WorldWideScience

Sample records for active butyrate-degrading microorganisms

  1. Population dynamics of biofilm development during start-up of a butyrate-degrading fluidized-bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Zellner, G.; Geveke, M.; Diekmann, H. (Hannover Univ. (Germany). Inst. fuer Mikrobiologie); Conway de Macario, E. (New York State Dept. of Health, Albany, NY (United States). Wadsworth Center for Laboratories and Research)

    1991-12-01

    Population dynamics during start-up of a fluidized-bed reactor with butyrate or butyrate plus acetate as sole substrates as well as biofilm development on the sand substratum were studied microbiologically, immunologically and by scanning electron microscopy. An adapted syntrophic consortium consisting of Syntrophospora sp., Methanothrix soehngenii, Methanosarcina mazei and Methanobrevibacter arboriphilus or Methanogenium sp. achieved high-rate butyrate degradation to methane and carbon dioxide. Desulfovibrio sp., Methanocorpusculum sp., and Methanobacterium sp. were also present in lower numbers. Immunological analysis demonstrated methanogens antigenically related to Methanobrevibacter ruminantium M1, Methanosarcina mazei S6, M. thermophila TM1, Methanobrevibacter arboriphilus AZ and Methanothrix soehngenii Opfikon in the biofilm. Immunological analysis also showed that the organisms isolated from the butyrate-degrading culture used as a source of inoculum were related to M. soehngenii Opfikon, Methanobacterium formicium MF and Methanospirillum hungatei JF1. (orig.).

  2. Effects of Heavy Metals on Activated Sludge Microorganism

    Institute of Scientific and Technical Information of China (English)

    XIE Bing; XI Dan-li; CHEN Ji-hua

    2002-01-01

    The efforts of heavy metals on activated sludge microorganisms are reviewed. Although some heavy metals play an important role in the life of microorganism, heavy metals concentrations above toxic levels inhibit biological processes. Copper, zinc, nickel,cadmium and chromium were mostly studied because of their toxicity and widely used, regardless of single or combination. The microorganism response to these heavy metals varied with species and concentrations of metals,factors such as pH, sludge age, MLSS etc. also affect toxicity on the microorganism. The acclimation could extend the microorganism tolerance of heavy metals. The effects of heavy metals on sludge microorganisms could be described with different models, such as Sigmoidal and Monod equation. The kinetic constants are the useful indexes to estimate the heavy metals inhibition on activated sludge system. Methods to measure the toxicity and effects on microorganism community were also reviewed.

  3. Effects of heat-activated persulfate oxidation on soil microorganisms

    DEFF Research Database (Denmark)

    Tsitonaki, Aikaterini; Smets, Barth F.; Bjerg, Poul Løgstrup

    2008-01-01

    /L). The results emphasize the necessity of using multiple toxicity assays and indigenous cultures in order to realistically assess the potential effects of in situ chemical oxidation on soil microorganisms. A comparison to other studies suggests that the effects of activated persulfate on soil microorganisms...

  4. [Bio-active substances derived from marine microorganisms].

    Science.gov (United States)

    Liu, Quanyong; Hu, Jiangchun; Xue, Delin; Ma, Chengxin; Wang, Shujin

    2002-07-01

    Marine microorganisms, which are taxonomically diverse and genetically special, have powerful potential in producing novel bio-active substances. This article summarized research progress in this respect. The results showed that marine bacteria which are main marine microorganism flora can produce rich kinds of bio-active substances and that even though marine actinomycetes and marine fungi are not as many as marine bacteria in species and quantity, they should be paid no less attention about their bio-active substances. Besides, present research are limited to those marine microorganisms which are easily cultured. One of the future research trends will be focused on bio-active substances derived from non-culturable marine microorganisms.

  5. Detection of extracellular enzymatic activity in microorganisms ...

    African Journals Online (AJOL)

    sunny t

    2015-09-18

    Sep 18, 2015 ... bacterial and 14 fungi strains that presented positive lipolytic activity were obtained by detection through Rhodamine B ... The samples were placed in plastic bags, then ..... The ecology of chitin degradation. In: Marshall KC.

  6. Are thermophilic microorganisms active in cold environments?

    Science.gov (United States)

    Cockell, Charles S.; Cousins, Claire; Wilkinson, Paul T.; Olsson-Francis, Karen; Rozitis, Ben

    2015-07-01

    The mean air temperature of the Icelandic interior is below 10 °C. However, we have previously observed 16S rDNA sequences associated with thermophilic lineages in Icelandic basalts. Measurements of the temperatures of igneous rocks in Iceland showed that solar insolation of these low albedo substrates achieved a peak surface temperature of 44.5 °C. We isolated seven thermophilic Geobacillus species from basalt with optimal growth temperatures of ~65 °C. The minimum growth temperature of these organisms was ~36 °C, suggesting that they could be active in the rock environment. Basalt dissolution rates at 40 °C were increased in the presence of one of the isolates compared to abiotic controls, showing its potential to be involved in active biogeochemistry at environmental temperatures. These data raise the possibility of transient active thermophilic growth in macroclimatically cold rocky environments, implying that the biogeographical distribution of active thermophiles might be greater than previously understood. These data show that temperatures measured or predicted over large scales on a planet are not in themselves adequate to assess niches available to extremophiles at micron scales.

  7. Distribution of Prx-linked hydroperoxide reductase activity among microorganisms.

    Science.gov (United States)

    Takeda, Kouji; Nishiyama, Yoshitaka; Yoda, Koji; Watanabe, Toshihiro; Nimura-Matsune, Kaori; Mura, Kiyoshi; Tokue, Chiyoko; Katoh, Tetzuya; Kawasaki, Shinji; Niimura, Youichi

    2004-01-01

    Peroxiredoxin (Prx) constitutes a large family of enzymes found in microorganisms, animals, and plants, but the detection of the activities of Prx-linked hydroperoxide reductases (peroxiredoxin reductases) in cell extracts, and the purification based on peroxide reductase activity, have only been done in bacteria and Trypanosomatidae. A peroxiredoxin reductase (NADH oxidase) from a bacterium, Amphibacillus, displayed only poor activities in the presence of purified Prx from Saccharomyces or Synechocystis, while it is highly active in the presence of bacterial Prx. These results suggested that an enzyme system different from that in bacteria might exist for the reduction of Prx in yeast and cyanobacteria. Prx-linked hydroperoxide reductase activities were detected in cell extracts of Saccharomyces, Synechocystis, and Chlorella, and the enzyme activities of Saccharomyces and Chlorella were induced under vigorously aerated culture conditions and intensive light exposure conditions, respectively. Partial purification of Prx-linked peroxidase from the induced yeast cells indicated that the Prx-linked peroxidase system consists of two protein components, namely, thioredoxin and thioredoxin reductase. This finding is consistent with the previous report on its purification based on its protein protection activity against oxidation [Chae et al., J. Biol. Chem., 269, 27670-27678 (1994)]. In this study we have confirmed that Prx-linked peroxidase activity are widely distributed, not only in bacteria species and Trypanosomatidae, but also in yeast and photosynthetic microorganisms, and showed reconstitution of the activity from partially purified interspecies components.

  8. DMPD: Signaling pathways activated by microorganisms. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17303405 Signaling pathways activated by microorganisms. Takeuchi O, Akira S. Curr ...Opin Cell Biol. 2007 Apr;19(2):185-91. Epub 2007 Feb 15. (.png) (.svg) (.html) (.csml) Show Signaling pathwa...ys activated by microorganisms. PubmedID 17303405 Title Signaling pathways activated by microorganisms. Auth

  9. Selenite bioremediation potential of indigenous microorganisms from industrial activated sludge.

    Science.gov (United States)

    Garbisu, C; Alkorta, I; Carlson, D E; Leighton, T; Buchanan, B B

    1997-12-01

    Ten bacterial strains were isolated from the activated sludge waste treatment system (BIOX) at the Exxon refinery in Benicia, California. Half of these isolates could be grown in minimal medium. When tested for selenite detoxification capability, these five isolates (members of the genera Bacillus, Pseudomonas, Enterobacter and Aeromonas), were capable of detoxifying selenite with kinetics similar to those of a well characterized Bacillus subtilis strain (168 Trp+) studied previously. The selenite detoxification phenotype of the Exxon isolates was stable to repeated transfer on culture media which did not contain selenium. Microorganisms isolated from the Exxon BIOX reactor were capable of detoxifying selenite. Treatability studies using the whole BIOX microbial community were also carried out to evaluate substrates for their ability to support growth and selenite bioremediation. Under the appropriate conditions, indigenous microbial communities are capable of remediating selenite in situ.

  10. Glyphosate-Degrading Microorganisms from Industrial Activated Sludge

    OpenAIRE

    Balthazor, Terry M.; Hallas, Laurence E.

    1986-01-01

    A plating medium was developed to isolate N-phosphonomethylglycine (glyphosate)-degrading microorganisms, with glyphosate as the sole phosphorus source. Two industrial biosystems treating glyphosate wastes contained elevated microbial counts on the medium. One purified isolate metabolized glyphosate to aminomethylphosphonic acid, mineralizing this accumulating intermediate during log growth. This microorganism has been identified as a Flavobacterium species.

  11. Influence of heavy metals occurrence on respiratory activity of microorganisms in the compost

    National Research Council Canada - National Science Library

    Vítězová, Monika; Vítěz, Tomáš

    .... We focused on comparing the respiratory activity of microorganisms in the compost after composting process in the presence of different concentrations of above mentioned metals and the measured...

  12. Antimicrobial activity of medicinal plants against oral microorganisms.

    Science.gov (United States)

    More, G; Tshikalange, T E; Lall, N; Botha, F; Meyer, J J M

    2008-10-28

    Ethanol extracts of eight plant species used traditionally in South Africa for the treatment of oral diseases were investigated for in vitro antimicrobial activity against oral pathogens namely Actinobacillus actinomycetemcomitans, Actinomyces naeslundii, Actinomyces israelii, Candida albicans, Porphyromonus gingivalis, Privotella intermedia and Streptococcus mutans using the disk diffusion method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of ethanol extracts were determined against these microorganisms using micro dilution. The cytotoxicity and therapeutic index (TI) of selected active extracts were also determined. Out of eight plants, six (Annona senegalensis, Englerophytum magalismontanum, Dicerocarym senecioides, Euclea divinorum, Euclea natalensis, Solanum panduriforme and Parinari curatellifolia) exhibited MIC values ranging from 25.0 mg/ml to 0.8 mg/ml. Gram negative bacteria were found to be more resistant to the plant extracts than Gram positive bacteria, except for Euclea natalensis which inhibited all three Gram negative bacteria tested in this study. All plant extracts showed moderate cytotoxicity on the Vero cell line. The fifty percent inhibitory concentration (IC(50)) of all plants tested range from 92.3 to 285.1 microg/ml.

  13. Humate effect on oil-oxidizing activity of hydrocarbon-oxidizing microorganisms

    Directory of Open Access Journals (Sweden)

    Faizulina Elmira

    2015-10-01

    Full Text Available The effect of humic substances on the activity of hydrocarbon-oxidizing microorganisms is studied. It is shown that sodium humate, aminogumic and sulfogumic acids did not have a negative impact on the growth of oiloxidizing microorganisms. Introduction of sodium humate in the culture medium stimulated the destructive activity of oil-oxidizing microorganisms. At its addition the degree of oil degradation was 72.5-84.5%, and atits absence – 70.7-78.3%.

  14. Antimicrobial activity of different disinfectants against cariogenic microorganisms

    Directory of Open Access Journals (Sweden)

    Esra UZER CELIK

    Full Text Available Abstract The aim of this study was to assess the in vitro antimicrobial effects of chlorhexidine digluconate (CHX, polyhexamethylene biguanide (PHBM, and octenidine dihydrochloride (OCT on cariogenic microorganisms by using their minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC. CHX, PHBM, and OCT were diluted in distilled water to the final test concentrations. Using the in-tube dilution method, Streptococcus mutans, Lactobacillus acidophilus, Lactobacillus rhamnosus, and Actinomyces viscosus were cultivated on blood agar and Mueller–Hinton broth (MHB at 37°C for 48 h. They were read using a spectrophotometer to detect MIC. To determine MBC, samples in the range of the turbidity threshold after 24 h were transferred onto blood agar and evaluated for growth after 24 h. Different MICs and MBCs were observed in all disinfectants against each microorganism. The lowest MIC and MBC against S. mutans (60 mg/L were obtained from PHBM. The lowest values against L. rhamnosus (15 mg/L, 30 mg/L, A. viscosus (30 mg/L, and L. acidophilus (15 mg/L, 30 mg/L were determined by OCT. PHBM and OCT have the potential to be replaced with CHX because they were effective against cariogenic microorganisms.

  15. ANTIBACTERIAL ACTIVITY OF SIMAROUBA GLAUCA LEAF EXTRACTS AGAINST FOOD BORNE SPOILAGE AND PATHOGENIC MICROORGANISMS

    Directory of Open Access Journals (Sweden)

    B. L. Jangale et al.

    2012-02-01

    Full Text Available Crude ethanol and methanol extracts from dried and fresh leaves of Simarouba glauca were tested for their inhibitory activity against two food borne pathogenic microorganisms (Staphylococcus aeureus and Escherichia coli and two food spoilage microorganism (Bacillus subtilis and Pseudomonas aeurogenosa. Screening for antimicrobial activity using well diffusion assay showed the inhibition against entire tested microorganisms. On the other hand the maximum zone of inhibition was recorded of fresh leaves methanol extract (FLM about 11 mm against Escherichia coli and the lowest zone of inhibition was recorded of fresh leaves methanol extract (FLM about 2 mm against Bacillus subtilis. Minimum inhibitory concentrations (MIC’s of extracts were determined using agar dilution method on the same test microorganisms. Fresh leaves methanol (FLM extract gave MIC value ranging from 160 to 10,240 parts per million (ppm. Result showed that the Bacillus subtilis was the most sensitive microorganism.

  16. Inquiry-Based Laboratory Activity to Investigate Physical Growth Requirements of Microorganisms

    Directory of Open Access Journals (Sweden)

    Michelle Furlong

    2014-08-01

    Full Text Available Standard "cookbook" laboratory activities that are used to teach students the optimal physical growth conditions of microorganisms should be modified so that they more effectively foster student's higher order cognitive skills and attract student interest.  This paper describes a laboratory activity that engages students in an inquiry-based approach to studying the physical growth requirements of microorganisms.  In this activity, students design and implement an experiment to obtain pure cultures of specific microorganisms, with distinct growth properties, that are provided to them in a mixed culture.

  17. Rhamnolipids as active protective agents for microorganisms against toxic substances

    Directory of Open Access Journals (Sweden)

    Marta Woźniak

    2012-12-01

    Full Text Available The presence of microbial biosurfactants decreases the toxicity of chlorophenols towards Pseudomonas putida 2A cells. The rhamnolipid-originating micelles selectively entrapped chlorophenol molecules, which resulted in their lower bioavailability to microbial cells. It was observed that the effective concentrations causing 50% growth inhibition increased by 0.5, 0.35 and 0.15 for phenol, 4-chlorophenol and 2.4-dichlorophenol, accordingly. The application of surfactants as protective agents for microorganisms brings about new possibilities of using this phenomenon in bioremediation techniques.

  18. [SCREENING AND SELECTION OF THE SOIL MICROORGANISMS ON THE ABILITY OF "NITROGEN-FIXING ACTIVITY"].

    Science.gov (United States)

    Patyka V Ph; Kyrychenko, O V; Kots, S Ya

    2015-01-01

    The isolates of microorganisms from the rhizosphere of spring barley plants and soil at the use of analytical selection method was isolated. Its isolates on the ability of "nitrogen-fixing activity" was tested. It was shown that isolates of microorganisms had different of the colonies formed and cultural growth on the Eshbi's selective medium as well as the ability to fixing of molecular nitrogen. The different levels of intensity and dynamics of isolates nitrogenase activity in vitro were identified. New isolates of the soil microorganisms complement of the gene pool diazotrophic bacteria. Its isolates are perspectivity for the study as the basis or components of the bacterial fertilizers for the crops.

  19. Assessment of the antimicrobial activity of Casearia sylvestris extract against oral pathogenic microorganisms

    Directory of Open Access Journals (Sweden)

    V. R. SANTOS

    2009-05-01

    Full Text Available An ethanolic extract of leaves from the tree Casearia sylvestris, known as guaçatonga in Brazil, was tested for in vitro activity against oral pathogenic bacteria and fungi. The results showed susceptibility of all the microorganisms tested. This study suggests a potential use of ethanolic extract of C. sylvestris as a novel treatment of oral infectious conditions, such as denture stomatitis, periodontitis and dental caries. Keywords: Casearia sylvestris; guaçatonga; oral microorganisms; antimicrobial activity.

  20. In vitro antibacterial activity of Camellia sinensis extract against cariogenic microorganisms

    OpenAIRE

    Anita, P.; Sivasamy, Shyam; Madan Kumar, P. D.; Balan, I. Nanda; Ethiraj, Sumathi

    2014-01-01

    Context: Dental caries, a ubiquitous multifactorial infectious disease, is primarily caused by microorganisms like Streptococcus mutans and Lactobacillus acidophilus. Use of antimicrobials is an important strategy to curb cariogenic microorganisms. Aim: The aim was to evaluate the in vitro antimicrobial activity of C. sinensis extract on S. mutans and L. acidophilus. Study Setting and Design: Experimental design, in vitro study, lab setting. Materials and Methods: Aqueous, acetone and ethanol...

  1. [Hydrolytic activity of microorganisms of the Dead Sea coastal ecosystems].

    Science.gov (United States)

    Varbanets', L D; Matseliukh, O V; Avdiiuk, K V; Hudzenko, O V; Nidialkova, N A; Romanovs'ka, V O; Tashirev, O B

    2014-01-01

    All strains tested are characterized by proteolytic (caseinolytic) activity, while elastase one was revealed only in two Gracilibacillus strains 6T2 and 7Tl. The activity was high enough (23.1 and 34.7 E/Ml, respectively). These values are at the level of bacterial producers which are described in literature: Bacillus mesentericus 316 M (6 E/Ml), Bacillus thuringiensis IMB B-7324 (50-55 E/Ml). The ability of two strains tested to synthesize enzyme, active against elastine, is important, so far as microbial enzyme may be perspective for using in medicine: elastases are able to dissociation of elastin fibres of connective tissues. These two strains display also fibrinolytic activity, however it was insignificant. Six of eight strains studied manifested alpha-amylase activity (0.01 - 1.173 E/Ml). It was shown that no strains, isolated from the Dead Sea costal ecosystems are able to manifest alpha-L-rhamnosidase activity.

  2. Antimycotic activity of 4-thioisosteres of flavonoids towards yeast and yeast-like microorganisms.

    Science.gov (United States)

    Buzzini, Pietro; Menichetti, Stefano; Pagliuca, Chiara; Viglianisi, Caterina; Branda, Eva; Turchetti, Benedetta

    2008-07-01

    Different substituted methoxy- and hydroxy-4-thioisosteres of flavonoids were prepared and their in vitro antimycotic activity towards yeast (Candida spp., Clavispora spp., Cryptococcus spp., Filobasidiella spp., Issatchenkia spp., Pichia spp., Kluyveromyces spp., Saccharomyces spp. and Yarrowia spp.) and yeast-like (Prototheca spp.) microorganisms was tested. Further insights in the biological activities of these antioxidant, oestrogenic and antimicrobial biomimetic derivatives were obtained.

  3. Identification and quantification of ice nucleation active microorganisms by digital droplet PCR (ddPCR)

    Science.gov (United States)

    Linden, Martin; Pöschl, Ulrich; Fröhlich-Nowoisky, Janine

    2015-04-01

    Several bioaerosol types, including bacteria, fungi, pollen and lichen, have been identified as sources of biological ice nucleators (IN) which induce ice formation already at temperatures as high as -10 °C or above. Accordingly, they potentially contribute widely to environmental ice nucleation in the atmosphere and are of great interest in the study of natural heterogenous ice nucleation processes. Ice nucleation active microorganisms have been found and studied among bacteria (Proteobacteria) and fungi (phyla Basidiomycota and Ascomycota). The mechanisms enabling the microorganisms to ice nucleation are subject to ongoing research. While it has been demonstrated that whole cells can act as ice nucleators in the case of bacteria due to the presence of specific membrane proteins, cell-free ice nucleation active particles seem to be responsible for this phenomenon in fungi and lichen. The identification and quantification of these ice nucleation active microorganisms and their IN in atmospheric samples is crucial to understand their contribution to the pool of atmospheric IN. This is not a trivial task since the respective microorganisms are often prevalent in lowest concentrations and a variety of states, be it viable cells, spores or cell debris from dead cells. Molecular biology provides tools to identify and quantify ice nucleation active microorganisms independent of their state by detecting genetic markers specific for the organism of interest. Those methods are not without their drawbacks in terms of sample material concentration required or reliable standardization. Digital Droplet Polymerase Chain Reaction (ddPCR) was chosen for our demands as a more elegant, quick and specific method in the investigation of ice nucleation active microorganisms in atmospheric samples. The advantages of ddPCR lie in the simultaneous detection and quantification of genetic markers and their original copy numbers in a sample. This is facilitated by the fractionation of the

  4. Removal of airborne microorganisms emitted from a wastewater treatment oxidation ditch by adsorption on activated carbon.

    Science.gov (United States)

    Li, Lin; Gao, Min; Liu, Junxin; Guo, Xuesong

    2011-01-01

    Bioaerosol emissions from wastewater and wastewater treatment processes are a significant subgroup of atmospheric aerosols. Most previous work has focused on the evaluation of their biological risks. In this study, however, the adsorption method was applied to reduce airborne microorganisms generated from a pilot scale wastewater treatment facility with oxidation ditch. Results showed adsorption on granule activated carbon (GAC) was an efficient method for the purification of airborne microorganisms. The GAC itself had a maximum adsorption capacity of 2217 CFU/g for airborne bacteria and 225 CFU/g for fungi with a flow rate of 1.50 m3/hr. Over 85% of airborne bacteria and fungi emitted from the oxidation ditch were adsorbed within 80 hr of continuous operation mode. Most of them had a particle size of 0.65-4.7 microm. Those airborne microorganisms with small particle size were apt to be adsorbed. The SEM/EDAX, BET and Boehm's titration methods were applied to analyse the physicochemical characteristics of the GAC. Relationships between GAC surface characteristics and its adsorption performance demonstrated that porous structure, large surface area, and hydrophobicity rendered GAC an effective absorber of airborne microorganisms. Two regenerate methods, ultraviolet irradiation and high pressure vapor, were compared for the regeneration of used activated carbon. High pressure vapor was an effective technique as it totally destroyed the microorganisms adhered to the activated carbon. Microscopic observation was also carried out to investigate original and used adsorbents.

  5. Screening of flocculant-producing microorganisms and flocculating activity

    Institute of Scientific and Technical Information of China (English)

    CHENG Jin-ping; ZHANG Lan-ying; WANG Wen-hua; YANG Yi-chen; ZHENG Min; JU Su-wei

    2004-01-01

    A strain saccharomycete STSM-1 with high flocculanting activity was isolated from activated sludge with conventional methods. The high production rate and the low cost STSM-1 medium was obtained by selecting different kinds of media, carbon source, nitrogen source and inorganic salt ion. The best flocculant- producing conditions were found by changing medium initial pH, culture temperature and ventilation flow. The best flocculating effect was obtained by changing positive ion types, density and concentration of flocculant.

  6. Biological activity of Terminalia arjuna on Human Pathogenic Microorganisms

    Directory of Open Access Journals (Sweden)

    Tariq Javed

    2016-01-01

    Full Text Available World’s population relies chiefly on traditional medicinal plants, using their extracts or active constituents. Terminalia arjuna of family Combretaceae reported to be effective as aphrodisiac, expectorant, tonic, styptic, antidysenteric, sweet, acrid, purgative, laxative, astringent, diuretic, astringent, cirrhosis, cardioprotective and cancer treatment.   In present study, antibacterial, antifungal, brine shrimp lethality and phytotoxic effect of Terminalia arjuna was performed. Our results showed that methanolic extract of Terminalia arjuna leaves has moderate antifungal effect against Microsporm canis and fruit extract possess good antibacterial activity against Staphylococus aureus  and  Preudomonas aeroginosa. Moreover, Dichloromethane extract of Terminalia arjuna bark and fruit posses moderate phytotoxic activity

  7. Studying the Activities of Microorganisms in Soil Using Slides.

    Science.gov (United States)

    Cullimore, D. Roy; Pipe, Annette E.

    1980-01-01

    Two implanted slide techniques are described by which activity of proteolylic bacteria and the growth of algae in the soil can be readily studied by school students using simple apparatus and methods. Variations are suggested for studying the effects of agricultural practices and environmental conditions on the soil bacteria and algae. (Author/DS)

  8. Effects of deep tillage and straw returning on soil microorganism and enzyme activities.

    Science.gov (United States)

    Ji, Baoyi; Hu, Hao; Zhao, Yali; Mu, Xinyuan; Liu, Kui; Li, Chaohai

    2014-01-01

    Two field experiments were conducted for two years with the aim of studying the effects of deep tillage and straw returning on soil microorganism and enzyme activity in clay and loam soil. Three treatments, (1) conventional tillage (CT), shallow tillage and straw returning; (2) deep tillage (DT), deep tillage and straw returning; and (3) deep tillage with no straw returning (DNT), were carried out in clay and loam soil. The results showed that deep tillage and straw returning increased the abundance of soil microorganism and most enzyme activities. Deep tillage was more effective for increasing enzyme activities in clay, while straw returning was more effective in loam. Soil microorganism abundance and most enzyme activities decreased with the increase of soil depth. Deep tillage mainly affected soil enzyme activities in loam at the soil depth of 20-30 cm and in clay at the depth of 0-40 cm. Straw returning mainly affected soil microorganism and enzyme activities at the depths of 0-30 cm and 0-40 cm, respectively.

  9. [Antimicrobial spectrum of dalbavancin. Mechanism of action and in vitro activity against Gram-positive microorganisms].

    Science.gov (United States)

    Cercenado, Emilia

    2017-01-01

    Because of the increase in bacterial resistance, there is a need for new antimicrobial agents. Dalbavancin is a semisynthetic glycopeptide that inhibits the late stages of bacterial cell wall synthesis in the same way as vancomycin, but in addition, its lipophilic side chain anchors dalbavancin to the cellular membrane and allows enhanced activity compared with that of vancomycin. Dalbavancin possesses a broad spectrum of in vitro activity against Gram-positive aerobic and anaerobic microorganisms, being 4-8 times more potent than vancomycin. The spectrum of dalbavancin includes staphylococci, enterococci, streptococci, and anaerobic Gram-positive cocci and bacilli. It is active against different species of multiresistant microorganisms, including methicillin-resistant Staphylococcus aureus and penicillin-resistant viridans streptococci and Streptococcus pneumoniae. Although it shows in vitro activity against Enterococcus spp., it is inactive against isolates expressing the VanA phenotype of vancomycin resistance. It also shows slow bactericidal activity against S. aureus, coagulase-negative staphylococci, and Streptococcus pyogenes. In general, the MIC90 (minimum inhibitory concentration 90%) against the majority of the microorganisms is 0.06mg/L and, more than 98% of the isolates that have been tested are inhibited at concentrations of ≤ 0.12mg/L. Dalbavancin is an interesting addition to the therapeutic armamentarium for the treatment of infections caused by Gram-positive microorganisms, including multidrug-resistant isolates.

  10. NREL Explains the Higher Cellulolytic Activity of a Vital Microorganism

    Energy Technology Data Exchange (ETDEWEB)

    2016-06-01

    The discovery of a new mode of action by C. thermocellum to convert biomass to biofuels is significant because the bacterium is already recognized as one of the most effective in the biosphere. Researchers found that, in addition to using common cellulase degradation mechanisms attached to cells, C. thermocellum also uses a new category of cell-free scaffolded enzymes. The new discovery will influence the strategies used to improve the cellulolytic activity of biomass degrading microbes going forward. Better understanding of this bacterium could lead to cheaper production of ethanol and drop-in fuels. Also, this discovery demonstrates that nature's biomass conversion behaviors are not fully understood and remain as opportunities for future microbial/enzyme engineering efforts.

  11. Identification of selected microorganisms from activated sludge capable of benzothiazole and benzotriazole transformation.

    Science.gov (United States)

    Kowalska, Katarzyna; Felis, Ewa

    2015-01-01

    Benzothiazole (BT) and benzotriazole (BTA) are present in the environment - especially in urban and industrial areas, usually as anthropogenic micropollutants. BT and BTA have been found in the municipal and industrial wastewater, rivers, soil, groundwater, sediments and sludge. The origins of those substances' presence in the environment are various industry branches (food, chemical, metallurgical, electrical), households and surface runoff from industrial areas. Increasingly strict regulations on water quality and the fact that the discussed compounds are poorly biodegradable, make them a serious problem in the environment. Considering this, it is important to look for environmentally friendly and socially acceptable ways to remove BT and BTA. The aim of this study was to identify microorganisms capable of BT and BTA transformation or/and degradation in aquatic environment. Selected microorganisms were isolated from activated sludge. The identification of microorganisms capable of BT and BTA removal was possible using molecular biology techniques (PCR, DNA sequencing). Among isolated microorganisms of activated sludge are bacteria potentially capable of BT and BTA biotransformation and/or removal. The most common bacteria capable of BT and BTA transformation were Rhodococcus sp., Enterobacter sp., Arthrobacter sp. They can grow in a medium with BT and BTA as the only carbon source. Microorganisms previously adapted to the presence of the studied substances at a concentration of 10 mg/l, showed a greater rate of growth of colonies on media than microorganisms unconditioned to the presence of such compounds. Results of the biodegradation test suggest that BT was degraded to a greater extent than BTA, 98-100% and 11-19%, respectively.

  12. Isolation of microorganisms with chinitase, protease and keratinase activities from petroleum contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Cervantes-Gonzalez, E.; Rojas-Avelizapa, L.; Cruz-Camarillo, R. [1 Escuela Nacional de Ciencias Biologicas Departamento de Microbiologia, Laboratorio de Enzimas Microbianas, Mexico City (Mexico); Rojas-Avelizapa, N.G. [Programa de Biotecnologia del Petroleo, Instituto Mexicano del Petroleo, Mexico City (Mexico)

    2005-07-01

    The most important part in one process of bio-remediation are the microorganisms with the capacities to degrade target compounds, this research is based to find microorganisms hydrocarbon-clastic with enzyme activities to degrade chicken feather (keratinolytic activity) which is also a contaminant and has been used such as sorbent of petroleum and can be composted after the oil spill cleanup is complete, the isolation was also to degrade shrimp waste (chitinolitic and proteolitic activity) which is waste material that can be used in compost or such as sorbent of petroleum too. We isolated mesofilic aerobic microorganisms from mexican soils located in Tabasco, Mexico. We achieved to isolate 105 bacteria from 10 soils, 90% was Bacillus Gram (-) which are common in soils and all were hydrocarbon-clastic, only 7 different bacteria had protease and chitinase activity and 12 bacteria had keratinase activity. So we found three fungi and one actinomycete with capacity to degrade hydrocarbons and presence of chitinase activity. The results of growth and enzyme activities in liquid culture showed that the protease activity was produced between 18 and 48 h in almost all bacteria, the chitinase activity started at 12 h but was slight , only 0.5 U/ml, and the keratinase activity was produced after 6 h of incubation and there were correlation between logarithmic phase of growth and enzymes production. With this study we showed the existence of some enzyme activities from microorganisms that live in hostile habitats. This, can be useful in bio-treatment soils by the possible use of this type of residues that can be bio-degraded at the same time that the hydrocarbons increasing the speed or the quality of cleanup in soils. (authors)

  13. Antimicrobial activity of Zhumeria majdae Rech.F.& Wendelbo essential oil against different microorganisms from Iran

    Directory of Open Access Journals (Sweden)

    Mahboubi Mohaddese

    2009-01-01

    Full Text Available The monotypic Zhumeria majdae Rech.F. & Wendelbo was recently described as the first member of new genus Zhumeria (Lamiaceae. In Iranian folk medicine, the leaves of plant were used for antiseptic properties. The antimicrobial activity of Zhumeria majdae essential oil was evaluated against a panel of microorganisms including gram negative, gram positive, yeast and fungi using disc diffusion method and micro broth dilution assay. Generally, the oil exhibited similar levels of antimicrobial activity against different microorganisms but some microorganisms appear to be more sensitive. In particular, oil showed significant power against Klebsiella pneumoniae followed by Staphylococcus aureus, Staphylococcus saprophyticus, Vibrio cholera, Staphylococcus epidermidis and Bacillus cereus. Klebsiella pneumoniae with MIC and MBC values 0.5, 1 μl ml -1 was the most sensitive among the tested microorganisms. The oil showed bactericidal activity against Staphylococcus aureus, Bacillus cereus, Escherichia coli and Enterobacter aerugenes. The oil showed inhibitory effect against Bacillus subtilis, Proteus vulgaris, Aspergillus flavus and Aspergillus niger. Salmonella typhi and Pseudomonas aeruginosa among Gram negative bacteria and Bacillus subtilis among Gram positive ones and Aspergillus niger among fungi and yeast were the most resistant to the essential oil.

  14. Removal of airborne microorganisms emitted from a wastewater treatment oxidation ditch by adsorption on activated carbon

    Institute of Scientific and Technical Information of China (English)

    Lin Li; Min Gao; Junxin Liu; Xuesong Guo

    2011-01-01

    Bioaerosol emissions from wastewater and wastewater treatment processes are a significant subgroup of atmospheric aerosols.Most previous work has focused on the evaluation of their biological risks.In this study, however, the adsorption method was applied to reduce airborne microorganisms generated from a pilot scale wastewater treatment facility with oxidation ditch.Results showed adsorption on granule activated carbon (GAC) was an efficient method for the purification of airborne microorganisms.The GAC itself had a maximum adsorption capacity of 2217 CFU/g for airborne bacteria and 225 CFU/g for fungi with a flow rate of 1.50 m3/hr.Over 85%of airborne bacteria and fungi emitted from thc oxidation ditch were adsorbed within 80 hr of continuous operation mode.Most of them had a particle size of 0.65-4.7 μm.Those airborne microorganisms with small particle size were apt to be adsorbed.The SEM/EDAX,BET and Boehm's titration methods were applied to analyse the physicochemical characteristics of the GAC.Relationships between GAC surface characteristics and its adsorption performance demonstrated that porous structure, large surface area, and hydrophobicity rendered GAC an effective absorber of airborne microorganisms.Two regenerate methods, ultraviolet irradiation and high pressure vapor, were compared for the regeneration of used activated carbon.High pressure vapor was an effective technique as it totally destroyed the microorganisms adhered to the activated carbon.Microscopic observation was also carried out to investigate original and used adsorbents.

  15. Distribution of the indigenous microorganisms and mechanisms of their orientational activation in Daqing Oilfield

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The distribution of indigenous microorganisms was surveyed in Block 1 of Daqing Oilfield. Based on this survey,the indigenous microorganisms in the formation water were activated with different activator systems at the simulated stratum ecological environment. The changes of the number of bacteria of various physiological groups were determined during the process of activation. Also changes of pH value and composition of gas productions were analyzed at the end of culturing. The results showed that the selected block formation water contained a great number of saprophytic bacteria,hydrocarbon-oxidizing bacteria,fermentative bacteria,methane-producing bacteria and sulfate-reducing bacteria. Under the conditions that the growth of sulfate-reducing bacteria was controlled the block had the potential to enhance oil recovery by activating beneficial bacteria. The growth of sulfate-reducing bacteria can be inhibited through the activation of nitrate-reducing bacteria. The number of nitratereducing bacteria reached 106―107 cells/mL,but sulfate-reducing bacteria reached only 0―45 cells/mL in A system. Methane-producing bacteria can be activated by C,D activators. The relative content of biological methane in the light hydrocarbon gas reached 80% in C,D systems. B activator was conducive to the propagation of acid-producing bacteria,so that the pH value of the culture medium decreased from 7.5 to around 5.0. Hydrocarbon-oxidizing bacteria can be activated by various activator systems. There was low molecular light hydrocarbon in gas production according to the analysis of gas chromatograph. According to the content of methane and the number of methane-producing bacteria,methane only can be generated through activating methane-producing bacteria. By choosing different activator systems,various populations of indigenous microorganisms can be activated accordingly.

  16. Environmental parameters altered by climate change affect the activity of soil microorganisms involved in bioremediation.

    Science.gov (United States)

    Alkorta, Itziar; Epelde, Lur; Garbisu, Carlos

    2017-09-15

    Bioremediation, based on the use of microorganisms to break down pollutants, can be very effective at reducing soil pollution. But the climate change we are now experiencing is bound to have an impact on bioremediation performance, since the activity and degrading abilities of soil microorganisms are dependent on a series of environmental parameters which are themselves being altered by climate change, such as soil temperature, moisture, amount of root exudates, etc. Many climate-induced effects on soil microorganisms occur indirectly through changes in plant growth and physiology derived from increased atmospheric CO2 concentrations and temperatures, the alteration of precipitation patterns, etc., with a concomitant effect on rhizoremediation performance (i.e. the plant-assisted microbial degradation of pollutants in the rhizosphere). But these effects are extremely complex and mediated by processes such as acclimation and adaptation. Besides, soil microorganisms form complex networks of interactions with a myriad of organisms from many taxonomic groups which will also be affected by climate change, further complicating data interpretation. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. [Effects of stereoscopic cultivation on soil microorganism, enzyme activity and the agronomic characters of Panax notoginseng].

    Science.gov (United States)

    Liao, Pei-ran; Cui, Xiu-ming; Lan, Lei; Chen, Wei-dong; Wang, Cheng-xiao; Yang, Xiao-yan; Liu, Da-hui; Yang, Ye

    2015-08-01

    Compartments of soil microorganism and enzymes between stereoscopic cultivation (three storeys) and field cultivation (CK) of Panax notoginseng were carried out, and the effects on P. notoginseng agronomic characters were also studied. Results show that concentration of soil microorganism of stereoscopic cultivation was lower than field cultivation; the activity of soil urea enzyme, saccharase and neutral phosphatase increased from lower storey to upper storey; the activity of soil urea enzyme and saccharase of lower and upper storeys were significantly lower than CK; agronomic characters of stereoscopic cultivated P. notoginsengin were inferior to field cultivation, the middle storey with the best agronomic characters among the three storeys. The correlation analysis showed that fungi, actinomycetes and neutral phosphatase were significantly correlated with P. notoginseng agronomic characters; concentration of soil fungi and bacteria were significantly correlated with the soil relative water content; actinomycete and neutral phosphatase were significantly correlated with soil pH and relative water content, respectively; the activities of soil urea enzyme and saccharase were significantly correlated with the soil daily maximum temperature difference. Inconclusion, The current research shows that the imbalance of soil microorganism and the acutely changing of soil enzyme activity were the main reasons that caused the agronomic characters of stereoscopic cultivated P. notoginseng were worse than field cultivation. Thus improves the concentration of soil microorganism and enzyme activity near to field soil by improving the structure of stereoscopic cultivation is very important. And it was the direction which we are endeavoring that built better soil ecological environment for P. notoginseng of stereoscopic cultivation.

  18. [Effects of tillage and straw returning on microorganism quantity, enzyme activities in soils and grain yield].

    Science.gov (United States)

    Zhao, Ya-li; Guo, Hai-bin; Xue, Zhi-wei; Mu, Xin-yuan; Li, Chao-hai

    2015-06-01

    A two-year field study with split plot design was conducted to investigate the effects of different soil tillage (conventional tillage, CT; deep tillage, DT; subsoil tillage, ST) and straw returning (all straw retention, AS; no straw returning, NS) on microorganism quantity, enzyme activities in soil and grain yield. The results showed that, deep or subsoil tillage and straw returning not only reduced the soil bulk density and promoted the content of organic carbon in soil, but increased the soil microbial quantity, soil enzyme activities and grain yield. Furthermore, such influences in maize season were greater than that in wheat season. Compared with CT+NS, DT+AS and ST+AS decreased the soil bulk density at 20-30 cm depth by 8.5% and 6.6%, increased the content of soil organic carbon by 14.8% and 12.4%, increased the microorganism quantity by 45.9% and 33.9%, increased the soil enzyme activities by 34.1% and 25.5%, increased the grain yield by 18.0% and 19.3%, respectively. No significant difference was observed between DT+AS and ST+AS. We concluded that retaining crop residue and deep or subsoil tillage improved soil microorganism quantity, enzyme activities and crop yield.

  19. Influence of heavy metals occurrence on respiratory activity of microorganisms in the compost

    Directory of Open Access Journals (Sweden)

    Monika Vítězová

    2012-01-01

    Full Text Available This work deals with the influence of selected heavy metals, copper, nickel, cobalt, zinc and cadmium on respiratory activity of microorganisms during the composting process. We focused on comparing the respiratory activity of microorganisms in the compost after composting process in the presence of different concentrations of above mentioned metals and the measured results were confronted with the valid Czech standard for industrial composts. The results show that the high inhibitory effect at low concentrations, about 1 mg/dm3, has cobalt, for which the limit concentration is no set by Czech standard. Other heavy metals exhibit an inhibitory effect at concentrations higher than maximum allowable concentration, which is set in Czech standard for compost class I and II, with regard to their application to agricultural land.

  20. Peptidomic analysis reveals proteolytic activity of kefir microorganisms on bovine milk proteins.

    Science.gov (United States)

    Dallas, David C; Citerne, Florine; Tian, Tian; Silva, Vitor L M; Kalanetra, Karen M; Frese, Steven A; Robinson, Randall C; Mills, David A; Barile, Daniela

    2016-04-15

    The microorganisms that make up kefir grains are well known for lactose fermentation, but the extent to which they hydrolyze and consume milk proteins remains poorly understood. Peptidomics technologies were used to examine the proteolytic activity of kefir grains on bovine milk proteins. Gel electrophoresis revealed substantial digestion of milk proteins by kefir grains, with mass spectrometric analysis showing the release of 609 protein fragments and alteration of the abundance of >1500 peptides that derived from 27 milk proteins. Kefir contained 25 peptides identified from the literature as having biological activity, including those with antihypertensive, antimicrobial, immunomodulatory, opioid and anti-oxidative functions. 16S rRNA and shotgun metagenomic sequencing identified the principle taxa in the culture as Lactobacillus species. The model kefir sample contained thousands of protein fragments released in part by kefir microorganisms and in part by native milk proteases. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Changes at an activated sludge sewage treatment plant alter the numbers of airborne aerobic microorganisms.

    Science.gov (United States)

    Fernando, Nadeesha L; Fedorak, Phillip M

    2005-11-01

    In 1976, the activated sludge sewage treatment plant in Edmonton, Canada, was surveyed to determine the numbers of culturable airborne microorganisms. Many changes have been made at the plant to reduce odors and improve treatment efficiency, so in 2004 another survey was done to determine if these changes had reduced the bioaerosols. Covering the grit tanks and primary settling tanks greatly reduced the numbers of airborne microbes. Changing the design and operation of indoor automated sampling taps and sinks also reduced bioaerosols. The secondary was expanded and converted from a conventional activated sludge process using coarse bubble aeration to a biological nutrient removal system using fine bubble aeration. Although the surface area of the secondary more than doubled, the average number of airborne microorganisms in this part of the plant in 2004 was about 1% of that in 1976.

  2. Antimicrobial activity of Arctium lappa constituents against microorganisms commonly found in endodontic infections.

    Science.gov (United States)

    Pereira, Juliana Vianna; Bergamo, Débora Cristina Baldoqui; Pereira, José Odair; França, Suzelei de Castro; Pietro, Rosemeire Cristina Linhares Rodrigues; Silva-Sousa, Yara T Corrêa

    2005-01-01

    This study evaluated in vitro the antimicrobial activity of rough extracts from leaves of Arctium lappa and their phases. The following microorganisms, commonly found in the oral cavity, specifically in endodontic infections, were used: Enterococcus faecalis, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis and Candida albicans. The agar-diffusion method allowed detection of the hexanic phase as an inhibitor of microbial growth. Bioautographic assays identified antimicrobial substances in the extract. The results showed the existence, in the rough hexanic phase and in its fractions, of constituents that have retention factors (Rf) in three distinct zones, thereby suggesting the presence of active constituents with chemical structures of different polarities that exhibited specificity against the target microorganisms. It may be concluded that the Arctium lappa constituents exhibited a great microbial inhibition potential against the tested endodontic pathogens.

  3. In vitro evaluation of marine-microorganism extracts for anti-viral activity

    OpenAIRE

    Yasuhara-Bell Jarred; Yang Yongbo; Barlow Russell; Trapido-Rosenthal Hank; Lu Yuanan

    2010-01-01

    Abstract Viral-induced infectious diseases represent a major health threat and their control remains an unachieved goal, due in part to the limited availability of effective anti-viral drugs and measures. The use of natural products in drug manufacturing is an ancient and well-established practice. Marine organisms are known producers of pharmacological and anti-viral agents. In this study, a total of 20 extracts from marine microorganisms were evaluated for their antiviral activity. These ex...

  4. Isolation of Soil Microorganisms Having Antibacterial Activity and Antimigratory Effects on Sphingosylphosphorylcholine-induced Migration of PANC-1 Cells

    OpenAIRE

    Kang, Jun Hee; Park, Mi Kyung; Kim, Hyun Ji; Kim, Yuri; Lee, Chang Hoon

    2011-01-01

    To obtain soil microorganisms producing antimigratory activity which is important in controlling the metastasis of cancer cells, more than three hundreds of soil microbes were isolated from sixteen soil sources including Namsan mountain and designated as DGU1001-10338. At first, their antibiotic activities were examined by paper-disc method. More than 40 soil microbes produced compounds with antibiotic activity. Then, antimigratory activities of selected soil microorganisms were examined in a...

  5. Isolation of Soil Microorganisms Having Antibacterial Activity and Antimigratory Effects on Sphingosylphosphorylcholine-induced Migration of PANC-1 Cells.

    Science.gov (United States)

    Kang, Jun Hee; Park, Mi Kyung; Kim, Hyun Ji; Kim, Yuri; Lee, Chang Hoon

    2011-12-01

    To obtain soil microorganisms producing antimigratory activity which is important in controlling the metastasis of cancer cells, more than three hundreds of soil microbes were isolated from sixteen soil sources including Namsan mountain and designated as DGU1001-10338. At first, their antibiotic activities were examined by paper-disc method. More than 40 soil microbes produced compounds with antibiotic activity. Then, antimigratory activities of selected soil microorganisms were examined in a sphingosylphosphorylcholine-induced migration assay in PANC-1 cells. Six of 42 soil microorganisms having antibacterial activity also had more than 45% inhibitory activity on migration of PANC-1 cells. These results suggested that selected soil microorganisms were a useful starting point to find compounds for controlling metastasis of cancer cells.

