07-01

    Several different radiolabeled probes have been developed to image Herpes Simplex Virus Type-1 thyrimidine kinase gene (HSV1-TK) expression. The nucleoside prodrugs under investigation for HSV1-TK imaging generally fall into two main chemical and radioisotope categories: the pyrimidine nucleosides, primarily radioiodinated, and the purin nucleosides, primarily radiofluorinated, and their respective analogues. In non-invasive imaging of the HSV1-TK system, many nucleoside derivatives have been recommended as HSV1-TK substrates. Most of these nucleoside derivatives have been developed as prodrugs for tumor proliferation imaging or as anti-viral drugs. For example, 5-fluorouracil (5-FU) and IUdR have been used as tumor agents and acyclovir (ACV), ganciclovir (GCV) and (E)-5-(2-bromovinyl)-2{sup '}- deoxyuridine (BVDU) as an anti-viral agents for virus infection several 5-substituted uracil nucleoside derivatives have been identified to have high sensitivity and selective accumulation in HSV1-TK expressing cells. Of those, IVDU was shown to be rapidly accumulated in HSV1- TK expressing cells in vitro. Imaging of the HSV1-TK reporter gene along with various reporter probes is of current interest. In contrast to the mammalian kinase, which phosphorylates thymidine preferentially, HSV1-TK is less discriminative and phosphorylates a wide range of nucleoside analogues such as acycloguanosines and 2{sup '}-fluoro-2{sup '}-deoxyuridine derivatives that are not phosphorylated efficiently by the native enzyme. More specifically, 5-substituted 2{sup '}-fluoro-2{sup '}-deoxyarabinofuranosyluracil nucleosides are efficiently phosphorylated by HSV- TK. This property, together with the presence of fluorine in the 2{sup '}-arabino-position, endows the 2{sup '}-fluoro-2{sup '}-deoxyuridines with antiviral activity against HSV.

  3. A Deoxyuridine-Based Far-Red Emitting Viscosity Sensor.

    Science.gov (United States)

    Wang, Mengyuan; Zhang, Yuanwei; Yue, Xiling; Yao, Sheng; Bondar, Mykhailo V; Belfield, Kevin D

    2016-05-30

    A novel deoxyuridine (dU) benzothiazolium (BZ) derivative, referred to as dU-BZ, is reported that was synthesized via Sonogashira coupling reaction methodology. The deoxyuridine building block was introduced to enhance hydrophilicity, while an alkynylated benzothiazolium dye was incorporated for long wavelength absorption to reduce potential phototoxicity that is characteristic of using UV light to excite common fluorphores, better discriminate from native autofluorescence, and potentially facilitate deep tissue imaging. An impressive 30-fold enhancement of fluorescence intensity of dU-BZ was achieved upon increasing viscosity. Fluorescence quantum yields in 99% glycerol/1% methanol (v/v) solution as a function of temperature (293-343 K), together with viscosity-dependent fluorescence lifetimes and radiative and non-radiative rate constants in glycerol/methanol solutions (ranging from 4.8 to 950 cP) were determined. Both fluorescence quantum yields and lifetimes increased with increased viscosity, consistent with results predicted by theory. This suggests that the newly-designed compound, dU-BZ, is capable of functioning as a probe of local microviscosity, an aspect examined by in vitro bioimaging experiments.

  4. A Deoxyuridine-Based Far-Red Emitting Viscosity Sensor

    Directory of Open Access Journals (Sweden)

    Mengyuan Wang

    2016-05-01

    Full Text Available A novel deoxyuridine (dU benzothiazolium (BZ derivative, referred to as dU-BZ, is reported that was synthesized via Sonogashira coupling reaction methodology. The deoxyuridine building block was introduced to enhance hydrophilicity, while an alkynylated benzothiazolium dye was incorporated for long wavelength absorption to reduce potential phototoxicity that is characteristic of using UV light to excite common fluorphores, better discriminate from native autofluorescence, and potentially facilitate deep tissue imaging. An impressive 30-fold enhancement of fluorescence intensity of dU-BZ was achieved upon increasing viscosity. Fluorescence quantum yields in 99% glycerol/1% methanol (v/v solution as a function of temperature (293–343 K, together with viscosity-dependent fluorescence lifetimes and radiative and non-radiative rate constants in glycerol/methanol solutions (ranging from 4.8 to 950 cP were determined. Both fluorescence quantum yields and lifetimes increased with increased viscosity, consistent with results predicted by theory. This suggests that the newly-designed compound, dU-BZ, is capable of functioning as a probe of local microviscosity, an aspect examined by in vitro bioimaging experiments.

  5. Identification of two alpha-ketoglutarate-dependent dioxygenases in extracts of Rhodotorula glutinis catalyzing deoxyuridine hydroxylation

    International Nuclear Information System (INIS)

    Stubbe, J.

    1985-01-01

    Attempts to isolate deoxyuridine 2'-hydroxylase from Rhodotorula glutinis J. Biol. Chem. 258, 10551-10557) have led to the identification and partial purification of a newly recognized alpha-ketoglutarate-requiring oxygenase. This activity, designated deoxyuridine (uridine) 1'-hydroxylase, in the presence of iron and ascorbate, catalyzes the conversion of deoxyuridine (uridine), O 2 , and alpha-ketoglutarate to uracil, deoxyribonolactone (ribonolactone), CO 2 , and succinate. Incubation of [1'- 3 H]uridine with this activity results in time-dependent formation of uracil concomitant with production of CO 2 and 3H 2 O. Also reported in this paper is the partial purification and characterization of the alpha-ketoglutarate-requiring enzyme, deoxyuridine 2'-hydroxylase. Incubation of [2'-alpha- 3 H]deoxyuridine with this activity results in concomitant production of uridine and 3H 2 O. Incubation with [2'-beta- 3 H] deoxyuridine results in the production of uridine whose specific activity is identical to that of the starting material. This enzyme catalyzes the conversion of deoxyuridine to uridine with retention of configuration. No isotope effect is observed on this transformation

  6. INVIVO DISTRIBUTION AND ANTITUMOR-ACTIVITY OF LIPOSOMAL 3',5'-O-DIPALMITOYL-5-FLUORO-2'-DEOXYURIDINE

    NARCIS (Netherlands)

    WAALKES, MV; FICHTNER, [No Value; DONTJE, B; LEMM, M; BECKER, M; ARNDT, D; SCHERPHOF, GL

    1992-01-01

    3',5'-O-dipalmitoyl-5-fluoro-2'-deoxyuridine (FUdR-dipalmitate), a lipophilic prodrug of 5-fluoro-2'-deoxyuridine (FUdR), was incorporated in different types of liposomes. The in vivo distribution and intrahepatic deacylation of liposomal FUdR-dipalmitate was found to be strongly dependent on

  7. Chlorovirus-mediated membrane depolarization of Chlorella alters secondary active transport of solutes.

    Science.gov (United States)

    Agarkova, Irina; Dunigan, David; Gurnon, James; Greiner, Timo; Barres, Julia; Thiel, Gerhard; Van Etten, James L

    2008-12-01

    Paramecium bursaria chlorella virus 1 (PBCV-1) is the prototype of a family of large, double-stranded DNA, plaque-forming viruses that infect certain eukaryotic chlorella-like green algae from the genus Chlorovirus. PBCV-1 infection results in rapid host membrane depolarization and potassium ion release. One interesting feature of certain chloroviruses is that they code for functional potassium ion-selective channel proteins (Kcv) that are considered responsible for the host membrane depolarization and, as a consequence, the efflux of potassium ions. This report examines the relationship between cellular depolarization and solute uptake. Annotation of the virus host Chlorella strain NC64A genome revealed 482 putative transporter-encoding genes; 224 are secondary active transporters. Solute uptake experiments using seven radioactive compounds revealed that virus infection alters the transport of all the solutes. However, the degree of inhibition varied depending on the solute. Experiments with nystatin, a drug known to depolarize cell membranes, produced changes in solute uptake that are similar but not identical to those that occurred during virus infection. Therefore, these studies indicate that chlorovirus infection causes a rapid and sustained depolarization of the host plasma membrane and that this depolarization leads to the inhibition of secondary active transporters that changes solute uptake.

  8. Toxicity of liposomal 3 '-5 '-O-dipalmitoyl-5-fluoro-2 '-deoxyuridine in mice

    NARCIS (Netherlands)

    Waalkes, MV; Goris, H; Dontje, BHJ; Schwendener, RA; Scherphof, G; Nijhof, W

    Toxicities of 5-fluoro-2'-deoxyuridine (FUdR) and its liposome-incorporated dipalmitoyl derivative (FUdR-dipalmitate) to mouse bone marrow, spleen, liver and ileum were compared after treatment for 6 consecutive days. The applied doses of the two formulations, which were shown earlier to have equal

  9. Purification, crystallization and preliminary crystallographic analysis of deoxyuridine triphosphate nucleotidohydrolase from Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Bajaj, Mamta; Moriyama, Hideaki

    2007-01-01

    The first crystallization of deoxyuridine triphosphate nucleotidohydrolase from plant, Arabidopsis thaliana, has been performed. An additive, taurine, was effective in producing the single crystal. The deoxyuridine triphosphate nucleotidohydrolase gene from Arabidopsis thaliana was expressed and the gene product was purified. Crystallization was performed by the hanging-drop vapour-diffusion method at 298 K using 2 M ammonium sulfate as the precipitant. X-ray diffraction data were collected to 2.2 Å resolution using Cu Kα radiation. The crystal belongs to the orthorhombic space group P2 1 2 1 2 1 , with unit-cell parameters a = 69.90, b = 70.86 Å, c = 75.55 Å. Assuming the presence of a trimer in the asymmetric unit, the solvent content was 30%, with a V M of 1.8 Å 3 Da −1

  10. Purification, crystallization and preliminary crystallographic analysis of deoxyuridine triphosphate nucleotidohydrolase from Arabidopsis thaliana

    Energy Technology Data Exchange (ETDEWEB)

    Bajaj, Mamta [School of Biological Sciences, University of Nebraska-Lincoln, Manter Hall, Lincoln, Nebraska 68588-0304 (United States); Moriyama, Hideaki, E-mail: hmoriyama2@unl.edu [Department of Chemistry, e-Toxicology and Biotechnology, University of Nebraska-Lincoln, Hamilton Hall, Lincoln, Nebraska 68588-0304 (United States); School of Biological Sciences, University of Nebraska-Lincoln, Manter Hall, Lincoln, Nebraska 68588-0304 (United States)

    2007-05-01

    The first crystallization of deoxyuridine triphosphate nucleotidohydrolase from plant, Arabidopsis thaliana, has been performed. An additive, taurine, was effective in producing the single crystal. The deoxyuridine triphosphate nucleotidohydrolase gene from Arabidopsis thaliana was expressed and the gene product was purified. Crystallization was performed by the hanging-drop vapour-diffusion method at 298 K using 2 M ammonium sulfate as the precipitant. X-ray diffraction data were collected to 2.2 Å resolution using Cu Kα radiation. The crystal belongs to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 69.90, b = 70.86 Å, c = 75.55 Å. Assuming the presence of a trimer in the asymmetric unit, the solvent content was 30%, with a V{sub M} of 1.8 Å{sup 3} Da{sup −1}.

  11. Uptake of iodinated deoxyuridine in a murine melonama following multiple-day intravenous infusions

    International Nuclear Information System (INIS)

    Laster, B.H.; Popenoe, E.; Commerford, S.L.; Matsui, K.; Coderre, J.; Fand, I.; Fairchild, R.

    1985-01-01

    Techniques are described for multi-day intravenous (i.v.) infusions of iodinated deoxyuridine (IdUrd) into mice. Percent incorporation into DNA as a thymidine (Thd) analog is reported, as measured by radioactive tag ( 125 IdUrd) and by neutron activation analysis (NAA). Quantitative measurements of IdUrd incorporation in DNA are requisite for meaningful evaluation of the effects of radiation enhancement resulting from radiation sensitization and the stimulation of Auger cascades (photon activation)

  12. PEMANFAATAN MIKROALGA LAUT Chlorella vulgaris SUMBER DHA DAN EPA

    OpenAIRE

    Anggraeni, Peni

    2016-01-01

    Penelitian tentang mikroalga laut jenis Chlorella vulgaris telah dilakukan. Chlorella vulgaris dipilih sebagai bahan penambah gizi untuk di fortifikasi kedalam makanan . Penelitian ini bertujuan untuk mengetahui kandungan gizi dengan menganalisis kandungan DHA dan EPA. Penelitian ini dilakukan dengan mengkultur fitoplankton Chlorella vulgaris dan dipanen setelah media kultur mencapai fase Stasioner. Kemudian, dikeringkan dengan menggunakan freeze dryer, biomassa kering dianalisis kandungan DH...

  13. Epigenetic modulation of Chlorella (Chlorella vulgaris) on exposure to polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Yang, Mihi; Youn, Je-In; Kim, Seung Joon; Park, Jong Y

    2015-11-01

    DNA methylation in promoter region can be a new chemopreventive marker against polycyclic aromatic hydrocarbons (PAHs). We performed a randomized, double blind and cross-over trial (N=12 healthy females) to evaluate chlorella (Chlorella vulgaris)-induced epigenetic modulation on exposure to PAHs. The subjects consumed 4 tablets of placebo or chlorella supplement (total chlorophyll ≈ 8.3mg/tablet) three times a day before meals for 2 weeks. When the subjects consumed chlorella, status of global hypermethylation (5-methylcytosine) was reduced, compared to placebo (p=0.04). However, DNA methylation at the DNMT1 or NQO1 was not modified by chlorella. We observed the reduced levels of urinary 1-hydroxypyrene (1-OHP), a typical metabolite of PAHs, by chlorella intake (pchlorella-induced changes in global hypermethylation and urinary 1-OHP (pchlorella works for PAH-detoxification through the epigenetic modulation, the interference of ADME of PAHs and the interaction of mechanisms. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Synthesis of {sup 99m}Tc(CO){sub 3}-deoxyuridine derivatives as potential HSV1-tk gene expression imaging agents

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Young [Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap-dong, Songpa-gu, Seoul 138-736 (Korea, Republic of); Department of Chemistry, Hankuk University of Foreign Studies, Yongin 449-791 (Korea, Republic of); Oh, Seung Jun [Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap-dong, Songpa-gu, Seoul 138-736 (Korea, Republic of)], E-mail: sjoh@amc.seoul.kr; Ryu, Jin Sook [Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap-dong, Songpa-gu, Seoul 138-736 (Korea, Republic of); Choi, Seon-Joo [Division of Radioisotope Production and Application, Hanaro Center, Korea Atomic Energy Research Institute, Yusongku, Taejeon 305-600 (Korea, Republic of); Ha, Hyun-Joon [Department of Chemistry, Hankuk University of Foreign Studies, Yongin 449-791 (Korea, Republic of); Moon, Dae Hyuk [Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap-dong, Songpa-gu, Seoul 138-736 (Korea, Republic of)

    2008-04-15

    In this study, we synthesized {sup 99m}Tc(CO){sub 3}-2'-aminomethylpyridyl-2'-deoxyuridine ({sup 99m}Tc(CO){sub 3}-AMPDU) and {sup 99m}Tc(CO){sub 3}-aminoethylpyridyl-2'-deoxyuridine ({sup 99m}Tc(CO){sub 3}-AEPDU) as potential agents for imaging the expression of the non-invasive herpes simplex virus type-1 thymidine kinase. AMPDU and AEPDU were synthesized from uridine in five chemical steps and then labeled with [{sup 99m}Tc(CO){sub 3}(H{sub 2}O){sub 3}]{sup +} (370 MBq/0.5 mL) at 100 {sup o}C for 10 min. Under optimal conditions (0.5 and 1.0 mg for AMPDU and AEPDU and heating for 10 min), the labeling efficiency was 95.3{+-}2.8% for AMPDU and 94.2{+-}5.1% for AEPDU. To validate the chemical structure of {sup 99m}Tc(CO){sub 3}-labeled compounds, we also synthesized ReBr(CO){sub 3}-AMPDU and ReBr(CO){sub 3}-AEPDU by reacting [Et{sub 4}N][ReBr{sub 3}(CO){sub 3}] and AMPDU or AEPDU in methanol at 25 {sup o}C for 6 h. {sup 99m}Tc(CO){sub 3}-AMPDU and {sup 99m}Tc(CO){sub 3}-AEPDU had the same retention time on HPLC analysis as ReBr(CO){sub 3}-AMPDU and ReBr(CO){sub 3}-AEPDU. {sup 99m}Tc(CO){sub 3}-AMPDU and {sup 99m}Tc(CO){sub 3}-AEPDU had high radiochemical stabilities of 98.1{+-}1.5% and 98.0{+-}1.7% for 6 h, respectively.

  15. Promoting increased Chlorella sorokiniana Shih. et Krauss ...

    African Journals Online (AJOL)

    Prof. Nweze

    2014-12-31

    Dec 31, 2014 ... Also, the extract obtained from the leaves of Moringa in 80% ethanol contains growth enhancing principles for higher plants. (Makkar and Becker, 1996). In view of the fact that. Chlorella biomass is much sought after for use as health food supplement and for biofuels among other uses, enhanced production ...

  16. WATER CONDITION IN CELLS OF CHLORELLA

    Directory of Open Access Journals (Sweden)

    I. V. Kuznetsova

    2015-01-01

    Full Text Available The water condition in cages of the paste of chlorella was investigated by the method of thermogravimetric analysis. With increasing heating rate endothermic effect corresponding to the dehydration process is shifted towards higher temperatures. Temperature intervals of chlorella dehydration are defined at rate of heating 2 К/min - 308-368 K, 5 К/min - 323-403 K, and 10 К/min - 348-403 K. Quantitative characteristics of kinetic unequal water in chlorella have been received for each step (∆, ∆Т, a mass fraction (w, energy of activation (Еа. This process is similar to the process of the dehydration in ion exchange membranes. The derived kinetic characteristics give the possibility to define an optimum temperature interval and rate of drying microalgae for the purpose of increase of periods of storage in the form of paste or a solid substance for the further use as the bioadditive. In addition the presence of three types of water chlorella in a cell set according to NMR with pulsed magnetic field gradient. Since free water is involved in biochemical, chemical and microbiological processes, it is desirable to remove during drying of the preparation. The resulting temperature range of 323-343 K (step 2 at a heating rate of 2 K / min corresponds to a temperature range of drying the chlorella in a production environment. It should be noted that the highest number of algae in a tightly-water (the last stage. Apparently, this is determined by a unique cell structure. Temperature ranges dehydration process are not clear and vary depending on the heating rate, which is fully in line with previous studies of thermal analysis for grains, vegetables and bakery products.

  17. Effect of immunomodulators and cytostatics in 125I-deoxyuridine and tumor catabolism (a rapid method of antitumour immunomodulators screening)

    International Nuclear Information System (INIS)

    Obernikhin, S.S.; Fuks, B.B.

    1992-01-01

    E1-4 and P-815 murine tumor cells labelled by 125 I-deoxyuridine or 51 Cr were administered in 7-day subcutaneous syngeneic tumors or subcutaneosly. At the same time different groups of mice were treated by immunomodulators and cytostatics. It was shown that cytostatics and immunomodulators significantly delayed catabolism and withdrawing of 125 I-deoxyuridine (that has not been incorporated in DNA) from tumor cells. This delay was correlated with the inhibition of tumor nodes growth rate. It is concluded that influence of cytostatics and immunomodulators on catabolism and withdrawing rate of 125 I-deoxyuridine from tumor cells relates to their cytostatic effect and may be used at the earliest screening step of immunomodulator analysis

  18. Enhancement of fluorescence quenching and exciplex formation in DNA major groove by double incorporation of modified fluorescent deoxyuridines.

    Science.gov (United States)

    Tanaka, Makiko; Oguma, Kazuhiro; Saito, Yoshio; Saito, Isao

    2012-06-15

    5-(1-Naphthalenylethynyl)-2'-deoxyuridine ((N)U) and 5-[(4-cyano-1-naphthalenyl)ethynyl]-2'-deoxyuridine ((CN)U) were synthesized and incorporated into oligodeoxynucleotides. Fluorescence emissions of modified duplexes containing double (N)U were efficiently quenched depending upon the sequence pattern of the naphthalenes in DNA major groove, as compared to the duplex possessing single (N)U. When one of the naphthalene moieties has a cyano substituent, the exciplex emission from the chromophores in DNA major groove was observed at longer wavelength. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. 5-Bromo-2'-deoxyuridine impairs long-term food aversion memory in edible snail.

    Science.gov (United States)

    Efimova, O I; Anokhin, K V

    2012-09-01

    We studied the involvement of DNA synthesis into molecular mechanisms of long-term memory. Nucleoside analogue 5-bromo-2'-deoxyuridine (BrdU) is known to incorporate into synthesizing DNA and prevent subsequent DNA replication from this region. To investigate the effect of BrdU administration on long-term memory, terrestrial gastropods edible snails Helix lucorum were trained in the food aversion paradigm. Single-session training (carrot presentation combined with application of 10% quinine solution, three carrot presentations with 10-min intervals) resulted in the formation of long-term memory that persisted for at least 45° days. BrdU administration (250 mg/kg) 30 min before training impaired long-term memory tested 24 h later. Immunohistochemical study revealed BrdU incorporation in the nuclei of identified neurons of defensive behavior.

  20. Systemic 5-Bromo-2-Deoxyuridine Induces Conditioned Flavor Aversion and C-Fos in the Visceral Neuraxis

    Science.gov (United States)

    Kimbrough, Adam; Kwon, Bumsup; Eckel, Lisa A.; Houpt, Thomas A.

    2011-01-01

    5-bromo-2-deoxyuridine (BrdU) is often used in studies of adult neurogenesis and olfactory learning, but it can also have toxic effects on highly proliferative tissue. We found that pairing Kool-Aid flavors with acute systemic injections of BrdU induced strong conditioned flavor aversions. Intermittent injections during Kool-Aid-glucose…

  1. Carborane-linked 2'-deoxyuridine 5'-O-triphosphate as building block for polymerase synthesis of carborane-modified DNA.

    Science.gov (United States)

    Balintová, Jana; Simonova, Anna; Białek-Pietras, Magdalena; Olejniczak, Agnieszka; Lesnikowski, Zbigniew J; Hocek, Michal

    2017-11-01

    5-[(p-Carborane-2-yl)ethynyl]-2'-deoxyuridine 5'-O-triphosphate was synthesized and used as a good substrate in enzymatic construction of carborane-modified DNA or oligonucleotides containing up to 21 carborane moieties in primer extension reactions by DNA polymerases. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Effect of nickel on growth and 14 CO2 fixation in Chlorella (Chlorella pyrenoidosa)

    International Nuclear Information System (INIS)

    Subrahmanyam, A.D.; Rathore, V.S.

    1996-01-01

    Influence of nickel on growth, 14 C fixation and allocation of carbon among different biochemical fractions was investigated in Chlorella pyrenoidosa. Nickel significantly reduced the fresh and dry weights of chlorella cells. 14 C fixation was significantly reduced by increasing nickel concentration in growth media. 14 C allocation into different biochemical fractions was also markedly altered by nickel. Reduction in 14 CO 2 assimilation and carbon allocation into pigment-lipid fraction and residue fraction resulted in decreased chlorophyll content and dry weight. (author). 15 refs., 4 figs

  3. Effects Of Heavy Metals On Growing Cultures Of Chlorella emersonii ...

    African Journals Online (AJOL)

    This work evaluates the effect of some metals on a green alga Chlorella emersonii, under continuous and batch culture conditions with added metal and another, batch culture with no added metal but where organism had been exposed to metal for 18 hours prior to growth. It was found that Chlorella growth under ...

  4. Bromovinyl-deoxyuridine: A selective substrate for mitochondrial thymidine kinase in cell extracts

    International Nuclear Information System (INIS)

    Franzolin, Elisa; Rampazzo, Chiara; Perez-Perez, Maria-Jesus; Hernandez, Ana-Isabel; Balzarini, Jan; Bianchi, Vera

    2006-01-01

    Cellular models of mitochondrial thymidine kinase (TK2) deficiency require a reliable method to measure TK2 activity in whole cell extracts containing two interfering deoxyribonucleoside kinases, thymidine kinase 1 (TK1) and deoxycytidine kinase. We tested the value of the thymidine analog (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU) as a TK2-specific substrate. With extracts of OSTTK1 - cells containing TK2 as the only thymidine kinase and a highly specific TK2 inhibitor we established conditions to detect the low TK2 activity commonly present in cells. With extracts of TK1-proficient osteosarcoma cells and normal human fibroblasts we showed that BVDU, but not 1-(β-D-arabinofuranosyl)thymine (Ara-T), discriminates TK2 activity even in the presence of 100-fold excess TK1. A comparison with current procedures based on TK2 inhibition demonstrated the better performance of the new TK2 assay. When cultured human fibroblasts passed from proliferation to quiescence TK2 activity increased by 3-fold, stressing the importance of TK2 function in the absence of TK1

  5. Bromovinyl-deoxyuridine: A selective substrate for mitochondrial thymidine kinase in cell extracts.

    Science.gov (United States)

    Franzolin, Elisa; Rampazzo, Chiara; Pérez-Pérez, María-Jesús; Hernández, Ana-Isabel; Balzarini, Jan; Bianchi, Vera

    2006-05-26

    Cellular models of mitochondrial thymidine kinase (TK2) deficiency require a reliable method to measure TK2 activity in whole cell extracts containing two interfering deoxyribonucleoside kinases, thymidine kinase 1 (TK1) and deoxycytidine kinase. We tested the value of the thymidine analog (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU) as a TK2-specific substrate. With extracts of OSTTK1- cells containing TK2 as the only thymidine kinase and a highly specific TK2 inhibitor we established conditions to detect the low TK2 activity commonly present in cells. With extracts of TK1-proficient osteosarcoma cells and normal human fibroblasts we showed that BVDU, but not 1-(beta-d-arabinofuranosyl)thymine (Ara-T), discriminates TK2 activity even in the presence of 100-fold excess TK1. A comparison with current procedures based on TK2 inhibition demonstrated the better performance of the new TK2 assay. When cultured human fibroblasts passed from proliferation to quiescence TK2 activity increased by 3-fold, stressing the importance of TK2 function in the absence of TK1.

  6. Photon activation therapy with 127I-deoxyuridine: measurement of dose enhancement in cultured mammalian cells

    International Nuclear Information System (INIS)

    Fairchild, R.G.; Laster, B.H.; Commerford, S.L.; Furcinitti, P.S.; Sylvester, B.; Gabel, D.; Popenoe, E.; Foster, S.

    1985-01-01

    A technique for radiation enhancement of conventional photon radiotherapy is outlined which has been called photon activation therapy (PAT) (6). High linear energy transfer (LET) radiations in the form of Auger electron distributions are generated by photons of appropriate energies, through photon activation of stable iodine incorporated as an analog of thymidine (Tyd) in DNA. Of the several halogenated deoxyribonucleosides evaluated, iodinated deoxyuridine (IdUrd) has been chosen as the only Tyd analog providing effective photon activation. This mechanism is combined with radiation sensitization produced by IdUrd to produce an overall radiation enhancement. Calculations show that at 5% replacement (IdUrd for Tyd) therapeutic (TG) will vary from ∼2 (single acute dose) to ∼17 (low dose rates associated with permanent implant brachytherapy). Parameters used in the calculation of TG have been evaluated in cell culture; dose enhancements obtained with x-rays (including photon activation) were found to be significantly higher than values measured with γ-rays (no photon activation). Comparison is made between theoretical and measured values. Because of the evident lack of repair of damage produced by both sensitization and photon activation, significant gains are expected to be realized following protracted irradiations. Exchanges (IdUrd for Tyd) for 105 have been obtained in vivo (murine tumors). The authors believe that the application of PAT would be most advantageous in the treatment of brain tumors (grade IV astrocytomas) with implanted 145 Sm sources

  7. Replication Banding Patterns in Human Chromosomes Detected Using 5-ethynyl-2'-deoxyuridine Incorporation

    International Nuclear Information System (INIS)

    Hoshi, Osamu; Ushiki, Tatsuo

    2011-01-01

    A novel technique using the incorporation of 5-ethynyl-2'-deoxyuridine (EdU) into replicating DNA is described for the analysis of replicating banding patterns of human metaphase chromosomes. Human lymphocytes were synchronized with excess thymidine and treated with EdU during the late S phase of the cell cycle. The incorporated EdU was then detected in metaphase chromosomes using Alexa Fluor® 488 azides, through the 1,3-dipolar cycloaddition reaction of organic azides with the terminal acetylene group of EdU. Chromosomes with incorporated EdU showed a banding pattern similar to G-banding of normal human chromosomes. Imaging by atomic force microscopy (AFM) in liquid conditions showed that the structure of the chromosomes was well preserved even after EdU treatment. Comparison between fluorescence microscopy and AFM images of the same chromosome 1 indicated the presence of ridges and grooves in the chromatid arm, features that have been previously reported in relation to G-banding. These results suggest an intimate relationship between EdU-induced replication bands and G- or R-bands in human chromosomes. This technique is thus useful for analyzing the structure of chromosomes in relation to their banding patterns following DNA replication in the S phase

  8. Dr Jekyll and Mr Hyde: a strange case of 5-ethynyl-2 '-deoxyuridine and 5-ethynyl-2 '- deoxycytidine

    Czech Academy of Sciences Publication Activity Database

    Ligasová, A.; Liboska, Radek; Friedecký, D.; Mičová, K.; Adam, T.; Oždian, T.; Rosenberg, Ivan; Koberna, K.

    2016-01-01

    Roč. 6, č. 1 (2016), č. článku 150172. ISSN 2046-2441 R&D Projects: GA MZd NV15-31604A Institutional support: RVO:61388963 Keywords : cytidine deaminase * dCMP deaminase * 5-ethynyl-2 '-deoxyuridine * 5-ethynyl-2 '-deoxycytidine * DNA replication Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.481, year: 2016 http://rsob.royalsocietypublishing.org/content/6/1/150172

  9. The chlorococcalean alga Chlorella in animal nutrition: a review

    Czech Academy of Sciences Publication Activity Database

    Kotrbáček, V.; Doubek, J.; Doucha, Jiří

    2015-01-01

    Roč. 27, č. 6 (2015), s. 2173-2180 ISSN 0921-8971 Institutional support: RVO:61388971 Keywords : Chlorella * Chlorophyta * Feed supplement Subject RIV: EE - Microbiology, Virology Impact factor: 2.372, year: 2015

  10. Uptake of uranium from underground drinking water by chlorella (Chlorella pyrendoidosa)

    International Nuclear Information System (INIS)

    Singhal, R.K.; Joshi, Shobha; Gurg, R.P.; Shenoy, N.S.; Ferandes, Neychelle; Gopale, Rajesh S.; Jhaveri, A.S.

    2002-01-01

    Naturally occurring uranium has found at elevated levels i.e. 300-1200 ppb in underground water, especially in the areas located around uranium mines and granite rocks sites. The U.S. Environmental Protection Agency (EPA) recently adopted drinking water standards requiring a maximum uranium concentration of 20 μgl. This limit is based on nephro-toxicity, rather than on radiological hazards. The concentration of uranium is to be monitored along with other parameters in well and other sources of drinking water in these areas. During this work a low cost kit was developed for removing uranium from under-ground water used for drinking purposes. This unit is capable of reducing uranium from 1000 ppb to 15-20 ppb. Chlorella (Chlorella pyrendoidosa), a fresh water algae, was immobilised in sodium alginate in the form of beads by using 0.2 M calcium chloride. These beads were put in container and the water is stirred occasionally. 99-100 % uranium adsorbed was recovered from the beads by using 0.1 M HNO 3 . These results suggest that the uptake of uranium by Chlorella depended upon the physico-chemical adsorption on the cell surface, but not upon the biological activity and that uranium in the algal cells was coupled with the ligands, which can be easily substituted with NO 3 -1 . (author)

  11. Atomic Scissors: A New Method of Tracking the 5-Bromo-2′-Deoxyuridine-Labeled DNA In Situ

    Czech Academy of Sciences Publication Activity Database

    Ligasová, Anna; Strunin, Dmytro; Liboska, Radek; Rosenberg, Ivan; Koberna, Karel

    2012-01-01

    Roč. 7, č. 12 (2012), e52584/1-e52584/11 E-ISSN 1932-6203 R&D Projects: GA AV ČR KAN200520801 Grant - others:GA ČR(CZ) GA204/09/0973 Program:GA Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z50520514; CEZ:AV0Z50040702 Keywords : DNA replication * light microscopy detection * 5-bromo-2´-deoxyuridine * copper ions * oxidative DNA cleavage Subject RIV: CC - Organic Chemistry Impact factor: 3.730, year: 2012

  12. Organic and Inorganic Nitrogen Impact Chlorella variabilis Productivity and Host Quality for Viral Production and Cell Lysis.

    Science.gov (United States)

    Cheng, Yu-Shen; Labavitch, John; VanderGheynst, Jean S

    2015-05-01

    Microalgae have been proposed as a potential feedstock for biofuel production; however, cell disruption is usually required for collection and utilization of cytoplasmic polysaccharides and lipids. Virus infection might be one approach to disrupt the cell wall. The concentration of yeast extract and presence of KNO3 in algae cultivation media were investigated to observe their effects on Chlorella variabilis NC64A physiology and composition and the subsequent effect on production of Chlorella virus and disruption of infected cells. Cytoplasmic starch accumulation increased from 5% to approximately 35% of the total dry weight when yeast extract decreased from 1 to 0.25 g L(-1). When cells were cultured with the lowest nitrogen levels, the total polysaccharide accounted for more than 50% of the cell wall, which was 1.7 times higher than the content in cells cultured with the highest nitrogen levels. The C/N ratio of the algal biomass decreased by a factor of approximately 2 when yeast extract increased from 0.25 to 1 g L(-1). After virus infection, cells with a low C/N ratio produced a 7.6 times higher burst size than cells with a high C/N ratio, suggesting that the nitrogen content in C. variabilis has a large influence on viral production and cell lysis. The results have implications on management of nitrogen for both the synthesis of products from algae and product recovery via viral lysis.

  13. Toxicity assessment of Chlorella vulgaris and Chlorella protothecoides following exposure to Pb(II).

    Science.gov (United States)

    Zhang, Wei; Xiong, Bang; Chen, Lin; Lin, Kuangfei; Cui, Xinhong; Bi, Huasong; Guo, Meijin; Wang, Weiliang

    2013-07-01

    The short- and long-term toxic effects of Pb(II) exposure on Chlorella vulgaris (C. vulgaris) and Chlorella protothecoides (C. protothecoides) were not well understood. The lab study was performed to observe the Pb(II) exposure induced changes. Results of the observations show: (1) higher level of Pb(II) (50 or 80mgL(-1)) could significantly inhibit the growth and chlorophyll a synthesis of both algae in almost all the treatments and dose-response relationships could be clearly observed, (2) the range of EC50 values (24-120h, 67.73-172.45mgL(-1)) indicated that Pb(II) had a relatively limited short-term toxicity to the two algae, while long-term tests (7-28d, 50.41-63.91mgL(-1)) displayed higher toxicity and (3) SOD and CAT activities of both algae after exposed to medium level of Pb(II) were significantly promoted, and their response might be more susceptible in short-term exposure. This research provides a basic understanding of Pb(II) toxicity to aquatic organisms. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Ionizing radiation and 5-brom-2'-deoxyuridine as tools for analysis of fundamental mechanism of aging in animals

    International Nuclear Information System (INIS)

    Akif'ev, A.P.; Potapenbko, A.I.; Rudakovskaya, E.G.

    1997-01-01

    The influence of gamma-irradiation and 5-brom-2'-deoxyuridine (BUDR) on the life span and behaviour (in photoactivity test) of D.melanogaster was studied. It was found that gamma-irradiation resulted in decrease of life span. However the form of surveys changed only under exposure to doses higher than 500 Gy. Treatment with BUDR distorted the form of survival curves and caused death of insects immediately after exclusion. It also caused abrupt decrease in photoactivity of insects, while irradiation even with very high doses did not affect this feature. It is proposed that initiating substrate in drosophila aging is DNA of nerve cells. The possible relationship between aging regularities and evolutional extinction of eukaryotic species in discussed

  15. Atomic scissors: a new method of tracking the 5-bromo-2'-deoxyuridine-labeled DNA in situ.

    Directory of Open Access Journals (Sweden)

    Anna Ligasová

    Full Text Available A new method of the light microscopy detection of BrdU-labeled DNA in situ is described. It is based on the oxidative attack at the deoxyribose moiety by copper(I in the presence of oxygen, which leads to the abstraction of hydrogen atom from deoxyribose culminating in the elimination of the nucleobase, scission of the nucleic-acid strand and formation of frequent gaps. The gaps allow the reaction of the antibodies with the commonly used markers of replication (e.g. 5-bromo-2'-deoxyuridine, which are otherwise masked. The method developed makes it possible to detect nuclear and mitochondrial DNA replication efficiently. In most cases, it does not inhibit effective protein detections and in addition enables simultaneous localization of newly-synthesized RNA. The alternative presently-used methods result in protein denaturation and/or extensive DNA cleavage followed by the DNA-bound proteins peeling off.

  16. Effect of 5-bromouracil and 5-bromo-2-deoxyuridine in combination with 8-azaadenine on UV sensitivity of bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, H.E. (Akademie der Wissenschaften der DDR, Jena. Zentralinstitut fuer Mikrobiologie und Experimentelle Therapie); Golovinsky, E. (Bylgarska Akademiya na Naukite, Sofia)

    1983-01-01

    The presence of 5-bromouracil (BU) as well as 5-bromo-2-deoxyuridine (BUdR) in the cultivation media of bacteria results in the distinct increase of UV sensitivity. With the nucleic acid base analogue 8-azaadenine (8-AA) a similar effect was confirmed, however, not so pronounced. The combined action of BU or BUdR and 8-AA on Escherichia coli, Proteus mirabilis, Bacillus subtilis and Bacillus cereus was investigated. The sensitization effect of BUdR does not increase if 8-AA is present additionally during cultivation. On the contrary, a decrease of sensibilization occurs. This may be caused by the protective effect of the adenine derivative against UV irradiation, if it is present in the cell, but not incorporated into the DNA.

  17. Effect of 5-bromouracil and 5-bromo-2-deoxyuridine in combination with 8-azaadenine on UV sensitivity of bacteria

    International Nuclear Information System (INIS)

    Jacob, H.E.; Golovinsky, E.

    1983-01-01

    The presence of 5-bromouracil (BU) as well as 5-bromo-2-deoxyuridine (BUdR) in the cultivation media of bacteria results in the distinct increase of UV sensitivity. With the nucleic acid base analogue 8-azaadenine (8-AA) a similar effect was confirmed, however, not so pronounced. The combined action of BU or BUdR and 8-AA on Escherichia coli, Proteus mirabilis, Bacillus subtilis and Bacillus cereus was investigated. The sensitization effect of BUdR does not increase if 8-AA is present additionally during cultivation. On the contrary, a decrease of sensibilization occurs. This may be caused by the protective effect of the adenine derivative against UV irradiation, if it is present in the cell, but not incorporated into the DNA. (author)

  18. Development and characteristics of a subline of Ehrlich ascites carcinoma cells persistently resistant to 5-fluoro-2'-deoxyuridine.

    Science.gov (United States)

    Jastreboff, M M; Zielińska, Z M

    1983-01-01

    A subline of Ehrlich ascites carcinoma (EAC) cells resistant to 5-fluoro-2'-deoxy-uridine (FdUrd) was developed by continuous exposure to progressively increasing concentrations of the drug (35-75 mg/kg per day) during 15 passages through mice. Since then, the EAC cells have been retransplanted more than 80 times through drug-untreated mice and continue to be resistant. After adaptation to growth in suspension culture the drug-adapted cells were 1000 times more resistant to FdUrd in comparison with parental ones, and remained near-tetraploid with doubling time longer than in parental line. The activity of thymidine kinase was deeply depressed (100-fold) whereas that of thymidylate synthetase several-fold increased in the resistant EAC cells, both grown in vivo and in vitro.

  19. Polyphosphate formation in Chlorella in relation to photosynthesis

    NARCIS (Netherlands)

    Wintermans, J.F.G.M.

    1955-01-01

    Suspensions of Chlorella converted orthophosphate into cellular phosphate in the light, especially in the absence of C0 2 , when orthophosphate was largely transformed into polyphosphate. Polyphosphate formation continued for several hours, slowly decreasing, and was saturated at

  20. Production of high-density Chlorella culture grown in fermenters

    Czech Academy of Sciences Publication Activity Database

    Doucha, Jiří; Lívanský, Karel

    2012-01-01

    Roč. 24, č. 1 (2012), s. 35-43 ISSN 0921-8971 R&D Projects: GA MŠk OE09025 Institutional support: RVO:61388971 Keywords : Chlorella vulgaris * Heterotrophic culture * Fed-batch Subject RIV: EE - Microbiology, Virology Impact factor: 2.326, year: 2012

  1. Fatty acids composition of microalgae Chlorella vulgaris can be ...

    African Journals Online (AJOL)

    Varying culture methods of Chlorella vulgaris (CV) has been associated with different nutrient composition. The aim of this study was to investigate the fatty acid contents and other nutrients of CV subjected to various culturing conditions. We found that CV cultured under 24 h light and 10% CO2 showed the best growth rates ...

  2. Chlorella vulgaris: A Multifunctional Dietary Supplement with Diverse Medicinal Properties.

    Science.gov (United States)

    Panahi, Yunes; Darvishi, Behrad; Jowzi, Narges; Beiraghdar, Fatemeh; Sahebkar, Amirhossein

    2016-01-01

    Chlorella vulgaris is a green unicellular microalgae with biological and pharmacological properties important for human health. C. vulgaris has a long history of use as a food source and contains a unique and diverse composition of functional macro- and micro-nutrients including proteinsChlorella vulgaris is a green unicellular microalgae with biological and pharmacological properties important for human health. C. vulgaris has a long history of use as a food source and contains a unique and diverse composition of functional macro- and micro-nutrients including proteins, omega-3 polyunsaturated fatty acids, polysaccharides, vitamins and minerals. Clinical trials have suggested that supplementation with C. vulgaris can ameliorate amelioration hyperlipidemia and hyperglycemia, and protect against oxidative stress, cancer and chronic obstructive pulmonary disease. In this review, we summarize the findings on the health benefits of Chlorella supplementation and the molecular mechanisms underlying these effects., omega-3 polyunsaturated fatty acids, polysaccharides, vitamins and minerals. Clinical trials have suggested that supplementation with C. vulgaris can ameliorate amelioration hyperlipidemia and hyperglycemia, and protect against oxidative stress, cancer and chronic obstructive pulmonary disease. In this review, we summarize the findings on the health benefits of Chlorella supplementation and the molecular mechanisms underlying these effects.

  3. Performance of Chlorella sorokiniana under simulated extreme winter conditions

    NARCIS (Netherlands)

    Cuaresma, M.; Buffing, M.F.; Janssen, M.G.J.; Lobato, C.V.; Wijffels, R.H.

    2012-01-01

    High annual microalgae productivities can only be achieved if solar light is efficiently used through the different seasons. During winter the productivity is low because of the light and temperature conditions. The productivity and photosynthetic efficiency of Chlorella sorokiniana were assessed

  4. Studies on the growth behavior of Chlorella, Haematococcus and ...

    African Journals Online (AJOL)

    Growth studies were conducted on green algae Chlorella, Scenedesmus and Haematococcus strains in batch mode cultures. In this study, the effect of sodium bicarbonate salt (NaHCO3) and carbon dioxide (CO2) gas as carbon source on microalgal cultures were investigated. For this purpose, growth response of the ...

  5. Production of lipids in 10 strains of Chlorella and Parachlorella, and enhanced lipid productivity in Chlorella vulgaris

    Czech Academy of Sciences Publication Activity Database

    Přibyl, Pavel; Cepák, Vladislav; Zachleder, Vilém

    2012-01-01

    Roč. 94, č. 2 (2012), s. 549-561 ISSN 0175-7598 R&D Projects: GA MŠk 1M0571 Institutional research plan: CEZ:AV0Z60050516; CEZ:AV0Z50200510 Institutional support: RVO:67985939 ; RVO:61388971 Keywords : Chlorella * Parachlorella * lipids Subject RIV: EF - Botanics Impact factor: 3.689, year: 2012

  6. LIPID ACCUMULATION OF CHLORELLA VULGARIS UNDER DIFFERENT PHOSPHATE CONCENTRATIONS

    Directory of Open Access Journals (Sweden)

    Magdalena Karolina Rokicka

    2017-04-01

    Full Text Available The cultivation and utilization of microalgae is now a intensively developing area of research. Some species of microalgae, under appropriate conditions, accumulate large amounts of lipids in the cells. This lipids have a suitable profile of fatty acids for biodiesel production. The culture of microalgae for lipids accumulation should be performed in certain physicochemical conditions. The aim of the study was to determine the effect of variable ortophophates concentrations in the culture medium for lipids accumulation of microalgae Chlorella vulgaris and to determine of parameters of the phosphoric shock in the medium. The study confirmed the possibility of the use of the phosphoric shock in the medium to maximize lipids accumulation by the microalgae Chlorella vulgaris. In the study, 45.23% of the oil was obtained from the biomass from the culture with phosphoric shock in the medium and 18% less of the oil was obtained from the biomass from the standard culture.

  7. Bioremediation of the textile waste effluent by Chlorella vulgaris

    OpenAIRE

    El-Kassas, Hala Yassin; Mohamed, Laila Abdelfattah

    2014-01-01

    The microalgae biomass production from textile waste effluent is a possible solution for the environmental impact generated by the effluent discharge into water sources. The potential application of Chlorella vulgaris for bioremediation of textile waste effluent (WE) was investigated using 22 Central Composite Design (CCD). This work addresses the adaptation of the microalgae C. vulgaris in textile waste effluent (WE) and the study of the best dilution of the WE for maximum biomass production...

  8. Dyes adsorption on magnetically modified Chlorella vulgaris cells

    Czech Academy of Sciences Publication Activity Database

    Šafaříková, Miroslava; Pona, B. M. R.; Mosiniewicz-Szablewska, E.; Weyda, František; Šafařík, Ivo

    2008-01-01

    Roč. 17, č. 4 (2008), s. 486-492 ISSN 1018-4619 R&D Projects: GA MŠk OC 108; GA MPO 2A-1TP1/094 Institutional research plan: CEZ:AV0Z60870520; CEZ:AV0Z50070508 Keywords : Chlorella vulgaris * magnetically modified cells * dyes Subject RIV: EI - Biotechnology ; Bionics Impact factor: 0.463, year: 2008

  9. DNA barcode of coastal alga ( Chlorella sorokiniana ) from Ago ...

    African Journals Online (AJOL)

    Five different loci 18S, UPA, rbcl, ITS and tufA were tested for their use as deoxyribonucleic acid (DNA) barcode in this study. Although the UPA primers were designed to amplify all phototrophic algae and cyanobacteria, UPA and 18S did not amplified at all for the genus Chlorella while ITS1, ITS2 rDNA and rbcL markers ...

  10. Experimental and computational study on molecular structure and vibrational analysis of a modified biomolecule: 5-Bromo-2'-deoxyuridine

    Science.gov (United States)

    Çırak, Çağrı; Sert, Yusuf; Ucun, Fatih

    In the present study, the experimental and theoretical vibrational spectra of 5-bromo-2'-deoxyuridine were investigated. The experimental FT-IR (400-4000 cm-1) and μ-Raman spectra (100-4000 cm-1) of the molecule in the solid phase were recorded. Theoretical vibrational frequencies and geometric parameters (bond lengths and bond angles) were calculated using ab initio Hartree Fock (HF) and density functional B3LYP method with 6-31G(d), 6-31G(d,p), 6-311++G(d) and 6-311++G(d,p) basis sets by Gaussian program, for the first time. The assignments of vibrational frequencies were performed by potential energy distribution by using VEDA 4 program. The optimized geometric parameters and theoretical vibrational frequencies are compared with the corresponding experimental data and they were seen to be in a good agreement with the each other. Also, the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies were found.

  11. Performance standard-based validation study for local lymph node assay: 5-bromo-2-deoxyuridine-flow cytometry method.

    Science.gov (United States)

    Ahn, Ilyoung; Kim, Tae-Sung; Jung, Eun-Sun; Yi, Jung-Sun; Jang, Won-Hee; Jung, Kyoung-Mi; Park, Miyoung; Jung, Mi-Sook; Jeon, Eun-Young; Yeo, Kyeong-Uk; Jo, Ji-Hoon; Park, Jung-Eun; Kim, Chang-Yul; Park, Yeong-Chul; Seong, Won-Keun; Lee, Ai-Young; Chun, Young Jin; Jeong, Tae Cheon; Jeung, Eui Bae; Lim, Kyung-Min; Bae, SeungJin; Sohn, Soojung; Heo, Yong

    2016-10-01

    Local lymph node assay: 5-bromo-2-deoxyuridine-flow cytometry method (LLNA: BrdU-FCM) is a modified non-radioisotopic technique with the additional advantages of accommodating multiple endpoints with the introduction of FCM, and refinement and reduction of animal use by using a sophisticated prescreening scheme. Reliability and accuracy of the LLNA: BrdU-FCM was determined according to OECD Test Guideline (TG) No. 429 (Skin Sensitization: Local Lymph Node Assay) performance standards (PS), with the participation of four laboratories. Transferability was demonstrated through successfully producing stimulation index (SI) values for 25% hexyl cinnamic aldehyde (HCA) consistently greater than 3, a predetermined threshold, by all participating laboratories. Within- and between-laboratory reproducibility was shown using HCA and 2,4-dinitrochlorobenzene, in which EC2.7 values (the estimated concentrations eliciting an SI of 2.7, the threshold for LLNA: BrdU-FCM) fell consistently within the acceptance ranges, 0.025-0.1% and 5-20%, respectively. Predictive capacity was tested using the final protocol version 1.3 for the 18 reference chemicals listed in OECD TG 429, of which results showed 84.6% sensitivity, 100% specificity, and 88.9% accuracy compared with the original LLNA. The data presented are considered to meet the performance criteria for the PS, and its predictive capacity was also sufficiently validated. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. MicroRNA-351 Regulates Two-Types of Cell Death, Necrosis and Apoptosis, Induced by 5-fluoro-2'-deoxyuridine.

    Directory of Open Access Journals (Sweden)

    Akira Sato

    Full Text Available Cell-death can be necrosis and apoptosis. We are investigating the mechanisms regulating the cell death that occurs on treatment of mouse cancer cell-line FM3A with antitumor 5-fluoro-2'-deoxyuridine (FUdR: necrosis occurs for the original clone F28-7, and apoptosis for its variant F28-7-A. Here we report that a microRNA (miR-351 regulates the cell death pattern. The miR-351 is expressed strongly in F28-7-A but only weakly in F28-7. Induction of a higher expression of miR-351 in F28-7 by transfecting an miRNA mimic into F28-7 resulted in a change of the death mode; necrosis to apoptosis. Furthermore, transfection of an miR-351 inhibitor into F28-7-A resulted in the morphology change, apoptosis to necrosis, in this death-by-FUdR. Possible mechanism involving lamin B1 in this miR-351's regulatory action is discussed.

  13. Modifying effect of 5-fluoro-2-deoxyuridine and thymidine at G1 phase on radiation and chemically induced chromosome rearrangement

    International Nuclear Information System (INIS)

    Azatyan, R.A.; Voskanyan, A.Z.; Avakyan, V.A.; Akif'ev, A.P.

    1978-01-01

    The yield of structural chromosome mutations induced in Crepis capillaris seeds by X-rays and nitrogen mustard was studied as a function of treatment (at G 1 phase) with an inhibitor of unscheduled DNA synthesis, 5-fluoro-2-deoxyuridine (FdU), and its antagonist, thymidine. Air-dry seeds were irradiated at 10 krad and immediately placed in aqueous solutions of FdU, thymidine, or FdU + thymidine. Ionizing radiation induced only chromosome exchanges in the seeds. When EdU was used, the number of chromosome exchanges was the same although the fraction of simple and isolocus deletions was significantly greater than additive. The effect of FdU was manifested only after 10-hour incubation of the cells. Thymidine alone did not appreciably alter the frequency of radiation-induced aberrations. At the same time, the FdU + thymidine combination decreased the mutation yield i.e. was protective. Frequencies of the chromosome aberration in this experiment were the same as in the control

  14. [In vitro study on intrathecal application of 5-fluoro-2'-deoxyuridine (FdUrd) for meningeal dissemination of malignant tumor].

    Science.gov (United States)

    Nakagawa, H; Yamada, M; Fukushima, M; Shimizu, K; Ikenaka, K

    1998-09-01

    To evaluate the possible clinical intrathecal use of 5-fluoro-2'-deoxyuridine (FdUrd) for malignant brain tumors, its anti-tumor activity and neurotoxicity were compared with that of 5-fluorouracil (5-FU) and 5-fluorouridine (FUrd) in vitro. FdUrd showed good tumoricidal activity against cultured mouse 203 glioma cells and rat Walker 256 carcinoma cells as well as A172 human glioblastoma cells. Daoy human medulloblastoma cells and CADO-LC4 human lung cancer cells. It also showed less toxicity for primary cultures of neurons from C57/BL6 mouse and human embryo compared to 5-FU and FUrd. Thymidine phosphorylase (TPase) and thymidine kinase (TK), key enzymes for metabolism of 5-FU derivatives, were measured in cerebrospinal fluid (CSF). TPase or TK activity was detected in the CSF of hardly any patients with malignant brain tumors including meningeal carcinomatosis. These data indicated that the CSF is a favorable site for FdUrd chemotherapy, because the rate of conversion of FdUrd injected to 5-FU would be minimal. In conclusion, FdUrd may be potentially useful for intrathecal treatment of meningeal carcinomatosis.

  15. Extraction of antioxidants from Chlorella sp. using subcritical water treatment

    Science.gov (United States)

    Zakaria, S. M.; Mustapa Kamal, S. M.; Harun, M. R.; Omar, R.; Siajam, S. I.

    2017-06-01

    Chlorella sp. microalgae is one of the main source of natural bioactive compounds used in the food and pharmaceutical industries. Subcritical water extraction is the technique that offers an efficient, non-toxic, and environmental-friendly method to obtain natural ingredients. In this work, the extracts of Chlorella sp. microalgae was evaluated in terms of: chemical composition, extraction (polysaccharides) yield and antioxidant activity, using subcritical water extraction. Extractions were performed at temperatures ranging from 100°C to 300°C. The results show that by using subcritical water, the highest yield of polysaccharides is 23.6 that obtained at 150°C. Analysis on the polysaccharides yield show that the contents were highly influenced by the extraction temperature. The individual antioxidant activity were evaluated by in vitro assay using a free radical method. In general, the antioxidant activity of the extracts obtained at different water temperatures was high, with values of 31.08-54.29 . The results indicated that extraction by subcritical water was effective and Chlorella sp. can be a useful source of natural antioxidants.

  16. Pertumbuhan Chlorella sp. pada beberapa konsentrasi limbah batubara (The growth rate of the Chlorella sp. at different concentrations of coal waste water

    Directory of Open Access Journals (Sweden)

    Zerli Selvika

    2016-12-01

    Full Text Available Chlorella sp. is a single-celled microalga that mostly grows in marine waters. Chlorella sp. can grow in heavy polluted waters and therefore it has potency as a bioremediation agent. This study aimed was to analyze the effect of coal on the growth of Chlorella sp. in plant isolation media and the quality of water in plant isolation media for Chlorella sp. The complete randomized design with 4 treatments of coal concentration was used in this study. Four concentration concentrations were tested namely, 0 ppt, 1 ppt, 3 ppt and 5 ppt. The results revealed that coal with different concentrations gave no significant effect on the growth of Chlorella sp. (p> 0.05. The density among the concentrations of 0 ppt, 1 ppt, 3 ppt and 5 ppt were not significantly different. In addition, the coal concentration gave no significant effect on temperature, salinity and potential hydrogen (pH (p>0.05. The Chlorella sp. can grow in the polluted water by coal, and therefore this alga can be used as potential organisms for bioremediation of coal waste. Chlorella sp. merupakan mikroalga bersel satu yang banyak tumbuh di perairan laut. Chlorella sp. dapat tumbuh di perairan yang tercemar berat sehingga berpotensi sebagai bioremediator. Penelitian ini bertujuan untuk menganalisis pengaruh konsentrasi batubara terhadap pertumbuhan Chlorella sp. dan kualitas air pada media kultur Chlorella sp. Metode yang digunakan dalam penelitian ini adalah metode eksperimen skala laboratorium. Rancangan percobaan yang digunakan adalah rancangan acak lengkap dengan 4 perlakuan konsentrasi batubara 0 ppt, 1 ppt, 3 ppt dan 5 ppt. Hasil penelitian menunjukkan bahwa batubara dengan konsentrasi yang berbeda tidak berpengaruh nyata terhadap laju pertumbuhan Chlorella sp (P>0,05. Kepadatan antara konsentrasi 0 ppt, 1 ppt, 3 ppt dan 5 ppt tidak terlalu jauh berbeda. Konsentrasi batubara juga tidak berpengaruh nyata terhadap parameter suhu, salinitas dan derajat keasaman (pH (p>0,05. Chlorella sp

  17. Dietary effects of lutein-fortified chlorella on milk components of Holstein cows.

    Science.gov (United States)

    Jeon, Jin-Young; Park, Keun-Kyu; Lee, Kyung-Woo; Jang, Seung-Wan; Moon, Byung-Hern; An, Byoung-Ki

    2016-01-01

    This study was conducted to investigate the dietary effect of conventional or lutein-fortified chlorella on milk production and lutein incorporation in milk. Fifteen Holstein cows in mid-lactation were used in a 3 × 3 Latin square design each with a 21-day period. Cows were top-dressed daily with 30 g of conventional or lutein-fortified chlorella for 3 weeks. Cows without chlorella served as the control. The feed intake and milk yield were not affected by dietary treatments. The concentrations of milk protein and solids non-fat in groups fed diets containing both conventional and lutein-fortified chlorella were significantly higher than those of the control group (P milk fat among groups. The levels of plasma glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, interferon-gamma and interleukin-2 were not influenced by the dietary treatments. Lutein content in milk was significantly increased in groups fed lutein-fortified chlorella as compared with those of conventional chlorella and control, respectively (P lutein-fortified chlorella has positive effects on milk components and the use of lutein-fortified chlorella in a dairy diet is effective in the production of milk enriched with lutein.

  18. Improving oxidative stability of virgin olive oil by addition of microalga Chlorella vulgaris biomass.

    Science.gov (United States)

    Alavi, Nasireh; Golmakani, Mohammad-Taghi

    2017-07-01

    Antioxidant activity of Chlorella ( Chlorella vulgaris ) was evaluated in virgin olive oil (VOO) at different concentrations of 0.5, 1.0, and 1.5% (w/w) under accelerated storage conditions. Antioxidant activity of Chlorella was compared with those of BHT and β-carotene. Chlorella samples significantly retarded the formation of primary, secondary, and total oxidation products in comparison with those of the control. The stability increased as concentrations of Chlorella increased. Samples containing 0.5, 1.0, and 1.5% Chlorella significantly improved VOO stability by 19.99, 28.83, and 33.14%, respectively. Observed effects can be related to the release in the assortment of bioactive compounds from Chlorella algae to the VOO. Among the different antioxidants evaluatedy, BHT exhibited the highest antioxidant activity. On the contrary, β-carotene had no preventive effect against the oxidation of VOO. It also proved incapable of limiting the progress of VOO oxidation and played role as pro-oxidant. In conclusion, Chlorella enhanced VOO oxidative stability. Thus it can be considered as a promising source of natural antioxidants.

  19. Enhancement of Protein and Pigment Content in Two Chlorella Species Cultivated on Industrial Process Water

    DEFF Research Database (Denmark)

    Safafar, Hamed; Uldall Nørregaard, Patrick; Ljubic, Anita

    2016-01-01

    Chlorella pyrenoidosa and Chlorella vulgaris were cultivated in pre-gasified industrial process water with high concentration of ammonia representing effluent from a local biogas plant. The study aimed to investigate the effects of growth media and cultivation duration on the nutritional...... pyrenoidosa produced the highest concentrations of protein (65.2% ± 1.30% DW) while Chlorella vulgaris accumulated extremely high concentrations of lutein and chlorophylls (7.14 ± 0.66 mg/g DW and 32.4 ± 1.77 mg/g DW, respectively). Cultivation of Chlorella species in industrial process water...... composition of biomass. Variations in proteins, lipid, fatty acid composition, amino acids, tocopherols, and pigments were studied. Both species grew well in industrial process water. The contents of proteins were affected significantly by the growth media and cultivation duration. Microalga Chlorella...

  20. [Research on characteristic of interrelationship between toxic organic compound BPA and Chlorella vulgaris].

    Science.gov (United States)

    Chen, Shan-Jia; Chen, Xiu-Rong; Yan, Long; Zhao, Jian-Guo; Zhang, Fei; Jiang, Zi-Jian

    2014-04-01

    The effects of different concentrations of bisphenol A (BPA) on Chlorella vulgaris and removal capacity of BPA by Chlorella vulgaris were investigated. Results showed that a low concentration (0-20 mg x L(-1)) of BPA promoted the growth of Chlorella vulgaris, whereas a relative high concentration (20-50 mg x L(-1)) of BPA inhibited the growth of Chlorella vulgaris, and the inhibition effect was positively correlated with the concentration of BPA. Likewise, a high dose of initial BPA (> 20 mg x L(-1)) led to a decline in the content of chlorephyll a. Chlorella vulgaris had BPA removal capacity when initial BPA concentration ranged from 2 mg x L(-1) to 50 mg x L(-1). There was positive correlation between the removal rate of BPA per cell and initial BPA concentration. The removal rate of BPA was the highest when initial BPA was 50 mg x L(-1), which appeared between lag phase and logarithmic phase.

  1. Acute and chronic toxic effects of chloramphenicol on Scenedesmus obliquus and Chlorella pyrenoidosa.

    Science.gov (United States)

    Zhang, Wei; Sun, Wenfang; An, Shuai; Xiong, Bang; Lin, Kuangfei; Cui, Xinhong; Guo, Meijin

    2013-08-01

    The acute and chronic toxicological effects of Chloramphenicol (CAP) on Scenedesmus obliquus and Chlorella pyrenoidosa are not well understood. The indoor experiments were carried to observe and analyze the CAP induced changes. Results of the observations have showed that CAP exposure could significantly inhibit the growth of Scenedesmus obliquus in almost all the treated groups, while Chlorella pyrenoidosa exhibited less sensitivity. Chlorophyll-a syntheses of Scenedesmus obliquus were all inhibited by CAP exposure, while Chlorella pyrenoidosa displayed obvious stimulation effect. Catalase (CAT) and Superoxide dismutase (SOD) activities of both algae were promoted in all the treatments. The experimental results indicated that the growth and Chlorophyll-a syntheses of Scenedesmus obliquus were more sensitive in response to CAP exposure than that of Chlorella pyrenoidosa. While for CAT and SOD activities, Chlorella pyrenoidosa showed more susceptible. This research provides a basic understanding of CAP toxicity to aquatic organisms.

  2. Inter-laboratory validation of the modified murine local lymph node assay based on 5-bromo-2'-deoxyuridine incorporation.

    Science.gov (United States)

    Kojima, Hajime; Takeyoshi, Masahiro; Sozu, Takashi; Awogi, Takumi; Arima, Kazunori; Idehara, Kenji; Ikarashi, Yoshiaki; Kanazawa, Yukiko; Maki, Eiji; Omori, Takashi; Yuasa, Atsuko; Yoshimura, Isao

    2011-01-01

    The murine local lymph node assay (LLNA) is a well-established alternative to the guinea pig maximization test (GPMT) or Buehler test (BT) for the assessment of the skin sensitizing ability of a drug, cosmetic material, pesticide or industrial chemical. Instead of radioisotope using in this method, Takeyoshi M. et al. (2001) has developed a modified LLNA based on the 5-bromo-2'-deoxyuridine (BrdU) incorporation (LLNA:BrdU-ELISA). The LLNA:BrdU-ELISA is practically identical to the LLNA methodology excluding the use of BrdU, for which a single intraperitoneal injection of BrdU is made on day 4, and colorimetric detection of cell turnover. We conducted the validation study to evaluate the reliability and relevance of LLNA:BrdU-ELISA. The experiment involved 7 laboratories, wherein 10 chemicals were examined under blinded conditions. In this study, 3 chemicals were examined in all laboratories and the remaining 7 were examined in 3 laboratories. The data were expressed as the BrdU incorporation using an ELISA method for each group, and the stimulation index (SI) for each chemical-treated group was determined as the increase in the BrdU incorporation relative to the concurrent vehicle control group. An SI of 2 was set as the cut-off value for exhibiting skin sensitization activity. The results obtained in the experiments conducted for all 10 chemicals were sufficiently consistent with small variations in their SI values. The sensitivity, specificity, and accuracy of LLNA:BrdU-ELISA against those of GPMT/BT were 7/7 (100%), 3/3 (100%), and 10/10 (100%), respectively. Copyright © 2010 John Wiley & Sons, Ltd.

  3. Mathematical model of 5-[125I]iodo-2'-deoxyuridine treatment: continuous infusion regimens for hepatic metastases

    International Nuclear Information System (INIS)

    Sgouros, George; O'Donoghue, Joseph A.; Larson, Steven M.; Macapinlac, Homer; Larson, Justine J.; Kemeny, Nancy

    1998-01-01

    Purpose: Due to the cytotoxicity of DNA-bound iodine-125, 5-[ 125 I]Iodo-2'-deoxyuridine ([ 125 I]IUdR), an analog of thymidine, has long been recognized as possessing therapeutic potential. In this work, the feasibility and potential effectiveness of hepatic artery infusion of [ 125 I]IUdR is examined. Methods: A mathematical model has been developed that simulates tumor growth and response to [ 125 I]IUdR treatment. The model is used to examine the efficacy and potential toxicity of prolonged infusion therapy. Treatment of kinetically homogeneous tumors with potential doubling times of either 4, 5, or 6 days is simulated. Assuming uniformly distributed activity, absorbed dose estimates to the red marrow, liver and whole-body are calculated to assess the potential toxicity of treatment. Results: Nine to 10 logs of tumor-cell kill over a 7- to 20-day period are predicted by the various simulations examined. The most slowly proliferating tumor was also the most difficult to eradicate. During the infusion time, tumor-cell loss consisted of two components: A plateau phase, beginning at the start of infusion and ending once the infusion time exceeded the potential doubling time of the tumor; and a rapid cell-reduction phase that was close to log-linear. Beyond the plateau phase, treatment efficacy was highly sensitive to tumor activity concentration. Conclusions: Model predictions suggest that [ 125 I]IUdR will be highly dependent upon the potential doubling time of the tumor. Significant tumor cell kill will require infusion durations that exceed the longest potential doubling time in the tumor-cell population

  4. Hubungan Kemelimpahan Chlorella sp Dengan Kualitas Lingkungan Perairan Pada Skala Semi Masal di BBBPBAP Jepara

    Directory of Open Access Journals (Sweden)

    Siska Aprilliyanti

    2016-10-01

      ABSTRACT Chlorella sp is one of the microalgae are often cultivated for various purposes such as pharmaceuticals, cosmetics, or for alternative biodiesel Chlorella sp an agent of bioremediation good, but can live in a polluted environment can also wear a heavy metal as the metal essential for metabolism. The many benefits that will be taken if it can develop Chlorella sp on a mass scale. With the emergence of Chlorella sp author conducted research using Chlorella sp as its object. The purpose of this study was to determine the relationship between the abundance of Chlorella sp with the quality of the water environment in the district of Jepara.Chlorella sp is cultivated outdoors with a light source coming from direct sunlight, aeration for mixing media using a blower that flowed through the hose and faucet aeration to mix media. Aeration used in this study with the aim of Chlorella sp cells can obtain nutrients evenly in cultivation media for their water circulation in the culture vessel (Amini, 2006. From the analysis of data obtained by the coefficient of determination (R2 = 0.995. This illustrates that there is a very strong relationship between the independent variables namely the five parameters of water quality (nitrates, phosphates, temperature, pH and salinity with the dependent variable abundance of Chlorella sp. Furthermore, multiple linear regression equation as follows: Y = -5323.54 -16.80 -60.78 nitrate phosphate + 111.09 + temperature; 997.26 -191.92 pH salinity. From the regression equation shows that the water quality parameters that have a unidirectional relationship (proportional is temperature and pH. While water quality parameters which have an inverse relationship, namely; nitrate, phosphate and salinity. Chlorella sp abundance relationships with water environmental quality semi massive scale strong, the results of the regression analysis obtained Adjusted R2 value of 0.995, meaning that the percentage contribution of variables influence

  5. Potential Health Effects of Enzymatic Protein Hydrolysates from Chlorella vulgaris

    Directory of Open Access Journals (Sweden)

    Mahsa Sedighi

    2016-06-01

    Full Text Available Background and Objective: Chlorella vulgaris is a multi-cellular edible algal species with abundant proteins. Extraction of high value protein fractions for pharmaceutical and nutritional applications can significantly increase the commercial value of microalga biomasses. There is no known report on the anticancer peptides derived from the Chlorella vulgaris abundant protein.Materials and Methods: This study examined the antimicrobial and anticancer effects of peptides from a hydrolyzed Chlorella vulgaris protein with 62 kDa molecular weight. Protein hydrolysis was done by pepsin as a gastrointestinal protease, and was monitored through protein content measurement, sodium dodecyl sulfate polyacrylamide gel electrophoresis, and high performance liquidchromatography measurements. Inhibitory effect of the produced peptides on Escherichia coli cells and breast cancer cell lines was assayed.Results and Conclusion: Hydrolyzed peptides induced a decrease of about 34.1% in the growth of Escherichia coli, and the peptides of 3 to 5 kDa molecular weight had strong impact on the viability of breast cancer cells with IC50 value of 50 μg μl-1. The peptide fractions demonstrating antimicrobial and anti-cancer activities have the potential for use as functional food ingredients for health benefits. These results demonstrate that inexpensive algae proteinscould be a new alternative to produce anticancer peptides.Conflict of interest: The authors declare that there is no conflict of interest.

  6. Dietary effects of lutein-fortified chlorella on milk components of Holstein cows

    OpenAIRE

    Jeon, Jin-Young; Park, Keun-Kyu; Lee, Kyung-Woo; Jang, Seung-Wan; Moon, Byung-Hern; An, Byoung-Ki

    2016-01-01

    This study was conducted to investigate the dietary effect of conventional or lutein-fortified chlorella on milk production and lutein incorporation in milk. Fifteen Holstein cows in mid-lactation were used in a 3???3 Latin square design each with a 21-day period. Cows were top-dressed daily with 30?g of conventional or lutein-fortified chlorella for 3?weeks. Cows without chlorella served as the control. The feed intake and milk yield were not affected by dietary treatments. The concentration...

  7. The comparative study of the effect of some radionuclides on chlorella populations

    International Nuclear Information System (INIS)

    Shvobene, R.Ya.; Marchyulenene, D.P.; Shuliene, R.I.

    1984-01-01

    In this report the data are presented of the comparative study of physiological and genetic effects on chlorella populations (Chlorella vUlgaris Beijer, strain LARG-1) of 90 Sr, 137 Cs and 144 Ce (equal concentrations) distinguished by the radiation dose produced, the physico-chemical properties, and the levels of accumulation and deposition thereof in plant cells. The effects of the radionuclides on chlorella populations were estimated with a reference to the rate of photosynthesis, cell density, and the number of mutant and lethally affected cells

  8. Study of a model for gamma radiation effects on chlorella

    International Nuclear Information System (INIS)

    Delforge, Jacques; Fabre, Henri; CEA Centre d'Etudes Nucleaires de Grenoble, 38

    1977-01-01

    The experimental data obtained by 60 Co γ irradiation of chlorella are especially interesting because they show a dose rate effect (change in the survival curve plotted versus dose as the dose rate varies) and a change in the survival fraction as a function of the time separating the end of irradiation and the starting of culture. The radiobiological models published until now are not able to illustrate all these experimental phenomena. An attempt is made here to find a model within the scope of P. DELATTRE's transformation system theory. The use of this precise theoretical framework enables to propose an experimental procedure which offers no special practical difficulty but leads to much more abundant information than the standard procedures. The model obtained reveals the existence of at least three different states amongst chlorella still able to multiply, and only one state amongst those temporarily deprived of their multiplying capacity. It shows the possibility of internal restorations in the elements still capable of multiplying, but also confirms the existence of non-lethal but irreparable lesions [fr

  9. Safety evaluation of Whole Algalin Protein (WAP) from Chlorella protothecoides.

    Science.gov (United States)

    Szabo, Nancy J; Matulka, Ray A; Chan, Teresa

    2013-09-01

    Microalgae such as Chlorella spp., were once consumed as traditional human foods; now they are being developed as ingredients for modern diets. Whole Algalin Protein (WAP) from dried milled Chlorella protothecoides was evaluated for dietary safety in a 13-week feeding trial in rodents with genotoxic potential evaluated using in vitro and in vivo assays and the likelihood of food allergy potential evaluated via human repeat-insult patch test (HRIPT). In the subchronic study, rats consumed feed containing 0, 25,000, 50,000 or 100,000 ppm WAP for 92-93 days. No treatment-related mortalities or effects in general condition, body weight, food consumption, ophthalmology, urinalysis, hematology, clinical chemistry, gross pathology, organ weights, and histopathology occurred. Several endpoints exhibited statistically significant effects, but none was dose-related. The no-observed-adverse-effect level (NOAEL) was based on the highest WAP concentration consumed by the rats and was equivalent to 4805 mg/kg/day in males and 5518 mg/kg/day in females. No mutagenicity occurred in Salmonella typhimurium or Escherichia coli tester strains (≤5000 μg/plate WAP) with or without mutagenic activation. No clastogenic response occurred in bone marrow from mice administered a single oral dose (2000 mg/kg WAP). Skin sensitization was not induced by WAP via HRIPT, indicating little potential for food allergy. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Stability and loading properties of curcumin encapsulated in Chlorella vulgaris.

    Science.gov (United States)

    Jafari, Yaser; Sabahi, Hossein; Rahaie, Mahdi

    2016-11-15

    Curcumin (Cur), a polyphenols with pharmacological function, was successfully encapsulated in algae (Alg) cell (Chlorella vulgaris) as confirmed by fluorescence microscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and Fourier transform-infrared spectroscopy (FT-IR). Fluorescence micrographs, TGA, DSC and FTIR spectra suggested the hypothesis inclusion Cur in Nano-empty spaces inside cell wall of Alg. The TGA analysis showed that the thermal stability of Alg and Cur at algae/curcumin complex was 3.8% and 33% higher than their free forms at 0-300°C and 300-600°C ranges, respectively. After encapsulation in Alg cells, the photostability of Cur was enhanced by about 2.5-fold. Adsorption isotherm of Cur into Alg was fitted with the Freundlich isotherm. The microcapsules were loaded with Cur up to about 55% w/w which is much higher than other reported bio-carriers. In conclusion, the data proved that Chlorella vulgaris cell can be used as a new stable carrier for Cur. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Assessing biodiesel quality parameters for wastewater grown Chlorella sp.

    Science.gov (United States)

    Bagul, Samadhan Yuvraj; K Bharti, Randhir; Dhar, Dolly Wattal

    2017-07-01

    Microalgae are reported as the efficient source of renewable biodiesel which should be able to meet the global demand of transport fuels. Present study is focused on assessment of wastewater grown indigenous microalga Chlorella sp. for fuel quality parameters. This was successfully grown in secondary treated waste water diluted with tap water (25% dilution) in glass house. The microalga showed a dry weight of 0.849 g L -1 with lipid content of 27.1% on dry weight basis on 21st day of incubation. After transesterification, the yield of fatty acid methyl ester was 80.64% with major fatty acids as palmitic, linoleic, oleic and linolenic. The physical parameters predicted from empirical equations in the biodiesel showed cetane number as 56.5, iodine value of 75.5 g I 2 100 g -1 , high heating value 40.1 MJ kg -1 , flash point 135 °C, kinematic viscosity 4.05 mm 2 s -1 with density of 0.86 g cm 3 and cold filter plugging point as 0.7 °C. Fourier transform infra-red (FTIR), 1 H, 13 C NMR spectrum confirmed the chemical nature of biodiesel. The results indicated that the quality of biodiesel was almost as per the criterion of ASTM standards; hence, wastewater grown Chlorella sp. can be used as a promising strain for biodiesel production.

  12. Production of lipids in 10 strains of Chlorella and Parachlorella, and enhanced lipid productivity in Chlorella vulgaris

    Energy Technology Data Exchange (ETDEWEB)

    Pribyl, Pavel; Cepak, Vladislav [Academy of Sciences of the Czech Republic, Trebon (Czech Republic). Algological Centre and Centre for Bioindication and Revitalization; Zachleder, Vilem [Academy of Sciences of the Czech Republic, Trebon (Czech Republic). Lab. of the Cell Cycles of Algae

    2012-04-15

    We tested 10 different Chlorella and Parachlorella strains under lipid induction growth conditions in autotrophic laboratory cultures. Between tested strains, substantial differences in both biomass and lipid productivity as well as in the final content of lipids were found. The most productive strain (Chlorella vulgaris CCALA 256) was subsequently studied in detail. The availability of nitrates and/or phosphates strongly influenced growth and accumulation of lipids in cells by affecting cell division. Nutrient limitation substantially enhanced lipid productivity up to a maximal value of 1.5 g l{sup -1} day{sup -1}. We also demonstrated the production of lipids through large-scale cultivation of C. vulgaris in a thin layer photobioreactor, even under suboptimal conditions. After 8 days of cultivation, maximal lipid productivity was 0.33 g l{sup -1} day{sup -1}, biomass density was 5.7 g l{sup -1} dry weight and total lipid content was more than 30% dry weight. C. vulgaris lipids comprise fatty acids with a relatively high degree of saturation compared with canola oil offering a possible alternative to the use of higher plant oils. (orig.)

  13. Sequential accumulation of starch and lipid induced by sulfur deficiency in Chlorella and Parachlorella species

    Czech Academy of Sciences Publication Activity Database

    Mizuno, Y.; Sato, A.; Watanabe, K.; Hirata, A.; Takeshita, T.; Shuhei, O.; Sato, N.; Zachleder, Vilém; Tsuzuki, M.; Kawano, S.

    2013-01-01

    Roč. 129, FEB 2013 (2013), s. 150-155 ISSN 0960-8524 Institutional support: RVO:61388971 Keywords : Sulfur deficiency * Chlorella spp * Parachlorella kessleri Subject RIV: EE - Microbiology, Virology Impact factor: 5.039, year: 2013

  14. Laboratory culture for 14C-labeling of Chlorella and Oedogonium

    International Nuclear Information System (INIS)

    Krzywicka, A.M.; Wagner, G.H.

    1975-01-01

    Algae were cultured in experiments that attained efficient CO 2 utilization permitting 14 C=labeling of cells and that compared growth characteristics of unicellular Chlorella sp. and filamentous Oedogonium sp. Culture vessels were 500ml glass tubes through which air enriched to 5% CO 2 was slowly metered. The tubes, used in a vertical position for growing Chlorella, were filled with culture medium and the cells kept in suspension using a mganetic stirrer. Tubes placed horizontally and half filled with medium were used for Oedogonium permitting the 3g/l. in 5 days for Chlorella and 1 g/0.5 1. in 10 days for 3g/l. in 2 days for Chlorella and 1 g/0.5 l. in 10 days for Oedogonium. Efficiency and rate of CO 2 fixation, cell size and cell weight for the two algae are evaluated. (author)

  15. Light acclimation and pH perturbations affect photosynthetic performance in Chlorella mass culture

    Czech Academy of Sciences Publication Activity Database

    Ihnken, S.; Beardall, J.; Kromkamp, J.C.; Serrano, C.G.; Torres, M.A.; Masojídek, Jiří; Malapartida, I.; Abdala, R.; Jerez, C.G.; Malapascua, José R.F.; Navarro, E.; Rico, R.M.; Peralta, E.; Ferreira Ezequil, J.P.; Figueroa, F.L.

    2014-01-01

    Roč. 22, č. 2 (2014), s. 95-110 ISSN 1864-7790 Institutional support: RVO:61388971 Keywords : Chlorella * Mass culture * pH * Chlorophyll fluorescence Subject RIV: EE - Microbiology, Virology Impact factor: 1.258, year: 2014

  16. Cultivation of Microalgae Chlorella sp on Fresh Water and Waste Water of Tofu Industry

    Science.gov (United States)

    Widayat; Philia, John; Wibisono, Jessica

    2018-02-01

    Chlorella sp. is a microalgae that potential for food supplement, pharmaceuticals, animal feed, aqua culture and cosmetics. Chlorella sp. commonly growth in sea water. Indonesia as a producer of tofu generated more liquid waste. Nutrient that contained in the tofu wastewater are very useful for the production of microalgae. Cultivation carried out for 7 days at different percent volume of tofu liquid waste showed that the more volume of tofu liquid waste make them longer process decipherment of polymer compounds in the waste, that's make the growth rate of Chlorella sp. are slowness. Variable of10%V has the fastest growth rate. While, 90% v/v variable has the highest concentration of algae. It shows that Chlorella sp. better to grows in tofu wastewater than seawater.

  17. Evidence for a plasma-membrane-bound nitrate reductase involved in nitrate uptake of Chlorella sorokiniana

    Science.gov (United States)

    Tischner, R.; Ward, M. R.; Huffaker, R. C.

    1989-01-01

    Anti-nitrate-reductase (NR) immunoglobulin-G (IgG) fragments inhibited nitrate uptake into Chlorella cells but had no affect on nitrate uptake. Intact anti-NR serum and preimmune IgG fragments had no affect on nitrate uptake. Membrane-associated NR was detected in plasma-membrane (PM) fractions isolated by aqueous two-phase partitioning. The PM-associated NR was not removed by sonicating PM vesicles in 500 mM NaCl and 1 mM ethylenediaminetetraacetic acid and represented up to 0.8% of the total Chlorella NR activity. The PM NR was solubilized by Triton X-100 and inactivated by Chlorella NR antiserum. Plasma-membrane NR was present in ammonium-grown Chlorella cells that completely lacked soluble NR activity. The subunit sizes of the PM and soluble NRs were 60 and 95 kDa, respectively, as determined by sodium-dodecyl-sulfate electrophoresis and western blotting.

  18. Potential Of Microalgae Chlorella vulgaris As Bioremediation Agents of Heavy Metal Pb (Lead On Culture Media

    Directory of Open Access Journals (Sweden)

    Rita Sulistya Dewi Endah

    2018-01-01

    Full Text Available The purpose of this study to determine the ability of Chlorella vulgaris in absorbing Pb (lead and the effect of the variation of Pb metal concentration on the growth of Chlorella vulgaris.This study using an experimental study with complete random design with 4 treatments, namely control (without the addition of metal, Pb1 (addition of metal 1 mg / l, Pb3 (3 mg / l and Pb5 (5 mg / l, respectively 3 replications. Exposure Pb ion in Chlorella vulgaris for 7 days. Analysis of the metal content of Pb concentration performed on culture media after exposure it at 3 hours after dispersion Chlorella vulgaris and on day 7 of culture using the AAS method. Do also counting the growth of cells each day. The results of the analysis of the average metal content of Pb in the culture medium at the end of the study was the control (0.1980, Pb1 (0.1453, Pb3 (0.4144 and Pb5 (0.5305. While the average growth of Chlorella vulgaris at the end of the study were control (630.1116 x 104, Pb1 (829.0012 x 104, Pb3 (1069.9446 x 104 and Pb 5 (808.94450 x 104. The results of the analysis of the content of Pb in the F test shown that the difference in concentration of water Pb given real influence on the ability of Chlorella vulgaris in absorbing Pb and growth. The conclusion of this study was Chlorella vulgaris has the ability to absorb metals in the waters, and the provision of various concentrations of Pb can affect the growth of Chlorella vulgaris.

  19. Optical Manipulation of Symbiotic Chlorella in Paramecium Bursaria Using a Fiber Axicon Microlens

    Science.gov (United States)

    Taguchi, K.; Hirota, S.; Nakayama, H.; Kunugihara, D.; Mihara, Y.

    2012-03-01

    In this paper, chemically etched axicon fiber was proposed for laser trapping of symbiotic chlorella from paramecium bursaria. We fabricated axicon micro lenses on a single-mode bare optical fiber by selective chemical etching technique. The laser beam from fiber axicon microlens was strongly focused and optical forces were sufficient to move a symbiotic chlorella. From experimental results, it was found that our proposed fiber axicon microlens was a promising tool for cell trapping without physical contact.

  20. Optical Manipulation of Symbiotic Chlorella in Paramecium Bursaria Using a Fiber Axicon Microlens

    International Nuclear Information System (INIS)

    Taguchi, K; Hirota, S; Nakayama, H; Kunugihara, D; Mihara, Y

    2012-01-01

    In this paper, chemically etched axicon fiber was proposed for laser trapping of symbiotic chlorella from paramecium bursaria. We fabricated axicon micro lenses on a single-mode bare optical fiber by selective chemical etching technique. The laser beam from fiber axicon microlens was strongly focused and optical forces were sufficient to move a symbiotic chlorella. From experimental results, it was found that our proposed fiber axicon microlens was a promising tool for cell trapping without physical contact.

  1. Lethal action of ionizing radiation on the chlorella vulgaris cells containing varying dmounts of intracellular cysteine

    International Nuclear Information System (INIS)

    Kamchatova, I.E.; Zakharov, I.A.; Korolev, V.G.; Gracheva, L.M.; Zheleznyakova, N.Yu.; AN SSSR, Leningrad. Inst. Yadernoj Fiziki)

    1975-01-01

    In experiments on related strains of Chlorella vulgaris it has been shown that the content of sulfhydryl groups in ''feeder'' mutant cells exceeds the content of the latter in the cells of initial wild strain. Radiosensitivity of chlorella mutant forms does not differ from that of the initial wild strain and revertant isolated from the mutant strain culture. The presence of a high level of sulfhydryl groups, maybe, does not determine its resistance to ionizing radiation

  2. Potential Of Microalgae Chlorella vulgaris As Bioremediation Agents of Heavy Metal Pb (Lead) On Culture Media

    Science.gov (United States)

    Dewi, Endah Rita Sulistya; Nuravivah, Riza

    2018-02-01

    The purpose of this study to determine the ability of Chlorella vulgaris in absorbing Pb (lead) and the effect of the variation of Pb metal concentration on the growth of Chlorella vulgaris.This study using an experimental study with complete random design with 4 treatments, namely control (without the addition of metal), Pb1 (addition of metal 1 mg / l), Pb3 (3 mg / l) and Pb5 (5 mg / l), respectively 3 replications. Exposure Pb ion in Chlorella vulgaris for 7 days. Analysis of the metal content of Pb concentration performed on culture media after exposure it at 3 hours after dispersion Chlorella vulgaris and on day 7 of culture using the AAS method. Do also counting the growth of cells each day. The results of the analysis of the average metal content of Pb in the culture medium at the end of the study was the control (0.1980), Pb1 (0.1453), Pb3 (0.4144) and Pb5 (0.5305). While the average growth of Chlorella vulgaris at the end of the study were control (630.1116 x 104), Pb1 (829.0012 x 104), Pb3 (1069.9446 x 104) and Pb 5 (808.94450 x 104). The results of the analysis of the content of Pb in the F test shown that the difference in concentration of water Pb given real influence on the ability of Chlorella vulgaris in absorbing Pb and growth. The conclusion of this study was Chlorella vulgaris has the ability to absorb metals in the waters, and the provision of various concentrations of Pb can affect the growth of Chlorella vulgaris.

  3. Effect of maternal Chlorella supplementation on carotenoid concentration in breast milk at early lactation.

    Science.gov (United States)

    Nagayama, Junya; Noda, Kiyoshi; Uchikawa, Takuya; Maruyama, Isao; Shimomura, Hiroshi; Miyahara, Michiyoshi

    2014-08-01

    Breast milk carotenoids provide neonates with a source of vitamin A and potentially, oxidative stress protection and other health benefits. Chlorella, which has high levels of carotenoids such as lutein, zeaxanthin and β-carotene, is an effective dietary source of carotenoids for humans. In this study, the effect of maternal supplementation with Chlorella on carotenoid levels in breast milk at early lactation was investigated. Ten healthy, pregnant women received 6 g of Chlorella daily from gestational week 16-20 until the day of delivery (Chlorella group); ten others did not (control group). Among the carotenoids detected in breast milk, lutein, zeaxanthin and β-carotene concentrations in the Chlorella group were 2.6-fold (p = 0.001), 2.7-fold (p = 0.001) and 1.7-fold (p = 0.049) higher, respectively, than those in the control group. Our study shows that Chlorella intake during pregnancy is effective in improving the carotenoid status of breast milk at early lactation.

  4. Digestibility and pricing of Chlorella sorokiniana meal for use in tilapia feeds

    Directory of Open Access Journals (Sweden)

    Rafael Simões Coelho Barone

    Full Text Available ABSTRACT: Several microalgae contain in excess of 50 % crude protein with amino acid profile comparable to that of fish meal. In addition, high polyunsaturated fatty acid contents encourage their use in animal feeding and nutrition, particularly in the formulation and processing of aquafeeds. This study aims at estimating the feasibility of Chlorella meal as feed ingredient for the feeding and nutrition of farmed tilapia based upon digestibility data. Juvenile tilapia were stocked in conical-bottomed tanks (200 L with superficial, continuous water flow, and fed to apparent satiation in three daily meals with a reference diet and a test diet containing 30 % lyophilized Chlorella sorokiniana added of an inert marker. Feces were collected overnight by sedimentation in refrigerated, plastic containers coupled to the tanks and analyzed for determination of chemical composition and inert marker contents to estimate apparent digestibility coefficients (ADCs of protein and energy of Chlorella meal; registered ADCs of Chlorella meal were 90.5 and 84.22, respectively. A pricing model considering the quantity of digestible nutrient was proposed based on ADCs of Chlorella and compared with the price of fishmeal (FM and soybean meal (SBM. The indicative prices to elicit the use of Chlorella as a protein source rather than FM or SBM for the feed and nutrition of tilapia were 2.65 USD kg−1 and 0.66 USD kg−1, respectively.

  5. Effect of caffeine on induction of endogenous type C virus in mouse cells in vitro

    International Nuclear Information System (INIS)

    Niwa, O.; Sugahara, T.

    1981-01-01

    The effect of caffeine on the expression of murine endogenous virus in mouse cells induced by radiation and chemicals was studied. Postirradiation treatment of K-BALB cells with caffeine enhanced cell killing as well as the induction of xenotropic virus after ultraviolet light irradiation. The degree of enhancement for the virus induction was comparable to that for cell killing. On the other hand, colony-forming ability and the expression of xenotropic virus of K-BALB cells after X-irradiation were unaffected by caffeine. These data suggest a linear relationship between the degree of endogenous virus expression and the amount of lethal damages after irradiation. For induction by halogenated pyrimidines, a 24-hr incubation of AKR2B cells with caffeine after 5-iodo-2'-deoxyuridine treatment resulted in marked suppression of the expression of ecotropic virus. On the contrary, in K-BALB cells, caffeine exerted only a small effect on 5-iodo-2'-deoxyuridine-induced expression of ecotropic and xenotropic viruses. These results indicate that, although using the same inducing agent, the pathway of endogenous virus induction may be different for AKR2B cells and for K-BALB cells

  6. Effect of gamma radiation on growth, productivity and protein content of Chlorella Pyrenoidosa; Efecto de la radiacion gamma sobre el crecimiento, productividad y contenido proteico de Chlorella Pyrenoidosa

    Energy Technology Data Exchange (ETDEWEB)

    Martin, C; Fernandez, J

    1983-07-01

    The effect of five doses of gamma radiation: 10, 100, 500, 1000 and 5000 Gy at a dose rate of 4.500 Gy/h on growth, productivity and protein content of Chlorella pyroneidosa has been studied. High doses of gamma radiation have been observed to inhibit cellular division of Chlorella pyrenoidosa. Culture growth stopped 48 hours after irradiation at 5.000 Gy and 72 hours after irradiation at 500 and 1000 Gy. The lowest dose (10 Gy) produced a little growth stimulation that not statistically significative. Protein and aminoacid content did not show any change for gamma radiation doses studied. (Author) 32 refs.

  7. PRODUCTIVITY OF MICROALGAE CHLORELLA VULGARIS IN LABORATORY CONDITION

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    Agnieszka Patyna

    2017-06-01

    Full Text Available Algae biomass is increasingly regarded as a potential resource that could be used to produce biofuels, electricity and heat. Algae contain a lot of nutrients, so they can be used as food for humans and livestock. Because of their valuable composition (many nutrients they are used as supplements of balanced diet, in turn taking into account their biosorption abbility they are used to detoxification of human body. Algae cultivation does not demand large areas of land to expose cells to sunlight, so their production rate is higher than vascular plants. Moreover algae cultivation lets to achieve high biomass concentration. Important cultivation factors are: illumination (light intensity is an important factor because it drives photosynthesis, CO2 supply, culture medium and mixing. The experimental research was conducted using Chlorella vulgaris BA 002 strain. The aim of this study was to determine the effectiveness of biomass growth in laboratory condition.

  8. Radiosensitivity of chlorella after medium energy accelerated electron irradiation

    International Nuclear Information System (INIS)

    Roux, J.C.

    1966-06-01

    The survival curves (capability of multiplication) of chlorella pyrenoidosa after irradiations can be used for soft electrons (0.65 and 1 MeV), hence penetrating into only 2 to 4 millimeters of water: the algae are laying on porous membranes and the doses are calculated from the power of the electron beam measured by the electric current on a metallic target or by Fricke's dosimetry. With these techniques, it is showed and discussed the part of anoxia in the radioprotection (magnitude or reduction of the dose calculated from the slope of survival curves: 2.5 ) that is more important than the restoration studied by the fractionation of the dose. The 0.65 and 1 MeV electrons have a biologic effect lesser than 180 keV X-rays (RBE - relative biological efficiency - calculated on the slope of survival curves is 0.92 in aerated irradiation, 0.56 in the deoxygenated irradiation). (author) [fr

  9. Anisotropic transport of microalgae Chlorella vulgaris in microfluidic channel

    International Nuclear Information System (INIS)

    Ishak, Nur Izzati; Muniandy, S V; Periasamy, Vengadesh; Ng, Fong-Lee; Phang, Siew-Moi

    2017-01-01

    In this work, we study the regional dependence of transport behavior of microalgae Chlorella vulgaris inside microfluidic channel on applied fluid flow rate. The microalgae are treated as spherical naturally buoyant particles. Deviation from the normal diffusion or Brownian transport is characterized based on the scaling behavior of the mean square displacement (MSD) of the particle trajectories by resolving the displacements in the streamwise (flow) and perpendicular directions. The channel is divided into three different flow regions, namely center region of the channel and two near-wall boundaries and the particle motions are analyzed at different flow rates. We use the scaled Brownian motion to model the transitional characteristics in the scaling behavior of the MSDs. We find that there exist anisotropic anomalous transports in all the three flow regions with mixed sub-diffusive, normal and super-diffusive behavior in both longitudinal and transverse directions. (paper)

  10. Thermogravimetric analysis of the gasification of microalgae Chlorella vulgaris.

    Science.gov (United States)

    Figueira, Camila Emilia; Moreira, Paulo Firmino; Giudici, Reinaldo

    2015-12-01

    The gasification of microalgae Chlorella vulgaris under an atmosphere of argon and water vapor was investigated by thermogravimetric analysis. The data were interpreted by using conventional isoconversional methods and also by the independent parallel reaction (IPR) model, in which the degradation is considered to happen individually to each pseudo-component of biomass (lipid, carbohydrate and protein). The IPR model allows obtaining the kinetic parameters of the degradation reaction of each component. Three main stages were observed during the gasification process and the differential thermogravimetric curve was satisfactorily fitted by the IPR model considering three pseudocomponents. The comparison of the activation energy values obtained by the methods and those found in the literature for other microalgae was satisfactory. Quantification of reaction products was performed using online gas chromatography. The major products detected were H2, CO and CH4, indicating the potential for producing fuel gas and syngas from microalgae. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Bioaccumulation and biodegradation of sulfamethazine in Chlorella pyrenoidosa

    Science.gov (United States)

    Sun, Ming; Lin, Hong; Guo, Wen; Zhao, Fazhen; Li, Jian

    2017-12-01

    Intensive use of sulfamethazine (SM2) in aquaculture has resulted in some detrimental effects to non-targeted organisms. In order to assess its potential ecological risk, it is crucial to have a good understanding on the bioaccumulation and biodegradation of SM2 in Chlorella pyrenoidosa. The microalgae were treated with 2, 4, and 8 mg L-1 of sulfamethazine for 13 days, respectively, showing that the inhibition effects of sulfamethazine on the growth of Chlorella pyrenoidosa increased progressively as the concentrations of sulfamethazine increasing from 2 to 8 mg L-1. The peak concentrations of sulfamethazine accumulated in C. pyrenoidosa were 0.225, 0.325, and 0.596 ng per mg FW on day 13 for three treatment groups, respectively, showing a great ability to deplete sulfamethazine from the culture media. On day 13, the percentages of biotic degradation were 48.45%, 60.21% and 69.93%, respectively. The EC50 of 10.05 mg L-1 was derived which showed no significant risk for C. pyrenoidosa with a calculated risk quotient catalase increased progressively in response to sulfamethazine and showed a positive correlation to the treatment concentrations. The highest superoxide dismutase activity was achieved at the concentration of 8 mg L-1 after 2 d of exposure, which was 1.89 folds higher than that of the control. The activity of catalase has a similar pattern to that of superoxide dismutase with the maximum activity achieved at day 2, which was 3.11 folds higher compared to that of the control. In contrast to superoxide dismutase and catalase, the maximum glutathione S-transferase activity was observed at day 6, showing 2.2 folds higher than that of the control.

  12. Effects of Pb(Ⅱ) exposure on Chlorella protothecoides and Chlorella vulgaris growth, malondialdehyde, and photosynthesis-related gene transcription.

    Science.gov (United States)

    Xiong, Bang; Zhang, Wei; Chen, Lin; Lin, Kuang-Fei; Guo, Mei-Jin; Wang, Wei-Liang; Cui, Xin-Hong; Bi, Hua-Song; Wang, Bin

    2014-11-01

    Greater exposure to Pb(Ⅱ) increases the likelihood of harmful effects in the environment. In this study, the aquatic unicellular alga Chlorella protothecoides (C. protothecoides) and Chlorella vulgaris (C. vulgaris) were chosen to assess the acute and chronic toxicity of Pb(Ⅱ) exposure. Results of the observations show dose-response relationships could be clearly observed between Pb(Ⅱ) concentration and percentage inhibition (PI). Exposure to Pb(Ⅱ) increased malondialdehyde (MDA) content by up to 4.22 times compared with the control, suggesting that there was some oxidative damage. ANOVA analysis shows that Pb(Ⅱ) decreased chlorophyll (chl) content, indicating marked concentration-dependent relationships, and the lowest levels of chl a, chl b, and total-chl were 14.53, 18.80, and 17.95% of the controls, respectively. A real-time PCR assay suggests the changes in transcript abundances of three photosynthetic-related genes. After 120 h exposure Pb(Ⅱ) reduced the transcript abundance of rbcL, psaB, and psbC, and the relative abundances of the three genes of C. protothecoides and C. vulgaris in response to Pb(Ⅱ) were 54.66-98.59, 51.68-95.59, 37.89-95.48, 36.04-94.94, 41.19-91.20, and 58.75-96.80% of those of the controls, respectively. As for 28 d treatments, the three genes displayed similar inhibitory trend. This research provides a basic understanding of Pb(Ⅱ) toxicity to aquatic organisms. Copyright © 2013 Wiley Periodicals, Inc.

  13. Chlorella intake attenuates reduced salivary SIgA secretion in kendo training camp participants

    Directory of Open Access Journals (Sweden)

    Otsuki Takeshi

    2012-12-01

    Full Text Available Abstract Background The green alga Chlorella contains high levels of proteins, vitamins, and minerals. We previously reported that a chlorella-derived multicomponent supplement increased the secretion rate of salivary secretory immunoglobulin A (SIgA in humans. Here, we investigated whether intake of this chlorella-derived supplement attenuated the reduced salivary SIgA secretion rate during a kendo training camp. Methods Ten female kendo athletes participated in inter-university 6-day spring and 4-day summer camps. They were randomized into two groups; one took placebo tablets during the spring camp and chlorella tablets during the summer camp, while the other took chlorella tablets during the spring camp and placebo tablets during the summer camp. Subjects took these tablets starting 4 weeks before the camp until post-camp saliva sampling. Salivary SIgA concentrations were measured by ELISA. Results All subjects participated in nearly all training programs, and body-mass changes and subjective physical well-being scores during the camps were comparable between the groups. However, salivary SIgA secretion rate changes were different between these groups. Salivary SIgA secretion rates decreased during the camp in the placebo group (before vs. second, middle, and final day of camp, and after the camp: 146 ± 89 vs. 87 ± 56, 70 ± 45, 94 ± 58, and 116 ± 71 μg/min, whereas no such decreases were observed in the chlorella group (121 ± 53 vs. 113 ± 68, 98 ± 69,115 ± 80, and 128 ± 59 μg/min. Conclusion Our results suggest that a use of a chlorella-derived dietary supplement attenuates reduced salivary SIgA secretion during a training camp for a competitive sport.

  14. Effect of Chlorella Ingestion on Oxidative Stress and Fatigue Symptoms in Healthy Men.

    Science.gov (United States)

    Okada, Hirotaka; Yoshida, Noriko; Kakuma, Tatsuyuki; Toyomasu, Kouji

    2018-05-21

    We examined the effects of dietary chlorella ingestion on oxidative stress and fatigue symptoms in healthy men under resting and fatigue conditions. We conducted a double-blind, parallel-arm controlled study. Twenty-seven healthy male volunteers (mean age, 35.4±10.4 years) were randomly divided into the chlorella and placebo groups, and received chlorella (6 g/day) and lactose as placebo (7.2 g/day), respectively, for 4 weeks. To simulate mild fatigue, subjects underwent exercise (40% of the heart rate reserve) for 30 minutes. Fatigue was measured using the visual analog scale of fatigue (F-VAS) pre- and post-exercise. Serum antioxidant capacity (AC), malondialdehyde levels, and other indices of oxidative stress were measured pre- and post-exercise. All measurements were repeated after the intervention period and the results were compared with baseline measurements. Under resting conditions, AC significantly increased after the intervention period in the chlorella group, but not in the placebo group. Malondialdehyde levels after the intervention period were significantly lower in the chlorella group than in the placebo group. There were no significant differences in any of the oxidative-stress indices measured pre- and post-exercise, either before or after intervention, in either group. F-VAS significantly increased after exercise at all measurement time-points in both groups, except after the intervention period in the chlorella group. Under fatigue conditions, there were no significant differences in oxidative stress indices between the groups. Our results suggest that chlorella ingestion has the potential to relieve oxidative stress and enhance tolerance for fatigue under resting conditions.

  15. The culture of Chlorella vulgaris with human urine in multibiological life support system experiments

    Science.gov (United States)

    Li, Ming; Liu, Hong; Tong, Ling; Fu, Yuming; He, Wenting; Hu, Enzhu; Hu, Dawei

    The Integrative Experimental System (IES) was established as a tool to evaluate the rela-tionship of the subsystems in Bioregenerative Life Support System, and Multibiological Life Support System Experiments (MLSSE) have been conducted in the IES. The IES consists of a higher plant chamber, an animal chamber and a plate photo bioreactor (PPB) which cultivated lettuce (Lactuca sativa L.), silkworm (Bombyx Mori L.) and microalgae (Chlorella vulgaris), respectively. In MLSSE, four volunteers took turns breathing the system air through a tube connected with the animal chamber periodically. According to the CO2 concentration in the IES, the automotive control system of the PPB changed the light intensity regulating the photosynthesis of Chlorella vulgaris to make CO2 /O2 in the system maintain at stable levels. Chlorella vulgaris grew with human urine by carrying certain amount of alga liquid out of the bioreactor every day with synthetic urine replenished into the system, and O2 was regenerated, at the same time human urine was purified. Results showed that this IES worked stably and Chlorella vulgaris grew well; The culture of Chlorella vulgaris could be used to keep the balance of CO2 and O2 , and the change of light intensity could control the gas composition in the IES; Microalgae culture could be used in emergency in the system, the culture of Chlorella vulgaris could recover to original state in 5 days; 15.6 ml of condensation water was obtained every day by the culture of Chlorella vulgaris; The removal efficiencies of N, P in human urine could reach to 98.2% and 99.5%.

  16. Effectiveness of anticancer drugs determined in nude mice inoculated with [125I]5-iodo-2'-deoxyuridine-prelabeled human melanoma cells

    International Nuclear Information System (INIS)

    Lockshin, A.; Giovanella, B.C.; Vardeman, D.M.; Mendoza, J.T.; Quian, C.; Kozielski, T.; Stehlin, J.S. Jr.

    1985-01-01

    Anticancer drugs were tested on NIH-2 nude mice inoculated ip with BRO human melanoma cells, which are rapidly lethal for these hosts. Criteria for drug activity were a) increased host survival and b) an increased rate of radioactivity loss from mice bearing BRO cells prelabeled with [ 125 I]5-iodo-2'-deoxyuridine. Diphtheria toxin, which is selectively toxic to human cells compared to mouse cells, prolonged host survival and accelerated 125 I elimination in a dose-dependent manner. Drugs that increased the rate of 125 I loss compared to the rate of untreated mice also prolonged the lives of treated mice. With one exception, drugs that did not accelerate 125 I elimination had little or no effect on the length of survival

  17. Plastid and mitochondrion genomic sequences from Arctic Chlorella sp. ArM0029B

    Science.gov (United States)

    2014-01-01

    Background Chorella is the representative taxon of Chlorellales in Trebouxiophyceae, and its chloroplast (cp) genomic information has been thought to depend only on studies concerning Chlorella vulgaris and GenBank information of C. variablis. Mitochondrial (mt) genomic information regarding Chlorella is currently unavailable. To elucidate the evolution of organelle genomes and genetic information of Chlorella, we have sequenced and characterized the cp and mt genomes of Arctic Chlorella sp. ArM0029B. Results The 119,989-bp cp genome lacking inverted repeats and 65,049-bp mt genome were sequenced. The ArM0029B cp genome contains 114 conserved genes, including 32 tRNA genes, 3 rRNA genes, and 79 genes encoding proteins. Chlorella cp genomes are highly rearranged except for a Chlorella-specific six-gene cluster, and the ArM0029B plastid resembles that of Chlorella variabilis except for a 15-kb gene cluster inversion. In the mt genome, 62 conserved genes, including 27 tRNA genes, 3 rRNA genes, and 32 genes encoding proteins were determined. The mt genome of ArM0029B is similar to that of the non-photosynthetic species Prototheca and Heicosporidium. The ArM0029B mt genome contains a group I intron, with an ORF containing two LAGLIDADG motifs, in cox1. The intronic ORF is shared by C. vulgaris and Prototheca. The phylogeny of the plastid genome reveals that ArM0029B showed a close relationship of Chlorella to Parachlorella and Oocystis within Chlorellales. The distribution of the cox1 intron at 721 support membership in the order Chlorellales. Mitochondrial phylogenomic analyses, however, indicated that ArM0029B shows a greater affinity to MX-AZ01 and Coccomyxa than to the Helicosporidium-Prototheca clade, although the detailed phylogenetic relationships among the three taxa remain to be resolved. Conclusions The plastid genome of ArM0029B is similar to that of C. variabilis. The mt sequence of ArM0029B is the first genome to be reported for Chlorella. Chloroplast

  18. Characterization of microalga Chlorella as a fuel and its thermogravimetric behavior

    International Nuclear Information System (INIS)

    Rizzo, Andrea Maria; Prussi, Matteo; Bettucci, Lorenzo; Libelli, Ilaria Marsili; Chiaramonti, David

    2013-01-01

    Highlights: ► Proximate and ultimate analysis of two microalgae (Nannochloropsis and Chlorella spp.). ► TGA of Chlorella spp. and Nannochloropsis investigated at 15 °C/min up to 800 °C. ► 1.2 kg of Chlorella pyrolyzed in a novel batch, intermediate pyrolysis pilot reactor at 450 °C. ► Bio-oil from Chlorella oil analysed and compared to pine chips fast pyrolysis oil. ► Bio-oil from Chlorella exhibited superior properties compared to lignocellulosic pyrolysis oil as intermediate energy carrier. -- Abstract: Microalgae are photosynthetic microorganisms living in marine or freshwater environment. In this study, samples of Chlorella spp. and Nannochloropsis from two different origins were analysed to settle a preliminary characterization of these microorganisms as intermediate energy carriers and their properties compared to a conventional lignocellulosic feedstock (pine chips). Both microalgae samples were characterized in terms of elemental composition (CHONS and P) and thermogravimetric behavior. This was investigated through non-isothermal thermogravimetric analysis in nitrogen atmosphere at heating rate of 15 °C min −1 and temperature up to 800 °C. Solid residues produced at 300 °C and 800 °C from TGA were also analysed to determine the ultimate composition of chars. Activation energy, reaction order and pre-exponential factor were calculated for the single step conversion mechanism of 1 g of Chlorella spp. and compared to literature data on Chlorella protothecoides and Spirulina platensis. Calculated kinetic parameters, given as intervals of several determinations, resulted to be: pre-exponential factor (A) 1.47–1.62E6 min −1 , activation energy (E) 7.13–7.92E4 J mol −1 , reaction order (n) 1.69–2.41. 1.2 kg of Chlorella spp. was then processed in a newly designed batch pyrolysis pilot reactor, capable of converting up to 1.5 kg h −1 of material, and pyrolysis liquid collected, analysed and compared with a sample of fast pyrolysis

  19. Enhancement of Protein and Pigment Content in Two Chlorella Species Cultivated on Industrial Process Water

    Directory of Open Access Journals (Sweden)

    Hamed Safafar

    2016-12-01

    Full Text Available Chlorella pyrenoidosa and Chlorella vulgaris were cultivated in pre-gasified industrial process water with high concentration of ammonia representing effluent from a local biogas plant. The study aimed to investigate the effects of growth media and cultivation duration on the nutritional composition of biomass. Variations in proteins, lipid, fatty acid composition, amino acids, tocopherols, and pigments were studied. Both species grew well in industrial process water. The contents of proteins were affected significantly by the growth media and cultivation duration. Microalga Chlorella pyrenoidosa produced the highest concentrations of protein (65.2% ± 1.30% DW while Chlorella vulgaris accumulated extremely high concentrations of lutein and chlorophylls (7.14 ± 0.66 mg/g DW and 32.4 ± 1.77 mg/g DW, respectively. Cultivation of Chlorella species in industrial process water is an environmentally friendly, sustainable bioremediation method with added value biomass production and resource valorization, since the resulting biomass also presented a good source of proteins, amino acids, and carotenoids for potential use in aquaculture feed industry.

  20. [Effect of magnesium deficiency on photosynthetic physiology and triacylglyceride (TAG) accumulation of Chlorella vulgaris].

    Science.gov (United States)

    Wang, Shan; Zhao, Shu-Xin; Wei, Chang-Long; Yu, Shui-Yan; Shi, Ji-Ping; Zhang, Bao-Guo

    2014-04-01

    As an excellent biological resource, Chlorella has wide applications for production of biofuel, bioactive substances and water environment restoration. Therefore, it is very important to understand the photosynthetic physiology characteristics of Chlorella. Magnesium ions play an important role in the growth of microalgae, not only the central atom of chlorophyll, but also the cofactor of some key enzyme in the metabolic pathway. A laboratory study was conducted to evaluate the effects of magnesium deficiency on several photosynthetic and physiological parameters and the triacylglyceride (TAG) accumulation of the green alga, Chlorella vulgaris, in the photoautotrophic culture process. Chlorella vulgaris biomass, protein, chlorophyll a and chlorophyll b contents decreased by 20%, 43.96%, 27.52% and 28.07% in response to magnesium deficiency, while the total oil content increased by 19.60%. Moreover, magnesium deficiency decreased the maximal photochemical efficiency F(v)/F(m) by 22.54%, but increased the non-photochemical quenching parameters qN. Our results indicated the decline of chlorophyll caused by magnesium, which affected the photosynthesis efficiency, lead to the growth inhibition of Chlorella vulgaris and affected the protein synthesis and increased the triacylglyceride (TAG) accumulation.

  1. Cultivation of Chlorella sp. as Biofuel Sources in Palm Oil Mill Effluent (POME

    Directory of Open Access Journals (Sweden)

    H Hadiyanto

    2012-07-01

    Full Text Available Renewable energy is essential and vital aspect for development in Indonesia especially less oil reserve for coming 15 years. Biodiesel has received much attention as renewable energy in recent years. One of potential biodiesel is produced from microalgae. Due to high content of nutrients in Palm Oil Mill Effluent (POME, this waste is a potential for nutrient growth for microalgae. Chlorella is one of high potential for biodiesel since it has high lipid content (20-30%. The objective of the research is to determine growth rate and biomass productivity in Chlorella Sp cultured in POME. Chlorella Sp was cultured in 20%, 50%, 70% POME using urea concentration 0.1gr/L (low nitrogen source and 1gr/l (high nitrogen source at flask disk, pH 6.8-7.2; aerated using aquarium pump and fluorescence lamp 3000-6000 lux as light. Medium was measured using spectrophotometer Optima Sp-300 OD at 680 wave length in 15 days to calculate specific growth rate. At end of cultivation, Chlorella sp was filtered and measured as dry weight. Result indicated that Chlorella sp at 50% POME 1gr/L urea showed higher specific growth rate (0.066/day. Factor affecting growth rate of microalgae is CNP ratio, POME concentration, and urea concentration.

  2. [Using Excess Activated Sludge Treated 4-Chlorophenol Contained Waste Water to Cultivate Chlorella vulgaris].

    Science.gov (United States)

    Wang, Lu; Chen, Xiu-rong; Yan, Long; He, Yi-xuan; Shi, Zhen-dong

    2015-04-01

    Using different rations of sludge extracts and supernate from 4-Chlorophenol (4-CP) simulated wastewater's excess sludge after centrifugation to cultivate the Chlorella vulgaris to achieve the goal of excess sludge utilization together with chlorella cultivating. The experiments were performed in 500 mL flasks with different rations of sludge extracts & BG-11 and supernate & BG-11 in a light growth chamber respectively. Number of algal cells, Chlorophyll, enzyme activity, oil and water total nitrogen (TN), total phosphorus (TP), total organic carbon (TOC), toxicity index were investigated. Result showed that the nutrition supplies and toxicity in the excess sludge were removed efficiently via Chlorella vulgaris, the removal rates of TN and TP were at least 40% and 90% respectively; After 10 days cultivation, the density growth of 50% sludge extracts was 20 times higher of the beginning while its chlorophyll content was lower than that of the blank group. Sludge extracts could promote the proliferation of algae, but were not conducive to the synthesis of chlorophyll. The quantity of SOD in per cell showed Chlorella vulgaris gave a positive response via stimulation from toxicant in sludge extracts and supernate. The best time for collecting chlorella vulgaris was the fifth day of cultivation, taking neutral oil accumulation as the evaluating indicator for its utilization combined with the removal of supplies and toxicity.

  3. Effects of hydrolyzed Chlorella vulgaris by malted barley on the immunomodulatory response in ICR mice and in Molt-4 cells.

    Science.gov (United States)

    Kim, Na-Hyung; Kim, Kyu-Yeob; Jeong, Hyun-Ja; Kim, Hyung-Min; Hong, Seung-Heon; Um, Jae-Young

    2010-07-01

    Chlorella vulgaris is a unicellular and microscopic algae that is currently used in a variety of forms of tablets, capsules and liquid as a biological response modifier. The aim of this study was to investigate the effects of hydrolyzed Chlorella vulgaris by malted barley for its potential reduction of the immobility time in ICR mice and on the cytokine regulation in human T cell line, Molt-4. After a forced swimming test, the changes in aspects of blood biochemical parameters due to the administration of hydrolyzed Chlorella vulgaris by malted barley were examined. The effect of hydrolyzed Chlorella vulgaris by the malted barley-treated group for 14 days on the immobility time was significantly reduced in comparison with that of the control group (P cells. These results indicate that hydrolyzed Chlorella vulgaris by malted barley is useful for immune function improvements, enhanced physical stamina, and as a candidate for an anti-fatigue or antidepressant agent.

  4. Cooperative effects between two acyclovir resistance loci in herpes simplex virus.

    Science.gov (United States)

    Darby, G; Churcher, M J; Larder, B A

    1984-01-01

    The acyclovir-resistant mutant SC16 R9C2 (H.J. Field, G. Darby, and P. Wildy , J. Gen. Virol. 49:115-124, 1980) has been shown to contain two resistance loci which segregate independently on recombination with wild-type virus. One locus is in thymidine kinase, and the other is in DNA polymerase. Both induced enzymes have altered properties, thymidine kinase showing a low affinity for acyclovir and low activity, and DNA polymerase showing a low affinity for acyclovir triphosphate. Other properties of both enzymes are described which distinguish them from their wild-type counterparts. Recombinants containing either mutant thymidine kinase ( RSC -11) or mutant DNA polymerase ( RSC -26), but not both, have been used to investigate the relative contribution of each lesion to resistance and pathogenicity. Although SC16 R9C2 and both recombinants grow as well as does wild-type virus in tissue culture, they are considerably attenuated in vivo, the greatest attenuation of virulence being seen with SC16 R9C2 and RSC -26. With respect to both acyclovir resistance and in vivo growth, the lesions appear to behave synergistically. Cross resistance studies have shown the recombinant RSC -26, which contains mutant DNA polymerase but which evidently expresses wild-type thymidine kinase, to be cross resistant to both 5-iodo-2'-deoxyuridine and 5-trifluoromethyl-2'-deoxyuridine but not to (E)-5-(2-bromovinyl)-2'-deoxyuridine or 9-beta-D-arabinofuranosyladenine. Images PMID:6328014

  5. Heterotrophic Growth and Production of Xanthophylls by Chlorella pyrenoidosa

    Science.gov (United States)

    Theriault, Robert J.

    1965-01-01

    The growth and level of xanthophylls of several representative species of green algae were investigated as a possible source of pigmentation for the egg yolk and broiler markets. Chlorella pyrenoidosa 7-11-05 was selected for fermentation studies because of its high level of xanthophylls and wide temperature range for growth. The heterotrophic metabolism was preferred because of the ease of adaptability to present fermentation equipment. When used as the sole carbon source, glucose was the only sugar, among many tested, that gave appreciable growth in illuminated shaken flasks. A dry cell weight of 90 g per liter and total xanthophylls of 450 mg per liter were obtained from 190 g per liter of glucose monohydrate in 168-hr illuminated shaken flasks. Higher levels of glucose decreased yields. In combination with glucose, monosaccharides, such as fructose and galactose, were readily assimilated. The 7-11-05 strain was adapted to galactose as the sole carbon source after six vegetative passages. Light of the proper intensity and duration stimulated total xanthophylls approximately 35%. The effect on dry cell weight and total xanthophylls of seven antibiotics added at various levels in shaken flasks was studied. Erythromycin was essentially stable throughout the fermentation and nontoxic up to 25 μg/ml, with only slight toxicity at higher levels. Both erythromycin and ristocetin were effective in controlling a high incidence of bacterial contamination in 30-liter fermentors. With the higher agitation and aeration rates possible in 30-liter fermentors, dry cell weights in excess of 100 g per liter and total xanthophylls of 467 to 512 mg per liter were readily obtained from 230 to 260 g per liter of glucose in 162-hr illuminated batch-type fermentations. Continuous-feed runs yielded a dry cell weight of 302 g per liter and total xanthophylls of 650 mg per liter from 520 g per liter of glucose. The type of Chlorella cell produced was an important consideration with

  6. Evidence for non-assimilation of Chlorella by the African freshwater snail Bulinus (Physopsis) globosus

    International Nuclear Information System (INIS)

    Van Aardt, W.J.; Wolmarans, C.T.

    1981-01-01

    Little is known about the assimilation of its natural food by South African basommatophorans. It is generally assumed that the snails are microphagus herbivores which ingest mainly periphytic algae, detritus and the bacterial component of their food. Preliminary observations indicated that Chlorella spp. were by far the dominant algal species on stems and leaves of Juncus on which the snails were usually found in our study. This report describes experiments to see whether Chlorella is ingested and assimilated by Bulinus (Physopsis) globosus. A closely related species, B. (B.) tropicus, which occupies the same niche was also included in the study for purposes of comparison. It was found that, although Chlorella was continuously ingested by both species, it was assimilated by neither. Possible reasons for this are given

  7. Biochemical System Analysis of Lutein Production by Heterotrophic Chlorella pyrenoidosa in a Fermentor

    Directory of Open Access Journals (Sweden)

    Zheng-Yun Wu

    2009-01-01

    Full Text Available Chlorella is a promising alternative source of lutein, as it can be cultivated heterotrophically with high efficiency. In this study, the carotenoids in Chlorella pyrenoidosa heterotrophically cultivated in a 19-litre fermentor have been analyzed and determined by using HPLC and HPLC-MS. A biochemical system theory (BST model was developed for understanding the regulatory features of carotenoid metabolism during the batch cultivation. Factors that influence lutein production by C. pyrenoidosa were discussed based on the model. It shows that low flux for lycopene formation is the major bottleneck for lutein production, while by-product syntheses and inhibitions affect the cellular lutein content much less. However, with further increase of the cellular lutein content, the inhibition on lycopene formation by lutein may become a limiting factor. Although speculative, these results may provide useful information for further elucidation of the regulatory mechanisms of carotenoid biosynthesis in Chlorella and modifying its metabolic network to enhance lutein production.

  8. Influence of cysteine and selenodicysteine on the uptake of zinc by Chlorella vulgaris Beijerinck

    International Nuclear Information System (INIS)

    Czauderna, M.; Samochocka, K.

    1982-01-01

    The uptake of zinc labelled with radioactive 65 Zn in the presence of cysteine and selenodicysteine by Chlorella vulgaris was examined. The concentration of zinc ions in the medium was 20 mg per 1. The uptake yield was found to be enhanced by selenodicysteine. At concentration of 10 - 7 -10 - 6 M the growth rate of Chlorella vulgaris was accelerated by the latter, provided that the specific activity of 65 Zn was 3.7 MBq/1. At this specific zinc activity cysteine increased the uptake yield during the initial 50 h of the incubation process. At specific 65 Zn-activity of 55.5 MBq/1 selenodicysteine and cysteine only slightly influenced the zinc uptake by Chlorella vulgaris. No increment in the biomass was observed at this specific zinc radioactivity. (author)

  9. Bioremediation of the textile waste effluent by Chlorella vulgaris

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    Hala Yassin El-Kassas

    2014-01-01

    Full Text Available The microalgae biomass production from textile waste effluent is a possible solution for the environmental impact generated by the effluent discharge into water sources. The potential application of Chlorella vulgaris for bioremediation of textile waste effluent (WE was investigated using 22 Central Composite Design (CCD. This work addresses the adaptation of the microalgae C. vulgaris in textile waste effluent (WE and the study of the best dilution of the WE for maximum biomass production and for the removal of colour and Chemical Oxygen Demand (COD by this microalga. The cultivation of C. vulgaris, presented maximum cellular concentrations Cmax and maximum specific growth rates μmax in the wastewater concentration of 5.0% and 17.5%, respectively. The highest colour and COD removals occurred with 17.5% of textile waste effluent. The results of C. vulgaris culture in the textile waste effluent demonstrated the possibility of using this microalga for the colour and COD removal and for biomass production. There was a significant negative relationship between textile waste effluent concentration and Cmax at 0.05 level of significance. However, sodium bicarbonate concentration did not significantly influence the responses of Cmax and the removal of colour and COD.

  10. Effect of the hydrocarbon phenanthrene on Chlorella vulgaris (Chlorellaceae) growth

    International Nuclear Information System (INIS)

    Otero Paternina, Angelica; Cruz Casallas, Pablo E; Velasco Santamaria, Yohana M

    2013-01-01

    The effects of the polycyclic aromatic hydrocarbon phenanthrene on the growth of chlorella vulgaris alga were evaluated under laboratory conditions. The algae were exposed during 72 h to different concentrations of phenanthrene (0, 1, 10, 100, 1000 and 10000 μg/l). The alga density was daily determined by a neubauer chamber. The average growth average, total biomass and inhibition percentage of the biomass were also determined. In addition, the content of chlorophyll a was determined at the beginning and the end of the experiment. the assays were carried out in glass bottles of 0,4 l using the complex NPK (remital m 17-6-18) at 1 g/l as an organic fertilizing. The results showed that phenanthrene inhibited progressively the alga growth being the lowest cellular growth observed in the medium with the highest phenanthrene concentration, reaching an inhibition percentage of 59 %. In the other treatments, the daily growth rate was relatively constant. The chlorophyll a concentration evaluated by spectrophotometry was not affected by the phenanthrene concentration. in conclusion, the growth of the alga c. vulgaris was affected negatively by the exposure to nominal concentrations of the polycyclic aromatic hydrocarbon phenanthrene higher than 1 μg/l.

  11. Studies on thermokinetic of Chlorella pyrenoidosa devolatilization via different models.

    Science.gov (United States)

    Chen, Zhihua; Lei, Jianshen; Li, Yunbei; Su, Xianfa; Hu, Zhiquan; Guo, Dabin

    2017-11-01

    The thermokinetics of Chlorella pyrenoidosa (CP) devolatilization were investigated based on iso-conversional model and different distributed activation energy models (DAEM). Iso-conversional process result showed that CP devolatilization roughly followed a single-step with mechanism function of f(α)=(1-α) 3 , and kinetic parameters pair of E 0 =180.5kJ/mol and A 0 =1.5E+13s -1 . Logistic distribution was the most suitable activation energy distribution function for CP devolatilization. Although reaction order n=3.3 was in accordance with iso-conversional process, Logistic DAEM could not detail the weight loss features since it presented as single-step reaction. The un-uniform feature of activation energy distribution in Miura-Maki DAEM, and weight fraction distribution in discrete DAEM reflected weight loss features. Due to the un-uniform distribution of activation and weight fraction, Miura-Maki DAEM and discreted DAEM could describe weight loss features. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Survival curves and cell restoration of gamma irradiated chlorella

    International Nuclear Information System (INIS)

    Gilet, Roland

    1970-01-01

    The characteristics of the living material used and the cultures developed are defined. The irradiation techniques and the dosimetry methods used are described. The clonal growth in a gelified nutrient solution was studied and the survival curves, which are very reproducible when anoxic conditions are eliminated, were established. It is shown that the radiosensitivity of Chlorella decreases with the age of the culture when the plateau of the growth curve is reached, and that for synchronous cells it varies slightly with the phase in the cycle at which the radiation is received. The restoration from sublethal damage occurs quickly and does not depend upon the continuation of the cell cycle when no multiplication occurs during the experiments and is not modified by anoxic conditions. The restoration rate is reduced at 0 deg. C. It explains the variations in the apparent radiosensitivity with the dose rate. In contrast with the results published for many cells, the restoration is incomplete. The problem of the elimination of sublethal damage during clonal development is posed. A model summarizing the experimental results and suggesting future work is given. (author) [fr

  13. Kinetics of Chlorella protothecoides microalgal oil using base catalyst

    Directory of Open Access Journals (Sweden)

    Mukesh Kumar

    2016-09-01

    Full Text Available Due to continuous diminishing of fossil fuel resources and emission of greenhouse gases, the search for alternative fuels such as biodiesel and bioethanol has become inevitable. Biodiesel, also known as fatty acid methyl or ethyl ester, has emerged as a substitute for diesel because of similar fuel properties. Presently, biodiesel is produced from edible, non-edible and microalgal oil. Chlorella protothecoides (lipid content 14.6–57.8% is being investigated as the potential microalgae species owing to high oil content, less land area required for cultivation and faster growth rate. The present investigation shows the results of the kinetics of transesterification of C. protothecoides microalgal oil carried out at optimum conditions of catalyst concentration, reaction temperature, molar ratio and reaction time. The percentage of methyl ester yield is the only parameter chosen to carry out the optimum parameter and the kinetics of transesterification. The reaction rate constant was to be 0.0618 min−1. Furthermore, microalgal biodiesel is characterized for physico-chemical properties that are found to meet American (ASTM D6751 and Indian (IS 15607 standards, especially in cold flow properties and stability of conventional biodiesel.

  14. Enhanced Harvesting of Chlorella vulgaris Using Combined Flocculants.

    Science.gov (United States)

    Ma, Xiaochen; Zheng, Hongli; Zhou, Wenguang; Liu, Yuhuan; Chen, Paul; Ruan, Roger

    2016-10-01

    In this study, a novel flocculation strategy for harvesting Chlorella vulgaris with combined flocculants, poly (γ-glutamic acid) (γ-PGA) and calcium oxide (CaO), has been developed. The effect of flocculant dosage, the order of flocculant addition, mixing speed, and growth stage on the harvesting efficiency was evaluated. Results showed that the flocculation using combined flocculants significantly decreases the flocculant dosage and settling time compared with control. It was also found that CaO and γ-PGA influenced microalgal flocculation by changing the zeta potential of cells and pH of microalgal suspension. The most suitable order of flocculant addition was CaO first and then γ-PGA. The optimal mixing speed was 200 rpm for 0.5 min, followed by 50 rpm for another 4.5 min for CaO and γ-PGA with the highest flocculation efficiency of 95 % and a concentration factor of 35.5. The biomass concentration and lipid yield of the culture reusing the flocculated medium were similar to those when a fresh medium was used. Overall, the proposed method requires low energy input, alleviates biomass and water contamination, and reduces utilization of water resources and is feasible for harvesting C. vulgaris for biofuel and other bio-based chemical production.

  15. Chlorella vulgaris triggers apoptosis in hepatocarcinogenesis-induced rats*

    Science.gov (United States)

    Mohd Azamai, Emey Suhana; Sulaiman, Suhaniza; Mohd Habib, Shafina Hanim; Looi, Mee Lee; Das, Srijit; Abdul Hamid, Nor Aini; Wan Ngah, Wan Zurinah; Mohd Yusof, Yasmin Anum

    2009-01-01

    Chlorella vulgaris (CV) has been reported to have antioxidant and anticancer properties. We evaluated the effect of CV on apoptotic regulator protein expression in liver cancer-induced rats. Male Wistar rats (200~250 g) were divided into eight groups: control group (normal diet), CDE group (choline deficient diet supplemented with ethionine in drinking water to induce hepatocarcinogenesis), CV groups with three different doses of CV (50, 150, and 300 mg/kg body weight), and CDE groups treated with different doses of CV (50, 150, and 300 mg/kg body weight). Rats were sacrificed at various weeks and liver tissues were embedded in paraffin blocks for immunohistochemistry studies. CV, at increasing doses, decreased the expression of anti-apoptotic protein, Bcl-2, but increased the expression of pro-apoptotic protein, caspase 8, in CDE rats, which was correlated with decreased hepatoctyes proliferation and increased apoptosis as determined by bromodeoxy-uridine (BrdU) labeling and terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL) assay, respectively. Our study shows that CV has definite chemopreventive effect by inducing apoptosis via decreasing the expression of Bcl-2 and increasing the expression of caspase 8 in hepatocarcinogenesis-induced rats. PMID:19198018

  16. Photon up-conversion increases biomass yield in Chlorella vulgaris.

    Science.gov (United States)

    Menon, Kavya R; Jose, Steffi; Suraishkumar, Gadi K

    2014-12-01

    Photon up-conversion, a process whereby lower energy radiations are converted to higher energy levels via the use of appropriate phosphor systems, was employed as a novel strategy for improving microalgal growth and lipid productivity. Photon up-conversion enables the utilization of regions of the solar spectrum, beyond the typical photosynthetically active radiation, that are usually wasted or are damaging to the algae. The effects of up-conversion of red light by two distinct sets of up-conversion phosphors were studied in the model microalgae Chlorella vulgaris. Up-conversion by set 1 phosphors led to a 2.85 fold increase in biomass concentration and a 3.2 fold increase in specific growth rate of the microalgae. While up-conversion by set 2 phosphors resulted in a 30% increase in biomass and 12% increase in specific intracellular neutral lipid, while the specific growth rates were comparable to that of the control. Furthermore, up-conversion resulted in higher levels of specific intracellular reactive oxygen species in C. vulgaris. Up-conversion of red light (654 nm) was shown to improve biomass yields in C. vulgaris. In principle, up-conversion can be used to increase the utilization range of the electromagnetic spectrum for improved cultivation of photosynthetic systems such as plants, algae, and microalgae. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Use of diluted urine for cultivation of Chlorella vulgaris.

    Science.gov (United States)

    Jaatinen, Sanna; Lakaniemi, Aino-Maija; Rintala, Jukka

    2016-01-01

    Our aim was to study the biomass growth of microalga Chlorella vulgaris using diluted human urine as a sole nutrient source. Batch cultivations (21 days) were conducted in five different urine dilutions (1:25-1:300), in 1:100-diluted urine as such and with added trace elements, and as a reference, in artificial growth medium. The highest biomass density was obtained in 1:100-diluted urine with and without additional trace elements (0.73 and 0.60 g L(-1), respectively). Similar biomass growth trends and densities were obtained with 1:25- and 1:300-diluted urine (0.52 vs. 0.48 gVSS L(-1)) indicating that urine at dilution 1:25 can be used to cultivate microalgal based biomass. Interestingly, even 1:300-diluted urine contained sufficiently nutrients and trace elements to support biomass growth. Biomass production was similar despite pH-variation from < 5 to 9 in different incubations indicating robustness of the biomass growth. Ammonium formation did not inhibit overall biomass growth. At the beginning of cultivation, the majority of the biomass consisted of living algal cells, while towards the end, their share decreased and the estimated share of bacteria and cell debris increased.

  18. Growth of Chlorella vulgaris and associated bacteria in photobioreactors

    Science.gov (United States)

    Lakaniemi, Aino‐Maija; Intihar, Veera M.; Tuovinen, Olli H.; Puhakka, Jaakko A.

    2012-01-01

    Summary The aim of this study was to test three flat plate photobioreactor configurations for growth of Chlorella vulgaris under non‐axenic conditions and to characterize and quantify associated bacterial communities. The photobioreactor cultivations were conducted using tap water‐based media to introduce background bacterial population. Growth of algae was monitored over time with three independent methods. Additionally, the quantity and quality of eukaryotes and bacteria were analysed using culture‐independent molecular tools based on denaturing gradient gel electrophoresis (PCR‐DGGE) and quantitative polymerase chain reaction (QPCR). Static mixers used in the flat plate photobioreactors did not generally enhance the growth at the low light intensities used. The maximum biomass concentration and maximum specific growth rate were 1.0 g l−1 and 2.0 day−1 respectively. Bacterial growth as determined by QPCR was associated with the growth of C. vulgaris. Based on PCR‐DGGE, bacteria in the cultures mainly originated from the tap water. Bacterial community profiles were diverse but reproducible in all flat plate cultures. Most prominent bacteria in the C. vulgaris cultures belonged to the class Alphaproteobacteria and especially to the genus Sphingomonas. Analysis of the diversity of non‐photosynthetic microorganisms in algal mass cultures can provide useful information on the public health aspects and unravel community interactions. PMID:21936882

  19. Physiological and biochemical responses of Chlorella vulgaris to Congo red.

    Science.gov (United States)

    Hernández-Zamora, Miriam; Perales-Vela, Hugo Virgilio; Flores-Ortíz, César Mateo; Cañizares-Villanueva, Rosa Olivia

    2014-10-01

    Extensive use of synthetic dyes in many industrial applications releases large volumes of wastewater. Wastewaters from dying industries are considered hazardous and require careful treatment prior to discharge into receiving water bodies. Dyes can affect photosynthetic activities of aquatic flora and decrease dissolved oxygen in water. The aim of this study was to evaluate the effect of Congo red on growth and metabolic activity of Chlorella vulgaris after 96h exposure. Exposure of the microalga to Congo red reduced growth rate, photosynthesis and respiration. Analysis of chlorophyll a fluorescence emission showed that the donor side of photosystem II was affected at high concentrations of Congo red. The quantum yield for electron transport (φEo), the electron transport rate (ETR) and the performance index (PI) also decreased. The reduction in the ability to absorb and use the quantum energy increased non-photochemical (NPQ) mechanisms for thermal dissipation. Overall, Congo red affects growth and metabolic activity in photosynthetic organisms in aquatic environments. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Enhancement of hydrolysis of Chlorella vulgaris by hydrochloric acid.

    Science.gov (United States)

    Park, Charnho; Lee, Ja Hyun; Yang, Xiaoguang; Yoo, Hah Young; Lee, Ju Hun; Lee, Soo Kweon; Kim, Seung Wook

    2016-06-01

    Chlorella vulgaris is considered as one of the potential sources of biomass for bio-based products because it consists of large amounts of carbohydrates. In this study, hydrothermal acid hydrolysis with five different acids (hydrochloric acid, nitric acid, peracetic acid, phosphoric acid, and sulfuric acid) was carried out to produce fermentable sugars (glucose, galactose). The hydrothermal acid hydrolysis by hydrochloric acid showed the highest sugar production. C. vulgaris was hydrolyzed with various concentrations of hydrochloric acid [0.5-10 % (w/w)] and microalgal biomass [20-140 g/L (w/v)] at 121 °C for 20 min. Among the concentrations examined, 2 % hydrochloric acid with 100 g/L biomass yielded the highest conversion of carbohydrates (92.5 %) into reducing sugars. The hydrolysate thus produced from C. vulgaris was fermented using the yeast Brettanomyces custersii H1-603 and obtained bioethanol yield of 0.37 g/g of algal sugars.

  1. Photosynthetic and cellular toxicity of cadmium in Chlorella vulgaris.

    Science.gov (United States)

    Ou-Yang, Hui-Ling; Kong, Xiang-Zhen; Lavoie, Michel; He, Wei; Qin, Ning; He, Qi-Shuang; Yang, Bin; Wang, Rong; Xu, Fu-Liu

    2013-12-01

    The toxic effects of cadmium (Cd) on the green alga Chlorella vulgaris were investigated by following the response to Cd of various toxicity endpoints (cell growth, cell size, photochemical efficiency of PSII in the light or Φ(PSII), maximal photochemical efficiency or Fv/Fm, chlorophyll a fluorescence, esterase activity, and cell viability). These toxicity endpoints were studied in laboratory batch cultures of C. vulgaris over a long-term 96-h exposure to different Cd concentrations using flow cytometry and pulse amplitude modulated fluorometry. The sequence of sensitivity of these toxicity endpoints was: cell yield > Φ(PSII) ≈ esterase activity > Fv/Fm > chlorophyll a fluorescence ≈ cell viability. It is shown that cell apoptosis or cell death only accounted for a minor part of the reduction in cell yield even at very high algistatic free Cd²⁺ concentrations, and other mechanisms such as blocked cell divisions are major contributors to cell yield inhibition. Furthermore, cadmium may affect both the electron donors and acceptors of the electron transport chain at high free Cd²⁺ concentration. Finally, the resistance of cells to cell death was size-dependent; medium-sized cells had the highest toxicity threshold. The present study brings new insights into the toxicity mechanisms of Cd in C. vulgaris and provides a detailed comparison of the sensitivity of various Cd toxicity endpoints. © 2013 SETAC.

  2. Hot water extract of Chlorella vulgaris induced DNA damage and apoptosis

    Science.gov (United States)

    Yusof, Yasmin Anum Mohd; Md. Saad, Suhana; Makpol, Suzana; Shamaan, Nor Aripin; Ngah, Wan Zurinah Wan

    2010-01-01

    OBJECTIVES: The aim of this study was to determine the antiproliferative and apoptotic effects of hot water extracts of Chlorella vulgaris on hepatoma cell line HepG2. INTRODUCTION: The search for food and spices that can induce apoptosis in cancer cells has been a major study interest in the last decade. Chlorella vulgaris, a unicellular green algae, has been reported to have antioxidant and anti‐cancer properties. However, its chemopreventive effects in inhibiting the growth of cancer cells have not been studied in great detail. METHODS: HepG2 liver cancer cells and WRL68 normal liver cells were treated with various concentrations (0‐4 mg/ml) of hot water extract of C. vulgaris after 24 hours incubation. Apoptosis rate was evaluated by TUNEL assay while DNA damage was assessed by Comet assay. Apoptosis proteins were evaluated by Western blot analysis. RESULTS: Chlorella vulgaris decreased the number of viable HepG2 cells in a dose dependent manner (p Chlorella vulgaris tested. Evaluation of apoptosis by TUNEL assay showed that Chlorella vulgaris induced a higher apoptotic rate (70%) in HepG2 cells compared to normal liver cells, WRL68 (15%). Western blot analysis showed increased expression of pro‐ apoptotic proteins P53, Bax and caspase‐3 in the HepG2 cells compared to normal liver cells WRL68, and decreased expression of the anti‐apoptotic protein Bcl‐2. CONCLUSIONS: Chlorella vulgaris may have anti‐cancer effects by inducing apoptosis signaling cascades via an increased expression of P53, Bax and caspase‐3 proteins and through a reduction of Bcl‐2 protein, which subsequently lead to increased DNA damage and apoptosis. PMID:21340229

  3. Effect of gamma radiation on starch content and cellular morphology of chlorella pyrenoidose

    International Nuclear Information System (INIS)

    Fernandez Gonzalez, J.; Martin Moreno, C.

    1983-01-01

    The effect of five doses of gamma radiation (10, 100, 500, 1000 and 5000 Gy) on starch content and fine structure of Chlorella pyrenoidose has been studied. Results show the accumulation of large amounts of starch on Chlorella cells after irradiation at 500, 1000 and 5000 Gy doses. The starch which is stored in the cytoplasm in form of great grains produces a disorganization of the chloroplast structure, observed by electron microscopy techniques. The microphotographs presented also show a significant increase in the cellular size after irradiation up to 500 Gy. (author)

  4. CO2 capture from air by Chlorella vulgaris microalgae in an airlift photobioreactor.

    Science.gov (United States)

    Sadeghizadeh, Aziz; Farhad Dad, Farid; Moghaddasi, Leila; Rahimi, Rahbar

    2017-11-01

    In this work, hydrodynamics and CO 2 biofixation study was conducted in an airlift bioreactor at the temperature of 30±2°C. The main objective of this work was to investigate the effect of high gas superficial velocity on CO 2 biofixation using Chlorella vulgaris microalgae and its growth. The study showed that Chlorella vulgaris in high input gas superficial velocity also had the ability to grow and remove the CO 2 by less than 80% efficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Effect of gamma radiation on growth, productivity and protein content of chlorella pyrenoidosa

    International Nuclear Information System (INIS)

    Fernandez Gonzalez, J.; Martin Moreno, C.

    1983-01-01

    The effect of five doses of gamma radiation: 10, 100, 500, 1000 and 5000 Gy at a dose rate of 4.500 Gy/h on growth, productivity and protein content of Chlorella Pyroneidosa has been studied. High doses of gamma radiation have been observed to inhibit cellular division of Chlorella Pyrenoidosa. Culture growth stopped 48 hours after irradiation at 5.000 Gy and 72 hours after irradiation at 500 and 1000 Gy. The lowest dose (10 Gy) produced a little growth stimulation that as not statistically significative. Protein and aminoacid content did not show any change for gamma radiation doses studied. (author)

  6. Effect of gamma radiation on starch content and cellular morphology of Chlorella pyrenoidosa

    International Nuclear Information System (INIS)

    Martin Moreno, C.; Fernandez Gonzalez, J.

    1983-01-01

    The effect of five doses of gamma radiation (10, 100, 500, 1000 and 5000 Gy) on starch content and fine structure of Chlorella pyrenoidosa has been studied. Results show the accumulation of large amounts of starch on Chlorella cells after irradiation at 500, 1000 and 5000 Gy doses. The starch which is stored in the cytoplasm in form of great grains produces a de organization of the chloroplast structure, observed by electron microscopy techniques. The microphotographs presented also show a significant increase in the cellular size after irradiation up to 500 Gy. (Author) 29 refs

  7. Effect of gamma radiation on growth, productivity and protein content of Chlorella Pyrenoidosa

    International Nuclear Information System (INIS)

    Martin Moreno, C.; Fernandez Gonzalez, J.

    1983-01-01

    The effect of five doses of gamma radiation: 10, 100, 500, 1000 and 5000 Gy at a dose rate of 4.500 Gy/h on growth, productivity and protein content of Chlorella pyroneidosa has been studied. High doses of gamma radiation have been observed to inhibit cellular division of Chlorella pyrenoidosa. Culture growth stopped 48 hours after irradiation at 5.000 Gy and 72 hours after irradiation at 500 and 1000 Gy. The lowest dose (10 Gyl produced a little growth stimulation that not statistically significative. Protein and aminoacid content did not show any change for gamma radiation doses studied. (Author) 32 refs

  8. The Influence of Chlorella and Its Hot Water Extract Supplementation on Quality of Life in Patients with Breast Cancer

    Directory of Open Access Journals (Sweden)

    Naoto Noguchi

    2014-01-01

    Full Text Available A self-control, randomized, and open-label clinical trial was performed to test the effects of the unicellular green algae Chlorella and hot water extract supplementation on quality of life (QOL in patients with breast cancer. Forty-five female patients with breast cancer who were living at home and not hospitalized were randomly assigned to 3 groups receiving vitamin mix tablet (control, Chlorella granules (test food-1, or Chlorella extract drink (test food-2 daily for one month. The Functional Assessment of Cancer Therapy-Breast (FACT-B, the Izumo scale for abdominal symptom-specific QOL, and a narrative-form questionnaire were used to determine outcomes. Data of thirty-six subjects were included for final analysis. FACT-B scores at presupplementation found no significant group differences in all subscales. Scores on the breast cancer subscale in the Chlorella granule group significantly increased during the supplementation period (P=0.042. Fifty percent of the Chlorella extract group reported positive effects by the test food such as reduction of fatigue and improvements of dry skin (P<0.01 versus control group. The findings suggested the beneficial effects of Chlorella on breast cancer-related QOL and of Chlorella extract on vitality status in breast cancer patients. These findings need to be confirmed in a larger study.

  9. The acclimation of Chlorella to high-level nitrite for potential application in biological NOx removal from industrial flue gases.

    Science.gov (United States)

    Li, Tianpei; Xu, Gang; Rong, Junfeng; Chen, Hui; He, Chenliu; Giordano, Mario; Wang, Qiang

    2016-05-20

    Nitrogen oxides (NOx) are the components of fossil flue gas that give rise to the greatest environmental concerns. This study evaluated the ability of the green algae Chlorella to acclimate to high level of NOx and the potential utilization of Chlorella strains in biological NOx removal (DeNOx) from industrial flue gases. Fifteen Chlorella strains were subject to high-level of nitrite (HN, 176.5 mmolL(-1) nitrite) to simulate exposure to high NOx. These strains were subsequently divided into four groups with respect to their ability to tolerate nitrite (excellent, good, fair, and poor). One strain from each group was selected to evaluate their photosynthetic response to HN condition, and the nitrite adaptability of the four Chlorella strains were further identified by using chlorophyll fluorescence. The outcome of our experiments shows that, although high concentrations of nitrite overall negatively affect growth and photosynthesis of Chlorella strains, the degree of nitrite tolerance is a strain-specific feature. Some Chlorella strains have an appreciably higher ability to acclimate to high-level of nitrite. Acclimation is achieved through a three-step process of restrict, acclimate, and thriving. Notably, Chlorella sp. C2 was found to have a high tolerance and to rapidly acclimate to high concentrations of nitrite; it is therefore a promising candidate for microalgae-based biological NOx removal. Copyright © 2016 Elsevier GmbH. All rights reserved.

  10. Detecting DNA synthesis of neointimal formation after catheter balloon injury in GK and in Wistar rats: using 5-ethynyl-2'-deoxyuridine

    Directory of Open Access Journals (Sweden)

    Guo Jingsheng

    2012-12-01

    Full Text Available Abstract Background Neointimal formation plays an important role in the pathogenesis of coronary restenosis after percutaneous coronary intervention (PCI, especially in patients with diabetes mellitus. Recently, some studies have shown that 5-ethynyl-2'-deoxyuridine (EdU incorporation can serve as a novel alternative to the 5-bromo-2'-deoxyuridine (BrdU antibody detection method for detection of DNA synthesis in regenerating avian cochlea, chick embryo and the adult nervous system. However, few studies have been performed to assess the suitability of EdU for detecting DNA synthesis in vascular neointima. Methods The carotid artery balloon injury model was established in Goto-Kakizaki (GK and Wistar rats. A Cell-LightTM EdU Kit was used to detect EdU-labeled cell nuclei of common carotid arteries at day 7 after catheter balloon injury. Different methods of injecting EdU were tested. The protein levels of proliferating cell nuclear antigen (PCNA and p-Akt (Ser473, as well as the mRNA levels of PCNA were evaluated by Western blotting and quantitative real-time PCR (qRT-PCR, respectively. Immunohistochemical staining was also employed to visualize PCNA-positive cells. Results At day 7 after catheter balloon injury, far more EdU-positive and PCNA-positive cells were observed in GK rats. When comparing groups that received different EdU doses, it was found that the percentage of EdU-positive cells at a dose of 100 mg/kg body weight was than at doses of 25 mg/kg and 50 mg/kg. The number of positive cells was significantly higher in the repeated injection group compared to the single injection group. Further, after balloon injury DNA synthesis in GK rats was more notable than in Wistar rats. Neointimal formation in GK rats was more obvious than in Wistar rats. The protein levels of PCNA and p-Akt (Ser473 and the mRNA levels of PCNA were increased in injured rats as compared to uninjured rats, and were significantly higher in GK rats than in Wistar rats

  11. The Degree of Fat Unsaturation in the Tissue and Potential Immune Response of Broiler Fed Chlorella sp.

    Directory of Open Access Journals (Sweden)

    Sugiharto

    2010-05-01

    Full Text Available This study was carried out to investigate the effect of Chlorella sp. administered in the diet of broilers on the degree of fat unsaturation, ratio of EPA to AA in the tissue and potential immune response of broiler. A total of 90 heads of one-day-old Ross chicks were assigned in completely randomized design by 3 dietary treatments with 6 repetitions and 5 chicks in each pen. The diets were T1: control (basal diet without enrichment with Chlorella sp.; T2: basal diet enriched with 5-g of Chlorella sp./kg feed; T3: basal diet enriched with 10-g of Chlorella sp./kg feed. Skinless breast meat was sampled for FA determination at d-36. Chickens were vaccinated at d-6 and d-17 with live vaccine against ND to activate antibodies production, and then 2 ml of blood was collected at d-24 for IgG and IgM quantification. Administration of Chlorella sp. in broiler’s diet had no significant effect on the degree of fat unsaturation, the ratio between EPA and AA contained in the breast muscle and the concentration of IgG and IgM of broiler. In conclusion administration of Chlorella sp. from tropical marine origin in the diet of broiler has no significant effect on the degree of fat unsaturation, ratio of EPA to AA in the tissue, and potential immune response of broiler. The culture temperature in which the Chlorella sp. was cultivated may affect the FA composition of Chlorella sp. (Animal Production 12(2: 96-99 (2010Abbreviations: AA: arachidonic acid, ALA: α-linolenic acid, EPA: eicosapentaenoic acid, FA: fatty acids, LA: linoleic acid, PGE2: Prostaglandin E2, PUFA: polyunsaturated fatty acids, SFA: saturated fatty acidKey Words: antibody, broiler, Chlorella sp., fatty acid, PUFA

  12. Influence of culture conditions on growth and protein metabolism in chlorella pyranosides; Influencia de las condiciones de cultivo sobre el crecimiento y metabolismo proteico de chlorella pyrenoidosa

    Energy Technology Data Exchange (ETDEWEB)

    Mazon Matanzo, M P; Fernandez Gonzalez, J; Batuecas Suarez, B

    1981-07-01

    Growth and protein metabolism of Chlorella pyranoside under different conditions of temperature, photo period and CO{sub 2} concentration was studied. The optimum of biomass production was observed at 25 degree centigree, 40.000 ppm of CO{sub 2} in air and a 20 h. light period, followed of 4 h. of darkness. Some variations in free aminoacids content was observed under different conditions but no change did occur in protein. (Author) 68 refs.