  6. Essential oil from Chenopodium ambrosioides and main components: activity against Leishmania, their mitochondria and other microorganisms.

    Science.gov (United States)

    Monzote, Lianet; García, Marley; Pastor, Jacinta; Gil, Lizette; Scull, Ramón; Maes, Louis; Cos, Paul; Gille, Lars

    2014-01-01

    Chenopodium ambrosioides is an aromatic herb used by native people to treat parasitic diseases. The aim of this work is to compare the in vitro anti-leishmanial activity of the essential oil (EO) from C. ambrosioides and its major components (ascaridole, carvacrol and caryophyllene oxide) and study their mechanism of action and activity against a panel of microorganism. Antileishmanial activity and cytotoxicity of the EO and major components was study. In addition, experiments to elucidate the mechanism of action were perform and activities against other microorganisms (bacteria, fungi and protozoa) were evaluate. All products were active against promastigote and amastigote forms of Leishmania. Ascaridole exhibited the better antileishmanial activity and the EO the highest selectivity index. The exploration of the mechanism suggests that the products cause a breakdown of mitochondrial membrane potential and a modification of redox indexes. Only EO showed antiprotozoal effect against Plasmodium falciparum and Trypanosoma brucei; while no activity against bacteria and fungi was observed. Our results demonstrate the potentialities of EO in cellular and molecular system, which could be consider in future studies to develop new antileishmanial drugs with a wide anti-parasitic spectrum. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Optimized dispersion of ZnO nanoparticles and antimicrobial activity against foodborne pathogens and spoilage microorganisms

    Science.gov (United States)

    Espitia, Paula Judith Perez; Soares, Nilda de Fátima Ferreira; Teófilo, Reinaldo F.; Vitor, Débora M.; Coimbra, Jane Sélia dos Reis; de Andrade, Nélio José; de Sousa, Frederico B.; Sinisterra, Rubén D.; Medeiros, Eber Antonio Alves

    2013-01-01

    Single primary nanoparticles of zinc oxide (nanoZnO) tend to form particle collectives, resulting in loss of antimicrobial activity. This work studied the effects of probe sonication conditions: power, time, and the presence of a dispersing agent (Na4P2O7), on the size of nanoZnO particles. NanoZnO dispersion was optimized by response surface methodology (RSM) and characterized by the zeta potential (ZP) technique. NanoZnO antimicrobial activity was investigated at different concentrations (1, 5, and 10 % w/w) against four foodborne pathogens and four spoilage microorganisms. The presence of the dispersing agent had a significant effect on the size of dispersed nanoZnO. Minimum size after sonication was 238 nm. An optimal dispersion condition was achieved at 200 W for 45 min of sonication in the presence of the dispersing agent. ZP analysis indicated that the ZnO nanoparticle surface charge was altered by the addition of the dispersing agent and changes in pH. At tested concentrations and optimal dispersion, nanoZnO had no antimicrobial activity against Pseudomonas aeruginosa, Lactobacillus plantarum, and Listeria monocytogenes. However, it did have antimicrobial activity against Escherichia coli, Salmonella choleraesuis, Staphylococcus aureus, Saccharomyces cerevisiae, and Aspergillus niger. Based on the exhibited antimicrobial activity of optimized nanoZnO against some foodborne pathogens and spoilage microorganisms, nanoZnO is a promising antimicrobial for food preservation with potential application for incorporation in polymers intended as food-contact surfaces.

  8. Immune signaling pathways activated in response to different pathogenic micro-organisms in Bombyx mori.

    Science.gov (United States)

    Liu, Wei; Liu, Jiabin; Lu, Yahong; Gong, Yongchang; Zhu, Min; Chen, Fei; Liang, Zi; Zhu, Liyuan; Kuang, Sulan; Hu, Xiaolong; Cao, Guangli; Xue, Renyu; Gong, Chengliang

    2015-06-01

    The JAK/STAT, Toll, Imd, and RNAi pathways are the major signaling pathways associated with insect innate immunity. To explore the different immune signaling pathways triggered in response to pathogenic micro-organism infections in the silkworm, Bombyx mori, the expression levels of the signal transducer and activator of transcription (BmSTAT), spatzle-1 (Bmspz-1), peptidoglycan-recognition protein LB (BmPGRP-LB), peptidoglycan-recognition protein LE (BmPGRP-LE), argonaute 2 (Bmago2), and dicer-2 (Bmdcr2) genes after challenge with Escherichia coli (E. coli), Serratiamarcescens (Sm), Bacillus bombyseptieus (Bab), Beauveriabassiana (Beb), nucleopolyhedrovirus (BmNPV), cypovirus (BmCPV), bidensovirus (BmBDV), or Nosemabombycis (Nb) were determined using real-time PCR. We found that the JAK/STAT pathway could be activated by challenge with BmNPV and BmBDV, the Toll pathway could be most robustly induced by challenge with Beb, the Imd pathway was mainly activated in response to infection by E. coli and Sm, and the RNAi pathway was not activated by viral infection, but could be triggered by some bacterial infections. These findings yield insights into the immune signaling pathways activated in response to different pathogenic micro-organisms in the silkworm.

  9. Antimicrobial activity of methanolic extracts of selected marine macroalgae against some pathogenic microorganisms

    Directory of Open Access Journals (Sweden)

    Ehab Omer Abdalla

    2016-05-01

    Full Text Available Objective: To evaluate the antimicrobial activity of methanolic extracts of six marine macroalgae belonging to green algae (Chlorophyceae, brown algae (Phaeophyceae and the red algae (Rhodophyceae collected from the intertidal area of the Sudanese Red Sea coast near Port Sudan. Methods: Methanol was used for extracting the active principles of the algae and the disc diffusion method was performed to examine the activity and the minimum inhibitory concentration of the samples against four pathogenic bacteria and two fungi. Results: All tested algal extracts exhibited considerable bioactivity and inhibited the growth of all pathogenic microorganisms under investigation. The green alga Caulerpa racemosa produced the maximum inhibition zone (21 mm against Candida albicans while the red alga Laurencia papillosa showed low antimicrobial activity with the minimum inhibition zone of 10 mm against Pseudomonas aeruginosa. The tested algal extracts did not show any special antimicrobial influence on the selected microorganisms when they were considered as Grampositive and Gram-negative bacteria and fungi but the most efficient methanolic extracts in inhibiting microbial growth were those of green macroalgae followed by the brown and the red macroalgae respectively. Conclusions: The study demonstrated that the tested marine macroalgae from Sudanese Red Sea coast may represent a potential and alternative source for secondary metabolites with antimicrobial activity.

  10. Antimicrobial activity of methanolic extracts of selected marine macroalgae against some pathogenic microorganisms

    Institute of Scientific and Technical Information of China (English)

    Ehab Omer Abdalla; Mohammed Taha Abdalla Shigidi; Hassan Elsubki Khalid; Nahid Abdel Rahim Osman

    2016-01-01

    Objective:To evaluate the antimicrobial activity of methanolic extracts of six marine macroalgae belonging to green algae (Chlorophyceae), brown algae (Phaeophyceae) and the red algae (Rhodophyceae) collected from the intertidal area of the Sudanese Red Sea coast near Port Sudan. Methods:Methanol was used for extracting the active principles of the algae and the disc diffusion method was performed to examine the activity and the minimum inhibitory concentration of the samples against four pathogenic bacteria and two fungi. Results: All tested algal extracts exhibited considerable bioactivity and inhibited the growth of all pathogenic microorganisms under investigation. The green alga Caulerpa racemosa produced the maximum inhibition zone (21 mm) againstCandida albicans while the red alga Laurencia papillosa showed low antimicrobial activity with the minimum inhibition zone of 10 mm againstPseudomonas aeruginosa. The tested algal extracts did not show any special antimicrobial influence on the selected microorganisms when they were considered as Gram-positive and Gram-negative bacteria and fungi but the most efficient methanolic extracts in inhibiting microbial growth were those of green macroalgae followed by the brown and the red macroalgae respectively. Conclusions: The study demonstrated that the tested marine macroalgae from Sudanese Red Sea coast may represent a potential and alternative source for secondary metabolites with antimicrobial activity.

  11. Evaluation of antimicrobial activity of alkaloids of Terminalia chebula Retz. against some multidrug-resistant microorganisms

    Directory of Open Access Journals (Sweden)

    Geeta Singh

    2012-01-01

    activity against nine bacteria (Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Staphylococcus aureus, Bacillus subtilis, Raoultella planticola, Enterobacter aerogens, Agrobacterium tumefaciens, and Klebsiella pneumoniae and two fungi (Aspergillus flavus and Aspergillus niger and one yeast (Candida albicans. Minimum inhibitory concentration, Minimum bactericidal/fungicidal concentration, and Total activity of the extracts, against each sensitive test pathogen, were also evaluated. Alkaloids from all plant parts showed good antimicrobial activity against almost all the test microorganisms except A. niger, against which, none of the tested extracts showed activity. The largest zone of inhibition (IZ 20.75 mm was observed against P. aeruginosa. The total activity of the leaf alkaloid was found to be the same and the highest (256.41ml/g was against E. aerogens and A. tumefaciens.

  12. Cometabolic degradation of organic wastewater micropollutants by activated sludge and sludge-inherent microorganisms.

    Science.gov (United States)

    Fischer, Klaus; Majewsky, Marius

    2014-08-01

    Municipal wastewaters contain a multitude of organic trace pollutants. Often, their biodegradability by activated sludge microorganisms is decisive for their elimination during wastewater treatment. Since the amounts of micropollutants seem too low to serve as growth substrate, cometabolism is supposed to be the dominating biodegradation process. Nevertheless, as many biodegradation studies were performed without the intention to discriminate between metabolic and cometabolic processes, the specific contribution of the latter to substance transformations is often not clarified. This minireview summarizes current knowledge about the cometabolic degradation of organic trace pollutants by activated sludge and sludge-inherent microorganisms. Due to their relevance for communal wastewater contamination, the focus is laid on pharmaceuticals, personal care products, antibiotics, estrogens, and nonylphenols. Wherever possible, reference is made to the molecular process level, i.e., cometabolic pathways, involved enzymes, and formed transformation products. Particular cometabolic capabilities of different activated sludge consortia and various microbial species are highlighted. Process conditions favoring cometabolic activities are emphasized. Finally, knowledge gaps are identified, and research perspectives are outlined.

  13. In vitro activity of Aloe vera inner gel against microorganisms grown in planktonic and sessile phases.

    Science.gov (United States)

    Cataldi, V; Di Bartolomeo, S; Di Campli, E; Nostro, A; Cellini, L; Di Giulio, M

    2015-12-01

    The failure of traditional antimicrobial treatments is becoming a worldwide problem. The use of Aloe vera is of particular interest for its role as curative agent and its efficacy in complementary therapies for a variety of illnesses. This study evaluated the antimicrobial activity of A. vera inner gel against a panel of microorganisms, Gram-positive and -negative bacteria, and Candida albicans. In addition to A. vera inner gel being used in the treatment of peptic ulcers, in dermatological treatments, and wound healing, it was also tested on the sessile phase of clinical Helicobacter pylori strains (including multi-drug-resistant strains) and on planktonic and sessile phase of Staphylococcus aureus/Pseudomonas aeruginosa clinical isolates from venous leg ulcers.A. vera inner gel expresses its prevalent activity against Gram-negative bacteria and C. albicans in respect to Gram-positive bacteria. The results of the A. vera antibiofilm activity showed a decrease of the produced biomass in a concentration-dependent-way, in each analyzed microorganism. The data obtained show that A. vera inner gel has both an antimicrobial and antibiofilm activity suggesting its potential use for the treatment of microbial infections, in particular for H. pylori gastric infection, especially in case of multi-drug-resistance, as well as for an effective wound dressing.

  14. Antimicrobial activity of potassium hydroxide and lauric acid against microorganisms associated with poultry processing.

    Science.gov (United States)

    Hinton, Arthur; Ingram, Kimberly D

    2006-07-01

    The antimicrobial activity of solutions of potassium hydroxide (KOH) and mixtures of KOH and lauric acid against microorganisms associated with poultry processing was determined. In vitro tests were performed by enumerating viable microorganisms recovered from bacterial cultures suspended in peptone water (control) and in solutions of 0.1% KOH or mixtures of 0.1% KOH and 0.25 or 0.50% lauric acid. Additional studies were conducted to identify changes in the native microbial flora of poultry skin washed in distilled water, KOH, or KOH-lauric acid. Although results of in vitro studies indicated that significantly fewer bacteria (P lauric acid than from cultures suspended in KOH. Results of experiments with broiler skin indicated that although rinsates of skin washed in 1.0% KOH solutions contained significantly fewer total aerobic bacteria and enterococci than did skin washed in water, significantly fewer of these microorganisms were generally recovered from rinsates of skin washed in mixtures of 1.0% KOH and 0.5, 1.0, 1.5, or 2.0% lauric acid than from skin washed in KOH alone. Washing of broiler skin in solutions of 0.25 to 1.00% KOH or mixtures containing these concentrations of KOH and two parts lauric acid (wt/vol) also significantly reduced the populations of bacteria and yeasts in the native flora of broiler skin. Enterococci, lactic acid bacteria, and staphylococci in the native flora of the skin had the highest level of resistance to the bactericidal activity of KOH-lauric acid. These findings indicate that the antimicrobial activity of KOH-lauric acid is significantly greater than that of KOH alone in vitro and on poultry skin. Thus, KOH-lauric acid may be useful for reducing the level of microbial contamination associated with poultry processing.

  15. VISUALIZATION OF BIOCHEMICAL ACTIVITY OF MICROORGANISMS GENUS AEROCOCCUS SPECIES AEROCOCCUS VIRIDANS

    Directory of Open Access Journals (Sweden)

    Stepansky DO

    2016-03-01

    Full Text Available Introduction. Aerococci are catalase-negative Gram-positive microorganisms, widespread in the environment, in the cold-blooded microbiocenoses [1, 2] and warm-blooded organisms [3]. Currently, there are seven species of the Aerococcus genus [4]. Type A. viridans got its name as a result of greening blood agar around the growing colonies. It was found that one of the products of A. viridans growth is hydrogen peroxide, has an antagonistic effect on various kinds of bacteria "in vitro" and "in vivo" [5]. It was subsequently found that hydrogen peroxide and superoxide radical are produced as a result of NAD-independent lactatoxidase [6,7] and piruvatoxidase functioning[8]. The oxidative ability of A. viridans is a distinctive feature and allows to visualize these properties using a specific indicator medium [9]. We have developed an indicator that enables to visualize oxidation and reduction properties of aerococci. Material & methods. Auto-symbiotic cultures of A. viridans was used for studying of oxidase - reductase activity, inoculated from human body, an industrial strain of A. viridans 167, used for the preparation of "A-bacterin", culture of Aureobasidium pullulans B5, isolated from the soil and having glucose oxidase activity [10]. Designed indicating medium were also tested in the inoculation of aerococci crops, having lactatoxidase activity of biomaterials from birds and mammals. As a basis for the indicating media (IM IM1 media was selected with following composition (g per 1 liter of water Iodide / potassium 26.0 Soluble starch 10.0 Nutrient agar 30.0 For visualization of oxidase-reductase activity of aerococci acellular components IM4 was developed based on IM3, in which distilled water after double purification was used instead of tap water and highly purified agar-agar was used instead of standard nutrient agar. Results & discussion. IM1 is used to test the oxidative properties of aerococci crops. IM manifests the appearance of a dark

  16. Active microorganisms as drivers of dynamic processes in soil: integration of basic teaching into research

    Science.gov (United States)

    Blagodatskaya, Evgenia; Kuzyakov, Yakov

    2013-04-01

    Traditionally lecture courses, seminars and even practical training are disconnected from real experimental studies and from ongoing research projects. As a result students passively participate in lectures and are helpless when they come to the laboratory to prepare their BSc or MSc theses. We introduce a training course, which is developed for Bachelor students to integrate the basic knowledge on soil microbiology and modern microbiological methods in ecological studies. The training course is focused on the importance of active microbial biomass as biogeochemical driver of soil processes. According to our concept soil functioning is closely related to and depends on the microbial activities, and only active microorganisms drive all processes. Despite this importance of active microorganisms, the most of methods are focused on the estimation of the total microbial biomass and fail to evaluate its activity. Our course demonstrates how the active physiological state of soil microorganisms can be related to the activity indicators such as respiration, molecular biomarkers and viable cell compartments (ATP, PLFA, RNA) determined in situ in soil. Each lecture begins with the set of provocative questions "What is wrong?" which help students to activate their knowledge from previous lectures. Information on on-going soil incubation experiments is integrated in the lectures as a special block. The students are required not only to learn the existing methods but to compare them and to evaluate critically the applicability of these methods to explain the results of on-going experiments. The seminars foreseen within training course are focused on critical discussions of the protocols and their adaptations to current experimental tasks. During practical part of training courses the students are associated in small research groups with a certain ecological tasks. Each group uses soil sub-samples from ongoing experiments and thus, the experimental data obtaining during the

  17. Use Of Amino Acid Racemization To Investigate The Metabolic Activity Of ?Dormant? Microorganisms In Siberian Permafrost

    Science.gov (United States)

    Tsapin, A.; McDonald, G.

    2002-12-01

    search for extraterrestrial life or its remnants is based on studying the most probable environments in which life (extant or extinct) may be found, and determining the maximum period of time over which such life could be preserved. The terrestrial permafrost, inhabited by cold adapted microbes, can be considered as an extraterrestrial analog environment. The cells and their metabolic end-products in Earth's permafrost can be used in the search for possible ecosystems and potential inhabitants on extraterrestrial cryogenic bodies. The study of microorganisms (or their remnants) that were buried for a few million years in permafrost provides us with a unique opportunity to determine the long-term viability of (micro)organisms. We have analyzed the degree of racemization of aspartic acid in permafrost samples from Northern Siberia (Brinton et al. 2002, Astrobiology 2, 77), an area from which microorganisms of apparent ages up to a few million years have previously been isolated and cultured. We find that the extent of aspartic acid racemization in permafrost cores increases very slowly up to an age of approximately 25,000 years (around 5 m depth). The apparent temperature of racemization over the age range 0-25,000 years, determined using measured aspartic acid racemization rate constants, is ?19 C. This apparent racemization temperature is significantly lower than the measured environmental temperature (?11 to ?13 C), and suggests active recycling of D-aspartic acid in Siberian permafrost up to an age of around 25,000 years. This indicates that permafrost organisms are capable of repairing some molecular damage incurred while they are in a ?dormant? state over geologic time.

  18. Biochemical activities of berberine, palmatine and sanguinarine mediating chemical defence against microorganisms and herbivores.

    Science.gov (United States)

    Schmeller, T; Latz-Brüning, B; Wink, M

    1997-01-01

    The alkaloids berberine, palmatine and sanguinarine are toxic to insects and vertebrates and inhibit the multiplication of bacteria, fungi and viruses. Biochemical properties which may contribute to these allelochemical activities were analysed. Acetylcholine esterase, butyrylcholinesterase, choline acetyl transferase, alpha 1- and alpha 2-adrenergic, nicotinergic, muscarinergic and serotonin2 receptors were substantially affected. Sanguinarine appears to be the most effective inhibitor of choline acetyl-transferase (IC50 284 nM), while the protoberberines were inactive at this target. Berberine and palmatine were most active at the alpha 2-receptor (binding with IC50 476 and 956 nM, respectively). Furthermore, berberine and sanguinarine intercalate DNA, inhibit DNA synthesis and reverse transcriptase. In addition, sanguinarine (but not berberine) affects membrane permeability and berberine protein biosynthesis. In consequence, these biochemical activities may mediate chemical defence against microorganisms, viruses and herbivores in the plants producing these alkaloids.

  19. Optimized dispersion of ZnO nanoparticles and antimicrobial activity against foodborne pathogens and spoilage microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Perez Espitia, Paula Judith; Ferreira Soares, Nilda de Fatima, E-mail: nfsoares1@gmail.com [Department of Food Technology, Federal University of Vicosa (Brazil); Teofilo, Reinaldo F. [Federal University of Vicosa, Department of Chemistry (Brazil); Vitor, Debora M.; Reis Coimbra, Jane Selia dos; Andrade, Nelio Jose de [Department of Food Technology, Federal University of Vicosa (Brazil); Sousa, Frederico B. de; Sinisterra, Ruben D. [Federal University of Minas Gerais, Department of Chemistry (Brazil); Medeiros, Eber Antonio Alves [Department of Food Technology, Federal University of Vicosa (Brazil)

    2013-01-15

    Single primary nanoparticles of zinc oxide (nanoZnO) tend to form particle collectives, resulting in loss of antimicrobial activity. This work studied the effects of probe sonication conditions: power, time, and the presence of a dispersing agent (Na{sub 4}P{sub 2}O{sub 7}), on the size of nanoZnO particles. NanoZnO dispersion was optimized by response surface methodology (RSM) and characterized by the zeta potential (ZP) technique. NanoZnO antimicrobial activity was investigated at different concentrations (1, 5, and 10 % w/w) against four foodborne pathogens and four spoilage microorganisms. The presence of the dispersing agent had a significant effect on the size of dispersed nanoZnO. Minimum size after sonication was 238 nm. An optimal dispersion condition was achieved at 200 W for 45 min of sonication in the presence of the dispersing agent. ZP analysis indicated that the ZnO nanoparticle surface charge was altered by the addition of the dispersing agent and changes in pH. At tested concentrations and optimal dispersion, nanoZnO had no antimicrobial activity against Pseudomonas aeruginosa, Lactobacillus plantarum, and Listeria monocytogenes. However, it did have antimicrobial activity against Escherichia coli, Salmonella choleraesuis, Staphylococcus aureus, Saccharomyces cerevisiae, and Aspergillus niger. Based on the exhibited antimicrobial activity of optimized nanoZnO against some foodborne pathogens and spoilage microorganisms, nanoZnO is a promising antimicrobial for food preservation with potential application for incorporation in polymers intended as food-contact surfaces.

  20. Overcoming of Soil Contamination with Pesticides in Forest Nurseries Using the Activity of Microorganisms

    Directory of Open Access Journals (Sweden)

    Irina A. Freiberg

    2010-01-01

    Full Text Available The use of pesticides during cultivation of pine seedlings in forest nurseries resultsin the formation two phenotypes of teratomorph seedlings – conditionally normal andabnormal. Growing forest cultures from teratomorph seedlings leads to their low survivalrate. It is known that pesticides and their metabolic products can remain in soil for manyyears. It is therefore impossible to rely only on natural degradation of pesticides in soil. Apromising way of removing pesticides from soil is their microbiological decomposition.This method is preferable because there is a meliorative organic substance not far from forestnurseries – i.e. forest litter rich in microorganisms. The purpose of these experimentswas to examine the influence of forest litter applied on pesticide decomposition in soil andmorphology of pine seedlings. The rates of forest litter that were most effective in decompositionof pesticides and the activity of microbial communities in litter, depending on foreststand structure, were determined. Estimation of that action was based on the morphologyof seedlings (rate of pine seedlings with normal, conditionally normal and abnormalphenotypes, intensity of CO2 emission from soil and catalase activity, which correlates withthe number of soil microorganisms. The results of these experiments showed the mosteffective activity of forest litter at the application rate of 20 kg/m2. The number of seedlingswith normal phenotype rose from 32% up to 40%. Besides, it was noted that saprophyteswere most effective in pine forest litter, which is characterized by a more acid reaction ofsoil solution, while most others were rich in fungi. The highest number of normal phenotypeseedlings, intensity of CO2 emission and activity of soil catalase were correlated withthe microbiological activity of the applied pine forest litter.

  1. Microorganism Billiards

    CERN Document Server

    Wahl, Colin; Spagnolie, Saverio E; Thiffeault, Jean-Luc

    2015-01-01

    Recent experiments and numerical simulations have shown that certain types of microorganisms "reflect" off of a flat surface at a critical angle of departure, independent of the angle of incidence. The nature of the reflection may be active (cell and flagellar contact with the surface) or passive (hydrodynamic) interactions. We explore the billiard-like motion of such a body inside a regular polygon and show that the dynamics can settle on a stable periodic orbit, or can be chaotic, depending on the swimmer's departure angle and the domain geometry. The dynamics are often found to be robust to the introduction of weak random fluctuations. The Lyapunov exponent of swimmer trajectories can be positive or negative, can have extremal values, and can have discontinuities depending on the degree of the polygon. A passive sorting device is proposed that traps swimmers of different departure angles into separate bins. We also study the external problem of a microorganism swimming in a patterned environment of square ...

  2. The cold adaptability of microorganisms with different carbon source in activated sludge treating synthetical wastewater.

    Science.gov (United States)

    Niu, Chuan; Geng, Jinju; Ren, Hongqiang; Ding, Lili; Xu, Ke

    2012-11-01

    The cold adaptability of microorganisms with different carbon source under 5°C was studied in activated sludge for treating synthetical wastewater. Phospholipid fatty acid (PLFA) analysis indicated contents of unsaturated fatty acids in cell membrane at 5°C were 13.66% and 24.96% higher for glucose and sodium acetate source than that at 25°C. PLFA biomarkers showed more Gram-negative bacteria enriched than Gram-positive bacteria in low-temperature activated sludge. The Shannon-Wiener diversity analysis demonstrated glucose fed reactor in low temperature had lower PLFA diversity index (1.21-1.30) than that at 25°C and sodium acetate source was reverse (1.08-0.69). The 16S rRNA analysis manifested certain microbes were considerably suitable for existence under cold environment, most of which belong to Gram-negative bacteria.

  3. A site-specific curated database for the microorganisms of activated sludge and anaerobic digesters

    DEFF Research Database (Denmark)

    McIlroy, Simon Jon; Kirkegaard, Rasmus Hansen; McIlroy, Bianca

    the composition and dynamics of the most abundant organisms. However, to understand the relationship between the population dynamics and operational parameters of the system, a functional role must be attributed to each organism. The Microbial Database for Activated Sludge (MiDAS) and Anaerobic Digesters (AD......) presented here provides a site specific curated taxonomy for abundant and important microorganisms and integrates it into a community knowledge web platform about the microbes in activated sludge (AS) and their associated ADs (www.midasfieldguide.org). The MiDAS taxonomy, a manual curation of the SILVA......, to improve the classification of unknown organisms and link these names to the wealth of present and future functional information about their ecology....

  4. Effect of Cl— on Behavior of Fertilizer Nitrogen, Number of Microorganisms and Enzyme Activities in Soils

    Institute of Scientific and Technical Information of China (English)

    SHIWEI-YONG; CHENGMEI-ZI; 等

    1994-01-01

    Pot experiments were conducted to study the effect of Cl- on transformation of fertilizer N,number of microorganisms and enzyme activities in soils.It is indicated that Cl- did not show significant influence on total number of bacteria,actinomyces and fungi,but significantly reduced the number of nitrosolbacteria, which led to decrease of NO3- content in the soil.Application of Cl- to soil could significantly enhance the adtivities of phosphatase and urease in the coastal saline soil and orthic aquisols,In hilly red soil,however,the application of Cl-1 at the rate of 500-1000mg Cl- kg-1 soil significantly decreased the activity of the two enzymes mentioned above.

  5. Investigating microbial activities of electrode-associated microorganisms in real-time

    Directory of Open Access Journals (Sweden)

    Sanja eAracic

    2014-11-01

    Full Text Available Electrode-associated microbial biofilms are essential to the function of bioelectrochemical systems. These systems exist in a number of different configurations but all rely on electroactive microorganisms utilizing an electrode as either an electron acceptor or an electron donor to catalyze biological processes. Investigations of the structure and function of electrode-associated biofilms are critical to further the understanding of how microbial communities are able to reduce and oxidize electrodes. The community structure of electrode-reducing biofilms is diverse and often dominated by Geobacter spp. whereas electrode-oxidizing biofilms are often dominated by other microorganisms. The application of a wide range of tools, such as high-throughput sequencing and metagenomic data analyses, provide insight into the structure and possible function of microbial communities on electrode surfaces. However, the development and application of techniques that monitor gene expression profiles in real-time are required for a more definite spatial and temporal understanding of the diversity and biological activities of these dynamic communities. This mini-review summarizes the key gene expression techniques used in bioelectrochemical systems research, which have led to a better understanding of population dynamics, cell-cell communication and molecule-surface interactions in mixed and pure BES communities

  6. Endowing non-cellulolytic microorganisms with cellulolytic activity aiming for consolidated bioprocessing.

    Science.gov (United States)

    Yamada, Ryosuke; Hasunuma, Tomohisa; Kondo, Akihiko

    2013-11-01

    With the exhaustion of fossil fuels and with the environmental issues they pose, utilization of abundant lignocellulosic biomass as a feedstock for biofuels and bio-based chemicals has recently become an attractive option. Lignocellulosic biomass is primarily composed of cellulose, hemicellulose, and lignin and has a very rigid and complex structure. It is accordingly much more expensive to process than starchy grains because of the need for extensive pretreatment and relatively large amounts of cellulases for efficient hydrolysis. Efficient and cost-effective methods for the production of biofuels and chemicals from lignocellulose are required. A consolidated bioprocess (CBP), which integrates all biological steps consisting of enzyme production, saccharification, and fermentation, is considered a promising strategy for reducing production costs. Establishing an efficient CBP using lignocellulosic biomass requires both lignocellulose degradation into glucose and efficient production of biofuels or chemicals from glucose. With this aim, many researchers are attempting to endow selected microorganisms with lignocellulose-assimilating ability. In this review, we focus on studies aimed at conferring lignocellulose-assimilating ability not only to yeast strains but also to bacterial strains by recombinant technology. Recent developments in improvement of enzyme productivity by microorganisms and in improvement of the specific activity of cellulase are emphasized.

  7. Biochar as carrier for plant nutrients and microorganisms - techniques of agro-activation

    Science.gov (United States)

    Schmidt, H.-P.

    2012-04-01

    The soil enhancing qualities of biochar are strongly linked to its influence on nutrient cycling dynamics, sorption dynamics and to changing habitat condition for soil fauna. But as shown in multiple studies, the addition of pure biochar to agricultural soils may provoke reduced plant growth caused by the immobilisation of plant nutrients. The very potent sorption dynamics of biochar makes it an effective carrier for plant nutrients and plant-root symbiotic microorganisms. At the Delinat-Institute, we tried sundry methods of charging biochars with organic and mineral plant nutrients as well as with microorganisms. This includes the use of biochar as bulk agent in aerobic composting, in malolactic fermentation and as treatment for liquid manure, but also formulations of mineral carbon-fertilizers. Those biochar products are tested in pot and also large scale field trials. Results and experiences of these trials as well as different activation methods will be explained. A short overview of industrial designing of biochar based products will be given.

  8. Enzyme activity and microorganisms diversity in soil contaminated with the Boreal 58 WG herbicide.

    Science.gov (United States)

    Kucharski, Jan; Tomkiel, Monika; Baćmaga, Małgorzata; Borowik, Agata; Wyszkowska, Jadwiga

    2016-07-02

    Next-generation herbicides are relatively safe when used properly, but the recommended rates are relatively low, which can lead to overdosing. This study evaluated the responses of soil-dwelling microorganisms and soil enzymes to contamination with the Boreal 58 WG herbicide. The analyzed product contains active ingredients flufenacet and isoxaflutole. All tests were performed under laboratory conditions. The analyzed material was sandy clay. Boreal 58 WG was introduced to soil in four doses. Soil without the addition of the herbicide served as the control. The soil was mixed with the tested herbicide, and its moisture content was maintained at 50% of capillary water capacity. Biochemical and microbiological analyses were performed on experimental days 0, 20, 40, 80 and 160. Accidental contamination of soil with the Boreal 58 WG herbicide led to a relatively minor imbalance in the soil microbiological and biochemical profile. The herbicide dose influenced dehydrogenase activity in only 0.84%, urease activity in 2.04%, β-glucosidase activity in 8.26%, catalase activity in 12.40%, arylsulfatase activity in 12.54%, acid phosphatase activity in 42.11%, numbers of organotrophic bacteria in 18.29%, actinomyces counts in 1.31% and fungi counts in 6.86%.

  9. Active sulfur cycling by diverse mesophilic and thermophilic microorganisms in terrestrial mud volcanoes of Azerbaijan.

    Science.gov (United States)

    Green-Saxena, A; Feyzullayev, A; Hubert, C R J; Kallmeyer, J; Krueger, M; Sauer, P; Schulz, H-M; Orphan, V J

    2012-12-01

    Terrestrial mud volcanoes (TMVs) represent geochemically diverse habitats with varying sulfur sources and yet sulfur cycling in these environments remains largely unexplored. Here we characterized the sulfur-metabolizing microorganisms and activity in four TMVs in Azerbaijan. A combination of geochemical analyses, biological rate measurements and molecular diversity surveys (targeting metabolic genes aprA and dsrA and SSU ribosomal RNA) supported the presence of active sulfur-oxidizing and sulfate-reducing guilds in all four TMVs across a range of physiochemical conditions, with diversity of these guilds being unique to each TMV. The TMVs varied in potential sulfate reduction rates (SRR) by up to four orders of magnitude with highest SRR observed in sediments where in situ sulfate concentrations were highest. Maximum temperatures at which SRR were measured was 60°C in two TMVs. Corresponding with these trends in SRR, members of the potentially thermophilic, spore-forming, Desulfotomaculum were detected in these TMVs by targeted 16S rRNA analysis. Additional sulfate-reducing bacterial lineages included members of the Desulfobacteraceae and Desulfobulbaceae detected by aprA and dsrA analyses and likely contributing to the mesophilic SRR measured. Phylotypes affiliated with sulfide-oxidizing Gamma- and Betaproteobacteria were abundant in aprA libraries from low sulfate TMVs, while the highest sulfate TMV harboured 16S rRNA phylotypes associated with sulfur-oxidizing Epsilonproteobacteria. Altogether, the biogeochemical and microbiological data indicate these unique terrestrial habitats support diverse active sulfur-cycling microorganisms reflecting the in situ geochemical environment.

  10. Synergized antimicrobial activity of eugenol incorporated polyhydroxybutyrate films against food spoilage microorganisms in conjunction with pediocin.

    Science.gov (United States)

    Narayanan, Aarthi; Neera; Mallesha; Ramana, Karna Venkata

    2013-07-01

    Biopolymers and biopreservatives produced by microorganisms play an essential role in food technology. Polyhydroxyalkanoates and bacteriocins produced by bacteria are promising components to safeguard the environment and for food preservation applications. Polyhydroxybutyrate (PHB)-based antimicrobial films were prepared incorporating eugenol, from 10 to 200 μg/g of PHB. The films were evaluated for antimicrobial activity against foodborne pathogens, spoilage bacteria, and fungi such as Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Bacillus cereus, Aspergillus flavus, Aspergillus niger, Penicillium sp., and Rhizopus sp. The synergistic antimicrobial activity of the films in the presence of crude pediocin was also investigated. The broth system containing pediocin (soluble form) as well as antimicrobial PHB film demonstrated an extended lag phase and a significant growth reduction at the end of 24 h against the bacteria. Crude pediocin alone could not elicit antifungal activity, while inhibition of growth and sporulation were observed in the presence of antimicrobial PHB film containing eugenol (80 μg/g) until 7 days in the case of molds, i.e., A. niger, A. flavus, Penicillium sp., and Rhizopus sp. in potato dextrose broth. In the present study, we identified that use of pediocin containing broth in conjunction with eugenol incorporated PHB film could function in synergized form, providing effective hurdle toward food contaminating microorganisms. Furthermore, tensile strength, percent crystallinity, melting point, percent elongation to break, glass transition temperature, and seal strength of the PHB film with and without eugenol incorporation were investigated. The migration of eugenol on exposure to different liquid food simulants was also analyzed using Fourier transform infrared spectroscopy. The study is expected to provide applications for pediocin in conjunction with eugenol containing PHB film to enhance the shelf life of foods in the

  11. [Electrochemically active microorganisms and electrolytically assisted fermentative hydrogen production--a review].

    Science.gov (United States)

    Li, Jianchang; Zhang, Wudi; Yin, Fang; Xu, Rui; Chen, Yubao

    2009-06-01

    Fermentative hydrogen production can be improved by electrolysis and electrochemically active microorganisms which are capable of using an electrode as an electron acceptor for the oxidation of organic matter, in particular, volatile acids produced after fermentation. Firstly volatile acids can be completely converted into CO2, electrons and protons on the surface of anode. Then the electrons flow to cathode through anode and wires, and at the same time the protons move to cathode through cation membrane between anode chamber and cathode chamber. Finally the electrons and the protons combine into hydrogen when they meet at the surface of cathode. In such a process, the fermentation barrier and the product inhibition can be avoided to improve the conversion of hydrogen. 8-9 mol H2/mol glucose of hydrogen potential can be obtained when glucose is used as substrate. This technology is very likely to be applied to produce hydrogen high efficiently from any energy crops, organic waste and wastewater.

  12. Antimicrobial activity of some essential oils against microorganisms deteriorating fruit juices.

    Science.gov (United States)

    Helal, G A; Sarhan, M M; Abu Shahla, A N K; Abou El-Khair, E K

    2006-12-01

    Seventeen microbial species including 10 fungal taxa, two yeasts and five bacteria, were isolated from freshly prepared orange, guava and banana juices kept in open bottles at room temperature for 7 days. Eight different essential oils, from local herbs, were tested for their antimicrobial activity against these test organisms. The essential oils of Cymbopogon citratus, Ocimum basilicum and Origanum majorana were found to be highly effective against these microorganisms. Aspergillus niger, A. flavus and Saccharomyces cerevisiae, the most prevalent microorganisms in juice, showed the highest resistance against these essential oils. GC-MS analysis showed that while e-citral, a'-myrcene, and z-citral represent the major components (75.1%) of the essential oil of Cymbopogon citratus; bezynen,1-methyl-4-(2-propenyl), 1,8-cineole and trans-a'-bisabolene were the main components (90.6%) of Ocimum basilicum; whereas 3-cyclohexen-1-01,4-methyl-1(1-methylethyl)-(CAS), c-terpinene and trans-caryophyllene represent the major components (65.1%) of Origanum majorana. These three essential oils were introduced into juices by two techniques namely, fumigation and direct contact. The former technique showed more fungicidal effect than the latter one against A. flavus, A. niger, and S. cerevisiae. The essential oil of Cymbopogon citratus by comparison to other test oils showed the strongest effect against these fungi with a minimum inhibitory concentration of 1.5 µl/ml medium and a sublethal concentration of 1.0 µl/ml. The antimicrobial activity of this oil is thermostable at 121℃ for 30 min.

  13. NUMBER AND ACTIVITY OF MICROORGANISMS IN SOIL INOCULATED WITH THE RHIZOCELL C BIOPREPARATION IN STRAWBERRY CULTIVATION (FRAGARIA × ANANASA DUCH.

    Directory of Open Access Journals (Sweden)

    Małgorzata Hawrot-Paw

    2016-04-01

    Full Text Available An experiment involving vegetation pots was conducted to assess the effect of inoculating the soil with the Rhizocell C biopreparation, which includes bacteria from the genus Bacillus amyloliquefaciens IT45, on the number and activity of selected groups of soil microorganisms. The biopreparation was applied in strawberries (Fragaria × ananasa Duch. in a dose recommended by the manufacturer. Microbiological analyses were conducted four times during the vegetation of plants. The obtained results led to a conclusion that the use of biopreparation affects biological activity of soil, and a majority of the observed changes were beneficial. The mean number of the most microorganisms after Rhizocell C biopreparation was higher than in the control object. Soil inoculation had an influence on the activity of microorganisms determined based on biomass content, but the differences were not significant.

  14. Selection of Psychrotolerant Microorganisms Producing Cold-Active Pectinases for Biotechnological Processes at Low Temperature

    Directory of Open Access Journals (Sweden)

    María S. Cabeza

    2011-01-01

    Full Text Available In winemaking, low temperatures are favourable for the production and retention of flavour and colour components, requiring the use of cold-active enzymes. For this reason, 'psychrotolerant' microorganisms have been isolated and selected based on their ability to produce pectinolytic enzymes with satisfactory activity at low temperatures. Different mature grape varieties with designation of origin were sampled from the region of San Rafael (Mendoza, Argentina, and pectinolytic bacterial, fungal and yeast strains were isolated. The pectinolytic activity was measured by cup-plate assay, quantification of released reducing sugars and viscosity reduction of pectin solution. Two bacteria (Bacillus sp. SC-G and SC-H and two yeast strains were selected for their good pectinase activity at low temperatures. Among them, the strain with the highest activity, Bacillus sp. SC-H, was selected. According to their 16S rRNA profiles, Bacillus sp. SC-G and SC-H can be classified as members of Bacillus subtilis. Among the assayed techniques, the rotary evaporation was found to be the most appropriate to obtain enzymatic extracts with highest activity. The optimal conditions for the enzymatic activity were 30 °C and pH=5.0 for the concentrated extract, and 45 °C and pH=6.0 for the filtered supernatant. The concentrated extract presented good activity at 3 °C, confirming that it was a cold-active enzyme. Natural extraction and enzymatic preparation were used to extract pigments and polyphenols from Malbec grapes. Better results were obtained for the enzymatic extract with regard to index, shade, CIELab coordinates, CIELab colour differences and polyphenols (measured using Folin-Ciocalteu.

  15. Activated zeolite--suitable carriers for microorganisms in anaerobic digestion processes?

    Science.gov (United States)

    Weiß, S; Lebuhn, M; Andrade, D; Zankel, A; Cardinale, M; Birner-Gruenberger, R; Somitsch, W; Ueberbacher, B J; Guebitz, G M

    2013-04-01

    Plant cell wall structures represent a barrier in the biodegradation process to produce biogas for combustion and energy production. Consequently, approaches concerning a more efficient de-polymerisation of cellulose and hemicellulose to monomeric sugars are required. Here, we show that natural activated zeolites (i.e. trace metal activated zeolites) represent eminently suitable mineral microhabitats and potential carriers for immobilisation of microorganisms responsible for anaerobic hydrolysis of biopolymers stabilising related bacterial and methanogenic communities. A strategy for comprehensive analysis of immobilised anaerobic populations was developed that includes the visualisation of biofilm formation via scanning electron microscopy and confocal laser scanning microscopy, community and fingerprint analysis as well as enzyme activity and identification analyses. Using SDS polyacrylamide gel electrophoresis, hydrolytical active protein bands were traced by congo red staining. Liquid chromatography/mass spectroscopy revealed cellulolytical endo- and exoglucanase (exocellobiohydrolase) as well as hemicellulolytical xylanase/mannase after proteolytic digestion. Relations to hydrolytic/fermentative zeolite colonisers were obtained by using single-strand conformation polymorphism analysis (SSCP) based on amplification of bacterial and archaeal 16S rRNA fragments. Thereby, dominant colonisers were affiliated to the genera Clostridium, Pseudomonas and Methanoculleus. The specific immobilisation on natural zeolites with functional microbes already colonising naturally during the fermentation offers a strategy to systematically supply the biogas formation process responsive to population dynamics and process requirements.

  16. Determination of the cellulolytic activities of microorganisms isolated from poultry litter for sawdust degradation

    Directory of Open Access Journals (Sweden)

    Akpomie O.OF

    2013-03-01

    Full Text Available Cellulolytic activities of bacterial and fungal isolates obtained from poultry droppings were determined using the ability of each isolate to produce clear zones on Carboxyl Methyl Cellulose Agar plates. The bacterial isolates were Klebsiella, Streptococcus, Celulomonas, Escherichia coli and Micrococus species. The cellulolytic counts ranged from 5.02 x 104 + 3.42 to 7.20 x 109 + 6.12 cfu/g. The cellulolytic activities of the bacterial isolates ranged from 0.04 to 0.26 iu/m with Cellulomonas having the highest cellulose activity. The fungal isolates were Aspergillus niger, Mucor mucedo, Trichoderma sp. and Penicllium chrysogenum with cellulose activities of 0.24 + 0.021 0.19 + 0.031, 0.23 + 0.05 and 0.23 + 0.028iu/ml respectively. All the isolates were able to degrade the sawdust to varying extent. The percentage degradation was highest with Micrococcus sp. (78.20% and least with Trichoderma sp. (65.83%. The study shows that is a potential source of cellulolytic microorganisms which could be employed in the degradation of sawdust.