  13. Extraction of intracellular protein from Chlorella pyrenoidosa using a combination of ethanol soaking, enzyme digest, ultrasonication and homogenization techniques.

    Science.gov (United States)

    Zhang, Ruilin; Chen, Jian; Zhang, Xuewu

    2018-01-01

    Due to the rigid cell wall of Chlorella species, it is still challenging to effectively extract significant amounts of protein. Mass methods were used for the extraction of intracellular protein from microalgae with biological, mechanical and chemical approaches. In this study, based on comparison of different extraction methods, a new protocol was established to maximize extract amounts of protein, which was involved in ethanol soaking, enzyme digest, ultrasonication and homogenization techniques. Under the optimized conditions, 72.4% of protein was extracted from the microalgae Chlorella pyrenoidosa, which should contribute to the research and development of Chlorella protein in functional food and medicine. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Characterization of iron uptake from hydroxamate siderophores by Chlorella vulgaris

    International Nuclear Information System (INIS)

    Allnutt, F.C.T.

    1985-01-01

    Iron uptake by Chlorella vulgaris from ferric-hydroxamate siderophores and the possible production of siderophores by these algae was investigated. No production of siderophores or organic acids was observed. Iron from the two hydroxamate siderophores tested, ferrioximine B (Fe 3+ -DFOB) and ferric-rhodotorulate (Fe 3+ -RA), was taken up at the same rate as iron chelated by citrate or caffeate. Two synthetic chelates, Fe 3+ -EDTA and Fe 3+ -EDDHA, provided iron at a slower rate. Iron uptake was inhibited by 50 μM CCCP or 1 mM vanadate. Cyanide (100 μM KCN) or 25 μM antimycin A failed to demonstrate a link between uptake and respiration. Labeled iron ( 55 Fe) was taken up while labeled ligands ([ 14 C] citrate or RA) were not accumulated. Cation competition from Ni 2+ and Co 2+ observed using Fe 3+ -DFOB and Fe 3+ -RA while iron uptake from Fe 3+ -citrate was stimulated. Iron-stress induced iron uptake from the hydroxamate siderophores. Ferric reduction from the ferric-siderophores was investigated with electron paramagnetic resonance (EPR) and bathophenathroline disulfonate (BPDS). Ferric reduction was induced by iron-stress and inhibited by CCCP. A close correlation between iron uptake and ferric reduction was measured by the EPR method. Ferric reduction measured by the BPDS method was greater than that measure by EPR. BPDS reduction was interpreted to indicate a potential for reduction while EPR measures the physiological rate of reduction. BPDS inhibition of iron uptake and ferricyanide interference with reduction indicate that reduction and uptake occur exposed to the external medium. Presumptive evidence using a binding dose response curve for Fe 3+ -DFOB indicated that a receptor may be involved in this mechanism

  15. Cell proliferation alterations in Chlorella cells under stress conditions

    International Nuclear Information System (INIS)

    Rioboo, Carmen; O'Connor, Jose Enrique; Prado, Raquel; Herrero, Concepcion; Cid, Angeles

    2009-01-01

    Very little is known about growth and proliferation in relation to the cell cycle regulation of algae. The lack of knowledge is even greater when referring to the potential toxic effects of pollutants on microalgal cell division. To assess the effect of terbutryn, a triazine herbicide, on the proliferation of the freshwater microalga Chlorella vulgaris three flow cytometric approaches were used: (1) in vivo cell division using 5-,6-carboxyfluorescein diacetate succinimidyl ester (CFSE) staining was measured, (2) the growth kinetics were determined by cytometric cell counting and (3) cell viability was evaluated with the membrane-impermeable double-stranded nucleic acid stain propidium iodide (PI). The results obtained in the growth kinetics study using CFSE to identify the microalgal cell progeny were consistent with those determined by cytometric cell counting. In all C. vulgaris cultures, each mother cell had undergone only one round of division through the 96 h of assay and the cell division occurred during the dark period. Cell division of the cultures exposed to the herbicide was asynchronous. Terbutryn altered the normal number of daughter cells (4 autospores) obtained from each mother cell. The number was only two in the cultures treated with 250 nM. The duration of the lag phase after the exposure to terbutryn could be dependent on the existence of a critical cell size to activate cytoplasmic division. Cell size, complexity and fluorescence of chlorophyll a of the microalgal cells presented a marked light/dark (day/night) cycle, except in the non-dividing 500 nM cultures, where terbutryn arrested cell division at the beginning of the cycle. Viability results showed that terbutryn has an algastatic effect in C. vulgaris cells at this concentration. The rapid and precise determination of cell proliferation by CFSE staining has allowed us to develop a model for assessing both the cell cycle of C. vulgaris and the in vivo effects of pollutants on growth and

  16. Two stage treatment of dairy effluent using immobilized Chlorella pyrenoidosa

    Science.gov (United States)

    2013-01-01

    Background Dairy effluents contains high organic load and unscrupulous discharge of these effluents into aquatic bodies is a matter of serious concern besides deteriorating their water quality. Whilst physico-chemical treatment is the common mode of treatment, immobilized microalgae can be potentially employed to treat high organic content which offer numerous benefits along with waste water treatment. Methods A novel low cost two stage treatment was employed for the complete treatment of dairy effluent. The first stage consists of treating the diary effluent in a photobioreactor (1 L) using immobilized Chlorella pyrenoidosa while the second stage involves a two column sand bed filtration technique. Results Whilst NH4+-N was completely removed, a 98% removal of PO43--P was achieved within 96 h of two stage purification processes. The filtrate was tested for toxicity and no mortality was observed in the zebra fish which was used as a model at the end of 96 h bioassay. Moreover, a significant decrease in biological oxygen demand and chemical oxygen demand was achieved by this novel method. Also the biomass separated was tested as a biofertilizer to the rice seeds and a 30% increase in terms of length of root and shoot was observed after the addition of biomass to the rice plants. Conclusions We conclude that the two stage treatment of dairy effluent is highly effective in removal of BOD and COD besides nutrients like nitrates and phosphates. The treatment also helps in discharging treated waste water safely into the receiving water bodies since it is non toxic for aquatic life. Further, the algal biomass separated after first stage of treatment was highly capable of increasing the growth of rice plants because of nitrogen fixation ability of the green alga and offers a great potential as a biofertilizer. PMID:24355316

  17. Cell proliferation alterations in Chlorella cells under stress conditions

    Energy Technology Data Exchange (ETDEWEB)

    Rioboo, Carmen [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n, 15008 A Coruna (Spain); O' Connor, Jose Enrique [Laboratorio de Citomica, Unidad Mixta de Investigacion CIPF-UVEG, Centro de Investigacion Principe Felipe, Avda. Autopista del Saler, 16, 46013 Valencia (Spain); Prado, Raquel; Herrero, Concepcion [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n, 15008 A Coruna (Spain); Cid, Angeles, E-mail: cid@udc.es [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n, 15008 A Coruna (Spain)

    2009-09-14

    Very little is known about growth and proliferation in relation to the cell cycle regulation of algae. The lack of knowledge is even greater when referring to the potential toxic effects of pollutants on microalgal cell division. To assess the effect of terbutryn, a triazine herbicide, on the proliferation of the freshwater microalga Chlorella vulgaris three flow cytometric approaches were used: (1) in vivo cell division using 5-,6-carboxyfluorescein diacetate succinimidyl ester (CFSE) staining was measured, (2) the growth kinetics were determined by cytometric cell counting and (3) cell viability was evaluated with the membrane-impermeable double-stranded nucleic acid stain propidium iodide (PI). The results obtained in the growth kinetics study using CFSE to identify the microalgal cell progeny were consistent with those determined by cytometric cell counting. In all C. vulgaris cultures, each mother cell had undergone only one round of division through the 96 h of assay and the cell division occurred during the dark period. Cell division of the cultures exposed to the herbicide was asynchronous. Terbutryn altered the normal number of daughter cells (4 autospores) obtained from each mother cell. The number was only two in the cultures treated with 250 nM. The duration of the lag phase after the exposure to terbutryn could be dependent on the existence of a critical cell size to activate cytoplasmic division. Cell size, complexity and fluorescence of chlorophyll a of the microalgal cells presented a marked light/dark (day/night) cycle, except in the non-dividing 500 nM cultures, where terbutryn arrested cell division at the beginning of the cycle. Viability results showed that terbutryn has an algastatic effect in C. vulgaris cells at this concentration. The rapid and precise determination of cell proliferation by CFSE staining has allowed us to develop a model for assessing both the cell cycle of C. vulgaris and the in vivo effects of pollutants on growth and

  18. Effect of gene transfer of Chlorella vulgaris n-3 fatty acid desaturase ...

    African Journals Online (AJOL)

    Chlorella vulgaris had the gene of n-3 fatty acid desaturase (CvFad3) which can synthesize the precursor of n-3 polyunsaturated fatty acids (PUFAs) or to convert n-6 to n-3 PUFAs. The objective of this study was to examine whether the CvFad3 gene from C. vulgaris can be functionally expressed in mammalian cells and ...

  19. Utilization of carbon dioxide by Chlorella kessleri in outdoor open thin-layer culture units

    Czech Academy of Sciences Publication Activity Database

    Lívanský, Karel; Doucha, Jiří

    2005-01-01

    Roč. 116, - (2005), s. 201-212 ISSN 0342-1120 R&D Projects: GA ČR GV104/97/S055 Institutional research plan: CEZ:AV0Z50200510 Keywords : chlorella kessleri * carbon dioxide * microalga Subject RIV: EE - Microbiology, Virology

  20. Presence of a chlorophyll d-like pigment in Chlorella extracts

    NARCIS (Netherlands)

    Michel-Wolwertz, M.R.; Sironval, C.; Goedheer, J.C.

    1965-01-01

    Three chlorophyll a isomers (a₁, a₂ and a₃) were separated by the chromatography of Chlorella extracts on paper 1. One of these, chlorophyll (a₃) showed additional absorption bands at 688 and 455 mμ in diethyl ether. Chromatographic analysis could not decide whether these bands were due to a₃ or

  1. Widespread green algae Chlorella and Stichococcus exhibit polar-temperate and tropical-temperate biogeography

    Czech Academy of Sciences Publication Activity Database

    Hodač, L.; Hallmann, Ch.; Spitzer, K.; Elster, Josef; Fasshauer, F.; Brinkmann, N.; Lepka, D.; Diwan, V.; Friedl, T.

    2016-01-01

    Roč. 92, č. 8 (2016), s. 1-16, č. článku fiw122. ISSN 0168-6496 Institutional support: RVO:67985939 Keywords : Chlorella * Stichococcus * biogeography Subject RIV: EH - Ecology, Behaviour Impact factor: 3.720, year: 2016

  2. Rapid algal toxicity assay using variable chlorophyll fluorescence for Chlorella kessleri (Chlorophyta)

    Czech Academy of Sciences Publication Activity Database

    Kvíderová, Jana

    2010-01-01

    Roč. 25, č. 6 (2010), s. 554-562 ISSN 1520-4081 R&D Projects: GA MŠk 1M0571 Institutional research plan: CEZ:AV0Z60050516 Keywords : bioassay * variable chlorophyll fluorescence * Chlorella kessleri Subject RIV: EF - Botanics Impact factor: 1.932, year: 2010

  3. Productivity correlated to photobiochemical performance of Chlorella mass cultures grown outdoors in thin-layer cascades

    Czech Academy of Sciences Publication Activity Database

    Masojídek, Jiří; Kopecký, Jiří; Giannelli, L.; Torzillo, G.

    2011-01-01

    Roč. 38, č. 2 (2011), s. 307-317 ISSN 1367-5435 R&D Projects: GA ČR GA521/09/0656 Institutional research plan: CEZ:AV0Z50200510 Keywords : Freshwater microalga Chlorella * Chlorophyll-fluorescence quenching * Photochemical activity Subject RIV: EE - Microbiology, Virology Impact factor: 2.735, year: 2011

  4. Production of lipids and formation and mobilization of lipid bodies in Chlorella vulgaris

    Czech Academy of Sciences Publication Activity Database

    Přibyl, Pavel; Cepák, Vladislav; Zachleder, Vilém

    2013-01-01

    Roč. 25, č. 2 (2013), 545-553 ISSN 0921-8971 R&D Projects: GA MŠk 1M0571 Institutional support: RVO:67985939 ; RVO:61388971 Keywords : Chlorella vulgaris * lipid body * ultrastructure Subject RIV: EF - Botanics Impact factor: 2.492, year: 2013

  5. First case of Chlorella wound infection in a human in Australia

    Directory of Open Access Journals (Sweden)

    J. Hart

    2014-07-01

    Full Text Available A 30-year-old man developed an infected knee wound 2 days after jumping his bicycle into a freshwater dam. He required repeated debridement and tissue grew bright green colonies typical of the alga Chlorella plus Aeromonas hydrophila. This, and one previously reported case, responded to surgical debridement and careful wound management.

  6. Effective production of bioenergy from marine Chlorella sp. by high-pressure homogenization

    Directory of Open Access Journals (Sweden)

    Woon Yong Choi

    2016-01-01

    Full Text Available This study investigated the use of a high-pressure homogenization process for the production of high shear stress on Chlorella sp. cells in order to effectively degrade their cell walls. The high-pressure homogenization process was conducted by using various pressure conditions in the range of 68.94–275.78 MPa with different numbers of repeated cycles. The optimal high-pressure homogenization pretreatment conditions were found to be two cycles at a pressure of 206.84 MPa, which provided an extraction yield of 20.35% (w/w total cellular lipids. In addition, based on the confocal microscopic images of Chlorella sp. cells stained by using nile red, the walls of Chlorella sp. cells were disrupted more effectively using this process when compared with the disruption achieved by conventional lipid-extraction processes. By using the by-product of Chlorella sp., 47.3% ethanol was obtained from Saccharomyces cerevisiae cultures. These results showed that the high-pressure homogenization process efficiently hydrolysed this marine resource for subsequent bioethanol production by using only water.

  7. Influence of processing parameters on disintegration of Chlorella cells in various types of homogenizers

    Czech Academy of Sciences Publication Activity Database

    Doucha, Jiří; Lívanský, Karel

    2008-01-01

    Roč. 81, č. 3 (2008), s. 431-440 ISSN 0175-7598 R&D Projects: GA ČR GV104/97/S055 Institutional research plan: CEZ:AV0Z50200510 Keywords : processing parameters * disintegration efficiency * chlorella Subject RIV: EE - Microbiology, Virology Impact factor: 2.569, year: 2008

  8. Effective harvesting of the microalgae Chlorella protothecoides via bioflocculation with cationic starch

    DEFF Research Database (Denmark)

    Letelier Gordo, Carlos Octavio; Holdt, Susan Løvstad; De Francisci, Davide

    2014-01-01

    In the present work, the flocculation efficiency of cationic starch (Greenfloc 120) was tested on the fresh water microalga Chlorella protothecoides under different conditions (pH and flocculant concentrations). Different concentrations of Greenfloc 120 (0, 2.5, 5, 10, 20, 40mgL-1) were screened...... to use, efficient and cost-effective flocculant for harvesting of microalgae....

  9. Use of microseaweeds (Chlorella pyrenoidosa) as a probiotic in dairy goats feeding

    DEFF Research Database (Denmark)

    Moreno-Indias, I.; Hernandez Castellano, Lorenzo E; Torres, C.

    2014-01-01

    Ten Majorera dairy goats were divided into two groups in order to observe the effects of the Chlorella pyrenoidosa oral administration on the colostrum and milk quality and on the animals' immune status. Treated animals received 5 g/day of seaweed from 40 days before partum to 40 days after partu...

  10. Biological CO2 mitigation from coal power plant by Chlorella fusca and Spirulina sp.

    Science.gov (United States)

    Duarte, Jessica Hartwig; de Morais, Etiele Greque; Radmann, Elisângela Martha; Costa, Jorge Alberto Vieira

    2017-06-01

    CO 2 biofixation by microalgae and cyanobacteria is an environmentally sustainable way to mitigate coal burn gas emissions. In this work the microalga Chlorella fusca LEB 111 and the cyanobacteria Spirulina sp. LEB 18 were cultivated using CO 2 from coal flue gas as a carbon source. The intermittent flue gas injection in the cultures enable the cells growth and CO 2 biofixation by these microorganisms. The Chlorella fusca isolated from a coal power plant could fix 2.6 times more CO 2 than Spirulina sp. The maximum daily CO 2 from coal flue gas biofixation was obtained with Chlorella fusca (360.12±0.27mgL -1 d -1 ), showing a specific growth rate of 0.17±<0.01d -1 . The results demonstrated the Chlorella fusca LEB 111 and Spirulina sp. LEB 18 potential to fix CO 2 from coal flue gas, and sequential biomass production with different biotechnological destinations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Production of Chlorella biomass enriched by selenium and its use in animal nutrition: a review

    Czech Academy of Sciences Publication Activity Database

    Doucha, Jiří; Lívanský, Karel; Kotrbáček, V.; Zachleder, Vilém

    2009-01-01

    Roč. 83, č. 6 (2009), s. 1001-1008 ISSN 0175-7598 R&D Projects: GA MŠk OE 221; GA MŠk OE09025 Institutional research plan: CEZ:AV0Z50200510 Keywords : Chlorella * Heterotrophic production * Nutrition Subject RIV: EE - Microbiology, Virology Impact factor: 2.896, year: 2009

  12. Sources of mycosporine-like amino acids in planktonic Chlorella-bearing ciliates (Ciliophora)

    Science.gov (United States)

    SONNTAG, BETTINA; SUMMERER, MONIKA; SOMMARUGA, RUBEN

    2007-01-01

    Mycosporine-like amino acids (MAAs) are a family of secondary metabolites known to protect organisms exposed to solar UV radiation. We tested their distribution among several planktonic ciliates bearing Chlorella isolated from an oligo-mesotrophic lake in Tyrol, Austria. In order to test the origin of these compounds, the MAAs were assessed by high performance liquid chromatography in both the ciliates and their symbiotic algae. Considering all Chlorella-bearing ciliates, we found: (i) seven different MAAs (mycosporine-glycine, palythine, asterina-330, shinorine, porphyra-334, usujirene, palythene); (ii) one to several MAAs per species and (iii) qualitative and quantitative seasonal changes in the MAAs (e.g. in Pelagodileptus trachelioides). In all species tested, concentrations of MAAs were always <1% of ciliate dry weight. Several MAAs were also identified in the Chlorella isolated from the ciliates, thus providing initial evidence for their symbiotic origin. In Uroleptus sp., however, we found evidence for a dietary source of MAAs. Our results suggest that accumulation of MAAs in Chlorella-bearing ciliates represents an additional benefit of this symbiosis and an adaptation for survival in sunlit, UV-exposed waters.

  13. Pulsed Electric Field for protein release of the microalgae Chlorella vulgaris and Neochloris oleoabundans

    NARCIS (Netherlands)

    Lam, 't Gerard; Postma, P.R.; Fernandes, D.A.; Timmermans, R.A.H.; Vermuë, M.H.; Barbosa, M.J.; Eppink, M.H.; Wijffels, R.H.; Olivieri, G.

    2017-01-01

    Pulsed Electric Field (PEF) is currently discussed as promising technology for mild and scalable cell disintegration of microalgae. In this study Chlorella vulgaris and Neochloris oleoabundans have been subjected to batch and continuous PEF treatments under a wide range of operating conditions

  14. Mild disintegration of the green microalgae Chlorella vulgaris using bead milling

    NARCIS (Netherlands)

    Postma, P.R.; Miron, T.L.; Olivieri, G.; Barbosa, M.J.; Wijffels, R.H.; Eppink, M.H.M.

    2015-01-01

    In this work, the mild disintegration of the microalgae Chlorella vulgaris for the release of intracellular products has been studied. By means of bead milling the microalgae suspensions were successfully disintegrated at different biomass concentrations (25–145 gDW kg-1) over a range of agitator

  15. The Use of Chlorella Vulgaris in a Simple Demonstration of Heavy Metal Toxicity.

    Science.gov (United States)

    Gipps, J. F.; Biro, P.

    1978-01-01

    An experimental system, suitable for secondary schools, uses Chlorella vulgaris to demonstrate the effects of mercury and cadmium. Very low concentrations of mercury or cadmium decrease growth, whereas lead or arsenic have little effect. Further experiments show additive interactions between mercury and cadmium and antagonistic interactions…

  16. Lipid accumulation from pinewood pyrolysates by rhodosporidium diobovatum and chlorella vulgaris for biodiesel production

    NARCIS (Netherlands)

    Luque, L.; Orr, V.C.A.; Chen, S.; Westerhof, Roel Johannes Maria; Oudenhoven, Stijn; van Rossum, G.; Kersten, Sascha R.A.; Berruti, F.; Rehmann, L.

    2016-01-01

    This study evaluated the suitability of pinewood pyrolysates as a carbon source for lipid production and cultivation of the oleaginous yeast Rhodosporidium diobovatum and the microalgae Chlorella vulgaris. Thermal decomposition of pinewood and fractional condensation were used to obtain an oil rich

  17. Subcellular Localization of Cadmium in Chlorella vulgaris Beijerinck Strain Bt-09

    Directory of Open Access Journals (Sweden)

    P.B. Lintongan

    2004-06-01

    Full Text Available Growth response curves of Chlorella vulgaris Beijerinck strain Bt-09 to sublethal concentrations of cadmium were evaluated. The growth responses of this microalgal isolate was determined through analysis of chlorophyll a levels. Cadmium was effectively taken up by the cells as determined by Flame Atomic Absorption Spectrophotometry (F-AAS. Subcellular fractionation was undertaken to locate sites that accumulate cadmium.

  18. Effect of pressurized liquids on extraction of antioxidants from Chlorella vulgaris.

    Science.gov (United States)

    Cha, Kwang Hyun; Kang, Suk Woo; Kim, Chul Young; Um, Byung Hun; Na, Ye Rim; Pan, Cheol-Ho

    2010-04-28

    Chlorella vulgaris is a green microalga that contains various antioxidants, such as carotenoids and chlorophylls. In this study, antioxidants from C. vulgaris were extracted using pressurized liquid extraction (PLE), which has been recently used for bioactive compound extraction. The antioxidant capacity of individual compounds in chlorella was determined by online HPLC ABTS(*+) analysis. According to the antioxidant analysis of total extracts, the extraction yield, radical scavenging activity, and phenolic compounds using PLE were relatively high compared to those obtained using maceration or ultrasound-assisted extraction. On the basis of online HPLC ABTS(*+) analysis, the 15 major antioxidants from chlorella extracts were identified as hydrophilic compounds, lutein and its isomers, chlorophylls, and chlorophyll derivatives. Using PLE at high temperature (85-160 degrees C) significantly increased antioxidant extraction from chlorella, improving the formation of hydrophilic compounds and yielding more antioxidative chlorophyll derivatives. Online HPLC ABTS(*+) analysis was a useful tool for the separation of main antioxidants from PLE extracts and allowed the simultaneous measurement of their antioxidant capacity, which clearly showed that PLE is an excellent method for extracting antioxidants from C. vulgaris.

  19. Intra-cerebral ventricular infusion of 5-iodo-2-deoxyuridine (IUDR) as a radiosensitizer in the treatment of a rat glioma

    International Nuclear Information System (INIS)

    Deutsch, M.; Rewers, A.B.; Redgate, S.; Fisher, E.R.; Boggs, S.S.

    1990-01-01

    The efficacy of 5-iodo-2-deoxyuridine (IUDR) as a radiosensitizer when administered by continuous infusion into the cerebral spinal fluid (CSF) of the lateral cerebral ventricle was evaluated in a 9L gliosarcoma rat brain tumor model. Stereotactic implantation of a 5 x 10(4) tumor cell suspension into the left caudate nucleus was carried out in four groups of 10 rats each. Control animals had a median survival of 16.9 days (range 16-21 days). IUDR, 8.4 mg over 7 days administered by continuous infusion into the left lateral ventricle produced a slight survival advantage (median survival 21.5 days, range 12-56). Irradiation of the entire brain, 8 Gy on days 4, 6 and 7 after tumor cell implantation also produced a slight improvement in survival (median 19.5 days, range 17-34). The combination of radiation and IUDR infusion into the CSF produced a marked survival advantage (median 30.5, range 22-54) compared to the control and single modality treatment groups. This is the first demonstration of the effectiveness of IUDR as a radiosensitizer when administered into the lateral cerebral ventricle in the treatment of an intraparenchymal brain tumor

  20. Assay for inhibitors of nucleoside transport based upon the use of 5-125I]Iodo-2-deoxyuridine as permeant

    International Nuclear Information System (INIS)

    Mahony, W.B.; Zimmerman, T.P.

    1986-01-01

    5[ 125 I]Iodo-2-deoxyuridine (IdUrd) has been shown to serve as a permeant for the nucleoside transport system of human erythrocytes and to be metabolically inert in these cells. Linear initial velocities were obtained at 20 0 C for 125 IdUrd transport, yielding a K/sub m/ of 73 +/- 18 μM (n = 6). Low-affinity inhibitors of 125 IdUrd transport, such as adenosine (K/sub i/ = 32 +/- 2 μM, n = 2), could be characterized by Michaelis-Menten kinetics. However, high-affinity inhibitors, such as 6-[4-nitrobenzyl)thio]9-β-D-ribofuranosylpurine, caused nonlinear initial velocities when added to the cells simultaneously with 125 IdUrd. Conditions were defined (viz., 20-min pretreatment of cells with test compound followed by 5.0-min incubation with 1.0 μM 125 IdUrd, all at 20 0 C) whereby high-affinity inhibitors of IdUrd transport can be identified and evaluated according to their 50% inhibitory concentrations. The use of 125 IdUrd as permeant greatly expedites the testing of compounds as inhibitors of nucleoside transport by allowing the cell pellets generated in these assays to be monitored directly in a gamma spectrometer, thereby circumventing the solubilization and decolorization of cell pellets required by assays that use 3 H- or 14 C-labeled nucleoside permeants

  1. Inhibition of lipase and inflammatory mediators by Chlorella lipid extracts for antiacne treatment.

    Science.gov (United States)

    Sibi, G

    2015-01-01

    Acne vulgaris is a chronic inflammatory disease, and its treatment is challenging due to the multifactorial etiology and emergence of antibiotic-resistant Propionibacterium acnes strains. This study was focused to reduce antibiotics usage and find an alternate therapeutic source for treating acne. Lipid extracts of six Chlorella species were tested for inhibition of lipase, reactive oxygen species (ROS) production, cytokine production using P. acnes (Microbial Type Culture Collection 1951). Lipase inhibitory assay was determined by dimercaprol Tributyrate - 5, 5'- dithiobis 2-nitrobenzoic acid method and ROS production assay was performed using nitro-blue tetrazolium test. The anti-inflammatory activity of algal lipid extracts was determined by in vitro screening method based on inhibition of pro-inflammatory cytokines, tumor necrosis factor-alpha (TNF-α) produced by human peripheral blood mononuclear cells. Minimum inhibitory concentration (MIC) values of lipid extracts were determined by microdilution method, and the fatty acid methyl esters (FAME) were analyzed by gas chromatography-mass spectroscopy. Chlorella ellipsoidea has the highest lipase inhibitory activity with 61.73% inhibition, followed by Chlorella vulgaris (60.31%) and Chlorella protothecoides (58.9%). Lipid extracts from C. protothecoides and C. ellipsoidea has significantly reduced the ROS production by 61.27% and 58.34% respectively. Inhibition of pro-inflammatory cytokines TNF-α showed the inhibition ranging from 58.39% to 78.67%. C. vulgaris has exhibited the MICvalue of 10 μg/ml followed by C. ellipsoidea, C. protothecoides and Chlorella pyrenoidosa (20 μg/ml). FAME analysis detected 19 fatty acids of which 5 were saturated fatty acids, and 14 were unsaturated fatty acids ranging from C14 to C24. The results suggest that lipid extracts of Chlorella species has significant inhibitory activity on P. acnes by inhibiting lipase activity. Further, anti-inflammatory reaction caused by the

  2. Inhibition of lipase and inflammatory mediators by Chlorella lipid extracts for antiacne treatment

    Directory of Open Access Journals (Sweden)

    G Sibi

    2015-01-01

    Full Text Available Acne vulgaris is a chronic inflammatory disease, and its treatment is challenging due to the multifactorial etiology and emergence of antibiotic-resistant Propionibacterium acnes strains. This study was focused to reduce antibiotics usage and find an alternate therapeutic source for treating acne. Lipid extracts of six Chlorella species were tested for inhibition of lipase, reactive oxygen species (ROS production, cytokine production using P. acnes (Microbial Type Culture Collection 1951. Lipase inhibitory assay was determined by dimercaprol Tributyrate - 5, 5′- dithiobis 2-nitrobenzoic acid method and ROS production assay was performed using nitro-blue tetrazolium test. The anti-inflammatory activity of algal lipid extracts was determined by in vitro screening method based on inhibition of pro-inflammatory cytokines, tumor necrosis factor-alpha (TNF-α produced by human peripheral blood mononuclear cells. Minimum inhibitory concentration (MIC values of lipid extracts were determined by microdilution method, and the fatty acid methyl esters (FAME were analyzed by gas chromatography-mass spectroscopy. Chlorella ellipsoidea has the highest lipase inhibitory activity with 61.73% inhibition, followed by Chlorella vulgaris (60.31% and Chlorella protothecoides (58.9%. Lipid extracts from C. protothecoides and C. ellipsoidea has significantly reduced the ROS production by 61.27% and 58.34% respectively. Inhibition of pro-inflammatory cytokines TNF-α showed the inhibition ranging from 58.39% to 78.67%. C. vulgaris has exhibited the MICvalue of 10 μg/ml followed by C. ellipsoidea, C. protothecoides and Chlorella pyrenoidosa (20 μg/ml. FAME analysis detected 19 fatty acids of which 5 were saturated fatty acids, and 14 were unsaturated fatty acids ranging from C14 to C24. The results suggest that lipid extracts of Chlorella species has significant inhibitory activity on P. acnes by inhibiting lipase activity. Further, anti-inflammatory reaction caused

  3. Starch and lipid accumulation in eight strains of six Chlorella species under comparatively high light intensity and aeration culture conditions

    Czech Academy of Sciences Publication Activity Database

    Takeshita, T.; Ota, M. S.; Yamazaki, T.; Hirata, A.; Zachleder, Vilém; Kawano, S.

    2014-01-01

    Roč. 158, č. 2 (2014), s. 127-134 ISSN 0960-8524 Institutional support: RVO:61388971 Keywords : Chlorella * alga * starch * lipids Subject RIV: EE - Microbiology, Virology Impact factor: 4.494, year: 2014

  4. The acclimation of Chlorella to high-level nitrite for potential application in biological NOx removal from industrial flue gases

    Czech Academy of Sciences Publication Activity Database

    Li, T.; Xu, G.; Rong, J.; Chen, H.; He, Ch.; Giordano, Mario; Wang, Q.

    2016-01-01

    Roč. 195, May (2016), s. 73-79 ISSN 0176-1617 Institutional support: RVO:61388971 Keywords : Acclimation * Biological NOx removal * Chlorella Subject RIV: EF - Botanics Impact factor: 3.121, year: 2016

  5. Effect of chlorella and its fractions on blood pressure, cerebral stroke lesions, and life-span in stroke-prone spontaneously hypertensive rats.

    Science.gov (United States)

    Sansawa, Hiroshi; Takahashi, Masatoshi; Tsuchikura, Satoru; Endo, Hiroshi

    2006-12-01

    Effects of Chlorella regularis (dried cell powder)--cultured axenically under heterotrophic conditions, and provided as a dietary supplement--and its fractions on the blood pressure, cerebral stroke lesions, and life-span of stroke-prone spontaneously hypertensive rats (SHRSP/Izm) were investigated. When SHRSP were fed on diets with supplemented Chlorella to a commercial diet (Funabashi SP), elevation of blood pressure was significantly lower in the Chlorella groups than in the control group. At 21 wk of feeding, serum total cholesterol was significantly lower in the Chlorella groups than in the control group. Histopathological examination revealed cerebral vascular accidents in the brains of the control group, but those of Chlorella groups showed apparently low incidence compared to the control group. The average life-span of the Chlorella groups were significantly longer than that of the control group (p vascular function of rats.

  6. Exceptionally diverse morphotypes and genomes of crenarchaeal hyperthermophilic viruses

    DEFF Research Database (Denmark)

    Prangishvili, D; Garrett, R A

    2004-01-01

    and Rudiviridae. They all have double-stranded DNA genomes and infect hyperthermophilic crenarchaea of the orders Sulfolobales and Thermoproteales. Representatives of the different viral families share a few homologous ORFs (open reading frames). However, about 90% of all ORFs in the seven sequenced genomes show...... no significant matches to sequences in public databases. This suggests that these hyperthermophilic viruses have exceptional biochemical solutions for biological functions. Specific features of genome organization, as well as strategies for DNA replication, suggest that phylogenetic relationships exist between...... crenarchaeal rudiviruses and the large eukaryal DNA viruses: poxviruses, the African swine fever virus and Chlorella viruses. Sequence patterns at the ends of the linear genome of the lipothrixvirus AFV1 are reminiscent of the telomeric ends of linear eukaryal chromosomes and suggest that a primitive telomeric...

  7. Culture of Chlorella ellipsoidea in different culture media

    Directory of Open Access Journals (Sweden)

    MM Mohshina

    2017-06-01

    Full Text Available An experiment of algal culture was conducted in natural light and temperature conditions at a balcony of a room at the 2nd floor of Fisheries Faculty Building facing the north. The experiment was done to evaluate the growth of Chlorella ellipsoidea in four different media, viz, medium I (inorganic, medium II (organic, whole pulse powder extract, medium III (organic, whole lentil powder extract and medium IV (organic, whole gram powder extract under natural environment conditions during January-June, 2015. Growth rates of the algal species in four different media were found not significantly different. The alga, C. ellipsoidea attained maximum cell density of 28.89×106 cell ml-1 in the 15th day in medium I, of 30.69×106 cell ml-1 in the 13th day in medium II, of 26.18×106 cell ml-1 in the 15th day in medium III and of 21.12×106 cell ml-1 in the 13th day in medium IV. The ranges of air temperature, water temperature and light intensity were 21°C to 38°C, 23°C to 36°C and 2.28×103to 9.60×103 Lux respectively during the culture period. The average sunshine period was 5.87±2.82 hrs. Total alkalinity, free CO2, pH , NO3-N and PO4-P of algal culture media I, II, III and IV were 128, 540, 554 and 322 mgL-1; 32, 162, 102, 70 mgL-1; 7.4, 8, 7.9 and 7.9; 180, 36.6, 62.4 and 150 mgL-1, and 25.2, 48.2, 42.4 and 45.6 mgL-1, respectively. According to ANOVA of cell densities of cultures of C. ellipsoidea under treatments are not significantly different (F=1.441077. It is clear that differences between them are not significant i.e. mean algal cell densities are more or less same as differences between treatments are less than 20%.

  8. Benefits of Preventive Administration of Chlorella sp. on Visceral Pain and Cystitis Induced by a Single Administration of Cyclophosphamide in Female Wistar Rat

    OpenAIRE

    Hidalgo-Lucas, Sophie; Rozan, Pascale; Guérin-Deremaux, Laetitia; Baert, Blandine; Violle, Nicolas; Saniez-Degrave, Marie-Hélène; Bisson, Jean-François

    2016-01-01

    Chlorella sp. is a green microalgae containing nutrients, vitamins, minerals, and chlorophyll. In some communities, Chlorella sp. is a traditional medicinal plant used for the management of inflammation-related diseases. In a rat model, ROQUETTE Chlorella sp. (RCs) benefits were investigated on visceral pain and associated inflammatory parameters related to cystitis both induced by cyclophosphamide (CYP). RCs was orally administered every day from day 1–16 (250 and 500 mg/kg body weight). Six...

  9. A human osteosarcoma cell line expressing herpes simplex type-1 thymidine kinase: studies with radiolabeled (E)-5-(2-iodovinyl)-2'-fluoro-2'-deoxyuridine

    International Nuclear Information System (INIS)

    Morin, Kevin W.; Duan Weili; Knaus, Edward E.; McEwan, Alexander J.B.; Wiebe, Leonard I.

    2005-01-01

    Introduction: (E)-5-(2-Iodovinyl)-2'-fluoro-2'-deoxyuridine (IVFRU) is a pyrimidine nucleoside analogue that accumulates selectively in murine cells expressing herpes simplex type-1 thymidine kinase (HSV-1 TK). The uptake of [ 125 I]IVFRU in human 143B osteosarcoma cells transduced with a retroviral vector bearing the HSV-1 TK gene (143B-LTK cells) is now reported. Methods: HSV-1 TK gene expression in 143B-LTK cells was confirmed by Western blotting and reverse transcriptase (RT)-PCR. Cell and subcellular uptake of [ 125 I]IVFRU was determined in cell culture, and whole body biodistribution after intravenous injection of [ 125 I]IVFRU was determined using nude mice bearing implanted 143B or 143B-LTK tumors. Results: Although IVFRU was less toxic to the human cell line expressing HSV-1 TK (143B-LTK) than ganciclovir, both IVFRU and ganciclovir were not toxic to the cell line not expressing HSV-1 TK (143B). When cells were exposed to [ 125 I]IVFRU in vitro, only the 143B-LTK cells accumulated radioactivity. The acid-soluble fraction from 143B-LTK cell lysates contained 8-fold greater activity than the acid-insoluble fraction after an 8-h exposure to [ 125 I]IVFRU. Biodistribution of [ 125 I]IVFRU in nude mice bearing subcutaneous 143B and 143B-LTK tumors revealed widespread distribution of the nucleoside in vivo but with specific localization in 143B-LTK tumors. Conclusion: The underlying biochemical process of metabolic entrapment of IVFRU in human osteosarcoma cells expressing HSV-1 TK is responsible for selective localization in these cells. The differences in subcellular distribution into the nucleic acid fraction, and in cytotoxicity, reflect the importance of cell type and lineage as determinants of the performance of gene imaging radiopharmaceuticals

  10. A human osteosarcoma cell line expressing herpes simplex type-1 thymidine kinase: studies with radiolabeled (E)-5-(2-iodovinyl)-2'-fluoro-2'-deoxyuridine

    Energy Technology Data Exchange (ETDEWEB)

    Morin, Kevin W. [Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, T6G 2N8 (Canada); Duan Weili [Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, T6G 2N8 (Canada); Knaus, Edward E. [Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, T6G 2N8 (Canada); McEwan, Alexander J.B. [Department of Radiology and Diagnostic Imaging, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, T6G 2N8 (Canada); Wiebe, Leonard I. [Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, T6G 2N8 (Canada)]. E-mail: leonard.wiebe@ualberta.ca

    2005-07-01

    Introduction: (E)-5-(2-Iodovinyl)-2'-fluoro-2'-deoxyuridine (IVFRU) is a pyrimidine nucleoside analogue that accumulates selectively in murine cells expressing herpes simplex type-1 thymidine kinase (HSV-1 TK). The uptake of [{sup 125}I]IVFRU in human 143B osteosarcoma cells transduced with a retroviral vector bearing the HSV-1 TK gene (143B-LTK cells) is now reported. Methods: HSV-1 TK gene expression in 143B-LTK cells was confirmed by Western blotting and reverse transcriptase (RT)-PCR. Cell and subcellular uptake of [{sup 125}I]IVFRU was determined in cell culture, and whole body biodistribution after intravenous injection of [{sup 125}I]IVFRU was determined using nude mice bearing implanted 143B or 143B-LTK tumors. Results: Although IVFRU was less toxic to the human cell line expressing HSV-1 TK (143B-LTK) than ganciclovir, both IVFRU and ganciclovir were not toxic to the cell line not expressing HSV-1 TK (143B). When cells were exposed to [{sup 125}I]IVFRU in vitro, only the 143B-LTK cells accumulated radioactivity. The acid-soluble fraction from 143B-LTK cell lysates contained 8-fold greater activity than the acid-insoluble fraction after an 8-h exposure to [{sup 125}I]IVFRU. Biodistribution of [{sup 125}I]IVFRU in nude mice bearing subcutaneous 143B and 143B-LTK tumors revealed widespread distribution of the nucleoside in vivo but with specific localization in 143B-LTK tumors. Conclusion: The underlying biochemical process of metabolic entrapment of IVFRU in human osteosarcoma cells expressing HSV-1 TK is responsible for selective localization in these cells. The differences in subcellular distribution into the nucleic acid fraction, and in cytotoxicity, reflect the importance of cell type and lineage as determinants of the performance of gene imaging radiopharmaceuticals.

  11. Combined effects of π-π stacking and hydrogen bonding on the (N1) acidity of uracil and hydrolysis of 2'-deoxyuridine.

    Science.gov (United States)

    Kellie, Jennifer L; Navarro-Whyte, Lex; Carvey, Matthew T; Wetmore, Stacey D

    2012-03-01

    M06-2X/6-31+G(d,p) is used to study the simultaneous effects of π-π stacking interactions with phenylalanine (modeled as benzene) and hydrogen bonding with small molecules (HF, H(2)O, and NH(3)) on the N1 acidity of uracil and the hydrolytic deglycosylation of 2'-deoxyuridine (dU) (facilitated by fully (OH(-)) or partially (HCOO(-)···H(2)O) activated water). When phenylalanine is complexed with isolated uracil, the proton affinity of all acceptor sites significantly increases (by up to 28 kJ mol(-1)), while the N1 acidity slightly decreases (by ~6 kJ mol(-1)). When small molecules are hydrogen bound to uracil, addition of the phenylalanine ring can increase or decrease the acidity of uracil depending on the number and nature (acidity) of the molecules bound. Furthermore, a strong correlation between the effects of π-π stacking on the acidity of U and the dU deglycosylation reaction energetics is found, where the hydrolysis barrier can increase or decrease depending on the nature and number of small molecules bound, the nucleophile considered (which dictates the negative charge on U in the transition state), and the polarity of the (bulk) environment. These findings emphasize that the catalytic (or anticatalytic) role of the active-site aromatic amino acid residues is highly dependent on the situation under consideration. In the case of uracil-DNA glycosylase (UNG), which catalyzes the hydrolytic excision of uracil from DNA, the type of discrete hydrogen-bonding interactions with U, the nature of the nucleophile, and the anticipated weak, nonpolar environment in the active site suggest that phenylalanine will be slightly anticatalytic in the chemical step, and therefore experimentally observed contributions to catalysis may entirely result from associated structural changes that occur prior to deglycosylation.

  12. Ebola Virus and Marburg Virus

    Science.gov (United States)

    Ebola virus and Marburg virus Overview Ebola virus and Marburg virus are related viruses that cause hemorrhagic fevers — illnesses marked by severe bleeding (hemorrhage), organ failure and, in many ...

  13. Biogenic synthesis of silver nanoparticle by using secondary metabolites from Pseudomonas aeruginosa DM1 and its anti-algal effect on Chlorella vulgaris and Chlorella pyrenoidosa.

    Science.gov (United States)

    Kumari, Rima; Barsainya, Manjari; Singh, Devendra Pratap

    2017-02-01

    Biogenic synthesis of silver nanoparticles (AgNPs) using extracellular metabolites from the bacterium Pseudomonas aeruginosa DM1 offers an eco-friendly and sustainable way of metal nanoparticle synthesis. The present work highlights the biotransformation of silver nitrate solution into AgNP, mediated by extracellular secondary metabolite pyoverdine, a siderophore produced by P. aeruginosa. The bioreduction of silver ions into AgNPs by using pyoverdine was recorded in terms of Fourier transform infrared spectroscopy (FTIR) analysis and color change in the reaction mixture (AgNO 3 + pyoverdine) from pale yellow to dark brown with absorption maxima at 415 nm. The results of X-ray diffraction (XRD) analysis of AgNPs showed its crystalline face-centered cubic structure. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) pictures of AgNPs showed spherical morphology of AgNP in the range of 45-100 nm, with tendency of agglomerations. The energy-dispersive X-ray (EDX) analysis of particles provided strong signal of elemental silver with few minor peaks of other impurities. The present approach offers a unique in vitro method of metal nanoparticle synthesis by exogenously produced bacterial secondary metabolites, where direct contact between the toxic metal and biological resource material can be avoided. The biologically synthesized AgNPs are found to have anti-algal effects against two species of Chlorella (Chlorella vulgaris and Chlorella pyenoidosa), as indicated by zone of growth inhibition on algal culture plates. Further results exhibit concentration-dependent progressive inhibition of chlorophyll content in the algal cells by AgNPs, confirming the algicidal effect of AgNPs.

  14. Studies on reduction of inorganic pollutants from wastewater by Chlorella pyrenoidosa and Scenedesmus abundans

    Directory of Open Access Journals (Sweden)

    B. Lekshmi

    2015-12-01

    Full Text Available The aim of this study was to identify the potential for cultivation of Chlorella pyrenoidosa and Scenedesmus abundans in raw and autoclaved domestic wastewater (sewage for nutrient removal, in a batch process. The growth was observed by measuring chlorophyll content. The inoculum size of 10% and 20% was used and the growth of microalgae and nutrient removal was monitored on daily basis. The maximum removal of ammonium nitrogen, phosphate and nitrates by Chlorella pyrenoidosa in raw samples was observed as 99%, 96% and 80%, respectively, whereas the maximum removal of ammonium nitrogen, phosphate and nitrates by Scenedesmus abundans in raw samples was observed as 98%, 95% and 83%, respectively. The maximum chlorophyll content was observed as 11.33 mg/l and 7.23 mg/l for C. pyrenoidosa and S. abundans, respectively, in raw samples. The experimental results reveal that both the microalgae are capable to grow and remove the nutrients from domestic wastewater.

  15. Caleosin from Chlorella vulgaris TISTR 8580 is salt-induced and heme-containing protein.

    Science.gov (United States)

    Charuchinda, Pairpilin; Waditee-Sirisattha, Rungaroon; Kageyama, Hakuto; Yamada, Daisuke; Sirisattha, Sophon; Tanaka, Yoshito; Mahakhant, Aparat; Takabe, Teruhiro

    2015-01-01

    Physiological and functional properties of lipid droplet-associated proteins in algae remain scarce. We report here the caleosin gene from Chlorella vulgaris encodes a protein of 279 amino acid residues. Amino acid sequence alignment showed high similarity to the putative caleosins from fungi, but less to plant caleosins. When the C. vulgaris TISTR 8580 cells were treated with salt stress (0.3 M NaCl), the level of triacylglycerol increased significantly. The mRNA contents for caleosin in Chlorella cells significantly increased under salt stress condition. Caleosin gene was expressed in E. coli. Crude extract of E. coli cells exhibited the cumene hydroperoxide-dependent oxidation of aniline. Absorption spectroscopy showed a peak around 415 nm which was decreased upon addition of cumene hydroperoxide. Native polyacrylamide gel electrophoresis suggests caleosin existed as the oligomer. These data indicate that a fresh water C. vulgaris TISTR 8580 contains a salt-induced heme-protein caleosin.

  16. Biomass Production Chlorella Vulgaris Buitenzorg Using Series of Bubble Column Photo Bioreactor with a Periodic Illumination

    Directory of Open Access Journals (Sweden)

    Anondho Wijanarko

    2010-10-01

    Full Text Available Chlorella vulgaris Buitenzorg cultivation using three bubble column photo bioreactors arranged in series with a volume of 200 mL for 130 hours shows an increase of biomass production of Chlorella vulgaris Buitenzorg up to 1.20 times and a decrease of the ability of CO2 fixation compared to single reactor at a periodic sun illumination cycle. The operation conditions on cultivation are as following: T, 29.0oC; P,1 atm.; UG, 2.40 m/h; CO2, 10%; Benneck medium; and illumination source by Phillip Halogen Lamp 20W /12V/ 50Hz. Other research parameters such as microbial carbon dioxide transferred rate (qco2, CO2 transferred rate (CTR, energy consumption for cellular formation (Ex, and cultural bicarbonate species concentration [HCO3] also give better results on series of reactor.

  17. Comparing Nutrient Removal from Membrane Filtered and Unfiltered Domestic Wastewater Using Chlorella vulgaris

    Science.gov (United States)

    Mayhead, Elyssia; Llewellyn, Carole A.; Fuentes-Grünewald, Claudio

    2018-01-01

    The nutrient removal efficiency of Chlorella vulgaris cultivated in domestic wastewater was investigated, along with the potential to use membrane filtration as a pre-treatment tool during the wastewater treatment process. Chlorella vulgaris was batch cultivated for 12 days in a bubble column system with two different wastewater treatments. Maximum uptake of 94.18% ammonium (NH4-N) and 97.69% ortho-phosphate (PO4-P) occurred in 0.2 μm membrane filtered primary wastewater. Membrane filtration enhanced the nutrient uptake performance of C. vulgaris by removing bacteria, protozoa, colloidal particles and suspended solids, thereby improving light availability for photosynthesis. The results of this study suggest that growing C. vulgaris in nutrient rich membrane filtered wastewater provides an option for domestic wastewater treatment to improve the quality of the final effluent. PMID:29351200

  18. Cloning and Characterization of the -Carotene Desaturase Gene from Chlorella protothecoides CS-41

    Directory of Open Access Journals (Sweden)

    Meiya Li

    2011-01-01

    Full Text Available To elucidate the lutein biosynthesis pathway in the lutein-producing alga, Chlorella protothecoides CS-41, the -carotene desaturase gene (zds was isolated from Chlorella protothecoides using the approach of rapid amplification of cDNA ends. The full-length cDNA sequence was 2031 bp and contained 1755 bp putative open reading frame which encodes a 584 amino acid deduced polypeptide whose computed molecular weight was 63.7 kDa. Sequence homology research indicated that the nucleotide and putative protein had sequence identities of 72.5% and 69.5% with those of the green alga Chlamydomonas reinhardtii, respectively. Phylogenetic analysis demonstrated that the ZDS from C. protothecoides CS-41 had a closer relationship with those of chlorophyta and higher plants than with those of other species. In addition, we also found that the zds gene expression was upregulated in response to light.

  19. Discoloration of wastewater from a paint industry by the microalgae Chlorella sp

    Directory of Open Access Journals (Sweden)

    Edgardo Angulo M

    2017-09-01

    Full Text Available Objective. Decoloring wastewater from a paint factory making use of Chlorella sp., microalgae as a biological way of treatment. Materials and methods. Samples of this microalgae previously cultivated with nourishing fertilizer under photoperiods of light and darkness were taken to test the microalgae Chlorella sp., initial concentration effect in the bioremoval process. For this purpose, it was cultivated in 0.10, 0.20 and 0.30 units of absorbance in bioreactors with 200 mL wastewater with and without nutrients. The biotest with the best rate of colour removal was chosen and the DBO5 and DQO were marked out. The immobilized Chlorella sp., in kappa carrageenan was also tested. Results. In the tests colour decrease percentage were 81.7, 69.7 and 58.3% without nutrients in the initial concentrations of 0.10, 0.20 and 0.30 units of absorbance respectively and 72.6, 69.0 and 86.8% for 0.10, 0.20 and 0.30 units of absorbance with nutrients respectively in the day of maximum growth. The immobilized microalgae score were 72.60% and 78.36% of color removal for 0.4 and 1.6 units of absorbance respectively. The higher colour removal test score was that with nutrients at 0.30 units of absorbance with several changes in DBO5 and DQO values. Conclusion. The biological wastewater treatment making use of Chlorella sp., microalgae can be considered as an effective choice in decolorating wastewater.

  20. CHANGES IN ENDOGENOUS CYTOKININ CONCENTRATIONS IN CHLORELLA (CHLOROPHYCEAE) IN RELATION TO LIGHT AND THE CELL CYCLE

    Czech Academy of Sciences Publication Activity Database

    Stirk, W. A.; van Staden, J.; Novák, Ondřej; Doležal, Karel; Strnad, Miroslav; Dobrev, Petre; Sipos, G.; Oerdoeg, V.; Balint, P.

    2011-01-01

    Roč. 47, č. 2 (2011), s. 291-301 ISSN 0022-3646 R&D Projects: GA ČR GA301/08/1649; GA ČR GA206/09/1284 Institutional research plan: CEZ:AV0Z50380511 Keywords : cell cycle * Chlorella * cis-zeatin * cytokinins * N6-(2-isopentenyl)adenine Subject RIV: EF - Botanics Impact factor: 2.071, year: 2011

  1. Potensi Air Dadih (Whey) Tahu Sebagai Nutrien Dalam Kultivasi Chlorella SP. Untuk Bahan Baku Pembuatan Biodisel

    OpenAIRE

    Arinto, Dhika Joko; Paramastri, Hayu Pradipta; Soetrisnanto, Danny

    2013-01-01

    An increase of population growth and energy demand has lead to a foster fuel consumption, therefore an alternative fuel is necessarily needed for a solution to solve the problem. Currently, one of the most popular solution offered is biodiesel. The development of biodiesel as renewable energy is done by using microalgae such as Chlorella sp. with 28-32% lipid content as its raw material. The objective of this research is to find out the effect of various concentration, biomass based on growth...

  2. Ecotoxicity tests using the green algae chlorella vulgaris — a useful tool in hazardous effluents management

    OpenAIRE

    Silva, Aurora; Figueiredo, Sónia Adriana; Sales, M. Goreti F.; Delerue-Matos, Cristina

    2009-01-01

    The treatment efficiency of laboratory wastewaters was evaluated and ecotoxicity tests with Chlorella vulgaris were performed on them to assess the safety of their environmental discharge. For chemical oxygen demand wastewaters, chromium (VI), mercury (II) and silver were efficiently removedby chemical treatments.Areduction of ecotoxicitywas achieved; nevertheless, an EC50 (effective concentration that causes a 50% inhibition in the algae growth) of 1.5% (v/v) indicated still high...

  3. Production of Microalgal Lipids as Biodiesel Feedstock with Fixation of CO2 by Chlorella vulgaris

    OpenAIRE

    Qiao Hu; Sen-Xiang Zhang; Zhong-Hua Yang; Hao Huang; Rong Zeng

    2014-01-01

    The global warming and shortage of energy are two critical problems for human social development. CO2 mitigation and replacing conventional diesel with biodiesel are effective routes to reduce these problems. Production of microalgal lipids as biodiesel feedstock by a freshwater microalga, Chlorella vulgaris, with the ability to fixate CO2 is studied in this work. The results show that nitrogen deficiency, CO2 volume fraction and photoperiod are the key factors responsible for the lipid accum...

  4. Effect of Nutrient Starvation under High Irradiance on Lipid and Starch Accumulation in Chlorella fusca (Chlorophyta)

    Czech Academy of Sciences Publication Activity Database

    Jerez, C.G.; Malapascua, José R.; Sergejevová, Magda; Figueroa, Felix L.; Masojídek, Jiří

    2016-01-01

    Roč. 18, č. 1 (2016), s. 24-36 ISSN 1436-2228 R&D Projects: GA MŠk ED2.1.00/03.0110; GA MŠk EE2.3.30.0059; GA MŠk(CZ) EE2.3.20.0203 Institutional support: RVO:61388971 Keywords : Microalgae * Chlorella * Lipid Subject RIV: EE - Microbiology, Virology Impact factor: 2.748, year: 2016

  5. Influence of culture conditions on growth and protein metabolism in chlorella pyranosides

    International Nuclear Information System (INIS)

    Mazon Matanzo, M. P.; Fernandez Gonzalez, J.; Batuecas Suarez, B.

    1981-01-01

    Growth and protein metabolism of Chlorella pyranoside under different conditions of temperature, photo period and CO 2 concentration was studied. The optimum of biomass production was observed at 25 degree centigree, 40.000 ppm of CO 2 in air and a 20 h. light period, followed of 4 h. of darkness. Some variations in free aminoacids content was observed under different conditions but no change did occur in protein. (Author) 68 refs

  6. Influence of culture conditions on growth and protein metabolism in chlorella pyrenoidosa

    International Nuclear Information System (INIS)

    Fernandez Gonzalez, J.; Mazon, M.P.; Batuecas, B.

    1981-01-01

    Growth and protein metabolism of chlorella pyrenoidosa under differents conditions of temperature, photoperiod and CO 2 concentration was studied. The optimum of biomas production was observed at 25 deg C, 40.000 ppm of CO 2 in air and a 20 h. light period, followed of 4 h. of darkness. Some variations in free aminoacids content was observed under differents conditions but no change did occur in protein. (author)

  7. Can Chlorella pyrenoidosa be a bioindicator for hazardous solid waste detoxification?

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Li-Fang, E-mail: hulif127@163.com [College of Quality and Safety Engineering, China Jiliang University, Hangzhou 310018 (China); Long, Yu-Yang; Shen, Dong-Sheng [School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012 (China); Jiang, Chen-Jing [The Second Institute of Oceanography, SOA, Hangzhou 310012 (China)

    2012-02-01

    Four kinds of solid waste residue (SWR, S1 to S4) from different stages in a sequential detoxification process were chosen. The biotoxicity of the leachates from S1 to S4 was tested by Chlorella pyrenoidosa. The growth inhibition, the chlorophyll a (chla) and chlorophyll b (chlb) concentrations, and the ultrastructural morphology of cells of C. pyrenoidosa were studied. It shows that the growth inhibition of C. pyrenoidosa significantly increased with increasing leachate concentration when exposed to the leachates from S1, S2, S3, and S4, respectively. It well reflects the toxicity difference of leachate from SWR at different treatment stages, namely S1 > S2 > S3 > S4. Correspondingly, the chla and chlb concentrations of C. pyrenoidosa increased gradually as SWR was treated deeply. Leachate disrupted chlorophyll synthesis and inhibited cell growth. The changing of the ultrastructural morphology of cells under different leachate exposures, such as volume of chloroplasts and quantity of thylakoids reducing, confirmed the toxicity decrease of leachates from different stages. C. pyrenoidosa is a good bioindicator for hazardous solid waste detoxification. The EC{sub 50} at difference scenarios also suggests that it was feasible to estimate ecological toxicity of leachates to C. pyrenoidosa after exposure times of 72 h. C. pyrenoidosa can be introduced to evaluate the effect of hazardous solid waste disposal by biotoxicity assessment. - Highlights: Black-Right-Pointing-Pointer The detoxification process of hazardous solid waste was evaluated by Chlorella pyrenoidosa. Black-Right-Pointing-Pointer The best exposure time of ecological toxicity assessment of Chlorella pyrenoidosa was presented. Black-Right-Pointing-Pointer The possible toxicity of the hazardous solid waste at different disposal stage on Chlorella pyrenoidosa was explored from cell tissue.

  8. Biodiesel Production from Chlorella protothecoides Oil by Microwave-Assisted Transesterification

    OpenAIRE

    G?lyurt, Mustafa ?mer; ?z?imen, Didem; ?nan, Benan

    2016-01-01

    In this study, biodiesel production from microalgal oil by microwave-assisted transesterification was carried out to investigate its efficiency. Transesterification reactions were performed by using Chlorella protothecoides oil as feedstock, methanol, and potassium hydroxide as the catalyst. Methanol:oil ratio, reaction time and catalyst:oil ratio were investigated as process parameters affected methyl ester yield. 9:1 methanol/oil molar ratio, 1.5% KOH catalyst/oil ratio and 10 min were opti...

  9. Single cell protein production of Chlorella sp. using food processing waste as a cultivation medium

    Science.gov (United States)

    Putri, D.; Ulhidayati, A.; Musthofa, I. A.; Wardani, A. K.

    2018-03-01

    The aim of this study was to investigate the effect of various food processing wastes on the production of single cell protein by Chlorella sp. Three various food processing wastes i.e. tofu waste, tempeh waste and cheese whey waste were used as cultivation medium for Chlorella sp. growth. Sea water was used as a control of cultivation medium. The addition of waste into cultivation medium was 10%, 20%, 30%, 40%, and 50%. The result showed that the highest yield of cell mass and protein content was found in 50% tofu waste cultivation medium was 47.8 × 106 cell/ml with protein content was 52.24%. The 50% tofu waste medium showed improved cell yield as nearly as 30% than tempeh waste medium. The yield of biomass and protein content when 30% tempeh waste was used as cultivation medium was 37.1 × 106 cell/ml and 52%, respectively. Thus, food processing waste especially tofu waste would be a promising candidate for cultivation medium for single cell production from Chlorella sp. Moreover, the utilization of waste can reduce environmental pollution and increase protein supply for food supplement or animal feed.

  10. Culture of a high-chlorophyll-producing and halotolerant Chlorella vulgaris.

    Science.gov (United States)

    Nakanishi, Koichi; Deuchi, Keiji

    2014-05-01

    In order to increase the value of freshwater algae as raw ingredients for health foods and feed for seawater-based farmed fish, we sought to breed high-chlorophyll halotolerant Chlorella with the objective of generating strains with both high chlorophyll concentrations (≥ 5%) and halotolerance (up to 1% NaCl). We used the Chlorella vulgaris K strain in our research institute culture collection and induced mutations with UV irradiation and acriflavine which is known to effect mutations of mitochondrial DNA that are associated with chlorophyll production. Screenings were conducted on seawater-based "For Chlorella spp." (FC) agar medium, and dark-green-colored colonies were visually selected by macroscopic inspection. We obtained a high-chlorophyll halotolerant strain (designated C. vulgaris M-207A7) that had a chlorophyll concentration of 6.7% (d.m.), a level at least three-fold higher than that of K strain. This isolate also exhibited a greater survival rate in seawater that of K strain. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  11. Isolation and partial characterization of mutants with elevated lipid content in Chlorella sorokiniana and Scenedesmus obliquus.

    Science.gov (United States)

    Vigeolas, Hélène; Duby, Francéline; Kaymak, Esra; Niessen, Guillaume; Motte, Patrick; Franck, Fabrice; Remacle, Claire

    2012-11-30

    This paper describes the isolation and partial biomass characterization of high triacylglycerol (TAG) mutants of Chlorella sorokiniana and Scenedesmus obliquus, two algal species considered as potential source of biodiesel. Following UV mutagenesis, 2000 Chlorella and 2800 Scenedesmus colonies were screened with a method based on Nile Red fluorescence. Several mutants with high Nile Red fluorescence were selected by this high-throughput method in both species. Growth and biomass parameters of the strongest mutants were analyzed in detail. All of the four Chlorella mutants showed no significant changes in growth rate, cell weight, cell size, protein and chlorophyll contents on a per cell basis. Whereas all contained elevated total lipid and TAG content per unit of dry weight, two of them were also affected for starch metabolism, suggesting a change in biomass/storage carbohydrate composition. Two Scenedesmus mutants showed a 1.5 and 2-fold increased cell weight and larger cells compared to the wild type, which led to a general increase of biomass including total lipid and TAG content on a per cell basis. Such mutants could subsequently be used as commercial oleaginous algae and serve as an alternative to conventional petrol. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Bioremoval of the azo dye Congo Red by the microalga Chlorella vulgaris.

    Science.gov (United States)

    Hernández-Zamora, Miriam; Cristiani-Urbina, Eliseo; Martínez-Jerónimo, Fernando; Perales-Vela, Hugo Virgilio; Ponce-Noyola, Teresa; Montes-Horcasitas, María del Carmen; Cañizares-Villanueva, Rosa Olivia

    2015-07-01

    Discharge of dye-containing wastewater by the textile industry can adversely affect aquatic ecosystems and human health. Bioremoval is an alternative to industrial processes for detoxifying water contaminated with dyes. In this work, active and inactive biomass of the microalga Chlorella vulgaris was assayed for the ability to remove Congo Red (CR) dye from aqueous solutions. Through biosorption and biodegradation processes, Chlorella vulgaris was able to remove 83 and 58 % of dye at concentrations of 5 and 25 mg L(-1), respectively. The maximum adsorption capacity at equilibrium was 200 mg g(-1). The Langmuir model best described the experimental equilibrium data. The acute toxicity test (48 h) with two species of cladocerans indicated that the toxicity of the dye in the effluent was significantly decreased compared to the initial concentrations in the influent. Daphnia magna was the species less sensitive to dye (EC50 = 17.0 mg L(-1)), followed by Ceriodaphnia dubia (EC50 = 3.32 mg L(-1)). These results show that Chlorella vulgaris significantly reduced the dye concentration and toxicity. Therefore, this method may be a viable option for the treatment of this type of effluent.

  13. Effect of inorganic fertilizer on the growth of freshwater Chlorella sp.

    Science.gov (United States)

    Rahardini, R. A.; Helmiati, S.; Triyatmo, B.

    2018-03-01

    One of the alternative nutrient sources in the culture of Chlorella sp. is inorganic fertilizer. The aim of this study was to determine the effect of inorganic fertilizer composition in the culture medium on the growth of Chlorella sp. This research was conducted by using the 2.5 L transparent containers containing 2 L freshwater. The culture was carried out in laboratory facilitated with an air conditioner, fluorescent light and continuous aeration for 14 days of culture. The treatments consisted of fertilizer composition of Urea:ZA:TSP i.e. P1 (1:1:0,50), P2 (2:2:0,70), P3 (3:3:1), P4 (4:4:1,25) and P0 (Walne medium) as a positive control. Each treatment was performed in triplicates and arranged based on the Completely Randomized Design. Chlorella sp. was inoculated with the initial density of 30 × 104 cells·mL-1. The results of this study showed that the inorganic fertilizer composition of 3:3:1 provided the highest growth rate of 25.9 %/day, and the highest population density reached 2.348 × 104 cells·mL-1. The doubling time was not affected by the inorganic fertilizer treatments.

  14. Health Food Supplements (Health Food Highly Nutritious From Chlorella And Oil Catfish (Pangasius hypopthalmus

    Directory of Open Access Journals (Sweden)

    Syahrul Syahrul

    2017-02-01

    Full Text Available AbstractThe utilization of microalgae as a food ingredient considered effective, because in addition to alternative food sources also contains nutrients chlorella microalgae in particular is very good for health. This microalgae rich in protein (60.5%, fat (11%, carbohydrates (20.1%, water, dietary fiber, vitamins and minerals Besides these microalgae contain pigments (chlorophyll, tocopherol and the active component (antimicrobial and antioxidants. This is what underlies microalgae is very useful to be used as a source of raw materials of health food supplements. Currently the health food supplements have become a necessity for people to maintain their health in order to remain vibrant. This study aims to produce high nutritious health food supplements from raw material chlorella enriched with fish protein concentrate and oil catfish. The method used in the manufacture of high nutritious health food supplement is a method of microencapsulation with different formulations. The results showed that the best formulations based on the profile of amino acids, fatty acids and standards AAE per day especially essential fatty acids oleic and linoleic is formulation B (chlorella 2%, 1% fish oil and fish protein concentrate 1%.

  15. Health Food Supplements (“Health Food” Highly Nutritious From Chlorella And Oil Catfish (Pangasius hypopthalmus

    Directory of Open Access Journals (Sweden)

    Syahrul Syahrul

    2016-12-01

    Full Text Available The utilization of microalgae as a food ingredient considered effective, because in addition to alternativefood sources also contains nutrients chlorella microalgae in particular is very good for health. This microalgaerich in protein (60.5%, fat (11%, carbohydrates (20.1%, water, dietary fiber, vitamins and minerals Besidesthese microalgae contain pigments (chlorophyll, tocopherol and the active component (antimicrobial andantioxidants. This is what underlies microalgae is very useful to be used as a source of raw materials ofhealth food supplements. Currently the health food supplements have become a necessity for people tomaintain their health in order to remain vibrant. This study aims to produce high nutritious health foodsupplements from raw material chlorella enriched with fish protein concentrate and oil catfish. The methodused in the manufacture of high nutritious health food supplement is a method of microencapsulation withdifferent formulations. The results showed that the best formulations based on the profile of amino acids,fatty acids and standards AAE per day especially essential fatty acids oleic and linoleic is formulation B(chlorella 2%, 1% fish oil and fish protein concentrate 1%.

  16. Anaerobic Digestion Effluents (ADEs) Treatment Coupling with Chlorella sp. Microalgae Production.

    Science.gov (United States)

    Zieliński, Marcin; Dębowski, Marcin; Szwaja, Stanisław; Kisielewska, Marta

    2018-02-01

      Nutrient removal effectiveness from anaerobic digestion effluents (ADEs) by Chlorella sp. cultivation and microalgae biomass productivity were evaluated in this study. The results showed that the highest Chlorella sp. biomass productivities of 386.5 ± 24.1 mg dry weight/L•d and 338.3 ± 11.0 mg dry weight/L•d were respectively obtained with the anaerobically digested effluent of municipal wastewater sludge and effluent from a fermentation tank treating dairy wastewater. Lower (p effluents of maize silage and swine slurry and cattle manure. The increase of the initial ammonia nitrogen concentration in ADEs to the level of 160 mg/L did not encourage Chlorella sp. productivity because of phosphorus limitation. The removal efficiencies of ammonia nitrogen, total nitrogen, total phosphorus, and chemical oxygen demand (COD) reached 99.7%, 98.6%, 88.2%, and 58.7%, respectively, depending on the source of ADE, but not on the initial ammonia nitrogen concentrations.

  17. Auger electron emitter against multiple myeloma - targeted endo-radio-therapy with 125I-labeled thymidine analogue 5-iodo-4'-thio-2'-deoxyuridine

    International Nuclear Information System (INIS)

    Morgenroth, Agnieszka; Dinger, Cornelia; Zlatopolskiy, Boris D.; Al-Momani, Ehab; Glatting, Gerhard; Mottaghy, Felix M.; Reske, Sven N.

    2011-01-01

    Introduction: Multiple myeloma (MM) is a plasma cell malignancy characterized by accumulation of malignant, terminally differentiated B cells in the bone marrow. Despite advances in therapy, MM remains an incurable disease. Novel therapeutic approaches are, therefore, urgently needed. Auger electron-emitting radiopharmaceuticals are attractive for targeted nano-irradiation therapy, given that DNA of malignant cells is selectively addressed. Here we evaluated the antimyeloma potential of the Auger electron-emitting thymidine analogue 125 I-labeled 5-iodo-4'-thio-2'-deoxyuridine ([ 125 I]ITdU). Methods: Cellular uptake and DNA incorporation of [ 125 I]ITdU were determined in fluorodeoxyuridine-pretreated KMS12BM, U266, dexamethasone-sensitive MM1.S and -resistant MM1.R cell lines. The effect of stimulation with interleukin 6 (IL6) or insulin-like growth factor 1 (IGF1) on the intracellular incorporation of [ 125 I]ITdU was investigated in cytokine-sensitive MM1.S and MM1.R cell lines. Apoptotic cells were identified using Annexin V. Cleavage of caspase 3 and PARP was visualized by Western blot. DNA fragmentation was investigated using laddering assay. Therapeutic efficiency of [ 125 I]ITdU was proven by clonogenic assay. Results: [ 125 I]ITdU was shown to be efficiently incorporated into DNA of malignant cells, providing a promising mechanism for delivering highly toxic Auger radiation emitters into tumor DNA. [ 125 I]ITdU had a potent antimyeloma effect in cell lines representing distinct disease stages and, importantly, in cell lines sensitive or resistant to the conventional therapeutic agent, but was not toxic for normal plasma and bone marrow stromal cells. Furthermore, [ 125 I]ITdU abrogated the protective actions of IL6 and IGF1 on MM cells. [ 125 I]ITdU induced massive damage in the DNA of malignant plasma cells, which resulted in efficient inhibition of clonogenic growth. Conclusion: These studies may provide a novel treatment strategy for overcoming

  18. Synthesis and biological properties of 5-azido-2'-deoxyuridine 5'-triphosphate, a photoactive nucleotide suitable for making light-sensitive DNA

    International Nuclear Information System (INIS)

    Evans, R.K.; Haley, B.E.

    1987-01-01

    A photoactive nucleotide analogue of dUTP, 5-azido-2'-deoxyuridine 5'-triphosphate (5-N 3 dUTP), was synthesized from dUMP in five steps. The key reaction in the synthesis of 5-N 3 dUTP is the nitration of dUMP in 98% yield in 5 min at 25 0 C using an excess of nitrosonium tetrafluoroborate in anhydrous dimethylformamide. Reduction of the resulting 5-nitro compound with zinc and 20 mM HCl gave 5-aminodeoxyuridine monophosphate (5-NH 2 dUMP). Diazotization of 5-NH 2 dUMP with HNO 2 followed by the addition NaN 3 to the acidic diazonium salt solution gave a photoactive nucleotide derivative in 80-90% yield. The monophosphate product was identified as 5-N 3 dUMP by proton NMR, UV, IR, and chromatographic analysis as well as by the mode of synthesis and its photosensitivity. After formation of 5-N 3 dUTP through a chemical coupling of pyrophosphate to 5-N 3 dUMP, the triphosphate form of the nucleotide was found to support DNA synthesis by Escherichia coli DNA polymerase I at a rate indistinguishable from that supported by dTTP. When UMP was used as the starting compound, 5-N 3 UTP was formed in an analogous fashion with similar yields and produced a photoactive nucleotide which is a substrate for E. coli RNA polymerase. To prepare [γ- 32 P]-5-N 3 dUTP for use as an active-site-directed photoaffinity labeling reagent, a simple method of preparing γ- 32 P-labeled pyrimidine nucleotides was developed. [γ- 32 P]-5-N 3 dUTP is an effective photoaffinity labeling reagent for DNA polymerase I and was found to bind to the active site with a 2-fold higher affinity than dTTP. The photoactivity of 5-N 3 dUMP is stable to extremes of pH, and [γ- 32 P]-5-N 3 dUTP was an effective photolabeling reagent even in the presence of 10 mM dithiothreitol

  19. Beneficial immunostimulatory effect of short-term Chlorella supplementation: enhancement of natural Killer cell activity and early inflammatory response (Randomized, double-blinded, placebo-controlled trial)

    NARCIS (Netherlands)

    Kwak, J.H.; Baek, S.H.; Woo, Y.; Han, J.K.; Lee, van L.

    2012-01-01

    Background - In vitro and animal studies have demonstrated that Chlorella is a potent biological response modifier on immunity. However, there were no direct evidences for the effect of Chlorella supplementation on immune/inflammation response in healthy humans. Methods - This study was designed for

  20. Chlorella sp : Extraction of fatty acid by using avocado oil as solvent and its application as an anti-aging cream

    Science.gov (United States)

    Putri, T. W.; Raya, I.; Natsir, H.; Mayasari, E.

    2018-03-01

    The study aimed to analyze the fatty acid content of Chlorella sp crude extract by using avocado oil solvent and determining the effectiveness of fatty acids Chlorella sp as the anti-aging cream The extraction of fatty acids from Chlorella sp using avocado oil as a solvent with three ratios were 1:10, 1:20 and 1:25 w/V. The highest lipid content was obtained at 1:20 w/V (gram microalgae: mL avocado oil) yielding 52.73%. Crude extracted were analysis by GC-MS and FTIR, and skin condition was determined by skin analyzer. The effectiveness test of Chlorella sp cream was applicated on the face of the panelists aged 20-60 years. From 10 panelists, the applied of Chlorella sp cream was 90% increased on the facial skin yielded moisture and oil content, 70% repair the skin structure. The composition of fatty acids Chlorella sp extract was palmitic acid, linoleic, oleic and stearate. Fatty acids crude extract of Chlorella sp can improve the effectiveness of anti-aging cream. The cream from Chlorella sp was more effective than the cream without containing microalgae. This is very promising because it is alternative to organic solvents i.e. green chemistry.

  1. Enhanced accumulation of starch and total carbohydrates in alginate-immobilized Chlorella spp. induced by Azospirillum brasilense: I. Autotrophic conditions.

    Science.gov (United States)

    Choix, Francisco J; de-Bashan, Luz E; Bashan, Yoav

    2012-10-10

    The effect of the microalgae-growth promoting bacterium Azospirillum brasilense on accumulation of total carbohydrates and starch in two species of Chlorella (Chlorella vulgaris and Chlorella sorokiniana), when the bacterium and each microalga were jointly immobilized in alginate beads was studied under autotrophic conditions for 144 h in synthetic medium. The interaction of the bacterium with the microalgae enhanced accumulation of total carbohydrate and starch. Cells of Chlorella accumulated the highest amounts of carbohydrate after incubation for 24h. Yet, this did not coincide with the highest affinity and volumetric productivity measured in these cultures. However, after incubation for 72 h, mainly in jointly immobilized treatments of both microalgae species, the cultures reached their highest total carbohydrate content (mainly as starch) and also the highest affinity and volumetric productivity. These results demonstrate the potential of A. brasilense to affect carbohydrates and starch accumulation in Chlorella spp. when both microorganisms are co-cultured, which can be an important tool for applications of microalgae. Copyright © 2012. Published by Elsevier Inc.

  2. PERFIL DE ÁCIDOS GRAXOS DAS MICROALGAS Chlorella vulgaris E Chlorella minutissima CULTIVADAS EM DIFERENTES CONDIÇÕES

    Directory of Open Access Journals (Sweden)

    J. A. V. COSTA

    2009-01-01

    Full Text Available

    Estudos recentes têm explorado o uso de microalgas para obtenção de lipídios, principalmente os de maior valor comercial como o ácido -linolênico. A microalga Chlorella possui ácidos graxos poliinsaturados, vitaminas e alto conteúdo protéico, e, além disso, possui o certificado GRAS (Generally Recognized As Safe. O objetivo deste trabalho foi estudar o cultivo das microalgas Chlorella vulgaris e Chlorella minutissima, a fim de verificar o perfil de ácidos graxos frente à variação de diferentes fatores físicoquímicos e nutricionais. Foi utilizado um Planejamento Fatorial Fracionário 24-1 IV para cada cepa estudada, onde foram variados os fatores temperatura, iluminância, fonte de carbono e concentração de nitrato no meio de cultivo. C. vulgaris cultivada a 35ºC, 2500 Lux, 16,8 g.L-1 de NaHCO3 e 1,0 g.L-1 de NO3 - apresentou biomassa máxima de 5,06 g.L-1 em 22 dias de cultivo. Para C. minutissima foi obtida biomassa máxima de 1,5g.L-1 em 22 dias quando cultivada a 35ºC, 1250 Lux, 16,8 g.L-1 de NaHCO3 e 0,5 g.L-1 de NO3 -. Os maiores teores de lipídios obtidos para C. vulgaris e C. minutissima foram 6,96% e 7,98%, respectivamente. A 35ºC e 2500 Lux foi obtido 7,66% de ácido linolênico.

  3. Effect of Organic Selenium from Se-enriched Alga (Chlorella spp. on Selenium Transfer from Sows to Their Progeny

    Directory of Open Access Journals (Sweden)

    Martin Svoboda

    2009-01-01

    Full Text Available The study was conducted to determine the efficacy of organic Se from Se-enriched alga Chlorella spp. in placental transfer to piglets. In group A (n = 8 the sows were fed during the gestation a diet supplemented with inorganic Se (sodium selenite, 0.3 mg/kg. In group B (n = 8 the diet of the sows was supplemented with organic Se from Se-enriched alga (0.3 mg/kg. The Se concentrations in the whole blood (P P Chlorella spp. in sows resulted in greater transfer of Se to their progeny.

  4. Using oxidized liquid and solid human waste as nutrients for Chlorella vulgaris and cyanobacterium Oscillatoria deflexa

    Science.gov (United States)

    Trifonov, Sergey V.; Kalacheva, Galina; Tirranen, Lyalya; Gribovskaya, Iliada

    At stationary terrestrial and space stations with closed and partially closed substance exchange not only plants, but also algae can regenerate atmosphere. Their biomass can be used for feeding Daphnia and Moina species, which, in their turn, serve as food for fish. In addition, it is possible to use algae for production of biological fuel. We suggested two methods of human waste mineralization: dry (evaporation with subsequent incineration in a muffle furnace) and wet (oxidation in a reactor using hydrogen peroxide). The research task was to prepare nutrient media for green alga Chlorella vulgaris and cyanobacterium Oscillatoria deflexa using liquid human waste mineralized by dry method, and to prepare media for chlorella on the basis of 1) liquid and 2) liquid and solid human waste mineralized by wet method. The algae were grown in batch culture in a climate chamber with the following parameters: illumination 7 klx, temperature 27-30 (°) C, culture density 1-2 g/l of dry weight. The control for chlorella was Tamiya medium, pH-5, and for oscillstoria — Zarrouk medium, pH-10. Maximum permissible concentrations of NaCl, Cl, urea (NH _{2}) _{2}CO, and native urine were established for algae. Missing ingredients (such as salts and acids) for experimental nutrient media were determined: their addition made it possible to obtain the biomass production not less than that in the control. The estimation was given of the mineral and biochemical composition of algae grown on experimental media. Microbiological test revealed absence of foreign microbial flora in experimental cultures.

  5. PIGMENT CONTENT OF Chlorella vulgaris BEIJ. UNDER INFLUENCE OF THE SODIUM SELENITE AND METALS IONS

    Directory of Open Access Journals (Sweden)

    O. I.

    2016-02-01

    Full Text Available The aim of the research was to determine the conditions obtaining in the aquaculture of Chlorella vulgaris Beij. algosubstantion enriched with selenium and bioactive metals. For this purpose, the content of seaweed pigments studied by the action of sodium selenite in a concentration based on Se4+: 0.5, 5.0, 10.0 and 20.0 mg / dm3 for 1, 3 and 7 days and while exposed 10.0 mg Se4 +/dm3 and Zn2+, Mn2 +, Co2 +, Cu2 +, Fe3 + in concentrations of 5.0 mg/dm 3, 0.25, 0.002, 0.008 and 0.05 mg/dm3, respectively, within 7 days of culturing. The content of pigments was determined spectrophotometrically, the cellular walls were given off in the percoll gradient and investigated microscopically. The pigments content in Ch. vulgaris increase by 1,5–2,5 times in comparison with control sample under the influence of 10 mg Se(IV/dm3 with and without metal ions. In the same condition a ratio of chlorophylls a/b increased, that accompanied by the formation in cells of the second cell wall as the sign of successful adaptation process in the Chlorella cells under the influence of these factors. Thus, the cultivation of chlorella, enriched with selenium and bioactive metals, is possible within 7 days under the influence of 10 mg Se (IV/dm3 and mentioned concentration of these metal ions.

  6. Suppression subtractive hybridization reveals transcript profiling of Chlorella under heterotrophy to photoautotrophy transition.

    Directory of Open Access Journals (Sweden)

    Jianhua Fan

    Full Text Available Microalgae have been extensively investigated and exploited because of their competitive nutritive bioproducts and biofuel production ability. Chlorella are green algae that can grow well heterotrophically and photoautotrophically. Previous studies proved that shifting from heterotrophy to photoautotrophy in light-induced environments causes photooxidative damage as well as distinct physiologic features that lead to dynamic changes in Chlorella intracellular components, which have great potential in algal health food and biofuel production. However, the molecular mechanisms underlying the trophic transition remain unclear.In this study, suppression subtractive hybridization strategy was employed to screen and characterize genes that are differentially expressed in response to the light-induced shift from heterotrophy to photoautotrophy. Expressed sequence tags (ESTs were obtained from 770 and 803 randomly selected clones among the forward and reverse libraries, respectively. Sequence analysis identified 544 unique genes in the two libraries. The functional annotation of the assembled unigenes demonstrated that 164 (63.1% from the forward library and 62 (21.8% from the reverse showed significant similarities with the sequences in the NCBI non-redundant database. The time-course expression patterns of 38 selected differentially expressed genes further confirmed their responsiveness to a diverse trophic status. The majority of the genes enriched in the subtracted libraries were associated with energy metabolism, amino acid metabolism, protein synthesis, carbohydrate metabolism, and stress defense.The data presented here offer the first insights into the molecular foundation underlying the diverse microalgal trophic niche. In addition, the results can be used as a reference for unraveling candidate genes associated with the transition of Chlorella from heterotrophy to photoautotrophy, which holds great potential for further improving its lipid and

  7. Effect of gamma radiation on chlorophylls contents, net photosynthesis and respiration of chlorella pyrenoidosa

    International Nuclear Information System (INIS)

    Fernandez Gonzalez, J.; Martin Moreno, C.

    1983-01-01

    The effect of five doses of gamma radiation: 10, 100, 500, 1000 and 5000 Gy on chlorophylls content, net photosynthesis and respiration of chlorella pyrenoidosa has been studied. A decrease in chlorophylls levels is produced after irradiation at 500, 1000 and 5000 Gy, being, at first 'b' chlorophyll affected to a greater extent than 'a' chlorophyll. Net photosynthesis and respiration decline throughout the time of the observations after irradiation, this depressing effect being much more remarkable for the first one. Net photosynthesis inhibition levels of about 30% have got only five hours post irradiation at a dose of 5000 Gy. (author)

  8. Designing of plant artificial chromosome (PAC) by using the Chlorella smallest chromosome as a model system.

    Science.gov (United States)

    Noutoshi, Y; Arai, R; Fujie, M; Yamada, T

    1997-01-01

    As a model for plant-type chromosomes, we have been characterizing molecular organization of the Chlorella vulgaris C-169 chromosome I. To identify chromosome structural elements including the centromeric region and replication origins, we constructed a chromosome I specific cosmid library and aligned each cosmid clones to generate contigs. So far, more than 80% of the entire chromosome I has been covered. A complete clonal physical reconstitution of chromosome I provides information on the structure and genomic organization of plant genome. We propose our strategy to construct an artificial chromosome by assembling the functional chromosome structural elements identified on Chrorella chromosome I.

  9. Lipids, fatty acids composition and carotenoids of Chlorella vulgaris cultivated in hydroponic wastewater

    Directory of Open Access Journals (Sweden)

    Barcelos Oliveira, Jorge Luiz

    2006-09-01

    Full Text Available Alternative culture media have been evaluated for the cultivation of microalgae, among them are, industrial and agriculture wastewaters, that make residue recycling possible by bioconverting it into a rich, nourishing biomass that can be used as a feeding complement in aquaculture and in diverse areas. The objective of this research is to determine the lipid, fatty acid profile and carotenoid produced by the microalgae Chlorella vulgaris cultivated in a hydroponic wastewater, with different dilutions. The results showed that lipid contents did not present significant differences. Fatty acids were predominantly 16:0, 18:0, 18:1 and 18:3n-6. For total carotenoids, the dilution of hydroponic wastewater did not stimulate the production of these pigments. From this study, it was determined that, the use of hydroponic wastewater as an alternative culture medium for  the cultivation of Chlorella vulgaris generates good perspectives for lipid, fatty acid and carotenoid production.Medios de cultivo alternativos vienen siendo evaluados para el cultivo de microalgas, entre ellos, están los afluentes industriales y agrícolas, que posibilitan la reciclaje del residuo, bioconvirtiéndose en una biomasa enriquecida bajo el punto de vista nutricional, que puede ser utilizada como complemento alimenticio, para la acuacultura y en varias otras áreas de actuación. El presente trabajo tuvo como objetivo determinar los contenidos de lípidos, composición de ácidos grasos y carotenoides producidos por la microalga Chlorella vulgaris cultivada en solución hidropónica residual, con diferentes diluciones. Los resultados de los contenidos de lípidos totales no presentaron diferencia significativa. Los ácidos grasos predominantes fueron los 16:0, 18:0, 18:1 e 18:3n-6. Para los carotenoides totales, la dilución de la solución hidropónica residual no estimuló la producción de estos pigmentos por la microalga. La utilización de la solución hidrop

  10. Effect of gamma radiation on photosynthetic metabolism of Chlorella pyrenoidosa studied by 14CO2 assimilation

    International Nuclear Information System (INIS)

    Martin Moreno, C.; Fernandez Gonzalez, J.

    1983-01-01

    The effect of five dose of gamma radiation (10, 100, 500, 1000 and 5000 Gy) on photosynthetic activity and metabolism of the primary products of photosynthesis has been studied, on Chlorella pyrenoidoBa cultures, by 14 C O 2 assimilation. The photosynthetic assimilation rate is remarkably depressed after irradiation at 500, 1000 and 5000 Gy dose, which also produce a significant change in radioactivity distribution pattern of primary compounds from photosynthesis. No significant effects have been observed on photosynthetic metabolism after irradiation at 10 and 100 Gy. (Author) 19 refs

  11. Biodiesel Production from Chlorella protothecoides Oil by Microwave-Assisted Transesterification.

    Science.gov (United States)

    Gülyurt, Mustafa Ömer; Özçimen, Didem; İnan, Benan

    2016-04-22

    In this study, biodiesel production from microalgal oil by microwave-assisted transesterification was carried out to investigate its efficiency. Transesterification reactions were performed by using Chlorella protothecoides oil as feedstock, methanol, and potassium hydroxide as the catalyst. Methanol:oil ratio, reaction time and catalyst:oil ratio were investigated as process parameters affected methyl ester yield. 9:1 methanol/oil molar ratio, 1.5% KOH catalyst/oil ratio and 10 min were optimum values for the highest fatty acid methyl ester yield.

  12. Comparative metabolism of 54Mn, 59Fe, 60Co and 65Zn incorporated into Chlorella and in inorganic form in rats

    International Nuclear Information System (INIS)

    Inaba, J.; Nishimura, Y.; Ichikawa, R.

    1980-01-01

    The objective of this study was to compare the whole-body retention and tissue distribution in rats of 54 Mn, 59 Fe, 60 Co and 65 Zn incorporated into chlorella with those in inorganic form. Chlorella vulgaris was cultured in a nutrient solution with one of the radionuclides for 10 days. The chlorella was separated from the solution by centrifuge and was given to rats using a stomach tube. Control groups of rats were given the radionuclide alone or together with nonradioactive chlorella. The whole-body retention and tissue distribution of the radionuclide was determined with an Armac counter. The result revealed that rats dosed with 60 Co incorporated into chlorella absorbed and retained much more 60 Co than those given 60 Cl 2 mixed with nonradioactive chlorella or 60 Cl 2 alone. In the cases of 54 Mn, 59 Fe and 65 Zn, however, the difference in whole-body retention and tissue distribution between the chlorella radionuclides and the control radionuclides was not significant. (author)

  13. Chlorella induces stomatal closure via NADPH oxidase-dependent ROS production and its effects on instantaneous water use efficiency in Vicia faba.

    Directory of Open Access Journals (Sweden)

    Yan Li

    Full Text Available Reactive oxygen species (ROS have been established to participate in stomatal closure induced by live microbes and microbe-associated molecular patterns (MAMPs. Chlorella as a beneficial microorganism can be expected to trigger stomatal closure via ROS production. Here, we reported that Chlorella induced stomatal closure in a dose-and time-dependent manner in epidermal peels of Vicia faba. Using pharmacological methods in this work, we found that the Chlorella-induced stomatal closure was almost completely abolished by a hydrogen peroxide (H2O2 scavenger, catalase (CAT, significantly suppressed by an NADPH oxidase inhibitor, diphenylene iodonium chloride (DPI, and slightly affected by a peroxidase inhibitor, salicylhydroxamic acid (SHAM, suggesting that ROS production involved in Chlorella-induced stomatal closure is mainly mediated by DPI-sensitive NADPH oxidase. Additionally, Exogenous application of optimal concentrations of Chlorella suspension improved instantaneous water use efficiency (WUEi in Vicia faba via a reduction in leaf transpiration rate (E without a parallel reduction in net photosynthetic rate (Pn assessed by gas-exchange measurements. The chlorophyll fluorescence and content analysis further demonstrated that short-term use of Chlorella did not influence plant photosynthetic reactions center. These results preliminarily reveal that Chlorella can trigger stomatal closure via NADPH oxidase-dependent ROS production in epidermal strips and improve WUEi in leave levels.

  14. The effect of dietary Chlorella vulgaris inclusion on goat's milk chemical composition, fatty acids profile and enzymes activities related to oxidation.

    Science.gov (United States)

    Tsiplakou, E; Abdullah, M A M; Mavrommatis, A; Chatzikonstantinou, M; Skliros, D; Sotirakoglou, K; Flemetakis, E; Labrou, N E; Zervas, G

    2018-02-01

    The impact of dietary supplementation with microalgae on goat's milk chemical composition, fatty acids (FA) profile and enzymes activities related to antioxidant mechanism has not been well documented. Thus, this study aimed to investigate the effects of dietary inclusion of Chlorella vulgaris on the following: (i) milk yield, chemical composition and FA profile, (ii) the activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione transferase (GST) and glutathione peroxidase (GSH-Px) in blood plasma and (iii) the activities of SOD, GR and lactoperoxidase (LPO) in milk of goats. Furthermore, the oxidative stress indicators for measuring total antioxidant and free radical scavenging activity [ferric reducing ability of plasma (FRAP) and 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays] and oxidative stress biomarkers [malondialdehyde (MDA) and protein carbonyls (PC)] were also determined in blood plasma and milk of the animals. For this purpose, 16 cross-bred goats were divided into two homogenous groups. Each goat of both groups was fed individually with alfalfa hay and concentrates separately. The concentrates of the control group (Control) had no microalgae, while those of the Chlorella group were supplemented with 10 g lyophilized Chlorella vulgaris/kg concentrates (Chlorella). Thus, the average intake was 5.15 g Chlorella vulgaris/kg DM. The results showed that the dietary inclusion of Chlorella vulgaris had not noticeable impact on goat's milk yield, chemical composition and FA profile. Significantly higher SOD (by 10.31%) and CAT (by 18.66%) activities in the blood plasma of goats fed with Chlorella vulgaris compared with the control were found. Moreover, the dietary supplementation with Chlorella vulgaris caused a significant increase in SOD (by 68.84%) activity and a reduction in PC (by 24.07%) content in goat's milk. In conclusion, the Chlorella vulgaris inclusion in goat's diets improved the

  15. The Influence of Hepatitis C Virus Therapy on the DNA Base Excision Repair System of Peripheral Blood Mononuclear Cells.

    Science.gov (United States)

    Czarny, Piotr; Merecz-Sadowska, Anna; Majchrzak, Kinga; Jabłkowski, Maciej; Szemraj, Janusz; Śliwiński, Tomasz; Karwowski, Bolesław

    2017-07-01

    Hepatitis C virus (HCV) can infect extrahepatic tissues, including lymphocytes, creating reservoir of the virus. Moreover, HCV proteins can interact with DNA damage response proteins of infected cells. In this article we investigated the influence of the virus infection and a new ombitasvir/paritaprevir/ritonavir ± dasabuvir ± ribavirin (OBV/PTV/r ± DSV ± RBV) anti-HCV therapy on the PBMCs (peripheral blood mononuclear cells, mainly lymphocytes) DNA base excision repair (BER) system. BER protein activity was analyzed in the nuclear and mitochondrial extracts (NE and ME) of PBMC isolated from patients before and after therapy, and from subjects without HCV, using modeled double-strand DNA, with 2'-deoxyuridine substitution as the DNA damage. The NE and ME obtained from patients before therapy demonstrated lower efficacy of 2'-deoxyuridine removal and DNA repair polymerization than those of the control group or patients after therapy. Moreover, the extracts from the patients after therapy had similar activity to those from the control group. However, the efficacy of apurinic/apyrimidinic site excision in NE did not differ between the studied groups. We postulate that infection of lymphocytes by the HCV can lead to a decrease in the activity of BER enzymes. However, the use of novel therapy results in the improvement of glycosylase activity as well as the regeneration of endonuclease and other crucial repair enzymes.

  16. ECHO virus

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/001340.htm ECHO virus To use the sharing features on this page, please enable JavaScript. Enteric cytopathic human orphan (ECHO) viruses are a group of viruses that can lead ...

  17. Inhibition of growth and metabolism of Chlorella and some other plant types by calcium dipicrylamine and other poisons

    NARCIS (Netherlands)

    Bierhuizen, J.F.

    1957-01-01

    If potassium is obtained from sea-water by precipitation with calcium dipicrylamine, potassium fertilizers and sea-water will be contaminated with a little dipicrylamine. The influence of calcium dipicrylamine on metabolism of Chlorella and some other aquatic and terrestrial plants was

  18. Structural Analysis of a Polysaccharide from Chlorella kessleri by Means of Gas Chromatography-Mass Spectrometry of Its Saccharide Alditols

    Czech Academy of Sciences Publication Activity Database

    Řezanka, Tomáš; Sigler, Karel

    2007-01-01

    Roč. 52, č. 3 (2007), s. 246-252 ISSN 0015-5632 Institutional research plan: CEZ:AV0Z50200510 Keywords : gas chromatographic * chlorella kessleri * oligosaccharide Subject RIV: EE - Microbiology, Virology Impact factor: 0.989, year: 2007

  19. Changes of the delayed fluorescence characteristics in Spirulina, Anabaena and Chlorella in response to chromatic adaptation and irradiance

    International Nuclear Information System (INIS)

    Znak, N.Y.; Morgun, V.N.

    1995-01-01

    Efficiency of the energy transformation for CO2 fixation (E), and kinetics of the initial O-2-mediated electron transport of Spirulina platensis (Gem. ) Geitl, and Chlorella vulgaris Beijerinck cells were measured after adaptation to various growth irradiances (I) by means of the delayed fluorescence (DF) induction curves. Maxima of the membrane potential expenses during induction period were observed at I half saturating oxygen evolution; they were shifted according to growth I remaining higher in Spirulina than in Chlorella. The alterations of absorbance and fluorescence spectra at 25 degrees C after adaptation to I demonstrated changes in composition of pigments of algae, created to compensate for the imbalance in radiation absorption between the two photosystems. For Spirulina cells, the value of E was higher after growing under low I, or under blue radiation absorbed mainly by photosystem (PS) 1 (400-500 nm) with excitation by yellow (570 nm) radiation. For Chlorella cells, it was also higher after growing under low I. Under such conditions the half-rise time for DP-phase of DF induction curve decreased, which reflected an acceleration of kinetics of the initial electron transport between photosystems. An opposite situation was observed with Spirulina cells grown under high I or yellow radiation, and Chlorella cells from high I. Enhancement of effective PS2/PS1 ratio associated with decrease of reaction centre (RC) 2/RC1 stoichiometry may because of the increase of E and high membrane energization under saturating I in algae adapted to low I

  20. Anaerobic co-digestion of chicken manure and microalgae Chlorella sp.: Methane potential, microbial diversity and synergistic impact evaluation.

    Science.gov (United States)

    Li, Ruirui; Duan, Na; Zhang, Yuanhui; Liu, Zhidan; Li, Baoming; Zhang, Dongming; Dong, Taili

    2017-10-01

    Anaerobic digestion (AD) is a promising alternative for livestock manure management. This paper presents the experimental results obtained through a batch experiment by using chicken manure (CM) and microalgae Chlorella sp. as co-substrates. The effect of co-digestion was evaluated by varying CM to Chlorella sp. ratios (0:10, 2:8, 4:6, 6:4, 8:2, 10: 0 based on the volatile solids (VS)). The major objective of this study is to evaluate the feasibility and synergistic impact of co-digestion of CM and Chlorella sp. Enhanced 14.20% and 76.86% methane production than CM and Chlorella sp. mono-digestion respectively was achieved in co-digestion at the ratio 8:2. In addition, the co-digestion at the ratio 8:2 showed significantly higher methane yield than the weighted average of the individual substrates' specific methane yield (WSMY), indicating strong synergy effect. The Illumina Miseq sequencing analysis showed that the AD process suppressed the acetoclastic methanogenesis Methanosaeta content; but partly enhanced hydrogenotrophic methanogenesis Methanosarcina, Methanospirillum and Methanobacterium, which was responsible for the methane production. The pre-treated microalgae was then introduced at the optimal ratio 8:2 to estimate the effect of pre-treatment of microalgae on AD process. However, the pre-treatment exhibited no positive effect. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Lipid Production of Heterotrophic Chlorella sp. from Hydrolysate Mixtures of Lipid-Extracted Microalgal Biomass Residues and Molasses.

    Science.gov (United States)

    Zheng, Hongli; Ma, Xiaochen; Gao, Zhen; Wan, Yiqin; Min, Min; Zhou, Wenguang; Li, Yun; Liu, Yuhuan; Huang, He; Chen, Paul; Ruan, Roger

    2015-10-01

    This study investigated the feasibility of lipid production of Chlorella sp. from waste materials. Lipid-extracted microalgal biomass residues (LMBRs) and molasses were hydrolyzed, and their hydrolysates were analyzed. Five different hydrolysate mixture ratios (w/w) of LMBRs/molasses (1/0, 1/1, 1/4, 1/9, and 0/1) were used to cultivate Chlorella sp. The results showed that carbohydrate and protein were the two main compounds in the LMBRs, and carbohydrate was the main compound in the molasses. The highest biomass concentration of 5.58 g/L, Y biomass/sugars of 0.59 g/g, lipid productivity of 335 mg/L/day, and Y lipids/sugars of 0.25 g/g were obtained at the hydrolysate mixture ratio of LMBRs/molasses of 1/4. High C/N ratio promoted the conversion of sugars into lipids. The lipids extracted from Chlorella sp. shared similar lipid profile of soybean oil and is therefore a potential viable biodiesel feedstock. These results showed that Chlorella sp. can utilize mixed sugars and amino acids from LMBRs and molasses to accumulate lipids efficiently, thus reducing the cost of microalgal biodiesel production and improving its economic viability.

  2. Selective extraction of intracellular components from the microalga Chlorella vulgaris by combined pulsed electric field-temperature treatment

    NARCIS (Netherlands)

    Postma, P.R.; Pataro, G.; Capitoli, M.; Barbosa, M.J.; Wijffels, R.H.; Eppink, M.H.M.; Olivieri, G.; Ferrari, G.

    2016-01-01

    The synergistic effect of temperature (25-65°C) and total specific energy input (0.55-1.11kWhkgDW -1) by pulsed electric field (PEF) on the release of intracellular components from the microalgae Chlorella vulgaris was studied. The combination of PEF with temperatures from

  3. Efficacy of Chlorella pyrenoidosa and Scenedesmus abundans for Nutrient Removal in Rice Mill Effluent (Paddy Soaked Water).

    Science.gov (United States)

    Abinandan, S; Bhattacharya, Ribhu; Shanthakumar, S

    2015-01-01

    Microalgae are product of sustainable development owing to its ability to treat variety of wastewater effluents and thus produced biomass can serve as value added product for various commercial applications. This paper deals with the cultivation of microalgae species namely Chlorella pyrenoidosa and Scenedesmus abundans in rice mill effluent (i.e., paddy soaked water) for nutrient removal. In order to investigate the nutrient removal capability, microalgae are subjected to cultivation in both raw and autoclaved samples. The maximum phosphate removal by Scenedesmus abundans and Chlorella pyrenoidosa in raw sample was 98.3% and 97.6%, respectively, whereas, the removal of ammoniacal nitrogen by Scenedesmus abundans and Chlorella pyrenoidosa in raw sample was 92% and 90.3%, respectively. The growth (measured in terms of chlorophyll content) of Scenedesmus abundans and Chlorella pyrenoidosa in raw sample was 3.88 mg/l and 5.55 mg/l, respectively. The results indicate the suitability of microalgae cultivation in rice mill effluent treatment for nutrient removal.

  4. Subcritical Water Technology for Extraction of Phenolic Compounds from Chlorella sp. Microalgae and Assessment on Its Antioxidant Activity.

    Science.gov (United States)

    Zakaria, Siti Maisurah; Kamal, Siti Mazlina Mustapa; Harun, Mohd Razif; Omar, Rozita; Siajam, Shamsul Izhar

    2017-07-03

    Chlorella sp . microalgae is a potential source of antioxidants and natural bioactive compounds used in the food and pharmaceutical industries. In this study, a subcritical water (SW) technology was applied to determine the phenolic content and antioxidant activity of Chlorella sp . This study focused on maximizing the recovery of Chlorella sp. phenolic content and antioxidant activity measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay as a function of extraction temperature (100-250 °C), time (5-20 min) and microalgae concentration (5-20 wt. %) using response surface methodology. The optimal operating conditions for the extraction process were found to be 5 min at 163 °C with 20 wt. % microalgae concentration, which resulted in products with 58.73 mg gallic acid equivalent (GAE)/g phenolic content and 68.5% inhibition of the DPPH radical. Under optimized conditions, the experimental values were in close agreement with values predicted by the model. The phenolic content was highly correlated (R² = 0.935) with the antioxidant capacity. Results indicated that extraction by SW technology was effective and that Chlorella sp . could be a useful source of natural antioxidants.

  5. Formulation of a minimal nutritional medium for enhanced lipid productivity in Chlorella sp. and Botryococcus sp. using response surface methodology.

    Science.gov (United States)

    Vishwakarma, Rashi; Dhar, Dolly Wattal; Pabbi, Sunil

    2018-03-01

    Chlorella sp. MCC 7 and Botryococcus sp. MCC 31 were investigated to enable large-scale biodiesel production from minimal constituents in the growth medium. Response surface methodology (RSM) was used to maximise the biomass productivity and lipid yield using only nitrogen (N), phosphorus (P) and potassium (K) as urea, single super phosphate and muriate of potash. The optimum values were 0.42 g/L nitrogen; 0.14 g/L phosphorus and 0.22 g/L potassium for Chlorella sp.; and 0.46 g/L; 0.14 g/L and 0.25 g/L for Botryococcus sp. Lipid yield of 42% for Chlorella sp. and 52% in Botryococcus sp. was observed. An enhancement in lipid yield by approximately 55% for Chlorella sp. and 73% for Botryococcus sp. was registered as compared to original nutrient medium. Fourier transform infrared (FTIR) analysis of extracted lipids revealed characteristic bands for triglycerides. This study provided utilisation of a practicable nutrient recipe in the form of N, P, K input for enhanced lipid yield from the selected microalgal strains.

  6. Effects of DDT and BHC on amino acid content and its varieties in Chlorella vulgaris Beij. and Cladophora sp.

    Science.gov (United States)

    Lin, Yixiong

    1991-03-01

    In Chlorella vulgaris Beij. and Cladophora sp. treated with different concentrations of r-BHC and p, p-DDT, the protein and free amino acid content in both were higher than those in the controls, and the free amino acid content was even higher than the protein amino acid content.

  7. Enhanced accumulation of starch and total carbohydrates in alginate-immobilized Chlorella spp. induced by Azospirillum brasilense: II. Heterotrophic conditions.

    Science.gov (United States)

    Choix, Francisco J; de-Bashan, Luz E; Bashan, Yoav

    2012-10-10

    The effect of the bacterium Azospirillum brasilense jointly immobilized with Chlorella vulgaris or C. sorokiniana in alginate beads on total carbohydrates and starch was studied under dark and heterotrophic conditions for 144 h in synthetic growth medium supplemented with either d-glucose or Na-acetate as carbon sources. In all treatments, enhanced total carbohydrates and starch content per culture and per cell was obtained after 24h; only jointly immobilized C. vulgaris growing on d-glucose significantly increased total carbohydrates and starch content after 96 h. Enhanced accumulation of carbohydrate and starch under jointly immobilized conditions was variable with time of sampling and substrate used. Similar results occurred when the microalgae was immobilized alone. In both microalgae growing on either carbon sources, the bacterium promoted accumulation of carbohydrates and starch; when the microalgae were immobilized alone, they used the carbon sources for cell multiplication. In jointly immobilized conditions with Chlorella spp., affinity to carbon source and volumetric productivity and yield were higher than when Chlorella spp. were immobilized alone; however, the growth rate was higher in microalgae immobilized alone. This study demonstrates that under heterotrophic conditions, A. brasilense promotes the accumulation of carbohydrates in two strains Chlorella spp. under certain time-substrate combinations, producing mainly starch. As such, this bacterium is a biological factor that can change the composition of compounds in microalgae in dark, heterotrophic conditions. Copyright © 2012. Published by Elsevier Inc.

  8. Isolation and characterization of a virus (CvV-BW1 that infects symbiotic algae of Paramecium bursaria in Lake Biwa, Japan

    Directory of Open Access Journals (Sweden)

    Kasahara Masahiro

    2010-09-01

    Full Text Available Abstract Background We performed an environmental study of viruses infecting the symbiotic single-celled algae of Paramecium bursaria (Paramecium bursaria Chlorella virus, PBCV in Lake Biwa, the largest lake in Japan. The viruses detected were all Chlorella variabilis virus (CvV = NC64A virus. One of them, designated CvV-BW1, was subjected to further characterization. Results CvV-BW1 formed small plaques and had a linear DNA genome of 370 kb, as judged by pulsed-field gel electrophoresis. Restriction analysis indicated that CvV-BW1 DNA belongs to group H, one of the most resistant groups among CvV DNAs. Based on a phylogenetic tree constructed using the dnapol gene, CvV was classified into two clades, A and B. CvV-BW1 belonged to clade B, in contrast to all previously identified virus strains of group H that belonged to clade A. Conclusions We conclude that CvV-BW1 composes a distinct species within C. variabilis virus.

  9. Mixotrophic Chlorella sp. UJ-3 cultivation in the typical anaerobic fermentation effluents.

    Science.gov (United States)

    Huo, Shuhao; Kong, Miao; Zhu, Feifei; Zou, Bin; Wang, Feng; Xu, Ling; Zhang, Cunsheng; Huang, Daming

    2018-02-01

    The growth of mixotrophic Chlorella sp. UJ-3 cultivated in the three typical anaerobic fermentation effluents was investigated in this paper. The results showed that the microalgae grew best under intermediate light intensity for all the types of fermentation effluents. The butyrate type fermentation effluents induced the fastest growth rate for Chlorella sp. UJ-3, with a maximal cell concentration of 3.8×10 7  cells/mL. Under intermediate light intensity, the volatile fatty acids (VFAs) were almost depleted on the fifth day of the cultivation for all the three types of fermentation systems. The ratios of chlorophyll a/b were all increased for the three systems, indicating enhanced energy-capturing capability of the microalgae for photosynthesis after the VFAs were depleted. The highest lipid content was 25.4%dwt achieved in the butyrate type fermentation, and the fatty acid compositions were found to be considerably different for these three types of fermentation systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. PENGARUH STATUS GIZI AWAL DAN KONSUMSI CHLORELLA GROWTH FACTOR TERHADAP KELUHAN KLINIS PENDERITA DEMAM BERDARAH DENGUE

    Directory of Open Access Journals (Sweden)

    Gina Apriani

    2012-03-01

    Full Text Available 800x600 Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 The objective of this study was to analyze the effect of pre-nutritional status and consumption of Chlorella Growth Factor (CGF on symptom of Dengue Hemorrhagic Fever (DHF. Design of this study was a randomized clinical trial with 37 subjects of intervention group and 37 subjects of control group. The subjects were DHF in-patient of economic class of Karya Bhakti Hospital. The criteria for subjects were DHF in-patients (grade II and III, age ≥ 17 years, fever up to 7 days, serology Dengue Ig M (+, platelet 0.01 was not significant, but the effect CGF consumption was significant (pd the symptom severity of DHF. Further studies required for identify the actual bioactive components of CGF effects on DHF; and effect of selected nutritional biomarkers on DHF. Key words: Dengue Hemorrhagic Fever, pre-nutritional status, chlorella growth factor.

  11. Enhancement of Chlorella vulgaris growth and bioremediation ability of aquarium wastewater using diazotrophs.

    Science.gov (United States)

    Ali, Sayeda Mohammed; Nasr, Hoda Shafeek; Abbas, Wafaa Tawfik

    2012-08-15

    Treatment of aquarium wastewater represents an important process to clean and recycle wastewater to be safely returned to the environment, used for cultivation or to minimize the multiple renewal of water. Chlorella vulgaris was an important freshwater microalgae which used in wastewater treatment, and increasing its potential of treatment can be achieved with existence of N2-fixing bacteria. Co-culturing of Chlorella vulgaris with the diazotrophs, Azospirillum brasilense or Azotobacter chroococcum in three different media; aquarium wastewater (AWW), sterile enriched natural aquarium wastewater (GPM) and synthetic wastewater media (SWW) were studied. Biomass yield of the microalgae was estimated by determination of chlorophylls (a and b), total carotenoid and the dry weight of C. vulgaris. Also determination of ammonia, nitrite, phosphate and nitrate in the culture were done. The presence of diazotrophs significantly increased the biomass of C. vulgaris by increasing its microalgae pigments (chlorophylls a and b, and total carotenoids). The highest pigments percentage was reported due to addition of A. brasilense to C. vulgaris (18.3-133.5%) compared to A. chroococcum (23.9-56.9%). As well as increased dry weight from 12 to 50%. There was also improved removal of nitrate, nitrite, ammonia and phosphate; where, the highest removal percentage was reported due to addition of A. chroococcum to C. vulgaris (0.0-52%) compared to A. brasilense (0.6-16.4%). A. brasilense and A. chroococcum can support C. vulgaris biomass production and bioremediation activity in the aquarium to minimize the periodical water renewal.

  12. Redistribution of metabolic fluxes in Chlorella protothecoides by variation of media nitrogen concentration

    Directory of Open Access Journals (Sweden)

    Saratram Gopalakrishnan

    2015-12-01

    Full Text Available In this study, the Elementary Metabolite Unit (EMU algorithm was employed to calculate intracellular fluxes for Chlorella protothecoides using previously generated growth and mass spec data. While the flux through glycolysis remained relatively constant, the pentose phosphate pathway (PPP flux increased from 3% to 20% of the glucose uptake during nitrogen-limited growth. The TCA cycle flux decreased from 94% to 38% during nitrogen-limited growth while the flux of acetyl-CoA into lipids increased from 58% to 109% of the glucose uptake, increasing total lipid accumulation. Phosphoenolpyruvate carboxylase (PEPCase activity was higher during nitrogen-sufficient growth. The glyoxylate shunt was found to be partially active in both cases, indicating the nutrient nature has an impact on flux distribution. It was found that the total NADPH supply within the cell remained almost constant under both conditions. In summary, algal cells substantially reorganize their metabolism during the switch from carbon-limited (nitrogen-sufficient to nitrogen-limited (carbon-sufficient growth. Keywords: Microalgae, Biofuels, Chlorella, MFA, EMU algorithm

  13. Electrical Performance of Distribution Insulators with Chlorella vulgaris Growth on its Surface

    Directory of Open Access Journals (Sweden)

    Herbert Enrique Rojas Cubides

    2015-06-01

    Full Text Available This paper presents a study about electrical performance of ceramic and polymeric insulators bio-contaminated with alga Chlorella vulgaris. The performed tests involve ANSI 55-2 and ANSI 52-1 ceramic insulators and ANSI DS-15 polymeric insulators, all of them used in distribution systems of Colombia. Biological contamination of insulators is realized using a controlled environment chamber that adjusts the temperature, humidity and light radiation. The laboratory tests include measurements of flashover voltages and leakage currents and they were performed to determine how insulators are affected by biological contamination. After a series of laboratory tests, it was concluded that the presence of Chlorella vulgaris on the contaminated ceramic insulators reduces the wet flashover voltage up to 12% and increases their leakage currents up to 80%. On the other hand, for polymeric insulators the effect of algae growth on flashover voltages was not to strong, although the leakage currents increase up to 60%.

  14. Formation of elemental sulfur by Chlorella fusca during growth on L-cysteine ethylester

    Energy Technology Data Exchange (ETDEWEB)

    Krauss, F.; Schafer, W.; Schmidt, A.

    1984-01-01

    During growth on L-cysteine ethylester, Chlorella fusca (211-8b) accumulated a substance which contained bound sulfide, which could be liberated by reduction with dithioerythritol (DTE) as inorganic sulfide. This substance was extracted with hot methanol and purified by thin layer chromatography. This substance liberated free sulfide when incubated with mono- and dithiols, and thiocyanate was formed after heating with KCN. The isolated substance cochromatographed with authentic sulfur flower using different solvent systems for thin layer chromatography, high pressure liquid chromatography, and the identical spectrum with a relative ..beta..max at 263 nm was found. The chemical structure was confirmed by mass spectrometry showing a molecular weight of 256 m/e for the S/sub 8/ configuration. No labeled elemental sulfur was detected when the cells were grown on (/sup 35/S)sulfate and L-cysteine ethylester. C. fusca seems to have enzymes for the metabolism of elemental sulfur, since it disappeared after prolonged growth into the stationary phase. Cysteine was formed from O-acetyl-L-serine and elemental sulfur in the presence of thiol groups and purified cysteine synthase from spinach or Chlorella.

  15. Induction of Maltose Release by Light in the Endosymbiont Chlorella variabilis of Paramecium bursaria.

    Science.gov (United States)

    Shibata, Aika; Takahashi, Fumio; Kasahara, Masahiro; Imamura, Nobutaka

    2016-11-01

    The endosymbiotic green algae of Paramecium bursaria are known to release a photosynthate to the host cells. The endosymbiont Chlorella variabilis F36-ZK isolated in Japan releases maltose under acidic conditions, and such release requires both light and low pH. However, whether photosynthate release is due to light sensing by photoreceptors or is merely a consequence of active photosynthesis is unclear. Herein, we studied the effect of light on maltose release from C. variabilis F36-ZK; we measured maltose release using a combination of 1-phenyl-3-methyl-5-pyrazolone derivative and 14 C-tracer methods. Blue (450nm) or red (around 600nm) light was most effective to stimulate maltose release. This suggests that the photosynthetic pathway probably participates in maltose release, because the effective wavelength corresponds to the absorption spectrum of chlorophyll. Furthermore, maltose release was slightly affected by addition of a photosynthetic inhibitor, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, but was abolished by another inhibitor of photosynthesis, 2,5-dibromo-6-isopropyl-3-methyl-1,4-benzoquinone, suggesting that electron flow through photosystem I may be more involved in maltose release. Interestingly, starving F36-ZK cells cultured under prolonged dark conditions did not release maltose but retained their photosynthetic capacity. Our results thus show that maltose release is regulated by light and cellular conditions in endosymbiotic Chlorella. Copyright © 2016. Published by Elsevier GmbH.

  16. Enhanced methane production of Chlorella vulgaris and Chlamydomonas reinhardtii by hydrolytic enzymes addition

    International Nuclear Information System (INIS)

    Mahdy, Ahmed; Mendez, Lara; Ballesteros, Mercedes; González-Fernández, Cristina

    2014-01-01

    Highlights: • Methane production of microalgae biomass is hampered by their cell wall. • Pretreatment should be designed in accordance to the microalgae specie. • Fresh Chlamydomonas reinhardtii exhibited high anaerobic biodegradability. • Chlorella vulgaris anaerobic biodegradability was enhanced by 50% using protease pretreatment. - Abstract: The effect of enzymatic hydrolysis on microalgae organic matter solubilisation and methane production was investigated in this study. Even though both biomasses, Chlamydomonas reinhardtii and Chlorella vulgaris, exhibited similar macromolecular distribution, their cell wall composition provided different behaviors. The addition of carbohydrolase (Viscozyme) and protease (Alcalase) resulted in high carbohydrates and protein solubilisation on both biomasses (86–96%). Despite the high carbohydrate solubilisation with the carbohydrolase, methane production was enhanced by 14% for C. vulgaris, while hydrolyzed C. reinhardtii did not show any improvement. The addition of protease to C. reinhardtii increased methane production by 1.17-fold. The low enhancement achieved together with the inherent high biodegradability of this biomass would not justify the cost associated to the enzyme addition. On the other hand, C. vulgaris hydrolyzed with the protease resulted in 86% anaerobic biodegradability compared to 54% of the raw biomass. Therefore, the application of protease prior anaerobic digestion of C. vulgaris could be a promising approach to decrease the energetic input required for cell wall disruption

  17. Investigation of mixotrophic, heterotrophic, and autotrophic growth of Chlorella vulgaris under agricultural waste medium.

    Science.gov (United States)

    Mohammad Mirzaie, M A; Kalbasi, M; Mousavi, S M; Ghobadian, B

    2016-01-01

    Growth of Chlorella vulgaris and its lipid production were investigated under autotrophic, heterotrophic, and mixotrophic conditions. Cheap agricultural waste molasses and corn steep liquor from industries were used as carbon and nitrogen sources, respectively. Chlorella vulgaris grew remarkably under this agricultural waste medium, which resulted in a reduction in the final cost of the biodiesel production. Maximum dry weight of 2.62 g L(-1) was obtained in mixotrophic growth with the highest lipid concentration of 0.86 g L(-1). These biomass and lipid concentrations were, respectively, 140% and 170% higher than autotrophic growth and 300% and 1200% higher than heterotrophic growth. In mixotrophic growth, independent or simultaneous occurrence of autotrophic and heterotrophic metabolisms was investigated. The growth of the microalgae was observed to take place first heterotrophically to a minimum substrate concentration with a little fraction in growth under autotrophic metabolism, and then the cells grew more autotrophically. It was found that mixotrophic growth was not a simple combination of heterotrophic and autotrophic growth.

  18. Chlorella vulgaris Induces Apoptosis of Human Non-Small Cell Lung Carcinoma (NSCLC) Cells.

    Science.gov (United States)

    Zhang, Zhi-Dong; Liang, Kai; Li, Kun; Wang, Guo-Quan; Zhang, Ke-Wei; Cai, Lei; Zhai, Shui-Ting; Chou, Kuo-Chen

    2017-01-01

    Chlorella vulgaris (C. vulgaris), a unicellular green microalga, has been widely used as a food supplement and reported to have antioxidant and anticancer properties. The current study was designed to assess the cytotoxic, apoptotic, and DNA-damaging effects of C. vulgaris growth factor (CGF), hot water C. vulgaris extracts, inlung tumor A549 and NCI-H460 cell lines. A549 cells, NCI-H460 cells, and normal human fibroblasts were treated with CGF at various concentrations (0-300 μg/ml) for 24 hr. The comet assay and γH2AX assay showed DNA damage in A549 and NCI-H460 cells upon CGF exposure. Evaluation of apoptosis by the TUNEL assay and DNA fragmentation analysis by agarose gel electrophoresis showed that CGF induced apoptosis in A549 and NCI-H460 cells. Chlorella vulgaris hot water extract induced apoptosis and DNA damage in human lung carcinoma cells. CGF can thus be considered a potential cytotoxic or genotoxic drug for treatment of lung carcinoma. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  19. Modulation of Cell Cycle Profile by Chlorella vulgaris Prevents Replicative Senescence of Human Diploid Fibroblasts

    Directory of Open Access Journals (Sweden)

    Tayyebeh Saberbaghi

    2013-01-01

    Full Text Available In this study, the effects of Chlorella vulgaris (CV on replicative senescence of human diploid fibroblasts (HDFs were investigated. Hot water extract of CV was used to treat HDFs at passages 6, 15, and 30 which represent young, presenescence, and senescence ages, respectively. The level of DNA damage was determined by comet assay while apoptosis and cell cycle profile were determined using FACSCalibur flow cytometer. Our results showed direct correlation between increased levels of damaged DNA and apoptosis with senescence in untreated HDFs (P<0.05. Cell cycle profile showed increased population of untreated senescent cells that enter G0/G1 phase while the cell population in S phase decreased significantly (P<0.05. Treatment with CV however caused a significant reduction in the level of damaged DNA and apoptosis in all age groups of HDFs (P<0.05. Cell cycle analysis showed that treatment with CV increased significantly the percentage of senescent HDFs in S phase and G2/M phases but decreased the population of cells in G0/G1 phase (P<0.05. In conclusion, hot water extract of Chlorella vulgaris effectively decreased the biomarkers of ageing, indicating its potential as an antiageing compound.

  20. Form of inorganic carbon utilized for photosynthesis in Chlorella vulgaris 11h cells

    International Nuclear Information System (INIS)

    Miyachi, Shigetoh; Shiraiwa, Yoshihiro

    1979-01-01

    The rate of photosynthetic 14 CO 2 fixation in Chlorella vulgaris 11h cells in the presence of 0.55 mM NaH 14 CO 3 at pH 8.0 (20 0 C) was greatly enhanced by the addition of carbonic anhydrase (CA). However, when air containing 400 ppm 14 CO 2 was bubbled through the algal suspension, the rate of 14 CO 2 fixation immediately after the start of the bubbling was suppressed by CA. These effects of CA were observed in cells which had been grown in air containing 2% CO 2 (high-CO 2 cells) as well as those grown in ordinary air (containing 0.04% CO 2 , low-CO 2 cells). We therefore concluded that, irrespective of the CO 2 concentration given to the algal cells during growth, the active species of inorganic carbon absorbed by Chlorella cells is free CO 2 and they cannot utilize bicarbonate. The effects observed in the high-CO 2 cells were much more pronounced than those in the low-CO 2 cells. This difference was accounted for by the difference in the affinity for CO 2 in photosynthesis between the high- and low-CO 2 cells. (author)

  1. Efficient harvesting of marine Chlorella vulgaris microalgae utilizing cationic starch nanoparticles by response surface methodology.

    Science.gov (United States)

    Bayat Tork, Mahya; Khalilzadeh, Rasoul; Kouchakzadeh, Hasan

    2017-11-01

    Harvesting involves nearly thirty percent of total production cost of microalgae that needs to be done efficiently. Utilizing inexpensive and highly available biopolymer-based flocculants can be a solution for reducing the harvest costs. Herein, flocculation process of Chlorella vulgaris microalgae using cationic starch nanoparticles (CSNPs) was evaluated and optimized through the response surface methodology (RSM). pH, microalgae and CSNPs concentrations were considered as the main independent variables. Under the optimum conditions of microalgae concentration 0.75gdry weight/L, CSNPs concentration 7.1mgdry weight/L and pH 11.8, the maximum flocculation efficiency (90%) achieved. Twenty percent increase in flocculation efficiency observed with the use of CSNPs instead of the non-particulate starch which can be due to the more electrostatic interactions between the cationic nanoparticles and the microalgae. Therefore, the synthesized CSNPs can be employed as a convenient and economical flocculants for efficient harvest of Chlorella vulgaris microalgae at large scale. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Outdoor Growth Characterization of an Unknown Microalga Screened from Contaminated Chlorella Culture

    Directory of Open Access Journals (Sweden)

    Shuhao Huo

    2017-01-01

    Full Text Available Outdoor microalgae cultivation process is threatened by many issues, such as pest pollution and complex, changeable weather. Therefore, it is difficult to have identical growth rate for the microalgae cells and to keep their continuous growth. Outdoor cultivation requires the algae strains not only to have a strong ability to accumulate oil, but also to adapt to the complicated external environment. Using 18S rRNA technology, one wild strain Scenedesmus sp. FS was isolated and identified from the culture of Chlorella zofingiensis. Upon contamination by Scenedesmus sp., the species could quickly replace Chlorella zofingiensis G1 and occupy ecological niche in the outdoor column photobioreactors. The results indicated that Scenedesmus sp. FS showed high alkali resistance. It also showed that even under the condition of a low inoculum rate (OD680, 0.08, Scenedesmus sp. FS could still grow in the outdoor raceway pond under a high alkaline environment. Even under unoptimized conditions, the oil content of Scenedesmus sp. FS could reach more than 22% and C16–C18 content could reach up to 79.68%, showing that this species has the potential for the biodiesel production in the near future.

  3. Utilization of carbon dioxide in industrial flue gases for the cultivation of microalga Chlorella sp.

    Science.gov (United States)

    Kao, Chien-Ya; Chen, Tsai-Yu; Chang, Yu-Bin; Chiu, Tzai-Wen; Lin, Hsiun-Yu; Chen, Chun-Da; Chang, Jo-Shu; Lin, Chih-Sheng

    2014-08-01

    The biomass and lipid productivity of Chlorella sp. MTF-15 cultivated using aeration with flue gases from a coke oven, hot stove or power plant in a steel plant of the China Steel Corporation in Taiwan were investigated. Using the flue gas from the coke oven, hot stove or power plant for cultivation, the microalgal strain obtained a maximum specific growth rate and lipid production of (0.827 d(-1), 0.688 g L(-1)), (0.762 d(-1), 0.961 g L(-1)), and (0.728 d(-1), 0.792 g L(-1)), respectively. This study demonstrated that Chlorella sp. MTF-15 could efficiently utilize the CO₂, NOX and SO₂ present in the different flue gases. The results also showed that the growth potential, lipid production and fatty acid composition of the microalgal strain were dependent on the composition of the flue gas and on the operating strategy deployed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Biosorption of chromium from electroplating and galvanizing industrial effluents under extreme conditions using Chlorella vulgaris

    Directory of Open Access Journals (Sweden)

    G. Sibi

    2016-07-01

    Full Text Available Hexavalent chromium [Cr(VI] is a toxic oxidized form and an important metal pollutant in the water bodies. Biosorption of chromium(VI offers a potential alternative to conventional metal removal methods. Dried biomass of Chlorella vulgaris was used as biosorbent for the removal of Cr(VI from electroplating and galvanizing industry effluents as a function of biosorbent dosage, contact time, pH, salinity and initial metal ion concentration. Batch experiments were conducted for biosorption and the optimum conditions were 1 g/L biomass, 4 h contact time, pH 2 and 2.893 mS/cm of electrical conductivity. The chromium biosorption was strictly pH dependent with a maximum Cr removal of 63.2 mg/L at pH 2. Highest Cr removal at a concentration of 81.3 mg/L was observed at Electrical conductivity (EC value of 2.893 mS/cm. A comparison of Langmuir and Freundlich isotherm models revealed that Freundlich isotherm model fitted the experimental data based on R2, qmax and standard error values. The results suggest that C. vulgaris biomass could be considered a promising low-cost biosorbent for the removal of Cr(VI from electroplating and galvanizing industry effluents. Keywords: Biosorption, Chlorella vulgaris, Microalgae, Hexavalent chromium

  5. Fate of H2S during the cultivation of Chlorella sp. deployed for biogas upgrading.

    Science.gov (United States)

    González-Sánchez, Armando; Posten, Clemens

    2017-04-15

    The H 2 S may play a key role in the sulfur cycle among the biogas production by the anaerobic digestion of wastes and the biogas upgrading by a microalgae based technology. The biogas is upgraded by contacting with slightly alkaline aqueous microalgae culture, then CO 2 and H 2 S are absorbed. The dissolved H 2 S could limit or inhibit the microalgae growth. This paper evaluated the role of dissolved H 2 S and other sulfured byproducts under prevailing biogas upgrading conditions using a microalgal technology. At initial stages of batch cultivation the growth of Chlorella sp. was presumably inhibited by dissolved H 2 S. After 2 days, the sulfides were oxidized mainly by oxic chemical reactions to sulfate, which was later rapidly assimilated by Chlorella sp., allowing high growing rates. The fate of H 2 S during the microalgae cultivation at pH > 8.5 was assessed by a mathematical model where the pentasulfide, thiosulfate and sulfite were firstly produced and converted finally to sulfate for posterior assimilation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Biosorption characteristics of Spirulina and Chlorella cells to accumulate heavy metals

    Directory of Open Access Journals (Sweden)

    Kőnig-Péter Anikó

    2015-01-01

    Full Text Available The heavy metal biosorption of dried Chlorella vulgaris and Spirulina platensis-Spirulina maxima cells was studied under various experimental conditions. The effect of biosorbent dosage, pH, adsorption time, temperature, initial metal concentration on biosorption was studied. Biosorption process can be divided into two parts: the first part follows zero-order, the second part pseudo second-order kinetics. Characterization of biosorption equilibrium was evaluated with Langmuir and Dubinin-Radushkevich models using non-linear regression. The optimum pH range was found to be 5.0 − 6.0 for Pb(II and 4.0 − 6.0 for Cu(II and Cd(II adsorption. The maximum adsorption capacities for Pb(II, Cd(II and Cu(II were 144, 161 and 138 mg g-1 by Chlorella cells and 370, 201 and 165 by Spirulina cells, based on the experimental data. The same values for activated carbon were 86, 134 and 43 mg g-1, respectively.

  7. DRY BIOMASS OF FRESH WATER ALGAE OF CHLORELLA GENUS IN THE COMBINED FORAGES FOR LAYING HENS

    Directory of Open Access Journals (Sweden)

    SVETLANA GRIGOROVA

    2006-07-01

    Full Text Available Dry biomass of algae is a good source of nutrients and biologically active substances, which in the last years attracted the interest of the specialists in their search for natural, ecologically and healthy sound foods for the animals. The aim of the present study was to characterize the chemical composition and the nutritive value of the dry biomass of fresh water algae of Chlorella genus cultivated in Bulgaria and to establish its effect on the laying hen productivity and the morphological characteristics of the table eggs. The tested product was analyzed for its crude protein content – 55 % to available wet, crude fats – 9,6 %, crude fi bres – 6,4 %, xanthophylls – 0,6 g/kg, essential amino acids: lysine – 5,5 %, methionine – 1,2 %, triptophan – 1,2 %. Adding 2 % and 10 % of dry biomass of fresh water algae of Chlorella genus to the combined forages for laying hens led to the improvement of the bird productivity and the morphological characteristics of the eggs and the egg yolk pigmentation was more intensive by 2,5 units by the Roche’s scale.

  8. Kinetic studies and thermodynamics of oil extraction and transesterification of Chlorella sp. for biodiesel production.

    Science.gov (United States)

    Ahmad, A L; Yasin, N H Mat; Derek, C J C; Lim, J K

    2014-01-01

    In this work, a mixture of chloroform and methanol (1:1, v/v) was applied to oil extraction from Chlorella sp. at 30, 40, 50 and 60 degrees C for 150 min extraction times. Kinetic studies revealed that the values of n and the rate constants were found to depend strongly on temperature. The activation energy was Ea = 38.893 kJ/mol, and the activation thermodynamic parameters at 60 degrees C were ΔS≠ = -180.190 J/mol , ΔH≠ = 36.124k J/mol and ΔG≠ = 96.128k J/mol. Both ΔH and ΔS yielded positive values, whereas ΔG was negative at 60 degrees C, indicating that this process is endothermic, irreversible and spontaneous. The acidic transesterification process was also investigated by gas chromatographic analysis of the microalgae fatty acid methyl esters (biodiesel) at different temperatures and reaction times. The fatty acid profile indicated that the main components were palmitic, linoleic and linolenic acids. The concentration of linolenic acid increased and oleic acid decreased as the temperature increased. Two-hour transesterification is the best reaction time for biodiesel production because it produces the highest percentage of unsaturated fatty acids (74%). These results indicate the potential of Chlorella sp. to produce biodiesel of good quality.

  9. Stem cell survival is severely compromised by the thymidineanalog EdU (5-ethynyl-2'-deoxyuridine), an alternative to BrdU for proliferation assays and stem cell tracing

    DEFF Research Database (Denmark)

    Andersen, Ditte C; Skovrind, Ida; Christensen, Marlene Louise

    2013-01-01

    Stem cell therapy has opened up the possibility of treating numerous degenerating diseases. However, we are still merely at the stage of identifying appropriate sources of stem cells and exploring their full differentiation potential. Thus, tracking the stem cells upon in vivo engraftment...... and during in vitro co-culture is very important and is an area of research embracing many pitfalls. 5-Ethynyl-2'-deoxyuridine (EdU), a rather new thymidine analog incorporated into DNA, has recently been suggested to be a novel highly valid alternative to other dyes for labeling of stem cells and subsequent...... tracing of their proliferation and differentiation ability. However, our results herein do not at any stage support this recommendation, since EdU severely reduces the viability of stem cells. Accordingly, we found that transplanted EdU-labeled stem cells hardly survive upon in vivo transplantation...

  10. On the uptake and binding of uranium (VI) by the green alga Chlorella Vulgaris; Zur Aufnahme und Bindung von Uran(VI) durch die Gruenalge Chlorella Vulgaris

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, Manja

    2011-07-01

    Uranium could be released into the environment from geogenic deposits and from former mining and milling areas by weathering and anthropogenic activities. The elucidation of uranium behavior in geo- and biosphere is necessary for a reliable risk assessment of radionuclide migration in the environment. Algae are widespread in nature and the most important group of organisms in the aquatic habitat. Because of their ubiquitous occurrence in nature the influence of algae on the migration process of uranium in the environment is of fundamental interest e.g. for the development of effective and economical remediation strategies for contaminated waters. Besides, algae are standing at the beginning of the food chain and play an economically relevant role as food and food additive. Therefore the transfer of algae-bound uranium along the food chain could arise to a serious threat to human health. Aim of this work was the quantitative and structural characterization of the interaction between U(VI) and the green alga Chlorella vulgaris in environmental relevant concentration and pH range with special emphasis on metabolic activity. Therefore a defined medium was created which assures the survival/growth of the algae as well as the possibility to predict the uranium speciation. The speciation of uranium in the mineral medium was calculated and experimentally verified by time-resolved laser-induced fluorescence spectroscopy (TRLFS). The results of the sorption experiments showed that both metabolic active and inactive algal cells bind uranium in significant amounts of around 14 mg U/g dry biomass and 28 mg U/g dry biomass, respectively. Another interesting observation was made during the growth of Chlorella cells in mineral medium at the environmental relevant uranium concentration of 5 {mu}M. Under these conditions and during ongoing cultivation a mobilization of the algae-bound uranium occurred. At higher uranium concentrations this effect was not observed due to the die off

  11. Mapping the active site of vaccinia virus RNA triphosphatase

    International Nuclear Information System (INIS)

    Gong Chunling; Shuman, Stewart

    2003-01-01

    The RNA triphosphatase component of vaccinia virus mRNA capping enzyme (the product of the viral D1 gene) belongs to a family of metal-dependent phosphohydrolases that includes the RNA triphosphatases of fungi, protozoa, Chlorella virus, and baculoviruses. The family is defined by two glutamate-containing motifs (A and C) that form the metal-binding site. Most of the family members resemble the fungal and Chlorella virus enzymes, which have a complex active site located within the hydrophilic interior of a topologically closed eight-stranded β barrel (the so-called ''triphosphate tunnel''). Here we queried whether vaccinia virus capping enzyme is a member of the tunnel subfamily, via mutational mapping of amino acids required for vaccinia triphosphatase activity. We identified four new essential side chains in vaccinia D1 via alanine scanning and illuminated structure-activity relationships by conservative substitutions. Our results, together with previous mutational data, highlight a constellation of six acidic and three basic amino acids that likely compose the vaccinia triphosphatase active site (Glu37, Glu39, Arg77, Lys107, Glu126, Asp159, Lys161, Glu192, and Glu194). These nine essential residues are conserved in all vertebrate and invertebrate poxvirus RNA capping enzymes. We discerned no pattern of clustering of the catalytic residues of the poxvirus triphosphatase that would suggest structural similarity to the tunnel proteins (exclusive of motifs A and C). We infer that the poxvirus triphosphatases are a distinct lineage within the metal-dependent RNA triphosphatase family. Their unique active site, which is completely different from that of the host cell's capping enzyme, recommends the poxvirus RNA triphosphatase as a molecular target for antipoxviral drug discovery

  12. Interactive Effects of Temperature and UV Radiation on Photosynthesis of Chlorella Strains from Polar, Temperate and Tropical Environments: Differential Impacts on Damage and Repair

    Science.gov (United States)

    Wong, Chiew-Yen; Teoh, Ming-Li; Phang, Siew-Moi; Lim, Phaik-Eem; Beardall, John

    2015-01-01

    Global warming and ozone depletion, and the resulting increase of ultraviolet radiation (UVR), have far-reaching impacts on biota, especially affecting the algae that form the basis of the food webs in aquatic ecosystems. The aim of the present study was to investigate the interactive effects of temperature and UVR by comparing the photosynthetic responses of similar taxa of Chlorella from Antarctic (Chlorella UMACC 237), temperate (Chlorella vulgaris UMACC 248) and tropical (Chlorella vulgaris UMACC 001) environments. The cultures were exposed to three different treatments: photosynthetically active radiation (PAR; 400–700 nm), PAR plus ultraviolet-A (320–400 nm) radiation (PAR + UV-A) and PAR plus UV-A and ultraviolet-B (280–320 nm) radiation (PAR + UV-A + UV-B) for one hour in incubators set at different temperatures. The Antarctic Chlorella was exposed to 4, 14 and 20°C. The temperate Chlorella was exposed to 11, 18 and 25°C while the tropical Chlorella was exposed to 24, 28 and 30°C. A pulse-amplitude modulated (PAM) fluorometer was used to assess the photosynthetic response of microalgae. Parameters such as the photoadaptive index (Ek) and light harvesting efficiency (α) were determined from rapid light curves. The damage (k) and repair (r) rates were calculated from the decrease in ΦPSIIeff over time during exposure response curves where cells were exposed to the various combinations of PAR and UVR, and fitting the data to the Kok model. The results showed that UV-A caused much lower inhibition than UV-B in photosynthesis in all Chlorella isolates. The three isolates of Chlorella from different regions showed different trends in their photosynthesis responses under the combined effects of UVR (PAR + UV-A + UV-B) and temperature. In accordance with the noted strain-specific characteristics, we can conclude that the repair (r) mechanisms at higher temperatures were not sufficient to overcome damage caused by UVR in the Antarctic Chlorella strain

  13. Interactive Effects of Temperature and UV Radiation on Photosynthesis of Chlorella Strains from Polar, Temperate and Tropical Environments: Differential Impacts on Damage and Repair.

    Directory of Open Access Journals (Sweden)

    Chiew-Yen Wong

    Full Text Available Global warming and ozone depletion, and the resulting increase of ultraviolet radiation (UVR, have far-reaching impacts on biota, especially affecting the algae that form the basis of the food webs in aquatic ecosystems. The aim of the present study was to investigate the interactive effects of temperature and UVR by comparing the photosynthetic responses of similar taxa of Chlorella from Antarctic (Chlorella UMACC 237, temperate (Chlorella vulgaris UMACC 248 and tropical (Chlorella vulgaris UMACC 001 environments. The cultures were exposed to three different treatments: photosynthetically active radiation (PAR; 400-700 nm, PAR plus ultraviolet-A (320-400 nm radiation (PAR + UV-A and PAR plus UV-A and ultraviolet-B (280-320 nm radiation (PAR + UV-A + UV-B for one hour in incubators set at different temperatures. The Antarctic Chlorella was exposed to 4, 14 and 20°C. The temperate Chlorella was exposed to 11, 18 and 25°C while the tropical Chlorella was exposed to 24, 28 and 30°C. A pulse-amplitude modulated (PAM fluorometer was used to assess the photosynthetic response of microalgae. Parameters such as the photoadaptive index (Ek and light harvesting efficiency (α were determined from rapid light curves. The damage (k and repair (r rates were calculated from the decrease in ΦPSIIeff over time during exposure response curves where cells were exposed to the various combinations of PAR and UVR, and fitting the data to the Kok model. The results showed that UV-A caused much lower inhibition than UV-B in photosynthesis in all Chlorella isolates. The three isolates of Chlorella from different regions showed different trends in their photosynthesis responses under the combined effects of UVR (PAR + UV-A + UV-B and temperature. In accordance with the noted strain-specific characteristics, we can conclude that the repair (r mechanisms at higher temperatures were not sufficient to overcome damage caused by UVR in the Antarctic Chlorella strain

  14. Cost effective and economic method for cultivation of Chlorella pyrenoidosa for the simultaneous treatment of biogas digester wastewater and biogas production

    OpenAIRE

    Rohit Sharma; Avanish K Tiwari; G. Sanjay Kumar; Bhawna Y. Lamba

    2015-01-01

    Microalgae have recently received a lot of attention as a new biomass source for the production of bio fuels and for the treatment of waste water. In this work, Chlorella pyrenoidosa was cultivated in biogas digester wastewater. The growth kinetics of the algae as well as the bio-remediation effect on the waste water was studied. The Chlorella pyrenoidosa can utilize the nitrogen content present in biogas digester wastewater as a substrate for its growth. The growth of microalgae was found to...

  15. Teor de clorofila e perfil de sais minerais de Chlorella vulgaris cultivada em solução hidropônica residual Chlorophyll content and minerals profile in the microalgae Chlorella vulgaris cultivated in hydroponic wastewater

    Directory of Open Access Journals (Sweden)

    Fabiano Cleber Bertoldi

    2008-02-01

    Full Text Available O cultivo de microalgas representa uma potencial fonte de biomassa rica em clorofila e sais minerais como: fósforo, ferro, manganês, cobre, zinco, magnésio e cálcio. Este experimento teve como objetivo avaliar a composição de minerais, bem como determinar o teor de clorofila a e b da microalga Chlorella vulgaris cultivada em solução hidropônica residual em três diferentes concentrações comparadas com um cultivo controle. Os resultados mostraram que os teores de clorofila a e b da microalga não apresentaram diferença significativa entre os cultivos. Com relação à composição dos sais minerais, a Chlorella cultivada na solução residual mais concentrada apresentou valores superiores quando comparada com a cultivada nos demais cultivos. Dessa forma, a biomassa da Chlorella vulgaris demonstrou ser uma potencial fonte de clorofila e de sais minerais, quando cultivada em solução hidropônica residual, possibilitando a utilização desse resíduo de forma sustentável.The microalgaes cultive represents a potential source of biomass rich in chlorophyll and minerals as: P, Fe, Mn, Cu, Zn, Mg and Ca. This research was aimed at evaluating the composition of minerals, as well as, determining the content of chlorophyll a and b from the microalgae Chlorella vulgaris cultivated in hydroponic wastewater in three different concentrations compared with the control cultive. The results showed that the contents of chlorophyll a and b of the microalgae did not show significant difference between the cultives. In relation to the composition of the minerals, the Chlorella cultivated in the most concentrated wastewater, showed higher values when compared with the one cultivated in the others cultures. In this manner, the Chlorella vulgaris biomass demonstrated to be a potential source of chlorophyll and minerals, when cultivated in hydroponic wastewater, allowing the use of this residue in a sustainable way.

  16. Beech wood Fagus sylvatica dilute-acid hydrolysate as a feedstock to support Chlorella sorokiniana biomass, fatty acid and pigment production.

    Science.gov (United States)

    Miazek, Krystian; Remacle, Claire; Richel, Aurore; Goffin, Dorothee

    2017-04-01

    This work evaluates the possibility of using beech wood (Fagus sylvatica) dilute-acid (H 2 SO 4 ) hydrolysate as a feedstock for Chlorella sorokiniana growth, fatty acid and pigment production. Neutralized wood acid hydrolysate, containing organic and mineral compounds, was tested on Chlorella growth at different concentrations and compared to growth under phototrophic conditions. Chlorella growth was improved at lower loadings and inhibited at higher loadings. Based on these results, a 12% neutralized wood acid hydrolysate (Hyd12%) loading was selected to investigate its impact on Chlorella growth, fatty acid and pigment production. Hyd12% improved microalgal biomass, fatty acid and pigment productivities both in light and in dark, when compared to photoautotrophic control. Light intensity had substantial influence on fatty acid and pigment composition in Chlorella culture during Hyd12%-based growth. Moreover, heterotrophic Chlorella cultivation with Hyd12% also showed that wood hydrolysate can constitute an attractive feedstock for microalgae cultivation in case of lack of light. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Removal of Nitrate and Phosphate from Municipal Wastewater Sludge by Chlorella vulgaris, Spirulina platensis and Scenedesmus quadricauda

    Directory of Open Access Journals (Sweden)

    Jalal K.C.A

    2011-12-01

    Full Text Available Nitrate and phosphorus in wastewater contribute to health and environmental threats as they are linked to illnesses as well as ecosystem disruption via algal blooms in contaminated water bodies. Based on above perspectives a comparative study was conducted on three local freshwater microalgae:Chlorella vulgaris, Spirulina platensis and Scenedesmus quadricauda to evaluate their effects on nitrate and phosphorus removal from municipal wastewater sludge (MWS. Algae performance in removing nitrate and phosphorus was evaluated by measuring nitrate and phosphorus content of MWS incubated with the strains for 7 days. Instantaneous readings were taken every 48 hours to determine periodic levels of the nutrients phosphate and nitrate. BOD5 was also evaluated to identify the strain with the most robust growth that would demand for oxygen the most in the dark. Spirulina platensis was shown as the most efficient microalgae to reduce nitrate in MWS and the best-growing among the three strains, while Chlorella vulgaris removed phosphorus the most effectively. Thus Spirulina and Chlorella could be potential candidates by showing their intrinsic merit for the reduction of phosphate and nitrate in wastewater treatment.ABSTRAK: Nitrat dan fosforus dalam air sisa menggugat kesihatan dan mengancam alam sekitar memandangkan ia berkait dengan penyakit-penyakit serta gangguan terhadap ekosistem melalui pembiakan alga dalam air yang tercemar. Berdasarkan perspektif di atas, satu kajian perbandingan telah dijalankan terhadap tiga mikro alga air tawar tempatan : Chlorella vulgaris, Spirulina platensis dan Scenedesmus quadricauda untuk dinilai kesannya terhadap penyingkiran nitrat dan fosforus dari enap cemar air sisa bandaran (municipal wastewater sludge (MWS. Kebolehan alga dalam penyingkiran nitrat dan fosforus dikaji dengan menyukat kandungan nitrat dan fosforus dalam MWS yang dieramkan dengan strain ini selama 7 hari. Bacaan serta-merta diambil setiap 48 jam untuk

  18. Mild disintegration of the green microalgae Chlorella vulgaris using bead milling.

    Science.gov (United States)

    Postma, P R; Miron, T L; Olivieri, G; Barbosa, M J; Wijffels, R H; Eppink, M H M

    2015-05-01

    In this work, the mild disintegration of the microalgae Chlorella vulgaris for the release of intracellular products has been studied. By means of bead milling the microalgae suspensions were successfully disintegrated at different biomass concentrations (25-145 gDW kg(-1)) over a range of agitator speeds (6-12 m s(-1)). In all cases over 97% of cell disintegration was achieved resulting in a release of water soluble proteins. A clear optimum rate of disintegration and protein release was observed at an agitator speed of 9-10 m s(-1) regardless of the biomass concentration. Selective extraction of water soluble proteins was observed as proteins released sooner than cell disintegration took place. Proteins could be released at 85% lower energy input than for cell disintegration resulting in specific energy consumptions well below 2.5 kWh kgDW(-1). Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Composition of the sheath produced by the green alga Chlorella sorokiniana.

    Science.gov (United States)

    Watanabe, K; Imase, M; Sasaki, K; Ohmura, N; Saiki, H; Tanaka, H

    2006-05-01

    To investigate the chemical characterization of the mucilage sheath produced by Chlorella sorokiniana. Algal mucilage sheath was hydrolysed with NaOH, containing EDTA. The purity of the hydrolysed sheath was determined by an ATP assay. The composition of polysaccharide in the sheath was investigated by high-performance anion-exchange chromatography with pulsed amperometric detection. Sucrose, galacturonic acid, xylitol, inositol, ribose, mannose, arabinose, galactose, rhamnose and fructose were detected in the sheath as sugar components. Magnesium was detected in the sheath as a divalent cation using inductively coupled argon plasma. The sheath matrix also contained protein. It appears that the sheath is composed of sugars and metals. Mucilage sheath contains many kinds of saccharides that are produced as photosynthetic metabolites and divalent cations that are contained in the culture medium. This is the first report on chemical characterization of the sheath matrix produced by C. sorokiniana.

  20. Development by flow cytometry of bioassays based on chlorella for environmental monitoring

    Directory of Open Access Journals (Sweden)

    Petrescu C-M,

    2016-05-01

    Full Text Available In ecotoxicological assessments, bioassays (ecotoxicity tests or biotests are one of the main tools, defined as methods which use living cells, tissues, organism or communities to assess exposure-related effects of chemicals. The increasing complexity of environmental degradation requires an increase in the capacity of scientific approach in monitoring and notification as early as possible risks. Our own objective concerns the detection of aquatic environment pollution in Romania and particularly in the Danube basin. For assessing aquatic environment pollution degree or for assessing cytotoxicity or ecotoxicity of pollutants (heavy metals, nanoparticles, pesticides, etc. we developed news experimental bioassays based on the use of viability and apoptosis biomarkers of Chlorella cells by flow cytometry. Our proposed bioassays could be rapid and very sensitive tests for in laboratory aquatic risk assessment and biomonitoring.

  1. Infecção disseminada por Chlorella sp. em um ovino

    Directory of Open Access Journals (Sweden)

    Everton Ferreira Lima

    2014-07-01

    Full Text Available Descreve-se um caso de infecção disseminada por Chlorella sp. em um ovino, na região semiárida da Paraíba, Brasil. O animal apresentou emagrecimento e aumento de volume abdominal há um mês. Na necropsia, foram observados nódulos esverdeados em fígado, pulmões, intestino e linfonodos. Histologicamente, os nódulos correspondiam a piogranulomas com miríades de algas intralesionais. Provavelmente, a infecção tenha ocorrido em consequência do consumo de água estagnada ou capim que tinha sido cortado em uma área irrigada, que são condições frequentes no período da seca na região semiárida.