  17. Investigation of the Activity of the Microorganisms in a Reblochon-Style Cheese by Metatranscriptomic Analysis.

    Science.gov (United States)

    Monnet, Christophe; Dugat-Bony, Eric; Swennen, Dominique; Beckerich, Jean-Marie; Irlinger, Françoise; Fraud, Sébastien; Bonnarme, Pascal

    2016-01-01

    The microbial communities in cheeses are composed of varying bacteria, yeasts, and molds, which contribute to the development of their typical sensory properties. In situ studies are needed to better understand their growth and activity during cheese ripening. Our objective was to investigate the activity of the microorganisms used for manufacturing a surface-ripened cheese by means of metatranscriptomic analysis. The cheeses were produced using two lactic acid bacteria (Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus), one ripening bacterium (Brevibacterium aurantiacum), and two yeasts (Debaryomyces hansenii and Geotrichum candidum). RNA was extracted from the cheese rinds and, after depletion of most ribosomal RNA, sequencing was performed using a short-read sequencing technology that generated ~75 million reads per sample. Except for B. aurantiacum, which failed to grow in the cheeses, a large number of CDS reads were generated for the inoculated species, making it possible to investigate their individual transcriptome over time. From day 5 to 35, G. candidum accounted for the largest proportion of CDS reads, suggesting that this species was the most active. Only minor changes occurred in the transcriptomes of the lactic acid bacteria. For the two yeasts, we compared the expression of genes involved in the catabolism of lactose, galactose, lactate, amino acids, and free fatty acids. During ripening, genes involved in ammonia assimilation and galactose catabolism were down-regulated in the two species. Genes involved in amino acid catabolism were up-regulated in G. candidum from day 14 to day 35, whereas in D. hansenii, they were up-regulated mainly at day 35, suggesting that this species catabolized the cheese amino acids later. In addition, after 35 days of ripening, there was a down-regulation of genes involved in the electron transport chain, suggesting a lower cellular activity. The present study has exemplified how

  18. Investigation of the activity of the microorganisms in a Reblochon-style cheese by metatranscriptomic analysis

    Directory of Open Access Journals (Sweden)

    Christophe eMonnet

    2016-04-01

    Full Text Available The microbial communities in cheeses are composed of varying bacteria, yeasts, and molds, which contribute to the development of their typical sensory properties. In situ studies are needed to better understand their growth and activity during cheese ripening. Our objective was to investigate the activity of the microorganisms used for manufacturing a surface-ripened cheese by means of metatranscriptomic analysis. The cheeses were produced using two lactic acid bacteria (Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus, one ripening bacterium (Brevibacterium aurantiacum, and two yeasts (Debaryomyces hansenii and Geotrichum candidum. RNA was extracted from the cheese rinds and, after depletion of most ribosomal RNA, sequencing was performed using a short-read sequencing technology that generated approximately 75 million reads per sample. Except for Brevibacterium aurantiacum, which failed to grow in the cheeses, a large number of CDS reads were generated for the inoculated species, making it possible to investigate their individual transcriptome over time. From day 5 to day 35, G. candidum accounted for the largest proportion of CDS reads, suggesting that this species was the most active. Only minor changes occurred in the transcriptomes of the lactic acid bacteria. For the two yeasts, we compared the expression of genes involved in the catabolism of lactose, galactose, lactate, amino acids and free fatty acids. During ripening, genes involved in ammonia assimilation and galactose catabolism were down-regulated in the two species. Genes involved in amino acid catabolism were up-regulated in G. candidum from day 14 to day 35, whereas in D. hansenii, they were up-regulated mainly at day 35, suggesting that this species catabolized the cheese amino acids later. In addition, after 35 days of ripening, there was a down-regulation of genes involved in the electron transport chain, suggesting a lower cellular activity. The

  19. Antibacterial and Antibiofilm Activity of Methanolic Plant Extracts against Nosocomial Microorganisms

    Science.gov (United States)

    García-Becerra, Ledy; Ortiz Martínez, David Mizael

    2016-01-01

    Biofilm is a complex microbial community highly resistant to antimicrobials. The formation of biofilms in biotic and abiotic surfaces is associated with high rates of morbidity and mortality in hospitalized patients. New alternatives for controlling infections have been proposed focusing on the therapeutic properties of medicinal plants and their antimicrobial effects. In the present study the antimicrobial and antibiofilm activities of 8 methanolic plant extracts were evaluated against clinical isolated microorganisms. Preliminary screening by diffusion well assay showed the antimicrobial activity of Prosopis laevigata, Opuntia ficus-indica, and Gutierrezia microcephala. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined ranging from 0.7 to >15 mg/mL. The specific biofilm formation index (SBF) was evaluated before and after the addition of plant extracts (MBC × 0.75). Opuntia ficus-indica caused the major reduction on SBF in dose-dependent manner. Cytotoxic activity of plant extracts was determined using brine shrimp lethality test (Artemia salina L.). Lethal Dose concentration (LD50 values) of the plant extracts was calculated. LD50 values for P. laevigata and G. microcephala were 141.6 and 323.3 µg/mL, respectively, while O. ficus-indica showed a slight lethality with 939.2 µg/mL. Phytochemical analyses reveal the presence of flavonoids, tannins, and coumarines. PMID:27429633

  20. Antibacterial and Antibiofilm Activity of Methanolic Plant Extracts against Nosocomial Microorganisms

    Directory of Open Access Journals (Sweden)

    Eduardo Sánchez

    2016-01-01

    Full Text Available Biofilm is a complex microbial community highly resistant to antimicrobials. The formation of biofilms in biotic and abiotic surfaces is associated with high rates of morbidity and mortality in hospitalized patients. New alternatives for controlling infections have been proposed focusing on the therapeutic properties of medicinal plants and their antimicrobial effects. In the present study the antimicrobial and antibiofilm activities of 8 methanolic plant extracts were evaluated against clinical isolated microorganisms. Preliminary screening by diffusion well assay showed the antimicrobial activity of Prosopis laevigata, Opuntia ficus-indica, and Gutierrezia microcephala. The minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC were determined ranging from 0.7 to >15 mg/mL. The specific biofilm formation index (SBF was evaluated before and after the addition of plant extracts (MBC × 0.75. Opuntia ficus-indica caused the major reduction on SBF in dose-dependent manner. Cytotoxic activity of plant extracts was determined using brine shrimp lethality test (Artemia salina L.. Lethal Dose concentration (LD50 values of the plant extracts was calculated. LD50 values for P. laevigata and G. microcephala were 141.6 and 323.3 µg/mL, respectively, while O. ficus-indica showed a slight lethality with 939.2 µg/mL. Phytochemical analyses reveal the presence of flavonoids, tannins, and coumarines.

  1. Heavy metal availability and impact on activity of soil microorganisms along a Cu/Zn contamination gradient

    Institute of Scientific and Technical Information of China (English)

    WANG Yuan-peng; SHI Ji-yan; LIN Qi; CHEN Xin-cai; CHEN Ying-xu

    2007-01-01

    All the regulations that define a maximum concentration of metals in the receiving soil are based on total soil metal concentration. However, the potential toxicity of a heavy metal in the soil depends on its speciation and availability. We studied the effects of heavy metal speciation and availability on soil microorganism activities along a Cu/Zn contamination gradient. Microbial biomass and enzyme activity of soil contaminated with both Cu and Zn were investigated. The results showed that microbial biomass was negatively affected by the elevated metal levels. The microbial biomass-C (Cmic)/organic C (Corg) ratio was closely correlated to heavy metal stress. There were negative correlations between soil microbial biomass, phosphatase activity and NH4NO3 extractable heavy metals. The soil microorganism activity could be predicted using empirical models with the availability of Cu and Zn. We observed that 72% of the variation in phosphatase activity could be explained by the NH4NO3-extractable and total heavy metal concentration. By considering different monitoring approaches and different viewpoints, this set of methods applied in this study seemed sensitive to site differences and contributed to a better understanding of the effects of heavy metals on the size and activity of microorganisms in soils. The data presented demonstrate the relationship between heavy metals availability and heavy metal toxicity to soil microorganism along a contamination gradient.

  2. Rapid Detection of Microorganisms Based on Active and Passive Modes of QCM

    Directory of Open Access Journals (Sweden)

    Zdeněk Farka

    2014-12-01

    Full Text Available Label-free immunosensors are well suited for detection of microorganisms because of their fast response and reasonable sensitivity comparable to infection doses of common pathogens. Active (lever oscillator and frequency counter and passive (impedance analyzer modes of quartz crystal microbalance (QCM were used and compared for rapid detection of three strains of E. coli. Different approaches for antibody immobilization were compared, the immobilization of reduced antibody using Sulfo‑SMCC was most effective achieving the limit of detection (LOD 8 × 104 CFU·mL−1 in 10 min. For the passive mode, software evaluating impedance characteristics in real-time was developed and used. Almost the same results were achieved using both active and passive modes confirming that the sensor properties are not limited by the frequency evaluation method but mainly by affinity of the antibody. Furthermore, reference measurements were done using surface plasmon resonance. Effect of condition of cells on signal was observed showing that cells ruptured by ultrasonication provided slightly higher signal changes than intact microbes.

  3. In vitro evaluation of marine-microorganism extracts for anti-viral activity

    Directory of Open Access Journals (Sweden)

    Yasuhara-Bell Jarred

    2010-08-01

    Full Text Available Abstract Viral-induced infectious diseases represent a major health threat and their control remains an unachieved goal, due in part to the limited availability of effective anti-viral drugs and measures. The use of natural products in drug manufacturing is an ancient and well-established practice. Marine organisms are known producers of pharmacological and anti-viral agents. In this study, a total of 20 extracts from marine microorganisms were evaluated for their antiviral activity. These extracts were tested against two mammalian viruses, herpes simplex virus (HSV-1 and vesicular stomatitis virus (VSV, using Vero cells as the cell culture system, and two marine virus counterparts, channel catfish virus (CCV and snakehead rhabdovirus (SHRV, in their respective cell cultures (CCO and EPC. Evaluation of these extracts demonstrated that some possess antiviral potential. In sum, extracts 162M(4, 258M(1, 298M(4, 313(2, 331M(2, 367M(1 and 397(1 appear to be effective broad-spectrum antivirals with potential uses as prophylactic agents to prevent infection, as evident by their highly inhibitive effects against both virus types. Extract 313(2 shows the most potential in that it showed significantly high inhibition across all tested viruses. The samples tested in this study were crude extracts; therefore the development of antiviral application of the few potential extracts is dependent on future studies focused on the isolation of the active elements contained in these extracts.

  4. In vitro evaluation of marine-microorganism extracts for anti-viral activity.

    Science.gov (United States)

    Yasuhara-Bell, Jarred; Yang, Yongbo; Barlow, Russell; Trapido-Rosenthal, Hank; Lu, Yuanan

    2010-08-07

    Viral-induced infectious diseases represent a major health threat and their control remains an unachieved goal, due in part to the limited availability of effective anti-viral drugs and measures. The use of natural products in drug manufacturing is an ancient and well-established practice. Marine organisms are known producers of pharmacological and anti-viral agents. In this study, a total of 20 extracts from marine microorganisms were evaluated for their antiviral activity. These extracts were tested against two mammalian viruses, herpes simplex virus (HSV-1) and vesicular stomatitis virus (VSV), using Vero cells as the cell culture system, and two marine virus counterparts, channel catfish virus (CCV) and snakehead rhabdovirus (SHRV), in their respective cell cultures (CCO and EPC). Evaluation of these extracts demonstrated that some possess antiviral potential. In sum, extracts 162M(4), 258M(1), 298M(4), 313(2), 331M(2), 367M(1) and 397(1) appear to be effective broad-spectrum antivirals with potential uses as prophylactic agents to prevent infection, as evident by their highly inhibitive effects against both virus types. Extract 313(2) shows the most potential in that it showed significantly high inhibition across all tested viruses. The samples tested in this study were crude extracts; therefore the development of antiviral application of the few potential extracts is dependent on future studies focused on the isolation of the active elements contained in these extracts.

  5. Soil application of dinitroaniline and arylphenoxy propionic herbicides influences the activities of phosphate-solubilizing microorganisms in soil.

    Science.gov (United States)

    Das, Amal Chandra; Nayek, Hemanta; Chakravarty, Arunabha

    2012-12-01

    An experiment was conducted under laboratory conditions to investigate the effect of two systemic herbicides, viz. pendimethalin (a dinitroaniline) and quizalofop (an arylphenoxy propionic acid) at their recommended field application rates (1.0 kg and 50 g active ingredient per hectare, respectively), either separately or in a combination, on growth and activities of phosphate-solubilizing microorganisms in relation to their effects on biochemical transformations and availability of organic carbon, total and available phosphorus in a Typic Haplustept soil of West Bengal, India. Application of herbicides, in general, significantly stimulated the growth and activities of phosphate-solubilizing microorganisms which increased microbial biomass resulting in higher accumulation of oxidizable organic carbon, total and available phosphorus in soil as compared to untreated control. The combined application of both the herbicides highly stimulated the proliferations of phosphate-solubilizing microorganisms, while pendimethalin alone significantly accentuated phosphate-solubilizing capacities 36.4% as compared to untreated control and retained highest amount of total phosphorus due to greater microbial activities in soil. The separate application of quizalofop also manifested an induced effect on the proliferations of phosphate-solubilizing microorganisms and accounted significant amounts of organic carbon and available phosphorus in the soil system. The results of the present study thus indicated that the cited herbicides at their field application rates can be safely used to eradicate weeds in the crop fields.

  6. Microorganism billiards

    Science.gov (United States)

    Spagnolie, Saverio E.; Wahl, Colin; Lukasik, Joseph; Thiffeault, Jean-Luc

    2017-02-01

    Recent experiments and numerical simulations have shown that certain types of microorganisms "reflect" off of a flat surface at a critical angle of departure, independent of the angle of incidence. The nature of the reflection may be active (cell and flagellar contact with the surface) or passive (hydrodynamic) interactions. We explore the billiard-like motion of a body with this empirical reflection law inside a regular polygon and show that the dynamics can settle on a stable periodic orbit or can be chaotic, depending on the swimmer's departure angle and the domain geometry. The dynamics are often found to be robust to the introduction of weak random fluctuations. The Lyapunov exponent of swimmer trajectories can be positive or negative, can have extremal values, and can have discontinuities depending on the degree of the polygon. A passive sorting device is proposed that traps swimmers of different departure angles into separate bins. We also study the external problem of a microorganism swimming in a patterned environment of square obstacles, where the departure angle dictates the possibility of trapping or diffusive trajectories.

  7. Biosurfactants from marine microorganisms

    OpenAIRE

    Suppasil Maneerat

    2005-01-01

    Biosurfactants are the surface-active molecules synthesized by microorganisms. With the advantage of environmental compatibility, the demand for biosurfactants has been steadily increasing and may eventually replace their chemically synthesized counterparts. Marine biosurfactants produced by some marine microorganisms have been paid more attention, particularly for the bioremediation of the sea polluted by crude oil. This review describes screening of biosurfactant-producing microorganisms, t...

  8. Antimicrobial Activity of Various Essential Oils Against Spoilage and Pathogenic Microorganisms Isolated from Meat Products

    National Research Council Canada - National Science Library

    Gochev, V. K; Girova, T. D

    2009-01-01

    ... from meat products was evaluated. Among used test microorganisms Pseudomonas aeruginosa demonstrated the highest resistance and Staphylococcus aureus demonstrated the highest susceptibility to all of the studied essential oils...

  9. Antimicrobial activity of pure platelet-rich plasma against microorganisms isolated from oral cavity

    National Research Council Canada - National Science Library

    Drago, Lorenzo; Bortolin, Monica; Vassena, Christian; Taschieri, Silvio; Del Fabbro, Massimo

    2013-01-01

    .... In this study, the antimicrobial effect of pure platelet-rich plasma (P-PRP) was evaluated against oral cavity microorganisms such as Enterococcus faecalis, Candida albicans, Streptococcus agalactiae, Streptococcus oralis and Pseudomonas aeruginosa...

  10. [Effect of fertilization levels on soil microorganism amount and soil enzyme activities].

    Science.gov (United States)

    Wang, Wei-Ling; Du, Jun-Bo; Xu, Fu-Li; Zhang, Xiao-Hu

    2013-11-01

    Field experiments were conducted in Shangluo pharmaceutical base in Shaanxi province to study the effect of nitrogen, phosphorus and potassium in different fertilization levels on Platycodon grandiflorum soil microorganism and activities of soil enzyme, using three-factor D-saturation optimal design with random block design. The results showed that N0P2K2, N2P2K0, N3P1K3 and N3P3K1 increased the amount of bacteria in 0-20 cm of soil compared with N0P0K0 by 144.34%, 39.25%, 37.17%, 53.58%, respectively. The amount of bacteria in 2040 cm of soil of N3P1K3 increased by 163.77%, N0P0K3 increased the amount of soil actinomycetes significantly by 192.11%, while other treatments had no significant effect. N2P0K2 and N3P1K3 increased the amounts of fungus significantly in 0-20 cm of soil compared with N0P0K0, increased by 35.27% and 92.21%, respectively. N3P0K0 increased the amounts of fungus significantly in 20-40 cm of soil by 165.35%, while other treatments had no significant effect. All treatments decrease soil catalase activity significantly in 0-20 cm of soil except for N2P0K2, and while N2P2K0 and NPK increased catalase activity significantly in 2040 cm of soil. Fertilization regime increased invertase activity significantly in 2040 cm of soil, and decreased phosphatase activity inordinately in 0-20 cm of soil, while increased phosphatase activity in 2040 cm of soil other than N1P3K3. N3P0K0, N0P0K3, N2P0K2, N2P2K0 and NPK increased soil urease activity significantly in 0-20 cm of soil compared with N0P0K0 by 18.22%, 14.87%,17.84%, 27.88%, 24.54%, respectively. Fertilization regime increased soil urease activity significantly in 2040 cm of soil other than N0P2K2.

  11. Quantitation of microorganic compounds in waters of the Great Lakes by adsorption on activated carbon

    Science.gov (United States)

    Daniels, Stacy L.; Kempe, Lloyd L.; Graham, E. S.; Beeton, Alfred M.

    1963-01-01

    Microorganic compounds in waters of Lakes Michigan and Huron have been sampled by adsorption on activated carbon in filters installed aboard the M/V Cisco and at the Hammond Bay Laboratory of the U.S. Bureau of Commercial Fisheries. The organic compounds were eluted from the carbon according to techniques developed at the U.S. Public Health Service. On the assumption that chloroform eluates represent less polar compounds from industrial sources and alcohol eluates the more polar varieties of natural origin, plots of chloroform eluates against alcohol eluates appear to be useful in judging water qualities. Based upon these criteria, the data in this paper indicate that both the waters of northern Lake Michigan and of Lake Huron, in the vicinity of Hammond Bay, Michigan, are relatively free from pollution. The limnetic waters of Lake Michigan showed a particularly high ratio of alcohol to chloroform eluates. Data for monthly samples indicated that this ratio fluctuated seasonally. The periodicity of the fluctuations was similar to those of lake levels and water temperatures.

  12. Aspects of tests and assessment of filtering materials used for respiratory protection against bioaerosols. Part I: type of active substance, contact time, microorganism species.

    Science.gov (United States)

    Majchrzycka, Katarzyna; Gutarowska, Beata; Brochocka, Agnieszka

    2010-01-01

    This paper presents the results of a study on antimicrobial activity of polymer filter nonwovens produced by needle-punching or melt-blowing with an addition of disinfecting agents. The first part of the paper discusses how the biocidal activity of nonwovens is a function of the active agent added to the nonwovens, the duration of the contact of microorganisms with nonwovens and the type of microorganisms. The types of fibres and disinfecting agents had a considerable effect on the biocidal activity of nonwovens. The biocidal effect of nonwovens increased with the duration of their contact with microorganisms. Fibre activity differed considerably depending on the species of the microorganism. The microorganisms most sensitive to biocidal activity of the active filter nonwoven were S. aureus, M. flavus and E. coli. There were no biocidal effects on spore-forming bacterium B. subtilis.

  13. DEVELOPMENT OF MICROORGANISMS WITH IMPROVED TRANSPORT AND BIOSURFACTANT ACTIVITY FOR ENHANCED OIL RECOVERY

    Energy Technology Data Exchange (ETDEWEB)

    M.J. McInerney; N. Youssef; T. Fincher; S.K. Maudgalya; M.J. Folmsbee; R. Knapp; D. Nagle

    2004-05-31

    Diverse microorganisms were screened for biosurfactant production and anaerobic growth at elevated salt concentrations to obtain candidates most suitable for microbial oil recovery. Seventy percent of the 205 strains tested, mostly strains of Bacillus mojavensis, Bacillus subtilis, Bacillus licheniformis, and Bacillus sonorensis, produced biosurfactants aerobically and 41% of the strains had biosurfactant activity greater than Bacillus mojavensis JF-2, the current candidate for oil recovery. Biosurfactant activity varied with the percentage of the 3-hydroxy-tetradecanoate isomers in the fatty acid portion of the biosurfactant. Changing the medium composition by incorporation of different precursors of 3-hydroxy tetradecanoate increased the activity of biosurfactant. The surface tension and critical micelle concentration of 15 different, biosurfactant-producing Bacillus strains was determined individually and in combination with other biosurfactants. Some biosurfactant mixtures were found to have synergistic effect on surface tension (e.g. surface tension was lowered from 41 to 31 mN/m in some cases) while others had a synergistic effect on CMD-1 values. We compared the transport abilities of spores from three Bacillus strains using a model porous system to study spore recovery and transport. Sand-packed columns were used to select for spores or cells with the best transport abilities through brine-saturated sand. Spores of Bacillus mojavensis strains JF-2 and ROB-2 and a natural recombinant, strain C-9, transported through sand at very high efficiencies. The earliest cells/spores that emerged from the column were re-grown, allowed to sporulate, and applied to a second column. This procedure greatly enhanced the transport of strain C-9. Spores with enhanced transport abilities can be easily obtained and that the preparation of inocula for use in MEOR is feasible. Tertiary oil recovery experiments showed that 10 to 40 mg/l of JF-2 biosurfactant in the presence of 0

  14. The Sound of Silence: Activating Silent Biosynthetic Gene Clusters in Marine Microorganisms

    Directory of Open Access Journals (Sweden)

    F. Jerry Reen

    2015-07-01

    Full Text Available Unlocking the rich harvest of marine microbial ecosystems has the potential to both safeguard the existence of our species for the future, while also presenting significant lifestyle benefits for commercial gain. However, while significant advances have been made in the field of marine biodiscovery, leading to the introduction of new classes of therapeutics for clinical medicine, cosmetics and industrial products, much of what this natural ecosystem has to offer is locked in, and essentially hidden from our screening methods. Releasing this silent potential represents a significant technological challenge, the key to which is a comprehensive understanding of what controls these systems. Heterologous expression systems have been successful in awakening a number of these cryptic marine biosynthetic gene clusters (BGCs. However, this approach is limited by the typically large size of the encoding sequences. More recently, focus has shifted to the regulatory proteins associated with each BGC, many of which are signal responsive raising the possibility of exogenous activation. Abundant among these are the LysR-type family of transcriptional regulators, which are known to control production of microbial aromatic systems. Although the environmental signals that activate these regulatory systems remain unknown, it offers the exciting possibility of evoking mimic molecules and synthetic expression systems to drive production of potentially novel natural products in microorganisms. Success in this field has the potential to provide a quantum leap forward in medical and industrial bio-product development. To achieve these new endpoints, it is clear that the integrated efforts of bioinformaticians and natural product chemists will be required as we strive to uncover new and potentially unique structures from silent or cryptic marine gene clusters.

  15. Antimicrobial activities of essential oils and crude extracts from tropical Citrus spp. against food-related microorganisms

    OpenAIRE

    Tipparat Hongpattarakere; Suphitchaya Chanthachum; Sumonrat Chanthaphon

    2008-01-01

    Ethyl acetate extracts and hydrodistillated-essential oils from peels of Citrus spp. were investigated for their antimicrobial activities against food related microorganisms by broth microdilution assay. Overall, ethyl acetate extracts from all citrus peels showed stronger antimicrobial activities than their essential oils obtained from hydrodistillation. The ethyl acetate extract of kaffir lime (Citrus hystrix DC.) peel showed broad spectrum of inhibition against all Gram-positive bacteria, ...

  16. Biological activities of Rosmarinus officinalis L. (rosemary) extract as analyzed in microorganisms and cells.

    Science.gov (United States)

    de Oliveira, Jonatas Rafael; de Jesus, Daiane; Figueira, Leandro Wagner; de Oliveira, Felipe Eduardo; Pacheco Soares, Cristina; Camargo, Samira Estves Afonso; Jorge, Antonio Olavo Cardoso; de Oliveira, Luciane Dias

    2017-03-01

    R. officinalis L. is an aromatic plant commonly used as condiment and for medicinal purposes. Biological activities of its extract were evaluated in this study, as antimicrobial effect on mono- and polymicrobial biofilms, cytotoxicity, anti-inflammatory capacity, and genotoxicity. Monomicrobial biofilms of Candida albicans, Staphylococcus aureus, Enterococcus faecalis, Streptococcus mutans and Pseudomonas aeruginosa and polymicrobial biofilms composed of C. albicans with each bacterium were formed in microplates during 48 h and exposed for 5 min to R. officinalis L. extract (200 mg/mL). Its cytotoxic effect was examined on murine macrophages (RAW 264.7), human gingival fibroblasts (FMM-1), human breast carcinoma cells (MCF-7), and cervical carcinoma cells (HeLa) after exposure to different concentrations of the extract, analyzed by MTT, neutral red (NR), and crystal violet (CV) assays. The anti-inflammatory activity was evaluated on RAW 264.7 non-stimulated or stimulated by lipopolysaccharide (LPS) from Escherichia coli and treated with different concentrations of the extract for 24 h. Interleukin-1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α) were quantified by ELISA. Genotoxicity was verified by the frequency of micronuclei (MN) at 1000 cells after exposure to concentrations of the extract for 24 h. Data were analyzed by T-Test or ANOVA and Tukey Test ( P ≤ 0.05). Thus, significant reductions in colony forming units per milliliter (CFU/mL) were observed in all biofilms. Regarding the cells, it was observed that concentrations ≤ 50 mg/mL provided cell viability of above 50%. Production of proinflammatory cytokines in the treated groups was similar or lower compared to the control group. The MN frequency in the groups exposed to extract was similar or less than the untreated group. It was shown that R. officinalis L. extract was effective on mono- and polymicrobial biofilms; it also provided cell viability of above 50% (at

  17. Chemical Composition of Mentha spicata L. subsp. tomentosa and M. pulegium L., and their Antimicrobial Activity on Strong Pathogen Microorganisms

    Directory of Open Access Journals (Sweden)

    Emre SEVİNDİK

    2017-03-01

    Full Text Available Mentha L., recognized as a medical and aromatic plant, is a general name affiliated to mint species and belongs to Labiatae family. Some species are used as fresh vegetables in the Turkish kitchen and they can also be used in salads. In addition, some species have been used as a spice in food. In this study, chemical composition and antimicrobial activity towards some pathogenics (gram + and gram - microorganisms of the essential oils Mentha spicata L. subsp. tomentosa (Briq. Harley, Mentha pulegium L. grown under West Anatolian ecological conditions were investigated. Extractions were carried out with Clevenger apparatus and essential oil composition was determined by Gas Chromatography-Mass Spectrometry (GC-MS. Microorganisms used for the antimicrobial studies were Methicillin-resistant Staphylococcus aureus (MRSA, Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa, Enterecoccus faecium DSM 13590, Escherichia coli Q157:H7 and Bacillus cereus CCM99.  As a result, M. pulegium and M. spicata subsp. tomentosa were found to be rich in piperitenone oxide: 72.77% and 28.84%, respectively. Each of the oils was found to possess antimicrobial properties against test microorganisms. Essential oils obtained from Mentha species give positive effect on all microorganisms.

  18. 40 CFR 725.239 - Use of specific microorganisms in activities conducted outside a structure.

    Science.gov (United States)

    2010-07-01

    ... resistance, the structural gene must be limited to the genera Bradyrhizobium and Rhizobium. (B) The...) Rhizobium meliloti. To qualify for an exemption under this section, all of the following conditions must be met for a test involving Rhizobium meliloti: (1) Characteristics of recipient microorganism....

  19. Antimicrobial activity of beta-lactams against multiresistant micro-organisms from the family Enterobacteriaceae, and genus Pseudomonas.

    Science.gov (United States)

    Niebla, A; González, I; Vallín, C

    1994-01-01

    The antimicrobial activity of twenty beta-lactams was determined against multiresistant micro-organisms from the Enterobacteriaceae family (450) and the genus Pseudomonas (90). The antimicrobial susceptibility was assessed by the disk diffusion method. The most effective antibiotics were cephalosporins of the second and third generation, and non-classical beta-lactams (imipenem and moxalactam). A pronounced resistance was found to carbenicillin, ampicillin, cephalotin and cefazolin. These resistance patterns corresponded to a high consumption of these antibiotics.

  20. Biosurfactants from marine microorganisms

    Directory of Open Access Journals (Sweden)

    Suppasil Maneerat

    2005-11-01

    Full Text Available Biosurfactants are the surface-active molecules synthesized by microorganisms. With the advantage of environmental compatibility, the demand for biosurfactants has been steadily increasing and may eventually replace their chemically synthesized counterparts. Marine biosurfactants produced by some marine microorganisms have been paid more attention, particularly for the bioremediation of the sea polluted by crude oil. This review describes screening of biosurfactant-producing microorganisms, the determination of biosurfactant activity as well as the recovery of marine surfactant. The uses of marine biosurfactants for bioremediation are also discussed.

  1. Development of Microorganisms with Improved Transport and Biosurfactant Activity for Enhanced Oil Recovery

    Energy Technology Data Exchange (ETDEWEB)

    M.J. McInerney; K.E. Duncan; N. Youssef; T. Fincher; S.K. Maudgalya; M.J. Folmsbee; R. Knapp; Randy R. Simpson; N.Ravi; D. Nagle

    2005-08-15

    The project had three objectives: (1) to develop microbial strains with improved biosurfactant properties that use cost-effective nutrients, (2) to obtain biosurfactant strains with improved transport properties through sandstones, and (3) to determine the empirical relationship between surfactant concentration and interfacial tension and whether in situ reactions kinetics and biosurfactant concentration meets appropriate engineering design criteria. Here, we show that a lipopeptide biosurfactant produced by Bacillus mojavensis strain JF-2 mobilized substantial amounts of residual hydrocarbon from sand-packed columns and Berea sandstone cores when a viscosifying agent and a low molecular weight alcohol were present. The amount of residual hydrocarbon mobilized depended on the biosurfactant concentration. Tertiary oil recovery experiments showed that 10 to 40 mg/l of JF-2 biosurfactant in the presence of 0.1 mM 2,3-butanediol and 1 g/l of partially hydrolyzed polyacrylamide (PHPA) recovered 10-40% of residual oil from Berea sandstone cores. Even low biosurfactant concentrations (16 mg/l) mobilized substantial amounts of residual hydrocarbon (29%). The bio-surfactant lowered IFT by nearly 2 orders of magnitude compared to typical IFT values of 28-29 mN/m. Increasing the salinity increased the IFT with or without 2,3-butanediol present. The lowest interfacial tension observed was 0.1 mN/m. A mathematical model that relates oil recovery to biosurfactant concentration was modified to include the stepwise changes in IFT as biosurfactant concentrations changes. This model adequately predicted the experimentally observed changes in IFT as a function of biosurfactant concentration. Theses data show that lipopeptide biosurfactant systems may be effective in removing hydrocarbon contamination sources in soils and aquifers and for the recovery of entrapped oil from low production oil reservoirs. Diverse microorganisms were screened for biosurfactant production and anaerobic

  2. A LAMP-based schematic prototype instrument for detection of microorganisms in human outer space activities

    Science.gov (United States)

    Hu, Yongfei; Liu, Zhiheng; Li, Junxiong; Zhu, Baoli

    One of the main tasks of human outer space exploration is to detect signs of life. Based on meteoritic evidence, common ancestry hypothesis has been posed. Therefore, searching for the fundamental molecules (DNA, RNA, and proteins) that constitute life as we know on Earth is feasible and now the typical approach. To achieve this goal, portable, robust, and highly sensitive instrument is also needed. In this study, based on Loop mediated isothermal amplification (LAMP) technique that targets life information storage molecular, DNA, we designed a schematic prototype instrument for microorganism detection. First, we designed LAMP primers used for amplification of DNA markers of Bacteria, Archaea, and Fungus; then, we optimized the LAMP reaction system for space using; and finally, we designed a prototype instrument and operating software system that are compatible with the LAMP reaction system. The results of simulation experiments showed that our instrument performed well for detecting representative microorganisms and the device can achieve semi-automatization. The detection process, from sample preparation to signal visualization, was completed in 1.5 hour. Our study provides a new method and corresponding device for detection of DNA molecular, which has great potential for applications in outer space exploration. Besides, the instrument we designed can also been used for monitoring changes of terrestrial microorganisms in outer space, for example in aircraft.

  3. The Characterization of Psychrophilic Microorganisms and their potentially useful Cold-Active Glycosidases Final Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Brenchly, Jean E.

    2008-06-30

    Our studies of novel, cold-loving microorganisms have focused on two distinct extreme environments. The first is an ice core sample from a 120,000 year old Greenland glacier. The results of this study are particularly exciting and have been highlighted with press releases and additional coverage. The first press release in 2004 was based on our presentation at the General Meeting of the American Society for Microbiology and was augmented by coverage of our publication (Appl. Environ. Microbiol. 2005. Vol. 71:7806) in the Current Topics section of the ASM news journal, “Microbe.” Of special interest for this report was the isolation of numerous, phylogenetically distinct and potentially novel ultrasmall microorganisms. The detection and isolation of members of the ultrasmall population is significant because these cells pass through 0.2 micron pore filters that are generally used to trap microorganisms from environmental samples. Thus, analyses by other investigators that examined only cells captured on the filters would have missed a significant portion of this population. Only a few ultrasmall isolates had been obtained prior to our examination of the ice core samples. Our development of a filtration enrichment and subsequent cultivation of these organisms has added extensively to the collection of, and knowledge about, this important population in the microbial world.

  4. Antimicrobial activity of zinc oxide particles on five micro-organisms of the Challenge Tests related to their physicochemical properties.

    Science.gov (United States)

    Pasquet, Julia; Chevalier, Yves; Couval, Emmanuelle; Bouvier, Dominique; Noizet, Gaëlle; Morlière, Cécile; Bolzinger, Marie-Alexandrine

    2014-01-02

    Zinc oxide is commonly used in pharmaceutical products to prevent or treat topical or systemic diseases owing to its antimicrobial properties, but it is scarcely used as preservative in topical formulations. The aim of this work was to investigate the antimicrobial activity of zinc oxide (ZnO) powders on the five microbial strains used for Challenge Tests in order to evaluate this inorganic compound as a preservative in topical formulation and assess relationships between the structural parameters of ZnO particles and their antimicrobial activity. For this purpose, the physicochemical characteristics of three ZnO grades were measured and their antimicrobial efficacy against the following micro-organisms - Escherichia coli; Staphylococcus aureus; Pseudomonas aeruginosa; Candida albicans; Aspergillus brasiliensis - was assessed using disc diffusion susceptibility tests and a broth dilution method. The comprehensive dataset of physicochemical characteristics and antimicrobial activities (MIC and MBC) is discussed regarding methodological issues related to the particulate nature of ZnO and structure-activity relationships. Every ZnO grade showed bactericidal and antifungal activity against the five tested micro-organisms in a concentration dependent manner. ZnO particles with smaller size, larger specific area and higher porosity exhibit higher antimicrobial activity. Such trends are related to their mechanisms of antimicrobial activity.

  5. INVESTIGATION OF ANTIMICROBIAL ACTIVITY COMBINED PREPARATIONS FOR CLINICAL STRAINS OF MICROORGANISMS ISOLATED FROM PATIENTS WITH BACTERIAL VAGINIT

    Directory of Open Access Journals (Sweden)

    Aslanian M. A.

    2015-12-01

    Full Text Available The problem of bacterial vaginit in some cases the cause of severe infectious diseases genitalia of the fetus and newborn, which can impair the health of future generations. It is noted that the treatment of antibacterial agents observed numerous negative side effects- reducing the biochemical activity of the intestinal microflora, abuse microbiota, leading to the development of dysbiosis, increasing the number of resistant strains of pathogens, the risk of allergic reaction sand immunological disorders. A study was conducted towards finding effective combinations of drugs from different pharmacological groups means to create a combination of drugs. The aim of the study was to develop and explore and Flamini combination of miramistin combined medicines to treat bacterial vaginit. As a result of studies in patients with bacterial vaginit pathological material was isolated and identified 72 strains of microorganisms (Staphylococcus spp, Streptococcus spp, Enterococcus spp, Escherichia coli, Haemophillu sssp, Candida albican sand various strains of anaerobic microorganisms. For the combined treatment of infectious and in flammatory diseases (mixed infections in humans the combined drugin tablet form. All clinical strains of microorganisms isolated from patients with bacterial vaginit were tested for sensitivity to the combined preparation in tablet form with Flamini and miramistin. The greatest sensitivity to the drugs found clinical strains of microorganisms: Staphylococcu saureus, Staphylococcus epidermidis, Peptococcus niger (diameter zone growth retardation is 25,5-23,5 mm. composition tablets number 1 (0.05 g Flamini, miramistini 0.02 g, which was selected for further study shows bacteriostatic effect against a wide range of microorganisms and fungi Rod Candida. IPC for Staphylococcus sp was 20-25 pg / mL for Streptococcus sp 35,0-40,0 mg / ml, for intestinal group 35,0-40,0 for fungi 30,0 mg / ml unlike pills number 2 and number 3, where the

  6. [Effects of combined application of biogas slurry and chemical fertilizer on winter wheat rhizosphere soil microorganisms and enzyme activities].

    Science.gov (United States)

    Feng, Wei; Guan, Tao; Wang, Xiao-yu; Zhu, Yun-ji; Guo, Tian-cai

    2011-04-01

    This paper studied the effects of combined application of biogas slurry and chemical fertilizer under same N application rate on the quantities of bacteria, actinomycetes and fungi as well as the activities of urease, protease and catalase in winter wheat rhizosphere soil. With the growth of winter wheat, the quantities of test microorganisms and the activities of urease and catalase showed a trend of increasing after an initial decrease, while the protease activity showed an S-type change. Combined application of biogas slurry and chemical fertilizer increased the quantities of test microorganisms significantly, and improved the activities of soil urease and protease. Applying 50% biogas slurry N as basal plus 50% chemical N as topdressing and applying 25% biogas slurry N as basal plus 75% chemical N as topdressing had the best effect, while applying single conventional urea or biogas slurry had the worst effect. At all growth stages, the activity of soil catalase was the highest in treatments 25% biogas slurry N as basal plus 75% chemical N as topdressing and single biogas slurry, but had greater differences in other treatments among the growth stages. The results suggested that proper biogas slurry application combined with chemical fertilization could increase the microbial quantity and enzyme activities in winter wheat rhizosphere soil.

  7. Using Short-Term Enrichments and Metagenomics to Obtain Genomes from uncultured Activated Sludge Microorganisms

    DEFF Research Database (Denmark)

    Karst, Søren Michael; Nielsen, Per Halkjær; Albertsen, Mads;

    is that they depend on system-specific reference genomes in order to analyze the vast amounts of data (Albertsen et al., 2012). This limits the application of -omics to environments for which a comprehensive catalogue of reference genomes exists e.g. the human gut. Several strategies for obtaining microbial genomes...... was reduced by short-term enrichment under defined conditions favoring certain functional groups of organisms. Bioinformatic genome extraction was greatly improved by utilizing multiple metagenomes where the microorganisms were in different abundances. In this study we retrieved 15 complete genomes...

  8. Development of Microorganisms with Improved Transport and Biosurfactant Activity for Enhanced Oil Recovery

    Energy Technology Data Exchange (ETDEWEB)

    M.J. McInerney; K.E. Duncan; N. Youssef; T. Fincher; S.K. Maudgalya; M.J. Folmsbee; R. Knapp; Randy R. Simpson; N.Ravi; D. Nagle

    2005-08-15

    The project had three objectives: (1) to develop microbial strains with improved biosurfactant properties that use cost-effective nutrients, (2) to obtain biosurfactant strains with improved transport properties through sandstones, and (3) to determine the empirical relationship between surfactant concentration and interfacial tension and whether in situ reactions kinetics and biosurfactant concentration meets appropriate engineering design criteria. Here, we show that a lipopeptide biosurfactant produced by Bacillus mojavensis strain JF-2 mobilized substantial amounts of residual hydrocarbon from sand-packed columns and Berea sandstone cores when a viscosifying agent and a low molecular weight alcohol were present. The amount of residual hydrocarbon mobilized depended on the biosurfactant concentration. Tertiary oil recovery experiments showed that 10 to 40 mg/l of JF-2 biosurfactant in the presence of 0.1 mM 2,3-butanediol and 1 g/l of partially hydrolyzed polyacrylamide (PHPA) recovered 10-40% of residual oil from Berea sandstone cores. Even low biosurfactant concentrations (16 mg/l) mobilized substantial amounts of residual hydrocarbon (29%). The bio-surfactant lowered IFT by nearly 2 orders of magnitude compared to typical IFT values of 28-29 mN/m. Increasing the salinity increased the IFT with or without 2,3-butanediol present. The lowest interfacial tension observed was 0.1 mN/m. A mathematical model that relates oil recovery to biosurfactant concentration was modified to include the stepwise changes in IFT as biosurfactant concentrations changes. This model adequately predicted the experimentally observed changes in IFT as a function of biosurfactant concentration. Theses data show that lipopeptide biosurfactant systems may be effective in removing hydrocarbon contamination sources in soils and aquifers and for the recovery of entrapped oil from low production oil reservoirs. Diverse microorganisms were screened for biosurfactant production and anaerobic

  9. Chromium accumulation, microorganism population and enzyme activities in soils around chromium-containing slag heap of steel alloy factory

    Institute of Scientific and Technical Information of China (English)

    HUANG Shun-hong; PENG Bing; YANG Zhi-hui; CHAI Li-yuan; ZHOU Li-cheng

    2009-01-01

    The environmental risk of chromium pollution is pronounced in soils adjacent to chromate industry. It is important to investigate the functioning of soil microorganisms in ecosystems exposed to long-term contamination by chromium. 45 soil samples obtained from different places of the slag heap in a steel alloy factory were analyzed for chromium contamination level and its effect on soil microorganisms and enzyme activities. The results show that the average concentrations of total Cr in the soil under the slag heap, adjacent to the slag heap and outside the factory exceed the threshold of Secondary Environmental Quality Standard for Soil in China by 354%, 540% and 184%, respectively, and are 15, 21 and 9 times higher than the local background value, respectively. Elevated chromium loadings result in changes in the activity of the soil microbe, as indicated by the negative correlations between soil microbial population and chromium contents. Dehydrogenase activity is greatly depressed by chromium in the soil. The results imply that dehydrogenase activity can be used as an indicator for the chromium pollution level in the area of the steel alloy factory.

  10. Antimicrobial activity and synergism of lactoferrin and lysozyme against cariogenic microorganisms.

    Science.gov (United States)

    de Andrade, Flaviana Bombarda; de Oliveira, Jair Caetano; Yoshie, Marjorie Takei; Guimarães, Bruno Martini; Gonçalves, Rafael Braga; Schwarcz, Waleska Dias

    2014-01-01

    The present study evaluated the antimicrobial in vitro effects of the salivary proteins lactoferrin and lysozyme on microorganisms involved in the carious process, obtaining their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Streptococcus mutans (ATCC 25175) and Lactobacillus casei (ATCC 7469) were submitted to broth macrodilution of lysozyme at 80 mg/mL and lactoferrin at 200 mg/mL. The tubes were read in a spectrophotometer after they had been incubated at 37 °C for 18 h, in a carbon dioxide chamber, in order to read the MIC. A new subculture was carried on agar plates to obtain the MBC. The agar diffusion method was also tested, using BHI agar with 100 µL of the standardized microbial inocula. Filter-paper disks soaked in 10 µL of the solutions lactoferrin (200 µg/mL) and lysozyme (80 µg/mL) were placed on the agar surface. Inhibition halos were not observed on the plates, showing the absence of the antimicrobial effects of these proteins in this method. The bactericidal and bacteriostatic effects of lysozyme on L. casei were 50.3 mg/mL and 43.1 mg/mL respectively. The bactericidal and bacteriostatic effects on S. mutans were 68.5 mg/mL and 58.7 mg/mL. Lactoferrin did not induce any inhibitory effects on any microorganism, even in the concentration of 200 mg/mL. There was not a synergic antimicrobial effect of proteins, when they were tested together, even in the concentration of 42.8 mg/mL of lysozyme and 114 mg/mL of lactoferrin (the highest values evaluated). S. mutans and L. casei were only inhibited by lysozyme, not affected by lactoferrin and by the synergic use of both proteins.

  11. Electrochemically active microorganisms from an acid mine drainage-affected site promote cathode oxidation in microbial fuel cells

    KAUST Repository

    Rojas, Claudia

    2017-08-03

    The limited database of acidophilic or acidotolerant electrochemically active microorganisms prevents advancements on microbial fuel cells (MFCs) operated under low pH. In this study, three MFCs were used to enrich cathodic biofilms using acid mine drainage (AMD) sediments as inoculum. Linear sweep voltammetry showed cathodic current plateaus of 5.5 (± 0.7) mA at about − 170 mV vs Ag/AgCl and 8.5 (± 0.9) mA between − 500 mV to − 450 mV vs Ag/AgCl for biofilms developed on small graphite fiber brushes. After gamma irradiation, biocathodes exhibited a decrease in current density approaching that of abiotic controls. Electrochemical impedance spectroscopy showed six-fold lower charge transfer resistance with viable biofilm. Pyrosequencing data showed that Proteobacteria and Firmicutes dominated the biofilms. Acidithiobacillus representatives were enriched in some biocathodes, supporting the potential importance of these known iron and sulfur oxidizers as cathodic biocatalysts. Other acidophilic chemolithoautotrophs identified included Sulfobacillus and Leptospirillum species. The presence of chemoautotrophs was consistent with functional capabilities predicted by PICRUSt related to carbon fixation pathways in prokaryotic microorganisms. Acidophilic or acidotolerant heterotrophs were also abundant; however, their contribution to cathodic performance is unknown. This study directs subsequent research efforts to particular groups of AMD-associated bacteria that are electrochemically active on cathodes.

  12. Antimicrobial activity of two South African honeys produced from indigenous Leucospermum cordifolium and Erica species on selected micro-organisms

    Directory of Open Access Journals (Sweden)

    Grobler Sias R

    2008-07-01

    Full Text Available Abstract Background Honey has been shown to have wound healing properties which can be ascribed to its antimicrobial activity. The antimicrobial activity can be effective against a broad spectrum of bacterial species especially those of medical importance. It has also been shown that there is considerable variation in the antimicrobial potency of different types of honey, which is impossible to predict. With this in mind we tested the antimicrobial activity of honeys produced from plants grown in South Africa for their antibacterial properties on selected standard strains of oral micro-organisms. Methods The honeys used were produced from the blossoms of Eucalyptus cladocalyx (Bluegum trees, an indigenous South African plant Leucospermum cordifolium (Pincushion, a mixture of wild heather shrubs, mainly Erica species (Fynbos and a Leptospermum scoparium (Manuka honey. Only pure honey which had not been heated was used. The honeys were tested for their antimicrobial properties with a broth dilution method. Results Although the honeys produced some inhibitory effect on the growth of the micro-organisms, no exceptionally high activity occurred in the South African honeys. The carbohydrate concentration plays a key role in the antimicrobial activity of the honeys above 25%. However, these honeys do contain other antimicrobial properties that are effective against certain bacterial species at concentrations well below the hypertonic sugar concentration. The yeast C. albicans was more resistant to the honeys than the bacteria. The species S. anginosus and S. oralis were more sensitive to the honeys than the other test bacteria. Conclusion The honeys produced from indigenous wild flowers from South Africa had no exceptionally high activity that could afford medical grade status.

  13. Features of soil enzyme activities and the number of microorganisms in plantations and their relationships with soil nutrients in the Qinling Mountains,. China

    Institute of Scientific and Technical Information of China (English)

    Gang FU; Zengwen LIU; Fangfang CUI

    2009-01-01

    We studied the distribution of soil nutrients, the number of soil microorganisms, soil enzyme activities, and their relationships in pure and mixed plantations. Soil enzyme activities, the number of soil microorganisms, and soil nutrients were measured in plantations of Chinese pine (Pinustabulaeformis), larch (Larix kaempferi), sharp tooth oak (Quercus aliena var. acuteserrata), Manchurian catalpa (Catalpa fargesii), and mixed plantations in the Qinling Mountains, China. Compared with pure plantations, the conifer-broad-leaved broadleaf mixed plantations increased total N, available N, total P, available K, and organic matter in the forest soil; promoted the activities ofinvertase and urease by 16.7% and 53.8%; and increased the total amount of soil microorganisms by 95.9% and the number of bacteria by 104.5% (p<0.05). The correlations between soil enzymes, number of microorganisms, and soil nutrients were significant(p<0.05), and the correlations between the number of soil bacteria and basic nutrient prosperities (total N, available N, available K, and organic matter (OM)) were significant or highly significant. The correlations between the number of soil actinomycetes, and soil total N, available N, OM, and pH were also significant or highly significant. A suitable mixture of planted conifers and broad-leaved species improves the quality and amount of soil nutrients, increases the number of soil microorganisms and changes their redistribution. The change of soil enzymes and the number of soil microorganisms are indications of the change tendency of soil nutrients.