  2. Reasons of chlorella strain's resistance to physical and chemical factors of environment

    Energy Technology Data Exchange (ETDEWEB)

    Apasheva, L M; Bujiashvilie, D M; Naydich, V I; Shevchenko, V A

    1979-07-01

    Under environmental pollution it is necessary to study the reasons of an organism's resistance as well as the specificity of it. Some chlorella strains were under the influence of uv- and x-irradiation, heat treatment, cadmium salts, insecticide, and detergent. It was shown that cells which were resistant to physical factors were resistant to chemical intoxication, as well. The positive correlation between resistance of strains and the described influences and the levels of endogenic thiols was found. The second reason for higher resistance is an increase of free radicals' concentration. It is linked with increasing P/sub 700/ quantity of electron-transport chains that make possible higher levels of photosynthetic reactions of resistant cells.

  3. [Effects of different trophic modes on growth characteristics, metabolism and cellular components of Chlorella vulgaris].

    Science.gov (United States)

    Kong, Weibao; Wang, Yang; Yang, Hong; Xi, Yuqin; Han, Rui; Niu, Shiquan

    2015-03-04

    We studied the effects of trophic modes related to glucose and light (photoautotrophy, mixotrophy and heterotrophy) on growth, cellular components and carbon metabolic pathway of Chlorella vulgaris. The parameters about growth of algal cells were investigated by using spectroscopy and chromatography techniques. When trophic mode changed from photoautotrophy to mixotrophy and to heterotrophy successively, the concentrations of soluble sugar, lipid and saturated C16/C18 fatty acids in C. vulgaris increased, whereas the concentrations of unsaturated C16, C18 fatty acids, proteins, photosynthetic pigments and 18 relative amino acids decreased. Light and glucose affect the growth, metabolism and the biochemical components biosynthesis of C. vulgaris. Addition of glucose can promote algal biomass accumulation, stimulate the synthesis of carbonaceous components, but inhibit nitrogenous components. Under illumination cultivation, concentration and consumption level of glucose decided the main trophic modes of C. vulgaris. Mixotrophic and heterotrophic cultivation could promote the growth of algal cells.

  4. Unstable pigment mutants of Chlorella vulgaris B. as induced by UV irradiation

    International Nuclear Information System (INIS)

    Chankova, S.; Vinarova, K.

    1987-01-01

    The dynamics of arising of unstable 'segregating' pigment mutants of Chlorella vulgaris B. has been investigated in dependence on the dose of UV-rays applied and the macro- and microstructural changes taking place. The mutants are found to occur with a low frequency, irrespective of the dose applied and the presence or absence of photo-reactivation. A constantly recurring process of decomposition into two subclones is observed: light green (unstable) and yellow-green (stable). The existence of two cellular populations - structurally damaged and structurally undamaged - in the light-green unstable subclone has been demonstrated. There exists a qualitative and a quantitative correlation between the structural deformations in the cell and the dose with which the unstable pigment mutants are induced. Disturbances in the cell division are observed,resulting in delayed growth rate and the formation of small colonies

  5. Effect of moderate static electric field on the growth and metabolism of Chlorella vulgaris.

    Science.gov (United States)

    Nezammahalleh, Hassan; Ghanati, Faezeh; Adams, Thomas A; Nosrati, Mohsen; Shojaosadati, Seyed Abbas

    2016-10-01

    An electric field (EF) generator device was fabricated and applied to the treatment of Chlorella vulgaris ISC33 at three distinct concentrations before cultivation. The EF of moderate intensity (2.7kVcm(-1)) has a hormetic effect on algal growth. The highest growth stimulation of 51% was observed after 50min treatment of 0.4gL(-1) algal suspension. The influence of EF on the system was then studied from both theoretical and experimental perspectives. The growth rate increased with treatment time up to a maximum because of improved membrane permeability, and then declined afterwards due to peroxide accumulation in the medium. The contents of chlorophylls, carotenoids, soluble carbohydrates, lipids, and proteins were also measured to understand possible changes on algal metabolism. The EF treatment of algal suspension has no observable effect on the cell metabolism while both algal growth and metabolism was significantly affected by the inoculum size. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Effect of isomers of hydroxybenzoic acid on the growth and metabolism of Chlorella vulgaris Beijerinck (Chlorophyceae

    Directory of Open Access Journals (Sweden)

    Andrzej Bajguz

    2014-01-01

    Full Text Available The isomers o-, m-, and p- of hydroxybenzoic acid (HBA in the concentration range 10-1-10-4 M in the unicellular green alga Chlorella vulgaris (Chlorophyceae display marked biological activity. The o-HBA isomer, commonly known as salicylic acid, in a concentration of 10-4 M exerted the most stimulating effect on the parameters analysed (the number of cells, dry mass, the content of chlorophylls a and h, carotenoids, soluble proteins and their secretion, monosaccharides, DNA and RNA whereas p-HBA had weak stimulating properties. On the other hand, m-HBA had a weak inhibitory effect on the growth of C. vulgaris and all the biochemical parameters analysed in comparison with the control culture of algae devoid of HBA isomers.

  7. Lipid accumulation from pinewood pyrolysates by Rhodosporidium diobovatum and Chlorella vulgaris for biodiesel production.

    Science.gov (United States)

    Luque, Luis; Orr, Valerie C A; Chen, Sean; Westerhof, Roel; Oudenhoven, Stijn; Rossum, Guus van; Kersten, Sascha; Berruti, Franco; Rehmann, Lars

    2016-08-01

    This study evaluated the suitability of pinewood pyrolysates as a carbon source for lipid production and cultivation of the oleaginous yeast Rhodosporidium diobovatum and the microalgae Chlorella vulgaris. Thermal decomposition of pinewood and fractional condensation were used to obtain an oil rich in levoglucosan which was upgraded to glucose by acid hydrolysis. Blending of pyrolytic sugars with pure glucose in both nitrogen rich and nitrogen limited conditions was studied for R. diobovatum, and under nitrogen limited conditions for C. vulgaris. Glucose consumption rate decreased with increasing proportions of pyrolytic sugars increasing cultivation time. While R. diobovatum was capable of growth in 100% (v/v) pyrolytic sugars, C. vulgaris growth declined rapidly in blends greater than 20% (v/v) until no growth was detected in blends >40%. Finally, the effects of pyrolysis sugars on lipid composition was evaluated and biodiesel fuel properties were estimated based on the lipid profiles. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Photosynthetic light reactions increase total lipid accumulation in carbon-supplemented batch cultures of Chlorella vulgaris.

    Science.gov (United States)

    Woodworth, Benjamin D; Mead, Rebecca L; Nichols, Courtney N; Kolling, Derrick R J

    2015-03-01

    Microalgae are an attractive biofuel feedstock because of their high lipid to biomass ratios, lipid compositions that are suitable for biodiesel production, and the ability to grow on varied carbon sources. While algae can grow autotrophically, supplying an exogenous carbon source can increase growth rates and allow heterotrophic growth in the absence of light. Time course analyses of dextrose-supplemented Chlorella vulgaris batch cultures demonstrate that light availability directly influences growth rate, chlorophyll production, and total lipid accumulation. Parallel photomixotrophic and heterotrophic cultures grown to stationary phase reached the same amount of biomass, but total lipid content was higher for algae grown in the presence of light (an average of 1.90 mg/mL vs. 0.77 mg/mL over 5 days of stationary phase growth). Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. OPTIMIZATION OF CELL DISRUPTION IN RAPHIDOCELIS SUBCAPITATA AND CHLORELLA VULGARIS FOR BIOMARKER EVALUATION

    Directory of Open Access Journals (Sweden)

    Adeolu Aderemi

    2015-06-01

    Full Text Available Raphidocelis subcapitata and Chlorella vulgaris are bioassay microalgae with rigid cellulosic cell wall which can hinder the release of intracellular proteins often studied as toxicity biomarkers. Since cell disruption is necessary for recovering intracellular biomolecules in these organisms, this study investigated the efficiency of ultrasonication bath; ultrasonication probe; vortexer; and bead mill in disintegrating the microalgae for anti-oxidative enzyme extraction. The extent of cell disruption was evaluated and quantified using bright field microscopy. Disrupted algae appeared as ghosts. The greatest disintegration of the microalgae (83-99.6 % was achieved using bead mill with 0.42-0.6 mm glass beads while the other methods induced little or no disruption. The degree of cell disruption using bead mill increased with exposure time, beads-solution ratio and agitation speed while larger beads caused less disruption. Findings revealed that bead milling, with specific parameters optimized, is one of the most effective methods of disintegrating the robust algal cells.

  10. Flocculation mechanism of the actinomycete Streptomyces sp. hsn06 on Chlorella vulgaris.

    Science.gov (United States)

    Li, Yi; Xu, Yanting; Zheng, Tianling; Wang, Hailei

    2017-09-01

    In this study, an actinomycete Streptomyces sp. hsn06 with the ability to harvest Chlorella vulgaris biomass was used to investigate the flocculation mechanism. Streptomyces sp. hsn06 exhibited flocculation activity on algal cells through mycelial pellets with adding calcium. Calcium was determined to promote flocculation activity of mycelial pellets as a bridge binding with mycelial pellets and algal cells, which implied that calcium bridging is the main flocculation mechanism for mycelial pellets. Characteristics of flocculation activity confirmed proteins in mycelial pellets involved in flocculation procedure. The morphology and structure of mycelial pellets also caused dramatic effects on flocculation activity of mycelial pellets. According to the results, Streptomyces sp. hsn06 can be used as a novel flocculating microbial resource for high-efficiency harvesting of microalgae biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Evaluation of radioprotective action of a mutant (E-25) form of Chlorella vulgaris in mice

    International Nuclear Information System (INIS)

    Sarma, L.; Tiku, A.B.; Kesavan, P.C.; Ogaki, M.

    1993-01-01

    The possible role of orally fed Chlorella vulgaris (E-25) in modulating the gamma-ray induced chromosomal damage in whole-body irradiated mice was evaluated using a micronucleus test. Different doses of E-25 were administered either chronically (once, twice or thrice a day for 28 days) or as single acute doses before/after irradiation. A significant radioprotective effect was observed in both acute and chronic pretreatments, but only at doses above 400 mg/kg body weight. However, in mice that received E-25 (500 mg/kg) three times a day for 28 days, there was no protective effect, and a significant loss in their body weight was observed. Interestingly, E-25 afforded significant radioprotection even when it was administered within 0.4 hr after irradiation. (author)

  12. Change in Photosystem II Photochemistry During Algal Growth Phases of Chlorella vulgaris and Scenedesmus obliquus.

    Science.gov (United States)

    Oukarroum, Abdallah

    2016-06-01

    Sensitivity of photosynthetic processes towards environmental stress is used as a bioanalytical tool to evaluate the responses of aquatic plants to a changing environment. In this paper, change of biomass density, chlorophyll a fluorescence and photosynthetic parameters during growth phases of two microalgae Chlorella vulgaris and Scenedesmus obliquus were studied. The photosynthetic growth behaviour changed significantly with cell age and algae species. During the exponential phase of growth, the photosynthesis capacity reached its maximum and decreased in ageing algal culture during stationary phase. In conclusion, the chlorophyll a fluorescence OJIP method and the derived fluorescence parameters would be an accurate method for obtaining information on maximum photosynthetic capacities and monitoring algal cell growth. This will contribute to more understanding, for example, of toxic actions of pollutants in microalgae test.

  13. Predictive modeling of biomass production by Chlorella vulgaris in a draft-tube airlift photobioreactor

    Directory of Open Access Journals (Sweden)

    Mohsen Mansouri

    2017-04-01

    Full Text Available The objective of this study was to investigate the growth rate of Chlorella vulgaris for CO2 biofixation and biomass production. Six mathematical growth models (Logistic, Gompertz, modified Gompertz, Baranyi, Morgan and Richards were used to evaluate the biomass productivity in continuous processes and to predict the following parameters of cell growth: lag phase duration (λ, maximum specific growth rate (μmax, and maximum cell concentration (Xmax. The low root-mean-square error (RMSE and high regression coefficients (R2 indicated that the models employed were well fitted to the experiment data and it could be regarded as enough to describe biomass production. Using statistical and physiological significance criteria, the Baranyi model was considered the most appropriate for quantifying biomass growth. The biological variables of this model are as follows: μmax=0.0309 h−1, λ=100 h, and Xmax=1.82 g/L.

  14. Effect of gamma radiation on chlorophylls content, net photosynthesis and respiration of Chlorella pyrenoidosa

    International Nuclear Information System (INIS)

    Martin Moreno, C.; Fernandez Gonzalez, J.

    1983-01-01

    The effect of five doses of gamma radiation: 10, 100, 500, 1000 and 5000 Gy on chlorophylls content, net photosynthesis and respiration of Chlorella pyrenoidosa has been studied. A decrease in chlorophylls levels is produced after irradiation at 500, 1000 and 5000 Gy, being, at first b chlorophyll affected to a greater extent than a chlorophyll. Net photosynthesis and respiration decline throughout the time of the observation after irradiation, this depressing effect being much more remarkable for the first one. Met photosynthesis inhibition levels of about 30% are got only five hours post irradiation at a dose of 5000 Gy. Radio estimation by low doses, although obtained in some cases for tho 10 Gy dose, has not been statistically confirmed. (Author) 23 refs

  15. Isolation and purification of lutein from the microalga Chlorella vulgaris by extraction after saponification.

    Science.gov (United States)

    Li, Hua-Bin; Jiang, Yue; Chen, Feng

    2002-02-27

    A simple and efficient method for the isolation and purification of lutein from the microalga Chlorella vulgaris was developed. Crude lutein was obtained by extraction with dichloromethane from the microalga after saponification. Partition values of lutein in the two-phase system of ethanol-water-dichloromethane at different ratios were measured by HPLC so as to assist the determination of an appropriate condition for washing water-soluble impurities in the crude lutein. Partition values of lutein in another two-phase system of ethanol-water-hexane at different ratios were also measured by HPLC for determining the condition for removing fat-soluble impurities. The water-soluble impurities in the crude lutein were removed by washing with 30% aqueous ethanol, and the fat-soluble impurities were removed by extraction with hexane. The final purity of lutein obtained was 90-98%, and the yield was 85-91%.

  16. Biochemical activity of di- and polyamines in the green alga Chlorella vulgaris Beijerinck (Chlorophyceae

    Directory of Open Access Journals (Sweden)

    Romuald Czerpak

    2011-01-01

    Full Text Available This study concerns on the influence of diamines (agmatine, putrescine and polyamines (spermine, spermidine upon the growth and the content of chlorophyll a and b, monosaccharides and proteins in the cells of alga Chlorella vulgaris Beijerinck (Chlorophyceae. In the experiments agmatine, putrescine, spermine and spermidine in the range of concentrations 10-6-10-3 M were used. At the concentration 10-3 M and the 1st day of cultivation, they have a toxic effect on growth of the algae. It was found that di- and polyamines used within the range of concentration 10-6-10-4 M stimulate the growth and the contents of analysed biochemical parameters in the cells of C. vulgaris. The most stimulating influence on metabolism of the alga was demonstrated by spermidine and putrescine at concentration of 10-4 M. Agmatine and spermine were characterised by a lower biological activity than spermidine and putrescine demonstrated the most stimulating influence.

  17. The culture of Chlorella vulgaris in a recycled supernatant: Effects on biomass production and medium quality

    KAUST Repository

    Hadj-Romdhane, F.; Zheng, Xing; Jaouen, Pascal; Pruvost, Jé ré my; Grizeau, Dominique; Croue, Jean-Philippe; Bourseau, Patrick

    2013-01-01

    Reusing supernatant of microalgae culture medium can have inhibitory or toxic effects on the biomass production because of the release of organic metabolites by cells in the culture medium during their growth. This work investigated the impact of Chlorella vulgaris medium recycling on culture productivity, cells quality and accumulation of excreted metabolites in the culture medium. No significant impact on the C. vulgaris growth was observed after 63days of recycling, the productivity remained stable at around 0.55kgm-3day-1. Organic matters accumulated in supernatant were identified as biopolymers (BP) poor in nitrogen and with a size above 40kDa (probably polysaccharides), and small organic molecules (SOM) richer in nitrogen with a molecular size ranging from 1 to 3kDa. The concentration of biopolymers in the supernatant increased till to a maximum and then decreased, possibly consumed by bacteria, whereas small organic compounds accumulated in the medium. © 2013 Elsevier Ltd.

  18. Thermogravimetric study on pyrolysis kinetics of Chlorella pyrenoidosa and bloom-forming cyanobacteria.

    Science.gov (United States)

    Hu, Mian; Chen, Zhihua; Guo, Dabin; Liu, Cuixia; Xiao, Bo; Hu, Zhiquan; Liu, Shiming

    2015-02-01

    The pyrolysis process of two microalgae, Chlorella pyrenoidosa (CP) and bloom-forming cyanobacteria (CB) was examined by thermo-gravimetry to investigate their thermal decomposition behavior under non-isothermal conditions. It has found that the pyrolysis of both microalgae consists of three stages and stage II is the major mass reduction stage with mass loss of 70.69% for CP and 64.43% for CB, respectively. The pyrolysis kinetics of both microalgae was further studied using single-step global model (SSGM) and distributed activation energy model (DAEM). The mean apparent activation energy of CP and CB in SSGM was calculated as 143.71 and 173.46 kJ/mol, respectively. However, SSGM was not suitable for modeling pyrolysis kinetic of both microalgae due to the mechanism change during conversion. The DAEM with 200 first-order reactions showed an excellent fit between simulated data and experimental results. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Kinetic modeling of growth and lipid body induction in Chlorella pyrenoidosa under heterotrophic conditions.

    Science.gov (United States)

    Sachdeva, Neha; Kumar, G Dinesh; Gupta, Ravi Prakash; Mathur, Anshu Shankar; Manikandan, B; Basu, Biswajit; Tuli, Deepak Kumar

    2016-10-01

    The aim of the present work was to develop a mathematical model to describe the biomass and (total) lipid productivity of Chlorella pyrenoidosa NCIM 2738 under heterotrophic conditions. Biomass growth rate was predicted by Droop's cell quota model, while changes observed in cell quota (utilization) under carbon excess conditions were used for the modeling and predicting the lipid accumulation rate. The model was simulated under non-limiting (excess) carbon and limiting nitrate concentration and validated with experimental data for the culture grown in batch (flask) mode under different nitrate concentrations. The present model incorporated two modes (growth and stressed) for the prediction of endogenous lipid synthesis/induction and aimed to predict the effect and response of the microalgae under nutrient starvation (stressed) conditions. MATLAB and Genetic Algorithm were employed for the prediction and validation of the model parameters. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. The culture of Chlorella vulgaris in a recycled supernatant: Effects on biomass production and medium quality

    KAUST Repository

    Hadj-Romdhane, F.

    2013-03-01

    Reusing supernatant of microalgae culture medium can have inhibitory or toxic effects on the biomass production because of the release of organic metabolites by cells in the culture medium during their growth. This work investigated the impact of Chlorella vulgaris medium recycling on culture productivity, cells quality and accumulation of excreted metabolites in the culture medium. No significant impact on the C. vulgaris growth was observed after 63days of recycling, the productivity remained stable at around 0.55kgm-3day-1. Organic matters accumulated in supernatant were identified as biopolymers (BP) poor in nitrogen and with a size above 40kDa (probably polysaccharides), and small organic molecules (SOM) richer in nitrogen with a molecular size ranging from 1 to 3kDa. The concentration of biopolymers in the supernatant increased till to a maximum and then decreased, possibly consumed by bacteria, whereas small organic compounds accumulated in the medium. © 2013 Elsevier Ltd.

  1. Evaluation of sample extraction methods for proteomics analysis of green algae Chlorella vulgaris.

    Science.gov (United States)

    Gao, Yan; Lim, Teck Kwang; Lin, Qingsong; Li, Sam Fong Yau

    2016-05-01

    Many protein extraction methods have been developed for plant proteome analysis but information is limited on the optimal protein extraction method from algae species. This study evaluated four protein extraction methods, i.e. direct lysis buffer method, TCA-acetone method, phenol method, and phenol/TCA-acetone method, using green algae Chlorella vulgaris for proteome analysis. The data presented showed that phenol/TCA-acetone method was superior to the other three tested methods with regards to shotgun proteomics. Proteins identified using shotgun proteomics were validated using sequential window acquisition of all theoretical fragment-ion spectra (SWATH) technique. Additionally, SWATH provides protein quantitation information from different methods and protein abundance using different protein extraction methods was evaluated. These results highlight the importance of green algae protein extraction method for subsequent MS analysis and identification. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Protein hydrolysates from the alga Chlorella vulgaris 87/1 with potentialities in immuno nutrition

    International Nuclear Information System (INIS)

    Morris, Humberto J; Carrillo, Olimpia; Almarales, Angel; Bermudez, Rosa C; Alonso, Maria E; Borges, Leonardo; Quintana, Maria M; Fontaine, Roberto; Llaurado, Gabriel; Hernandez, Martha

    2009-01-01

    Chlorella vulgaris (Chlorophyta, Chlorophyceae) has received a particular attention in the programmes of microalgae utilisation in biotechnology. Enzymatic hydrolysis of cell proteins represents a very promising method to increase protein digestibility and thus, for obtaining hydrolysates with improved nutritional and functional properties. However, this technology has been little approached and the biological evaluation of hydrolysates has had a strictly nutritional nature. The design of hydrolysis conditions that combined for the first time, the use of C.vulgaris 87/1 treated with ethanol and pancreatin at pH values of 7.5-8.0, led to a product with a degree of hydrolysis of 20-22% and yields of 50-55%, characterised by a high digestibility (97.2%) and nitrogen solubility over a wide pH range (2.0-10.0). Hydrolysis curves were fitted to an exponential model, common to many food proteins. The bulk of the product dry matter consists of soluble peptides and free amino acids (47.7%) with three main peptides of molecular masses between 2 and 5 kDa. The oral administration of Chlorella hydrolysate (500 mg/kg) to undernourished Balb/c mice provided benefits in terms of liver protein metabolism and the induction of anabolic processes in gut mucosa. The hydrolysate also enhanced the immunological recovery, as judged by the stimulation of haemopoiesis, monocyte macrophage system activation, as well as humoral and cell mediated immune functions, like T-dependent antibody response and the reconstitution of delayed-type hypersensitivity (DTH) response. These results represent the first findings in the world concerning the immunomodulating effects of a microalgae protein hydrolysate. (author)

  3. Evaluation of antiangiogenic and antiproliferative potential of the organic extract of green algae chlorella pyrenoidosa

    Science.gov (United States)

    Kyadari, Mahender; Fatma, Tasneem; Azad, Rajvardhan; Velpandian, Thirumurthy

    2013-01-01

    Objective: algae isolates obtained from fresh and marine resources could be one of the richest sources of novel bioactive secondary metabolites expected to have pharmaceutical significance for new drug development. This study was conducted to evaluate the antiangiogenic and antiproliferative activity of Chlorella pyrenoidosa in experimental models of angiogenesis and by MTT assay. Materials and Methods: lyophilized extract of C. pyrenoidosa was extracted using dichloromethane/methanol (2:1), concentrated and vacuum evaporated to obtain the dried extract. The crude extract was evaluated in the vascular endothelial growth factor (VEGF)-induced angiogenesis in in ovo chick chorioallantoic membrane assay (CAM) at various concentrations (n = 8) using thalidomide and normal saline as positive and untreated control groups, respectively. The crude extract was also subjected to the antiangiogenic activity in the silver nitrate/potassium nitrate cautery model of corneal neovascularization (CN) in rats where topical bevacizumab was used as a positive control. The vasculature was photographed and blood vessel density was quantified using Aphelion imaging software. The extract was also evaluated for its anti proliferative activity by microculture tetrazolium test (MTT) assay using HeLa cancer cell line (ATCC). Results: VEGF increased the blood vessel density by 220% as compared to normal and thalidomide treatment decreased it to 67.2% in in ovo assay. In the in-vivo CN model, the mean neovascular density in the control group, the C. pyrenoidosa extract and bevacizumab group were found to be 100%, 59.02%, and 32.20%, respectively. The Chlorella pyrenoidosa extract negatively affected the viability of HeLa cells. An IC50 value of the extract was 570 μg/ml, respectively. Conclusion: a significant antiangiogenic activity was observed against VEGF-induced neovascularization and antiproliferative activity by MTT assay. In this study, it could be attributed that the activity may be

  4. Energetic response of Chlorella vulgaris to alpha radiation and PCB stress

    International Nuclear Information System (INIS)

    Schaffer, S.A.

    1982-01-01

    This research project has evaluated the bioenergetic response of the green alga Chlorella vulgaris following acute exposure to either the physical stress of radiation or the chemical stress of PCBs. After exposure, changes in survival or growth, adenylate pools (ATP, ADP, and AMP), CO 2 fixation and oxygen evolution and uptake were measured. By employing anaerobic conditions, or the electron transport inhibitor DCMU or dark conditions separately and in specific combinations, this study evaluated the response of three separate algal ATP producing mechanisms (respiration, total and cyclic photophosphorylation) to alpha radiation or PCB. The use of the adenylate energy charge ratio as an indicator of stress was also evaluated. The results of the radiation experiments indicated that alpha particle exposure between 25 to 275 rads caused a one-hour latent demand for ATP due to radioinduced DNA repair. In order to compensate for this ATP demand, nonessential utilization of ATP was decreased by slowing the rate of carbon fixation. The results also suggest that use of radiation as a tool to study algal physiology. The data obtained from the PCB experiments again showed each phosphorylation mechanism to be insensitive to 10, 100 and 200 ppm Aroclor 1254 exposures. Data suggest, however, that PCBs caused an increased photosynthetic rate, and total adenylate pool with decreased growth. The use of the adenylate energy charge ratio as a stress indicator was assessed. Because this ratio did not fluctuate at doses of radiation or PCBs that caused reduced survival and growth rates, this study concluded that for Chlorella the adenylate energy charge ration was a poor indicator of sublethal stress

  5. Setting the conditions for phycoremediation of radionuclide microalgae Dunaliella salina and Chlorella vulgaris

    International Nuclear Information System (INIS)

    Tatarova, D.; Galanda, D.; Kuruc, J.

    2016-01-01

    This presentation deals with bioremediation using microalgae - by phycoremediation. Microalgae are economically low profile compared to the plants, their cultivation can be carried out in laboratory conditions. They can survive in extreme conditions, they occur in all habitats and have faster growth. Halophilous green D. salina can accumulate heavy metals such as Zn, Cu and Cd. It occurs in hypersaline environment with tolerance (0.2 to 35) % NaCl. It contains high amounts of carotenoids, which protect it against formation of free radicals from UV radiation. Chlorella vulgaris is a representative of eukaryotic green microalgae with the highest chlorophyll content with the appearance in fresh water. Its phycoremediant ability are found in N and P elements, which are used as its nutritional components as well as for Cu, Cr, Cd, Pb, Au. The experiments were carried out using a peristaltic pump ISMATEC Model: ISM851 (flow rate 2 cm"3 min"-"1) followed by monitoring of time dependence of decrease of activity of the microalgae solutions. For evaluation of the samples was used HPGe gamma spectrometer (measurement time of the samples: 600 sec) from ORTEC Company and measured spectra were evaluated with software GammaVision from ORTEC. The measured results showed that the most effective phycoremediation of microalgae Dunaliella salina toke place in an environment of pH 3, and even more at pH 8. The fact that the D. salina is able of phycoremediation at so acidic pH can contribute to its applications in extreme conditions or in the coastal areas in view of that it is halophilic. At freshwater microalgae Chlorella vulgaris was found the best phytoremediation potential in its natural environment at pH of 6. Because this microalgae is freshwater, it may find application in inland or in liquid radioactive waste from nuclear facilities.(authors)

  6. Wet torrefaction of microalga Chlorella vulgaris ESP-31 with microwave-assisted heating

    International Nuclear Information System (INIS)

    Bach, Quang-Vu; Chen, Wei-Hsin; Lin, Shih-Cheng; Sheen, Herng-Kuang; Chang, Jo-Shu

    2017-01-01

    Highlights: • A microwave-assisted heating system is used for wet torrefaction (WT) of microalga. • Microalga Chlorella vulgaris ESP-31 is adopted as the feedstock. • The ash content in the microalga is reduced after WT. • The calorific value of the microalga can be intensified up to 21% after WT. • At least 61.5% of energy in the biomass is retained after WT. - Abstract: Microalgae are a prime source of third generation biofuels. Many thermochemical processes can be applied to convert them into fuels and other valuable products. However, some types of microalgae are characterized by very high moisture and ash contents, thereby causing several problems in further conversion processes. This study presents wet torrefaction (WT) as a promising pretreatment method to overcome the aforementioned drawbacks coupled with microalgal biomass. For this purpose, a microwave-assisted heating system was used for WT of microalga Chlorella vulgaris ESP-31 at different reaction temperatures (160, 170, and 180 °C) and durations (5, 10, and 30 min). The results show several improvements in the fuel properties of the microalga after WT such as increased calorific value and hydrophobicity as well as reduced ash content. A correlation in terms of elemental analysis can be adopted to predict the higher heating value of the torrefied microalga. The structure analysis by Fourier transform infrared (FT-IR) spectroscopy reveals that the carbohydrate content in the torrefied microalgae is lowered, whereas their protein and lipid contents are increased if the WT extent is not severe. However, the protein and lipid contents are reduced significantly at more severe WT conditions. The thermogravimetric analysis shows that the torrefied microalgae have lower ignition temperatures but higher burnout temperatures than the raw microalga, revealing significant impact of WT on the combustion reactivity of the microalga. Overall, the calorific value of the microalga can be intensified up to

  7. Effects of parameters affecting biomass yield and thermal behaviour of Chlorella vulgaris.

    Science.gov (United States)

    Bhola, Virthie; Desikan, Ramesh; Santosh, Sheena Kumari; Subburamu, Karthikeyan; Sanniyasi, Elumalai; Bux, Faizal

    2011-03-01

    Conventional fossil fuels are facing a global challenge which lead scientists to explore alternative fuel production from biological sources. The algae-based fuels are gaining rapid attention as it has potential to replace petroleum-based fuels. An indigenous high lipid producing microalgae was isolated from a freshwater pond in the KwaZulu-Natal province of South Africa. The isolate was later identified as Chlorella vulgaris, based on partial 28S large subunit ribosomal RNA gene sequence. The growth kinetics, pyrolytic characteristics and photosynthetic efficiency of Chlorella was evaluated in vitro. The optimized conditions for higher biomass yield of the selected strain were at 4% CO(2), 0.5 g l(-1) NO(3) and 0.04 g l(-1) PO(4), respectively. The pulse amplitude modulation results indicated that C. vulgaris could withstand a light intensity ranging from 150 to 350 μmol photons m(-2)s(-1). Further increase in light intensity resulted in a decline of the electron transport rate. Carbon fixation rate, lipid content and calorific value of C. vulgaris was 6.17 mg l(-1)h(-1), 21% and 17.44 kJ g(-1), respectively. The pyrolitic studies under inert atmosphere at different heating rates of 15, 30, 40 and 50°C min(-1) from ambient temperature to 800°C showed that the overall final weight loss recorded for the four different heating rates was in the range of 78.9-81%. These studies could be useful to appraise the biofuel potential of the isolated C. vulgaris strain, which can later be taken for pilot scale production. Copyright © 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  8. Simultaneous Production of Triacylglycerol and High-Value Carotenoids by the Astaxanthin-Producing Oleaginous Green Microalga Chlorella zofingiensis

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jin; Mao, Xuemei; Zhou, Wenguang; Guarnieri, Michael T.

    2016-08-01

    The production of lipids and astaxanthin, a high-value carotenoid, by Chlorella zofingiensis was investigated under different culture conditions. Comparative analysis revealed a good correlation between triacylglycerol (TAG) and astaxanthin accumulation in C. zofingiensis. Stress conditions promoted cell size and weight and induced the accumulation of neutral lipids, especially TAG and astaxanthin, with a concomitant decrease in membrane lipids. The highest contents of TAG and astaxanthin achieved were 387 and 4.89 mg g-1 dry weight, respectively. A semi-continuous culture strategy was developed to optimize the TAG and astaxanthin productivities, which reached 297 and 3.3 mg L-1 day-1, respectively. Additionally, astaxanthin accumulation was enhanced by inhibiting de novo fatty acid biosynthesis. In summary, our study represents a pioneering work of utilizing Chlorella for the integrated production of lipids and high-value products and C. zofingiensis has great potential to be a promising production strain and serve as an emerging oleaginous model alga.

  9. Cultivation of Chlorella Vulgaris Using Airlift Photobioreactor Sparged with 5%CO 2 -Air as a Biofixing Process

    Directory of Open Access Journals (Sweden)

    Mahmood Khazzal Hummadi AL-Mashhadani

    2017-04-01

    Full Text Available The present paper addresses cultivation of Chlorella vulgaris microalgae using airlift photobioreactor that sparged with 5% CO 2 /air. The experimental data were compared with that obtained from bioreactor aerated with air and unsparged bioreactor. The results showed that the concentration of biomass is 0.36 g l -1 in sparged bioreactor with CO2/air, while, the concentration of biomass reached to 0.069 g l -1 in the unsparged bioreactor. They showed also that aerated ioreactor.with CO2/air gives more biomass production even the bioreactor was aerated with air. This study proved that application of sparging system for ultivation of Chlorella vulgaris microalgae using either CO2/air mixture or air has a significant growth rate, since the bioreactors become more thermodynamically favorable and provide impetus for a higher level of production. biofixing process

  10. Biosynthesis of lipids in Chlorella vulgaris Beijer. under the action of Mn2+, Zn2+, Cu2+, and Pb2+

    International Nuclear Information System (INIS)

    Gorda, A.Yi.; Grubyinko, V.V.

    2011-01-01

    We study the influence of Mn 2+ , Zn 2+ , Cu 2+ , and Pb 2+ on the intensity of biosynthesis of lipids in unicellular algae Chlorella vulgaris Beijer. In all cases, there is a general tendency to the accumulation of triacylglycerols, dyacylglycerols, and nonesterified fatty acids, which participate in protecting the cages of algae from an unfavorable action, and to a decrease of the content of phospholipids. For the actions of Zn 2+ , Cu 2+ , and Pb 2+ , 14 C-acetate is maximally included in phospholipids, for the actions of Mn 2+ - in dyacylglycerols, and the synthesis of other classes of lipids is inhibited. The content of chlorophylls a and b grows substantially for the actions of ions of zinc and lead and diminishes for the actions of ions of copper and manganese. We discuss the regulatory role and the toxic influence of ions of metals on the lipid metabolism in chlorella.

  11. Ultrastructure of chlorella pyrenoidosa (Strain g-11-1) cell grown for a long time under conditions of space flight

    International Nuclear Information System (INIS)

    Sitnik, K.M.; Kordyum, Ye.L.; Mashins'kij, O.L.; Popova, A.F.; Grechko, G.M.

    1979-01-01

    Presented are the data on the electron-microscopic analysis of the Chlorella pyrenoidosa culture (the D-11-1 strain, a pigmentary mutant) growing in the IFS-2 instruments (an organic nutrient medium, darkness) during 28 days on board the space laboratory ''Salyut-6''. The cell density in the experimental culture is 4.6 times greater than the one under control. A number of differences in the structural-functional organization of experimental and control cells is shown. The investigations performed have shown that the cosmic flight factors significantly affect the growth and vital activity of the Chlorella culture having been in a physiologically active state for a long time under conditions of space flight

  12. Synergistic effect of UV radiation and nutrient limitation on Chlorella fusca (Chlorophyta) cultures grown in outdoor cylindrical photobioreactors

    Czech Academy of Sciences Publication Activity Database

    Malpartida, I.; Jerez, C.G.; Morales, M.M.; Nascimento, E.; Freire, I.; Ezequiel, J.; Rico, R.M.; Peralta, E.; Malapascua, J.R.; Florez, Y.; Masojídek, Jiří; Abdala, R.; Figueroa, F.L.; Navarro, E.

    2014-01-01

    Roč. 22, č. 2 (2014), s. 141-158 ISSN 1864-7790 Grant - others:Univ. Málaga, Ministry of Economy and Competitiveness of Spanish Government(ES) Acción Complementaria CTM2011-15659-E; Spanish Ministry of Economy and Competitiveness of Spanish Government(ES) BFU2010-22053 Institutional support: RVO:61388971 Keywords : bio-optics * radiation * Chlorella * chlorophyll Subject RIV: EE - Microbiology, Virology Impact factor: 1.258, year: 2014

  13. Chloroplast NADPH-Dependent Thioredoxin Reductase from Chlorella vulgaris Alleviates Environmental Stresses in Yeast Together with 2-Cys Peroxiredoxin

    Science.gov (United States)

    Machida, Takeshi; Ishibashi, Akiko; Kirino, Ai; Sato, Jun-ichi; Kawasaki, Shinji; Niimura, Youichi; Honjoh, Ken-ichi; Miyamoto, Takahisa

    2012-01-01

    Chloroplast NADPH-dependent thioredoxin reductase (NTRC) catalyzes the reduction of 2-Cys peroxiredoxin (2-Cys Prx) and, thus, probably functions as an antioxidant system. The functions of the enzyme in oxidative and salt stresses have been reported previously. We have previously identified and characterized NTRC in Chlorella vulgaris. In the present study, we isolated a full-length cDNA clone encoding 2-Cys Prx from C. vulgaris and investigated the involvement of Chlorella NTRC/2-Cys Prx system in several environmental stress tolerances by using yeast as a eukaryotic model. Deduced Chlorella 2-Cys Prx was homologous to those of chloroplast 2-Cys Prxs from plants, and two conserved cysteine residues were found in the deduced sequence. Enzyme assay showed that recombinant mature C. vulgaris NTRC (mCvNTRC) transferred electrons from NADPH to recombinant mature C. vulgaris 2-Cys Prx (mCvPrx), and mCvPrx decomposed hydrogen peroxide, tert-butyl hydroperoxide, and peroxynitrite by cooperating with mCvNTRC. Based on the results, the mCvNTRC/mCvPrx antioxidant system was identified in Chlorella. The antioxidant system genes were expressed in yeast separately or coordinately. Stress tolerances of yeast against freezing, heat, and menadione-induced oxidative stresses were significantly improved by expression of mCvNTRC, and the elevated tolerances were more significant when both mCvNTRC and mCvPrx were co-expressed. Our results reveal a novel feature of NTRC: it functions as an antioxidant system with 2-Cys Prx in freezing and heat stress tolerances. PMID:23029353

  14. Analytical evaluation of different carbon sources and growth stimulators on the biomass and lipid production of Chlorella vulgaris – Implications for biofuels

    International Nuclear Information System (INIS)

    Josephine, A.; Niveditha, C.; Radhika, A.; Shali, A. Brindha; Kumar, T.S.; Dharani, G.; Kirubagaran, R.

    2015-01-01

    The key challenges in lipid production from marine microalgae include the selection of appropriate strain, optimization of the culture conditions and enhancement of biolipid yield. This study is aimed at evaluating the optimal harvest time and effect of chlorella growth factor (CGF) extract, carbon sources and phytohormones on the biomass and lipid production in Chlorella vulgaris. CGF, extracted using hot water from Chlorella has been reported to possess various medicinal properties. However, in the present study, for the first time in C. vulgaris, CGF was found as a best growth stimulator by enhancing the biomass level (1.208 kg m −3 ) significantly on day 5. Gibberellin and citrate augmented the biomass by 0.935 kg m −3 and 1.025 kg m −3 . Combination of CGF and phytohormones were more effective than CGF and carbon sources. Analysis of fatty acid methyl esters indicated that the ratio of saturated to unsaturated fatty acids is higher in cytokinin, abscisic acid and CGF, and are also rich in short chain carbon atoms, ideal criteria for biodiesel. Nitrogen starvation favoured synthesis of more unsaturated fatty acids than saturated. This study shows that CGF enhances the biomass and lipid significantly and thus can be used for large scale biomass production. - Highlights: • Optimization studies revealed 7th day to be the ideal period for harvesting Chlorella vulgaris. • Chlorella growth factor extract acted as a chief growth promoting factor of C. vulgaris. • Chlorella growth factor with carbon sources or phytohormones was not effective than chlorella growth factor extract alone. • Cytokinin treatment increased saturated fatty acids level, although the biomass production was not significant

  15. The acute toxic effects of 1-alkyl-3-methylimidazolium nitrate ionic liquids on Chlorella vulgaris and Daphnia magna.

    Science.gov (United States)

    Zhang, Cheng; Zhang, Shuai; Zhu, Lusheng; Wang, Jinhua; Wang, Jun; Zhou, Tongtong

    2017-10-01

    Given their increasingly widespread application, the toxic effects of ionic liquids (ILs) have become the subject of significant attention in recent years. Therefore, the present study assessed the acute toxic effects of 1-alkyl-3-methylimidazolium nitrate ([C n mim]NO 3 (n = 2, 4, 6, 8, 10, 12)) on Chlorella vulgaris and Daphnia magna. The sensitivity of the tested organism Daphnia magna and the investigated IL concentrations in water using high-performance liquid chromatography (HPLC) were also evaluated to demonstrate the reliability of the present study. The results illustrated that Daphnia magna is indeed sensitive to the reference toxicant and the investigated ILs were stable in the aquatic environment. The 50% effect concentration (EC 50 ) was used to represent the acute toxic effects on Chlorella vulgaris and Daphnia magna. With the increasing alkyl-chain lengths, the toxicity of the investigated ILs increased in both the test organisms. Accordingly, the alkyl-chain lengths can cause significantly toxic effects on aquatic organisms, and Daphnia magna are much more sensitive than Chlorella vulgaris to the imidazolium-based ILs used in the present study. Furthermore, the present study provides more information on the acute toxic effects of 1-alkyl-3-methylimidazolium nitrate. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Effects of nutrient ratios and carbon dioxide bio-sequestration on biomass growth of Chlorella sp. in bubble column photobioreactor.

    Science.gov (United States)

    Vo, Hoang-Nhat-Phong; Bui, Xuan-Thanh; Nguyen, Thanh-Tin; Nguyen, Dinh Duc; Dao, Thanh-Son; Cao, Ngoc-Dan-Thanh; Vo, Thi-Kim-Quyen

    2018-08-01

    Photobioreactor technology, especially bubble column configuration, employing microalgae cultivation (e.g., Chlorella sp.), is an ideal man-made environment to achieve sufficient microalgae biomass through its strictly operational control. Nutrients, typically N and P, are necessary elements in the cultivation process, which determine biomass yield and productivity. Specifically, N:P ratios have certain effects on microalgae's biomass growth. It is also attractive that microalgae can sequester CO 2 by using that carbon source for photosynthesis and, subsequently, reducing CO 2 emission. Therefore, this study aims to investigate the effect of N:P ratios on Chlorella sp.'s growth, and to study the dynamic of CO 2 fixation in the bubble column photobioreactor. According to our results, N:P ratio of 15:1 could produce the highest biomass yield (3568 ± 158 mg L -1 ). The maximum algae concentration was 105 × 10 6  cells mL -1 , receiving after 92 h. Chlorella sp. was also able to sequester CO 2 at 28 ± 1.2%, while the specific growth rate and carbon fixation rate were observed at 0.064 h -1 and 68.9 ± 1.91 mg L -1  h -1 , respectively. The types of carbon sources (e.g., organic and inorganic carbon) possessed potential impact on microalgae's cultivation. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. The Next Generation Feedstock of Biofuel: Jatropha or Chlorella as Assessed by Their Life-Cycle Inventories

    Directory of Open Access Journals (Sweden)

    Pu Peng

    2014-07-01

    Full Text Available Promising energy crops such as Jatropha curcas Linnaeus (JCL, which are planted on marginal lands, or microalgae such as Chlorella, which are cultivated in ponds located on mudflats or deserts, have been regarded with high hopes to solve the shortage of food crops and increase the amount of biodiesel (Fatty Acid Methyl Ester, FAME production. However, the annual yields of biomass and transport fuels (t/ha of both are still unclear and often exaggerated in the literature. Large portions of JCL biomass, including tree trunks and leaves, can also be used to generate electricity along with FAME, which is produced from seed lipids. Meanwhile, lipid extracted algae (LEA are composed of proteins, polysaccharides, and lipids other than glycerides which are unable to be esterified to form FAME and much more abundant in the microalgae than oil cake in the oil crops. Therefore, it has been strongly suggested that not only transesterification or esterification but also Fischer-Tropsch (FT process and bio-electricity generation should be considered as routes to produce biofuels. Otherwise, the yield of biofuel would be extremely low using either JCL or Chlorella as feedstock. The Life-Cycle Inventories (LCI of the biofuel processes with whole biomass of JCL and Chlorella were compared based on their net energy ratio (NER and CO2 emission saving (CES. It was shown that the technological improvement of irrigation, cultivation, and processing for either economic-crops or microalgae were all necessary to meet the requirements of commercial biofuel production.

  18. Chikungunya virus

    Science.gov (United States)

    Chikungunya virus infection; Chikungunya ... Where Chikungunya is Found Before 2013, the virus was found in Africa, Asia, Europe, and the Indian and Pacific oceans. In late 2013, outbreaks occurred for the first time in the ...

  19. Zika Virus

    Science.gov (United States)

    ... through blood transfusions. There have been outbreaks of Zika virus in the United States, Africa, Southeast Asia, the ... not travel to areas where there is a Zika virus outbreak. If you do decide to travel, first ...

  20. Zika Virus

    Science.gov (United States)

    ... Funding CDC Activities For Healthcare Providers Clinical Evaluation & Disease Sexual Transmission HIV Infection & Zika Virus Testing for Zika Test Specimens – At Time of Birth Diagnostic Tests Understanding Zika Virus Test Results ...

  1. Taxonomic identification and lipid production of two Chilean Chlorella-like strains isolated from a marine and an estuarine coastal environment

    Science.gov (United States)

    González, Mariela A.; Pröschold, Thomas; Palacios, Yussi; Aguayo, Paula; Inostroza, Ingrid; Gómez, Patricia I.

    2013-01-01

    The genus Chlorella was the first microalga to be massively cultured as food, feed and as a source of nutraceuticals. More recently, some species have been suggested as candidates for biodiesel production. One of the most difficult tasks in studying the systematics of green coccoids is the identification of species assigned to the genus Chlorella. In the context of several projects carried out by our research group we isolated two Chlorella-like strains from a marine and an estuarine coastal environment in Chile (Coliumo strain and Baker strain, respectively). The main objectives of this research were to identify these Chilean strains—at the species level—and determine and compare their lipid production when cultured under identical conditions. Cell size and shape, autospore number and sizes, and chloroplast and pyrenoid ultrastructure were considered as taxonomic descriptors, and 18S rDNA sequences and internal transcribed spacer ITS-1 + ITS-2 sequences and secondary structure were adopted as phylogenetic tools. The combined use of these morphological, ultrastructural and molecular attributes revealed that only the Baker strain belongs to the genus Chlorella (C. vulgaris), while the Coliumo strain corresponds to the recently amended genus Chloroidium (C. saccharophilum). Lipid characterization of the biomass obtained from these strains showed that Chlorella vulgaris (Baker strain) appears to be suitable as a raw material for biodiesel production, while Chloroidium saccharophilum (Coliumo strain) would be more appropriate for animal nutrition.

  2. Daily oral intake of theanine prevents the decline of 5-bromo-2′-deoxyuridine incorporation in hippocampal dentate gyrus with concomitant alleviation of behavioral abnormalities in adult mice with severe traumatic stress

    Directory of Open Access Journals (Sweden)

    Takeshi Takarada

    2015-03-01

    Full Text Available Posttraumatic stress disorder is a long-lasting psychiatric disease with the consequence of hippocampal atrophy in humans exposed to severe fatal stress. We demonstrated a positive correlation between the transient decline of 5-bromo-2′-deoxyuridine (BrdU incorporation in the hippocampal dentate gyrus (DG and long-lasting behavioral abnormalities in mice with traumatic stress. Here, we investigated pharmacological properties of theanine on the declined BrdU incorporation and abnormal behaviors in mice with traumatic stress. Prior daily oral administration of theanine at 50–500 mg/kg for 5 days significantly prevented the decline of BrdU incorporation, while theanine significantly prevented the decline in the DG even when administered for 5 days after stress. Consecutive daily administration of theanine significantly inhibited the prolonged immobility in mice with stress in forced swimming test seen 14 days later. Although traumatic stress significantly increased spontaneous locomotor activity over 30 min even when determined 14 days later, the increased total locomotion was significantly ameliorated following the administration of theanine at 50 mg/kg for 14 days after stress. These results suggest that theanine alleviates behavioral abnormalities together with prevention of the transient decline of BrdU incorporation in the hippocampal DG in adult mice with severe traumatic stress.

  3. On the uptake and binding of uranium (VI) by the green alga Chlorella Vulgaris

    International Nuclear Information System (INIS)

    Vogel, Manja

    2011-01-01

    Uranium could be released into the environment from geogenic deposits and from former mining and milling areas by weathering and anthropogenic activities. The elucidation of uranium behavior in geo- and biosphere is necessary for a reliable risk assessment of radionuclide migration in the environment. Algae are widespread in nature and the most important group of organisms in the aquatic habitat. Because of their ubiquitous occurrence in nature the influence of algae on the migration process of uranium in the environment is of fundamental interest e.g. for the development of effective and economical remediation strategies for contaminated waters. Besides, algae are standing at the beginning of the food chain and play an economically relevant role as food and food additive. Therefore the transfer of algae-bound uranium along the food chain could arise to a serious threat to human health. Aim of this work was the quantitative and structural characterization of the interaction between U(VI) and the green alga Chlorella vulgaris in environmental relevant concentration and pH range with special emphasis on metabolic activity. Therefore a defined medium was created which assures the survival/growth of the algae as well as the possibility to predict the uranium speciation. The speciation of uranium in the mineral medium was calculated and experimentally verified by time-resolved laser-induced fluorescence spectroscopy (TRLFS). The results of the sorption experiments showed that both metabolic active and inactive algal cells bind uranium in significant amounts of around 14 mg U/g dry biomass and 28 mg U/g dry biomass, respectively. Another interesting observation was made during the growth of Chlorella cells in mineral medium at the environmental relevant uranium concentration of 5 μM. Under these conditions and during ongoing cultivation a mobilization of the algae-bound uranium occurred. At higher uranium concentrations this effect was not observed due to the die off of

  4. Effect of Antiviral Agents in Equine Abortion Virus-Infected Hamsters1

    Science.gov (United States)

    Lieberman, Melvin; Pascale, Andrea; Schafer, Thomas W.; Came, Paul E.

    1972-01-01

    Equine abortion virus, a member of the herpesvirus group, produces a lethal infection in hamsters. With this system, the protective effect of certain inhibitors of deoxyribonucleic acid viruses, inducers of interferon and exogenous interferon, was evaluated. Of the various agents studied, 9-β-d-arabinofuranosyladenine markedly suppressed mortality, and 5-iodo-2′-deoxyuridine, distamycin A, and N-ethylisatin β-thiosemicarbazone were inactive. Of the inducers tested, statolon, ultraviolet-irradiated Newcastle disease virus, and polyriboinosinic:polyribocytidylic acid (poly I:C) were protective, and endotoxin, polyacrylic acid, and polymethacrylic acid did not protect. Administration of exogenous interferon did not afford protection. Statolon and ultraviolet-irradiated Newcastle disease virus induced circulating interferon in hamsters, whereas poly I:C, endotoxin, and polyacrylic acid did not produce interferon. Because of the severity of the disease produced in hamsters by equine abortion virus, lack of protective activity by an agent in this system should not preclude possible efficacy against other members of the herpesvirus group. PMID:4376907

  5. KATALIS HETEROGEN DARI ABU VULKANIK UNTUK PEMBUATAN BIODIESEL DARI MINYAK MIKROALGA 1,2 CHLORELLA Sp

    Directory of Open Access Journals (Sweden)

    Catur Rini Widyastuti

    2015-02-01

    Full Text Available Proses produksi biodiesel secara konvensional menggunakan bahan baku yang terbatas jumlahnya, proses yang rumit, dan banyaknya limbah yang dihasilkan menyebabkan produksi biodiesel dalam skala besar tidak dapat direalisasikan dengan mudah. Mikroalga merupakan sumber bahan alam terbarukan yang sangat potensial untuk produksi biodiesel karena kandungan minyaknya yang tinggi, kecepatannya tumbuh pada lahan yang terbatas, serta merupakan produk non-pangan. Salah satu jenis mikroalga dengan kandungan minyak yang relatif besar (28-32% berat kering adalah mikroalga Chlorella sp. Selain bahan baku, pemilihan proses yang lebih sederhana dan ekonomis perlu dikembangkan. Selama ini, proses produksi biodiesel konvensioanal banyak menghasilkan air limbah pada tahap pemisahan produk dari katalis yang larut dan produk samping yang dihasilkan. Oleh karena itu, untuk mengurangi limbah yang dihasilkan selama proses pemisahan tersebut, jenis katalis heterogen dapat digunakan untuk menggantikan katalis homogen alkali yang biasa digunakan. Katalis padat tersebut dapat disintesis dari abu vulkanik yang mengandung unsur-unsur seperti SiO2, Al2O3, Fe2O3, TiO2, MnO, CaO, MgO, Na2O, K2O, P2O5, serta beberapa elemen minor seperti Zr, Sr, dan V. Penelitian ini bertujuan untuk mengkaji jenis katalis dan aktivitasnya dalam reaksi transesterifikasi minyak mikroalga Chlorella sp menjadi biodiesel. Tahap awal penelitian yang dilakukan adalah preparasi minyak mikroalga yang akan digunakan untuk uji aktivitas katalis. Minyak mikroalga diperoleh dengan ekstraksi menggunakan metode maserasi menggunakan pelarut n-heksana. Rendemen minyak yang diperoleh sebesar 12,26%. Dari hasil uji GC-MS diketahui dua kandungan asam lemak terbesar dalam minyak mikroalga, yaitu Dodecanoic acid sebesar 59.52% dan n-Decanoic acid sebesar 12.64%. Selanjutnya minyak mikroalga direaksikan dengan metanol dengan rasio molar 1:6 menggunakan jenis katalis yang disintesis dari abu vulkanik. Preparasi katalis

  6. SINTESIS BIODIESEL DARI MINYAK MIKROALGA Chlorella vulgaris DENGAN REAKSI TRANSESTERIFIKASI MENGGUNAKAN KATALIS KOH

    Directory of Open Access Journals (Sweden)

    Catur Rini Widyastuti

    2014-10-01

    Full Text Available Biodiesel merupakan salah satu energi alternatif yang dianggap mampu menjawab permasalahan kelangkaan bahan bakar minyak. Biodiesel dapat disintesis dari minyak nabati melalui reaksi transesterifikasi. Sumber minyak nabati yang potensial adalah mikroalga yang memiliki produktifitas minyak yang lebih tinggi per satuan luas lahan yang digunakan jika dibandingkan dengan tanaman darat. Mikroalga jenis Chlorella sp diketahui mengandung komponen lipid cukup tinggi yaitu sebesar 14-22%. Langkah-langkah penelitian yang dilakukan meliputi ekstraksi minyak mikroalga dengan n-heksana, reaksi transesterifikasi minyak mikroalga dan metanol dengan katalis KOH, dilanjutkan dengan filtrasi untuk memisahkan produk biodiesel dengan gliserol yang terbentuk. Untuk mengetahui kandungan kimia dalam bahan baku dan produk, minyak hasil ekstraksi mikroalga dan biodiesel yang dihasilkan dianalisis dengan GC-MS. Dari hasil uji GC-MS diketahui dua kandungan asam lemak terbesar dalam minyak mikroalga, yaitu Dodecanoic acid sebesar 59.52% dan n-Decanoic acid sebesar 12.64%. Dari proses transesterifikasi, yield biodiesel yang diperoleh sebesar 59.85% dengan densitas 0.88 g/cm3. Kandungan kimia biodiesel diketahui terdiri dari senyawa Fatty Acid Methyl Ester (FAME sebesar 15.4% dan Fatty Acid Ethyl Ester (FAEE sebesar 21.14%.Biodiesel is one of the alternative energy which expected to provide a solution towards our dependence of fossil fuel. Biodiesel could be synthesized from vegetable oil through transesterification process. One of the most potential sources of vegetable oil is microalgae which is more productive than a land-based plant. One of the species of microalgae which is Chlorella sp is known for containing high lipid content from 14 to 22%. The steps of the research including extraction of microalgae oil using n-hexane, transesterification reaction between microalgae and methanol using KOH as a catalyst, and continued by filtration to separate the biodiesel product

  7. Analysis of removal of cadmium by action of immobilized Chlorella sp. micro-algae in alginate beads [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Christian Valdez

    2018-01-01

    Full Text Available Cadmium (Cd is a metal that can negatively interfere with the metabolic systems of living beings. The objective of this work was to evaluate the capacity for cadmium removal in aqueous solutions by immobilized Chlorella sp. in calcium alginate beads. Beads without Chlorella sp. were used as a control. All the treatments were established in triplicate for 80 min, at four concentrations of cadmium (0, 20, 100 and 200 ppm, taking samples of aqueous solution every 10 min, to be read using atomic absorption equipment. The study determined that the treatment of alginate beads with immobilized Chlorella sp. removed 59.67% of cadmium at an initial concentration of 20 ppm, this being the best removal result.

  8. Cultivation of Chlorella protothecoides with urban wastewater in continuous photobioreactor: biomass productivity and nutrient removal.

    Science.gov (United States)

    Ramos Tercero, E A; Sforza, E; Morandini, M; Bertucco, A

    2014-02-01

    The capability to grow microalgae in nonsterilized wastewater is essential for an application of this technology in an actual industrial process. Batch experiments were carried out with the species in nonsterilized urban wastewater from local treatment plants to measure both the algal growth and the nutrient consumption. Chlorella protothecoides showed a high specific growth rate (about 1 day(-1)), and no effects of bacterial contamination were observed. Then, this microalgae was grown in a continuous photobioreactor with CO₂-air aeration in order to verify the feasibility of an integrated process of the removal of nutrient from real wastewaters. Different residence times were tested, and biomass productivity and nutrients removal were measured. A maximum of microalgae productivity was found at around 0.8 day of residence time in agreement with theoretical expectation in the case of light-limited cultures. In addition, N-NH₄ and P-PO₄ removal rates were determined in order to model the kinetic of nutrients uptake. Results from batch and continuous experiments were used to propose an integrated process scheme of wastewater treatment at industrial scale including a section with C. protothecoides.

  9. Comparison of Chlorella vulgaris and cyanobacterial biomass: cultivation in urban wastewater and methane production.

    Science.gov (United States)

    Mendez, Lara; Sialve, Bruno; Tomás-Pejó, Elia; Ballesteros, Mercedes; Steyer, Jean Philippe; González-Fernández, Cristina

    2016-05-01

    Anaerobic digestion of microalgae is hampered by its complex cell wall. Against this background, cyanobacteria cell walls render this biomass as an ideal substrate for overcoming this drawback. The aim of the present study was to compare the growth of two cyanobacteria (Aphanizomenon ovalisporum and Anabaena planctonica) and a microalga (Chlorella vulgaris) in urban wastewater when varying the temperature (22, 27 and 32 °C). Cyanobacterial optimal growth for both strains was attained at 22 °C, while C. vulgaris did not show remarkable differences among temperatures. For all the microorganisms, ammonium removal was higher than phosphate. Biomass collected was subjected to anaerobic digestion. Methane yield of C. vulgaris was 184.8 mL CH4 g COD in(-1) while with A. ovalisporum and A. planctonica the methane production was 1.2- and 1.4-fold higher. This study showed that cyanobacteria growth rates could be comparable to microalgae while presenting the additional benefit of an increased anaerobic digestibility.

  10. Polishing of anaerobic secondary effluent by Chlorella vulgaris under low light intensity

    KAUST Repository

    Cheng, Tuoyuan; Wei, Chunhai; Leiknes, TorOve

    2017-01-01

    To investigate anaerobic secondary effluent polishing by microalgae (Chlorella vulgaris) under low light intensity (14 μmol/m2/s), bubbling column reactors were operated in batches of 8 d with initial ammonium nitrogen 10-50 mg/L, initial phosphate phosphorus 2-10 mg/L and microalgal seed 40 mg/L. Maximum microalgal biomass and minimum generation time were 370.9 mg/L and 2.5 d, respectively. Nitrogen removal (maximum 99.6%) was mainly attributed to microalgal growth rate, while phosphorus removal (maximum 49.8%) was related to microalgal growth rate, cell phosphorus content (maximum 1.5%) and initial nutrients ratio. Dissolved microalgal organics release in terms of chemical oxygen demand (maximum 63.2 mg/L) and hexane extractable material (i.e., oil and grease, maximum 8.5 mg/L) was firstly reported and mainly affected by nitrogen deficiency and deteriorated effluent quality. Ultrafiltration critical flux (16.6-39.5 L/m2/h) showed negative linear correlation to microalgal biomass. Anaerobic membrane bioreactor effluent polishing showed similar results with slight inhibition to synthetic effluent.

  11. Moringa oleifera Seed Derivatives as Potential Bio-Coagulant for Microalgae Chlorella sp. Harvesting

    International Nuclear Information System (INIS)

    Azizah Endut; Azizah Endut; Siti Hajar Abdul Hamid; Fathurrahman Lananan; Helena Khatoon

    2016-01-01

    Microalgae is an economical and potential raw material of biomass energy, which offer a wide range of commercial potential to produce valuable substances for applications in aquaculture feed, pharmaceutical purposes and bio fuels production. However, lack of an economical, efficient and convenient method to harvest microalgae is a bottleneck to boost their full-scale application. Hence, this study was performed to investigate the potentialities of Moringa oleifera seed derivatives as an environmentally bio-coagulant to harvest microalgae Chlorella sp. biomass from the water column, which acts as a binder to coagulate particulate impurities to form larger aggregates. Results shown M. oleifera to have better biomass recovery of 122.51 % as compared to 37.08 % of alum at similar dosages of 10 mgL"-"1. In addition, it was found that the zeta potential values of mixed microalgae-coagulant suspension shows positive correlation on the flocculation parameters. For biomass recovery, the correlation for M. oleifera protein powder showed the R"2-value of 0.9565 whereas the control chemical flocculant, alum with the R"2-value of 0.7920. It was evidence that M. oleifera has a great potential in efficient and economical for environmentally microalgae harvesting and the adaptation of biological harvesting technology especially for the purpose of aquaculture feed in Malaysia. (author)

  12. Polishing of anaerobic secondary effluent by Chlorella vulgaris under low light intensity

    KAUST Repository

    Cheng, Tuoyuan

    2017-05-29

    To investigate anaerobic secondary effluent polishing by microalgae (Chlorella vulgaris) under low light intensity (14 μmol/m2/s), bubbling column reactors were operated in batches of 8 d with initial ammonium nitrogen 10-50 mg/L, initial phosphate phosphorus 2-10 mg/L and microalgal seed 40 mg/L. Maximum microalgal biomass and minimum generation time were 370.9 mg/L and 2.5 d, respectively. Nitrogen removal (maximum 99.6%) was mainly attributed to microalgal growth rate, while phosphorus removal (maximum 49.8%) was related to microalgal growth rate, cell phosphorus content (maximum 1.5%) and initial nutrients ratio. Dissolved microalgal organics release in terms of chemical oxygen demand (maximum 63.2 mg/L) and hexane extractable material (i.e., oil and grease, maximum 8.5 mg/L) was firstly reported and mainly affected by nitrogen deficiency and deteriorated effluent quality. Ultrafiltration critical flux (16.6-39.5 L/m2/h) showed negative linear correlation to microalgal biomass. Anaerobic membrane bioreactor effluent polishing showed similar results with slight inhibition to synthetic effluent.

  13. Sonication-based isolation and enrichment of Chlorella protothecoides chloroplasts for illumina genome sequencing

    Energy Technology Data Exchange (ETDEWEB)

    Angelova, Angelina [University of Arizona; Park, Sang-Hycuk [University of Arizona; Kyndt, John [Bellevue University; Fitzsimmons, Kevin [University of Arizona; Brown, Judith K [University of Arizona

    2013-09-01

    With the increasing world demand for biofuel, a number of oleaginous algal species are being considered as renewable sources of oil. Chlorella protothecoides Krüger synthesizes triacylglycerols (TAGs) as storage compounds that can be converted into renewable fuel utilizing an anabolic pathway that is poorly understood. The paucity of algal chloroplast genome sequences has been an important constraint to chloroplast transformation and for studying gene expression in TAGs pathways. In this study, the intact chloroplasts were released from algal cells using sonication followed by sucrose gradient centrifugation, resulting in a 2.36-fold enrichment of chloroplasts from C. protothecoides, based on qPCR analysis. The C. protothecoides chloroplast genome (cpDNA) was determined using the Illumina HiSeq 2000 sequencing platform and found to be 84,576 Kb in size (8.57 Kb) in size, with a GC content of 30.8 %. This is the first report of an optimized protocol that uses a sonication step, followed by sucrose gradient centrifugation, to release and enrich intact chloroplasts from a microalga (C. prototheocoides) of sufficient quality to permit chloroplast genome sequencing with high coverage, while minimizing nuclear genome contamination. The approach is expected to guide chloroplast isolation from other oleaginous algal species for a variety of uses that benefit from enrichment of chloroplasts, ranging from biochemical analysis to genomics studies.

  14. Photoreduction of chromium(VI) in the presence of algae, Chlorella vulgaris

    International Nuclear Information System (INIS)

    Deng Lin; Wang Hongli; Deng Nansheng

    2006-01-01

    In this thesis, the photochemical reduction of hexavalent chromium Cr(VI) in the presence of algae, Chlorella vulgaris, was investigated under the irradiation of metal halide lamps (λ=365nm, 250W). The affecting factors of photochemical reduction were studied in detail, such as exposure time, initial Cr(VI) concentration, initial algae concentration and pH. The rate of Cr(VI) photochemical reduction increased with algae concentration increasing, exposure time increasing, initial Cr(VI) concentration decreasing and the decrease of pH. When pH increased to 6, the rate of Cr(VI) photochemical reduction nearly vanished. When initial Cr(VI) concentration ranged from 0.4 to 1.0mgL -1 and initial algae concentration ranged from ABS algae (the absorbency of algae)=0.025 to ABS algae =0.180, According to the results of kinetic analyses, the kinetic equation of Cr(VI) photochemical reduction in aqueous solution with algae under 250W metal halide lamps was V 0 =kC 0 0.1718 A algae 0.5235 (C 0 was initial concentration of Cr(VI); A algae was initial concentration of algae) under the condition of pH 4

  15. Harvesting Chlorella vulgaris by natural increase in pH: effect of medium composition.

    Science.gov (United States)

    Nguyen, Thi Dong Phuong; Frappart, Matthieu; Jaouen, Pascal; Pruvost, Jérémy; Bourseau, Patrick

    2014-01-01

    The freshwater microalga Chlorella vulgaris was harvested by autoflocculation resulting from the precipitation of magnesium or calcium compounds induced by a slow increase in pH in the absence of CO2 input. Autoflocculation was tested in two culture media with, respectively, ammonium (NH4+) and nitrate (NO3-) ions as nitrogen source. The culture pH increased because of photosynthesis and CO2 stripping. pH rose to 11 after 8 h in the NO3- medium, but did not exceed 9 in the NH4+ medium. No flocculation took place in any of the media. Autoflocculation tests were repeated in the NO(3-)-based culture medium by progressively increasing the concentrations of Ca2+ and Mg2+ until inorganic compounds precipitated and flocculated microalgae. The minimal concentrations for flocculation were found to be 120 mg Ca2 L(-1) and 1000 mg Mg2+ L(-1). These values were, respectively, 3.5 times and 20 times higher than those allowing flocculation by NaOH addition. Energy-dispersive X-ray spectroscopy, zeta potential measurement, and ionic chromatography suggest that the mechanisms involved are different. The rate of cell removal was close to 90% in both cases, but cells were more concentrated in the aggregates obtained by magnesium compound precipitation, with an estimated concentration close to 33 g (dry matter) L(-1), against 19 g L(-1) for calcium phosphates.

  16. Mixotrophic transition induced lipid productivity in Chlorella pyrenoidosa under stress conditions for biodiesel production

    Directory of Open Access Journals (Sweden)

    Hari Prasad Ratnapuram

    2018-01-01

    Full Text Available Influence of mixotrophic mode and its transition to various trophic modes under stress conditions was assessed during two stage cultivation of Chlorella pyrenoidosa. Significant lipid productivity was triggered under low light intensity, glucose + bicarbonate supplementation and nitrogen starvation. The association between biomass and lipid productivity, fatty acid composition during mixotrophic transition was critically evaluated. Biomass in growth phase (GP and stress phase (SP was 6.14 g/l and 5.14 g/l, respectively, in mixotrophic mode. Higher lipid productivity of 284 g/kg and 154.3 g/kg of neutral lipids was achieved in SP in mixotrophic-mixotrophic (MM and mixotrophic-heterotrophic (MH modes, respectively. Stress conditions resulted in high unsaturated fatty acid methyl esters in MH mode. In addition, neutral lipid content was 58% in MH and 52% in MM, that can be attributed to carbon source that is supplemented even in stress phase. Exploring such novel strategies can generate sustainable avenues for biodiesel production.

  17. Inhibition of Alkaline Flocculation by Algal Organic Matter for Chlorella vulgaris

    Energy Technology Data Exchange (ETDEWEB)

    Vandamme, Dries; Beuckels, Annelies; Vadelius, Eric; Depraetere, Orily; Noppe, Wim; Dutta, Abhishek; Foubert, Imogen; Laurens, Lieve; Muylaert, Koenraad

    2016-01-01

    Alkaline flocculation is a promising strategy for the concentration of microalgae for bulk biomass production. However, previous studies have shown that biological changes during the cultivation negatively affect flocculation efficiency. The influence of changes in cell properties and in the quality and composition of algal organic matter (AOM) were studied using Chlorella vulgaris as a model species. In batch cultivation, flocculation was increasingly inhibited over time and mainly influenced by changes in medium composition, rather than biological changes at the cell surface. Total carbohydrate content of the organic matter fraction sized bigger than 3 kDa increased over time and this fraction was shown to be mainly responsible for the inhibition of alkaline flocculation. The monosaccharide identification of this fraction mainly showed the presence of neutral and anionic monosaccharides. An addition of 30–50 mg L-1 alginic acid, as a model for anionic carbohydrate polymers containing uronic acids, resulted in a complete inhibition of flocculation. Furthermore, these results suggest that inhibition of alkaline flocculation was caused by interaction of anionic polysaccharides leading to an increased flocculant demand over time.

  18. Effects of Escherichia coli on mixotrophic growth of Chlorella minutissima and production of biofuel precursors.

    Directory of Open Access Journals (Sweden)

    Brendan T Higgins

    Full Text Available Chlorella minutissima was co-cultured with Escherichia coli in airlift reactors under mixotrophic conditions (glucose, glycerol, and acetate substrates to determine possible effects of bacterial contamination on algal biofuel production. It was hypothesized that E. coli would compete with C. minutissima for nutrients, displacing algal biomass. However, C. minutissima grew more rapidly and to higher densities in the presence of E. coli, suggesting a symbiotic relationship between the organisms. At an initial 1% substrate concentration, the co-culture produced 200-587% more algal biomass than the axenic C. minutissima cultures. Co-cultures grown on 1% substrate consumed 23-737% more of the available carbon substrate than the sum of substrate consumed by E. coli and C. minutissima alone. At 1% substrate, total lipid and starch productivity were elevated in co-cultures compared to axenic cultures indicating that bacterial contamination was not detrimental to the production of biofuel precursors in this specific case. Bio-fouling of the reactors observed in co-cultures and acid formation in all mixotrophic cultures, however, could present challenges for scale-up.

  19. Optimization of the biomass production of oil algae Chlorella minutissima UTEX2341.

    Science.gov (United States)

    Li, ZhaoSheng; Yuan, HongLi; Yang, JinShui; Li, BaoZhen

    2011-10-01

    High production cost is a major obstacle to the extensive use of microalgae biodiesel. To cut the cost and achieve higher biomass productivity, Chlorella minutissima UTEX2341 was cultured under photoheterotrophic conditions. With the carbon, nitrogen and phosphorus concentration of 26.37, 2.61 and 0.03 g L⁻¹ d⁻¹ respectively, a maximum biomass productivity of 1.78 g L⁻¹ d⁻¹ was obtained, which was 59 times more than that cultured under autotrophic condition. The lipid productivity reached 0.29 g L⁻¹ d⁻¹, which was 11.9 times higher than the highest value reported by Oh et al. (2010). The conversion rate of microalgae lipids to FAME was found to be elevated from 45.65% to 62.97% and the FAME productivity increased from 1.16 to 180.68 mg L⁻¹ d⁻¹ after the optimization. 94% of the fatty acid of C. minutissima UTEX2341 was found to be composed of palmitic, oleic, linoleic and γ linoleic and the unsaturated fatty acids were the main parts (79.42%). Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Diuron sorbed to carbon nanotubes exhibits enhanced toxicity to Chlorella vulgaris.

    Science.gov (United States)

    Schwab, Fabienne; Bucheli, Thomas D; Camenzuli, Louise; Magrez, Arnaud; Knauer, Katja; Sigg, Laura; Nowack, Bernd

    2013-07-02

    Carbon nanotubes (CNT) are more and more likely to be present in the environment, where they will associate with organic micropollutants due to strong sorption. The toxic effects of these CNT-micropollutant mixtures on aquatic organisms are poorly characterized. Here, we systematically quantified the effects of the herbicide diuron on the photosynthetic activity of the green alga Chlorella vulgaris in presence of different multiwalled CNT (industrial, purified, pristine, and oxidized) or soot. The presence of carbonaceous nanoparticles reduced the adverse effect of diuron maximally by diuron concentrations in the range 0.73-2990 μg/L. However, taking into account the measured dissolved instead of the nominal diuron concentration, the toxic effect of diuron was equal to or stronger in the presence of CNT by a factor of up to 5. Sorbed diuron consequently remained partially bioavailable. The most pronounced increase in toxicity occurred after a 24 h exposure of algae and CNT. All results point to locally elevated exposure concentration (LEEC) in the proximity of algal cells associated with CNT as the cause for the increase in diuron toxicity.

  1. Growing Chlorella sp. on meat processing wastewater for nutrient removal and biomass production.

    Science.gov (United States)

    Lu, Qian; Zhou, Wenguang; Min, Min; Ma, Xiaochen; Chandra, Ceria; Doan, Yen T T; Ma, Yiwei; Zheng, Hongli; Cheng, Sibo; Griffith, Richard; Chen, Paul; Chen, Chi; Urriola, Pedro E; Shurson, Gerald C; Gislerød, Hans R; Ruan, Roger

    2015-12-01

    In this work, Chlorella sp. (UM6151) was selected to treat meat processing wastewater for nutrient removal and biomass production. To balance the nutrient profile and improve biomass yield at low cost, an innovative algae cultivation model based on wastewater mixing was developed. The result showed that biomass yield (0.675-1.538 g/L) of algae grown on mixed wastewater was much higher than that on individual wastewater and artificial medium. Wastewater mixing eased the bottleneck for algae growth and contributed to the improved biomass yield. Furthermore, in mixed wastewater with sufficient nitrogen, ammonia nitrogen removal efficiencies (68.75-90.38%) and total nitrogen removal efficiencies (30.06-50.94%) were improved. Wastewater mixing also promoted the synthesis of protein in algal cells. Protein content of algae growing on mixed wastewater reached 60.87-68.65%, which is much higher than that of traditional protein source. Algae cultivation model based on wastewater mixing is an efficient and economical way to improve biomass yield. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Stereocontrolled reduction of alpha- and beta-keto esters with micro green algae, Chlorella strains.