  14. [Distribution and activity of microorganisms in the deep repository for liquid radioactive waste at the Siberian Chemical Combine].

    Science.gov (United States)

    Nazina, T N; Luk'ianova, E A; Zakharova, E V; Ivoĭlov, V S; Poltaraus, A B; Kalmykov, S N; Beliaev, S S; Zubkov, A A

    2006-01-01

    The physicochemical conditions, composition of microbial communities, and the rates of anaerobic processes in the deep sandy horizons used as a repository for liquid radioactive wastes (LRW) at the Siberian Chemical Combine (Seversk, Tomsk oblast), were studied. Formation waters from the observation wells drilled into the production horizons of the radioactive waste disposal site were found to be inhabited by microorganisms of different physiological groups, including aerobic organotrophs, anaerobic fermentative, denitrifying, sulfate-reducing, and methanogenic bacteria. The density of microbial population, as determined by cultural methods, was low and usually did not exceed 10(4) cells/ml. Enrichment cultures of microorganisms producing gases (hydrogen, methane, carbon dioxide, and hydrogen sulfide) and capable of participation in the precipitation of metal sulfides were obtained from the waters of production horizons. The contemporary processes of sulfate reduction and methanogenesis were assayed; the rates of these terminal processes of organic matter destruction were found to be low. The denitrifying bacteria from the underground repository were capable of reducing the nitrates contained in the wastes, provided sources of energy and biogenic elements were available. Biosorption of radionuclides by the biomass of aerobic bacteria isolated from groundwater was demonstrated. The results obtained give us insight into the functional structure of the microbial community inhabiting the waters of repository production horizons. This study indicates that the numbers and activity of microbial cells are low both inside and outside the zone of radioactive waste dispersion, in spite of the long period of waste discharge.

  15. [Microbiological contamination and antimicrobial activity of cristalised cane sugar on some medically important microorganisms in Costa Rica].

    Science.gov (United States)

    Pujol, Verónica; Diaz, Jendry; Rodríguez, Evelyn; Arias, María Laura

    2008-06-01

    Microbiological contamination and antimicrobial activity of cristalised cane sugar on some medically important microorganisms in Costa Rica. Unrefined cristalised cane sugar, obtained after the filtration and evaporation of sugar cane juice, is a nutritional product of traditional consumption in Costa Rica and other Neotropical countries. It has been used in the topic treatment of infected wounds, with satisfactory results even with some antibiotic-ressistant bacteria. We studied the microbiological quality of 50 commercial samples. The analyses included total aerobic and anaerobic bacteria plate count; aerobic and anaerobic spore count; mold and yeast count; total and fecal coliforms; and presence of Clostridium botulinum. The antimicrobial effect was tested for Staphylococcus aureus (ATCC 25923), S. epidermidis (UCR 2902), Pseudomonas aeruginosa (ATCC 9027), Escherichia coli (ATCC 25922), Salmonella enteritidis (ATCC 13076), Listeria monocytogenes (ATCC 19116) and Aspergillus niger (Asni 06). Most of the samples (76%) presented counts lower than 100 CFU/g especially for sporulated forms (90% lower than 20 CFU/g), the mold and yeast count was higher (38% higher than 10(2) CFU/g), demonstrating the importance of these microorganisms in the spoilage of the product; 76% of the samples presented fecal contamination; C. botulinum was not isolated with the methodology employed. No inhibitory effect was observed for A. niger, but all samples han an inhibitory effect over the other species, especially for P. aeruginosa and S. aureus.

  16. DEVELOPMENT OF MICROORGANISMS WITH IMPROVED TRANSPORT AND BIOSURFACTANT ACTIVITY FOR ENHANCED OIL RECOVERY

    Energy Technology Data Exchange (ETDEWEB)

    M.J. McInerney; R.M. Knapp; D.P. Nagle, Jr.; Kathleen Duncan; N. Youssef; M.J. Folmsbee; S. Maudgakya

    2003-06-26

    production. As an initial step in the search for a better biosurfactant-producing microorganism, 157 bacterial strains were screened for biosurfactant production under both aerobic and anaerobic conditions. A hundred and forty seven strains produced either equal or higher amounts of biosurfactant compared to B. mojavensis JF-2 and the 10 best strains were chosen for further study. In an attempt to increase biosurfactant production, a genetic recombination experiment was conducted by mixing germinating spores of four of the best strains with B. mojavensis JF-2. Biosurfactant production was higher with the mixed spore culture than in the cocultures containing B. mojavensis JF-2 and each of the other 4 strains or in a mixed culture containing all five strains that had not undergone genetic exchange. Four isolates were obtained from the mixed spores culture that gave higher biosurfactant production than any of the original strains. Repetitive sequence-based polymerase chain reaction analysis showed differences in the band pattern for these strains compared to the parent strains, suggesting the occurrence of genetic recombination. We have a large collection of biosurfactant-producing microorganisms and a natural mechanism to improve biosurfactant production in these organisms.

  17. Isolation and identification of microorganisms and antibacterial activity of Laban Zeer, an Egyptian traditional fermented milk product

    Directory of Open Access Journals (Sweden)

    Farag Ali Saleh

    2013-03-01

    Full Text Available Laban Zeer is a traditional Egyptian fermented milk product. The microorganisms of Laban Zeer were isolated and identified to species level, as well as the antibacterial activity of Laban Zeer was also studied against pathogenic bacteria. Total viable microorganisms, including, lactic acid bacteria (LAB, aerobic mesophilic bacterial, Enterococus and Enterobacteriaceae were enumerated. A total forty eight LAB and twenty eight yeast isolates were isolated from four Laban Zeer samples and identified by API 50 CHL and API 20C AUX identification system, respectively. The avenger of LAB counts were 7.4 cfu/g, while yeast and Enterococus counts were 4.67 and 4.39 cfu/g, respectively. It is noted that the count of bacteria belonging to the family of Enterobacteriaceae was not detected in all tested samples. The LAB species were identified as Leuconostoc mesenteroides subsp. cremoris, Lb. rhamnosus, Lb.  plantarum, Lb. paracasei subsp paracasei, Lb. delbercii subsp bulgaricus, Lb. curvatus subsp curvatus and Lb acidophilus. The isolated yeasts were identified as Sccharomyces cervisiae, Candida kefyr, Candida utilis and Rhodotorula mucilaginosa. The most frequently isolated species was found to be Leuconostoc mesenteroides subsp. cremoris (37.5%, Lb. rhamnosus (20.8%, Sccharomyces cervisiae (41.9% and Candida kefyr (29.0%.  The antimicrobial activities of Laban Zeer were evaluated in vitro using an agar well diffusion method and in situ method. The major supernatants of Laban Zeer samples inhibited the growth of pathogenic bacteria, belonging to Escherichia, Pseudomonas, Salmonella, Listeria and Staphylococcus genera in various degrees. The in situ method was performed by the inoculation of Staph. aureus and E. coli in Laban Zeer samples separately at an initial level around of 6 log cfu/ml. The count of Staph. aureus and E. coli were not detected after 12 and 3 days of refrigerated storage period,  respectively in samples number 2 and 3. Laban Zeer is

  18. Antimicrobial activities of essential oil and hexane extract of Florence fennel [Foeniculum vulgare var. azoricum (Mill.) Thell.] against foodborne microorganisms.

    Science.gov (United States)

    Cetin, Bülent; Ozer, Hakan; Cakir, Ahmet; Polat, Taşkin; Dursun, Atilla; Mete, Ebru; Oztürk, Erdoğan; Ekinci, Melek

    2010-02-01

    The objective of this study was to determine the chemical compositions of the essential oil and hexane extract isolated from the inflorescence, leaf stems, and aerial parts of Florence fennel and the antimicrobial activities of the essential oil, hexane extract, and their major component, anethole, against a large variety of foodborne microorganisms. Gas chromatography and gas chromatography-mass spectrometry analysis showed that the essential oils obtained from inflorescence, leaf stems, and whole aerial parts contained (E)-anethole (59.28-71.69%), limonene (8.30-10.73%), apiole (trace to 9.23%), beta-fenchyl acetate (3.02-4.80%), and perillene (2.16-3.29%) as the main components. Likewise, the hexane extract of the plant sample exhibited a similar chemical composition, and it contained (E)-anethole (53.00%), limonene (27.16%), gamma-terpinene (4.09%), and perillene (3.78%). However, the hexane extract also contained less volatile components such as n-hexadecanoic acid (1.62%), methyl palmitate (1.17%), and linoleic acid (1.15%). The in vitro antimicrobial assays showed that the essential oil, anethole, and hexane extract were effective against most of the foodborne pathogenic, saprophytic, probiotic, and mycotoxigenic microorganisms tested. The results of the present study revealed that (E)-anethole, the main component of Florence fennel essential oil, is responsible for the antimicrobial activity and that the essential oils as well as the hexane extract can be used as a food preservative. This study is the first report showing the antimicrobial activities of essential oil and hexane extract of Florence fennel against probiotic bacteria.

  19. [ACTIVITY OF ANTIMICROBIAL NANOSTRUCTURED BARRIER LAYERS BASED ON POLYETHYLENETEREPHTHALATE IN RELATION TO CLINICAL STRAINES OF MICROORGANISMS FOR SICK PERSONS OF GASTROENTEROLOGICAL PROFILE].

    Science.gov (United States)

    Elinson, V M; Rusanova, E V; Vasilenko, I A; Lyamin, A N; Kostyuchenko, L N

    2015-01-01

    Homeostasis transgressions of enteral medium including disbiotic ones are often accompanying deseases of digestive tract. Espessially it touches upon sick persons connected with probe nourishing. One of the way for solving this problem is normalization of digestion microflore by means of wares with nanotechnological modifications of walls (probes, stomic tubes) which provide them antimicrobial properties and assist to normalization of digestive microbiotis and enteral homeostasis completely. The aim to study is research of antimicrobial activity of of nanostructured barrier layers based on polyethyleneterephthalate (PET) in relation to clinical straines of microorganisms. For barrier layer creation the approach on the base of methods of ion-plasma technology was used including ion-plasma treatment (nanostructuring) of the surface by ions noble and chemically active gases and following formation nanodimensional carbon films on the surface/ For the study of antimicrobial activity in relation to clinical straines of microorganisms we used the technique which allowed to establish the influence of parting degree of microorganisms suspension and time for samples exposing and microorganisms adsorbed on the surface. In experiment clinical straines obtained from different materials were used: Staphylococcus Hly+ and Calbicans--from pharyngeal mucosa, E. coli--from feces, K.pneumoniae--from urine. Sharing out and species identification of microorganisms were fulfilled according with legasy documents. In results of the study itwas obtained not only the presence of staticticaly confirmed antimicrobial activity of PET samples with nanostructured barrier layers in relation to different stimulators of nosocomical infections but also the influence of different factors connected with formation of nanostructured layers and consequently based with them physicochemical characteristics such as, in particular, surface energy, surface relief parameters, surface charg and others, as well

  20. Nucleic-acid characterization of the identity and activity of subsurface microorganisms

    Science.gov (United States)

    Madsen, E. L.

    Nucleic-acid approaches to characterizing naturally occurring microorganisms in their habitats have risen to prominence during the last decade. Extraction of deoxyribonucleic-acid (DNA) and ribonucleic-acid (RNA) biomarkers directly from environmental samples provides a new means of gathering information in microbial ecology. This review article defines: (1) the subsurface habitat; (2) what nucleic-acid procedures are; and (3) the types of information nucleic-acid procedures can and cannot reveal. Recent literature examining microbial nucleic acids in the terrestrial subsurface is tabulated and reviewed. The majority of effort to date has focused upon insights into the identity and phylogeny of subsurface microorganisms afforded by analysis of their 16S rRNA genes. Given the power of nucleic-acid-based procedures and their limited application to subsurface habitats to date, many future opportunities await exploration. Au cours des derniers dix ans, les approches basées sur les acides nucléiques sont apparues et devenues essentielles pour caractériser dans leurs habitats les microorganismes existant à l'état naturel. L'extraction directe de l'ADN et de l'ARN, qui sont des biomarqueurs, d'échantillons environnementaux a fourni un nouveau moyen d'obtenir des informations sur l'écologie microbienne. Cet article synthétique définit 1) l'habitat souterrain, 2) ce que sont les procédures basées sur les acides nucléiques, 3) quel type d'informations ces procéedures peuvent et ne peuvent pas révéler. Les travaux récemment publiés concernatn les acides nucléiques microbiens dans le milieu souterrain terrestre sont catalogués et passés en revue. La majorité des efforts pour obtenir es données s'est concentrée sur l'identité et la phylogénie des microorganismes souterrains fournies par l'analyse de leurs gènes 16S rRNA. Étant donné la puissance des procédures basées sur les acides nucléiques et leur application limitée aux habitats souterrains

  1. Determination of bacteriocin activity with bioassays carried out on solid and liquid substrates: assessing the factor "indicator microorganism"

    OpenAIRE

    Ambrosiadis Ioannis; Dasiou Despina; Filioussis George; Avramidis Nicholaos; Papagianni Maria

    2006-01-01

    Abstract Background Successful application of growth inhibition techniques for quantitative determination of bacteriocins relies on the sensitivity of the applied indicator microorganism to the bacteriocin to which is exposed. However, information on indicator microorganisms' performance and comparisons in bacteriocin determination with bioassays is almost non-existing in the literature. The aim of the present work was to evaluate the parameter "indicator microorganism" in bioassays carried o...

  2. Antimicrobial activity of selected Iranian medicinal plants against a broad spectrum of pathogenic and drug multiresistant micro-organisms.

    Science.gov (United States)

    Abedini, A; Roumy, V; Mahieux, S; Gohari, A; Farimani, M M; Rivière, C; Samaillie, J; Sahpaz, S; Bailleul, F; Neut, C; Hennebelle, T

    2014-10-01

    The antimicrobial activities of 44 methanolic extracts from different parts of Iranian indigenous plant species used in traditional medicines of Iran were tested against a panel of 35 pathogenic and multiresistant bacteria and 1 yeast. The antimicrobial efficacy was determined using Müller-Hinton agar in Petri dishes seeded by a multiple inoculator and minimal inhibition concentration (MIC) method. The 21 most active extracts (MIC micro-organisms) were submitted to a more refined measurement. The best antibacterial activity was obtained by 10 plants. Microdilution assays allowed to determinate the MIC and MBC of the 21 most active extracts. The lowest achieved MIC value was 78 μg ml(-1), with 4 extracts. This work confirms the antimicrobial activity of assayed plants and suggests further examination to identify the chemical structure of their antimicrobial compounds. Significance and impact of the study: This study describes the antimicrobial screening of Iranian plant extracts chosen according to traditional practice against 36 microbial strains, from reference culture collections or recent clinical isolates, and enables to select 4 candidates for further chemical characterization and biological assessment: Dorema ammoniacum, Ferula assa-foetida, Ferulago contracta (seeds) and Perovskia abrotanoides (aerial parts). This may be useful in the development of potential antimicrobial agents, from easily harvested and highly sustainable plant parts. Moreover, the weak extent of cross-resistance between plant extracts and antibiotics warrants further research and may promote a strategy based on less potent but time-trained products.

  3. Biomass of active microorganisms is not limited only by available carbon in the rhizosphere

    Science.gov (United States)

    Gilmullina, Aliia

    2017-04-01

    Microbial activity is generally limited by carbon (C) availability. The easily available substrate release by roots creates so called "hotspots" in the rhizosphere that drives microbial activity removing C limitation. We simulated a gradient of root exudates by glucose addition at different concentrations to stimulate the activation of microbial biomass (MB). Glucose was added at the rates lower than MB (5, 10, 25 and 50%) and at the rates similar or higher than MB (100, 150, 200, 250, 300 and 400%). During incubation CO2 efflux was measured by conductometry, the size of active MB and specific growth rate were estimated by substrate-induced growth response method. We tested a hypothesis that glucose addition exceeding 100% MB is able to activate major fraction of soil microbial community. Addition of glucose at concentrations higher than 5% decreased specific growth rate, demonstrating the shift of microbial community from r-strategy to K-strategy. The percentage of active MB grew up by the increase of glucose concentration. The treatment with glucose at 100% presented a dramatic shift in the activation of MB up to 14%. Contrary to our hypothesis, further increase in glucose rate caused moderate stimulation of active MB up to 22% of total MB. Furthermore, glucose addition above 200% did not increase the fraction of active biomass indicating glucose oversaturation and possible limitation by other nutrients. The results suggest that despite the fact that C is the most important limitation factor, limitless C supply is not able to activate MB up to 100%. Thus, if the rhizosphere is limited by nutrients, the fraction of active biomass remains at low level despite an excess of available C.

  4. Effects of glyphosate and foliar amendments on activity of microorganisms in the soybean rhizosphere.

    Science.gov (United States)

    Means, Nathan E; Kremer, Robert J; Ramsier, Clifford

    2007-02-01

    A field study was conducted to determine the effects of glyphosate on microbial activity in the rhizosphere of glyphosate-resistant (GR) soybean and to evaluate interactions with foliar amendments. Glyphosate at 0.84 kg ae ha(-1) was applied GR soybean at the V4-V5 development stages. Check treatments included a conventional herbicide tank mix (2003 study only) and no herbicides (hand-weeded). Ten days after herbicide application, a commercially available biostimulant and a urea solution (21.0% N) were applied to soybean foliage at 33.5 mL ha(-1) and 9.2 kg ha(-1), respectively. Soil and plant samples were taken 0, 5, 10, 15, 20 and 25 days after herbicide application then assayed for enzyme and respiration activities. Soil respiration and enzyme activity increased with glyphosate and foliar amendment applications during the 2002 growing season; however, similar increases were not observed in 2003. Contrasting cumulative rainfall between 2002 and 2003 likely accounted for differences in soil microbial activities. Increases in soil microbial activity in 2002 suggest that adequate soil water and glyphosate application acted together to increase microbial activity. Our study suggests that general soil microbial properties including those involving C and N transformations are not sensitive enough to detect effects of glyphosate on rhizosphere microbial activity. Measurements of soil-plant-microbe relationships including specific microbial groups (i.e., root-associated Fusarium spp.) are likely better indicators of impacts of glyphosate on soil microbial ecology.

  5. The effect of chlorsulfurone and MCPB-Na on the enzymatic activity of microorganisms

    Directory of Open Access Journals (Sweden)

    Filimon Marioara Nicoleta

    2014-01-01

    Full Text Available herbicides, have a broad spectrum effect on weeds, in relatively low doses and with a much reduced toxicity on livestock. In this study were used two herbicides: dacsulfuron with the active substance chlorsulfuron (0.005 - 0.035 μg/g soil and butoxone with the active substance MCPB-Na (0.005 - 0.035 mg/L/g soil. The samples were collected from a depth of 0-20 cm from chernozem soil. The effect of herbicide was estimated by measuring the activity of catalase, actual and potential dehydrogenase, urease and cellulase activities. All samples being incubated for 10 days at 27°C using Sapp medium for isolation and study of cellulosolytic bacteria. The inhibitory effect of the tested herbicides was the most intense for the urease and dehydrogenase enzymatic activities. The most resistant cellulosolytic bacteria to the effects of dacsulfuron were Cellfalcicula fusca, Cellfalcicula viridis, Cellvibrio fulvus and Fuseaux veris and for butoxone Cellfalcicula mucosa, C. viridis and C. fulvus.

  6. Biofilm inhibition activity of traditional medicinal plants from Northwestern Argentina against native pathogen and environmental microorganisms

    Directory of Open Access Journals (Sweden)

    Cintia Mariana Romero

    Full Text Available Abstract: INTRODUCTION: Plants have been commonly used in popular medicine of most cultures for the treatment of disease. The in vitro antimicrobial activity of certain Argentine plants used in traditional medicine has been reported. The aim of this study was to investigate the antimicrobial, anti-biofilm, and anti-cell adherence activities of native plants (Larrea divaricata, Tagetes minuta, Tessaria absinthioides, Lycium chilense, and Schinus fasciculatus collected in northwestern Argentina. METHODS: The activities of the five plant species were evaluated in Bacillus strains and clinical strains of coagulase-negative Staphylococcus isolated from northwestern Argentina and identified by 16S rDNA. RESULT: Lycium chilense and Schinus fasciculatus were the most effective antimicrobial plant extracts (15.62µg/ml and 62.50µg/ml for Staphylococcus sp. Mcr1 and Bacillus sp. Mcn4, respectively. The highest (66% anti-biofilm activity against Bacillus sp. Mcn4 was observed with T. absinthioides and L. divaricate extracts. The highest (68% anti-biofilm activity against Staphylococcus sp. Mcr1 was observed with L. chilense extract. T. minuta, T. absinthioides, and L. divaricata showed percentages of anti-biofilm activity of between 55% and 62%. The anti-adherence effects of T. minuta and L. chilense observed in Bacillus sp. Mcn4 reflected a difference of only 22% and 10%, respectively, between anti-adherence and biofilm inhibition. Thus, the inhibition of biofilm could be related to cell adherence. In Staphylococcus sp. Mcr1, all plant extracts produced low anti-adherence percentages. CONCLUSION: These five species may represent a source of alternative drugs derived from plant extracts, based on ethnobotanical knowledge from northwest Argentina.

  7. Lignite microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Bulankina, M.A.; Lysak, L.V.; Zvyagintsev, D.G. [Moscow MV Lomonosov State University, Moscow (Russian Federation). Faculty of Soil Science

    2007-03-15

    The first demonstration that samples of lignite at a depth of 10 m are considerably enriched in bacteria is reported. According to direct microscopy, the abundance of bacteria was about 10{sup 7} cells/g. About 70% of cells had intact cell membranes and small size, which points to their anabiotic state. The fungal mycelium length was no more than 1 m. Lignite inoculation onto solid glucose-yeast-peptone medium allowed us to isolate bacteria of the genera Bacillus, Rhodococcus, Arthrobacter, Micrococcus, Spirillum, and Cytophaga. Representatives of the genera Penicillium and Trichoderma were identified on Czapek medium. Moistening of lignite powder increased the microbial respiration rate and microbial and fungal abundance but did not increase their generic diversity. This finding suggests that the studied microorganisms are autochthonous to lignite.

  8. QSAR study and the hydrolysis activity prediction of three alkaline lipases from different lipase-producing microorganisms.

    Science.gov (United States)

    Wang, Haikuan; Wang, Xiaojie; Li, Xiaolu; Zhang, Yehong; Dai, Yujie; Guo, Changlu; Zheng, Heng

    2012-09-28

    The hydrolysis activities of three alkaline lipases, L-A1, L-A2 and L-A3 secreted by different lipase-producing microorganisms isolated from the Bay of Bohai, P. R. China were characterized with 16 kinds of esters. It was found that all the lipases have the ability to catalyze the hydrolysis of the glycerides, methyl esters, ethyl esters, especially for triglycerides, which shows that they have broad substrate spectra, and this property is very important for them to be used in detergent industry. Three QSAR models were built for L-A1, L-A2 and L-A3 respectively with GFA using Discovery studio 2.1. The models equations 1, 2 and 3 can explain 95.80%, 97.45% and 97.09% of the variances (R(2)(adj)) respectively while they could predict 95.44%, 89.61% and 93.41% of the variances (R(2)(cv)) respectively. With these models the hydrolysis activities of these lipases to mixed esters were predicted and the result showed that the predicted values are in good agreement with the measured values, which indicates that this method can be used as a simple tool to predict the lipase activities for single or mixed esters.

  9. QSAR study and the hydrolysis activity prediction of three alkaline lipases from different lipase-producing microorganisms

    Directory of Open Access Journals (Sweden)

    Wang Haikuan

    2012-09-01

    Full Text Available Abstract The hydrolysis activities of three alkaline lipases, L-A1, L-A2 and L-A3 secreted by different lipase-producing microorganisms isolated from the Bay of Bohai, P. R. China were characterized with 16 kinds of esters. It was found that all the lipases have the ability to catalyze the hydrolysis of the glycerides, methyl esters, ethyl esters, especially for triglycerides, which shows that they have broad substrate spectra, and this property is very important for them to be used in detergent industry. Three QSAR models were built for L-A1, L-A2 and L-A3 respectively with GFA using Discovery studio 2.1. The models equations 1, 2 and 3 can explain 95.80%, 97.45% and 97.09% of the variances (R2adj respectively while they could predict 95.44%, 89.61% and 93.41% of the variances (R2cv respectively. With these models the hydrolysis activities of these lipases to mixed esters were predicted and the result showed that the predicted values are in good agreement with the measured values, which indicates that this method can be used as a simple tool to predict the lipase activities for single or mixed esters.

  10. Occurrence and activity of iron- and sulfur-oxidizing microorganisms in alkaline coal strip mine spoils.

    Science.gov (United States)

    Olson, G J; McFeters, G A; Temple, K L

    1981-03-01

    Spoils samples collected from a coal strip mine in southeastern Montana were examined for populations and activities of iron- and sulfur-oxidizing bacteria. Spoils examined were of three types: (a) acidic pyrite-rich waste coal, (b) oxidation halo material, and (c) alkaline material, which was the most widespread type. Bacterial numbers, sulfur oxidation, and(14)CO2 uptake activity declined to low levels in the summer when spoils were dry. Even in wetter spring months pyritic spoils contained relatively low numbers of acidophilic iron- and sulfur-oxidizing bacteria, probably indicative of water stress since the same spoils incubated with excess water or dilute mineral salts showed considerably greater bacterial numbers and activity. Certain wells in coal and spoils aquifers contained substantial populations of iron-oxidizing acidophilic bacteria. However, these wells were always of alkaline or neutral pH, indicating that bacterial pyrite oxidation occurred where groundwaters contacted either replaced spoils or coal that contained pyrite or other metal sulfides. Bacterial activity may contribute to trace metal and sulfate leaching in the area.

  11. The Development of a New Practical Activity: Using Microorganisms to Model Gas Cycling

    Science.gov (United States)

    Redfern, James; Burdass, Dariel; Verran, Joanna

    2014-01-01

    For many in the school science classroom, the term "microbiology" has become synonymous with "bacteriology". By overlooking other microbes, teachers may miss out on powerful practical tools. This article describes the development of an activity that uses algae and yeast to demonstrate gas cycling, and presents full instructions…

  12. Agar composition affects in vitro screening of biocontrol activity of antagonistic microorganisms.

    Science.gov (United States)

    Bosmans, L; De Bruijn, I; De Mot, R; Rediers, H; Lievens, B

    2016-08-01

    Agar-based screening assays are the method of choice when evaluating antagonistic potential of bacterial biocontrol-candidates against pathogens. We showed that when using the same medium, but different agar compositions, the activity of a bacterial antagonist against Agrobacterium was strongly affected. Consequently, results from in vitro screenings should be interpreted cautiously.

  13. Agar composition affects in vitro screening of biocontrol activity of antagonistic microorganisms

    NARCIS (Netherlands)

    Bosmans, Lien; De Bruijn, I.; de Mot, Rene; Readers, Hans; Lievens, Bart

    2016-01-01

    Agar-based screening assays are the method of choice when evaluating antagonistic potential of bacterial biocontrol-candidates against pathogens.Weshowed thatwhen using the samemedium, but different agar compositions, the activity of a bacterial antagonist against Agrobacteriumwas strongly affected.

  14. Agar composition affects in vitro screening of biocontrol activity of antagonistic microorganisms

    NARCIS (Netherlands)

    Bosmans, Lien; De Bruijn, I.; de Mot, Rene; Readers, Hans; Lievens, Bart

    2016-01-01

    Agar-based screening assays are the method of choice when evaluating antagonistic potential of bacterial biocontrol-candidates against pathogens.Weshowed thatwhen using the samemedium, but different agar compositions, the activity of a bacterial antagonist against Agrobacteriumwas strongly affected.

  15. The Development of a New Practical Activity: Using Microorganisms to Model Gas Cycling

    Science.gov (United States)

    Redfern, James; Burdass, Dariel; Verran, Joanna

    2014-01-01

    For many in the school science classroom, the term "microbiology" has become synonymous with "bacteriology". By overlooking other microbes, teachers may miss out on powerful practical tools. This article describes the development of an activity that uses algae and yeast to demonstrate gas cycling, and presents full instructions…

  16. ANTIMICROBIAL ACTIVITY OF MICROORGANISMS AND COLLOIDAL SILVER BASED ON COMPLEX MATERIALS

    Directory of Open Access Journals (Sweden)

    Voitenko O. Yu.

    2014-02-01

    Full Text Available The antimicrobial properties of complex materials containing ultradispersed silver particles directly formed in the Candida albіcans, Escherichia сolі, Pseudomonas fluorescens, and Bacillus cereus cell walls were investigated. Complex material based on pseudomonas was more active against gram-positive bacteria, the yeast like fungi based material was mainly active against colibacillus. After a cell-matrix treatment in a hypertonic solution or by acid hydrolysis, the antimicrobial properties of complex materials increased by 20—40%. In a liquid-phase medium, the complex materials with incorporated silver particles in composition with antibiotics strengthened anti-microbial properties of chloramphenicol, tetracycline and amoxiclav antibiotics with respect to E. faecalis, as well as penicillin antibiotics (ceftriaxone, cefotaxime, amoxicillin, amoxiclav against E. coli. The obtained data can serve as a basis for development of the new antibacterial and fungicide cells based materials impregnated with ultradispersed substances.

  17. Rapid determination of filamentous microorganisms in activated sludge; Determinacion rapida de microorganismos filamentosos en fangos activados

    Energy Technology Data Exchange (ETDEWEB)

    Arnaiz, C.; Jimenez, C.; Estevez, F. [Empresa Municipal de Abastecimiento y Saneamiento de Aguas de Sevilla (Spain)

    1999-07-01

    Despite many methods available biomass estimation of a bioprocess may sometimes become laborious and impracticable. Samples containing filamentous organisms, as in Wastewater Treatment Plants, present special counting difficulties. If they are abundant they may need to be estimated separately. In this work a counting method for these organisms is show. The main goal is to improve chlorination of activated sludge suffering bulking or foaming through a quantitative record of filamentous bacteria. (Author) 12 refs.

  18. Analysis of the Expression and Activity of Nitric Oxide Synthase from Marine Photosynthetic Microorganisms.

    Science.gov (United States)

    Foresi, Noelia; Correa-Aragunde, Natalia; Santolini, Jerome; Lamattina, Lorenzo

    2016-01-01

    Nitric oxide (NO) functions as a signaling molecule in many biological processes in species belonging to all kingdoms of life. In animal cells, NO is synthesized primarily by NO synthase (NOS), an enzyme that catalyze the NADPH-dependent oxidation of L-arginine to NO and L-citrulline. Three NOS isoforms have been identified, the constitutive neuronal NOS (nNOS) and endothelial NOS (eNOS) and one inducible (iNOS). Plant NO synthesis is complex and is a matter of ongoing investigation and debate. Despite evidence of an Arg-dependent pathway for NO synthesis in plants, no plant NOS homologs to animal forms have been identified to date. In plants, there is also evidence for a nitrate-dependent mechanism of NO synthesis, catalyzed by cytosolic nitrate reductase. The existence of a NOS enzyme in the plant kingdom, from the tiny single-celled green alga Ostreococcus tauri was reported in 2010. O. tauri shares a common ancestor with higher plants and is considered to be part of an early diverging class within the green plant lineage.In this chapter we describe detailed protocols to study the expression and characterization of the enzymatic activity of NOS from O. tauri. The most used methods for the characterization of a canonical NOS are the analysis of spectral properties of the oxyferrous complex in the heme domain, the oxyhemoglobin (oxyHb) and citrulline assays and the NADPH oxidation for in vitro analysis of its activity or the use of fluorescent probes and Griess assay for in vivo NO determination. We further discuss the advantages and drawbacks of each method. Finally, we remark factors associated to the measurement of NOS activity in photosynthetic organisms that can generate misunderstandings in the interpretation of results.

  19. Biomass and activity soil microorganisms in grazing and secondary forests areasA

    OpenAIRE

    WingChing-Jones, Rodolfo; Uribe Lorío, Lidieth

    2016-01-01

    Sustainable livestock production generates benefits for the environment, such as water capture, increased biodiversity and carbon dioxide capture. To measure these factors in a tropical setting, in 2007 we took three samples of a milk production system in Turrialba, Cartago, Costa Rica, in areas with permanent African Star grass cover (under grazing) and a secondary forest with 15 years of regeneration. We estimated carbon content in the microbial biomass, microbial activity (breathing techni...

  20. Volatile constituents of Dianthus rupicola Biv. from Sicily: activity against microorganisms affecting cellulosic objects.

    Science.gov (United States)

    Casiglia, Simona; Bruno, Maurizio; Senatore, Felice

    2014-01-01

    Dianthus rupicola Biv. (cliffs carnation) is a camephytic, suffruticous, perennial plant growing up to 40 cm high. The plant is widespread in Sicily and neighbouring islands (Egadi, Lampedusa, Lipari) and in some areas of southern Italy. GC and GC-MS analyses of the essential oil distilled from the flowers showed the presence of 66 components. Its composition is characterised by the high content of thymol and carvacrol derivatives. A good antibacterial activity against Bacillus cereus and Bacillussubtilis, both infesting cellulosic historical material, was shown, whereas the antioxidant capacity was determined to be quite poor.

  1. Screening of novel microorganisms for biosurfactant and biocontrol activity against Phytophthora infestans.

    Science.gov (United States)

    Tomar, Sonica; Singh, B P; Lal, Mehi; Ma, Khan; Hussain, Touseef; Sharma, Sanjeev; Kaushik, S K; Kumar, Satish

    2014-09-01

    In the present study, 95 isolates of bacteria were tested for their biosurfactant as well as biocontrol activity against Phytophthora infestans. The results revealed that only 15.8% isolates showed biosurfactant activity. The emulsification index ranged from 0-68% and 24.2% isolates showed positive reaction for biosurfactant properties. In emulsification assay and oil spreading test, 18.95% and 5.26% isolates, respectively scored positive for biosurfactant production. Among all, only five isolates were found effective against P. infestans, for biocontrol properties. Pseudomonas aeruginosa-1 showed 62.22% inhibition zone after 72 hrs while P. aeruginosa-3 showed 46.42%. Forty-eight hrs old culture supernatants were highly effective in food-poisoning test, tuber slice test and detached leaf method against P. infestans. In whole potato plant test, bacterial cell based formulation, culture supernatant and bacterial cell suspension of P. aeruginosa-1 showed 10.42%, 9.94% and 17.96% diseases severity respectively, as against 53.96% in control. This isolate holds promise as biological control agent against P. infestans in field.

  2. Growth and activity of reservoir microorganisms under carbon capture and storage conditions

    Science.gov (United States)

    Rakoczy, Jana; Gniese, Claudia; Krüger, Martin

    2015-04-01

    Carbon capture and storage is a technology to decelerate global warming by reducing CO2 emissions into the atmosphere. To ensure safe long-term storage of CO2 in the underground a number of factors need to be considered. One of them is microbial activity in storage reservoirs, which can lead to the formation of acidic metabolites, H2S or carbonates which then might affect injectivity, permeability, pressure build-up and long-term operability. Our research focused on the effect of high CO2 concentrations on growth and activity of selected thermophilic fermenting and sulphate-reducing bacteria isolated from deep reservoirs. Experiments with supercritical carbon dioxide at 100 bar completely inhibited growth of freshly inoculated cultures and also caused a rapid decrease of growth of a pre-grown culture. This demonstrated that supercritical carbon dioxide had a certain sterilizing effect on cells. This effect was not observed in control cultures with 100 bar of hydrostatic pressure. However, when provided with a surface for attachment, CO2-inhibited cells restarted growth after CO2 release. The same was observed for organisms able to form spores. Further experiments will examine physiological and molecular properties of the model organism allowing for prediction of its sensitivity and/or adaptability to carbon dioxide in potential future storage sites.

  3. Effect of olive mill wastewaters on the oxygen consumption by activated sludge microorganisms: an acute toxicity test method.

    Science.gov (United States)

    Paixão, S M; Anselmo, A M

    2002-01-01

    The test for inhibition of oxygen consumption by activated sludge (ISO 8192-1986 (E)) was evaluated as a tool for assessing, the acute toxicity of olive mill wastewaters (OMW). According to the ISO test, information generated by this method may be helpful in estimating the effect of a test material on bacterial communities in the aquatic environment, especially in aerobic biological treatment systems. However, the lack of standardized bioassay methodology for effluents imposed that the test conditions were modified and adapted. The experiments were conducted in the presence or absence of an easily biodegradable carbon source (glucose) with different contact times (20 min and 24 h). The results obtained showed a remarkable stimulatory effect of this effluent to the activated sludge microorganisms. In fact, the oxygen uptake rate values increase with increasing effluent concentrations and contact times up to 0.98 microl O(2) h(-1) mg(-1) dry weight for a 100% OMW sample, 24 h contact time, with blanks exhibiting an oxygen uptake rate of ca. 1/10 of this value (0.07-0.10). It seems that the application of the ISO test as an acute toxicity test for effluents should be reconsidered, with convenient adaptation for its utilization as a method of estimating the effect on bacterial communities present in aerobic biological treatment systems.

  4. Activity and phylogenetic diversity of sulfate-reducing microorganisms in low-temperature subsurface fluids within the upper oceanic crust

    Directory of Open Access Journals (Sweden)

    Alberto eRobador

    2015-01-01

    Full Text Available The basaltic ocean crust is the largest aquifer system on Earth, yet the rates of biological activity in this environment are unknown. Low-temperature (<100 °C fluid samples were investigated from two borehole observatories in the Juan de Fuca Ridge flank, representing a range of upper oceanic basement thermal and geochemical properties. Microbial sulfate reduction rates were measured in laboratory incubations with 35S-sulfate over a range of temperatures, with microbial activity limited by the availability of organic electron donors. Thermodynamic calculations indicate energetic constraints for metabolism in the higher temperature, more altered and isolated fluids, which together with relatively higher cell-specific sulfate reduction rates reveal increased maintenance requirements, consistent with novel species-level dsrAB phylotypes of thermophilic sulfate-reducing microorganisms. Our estimates suggest that microbially-mediated sulfate reduction may account for the removal of organic matter in fluids within the upper oceanic crust and underscore the potential quantitative impact of microbial processes in deep subsurface marine crustal fluids on marine and global biogeochemical carbon cycling.

  5. Antibacterial, Antifungal and Anticancer Activity of Five Strains of Soil Microorganisms Isolated From Tangkuban Perahu Mountain by Fermentation

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    Desak Gede Sri Andayani

    2015-10-01

    Full Text Available Microorganisms were isolated from soil taken from Tangkuban Perahu mountain. Five strains were investigated in this study, designated TP1, TP2, TP3, TP4, and TP5, respectively. Morphological, biochemical and molecular identifications were conducted for all five strains. These isolates were shown to be closely related to Nocardia sp. YIM 65630 (90%, Streptomyces galbus (99%, Aspergillus unguis (86%, Paecilomyces marquandii (100% and Nocardia niigatensis (95%, respectively. Production of antibacterial, antifungal and anticancer metabolites was done by fermentation. Screening for bioactivity of five isolates was done by testing the fermentation broth against resistant and pathogenic bacteria, fungi and T47D breast cancer cell line. TP2 strain showed the best bioactivity; the metabolite was purified by extraction with ethyl acetate. Antibacterial, antifungal and anticancer activities from the ethyl acetate extract of TP2 strain were tested by agar diffusion, microdilution and MTT. The extract was shown to be active against methicillin resistant Staphylococcus, methicillin sensitive Staphylococcus aureus, methicillin resistant coagulase negative Staphylococcus, vancomycin resistant Enterococcus, Escherichia coli, Microsforum gypseum with the minimum inhibitory concentration (μg/mL and diameter of inhibition (mm: 150, 35; 150, 30; 300, 35; 300, 35; 300, 29; 4.7, 36, respectively. The IC50 value of the T47D cell line was 457 μg/mL.

  6. Antimicrobial activities of essential oils and crude extracts from tropical Citrus spp. against food-related microorganisms

    Directory of Open Access Journals (Sweden)

    Tipparat Hongpattarakere

    2008-04-01

    Full Text Available Ethyl acetate extracts and hydrodistillated-essential oils from peels of Citrus spp. were investigated for their antimicrobial activities against food related microorganisms by broth microdilution assay. Overall, ethyl acetate extracts from all citrus peels showed stronger antimicrobial activities than their essential oils obtained from hydrodistillation. The ethyl acetate extract of kaffir lime (Citrus hystrix DC. peel showed broad spectrum of inhibition against all Gram-positive bacteria, yeast and molds including Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Saccharomyces cerevisiae var. sake and Aspergillus fumigatus TISTR 3180. It exhibited minimum inhibitory concentration (MIC values of 0.28 and 0.56 mg/ml against Sac. cerevisiae var. sake and B. cereus, respectively while the minimum bactericidal concentration (MBC values against both microbes were 0.56 mg/ml. The MIC values of the extract against L. monocytogenes, A. fumigatus TISTR 3180 and S. aureus were 1.13 mg/ml while the MBC values against L. monocytogenes as well as A. fumigatus TISTR 3180 and S. aureus were 2.25 and 1.13 mg/ml, respectively. The major components of the ethyl acetate extract from kaffir lime were limonene (31.64 %, citronellal (25.96 % and b-pinene (6.83 % whereas b-pinene (30.48 %, sabinene (22.75 % and citronellal (15.66 % appeared to be major compounds of the essential oil obtained from hydrodistillation.

  7. Transformation of the insecticide teflubenzuron by microorganisms

    NARCIS (Netherlands)

    Finkelstein, Z.I.; Baskunov, B.P.; Rietjens, I.M.C.M.; Boersma, M.G.; Vervoort, J.; Golovleva, L.A.

    2001-01-01

    Transformation of teflubenzuron, the active component in the insecticide commercialized as Nomolt, by soil microorganisms was studied. It was shown that microorganisms, belonging to Bacillus, Alcaligenes, Pseudomonas and Acinetobacter genera are capable to perform the hydrolytic cleavage of the phen

  8. Effect of magnetic field on the accumulation of polyhydroxyalkanoates (PHAs) by microorganism in activated sludge.

    Science.gov (United States)

    Zhu, Sai-Chang; Xu, Zhen-Lan; Meng, Hui-Juan; Zhou, Jun; Chen, Hong

    2012-08-01

    The effect of static magnetic field on polyhydroxyalkanoates (PHAs) syntheses by activated sludge under aerobic dynamic feeding (ADF) was evaluated in sequence batch reactors (SBR), with magnetic field intensities of 42, 21, 11 and 7 millitesla (mT) exposure in the feast, feast-famine and famine periods, respectively, and one control group without magnetic field exposure. Under each level of magnetic field intensity, the effect of magnetic field exposed in the famine period to PHAs syntheses was most significant in comparison with that in the feast or feast-famine period. Maximal hydroxybutyrate (HB) and (HV) yield occurred at 21 and 11 mT, respectively, and the minimal yield occurred at 42 mT during exposure in the famine period. The maximum biodegradable rate constant of PHA was noted at 11 mT during exposure in the famine period.

  9. Screening of antagonistic activity of microorganisms against Colletotrichum acutatum and Colletotrichum gloeosporioides

    Directory of Open Access Journals (Sweden)

    Živković Svetlana

    2010-01-01

    Full Text Available The antagonistic activities of five biocontrol agents: Trichoderma harzianum, Gliocladium roseum, Bacillus subtilis, Streptomyces noursei and Streptomyces natalensis, were tested in vitro against Colletotrichum acutatum and Colletotrichum gloeosporioides, the causal agents of anthracnose disease in fruit crops. The microbial antagonists inhibited mycelial growth in the dual culture assay and conidial germination of Colletotrichum isolates. The two Streptomyces species exhibited the strongest antagonism against isolates of C. acutatum and C. gloeosporioides. Microscopic examination showed that the most common mode of action was antibiosis. The results of this study identify T. harzianum, G. roseum, B. subtilis, S. natalensis and S. noursei as promising biological control agents for further testing against anthracnose disease in fruits. .

  10. ISOLATION AND CHARACTERIZATION OF STREPTOMYCES RISHIRIENSIS (VY31 WITH ANTIBIOTIC ACTIVITY AGAINST VARIOUS PATHOGENIC MICROORGANISMS

    Directory of Open Access Journals (Sweden)

    Ivana Charousová

    2015-02-01

    Full Text Available Actinomycete strain VY31 was isolated from agriculture soil of region Východná, Slovakia. Morphological, physiological and biochemical studies indicated that this isolate belongs to the genus Streptomyces. The 16S rRNA sequence data supported the assignment of the isolate to the genus Streptomyces rishiriensis (sequence similarity 97%. Tested isolate was able to produce melanin dark pigment and exopigments on ISP6, ISP7 and SSM+T cultivating media. The optimal pH range was from 6-8 and optimal temperature at 30 °C. The strain exhibited salt tolerance up to 5 % and utilized the carbon sources such as glucose, arabinose, xylose, inositol, mannose, fructose, rhamnose and rafinose. Using ApiZym® stripes, the highest production of enzymes was determined for phosphatase alkaline, leucinearylamidase, valinearylamidase, phosphatase acid, naphtol-AS-BI-phosphohydrolase, galactosidase and glucosidase (>40 nmol. According to ApiCoryne® results, positive reaction was confirmed in case of esculin, alkaline phosphatase, and this strain was also able to hydrolyze gelatine. Minimum Inhibitory Concentration (MIC of the purified extract of isolate was evaluated against Gram-positive bacteria Staphylococcus aureus and Enterococcus faecium, Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa and against yeast Candida albicans. On the basis of MIC results, strain VY31 had noticeable antibacterial activity against Staphylococcus aures N315 (MRSA from collection database of University Hospital in Hamburg, Germany. This isolate could be used in the development of new antibiotics for pharmaceutical purposes.

  11. "Petit suisse" cheese from kefir: an alternative dessert with microorganisms of probiotic activity

    Directory of Open Access Journals (Sweden)

    Thanise Sabrina Souza Santos

    2012-09-01

    Full Text Available "Petit Suisse" is a creamy cheese. Kefir is a symbiotic mixture of lactic acid bacteria and yeasts with probiotic activity including immunomodulation and balance of intestinal microflora. The present study aims to develop "Petit Suisse" cheese from kefir. Kefir grains were grown in pasteurized cow milk, and after the separation of kefir the serum was discarded and the "Petit Suisse" cheese was prepared using strawberry, mangaba, herbs, and dried tomatoes. The acceptance of the different preparations was evaluated using a nine-point hedonic scale followed by ANOVA. The sweet and salty products were compared by the Student's t-test. Purchase intent was evaluated by the means test and frequency distribution. All products were well accepted by the judges. The product was characterized by low yield, but it can be prepared at home at low cost. The nutritional composition analyses and the variety of flavors as well as the range of age of the judges are alternatives for further studies.

  12. Antimicrobial activity of essential oil components against potential food spoilage microorganisms.

    Science.gov (United States)

    Klein, G; Rüben, C; Upmann, M

    2013-08-01

    The antimicrobial activity of six essential oil components against the potential food spoilage bacteria Aeromonas (A.) hydrophila, Escherichia (E.) coli, Brochothrix (B.) thermosphacta, and Pseudomonas (P.) fragi at single use and in combination with each other was investigated. At single use, the most effective oil components were thymol (bacteriostatic effect starting from 40 ppm, bactericidal effect with 100 ppm) and carvacrol (50 ppm/100 ppm), followed by linalool (180 ppm/720 ppm), α-pinene (400 ppm/no bactericidal effect), 1,8-cineol (1,400 ppm/2,800 ppm), and α-terpineol (600 ppm/no bactericidal effect). Antimicrobial effects occurred only at high, sensorial not acceptable concentrations. The most susceptible bacterium was A. hydrophila, followed by B. thermosphacta and E. coli. Most of the essential oil component combinations tested showed a higher antimicrobial effect than tested at single use. Antagonistic antimicrobial effects were observed particularly against B. thermosphacta, rarely against A. hydrophila. The results show that the concentration of at least one of the components necessary for an antibacterial effect is higher than sensorial acceptable. So the use of herbs with a high content of thymol, carvacrol, linalool, 1,8-cineol, α-pinene or α-terpineol alone or in combination must be weighted against sensorial quality.

  13. EVALUATION OF PHOSPHATE SOLUBILIZING MICROORGANISMS (PSMs FROM RHIZOSPHERE SOIL OF DIFFERENT CROP PLANTS AND ITS ANTAGONISTIC ACTIVITY

    Directory of Open Access Journals (Sweden)

    Samikan Krishnakumar

    2014-04-01

    Full Text Available Indigenous rhizosphere soil samples were collected during study period (October 2011 – March 2012 of different crop plant from Thiruvannamalai District, Tamilnadu, India for the enumeration of Phosphate solubilizing microorganisms (PSMs. Efficient phosphate solubilizing bacteria, fungi and heterotrophic bacteria were enumerated. Maximum heterotrophic bacterial populations (19.4 X105, phosphate solubilizing bacteria (4.7 X 105 were recorded in the month of February and phosphate solubilizing fungi (3.9 X 102 were documented in the month of December in rhizosphere soil of ground nut. Minimum bacterial populations (14.3 X 105 were observed in rhizosphere soil of chilli in the month of March. Lowest phosphate solubilizing bacteria (1.2 X105 and phosphate solubilzing fungi (1.2 X 102 were observed in rhizosphere soil of paddy during the month of October. Phosphate solubilizing bacteria Pseudomonassp. - BS1, Bacillus sp. – BS2, Micrococcus sp. – BS3 and fungi Aspergillus sp. – FS1, Penicillium sp. – FS2.and Trichoderma sp. – FS3 were identified. Pseudomonas sp. - BS1. exhibited maximum solubilizing efficiency (SE and solubilizing index (SI of 300.0 and 4.0 respectively. In fungi Aspergillus sp. – FS1 showed a maximum solubilizing efficiency (SE and solubilizing index(SI of 283.3 and 3.8 respectively. Antagonistic activity of P-solubilizing Pseudomonassp. - BS1 was deliberated against selected fungal plant pathogens. Among pathogens studied Aspergillus sp. showed a maximum inhibition activity (16 mm and minimum activity (12 mm was observed against Fusarium sp. Moreover inhibition efficiency (IE and inhibition index (II of Pseudomonas sp. - BS1. also calculated base on the antagonistic activity. Aspergillus sp. exhibited highest inhibition efficiency and inhibition index of 166.6 and 3.6 respectively.

  14. Biological Activity of Methyl tert-butyl Ether in Relation to Soil Microorganisms has a Negative Environmental Impact

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    Gholam H.S. Bonjar

    2005-01-01

    Full Text Available Fuel oxygenates are added to gasoline to enhance combustion efficiency of automobiles and reduce air pollution. Methyl tert-butyl ether (MTBE is the most commonly used oxygenate because of its low cost, high-octane level and ease of blending with gasoline. However, due to its water solubility, high mobility and low biodegradability it leaches in soil subsurface at the speed of groundwater. Amending gasoline with MTBE has made a widespread contamination of groundwater, surface waters in coastal environments and at low levels in well water. Although current public concern about MTBE contamination is widely discussed, but its adverse effects on soil micro flora is not yet understood. Soil Streptomycetes are beneficial to soil productivity and are of the major contributors to the biological buffering of soils having antagonistic activity against wide spectrum of pathogenic bacteria and fungi. Streptomyceticidal activity of Methyl tert-butyl ether (MTBE is being reported here. Adverse effect of MTBE against four soil-inhabitant Streptomyces spp. isolates and two plant root-pathogens was investigated. To elucidate antimicrobial activity of MTBE, it was tested against four soil isolates of Streptomyces; a plant bacterial-pathogen, Erwinia carotovora and a plant root fungal-pathogen, Fusarium solani. MTBE did not reveal any growth inhibitory-activity against E. carotovora and F. solani but showed strong inhibitory effect against Streptomyces spp. isolates. The Minimum Inhibitory Concentration (MIC was 1/800 of the original MTBE. Fuel leaks and spills can adversely suppress or eliminate the Streptomyces role in the soil causing alteration in the balance of soil micro flora. This change will lead to domination of microorganisms with adverse biological or ecological effects. Fortunately, major oil companies have decided to phase out MTBE from automobile fuels because of its adverse effect on environment and human health.

  15. Diversity, abundance and activity of ammonia-oxidizing microorganisms in fine particulate matter

    Science.gov (United States)

    Gao, Jing-Feng; Fan, Xiao-Yan; Pan, Kai-Ling; Li, Hong-Yu; Sun, Li-Xin

    2016-12-01

    Increasing ammonia emissions could exacerbate air pollution caused by fine particulate matter (PM2.5). Therefore, it is of great importance to investigate ammonia oxidation in PM2.5. This study investigated the diversity, abundance and activity of ammonia oxidizing archaea (AOA), ammonia oxidizing bacteria (AOB) and complete ammonia oxidizers (Comammox) in PM2.5 collected in Beijing-Tianjin-Hebei megalopolis, China. Nitrosopumilus subcluster 5.2 was the most dominant AOA. Nitrosospira multiformis and Nitrosomonas aestuarii were the most dominant AOB. Comammox were present in the atmosphere, as revealed by the occurrence of Candidatus Nitrospira inopinata in PM2.5. The average cell numbers of AOA, AOB and Ca. N. inopinata were 2.82 × 104, 4.65 × 103 and 1.15 × 103 cell m‑3 air, respectively. The average maximum nitrification rate of PM2.5 was 0.14 μg (NH4+-N) [m3 air·h]‑1. AOA might account for most of the ammonia oxidation, followed by Comammox, while AOB were responsible for a small part of ammonia oxidation. Statistical analyses showed that Nitrososphaera subcluster 4.1 was positively correlated with organic carbon concentration, and Nitrosomonas eutropha showed positive correlation with ammonia concentration. Overall, this study expanded our knowledge concerning AOA, AOB and Comammox in PM2.5 and pointed towards an important role of AOA and Comammox in ammonia oxidation in PM2.5.

  16. Appraisal of multifarious brands of Cephradine for their in vitro antibacterial activity against varied microorganisms.

    Science.gov (United States)

    Bashir, Sajid; Akhtar, Shamshad; Hussain, Shahzad; Malik, Farnaz; Mahmood, Sidra; Erum, Alia; Ruqiatulain, Ume

    2013-09-01

    The astounding and exceptional growth of generic pharmaceutical Industry in Pakistan has raised certain questions for drug regulatory authorities contemplating their efficacy and quality. The current study focuses on assessing the in-vitro antimicrobial activity of 24 brands of Cephradine 500mg capsules against 4 different strains by employing standardized methods. Disk diffusion method was performed on all brands to look into the susceptibility and resistance patterns. Standard disk of 5µg Cephradine powder were used during evaluation. The zones of inhibitions were ranged from 24-40mm against S. aureus, 24-40mm against E. coli, 20-25mm against K. pneumonia and 19-23mm P. mirabilis. On the basis of mean value, the multinational brands were found to have better zone of inhibitions and were better than local Pharmaceutical companies but ANOVA cooperative study showed that all brands of Cephradine showed similar comparable results. Further investigations by employing MIC method, quality of raw material with special emphasis on the shelf-life, excepients and method of manufacturing will be needed to obtain more authenticated results. The price of National and Multinational brands ranges from Rs.156.00-212.00 for 10 capsules. It is concluded that Public health is at risk because of noticeable growing widespread curse of the manufacture and trade of sub-standard or below par pharmaceuticals. The pecuniary accountability of management of pharmaceutical agents is additionally apparent. The results of the study need to be made public to boost the confidence of medical profession about the quality of locally manufactured pharmaceuticals. It will succour the foreign exchange being incurred on the trade in of medicines.

  17. Serine Hydroxymethyltransferase from the Cold Adapted Microorganism Psychromonas ingrahamii: A Low Temperature Active Enzyme with Broad Substrate Specificity

    Directory of Open Access Journals (Sweden)

    Stefano Pascarella

    2012-01-01

    Full Text Available Serine hydroxymethyltransferase from the psychrophilic microorganism Psychromonas ingrahamii was expressed in Escherichia coli and purified as a His-tag fusion protein. The enzyme was characterized with respect to its spectroscopic, catalytic, and thermodynamic properties. The properties of the psychrophilic enzyme have been contrasted with the characteristics of the homologous counterpart from E. coli, which has been structurally and functionally characterized in depth and with which it shares 75% sequence identity. Spectroscopic measures confirmed that the psychrophilic enzyme displays structural properties almost identical to those of the mesophilic counterpart. At variance, the P. ingrahamii enzyme showed decreased thermostability and high specific activity at low temperature, both of which are typical features of cold adapted enzymes. Furthermore, it was a more efficient biocatalyst compared to E. coli serine hydroxymethyltransferase (SHMT particularly for side reactions. Many β-hydroxy-α-amino acids are SHMT substrates and represent important compounds in the synthesis of pharmaceuticals, agrochemicals and food additives. Thanks to these attractive properties, this enzyme could have a significant potential for biotechnological applications.

  18. Determination of bacteriocin activity with bioassays carried out on solid and liquid substrates: assessing the factor "indicator microorganism"

    Directory of Open Access Journals (Sweden)

    Ambrosiadis Ioannis

    2006-10-01

    Full Text Available Abstract Background Successful application of growth inhibition techniques for quantitative determination of bacteriocins relies on the sensitivity of the applied indicator microorganism to the bacteriocin to which is exposed. However, information on indicator microorganisms' performance and comparisons in bacteriocin determination with bioassays is almost non-existing in the literature. The aim of the present work was to evaluate the parameter "indicator microorganism" in bioassays carried out on solid -agar diffusion assay- and liquid -turbidometric assay- substrates, applied in the quantification of the most studied bacteriocin nisin. Results The performance of characterized microorganisms of known sources, belonging to the genera of Lactobacillus, Pediococcus, Micrococcus and Leuconostoc, has been assessed in this work in the assays of plate agar diffusion and turbidometry. Dose responses and sensitivities were examined and compared over a range of assay variables in standard bacteriocin solutions, fermentation broth filtrates and processed food samples. Measurements on inhibition zones produced on agar plates were made by means of digital image analysis. The data produced were analyzed statistically using the ANOVA technique and pairwise comparisons tests. Sensitivity limits and linearity of responses to bacteriocin varied significantly among different test-microorganisms in both applied methods, the lower sensitivity limits depending on both the test-microorganism and the applied method. In both methods, however, only two of the nine tested microorganisms (Lactobacillus curvatus ATCC 51436 and Pediococcus acidilactici ATCC 25740 were sensitive to very low concentrations of the bacteriocin and produced a linear-type of response in all kinds of samples used in this work. In all cases, very low bacteriocin concentrations, e.g. 1 IU/ml nisin, were more accurately determined in the turbidometric assay. Conclusion The present work shows that in

  19. Antimicrobial activity of Calendula officinalis, Camellia sinensis and chlorhexidine against the adherence of microorganisms to sutures after extraction of unerupted third molars

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    Raquel Lourdes Faria

    2011-10-01

    Full Text Available OBJECTIVE: The objective of this study was to compare the antimicrobial effect of mouthwashes containing Calendula officinalis L., Camellia sinensis (L. Kuntze and 0.12% chlorhexidine digluconate on the adherence of microorganisms to suture materials after extraction of unerupted third molars. MATERIAL AND METHODS: Eighteen patients with unerupted maxillary third molars indicated for extraction were selected (n=6 per mouthwash. First, the patients were subjected to extraction of the left tooth and instructed not to use any type of antiseptic solution at the site of surgery (control group. After 15 days, the right tooth was extracted and the patients were instructed to use the Calendula officinalis, Camellia sinensis or chlorhexidine mouthwash during 1 week (experimental group. For each surgery, the sutures were removed on postoperative day 7 and placed in sterile phosphate-buffered saline. Next, serial dilutions were prepared and seeded onto different culture media for the growth of the following microorganisms: blood agar for total microorganism growth; Mitis Salivarius bacitracin sucrose agar for mutans group streptococci; mannitol agar for Staphylococcus spp.; MacConkey agar for enterobacteria and Pseudomonas spp., and Sabouraud dextrose agar containing chloramphenicol for Candida spp. The plates were incubated during 24-48 h at 37ºC for microorganism count (CFU/mL. RESULTS: The three mouthwashes tested reduced the number of microorganisms adhered to the sutures compared to the control group. However, significant differences between the control and experimental groups were only observed for the mouthwash containing 0.12% chlorhexidine digluconate. CONCLUSIONS: Calendula officinalis L. and Camellia sinensis (L. Kuntze presented antimicrobial activity against the adherence of microorganisms to sutures but were not as efficient as chlorhexidine digluconate.

  20. Antimicrobial activity of Calendula officinalis, Camellia sinensis and chlorhexidine against the adherence of microorganisms to sutures after extraction of unerupted third molars

    Science.gov (United States)

    FARIA, Raquel Lourdes; CARDOSO, Lincoln Marcelo Lourenço; AKISUE, Gokithi; PEREIRA, Cristiane Aparecida; JUNQUEIRA, Juliana Campos; JORGE, Antonio Olavo Cardoso; SANTOS JÚNIOR, Paulo Villela

    2011-01-01

    Objective The objective of this study was to compare the antimicrobial effect of mouthwashes containing Calendula officinalis L., Camellia sinensis (L.) Kuntze and 0.12% chlorhexidine digluconate on the adherence of microorganisms to suture materials after extraction of unerupted third molars. Material and Methods Eighteen patients with unerupted maxillary third molars indicated for extraction were selected (n=6 per mouthwash). First, the patients were subjected to extraction of the left tooth and instructed not to use any type of antiseptic solution at the site of surgery (control group). After 15 days, the right tooth was extracted and the patients were instructed to use the Calendula officinalis, Camellia sinensis or chlorhexidine mouthwash during 1 week (experimental group). For each surgery, the sutures were removed on postoperative day 7 and placed in sterile phosphate-buffered saline. Next, serial dilutions were prepared and seeded onto different culture media for the growth of the following microorganisms: blood agar for total microorganism growth; Mitis Salivarius bacitracin sucrose agar for mutans group streptococci; mannitol agar for Staphylococcus spp.; MacConkey agar for enterobacteria and Pseudomonas spp., and Sabouraud dextrose agar containing chloramphenicol for Candida spp. The plates were incubated during 24-48 h at 37ºC for microorganism count (CFU/mL). Results The three mouthwashes tested reduced the number of microorganisms adhered to the sutures compared to the control group. However, significant differences between the control and experimental groups were only observed for the mouthwash containing 0.12% chlorhexidine digluconate. Conclusions Calendula officinalis L. and Camellia sinensis (L.) Kuntze presented antimicrobial activity against the adherence of microorganisms to sutures but were not as efficient as chlorhexidine digluconate. PMID:21986652

  1. Phytochemical profiles and antimicrobial activity of aromatic Malaysian herb extracts against food-borne pathogenic and food spoilage microorganisms.

    Science.gov (United States)

    Aziman, Nurain; Abdullah, Noriham; Noor, Zainon Mohd; Kamarudin, Wan Saidatul Syida Wan; Zulkifli, Khairusy Syakirah

    2014-04-01

    Preliminary phytochemical and flavonoid compounds of aqueous and ethanolic extracts of 6 aromatic Malaysian herbs were screened and quantified using Reverse-Phase High Performance Liquid Chromatography (RP-HPLC). The herbal extracts were tested for their antimicrobial activity against 10 food-borne pathogenic and food spoilage microorganisms using disk diffusion assay. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)/minimum fungicidal concentration (MFC) of herbal extracts were determined. In the phytochemical screening process, both aqueous and ethanolic extracts of P. hydropiper exhibited presence of all 7 tested phytochemical compounds. Among all herbal extracts, the aqueous P. hydropiper and E. elatior extracts demonstrated the highest antibacterial activity against 7 tested Gram-positive and Gram-negative bacteria with diameter ranging from 7.0 to 18.5 mm and 6.5 to 19 mm, respectively. The MIC values for aqueous and ethanolic extracts ranged from 18.75 to 175 mg/mL and 0.391 to 200 mg/mL, respectively while the MBC/MFC values for aqueous and ethanolic extracts ranged from 25 to 200 mg/mL and 3.125 to 50 mg/mL, respectively. Major types of bioactive compounds in aqueous P. hydropiper and E. elatior extracts were identified using RP-HPLC instrument. Flavonoids found in these plants were epi-catechin, quercetin, and kaempferol. The ability of aqueous Persicaria hydropiper (L.) H. Gross and Etlingera elatior (Jack) R.M. Sm. extracts to inhibit the growth of bacteria is an indication of its broad spectrum antimicrobial potential. Hence these herbal extracts may be used as natural preservative to improve the safety and shelf-life of food and pharmaceutical products.

  2. Chemical Composition and Antimicrobial Activity of Essential Oils from Black Pepper, Cumin, Coriander and Cardamom Against Some Pathogenic Microorganisms

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    Teneva Desislava

    2016-12-01

    Full Text Available Four popular spices black pepper (Piper nigrum L., cumin (Cuminum cyminum L., coriander (Coriandrum sativum L. and cardamom (Elettaria cardamomum were analyzed for their oil composition by GC-MS. Thirty compounds were identified in the black pepper oil and the main components were β-caryophyllene (20.225 %, sabinene (18.054 %, limonene (16.924 %, α-pinene (9.171 % and α-phellandrene (5.968 %. Twenty five compounds were identified in the cumin oil – cuminaldehyde (30.834 %, 3-caren-10-al (17.223 %, β-pinene (14.837 %, γ–terpinene (11.928 %, 2-caren-10-al (8.228 % and pcymene (6.429 %. Twenty nine compounds were identified in the coriander oil – β-linalool (58.141 %, α-pinene (8.731 %, γ-terpinene (6.347 % and p-cymene (5.227 %. Twenty nine compounds were identified in the cardamom oil – α-terpinyl acetate (39.032 %, eucalyptol (31.534 %, β-linalool (4.829 %, sabinene (4.308 % and α-terpineol (4.127 %. The antimicrobial activity of essential oils against pathogenic (Escherichia coli ATCC 25922, Escherichia coli ATCC 8739, Salmonella sp. (clinical isolate, Staphylococcus aureus ATCC 6538P, Proteus vulgaris G microorganisms by disc-diffusion method was examined. Gram-positive bacteria were more sensitive to the oils (inhibition zones being between 8 and 12.5 mm and the minimum inhibitory concentration was more than 600 ppm; Gram-negative bacteria were less sensitive. The obtained essential oils are suitable for use as biopreservative agents.

  3. Synthesis, spectroscopic properties and photodynamic activity of two cationic BODIPY derivatives with application in the photoinactivation of microorganisms.

    Science.gov (United States)

    Agazzi, Maximiliano L; Ballatore, M Belén; Reynoso, Eugenia; Quiroga, Ezequiel D; Durantini, Edgardo N

    2017-01-27

    Two cationic BODIPYs 3 and 4 were synthesized by acid-catalyzed condensation of the corresponding pyrrole and benzaldehyde, followed by complexation with boron and methylation. Compound 3 contains methyl at the 1,3,5 and 7 positions of the s-indacene ring and a N,N,N-trimethylamino group attached to the phenylene unit, while 4 is not substituted by methyl groups and the cationic group is bound by an aliphatic spacer. UV-visible absorption spectra of these BODIPYs show an intense band at ∼500 nm in solvents of different polarities and n-heptane/sodium bis(2-ethylhexyl)sulfosuccinate (AOT)/water reverse micelles. Compound 3 exhibits a higher fluorescence quantum yield (ΦF = 0.29) than 4 (ΦF = 0.030) in N,N-dimethylformamide (DMF) due to sterically hindered rotation of the phenylene ring. BODIPYs 3 and 4 induce photosensitized oxidation of 1,3-diphenylisobenzofuran (DPBF) with yields of singlet molecular oxygen of 0.07 and 0.03, respectively. However, the photodynamic activity increases in a microheterogenic medium formed by AOT micelles. Also, both BODIPYs sensitize the photodecomposition of l-tryptophan (Trp). In presence of diazabicyclo[2.2.2]octane (DABCO) or D-mannitol, a reduction in the photooxidation of Trp was found, indicating a contribution of type I photoprocess. Moreover, the addition of KI produces fluorescence quenching of BODIPYs and reduces the photooxidation of DPBF. In contrast, this inorganic salt increases the photoinduced decomposition of Trp, possibly due to the formation of reactive iodine species. The effect of KI was also observed in the potentiation of the photoinactivation of microorganisms. Therefore, the presence of KI could increase the decomposition of biomolecules induced by these BODIPYs in a biological media, leading to a higher cell photoinactivation.

  4. 3,4-Dimethylpyrazole phosphate (DMPP) reduces activity of ammonia oxidizers without adverse effects on non-target soil microorganisms and functions

    DEFF Research Database (Denmark)

    Kong, Xianwang; Duan, Yun-Feng (Kevin); Schramm, Andreas;

    2016-01-01

    The nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) is widely used within agriculture to reduce nitrate leaching and improve nitrogen use efficiency of fertilizers, but few studies examined effects on non-target soil functions and microorganisms, i.e. other than the intended delay......) and archaea (AOA) were quantified, and cell-specific nitrification rates were estimated. There was a general trend of increasing AOA and AOB abundance towards the end of incubation irrespective of DMPP treatment, whereas cell-specific activity of AOA and/or AOB was reduced in the presence of DMPP. Overall......, this study indicated that DMPP effectively inhibited nitrification activity without effects on ammonia oxidizer populations, as well as non-target soil microorganisms or functions....

  5. Stefan blowing effects on MHD bioconvection flow of a nanofluid in the presence of gyrotactic microorganisms with active and passive nanoparticles flux

    Science.gov (United States)

    Giri, Shib Sankar; Das, Kalidas; Kundu, Prabir Kumar

    2017-02-01

    The present paper investigates the effect of Stefan blowing on the hydro-magnetic bioconvection of a water-based nanofluid flow containing gyrotactic microorganisms through a permeable surface. Also we studied both actively and passively the controlled flux of nanoparticles and the effect of a surface slip at the wall. We adopt a similarity approach to reduce the leading partial differential equations into ordinary differential equations along with two separate boundary conditions (active and passive) and solve the resulting equations numerically by employing the RK-4 method through the shooting technique to perform the flow analysis. Discussions on the effect of emerging flow parameter on the flow characteristic are made properly through graphs and charts. We observed that the effects of the traditional Lewis number and suction/blowing parameter on temperature distribution and microorganism concentration are converse to each other. A fair result comparison of the present paper with formerly obtained results is given.

  6. Chemical composition of the essential oil of Moluccella spinosa L. (Lamiaceae) collected wild in Sicily and its activity on microorganisms affecting historical textiles.

    Science.gov (United States)

    Casiglia, Simona; Jemia, Mariem Ben; Riccobono, Luana; Bruno, Maurizio; Scandolera, Elia; Senatore, Felice

    2015-01-01

    In this study the chemical composition of the essential oil from aerial parts of Moluccella spinosa L. collected in Sicily was evaluated by GC and GC-MS. The main components of M. spinosa L. were α-pinene (26.6%), caryophyllene oxide (16.8%) and β-caryophyllene (8.6%). A comparison with other studied oils of genus Moluccella is made. Antibacterial and antifungal activities against some microorganisms infesting historical textiles were also determined.

  7. Changes in Leaf Anatomical Traits Enhanced Photosynthetic Activity of Soybean Grown in Hydroponics with Plant Growth-Promoting Microorganisms.

    Science.gov (United States)

    Paradiso, Roberta; Arena, Carmen; De Micco, Veronica; Giordano, Maria; Aronne, Giovanna; De Pascale, Stefania

    2017-01-01

    The use of hydroponic systems for cultivation in controlled climatic conditions and the selection of suitable genotypes for the specific environment help improving crop growth and yield. We hypothesized that plant performance in hydroponics could be further maximized by exploiting the action of plant growth-promoting organisms (PGPMs). However, the effects of PGPMs on plant physiology have been scarcely investigated in hydroponics. Within a series of experiments aimed to identify the best protocol for hydroponic cultivation of soybean [Glycine max (L.) Merr.], we evaluated the effects of a PGPMs mix, containing bacteria, yeasts, mycorrhiza and trichoderma beneficial species on leaf anatomy, photosynthetic activity and plant growth of soybean cv. 'Pr91m10' in closed nutrient film technique (NFT). Plants were grown in a growth chamber under semi-aseptic conditions and inoculated at seed, seedling and plant stages, and compared to non-inoculated (control) plants. Light and epi-fluorescence microscopy analyses showed that leaves of inoculated plants had higher density of smaller stomata (297 vs. 247 n/mm(2)), thicker palisade parenchyma (95.0 vs. 85.8 μm), and larger intercellular spaces in the mesophyll (57.5% vs. 52.2%), compared to non-inoculated plants. The modifications in leaf functional anatomical traits affected gas exchanges; in fact starting from the reproductive phase, the rate of leaf net photosynthesis (NP) was higher in inoculated compared to control plants (8.69 vs. 6.13 μmol CO2 m(-2) s(-1) at the beginning of flowering). These data are consistent with the better maximal PSII photochemical efficiency observed in inoculated plants (0.807 vs. 0.784 in control); conversely no difference in leaf chlorophyll content was found. The PGPM-induced changes in leaf structure and photosynthesis lead to an improvement of plant growth (+29.9% in plant leaf area) and seed yield (+36.9%) compared to control. Our results confirm that PGPMs may confer benefits in

  8. Changes in Leaf Anatomical Traits Enhanced Photosynthetic Activity of Soybean Grown in Hydroponics with Plant Growth-Promoting Microorganisms

    Directory of Open Access Journals (Sweden)

    Roberta Paradiso

    2017-05-01

    Full Text Available The use of hydroponic systems for cultivation in controlled climatic conditions and the selection of suitable genotypes for the specific environment help improving crop growth and yield. We hypothesized that plant performance in hydroponics could be further maximized by exploiting the action of plant growth-promoting organisms (PGPMs. However, the effects of PGPMs on plant physiology have been scarcely investigated in hydroponics. Within a series of experiments aimed to identify the best protocol for hydroponic cultivation of soybean [Glycine max (L. Merr.], we evaluated the effects of a PGPMs mix, containing bacteria, yeasts, mycorrhiza and trichoderma beneficial species on leaf anatomy, photosynthetic activity and plant growth of soybean cv. ‘Pr91m10’ in closed nutrient film technique (NFT. Plants were grown in a growth chamber under semi-aseptic conditions and inoculated at seed, seedling and plant stages, and compared to non-inoculated (control plants. Light and epi-fluorescence microscopy analyses showed that leaves of inoculated plants had higher density of smaller stomata (297 vs. 247 n/mm2, thicker palisade parenchyma (95.0 vs. 85.8 μm, and larger intercellular spaces in the mesophyll (57.5% vs. 52.2%, compared to non-inoculated plants. The modifications in leaf functional anatomical traits affected gas exchanges; in fact starting from the reproductive phase, the rate of leaf net photosynthesis (NP was higher in inoculated compared to control plants (8.69 vs. 6.13 μmol CO2 m-2 s-1 at the beginning of flowering. These data are consistent with the better maximal PSII photochemical efficiency observed in inoculated plants (0.807 vs. 0.784 in control; conversely no difference in leaf chlorophyll content was found. The PGPM-induced changes in leaf structure and photosynthesis lead to an improvement of plant growth (+29.9% in plant leaf area and seed yield (+36.9% compared to control. Our results confirm that PGPMs may confer benefits in

  9. Inhibition of microorganisms on a carrion breeding resource: the antimicrobial peptide activity of burying beetle (Coleoptera: Silphidae) oral and anal secretions.

    Science.gov (United States)

    Hall, Carrie L; Wadsworth, Nicholas K; Howard, Daniel R; Jennings, Eleanor M; Farrell, Larry D; Magnuson, Timothy S; Smith, Rosemary J

    2011-06-01

    Competition between scavengers and microorganisms for the nutrients within carrion is well documented. As a significant contributor to food web energetics, carrion serves not only as a food source for scavengers, but also as a reproductive resource for many insects. One example are the burying beetles of the Nicrophorus genus (Coleoptera: Silphidae) whose reproduction is dependent on locating and successfully sequestering vertebrate carrion. Throughout the cooperative preparation of carrion and feeding of the larval offspring, parental beetles coat the carrion with oral and anal secretions known to attenuate the growth of molds and bacteria in the laboratory. We test the hypotheses that Nicrophorus secretions attenuate the growth of naturally occurring microorganisms likely to be found colonizing the carrion resource, and that the active antimicrobial components of the secretions are small antimicrobial peptides (AMPs) similar to those produced by other insects.

  10. Antibacterial, Antifungal and Anticancer Activity of Five Strains of Soil Microorganisms Isolated From Tangkuban Perahu Mountain by Fermentation

    OpenAIRE

    Desak Gede Sri Andayani; Ukan Sukandar; Elin Y. Sukandar; I Ketut Adnyana

    2015-01-01

    Microorganisms were isolated from soil taken from Tangkuban Perahu mountain. Five strains were investigated in this study, designated TP1, TP2, TP3, TP4, and TP5, respectively. Morphological, biochemical and molecular identifications were conducted for all five strains. These isolates were shown to be closely related to Nocardia sp. YIM 65630 (90%), Streptomyces galbus (99%), Aspergillus unguis (86%), Paecilomyces marquandii (100%) and Nocardia niigatensis (95%), respectively. Production of a...

  11. 2-(Nitroaryl)benzothiazole and benzoxazole derivatives as fluorogenic substrates for the detection of nitroreductase activity in clinically important microorganisms.

    Science.gov (United States)

    Cellier, Marie; Gignoux, Amandine; James, Arthur L; Orenga, Sylvain; Perry, John D; Robinson, Shaun N; Stanforth, Stephen P; Turnbull, Graeme

    2015-12-15

    A series of carboxy-substituted 2-(nitroaryl)benzothiazole derivatives and carboxy-substituted 2-(nitroaryl)benzoxazole derivatives were prepared and evaluated as potential nitroreductase substrates for the purpose of detecting clinically important microorganisms. Several of the substrates produced highly fluorescent colonies with the majority of a panel of 10 Gram-negative bacteria and also with two of a panel of 8 Gram-positive bacteria.

  12. Response of microbial extracellular enzyme activities and r- vs. K- selected microorganisms to elevated atmospheric CO2 depends on soil aggregate size

    Science.gov (United States)

    Dorodnikov, Maxim; Blagodatskaya, Evgenia; Blagodatskiy, Sergey; Kuzyakov, Yakov

    2014-05-01

    Increased belowground carbon (C) transfer by plant roots under elevated atmospheric CO2 and the contrasting environment in soil macro- and microaggregates could affect properties of the microbial community in the rhizosphere. We evaluated the effect of 5 years of elevated CO2 (550 ppm) on four extracellular enzymes: ß-glucosidase, chitinase, phosphatase, and sulfatase along with the contribution of fast- (r-strategists) and slow-growing microorganisms (K-strategists) in soil aggregates. We fractionated the bulk soil from the ambient and elevated CO2 treatments of FACE-Hohenheim (Stuttgart) into large macro- (>2 mm), small macro- (0.25-2.00 mm), and microaggregates (soil and aggregates amended with glucose and nutrients. In the bulk soil and isolated aggregates before and after activation with glucose, the actual and the potential enzyme activities were measured. Although C-org and C-mic as well as the activities of ß-glucosidase, phosphatase, and sulfatase were unaffected in bulk soil and in aggregate-size classes by elevated CO2, significant changes were observed in potential enzyme production after substrate amendment. After adding glucose, enzyme activities under elevated CO2 were 1.2-1.9-fold higher than under ambient CO2. In addition, µ values were significantly higher under elevated than ambient CO2 for bulk soil, small macroaggregates, and microaggregates. Based on changes in µ, GMB, and lag-period, we conclude that elevated atmospheric CO2 stimulated the r-selected microorganisms, especially in soil microaggregates. In contrast, significantly higher chitinase activity in bulk soil and in large macroaggregates under elevated CO2 revealed an increased contribution of fungi to turnover processes. We conclude that quantitative and qualitative changes of C input by plants into the soil at elevated CO2 affect microbial community functioning, but not its total content. An increase in r-selected microorganisms could accelerate C turnover in terrestrial

  13. Abundance and activity of soil microorganisms in Cedrus atlantica forests are more related to land use than to altitude or latitude

    Science.gov (United States)

    Ramírez Rojas, Irene; Perez Fernandez, María; Moreno Gallardo, Laura; Lechuga Ordoñez, Victor; Linares, Juan Carlos

    2016-04-01

    Several environmental traits might change the abundance and the function of soil microorganisms in forest soils by plant-mediated reactions. Few studies have related the landscape-scale forest structural diversity with the micro-scale distribution of microorganism and their activities. High mountain environments harbor ecosystems that are very sensitive to global change and hence highly vulnerable, as those of Atlantic cedar. Altitudinal gradients in mountains are orrelated with changes in vegetation. We propose that altitudinal gradients drive shifts in microbial communities and are correlated with land uses. Thus, the latitudinal and longitudinal pattern of abundance and activity of soil micro-organisms was studied in an intercontinental comparison. We investigate soil extractable organic carbon (EOC) and nitrogen and carbon, microbial biomass and microbial metabolic activities at eight different sites along the latitudinal range of Cedrus atlantica, covering different altitudes and soils characteristics both in Southern Spain and Northern Morocco. Analyses of the abundances of total bacteria, (16S rRNA gene), was conducted using the Ilumina metagenomics technique. Results show that the stands at the highest altitudes had distinct microbial and biochemical characteristics compared with other areas. Overall, microbial activity, as measured by soil respiration, is higher in forests subjected to lower human pressure than in stands highly degraded, probably reflecting the quality of litter input that results of the influence of local assemblage of different tree, shrub and annual species, though changes in the soil N and C contents. Indeed, total soil C and N contents explained the microbial properties at every scale. Our results suggest that in contrast to the observed pronounced altitudinal changes, the kind of human-mediate land management has a stronger role in defining changes in microbial composition and activities in the investigated forest systems.

  14. Textiles for protection against microorganism

    Science.gov (United States)

    Sauperl, O.

    2016-04-01

    Concerning micro-organisms such as bacteria, viruses and fungi, there is a huge progress in the development of textile materials and procedures which should effectively protect against these various pathogens. In this sense there is especially problematic hospital environment, where it is necessary to take into account properly designed textile material which, when good selected and composed, act as a good barrier against transfer of micro-organisms through material mainly in its wet state. Respect to this it is necessary to be familiar with the rules regarding selection of the input material, the choice of proper yarn construction, the choice of the proper weaving mode, the rules regarding selection of antimicrobial-active compound suitable for (eco-friendly) treatment, and the choice of the most appropriate test method by which it is possible objectively to conclude on the reduction of selected microorganism. As is well known, fabrics are three-dimensional structures with void and non-void areas. Therefore, the physical-chemical properties of the textile material/fabric, the surface characteristics together with the shape of microorganism, and the carriers' characteristics contribute to control the transfer of microorganism through textile material. Therefore, careful planning of textile materials and treatment procedure with the compound which is able to reduce micro-organism satisfactory is particularly important, especially due to the fact that in hospital environment population with impaired immune system is mainly presented.

  15. [Soil microorganisms, nutrients and enzyme activity of Larix kaempferi plantation under different ages in mountainous region of eastern Liaoning Province, China].

    Science.gov (United States)

    Niu, Xiao-yun; Sun, Xiao-mei; Chen, Dong-sheng; Zhang, Shou-gong

    2015-09-01

    We studied the community of soil microorganisms, enzyme activity and soil nutrients under 11-, 20-, 34-and 47-year-old Larix kaempferi plantations in mountainous region of eastern Liaoning Province to discuss the soil biological properties of L. kaempferi plantations of different stand ages and their relationships with soil nutrients. The results showed that the indexes reflecting soil micro-organisms, enzyme activity and soil nutrients of L. kaempferi plantations were the highest under the 11- or 47-year-old stand and the lowest in the 20- or 34-year-old stand. Soil productivity appeared in a decline trend with the increasing stand age, and the changes of soil microbial community structure and enzyme activity were responsive to soil degradation. The difference of fungi community was more noticeable than that of bacteria community among the plantations with different stand ages. The results of CCA showed soil nutrient and pH had no effect on seasonal difference of community structure, but had effects on community, structure among different stand ages. The total N, organic carbon, C/N, available nitrogen, exchangeable Mg2+ and pH had greater effects on bacteria community, while available P, total K and pH had greater effect on fungi community among different age forests. The main T-RFs of bacteria and fungi had higher correlation with N and P, and the fungi community had higher correlation with organic carbon and K than bacteria community. The microor-ganism community of the 11- and 47-year-old stands had greater correlation with soil nutrients and enzyme activity than that of 20- and 34-year-old stands. Consequently, soil organisms, in particular soil fungi, could be used to indicate soil degradation.

  16. Microorganisms, Organic Carbon, and Their Relationship with Oxidant Activity in Hyper-Arid Mars-Like Soils: Implications for Soil Habitability

    Science.gov (United States)

    Valdivia-Silva, Julio E.; Karouia, Fathi; Navarro-Gonzalez, Rafael; McKay, Christopher

    2016-01-01

    Soil samples from the hyper-arid region in the Atacama 23 Desert in Southern Peru (La Joya Desert) were analyzed for total and labile organic carbon (TOC & LOC), phospholipid fatty acids analysis (PLFA), quantitative real time polymerase chain reaction (qRT-PCR), 4',6- diamidino-2-phenylindole (DAPI)-fluorescent microscopy, culturable microorganisms, and oxidant activity, in order to understand the relationship between the presence of organic matter and microorganisms in these types of soils. TOC content levels were similar to the labile pool of carbon suggesting the absence of recalcitrant carbon in these soils. The range of LOC was from 2 to 60 micro-g/g of soil. PLFA analysis indicated a maximum of 2.3 x 10(exp 5) cell equivalents/g. Culturing of soil extracts yielded 1.1 x 10(exp 2)-3.7 x 10(exp 3) CFU/g. qRT-PCR showed between 1.0 x 10(exp 2) and 8 x 10(exp 3) cells/g; and DAPI fluorescent staining indicated bacteria counts up to 5 x 104 cells/g. Arid and semiarid samples (controls) showed values between 10(exp 7) and 10(exp 11) cells/g with all of the methods used. Importantly, the concentration of microorganisms in hyper-arid soils did not show any correlation with the organic carbon content; however, there was a significant dependence on the oxidant activity present in these soil samples evaluated as the capacity to decompose sodium formate in 10 hours. We suggest that the analysis of oxidant activity could be a useful indicator of the microbial habitability in hyper-arid soils, obviating the need to measure water activity over time. This approach could be useful in astrobiological studies on other worlds.

  17. ATIVIDADE ENZIMÁTICA DE MICRORGANISMOS ISOLADOS DO JACATUPÉ (Pachyrhizus erosus L. Urban ENZYMATIC ACTIVITY OF MICROORGANISMS ISOLATED FROM YAM BEAN LEGUME (Pachyrhizus erosus L. Urban

    Directory of Open Access Journals (Sweden)

    Tânia L. Montenegro STAMFORD

    1998-10-01

    Full Text Available O isolamento e a identificação de microrganismos produtores de enzimas de interesse comercial, utilizando tubérculos de jacatupé (Pachyrhizus erosus L. Urban, foi o objetivo principal deste trabalho. Isolaram-se microrganismos endofíticos e epifíticos identificados por observação micromorfológica. A avaliação da atividade enzimática das linhagens foi determinada pelo método de difusão em ágar. As sessenta e oito linhagens isoladas dos tubérculos de jacatupé foram cultivadas em meio sólido específico para amilase, lipase, protease e celulase por 96h a 280 C. Os microrganismos epifíticos encontrados foram Pithomyces (7,3%, Aspergillus (19,2%, Fusarium (5,9% e Trichoderma (5,8%, e os endofíticos foram Mucor (7,3%, Rhizopus (10,3%, Bacillus (19,0%, Staphylococcus (10,3% e Nocardiopsis (15%. As linhagens de Nocardiopsis sp. apresentaram atividade lipolítica superior à do padrão, porém a atividade amilolítica não apresentou diferença significativa comparada com o padrão. As linhagens de Mucor sp., Pithomyces sp. e Staphylococcus sp. produziram atividade proteolítica abaixo do padrão. Nenhum isolado apresentou atividade celulolítica.The isolation and identification of microorganisms that produce enzyme of commercial interest utilizing tubers of yam bean legume (Pachyrrizus erosus L. Urban was the main objective of this work. Endophytic and epiphytic microorganisms were isolated by micromorphologyc observation. The agar diffusion method was used to determine the enzymatic activity. Sixty-eight isolates from yam bean tubers were cultured at 280 C in solid medium specific to amylase, lipase, protease and cellulase for 96h. The epiphytic microorganisms Pithomyces (7,3%, Aspergillus (19,2%, Fusarium (5,9% and Trichoderma (5,8% and the endophytic microorganisms Mucor (7,3%, Rhizopus (10,3% Bacillus (19%, Staphylococcus (10,3% and Nocardiopsis (15% were isolated. Compared to the specific standard culture Nocardiopsis sp. showed

  18. In vitro antiplaque activity of octenidine dihydrochloride (WIN 41464-2) against preformed plaques of selected oral plaque-forming microorganisms.

    Science.gov (United States)

    Slee, A M; O'Connor, J R

    1983-01-01

    The antibacterial activity of octenidine dihydrochloride (WIN 41464-2) against intact preformed in vitro plaques of four indigenous oral plaque-forming microorganisms, Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus, and Actinomyces naeslundii, was studied. Both absolute (plaque bactericidal index) and relative (chlorhexidine coefficient) indices of antiplaque efficacy were established. Octenidine dihydrochloride compared favorably with chlorhexidine digluconate with respect to overall antiplaque potency in this in vitro plaque bactericidal model. These data indicate that prudent selection of treatment concentration and duration and frequency of exposure should provide an effective means to aid in controlling dental caries and Actinomyces-associated disease in vivo. PMID:6847170

  19. Chemical composition of essential oils of Anthemis secundiramea Biv. subsp. secundiramea (Asteraceae) collected wild in Sicily and their activity on micro-organisms affecting historical art craft.

    Science.gov (United States)

    Casiglia, Simona; Bruno, Maurizio; Senatore, Felice; Rosselli, Sergio

    2016-04-04

    In the present study, the chemical composition of the essential oil from the aerial parts of Anthemis secundiramea Biv. subsp. secundiramea L. collected in Sicily was evaluated by GC and gas chromatography-mass spectrometry. The main components of A. secundiramea were (Z)-lyratyl acetate (14.6%), (Z)-chrysanthenyl acetate (9.9%), (Z)-chrysanthenol (8.7%) and (E)-chrysanthenyl acetate (7.7%). The comparing with other studied oils of genus Anthemis belonging to the same clade is discussed. Antibacterial and antifungal activities against some micro-organisms infesting historical art craft, were also determined.

  20. A novel bioassay for high-throughput screening microorganisms with N-acyl homoserine lactone degrading activity.

    Science.gov (United States)

    Liu, Pengfu; Gao, Yang; Huang, Wei; Shao, Zongze; Shi, Jiping; Liu, Ziduo

    2012-05-01

    A novel biosensor strain (Escherichia coli ALM403) that responded to N-acyl homoserine lactone (AHL) was constructed using a luxR-Plux cassette as a regulatory sequence and β-mannanase as a reporter gene. Dinitrosalicylic acid method was used to detect the response of the sensor strain to N-acyl homoserine lactone. By investigating the response to a range of concentrations of N-β-oxooctanoyl-L-homoserine lactone (OOHL), it was demonstrated that the expression of mannanase in E. coli ALM403 could be greatly enhanced by OOHL and resulted in an assayable phenotype. A high-throughput screening approach was developed to isolate AHL-degrading microorganisms, and a marine Halomonas sp. S66-4 showing a marked AHL-degrading ability was successfully isolated. In conclusion, the bioassay system provided a simple and efficient approach to isolate AHL-degrading bacteria.

  1. Why are some microorganisms boring?

    Science.gov (United States)

    Cockell, Charles S; Herrera, Aude

    2008-03-01

    Microorganisms from diverse environments actively bore into rocks, contributing significantly to rock weathering. Carbonates are the most common substrate into which they bore, although there are also reports of microbial borings into volcanic glass. One of the most intriguing questions in microbial evolutionary biology is why some microorganisms bore. A variety of possible selection pressures, including nutrient acquisition, protection from UV radiation and predatory grazing could promote boring. None of these pressures is mutually exclusive and many of them could have acted in concert with varying strengths in different environments to favour the development of microorganisms that bore. We suggest that microbial boring might have begun in some environments as a mechanism against entombment by mineralization.