    Science.gov (United States)

    Ishihara, K; Yamaguchi, H; Adachi, N; Hamada, H; Nakajima, N

    2000-10-01

    The stereocontrolled reduction of alpha- and beta-keto esters using micro green algae was accomplished by a combination of the cultivation method and the introduction of an additive. The reduction of ethyl pyruvate and ethyl benzoylformate by the photoautotrophically cultivated Chlorella sorokiniana gave the corresponding alcohol in high e.e. (>99% e.e. (S) and >99% e.e. (R), respectively). In the presence of glucose as an additive, the reduction of ethyl 3-methyl-2-oxobutanoate by the heterotrophically cultivated C. sorokiniana afforded the corresponding (R)-alcohol. On the other hand, the reduction in the presence of ethyl propionate gave the (S)-alcohol. Ethyl 2-methyl-3-oxobutanoate was reduced in the presence of glycerol by the photoautotrophically cultivated C. sorokiniana or the heterotrophically cultivated C. sorokiniana to the corresponding syn-(2R,3S)-hydroxy ester with high diastereo- and enantiomeric excess (e.e.). Some additives altered the stereochemical course in the reduction of alpha- and beta-keto esters.

  3. Production of biodiesel from Chlorella sp. enriched with oyster shell extracts.

    Science.gov (United States)

    Choi, Cheol Soon; Choi, Woon Yong; Kang, Do Hyung; Lee, Hyeon Yong

    2014-01-01

    This study investigated the cultivation of the marine microalga Chlorella sp. without supplying an inorganic carbon source, but instead with enriching the media with extracts of oyster shells pretreated by a high-pressure homogenization process. The pretreated oyster shells were extracted by a weak acid, acetic acid, that typically has harmful effects on cell growth and also poses environmental issues. The concentration of the residual dissolved carbon dioxide in the medium was sufficient to maintain cell growth at 32 ppm and pH 6.5 by only adding 5% (v/v) of oyster shell extracts. Under this condition, the maximum cell density observed was 2.74 g dry wt./L after 27 days of cultivation. The total lipid content was also measured as 18.1 (%, w/w), and this value was lower than the 23.6 (%, w/w) observed under nitrogen deficient conditions or autotrophic conditions. The fatty acid compositions of the lipids were also measured as 10.9% of C16:1 and 16.4% of C18:1 for the major fatty acids, which indicates that the biodiesel from this culture process should be a suitable biofuel. These results suggest that oyster shells, environmental waste from the food industry, can be used as a nutrient and carbon source with seawater, and this reused material should be important for easily scaling up the process for an outdoor culture system.

  4. Incorporation of Chlorella vulgaris and Spirulina maxima biomass in pasta products. Part 1: Preparation and evaluation.

    Science.gov (United States)

    Fradique, Mónica; Batista, Ana Paula; Nunes, M Cristiana; Gouveia, Luísa; Bandarra, Narcisa M; Raymundo, Anabela

    2010-08-15

    Microalgae are able to enhance the nutritional content of conventional foods and hence to positively affect human health, due to their original chemical composition. The aim of the present study was to prepare fresh spaghetti enriched with different amounts of microalgae biomass (Chlorella vulgaris and Spirulina maxima) and to compare the quality parameters (optimal cooking time, cooking losses, swelling index and water absorption), chemical composition, instrumental texture and colour of the raw and cooked pasta enriched with microalgae biomass with standard semolina spaghetti. The incorporation of microalgae results in an increase of quality parameters when compared to the control sample. The colour of microalgae pastas remained relatively stable after cooking. The addition of microalgae resulted in an increase in the raw pasta firmness when compared to the control sample. Of all the microalgae studied, an increase in the biomass concentration (0.5-2.0%) resulted in a general tendency of an increase in the pasta firmness. Sensory analysis revealed that microalgae pastas had higher acceptance scores by the panellists than the control pasta. Microalgae pastas presented very appellative colours, such as orange and green, similar to pastas produced with vegetables, with nutritional advantages, showing energetic values similar to commercial pastas. The use of microalgae biomass can enhance the nutritional and sensorial quality of pasta, without affecting its cooking and textural properties. Copyright (c) 2010 Society of Chemical Industry.

  5. Oral administration of hot water extracts of Chlorella vulgaris increases physical stamina in mice.

    Science.gov (United States)

    An, Hyo-Jin; Choi, Hyun-Myung; Park, Hyeung-Suk; Han, Jae-Gab; Lee, Eun-Hee; Park, Young-Sig; Um, Jae-Young; Hong, Seung-Heon; Kim, Hyung-Min

    2006-01-01

    A unicellular algae, Chlorella vulgaris, was used as a biological response modifier. Although hot water extracts of C. vulgaris (CVE) are thought to augment immune responses, the effect of CVE on fatigue and physical stamina has not been studied. In the present study, we investigated the effect of CVE on forced swimming test and blood biochemical parameters related to fatigue, blood urea nitrogen (BUN), creatine kinase (CK), lactic dehydrogenase (LDH), glucose (Glc), and total protein (TP). CVE (0.05-0.15 g/kg/day) was orally administered to mice. After 7 days, the immobility time was decreased in the 0.1- and 0.15-g/kg CVE-treated groups (179 +/- 8.3 and 175 +/- 2.1 s) in comparison with the control group (223 +/- 5.4 s). In addition, the contents of BUN, CK, and LDH in the blood serum were decreased in the CVE-fed group. However, they had no effect on the elevation of Glc and TP level. The results predict a potential benefit of CVE for enhancing immune function and improving physical stamina. Copyright 2006 S. Karger AG, Basel.

  6. Ecotoxicity tests using the green algae Chlorella vulgaris--a useful tool in hazardous effluents management.

    Science.gov (United States)

    Silva, Aurora; Figueiredo, Sónia A; Sales, M Goreti; Delerue-Matos, Cristina

    2009-08-15

    The treatment efficiency of laboratory wastewaters was evaluated and ecotoxicity tests with Chlorella vulgaris were performed on them to assess the safety of their environmental discharge. For chemical oxygen demand wastewaters, chromium (VI), mercury (II) and silver were efficiently removed by chemical treatments. A reduction of ecotoxicity was achieved; nevertheless, an EC50 (effective concentration that causes a 50% inhibition in the algae growth) of 1.5% (v/v) indicated still high level of ecotoxicity. For chloride determination wastewaters, an efficient reduction of chromium and silver was achieved after treatment. Regarding the reduction of ecotoxicity observed, EC50 increased from 0.059% to 0.5%, only a 0.02% concentration in the aquatic environment would guarantee no effects. Wastewaters containing phenanthroline/iron (II) complex were treated by chemical oxidation. Treatment was satisfactory concerning chemical parameters, although an increase in ecotoxicity was observed (EC50 reduced from 0.31% to 0.21%). The wastes from the kinetic study of persulphate and iodide reaction were treated with sodium bisulphite until colour was removed. Although they did not reveal significant ecotoxicity, only over 1% of the untreated waste produced observable effects over algae. Therefore, ecotoxicity tests could be considered a useful tool not only in laboratory effluents treatment, as shown, but also in hazardous wastewaters management.

  7. The transformation of nitrogen during pressurized entrained-flow pyrolysis of Chlorella vulgaris.

    Science.gov (United States)

    Maliutina, Kristina; Tahmasebi, Arash; Yu, Jianglong

    2018-08-01

    The transformation of nitrogen in microalgae during entrained-flow pyrolysis of Chlorella vulgaris was systematically investigated at the temperatures of 600-900 °C and pressures of 0.1-4.0 MPa. It was found that pressure had a profound impact on the transformation of nitrogen during pyrolysis. The nitrogen retention in bio-char and its content in bio-oil reached a maximum value at 1.0 MPa. The highest conversion of nitrogen (50.25 wt%) into bio-oil was achieved at 1.0 MPa and 800 °C, which was about 7 wt% higher than that at atmospheric pressure. Higher pressures promoted the formation of pyrrolic-N (N-5) and quaternary-N (N-Q) compounds in bio-oil at the expense of nitrile-N and pyridinic-N (N-6) compounds. The X-Ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) results on bio-chars clearly evidenced the transformation of N-5 structures into N-6 and N-Q structures at elevated pressures. The nitrogen transformation pathways during pyrolysis of microalgae were proposed and discussed. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Statistical optimization of harvesting Chlorella vulgaris using a novel bio-source, Strychnos potatorum

    Directory of Open Access Journals (Sweden)

    Sirajunnisa Abdul Razack

    2015-09-01

    Full Text Available The present study was aimed at harvesting microalga, Chlorella vulgaris, by bioflocculation using seed powder of clearing nut, Strychnos potatorum. The research was essentially the prime step to yield a large biomass for utilising the cells in biodiesel production. Optimization of the parameters influencing bioflocculation was carried out statistically using RSM. The optimized conditions were 100 mg L−1 bioflocculant concentration, 35 °C temperature, 150 rpm agitation speed and 30 min incubation time and resulted in a maximum efficiency of 99.68%. Through cell viability test, using Trypan blue stain, it was found that cells were completely intact when treated with bioflocculant, but destroyed when exposed to chemical flocculant, alum. The overall study represented that S. potatorum could potentially be a bioflocculant of microalgal cells and a promising substitute for expensive and hazardous chemical flocculants. Moreover, this bioflocculant demonstrated their utility to harvest microalgal cells by economically, effectively and in an ecofriendly way.

  9. Production of Microalgal Lipids as Biodiesel Feedstock with Fixation of CO2 by Chlorella vulgaris

    Directory of Open Access Journals (Sweden)

    Qiao Hu

    2014-01-01

    Full Text Available The global warming and shortage of energy are two critical problems for human social development. CO2 mitigation and replacing conventional diesel with biodiesel are effective routes to reduce these problems. Production of microalgal lipids as biodiesel feedstock by a freshwater microalga, Chlorella vulgaris, with the ability to fixate CO2 is studied in this work. The results show that nitrogen deficiency, CO2 volume fraction and photoperiod are the key factors responsible for the lipid accumulation in C. vulgaris. With 5 % CO2, 0.75 g/L of NaNO3 and 18:6 h of light/dark cycle, the lipid content and overall lipid productivity reached 14.5 % and 33.2 mg/(L·day, respectively. Furthermore, we proposed a technique to enhance the microalgal lipid productivity by activating acetyl-CoA carboxylase (ACCase with an enzyme activator. Citric acid and Mg2+ were found to be efficient enzyme activators of ACCase. With the addition of 150 mg/L of citric acid or 1.5 mmol/L of MgCl2, the lipid productivity reached 39.1 and 38.0 mg/(L·day, respectively, which was almost twofold of the control. This work shows that it is practicable to produce lipids by freshwater microalgae that can fixate CO2, and provides a potential route to solving the global warming and energy shortage problems.

  10. Isolation and characterization of two different flavodoxins from the eukaryote Chlorella fusca.

    Science.gov (United States)

    Peleato, M L; Ayora, S; Inda, L A; Gómez-Moreno, C

    1994-01-01

    Two different molecular forms of flavodoxin from the green alga Chlorella fusca have been purified to homogeneity and their properties compared. The molecular masses are 22 kDa (flavodoxin I) and 20 kDa (flavodoxin II). Western blots of axenic crude extract show the two bands. Both are single polypeptide chains and their N-terminal sequences differ but are very similar. Each form contains 1 mol of FMN/mol of apoprotein, exhibits a typical flavodoxin u.v.-visible absorption spectrum and does not contain covalently bound phosphate. The oxidation-reduction properties of the FMN in the flavodoxins differ considerably. Redox potentials of flavodoxin I at pH8 are -240 mV for the oxidized/semiquinone couple and -350 mV for the semiquinone/hydroquinone couple. Flavodoxin II gives more electronegative values: -278 mV and -458 mV respectively. Flavodoxin II fulfils better the redox requirements for photosynthetic electron transport and, as expected, it is more efficient at mediating NADP+ photoreduction in the photosynthetic electron flow. A new h.p.l.c. method for flavodoxin purification is described, which is useful for the isolation of very similar anionic proteins. Images Figure 2 Figure 3 PMID:7945206

  11. Effects of iron and manganese on the formation of HAAs upon chlorinating Chlorella vulgaris

    International Nuclear Information System (INIS)

    Ge, Fei; Wu, Xiuzhen; Wang, Na; Zhu, Runliang; Wang, Tong; Xu, Yin

    2011-01-01

    The major objective of the present study was to investigate the role of iron and manganese on the formation of haloacetic acids (HAAs) when algae are chlorinated at different pHs. The results showed that both iron and manganese can reduce the yields of dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) on chlorinating green alga Chlorella vulgaris (C. vulgaris) at a pH range of 6.0-9.0, and the decline of DCAA and TCAA was shown to be more significant at the low pH range. At pH 6.0, DCAA and TCAA yields decreased by 44.5% and 57.3%, respectively with the addition of 0.5 mg L -1 iron, and decreased 39.5% and 49.4%, respectively with the addition of 0.5 mg L -1 manganese. The main reason for decreasing the yields of HAAs as shown by scanning electron microscope (SEM) is that Fe(OH) 3(am) or MnO 2(am) coat the algal cells , which then improves their agglomeration of algal cells which is also revealed by the laser particle size analysis (LPSA).

  12. Photoreduction of chromium(VI) in the presence of algae, Chlorella vulgaris

    Energy Technology Data Exchange (ETDEWEB)

    Deng Lin [School of Resources and Environmental Science, Wuhan University, Wuhan 430072 (China); Wang Hongli [School of Resources and Environmental Science, Wuhan University, Wuhan 430072 (China); Deng Nansheng [School of Resources and Environmental Science, Wuhan University, Wuhan 430072 (China)]. E-mail: nsdengwhu@163.com

    2006-11-16

    In this thesis, the photochemical reduction of hexavalent chromium Cr(VI) in the presence of algae, Chlorella vulgaris, was investigated under the irradiation of metal halide lamps ({lambda}=365nm, 250W). The affecting factors of photochemical reduction were studied in detail, such as exposure time, initial Cr(VI) concentration, initial algae concentration and pH. The rate of Cr(VI) photochemical reduction increased with algae concentration increasing, exposure time increasing, initial Cr(VI) concentration decreasing and the decrease of pH. When pH increased to 6, the rate of Cr(VI) photochemical reduction nearly vanished. When initial Cr(VI) concentration ranged from 0.4 to 1.0mgL{sup -1} and initial algae concentration ranged from ABS{sub algae} (the absorbency of algae)=0.025 to ABS{sub algae}=0.180, According to the results of kinetic analyses, the kinetic equation of Cr(VI) photochemical reduction in aqueous solution with algae under 250W metal halide lamps was V{sub 0}=kC{sub 0}{sup 0.1718}A{sub algae}{sup 0.5235} (C{sub 0} was initial concentration of Cr(VI); A{sub algae} was initial concentration of algae) under the condition of pH 4.

  13. Enhancement of Chlorella vulgaris Biomass Cultivated in POME Medium as Biofuel Feedstock under Mixotrophic Conditions

    Directory of Open Access Journals (Sweden)

    M.M. Azimatun Nur

    2015-10-01

    Full Text Available Microalgae cultivated in mixotrophic conditions have received significant attention as a suitable source of biofuel feedstock, based on their high biomass and lipid productivity. POME is one of the wastewaters generated from palm oil mills, containing important nutrients that could be suitable for mixotrophic microalgae growth. The aim of this research was to identify the growth of Chlorella vulgaris cultured in POME medium under mixotrophic conditions in relation to a variety of organic carbon sources added to the POME mixture. The research was conducted with 3 different carbon sources (D-glucose, crude glycerol and NaHCO3 in 40% POME, monitored over 6 days, under an illumination of 3000 lux, and with pH = 7. The biomass was harvested using an autoflocculation method and dry biomass was extracted using an ultrasound method in order to obtain the lipid content. The results show that C. vulgaris using D-glucose as carbon source gained a lipid productivity of 195 mg/l/d.

  14. Ecotoxicity tests using the green algae Chlorella vulgaris-A useful tool in hazardous effluents management

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Aurora [REQUIMTE, Instituto Superior de Engenharia do Instituto Politecnico do Porto, R. Antonio Bernardino de Almeida, 431 4200-072 Porto (Portugal); Figueiredo, Sonia A., E-mail: saf@isep.ipp.pt [REQUIMTE, Instituto Superior de Engenharia do Instituto Politecnico do Porto, R. Antonio Bernardino de Almeida, 431 4200-072 Porto (Portugal); Sales, M. Goreti; Delerue-Matos, Cristina [REQUIMTE, Instituto Superior de Engenharia do Instituto Politecnico do Porto, R. Antonio Bernardino de Almeida, 431 4200-072 Porto (Portugal)

    2009-08-15

    The treatment efficiency of laboratory wastewaters was evaluated and ecotoxicity tests with Chlorella vulgaris were performed on them to assess the safety of their environmental discharge. For chemical oxygen demand wastewaters, chromium (VI), mercury (II) and silver were efficiently removed by chemical treatments. A reduction of ecotoxicity was achieved; nevertheless, an EC50 (effective concentration that causes a 50% inhibition in the algae growth) of 1.5% (v/v) indicated still high level of ecotoxicity. For chloride determination wastewaters, an efficient reduction of chromium and silver was achieved after treatment. Regarding the reduction of ecotoxicity observed, EC50 increased from 0.059% to 0.5%, only a 0.02% concentration in the aquatic environment would guarantee no effects. Wastewaters containing phenanthroline/iron (II) complex were treated by chemical oxidation. Treatment was satisfactory concerning chemical parameters, although an increase in ecotoxicity was observed (EC50 reduced from 0.31% to 0.21%). The wastes from the kinetic study of persulphate and iodide reaction were treated with sodium bisulphite until colour was removed. Although they did not reveal significant ecotoxicity, only over 1% of the untreated waste produced observable effects over algae. Therefore, ecotoxicity tests could be considered a useful tool not only in laboratory effluents treatment, as shown, but also in hazardous wastewaters management.

  15. Effects of sodium pentaborate pentahydrate exposure on Chlorella vulgaris growth, chlorophyll content, and enzyme activities.

    Science.gov (United States)

    Chen, Xueqing; Pei, Yuansheng

    2016-10-01

    Sodium pentaborate pentahydrate (SPP) is a rare mineral. In this study, SPP was synthesized from boric acid and borax through low-temperature crystallization, and its effects on the growth of the alga, Chlorella vulgaris (C. vulgaris) were assessed. The newly synthesized SPP was characterized by chemical analysis, X-ray diffraction, Fourier-transform infrared spectroscopy, Raman spectroscopy, thermogravimetric analysis, and differential thermal analysis. The changes in C. vulgaris growth, chlorophyll content, and enzyme activities upon exposure to SPP for 168h were evaluated. Results showed that SPP treatment was detrimental to C. vulgaris growth during the first 24-120h of exposure. The harmful effects, however, diminished over time (168h), even at an effective medium concentration of 226.37mg BL(-1) (the concentration of boron applied per liter of culture medium). A similar trend was observed for chlorophyll content (chlorophyll a and b) and indicated that the photosynthesis of C. vulgaris was not affected and that high levels of SPP may even promote chlorophyll synthesis. Superoxide dismutase and catalase activities of C. vulgaris increased during 24-120h exposure to SPP, but these activities gradually decreased as culture time progressed. In other words, the initial detrimental effects of synthetic SPP on C. vulgaris were temporary and reversible. This research provides a scientific basis for applications of SPP in the environment. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Combined effect of copper and cadmium on Chlorella vulgaris growth and photosynthesis-related gene transcription

    International Nuclear Information System (INIS)

    Qian Haifeng; Li Jingjing; Sun Liwei; Chen Wei; Sheng, G. Daniel; Liu Weiping; Fu Zhengwei

    2009-01-01

    Chlorella vulgaris was tested to assess their toxicities in freshwater contaminated by the metal compounds of copper (Cu) and cadmium (Cd), both singly and combined. Exposure to 0.5 and 1.5 μM Cu or 1.0 and 2.0 μM Cd alone significantly decreased algal growth and chlorophyll content and increased reactive oxygen species (ROS) content. Two-way ANOVA analysis shows that the combination of these two metal compounds decreased cell growth, chlorophyll content and increased ROS content synergistically. The highest algal cell inhibition was 78.55%, the lowest levels of chl a, chl b and total-chl were 10.59%, 33.33% and 17.94% of the control, respectively. The highest increase in ROS was 9.15-fold greater than that of the control when exposed to Cu(1.5) + Cd(2.0). Real-time PCR shows that Cu and Cd reduced the transcript abundance of psbA and rbcL, but without a synergistic interaction, whereas Cu and Cd increased the transcript abundance of psaB synergistically. These results demonstrate that Cu and Cd independently inhibit PSII activity and CO 2 assimilation, but synergistically increase ROS content to disrupt chlorophyll synthesis and inhibit cell growth.

  17. Investigation of high pressure steaming (HPS) as a thermal treatment for lipid extraction from Chlorella vulgaris.

    Science.gov (United States)

    Aguirre, Ana-Maria; Bassi, Amarjeet

    2014-07-01

    Biofuels from algae are considered a technically viable energy source that overcomes several of the problems present in previous generations of biofuels. In this research high pressure steaming (HPS) was studied as a hydrothermal pre-treatment for extraction of lipids from Chlorella vulgaris, and analysis by response surface methodology allowed finding operational points in terms of target temperature and algae concentration for high lipid and glucose yields. Within the range covered by these experiments the best conditions for high bio-crude yield are temperatures higher than 174°C and low biomass concentrations (<5 g/L). For high glucose yield there are two suitable operational ranges, either low temperatures (<105°C) and low biomass concentrations (<4 g/L); or low temperatures (<105°C) and high biomass concentrations (<110 g/L). High pressure steaming is a good hydrothermal treatment for lipid recovery and does not significantly change the fatty acids profile for the range of temperatures studied. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Exploration of upstream and downstream process for microwave assisted sustainable biodiesel production from microalgae Chlorella vulgaris.

    Science.gov (United States)

    Sharma, Amit Kumar; Sahoo, Pradeepta Kumar; Singhal, Shailey; Joshi, Girdhar

    2016-09-01

    The present study explores the integrated approach for the sustainable production of biodiesel from Chlorella vulgaris microalgae. The microalgae were cultivated in 10m(2) open raceway pond at semi-continuous mode with optimum volumetric and areal production of 28.105kg/L/y and 71.51t/h/y, respectively. Alum was used as flocculent for harvesting the microalgae and optimized at different pH. Lipid was extracted using chloroform: methanol (2:1) and having 12.39% of FFA. Effect of various reaction conditions such as effect of catalyst, methanol:lipid ratio, reaction temperature and time on biodiesel yields were studied under microwave irradiation; and 84.01% of biodiesel yield was obtained under optimized reaction conditions. A comparison was also made between the biodiesel productions under conventional heating and microwave irradiation. The synthesized biodiesel was characterized by (1)H NMR, (13)C NMR, FTIR and GC; however, fuel properties of biodiesel were also studied using specified test methods as per ASTM and EN standards. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. The boosted biomass and lipid accumulation in Chlorella vulgaris by supplementation of synthetic phytohormone analogs.

    Science.gov (United States)

    Liu, Tingting; Liu, Fei; Wang, Chao; Wang, Zhenyao; Li, Yuqin

    2017-05-01

    This study attempted at maximizing biomass and lipid accumulation in Chlorella vulgaris by supplementation of natural abscisic acid (ABA) or synthetic 2,4-dichlorophenoxyacetic acid (2,4-D) and 1-naphthaleneacetic acid (NAA) hormone analogs. Amongst three tested additives, NAA-treatment performed remarkable promoting effect on cell growth and lipid biosynthesis. The favorable lipid productivity (418.6mg/L/d) of NAA-treated cells showed 1.48 and 2.24 times more than that of 2,4-D and ABA. NAA-treatment also positively modified the proportions of saturated (C16:0 and C18:0) and monounsaturated fatty acids (C18:1) which were prone to high-quality biofuels-making. Further, NAA-treatment manipulated endogenous phytohormones metabolism leading to the elevated levels of indole-3-acetic acid, jasmonic acid, and salicylic acid and such hormone accumulation might be indispensable for signal transduction in regulating cell growth and lipid biosynthesis in microalgae. In addition, the economic-feasibility and eco-friendly estimation of NAA additive indicated the higher possibilities in developing affordable and scalable microalgal lipids for biofuels. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Combined effect of copper and cadmium on Chlorella vulgaris growth and photosynthesis-related gene transcription

    Energy Technology Data Exchange (ETDEWEB)

    Qian Haifeng; Li Jingjing; Sun Liwei; Chen Wei; Sheng, G. Daniel; Liu Weiping [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China); Fu Zhengwei, E-mail: azwfu2003@yahoo.com.cn [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China)

    2009-08-13

    Chlorella vulgaris was tested to assess their toxicities in freshwater contaminated by the metal compounds of copper (Cu) and cadmium (Cd), both singly and combined. Exposure to 0.5 and 1.5 {mu}M Cu or 1.0 and 2.0 {mu}M Cd alone significantly decreased algal growth and chlorophyll content and increased reactive oxygen species (ROS) content. Two-way ANOVA analysis shows that the combination of these two metal compounds decreased cell growth, chlorophyll content and increased ROS content synergistically. The highest algal cell inhibition was 78.55%, the lowest levels of chl a, chl b and total-chl were 10.59%, 33.33% and 17.94% of the control, respectively. The highest increase in ROS was 9.15-fold greater than that of the control when exposed to Cu(1.5) + Cd(2.0). Real-time PCR shows that Cu and Cd reduced the transcript abundance of psbA and rbcL, but without a synergistic interaction, whereas Cu and Cd increased the transcript abundance of psaB synergistically. These results demonstrate that Cu and Cd independently inhibit PSII activity and CO{sub 2} assimilation, but synergistically increase ROS content to disrupt chlorophyll synthesis and inhibit cell growth.

  1. Ecotoxicity tests using the green algae Chlorella vulgaris-A useful tool in hazardous effluents management

    International Nuclear Information System (INIS)

    Silva, Aurora; Figueiredo, Sonia A.; Sales, M. Goreti; Delerue-Matos, Cristina

    2009-01-01

    The treatment efficiency of laboratory wastewaters was evaluated and ecotoxicity tests with Chlorella vulgaris were performed on them to assess the safety of their environmental discharge. For chemical oxygen demand wastewaters, chromium (VI), mercury (II) and silver were efficiently removed by chemical treatments. A reduction of ecotoxicity was achieved; nevertheless, an EC50 (effective concentration that causes a 50% inhibition in the algae growth) of 1.5% (v/v) indicated still high level of ecotoxicity. For chloride determination wastewaters, an efficient reduction of chromium and silver was achieved after treatment. Regarding the reduction of ecotoxicity observed, EC50 increased from 0.059% to 0.5%, only a 0.02% concentration in the aquatic environment would guarantee no effects. Wastewaters containing phenanthroline/iron (II) complex were treated by chemical oxidation. Treatment was satisfactory concerning chemical parameters, although an increase in ecotoxicity was observed (EC50 reduced from 0.31% to 0.21%). The wastes from the kinetic study of persulphate and iodide reaction were treated with sodium bisulphite until colour was removed. Although they did not reveal significant ecotoxicity, only over 1% of the untreated waste produced observable effects over algae. Therefore, ecotoxicity tests could be considered a useful tool not only in laboratory effluents treatment, as shown, but also in hazardous wastewaters management.

  2. Cultivating Chlorella vulgaris and Scenedesmus quadricauda microalgae to degrade inorganic compounds and pesticides in water.

    Science.gov (United States)

    Baglieri, Andrea; Sidella, Sarah; Barone, Valeria; Fragalà, Ferdinando; Silkina, Alla; Nègre, Michèle; Gennari, Mara

    2016-09-01

    This work evaluates the possibility of cultivating Scenedesmus quadricauda and Chlorella vulgaris microalgae in wastewater from the hydroponic cultivation of tomatoes with the aim of purifying the water. S. quadricauda and C. vulgaris were also used in purification tests carried out on water contaminated by the following active ingredients: metalaxyl, pyrimethanil, fenhexamid, iprodione, and triclopyr. Fifty-six days after the inoculum was placed, a reduction was found in the concentration of nitric nitrogen, ammonia nitrogen, and soluble and total phosphorus. The decrease was 99, 83, 94, and 94 %, respectively, for C. vulgaris and 99, 5, 88, and 89 %, respectively, for S. quadricauda. When the microalgae were present, all the agrochemicals tested were removed more quickly from the water than from the sterile control (BG11). The increase in the rate of degradation was in the order metalaxyl > fenhexamid > iprodione > triclopyr > pyrimethanil. It was demonstrated that there was a real degradation of fenhexamid, metalaxyl, triclopyr, and iprodione, while in the case of pyrimethanil, the active ingredient removed from the substrate was absorbed onto the cells of the microalgae. It was also found that the agrochemicals used in the tests had no significant effect on the growth of the two microalgae. The experiment highlighted the possibility of using cultivations of C. vulgaris and S. quadricauda as purification systems for agricultural wastewater which contains eutrophic inorganic compounds such as nitrates and phosphates and also different types of pesticides.

  3. First evidence of bioflocculant from Shinella albus with flocculation activity on harvesting of Chlorella vulgaris biomass.

    Science.gov (United States)

    Li, Yi; Xu, Yanting; Liu, Lei; Jiang, Xiaobing; Zhang, Kun; Zheng, Tianling; Wang, Hailei

    2016-10-01

    Bioflocculant from Shinella albus xn-1 could be used to harvest energy-producing microalga Chlorella vulgaris biomass for the first time. In this study, we investigated the flocculation activity and mode of strain xn-1, the characteristics of bioflocculant, the effect of flocculation conditions and optimized the flocculation efficiency. The results indicated that strain xn-1 exhibited flocculation activity through secreting bioflocculant; the bioflocculant with high thermal stability, pH stability and low molecular weight was proved to be not protein and polysaccharide, and flocculation active component was confirmed to contain triple bond and cumulated double bonds; algal pH, temperature and metal ions showed great impacts on the flocculation efficiency of bioflocculant; the maximum flocculation activity of bioflocculant reached 85.65% after the response surface optimization. According to the results, the bioflocculant from S. albus xn-1 could be a good potential in applications for high-efficiency harvesting of microalgae. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Effects of iron and manganese on the formation of HAAs upon chlorinating Chlorella vulgaris

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Fei, E-mail: gefei@xtu.edu.cn [Department of Environmental Science and Engineering, Xiangtan University, Egongtang Road, Xiangtan, Hunan 411105 (China); Wu, Xiuzhen; Wang, Na; Zhu, Runliang; Wang, Tong; Xu, Yin [Department of Environmental Science and Engineering, Xiangtan University, Egongtang Road, Xiangtan, Hunan 411105 (China)

    2011-05-15

    The major objective of the present study was to investigate the role of iron and manganese on the formation of haloacetic acids (HAAs) when algae are chlorinated at different pHs. The results showed that both iron and manganese can reduce the yields of dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) on chlorinating green alga Chlorella vulgaris (C. vulgaris) at a pH range of 6.0-9.0, and the decline of DCAA and TCAA was shown to be more significant at the low pH range. At pH 6.0, DCAA and TCAA yields decreased by 44.5% and 57.3%, respectively with the addition of 0.5 mg L{sup -1} iron, and decreased 39.5% and 49.4%, respectively with the addition of 0.5 mg L{sup -1} manganese. The main reason for decreasing the yields of HAAs as shown by scanning electron microscope (SEM) is that Fe(OH){sub 3(am)} or MnO{sub 2(am)} coat the algal cells{sub ,} which then improves their agglomeration of algal cells which is also revealed by the laser particle size analysis (LPSA).

  5. The Bioconcentration and Degradation of Nonylphenol and Nonylphenol Polyethoxylates by Chlorella vulgaris

    Directory of Open Access Journals (Sweden)

    Hong-Wen Sun

    2014-01-01

    Full Text Available Nonylphenol polyethoxylates (NPnEOs, a major class of nonionic surfactants, can easily enter into aquatic environments through various pathways due to their wide applications, which leads to the extensive existence of their relative stable metabolites, namely nonylphenol (NP and mono- to tri-ethoxylates. This study investigated the bioconcentration and degradation of NP and NPnEO oligomers (n = 1–12 by a green algae, Chlorella vulgaris. Experimental results showed that C. vulgaris can remove NP from water phase efficiently, and bioconcentration and degradation accounted for approximately half of its loss, respectively, with a 48 h BCF (bioconcentration factor of 2.42 × 103. Moreover, C. vulgaris could concentrate and degrade NPnEOs, distribution profiles of the series homologues of the NPnEOs in algae and water phase were quite different from the initial homologue profile. The 48 h BCF of the NPnEO homologues increased with the length of the EO chain. Degradation extent of total NPnEOs by C. vulgaris was 95.7%, and only 1.1% remained in water phase, and the other 3.2% remained in the algal cells. The algae removed the NPnEOs mainly through degradation. Due to rapid degradation, concentrations of the long chain NPnEO homologous in both water (n ≥ 2 and the algal phase (n ≥ 5 was quite low at the end of a 48 h experiment.

  6. Assessment of Chlorella vulgaris and indigenous microalgae biomass with treated wastewater as growth culture medium.

    Science.gov (United States)

    Fernández-Linares, Luis C; Guerrero Barajas, Claudia; Durán Páramo, Enrique; Badillo Corona, Jesús A

    2017-11-01

    The aim of the present work was to evaluate the feasibility of microalgae cultivation using secondary treated domestic wastewater. Two Chlorella vulgaris strains (CICESE and UTEX) and an indigenous consortium, were cultivated on treated wastewater enriched with and without the fertilizer Bayfolan®. Biomass production for C. vulgaris UTEX, CICESE and the indigenous consortium grown in treated wastewater was 1.167±0.057, 1.575±0.434 and 1.125±0.250g/L, with a total lipid content of 25.70±1.24, 23.35±3.01and 20.54±1.23% dw, respectively. The fatty acids profiles were mainly composed of C16 and C18. Regardless of the media used, in all three strains unsaturated fatty acids were the main FAME (fatty acids methyl esters) accumulated in a range of 45-62%. An enrichment of treated wastewater with Bayfolan® significantly increased the production of biomass along with an increase in pigments and proteins of ten and threefold, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Metal distributions in complexes with Chlorella vulgaris in seawater and wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Pascucci, P.R.; Kowalak, A.D.

    1999-10-01

    Divalent cadmium (Cd), copper (Cu), iron (Fe), nickel (Ni), lead (Pb), and zinc (Zn) simultaneous complexes with an algal biomass Chlorella vulgaris were studied for bioremediation purposes in various aqueous media: distilled-deionized water (DDIW), seawater, nuclear-reactor pool water, and process wastewater. Reactions were monitored using various dry masses of algae at constant temperature and constant metal concentrations for reaction times ranging from 0 to 150 minutes. Complexes occurred within 30 minutes and reached a steady state after 80 to 120 minutes. Distribution constants (K{prime}{sub d}) were calculated for the complexes and relative orders of K{prime}{sub d} were reported. The K{prime}{sub d} are used to evaluate relative efficiency of metal remediation from waters. Lead, Cu, and Ni complexes had the greatest K{prime}{sub d} values and those metals were most efficiently removed from these waters. Zinc and Fe formed the most labile complexes. The order of K{prime}{sub d} values for complexes in DDIW was Pb > Cu > Cd > Zn, then Cu > Cd > Zn in seawater, Cd > Cu > Zn in reactor pool water, and Ni > Cd > Cu > Zn > Fe in wastewater. C. vulgaris biomass may potentially be used as an alternative to traditional water treatment methods for simultaneous extraction of metals from seawater, process wastewater, or drinking water.

  8. UVA-induced reset of hydroxyl radical ultradian rhythm improves temporal lipid production in Chlorella vulgaris.

    Science.gov (United States)

    Balan, Ranjini; Suraishkumar, G K

    2014-01-01

    We report for the first time that the endogenous, pseudo-steady-state, specific intracellular levels of the hydroxyl radical (si-OH) oscillate in an ultradian fashion (model system: the microalga, Chlorella vulgaris), and also characterize the various rhythm parameters. The ultradian rhythm in the endogenous levels of the si-OH occurred with an approximately 6 h period in the daily cycle of light and darkness. Further, we expected that the rhythm reset to a shorter period could rapidly switch the cellular redox states that could favor lipid accumulation. We reset the endogenous rhythm through entrainment with UVA radiation, and generated two new ultradian rhythms with periods of approximately 2.97 h and 3.8 h in the light phase and dark phase, respectively. The reset increased the window of maximum lipid accumulation from 6 h to 12 h concomitant with the onset of the ultradian rhythms. Further, the saturated fatty acid content increased approximately to 80% of total lipid content, corresponding to the peak maxima of the hydroxyl radical levels in the reset rhythm. © 2014 American Institute of Chemical Engineers.

  9. Rapid induction of lipid droplets in Chlamydomonas reinhardtii and Chlorella vulgaris by Brefeldin A.

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    Sangwoo Kim

    Full Text Available Algal lipids are the focus of intensive research because they are potential sources of biodiesel. However, most algae produce neutral lipids only under stress conditions. Here, we report that treatment with Brefeldin A (BFA, a chemical inducer of ER stress, rapidly triggers lipid droplet (LD formation in two different microalgal species, Chlamydomonas reinhardtii and Chlorella vulgaris. LD staining using Nile red revealed that BFA-treated algal cells exhibited many more fluorescent bodies than control cells. Lipid analyses based on thin layer chromatography and gas chromatography revealed that the additional lipids formed upon BFA treatment were mainly triacylglycerols (TAGs. The increase in TAG accumulation was accompanied by a decrease in the betaine lipid diacylglyceryl N,N,N-trimethylhomoserine (DGTS, a major component of the extraplastidic membrane lipids in Chlamydomonas, suggesting that at least some of the TAGs were assembled from the degradation products of membrane lipids. Interestingly, BFA induced TAG accumulation in the Chlamydomonas cells regardless of the presence or absence of an acetate or nitrogen source in the medium. This effect of BFA in Chlamydomonas cells seems to be due to BFA-induced ER stress, as supported by the induction of three homologs of ER stress marker genes by the drug. Together, these results suggest that ER stress rapidly triggers TAG accumulation in two green microalgae, C. reinhardtii and C. vulgaris. A further investigation of the link between ER stress and TAG synthesis may yield an efficient means of producing biofuel from algae.

  10. Enhanced removal of Zn(2+) or Cd(2+) by the flocculating Chlorella vulgaris JSC-7.

    Science.gov (United States)

    Alam, Md Asraful; Wan, Chun; Zhao, Xin-Qing; Chen, Li-Jie; Chang, Jo-Shu; Bai, Feng-Wu

    2015-05-30

    Microalgae are attracting attention due to their potentials in mitigating CO2 emissions and removing environmental pollutants. However, harvesting microalgal biomass from diluted cultures is one of the bottlenecks for developing economically viable processes for this purpose. Microalgal cells can be harvested by cost-effective sedimentation when flocculating strains are used. In this study, the removal of Zn(2+) and Cd(2+) by the flocculating Chlorella vulgaris JSC-7 was studied. The experimental results indicated that more than 80% Zn(2+) and 60% Cd(2+) were removed by the microalgal culture within 3 days in the presence up to 20.0mg/L Zn(2+) and 4.0mg/L Cd(2+), respectively, which were much higher than that observed with the culture of the non-flocculating C. vulgaris CNW11. Furthermore, the mechanism underlying this phenomenon was explored by investigating the effect of Zn(2+) and Cd(2+) on the growth and metabolic activities of the microalgal strains. It was found that the flocculation of the microalga improved its growth, synthesis of photosynthetic pigments and antioxidation activity under the stressful conditions, indicating a better tolerance to the heavy metal ions for a potential in removing them more efficiently from contaminated wastewaters, together with a bioremediation of other nutritional components contributed to the eutrophication of aquatic ecosystems. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Microalgae Harvest through Fungal Pelletization—Co-Culture of Chlorella vulgaris and Aspergillus niger

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    Sarman Oktovianus Gultom

    2014-07-01

    Full Text Available Microalgae harvesting is a labor- and energy-intensive process and new approaches to harvesting microalgae need to be developed in order to decrease the costs. In this study; co-cultivatation of filamentous fungus (Aspergillus niger and microalgae (Chlorella vulgaris to form cell pellets was evaluated under different conditions, including organic carbon source (glucose; glycerol; and sodium acetate concentration; initial concentration of fungal spores and microalgal cells and light. Results showed that 2 g/L of glucose with a 1:300 ratio of fungi to microalgae provided the best culturing conditions for the process to reach >90% of cell harvest efficiency. The results also showed that an organic carbon source was required to sustain the growth of fungi and form the cell pellets. The microalgae/fungi co-cultures at mixotrophic conditions obtained much higher total biomass than pure cultures of each individual strains; indicating the symbiotic relationship between two strains. This can benefit the microbial biofuel production in terms of cell harvest and biomass production.

  12. Mixotrophic growth and biochemical analysis of Chlorella vulgaris cultivated with diluted monosodium glutamate wastewater.

    Science.gov (United States)

    Ji, Yan; Hu, Wenrong; Li, Xiuqing; Ma, Guixia; Song, Mingming; Pei, Haiyan

    2014-01-01

    Monosodium glutamate wastewater (MSGW) is a potential medium for microbial cultivation because of containing abundant organic nutrient. This paper seeks to evaluate the feasibility of growing Chlorella vulgaris with MSGW and assess the influence of MSGW concentration on the biomass productivity and biochemical compositions. The MSGW diluted in different concentrations was prepared for microalga cultivation. C. vulgaris growth was greatly promoted with MSGW compared with the inorganic BG11 medium. C. vulgaris obtained the maximum biomass concentration (1.02 g/L) and biomass productivity (61.47 mg/Ld) with 100-time diluted MSGW. The harvested biomass was rich in protein (36.01-50.64%) and low in lipid (13.47-25.4%) and carbohydrate (8.94-20.1%). The protein nutritional quality and unsaturated fatty acids content of algal increased significantly with diluted MSGW. These results indicated that the MSGW is a feasible alternative for mass cultivation of C. vulgaris. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Ultrasound-assisted extraction of lipids from Chlorella vulgaris using [Bmim][MeSO4

    International Nuclear Information System (INIS)

    Kim, Young-Hoo; Park, Saerom; Kim, Min Hoo; Choi, Yong-Keun; Yang, Yung-Hun; Kim, Hyung Joo; Kim, Hyungsup; Kim, Han-Soo; Song, Kyung-Guen; Lee, Sang Hyun

    2013-01-01

    Lipids from Chlorella vulgaris were successfully extracted using an ionic liquid, [Bmim][MeSO 4 ]. [Bmim][MeSO 4 ] dissolved C. vulgaris, leaving the lipids insoluble. The undissolved lipids could easily be recovered due to the lower density of the lipid phase. Furthermore, ultrasound irradiation highly enhanced the extraction rate and yield with [Bmim][MeSO 4 ]. The total amounts of lipid extracted from C. vulgaris by the Soxhlet method and the Bligh and Dyer's method were 21 and 29 mg/g dry cell weight (DCW), respectively, whereas it was 47 mg/g DCW with [Bmim][MeSO 4 ]. Additionally, the amount of lipid extracted using [Bmim][MeSO 4 ] was 1.6 times greater with ultrasound irradiation. The rate of extraction of lipids from C. vulgaris with [Bmim][MeSO 4 ] was also 2.7 times greater with ultrasound irradiation. The fatty acid profiles of the lipids extracted using [Bmim][MeSO 4 ] were very similar to those of the lipids obtained by Bligh and Dyer's method. -- Highlights: •[Bmim][MeSO 4 ] efficiently extracted lipids from algae without pretreatment. •Ultrasound irradiation highly enhanced the extraction rate and yield of the extraction system using IL. •Fatty acid profiles of lipids extracted using [Bmim][MeSO 4 ] were similar to those of the lipids obtained by conventional methods

  14. Study of optimizing the process of Cadmium adsorption by synthesized silver nanoparticles using Chlorella vulgaris

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    Faezeh Sajadi

    2016-05-01

    Full Text Available Background and Aim: Cadmium (Cd is one of the most toxic heavy metals in water that mostly enters the water cycle through industrial waste water. Silver nanoparticles have the capacity to remove heavy metals from the water resources through the mechanism of adsorption. The present study aimed at producing  silver bio-nanoparticles and optimizing . Cd removal from aquatic solutions. Materials and Methods: Silver bio-nanoparticles were extracted via a micro-algae Chlorella vulgaris extract and silver nitrate synthesis. Then, the characteristics of the particles were  determined using FT-IR, XRD, SEM devices. In order to optimize Cadmium adsorption by means of silver nanoparticles, parameters including pH, reaction time, initial concentration of Cd and concentrations of nanoparticles were studied under different conditions. Results: The resulting nanoparticles were spherical, single and crystalline, whose sizes were 10-45 nm.  Under the condition of PH = 8, the initial concentration of cadmium 0.5 mg/L, adsorbent dosage of 0.5 mg, reaction time of 10 min, temperature of 300C and mixing speed of 200 rpm, 99% of cadmium was removed. Isotherm of Cadmium-ion adsorption followed Langmuir (R2> 0/96 (and Freundlich (R2> 0/94 models. Conclusion: Under optimal conditions, silver bio-nanoparticles had the capacity of quick and effective adsorption of cadmium. Thus, with a cheap, non-toxic and environmentally friendly method  can remove heavy metals in a short time.

  15. Dietary Chlorella vulgaris Ameliorates Altered Immunomodulatory Functions in Cyclophosphamide-Induced Immunosuppressive Mice

    Science.gov (United States)

    Cheng, Dai; Wan, Zhaodong; Zhang, Xinyu; Li, Jian; Li, He; Wang, Chunling

    2017-01-01

    Based on the well-known toxicity of cyclophosphamide (CYP) on the immune system, this research investigated the modulating effects of the long-term dietary Chlorella vulgaris (CV) supplementation on the immunosuppression induced by CYP in mice, in order to provide a novel dietary design to mitigate the side effects of CYP therapy. Control, CYP-treated, CYP + CV (6%), CYP + CV (12%) and CYP + CV (24%) were used for 6 weeks, CV supplement in diet recovered the significantly reduced immunological function in CYP treated mice. As CV may have a modulating function through the inducible expression of cytokines, we assayed the expressions of interleukin-2 (IL-2), interleukin-12 (IL-12), tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ). Our results suggested that CYP significantly reduced the lymphocytes proliferation and phagocytic activities of macrophages, and stimulated the production of IL-2, IL-12, TNF-α and IFN-γ and that this impairment has been successfully adjusted by CV supplementation. Treatment with the algae also enhanced the natural killer (NK) cells cytotoxicity, and ameliorate histological changes of the spleen in CYP-treated mice. Therefore, as we found in this study, a diet supplemented with whole CV has beneficial effects on CVP-induced immunosuppression, through its immunomodulatory potential. PMID:28684674

  16. Combined Extraction Processes of Lipid from Chlorella vulgaris Microalgae: Microwave Prior to Supercritical Carbon Dioxide Extraction

    Science.gov (United States)

    Dejoye, Céline; Vian, Maryline Abert; Lumia, Guy; Bouscarle, Christian; Charton, Frederic; Chemat, Farid

    2011-01-01

    Extraction yields and fatty acid profiles from freeze-dried Chlorella vulgaris by microwave pretreatment followed by supercritical carbon dioxide (MW-SCCO2) extraction were compared with those obtained by supercritical carbon dioxide extraction alone (SCCO2). Work performed with pressure range of 20–28 Mpa and temperature interval of 40–70 °C, gave the highest extraction yield (w/w dry weight) at 28 MPa/40 °C. MW-SCCO2 allowed to obtain the highest extraction yield (4.73%) compared to SCCO2 extraction alone (1.81%). Qualitative and quantitative analyses of microalgae oil showed that palmitic, oleic, linoleic and α-linolenic acid were the most abundant identified fatty acids. Oils obtained by MW-SCCO2 extraction had the highest concentrations of fatty acids compared to SCCO2 extraction without pretreatment. Native form, and microwave pretreated and untreated microalgae were observed by scanning electronic microscopy (SEM). SEM micrographs of pretreated microalgae present tearing wall agglomerates. After SCCO2, microwave pretreated microalgae presented several micro cracks; while native form microalgae wall was slightly damaged. PMID:22272135

  17. Ecotoxicological effects of carbon nanotubes and cellulose nanofibers in Chlorella vulgaris

    Science.gov (United States)

    2014-01-01

    Background MWCNT and CNF are interesting NPs that possess great potential for applications in various fields such as water treatment, reinforcement materials and medical devices. However, the rapid dissemination of NPs can impact the environment and in the human health. Thus, the aim of this study was to evaluate the MWCNT and cotton CNF toxicological effects on freshwater green microalgae Chlorella vulgaris. Results Exposure to MWCNT and cotton CNF led to reductions on algal growth and cell viability. NP exposure induced reactive oxygen species (ROS) production and a decreased of intracellular ATP levels. Addition of NPs further induced ultrastructural cell damage. MWCNTs penetrate the cell membrane and individual MWCNTs are seen in the cytoplasm while no evidence of cotton CNFs was found inside the cells. Cellular uptake of MWCNT was observed in algae cells cultured in BB medium, but cells cultured in Seine river water did not internalize MWCNTs. Conclusions Under the conditions tested, such results confirmed that exposure to MWCNTs and to cotton CNFs affects cell viability and algal growth. PMID:24750641

  18. Use of Chlorella vulgaris for CO{sub 2} mitigation in a photobioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Keffer, J.E.; Kleinheinz, G.T.

    2002-07-01

    One of the most understudied methods for CO{sub 2} mitigation is the use of biological processes in engineered systems such as photobioreactors. This research project describes the effectiveness of Chlorella vulgaris, used in a photobioreactor with a very short gas residence time, in sequestering CO{sub 2} from an elevated CO{sub 2} airstream. We evaluated a flow-through photobioreactor's operational parameters, as well as the growth characteristics of the C. vulgaris inoculum when exposed to an airstream with over 1850 ppm CO{sub 2}. When using dry weight, chlorophyll, and direct microscopic measurements, it was apparent that the photobioreactor's algal inoculum responded well to the elevated CO{sub 2} levels and there was no build-up of CO{sub 2} or carbonic acid in the photobioreactor. The photobioreactor, with a gas residence time of approximately 2 s, was able to remove up to 74% of the CO{sub 2} in the airstream to ambient levels. This corresponded to a 63.9-g/m(3)/h bulk removal for the experimental photobioreactor. Consequently, this photobioreactor shows that biological processes may have some promise for treating point source emissions of CO{sub 2} and deserve further study.

  19. Toxicity of Nickel Oxide Nanoparticles on a Freshwater Green Algal Strain of Chlorella vulgaris

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    Abdallah Oukarroum

    2017-01-01

    Full Text Available A freshwater microalga strain of Chlorella vulgaris was used to investigate toxic effects induced by nickel oxide nanoparticles (NiO-NPs in suspension. Algal cells were exposed during 96 h to 0–100 mg L−1 of NiO-NPs and analyzed by flow cytometry. Physicochemical characterization of nanoparticles in tested media showed a soluble fraction (free Ni2+ of only 6.42% for 100 mg L−1 of NiO-NPs, indicating the low solubility capacity of these NPs. Toxicity analysis showed cellular alterations which were related to NiO-NPs concentration, such as inhibition in cell division (relative cell size and granularity, deterioration of the photosynthetic apparatus (chlorophyll synthesis and photochemical reactions of photosynthesis, and oxidative stress (ROS production. The change in cellular viability demonstrated to be a very sensitive biomarker of NiO-NPs toxicity with EC50 of 13.7 mg L−1. Analysis by TEM and X-ray confirmed that NiO-NPs were able to cross biological membranes and to accumulate inside algal cells. Therefore, this study provides a characterization of both physicochemical and toxicological properties of NiO-NPs suspensions in tested media. The use of the freshwater strain of C. vulgaris demonstrated to be a sensitive bioindicator of NiO-NPs toxicity on the viability of green algae.

  20. Enhancing lipid productivity of Chlorella vulgaris using oxidative stress by TiO2 nanoparticles

    International Nuclear Information System (INIS)

    Kang, Nam Kyu; Lee, Bongsoo; Choi, Gang-Guk; Moon, Myounghoon; Park, Min S.; Yang, Ji-Won; Lim, JitKang

    2014-01-01

    Ability to increase the lipid production in microalgae is one of the heavily sought-after ideas to improve the economic feasibility of microalgae-derived transportation fuels for commercial applications. We used the oxidative stress by TiO 2 nanoparticles, a well-known photocatalyst, to induce lipid production in microalgae. Chlorella vulgaris UTEX 265 was cultivated under various concentrations of TiO 2 ranging from 0.1 to 5 g/L under UV-A illumination. Maximum specific growth rate was affected in responding to TiO 2 concentrations. In the presence of UV-A, chlorophyll concentration was decreased at the highest concentration of TiO 2 (5 g/L TiO 2 ) by oxidative stress. The fatty acid methyl ester (FAME) composition analysis suggested that oxidative stress causes the accumulation and decomposition of lipids. The highest FAME productivity was 18.2 g/L/d under low concentrations of TiO 2 (0.1 g/L) and a short induction time (two days). The controlled condition of TiO 2 /UV-A inducing oxidative stress (0.1 g/L TiO 2 and two days induction) could be used to increase the lipid productivity of C. vulgaris UTEX 265. Our results show the possibility of modulating the lipid induction process through oxidative stress with TiO 2 /UV-A

  1. Mutual facilitations of food waste treatment, microbial fuel cell bioelectricity generation and Chlorella vulgaris lipid production.

    Science.gov (United States)

    Hou, Qingjie; Pei, Haiyan; Hu, Wenrong; Jiang, Liqun; Yu, Ze

    2016-03-01

    Food waste contains large amount of organic matter that may be troublesome for handing, storage and transportation. A microbial fuel cell (MFC) was successfully constructed with different inoculum densities of Chlorella vulgaris for promoting food waste treatment. Maximum COD removal efficiency was registered with 44% and 25 g CODL(-1)d(-1) of substrate degradation rate when inoculated with the optimal initial density (150 mg L(-1)) of C. vulgaris, which were 2.9 times and 3.1 times higher than that of the abiotic cathode. With the optimum inoculum density of C. vulgaris, the highest open circuit voltage, working voltage and power density of MFC were 260 mV, 170 mV and 19151 mW m(-3), respectively. Besides the high biodiesel quality, promoted by MFC stimulation the biomass productivity and highest total lipid content of C. vulgaris were 207 mg L(-1)d(-1) and 31%, which were roughly 2.7 times and 1.2 times higher than the control group. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Combined Extraction Processes of Lipid from Chlorella vulgaris Microalgae: Microwave Prior to Supercritical Carbon Dioxide Extraction

    Directory of Open Access Journals (Sweden)

    Farid Chemat

    2011-12-01

    Full Text Available Extraction yields and fatty acid profiles from freeze-dried Chlorella vulgaris by microwave pretreatment followed by supercritical carbon dioxide (MW-SCCO2 extraction were compared with those obtained by supercritical carbon dioxide extraction alone (SCCO2. Work performed with pressure range of 20–28 Mpa and temperature interval of 40–70 °C, gave the highest extraction yield (w/w dry weight at 28 MPa/40 °C. MW-SCCO2 allowed to obtain the highest extraction yield (4.73% compared to SCCO2 extraction alone (1.81%. Qualitative and quantitative analyses of microalgae oil showed that palmitic, oleic, linoleic and α-linolenic acid were the most abundant identified fatty acids. Oils obtained by MW-SCCO2 extraction had the highest concentrations of fatty acids compared to SCCO2 extraction without pretreatment. Native form, and microwave pretreated and untreated microalgae were observed by scanning electronic microscopy (SEM. SEM micrographs of pretreated microalgae present tearing wall agglomerates. After SCCO2, microwave pretreated microalgae presented several micro cracks; while native form microalgae wall was slightly damaged.

  3. Cloning and Expression of a Cytosolic HSP90 Gene in Chlorella vulgaris

    Directory of Open Access Journals (Sweden)

    Zhengyi Liu

    2014-01-01

    Full Text Available Heat shock protein 90 (HSP90, a highly conserved molecular chaperone, plays essential roles in folding, keeping structural integrity, and regulating the subset of cytosolic proteins. We cloned the cDNA of Chlorella vulgaris HSP90 (named CvHSP90 by combining homology cloning with rapid amplification of cDNA ends (RACE. Sequence analysis indicated that CvHSP90 is a cytosolic member of the HSP90 family. Quantitative RT-PCR was applied to determine the expression level of messenger RNA (mRNA in CvHSP90 under different stress conditions. C. vulgaris was kept in different temperatures (5–45°C for 1 h. The mRNA expression level of CvHSP90 increased with temperature from 5 to 10°C, went further from 35 to 40°C, and reached the maximum at 40°C. On the other hand, for C. vulgaris kept at 35°C for different durations, the mRNA expression level of CvHSP90 increased gradually and reached the peak at 7 h and then declined progressively. In addition, the expression level of CvHSP90 at 40 or 45 in salinity (‰ was almost fourfold of that at 25 in salinity (‰ for 2 h. Therefore, CvHSP90 may be a potential biomarker to monitor environment changes.

  4. Polishing of anaerobic secondary effluent by Chlorella vulgaris under low light intensity.

    Science.gov (United States)

    Cheng, Tuoyuan; Wei, Chun-Hai; Leiknes, TorOve

    2017-10-01

    To investigate anaerobic secondary effluent polishing by microalgae (Chlorella vulgaris) under low light intensity (14μmol/m 2 /s), bubbling column reactors were operated in batches of 8 d with initial ammonium nitrogen 10-50mg/L, initial phosphate phosphorus 2-10mg/L and microalgal seed 40mg/L. Maximum microalgal biomass and minimum generation time were 370.9mg/L and 2.5d, respectively. Nitrogen removal (maximum 99.6%) was mainly attributed to microalgal growth rate, while phosphorus removal (maximum 49.8%) was related to microalgal growth rate, cell phosphorus content (maximum 1.5%) and initial nutrients ratio. Dissolved microalgal organics release in terms of chemical oxygen demand (maximum 63.2mg/L) and hexane extractable material (i.e., oil and grease, maximum 8.5mg/L) was firstly reported and mainly affected by nitrogen deficiency and deteriorated effluent quality. Ultrafiltration critical flux (16.6-39.5L/m 2 /h) showed negative linear correlation to microalgal biomass. Anaerobic membrane bioreactor effluent polishing showed similar results with slight inhibition to synthetic effluent. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Chlorella vulgaris vs cyanobacterial biomasses: Comparison in terms of biomass productivity and biogas yield

    International Nuclear Information System (INIS)

    Mendez, Lara; Mahdy, Ahmed; Ballesteros, Mercedes; González-Fernández, Cristina

    2015-01-01

    Highlights: • Cyanobacteria and C. vulgaris were compared in terms of growth and methane production. • Biomasses were subjected to anaerobic digestion without applying any disruption method. • Cyanobacteria showed an increased methane yield in comparison with C. vulgaris. - Abstract: The aim of the present study was to compare cyanobacteria strains (Aphanizomenon ovalisporum, Anabaena planctonica, Borzia trilocularis and Synechocystis sp.) and microalgae (Chlorella vulgaris) in terms of growth rate, biochemical profile and methane production. Cyanobacteria growth rate ranged 0.5–0.6 day −1 for A. planctonica, A. ovalisporum and Synecochystis sp. and 0.4 day −1 for B. tricularis. Opposite, C. vulgaris maximum growth rate was double (1.2 day −1 ) than that of cyanobacteria. Regarding the methane yield, microalgae C. vulgaris averaged 120 mL CH 4 g COD in −1 due to the presence of a strong cell wall. On the other hand, anaerobic digestion of cyanobacteria supported higher methane yields. B. trilocularis and A. planctonica presented 1.42-fold higher methane yield than microalgae while this value was raised to approximately 1.85-fold for A. ovalisporum and Synechochystis sp. In the biogas production context, this study showed that the low growth rates of cyanobacteria can be overcome by their increased anaerobic digestibility when compared to their microalgae counterpartners, such is the case of C. vulgaris

  6. Effect of Ethephon as an Ethylene-Releasing Compound on the Metabolic Profile of Chlorella vulgaris.

    Science.gov (United States)

    Kim, So-Hyun; Lim, Sa Rang; Hong, Seong-Joo; Cho, Byung-Kwan; Lee, Hookeun; Lee, Choul-Gyun; Choi, Hyung-Kyoon

    2016-06-15

    In this study, Chlorella vulgaris (C. vulgaris) was treated with ethephon at low (50 μM) and high (200 μM) concentrations in medium and harvested at 0, 7, and 14 days, respectively. The presence of ethephon led to significant metabolic changes in C. vulgaris, with significantly higher levels of α-tocopherol, γ-aminobutyric acid (GABA), asparagine, and proline, but lower levels of glycine, citrate, and galactose relative to control. Ethephon induced increases in saturated fatty acids but decreases in unsaturated fatty acids. The levels of highly saturated sulfoquinovosyldiacylglycerol species and palmitic acid bound phospholipids were increased on day 7 of ethephon treatment. Among the metabolites, the productivities of α-tocopherol (0.70 μg/L/day) and GABA (1.90 μg/L/day) were highest for 50 and 200 μM ethephon on day 7, respectively. We propose that ethephon treatment involves various metabolic processes in C. vulgaris and can be an efficient way to enrich the contents of α-tocopherol and GABA.

  7. Magnesium Uptake by the Green Microalga Chlorella vulgaris in Batch Cultures.

    Science.gov (United States)

    Ben Amor-Ben Ayed, Hela; Taidi, Behnam; Ayadi, Habib; Pareau, Dominique; Stambouli, Moncef

    2016-03-01

    The accumulation (internal and superficial distribution) of magnesium ions (Mg(2+)) by the green freshwater microalga Chlorella vulgaris (C. vulgaris) was investigated under autotrophic culture in a stirred photobioreactor. The concentrations of the three forms of Mg(2+) (dissolved, extracellular, and intracellular) were determined with atomic absorption spectroscopy during the course of C. vulgaris growth. The proportions of adsorbed (extracellular) and absorbed (intracellular) Mg(2+) were quantified. The concentration of the most important pigment in algal cells, chlorophyll a, increased over time in proportion to the increase in the biomass concentration, indicating a constant chlorophyll/biomass ratio during the linear growth phase. The mean-average rate of Mg(2+) uptake by C. vulgaris grown in a culture medium starting with 16 mg/l of Mg(2+) concentration was measured. A clear relationship between the biomass concentration and the proportion of the Mg(2+) removal from the medium was observed. Of the total Mg(2+) present in the culture medium, 18% was adsorbed on the cell wall and 51% was absorbed by the biomass by the end of the experiment (765 h). Overall, 69% of the initial Mg(2+) were found to be removed from the medium. This study supported the kinetic model based on a reversible first-order reaction for Mg(2+) bioaccumulation in C. vulgaris, which was consistent with the experimental data.

  8. Zinc-induced differential oxidative stress and antioxidant responses in Chlorella sorokiniana and Scenedesmus acuminatus.

    Science.gov (United States)

    Hamed, Seham M; Zinta, Gaurav; Klöck, Gerd; Asard, Han; Selim, Samy; AbdElgawad, Hamada

    2017-06-01

    Algae are frequently exposed to toxic metals, and zinc (Zn) is one of the major toxicants present. We exposed two green microalgae, Chlorella sorokiniana and Scenedesmus acuminatus, to sub-lethal concentrations (1.0 and 0.6mM) of Zn for seven days. Algal responses were analysed at the level of growth, oxidative stress, and antioxidants. Growth parameters such as cell culture yield and pigment content were less affected by Zn in C. sorokiniana, despite the fact that this alga accumulated more zinc than S. acuminatus. Also, C. sorokiniana, but not S. acuminatus, was able to acclimatize during long-term exposure to toxic concentrations of the test metals (specific growth rate (µ) was 0.041/day and total chlorophyll was 14.6mg/mL). Although, Zn induced oxidative stress in both species, C. sorokiniana experienced less stress than S. acuminatus. This could be explained by a higher accumulation of antioxidants in C. sorokiniana, where flavonoids, polyphenols, tocopherols, glutathione (GSH) and ascorbate (ASC) content increased. Moreover, antioxidant enzymes glutathione S transferase (GST), glutathione reductase (GR), superoxide dismutase (SOD), peroxidase (POX) and ascorbate peroxidase (APX), showed increased activities in C. sorokiniana. In addition to, and probably also underlying, the higher Zn tolerance in C. sorokiniana, this alga also showed higher Zn biosorption capacity. Use of C. sorokiniana as a bio-remediator, could be considered. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Acute and chronic toxic effects of bisphenol A on Chlorella pyrenoidosa and Scenedesmus obliquus.

    Science.gov (United States)

    Zhang, Wei; Xiong, Bang; Sun, Wen-Fang; An, Shuai; Lin, Kuang-Fei; Guo, Mei-Jin; Cui, Xin-Hong

    2014-06-01

    The acute and chronic toxic effects of Bisphenol A (BPA) on Chlorella pyrenoidosa (C. pyrenoidosa) and Scenedesmus obliquus (S. obliquus) were not well understood. The indoor experiments were carried out to observe and analyze the BPA-induced changes. Results of the observations showed that in acute tests BPA could significantly inhibit the growth of both algae, whereas chronic exposure hardly displayed similar trend. Superoxide dismutase (SOD) and Catalase (CAT) activities of both algae were promoted in all the treatments. Chlorophyll a synthesis of the two algae exhibited similar inhibitory trend in short-term treatments, and in chronic tests C. pyrenoidosa hardly resulted in visible influence, whereas in contrast, dose-dependent inhibitory effects of S. obliquus could be clearly observed. The experimental results indicated that the growth and Chlorophyll a syntheses of S.obliquus were more sensitive in response to BPA than that of C. pyrenoidosa, whereas for SOD andCAT activities, C. pyrenoidosa was more susceptible. This research provides a basic understanding of BPA toxicity to aquatic organisms. Copyright © 2012 Wiley Periodicals, Inc.

  10. Enhancing lipid productivity of Chlorella vulgaris using oxidative stress by TiO{sub 2} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Nam Kyu; Lee, Bongsoo; Choi, Gang-Guk; Moon, Myounghoon; Park, Min S.; Yang, Ji-Won [Daejeon, Daejeon (Korea, Republic of); Lim, JitKang [Universiti Sains Malaysia, Penang (Malaysia)

    2014-05-15

    Ability to increase the lipid production in microalgae is one of the heavily sought-after ideas to improve the economic feasibility of microalgae-derived transportation fuels for commercial applications. We used the oxidative stress by TiO{sub 2} nanoparticles, a well-known photocatalyst, to induce lipid production in microalgae. Chlorella vulgaris UTEX 265 was cultivated under various concentrations of TiO{sub 2} ranging from 0.1 to 5 g/L under UV-A illumination. Maximum specific growth rate was affected in responding to TiO{sub 2} concentrations. In the presence of UV-A, chlorophyll concentration was decreased at the highest concentration of TiO{sub 2} (5 g/L TiO{sub 2}) by oxidative stress. The fatty acid methyl ester (FAME) composition analysis suggested that oxidative stress causes the accumulation and decomposition of lipids. The highest FAME productivity was 18.2 g/L/d under low concentrations of TiO{sub 2} (0.1 g/L) and a short induction time (two days). The controlled condition of TiO{sub 2}/UV-A inducing oxidative stress (0.1 g/L TiO{sub 2} and two days induction) could be used to increase the lipid productivity of C. vulgaris UTEX 265. Our results show the possibility of modulating the lipid induction process through oxidative stress with TiO{sub 2}/UV-A.

  11. Influence of Speciation of Thorium on Toxic Effects to Green Algae Chlorella pyrenoidosa

    Directory of Open Access Journals (Sweden)

    Can Peng

    2017-04-01

    Full Text Available Thorium (Th is a natural radioactive element present in the environment and has the potential to be used as a nuclear fuel. Relatively little is known about the influence and toxicity of Th in the environment. In the present study, the toxicity of Th to the green algae Chlorella pyrenoidosa (C. pyrenoidosa was evaluated by algal growth inhibition, biochemical assays and morphologic observations. In the cultural medium (OECD TG 201, Th(NO34 was transformed to amorphous precipitation of Th(OH4 due to hydrolysis. Th was toxic to C. pyrenoidosa, with a 96 h half maximum effective concentration (EC50 of 10.4 μM. Scanning electron microscopy shows that Th-containing aggregates were attached onto the surface of the algal cells, and transmission electron microscopy indicates the internalization of nano-sized Th precipitates and ultrastructural alterations of the algal cells. The heteroagglomeration between Th(OH4 precipitation and alga cells and enhanced oxidative stress might play important roles in the toxicity of Th. To our knowledge, this is the first report of the toxicity of Th to algae with its chemical species in the exposure medium. This finding provides useful information on understanding the fate and toxicity of Th in the aquatic environment.

  12. Mechanistically harvesting of Chlorella vulgaris and Rhodotorula glutinis via modified montmorillonoid.

    Science.gov (United States)

    Liu, Jing; Zhang, Xu; Tan, Tianwei

    2016-10-01

    In this study, the flocculation process of Chlorella vulgaris and Rhodotorula glutinis induced by inorganic salts modified montmorillonoid was conducted. The maximum flocculation efficiency (FE) of 98.50% for C. vulgaris and 11.83% for R. glutinis were obtained with 4g/L and 5g/L flocculant within the dosage scope of 1-5g/L. The difference of FE was then thermodynamically explained by the extended DLVO theory and the FE of R. glutinis was mechanically enhanced to 90.66% with 0.06g/L cationic polyacrylamide (CPAM) at an optimum pH of 9. After that, aimed to utilize the remainder flocculant capacity, C. vulgaris culture was added to the aggregation of R. glutinis. Fortunately, the coagulation of R. glutinis and C. Vulgaris was achieved with 0.05g/L CPAM and 5g/L flocculant at pH 9 and the FE reached 90.15% and 91.24%, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Comparison of different artificial neural network architectures in modeling of Chlorella sp. flocculation.

    Science.gov (United States)

    Zenooz, Alireza Moosavi; Ashtiani, Farzin Zokaee; Ranjbar, Reza; Nikbakht, Fatemeh; Bolouri, Oberon

    2017-07-03

    Biodiesel production from microalgae feedstock should be performed after growth and harvesting of the cells, and the most feasible method for harvesting and dewatering of microalgae is flocculation. Flocculation modeling can be used for evaluation and prediction of its performance under different affective parameters. However, the modeling of flocculation in microalgae is not simple and has not performed yet, under all experimental conditions, mostly due to different behaviors of microalgae cells during the process under different flocculation conditions. In the current study, the modeling of microalgae flocculation is studied with different neural network architectures. Microalgae species, Chlorella sp., was flocculated with ferric chloride under different conditions and then the experimental data modeled using artificial neural network. Neural network architectures of multilayer perceptron (MLP) and radial basis function architectures, failed to predict the targets successfully, though, modeling was effective with ensemble architecture of MLP networks. Comparison between the performances of the ensemble and each individual network explains the ability of the ensemble architecture in microalgae flocculation modeling.

  14. Tritium oxide uptake and desorption kinetics in a primary producer: chlorella pyrenoidosa

    International Nuclear Information System (INIS)

    Dunstall, T.G.

    1983-01-01

    The alga Chlorella pyrenoidosa grown in batch culture under chronic tritium oxide exposure was used to model behavior of tritium at the primary producer level of an aquatic food chain. The specific activity ratio of organically bound tritium to medium tritium increased during initial growth stages, then reached an asymptotic steady state value of 0.59 after approximately seven cell doublings. The intracellular to extracellular concentrations of tritium oxide appeared to be in equilibrium. Loss of previously formed organically bound tritium in cells transferred to tritium-free media averaged less than 5 % for exponential growth phase cultures which had undergone more than three cell doublings. Over a comparable time period, a greater loss of organically bound tritium from stationary cells (average 13.4 %) was attributed to increased degradative metabolism in senescent cultures. Concentration of tritium in organically bound form may exceed environmental tritium oxide levels under dynamic conditions in which a pulse of tritium oxide to the environment is dissipated over time

  15. Growth and biochemical composition of Chlorella vulgaris in different growth media

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    MATHIAS A. CHIA

    2013-10-01

    Full Text Available The need for clean and low-cost algae production demands for investigations on algal physiological response under different growth conditions. In this research, we investigated the growth, biomass production and biochemical composition of Chlorella vulgaris using semi-continuous cultures employing three growth media (LC Oligo, Chu 10 and WC media. The highest cell density was obtained in LC Oligo, while the lowest in Chu medium. Chlorophyll a, carbohydrate and protein concentrations and yield were highest in Chu and LC Oligo media. Lipid class analysis showed that hydrocarbons (HC, sterol esthers (SE, free fatty acids (FFA, aliphatic alcohols (ALC, acetone mobile polar lipids (AMPL and phospholipids (PL concentrations and yields were highest in the Chu medium. Triglyceride (TAG and sterol (ST concentrations were highest in the LC Oligo medium. The results suggested that for cost effective cultivation, LC Oligo medium is the best choice among those studied, as it saved the cost of buying vitamins and EDTA associated with the other growth media, while at the same time resulted in the best growth performance and biomass production.

  16. Optimization of biodiesel production from Chlorella protothecoides oil via ultrasound assisted transesterification

    Directory of Open Access Journals (Sweden)

    Özçimen Didem

    2017-01-01

    Full Text Available There is a growing interest in biodiesel as an alternative fuel for diesel engines because of the high oil prices and environmental issues related to massive greenhouse gas emissions. Nowadays, microalgal biomass has become a promising biodiesel feedstock. However, traditional biodiesel production from microalgae consumes a lot of energy and solvents. It is necessary to use an alternative method that can reduce the energy and alcohol consumption and save time. In this study, biodiesel production from Chlorella protothecoides oil by ultrasound assisted transesterification was conducted and effects of reaction parameters such as methanol:oil ratio, catalyst/oil ratio and reaction time on fatty acid methyl ester yields were investigated. The transesterification reactions were carried out by using methanol as alcohol and potassium hydroxide as the catalyst. The highest methyl ester production was obtained under the conditions of 9:1 methanol/oil mole ratio, 1.5% potassium hydroxide catalyst in oil, and for reaction time of 40 min. It was also found that catalyst/oil molar ratio was the most effective parameter on methyl ester yield according to statistical data. The results showed that ultrasound-assisted transesterification may be an alternative and cost effective way to produce biodiesel efficiently.

  17. Toxicity of diesel water accommodated fraction toward microalgae, Pseudokirchneriella subcapitata and Chlorella sp. MM3.

    Science.gov (United States)

    Ramadass, Kavitha; Megharaj, Mallavarapu; Venkateswarlu, Kadiyala; Naidu, Ravi

    2017-08-01

    Diesel is a commonly used fuel and a key pollutant on water surface through leaks and accidental spills, thus creating risk directly to planktons as well as other aquatic organisms. We assessed the toxicty of diesel and its water accommodated fraction (WAF) towards two microalgal species, Pseudokirchneriella subcapitata and Chlorella sp. MM3. The toxicity criteria included were: chlorophyll a content as a growth parameter and induction of enzyme activities linked to oxidative stress. Increase in concentrations of diesel or its WAF significantly increased toxicity towards growth, measured in terms of chlorophyll a content in both the algae. Activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POX) and catalase (CAT) in response to addition of diesel or diesel WAF to the microalgal cultures were dose-dependent. Diesel WAF was more toxic than diesel itself, suggesting that use of WAF may be more relevant for environmental risk assessment of diesel. The overall response of the antioxidant enzymes to toxicants' stress followed the order: POX≥SOD>CAT. The present study clearly demonstrated the use of SOD, POX and CAT as suitable biomarkers for assessing diesel pollution in aquatic ecosystem. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Sorption Capacity Measurement of Chlorella Vulgaris and Scenedesmus Acutus to Remove Chromium from Tannery Waste Water

    Science.gov (United States)

    Ardila, Liliana; Godoy, Rubén; Montenegro, Luis

    2017-08-01

    Tanning process is a polluting activity due to the release of toxic agents into the environment. One of the most important of those toxic chemicals is chromium. Different alternatives have been proposed for the removal of this metal from tanning waste water which include the optimization of the productive processes, physicochemical and biochemical waste water treatment. In this study, the biological adsorption process of trivalent chromium was carried out in synthetic water and tannery waste water through two types of native green microalgae, called Chlorella vulgaris and Scenedesmus acutus in Free State and immobilized in PVA state. This, considering that cellular wall of microalgae has functional groups like amines and carboxyl that might bind with trivalent chromium. Statistical significance of variables as pH temperature, chromium and algae concentrations was evaluated just like bio sorption capacity of different types of water and kind of bioadsorbent was calculated to determine if this process is a competitive solution comparing to other heavy metal removal processes.