  2. Activity of microorganisms in acid mine water. I. Influence of acid water on aerobic heterotrophs of a normal stream.

    Science.gov (United States)

    Tuttle, J H; Randles, C I; Dugan, P R

    1968-05-01

    Comparison of microbial content of acid-contaminated and nonacid-contaminated streams from the same geographical area indicated that nonacid streams contained relatively low numbers of acid-tolerant heterotrophic microorganisms. The acid-tolerant aerobes survived when acid entered the stream and actually increased in number to about 2 x 10(3) per ml until the pH approached 3.0. The organisms then represented the heterotrophic aerobic microflora of the streams comprised of a mixture of mine drainage and nonacid water. A stream which was entirely acid drainage did not have a similar microflora. Most gram-positive aerobic and anaerobic bacteria died out very rapidly in acidic water, and they comprised a very small percentage of the microbial population of the streams examined. Iron- and sulfur-oxidizing autotrophic bacteria were present wherever mine water entered a stream system. The sulfur-oxidizing bacteria predominated over iron oxidizers. Ecological data from the field were verified by laboratory experiments designed to simulate stream conditions.

  3. The Effect of Sedimentation Conditions of Frozen Deposits at the Kolyma Lowland on the Distribution of Methane and Microorganisms Activity

    Science.gov (United States)

    Oshurkova, V.; Kholodov, A. L.; Spektor, V.; Sherbakova, V.; Rivkina, E.

    2014-12-01

    Biogeochemical and microbiological investigations of methane distribution and origin in Northeastern Arctic permafrost sediments indicated that microbial methane production was observed in situ in thawed and permanently frozen deposits (Rivkina et al., 2007). To check the hypothesis about the correlation between permafrost ground type and quantity of methane, produced by microorganisms, the samples from deposits of thermokarst depression (alas), Yedoma and fluvial deposits of Kolyma floodplain for gas measurements and microbiological study were collected and the experiment with anaerobic incubation was conducted. Gas analysis indicated that alas and floodplain samples were characterized by high methane concentrations whereas Yedoma samples had only traces of methane. Two media with different substrates were prepared anaerobically for incubation. First medium contained sucrose as a substrate for hydrolytic microflora and the second one contained acetate as a substrate for methanogens. Two samples from alas, one sample from Yedoma and one from floodplain were placed in anaerobic bottles and media under gas mixture (N2, CO2 and H2) were added. The bottles were incubated for 2 weeks at room temperature. The results of the experiment showed that there was the increase of methane concentrations in the bottles with Yedoma and Floodplain samples to 52-60 and 67-90 %, respectively, from initial concentrations in contrast with Alas sample inoculated bottles. At the same time the concentration of methane in control bottles, which did not include substrates, increased to 15-19%. Current research is a part of NSF funded project "The Polaris".

  4. Isolation and initial characterization of a novel type of Baeyer-Villiger monooxygenase activity from a marine microorganism.

    Science.gov (United States)

    Willetts, Andrew; Joint, Ian; Gilbert, Jack A; Trimble, William; Mühling, Martin

    2012-07-01

    A novel type of Baeyer-Villiger monooxygenase (BVMO) has been found in a marine strain of Stenotrophomonas maltophila strain PML168 that was isolated from a temperate intertidal zone. The enzyme is able to use NADH as the source of reducing power necessary to accept the atom of diatomic oxygen not incorporated into the oxyfunctionalized substrate. Growth studies have establish that the enzyme is inducible, appears to serve a catabolic role, and is specifically induced by one or more unidentified components of seawater as well as various anthropogenic xenobiotic compounds. A blast search of the primary sequence of the enzyme, recovered from the genomic sequence of the isolate, has placed this atypical BVMO in the context of the several hundred known members of the flavoprotein monooxygenase superfamily. A particular feature of this BVMO lies in its truncated C-terminal domain, which results in a relatively small protein (357 amino acids; 38.4 kDa). In addition, metagenomic screening has been conducted on DNA recovered from an extensive range of marine environmental samples to gauge the relative abundance and distribution of similar enzymes within the global marine microbial community. Although low, abundance was detected in samples from many marine provinces, confirming the potential for biodiscovery in marine microorganisms.

  5. Microorganisms interacting in a bio filter

    Energy Technology Data Exchange (ETDEWEB)

    Barba-Avila, M. D.; Flores-Tene, F. J.; Moreno-Terrazas, R.; Ramirez-Lopez, E. M.

    2009-07-01

    Biofilm microorganisms developed on a bio filter support media allow the metabolism of volatile organic compounds (VOCs) to carbon dioxide and water. VOCs are present in polluted gaseous streams for varied industrial activities. The main objective of this study was to identify the microorganisms present in the biofilm developed on a bio filter support media using molecular biology techniques. (Author)

  6. Activity and population dynamics of heterotrophic and ammonia-oxidizing microorganisms in soil surrounding sludge bands spiked with linear alkylbenzene sulfonate

    DEFF Research Database (Denmark)

    Brandt, K. K.; Sørensen, J.; Krogh, P. H.

    2003-01-01

    Recent research has documented soil microorganisms to be rather sensitive to linear alkylbenzene sulfonates (LAS), which may enter the soil environment in considerable quantities following sewage sludge disposal. We here report field effects of LAS on selected microbial populations present...... in a sandy soil surrounding well-defined sludge bands spiked with high but realistic LAS levels (7.1 or 31.3 g/kg). Surprisingly, LAS had no effect on heterotrophic respiration in the sludge compartment per se but stimulated activity and metabolic quotient (microbial activity per unit of biomass......) in the surrounding soil. By contrast, autotrophic ammonia oxidation was initially inhibited in the LAS-spiked sludge. This led to dramatic transient increases of NH+4 availability in the sludge and surrounding soil, subsequently stimulating soil ammonia oxidizers. As judged from a Nitrosomonas europaea...

  7. Analysis on Microorganisms and Enzymes Activity in Soil of Tobacco Field%烟草土壤微生物与土壤酶活性分析

    Institute of Scientific and Technical Information of China (English)

    张翼; 曹仕明; 史俊; 孟贵星; 谭军; 赵秀云

    2012-01-01

    Bacteria, actinomycetes, ammonifying bacteria, nitrifying bacteria and fungi were isolated from soil samples collected from tobacco (Nicotiana tabacum L.) field of Xianfeng county and Enshi city, Hubei Province by dilution spread plate method. Activitiy of sucrase, urease, phosphatase, and catalase were determined using spectrophotometry method. The results showed that quantity of ammonifying bacteria was the most while of actinomycetes and fungi were the least. Quantity of different microorganism fluctuated during tobacco growth period and changed in different trend. Generally, the microorganism increased during tobacco growth period. Quantity of microorganisms was the most at vigorous growing stage of tobacco. Urease activity was high at early period of tobacco growth; while phosphatase activity was high at early and metaphase. During the later period of tobacco growth, sucrase activity increased obviously. Activity of catalase was stable during the whole growth period.%从湖北省恩施咸丰县烟田采集烟草(Nicotiana tabacum L.)不同生长时期的土壤样品,采用稀释平板涂布法进行细菌、放线菌、氨化细菌、硝化细菌、真菌的分离并对土壤蔗糖酶、脲酶、磷酸酶、过氧化氢酶进行酶活性的测定.试验结果表明,①土壤中氨化细菌数量最多,真菌数量最少.各种类群微生物在烟草整个生育期间变化波动较大,不同类群微生物消长趋势不同,整体呈上升趋势;其中,烟草生长旺盛期微生物数量最多.②在烟草生长前期,土壤脲酶活性较高;磷酸酶活性在前、中期均处于比较高的水平;在后期,随着土壤熟化程度的提高,蔗糖酶活性增强较明显;过氧化氢酶活性在各个时期的变化较平稳.

  8. Microorganisms (Microbes), Role of

    DEFF Research Database (Denmark)

    Fenchel, Tom

    2013-01-01

    Microorganisms (microbes) are those life forms too small to be seen by the naked eye; that is, those that require a microscope or other form of magnification in order to be observed. The term microorganism is thus a functional description rather than a taxonomic one, and the grouping includes...

  9. Microorganisms (Microbes), Role of

    DEFF Research Database (Denmark)

    Fenchel, Tom

    2013-01-01

    Microorganisms (microbes) are those life forms too small to be seen by the naked eye; that is, those that require a microscope or other form of magnification in order to be observed. The term microorganism is thus a functional description rather than a taxonomic one, and the grouping includes a w...

  10. Biofouling of marbles by oxygenic photosynthetic microorganisms.

    Science.gov (United States)

    Karaca, Zeki; Öztürk, Ayten; Çolak, Emel

    2015-08-01

    Phototrophic microorganisms disfigure the surfaces of different types of stone. Stone structure is damaged by the activity of photoautotrophic and other microorganisms. However, to date few, investigations have been undertaken into the relationship between microorganisms and the properties of different types of marble. In this study, biological activity of photoautotrophic microorganisms on three types of marble (Yatagan White, Giallo Anticato and Afyon White) was investigated under laboratory conditions over a short period of time. The three types of marble supported the growth of phototrophic microbial communities on their outer and inner layers, turning their original colour from white to a yellowish green colour. The porosity of the marble types facilitated filamentous microbial growth in the presence of water. Scanning electron microscope analysis revealed the accumulation of aggregates such as small spherical, fibrillar, calcified globular bodies on the inner surfaces of the marbles. This suggests that the microscopic characteristics of particular marble types may stimulate the growth of certain types of microorganisms.

  11. Antimicrobial activity of a pullulan-caraway essential oil coating on reduction of food microorganisms and quality in fresh baby carrot.

    Science.gov (United States)

    Gniewosz, Małgorzata; Kraśniewska, Karolina; Woreta, Marcin; Kosakowska, Olga

    2013-08-01

    This research evaluated the antimicrobial efficacy of pullulan films containing caraway essential oil (CEO). The films were prepared from a 10% of pullulan, containing from 0.12% to 10.0% of CEO. The composition of the CEO was analyzed with the use of gas chromatography. The antimicrobial activity of the CEO was evaluated with the method of serial microdilutions, and the films containing CEO-with the agar diffusion method against selected Gram-negative, Gram-positive bacteria, and fungi. The structure of the film surface and its cross-section were analyzed using a scanning electron microscope (SEM). Analyses were also carried out to determine the efficacy of a pullulan coating with 10% CEO on baby carrots experimentally inoculated with Salmonella enteritidis, Staphylococcus aureus, Saccharomyces cerevisiae, or Aspergillus niger and stored at a room temperature for 7 d. At a concentration of 0.12%, CEO inhibited the growth of all the tested microorganisms. Pullulan films containing 8% to 10% of CEO were active against all tested microorganisms. Populations of S. aureus on carrot samples were reduced by approximately 3 log CFU/g, while those of A. niger and S. cerevisiae by, respectively, 5 and 4 log CFU/g, after 7 d of storage. S. enteritidis was the most resistant among the tested species, since it was not significantly reduced after 7 d of storage. At the end of storage, samples treated with pullulan-caraway oil coating maintained better visual acceptability than control samples. Results of this study suggest the feasibility of applying a pullulan film with incorporated CEO to extend the microbiological stability of minimally processed foods.

  12. Quantifying filamentous microorganisms in activated sludge before, during, and after an incident of foaming by oligonucleotide probe hybridizations and antibody staining.

    Science.gov (United States)

    Oerther, D B; de los Reyes, F L; de los Reyes, M F; Raskin, L

    2001-10-01

    Quantitative oligonucleotide probe hybridizations, immunostaining, and a simple foaming potential test were used to follow an incident of seasonal filamentous foaming at the Urbana-Champaign Sanitary District, Northeast Wastewater Treatment Plant. A positive correlation was observed between an increase in foaming potential and the appearance of foam on the surfaces of aeration basins and secondary clarifiers. In addition, during the occurrence of foaming, the mass and activity of Gordonia spp. increased as measured by fluorescence in situ hybridization, antibody staining, and quantitative membrane hybridization of RNA extracts. An increase in Gordonia spp. rRNA levels from 0.25 to 1.4% of total rRNA was observed using quantitative membrane hybridizations, whereas during the same period, the fraction of mixed liquor volatile suspended solids attributed to Gordonia spp. increased from 4% to more than 32% of the total mixed liquor volatile suspended solids. These results indicate that both the activity and biomass level of Gordonia spp. in activated sludge increased relative to the activity aid the biomass level of the complete microbial community during a seasonal occurrence of filamentous foaming. Thus, Gordonia spp. may represent a numerically dominant but metabolically limited fraction of the total biomass, and the role of Gordonia spp. in filamentous foaming may be linked more tightly to the physical presence of filamentous microorganisms than to the metabolic activity of the cells.

  13. Recombinant microorganisms for increased production of organic acids

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Jian; Kleff, Susanne; Guettler, Michael V

    2013-04-30

    Disclosed are recombinant microorganisms for producing organic acids. The recombinant microorganisms express a polypeptide that has the enzymatic activity of an enzyme that is utilized in the pentose phosphate cycle. The recombinant microorganism may include recombinant Actinobacillus succinogenes that has been transformed to express a Zwischenferment (Zwf) gene. The recombinant microorganisms may be useful in fermentation processes for producing organic acids such as succinic acid and lactic acid. Also disclosed are novel plasmids that are useful for transforming microorganisms to produce recombinant microorganisms that express enzymes such as Zwf.

  14. Characterization of functional microorganism groups and substrate in activated sludge and wastewater by AUR, NUR and OUR

    DEFF Research Database (Denmark)

    Kristensen, G. Holm; Jørgensen, P. Elberg; Henze, Mogens

    1992-01-01

    . The results indicated that influent biomass is of significance for the obtained fraction of denitrifiers to heterotrophs. For a separate nitrification stage activated sludge without denitrification a fraction of denitrifiers of 15-20% was found. The results of endogenous NUR and OUR determinations indicated...... that hydrolysis of activated sludge COD takes place with the same rate under anoxic and aerobic process conditions....

  15. Interactions of Marsh Orchid (Dactylorhiza spp.) and Soil Microorganisms in Relation to Extracellular Enzyme Activities in a Peat Soil

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The nature of the interactions between microbes and roots of plants in a peaty soil were studied in a laboratorybased experiment by measuring activities of β-glucosidase, phosphatase, N-acetylglucosaminidase, and arylsulphatase. The experiment was based on control (autoclaved), bacteria-inoculated, and plant (transplanted with Dactylorhiza) treatments,and samples were collected over 4 sampling intervals. Higher enzyme activities were associated with the bacteria-inoculated treatment, suggesting that soil enzyme activities are mainly of microbial origin. For example, β-glucosidase activity varied between 25-30 μmol g-1 min-1 in the bacteria-inoculated samples whilst the activity of the control ranged between 4-12μmol g-1 min-1. A similar pattern was found for all other enzymes.At the end of the incubation, the microcosms were destructively sampled and the enzyme activities determined in bulk soil, rhizospheric soil, and on the root surface. Detailed measurement in different fractions of the peat indicated that higher activities were found in rhizosphere. However, the higher activities ofβ-glucosidase, N-acetylglucosaminidase, and arylsulphatase appeared to be associated with bacterial proliferation on the root surface, whilst a larger proportion of phosphatase appeared to be released from root surface.

  16. Soil microorganisms and activity of soil enzymes in mangrove%红树林土壤微生物与土壤酶活性分析

    Institute of Scientific and Technical Information of China (English)

    李倩茹; 符夏梨

    2009-01-01

    The soil samples were collected from the mangrove area and non-mangrove of the Donghai Island of Zhanjiang City. Bacteria, actinomycetes and fungi were isolated with dilution spread plate method from soil samples. Activities of Catalase and sucrase were determined using titration method and activities of urease and polyphenoloxidase were determined using spectrophotometry method. The results showed that bacteria was the most, actinomycetes was the second and fung was the least in quantity. Soil microorganism quantity of mangrove were more than that of non-mangrove. Catalase, sucrase and urease activity of Kandelia candel were the highest, but polyphenoloxidase activity was the lowest. Catalase, sucrase and urease activity of mangrove was higher than that of non-mangrove. Catalase, sucrase, urease activities were positive correlative with soil microorganisms.%从湛江市东海岛大坝红树林区和非红树林区采集土壤样品,采用稀释平板涂布法进行细菌、放线菌和真菌的分离;采用滴定法对过氧化氢酶和蔗糖酶进行酶活性的测定.采用比色法对脲酶和多酚氧化酶进行酶活性测定.试验结果表明,土壤中细菌数量最多.其次是放线菌.真菌数量最少.通过比较发现.红树林土壤微生物数最多于非红树林土壤微生物数量,且不同红树植物林地土壤微生物多少也不一样.从酶的活性看,红树林土壤过氧化氢酶、蔗糖酶和脲酶活性高于非红树林土壤,且这几种酶的活性与土壤微生物的数量呈正相关.

  17. Activity and interactions of methane seep microorganisms assessed by parallel transcription and FISH-NanoSIMS analyses.

    Science.gov (United States)

    Dekas, Anne E; Connon, Stephanie A; Chadwick, Grayson L; Trembath-Reichert, Elizabeth; Orphan, Victoria J

    2016-03-01

    To characterize the activity and interactions of methanotrophic archaea (ANME) and Deltaproteobacteria at a methane-seeping mud volcano, we used two complimentary measures of microbial activity: a community-level analysis of the transcription of four genes (16S rRNA, methyl coenzyme M reductase A (mcrA), adenosine-5'-phosphosulfate reductase α-subunit (aprA), dinitrogenase reductase (nifH)), and a single-cell-level analysis of anabolic activity using fluorescence in situ hybridization coupled to nanoscale secondary ion mass spectrometry (FISH-NanoSIMS). Transcript analysis revealed that members of the deltaproteobacterial groups Desulfosarcina/Desulfococcus (DSS) and Desulfobulbaceae (DSB) exhibit increased rRNA expression in incubations with methane, suggestive of ANME-coupled activity. Direct analysis of anabolic activity in DSS cells in consortia with ANME by FISH-NanoSIMS confirmed their dependence on methanotrophy, with no (15)NH4(+) assimilation detected without methane. In contrast, DSS and DSB cells found physically independent of ANME (i.e., single cells) were anabolically active in incubations both with and without methane. These single cells therefore comprise an active 'free-living' population, and are not dependent on methane or ANME activity. We investigated the possibility of N2 fixation by seep Deltaproteobacteria and detected nifH transcripts closely related to those of cultured diazotrophic Deltaproteobacteria. However, nifH expression was methane-dependent. (15)N2 incorporation was not observed in single DSS cells, but was detected in single DSB cells. Interestingly, (15)N2 incorporation in single DSB cells was methane-dependent, raising the possibility that DSB cells acquired reduced (15)N products from diazotrophic ANME while spatially coupled, and then subsequently dissociated. With this combined data set we address several outstanding questions in methane seep microbial ecosystems and highlight the benefit of measuring microbial activity in

  18. Active microorganisms in forest soils differ from the total community yet are shaped by the same environmental factors: the influence of pH and soil moisture.

    Science.gov (United States)

    Romanowicz, Karl J; Freedman, Zachary B; Upchurch, Rima A; Argiroff, William A; Zak, Donald R

    2016-10-01

    Predicting the impact of environmental change on soil microbial functions requires an understanding of how environmental factors shape microbial composition. Here, we investigated the influence of environmental factors on bacterial and fungal communities across an expanse of northern hardwood forest in Michigan, USA, which spans a 500-km regional climate gradient. We quantified soil microbial community composition using high-throughput DNA sequencing on coextracted rDNA (i.e. total community) and rRNA (i.e. active community). Within both bacteria and fungi, total and active communities were compositionally distinct from one another across the regional gradient (bacteria P = 0.01; fungi P soil moisture, pH, SOM carboxyl content, as well as C and N concentration. Our study highlights the importance of distinguishing between metabolically active microorganisms and the total community, and emphasizes that the same environmental factors shape the total and active communities of bacteria and fungi in this ecosystem. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. Characterization of EstB, a novel cold-active and organic solvent-tolerant esterase from marine microorganism Alcanivorax dieselolei B-5(T).

    Science.gov (United States)

    Zhang, Shanshan; Wu, Guojie; Liu, Zhixiang; Shao, Zongze; Liu, Ziduo

    2014-03-01

    A novel esterase gene, estB, was cloned from the marine microorganism Alcanivorax dieselolei B-5(T) and overexpressed in E. coli DE3 (BL21). The expressed protein EstB with a predicted molecular weight of 45.1 kDa had a distinct catalytic triad (Ser(211)-Trp(353)-Gln(385)) and the classical consensus motif conserved in most lipases and esterases Gly(209)-X-Ser(211)-X-Gly(213). EstB showed very low similarity to any known proteins and displayed the highest similarity to the hypothetical protein (46%) from Rhodococcus jostii RHA1. EstB showed the optimal activity around pH 8.5 and 20 °C and was identified to be extremely cold-adaptative retaining more than 95% activity between 0 and 10 °C. The values of kinetic parameters on p-NP caproate (K m, K cat and K cat/K m) were 0.15 mM, 0.54 × 10(3) s(-1) and 3.6 × 10(3) s(-1) mM(-1), respectively. In addition, EstB showed remarkable stability in several studied organic solvents and detergents of high concentrations with the retention of more than 70% activity after treatment for 30 min. The cold activity and its tolerance towards organic solvents made it a promising biocatalyst for industrial applications under extreme conditions.

  20. OPPORTUNISTIC MICROORGANISMS IN RHEUMATIC DISEASES

    Directory of Open Access Journals (Sweden)

    M. Yu. Gulneva

    2016-01-01

    Full Text Available The paper gives the data available in the literature on the role of opportunistic microorganisms (OMs in rheumatic diseases (RDs. OMs are anticipated to be involved as triggers initiating the development of chronic inflammation. Along with this, OMs in autoimmune diseases may play a defensive role through the interaction with Toll-like receptors and the activation of T cells that have suppressor activity. The possible involvement of OMs in the pathogenesis of RDs provides support not only the isolation of microorganisms, but also the detection of antibacterial antibodies of different classes. Of great importance are OMs in the etiology of comorbid infections, the risk of which is due to both the presence of autoimmune RDs and the necessity of using the drugs having immunosuppressive activity. The active clinical introduction of biological agents is followed by a rise in the rate and severity of different infections, including those caused by OMs. Having a marked biological and environmental plasticity, OMs are able to persist long when there are changes in the immune defense of patients with RDs. There is evidence for the higher adhesive properties and persistent potential of the microorganisms that colonize the body of patients with RDs. In the latter, OMs that are distinguished by pronounced antibiotic polyresistance are isolated, making the treatment and prevention of opportunistic infections more difficult in rheumatology. The results of the papers analyzed in the review suggest that the study of OMs in RDs is of practical importance.

  1. The Role of Microorganisms in Marine Corrosion

    Science.gov (United States)

    1990-02-12

    Electrochemical evaluation of hydrogen embrittlement by microorganisms. ’The Electrochemical Society ,’ 175th meeting, Los Angeles, CA. 4. Black, J.P...microbiologically-produced hydrogen permeation through palladium. Journal of the Electrochemical Society . (In Press). INVENTIONS: None TRAINING ACTIVITIES

  2. Antimicrobial Activity of neo-Clerodane Diterpenoids isolated from Lamiaceae Species against Pathogenic and Food Spoilage Microorganisms.

    Science.gov (United States)

    Bozov, Petko; Girova, Tania; Prisadova, Natalia; Hristova, Yana; Gochev, Velizar

    2015-11-01

    Antimicrobial activity of nineteen neo-clerodane diterpenoids, isolated from the acetone extracts of the aerial parts of Scutellaria and Salvia species (Lamiaceae) were tested against thirteen strains belonging to nine different species of pathogenic and food spoilage bacteria Aeromonas hydrophila, Bacillus cereus, Escherichia coli, Listeria monocytogenes, Proteus vulgaris, Pseudomonas aeruginosa, Pseudomonas fluorescens, Salmonella abony and Staphylococcus aureus as well as against two yeast strains belonging to species Candida albicans. Seven of the evaluated compounds scutalpin A, scutalpin E, scutalpin F, salviarin, splenolide A, splenolide B and splendidin demonstrated antimicrobial activity against used test microbial strains, the rest of the compounds were inactive within the studied concentration range. Among all of the tested compounds the highest antimicrobial activity was detected for scutalpin A against Staphylococcus aureus (MIC 25 µg/mL).

  3. Microorganisms involved in MIC

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, K. [Danish Technological Institute (Denmark)

    2011-07-01

    Microbiologically influenced corrosion (MIC) is a widespread problem that is difficult to detect and assess because of its complex mechanism. This paper presents the involvement of microorganisms in MIC. Some of the mechanisms that cause MIC include hydrogen consumption, production of acids, anode-cathode formation and electron shuttling. A classic bio-corrosive microorganism in the oil and gas industry is sulphate-reducing prokaryotes (SRP). Methanogens also increase corrosion rates in metals. Some of the phylogenetic orders detected while studying SRP and methanogens are archaeoglobales, clostridiales, methanosarcinales and methanothermococcus. There were some implications, such as growth of SRP not being correlated with growth of methanogens; methanogens were included in MIC risk assessment. A few examples are used to display how microorganisms are involved in topside corrosion and microbial community in producing wells. From the study, it can be concluded that, MIC risk assessment includes system data and empirical knowledge of the distribution and number of microorganisms in the system.

  4. Antimicrobial Activities of Essential Oils and Hexane Extracts of Two Turkish Spice Plants, Cymbocarpum erythraeum (DC. Boiss. and Echinophora tenuifolia L. Against Foodborne Microorganisms

    Directory of Open Access Journals (Sweden)

    Bülent Çetin

    2016-01-01

    Full Text Available The hydrodistillated essential oils and hexane extracts of two spice plants, Cymbocarpum erythraeum (DC. Boiss. and Echinophora tenuifolia L. were analyzed by GC and GC-MS. C. erythraeum oil is rich in aliphatic aldehydes, alcohols and acids and (E-2-decenal (26.1%, (E-2-decen-1-ol (15.7%, (E-2-dodecenal (13.2% and decanal (7.8% were the predominant components. However, ethyl palmitate (16.4%, 2-decenoic acid (14.1% and (E-2-dodecenal (5.2% were the major components of the hexane extract of C. erythraeum. E. tenuifolia oil contained mainly methyl eugenol (53.0%, p-cymene (17.0% and α-phellandrene (13.2%. The hexane extract displayed a different chemical composition, and n-tricosane (75.0% and n-pentacosane (7.6% were found to be the major compounds. The oils showed antimicrobial activity against various microorganisms and they were more active against the tested fungal species as compared with bacteria. The growths of important food-borne pathogens, Salmonella, Staphylococcus aureus and Escherichia coli were also inhibited by the oils. However, hexane extract of C. erythraeum was showed weak antibacterial activity against limited number of tested bacteria. The current results showed that the essential oils of C. erythraeumand E. tenuifolia can be used in food preservation.

  5. Seasonality and depth distribution of the abundance and activity of ammonia oxidizing microorganisms in marine coastal sediments (North Sea

    Directory of Open Access Journals (Sweden)

    Yvonne Antonia Lipsewers

    2014-09-01

    Full Text Available Microbial processes such as nitrification and anaerobic ammonium oxidation (anammox are important for nitrogen cycling in marine sediments. Seasonal variations of archaeal and bacterial ammonia oxidizers (AOA and AOB and anammox bacteria, as well as the environmental factors affecting these groups, are not well studied. We have examined the seasonal and depth distribution of the abundance and potential activity of these microbial groups in coastal marine sediments of the southern North Sea. This was achieved by quantifying specific intact polar lipids (IPLs as well as the abundance and gene expression of their 16S rRNA gene, the ammonia monooxygenase subunit A (amoA gene of AOA and AOB, and the hydrazine synthase (hzsA gene of anammox bacteria. AOA, AOB and anammox bacteria were detected and transcriptionally active down to 12 cm sediment depth. In all seasons, the abundance of AOA was higher compared to the AOB abundance suggesting that AOA play a more dominant role in aerobic ammonia oxidation in these sediments. Anammox bacteria were abundant and active even in oxygenated and bioturbated parts of the sediment. The abundance of AOA and AOB was relatively stable with depth and over the seasonal cycle, while anammox bacteria abundance and transcriptional activity were highest in August. North Sea sediments thus seem to provide a common, stable, ecological niche for AOA, AOB and anammox bacteria.

  6. The antimicrobial efficacy and structure activity relationship of novel carbohydrate fatty acid derivatives against Listeria spp. and food spoilage microorganisms.

    Science.gov (United States)

    Nobmann, Patricia; Smith, Aoife; Dunne, Julie; Henehan, Gary; Bourke, Paula

    2009-01-15

    Novel mono-substituted carbohydrate fatty acid (CFA) esters and ethers were investigated for their antibacterial activity against a range of pathogenic and spoilage bacteria focussing on Listeria monocytogenes. Carbohydrate derivatives with structural differences enable comparative studies on the structure/activity relationship for antimicrobial efficacy and mechanism of action. The antimicrobial efficacy of the synthesized compounds was compared with commercially available compounds such as monolaurin and monocaprylin, as well as the pure free fatty acids, lauric acid and caprylic acid, which have proven antimicrobial activity. Compound efficacy was compared using an absorbance based broth microdilution assay to determine the minimum inhibitory concentration (MIC), increase in lag phase and decrease in maximum growth rate. Among the carbohydrate derivatives synthesized, lauric ether of methyl alpha-d-glucopyranoside and lauric ester of methyl alpha-d-mannopyranoside showed the highest growth-inhibitory effect with MIC values of 0.04 mM, comparable to monolaurin. CFA derivatives were generally more active against Gram positive bacteria than Gram negative bacteria. The analysis of both ester and ether fatty acid derivatives of the same carbohydrate, in tandem with alpha and beta configuration of the carbohydrate moiety suggest that the carbohydrate moiety is involved in the antimicrobial activity of the fatty acid derivatives and that the nature of the bond also has a significant effect on efficacy, which requires further investigation. This class of CFA derivatives has great potential for developing antibacterial agents relevant to the food industry, particularly for control of Listeria or other Gram-positive pathogens.

  7. Micro-Organ Device

    Science.gov (United States)

    Gonda, Steve R. (Inventor); Chang, Robert C. (Inventor); Starly, Binil (Inventor); Culbertson, Christopher (Inventor); Holtorf, Heidi L. (Inventor); Sun, Wei (Inventor); Leslie, Julia (Inventor)

    2013-01-01

    A method for fabricating a micro-organ device comprises providing a microscale support having one or more microfluidic channels and one or more micro-chambers for housing a micro-organ and printing a micro-organ on the microscale support using a cell suspension in a syringe controlled by a computer-aided tissue engineering system, wherein the cell suspension comprises cells suspended in a solution containing a material that functions as a three-dimensional scaffold. The printing is performed with the computer-aided tissue engineering system according to a particular pattern. The micro-organ device comprises at least one micro-chamber each housing a micro-organ; and at least one microfluidic channel connected to the micro-chamber, wherein the micro-organ comprises cells arranged in a configuration that includes microscale spacing between portions of the cells to facilitate diffusion exchange between the cells and a medium supplied from the at least one microfluidic channel.

  8. Rumen microorganisms and fermentation

    Directory of Open Access Journals (Sweden)

    AR Castillo-González

    2014-01-01

    Full Text Available The rumen consists of a complex ecosystem where nutrients consumed by ruminants are digested by fermentation process, which is executed by diverse microorganisms such as bacteria, protozoa, and fungi. A symbiotic relationship is found among different groups of microorganisms due to the diverse nature of these microbial species and their adaptability and interactions also coexist. The ruminant provides the necessary environment for the establishment of such microorganisms, while the microorganisms obtain energy from the host animal from microbial fermentation end products. Within the ruminal ecosystem, the microorganisms coexist in a reduced environment and pH remains close to neutral. Rumen microorganisms are involved in the fermentation of substrates contained in thedietof the animals (carbohydrates, proteins and lipids. However, the fermentation process is not 100% effective because there are energy losses mainly in the form of methane gas (CH4, which is a problem for the environment since it is a greenhouse gas. In order to improve the efficiency of ruminant production systems, nutritional strategies that aim to manipulate ruminal fermentation using additives in the diet such as monensin, tallow, buffers, nitrogen compounds, probiotics, and others have been used. These additives allow changing the ruminal fermentation process in ways that produce better growth efficiency while decreasing energy loss. The purpose of this review is to contribute to a better understanding of the fermentation processes taking place in the rumen, providing information that can be applied in the development of new nutritional strategies for the improvement of the digestion process to achieve maximum production.

  9. Inhibition of boric acid and sodium borate on the biological activity of microorganisms in an aerobic biofilter.

    Science.gov (United States)

    Güneş, Y

    2013-01-01

    The aim of this work was to study the inhibition effect of boric acid and sodium borate on the treatment of boron containing synthetic wastewater by a down flow aerobic fixed bed biofilm reactor at various chemical oxygen demand (COD)/boron ratios (0.47-20.54). The inhibitory effect of boron on activated sludge was evaluated on the basis of COD removal during the experimental period. The biofilter (effective volume = 2.5 L) was filled with a ring of plastic material inoculated with acclimated activated sludge. The synthetic wastewater composed of glucose, urea, KH2PO4, MgSO4, Fe2 SO4, ZnSO4 x 7H20, KCl, CaCl2, and di-sodium tetraborate decahydrate or boric acid (B = 100-2000 mg L(-1)). The biological treatment of boron containing wastewater resulted in a low treatment removal rate due to the reduced microbial activity as a result of toxic effects of high boron concentrations. The decrease in the COD removal rate by the presence of either boric acid or sodium borate was practically indistinguishable. It was observed from the experiments that about 90-95% of COD removal was possible at high COD/boron ratios.

  10. Poly(3-hydroxybutyrate)/metribuzin formulations: characterization, controlled release properties, herbicidal activity, and effect on soil microorganisms.

    Science.gov (United States)

    Volova, Tatiana; Zhila, Natalia; Kiselev, Evgeniy; Prudnikova, Svetlana; Vinogradova, Olga; Nikolaeva, Elena; Shumilova, Anna; Shershneva, Anna; Shishatskaya, Ekaterina

    2016-12-01

    Slow-release formulations of the herbicide metribuzin (MET) embedded in the polymer matrix of degradable poly-3-hydroxybutyrate [P(3HB)] in the form of microparticles, films, microgranules, and pellets were developed and tested. The kinetics of polymer degradation, MET release, and accumulation in soil were studied in laboratory soil microecosystems with higher plants. The study shows that MET release can be controlled by using different techniques of constructing formulations and by varying MET loading. MET accumulation in soil occurs gradually, as the polymer is degraded. The average P(3HB) degradation rates were determined by the geometry of the formulation, reaching 0.17, 0.12, 0.04, and 0.05 mg/day after 60 days for microparticles, films, microgranules, and pellets, respectively. The herbicidal activities of P(3HB)/MET formulations and commercial formulation Sencor Ultra were tested on the Agrostis stolonifera and Setaria macrocheata plants. The parameters used to evaluate the herbicidal activity were plant density and the weight of fresh green biomass measured at days 10, 20, and 30 after sowing. All P(3HB)/MET formulations had pronounced herbicidal activity, which varied depending on MET loading and the stage of the experiment. In the early phases of the experiment, the herbicidal effect of P(3HB)/MET formulations with the lowest MET loading (10 %) was comparable with that of the commercial formulation. The herbicidal effect of P(3HB)/MET formulations with higher MET loadings (25 and 50 %) at later stages of the experiment were stronger than the effect of Sencor Ultra.

  11. Effect of Erica sp. Honey against Microorganisms of Clinical Importance: Study of the Factors Underlying this Biological Activity

    Directory of Open Access Journals (Sweden)

    Leticia M. Estevinho

    2013-04-01

    Full Text Available This study aimed to determine the factors (phenolic compounds, flavonoids, sugars or H2O2 that contribute the most to the antimicrobial activity of heather honey samples against four yeasts and four bacteria with medical importance. To discard the effect of H2O2 in the antimicrobial activity, catalase was added. To evaluate the osmotic pressure’s effect, artificial honey was also used. Phenolic compounds and flavonoids were determined and Pearson’s correlation analysis was performed to assess whether these correlated with antimicrobial activity. The amount of phenolic compounds ranged from 630.89 ± 5.21 GAE kg−1 to 718.92 ± 4.41 GAE kg−1, while the flavonoids varied between 450.72 ± 5.67 CAE kg−1 and 673.98 ± 4.33 CAE kg−1. For the bacteria, the minimum inhibitory concentration (MIC of the honey without catalase ranged from 1.01 ± 0.50% to 10.00 ± 4.72% and was between 2.00 ± 0.94% and 13.27 ± 5.23% for honey with catalase. Concerning the yeasts, the MICs was between 13.16 ± 4.08% and 20.00 ± 5.09% for honey without catalase and between 14.95 ± 4.16% and 25.67 ± 5.50% for honey with catalase. The elucidation of the antimicrobial factors and action mechanisms is essential for the correct use of honey in therapeutic applications.

  12. 环境微生物果胶酶活性研究%Study on Environmental Microorganism Pectinase Activity

    Institute of Scientific and Technical Information of China (English)

    谭秀华; 闫苗苗

    2009-01-01

    [目的]对从环境中筛选到的一种产果胶酶酶活较高的菌株进行酶学特征研究.[方法]通过功能平板从果园土壤中筛选到一种产果胶酶的菌株,通过DNS法在不同的温度和pH值条件下测定该酶酶活力.[结果]对菌株TP1粗酶进行的分析表明:其最适温度为60℃,最适pH值为7.50,酶活为38 U,半衰期为1 h,在80℃保温5 min其酶活由最初酶活的79%下降到15%,温度下降到65℃后活性可恢复到最初酶活的65%以上.[结论]菌株TP1所产果胶酶的酶学特征适合推广,有进一步研究的价值.%[Objective] The aim was to study the enzymatic properties of a highly producing pectinase bacterial strain which was obtained from soil. [Method] The bactrerial strain was isolated from orchard soil by functional plates. The enzymatic activity was detected by DNS with different temperature and pH values. [Result] TheResults showed that optimal temperature and pH value of the pectinase were 60 ℃ and 7.50. The enzymatic activity reached 38 with a half life of one hour. After keeping at 80 ℃ for 5 min, the enzymatic activity declined from 79% to 15% and the enzymatic activity could recover up to more than 65% when the temperature descended to 65 ℃. [Conclusion] The pectinase produced by strain TP1 was suit to be popularized and need further studies on it.

  13. Effects of Metal Nanoparticles on Methane Production from Waste-Activated Sludge and Microorganism Community Shift in Anaerobic Granular Sludge

    Science.gov (United States)

    Wang, Tao; Zhang, Dong; Dai, Lingling; Chen, Yinguang; Dai, Xiaohu

    2016-05-01

    Extensive use of nanoparticles (NPs) in consumer and industrial products has led to concerns about their potential environmental impacts; however, the influences of different NPs (e.g., nZVI (nano zero-valent iron), Ag NPs, Fe2O3 NPs and MgO NPs) on the anaerobic digestion of sludge have not yet been studied in depth. Additionally, a new guideline or the use of different NPs in the anaerobic digestion of sludge should be established to improve the anaerobic digestion of sludge and avoid inhibitory effects. This study investigated the effects of four representative NPs (i.e., nZVI, Ag NPs, Fe2O3 NPs and MgO NPs) on methane production during the anaerobic digestion of waste activated sludge (WAS). The presence of 10 mg/g total suspended solids (TSS) nZVI and 100 mg/g TSS Fe2O3 NPs increased methane production to 120% and 117% of the control, respectively, whereas 500 mg/g TSS Ag NPs and 500 mg/g TSS MgO NPs generated lower levels of methane production (73.52% and 1.08% that of the control, respectively). These results showed that low concentrations of nZVI and Fe2O3 NPs promoted the amount of microbes (Bacteria and Archaea) and activities of key enzymes but that higher concentrations of Ag NPs and MgO NPs inhibited them.

  14. 海洋微生物次级代谢产物抗菌作用研究进展%Antimicrobial activity of the secondary metabolites from marine microorganisms:research advances

    Institute of Scientific and Technical Information of China (English)

    尹慢慢; 刘炎东; 张黎明

    2014-01-01

    The aim of the paper is to review the research progress on the secondary metabolites from marine microorganisms in recent years and to summarize its application in antimicrobial activity. We have earched and collected the published articles which are focused on the secondary metabolites from marine microorganisms; analysed the structure and function of the secondary metabolites and summed up the antimicrobial activities of the production from marine microorganisms; in addition,investigated the mechanism of action about the antimicrobial activities of the secondary metabolites from marine microorganisms. The secondary metabolites from marine microorganisms have rich structural diversity and different mechanisms of action. Marine microorganisms have the potential to produce large numbers of bioactive metabolites, among which the antimicrobial substance is the most prominent,making it an important resource in the development of novel marine drugs.%海洋微生物次级代谢产物种类繁多,具有丰富的结构多样性和不同的抗菌功能。其中以抗菌活性物质最为突出,已经成为近年来新药筛选的重要资源,在药品开发应用中具有良好的发展前景。本文结合近年关于海洋微生物次级代谢产物的报道,分析海洋微生物次级代谢产物的结构和功能;并对海洋微生物次级代谢产物在抗菌方面的作用及其抗菌作用机制的研究进展进行总结。

  15. Activity and population dynamics of heterotrophic and ammonia-oxidizing microorganisms in soil surrounding sludge bands spiked with linear alkylbenzene sulfonate: a field study.

    Science.gov (United States)

    Brandt, Kristian Koefoed; Krogh, Paul Henning; Sørensen, Jan

    2003-04-01

    Recent research has documented soil microorganisms to be rather sensitive to linear alkylbenzene sulfonates (LAS), which may enter the soil environment in considerable quantities following sewage sludge disposal. We here report field effects of LAS on selected microbial populations present in a sandy soil surrounding well-defined sludge bands spiked with high but realistic LAS levels (7.1 or 31.3 g/kg). Surprisingly, LAS had no effect on heterotrophic respiration in the sludge compartment per se but stimulated activity and metabolic quotient (microbial activity per unit of biomass) in the surrounding soil. By contrast, autotrophic ammonia oxidation was initially inhibited in the LAS-spiked sludge. This led to dramatic transient increases of NH4+ availability in the sludge and surrounding soil, subsequently stimulating soil ammonia oxidizers. As judged from a Nitrosomonas europaea bioluminescence toxicity assay, however, LAS or other sludge components never accumulated to toxic levels in the soil compartments and the LAS tolerance of the indigenous microbes further remained unchanged following LAS exposure. LAS effects on the investigated microbial populations largely occurred during the first two months and were confined to soil closer than 30 mm from LAS-spiked sludge. Our results strongly suggest that disposal of LAS-contaminated sludge does not pose a major risk to the function of the soil microbial community under field conditions.

  16. Effects of Short-Term Set-Aside Management Practices on Soil Microorganism and Enzyme Activity in China.

    Science.gov (United States)

    Li, Guangyu; Wu, Cifang

    2017-08-14

    Set-aside farmland can effectively improve the self-rehabilitation of arable soil. Long-term set-asides however cannot satisfy provisionment, therefore the use of short-term set-asides to restore cultivated soil is a better option. Few studies have compared short-term set-aside patterns, and the effects of set-asides on soil microbial community and enzyme enzymes. We analyzed the bacterial structure, microbial biomass carbon/nitrogen and enzyme activity of farmland soil under different set-aside regimes in the Yellow River Delta of China. Bacterial alpha diversity was relatively lower under only irrigation, and farmyard manure applications showed clear advantages. Set-asides should consider their influence on soil organic carbon and nitrogen, which were correlated with microbial community structure. Nitrospira (0.47-1.67%), Acidobacteria Gp6 (8.26-15.91%) and unclassified Burkholderiales (1.50-2.81%) were significantly altered (p functions of these genera, some set-aside patterns led to a relative balance in nitrogen and carbon turnover. Partial treatments showed a deficiency in organic matter. In addition, farmyard manure may lead to the increased consumption of organic matter, with the exception of native plants set-asides. Conventional farming (control group) displayed a significant enzyme activity advantage. Set-aside management practices guided soil microbial communities to different states. Integrated soil microbiota and the content of carbon and nitrogen, native plants with farmyard manure showed an equilibrium state relatively, which would be helpful to improve land quality in the short-term.

  17. Effects of Antibiotics on Bacterial Species Composition and Metabolic Activities in Chemostats Containing Defined Populations of Human Gut Microorganisms

    Science.gov (United States)

    Newton, Dorothy F.; Macfarlane, George T.

    2013-01-01

    The composition and metabolic activities of the human colonic microbiota are modulated by a number of external factors, including diet and antibiotic therapy. Changes in the structure and metabolism of the gut microbiota may have long-term consequences for host health. The large intestine harbors a complex microbial ecosystem comprising several hundreds of different bacterial species, which complicates investigations on intestinal physiology and ecology. To facilitate such studies, a highly simplified microbiota consisting of 14 anaerobic and facultatively anaerobic organisms (Bacteroides thetaiotaomicron, Bacteroides vulgatus, Bifidobacterium longum, Bifidobacterium infantis, Bifidobacterium pseudolongum, Bifidobacterium adolescentis, Clostridium butyricum, C. perfringens, C. bifermentans, C. innocuum, Escherichia coli, Enterococcus faecalis, Enterococcus faecium, Lactobacillus acidophilus) was used in this investigation. Ampicillin [9.2 μg (ml culture)−1] was added to two chemostats operated at different dilution rates (D; 0.10 h−1 and 0.21 h−1), and metronidazole [76.9 μg (ml culture)−1] was added to a third vessel (D = 0.21 h−1). Perturbations in bacterial physiology and metabolism were sampled over a 48-h period. Lactobacillus acidophilus and C. bifermentans populations did not establish in the fermentors under the imposed growth conditions. Ampicillin resulted in substantial reductions in bacteroides and C. perfringens populations at both dilution rates. Metronidazole strongly affected bacteroides communities but had no effect on bifidobacterial communities. The bacteriostatic effect of ampicillin on bifidobacterial species was growth rate dependent. Several metabolic activities were affected by antibiotic addition, including fermentation product formation and enzyme synthesis. The growth of antibiotic-resistant bifidobacteria in the large bowel may enable them to occupy ecological niches left vacant after antibiotic administration, preventing

  18. 海带及其共附微生物的生物活性研究进展%Advances in Biological Activity of Laminaria Japonica Aresch and the Symbiotic and Epiphytic Microorganism from seaweed

    Institute of Scientific and Technical Information of China (English)

    张瑛; 张付云; 李妍; 李云冰

    2011-01-01

    The research advance in biological activities of kelp and the symbiotic and epiphytic microorganism from seaweed were described.%综述了海带的活性物质及其共附生微生物的生物活性研究进展。

  19. PAH-biodegradation potential of indigenous microorganisms: evidence from the respiratory activity of surface sediments in the Quanzhou Bay in China

    Institute of Scientific and Technical Information of China (English)

    GU Tihua; WANG Zhaoshou; TIAN Yun; HUANG Bangqin; ZHENG Tianling

    2009-01-01

    Seven stations were established in the Quanzhou Bay (24.73°-24.96°N, 118.50°-118.70°E) in China on three cruises to determine the concentrations of polycyclic aromatic hydrocarbons (PAHs) and the numbers of PAH-degrading bacteria in surface sediments. Assessing the biodegradation poten-tial of indigenous microorganisms by measuring the respiratory intensity with the addition of PAHs in sediment samples was also one of the aims of this study. The results show that the total PAH concentrations of the sediments were 99.23-345.53 ng/g dry weight (d.w.), and the PAHs compo-sition pattern in the sediments was dominated by phenanthrene, fluoranthene and pyrene. The numbers of phenanthrene, fluoranthene and pyrene-degrading bacteria during three cruises were 1.42×103-8.93×104 CFU/g d.w., 8.29×103-9.43×104 CFU/g d.w. and 7.05×103-9.43×4 CFU/g d.w., respectively. The addition of three model PAH compounds (phenanthrene, fluoranthene and pyrene) showed a great influence on the increasing of the microbial activity in the sediments. And there was a significant correlation among the change of respiratory activity, PAH concentration and the number of PAH-degrading bacteria. The change in respiratory activity under PAHs selective pressure could, to a certain extent, indicate the potential degradative activity of the PAH-degrading microbial community.

  20. Elastohydrodynamics of flagellated microorganisms

    Science.gov (United States)

    Li, Gaojin; Ardekani, Arezoo

    2016-11-01

    The swimming motion of many microorganisms and cells are achieved by the waving deformation of their cilia and flagella. The typical structure of flagella and cilia contains nine doublets of parallel microtubules in a cylindrical arrangement surrounding one pair of microtubules in the center. The dynein molecular motors internally drive the sliding motion between the neighboring microtubules and cause the bending motion of the flagella and cilia and drive the microorganism swimming motion. In this work, we develop a numerical model for a microorganism swimming by an internally self-driven filament. Our numerical method captures the interaction between the elasticity of the flagellum and the surround fluid. The no-slip boundary conditions are satisfied by an iterative distributed Lagrangian multiplier method. We also investigate the effects of the non-Newtonian fluid rheology on the motion of an elastic flagellum near a wall.

  1. Replacement of alfalfa hay (Medicago sativa L.) with subabul (Leucaena leucocephala) leaf meal in diets of Najdi goats: effect on digestion activity of rumen microorganisms.

    Science.gov (United States)

    Mohammadabadi, Tahereh; Jolazadeh, Alireza

    2017-08-01

    This study investigated the effect of replacing alfalfa hay by subabul leaf meal (SLM) on digestion, fermentation parameters and rumen bacteria and fungi activity of Najdi goats. Six Najdi goats (150 ± 15 days of age and initial body weight of 35 ± 1.1 kg) were randomly assigned to one of two dietary treatments in a balanced completely randomized design (three goats per treatment) for 56 days. Experimental treatments included alfalfa hay as control group and diet containing SLM (SLM replacing alfalfa hay at 50% level). Bacterial and fungi activity and rumen fermentation parameters of animals fed experimental diets were determined. Dry matter disappearance (DMD) was unaffected by replacing SLM with alfalfa hay for both rumen bacteria and fungi in different incubation times, except for 48 h of incubation in specific culture medium of mixed rumen bacteria, which decreased for SLM group (P > 0.05). NDF disappearance (NDFD) and ADF disappearance (ADFD) after 24 and 48 h of incubation in specific culture medium of mixed rumen bacteria was not affected by experimental diets (P > 0.05). However, 72 h after incubation, NDFD in SLM treatment decreased (P > 0.05). Gas production parameters of rumen bacteria were similar for both experimental diets, but partitioning factor (PF), efficiency microbial biomass production (EMBP), microbial protein production (MP), and organic matter truly digested (OMTD) decreased (p alfalfa hay by SLM had no major effect on rumen microorganisms' activity of Najdi goats, so it may be used as an alternative for alfalfa (at 50% level) in susceptible areas.

  2. 中高温油藏内源微生物厌氧激活%Anaerobic activation of indigenous microorganism in the middle and high temperature reservoir

    Institute of Scientific and Technical Information of China (English)

    冯云; 段传慧; 林军章; 孙刚正

    2016-01-01

    In order to define the characteristics of gas production by indigenous microorganism under anaerobic activation,11 blocks of middle and high temperature reservoir were selected to research in the Shengli Oilfield,which temperature ranges were 55 to 65 ℃,65 to 79 ℃ and 79 to 95 ℃. Indigenous microorganism could be activated to produce gas below 79℃ under simulated reservoir condition,whereas no significant methane gas was produced when temperature was above 79 ℃. The maximum methane production rate was up to 1 500 μmol/( g·d ) when H2/CO2 was used as carbon source, significantly higher than those of sodium acetate and starch. Furthermore,Methanobacterium was activated to become the dominant microflora under anaerobic condition in Zhengli Zhuang Zhengnan block,which favored to produce methane gas in the reservoir.Before anaerobic activation,the dominant bacteria were Pseudomonas in the samples and the dominant bacteria were changed under different activation conditions.H2/CO2 and starch can activate Thermotoga, whereas sodium acetate mainly activated Deferribacter in oil wells. In addition,the dominant flora of different oil wells tended to be identical in the block, but there were significant differences in the dominant microflora between oil well and water well. Our findings on the anaerobic activation of the internal microorganism could serve reference for further enhancing the effect of microbial oil recovery.%为了明确中高温油藏内源微生物厌氧激活产气的特点,在胜利油田选取了11个区块开展产气研究,温度范围分别为55~65℃、65~79℃、79~95℃。在模拟油藏条件下厌氧激活发现,低于79℃时,油藏内源微生物普遍能被激活并代谢产气;而高于79℃时,无明显甲烷气产生。利用不同碳源激活后发现,H2/CO2为碳源时,最大产甲烷速率可达1500μmol/( g·d),显著高于乙酸钠和淀粉,这表明中高温油藏内产甲烷古菌以氢

  3. Modelling microorganisms in food

    NARCIS (Netherlands)

    Brul, S.; Gerwen, van S.; Zwietering, M.H.

    2007-01-01

    Predicting the growth and behaviour of microorganisms in food has long been an aim in food microbiology research. In recent years, microbial models have evolved to become more exact and the discipline of quantitative microbial ecology has gained increasing importance for food safety management, part

  4. Novel Industrial Enzymes from Uncultured Arctic Microorganisms

    DEFF Research Database (Denmark)

    Vester, Jan Kjølhede

    on the diversity of microorganisms from the ikaite columns as well as bioprospecting for enzyme activities using both culture dependent and independent methods. Two cold-active β-galactosidases and one extremely cold-active α-amylase, all related to Clostridia, were characterized in more details....

  5. Inactivation of Microorganisms

    Science.gov (United States)

    Alzamora, Stella Maris; Guerrero, Sandra N.; Schenk, Marcela; Raffellini, Silvia; López-Malo, Aurelio

    Minimal processing techniques for food preservation allow better retention of product flavor, texture, color, and nutrient content than comparable conventional treatments. A wide range of novel alternative physical factors have been intensely investigated in the last two decades. These physical factors can cause inactivation of microorganisms at ambient or sublethal temperatures (e.g., high hydrostatic pressure, pulsed electric fields, ultrasound, pulsed light, and ultraviolet light). These technologies have been reported to reduce microorganism population in foods while avoiding the deleterious effects of severe heating on quality. Among technologies, high-energy ultrasound (i.e., intensities higher than 1 W/cm2, frequencies between 18 and 100 kHz) has attracted considerable interest for food preservation applications (Mason et al., 1996; Povey and Mason, 1998).

  6. Informative communication of microorganisms

    Directory of Open Access Journals (Sweden)

    G. N. Kremenchutskу

    2010-06-01

    Full Text Available Macroorganism in combination with microbiota is considered as a “superorganism”. Microorganisms, belonging to the microbiota, are in dynamic equilibrium with a macroorganism. This balance is achieved through a molecular “language” of communication between prokaryotic and eukaryotic cells. Molecular communication between cells leads to positive and negative results. A large number of metabolites of microorganisms that carry the information load: autoinducers is revealed. Autoinducer affect on the immune systems, and variety of metabolic processes. This affects on practically all organs and systems of maсroorganism. Studied metabolites of aerococci affect on the immune system, regenerative cycles and other processes of macroorganism. The problem of informative communication between prokaryotes and eukaryotes provides new insights about vital functions of “superorganisms”.

  7. 秸秆还田配施化肥及微生物菌剂对水田土壤酶活性和微生物数量的影响%Effects of returning rice straw to fields with fertilizers and microorganism liquids on soil enzyme activities and microorganisms in paddy fields

    Institute of Scientific and Technical Information of China (English)

    钱海燕; 杨滨娟; 黄国勤; 严玉平; 樊哲文; 方豫

    2012-01-01

    Paddy rice straw is widely used to improve soil fertility in China by returning it back to the fields after harvest. However, the straw's nutrients need a long time to be plant available. This paper examined how to accelerate the nutrients transformation to be plant available within a short period of time. In particular, the paper studied the causal connection between returning straw to fields with varying application of fertilizers and microorganism liquids on soil enzyme activities and the number of microorganisms in paddy fields. The investigation has been carried out in Experiment Base of Jiangxi Agriculture University, Nanchang, Jiangxi Province. Surface soil samples were collected from paddy fields. The experiment included eight components ranging from straw purely, straw with N-fertilizer, straw with compound fertilizer, and straw with microorganism liquids. In detail, the following fertilizer applications have been used: (1) straw 3 000 kghm-2·a-1, (2) straw 3 000 kg·hm-2a-1with Nitrogen 150 kghm-2· a-1, (3) straw 3 000 kg·hm-2·a-1with N 225 kg·hm-2·a-1, (4) straw 3000 kg·hm-2·A-1 with P2O5 75 kg·hm-2·a-1, (5) straw 3 000 kg·hm-2·a-1 with P2O5112.5 kg·hm-2·a-1, (6) straw 3 000 kghmV with N 150 kg·hm-2·a-1, P2O5 75 kg·hm-2·a-1, and K2O 37.5 kg·hm-2·a-1, (7) straw 3 000 kg·hm-2·a-1 with N 225 kg·hm-2·a-1, P2O5 112.5 kg·hm-2·a-1, and K2O 56.3 kg hm-2 a-1, (8) straw 3 000 kghm-2·a-1 with microorganism liquids 15 L·hm-2·a-1. The relationship between soil enzyme activities and microorganisms were determined by multivariate statistical analysis. In contrast to returning straw only to the field (treatment 1), the results showed that combined application of straw with NPK fertilizers and microorganism liquids increased soil catalase (37.5%-68.8%), invertase (32.3%-61.5%), urease activities (48.8%-I02%) significantly. Furthermore, the population of both, bacteria and fungi in soil rose by 95.3%-174% and 286%-351%, respectively, while the

  8. Antibacterial activity of propolis and its active principles alone and in combination with macrolides, beta-lactams and fluoroquinolones against microorganisms responsible for respiratory infections.

    Science.gov (United States)

    Speciale, A; Costanzo, R; Puglisi, S; Musumeci, R; Catania, M R; Caccamo, F; Iauk, L

    2006-04-01

    Propolis is produced by bees and is reported to have several pharmaceutical properties. Its antibacterial activity against strains causing upper respiratory tract infections is particularly important: propolis might be used as a therapeutic agent to prevent the bacterial infections that sometimes overlap viral infections. In this study the in vitro activity of both an alcoholic solution and a hydroglyceric extract of propolis, as well as its active principles, was tested against bacteria responsible for respiratory infections (Streptococcus pneumoniae, Haemophilus influenzae, Haemophilus parainfluenzae, Moraxella catarrhalis and Streptococcus pyogenes). We also evaluated the in vitro activity of a combination of propolis and its active principles and some beta-lactams, macrolides and fluoroquinolones. Our results, though not demonstrating a clearly synergistic activity between antibiotics and propolis and its constituents, show the possibility of using natural preparations, due to their antimicrobial and anti-inflammatory properties, to enhance antibacterial therapy.

  9. An iterative sensory procedure to select odor-active associations in complex consortia of microorganisms: application to the construction of a cheese model.

    Science.gov (United States)

    Bonaïti, C; Irlinger, F; Spinnler, H E; Engel, E

    2005-05-01

    The aim of this study was to develop and validate an iterative procedure based on odor assessment to select odor-active associations of microorganisms from a starting association of 82 strains (G1), which were chosen to be representative of Livarot cheese biodiversity. A 3-step dichotomous procedure was applied to reduce the starting association G1. At each step, 3 methods were used to evaluate the odor proximity between mother (n strains) and daughter (n/2 strains) associations: a direct assessment of odor dissimilarity using an original bidimensional scale system and 2 indirect methods based on comparisons of odor profile or hedonic scores. Odor dissimilarity ratings and odor profile gave reliable and sometimes complementary criteria to select G3 and G4 at the first iteration, G31 and G42 at the second iteration, and G312 and G421 at the final iteration. Principal component analysis of odor profile data permitted the interpretation at least in part, of the 2D multidimensional scaling representation of the similarity data. The second part of the study was dedicated to 1) validating the choice of the dichotomous procedure made at each iteration, and 2) evaluating together the magnitude of odor differences that may exist between G1 and its subsequent simplified associations. The strategy consisted of assessing odor similarity between the 13 cheese models by comparing the contents of their odor-active compounds. By using a purge-and-trap gas chromatography-olfactory/mass spectrometry device, 50 potent odorants were identified in models G312, G421, and in a typical Protected Denomination of Origin Livarot cheese. Their contributions to the odor profile of both selected model cheeses are discussed. These compounds were quantified by purge and trap-gas chromatography-mass spectrometry in the 13 products and the normalized data matrix was transformed to a between-product distance matrix. This instrumental assessment of odor similarities allowed validation of the choice

  10. Biosurfactants, bioemulsifiers and exopolysaccharides from marine microorganisms.

    Science.gov (United States)

    Satpute, Surekha K; Banat, Ibrahim M; Dhakephalkar, Prashant K; Banpurkar, Arun G; Chopade, Balu A

    2010-01-01

    Marine biosphere offers wealthy flora and fauna, which represents a vast natural resource of imperative functional commercial grade products. Among the various bioactive compounds, biosurfactant (BS)/bioemulsifiers (BE) are attracting major interest and attention due to their structural and functional diversity. The versatile properties of surface active molecules find numerous applications in various industries. Marine microorganisms such as Acinetobacter, Arthrobacter, Pseudomonas, Halomonas, Myroides, Corynebacteria, Bacillus, Alteromonas sp. have been studied for production of BS/BE and exopolysaccharides (EPS). Due to the enormity of marine biosphere, most of the marine microbial world remains unexplored. The discovery of potent BS/BE producing marine microorganism would enhance the use of environmental biodegradable surface active molecule and hopefully reduce total dependence or number of new application oriented towards the chemical synthetic surfactant industry. Our present review gives comprehensive information on BS/BE which has been reported to be produced by marine microorganisms and their possible potential future applications.

  11. Cellulolytic Microorganisms from Thermal Environments

    Energy Technology Data Exchange (ETDEWEB)

    Vishnivetskaya, Tatiana A [ORNL; Raman, Babu [ORNL; Phelps, Tommy Joe [ORNL; Podar, Mircea [ORNL; Elkins, James G [ORNL

    2012-01-01

    Thermal, anaerobic environments rich in decaying plant material are a potential source of novel cellulolytic bacteria. Samples collected from geothermal aquifers in the Yellowstone National Park (YNP) were used to select for cellulolytic thermophiles. Laboratory enrichments on dilute-acid pretreated plant biomass (switchgrass, Populus), and crystalline cellulose (Avicel) resulted in the isolation of 247 environmental clones. The majority of individual clones were affiliated with the cellulolytic bacteria of phylum Firmicutes, followed by xylanolytic and saccharolytic members of the phylum Dictyoglomi. Among the Firmicutes, the clones were affiliated with the genera Caldicellulosiruptor (54.4%), Caloramator (11.5%), Thermoanaerobacter (8.8%), Thermovenabulum (4.1%), and Clostridium (2.0%). From established anaerobic thermophilic enrichments a total of 81 single strains of the genera Caldicellulosiruptor (57%) and Thermoanaerobacter (43%) were isolated. With continuous flow enrichment on Avicel, increases in the relative abundance of Caloramator sp. was observed over clones detected from the Caldicellulosiruptor. Complex communities of interacting microorganisms bring about cellulose decomposition in nature, therefore using up-to-date approaches may yield novel cellulolytic microorganisms with high activity and a rapid rate of biomass conversion to biofuels.

  12. Effect of breeding activity on the microflora of the external genitalia and in the semen of stallions, and the relationship between micro-organisms on the skin and on the external genitalia.

    Science.gov (United States)

    Guimarães, T; Miranda, C; Pinto, M; Silva, E; Damásio, L; Costa, A L; Correia, M J; Duarte, J C; Cosinha, C; Lopes, G; Thompson, G; Rocha, A

    2014-12-01

    A possible role of breeding activities in the composition of the microbial population in stallions' external genitalia (EG) and the relationship between micro-organisms colonizing the skin of the abdomen and the ones colonizing the EG have not been studied. In experiment 1, EG microbiological samples were collected from 41 stallions used for both natural cover and semen collection (BST) and from 18 non-breeding stallions (NBST). A higher (p micro-organisms isolated from the EG were present in semen, albeit with a numerically lower prevalence. In 7 stallions, six microbial species isolated from semen were absent from the EG cultures, suggesting contamination by the operator. In experiment 3, a numerically higher number of micro-organism species was isolated from the EG of 31 stallions, than from their skin of the ventral abdomen in contact with the penis or from the skin of the thorax. With the sole exception of Escherichia coli, potentially pathogenic bacteria were only isolated from the EG but not from the skin. Results suggest that breeding activity increased the number of species colonizing the EG; most species isolated from the EG were also found in semen even if with a lower frequency, and additional semen contamination seemed to occur during its manipulation. Many micro-organism species of the skin were also isolated from the penis, but independently of being or not in contact with the penis, skin did not seem to provide an adequate environment for the growth of potentially pathogenic bacteria that were isolated from EG, with the sole exception for E. coli.

  13. Application of thermotolerant microorganisms for biofertilizer preparation.

    Science.gov (United States)

    Chen, Kuo-Shu; Lin, Yann-Shying; Yang, Shang-Shyng

    2007-12-01

    Intensive agriculture is practised in Taiwan, and compost application is very popular as a means of improving the soil physical properties and supplying plant nutrition. We tested the potential of inoculation with thermotolerant microorganisms to shorten the maturity and improve the quality of biofertilizer prepared by composting. Thermotolerant microorganisms were isolated from compost and reinoculated for the preparation of biofertilizer. The physical, chemical and biological properties of the biofertilizer were determined during composting. The effects of biofertilizer application on the growth and yield of rape were also studied. Among 3823 colonies of thermotolerant microorganisms, Streptomyces thermonitrificans NTU-88, Streptococcus sp. NTU-130 and Aspergillus fumigatus NTU-132 exhibited high growth rates and cellulolytic and proteolytic activities. When a mixture of rice straw and swine manure were inoculated with these isolates and composted for 61 days, substrate temperature increased initially and then decreased gradually during composting. Substrate pH increased from 7.3 to 8.5. Microbial inoculation enhanced the rate of maturity, and increased the content of ash and total and immobilized nitrogen, improved the germination rate of alfalfa seed, and decreased the content of total organic carbon and the carbon/nitrogen ratio. Biofertilizer application increased the growth and yield of rape. Inoculation of thermotolerant and thermophilic microorganisms to agricultural waste for biofertilizer preparation enhances the rate of maturity and improves the quality of the resulting biofertilizer. Inoculation of appropriate microorganisms in biofertilizer preparation might be usefully applied to agricultural situations.

  14. How Microorganisms Affect Food Safety and Quality

    OpenAIRE

    Bacon, Karleigh

    2012-01-01

    The main methods of preservation for shelf-stable foods are controlling the water activity or lowering the pH. Factors are often combined, like lowering pH AND using refrigeration. Understanding how food supports the growth of microorganisms can help improve both food safety AND food quality. This guide can help you manipulate your food to create a safe product.

  15. Activity of extracts from two kinds of Lagotises against microorganisms in vitro%两种兔耳草提取物的体外抑菌作用

    Institute of Scientific and Technical Information of China (English)

    张忠; 李科玮; 毕阳; 王义; 任亚琳; 毕文

    2012-01-01

    Traditional Tibetan Medicine of Lagotis brachystachy Maxim and Lagotis brevituba Maxim imparted antimicrobial and antiinflammatory functions.To investigate the activity of extracts from these two plants against microorganisms in vitro,the agar well diffusion method and 96-well plate double dilution method were utilized to assess the inhibition ratios and minimum inhibitive concentration of their various extracts through successive extraction via solvents with gradient polarity.It showed that among bioassay fungi,F.semitectum and P.expansum were inhibited by some extracts from Lagotis brevituba Maxim and P.expansum and A.alternata were inhibited by extracts from Lagotis brachystachy Maxim.Extracts from both botanical species exhibited stronger inhibition power against bacteria than fungi in general.L.brevituba Maxim extracts inhibited S.aureus and P.fluorescence growth.L.brachystachy Maxim had power against all four bioassay bacteria.The lowest minimum inhibitory concentration of extracts to bacteria was 0.05g/mL.It was concluded that extracts from the two species embodied with broader spectral range and stronger antimicrobial activity.%短管兔耳草(Lagotis brevituba Maxim)和短穗兔耳草(Lagotis brachystachy Maxim)在传统藏药中具有抑菌消炎的功效。采用琼脂孔扩散法和96孔培养板对倍稀释法测定了这两种植物不同极性溶剂逐级提取物对4种采后真菌和4种腐败细菌的体外抑菌率和最低抑制浓度。结果表明:在供试真菌中,短管兔耳草提取物对F.semitectum和P.expansum具有抑菌活性,短穗兔耳草提取物对P.expansum和A.alternate具有抑菌活性。两种植物的提取物对供试细菌的抑菌活性整体上较强,短管兔耳草提取物对S.aureus和P.fluorescence有抑菌活性,而短穗兔耳草提取物对S.aureus,E.coli,B.subtilis和P.fluorescence都有抑菌活性。提取物对细菌的最低抑菌浓度最低可达0.05g/mL。结论:这两

  16. Combating Antimicrobial Resistance in Foodborne Microorganisms.

    Science.gov (United States)

    Lai, Edward P C; Iqbal, Zafar; Avis, Tyler J

    2016-02-01

    This review addresses an important public health hazard affecting food safety. Antimicrobial agents are used in foods to reduce or eliminate microorganisms that cause disease. Many traditional organic compounds, novel synthetic organic agents, natural products, peptides, and proteins have been extensively studied for their effectiveness as antimicrobial agents against foodborne Campylobacter spp., Escherichia coli, Listeria spp. and Salmonella. However, antimicrobial resistance can develop in microorganisms, enhancing their ability to withstand the inhibiting or killing action of antimicrobial agents. Knowledge gaps still exist with regard to the actual chemical and microbiological mechanisms that must be identified to facilitate the search for new antimicrobial agents. Technical implementation of antimicrobial active packing films and coatings against target microorganisms must also be improved for extended product shelf life. Recent advances in antimicrobial susceptibility testing can provide researchers with new momentum to pursue their quest for a resistance panacea.

  17. Bioremediation of Industrial Waste Through Enzyme Producing Marine Microorganisms.

    Science.gov (United States)

    Sivaperumal, P; Kamala, K; Rajaram, R

    2017-01-01

    Bioremediation process using microorganisms is a kind of nature-friendly and cost-effective clean green technology. Recently, biodegradation of industrial wastes using enzymes from marine microorganisms has been reported worldwide. The prospectus research activity in remediation area would contribute toward the development of advanced bioprocess technology. To minimize industrial wastes, marine enzymes could constitute a novel alternative in terms of waste treatment. Nowadays, the evidence on the mechanisms of bioremediation-related enzymes from marine microorganisms has been extensively studied. This review also will provide information about enzymes from various marine microorganisms and their complexity in the biodegradation of comprehensive range of industrial wastes.

  18. 江蓠及其共附微生物活性物质的研究进展%Research Progress of Active Substances in Gracilaria and Symbiotic and Epiphytic Microorganism

    Institute of Scientific and Technical Information of China (English)

    李云冰; 张付云; 李妍; 杨阳; 苍桂璐

    2011-01-01

    The Gracilaria is one kind of rhodophyta, which contains many kinds of active substances and possesses nutrition and health function. The research progress of active substances in Gracilaria and symbiotic and epiphytic microorganism were summarized, so as to provide theoretical basis for development and utilization of Gracilaria.%江蓠属于大型红藻,含有多种活性物质,具有营养保健功能.对江蓠及其共附微生物的活性物质研究进展进行了概述,旨在为开发利用江蓠资源提供理论基础.

  19. Pesticides in Soil: Effects on Microorganisms

    Directory of Open Access Journals (Sweden)

    Ljiljana Radivojević

    2007-01-01

    Full Text Available Since their discovery to the present day, pesticides have been an inevitable segment of agricultural production and efforts have been made to synthesize compounds that would share a required efficacy along with selectivity, sufficient persistence on the object of protection and favourable toxicological and ecotoxicological characteristics so as to minimize their effect on the environment.When a pesticide gets into soil after application, it takes part in a number of physical, chemical and biological processes that depend not only on the compound itself, but a number of other factors as well, such as: physical, chemical and biological characteristics of soil; climatic factors, equipment used, method of application, method of storage, handling and disposal of waste, site characteristics (proximity of ground and underground waters, biodiversity and sensitivity of the environment. Microorganisms play an important role in pesticide degradation as they are able to utilize the biogenic elements from those compounds, as well as energy for their physiological processes. On the other hand, pesticides are more or less toxic substances that can have adverse effect on populations of microorganisms and prevent their development, reduce their abundance, deplete their taxonomic complexity and create communities with a lower level of diversity and reduced physiological activity.The article discusses complex interactions between pesticides and microorganisms in soil immediately after application and over the ensuing period. Data on changes in the abundance of some systematic and physiological groups of microorganisms, their microbial biomass and enzymatic activity caused under pesticide activity are discussed as indicators of these processes.

  20. Radiation sensitivity of hyperthermal composting microorganisms

    Science.gov (United States)

    Choi, Jong-Il; Yoon, Min-Chul; Kim, Jae-Hun; Yamashita, Masamichi; Kim, Geun Joong; Lee, Ju-Woon

    In the space station and vehicles designed for long human mission, high-temperature compost is a promising technology for decomposing organic waste and producing the fertilizers. In space, the microorganisms could have the changed biological activities or even be mutated by ionizing irradiation. Therefore, in this study, the effect of gamma irradiation on the sensitivity of bacteria in hyperthermal composting was investigated. The sequence analysis of the amplified 16s rDNA genes and amoA gene were used for the identification of composting microorganisms. Viability of microorganisms in compost soil after gamma irradiation was directly visualized with LIVE/DEAD Baclight viability kit. The dominant bacterial genera are Weissella cibaria and Leuconostoc sp. and fungus genera are Metschnikowia bicuspidate and Pichia guilliermondii, respectively. By the gamma irradiation up to the dose of 1 kGy, the microbial population was not changed. Also, the enzyme activities of amylase and cellulose were sustained by the gamma irradiation. These results show that these hyperthermia microorganisms might have the high resistance to gamma radiation and could be used for agriculture in the Space Station.

  1. Effect of Fertilizer to Content of Soil Nutrient, Amount of Soil Microorganism and Soil Enzyme Activities%施肥对土壤养分含量、微生物数量和酶活性的影响

    Institute of Scientific and Technical Information of China (English)

    郭萍; 文庭池; 董玲玲; 魏成熙; 石俊雄; 李波

    2011-01-01

    This paper studies the dynamic change laws of the content of the soil nutrient and the amount of the soil microorganism and soil enzyme activities under the different fertilizer treatment conditions. The result of the experiment shows: different fertilizer treatments have significant influence towards the soil available nutrients. The fertilizer can significantly increase the level of soil available nutrients; especially by using tobacco specialty fertilizer together with EM liquid. The soil microorganism quantities and the soil enzyme activities have various different under the different fertilizer treatments. Apply fertilizer can remarkably raise the amount of the microorganism in the soil and enhance the enzyme activity of the soil. By regressing analysis of the soil nutrient and the soil microbiology attributes, we found that they are correlated to some degree. The amounts of the soil microorganism and soil enzyme activities are more sensible to the change of the environment, comparing with soil nutrient. As a result, it can be used as an important basis to reflect the change of the soil quality.%本文研究了施肥对烟田土壤养分含量和微生物数量及酶活性的动态变化的影响.试验结果表明:施肥对土壤养分含量有显著影响,施肥能显著增加土壤养分的含量,尤其以施用烟草专用肥+菌液最为显著.土壤微生物数量和酶活性对不同施肥处理响应是不同的,施肥能够显著增加土壤中微生物的数量、增强土壤酶的活性.将土壤养分与土壤微生物数量、酶活性进行回归分析可以发现,其间存在一定的相关性.与土壤养分相比,土壤微生物数量、酶活性变化更加敏感,其作为土壤肥力的评价指标更为合理.

  2. Effect of short-term grazing on soil microorganisms and soil enzyme activities in Meadow Steppe%短期放牧对草甸草原土壤微生物与土壤酶活性的影响

    Institute of Scientific and Technical Information of China (English)

    曹淑宝; 刘全伟; 王立群; 王浩然; 王婧瑶

    2012-01-01

    [Objective] In order to provide microbiology basis for protection, restoration and reconstruction of meadow steppe ecosystem in Inner Mongolian Region. To investigate the response of grassland soil microbes and enzyme activity in different grazing intensity. [Methods] Soil samples were collected from six different grazing intensity, the variation of different grazing intensities on the soil microorganisms, soil microbial biomasses (Carbon and nitrogen), soil enzyme activity and the interrelationship among them were analysised. [Results] The reseults showed that the number of microorganisms in different grazing areas had the same changing trends: bacteria>actinomycetes>fungi. The number of soil microorganisms and soil microbial biomass (Carbon and nitrogen) were higher in grazing areas than no-grazing areas. In 0-10 cm soil depth, the trend of the activities of catalase, invertase and protease was performed increased first and then decreased along with the increasing of grazing intensity, Moreover the activities of these enzymes in grazing areas was higher than no-grazing area. Compared with 0-10 cm, the descending range of the number of bacteria and fungi and the microbial biomasses (Carbon and nitrogen) were increased along with the increasing of grazing intensity in 10 cm-20 cm soil depth. The number of soil microorganism, soil microbial biomass, the activity of soil enzyme were higher in soil depth 0-10 cm than 10 cm-20 cm in the vertical distribution. Correlation analysis indicated that the number of soil microorganism was significantly correlated with soil microbial biomass. The soil enzyme activ-itiy was positively related to the number of soil microorganism and soil microbial biomass. The activities of catalase and invertase were extreme-significantly correlated with the number of bacteria and actinomycetes (P<0.01), and significantly related to soil microbial biomass C (P<0.05); the activity of the protease was extreme-significantly correlated with

  3. Effects of tourmaline on growth of three kinds of microorganisms

    African Journals Online (AJOL)

    AJL

    2012-05-22

    May 22, 2012 ... Key words: Microcalorimetric, water cluster, growth rate, inhibitory ratio. ... study the effect of tourmaline on some microorganism (Ni et al., 2008), there are ..... the activities of compounds on metabolism of Escherichia coli: A.

  4. Assessment of microorganisms from Indonesian Oil Fields

    Energy Technology Data Exchange (ETDEWEB)

    Kadarwati, S.; Udiharto, M.; Rahman, M.; Jasjfi, E.; Legowo, E.H. [Research and Development Centre for Oil and Gas Technology LEMIGAS, Jakarta Selatan (Indonesia)

    1995-12-31

    Petroleum resources have been the mainstay of the national development in Indonesia. However, resources are being depleted after over a century of exploitation, while the demand continues to grow with the rapid economic development of the country. In facing the problem, EOR has been applied in Indonesia, such as the steamflooding project in Duri field, but a more energy efficient technology would be preferable. Therefore, MEOR has been recommended as a promising solution. Our study, aimed at finding indigenous microorganisms which can be developed for application in MEOR, has isolated microbes from some oil fields of Indonesia. These microorganisms have been identified, their activities studied, and the effects of their metabolisms examined. This paper describes the research carried out by LEMIGAS in this respect, giving details on the methods of sampling, incubation, identification, and activation of the microbes as well as tests on the effects of their metabolites, with particular attention to those with potential for application in MEOR.

  5. Control of microorganisms in flowing nutrient solutions.

    Science.gov (United States)

    Evans, R D

    1994-11-01

    Controlling microorganisms in flowing nutrient solutions involves different techniques when targeting the nutrient solution, hardware surfaces in contact with the solution, or the active root zone. This review presents basic principles and applications of a number of treatment techniques, including disinfection by chemicals, ultrafiltration, ultrasonics, and heat treatment, with emphasis on UV irradiation and ozone treatment. Procedures for control of specific pathogens by nutrient solution conditioning also are reviewed.

  6. Role of microorganisms in mural paintings decay

    OpenAIRE

    Rosado, T; J. Mirão; Gil, M.; Candeias, A.; Caldeira, A. T.

    2014-01-01

    The action of microbial communities on mural paintings, particularly in mortars and in pictorial layers, triggered numerous studies to identify the main biodeteriogenic agents and to better understand the role of microorganisms in the biodeterioration/biodegradation of these artworks. The biodegradation phenomenon is an important issue for the conservation of cultural heritage that needs urgent answers to their rehabilitation. Microbial activity and their ability to obtain elements by bios...

  7. Sheen Screen, a Miniaturized Most-Probable-Number Method for Enumeration of Oil-Degrading Microorganisms

    OpenAIRE

    Brown, Edward J.; Braddock, Joan F.

    1990-01-01

    Sheen Screen is a miniaturized method for enumerating oil-degrading microorganisms. The technique relies on the ability of oil-degrading microorganisms to emulsify oil when provided as a sole carbon source in 24-well tissue culture plates. Sediments that actively respire hydrocarbons have high numbers of Sheen Screen-positive microorganisms.

  8. Bioemulsan Production by Iranian Oil Reservoirs Microorganisms

    Directory of Open Access Journals (Sweden)

    A Amiriyan, M Mazaheri Assadi, VA Saggadian, A Noohi

    2004-10-01

    Full Text Available The biosurfactants are believed to be surface active components that are shed into the surrounding medium during the growth of the microorganisms. The oil degrading microorganism Acinetobacter calcoaceticus RAG-1 produces a poly-anionic biosurfactant, hetero-polysaccharide bioemulsifier termed as emulsan which forms and stabilizes oil-water emulsions with a variety of hydrophobic substrates. In the present paper results of the possibility of biosurfactant (Emulsan production by microorganisms isolated from Iranian oil reservoirs is presented. Fourthy three gram negative and gram positive, non fermentative, rod bacilli and coccobacilli shaped baceria were isolated from the oil wells of Bibi Hakimeh, Siri, Maroon, Ilam , East Paydar and West Paydar. Out of the isolated strains, 39 bacterial strains showed beta haemolytic activity, further screening revealed the emulsifying activity and surface tension. 11 out of 43 tested emulsifiers were identified as possible biosurfactant producers and two isolates produced large surface tension reduction, indicating the high probability of biosurfactant production. Further investigation revealed that, two gram negative, oxidase negative, aerobic and coccoid rods isolates were the best producers and hence designated as IL-1, PAY-4. Whole culture broth of isolates reduced surface tension from 68 mN /m to 30 and 29.1mN/m, respectively, and were stable during exposure to high salinity (10%NaCl and elevated temperatures(120C for 15 min .

  9. FUNCTIONAL POLYHYDROXYALKANOATES SYNTHESIZED BY MICROORGANISMS

    Institute of Scientific and Technical Information of China (English)

    Guo-qiang Chen; Qiong Wu; Kai Zhao; Peter H.Yu

    2000-01-01

    Many bacteria have been found to synthesize a family of polyesters termed polyhydroxyalkanoate, abbreviated as PHA. Some interesting physical properties of PHAs such as piezoelectricity, non-linear optical activity, biocompatibility and biodegradability offer promising applications in areas such as degradable packaging, tissue engineering and drug delivery.Over 90 PHAs with various structure variations have been reported and the number is still increasing. The mechanical property of PHAs changes from brittle to flexible to elastic, depending on the side-chainlength of PHA. Many attempts have been made to produce PHAs as biodegradable plastics using various microorganisms obtained from screening natural environments, genetic engineering and mutation. Due to the high production cost, PHAs still can not compete with the nondegradable plastics, such as polyethylene and polypropylene. Various processes have been developed using low cost raw materials for fermentation and an inorganic extraction process for PHA purification. However, a super PHA production strain may play the most critical role for any large-scale PHA production. Our recent study showed that PHA synthesis is a common phenomenon among bacteria inhabiting various locations, especially oil-contaminated soils. This is very important for finding a suitable bacterial strain for PHA production. In fact, PHA production strains capable of rapid growth and rapid PHA synthesis on cheap molasses substrate have been found on molasses contaminated soils. A combination of novel properties and lower cost will allow easier commercialization of PHA for many applications.

  10. Butanol tolerance in microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Bramucci, Michael G.; Nagarajan, Vasantha

    2016-03-01

    Provided herein are recombinant yeast host cells and methods for their use for production of fermentation products from a pyruvate utilizing pathway. Yeast host cells provided herein comprise reduced pyruvate decarboxylase activity and modified adenylate cyclase activity. In embodiments, yeast host cells provided herein comprise resistance to butanol and increased biomass production.

  11. Atividade de microrganismos solubilizadores de fosfatos na presença de nitrogênio, ferro, cálcio e potássio Phosphate solubilizing activity of microorganisms in the presence of nitrogen, iron, calcium and potassium

    Directory of Open Access Journals (Sweden)

    Germano Nunes Silva Filho

    2001-12-01

    Full Text Available A capacidade e o potencial de solubilização de 21 isolados de microrganismos solubilizadores de fosfatos (Bacillus, Pseudomonas, Enterobacteriaceae, Penicillium, Aspergillus e Paecilomyces foram avaliados em cultivos em meio de cultura Glicose-Extrato de Levedura contendo diferentes fosfatos (Ca, Al ou Fe, na presença de fontes de N (peptona, amônio e nitrato e teores de Fe, Ca e K. O crescimento e a atividade solubilizadora variaram em função do tipo de microrganismo e dos fatores nutricionais. Em relação às fontes de N, a presença de amônio favoreceu a solubilização em seis isolados; destes, três solubilizaram somente nesta fonte. O nitrato diminuiu a atividade solubilizadora, reduzindo ou inibindo a solubilização. Para a maioria dos microrganismos, a atividade solubilizadora não foi afetada pelas variações nos teores de ferro. Baixos teores de Ca e K limitaram o crescimento de cinco isolados que apresentam características de amplo crescimento (Aspergillus. Em dois desses isolados, a solubilização de fosfato de Ca foi favorecida. Variações na capacidade e no potencial de solubilização dos microrganismos, em resposta às condições do meio de cultura, indicam que o processo ocorre com eficiência variável ou sugerem a presença de diferentes mecanismos de solubilização.Twenty-one isolates of phosphate solubilizing microorganisms (Bacillus, Pseudomonas, Enterobacteriaceae, Penicillium, Aspergillus and Paecilomyces were evaluated for their solubilizing capacity and potential in broth media (Glucose-Yeast Extract amended with different types of phosphates (Ca, Al or Fe, in the presence of N sources (peptone, ammonium and nitrate as well as concentrations of Fe, Ca and potassium. Microbial growth and phosphate solubilizing activity varied according to the microorganism and the nutrient supplied. Ammonium increased solubilization activity of six isolates and three of these solubilized only in this source. Nitrate

  12. Airborne microorganisms in Lascaux Cave (France

    Directory of Open Access Journals (Sweden)

    Pedro M Martin-Sanchez

    2014-09-01

    Full Text Available Lascaux Cave in France contains valuable Palaeolithic paintings. The importance of the paintings, one of the finest examples of European rock art paintings, was recognized shortly after their discovery in 1940. In the 60’s of the past century the cave received a huge number of visitors and suffered a microbial crisis due to the impact of massive tourism and the previous adaptation works carried out to facilitate visits. In 1963, the cave was closed due to the damage produced by visitors’ breath, lighting and algal growth on the paintings. In 2001, an outbreak of the fungus Fusarium solani covered the walls and sediments. Later, black stains, produced by the growth of the fungus Ochroconis lascauxensis, appeared on the walls. In 2006, the extensive black stains constituted the third major microbial crisis. In an attempt to know the dispersion of microorganisms inside the cave, aerobiological and microclimate studies were carried out in two different seasons, when a climate system for preventing condensation of water vapor on the walls was active (September 2010 or inactive (February 2010. The data showed that in September the convection currents created by the climate system evacuated the airborne microorganisms whereas in February they remained in suspension which explained the high concentrations of bacteria and fungi found in the air. This double aerobiological and microclimate study inLascauxCave can help to understand the dispersion of microorganisms and to adopt measures for a correct cave management.

  13. Isolation and characterization of Arctic microorganisms decomposing bioplastics.

    Science.gov (United States)

    Urbanek, Aneta K; Rymowicz, Waldemar; Strzelecki, Mateusz C; Kociuba, Waldemar; Franczak, Łukasz; Mirończuk, Aleksandra M

    2017-12-01

    The increasing amount of plastic waste causes significant environmental pollution. In this study, screening of Arctic microorganisms which are able to degrade bioplastics was performed. In total, 313 microorganisms were isolated from 52 soil samples from the Arctic region (Spitsbergen). Among the isolated microorganisms, 121 (38.66%) showed biodegradation activity. The ability of clear zone formation on emulsified poly(butylene succinate-co-adipate) (PBSA) was observed for 116 microorganisms (95.87%), on poly(butylene succinate) (PBS) for 73 microorganisms (60.33%), and on poly(ɛ-caprolactone) (PCL) for 102 microorganisms (84.3%). Moreover, the growth of microorganisms on poly(lactic acid) (PLA) agar plates was observed for 56 microorganisms (46.28%). Based on the 16S rRNA sequence, 10 bacterial strains which showed the highest ability for biodegradation were identified as species belonging to Pseudomonas sp. and Rhodococcus sp. The isolated fungal strains were tested for polycaprolactone films and commercial corn and potato starch bags degradation under laboratory conditions. Strains 16G (based on the analysis of a partial 18S rRNA sequence, identified as Clonostachys rosea) and 16H (identified as Trichoderma sp.) showed the highest capability for biodegradation. A particularly high capability for biodegradation was observed for the strain Clonostachys rosea, which showed 100% degradation of starch films and 52.91% degradation of PCL films in a 30-day shake flask experiment. The main advantage of the microorganisms isolated from Arctic environment is the ability to grow at low temperature and efficient biodegradation under this condition. The data suggest that C. rosea can be used in natural and laboratory conditions for degradations of bioplastics.

  14. Isolation of microorganisms of cheese whey with lipolytic activity for removal of COD Isolamento de microrganismos do soro de queijo com atividade lipásica para remoção de DQO

    Directory of Open Access Journals (Sweden)

    Eliane Hermes

    2013-04-01

    Full Text Available The aim of this study was to isolate microorganisms that produce lipase and to assess the efficiency of COD removal intreatment of cheese whey under different operating conditions. The microorganisms were isolated from cheese whey and a commercial product; it was selectedthreemicroorganisms that obtained the best response to the lipolytic activity test through the enzyme index. Then, the microorganisms were inoculated in sterilized cheese whey samples, for two pH values (6.2 and 7.0, incubated at 35 °C and 150 rpm in shaker and the lipolityc activity and the efficiency of COD removal were measured in two time periods (24 and 48h. After incubation, it was observed that the treatments showed a good removal efficiency of COD for the pre-treatment and the isolated microorganism (S1 from the cheese whey showed the highest lipase production. Regarding the pH and time variables, there was not significant effect between the two evaluated factors. Among all treatments, T2 (S1, pH 7.0 and 24h obtained more enzyme production (4.87 U mL-1.O objetivo deste estudo foi isolar microrganismos produtores de lipase e avaliar a eficiência de remoção de DQO no tratamento de soro de leite sob diferentes condições operacionais. Os microrganismos foram isolados a partir do soro de queijo e de um produto comercial,e foram selecionados os três microrganismos que obtiveram a melhor resposta no teste da atividade lipolítica, através do índice enzimático. Em seguida, inocularam-se os micro-organismos em amostras de soro de queijo esterilizado, para dois valores de pH (6,2 e 7,0, incubaram-se a 35 ºC e 150 rpm em shaker e mensuram-se em dois períodos de tempo (24 e 48 h a atividade lipásica e a eficiência de remoção de DQO.Após a incubação, observou-se que os tratamentos apresentaram boa eficiência de remoção de DQO para o pré-tratamento,e o microrganismo (S1 isolado a partir do soro de queijo apresentou a maior produção de lipase. Com relação

  15. [Immobilized microorganisms and water purification].

    Science.gov (United States)

    Mogilevich, N F

    1995-01-01

    Advantages and disadvantages of cells of aerobic microorganisms immobilized by the type of adhesion and incorporation into the gel beads, the amount of retained biomass, limitations of diffusion of oxygen and nutrients, viability, morphology, biochemical properties are described. Immobilized biocatalysts are discussed in the aspect of their use in purification of sewage waters.

  16. Airborne microorganisms from waste containers.

    Science.gov (United States)

    Jedlicka, Sabrina S; Stravitz, David M; Lyman, Charles E

    2012-01-01

    In physician's offices and biomedical labs, biological waste is handled every day. This waste is disposed of in waste containers designed for holding red autoclave bags. The containers used in these environments are closed hands-free containers, often with a step pedal. While these containers protect the user from surface-borne microorganisms, the containers may allow airborne microorganisms to escape via the open/close mechanism because of the air current produced upon open/close cycles. In this study, the air current was shown to be sufficient to allow airborne escape of microorganisms held in the container, including Aspergillus niger. However, bacterial cultures, such as Escherichia coli and Lactococcus lactis did not escape. This may be due to the choice of bacterial cultures and the absence of solid waste, such as dust or other particulate matter in the waste containers, that such strains of bacteria could travel on during aerosolization. We compared these results to those obtained using a re-designed receptacle, which mimimizes air currents, and detected no escaping microorganisms. This study highlights one potential source of airborne contamination in labs, hospitals, and other environments that dispose of biological waste.

  17. Biofuel production by recombinant microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Liao, James C.; Atsumi, Shota; Cann, Anthony F.

    2017-07-04

    Provided herein are metabolically-modified microorganisms useful for producing biofuels. More specifically, provided herein are methods of producing high alcohols including isobutanol, 1-butanol, 1-propanol, 2-methyl-1-butanol, 3-methyl-1-butanol and 2-phenylethanol from a suitable substrate.