  19. Effect of electromagnetic fields on duckweed (lemna minor) and alga (chlorella kessleri)

    International Nuclear Information System (INIS)

    Tkalec, M.; Malaric, K.; Malaric, R.; Vidakovic-Cifrek, Z.; Pevalek-Kozlina, B.

    2005-01-01

    Electricity produces extremely low frequency fields (50-60 Hz) while various kinds of radiofrequency fields (10 MHz-300 GHz) are used to transmit information (TV, radio, mobile phones and satellite communications). Duckweed (Lemna minor) and green algae (Chlorella kessleri) were exposed to the magnetic field of 50 Hz in a Helmholtz coil, to an electric field of 50 Hz between two parallel circle electrodes, and to electromagnetic fields of 400 and 900 MHz in a Gigahertz Transversal Electromagnetic Mode cell. The relative growth of Lemna minor exposed to extremely low frequency alternating magnetic field of 50 Hz (1 mT) for 24 hours was slightly reduced at the beginning of the experiment while a 50 Hz electric field (25 kV/m) slightly reduced its growth during the second week of the experiment. Radio frequencies of 400 and 900 MHz (23 V/m) applied for two hours decreased the duckweed growth after the third day, but only 900 MHz affected it significantly. The rate of photosynthesis in green algae increased after exposure to the magnetic field of 50 Hz, but decreased after exposure to the electric field of 50 Hz. Radio frequencies of 400 and 900 MHz generally increased its rate of photosynthesis.(author)

  20. Oxy-fuel combustion characteristics and kinetics of microalgae Chlorella vulgaris by thermogravimetric analysis.

    Science.gov (United States)

    Chen, Chunxiang; Lu, Ziguang; Ma, Xiaoqian; Long, Jun; Peng, Yuning; Hu, Likun; Lu, Quan

    2013-09-01

    Oxy-fuel or O2/CO2 combustion technology was used to investigate the combustion of Chlorella vulgaris by thermogravimetric analysis (TGA). Oxy-fuel combustion occurs in an O2/CO2 atmosphere instead of an O2/N2 atmosphere and offers an alternative method of C. vulgaris preparation for biofuels processing. Our results show that three stages were observed during C. vulgaris combustion and the main combustion process occurred at the second stage. Compared with a 20%O2/80%N2 atmosphere, the mass loss rate at the DTG peaks (Rp) and the average reaction rate (Rv) in a 20%O2/80%CO2 atmosphere was lower, while the ignition temperature (TI) was higher. As oxygen concentration increases in an O2/CO2 atmosphere, Rp, Rv and the apparent activation energy (E) increases, while TI, the final temperature detected as mass stabilization (Tf) and the residue mass (Mr) decreases; As the heating rate (β) increases, TI, Tf and Rp increase, while Mr decreases. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  1. KATALIS HETEROGEN DARI ABU VULKANIK UNTUK PEMBUATAN BIODIESEL DARI MINYAK MIKROALGA CHLORELLA SP

    Directory of Open Access Journals (Sweden)

    Catur Rini Widyastuti

    2014-02-01

    Full Text Available Selama ini, proses produksi biodiesel konvensioanal banyak menghasilkan air limbah pada tahap pemisahan produk dari katalis yang larut dan produk samping yang dihasilkan. Oleh karena itu, untuk mengurangi limbah yang dihasilkan selama proses pemisahan tersebut, jenis katalis heterogen dapat digunakan untuk menggantikan katalis homogen alkali yang biasa digunakan. Penelitian ini bertujuan untuk mengkaji jenis katalis dan aktivitasnya dalam reaksi transesterifikasi minyak mikroalga Chlorella sp menjadi biodiesel. Tahap awal penelitian yang dilakukan adalah preparasi minyak mikroalga yang akan digunakan untuk uji aktivitas katalis. Minyak mikroalga diperoleh dengan ekstraksi menggunakan metode maserasi menggunakan pelarut n-heksana. Rendemen minyak yang diperoleh sebesar 12,26%. Dari hasil uji GC-MS diketahui dua kandungan asam lemak terbesar dalam minyak mikroalga, yaitu Dodecanoic acid sebesar 59.52% dan n-Decanoic acid sebesar 12.64%. Selanjutnya minyak mikroalga direaksikan dengan metanol dengan rasio molar 1:6 menggunakan katalis yang disintesis dari abu vulkanik. Preparasi katalis dilakukan dengan dua metode yang berbeda, yaitu refluks dengan larutan H 2 SO 2 M dan secara alkali hidrotermal menggunakan larutan NaOH 2M. Reaksi transesterifikasi berlangsung pada suhu 60 o 4 C dengan penambahan katalis padat sebanyak 5% selama 60 menit. Yield biodiesel yang diperoleh dari reaksi menggunakan katalis yang dipreparasi dengan larutan H 2 SO adalah 28,27% dengan densitas 0,684 g/ mL. Sedangkan reaksi dengan katalis yang dipreparasi secara alkali hidrotermal menghasilkan biodiesel sebanyak 23% dengan densitas 0,69 g/mL.

  2. Direct Biodiesel Production from Wet Microalgae Biomass of Chlorella pyrenoidosa through In Situ Transesterification

    Science.gov (United States)

    Cao, Hechun; Zhang, Zhiling; Wu, Xuwen; Miao, Xiaoling

    2013-01-01

    A one-step process was applied to directly converting wet oil-bearing microalgae biomass of Chlorella pyrenoidosa containing about 90% of water into biodiesel. In order to investigate the effects of water content on biodiesel production, distilled water was added to dried microalgae biomass to form wet biomass used to produce biodiesel. The results showed that at lower temperature of 90°C, water had a negative effect on biodiesel production. The biodiesel yield decreased from 91.4% to 10.3% as water content increased from 0% to 90%. Higher temperature could compensate the negative effect. When temperature reached 150°C, there was no negative effect, and biodiesel yield was over 100%. Based on the above research, wet microalgae biomass was directly applied to biodiesel production, and the optimal conditions were investigated. Under the optimal conditions of 100 mg dry weight equivalent wet microalgae biomass, 4 mL methanol, 8 mL n-hexane, 0.5 M H2SO4, 120°C, and 180 min reaction time, the biodiesel yield reached as high as 92.5% and the FAME content was 93.2%. The results suggested that biodiesel could be effectively produced directly from wet microalgae biomass and this effort may offer the benefits of energy requirements for biodiesel production. PMID:24195081

  3. Direct Biodiesel Production from Wet Microalgae Biomass of Chlorella pyrenoidosa through In Situ Transesterification

    Directory of Open Access Journals (Sweden)

    Hechun Cao

    2013-01-01

    Full Text Available A one-step process was applied to directly converting wet oil-bearing microalgae biomass of Chlorella pyrenoidosa containing about 90% of water into biodiesel. In order to investigate the effects of water content on biodiesel production, distilled water was added to dried microalgae biomass to form wet biomass used to produce biodiesel. The results showed that at lower temperature of 90°C, water had a negative effect on biodiesel production. The biodiesel yield decreased from 91.4% to 10.3% as water content increased from 0% to 90%. Higher temperature could compensate the negative effect. When temperature reached 150°C, there was no negative effect, and biodiesel yield was over 100%. Based on the above research, wet microalgae biomass was directly applied to biodiesel production, and the optimal conditions were investigated. Under the optimal conditions of 100 mg dry weight equivalent wet microalgae biomass, 4 mL methanol, 8 mL n-hexane, 0.5 M H2SO4, 120°C, and 180 min reaction time, the biodiesel yield reached as high as 92.5% and the FAME content was 93.2%. The results suggested that biodiesel could be effectively produced directly from wet microalgae biomass and this effort may offer the benefits of energy requirements for biodiesel production.

  4. Encapsulation of lycopene in Chlorella pyrenoidosa: Loading properties and stability improvement.

    Science.gov (United States)

    Pu, Chuanfen; Tang, Wenting

    2017-11-15

    Aiming to improve the stability of lycopene and incorporate it into a complex nutraceutical, exogenous lycopene-loaded Chlorella pyrenoidosa cells (CPCs) were developed. The complex had an encapsulation yield of 13.06±0.89% and an encapsulation efficiency of 96.31±3.10%. Fluorescence analyses indicated that lycopene was encapsulated in the CPCs. X-ray diffraction, thermogravimetric and differential scanning calorimetric analyses were conducted and compared to those of the non-loaded CPCs, lycopene and their physical mixture. These studies demonstrated that lycopene was amorphous in the complex. The degradation kinetics indicated that encapsulation increased the stability of lycopene. The antioxidant activity of lycopene loaded CPCs against DPPH free radicals was higher than that of the unencapsulated lycopene after storage at 25°C for 25d. This study proved the feasibility of encapsulation of lycopene in the CPCs and combined the activities of both materials, which could be employed in the production of novel nutraceuticals to reduce oxidative stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Growing Chlorella vulgaris on thermophilic anaerobic digestion swine manure for nutrient removal and biomass production.

    Science.gov (United States)

    Deng, Xiang-Yuan; Gao, Kun; Zhang, Ren-Chuan; Addy, Min; Lu, Qian; Ren, Hong-Yan; Chen, Paul; Liu, Yu-Huan; Ruan, Roger

    2017-11-01

    Liquid swine manure was subjected to thermophilic anaerobic digestion, ammonia stripping and centrifugation in order to increase the available carbon sources and decrease the ammonia concentration and turbidity. Chlorella vulgaris (UTEX 2714) was grown on minimally diluted (2×, 3× and 4×) autoclaved and non-autoclaved pretreated anaerobic digestion swine manure (PADSM) in a batch-culture system for 7days. Results showed that C. vulgaris (UTEX 2714) grew best on 3× PADSM media, and effectively removed NH 4 + -N, TN, TP and COD by 98.5-99.8%, 49.2-55.4%, 20.0-29.7%, 31.2-34.0% and 99.8-99.9%, 67.4-70.8%, 49.3-54.4%, 73.6-78.7% in differently diluted autoclaved and non-autoclaved PADSM, respectively. Results of chemical compositions indicated that contents of pigment, carbohydrate, protein and lipid in C. vulgaris (UTEX 2714) changed with the culture conditions. Moreover, its fatty acid profiles suggested that this alga could be used as animal feed if cultivated in autoclaved PADSM or as good-quality biodiesel feedstock if cultivated in non-autoclaved PADSM. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Synergistic dynamics of nitrogen and phosphorous influences lipid productivity in Chlorella minutissima for biodiesel production.

    Science.gov (United States)

    Arora, Neha; Patel, Alok; Pruthi, Parul A; Pruthi, Vikas

    2016-08-01

    The study synergistically optimized nitrogen and phosphorous concentrations for attainment of maximum lipid productivity in Chlorella minutissima. Nitrogen and phosphorous limited cells (N(L)P(L)) showed maximum lipid productivity (49.1±0.41mg/L/d), 1.47 folds higher than control. Nitrogen depletion resulted in reduced cell size with large sized lipid droplets encompassing most of the intracellular space while discrete lipid bodies were observed under nitrogen sufficiency. Synergistic N/P starvations showed more prominent effect on photosynthetic pigments as to individual deprivations. Phosphorous deficiency along with N starvation exhibited 17.12% decline in carbohydrate while no change in nitrogen sufficient cells were recorded. The optimum N(L)P(L) concentration showed balance between biomass and lipid by maintaining intermediate cell size, pigments, carbohydrate and proteins. FAME profile showed C14-C18 carbon chains in N(L)P(L) cells with biodiesel properties comparable to plant oil methyl esters. Hence, synergistic N/P limitation was effective for enhancing lipid productivity with reduced consumption of nutrients. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Dewatering of Chlorella pyrenoidosa using diatomite dynamic membrane: filtration performance, membrane fouling and cake behavior.

    Science.gov (United States)

    Zhang, Yalei; Zhao, Yangying; Chu, Huaqiang; Zhou, Xuefei; Dong, Bingzhi

    2014-01-01

    The diatomite dynamic membrane (DDM) was utilized to dewater Chlorella pyrenoidosa of 2 g dry weight/L under continuous-flow mode, whose ultimate algae concentration ranged from 43 g to 22 g dry weight/L of different culture time. The stable flux of DDM could reach 30 L/m(2) h over a 24 h operation time without backwash. Influences of extracellular organic matters (EOM) on filtration behavior and membrane fouling were studied. The DDM was divided into three sub-layers, the slime layer, the algae layer and the diatomite layer from the outside to the inside of the cake layer based on components and morphologies. It was found that EOM caused membrane fouling by accumulating in the slime and algae layers. The DDM intercepted polysaccharides, protein-like substances, humic-like substances and some low-MW organics. Proteins were indicated the major membrane foulants with increased protein/polysaccharide ratio from the slime layer to the diatomite layer as culture time increased. This method could be applied to subsequent treatment of microalgae coupling technology of wastewater treatment or microalgae harvesting for producing biofuel. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Direct biodiesel production from wet microalgae biomass of Chlorella pyrenoidosa through in situ transesterification.

    Science.gov (United States)

    Cao, Hechun; Zhang, Zhiling; Wu, Xuwen; Miao, Xiaoling

    2013-01-01

    A one-step process was applied to directly converting wet oil-bearing microalgae biomass of Chlorella pyrenoidosa containing about 90% of water into biodiesel. In order to investigate the effects of water content on biodiesel production, distilled water was added to dried microalgae biomass to form wet biomass used to produce biodiesel. The results showed that at lower temperature of 90°C, water had a negative effect on biodiesel production. The biodiesel yield decreased from 91.4% to 10.3% as water content increased from 0% to 90%. Higher temperature could compensate the negative effect. When temperature reached 150°C, there was no negative effect, and biodiesel yield was over 100%. Based on the above research, wet microalgae biomass was directly applied to biodiesel production, and the optimal conditions were investigated. Under the optimal conditions of 100 mg dry weight equivalent wet microalgae biomass, 4 mL methanol, 8 mL n-hexane, 0.5 M H2SO4, 120°C, and 180 min reaction time, the biodiesel yield reached as high as 92.5% and the FAME content was 93.2%. The results suggested that biodiesel could be effectively produced directly from wet microalgae biomass and this effort may offer the benefits of energy requirements for biodiesel production.

  9. Photosystem II excitation pressure and photosynthetic carbon metabolism in Chlorella vulgaris

    International Nuclear Information System (INIS)

    Savitch, L.V.; Maxwell, D.P.; Huner, N.P.A.

    1996-01-01

    Chlorella vulgaris grown at 5 degrees C/150 micromoles m -2 s -1 mimics cells grown under high irradiance (27 degrees C/2200 micromoles m -2 s -1 ). This has been rationalized through the suggestion that both populations of cells were exposed to comparable photosystem II (PSII) excitation pressures measured as the chlorophyll a fluorescence quenching parameter, 1 - qP (D.P. Maxwell, S. Falk, N.P.A. Huner [1995] Plant Physiol 107: 687-694). To assess the possible role(s) of feedback mechanisms on PSII excitation pressure, stromal and cytosolic carbon metabolism were examined. Sucrose phosphate synthase and fructose-1,6-bisphosphatase activities as well as the ratios of fructose-1,6-bisphosphate/fructose-6 phosphate and sucrose/starch indicated that cells grown at 27 degrees C/2200 micromoles m -2 s -1 appeared to exhibit a restriction in starch metabolism. In contrast, cells grown at 5 degrees C/150 micromoles-1 m -2 s -1 appeared to exhibit a restriction in the sucrose metabolism based on decreased cytosolic fructose-1,6-bisphosphatase and sucrose phosphate synthase activities as well as a low sucrose/starch ratio. These metabolic restrictions may feedback on photosynthetic electron transport and, thus, contribute to the observed PSII excitation pressure. We conclude that, although PSII excitation pressure may reflect redox regulation of photosynthetic acclimation to light and temperature in C. vulgaris, it cannot be considered the primary redox signal. Alternative metabolic sensing/signaling mechanisms are discussed

  10. Effective flocculation of Chlorella vulgaris using chitosan with zeta potential measurement

    Science.gov (United States)

    Low, Y. J.; Lau, S. W.

    2017-06-01

    Microalgae are considered as one promising source of third-generation biofuels due to their fast growth rates, potentially higher yield rates and wide ranges of growth conditions. However, the extremely low biomass concentration in microalgae cultures presents a great challenge to the harvesting of microalgae because a large volume of water needs to be removed to obtain dry microalgal cells for the subsequent oil extraction process. In this study, the fresh water microalgae Chlorella vulgaris (C. vulgaris) was effectively harvested using both low molecular weight (MW) and high MW chitosan flocculants. The flocculation efficiency was evaluated by physical appearance, supernatant absorbance, zeta potential and solids content after centrifugal dewatering. High flocculation efficiency of 98.0-99.0% was achieved at the optimal dosage of 30-40 mg/g with formation of large microalgae flocs. This study suggests that the polymer bridging mechanism was governing the flocculation behaviour of C. vulgaris using high MW chitosan. Besides, charge patch neutralisation mechanism prevailed at low MW chitosan where lower dosage was sufficient to reach near-zero zeta potential compared with the high MW chitosan. The amount of chitosan polymer present in the culture may also affect the mechanism of flocculation.

  11. Efecto de la radiación ultravioleta B en la producción de polifenoles en la microalga marina Chlorella sp. Effect of ultraviolet B radiation on the production of polyphenols in the marine microalga Chlorella sp.

    Directory of Open Access Journals (Sweden)

    Jaime Copia

    2012-03-01

    Full Text Available Las algas marinas son una fuente importante de compuestos antioxidantes (fenoles y polifenoles, generados como mecanismos de defensa frente a factores de estrés (radiación UV, temperatura, herbívora. El objetivo de este trabajo es evaluar la estrategia de adaptación al efecto de la radiación ultravioleta B (RUV-B, 280-315 nm en la microalga marina Chlorella sp. mediante la producción de polifenoles y capacidad antioxidante total. Se expusieron cultivos de Chlorella sp. fueron expuestos a radiación UV-B (470 μW cm-2 por periodo de tiempos ascendentes. Se evaluó la capacidad antioxidante total DPPH, polifenoles totales, clorofila-a y b así como la densidad celular en cultivos expuestos y no expuestos. Los resultados indicaron que la RUV-B genera una disminución de la densidad celular en los cultivos irradiados por primera vez (1ª etapa, existiendo un aumento significativo (P Marine algae are an important source of antioxidant compounds (phenols and polyphenols, generated as defense mechanisms against stress factors (UV radiation, temperature, herbivory. The aim of this study was to evaluate the strategy of adaptation to the effect of ultraviolet B radiation (UV-B, 280-315 nm in the marine microalga Chlorella sp. through, the production of polyphenols and total antioxidant capacity. Chlorella sp. cultures were exposed to UV-B radiation (470 μW cm-2 over increasing time periods. We evaluated the total antioxidant capacity DPPH, total polyphenols, chlorophyll-a and b, and cell densities in exposed and unexposed cultures. The results indicated that UV-B caused a decrease in cell density in cultures irradiated for the first time (1st stage, with a significant increment (P < 0.05, lower than the control in the 2nd and 3rd stages only through the 4th stage (day 7, corresponding to a dose of 16,920 J m-2. The production of total phenols increased significantly (P < 0.05 for the IVth extract with respect to the control, confirming that the

  12. Combining and Comparing Coalescent, Distance and Character-Based Approaches for Barcoding Microalgaes: A Test with Chlorella-Like Species (Chlorophyta.

    Directory of Open Access Journals (Sweden)

    Shanmei Zou

    Full Text Available Several different barcoding methods of distinguishing species have been advanced, but which method is the best is still controversial. Chlorella is becoming particularly promising in the development of second-generation biofuels. However, the taxonomy of Chlorella-like organisms is easily confused. Here we report a comprehensive barcoding analysis of Chlorella-like species from Chlorella, Chloroidium, Dictyosphaerium and Actinastrum based on rbcL, ITS, tufA and 16S sequences to test the efficiency of traditional barcoding, GMYC, ABGD, PTP, P ID and character-based barcoding methods. First of all, the barcoding results gave new insights into the taxonomic assessment of Chlorella-like organisms studied, including the clear species discrimination and resolution of potentially cryptic species complexes in C. sorokiniana, D. ehrenbergianum and C. Vulgaris. The tufA proved to be the most efficient barcoding locus, which thus could be as potential "specific barcode" for Chlorella-like species. The 16S failed in discriminating most closely related species. The resolution of GMYC, PTP, P ID, ABGD and character-based barcoding methods were variable among rbcL, ITS and tufA genes. The best resolution for species differentiation appeared in tufA analysis where GMYC, PTP, ABGD and character-based approaches produced consistent groups while the PTP method over-split the taxa. The character analysis of rbcL, ITS and tufA sequences could clearly distinguish all taxonomic groups respectively, including the potentially cryptic lineages, with many character attributes. Thus, the character-based barcoding provides an attractive complement to coalescent and distance-based barcoding. Our study represents the test that proves the efficiency of multiple DNA barcoding in species discrimination of microalgaes.

  13. Differential regulation of fatty acid biosynthesis in two Chlorella species in response to nitrate treatments and the potential of binary blending microalgae oils for biodiesel application.

    Science.gov (United States)

    Cha, Thye San; Chen, Jian Woon; Goh, Eng Giap; Aziz, Ahmad; Loh, Saw Hong

    2011-11-01

    This study was undertaken to investigate the effects of different nitrate concentrations in culture medium on oil content and fatty acid composition of Chlorella vulgaris (UMT-M1) and Chlorella sorokiniana (KS-MB2). Results showed that both species produced significant higher (pdifferentially regulated fatty acid accumulation patterns in response to nitrate treatments at early stationary growth phase. Their potential use for biodiesel application could be enhanced by exploring the concept of binary blending of the two microalgae oils using developed mathematical equations to calculate the oil mass blending ratio and simultaneously estimated the weight percentage (wt.%) of desirable fatty acid compositions. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Fatty acid composition of Spirulina sp., Chlorella sp. and Chaetoceros sp. microalgae and introduction as potential new sources to extinct omega 3 and omega 6

    Directory of Open Access Journals (Sweden)

    Homan Gorjzdadeh

    2016-05-01

    Full Text Available Background: This study was carried out to determine the oil fatty acids from two special species of microalgae; Spirulina sp.,Chlorella sp. and also Chaetoceros sp. collected from Bahmanshir River. Materials and Methods: Sampling of microalgae Chaetoceros sp. from Bahmanshir River was under taken using bottle samplers during spring season of 2013. Microalgae Spirulina sp. and Chlorella sp. were supplied from Shrimp Research Institute of Iran in Bushehr Province. Samples then were cultured under controlled laboratory conditions and mass culture for 100 liters was undertaken. Isolation of microalgae species from water of cultured media was carried out using filtration and centrifugation methods. The fatty acid compositions were determined by Gas – FID chromatography. Results: Results showed that regarding Saturated Fatty Acids (SFA obtained from purified culture of Chaetoceros sp., Spirulina sp. and Chlorella sp. the maximum amount of total fatty acids were belonged to palmitic acids (C16:0 with 15.21%, 30.1% and 25.17% of total fatty acids  respectively. Analysis of Mono Unsaturated Fatty Acids (MUFA showed that in the Oleic acid was maximum amount of 34% in Spirulina sp. In addition the amount of MUFA in Chlorella sp. was 16.37% of total fatty acids. On the other hand the amount of palmeotic acid in purified culture of Chaetoceros sp. was 30.33% from total content of fatty acids. Analysis of Poly Unsaturated Fatty Acids (PUFA, Linoleic acid (C18:2 (Omega 6, revealed maximum percentage in Spirulina sp. with 18.8%. Results of Alpha linoleic acid (C18:3 (Omega3 analysis showed maximum amount of 9.66% in Chlorella sp. compared to other microalgae with lower omega 3 contents. Spirulina sp. contained maximum amount of Linoleic acid (C18:2 with 18.8% of total fatty acids. Therefore, Spirulina sp. can be considered as a rich source of omega 6 for the purpose of fatty acid extractions. The presence of PUFA in Chlorella sp. and Spirulina sp. was

  15. Effect of laser radiation on the cultivation rate of the microalga Chlorella sorokiniana as a source of biofuel

    Science.gov (United States)

    Politaeva, N.; Smyatskaya, Y.; Slugin, V.; Toumi, A.; Bouabdelli, M.

    2018-01-01

    This article studies the influence of laser radiation on the growth of micro-algal biomass of Chlorella sorokiniana. The composition of nutrient medium and the effect the laser beam (2 and 5 cm diameter, 1, 5, 10, 15 and 20 minutes exposure time) for accelerated cultivation of microalgal biomass were studied. The source of laser radiation (LR) was a helium-neon laser with a nominal output power of 1.6 mW and a wavelength of 0.63 μm. The greatest increase in biomass was observed when LR was applied to a suspension of microalga Chlorella sorokiniana with a beam of 5 cm diameter for a time of 10, 15 and 20 minutes. The results of the microscopic study of the microalga cells show a significant increase in the number of cells after an exposure to LR with a beam diameter of 5 cm in diameter. These cells were characterized by a large vacuole, a thickened lipid shell and a large accumulation of metabolites prone to agglutination. This study proposed to obtain valuable components (lipids, carotenoids, and pectin) from the obtained biomass by extraction method and to use the residual biomass formed wastes, after the extraction of valuable components, as a co-substrate for anaerobic digestion to produce biogas. The composition of biogas consists mainly of methane and carbon dioxide. Methane is recommended to be used for economic needs in supplying the whole process with heat and electricity. The carbon dioxide formed during fermentation and after combustion of methane for energy production, is planned to be used as a carbon source in the cultivation of Chlorella sorokiniana for photoautotrophic biomass production.

  16. Bioaccumulation study of acrylate monomers in algae (Chlorella Kessleri) by PY-GC and PY-GC/MS

    International Nuclear Information System (INIS)

    Halas, L.; Orinak, A.; Adamova, M.; Ladomersky, J.

    2004-01-01

    Acrylate monomers methylmethacrylate (MMA) and cyclohexylmethacrylate (CHMA) bioaccumulation has been determined in aquatic organism, algae (Chlorella kessleri). Algae were collected in amount of 0.4 mg and directly injected to the paralytic cell. In algae bodies accumulated monomers were analysed by pyrolysis gas chromatography (Py-GC) and pyrolysis gas chromatography coupled with mass spectrometry (Py-GC/MS). Traces of the accumulated monomers in algae body can be determined after 1-, 2 -, 3-weeks of incubation. Maximum content of MMA was determined after 3-week of experiment, contrariwise in the case of CHMA after 2-week exposition. Relationship with pyrolysis temperature has also been studied. (authors)

  17. Demography of zooplankton (Anuraeopsis fissa, Brachionus rubens and Moina macrocopa) fed Chlorella vulgaris and Scenedesmus acutus cultured on different media.

    Science.gov (United States)

    Morales-Ventura, Jesús; Nandini, S; Sarma, S S S; Castellanos-Páez, Maria Elena

    2012-09-01

    Generally zooplankton growth is often limited by the quality of their algal diet. A cheaper common practice in aquaculture, is to culture algae with fertilizers; however, the demography of zooplankton when fed these algae has not yet been evaluated. We studied the population growth and life table demography of the rotifers Anuraeopsis fissa and Brachionus rubens, and the cladoceran Moina macrocopa. For this, the algae Scenedesmus acutus or Chlorella vulgaris were cultured on defined (Bold's basal) medium or the commercial liquid fertilizer (Bayfolan). Experiments were conducted at one algal concentration 1.0 x 10(6) cells/mL of C. vulgaris or its equivalent dry weight of 0.5 x 10(6) cells/mL of S. acutus. The population dynamics were tested at 23 +/- 1 degrees C in 100 mL transparent jars, each with 50mL of the test medium, with an initial density of 0.5indiv/mL, for a total of 48 test jars (3 zooplankton 2 algal species x 2 culture media x 4 replicates). For the life table experiments with M. macrocopa, we introduced 10 neonates (vulgaris cultured in Bold medium. Regardless of the culture medium, Chlorella resulted in significantly higher gross and net reproductive rates for B. rubens than S. acutus diets. The reproductive rates of M. macrocopa were significantly higher in all the tested diets except when fed with S. acutus in Bold medium. The population increase rate, derived from growth experiments of A. fissa and B. rubens, ranged from 0.1-0.25/d and were significantly higher on C vulgaris cultured in liquid fertilizer as compared to the other diets. The growth rates of M. macrocopa ranged from 0.1 to 0.38/d, and were highest with diets of C. vulgaris cultured in Bold medium and S. acutus cultured in fertilizer. Thus, regardless of the culture medium used, the growth rates of the evaluated zooplankton species were higher with Chlorella than with Scenedesmus. The peak population density was highest (2 800ind/mL) for A. fissa fed Chlorella that was cultured on

  18. Influence of ultraviolet irradiation on nutrient-gleaning capacity of two unicellular algae. [Anacystis nidulans and Chlorella vulgaris

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, H D; Sharma, V; Bisaria, G P

    1975-01-01

    Two unicellular algae, viz., Anacystis nidulans and Chlorella vulgaris, growing in polluted effluents, were isolated in unialgal and bacteria free culture. They were mutagenically exposed to ultraviolet radiation and variant strains endowed with differing capacities for growth and nutrient-gleaning were successfully isolated as distinct clones on agar plates. One such clone each of the two species was tested further and found stable. While these variant strains grew more slowly than untreated controls, statistically significant differences with respect to phosphate and nitrate uptake were found between treated and control strains of the two species.

  19. Hydrodynamics and photosynthesis performance of Chlorella fusca (Chlorophyta) grown in a thin-layer cascade (TLC) system

    Czech Academy of Sciences Publication Activity Database

    Jerez, Celia G.; Navarro, E.; Rico, Rosa M.; Malpartida, I.; Masojídek, Jiří; Abdala, R.; Figueroa, Félix L.

    2014-01-01

    Roč. 22, č. 2 (2014), s. 111-122 ISSN 1864-7790 R&D Projects: GA MŠk ED2.1.00/03.0110 Grant - others:Government of Spain (ES) Project Ecolife CGL08-05407-C03-01; Junta de Andalucía(ES) RNM-295; Ministry of Economy and Competitiveness(ES) CTM2011-15659-E Institutional support: RVO:61388971 Keywords : Chlorella fusca * TLC * cultivation * photosynthesis Subject RIV: EE - Microbiology, Virology Impact factor: 1.258, year: 2014

  20. Differential effects of P25 TiO{sub 2} nanoparticles on freshwater green microalgae: Chlorella and Scenedesmus species

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Rajdeep; Parashar, Abhinav; Bhuvaneshwari, M.; Chandrasekaran, N.; Mukherjee, Amitava, E-mail: amit.mookerjea@gmail.com

    2016-07-15

    Highlights: • Differential effects of P25 TiO{sub 2} NPs on Chlorella and Scenedesmus. • Concentration dependent effects in morphology and viability. • Increased ROS, catalase activity & LPO release with loss in SOD & GSH activity. • Dose dependent differential TiO{sub 2} NPs uptake affected by colonization of algae. - Abstract: P25 TiO{sub 2} nanoparticles majorly used in cosmetic products have well known detrimental effects towards the aquatic environment. In a freshwater ecosystem, Chlorella and Scenedesmus are among the most commonly found algal species frequently used to study the effects of metal oxide nanoparticles. A comparative study has been conducted herein to investigate differences in the toxic effects caused by these nanoparticles towards the two algae species. The three different concentrations of P25 TiO{sub 2} NPs (0.01, 0.1 & 1 μg/mL, i.e., 0.12, 1.25 and 12.52 μM) were selected to correlate surface water concentrations of the nanoparticles, and filtered and sterilized fresh water medium was used throughout this study. There was significant increase (p < 0.001) in hydrodynamic diameter of nanoparticles with respect to both, time (0, 24, 48 and 72 h) as well as concentration under all the exposure conditions. Although, significant dose-dependent morphological (surface area & biovolume) interspecies variations were not observed, it was evident at the highest concentration of exposure within individuals. At 1 μg/mL exposure concentration, a significant difference in toxicity was noted between Chlorella and Scenedesmus under only visible light (p < 0.001) and UVA (p < 0.01) irradiation conditions. The viability data were well supported by the results obtained for oxidative stress induced by NPs on the cells. At the highest exposure concentration, superoxide dismutase and reduced glutathione activities were assessed for both the algae under all the irradiation conditions. Increased catalase activity and LPO release complemented the cytotoxic

  1. Phytophthora viruses.

    Science.gov (United States)

    Cai, Guohong; Hillman, Bradley I

    2013-01-01

    Phytophthora sp. is a genus in the oomycetes, which are similar to filamentous fungi in morphology and habitat, but phylogenetically more closely related to brown algae and diatoms and fall in the kingdom Stramenopila. In the past few years, several viruses have been characterized in Phytophthora species, including four viruses from Phytophthora infestans, the late blight pathogen, and an endornavirus from an unnamed Phytophthora species from Douglas fir. Studies on Phytophthora viruses have revealed several interesting systems. Phytophthora infestans RNA virus 1 (PiRV-1) and PiRV-2 are likely the first members of two new virus families; studies on PiRV-3 support the establishment of a new virus genus that is not affiliated with established virus families; PiRV-4 is a member of Narnaviridae, most likely in the genus Narnavirus; and Phytophthora endornavirus 1 (PEV1) was the first nonplant endornavirus at the time of reporting. Viral capsids have not been found in any of the above-mentioned viruses. PiRV-1 demonstrated a unique genome organization that requires further examination, and PiRV-2 may have played a role in late blight resurgence in 1980s-1990s. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Schmallenberg Virus

    Indian Academy of Sciences (India)

    IAS Admin

    explore the potential of this infection crossing the species barrier and thereby .... The virus targets mainly the brain of the unborn animal resulting in neurological ... The virus is located in the blood of the adult infected animal or in the central ...

  3. Zika Virus

    Science.gov (United States)

    ... with facebook share with twitter share with linkedin Zika Virus Credit: NIAID A female Aedes mosquito. This type of mosquito can transmit Zika, ... transmitted to humans through the bite of infected Aedes aegypti mosquitoes. Zika virus can be transmitted from an infected pregnant woman ...

  4. CHANDIPURA VIRUS

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. CHANDIPURA VIRUS. First isolated from a village called Chandipura near Nagpur in 1965 in India. Belongs to rhabdoviridae family. Used as a Model System to study RNA virus multiplication in the infected cell at molecular level. Notes:

  5. Lipid composition of Chlorella vulgaris (Trebouxiophyceae) as a function of different cadmium and phosphate concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Chia, Mathias Ahii, E-mail: chia28us@yahoo.com [Department of Botany, Federal University of São Carlos, Rodovia Washington Luis, km 235, São Carlos, SP, Cep 13565905 (Brazil); Department of Biological Sciences, Ahmadu Bello University, Zaria, Nigeria -PMB 1013, Postal Code 810001 (Nigeria); Lombardi, Ana Teresa [Department of Botany, Federal University of São Carlos, Rodovia Washington Luis, km 235, São Carlos, SP, Cep 13565905 (Brazil); Melão, Maria da Graça G. [Department of Hydrobiology, Federal University of São Carlos, Rodovia Washington Luis, km 235, São Carlos, SP, Cep 13565905 (Brazil); Parrish, Christopher C. [Ocean Sciences Centre, Memorial University of Newfoundland, St. John' s, Newfoundland A1C 5S7 (Canada)

    2013-03-15

    Highlights: ► We studied the effect of Cd and phosphorus (P) on lipids of Chlorella vulgaris. ► Triacylglycerol (TAG) concentration increased under P limitation and Cd stress. ► Fatty acids (FA) saturation increased with P limitation and Cd exposure. ► Lower PUFA were obtained under P limitation and Cd stress. ► Combined P limitation/Cd stress increased total lipid production of the microalga. -- Abstract: Fatty acids are the fundamental structural components of membrane lipids, and the degree of saturation of the long hydrocarbon chains in microalgae contributes to regulation of growth, biomass production and reproduction of aquatic consumers. This research aimed at evaluating the effects of cadmium (2 × 10{sup −8}; 10{sup −7} mol L{sup −1} Cd) on lipid class and fatty acid composition of the microalga Chlorella vulgaris under varying phosphate (PO{sub 4}{sup 3−}) concentrations (6.0 × 10{sup −7} to 2.3 × 10{sup −4} mol L{sup −1}). Under PO{sub 4}{sup 3−} limitation and Cd stress, the storage lipid class triacylglycerol (TAG) was the most accumulated among the lipid classes. Fatty acid composition revealed that the degree of saturation increased with increasing Cd stress and PO{sub 4}{sup 3−} limitation. Decreasing PO{sub 4}{sup 3−} and increasing Cd concentrations resulted in higher saturated fatty acid (SAFA) and monounsaturated FA (MUFA) concentrations. Total polyunsaturated FA (PUFA) and ω3 PUFA, and PUFA:SAFA ratios were higher in the control (2.3 × 10{sup −4} mol L{sup −1} PO{sub 4}{sup 3−}) cells than in either PO{sub 4}{sup 3−} limitation or Cd stress, or in the combination of both stresses. Contrasting with all the other PUFAs, 18:2n – 6 increased as PO{sub 4}{sup 3−} limitation increased. A significant positive relationship of PUFAs, acetone mobile polar lipids (AMPL) and phospholipids (PL) with phosphate concentration in the culture media was obtained, while TAG concentrations had a positive association

  6. Enhancement of Lutein Production in Chlorella sorokiniana (Chorophyta by Improvement of Culture Conditions and Random Mutagenesis

    Directory of Open Access Journals (Sweden)

    Maria Angeles Vargas

    2011-09-01

    Full Text Available Chlorella sorokiniana has been selected for lutein production, after a screening of thirteen species of microalgae, since it showed both a high content in this carotenoid and a high growth rate. The effects of several nutritional and environmental factors on cell growth and lutein accumulation have been studied. Maximal specific growth rate and lutein content were attained at 690 µmol photons m−2 s−1, 28 °C, 2 mM NaCl, 40 mM nitrate and under mixotrophic conditions. In general, optimal conditions for the growth of this strain also lead to maximal lutein productivity. High lutein yielding mutants of C. sorokiniana have been obtained by random mutagenesis, using N-methyl-N′-nitro-nitrosoguanidine (MNNG as a mutagen and selecting mutants by their resistance to the inhibitors of the carotenogenic pathway nicotine and norflurazon. Among the mutants resistant to the herbicides, those exhibiting both high content in lutein and high growth rate were chosen. Several mutants exhibited higher contents in this carotenoid than the wild type, showing, in addition, either a similar or higher growth rate than the latter strain. The mutant MR-16 exhibited a 2.0-fold higher volumetric lutein content than that of the wild type, attaining values of 42.0 mg L−1 and mutants DMR-5 and DMR-8 attained a lutein cellular content of 7.0 mg g−1 dry weight. The high lutein yield exhibited by C. sorokiniana makes this microalga an excellent candidate for the production of this commercially interesting pigment.

  7. Biofuels from the Fresh Water Microalgae Chlorella vulgaris (FWM-CV for Diesel Engines

    Directory of Open Access Journals (Sweden)

    Saddam H. Al-lwayzy

    2014-03-01

    Full Text Available This work aims to investigate biofuels for diesel engines produced on a lab-scale from the fresh water microalgae Chlorella vulgaris (FWM-CV. The impact of growing conditions on the properties of biodiesel produced from FWM-CV was evaluated. The properties of FWM-CV biodiesel were found to be within the ASTM standards for biodiesel. Due to the limited amount of biodiesel produced on the lab-scale, the biomass of dry cells of FWM-CV was used to yield emulsified water fuel. The preparation of emulsion fuel with and without FWM-CV cells was conducted using ultrasound to overcome the problems of large size microalgae colonies and to form homogenized emulsions. The emulsified water fuels, prepared using ultrasound, were found to be stable and the size of FWM-CV colonies were effectively reduced to pass through the engine nozzle safely. Engine tests at 3670 rpm were conducted using three fuels: cottonseed biodiesel CS-B100, emulsified cottonseed biodiesel water fuel, water and emulsifier (CS-E20 and emulsified water containing FWM-CV cells CS-ME20. The results showed that the brake specific fuel consumption (BSFC was increased by about 41% when the engine was fueled with emulsified water fuels compared to CS-B100. The engine power, exhaust gas temperature, NOx and CO2 were significantly lower than that produced by CS-B100. The CS-ME20 produced higher power than CS-E20 due to the heating value improvement as a result of adding FWM-CV cells to the fuel.

  8. Use of solvent mixtures for total lipid extraction of Chlorella vulgaris and gas chromatography FAME analysis.

    Science.gov (United States)

    Moradi-Kheibari, Narges; Ahmadzadeh, Hossein; Hosseini, Majid

    2017-09-01

    Lipid extraction is the bottleneck step for algae-based biodiesel production. Herein, 12 solvent mixture systems (mixtures of three non-polar and two polar organic solvents) were examined to evaluate their effects on the total lipid yield from Chlorella vulgaris (C. vulgaris). Moreover, the extraction yields of three solvent systems with maximum extraction efficiency of esterifiable lipids were determined by acidic transesterification and GC-FID analysis. Three solvent systems, which resulted in a higher extraction yield, were further subjected to fatty acid methyl ester (FAME) analysis. The total lipid extraction yields (based on dry biomass) were (38.57 ± 1.51), (25.33 ± 0.58), and (25.17 ± 1.14) %, for chloroform-methanol (1:2) (C1M2), hexane-methanol (1:2) (H1M2), and chloroform-methanol (2:1) (C2M1), respectively. The extraction efficiency of C1M2 was approximately 1.5 times higher than H1M2 and C2M1, whereas the FAME profile of extracted lipids by H1M2 and C1M2 were almost identical. Moreover, the esterifiable lipid extraction yields of (18.14 ± 2.60), (16.66 ± 0.35), and (13.22 ± 0.31) % (based on dry biomass) were obtained for C1M2, H1M2, and C2M1 solvent mixture systems, respectively. The biodiesel fuel properties produced from C. vulgaris were empirically predicted and compared to that of the EN 14214 and ASTM 6751 standard specifications.

  9. CO2 Biofixation and Growth Kinetics of Chlorella vulgaris and Nannochloropsis gaditana.

    Science.gov (United States)

    Adamczyk, Michał; Lasek, Janusz; Skawińska, Agnieszka

    2016-08-01

    CO2 biofixation was investigated using tubular bioreactors (15 and 1.5 l) either in the presence of green algae Chlorella vulgaris or Nannochloropsis gaditana. The cultivation was carried out in the following conditions: temperature of 25 °C, inlet-CO2 of 4 and 8 vol%, and artificial light enhancing photosynthesis. Higher biofixation were observed in 8 vol% CO2 concentration for both microalgae cultures than in 4 vol%. Characteristic process parameters such as productivity, CO2 fixation, and kinetic rate coefficient were determined and discussed. Simplified and advanced methods for determination of CO2 fixation were compared. In a simplified method, it is assumed that 1 kg of produced biomass equals 1.88 kg recycled CO2. Advance method is based on empirical results of the present study (formula with carbon content in biomass). It was observed that application of the simplified method can generate large errors, especially if the biomass contains a relatively low amount of carbon. N. gaditana is the recommended species for CO2 removal due to a high biofixation rate-more than 1.7 g/l/day. On day 10 of cultivation, the cell concentration was more than 1.7 × 10(7) cells/ml. In the case of C. vulgaris, the maximal biofixation rate and cell concentration did not exceed 1.4 g/l/day and 1.3 × 10(7) cells/ml, respectively.

  10. Growth-inhibitory and metal-binding proteins in Chlorella vulgaris exposed to cadmium or zinc

    International Nuclear Information System (INIS)

    Huang Zhiyong; Li Lianping; Huang Gaoling; Yan Qingpi; Shi Bing; Xu Xiaoqin

    2009-01-01

    Phytochelatins, with the general structure of (γ-Glu-Cys)n-Gly (n = 2-11), are usually recognized as being strongly induced by metals in microalgae and play an important role in the detoxification of heavy metals in environment. However, there have been few studies on metallothionein (MT) synthesis in Chlorella vulgaris (C. vulgaris) exposed to heavy metals. The present study describes the growth inhibition of C. vulgaris exposed to different concentrations of cadmium and zinc, and the induction of metal-binding MT-like proteins in the cells. The amounts of metal-binding proteins, induced in the alga exposed to different concentrations of Cd and Zn, were analyzed with a size-exclusion HPLC coupled to ICP-MS. After being purified with a gel filtration column (Sephadex G-75, 3.5 cm x 80 cm) and a desalting column (G-25, 1.5 cm x 30 cm), the isoforms and sub-isoforms of Zn-binding protein were characterized by a reverse phase-HPLC coupled to electrospray ionization and a triple quadrupole mass spectrometer (HPLC-ESI-MS/MS). In addition, the ultraviolet spectra of purified Zn-binding proteins were analyzed in media with different pH values. The results showed that the significant inhibitory effects (at p -1 of Cd, and 60 and 80 μmol l -1 of Zn were added. The Cd/Zn-binding proteins induced in C. vulgaris exposed to Cd and Zn were referred to as Cd/Zn-MT-like proteins in which the mean molecular mass of the apo-MT-like was 6152 Da. The induced Cd/Zn-MT-like proteins might be involved in the detoxification of heavy metals, such as cadmium and zinc, by the alga

  11. Photo-induced transformations of mercury(II) species in the presence of algae, Chlorella vulgaris

    Energy Technology Data Exchange (ETDEWEB)

    Deng Lin, E-mail: dlwhu@163.com [Department of Municipal Engineering, Southeast University, Nanjing 210096 (China); Fu Dafang [Department of Municipal Engineering, Southeast University, Nanjing 210096 (China); Deng Nansheng [School of Resources and Environmental Science, Wuhan University, Wuhan 430072 (China)

    2009-05-30

    The effects of algae (i.e., Chlorella vulgaris), Fe(III), humic substances, and pH on the photoreduction of Hg(II) under the irradiation of metal halide lamps ({lambda} {>=} 365 nm, 250 W) were investigated in this paper. The photoreduction rate of Hg(II) was found to increase with the increasing concentration of algae, Fe(III), and humic substances. The cooperation action of Fe(III) and humic substances accelerated the photoreduction of Hg(II). When the initial concentration of Hg(II) was in the range of 0.0-200.0 {mu}g L{sup -1} with initial algae concentrations 7.0 x 10{sup 9} cells L{sup -1} at pH 7.0, the initial photoreduction rate of Hg(II) could be expressed by the equation: -dC{sub Hg(II)}/dt = 0.65 x [C{sub Hg(II)}]{sup 0.39} with a correlation coefficient of R = 0.9912. The study on the photochemical process in terms of total mercury mass balance revealed that more than 40.86% of Hg(II) from the algal suspension was reduced to volatile metallic mercury. This paper discussed the photoreduction mechanism of Hg(II) in the presence of algae. This research will provide information for predicting the photoreduction of Hg(II) in the real environment. It will be helpful for understanding the photochemical transformation of Hg(II) and the formation of DGM in natural water in the presence of algae complexes. It will also be helpful for providing new methods to deal with heavy metal pollution.

  12. Growth of Chlorella vulgaris and nutrient removal in the wastewater in response to intermittent carbon dioxide.

    Science.gov (United States)

    Liu, Xiaoning; Ying, Kezhen; Chen, Guangyao; Zhou, Canwei; Zhang, Wen; Zhang, Xihui; Cai, Zhonghua; Holmes, Thomas; Tao, Yi

    2017-11-01

    In this study, Chlorella vulgaris (C. vulgaris) were cultured in cell culture flask supplied with intermittent CO 2 enriched gas. The impact of CO 2 concentration (from 1% to 20% v/v) on the growth of C. vulgaris cultured in domestic wastewater was exploited in various perspectives which include biomass, specific growth rate, culture pH, carbon consumption, and the removal of nitrogen and phosphorus compounds. The results showed that the maximum microalgal biomass concentration, 1.12 g L -1 , was achieved with 10% CO 2 as a feed gas. At 20% CO 2 the growth of C. vulgaris suffered from inhibition during initial 1.5 d, but acclimated to low pH (6.3 in average) with relatively higher specific growth rate (0.3-0.5 d -1 ) during subsequent culture period. After the rapid consumption of ammonium in the wastewater, an obvious decline in the nitrate concentration was observed, indicating that C. vulgaris prefer ammonium as a primary nitrogen source. The total nitrogen and phosphorus decreased from 44.0 mg L -1 to 2.1-5.4 mg L -1 and from 5.2 mg L -1 to 0-0.6 mg L -1 within 6.5 d under the aeration of 1-20% CO 2 , respectively, but no significant difference in consumed nitrogen versus phosphorus ratio was observed among different CO 2 concentration. The kinetics of nutrients removal were also determined through the application of pseudo first order kinetic model. 5-10% CO 2 aeration was optimal for the growth of C. vulgaris in the domestic wastewater, based on the coupling of carbon consumption, microalgal biomass, the nutrients removal and kinetics constants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Improving productivity and quality of biodiesel from Chlorella vulgaris SDEC-3M through customized process designs

    International Nuclear Information System (INIS)

    Qi, Feng; Pei, Haiyan; Ma, Guixia; Zhang, Shuo; Mu, Ruimin

    2016-01-01

    Highlights: • Responses of growth and lipid in SDEC-3M to N concentrations were described. • The high lipid accumulation and biomass production were coexisted in buffer period. • Shorting N-deficient culture stage could improve lipid productivity. • A scheme of optimal designs was suggested to improve lipid productivity. • Biodiesels were meet standards and their performances varied with N-deficient time. - Abstract: In this study, temporal variations of microalgae growth and lipid accumulation in response to different nitrogen concentrations in media were investigated and discussed in detail, using a mutant Chlorella vulgaris SDEC-3M as a model. The results show that a short-term of dramatic lipid accumulation and nonsignificant descent of biomass productivities can be concomitant in SDEC-3M during early N-deficient stage (buffer period). It was found that the maximum lipid productivities of 63.52 mg L"−"1 d"−"1 occurred after 24 h N-shift. It means that, obtained lipid productivity under two-stage strategy with 24 h N-deficient stage was approximately three times as high as the maximum one obtained under N-rich condition and the final one obtained during longer N-deficient culture. Batch culture mode, higher light intensity and light/dark cycle in cooperation with N-rich/N-deficient cycle were also suggested as feasible scheme to improve lipid productivity in large scale culture. Additionally, the fatty acid profiles analysis indirectly showed that the properties of biodiesel from SDEC-3M majorly satisfied biodiesel standards. The fuel performances varied with N-deficient culture time, meaning that better combustion performance, oxidation stability, and exhaust emissions level related to longer N-deficient stage, while the biodiesel produced form N-deficient would perform well under low temperature. The results mean that SDEC-3M-derived biodiesels with customized process designs have commercial potential in the aspects of productivity and quality.

  14. Optimising the bioreceptivity of porous glass tiles based on colonization by the alga Chlorella vulgaris

    International Nuclear Information System (INIS)

    Ferrándiz-Mas, V.; Bond, T.; Zhang, Z.; Melchiorri, J.; Cheeseman, C.R.

    2016-01-01

    Green façades on buildings can mitigate greenhouse gas emissions. An option to obtain green facades is through the natural colonisation of construction materials. This can be achieved by engineering bioreceptive materials. Bioreceptivity is the susceptibility of a material to be colonised by living organisms. The aim of this research was to develop tiles made by sintering granular waste glass that were optimised for bioreceptivity of organisms capable of photosynthesis. Tiles were produced by pressing recycled soda-lime glass with a controlled particle size distribution and sintering compacted samples at temperatures between 680 and 740 °C. The primary bioreceptivity of the tiles was evaluated by quantifying colonisation by the algae Chlorella vulgaris (C. vulgaris), which was selected as a model photosynthetic micro-organism. Concentrations of C. vulgaris were measured using chlorophyll-a extraction. Relationships between bioreceptivity and the properties of the porous glass tile, including porosity, sorptivity, translucency and pH are reported. Capillary porosity and water sorptivity were the key factors influencing the bioreceptivity of porous glass. Maximum C. vulgaris growth and colonisation was obtained for tiles sintered at 700 °C, with chlorophyll-a concentrations reaching up to 11.1 ± 0.4 μg/cm"2 of tile. Bioreceptivity was positively correlated with sorptivity and porosity and negatively correlated with light transmittance. The research demonstrates that the microstructure of porous glass, determined by the processing conditions, significantly influences bioreceptivity. Porous glass tiles with high bioreceptivity that are colonised by photosynthetic algae have the potential to form carbon-negative façades for buildings and green infrastructure. - Highlights: • Porous tiles made by sintering waste glass at variable temperatures • Bioreceptivity assessed by measuring colonisation by the algae C. vulgaris • Tiles sintered at 700 °C gave maximum

  15. Photo-induced transformations of mercury(II) species in the presence of algae, Chlorella vulgaris

    International Nuclear Information System (INIS)

    Deng Lin; Fu Dafang; Deng Nansheng

    2009-01-01

    The effects of algae (i.e., Chlorella vulgaris), Fe(III), humic substances, and pH on the photoreduction of Hg(II) under the irradiation of metal halide lamps (λ ≥ 365 nm, 250 W) were investigated in this paper. The photoreduction rate of Hg(II) was found to increase with the increasing concentration of algae, Fe(III), and humic substances. The cooperation action of Fe(III) and humic substances accelerated the photoreduction of Hg(II). When the initial concentration of Hg(II) was in the range of 0.0-200.0 μg L -1 with initial algae concentrations 7.0 x 10 9 cells L -1 at pH 7.0, the initial photoreduction rate of Hg(II) could be expressed by the equation: -dC Hg(II) /dt = 0.65 x [C Hg(II) ] 0.39 with a correlation coefficient of R = 0.9912. The study on the photochemical process in terms of total mercury mass balance revealed that more than 40.86% of Hg(II) from the algal suspension was reduced to volatile metallic mercury. This paper discussed the photoreduction mechanism of Hg(II) in the presence of algae. This research will provide information for predicting the photoreduction of Hg(II) in the real environment. It will be helpful for understanding the photochemical transformation of Hg(II) and the formation of DGM in natural water in the presence of algae complexes. It will also be helpful for providing new methods to deal with heavy metal pollution.

  16. Treatment of real wastewater using co-culture of immobilized Chlorella vulgaris and suspended activated sludge.

    Science.gov (United States)

    Mujtaba, Ghulam; Lee, Kisay

    2017-09-01

    The use of algal-bacterial symbiotic association establishes a sustainable and cost-effective strategy in wastewater treatment. Using municipal wastewater, the removal performances of inorganic nutrients (nitrogen and phosphorus) and organic pollutants were investigated by the co-culture system having different inoculum ratios (R) of suspended activated sludge to alginate-immobilized microalgae Chlorella vulgaris. The co-culture reactors with lower R ratios obtained more removal of nitrogen than in pure culture of C. vulgaris. The reactor with R = 0.5 (sludge/microalgae) showed the highest performance representing 66% removal after 24 h and 95% removal after 84 h. Phosphorus was completely eliminated (100%) in the co-culture system with inoculum ratios of 0.5 and 1.0 after 24 h and in the pure C. vulgaris culture after 36 h. The COD level was greatly reduced in the activated sludge reactor, while, it was increasing in pure C. vulgaris culture after 24 h of incubation. However, COD was almost stabilized after 24 h in the reactors with high R ratios such as 2.0, 5.0, and 10 due to the higher concentration of activated sludge. The growth of C. vulgaris was promoted from 0.03 g/L/d to 0.05 g/L/d in the co-culture of low inoculum ratios such as R = 0.5, implying that there exist an optimum inoculum ratio in the co-culture system in order to achieve efficient removal of nutrients. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Growth-inhibitory and metal-binding proteins in Chlorella vulgaris exposed to cadmium or zinc

    Energy Technology Data Exchange (ETDEWEB)

    Huang Zhiyong [College of Bioengineering, Jimei University, Xiamen, 361021 (China)], E-mail: zhyhuang@jmu.edu.cn; Li Lianping; Huang Gaoling [College of Bioengineering, Jimei University, Xiamen, 361021 (China); Yan Qingpi [College of fisheries, Jimei University, Xiamen, 361021 (China); Shi Bing; Xu Xiaoqin [Xiamen Products Quality Inspection Institute, Xiamen, 361004 (China)

    2009-01-18

    Phytochelatins, with the general structure of ({gamma}-Glu-Cys)n-Gly (n = 2-11), are usually recognized as being strongly induced by metals in microalgae and play an important role in the detoxification of heavy metals in environment. However, there have been few studies on metallothionein (MT) synthesis in Chlorella vulgaris (C. vulgaris) exposed to heavy metals. The present study describes the growth inhibition of C. vulgaris exposed to different concentrations of cadmium and zinc, and the induction of metal-binding MT-like proteins in the cells. The amounts of metal-binding proteins, induced in the alga exposed to different concentrations of Cd and Zn, were analyzed with a size-exclusion HPLC coupled to ICP-MS. After being purified with a gel filtration column (Sephadex G-75, 3.5 cm x 80 cm) and a desalting column (G-25, 1.5 cm x 30 cm), the isoforms and sub-isoforms of Zn-binding protein were characterized by a reverse phase-HPLC coupled to electrospray ionization and a triple quadrupole mass spectrometer (HPLC-ESI-MS/MS). In addition, the ultraviolet spectra of purified Zn-binding proteins were analyzed in media with different pH values. The results showed that the significant inhibitory effects (at p < 0.05) on the cell growth were observed when excessive metals such as 80 {mu}mol l{sup -1} of Cd, and 60 and 80 {mu}mol l{sup -1} of Zn were added. The Cd/Zn-binding proteins induced in C. vulgaris exposed to Cd and Zn were referred to as Cd/Zn-MT-like proteins in which the mean molecular mass of the apo-MT-like was 6152 Da. The induced Cd/Zn-MT-like proteins might be involved in the detoxification of heavy metals, such as cadmium and zinc, by the alga.

  18. Adjusting irradiance to enhance growth and lipid production of Chlorella vulgaris cultivated with monosodium glutamate wastewater.

    Science.gov (United States)

    Jiang, Liqun; Ji, Yan; Hu, Wenrong; Pei, Haiyan; Nie, Changliang; Ma, Guixia; Song, Mingming

    2016-09-01

    Light is one of the most important factors affecting microalgae growth and biochemical composition. The influence of illumination on Chlorella vulgaris cultivated with diluted monosodium glutamate wastewater (MSGW) was investigated. Six progressive illumination intensities (0, 30, 90, 150, 200 and 300μmol·m(-2)s(-1)), were used for C. vulgaris cultivation at 25°C. Under 150μmol·m(-2)s(-1), the corresponding specific light intensity of 750×10(-6)μmol·m(-2)s(-1) per cell, algae obtained the maximum biomass concentration (1.46g·L(-1)) on the 7th day, which was 3.5 times of that under 0μmol·m(-2)s(-1), and the greatest average specific growth rate (0.79 d(-1)) in the first 7days. The results showed the importance role of light in mixotrophic growth of C. vulgaris. High light intensities of 200 and 300μmol·m(-2)s(-1) would inhibit microalgae growth to a certain degree. The algal lipid content was the greatest (30.5%) at 150μmol·m(-2)s(-1) light intensity, which was 2.42 times as high as that cultured in dark. The protein content of C. vulgaris decreased at high light intensities of 200 and 300μmol·m(-2)s(-1). The effect of irradiance on carbohydrate content was inversely correlated with that on protein. The available light at an appropriate intensity, not higher than 200μmol·m(-2)s(-1), was feasible for economical cultivation of C. vulgaris in MSGW. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Candida utilis and Chlorella vulgaris counteract intestinal inflammation in Atlantic salmon (Salmo salar L..

    Directory of Open Access Journals (Sweden)

    Fabian Grammes

    Full Text Available Intestinal inflammation, caused by impaired intestinal homeostasis, is a serious condition in both animals and humans. The use of conventional extracted soybean meal (SBM in diets for Atlantic salmon and several other fish species is known to induce enteropathy in the distal intestine, a condition often referred to as SBM induced enteropathy (SBMIE. In the present study, we investigated the potential of different microbial ingredients to alleviate SBMIE in Atlantic salmon, as a model of feed-induced inflammation. The dietary treatments consisted of a negative control based on fish meal (FM, a positive control based on 20% SBM, and four experimental diets combining 20% SBM with either one of the three yeasts Candida utilis (CU, Kluyveromyces marxianus (KM, Saccharomyces cerevisiae (SC or the microalgae Chlorella vulgaris (CV. Histopathological examination of the distal intestine showed that all fish fed the SC or SBM diets developed characteristic signs of SBMIE, while those fed the FM, CV or CU diets showed a healthy intestine. Fish fed the KM diet showed intermediate signs of SBMIE. Corroborating results were obtained when measuring the relative length of PCNA positive cells in the crypts of the distal intestine. Gene set enrichment analysis revealed decreased expression of amino acid, fat and drug metabolism pathways as well as increased expression of the pathways for NOD-like receptor signalling and chemokine signalling in both the SC and SBM groups while CV and CU were similar to FM and KM was intermediate. Gene expression of antimicrobial peptides was reduced in the groups showing SBMIE. The characterisation of microbial communities using PCR-DGGE showed a relative increased abundance of Firmicutes bacteria in fish fed the SC or SBM diets. Overall, our results show that both CU and CV were highly effective to counteract SBMIE, while KM had less effect and SC had no functional effects.

  20. Characterization of the flocculating agent from the spontaneously flocculating microalga Chlorella vulgaris JSC-7.

    Science.gov (United States)

    Alam, Md Asraful; Wan, Chun; Guo, Suo-Lian; Zhao, Xin-Qing; Huang, Zih-You; Yang, Yu-Liang; Chang, Jo-Shu; Bai, Feng-Wu

    2014-07-01

    High cost of biomass recovery is one of the bottlenecks for developing cost-effective processes with microalgae, particularly for the production of biofuels and bio-based chemicals through biorefinery, and microalgal biomass recovery through cell flocculation is a promising strategy. Some microalgae are naturally flocculated whose cells can be harvested by simple sedimentation. However, studies on the flocculating agents synthesized by microalgae cells are still very limited. In this work, the cell flocculation of a spontaneously flocculating microalga Chlorella vulgaris JSC-7 was studied, and the flocculating agent was identified to be cell wall polysaccharides whose crude extract supplemented at low dosage of 0.5 mg/L initiated the more than 80% flocculating rate of freely suspended microalgae C. vulgaris CNW11 and Scenedesmus obliquus FSP. Fourier transform infrared (FTIR) analysis revealed a characteristic absorption band at 1238 cm(-1), which might arise from PO asymmetric stretching vibration of [Formula: see text] phosphodiester. The unique cell wall-associated polysaccharide with molecular weight of 9.86×10(3) g/mol, and the monomers consist of glucose, mannose and galactose with a molecular ratio of 5:5:2. This is the first time to our knowledge that the flocculating agent from C. vulgaris has been characterized, which could provide basis for understanding the cell flocculation of microalgae and breeding of novel flocculating microalgae for cost-effective biomass harvest. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  1. Nutrient removal by Chlorella vulgaris F1068 under cetyltrimethyl ammonium bromide induced hormesis.

    Science.gov (United States)

    Zhou, Qiongzhi; Li, Feng; Ge, Fei; Liu, Na; Kuang, Yangduo

    2016-10-01

    Toxicants are generally harmful to biotechnology in wastewater treatment. However, trace toxicant can induce microbial hormesis, but to date, it is still unknown how this phenomenon affects nutrient removal during municipal wastewater treatment process. Therefore, this study focused on the effects of hormesis induced by cetyltrimethyl ammonium bromide (CTAB), a representative quaternary ammonium cationic surfactant, on nutrient removal by Chlorella vulgaris F1068. Results showed that when the concentration of CTAB was less than 10 ng/L, the cellular components chlorophyll a, proteins, polysaccharides, and total lipids increased by 10.11, 58.17, 38.78, and 11.87 %, respectively, and some enzymes in nutrient metabolism of algal cells, such as glutamine synthetase (GS), acid phosphatase (ACP), H(+)-ATPase, and esterase, were also enhanced. As a result, the removal efficiencies of ammonia nitrogen (NH4 (+)) and total phosphorus (TP) increased by 14.66 and 8.51 %, respectively, compared to the control during a 7-day test period. The underlying mechanism was mainly due to an enhanced photosynthetic activity of C. vulgaris F1068 indicated by the increase in chlorophyll fluorescence parameters (the value of Fv/Fm, ΦII, Fv/Fo, and rETR increased by 12.99, 7.56, 25.59, and 8.11 %, respectively) and adenylate energy charge (AEC) (from 0.68 to 0.72). These results suggest that hormesis induced by trace toxicants could enhance the nutrient removal, which would be further considered in the design of municipal wastewater treatment processes. Graphical abstract The schematic mechanism of C. vulgaris F1068 under CTAB induced hormesis. Green arrows ( ) represent the increase and the red arrow ( ) represents the decrease.

  2. Oxidative damage to chloroplasts from Chlorella vulgaris exposed to ultraviolet-B radiation

    International Nuclear Information System (INIS)

    Malanga, G.; Calmanovici, G.; Puntarulo, S.

    1997-01-01

    Upon UV-B irradiation, Chlorella vulgaris cells and isolated chloroplasts increased in size and starch accumulation. Photosynthetic capacity and chlorophyll content of chloroplasts isolated from irradiated algae decreased by 72 and 66%, as compared to chloroplasts isolated from control cells. Dihydrorhodamine 123 conversion to rhodamine 123 was used as a sensitive method for detection of peroxide (presumably hydrogen peroxide) formation in isolated chloroplasts. The accumulation of rhodamine 123 is higher in irradiated than in nonirradiated chloroplasts and the increased accumulation of rhodamine 123 depended on the UV-B dose. Quantitation of alkyl radical-EPR signals in chloroplasts indicated that UV-B exposure significantly increased radical content in the membranes. The content of an oxidized DNA base (8-hydroxy-2′-deoxyguanosine) in chloroplasts was increased by 72 and 175% after irradiation of the algal culture with 17.3 and 42.6 kJ m −2 , respectively. The chloroplastic activity of superoxide dismutase decreased by 50% as compared with control values after irradiation with 42.6 kJ m −2 and no changes in ascorbate peroxidase activity and ascorbic acid content were detected at the irradiation doses tested. The β-carotene content in chloroplasts was not affected by the irradiation, but the α-tocopherol content increased approximately 4-fold after UV-B irradiation. The results suggest that oxidative damage related to UV-B exposure is responsible for alterations in chloroplasts function and integrity, and that an antioxidant response is triggered in chloroplasts through an increase in α-tocopherol content. (author)

  3. EVALUACIÓN DEL EFECTO DEL HIDROCARBURO FENANTRENO SOBRE EL CRECIMIENTO DE Chlorella vulgaris (CHLORELLACEAE

    Directory of Open Access Journals (Sweden)

    Angélica María Otero-Paternina

    2013-01-01

    Full Text Available Se evaluó el efecto del hidrocarburo policíclico aromático fenantreno sobre el crecimiento de la microalga Chlorella vulgaris  bajo condiciones de laboratorio. Las microalgas fueron expuestas a diferentes concentraciones de fenantreno (0, 1, 10, 100, 1000 y 10000 μg/l. El tiempo de exposición fue de 72 h, determinándose diariamente la densidad algal mediante recuento en cámara de Neubauer. Se determinó la tasa promedio de crecimiento, la biomasa total y el porcentaje de inhibición de la biomasa. También se evaluó el contenido de clorofila a, al inicio y final del experimento. Los ensayos fueron realizados en recipientes de vidrio de 0,4 l, utilizando como medio de cultivo fertilizante inorgánico del complejo NPK (REMITAL® m – 17-6-18 a razón de 1 g/l. Los resultados mostraron que el fenantreno inhibió progresivamente el crecimiento de la microalga, observándose el menor crecimiento celular en el medio con la mayor concentración de fenantreno, el cual alcanzó un porcentaje de inhibición del crecimiento del 59 %. Las tasas de crecimiento diario se mantuvieron relativamente constantes en los demás tratamientos. La concentración de clorofila a, medida mediante espectrofotometría, no se afectó por las diferentes concentraciones del hidrocarburo. En conclusión, el crecimiento de la microalga C. vulgaris  puede afectarse negativamente por la exposición a concentraciones nominales superiores a 1 μg/l de fenantreno.

  4. Long-term outdoor cultivation by perfusing spent medium for biodiesel production from Chlorella minutissima.

    Science.gov (United States)

    Oh, Sung Ho; Kwon, Min Chul; Choi, Woon Yong; Seo, Yong Chang; Kim, Ga Bin; Kang, Do Hyung; Lee, Shin Young; Lee, Hyeon Yong

    2010-08-01

    A unique perfusion process was developed to maintain high concentrations of marine alga, Chlorella minutissima. This method is based on recycling cells by continuous feeding with warm spent sea water from nuclear power plants, which has very similar properties as sea water. A temperature of at least 30 degrees C in a 200 L photo-bioreactor was maintained in this system by perfusion of the thermal plume for 80 days in the coldest season. The maximum cell concentration and total lipid content was 8.3 g-dry wt./L and 23.2 %, w/w, respectively, under mixotrophic conditions. Lipid production was found to be due to a partially or non-growth related process, which implies that large amounts of biomass are needed for a high accumulation of lipids within the cells. At perfusion rates greater than 1.5 L/h, the temperature of the medium inside the reactor was around 30 degrees C, which was optimal for cell growth. For this system, a perfusion rate of 2.8 L/h was determined to be optimal for maintaining rapid cell growth and lipid production during outdoor cultivation. It was absolutely necessary to maintain the appropriate perfusion rate so that the medium temperature was optimal for cell growth. In addition, the lipids produced using this process were shown to be feasible for biodiesel production since the lipid composition of C. minutissima grown under these conditions consisted of 17 % (w/w) of C(16) and 47% (w/w) of C(18). The combined results of this study clearly demonstrated that the discharged energy of the thermal plume could be reused to cultivate marine alga by maintaining a relatively constant temperature in an outdoor photo-bioreactor without the need for supplying any extra energy, which could allow for cheap production of biodiesel from waste energy. Copyright 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  5. Effect of pulsed electric field treatments on permeabilization and extraction of pigments from Chlorella vulgaris.

    Science.gov (United States)

    Luengo, Elisa; Condón-Abanto, Santiago; Álvarez, Ignacio; Raso, Javier

    2014-12-01

    The effect of pulsed electric field (PEF) treatments of different intensities on the electroporation of the cytoplasmatic membrane of Chlorella vulgaris, and on the extraction of carotenoids and chlorophylls were investigated. Staining the cells with propidium iodide before and after the PEF treatment revealed the existence of reversible and irreversible electroporation. Application of PEF treatments in the range of 20-25 kV cm(-1) caused most of the population of C. vulgaris to be irreversibly electroporated even at short treatment times (5 pulses of 3 µs). However, at lower electric field strengths (10 kV cm(-1)), cells that were reversibly electroporated were observed even after 50 pulses of 3 µs. The electroporation of C. vulgaris cells by PEF higher than 15 kV cm(-1) and duration is higher than 15 µs increased significantly the extraction yield of intracellular components of C. vulgaris. The application of a 20 kV cm(-1) for 75 μs increased the extraction yield just after the PEF treatment of the carotenoids, and chlorophylls a and b 0.5, 0.7, and 0.8 times, respectively. However, further increments in electric field strength and treatment time did not cause significant increments in the extraction yield. The extraction of carotenoids from PEF-treated C. vulgaris cells after 1 h of the application of the treatment significantly increased the extraction yield in comparison to the yield obtained from the cells extracted just after the PEF treatment. After PEF treatment at 20 kV cm(-1) for 75 µs, extraction yield for carotenoids, and chlorophylls a and b increased 1.2, 1.6, and 2.1 times, respectively. A high correlation was observed between irreversible electroporation and percentage of yield increase when the extraction was conducted after 1 h of the application of PEF treatment (R: 0.93), but not when the extraction was conducted just after PEF treatment (R: 0.67).

  6. Karakteristik dan Aktivitas Antioksidan Sabun Padat Transparan yang Diperkaya dengan Ekstrak Kasar Karotenoid Chlorella pyrenoidosa

    Directory of Open Access Journals (Sweden)

    Wayan Agustini

    2017-06-01

    Full Text Available Sabun berfungsi membersihkan kulit, tidak merusak kulit serta mampu melindungi kulit dari efek radikal bebas. Senyawa yang mampu menangkal radikal bebas adalah antioksidan yang antara lain bersumber dari Chlorella pyrenoidosa. Tujuan dari penelitian ini adalah untuk mengetahui aktivitas antioksidan dari ekstrak kasar karotenoid C. pyrenoidosa yang diformulasikan pada sabun padat transparan dan karakteristik sabun yang dihasilkan. Konsentrasi ekstrak kasar karotenoid yang digunakan adalah 5%, 10% dan 15%. Sabun padat transparan dibuat dengan metode setengah panas (semi-boiled. Evaluasi sediaan meliputi warna, kekerasan sabun, pH, kadar air, asam lemak bebas, lemak tidak tersabunkan, aktivitas antioksidan dan daya stabilitas sabun pada penyimpanan suhu 25-30 °C dan 60 °C selama 3 minggu. Hasil studi menunjukkan bahwa sabun padat transparan yang mengandung ekstrak kasar karotenoid sebanyak 5%, 10%, dan 15% memiliki aktivitas antioksidan dengan nilai IC50 berturut-turut sebesar 66,42 µg/ml,              59,18 µg/ml, dan 10,21 µg/ml. Sabun padat transparan dengan kandungan ekstrak kasar karotenoid sebanyak 5% berwarna kuning neon carrot, ekstrak 10% berwarna kuning pizzaz dan ekstrak 15% berwarna kuning pumpkin. Seluruh sabun beraroma lemongrass. Sabun padat transparan memiliki nilai pH sebesar 9,31-10,47, kadar air 14,45-16,28%, kekerasan sabun 1,40-1,81 mm/detik, jumlah asam lemak bebas 0,42-0,68% dan lemak tidak tersabunkan 1,79-1,84%. Berdasarkan hasil uji stabilitas, sabun tahan disimpan dalam suhu kamar selama 2 tahun, karena sabun relatif stabil pada penyimpanan suhu 60 °C selama 3 minggu.

  7. Biological CO2 fixation using Chlorella vulgaris and its thermal characteristics through thermogravimetric analysis.

    Science.gov (United States)

    Razzak, Shaikh A; Ali, Saad Aldin M; Hossain, Mohammad M; Mouanda, Alexis Nzila

    2016-11-01

    The present research is focused on cultivation of microalgae strain Chlorella vulgaris for bio-fixation of CO2 coupled with biomass production. In this regard, a single semi-batch vertical tubular photobioreactor and four similar photobioreactors in series have been employed. The concentration of CO2 in the feed stream was varied from 2 to 12 % (v/v) by adjusting CO2 to air ratio. The amount of CO2 capture and algae growth were monitored by measuring decrease of CO2 concentration in the gas phase, microalgal cell density, and algal biomass production rate. The results show that 4 % CO2 gives maximum amount of biomass (0.9 g L(-1)) and productivity (0.118 g L(-1) day(-1)) of C. vulgaris in a single reactor. In series reactors, average productivity per reactor found to be 0.078 g L(-1) day(-1). The maximum CO2 uptake for single reactor also found with 4 % CO2, and it is around 0.2 g L(-1) day(-1). In series reactors, average CO2 uptake is 0.13 g L(-1) day(-1) per reactor. TOC analysis shows that the carbon content of the produced biomass is around 40.67 % of total weight. The thermochemical characteristics of the cultivated C. vulgaris samples were analyzed in the presence of air. All samples burn above 200 °C and the combustion rate become faster at around 600 °C. Almost 98 wt% of the produced biomass is combustible in this range.

  8. Effect of dietary sodium selenite, Se-enriched yeast and Se-enriched Chlorella on egg Se concentration, physical parameters of eggs and laying hen production

    Czech Academy of Sciences Publication Activity Database

    Skřivan, M.; Šimáně, J.; Dlouhá, G.; Doucha, Jiří

    2006-01-01

    Roč. 51, č. 4 (2006), s. 163-167 ISSN 1212-1819 Institutional research plan: CEZ:AV0Z50200510 Keywords : sodium selenite * se-yeast * se-chlorella Subject RIV: EE - Microbiology, Virology Impact factor: 0.421, year: 2006

  9. Genetic effects induced by radionuclides in the populations of the chlorella and antimutagenic influence of the vitamins C and B12

    International Nuclear Information System (INIS)

    Shvobiene, R.Ya.; Marchiulioniene, D.P.

    1987-01-01

    Genetic influence of 90 Sr, 137 Cs and 144 Ce on the chlorella populations has been studied, as well as antimutagenic effect of C and B 12 vitamins on the influenced by 90 Sr and 144 Ce chlorella populations. The radionuclides 90 Sr, 137 Cs and 144 Ce have been determined to increase the number of lethal and mutant cells in the chlorella populations. It has been shown that according to the influence of the number of lethally injured cells the radionuclides under study (within the concentration range 3.7X10 4 - 3.7X10 6 Bk/l) may be presented by the sequence 144 Ce> 137 Cs≥ 90 Sr, while according to the influence of the number of mutant cells - by the reverse sequence 90 Sr> 137 Cs≥ 144 Ce. Such different effect of the radionuclides on the chlorella populations may, possibly, be explained by different physical-chemical state of these radionuclides in water medium, their different uptake mechanism in plant cells, and different localization in them. A conclusion is drawn that C and B 12 vitamins reduce radiosensitivity of water organisms, especially their lethality. B 12 vitamin is stornger a mutagen than vitamin C

  10. A study of the growth for the microalga Chlorella vulgaris by photo-bio-calorimetry and other on-line and off-line techniques

    NARCIS (Netherlands)

    Patino, R.; Janssen, M.G.J.; Stockar, von U.

    2007-01-01

    Calorimetry and other on-line techniques are used for the first time as complement to the traditional off-line methods in order to follow the growth of the green Chlorella vulgaris microalgae. A 2-L photo-bio-reactor was adapted from a commercial calorimeter used previously to study heterotrophic

  11. The effect of AgNO3 on the bioenergetic processes and the ultrastructure of Chlorella and Dunaliella cells exposed to different saline conditions

    International Nuclear Information System (INIS)

    Loseva, N.L.; Alyabyev, A.Ju.; Gordon, L.Kh.; Andreyeva, I.N.; Kolesnikov, O.P.; Ponomareva, A.A.; Kemp, R.B.

    2007-01-01

    The effect of AgNO 3 , an inhibitor of the H + pump in the plasma membrane, on the bioenergetic processes and on the ultrastructure of the microalgae Chlorella vulgaris (salt sensitive) and Dunaliella maritima (salt resistant) was examined under varying salt concentrations. Differences between them were observed in changes of the cellular energy metabolism depending on their salt sensitivity and the inhibition of the H + pump activity. A decrease was observed in the rates of heat production (about 45%), O 2 uptake (greater than 40-50% of the control) and particularly photosynthesis (more than 80%) in Chlorella cells under the simultaneous action of NaCl and AgNO 3 . Dunaliella cells showed small to moderate rate increases for heat production (less than 7%), O 2 uptake (10-15%) and O 2 evolution (40%) in higher salt concentrations and under the action of AgNO 3 . The production of active oxygen species was studied as an early unspecific response of microalgal cells to possible unfavorable conditions, including salt stress. The amount of superoxide formed by the Dunaliella cells was higher than that by the Chlorella cells. However, Ag + ions increased the generation rate of superoxide radicals considerably in both Chlorella and Dunaliella cells. The electron microscopy showed that changes of the algal ultrastructure of cells exposed to the action of Ag + ions were connected with the observed physiological changes and to a large extent with the alteration of the bioenergetic processes in them

  12. Dietary Chlorella supplementation effect on immune responses and growth performances of broiler chickens exposed to post hatch holding time

    DEFF Research Database (Denmark)

    Sugiharto, S; Lauridsen, Charlotte

    2016-01-01

    The study was carried out to investigate the effect of dietary Chlorella sp. supplementation on immune response and growth performance of broiler chickens exposed to post hatch holding time. Allotted in 36 pens, a total of 180 newly hatched chicks were assigned in a 3 × 2 factorial design, with d...

  13. Ability of an alkali-tolerant mutant strain of the microalga Chlorella sp. AT1 to capture carbon dioxide for increasing carbon dioxide utilization efficiency.

    Science.gov (United States)

    Kuo, Chiu-Mei; Lin, Tsung-Hsien; Yang, Yi-Chun; Zhang, Wen-Xin; Lai, Jinn-Tsyy; Wu, Hsi-Tien; Chang, Jo-Shu; Lin, Chih-Sheng

    2017-11-01

    An alkali-tolerant Chlorella sp. AT1 mutant strain was screened by NTG mutagenesis. The strain grew well in pH 6-11 media, and the optimal pH for growth was 10. The CO 2 utilization efficiencies of Chlorella sp. AT1 cultured with intermittent 10% CO 2 aeration for 10, 20 and 30min at 3-h intervals were approximately 80, 42 and 30%, respectively. In alkaline medium (pH=11) with intermittent 10% CO 2 aeration for 30min at 3-, 6- and 12-h intervals, the medium pH gradually changed to 10, and the biomass productivities of Chlorella sp. AT1 were 0.987, 0.848 and 0.710gL -1 d -1 , respectively. When Chlorella sp. AT1 was aerated with 10% CO 2 intermittently for 30min at 3-h intervals in semi-continuous cultivation for 21days, the biomass concentration and biomass productivity were 4.35gL -1 and 0.726gL -1 d -1 , respectively. Our results show that CO 2 utilization efficiency can be markedly increased by intermittent CO 2 aeration and alkaline media as a CO 2 -capturing strategy for alkali-tolerant microalga cultivation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Microalgal biomass production and on-site bioremediation of carbon dioxide, nitrogen oxide and sulfur dioxide from flue gas using Chlorella sp. cultures.

    Science.gov (United States)

    Chiu, Sheng-Yi; Kao, Chien-Ya; Huang, Tzu-Ting; Lin, Chia-Jung; Ong, Seow-Chin; Chen, Chun-Da; Chang, Jo-Shu; Lin, Chih-Sheng

    2011-10-01

    The growth and on-site bioremediation potential of an isolated thermal- and CO₂-tolerant mutant strain, Chlorella sp. MTF-7, were investigated. The Chlorella sp. MTF-7 cultures were directly aerated with the flue gas generated from coke oven of a steel plant. The biomass concentration, growth rate and lipid content of Chlorella sp. MTF-7 cultured in an outdoor 50-L photobioreactor for 6 days was 2.87 g L⁻¹ (with an initial culture biomass concentration of 0.75 g L⁻¹), 0.52 g L⁻¹ d⁻¹ and 25.2%, respectively. By the operation with intermittent flue gas aeration in a double-set photobioreactor system, average efficiency of CO₂ removal from the flue gas could reach to 60%, and NO and SO₂ removal efficiency was maintained at approximately 70% and 50%, respectively. Our results demonstrate that flue gas from coke oven could be directly introduced into Chlorella sp. MTF-7 cultures to potentially produce algal biomass and efficiently capture CO₂, NO and SO₂ from flue gas. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Cultivation of Chlorella vulgaris in a pilot-scale sequential-baffled column photobioreactor for biomass and biodiesel production

    International Nuclear Information System (INIS)

    Lam, Man Kee; Lee, Keat Teong

    2014-01-01

    Highlights: • A new sequential baffled photobioreactor was developed to cultivate microalgae. • Organic fertilizer was used as the main nutrients source. • Negative energy balance was observed in producing microalgae biodiesel. - Abstract: Pilot-scale cultivation of Chlorella vulgaris in a 100 L sequential baffled photobioreactor was carried out in the present study. The highest biomass yield attained under indoor and outdoor environment was 0.52 g/L and 0.28 g/L, respectively. Although low microalgae biomass yield was attained under outdoor cultivation, however, the overall life cycle energy efficiency ratio was 3.3 times higher than the indoor cultivation. In addition, negative energy balance was observed in producing microalgae biodiesel under both indoor and outdoor cultivation. The minimum production cost of microalgae biodiesel was about RM 237/L (or USD 73.5/L), which was exceptionally high compared to the current petrol diesel price in Malaysia (RM 3.6/L or USD 1.1/L). On the other hand, the estimated production cost of dried microalgae biomass cultivated under outdoor environment was RM 46/kg (or USD 14.3/kg), which was lower than cultivation using chemical fertilizer (RM 111/kg or USD 34.4/kg) and current market price of Chlorella biomass (RM 145/kg or USD 45/kg)

  16. Biofilm Attached Cultivation of Chlorella pyrenoidosa Is a Developed System for Swine Wastewater Treatment and Lipid Production

    Directory of Open Access Journals (Sweden)

    Pengfei Cheng

    2017-09-01

    Full Text Available This study showed the new potential of using soluble contents and heavy metals in swine wastewater as nutrient supplements for the algae Chlorella pyrenoidosa with biofilm attached method. Algae with biofilm attached cultivation grew well in unpasteurized wastewater reaching a biomass productivity of 5.03 g m−2 d−1, lipid content of 35.9% and lipid productivity of 1.80 g m−2 d−1. Chlorella grew in BG11 medium delivered lower values for each of the aforementioned parameters. The FAMEs compositions in the algae paste were mainly consisted of C16:0, C18:2, and C18:3. Algae removed NH4+–N, total phosphorus (TP, and COD by 75.9, 68.4, and 74.8%, respectively. Notably, Zn2+, Cu+, and Fe2+ were removed from wastewater with a ratio of 65.71, 53.64, and 58.89%, respectively. Biofilm attached cultivation of C. pyrenoidosa in swine wastewater containing heavy metals could accumulate considerable biomass and lipid, and the removal ratio of NH4+–N, TP, COD, and as well as heavy metal were high. Treatment of wastewater with biofilm attached cultivation showed an increasingly popular for the concentration of microalgae and environmental sustainability.

  17. Characterization of biosynthesized gold nanoparticles from aqueous extract of Chlorella vulgaris and their anti-pathogenic properties

    Science.gov (United States)

    Annamalai, Jayshree; Nallamuthu, Thangaraju

    2015-06-01

    In this study, biosynthesis of self-assembled gold nanoparticles (GNPs) was accomplished using an aqueous extract of green microalga, Chlorella vulgaris. The optical, physical, chemical and bactericidal properties of the GNPs were investigated to identify their average shape and size, crystal nature, surface chemistry and toxicity, via UV-visible spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and antimicrobial activity. The sizes of the spherical self-assembled cores of the synthesized GNPs ranged from 2 to 10 nm. The XRD patterns showed a (111) preferential orientation and the crystalline nature of the GNPs. The results of the FTIR analysis suggested that the peptides, proteins, phenol and flavonoid carried out the dual function of effective Au III reduction and successful capping of the GNPs. Human pathogen Candida albicans and Staphylococcus aureus were susceptible to synthesized aqueous GNPs. Thus, biosynthesis, stabilization and self-assembly of the GNPs by Chlorella vulgaris extract can be an example of green chemistry and effective drug in the medicinal field.

  18. Evidence and analysis of radioresistance induced by protracted gamma irradiation of Chlorella pyrenoidosa chick, green unicellular alga

    International Nuclear Information System (INIS)

    Santier-Riviere, S.

    1984-06-01

    Chlorella cells, unicellular green algae, are a suitable living material to study radiosensitivity of eucaryotic cells after acute or protracted gamma irradiations. Cell survival and survival curves are taken as end-points. Methods of irradiation were defined taking in account interferences of the different factors which can intervene during the experimentation. Survival curves after protracted irradiation of Chlorella cell cultures in plateau-phase have a shape that can be explained by radioresistance. The population of surviving cells becomes radioresistant in front of protracted and acute irradiations, acute irradiation allowing us to analyze radioresistance. Radioresistance increases with the total dose of protracted irradiation. The decrease of radiosensitivity with aging of cells is not able to explain the phenomenon. It is not due to selection of radioresistance cells by protracted irradiation. All the cells get radioresistance. Radioresistance decreases with the time when protracted irradiation is suppressed. It is not found in offspring. It is not a mutation but perhaps the effect of a stimulation of repair processes, but not potentially lethal damage repair [fr

  19. Tolerance and nutrients consumption of Chlorella vulgaris growing in mineral medium and real wastewater under laboratory conditions

    Directory of Open Access Journals (Sweden)

    María de Lourdes Franco Martínez

    2017-02-01

    Full Text Available Microalgae have the potential of consuming high amounts of nitrogen and phosphorus from wastewater; thus, avoiding the risk of eutrophication of the water bodies. Nevertheless, ammonium can usually inhibit the growth of microalgae. Tolerance to ammonium is specific of each strain; so, the development of tertiary wastewater treatment proposals, employing microalgae, has as a first step the study of its tolerance to N-NH3. In this work, the tolerance of Chlorella vulgaris to N-NH3, using mineral medium, was studied. Afterward, C. vulgaris was used to remove nitrogen and phosphorus from a real wastewater. The maximal biomass concentration was reached at 66 ppm N-NH3 (0.49 gL-1 with the complete depletion of the ammonium and a phosphorus consumption of 2 mgPi L-1d-1 in all the experiments. When C. vulgaris was grown in real wastewater, the final biomass concentration was 0.267 g L-1 and the nutrients (N and P were totally consumed after 3 days. According with these results, this strain of Chlorella has the potential for the removal of nitrogen and phosphorus from tertiary wastewater and the biomass produced in the process can be used for the production of high value products, such as pigments, proteins, carbohydrate or used for animal feed.

  20. THE EFFECT OF BIOMASS FROM GREEN ALGAE OF CHLORELLA GENUS ON THE BIOCHEMICAL CHARACTERISTICS OF TABLE EGGS

    Directory of Open Access Journals (Sweden)

    SVETLANA GRIGOROVA

    2006-10-01

    Full Text Available An analysis was made of the fatty-acid content of the dry biomass from green algae of Chlorella genus cultivated in Bulgaria, with the aim of establishing its effect on the content of total lipids, cholesterol, phospholipids and the fattyacid content of the table eggs. The fatty-acid composition of the dry biomass from green microalgae of Chlorella genus was characterized by its high content of α linolenic acid – 36,5 %, palmitic acid – 20,4 %, linoleic acid – 15 % and oleic acid – 10,3 % of the total amount of fatty acids in the product. Omega-3/Omega-6 fatty acids ratio in the biomass was 0,4. When adding 2 % and 10 % of alga biomass to the forage for the laying hens the total cholesterol content in 100 g of yolk decreased in the experimental groups compared to the control one, however, the differences were statistically insignifi cant. The supplement of 2 % and 10 % of the studied product exerted an effect on the fatty-acid content of the egg yolk and it led to the increase of the amount of palmitic and linoleic acids and to the decrease of the docosatetraenic acid.

  1. Biofilm Attached Cultivation of Chlorella pyrenoidosa Is a Developed System for Swine Wastewater Treatment and Lipid Production

    Science.gov (United States)

    Cheng, Pengfei; Wang, Yuanzhu; Liu, Tianzhong; Liu, Defu

    2017-01-01

    This study showed the new potential of using soluble contents and heavy metals in swine wastewater as nutrient supplements for the algae Chlorella pyrenoidosa with biofilm attached method. Algae with biofilm attached cultivation grew well in unpasteurized wastewater reaching a biomass productivity of 5.03 g m−2 d−1, lipid content of 35.9% and lipid productivity of 1.80 g m−2 d−1. Chlorella grew in BG11 medium delivered lower values for each of the aforementioned parameters. The FAMEs compositions in the algae paste were mainly consisted of C16:0, C18:2, and C18:3. Algae removed NH4+–N, total phosphorus (TP), and COD by 75.9, 68.4, and 74.8%, respectively. Notably, Zn2+, Cu+, and Fe2+ were removed from wastewater with a ratio of 65.71, 53.64, and 58.89%, respectively. Biofilm attached cultivation of C. pyrenoidosa in swine wastewater containing heavy metals could accumulate considerable biomass and lipid, and the removal ratio of NH4+–N, TP, COD, and as well as heavy metal were high. Treatment of wastewater with biofilm attached cultivation showed an increasingly popular for the concentration of microalgae and environmental sustainability. PMID:28983302

  2. Mixotrophic cultivation of oleaginous Chlorella sp. KR-1 mediated by actual coal-fired flue gas for biodiesel production.

    Science.gov (United States)

    Praveenkumar, Ramasamy; Kim, Bohwa; Choi, Eunji; Lee, Kyubock; Cho, Sunja; Hyun, Ju-Soo; Park, Ji-Yeon; Lee, Young-Chul; Lee, Hyun Uk; Lee, Jin-Suk; Oh, You-Kwan

    2014-10-01

    Flue gases mainly consist of CO2 that can be utilized to facilitate microalgal culture for bioenergy production. In the present study, to evaluate the feasibility of the utilization of flue gas from a coal-burning power plant, an indigenous and high-CO2-tolerant oleaginous microalga, Chlorella sp. KR-1, was cultivated under mixotrophic conditions, and the results were evaluated. When the culture was mediated by flue gas, highest biomass (0.8 g cells/L·d) and FAME (fatty acid methyl esters) productivity (121 mg/L·d) were achieved in the mixotrophic mode with 5 g/L glucose, 5 mM nitrate, and a flow rate of 0.2 vvm. By contrast, the photoautotrophic cultivation resulted in a lower biomass (0.45 g cells/L·d) and a lower FAME productivity (60.2 mg/L·d). In general, the fatty acid profiles of Chlorella sp. KR-1 revealed meaningful contents (>40 % of saturated and mono-unsaturated fatty acids) under the mixotrophic condition, which enables the obtainment of a better quality of biodiesel than is possible under the autotrophic condition. Conclusively then, it was established that a microalgal culture mediated by flue gas can be improved by adoption of mixotrophic cultivation systems.

  3. Selenium Accumulation in Unicellular Green Alga Chlorella vulgaris and Its Effects on Antioxidant Enzymes and Content of Photosynthetic Pigments

    Science.gov (United States)

    Sun, Xian; Zhong, Yu; Huang, Zhi; Yang, Yufeng

    2014-01-01

    The aim of the present study was to investigate selenite effects in the unicellular green algae Chlorella vulgaris as a primary producer and the relationship with intracellular bioaccumulation. The effects of selenite were evaluated by measuring the effect of different selenite concentrations on algal growth during a 144 h exposure period. It was found that lower Se concentrations (≤75 mg L−1) positively promoted C. vulgaris growth and acted as antioxidant by inhibiting lipid peroxidation (LPO) and intracellular reactive oxygen species (ROS). The antioxidative effect was associated with an increase in guaiacol peroxidase (GPX), catalase (CAT), superoxide dismutase (SOD) and photosynthetic pigments. Meanwhile, significant increase in the cell growth rate and organic Se content was also detected in the algae. In contrast, these changes were opposite in C. vulgaris exposed to Se higher than 100 mg L−1. The antioxidation and toxicity appeared to be correlated to Se bioaccumulation, which suggests the appropriate concentration of Se in the media accumulation of C. vulgaris should be 75 mg L−1. Taken together, C. vulgaris possesses tolerance to Se, and Se-Chlorella could be developed as antioxidative food for aquaculture and human health. PMID:25375113

  4. Chlorella vulgaris Attenuates Dermatophagoides Farinae-Induced Atopic Dermatitis-Like Symptoms in NC/Nga Mice

    Science.gov (United States)

    Kang, Heerim; Lee, Chang Hyung; Kim, Jong Rhan; Kwon, Jung Yeon; Seo, Sang Gwon; Han, Jae Gab; Kim, Byung Gon; Kim, Jong-Eun; Lee, Ki Won

    2015-01-01

    Atopic dermatitis (AD) is a chronic and inflammatory skin disease that can place a significant burden on quality of life for patients. AD most frequently appears under the age of six and although its prevalence is increasing worldwide, therapeutic treatment options are limited. Chlorella vulgaris (CV) is a species of the freshwater green algae genus chlorella, and has been reported to modulate allergy-inducible factors when ingested. Here, we examined the effect of CV supplementation on AD-like symptoms in NC/Nga mice. CV was orally administrated for six weeks while AD-like symptoms were induced via topical application of Dermatophagoides farinae extract (DFE). CV treatment reduced dermatitis scores, epidermal thickness, and skin hydration. Histological analysis also revealed that CV treatment reduced DFE-induced eosinophil and mast cell infiltration into the skin, while analysis of serum chemokine levels indicated that CV treatment downregulated thymus- and activation-regulated chemokine (TARC) and macrophage-derived chemokine (MDC) levels. In addition, CV treatment downregulated mRNA expression levels of IL-4 and IFN-γ. Taken together, these results suggest that CV extract may have potential as a nutraceutical ingredient for the prevention of AD. PMID:26404252

  5. Chlorella vulgaris Attenuates Dermatophagoides Farinae-Induced Atopic Dermatitis-Like Symptoms in NC/Nga Mice

    Directory of Open Access Journals (Sweden)

    Heerim Kang

    2015-09-01

    Full Text Available Atopic dermatitis (AD is a chronic and inflammatory skin disease that can place a significant burden on quality of life for patients. AD most frequently appears under the age of six and although its prevalence is increasing worldwide, therapeutic treatment options are limited. Chlorella vulgaris (CV is a species of the freshwater green algae genus chlorella, and has been reported to modulate allergy-inducible factors when ingested. Here, we examined the effect of CV supplementation on AD-like symptoms in NC/Nga mice. CV was orally administrated for six weeks while AD-like symptoms were induced via topical application of Dermatophagoides farinae extract (DFE. CV treatment reduced dermatitis scores, epidermal thickness, and skin hydration. Histological analysis also revealed that CV treatment reduced DFE-induced eosinophil and mast cell infiltration into the skin, while analysis of serum chemokine levels indicated that CV treatment downregulated thymus- and activation-regulated chemokine (TARC and macrophage-derived chemokine (MDC levels. In addition, CV treatment downregulated mRNA expression levels of IL-4 and IFN-γ. Taken together, these results suggest that CV extract may have potential as a nutraceutical ingredient for the prevention of AD.

  6. Inmovilización de las microalgas Scenedesmus ovalternus (Scenedesmaceae y Chlorella vulgaris (Chlorellaceae en esferas de alginato de calcio.

    Directory of Open Access Journals (Sweden)

    Mario Andres Forero-Cujiño

    2016-05-01

    Full Text Available En este trabajo se describe la técnica de inmovilización de microalgas en esferas de alginato de calcio. Se emplearon las especies Scenedesmus ovalternus y Chlorella vulgaris, se determinó la estabilidad de las esferas, la cinética de crecimiento y la concentración de las microalgas en el interior de las esferas. Chlorella vulgaris alcanzó mayores densidades poblacionales y tasas de crecimiento más altas cuando se inmovilizó en concentraciones del 10 % v/v con el alginato (1,31*106 cél/ml. Para Scenedesmus ovalternus se observó una mayor densidad poblacional y una mayor tasa de crecimiento cuando se inmovilizó en concentraciones del 20 % v/v (7,06*105 cél/ml. Estos resultados son útiles para aplicaciones prácticas de las algas encapsuladas, tales como el biomonitoreo o la biorremediación.

  7. In Situ Biodiesel Production from Fast-Growing and High Oil Content Chlorella pyrenoidosa in Rice Straw Hydrolysate

    Science.gov (United States)

    Li, Penglin; Miao, Xiaoling; Li, Rongxiu; Zhong, Jianjiang

    2011-01-01

    Rice straw hydrolysate was used as lignocellulose-based carbon source for Chlorella pyrenoidosa cultivation and the feasibility of in situ biodiesel production was investigated. 13.7 g/L sugar was obtained by enzymatic hydrolyzation of rice straw. Chlorella pyrenoidosa showed a rapid growth in the rice straw hydrolysate medium, the maximum biomass concentration of 2.83 g/L was obtained in only 48 hours. The lipid content of the cells reached as high as 56.3%. In situ transesterification was performed for biodiesel production. The optimized condition was 1 g algal powder, 6 mL n-hexane, and 4 mL methanol with 0.5 M sulfuric acid at the temperature of 90°C in 2-hour reaction time, under which over 99% methyl ester content and about 95% biodiesel yield were obtained. The results suggested that the method has great potential in the production of biofuels with lignocellulose as an alternative carbon source for microalgae cultivation. PMID:21318171

  8. Use of mixed wastewaters from piggery and winery for nutrient removal and lipid production by Chlorella sp. MM3.

    Science.gov (United States)

    Ganeshkumar, Vimalkumar; Subashchandrabose, Suresh R; Dharmarajan, Rajarathnam; Venkateswarlu, Kadiyala; Naidu, Ravi; Megharaj, Mallavarapu

    2018-05-01

    The larger-scale generation of piggery and winery wastewaters and consequent eutrophication are quite alarming, necessitating the use of a cost-effective treatment. This study attempted to remediate wastewaters from piggery and winery mixed in the ratios of 20:80, 50:50, 80:20, 100:0 and 0:100, in terms of nutrient removal and subsequent lipid accumulation by soil microalga, Chlorella sp. MM3. The per cent removal of total nitrogen and phosphates by the alga from mixed wastewaters within 10-days ranged between 51 and 89 and 26-49, respectively. As determined by FTIR spectroscopy, the lipid accumulation in the microalgal cells grown in wastewater mixtures ranged between 29 and 51%. Our results suggest that Chlorella sp. MM3 could be a potential candidate for bioremediation of wastewaters derived from piggery farm and winery industry, and that mixing of these wastewaters in 20:80 ratio would be an efficient approach for phycoremediation of mineral-rich effluents and subsequent yield of fairly good amounts of biofuel. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Antioxidant enzyme activity and malondialdehyde levels can be modulated by Piper betle, tocotrienol rich fraction and Chlorella vulgaris in aging C57BL/6 mice.

    Science.gov (United States)

    Aliahmat, Nor Syahida; Noor, Mohd Razman Mohd; Yusof, Wan Junizam Wan; Makpol, Suzana; Ngah, Wan Zurinah Wan; Yusof, Yasmin Anum Mohd

    2012-12-01

    The aim of this study was to determine the erythrocyte antioxidant enzyme activity and the superoxide dismutase, catalase, glutathione peroxidase, and plasma malondialdehyde levels in aging mice and to evaluate how these measures are modulated by potential antioxidants, including the tocotrienol-rich fraction, Piper betle, and Chlorella vulgaris. One hundred and twenty male C57BL/6 inbred mice were divided into three age groups: young (6 months old), middle-aged (12 months old), and old (18 months old). Each age group consisted of two control groups (distilled water and olive oil) and three treatment groups: Piper betle (50 mg/kg body weight), tocotrienol-rich fraction (30 mg/kg), and Chlorella vulgaris (50 mg/kg). The duration of treatment for all three age groups was two months. Blood was withdrawn from the orbital sinus to determine the antioxidant enzyme activity and the malondialdehyde level. Piper betle increased the activities of catalase, glutathione peroxidase, and superoxide dismutase in the young, middle, and old age groups, respectively, when compared to control. The tocotrienol-rich fraction decreased the superoxide dismutase activity in the middle and the old age groups but had no effect on catalase or glutathione peroxidase activity for all age groups. Chlorella vulgaris had no effect on superoxide dismutase activity for all age groups but increased glutathione peroxidase and decreased catalase activity in the middle and the young age groups, respectively. Chlorella vulgaris reduced lipid peroxidation (malondialdehyde levels) in all age groups, but no significant changes were observed with the tocotrienol-rich fraction and the Piper betle treatments. We found equivocal age-related changes in erythrocyte antioxidant enzyme activity when mice were treated with Piper betle, the tocotrienol-rich fraction, and Chlorella vulgaris. However, Piper betle treatment showed increased antioxidant enzymes activity during aging.

  10. Antioxidant enzyme activity and malondialdehyde levels can be modulated by Piper betle, tocotrienol rich fraction and Chlorella vulgaris in aging C57BL/6 mice

    Directory of Open Access Journals (Sweden)

    Nor Syahida Aliahmat

    2012-12-01

    Full Text Available OBJECTIVE: The aim of this study was to determine the erythrocyte antioxidant enzyme activity and the superoxide dismutase, catalase, glutathione peroxidase, and plasma malondialdehyde levels in aging mice and to evaluate how these measures are modulated by potential antioxidants, including the tocotrienol-rich fraction, Piper betle, and Chlorella vulgaris. METHOD: One hundred and twenty male C57BL/6 inbred mice were divided into three age groups: young (6 months old, middle-aged (12 months old, and old (18 months old. Each age group consisted of two control groups (distilled water and olive oil and three treatment groups: Piper betle (50 mg/kg body weight, tocotrienol-rich fraction (30 mg/kg, and Chlorella vulgaris (50 mg/kg. The duration of treatment for all three age groups was two months. Blood was withdrawn from the orbital sinus to determine the antioxidant enzyme activity and the malondialdehyde level. RESULTS: Piper betle increased the activities of catalase, glutathione peroxidase, and superoxide dismutase in the young, middle, and old age groups, respectively, when compared to control. The tocotrienol-rich fraction decreased the superoxide dismutase activity in the middle and the old age groups but had no effect on catalase or glutathione peroxidase activity for all age groups. Chlorella vulgaris had no effect on superoxide dismutase activity for all age groups but increased glutathione peroxidase and decreased catalase activity in the middle and the young age groups, respectively. Chlorella vulgaris reduced lipid peroxidation (malondialdehyde levels in all age groups, but no significant changes were observed with the tocotrienol-rich fraction and the Piper betle treatments. CONCLUSION: We found equivocal age-related changes in erythrocyte antioxidant enzyme activity when mice were treated with Piper betle, the tocotrienol-rich fraction, and Chlorella vulgaris. However, Piper betle treatment showed increased antioxidant enzymes

  11. Combining and Comparing Coalescent, Distance and Character-Based Approaches for Barcoding Microalgaes: A Test with Chlorella-Like Species (Chlorophyta)

    Science.gov (United States)

    Zou, Shanmei; Fei, Cong; Song, Jiameng; Bao, Yachao; He, Meilin; Wang, Changhai

    2016-01-01

    Several different barcoding methods of distinguishing species have been advanced, but which method is the best is still controversial. Chlorella is becoming particularly promising in the development of second-generation biofuels. However, the taxonomy of Chlorella–like organisms is easily confused. Here we report a comprehensive barcoding analysis of Chlorella-like species from Chlorella, Chloroidium, Dictyosphaerium and Actinastrum based on rbcL, ITS, tufA and 16S sequences to test the efficiency of traditional barcoding, GMYC, ABGD, PTP, P ID and character-based barcoding methods. First of all, the barcoding results gave new insights into the taxonomic assessment of Chlorella-like organisms studied, including the clear species discrimination and resolution of potentially cryptic species complexes in C. sorokiniana, D. ehrenbergianum and C. Vulgaris. The tufA proved to be the most efficient barcoding locus, which thus could be as potential “specific barcode” for Chlorella-like species. The 16S failed in discriminating most closely related species. The resolution of GMYC, PTP, P ID, ABGD and character-based barcoding methods were variable among rbcL, ITS and tufA genes. The best resolution for species differentiation appeared in tufA analysis where GMYC, PTP, ABGD and character-based approaches produced consistent groups while the PTP method over-split the taxa. The character analysis of rbcL, ITS and tufA sequences could clearly distinguish all taxonomic groups respectively, including the potentially cryptic lineages, with many character attributes. Thus, the character-based barcoding provides an attractive complement to coalescent and distance-based barcoding. Our study represents the test that proves the efficiency of multiple DNA barcoding in species discrimination of microalgaes. PMID:27092945

  12. Auger electron emitter against multiple myeloma - targeted endo-radio-therapy with {sup 125}I-labeled thymidine analogue 5-iodo-4'-thio-2'-deoxyuridine

    Energy Technology Data Exchange (ETDEWEB)

    Morgenroth, Agnieszka, E-mail: amorgenroth@ukaachen.de [Nuclear Medicine Clinic, University Ulm, Albert-Einstein-Allee 23, D-89081 Ulm (Germany); Nuclear Medicine Clinic, University Aachen, RWTH, Pauwelsstrasse 30, D-52074 Aachen (Germany); Dinger, Cornelia; Zlatopolskiy, Boris D.; Al-Momani, Ehab; Glatting, Gerhard [Nuclear Medicine Clinic, University Ulm, Albert-Einstein-Allee 23, D-89081 Ulm (Germany); Mottaghy, Felix M. [Nuclear Medicine Clinic, University Aachen, RWTH, Pauwelsstrasse 30, D-52074 Aachen (Germany); Reske, Sven N. [Nuclear Medicine Clinic, University Ulm, Albert-Einstein-Allee 23, D-89081 Ulm (Germany)

    2011-10-15

    Introduction: Multiple myeloma (MM) is a plasma cell malignancy characterized by accumulation of malignant, terminally differentiated B cells in the bone marrow. Despite advances in therapy, MM remains an incurable disease. Novel therapeutic approaches are, therefore, urgently needed. Auger electron-emitting radiopharmaceuticals are attractive for targeted nano-irradiation therapy, given that DNA of malignant cells is selectively addressed. Here we evaluated the antimyeloma potential of the Auger electron-emitting thymidine analogue {sup 125}I-labeled 5-iodo-4'-thio-2'-deoxyuridine ([{sup 125}I]ITdU). Methods: Cellular uptake and DNA incorporation of [{sup 125}I]ITdU were determined in fluorodeoxyuridine-pretreated KMS12BM, U266, dexamethasone-sensitive MM1.S and -resistant MM1.R cell lines. The effect of stimulation with interleukin 6 (IL6) or insulin-like growth factor 1 (IGF1) on the intracellular incorporation of [{sup 125}I]ITdU was investigated in cytokine-sensitive MM1.S and MM1.R cell lines. Apoptotic cells were identified using Annexin V. Cleavage of caspase 3 and PARP was visualized by Western blot. DNA fragmentation was investigated using laddering assay. Therapeutic efficiency of [{sup 125}I]ITdU was proven by clonogenic assay. Results: [{sup 125}I]ITdU was shown to be efficiently incorporated into DNA of malignant cells, providing a promising mechanism for delivering highly toxic Auger radiation emitters into tumor DNA. [{sup 125}I]ITdU had a potent antimyeloma effect in cell lines representing distinct disease stages and, importantly, in cell lines sensitive or resistant to the conventional therapeutic agent, but was not toxic for normal plasma and bone marrow stromal cells. Furthermore, [{sup 125}I]ITdU abrogated the protective actions of IL6 and IGF1 on MM cells. [{sup 125}I]ITdU induced massive damage in the DNA of malignant plasma cells, which resulted in efficient inhibition of clonogenic growth. Conclusion: These studies may provide a

  13. Ganjam virus.

    Science.gov (United States)

    Sudeep, A B; Jadi, R S; Mishra, A C

    2009-11-01

    Ganjam virus (GANV), a member of genus Nairovirus of family Bunyavirdae is of considerable veterinary importance in India. Though, predominantly tick borne, GANV was also isolated from mosquitoes, man and sheep. Neutralizing and complement fixing antibodies to GANV have been detected in animal and human sera collected from different parts of the country. Thirty three strains of GANV have been isolated from India, mainly from Haemaphysalis ticks. The virus replicated in certain vertebrate and mosquito cell lines and found pathogenic to laboratory animals. One natural infection and five laboratory-acquired infections in men were also reported. GANV is antigenically related to Nairobi sheep disease virus (NSDV) of Africa, which is highly pathogenic for sheep and goats causing 70-90 per cent mortality among the susceptible population. Recent molecular studies have demonstrated that GANV is an Asian variant of NSDV and both these viruses are related to the dreaded Crimean Congo haemorrhagic fever (CCHF) group viruses. The versatility of the virus to replicate in different arthropod species, its ability to infect sheep, goat and man makes it an important zoonotic agent.

  14. Powassan (POW) Virus Basics

    Science.gov (United States)

    ... Health Professionals Related Topics For International Travelers Powassan Virus Disease Basics Download this fact sheet formatted for ... Virus Disease Fact Sheet (PDF) What is Powassan virus? Powassan virus is a tickborne flavivirus that is ...

  15. Optimising the bioreceptivity of porous glass tiles based on colonization by the alga Chlorella vulgaris

    Energy Technology Data Exchange (ETDEWEB)

    Ferrándiz-Mas, V., E-mail: v.ferrandiz@imperial.ac.uk [Department of Civil and Environmental Engineering, Imperial College London, London SW7 2BU (United Kingdom); Bond, T., E-mail: t.bond@imperial.ac.uk [Department of Civil and Environmental Engineering, Imperial College London, London SW7 2BU (United Kingdom); Zhang, Z., E-mail: zhen.zhang14@imperial.ac.uk [Department of Civil and Environmental Engineering, Imperial College London, London SW7 2BU (United Kingdom); Melchiorri, J., E-mail: jpmelchiorri@gmail.com [ARBOREA Research, Bessemer Building, Prince Consort Road, London SW7 2AZ (United Kingdom); Cheeseman, C.R., E-mail: c.cheeseman@imperial.ac.uk [Department of Civil and Environmental Engineering, Imperial College London, London SW7 2BU (United Kingdom)

    2016-09-01

    Green façades on buildings can mitigate greenhouse gas emissions. An option to obtain green facades is through the natural colonisation of construction materials. This can be achieved by engineering bioreceptive materials. Bioreceptivity is the susceptibility of a material to be colonised by living organisms. The aim of this research was to develop tiles made by sintering granular waste glass that were optimised for bioreceptivity of organisms capable of photosynthesis. Tiles were produced by pressing recycled soda-lime glass with a controlled particle size distribution and sintering compacted samples at temperatures between 680 and 740 °C. The primary bioreceptivity of the tiles was evaluated by quantifying colonisation by the algae Chlorella vulgaris (C. vulgaris), which was selected as a model photosynthetic micro-organism. Concentrations of C. vulgaris were measured using chlorophyll-a extraction. Relationships between bioreceptivity and the properties of the porous glass tile, including porosity, sorptivity, translucency and pH are reported. Capillary porosity and water sorptivity were the key factors influencing the bioreceptivity of porous glass. Maximum C. vulgaris growth and colonisation was obtained for tiles sintered at 700 °C, with chlorophyll-a concentrations reaching up to 11.1 ± 0.4 μg/cm{sup 2} of tile. Bioreceptivity was positively correlated with sorptivity and porosity and negatively correlated with light transmittance. The research demonstrates that the microstructure of porous glass, determined by the processing conditions, significantly influences bioreceptivity. Porous glass tiles with high bioreceptivity that are colonised by photosynthetic algae have the potential to form carbon-negative façades for buildings and green infrastructure. - Highlights: • Porous tiles made by sintering waste glass at variable temperatures • Bioreceptivity assessed by measuring colonisation by the algae C. vulgaris • Tiles sintered at 700 °C gave

  16. Spacecraft cabin environment effects on the growth and behavior of Chlorella vulgaris for life support applications

    Science.gov (United States)

    Niederwieser, Tobias; Kociolek, Patrick; Klaus, David

    2018-02-01

    An Environmental Control and Life Support System (ECLSS) is necessary for humans to survive in the hostile environment of space. As future missions move beyond Earth orbit for extended durations, reclaiming human metabolic waste streams for recycled use becomes increasingly important. Historically, these functions have been accomplished using a variety of physical and chemical processes with limited recycling capabilities. In contrast, biological systems can also be incorporated into a spacecraft to essentially mimic the balance of photosynthesis and respiration that occurs in Earth's ecosystem, along with increasing the reuse of biomass throughout the food chain. In particular, algal photobioreactors that use Chlorella vulgaris have been identified as potential multifunctional components for use as part of such a bioregenerative life support system (BLSS). However, a connection between the biological research examining C. vulgaris behavior and the engineered spacecraft cabin environmental conditions has not yet been thoroughly established. This review article characterizes the ranges of prior and expected cabin parameters (e.g. temperature, lighting, carbon dioxide, pH, oxygen, pressure, growth media, contamination, gravity, and radiation) and reviews algal metabolic response (e.g. growth rate, composition, carbon dioxide fixation rates, and oxygen evolution rates) to changes in those parameters that have been reported in prior space research and from related Earth-based experimental observations. Based on our findings, it appears that C. vulgaris offers many promising advantages for use in a BLSS. Typical atmospheric conditions found in spacecraft such as elevated carbon dioxide levels are, in fact, beneficial for algal cultivation. Other spacecraft cabin parameters, however, introduce unique environmental factors, such as reduced total pressure with elevated oxygen concentration, increased radiation, and altered gravity, whose effects on the biological responses

  17. Effect and mechanism of TiO2 nanoparticles on the photosynthesis of Chlorella pyrenoidosa.

    Science.gov (United States)

    Middepogu, Ayyaraju; Hou, Jie; Gao, Xuan; Lin, Daohui

    2018-06-14

    Titanium dioxide nanoparticles (n-TiO 2 ) have been used in numerous applications, which results in their release into aquatic ecosystems and impact algal populations. A possible toxic mechanism of n-TiO 2 on algae is via the disruption of the photosynthetic biochemical pathways, which yet remains to be demonstrated. In this study, Chlorella pyrenoidosa was exposed to different concentrations (0, 0.1, 1, 5, 10, and 20 mg/L) of a type of anatase n-TiO 2 , and the physiological, biochemical, and molecular responses involved in photosynthesis were investigated. The 96 h half growth inhibition concentration (IC 50 ) of the n-TiO 2 to algae was determined to be 9.1 mg/L. A variety of cellular and sub-cellular damages were observed, especially the blurry lamellar structure of thylakoids, indicating the n-TiO 2 impaired the photosynthetic function of chloroplasts. Malondialdehyde (MDA) and glutathione disulfide (GSSG) significantly increased while the glutathione (GSH) content decreased. This implies the increased consumption of GSH by the increased intracellular oxidative stress upon n-TiO 2 was insufficient to eliminate the lipid peroxidation. The contents of photosynthetic pigments, including chlorophyll a (Chl a) and phycobiliproteins (PBPs) in the exposed algal cells increased along with the up-regulation of genes encoding Chl a and photosystem II (PS II), which could be explained by a compensatory effect to overcome the toxicity induced by the n-TiO 2 . On the other hand, the photosynthetic activity was significantly inhibited, indicating the impairment on the photosynthesis via damaging the reaction center of PS II. In addition, lower productions of adenosine triphosphate (ATP) and glucose, together with the change of gene expressions suggested that the n-TiO 2 disrupted the material and energy metabolisms in the photosynthesis. These findings support a paradigm shift of the toxic mechanism of n-TiO 2 from physical and oxidative damages to metabolic

  18. Chlorella mirabilis as a Potential Species for Biomass Production in Low-Temperature Environment.

    Science.gov (United States)

    Shukla, S P; Kvíderová, J; Tříska, J; Elster, J

    2013-01-01

    Successful adaptation/acclimatization to low temperatures in micro-algae is usually connected with production of specific biotechnologically important compounds. In this study, we evaluated the growth characteristics in a micro-scale mass cultivation of the Antarctic soil green alga Chlorella mirabilis under different nitrogen and carbon sources followed by analyses of fatty acid contents. The micro-scale mass cultivation was performed in stable (in-door) and variable (out-door) conditions during winter and/or early spring in the Czech Republic. In the in-door cultivation, the treatments for nitrogen and carbon sources determination included pure Z medium (control, Z), Z medium + 5% glycerol (ZG), Z medium + 5% glycerol + 50 μM KNO3 (ZGN), Z medium + 5% glycerol + 200 μM NH4Cl (ZGA), Z medium + 5% glycerol + 1 mM Na2CO3 (ZNC), Z medium + 5% glycerol + 1 mM Na2CO3 + 200 μM NH4Cl (ZGCA) and Z medium + 5% glycerol + 1 mM Na2CO3 + 50 μM KNO3 (ZGCN) and were performed at 15°C with an irradiance of 75 μmol m(-2) s(-1). During the out-door experiments, the night-day temperature ranged from -6.6 to 17.5°C (daily average 3.1 ± 5.3°C) and irradiance ranged from 0 to 2,300 μmol m(-2) s(-1) (daily average 1,500 ± 1,090 μmol m(-2) s(-1)). Only the Z, ZG, ZGN, and ZGC treatments were used in the out-door cultivation. In the in-door mass cultivation, all nitrogen and carbon sources additions increased the growth rate with the exception of ZGA. When individual sources were considered, only the effect of 5% glycerol addition was significant. On the other hand, the growth rate decreased in the ZG and ZGN treatments in the out-door experiment, probably due to carbon limitation. Fatty acid composition showed increased production of linoleic acid in the glycerol treatments. The studied strain of C. mirabilis is proposed to be a promising source of linoleic acid in low

  19. Chlorella mirabilis as a potential species for biomass production in low temperature environment

    Directory of Open Access Journals (Sweden)

    Satya Prakash Shukla

    2013-04-01

    Full Text Available Successful adaptation/acclimatization to low temperatures in micro-algae is usually connected with production of specific biotechnologically important compounds. In this study, we evaluated the growth characteristics in a micro-scale mass cultivation of the Antarctic soil green alga Chlorella mirabilis under different nitrogen and carbon sources followed by analyses of fatty acid contents. The micro-scale mass cultivation was performed in stable (in-door and variable (out-door conditions during winter and/or early spring in the Czech Republic. In the in-door cultivation, the treatments for nitrogen and carbon sources determination included pure Z medium (control, Z, Z medium + 5% glycerol (ZG, Z medium + 5% glycerol + 50 µM KNO3 (ZGN, Z medium + 5% glycerol + 200µM NH4Cl (ZGA, Z medium + 5% glycerol + 1 mM Na2CO3 (ZNC, Z medium + 5% glycerol + 1 mM Na2CO3 + 200µM NH4Cl (ZGCA and Z medium + 5% glycerol + 1 mM Na2CO3 + 50 µM KNO3 (ZGCN and were performed at 15°C with an irradiance of 75 µmol m-2 s-1. During the out-door experiments, the night-day temperature ranged from -6.6°C to 17.5°C (daily average 3.1±5.3 °C and irradiance ranged from 0 to 2300 µmol m-2 s-1 (daily average 1500±1090 µmol m-2 s-1. Only the Z, ZG, ZGN and ZGC treatments were used in the out-door cultivation. In the in-door mass cultivation, all nitrogen and carbon sources additions increased the growth rate with the exception of ZGA. When individual sources were considered, only the effect of 5% glycerol addition was significant. On the other hand, the growth rate decreased in the ZG and ZGN treatments in the out-door experiment, probably due to carbon limitation. Fatty acid composition showed increased production of linoleic acid in the glycerol treatments. The studied strain of C. mirabilis is proposed to be a promising source of linoleic acid in low temperature mass cultivation biotechnology. This strain is a perspective model organism for biotechnology in low

  20. Inhibition of Pro-inflammatory Mediators and Cytokines by Chlorella Vulgaris Extracts.

    Science.gov (United States)

    Sibi, G; Rabina, Santa

    2016-01-01

    The aim of this study was to determine the in vitro anti-inflammatory activities of solvent fractions from Chlorella vulgaris by inhibiting the production of pro-inflammatory mediators and cytokines. Methanolic extracts (80%) of C. vulgaris were prepared and partitioned with solvents of increasing polarity viz., n-hexane, chloroform, ethanol, and water. Various concentrations of the fractions were tested for cytotoxicity in RAW 264.7 cells using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, and the concentrations inducing cell growth inhibition by about 50% (IC50) were chosen for further studies. Lipopolysaccharide (LPS) stimulated RAW 264.7 cells were treated with varying concentrations of C. vulgaris fractions and examined for its effects on nitric oxide (NO) production by Griess assay. The release of prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), and interleukin 6 (IL-6) were quantified using enzyme-linked immunosorbent assay using Celecoxib and polymyxin B as positive controls. MTT assay revealed all the solvent fractions that inhibited cell growth in a dose-dependent manner. Of all the extracts, 80% methanolic extract exhibited the strongest anti-inflammatory activity by inhibiting NO production (P < 0.01), PGE2 (P < 0.05), TNF-α, and IL-6 (P < 0.001) release in LPS induced RAW 264.7 cells. Both hexane and chloroform fractions recorded a significant (P < 0.05) and dose-dependent inhibition of LPS induced inflammatory mediators and cytokines in vitro. The anti-inflammatory effect of ethanol and aqueous extracts was not significant in the study. The significant inhibition of inflammatory mediators and cytokines by fractions from C. vulgaris suggests that this microalga would be a potential source of developing anti-inflammatory agents and a good alternate for conventional steroidal and nonsteroidal anti-inflammatory drugs. C. vulgaris extracts have potential anti-inflammatory activitySolvent extraction using methanol

  1. Evaluation of agricultural fertilizers on the productivity of microalgae Chlorella sorokiniana.

    Directory of Open Access Journals (Sweden)

    Ana Margarita Silva-Benavides

    2016-06-01

    Full Text Available The aim of this study was to evaluate the productivity of microalgae Chlorella sorokiniana UTEX 1230 with two different foliar fertilizers used in agriculture and the comparison with the nutrient medium Kolwitz (K3.Variables assessed were cell growth, productivity, chlorophyll concentration, fluorescence (Fv/Fm, proteins, and carbohydrates. Two commercial fertilizers with NPK 20-20-20 and NPK 22-10-7 formula were used as nutrient media. The study was conducted at the Institute of Ecosystem Studies, Florence, Italy, in 2014. Each experiment was repeated five times using three replicates in each experiment under a light intensity of 150 μmol photons m2/s, temperature 28 °C and CO2/air (2:98v/v. The culture media were prepared by using the following fertilizers: 1 NPK 20-20-20 (1.00 g/l + 0.27 g/l MgSO4.7H2O, 2 NPK 22-10-7 (+2 MgO (1.00 g/l + 0.27 g/l MgSO4.7H2O, 3 NPK 22-10-7 (+2 MgO (1.00 g/l, 4 NPK 20-20-20 (1.00 g/l. The nutrient medium Kolwitz (K3 was used as a control. Higher cell concentrations, productivity, chlorophyll, fluorescence, proteins, and carbohydrates were obtained in cultures grown in the media prepared with magnesium sulfate (NPK 20-20-20 (1.00 g/l + 0.27 g/l MgSO4.7H2O, and NPK 22-10-7 (+2 MgO (1.00 g/l + 0.27 g/l MgSO4.7H2O. Lower biomass growth was obtained in cultures lacking magnesium sulfate. Sulfide and magnesium, as well as the amounts of urea and ammonia in the chemical composition of each fertilizer, had a positive effect on the culture growth and productivity. 

  2. Chlorella vulgaris as Protein Source in the Diets of African Catfish Clarias gariepinus

    Directory of Open Access Journals (Sweden)

    Uchechukwu D. Enyidi

    2017-10-01

    Full Text Available Plant proteins substitutes of fishmeal in aquafeed are usually lacking in some essential amino acids and fatty acids. The microalgae Chlorella vulgaris has good-quality protein with amino acids rich in methionine, lysine and alanine. Four novel diets having C. vulgaris as the main source of protein were produced for African catfish Clarias gariepinus with an initial average weight of 1.09 ± 0.05 g. The diets were labeled Feed 1 (F1 to feed 4 (F4. The treatment diets were included 25% (F1, 15% (F2, 5% (F3 and 0% (F4 green algae meal. The basal ingredients of the feed were corn (maize included as F1, 40%, F2, 43%, F3, 53% and F4, 43%; and millet meal, which varied in F1 as 23%, F2, 30%, F3, 30% and F4, 30%. The ingredients were preconditioned at 110 °C and pelleted. Post-fingerling African catfish were stocked at 10 fish per aquarium. There were three replicate aquariums for each feed type and the fish were fed for 60 d. The specific growth rate was best for the catfish fed with 25% C. vulgaris diet 7.86 ± 0% day−1, and worst at 6.77 ± 0.07% day−1 for the control group F4, 0% algal meal. The food conversion ratio (FCR was lowest (1.88 ± 0.02 for 25% algal meal diet (F1 and highest (2.98 ± 0.01 for the 0% algal meal diet F4. Similarly, catfish had average weight gain of 121.02 ± 0.04 g for those fed with F1 compared to 62.50 ± 0.0 g for those fed with 0% algae F4. Protein efficiency ratio was highest for the F1-fed fish (2.46 ± 0.22 and lowest for those fed with F4 (2.02 ± 0.09. The hepatosomatic index was lowest for F1-fed fish (1.48 ± 0.01 and highest for catfish fed with F4 (2.50 ± 0.59. Based on the results, C. vulgaris is a good protein source for African catfish and can also substitute fishmeal in the catfish diets.

  3. A randomized controlled trial of 6-week Chlorella vulgaris supplementation in patients with major depressive disorder.

    Science.gov (United States)

    Panahi, Yunes; Badeli, Roghayeh; Karami, Gholam-Reza; Badeli, Zeinab; Sahebkar, Amirhossein

    2015-08-01

    Major depressive disorder (MDD) is a widespread psychiatric disorder with incapacitating symptoms. Oxidative stress has been identified to play a role in the pathophysiology of MDD. To evaluate the therapeutic effectiveness of a chemically defined and antioxidant-rich Chlorella vulgaris extract (CVE) as adjunct to standard treatment in patients suffering from MDD. Subjects with MDD diagnosis according to DSM-IV criteria who were receiving standard antidepressant therapy were assigned to add-on therapy with CVE (1800 mg/day; n=42), or continued standard antidepressant therapy alone (n=50) for a period of 6 weeks. Changes in the frequency of depressive symptoms were assessed using the Hospital Anxiety and Depression Scale (HADS) and Beck Depression Inventory II (BDI-II) scale. There were significant reductions in total and subscale BDI-II and HADS scores in both CVE and control groups by the end of trial. The magnitude of reductions in total BDI-II score [-4.14 (-5.30 to -2.97)] as well as physical [-2.34 (-2.84 to -1.84)] and cognitive [-1.12 (-1.62 to -0.61)] subscales were significantly greater in the CVE versus control group, however, reduction of the affective symptoms was greater in the control compared with the CVE group [0.95 (0.18-0.72)]. Total HADS [-3.71 (-4.44 to -2.98)] as well as individual subscales of depression [-1.46 (-2.02 to -0.90)] and anxiety [-2.25 (-2.74 to -1.76)] were reduced to a greater degree in the CVE group. CVE was well tolerated and no serious adverse event was reported. This pilot exploratory trial provides the first clinical evidence on the efficacy and safety of adjunctive therapy with CVE in improving physical and cognitive symptoms of depression as well as anxiety symptoms in patients who are receiving standard antidepressant therapy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Polishing of Anaerobic Secondary Effluent and Symbiotic Bioremediation of Raw Municipal Wastewater by Chlorella Vulgaris

    KAUST Repository

    Cheng, Tuoyuan

    2016-05-01

    To assess polishing of anaerobic secondary effluent and symbiotic bioremediation of primary effluent by microalgae, bench scale bubbling column reactors were operated in batch modes to test nutrients removal capacity and associated factors. Chemical oxygen demand (COD) together with oil and grease in terms of hexane extractable material (HEM) in the reactors were measured after batch cultivation tests of Chlorella Vulgaris, indicating the releasing algal metabolites were oleaginous (dissolved HEM up to 8.470 mg/L) and might hazard effluent quality. Ultrafiltration adopted as solid-liquid separation step was studied via critical flux and liquid chromatography-organic carbon detection (LC-OCD) analysis. Although nutrients removal was dominated by algal assimilation, nitrogen removal (99.6% maximum) was affected by generation time (2.49 days minimum) instead of specific nitrogen removal rate (sN, 20.72% maximum), while phosphorus removal (49.83% maximum) was related to both generation time and specific phosphorus removal rate (sP, 1.50% maximum). COD increase was affected by cell concentration (370.90 mg/L maximum), specific COD change rate (sCOD, 0.87 maximum) and shading effect. sCOD results implied algal metabolic pathway shift under nutrients stress, generally from lipid accumulation to starch accumulation when phosphorus lower than 5 mg/L, while HEM for batches with initial nitrogen of 10 mg/L implied this threshold around 8 mg/L. HEM and COD results implied algal metabolic pathway shift under nutrients stress. Anaerobic membrane bioreactor effluent polishing showed similar results to synthetic anaerobic secondary effluent with slight inhibition while 4 symbiotic bioremediation of raw municipal wastewater with microalgae and activated sludge showed competition for ammonium together with precipitation or microalgal luxury uptake of phosphorus. Critical flux was governed by algal cell concentration for ultrafiltration membrane with pore size of 30 nm, while

  5. Optimized inorganic carbon regime for enhanced growth and lipid accumulation in Chlorella vulgaris.

    Science.gov (United States)

    Lohman, Egan J; Gardner, Robert D; Pedersen, Todd; Peyton, Brent M; Cooksey, Keith E; Gerlach, Robin

    2015-01-01

    Large-scale algal biofuel production has been limited, among other factors, by the availability of inorganic carbon in the culture medium at concentrations higher than achievable with atmospheric CO2. Life cycle analyses have concluded that costs associated with supplying CO2 to algal cultures are significant contributors to the overall energy consumption. A two-phase optimal growth and lipid accumulation scenario is presented, which (1) enhances the growth rate and (2) the triacylglyceride (TAG) accumulation rate in the oleaginous Chlorophyte Chlorella vulgaris strain UTEX 395, by growing the organism in the presence of low concentrations of NaHCO3 (5 mM) and controlling the pH of the system with a periodic gas sparge of 5 % CO2 (v/v). Once cultures reached the desired cell densities, which can be "fine-tuned" based on initial nutrient concentrations, cultures were switched to a lipid accumulation metabolism through the addition of 50 mM NaHCO3. This two-phase approach increased the specific growth rate of C. vulgaris by 69 % compared to cultures sparged continuously with 5 % CO2 (v/v); further, biomass productivity (g L(-1) day(-1)) was increased by 27 %. Total biodiesel potential [assessed as total fatty acid methyl ester (FAME) produced] was increased from 53.3 to 61 % (FAME biomass(-1)) under the optimized conditions; biodiesel productivity (g FAME L(-1) day(-1)) was increased by 7.7 %. A bicarbonate salt screen revealed that American Chemical Society (ACS) and industrial grade NaHCO3 induced the highest TAG accumulation (% w/w), whereas Na2CO3 did not induce significant TAG accumulation. NH4HCO3 had a negative effect on cell health presumably due to ammonia toxicity. The raw, unrefined form of trona, NaHCO3∙Na2CO3 (sodium sesquicarbonate) induced TAG accumulation, albeit to a slightly lower extent than the more refined forms of sodium bicarbonate. The strategic addition of sodium bicarbonate was found to enhance growth and lipid accumulation rates in

  6. Effect of gamma radiation on chlorophylls content, net photosynthesis and respiration of Chlorella pyrenoidosa; Efecto de la radiacion gamma sobre la fotosintesis neta y la respiracion de Chlorella pyrenoidosa

    Energy Technology Data Exchange (ETDEWEB)

    Martin, C; Fernandez, J

    1983-07-01

    The effect of five doses of gamma radiation: 10, 100, 500, 1000 and 5000 Gy on chlorophylls content, net photosynthesis and respiration of Chlorella pyrenoidosa has been studied. A decrease in chlorophylls levels is produced after irradiation at 500, 1000 and 5000 Gy, being, at first b chlorophyll affected to a greater extent than a chlorophyll. Net photosynthesis and respiration decline throughout the time of the observation after irradiation, this depressing effect being much more remarkable for the first one. Met photosynthesis inhibition levels of about 30% are got only five hours post irradiation at a dose of 5000 Gy. Radio estimation by low doses, although obtained in some cases for tho 10 Gy dose, has not been statistically confirmed. (Author) 23 refs.

  7. Ebola Virus

    Directory of Open Access Journals (Sweden)

    Anusha Rangare Lakshman

    2015-09-01

    Full Text Available The disease Ebola takes its name from the Ebola River situated near a village in the Democratic Republic of Congo, where the disease first appeared in 1976. It is caused by a virus from the Filoviridae family (filovirus. The present outbreak of Ebola Virus Disease (EVD concerns four countries in West Africa, namely Guinea, Liberia, Sierra Leone and Nigeria till date. Further to widespread transmission of the disease, it has been declared as a Public Health Emergency of International Concern by the World Health Organisation on 8 August 2014. As of 4 August 2014, countries have reported 1,711 cases (1,070 confirmed, 436 probable, 205 suspect, including 932 deaths. This review paper enlightens about the awareness of Ebola virus and its preventive measures. [Archives Medical Review Journal 2015; 24(3.000: 296-305

  8. Demography of zooplankton (Anuraeopsis fissa, Brachionus rubens and Moina macrocopa fed Chlorella vulgaris and Scenedesmus acutus cultured on different media

    Directory of Open Access Journals (Sweden)

    Jesús Morales-Ventura

    2012-09-01

    Full Text Available Generally zooplankton growth is often limited by the quality of their algal diet. A cheaper common practice in aquaculture, is to culture algae with fertilizers; however, the demography of zooplankton when fed these algae has not yet been evaluated. We studied the population growth and life table demography of the rotifers Anuraeopsis fissa and Brachionus rubens, and the cladoceran Moina macrocopa. For this, the algae Scenedesmus acutus or Chlorella vulgaris were cultured on defined (Bold’s basal medium or the commercial liquid fertilizer (Bayfolan. Experiments were conducted at one algal concentration 1.0x10(6cells/mL of C. vulgaris or its equivalent dry weight of 0.5x10(6cells/mL of S. acutus. The population dynamics were tested at 23±1ºC in 100mL transparent jars, each with 50mL of the test medium, with an initial density of 0.5indiv/mL, for a total of 48 test jars (3 zooplankton 2 algal species x 2 culture media x 4 replicates. For the life table experiments with M. macrocopa, we introduced 10 neonates (<24h old into each test jar containing the specific algal type and concentration. For the rotifer experiments, we set 5mL tubes with one neonate each and 10 replicates for each algal species and culture medium. We found that the average rotifer life span was not influenced by the diet, but for M. macrocopa fed S. acutus cultured in Bold’s medium, the average lifespan was significantly lower than with the other diets. The gross and net reproductive rates of A. fissa (ranging from 18-36 offspring per female were significantly higher for C. vulgaris cultured in Bold medium. Regardless of the culture medium, Chlorella resulted in significantly higher gross and net reproductive rates for B. rubens than S. acutus diets. The reproductive rates of M. macrocopa were significantly higher in all the tested diets except when fed with S. acutus in Bold medium. The population increase rate, derived from growth experiments of A. fissa and B. rubens

  9. Nutrient utilization and oxygen production by Chlorella Vulgaris in a hybrid membrane bioreactor and algal membrane photobioreactor system

    KAUST Repository

    Najm, Yasmeen Hani Kamal

    2017-02-17

    This work studied oxygen production and nutrient utilization by Chlorella Vulgaris at different organic/inorganic carbon (OC/IC) and ammonium/nitrate (NH4+-N/NO3--N) ratios to design a hybrid aerobic membrane bioreactor (MBR) and membrane photobioreactor (MPBR) system. Specific oxygen production by C. vulgaris was enough to support the MBR if high growth is accomplished. Nearly 100% removal (or utilization) of PO43--P and IC was achieved under all conditions tested. Optimal growth was achieved at mixotrophic carbon conditions (0.353 d-1) and the highest NH4+-N concentration (0.357 d-1), with preferable NH4+-N utilization rather than NO3--N. The results indicate the potential of alternative process designs to treat domestic wastewater by coupling the hybrid MBR - MPBR systems.

  10. Potencialidades de Chlorella vulgaris cultivada em meio à base de concentrado de dessalinização

    OpenAIRE

    Matos, Ângelo Paggi

    2012-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias. Programa de Pós-Graduação em Ciência dos Alimentos. O objetivo deste trabalho foi avaliar as propriedades físicoquímicas da biomassa de Chlorella vulgaris em um meio à base de concentrado de dessalinização proveniente do processo de dessalinização de águas subterrâneas na comunidade de Uruçu, no município de São João do Cariri # Paraíba. O concentrado de dessalinização possui alta concentração de ...

  11. Lipid production by pure and mixed cultures of Chlorella pyrenoidosa and Rhodotorula mucilaginosa isolated in Nuevo Leon, Mexico.

    Science.gov (United States)

    Reyna-Martínez, Raúl; Gomez-Flores, Ricardo; López-Chuken, Ulrico J; González-González, Rosario; Fernández-Delgadillo, Sergio; Balderas-Rentería, Isaias

    2015-01-01

    Given the well-known environmental drawbacks of using fossil fuels, advances in the field of alternative energy have become a worldwide technological priority. Special interest has been focused on the production of biodiesel obtained from oleaginous microorganisms. In the present research, lipid production by two species, microalgae Chlorella pyrenoidosa and yeast Rhodotorula mucilaginosa was assessed, independently and in mixed culture to evaluate a possible synergy. Fatty acid analysis was performed by gas chromatography. Among pure and mixed cultures of both strains and several culturing conditions, the highest biomass and lipid productivity was obtained by C. pyrenoidosa (8.05 and 1.62 g/L, respectively). The results of this study showed that both strains used are in fact oleaginous strains as they were found to reach up to 20 % of lipids, in addition, lipids in both pure and mixed cultures were mainly of triglycerides (>90 %), composed of fatty acid chains between 16 and 18 carbons.

  12. GROWTH KINETIC STUDY OF CHLORELLA VULGARIS USING LAB-SCALE AND PILOT-SCALE PHOTOBIOREACTOR: EFFECT OF CO2 CONCENTRATION

    Directory of Open Access Journals (Sweden)

    MAN KEE LAM

    2016-07-01

    Full Text Available In the present study, growth kinetic of Chlorella vulgaris was performed when the microalgae was cultivated with different concentrations of CO2 . The experiments were carried out using lab-scale and pilot-scale photobioreactors, and the growth results were analyzed using POLYMATH 6.0 with different growth kinetic models. The growth of the microalgae was found fitted well to the Richards growth model with attainable high R2 values as demonstrated in all studied cases, in concert with low values of root mean squares deviation (RMSD and variance. In addition, the output from the plots of experimental values versus predicted values and residual plots further confirmed the good fit of Richards model. The predicted specific growth rate from Richards model was similar to the experimental specific growth rate with deviation lesser than 5%. The attained results paved a preliminary prediction of microalgae growth characteristic when the cultivation is scaled-up to commercial scale.

  13. Using Chlorella vulgaris to treat toxic excess sludge extract, and identification of its response mechanism by proteomics approach.

    Science.gov (United States)

    Wang, Lu; Wang, Hualin; Chen, Xiurong; Xu, Yan; Zhou, Tianjun; Wang, Xiaoxiao; Lu, Qian; Ruan, Roger

    2018-04-01

    Chlorella vulgaris was cultivated in varying proportions of toxic sludge extracts obtained from a sequencing batch reactor for treating synthetic wastewater containing chlorophenols. C. vulgaris could reduce the ecotoxicity from sludge extracts, and a positive correlation was noted between ecotoxicity removal and total organic carbon removal. In terms of cell density, the optimal proportion of sludge extracts required for the cultivation of C. vulgaris was lower than 50%. The correlation between protein content in per 10 6 algae and inhibition extent of ecotoxicity of the 5 groups on the day of inoculation (0.9182, p vulgaris produced proteins that involved in the stress response/redox system and energy metabolism/biosynthesis to respond to the toxic environment and some other proteins related to mixotrophic metabolism. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Impact of changes in broth composition on Chlorella vulgaris cultivation in a membrane photobioreactor (MPBR) with permeate recycle.

    Science.gov (United States)

    Discart, V; Bilad, M R; Marbelia, L; Vankelecom, I F J

    2014-01-01

    A membrane photobioreactor (MPBR) is a proven and very useful concept in which microalgae can be simultaneously cultivated and pre-harvested. However, the behavior with respect to accumulation of algogenic organic matter, including transparent exopolymeric particles (TEPs), counter ions and unassimilated nutrients due to the recycling of the medium is still unclear, even though the understanding of this behavior is essential for the optimization of microalgae processing. Therefore, the dynamics of these compounds, especially TEPs, during coupled cultivation and harvesting of Chlorella vulgaris in an MPBR with permeate recycle are addressed in this study. Results show that TEPs are secreted during algae cell growth, and that their presence is thus inevitable. In the system with permeate recycle, substances such as counter ions and unassimilated nutrients get accumulated in the system. This was proven to limit the algae growth, together with the occurrence of bioflocculation due to an increasing broth pH. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Nutrient utilization and oxygen production by Chlorella Vulgaris in a hybrid membrane bioreactor and algal membrane photobioreactor system

    KAUST Repository

    Najm, Yasmeen Hani Kamal; Jeong, Sanghyun; Leiknes, TorOve

    2017-01-01

    This work studied oxygen production and nutrient utilization by Chlorella Vulgaris at different organic/inorganic carbon (OC/IC) and ammonium/nitrate (NH4+-N/NO3--N) ratios to design a hybrid aerobic membrane bioreactor (MBR) and membrane photobioreactor (MPBR) system. Specific oxygen production by C. vulgaris was enough to support the MBR if high growth is accomplished. Nearly 100% removal (or utilization) of PO43--P and IC was achieved under all conditions tested. Optimal growth was achieved at mixotrophic carbon conditions (0.353 d-1) and the highest NH4+-N concentration (0.357 d-1), with preferable NH4+-N utilization rather than NO3--N. The results indicate the potential of alternative process designs to treat domestic wastewater by coupling the hybrid MBR - MPBR systems.

  16. Selective extraction of intracellular components from the microalga Chlorella vulgaris by combined pulsed electric field-temperature treatment.

    Science.gov (United States)

    Postma, P R; Pataro, G; Capitoli, M; Barbosa, M J; Wijffels, R H; Eppink, M H M; Olivieri, G; Ferrari, G

    2016-03-01

    The synergistic effect of temperature (25-65 °C) and total specific energy input (0.55-1.11 kWh kgDW(-1)) by pulsed electric field (PEF) on the release of intracellular components from the microalgae Chlorella vulgaris was studied. The combination of PEF with temperatures from 25 to 55 °C resulted in a conductivity increase of 75% as a result of cell membrane permeabilization. In this range of temperatures, 25-39% carbohydrates and 3-5% proteins release occurred and only for carbohydrate release a synergistic effect was observed at 55 °C. Above 55 °C spontaneous cell lysis occurred without PEF. Combined PEF-temperature treatment does not sufficiently disintegrate the algal cells to release both carbohydrates and proteins at yields comparable to the benchmark bead milling (40-45% protein, 48-58% carbohydrates). Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Demography of zooplankton (Anuraeopsis fissa, Brachionus rubens and Moina macrocopa fed Chlorella vulgaris and Scenedesmus acutus cultured on different media

    Directory of Open Access Journals (Sweden)

    Jesús Morales-Ventura

    2012-09-01

    Full Text Available Generally zooplankton growth is often limited by the quality of their algal diet. A cheaper common practice in aquaculture, is to culture algae with fertilizers; however, the demography of zooplankton when fed these algae has not yet been evaluated. We studied the population growth and life table demography of the rotifers Anuraeopsis fissa and Brachionus rubens, and the cladoceran Moina macrocopa. For this, the algae Scenedesmus acutus or Chlorella vulgaris were cultured on defined (Bold’s basal medium or the commercial liquid fertilizer (Bayfolan. Experiments were conducted at one algal concentration 1.0x10(6cells/mL of C. vulgaris or its equivalent dry weight of 0.5x10(6cells/mL of S. acutus. The population dynamics were tested at 23±1ºC in 100mL transparent jars, each with 50mL of the test medium, with an initial density of 0.5indiv/mL, for a total of 48 test jars (3 zooplankton 2 algal species x 2 culture media x 4 replicates. For the life table experiments with M. macrocopa, we introduced 10 neonates (Generalmente el crecimiento del zooplancton está a menudo limitado por la calidad de su dieta de algas. La demografía del zooplancton durante la alimentación con algas no ha sido estudiada, a pesar de que el cultivo de algas con fertilizantes es una práctica económica común en acuacultura. Se analizó la demografía de Anuraeopsis fissa y Brachionus rubens (rotíferos y Moina macrocopa (cladóceros, alimentados con las algas verdes Scenedesmus acutus o Chlorella vulgaris cultivadas en medio Bold o fertilizante líquido comercial (Bayfolan, de Bayer. En los rotíferos no se observaron diferencias significativas en el promedio de vida, sin embargo, este parámetro en M. macrocopa con S. acutus cultivada en Medio Bold, fue significativamente menor que en otras dietas. Las tasas de reproducción bruta y neta de A. fissa fueron significativamente mayores con C. vulgaris cultivada en medio Bold, que con el fertilizante; estas tasas en B

  18. Using straw hydrolysate to cultivate Chlorella pyrenoidosa for high-value biomass production and the nitrogen regulation for biomass composition.

    Science.gov (United States)

    Zhang, Tian-Yuan; Wang, Xiao-Xiong; Wu, Yin-Hu; Wang, Jing-Han; Deantes-Espinosa, Victor M; Zhuang, Lin-Lan; Hu, Hong-Ying; Wu, Guang-Xue

    2017-11-01

    Heterotrophic cultivation of Chlorella pyrenoidosa based on straw substrate was proposed as a promising approach in this research. The straw pre-treated by ammonium sulfite method was enzymatically hydrolyzed for medium preparation. The highest intrinsic growth rate of C. pyrenoidosa reached to 0.097h -1 in hydrolysate medium, which was quicker than that in glucose medium. Rising nitrogen concentration could significantly increase protein content and decrease lipid content in biomass, meanwhile fatty acids composition kept stable. The highest protein and lipid content in microalgal biomass reached to 62% and 32% under nitrogen excessive and deficient conditions, respectively. Over 40% of amino acids and fatty acids in biomass belonged to essential amino acids (EAA) and essential fatty acids (EFA), which were qualified for high-value uses. This research revealed the rapid biomass accumulation property of C. pyrenoidosa in straw hydrolysate medium and the effectiveness of nitrogen regulation to biomass composition at heterotrophic condition. Copyright © 2017. Published by Elsevier Ltd.

  19. Stimulatory effect of auxins and cytokinins on carotenes, with differential effects on xanthophylls in the green alga Chlorella pyrenoidosa Chick.

    Directory of Open Access Journals (Sweden)

    Romuald Czerpak

    2014-01-01

    Full Text Available Research concerning the influence of auxins and cytokinins on the content of carotenoids in Chlorella pyrenoidosa (Chlorophyceae has been conducted. The strongest stimulating effect on carotenoids content in Ch. pyrenoidosa biomass was exerted by cytokinins (N-6-benzylaminopurine and N-6-furfurylaminopurine and allantoin, weaker by auxins and their chemical analogues, and the weakest by tryptamine and 2,4-dichlorophenoxyacetic acid compared to the control. Under the influence of cytokinins the content of α- and β-carotene have been stimulated several times stronger than by auxins, and especially 2,4- dichlorophenoxyacetic acid and tryptamine. However, oxygen-rich xanthophylls content was most strongly reduced by cytokinins (60-70% in relation to the control in the 20 day lasting of Ch. pyrenoidosa cultivation, similarly to auxins: 1-naphthaleneacetic acid, indole-3-butyric acid, 2,4- dichlorophenoxyacetic acid.

  20. Highly efficient extraction and lipase-catalyzed transesterification of triglycerides from Chlorella sp. KR-1 for production of biodiesel.

    Science.gov (United States)

    Lee, Ok Kyung; Kim, Young Hyun; Na, Jeong-Geol; Oh, You-Kwan; Lee, Eun Yeol

    2013-11-01

    We developed a method for the highly efficient lipid extraction and lipase-catalyzed transesterification of triglyceride from Chlorella sp. KR-1 using dimethyl carbonate (DMC). Almost all of the total lipids, approximately 38.9% (w/w) of microalgae dry weight, were extracted from the dried microalgae biomass using a DMC and methanol mixture (7:3 (v/v)). The extracted triglycerides were transesterified into fatty acid methyl esters (FAMEs) using Novozyme 435 as the biocatalyst in DMC. Herein, DMC was used as the reaction medium and acyl acceptor. The reaction conditions were optimized and the FAMEs yield was 293.82 mg FAMEs/g biomass in 6 h of reaction time at 60 °C in the presence of 0.2% (v/v) water. Novozyme 435 was reused more than ten times while maintaining relative FAMEs conversion that was greater than 90% of the initial FAMEs conversion. Copyright © 2013 Elsevier Ltd. All rights reserved.