  18. Latest improvements in CIEF: from proteins to microorganisms.

    Science.gov (United States)

    Šalplachta, Jiří; Kubesová, Anna; Horká, Marie

    2012-10-01

    In recent years, characterization and identification of microorganisms has become very important in different fields of human activity. Conventional laboratory methods are time consuming, laborious, and they may provide both false positive or negative results, especially for closely related microorganisms. On that account, new methods for fast and reliable microbial characterization are of great interest. In particular, capillary electrophoretic techniques have a great potential for characterization of microorganisms due to their unique surface properties. Cell surface proteins play a key role in this respect. Since CIEF represents one of the most efficient techniques for protein separation, it was consequently applied to the analysis of microbial cells. This review describes, after a brief introduction to CIEF of proteins, recent developments in CIEF of diverse microorganisms (viruses, bacteria, yeasts, and fungi). Possible application schemes in human and veterinary medicine as well as in plant protection and in biosecurity are outlined.

  19. Complete genome sequence of Lactobacillus plantarum LZ206, a potential probiotic strain with antimicrobial activity against food-borne pathogenic microorganisms.

    Science.gov (United States)

    Li, Ping; Gu, Qing; Zhou, Qingqing

    2016-11-20

    Lactobacilli strains have been considered as important candidates for manufacturing "natural food", due to their antimicrobial properties and generally regarded as safe (GRAS) status. Lactobacillus plantarum LZ206 is a potential probiotic strain isolated from raw cow milk, with antimicrobial activity against various pathogens, including Gram-positive bacteria (Staphylococcus aureus and Listeria monocytogenes), Gram-negtive bacteria (Escherichia coli and Salmonella enterica), and fungus Candida albicans. To better understand molecular base for its antimicrobial activity, entire genome of LZ206 was sequenced. It was revealed that genome of LZ206 contained a circular 3,212,951-bp chromosome, two circular plasmids and one predicted linear plasmid. A plantaricin gene cluster, which is responsible for bacteriocins biosynthesis and could be associated with its broad-spectrum antimicrobial activity, was identified based on comparative genomic analysis. Whole genome sequencing of L. plantarum LZ206 might facilitate its applications to protect food products from pathogens' contamination in the dairy industry.

  20. Assessment of cellulolytic microorganisms in soils of Nevados Park, Colombia

    Directory of Open Access Journals (Sweden)

    Lizeth Manuela Avellaneda-Torres

    2014-12-01

    Full Text Available A systematized survey was conducted to find soil-borne microbes that degrade cellulose in soils from unique ecosystems, such as the Superpáramo, Páramo, and the High Andean Forest in the Nevados National Natural Park (NNNP, Colombia. These high mountain ecosystems represent extreme environments, such as high levels of solar radiation, low atmospheric pressure, and extreme daily changes in temperature. Cellulolytic activity of the microorganisms was evaluated using qualitative tests, such as growth in selective media followed by staining with congo red and iodine, and quantitative tests to determine the activity of endoglucanase, β-glucosidase, exoglucanase, and total cellulase. Microorganisms were identified using molecular markers, such as the 16S rRNA gene for bacteria and the internal transcribed spacer region (ITS of ribosomal DNA for fungi. Multivariate statistical analysis (MVA was used to select microorganisms with high cellulolytic capacity. A total of 108 microorganisms were isolated from the soils and, in general, the enzymatic activities of fungi were higher than those of bacteria. Our results also found that none of the organisms studied were able to degrade all the components of the cellulose and it is therefore suggested that a combination of bacteria and/or fungi with various enzymatic activities be used to obtain high total cellulolytic activity. This study gives an overview of the potential microorganism that could be used for cellulose degradation in various biotechnological applications and for sustainable agricultural waste treatment.

  1. Green biosynthesis of floxuridine by immobilized microorganisms.

    Science.gov (United States)

    Rivero, Cintia W; Britos, Claudia N; Lozano, Mario E; Sinisterra, Jose V; Trelles, Jorge A

    2012-06-01

    This work describes an efficient, simple, and green bioprocess for obtaining 5-halogenated pyrimidine nucleosides from thymidine by transglycosylation using whole cells. Biosynthesis of 5-fluoro-2'-deoxyuridine (floxuridine) was achieved by free and immobilized Aeromonas salmonicida ATCC 27013 with an 80% and 65% conversion occurring in 1 h, respectively. The immobilized biocatalyst was stable for more than 4 months in storage conditions (4 °C) and could be reused at least 30 times without loss of its activity. This microorganism was able to biosynthesize 2.0 mg L(-1) min(-1) (60%) of 5-chloro-2'-deoxyuridine in 3 h. These halogenated pyrimidine 2'-deoxynucleosides are used as antitumoral agents.

  2. Toolbox for Antibiotics Discovery from Microorganisms.

    Science.gov (United States)

    Fisch, Katja M; Schäberle, Till F

    2016-09-01

    Microorganisms produce a vast array of biologically active metabolites. Such compounds are applied by humans to positively influence their health and, therefore, natural products serve as drug leads for pharmaceutical and medicinal chemistry. In this minireview, tools for the discovery and the production of potential drug leads are explained. A snapshot is provided, starting from the isolation of new producer strains, across genomic mining of (meta)genomes to identify biosynthetic gene clusters corresponding to natural products, toward heterologous expression to produce potential drug leads. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. In vitro Antimicrobial Activity of Chlorquinaldol against Microorganisms Responsible for Skin and Soft Tissue Infections: Comparative Evaluation with Gentamicin and Fusidic Acid

    Directory of Open Access Journals (Sweden)

    Monica Bortolin

    2017-06-01

    Full Text Available Skin and soft tissue infections (SSTIs are a major therapeutic challenge for clinicians. The emergence of pathogens with decreased susceptibility to available therapies has become an emerging problem often associated with treatment failure. Hence, there is an urgent need for novel broad-spectrum antimicrobial agents. The purpose of this study was to assess the feasibility of chlorquinaldol as an alternative approach to currently used topical antibiotics for the treatment of skin and soft tissue infections. The activity of chlorquinaldol was investigated against a collection of bacterial isolates responsible for skin infections, including strains resistant to fusidic acid and gentamicin. After determination of MIC and MBC, time-kill experiments were carried out by counting colonies grown after 0, 3, 6, 9, 24, and 48 h of incubation with concentrations equal to ¼×, ½×, 1×, 2×, and 4× MIC of chlorquinaldol, gentamicin, or fusidic acid. Staphylococci resulted the Gram-positives most sensitive to chlorquinaldol, with MIC-values ranging from 0.016 to 0.5 mg/L. A lower activity was observed against Gram-negative bacteria, with 77% of the isolates being inhibited at concentrations ranging from 128 to 512 mg/L. Generally, in time-kill studies, chlorquinaldol showed a bactericidal activity at the higher concentrations (2×, 4× MIC after 24–48 h of incubation. In conclusion, chlorquinaldol may represent a valuable alternative to conventional topical antibiotics for the treatment of skin and soft tissue infections.

  4. Microorganisms as bioindicators of pollutants in soil

    Directory of Open Access Journals (Sweden)

    Milošević Nada

    2010-01-01

    Full Text Available Microorganisms are the predominant portion of the soil's biological phase and they are indicators of soil health and quality. Soil microorganisms a take part in degradation of organic and inorganic compounds, b their activity, number and diversity may serve as bioindicators of toxic effects on soil biological activity, c some microbial species may be used for soil bioremediation and d some sensitive microbes are used in eco-toxicity tests. The primary microbial population starts to decompose herbicides several days after their arrival into the soil. The secondary population produces induced enzymes and decomposes herbicides after a period of adaptation. Certain microbial groups are indifferent to the applied herbicides. Effect of heavy metals on soil microbial activity depends on the element, their concentration, microbial species, as well as physical and chemical soil properties. Toxic level of individual pollutants depends on their origin and composition. However, combined application of chemicals makes room for the occurrence of synergistic toxic effects detrimental for the ecosystem and human health. .

  5. Metagenomic insights into the carbohydrate-active enzymes carried by the microorganisms adhering to solid digesta in the rumen of cows.

    Directory of Open Access Journals (Sweden)

    Lingling Wang

    Full Text Available The ruminal microbial community is a unique source of enzymes that underpin the conversion of cellulosic biomass. In this study, the microbial consortia adherent on solid digesta in the rumen of Jersey cattle were subjected to an activity-based metagenomic study to explore the genetic diversity of carbohydrolytic enzymes in Jersey cows, with a particular focus on cellulases and xylanases. Pyrosequencing and bioinformatic analyses of 120 carbohydrate-active fosmids identified genes encoding 575 putative Carbohydrate-Active Enzymes (CAZymes and proteins putatively related to transcriptional regulation, transporters, and signal transduction coupled with polysaccharide degradation and metabolism. Most of these genes shared little similarity to sequences archived in databases. Genes that were predicted to encode glycoside hydrolases (GH involved in xylan and cellulose hydrolysis (e.g., GH3, 5, 9, 10, 39 and 43 were well represented. A new subfamily (S-8 of GH5 was identified from contigs assigned to Firmicutes. These subfamilies of GH5 proteins also showed significant phylum-dependent distribution. A number of polysaccharide utilization loci (PULs were found, and two of them contained genes encoding Sus-like proteins and cellulases that have not been reported in previous metagenomic studies of samples from the rumens of cows or other herbivores. Comparison with the large metagenomic datasets previously reported of other ruminant species (or cattle breeds and wallabies showed that the rumen microbiome of Jersey cows might contain differing CAZymes. Future studies are needed to further explore how host genetics and diets affect the diversity and distribution of CAZymes and utilization of plant cell wall materials.

  6. Biosurfactants Produced by Marine Microorganisms with Therapeutic Applications.

    Science.gov (United States)

    Gudiña, Eduardo J; Teixeira, José A; Rodrigues, Lígia R

    2016-02-18

    Marine microorganisms possess unique metabolic and physiological features and are an important source of new biomolecules, such as biosurfactants. Some of these surface-active compounds synthesized by marine microorganisms exhibit antimicrobial, anti-adhesive and anti-biofilm activity against a broad spectrum of human pathogens (including multi-drug resistant pathogens), and could be used instead of existing drugs to treat infections caused by them. In other cases, these biosurfactants show anti-cancer activity, which could be envisaged as an alternative to conventional therapies. However, marine biosurfactants have not been widely explored, mainly due to the difficulties associated with the isolation and growth of their producing microorganisms. Culture-independent techniques (metagenomics) constitute a promising approach to study the genetic resources of otherwise inaccessible marine microorganisms without the requirement of culturing them, and can contribute to the discovery of novel biosurfactants with significant biological activities. This paper reviews the most relevant biosurfactants produced by marine microorganisms with potential therapeutic applications and discusses future perspectives and opportunities to discover novel molecules from marine environments.

  7. Geochemical constraints on the diversity and activity of H2 -oxidizing microorganisms in diffuse hydrothermal fluids from a basalt- and an ultramafic-hosted vent.

    Science.gov (United States)

    Perner, Mirjam; Petersen, Jillian M; Zielinski, Frank; Gennerich, Hans-Hermann; Seifert, Richard

    2010-10-01

    Mixing processes of reduced hydrothermal fluids with oxygenated seawater and fluid-rock reactions contribute to the chemical signatures of diffuse venting and likely determine the geochemical constraints on microbial life. We examined the influence of fluid chemistry on microbial diversity and activity by sampling diffuse fluids emanating through mussel beds at two contrasting hydrothermal vents. The H(2) concentration was very low at the basalt-hosted Clueless site, and mixing models suggest O(2) availability throughout much of the habitat. In contrast, effluents from the ultramafic-hosted Quest site were considerably enriched in H(2) , while O(2) is likely limited to the mussel layer. Only two different hydrogenase genes were identified in clone libraries from the H(2) -poor Clueless fluids, but these fluids exhibited the highest H(2) uptake rates in H(2) -spiked incubations (oxic conditions, at 18 °C). In contrast, a phylogenetically diverse H(2) -oxidizing potential was associated with distinct thermal conditions in the H(2) -rich Quest fluids, but under oxic conditions, H(2) uptake rates were extremely low. Significant stimulation of CO(2) fixation rates by H(2) addition was solely illustrated in Quest incubations (P-value <0.02), but only in conjunction with anoxic conditions (at 18 °C). We conclude that the factors contributing toward differences in the diversity and activity of H(2) oxidizers at these sites include H(2) and O(2) availability.

  8. Atividade antibacteriana de óleos essenciais em cepas isoladas de infecção urinária Antibacterial activity of essential oils on microorganisms isolated from urinary tract infection

    Directory of Open Access Journals (Sweden)

    Rogério Santos Pereira

    2004-04-01

    Full Text Available A análise da atividade antibacteriana de óleos essenciais de ervas medicinais (Ocimum gratissimum, L., Cybopogum citratus (DC Stapf. e Salvia officinalis, L. foi verificada frente a 100 cepas de bactérias isoladas de indivíduos da comunidade com diagnóstico de infecção urinária. Os microrganismos foram semeados em ágar Muller Hinton e os extratos aplicados com replicador de Steers e incubados a 37°C por 24 horas. Verificou-se que Salvia officinalis, L. apresentou ação inibitória superior às outras ervas, tendo eficácia de 100% quando testadas em espécies de Klebsiella e Enterobacter, 96% em Escherichia coli, 83% contra Proteus mirabilis e 75% contra Morganella morganii.The antibacterial activity of essential oils extracted from medicinal plants (Ocimum gratissimum, L., Cybopogum citratus (DC Stapf., and Salvia officinalis, L. was assessed on bacterial strains derived from 100 urine samples. Samples were taken from subjects diagnosed with urinary tract infection living in the community. Microorganisms were plated on Müller Hinton agar. Plant extracts were applied using a Steers replicator and petri dishes were incubated at 37°C for 24 hours. Salvia officinalis, L. showed enhanced inhibitory activity compared to the other two herbs, with 100% efficiency against Klebsiella and Enterobacter species, 96% against Escherichia coli, 83% against Proteus mirabilis, and 75% against Morganella morganii.

  9. Phosphate Biomineralization of Cambrian Microorganisms

    Science.gov (United States)

    McKay, David S.; Rozanov, Alexei Yu.; Hoover, Richard B.; Westall, Frances

    1998-01-01

    As part of a long term study of biological markers (biomarkers), we are documenting a variety of features which reflect the previous presence of living organisms. As we study meteorites and samples returned from Mars, our main clue to recognizing possible microbial material may be the presence of biomarkers rather than the organisms themselves. One class of biomarkers consists of biominerals which have either been precipitated directly by microorganisms, or whose precipitation has been influenced by the organisms. Such microbe-mediated mineral formation may include important clues to the size, shape, and environment of the microorganisms. The process of fossilization or mineralization can cause major changes in morphologies and textures of the original organisms. The study of fossilized terrestrial organisms can help provide insight into the interpretation of mineral biomarkers. This paper describes the results of investigations of microfossils in Cambrian phosphate-rich rocks (phosphorites) that were found in Khubsugul, Northern Mongolia.

  10. Smaller Fleas: Viruses of Microorganisms

    OpenAIRE

    Paul Hyman; Stephen T. Abedon

    2012-01-01

    Life forms can be roughly differentiated into those that are microscopic versus those that are not as well as those that are multicellular and those that, instead, are unicellular. Cellular organisms seem generally able to host viruses, and this propensity carries over to those that are both microscopic and less than truly multicellular. These viruses of microorganisms, or VoMs, in fact exist as the world’s most abundant somewhat autonomous genetic entities and include the viruses of domain B...

  11. Microorganism Utilization for Synthetic Milk

    Science.gov (United States)

    Morford, Megan A.; Khodadad, Christina L.; Caro, Janicce I.; Spencer, LaShelle E.; Richards, Jeffery T.; Strayer, Richard F.; Birmele, Michele N.; Wheeler, Raymond M.

    2014-01-01

    A desired architecture for long duration spaceflight, like aboard the International Space Station or for future missions to Mars, is to provide a supply of fresh food crops for the astronauts. However, some crops can create a high proportion of inedible plant waste. The main goal of the Synthetic Biology project, Cow in a Column, was to produce the components of milk (sugar, lipid, protein) from inedible plant waste by utilizing microorganisms (fungi, yeast, bacteria). Of particular interest was utilizing the valuable polysaccharide, cellulose, found in plant waste, to naturally fuel-through microorganism cellular metabolism- the creation of sugar (glucose), lipid (milk fat), and protein (casein) in order to produce a synthetic edible food product. Environmental conditions such as pH, temperature, carbon source, aeration, and choice microorganisms were optimized in the laboratory and the desired end-products, sugars and lipids, were analyzed. Trichoderma reesei, a known cellulolytic fungus, was utilized to drive the production of glucose, with the intent that the produced glucose would serve as the carbon source for milk fat production and be a substitute for the milk sugar lactose. Lipid production would be carried out by Rhodosporidium toruloides, yeast known to accumulate those lipids that are typically found in milk fat. Results showed that glucose and total lipid content were below what was expected during this phase of experimentation. In addition, individual analysis of six fatty acids revealed that the percentage of each fatty acid was lower than naturally produced bovine milk. Overall, this research indicates that microorganisms could be utilized to breakdown inedible solid waste to produce useable products. For future work, the production of the casein protein for milk would require the development of a genetically modified organism, which was beyond the scope of the original project. Additional trials would be needed to further refine the required

  12. PROBIOTICS BASED ON TRANSGENIC MICROORGANISMS

    Directory of Open Access Journals (Sweden)

    S. А. Starovoitova

    2012-02-01

    Full Text Available Modern tendencies of recombinant microorganisms creation for obtaining on their basis a new effective biopreparations (probiotics with wider spectrum of biological and therapeutic properties were considered. A lot of attention was focused on the main genera of perspective bacteria for creation of recombinant probiotics particularly: Lactococcus, Bifidobac terium,Bacillus, Escherichia. The main created Ukrainian and foreign gene-modified strains, that are widely used today in creation of effective recombinant biopreparations were characterized. Some fundamental directions and methods of gene-modified strains obtaining, which are used in getting effective biopreparations that used for therapy and prophylactic illness were reported, under which this group of pharmaceutical drugs were not used earlier. The safety matters of probiotics using on basis of genemodified strains were examined. Medical and veterinary biopreparations on basis of recombinant microorganisms could be used directly and effectively for therapy and prophylaxis of different illness, beginning from disbacteriosis up to cardiovascular diseases. It is related with some probiotic microorganisms ability for lowering of serum cholesterol at the host organism.

  13. Secondary metabolites from marine microorganisms

    Directory of Open Access Journals (Sweden)

    KELECOM ALPHONSE

    2002-01-01

    Full Text Available After 40 years of intensive research, chemistry of marine natural products has become a mature field. Since 1995, there are signals of decreased interest in the search of new metabolites from traditional sources such as macroalgae and octocorals, and the number of annual reports on marine sponges stabilized. On the contrary, metabolites from microorganisms is a rapidly growing field, due, at least in part, to the suspicion that a number of metabolites obtained from algae and invertebrates may be produced by associated microorganisms. Studies are concerned with bacteria and fungi, isolated from seawater, sediments, algae, fish and mainly from marine invertebrates such as sponges, mollusks, tunicates, coelenterates and crustaceans. Although it is still to early to define tendencies, it may be stated that the metabolites from microorganisms are in most cases quite different from those produced by the invertebrate hosts. Nitrogenated metabolites predominate over acetate derivatives, and terpenes are uncommon. Among the latter, sesquiterpenes, diterpenes and carotenes have been isolated; among nitrogenated metabolites, amides, cyclic peptides and indole alkaloids predominate.

  14. Microorganism Reduction Methods in Meat Products

    OpenAIRE

    ZÁHOROVÁ, Jana

    2011-01-01

    In Bachelor thesis I deal with a theme of the influences on the reduction of microorganisms of meat products. First, I focused on the characteristics of individual organisms, the factors affecting their growth, incidence of microorganisms in meat, forms of microbial degradation and contamination of meat microorganisms in slaughterhouses. The next section deals with the means to fight against microorganisms and methods which can reduce their presence in meat products. In the end there is menti...

  15. In vitro antimicrobial activity of sodium hypochlorite, chlorhexidine gluconate and octenidine dihydrochloride in elimination of microorganisms within dentinal tubules of primary and permanent teeth.

    Science.gov (United States)

    Tirali, Resmiye-Ebru; Bodur, Haluk; Ece, Gülden

    2012-05-01

    The aim of this study was to evaluate the effectiveness of different irrigation solutions at different time intervals for the elimination of E. faecalis and C. albicans penetrated into the dentine tubules of primary and permanent teeth in vitro. The 4 mm primary and permanent teeth sections were sterilized and contaminated with a mixture of E. faecalis and C. albicans strains. After the application of different irrigation solutions (Sodium hypochlorite, Chlorhexidine gluconate, Octenidine Dihydrochloride, saline) to the contaminated tooth sections according to study groups, neutralizers were applied for inactivation of the solutions after 30 sec, 1 min and 5 min. Dentine shavings were placed into TSB and 10 µL from each tube was inoculated on agar plates, followed by an incubation period of 24 h at 37°C. The colonies were counted macroscopically. The results were compared by using Kruskal-Wallis and Mann Whitney U tests, with a significance level at pOctenidine Dihydrochloride. The antibacterial effects of the tested solutions on the same time periods against C. albicans revealed no significant difference. There were no statistically significant differences between primary and permanent teeth with respect to the antimicrobial activity of the tested solutions. Moreover, Octenidine Dihydrochloride may be used as an alternative endodontic irrigant.

  16. ANTI-MICROORGANISM ACTIVITIES AND APPLICATIONS OF CHLORINE DIOXIDE%化学消毒剂二氧化氯抗微生物作用及应用

    Institute of Scientific and Technical Information of China (English)

    熊中奎; 郎娟; 夏国园

    2011-01-01

    二氧化氯(C102)作为一种高效化学消毒剂,能有效地杀灭或抑制病毒、细菌、真菌和寄生虫等各种病原体,在饮用水处理、食品保鲜防腐、废水处理、室内环境消毒、医疗设备和口腔科消毒等领域都具有广阔的应用前景.但是由于存在一些安全性问题,在一定程度上限制了C102推广应用.%Chlorine dioxide, as a chemical sanitizer, is highly effective for sterilizing or inhibiting many pathogens, such as viruses, bacteria, fungi and parasites, so it illustrates a good prospect of application in drinking water treatment, food preservation, effluent disposal, disinfections of interior space and medical equipments, and antisepsis of medical activities in department of stomatology. To some degrees, it is restricted in application and extension for its security fla13:34 2012-7-25ws.

  17. [Regulation of geochemical activity of microorganisms in a petroleum reservoir by injection of H2O2 or water-air mixture].

    Science.gov (United States)

    Nazina, T N; Pavlova, N K; Ni, F; Shestakova, N M; Ivoĭlov, V S; Feng, Q; Dongyun, Z; Prusakova, T S; Beliaev, S S; Ivanov, M V

    2008-01-01

    In the course of pilot trials of biotechnologies for the enhancement of oil recovery in the Gangxi bed of the Dagang oil field (China), microbiological processes were investigated. The biotechnologies were based on injection into the petroleum reservoir of different oxygen sources (H2O2 solution or a water-air mixture) with nitrogen and phosphorus salts. The injection of water-air mixture with nitrogen and phosphorus salts resulted in an increase in the number of aerobic and anaerobic organotrophic bacteria, rates of sulfate reduction and methanogenesis in formation water and also the content of CO2 (from 4.8-12 to 15-23.2%) and methane (from 86-88 to 91.8%) in the gas. The preferential consumption of isotopically light bicarbonate by methanogens resulted in a higher content of the light 12C in methane; the delta13C/CH4 value changed from -45.1...-48.3 to -50.7...-59.3 per thousand). At the same time, mineral carbonates of the formation water became isotopically heavier; the delta13C/Sigmacarbonates value increased from 3.4...4.0 to 5.4...9.6 per thousand. Growth of hydrocarbon-oxidizing bacteria was accompanied by production of biosurfactants and decreased interfacial tension of formation water. Injection of H2O2 solution resulted in the activation of aerobic processes and in suppression of both sulfate reduction and methanogenesis. Methane content in the gas decreased from 86-88 to 75.4-79.8%, probably due to its consumption by methanotrophs. Due to consumption of isotopically light methane, the residual methane carbon became heavier, with the delta13C/CH4 values from -39.0 to -44.3 per thousand. At the same time, mineral carbonates of the formation water became isotopically considerably lighter; the delta13C/Sigmacarbonates value decreased from 5.4... 9.6 to -1.4...2.7 per thousand). The additional amount of oil recovered during the trial of both variants of biotechnological treatment was 3819 t.

  18. Determination of antibody to Streptococcus mutans from radiation-induced xerostomia patients. Agglutination activity against cariogenic microorganisms, active immunoglobulin classes, and post-irradiation caries activity in cancer patients. Final report 15 jul 77-14 apr 79

    Energy Technology Data Exchange (ETDEWEB)

    Brown, L.R.; O' Neill, P.A.; Dreizen, S.

    1979-07-01

    The relationship between specific agglutination (Ag) and caries activity during 30 month post radiation was assessed in 36 head and neck cancer patients. Ag titers in 444 saliva and 481 serum samples from these patients and 16 noncancer controls were determined against formalinized cellular antigens of Streptococcus mutans (Sm), Streptococcus sanguis (Ss), Streptococcus mitis, Lactobacillus fermenti (Lf), and Lactobacillus casei. Saliva IgA and IgG levels and Ag titers were significantly higher in cancer patients than in noncancer controls. Post radiation-induced xerostomic changes in saliva IgA reflected changes in specific Ag against oral microbes, particularly Sm serotype c. Patients with high saliva IgA levels had significantly higher saliva Ag titers to Sm, Ss and Lf, lower plaque Sm counts and lower caries activity than patients with low saliva IgA levels. Serum Ag titers, however, showed no significant relationship with either serum Ig levels, microbial counts or caries activity. Chromatographic separation of Ig classes showed that Ag activity in saliva stemmed mainly from secretory IgA. Most serum Ag activity was found in regions corresponding to IgG and 7S IgA.

  19. Organic acid-tolerant microorganisms and uses thereof for producing organic acids

    Science.gov (United States)

    Pfleger, Brian Frederick; Begemann, Matthew Brett

    2014-05-06

    Organic acid-tolerant microorganisms and methods of using same. The organic acid-tolerant microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid (3HP), acrylic acid, and propionic acid. Further modifications to the microorganisms such as increasing expression of malonyl-CoA reductase and/or acetyl-CoA carboxylase provide or increase the ability of the microorganisms to produce 3HP. Methods of generating an organic acid with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers include replacing acsA or homologs thereof in cells with genes of interest and selecting for the cells comprising the genes of interest with amounts of organic acids effective to inhibit growth of cells harboring acsA or the homologs.

  20. Identification and Characterization of Extremophile Microorganisms with Significance to Astrobiology

    Science.gov (United States)

    Bej, Asim K.

    2003-01-01

    It is now well recognized that microorganisms thrive in extreme ecological conditions such as geothermal vents, polar region, acid and alkaline lakes, and the cold pressurized depth of the ocean floor of this planet. Morphological, physiological, biochemical and genetic adaptations to extreme environments by these extremophile microorganisms have generated immense interest amongst astrobiologists who increasingly believe in the existence of extraterrestrial life. The evidence collected by NASA's space probe Galileo suggested the presence of liquid water and volcanic activity on Mars and Jupiter's satellite Europa. Volcanic activity provides some of the heat necessary to keep the water on Europa from freezing that could provide important dissolved chemicals needed by living organisms. The possibility of the existence of hypersaline alkaline lakes and evaporites confined within closed volcanic basins and impact craters on Mars, and a layer of liquid water under the ice on Europa provide sufficient 'raison d'etre' to study microorganisms in similar extreme environments on Earth, which could provide us with a model that would help establish the existence of extraterrestrial life on other planetary bodies. The objectives of the summer research project were as follows: (1) application of molecular approaches to help establish new species of extremophile microorganisms isolated from a hypersaline alkaline lake; and (2) identification of a major cold-shock gene (cspA) homolog from a psychrotolerant microorganism, PmagG1.

  1. Mini-review: Inhibition of biofouling by marine microorganisms.

    Science.gov (United States)

    Dobretsov, Sergey; Abed, Raeid M M; Teplitski, Max

    2013-01-01

    Any natural or artificial substratum exposed to seawater is quickly fouled by marine microorganisms and later by macrofouling species. Microfouling organisms on the surface of a substratum form heterogenic biofilms, which are composed of multiple species of heterotrophic bacteria, cyanobacteria, diatoms, protozoa and fungi. Biofilms on artificial structures create serious problems for industries worldwide, with effects including an increase in drag force and metal corrosion as well as a reduction in heat transfer efficiency. Additionally, microorganisms produce chemical compounds that may induce or inhibit settlement and growth of other fouling organisms. Since the last review by the first author on inhibition of biofouling by marine microbes in 2006, significant progress has been made in the field. Several antimicrobial, antialgal and antilarval compounds have been isolated from heterotrophic marine bacteria, cyanobacteria and fungi. Some of these compounds have multiple bioactivities. Microorganisms are able to disrupt biofilms by inhibition of bacterial signalling and production of enzymes that degrade bacterial signals and polymers. Epibiotic microorganisms associated with marine algae and invertebrates have a high antifouling (AF) potential, which can be used to solve biofouling problems in industry. However, more information about the production of AF compounds by marine microorganisms in situ and their mechanisms of action needs to be obtained. This review focuses on the AF activity of marine heterotrophic bacteria, cyanobacteria and fungi and covers publications from 2006 up to the end of 2012.

  2. Biosynthesis of anti-HCV compounds using thermophilic microorganisms.

    Science.gov (United States)

    Rivero, Cintia W; De Benedetti, Eliana C; Sambeth, Jorge E; Lozano, Mario E; Trelles, Jorge A

    2012-10-01

    This work describes the application of thermophilic microorganisms for obtaining 6-halogenated purine nucleosides. Biosynthesis of 6-chloropurine-2'-deoxyriboside and 6-chloropurine riboside was achieved by Geobacillus stearothermophilus CECT 43 with a conversion of 90% and 68%, respectively. Furthermore, the selected microorganism was satisfactorily stabilized by immobilization in an agarose matrix. This biocatalyst can be reused at least 70 times without significant loss of activity, obtaining 379mg/L of 6-chloropurine-2'-deoxyriboside. The obtained compounds can be used as antiviral agents.

  3. Biotechnologies for Marine Oil Spill Cleanup: Indissoluble Ties with Microorganisms

    KAUST Repository

    Mapelli, Francesca

    2017-05-13

    The ubiquitous exploitation of petroleum hydrocarbons (HCs) has been accompanied by accidental spills and chronic pollution in marine ecosystems, including the deep ocean. Physicochemical technologies are available for oil spill cleanup, but HCs must ultimately be mineralized by microorganisms. How environmental factors drive the assembly and activity of HC-degrading microbial communities remains unknown, limiting our capacity to integrate microorganism-based cleanup strategies with current physicochemical remediation technologies. In this review, we summarize recent findings about microbial physiology, metabolism and ecology and describe how microbes can be exploited to create improved biotechnological solutions to clean up marine surface and deep waters, sediments and beaches.

  4. Methods for identifying lipoxygenase producing microorganisms on agar plates

    NARCIS (Netherlands)

    Nyyssola, A.; Heshof, R.; Haarmann, T.; Eidner, J.; Westerholm-Parvinen, A.; Langfelder, K.; Kruus, K.; Graaff, de L.H.; Buchert, J.

    2012-01-01

    Plate assays for lipoxygenase producing microorganisms on agar plates have been developed. Both potassium iodide-starch and indamine dye formation methods were effective for detecting soybean lipoxygenase activity on agar plates. A positive result was also achieved using the beta-carotene bleaching

  5. Antarctic bacteria inhibit growth of foodborne microorganisms at low temperatures.

    NARCIS (Netherlands)

    A.C. O'Brien; R. Sharp; N.J. Russell; S. Roller

    2004-01-01

    The aim of this study was to identify Antarctic microorganisms with the ability to produce cold-active antimicrobial compounds with potential for use in chilled food preservation. Colonies (4496) were isolated from 12 Antarctic soil samples and tested against Listeria innocua, Pseudomonas fragi and

  6. Recent Researches of Bioactive Metabolites in Marine Organisms-associated Microor-ganisms

    Institute of Scientific and Technical Information of China (English)

    GU Qianqun; LU Jia; CUI Chengbin; ZHU Tianjiao; FANG Yuchun; LIU Hongbing; ZHU Weiming

    2004-01-01

    Recent researches have shown that some compounds isolated from marine organisms have striking structural similarities with the metabolites from known microorganisms. It is inferred from the researches that the symbiotic or associated marine microorganisms may be the true sources of those compounds or at least involved in the biosynthesizing process. This view has been further evidenced by the researches for many sponges and sponge-associated microorganisms. Importantly, growing evidence has highlighted that the symbiotic or associated marine microorganisms live in the microenvironment within the hosts, and they also produce secondary metabolites which are new and original in structure and unique in activity. All these suggest that the microorganisms associated with marine organisms are the sources with very high potential to be new natural bioactive agents. This article reviews briefly the research advances in the study of new bioactive metabolites from marine organisms-associated microorganisms since 2000.

  7. Use of Probiotic Microorganisms for Bio-Protective Aims

    Directory of Open Access Journals (Sweden)

    Filiz YANGILAR

    2015-03-01

    Full Text Available It was known that some diseases can be treated as the result of the use of antibiotics in certain periods and at certain dosages while inactivating and deteriorating normal microorganisms performing useful activities in human metabolism (in especially intestinal flora. It was occured that after the use of antibiotics, some defects can be seen resulting from antibiotics (such as allergy, diarrhea, gas formation etc. With this aim, nutraceutics and functional food have gained importance over the last years and consumers began to be interested in probiotics, natural antioxidants, dietary fibres, products with low calorie and cholesterol contents, especially the products containing probioticbacteria. Bacteriocins produced by probiotic bacteria can play important roles as food protective and safeguarding since they can compete with unwanted or pathogen microorganisms survive in the media and colonize in intestines. In this review, is aimed to emphasis bioprotective compounds, advantages and disadvantages of biopreservation method and the importance of the mechanisms of probiotic microorganisms.

  8. Microorganisms as potential corrosion inhibitors of metallic materials

    Directory of Open Access Journals (Sweden)

    Tasić Žaklina Z.

    2016-01-01

    Full Text Available Corrosion presents the destruction of materials through chemical or electrochemical interactions with their environment. Interactions between the metal surface and bacterial cells or products of their metabolic activities can lead to microbially-influenced corrosion. Also, it is known that certain microorganisms can contribute to corrosion inhibition. In accordance to that, the literature dealing with the application of different microorganisms as a potentialy corrosion inhibitors of metals is investigated. Different bacterial strains as a corrosion inhibitor of a metalic materials are examined. Further, the role of extracellular polymeric substances in corrosion behavior of metals is emphasized. Based on the data presented in this work, it can be said that inhibition efficiency depends on microorganism as well as type of metal. Also, it is presented that some bacterial species can be used as a good corrosion inhibitor instead of toxic organic compounds.

  9. Potential role of microorganisms in the pathogenesis of rosacea.

    Science.gov (United States)

    Holmes, Anna D

    2013-12-01

    Rosacea is a skin condition of abnormal inflammation and vascular dysfunction. The active contribution of a microbial agent in the development or progression of rosacea continues to be debated. Research supports the presence of commensal Demodex folliculorum mites at increased density in the skin and associates Helicobacter pylori infection of the gut with rosacea. Fewer studies implicate Staphylococcus epidermidis, Chlamydophila pneumoniae, and the Demodex-associated bacteria Bacillus oleronius. No research, however, provides a mechanism by which colonization by a microorganism translates to manifestation of the condition. Prevailing and emerging principles in the biology of the microbiome and the pathophysiology of rosacea may help to reconcile these lingering questions. Here the microorganisms implicated in rosacea are reviewed and the reaction of the microbiome to inflammation and to changes in microenvironments and macroenvironments are discussed to explain potential roles for microorganisms in rosacea pathophysiology.

  10. Isolation and identification of a denitrogenation microorganism and its nitrogen removal activity%一株脱氮细菌的分离鉴定及脱氮活性检测

    Institute of Scientific and Technical Information of China (English)

    高存川; 张晓慧; 徐春厚

    2012-01-01

    A denitrogenation microorganism FX7 was isolated with silicate plate from soil. The experiment results showed that under aerobic conditions the reduction efficiency within 48 hours was up to 45% with initial nitrite nitrogen concentration of 2500 mg/L. On the basis of its physiological and molecular properties, strain FX7 was identified as Pseudomonas sp. Though the nitrite nitrogen removal ability of strain FX7 was strongly inhibited by ions Pb^2+, Hg^2+and Cr^7+, the nitrite nitrogen removal ability was activated by ions ofZn^2+ and Fe^3+ with low concentration.%利用硅胶平板从淤泥中分离到一株脱氮茵FX7,该菌株在好氧条件下具有降解亚硝态氮的能力。亚硝态氮初始浓度为2500mg/L时,该菌株在48h内亚硝态氮降解率为45%。通过形态学特征、生理生化特性及16SrDNA同源性比较对菌株FX7进行鉴定,初步判断其为假单胞菌(Pseudomonassp)。Pb^2+、Hg^2+和Cr^2+对菌株FX7的亚硝态氮降解活性有很强的抑制作用,而低浓度的Zn^2+和Fe^3+对其活性有一定的激活作用。

  11. Feeding, Swimming and Navigation of Colonial Microorganisms

    Science.gov (United States)

    Kirkegaard, Julius; Bouillant, Ambre; Marron, Alan; Leptos, Kyriacos; Goldstein, Raymond

    2016-11-01

    Animals are multicellular in nature, but evolved from unicellular organisms. In the closest relatives of animals, the choanoflagellates, the unicellular species Salpincgoeca rosetta has the ability to form colonies, resembling true multicellularity. In this work we use a combination of experiments, theory, and simulations to understand the physical differences that arise from feeding, swimming and navigating as colonies instead of as single cells. We show that the feeding efficiency decreases with colony size for distinct reasons in the small and large Péclet number limits, and we find that swimming as a colony changes the conventional active random walks of microorganism to stochastic helices, but that this does not hinder effective navigation towards chemoattractants.

  12. Models of Micro-Organisms: Children's Knowledge and Understanding of Micro-Organisms from 7 to 14 Years Old

    Science.gov (United States)

    Byrne, Jenny

    2011-01-01

    This paper describes the expressed models that children aged 7, 11, and 14 years have about micro-organisms and microbial activity. These were elicited using a variety of data collection techniques that complemented each other, resulting in a rich dataset, and provided information about the level of knowledge and progression of ideas across the…

  13. Functional Basis of Microorganism Classification.

    Directory of Open Access Journals (Sweden)

    Chengsheng Zhu

    2015-08-01

    Full Text Available Correctly identifying nearest "neighbors" of a given microorganism is important in industrial and clinical applications where close relationships imply similar treatment. Microbial classification based on similarity of physiological and genetic organism traits (polyphasic similarity is experimentally difficult and, arguably, subjective. Evolutionary relatedness, inferred from phylogenetic markers, facilitates classification but does not guarantee functional identity between members of the same taxon or lack of similarity between different taxa. Using over thirteen hundred sequenced bacterial genomes, we built a novel function-based microorganism classification scheme, functional-repertoire similarity-based organism network (FuSiON; flattened to fusion. Our scheme is phenetic, based on a network of quantitatively defined organism relationships across the known prokaryotic space. It correlates significantly with the current taxonomy, but the observed discrepancies reveal both (1 the inconsistency of functional diversity levels among different taxa and (2 an (unsurprising bias towards prioritizing, for classification purposes, relatively minor traits of particular interest to humans. Our dynamic network-based organism classification is independent of the arbitrary pairwise organism similarity cut-offs traditionally applied to establish taxonomic identity. Instead, it reveals natural, functionally defined organism groupings and is thus robust in handling organism diversity. Additionally, fusion can use organism meta-data to highlight the specific environmental factors that drive microbial diversification. Our approach provides a complementary view to cladistic assignments and holds important clues for further exploration of microbial lifestyles. Fusion is a more practical fit for biomedical, industrial, and ecological applications, as many of these rely on understanding the functional capabilities of the microbes in their environment and are less

  14. Color-Removal by Microorganisms Isolated from Human Hands

    Directory of Open Access Journals (Sweden)

    Tsukasa Ito

    2013-08-01

    Full Text Available Microorganisms are essential for human life. Microorganisms decompose the carbon compounds in dead animals and plants and convert them into carbon dioxide. Intestinal bacteria assist in food digestion. Some vitamins are produced by bacteria that live in the intestines. Sewage and industrial wastewater are treated by activated sludge composed of microbial communities. All of these are due to the ability of microbes to produce many enzymes that can degrade chemicals. How do teachers make students understand that microorganisms are always associated with humans, and that microorganisms have the ability to degrade chemicals? The presence of microorganisms on humans can be shown by incubating agar plates after they are touched by the hands of students. The ability of microorganisms to degrade chemicals can be shown by an analytical measurement of the degradation of chemicals. When the chemicals are dyes (colorants in water, microbial activity on degradation of dyes can be demonstrated by observing a decreasing degree of color as a result of the enzymatic activity (e.g., azoreductase. Dyes are widely used in the textile, food, and cosmetic industries. They are generally resistant to conventional biological wastewater treatment systems such as the activated sludge process (4. The discharge of wastewater containing dye pollutes surface water. The ability of microorganisms to decolorize and degrade dyes has been widely investigated to use for bioremediation purposes (5. The goal of this tip is to understand the presence of bacteria on human skin and the ability of bacteria to degrade colorant chemicals (decolorization. In this tip, students first cultivate and isolate bacteria on their hands, and then examine potential decolorization activity of each bacterium by observing the degree of color of the liquid in tubes in which bacteria isolated from students’ hands were inoculated. Decolorization activity of bacterial isolates from human skin has been

  15. Biocorrosion produced by Thiobacillus-like microorganisms.

    Science.gov (United States)

    López, A I; Marín, I; Amils, R

    1994-01-01

    Biocorrosion can be produced by many different microorganisms through diverse mechanisms. The biocorrosion produced by acidophilic microorganisms of the genus Thiobacillus is based on the production of sulfuric acid and ferric ion from pyrites or related mineral structures, as a result of the chemolithotrophic metabolism of these microorganisms. The products of this aerobic respiration are also powerful oxidant elements, which can produce chemical oxidations of other metallic structures. The Tinto River, a very unusual extremophilic habitat (pH around 2, and high concentration of ferric ion), product of the growth of strict chemolithotrophic microorganisms, is discussed as a model case.

  16. Alkalizing Reactions Streamline Cellular Metabolism in Acidogenic Microorganisms

    Science.gov (United States)

    Arioli, Stefania; Ragg, Enzio; Scaglioni, Leonardo; Fessas, Dimitrios; Signorelli, Marco; Karp, Matti; Daffonchio, Daniele; De Noni, Ivano; Mulas, Laura; Oggioni, Marco; Guglielmetti, Simone; Mora, Diego

    2010-01-01

    An understanding of the integrated relationships among the principal cellular functions that govern the bioenergetic reactions of an organism is necessary to determine how cells remain viable and optimise their fitness in the environment. Urease is a complex enzyme that catalyzes the hydrolysis of urea to ammonia and carbonic acid. While the induction of urease activity by several microorganisms has been predominantly considered a stress-response that is initiated to generate a nitrogen source in response to a low environmental pH, here we demonstrate a new role of urease in the optimisation of cellular bioenergetics. We show that urea hydrolysis increases the catabolic efficiency of Streptococcus thermophilus, a lactic acid bacterium that is widely used in the industrial manufacture of dairy products. By modulating the intracellular pH and thereby increasing the activity of β-galactosidase, glycolytic enzymes and lactate dehydrogenase, urease increases the overall change in enthalpy generated by the bioenergetic reactions. A cooperative altruistic behaviour of urease-positive microorganisms on the urease-negative microorganisms within the same environment was also observed. The physiological role of a single enzymatic activity demonstrates a novel and unexpected view of the non-transcriptional regulatory mechanisms that govern the bioenergetics of a bacterial cell, highlighting a new role for cytosol-alkalizing biochemical pathways in acidogenic microorganisms. PMID:21152088

  17. Alkalizing reactions streamline cellular metabolism in acidogenic microorganisms.

    Directory of Open Access Journals (Sweden)

    Stefania Arioli

    Full Text Available An understanding of the integrated relationships among the principal cellular functions that govern the bioenergetic reactions of an organism is necessary to determine how cells remain viable and optimise their fitness in the environment. Urease is a complex enzyme that catalyzes the hydrolysis of urea to ammonia and carbonic acid. While the induction of urease activity by several microorganisms has been predominantly considered a stress-response that is initiated to generate a nitrogen source in response to a low environmental pH, here we demonstrate a new role of urease in the optimisation of cellular bioenergetics. We show that urea hydrolysis increases the catabolic efficiency of Streptococcus thermophilus, a lactic acid bacterium that is widely used in the industrial manufacture of dairy products. By modulating the intracellular pH and thereby increasing the activity of β-galactosidase, glycolytic enzymes and lactate dehydrogenase, urease increases the overall change in enthalpy generated by the bioenergetic reactions. A cooperative altruistic behaviour of urease-positive microorganisms on the urease-negative microorganisms within the same environment was also observed. The physiological role of a single enzymatic activity demonstrates a novel and unexpected view of the non-transcriptional regulatory mechanisms that govern the bioenergetics of a bacterial cell, highlighting a new role for cytosol-alkalizing biochemical pathways in acidogenic microorganisms.

  18. Effects of Five Kinds of Cultivation on the Soil Microorganisms and Enzyme Activities of Camellia oleifera Forestry%5种栽培模式对油茶土壤微生物及酶活性的影响

    Institute of Scientific and Technical Information of China (English)

    冯金玲; 郑新娟; 杨志坚; 陈世品; 陈辉

    2016-01-01

    In this paper,five cultivation modes of experiment which are interplant of Soybean,peanut,mung bean,kidney bean and the covering grass,were explored to discuss the effects of different cultivation on Camellia oleifera,soil microorganisms and enzyme activities.The results indicated that new-tip length,the yield of single tree and oil yield of the five cultivation modes had significantly differences,except for fresh seeds yield.The quan-tities of microbes and the activities of enzymes in the rhizosphere soil were higher than in the non-rhizosphere soil. Based on the above analysis,interplant of soy beans and mung beans were the most beneficial modes to C.Oleif-era.The bacteria was significant correlation with various kinds of soil enzyme and oil yield,which illustrated that the quantity of bacteria could be used as biological indicator to detect soil fertility,and providing the basis to judge C.Oleifera oil production.%以毛豆、花生、绿豆、四季豆套种及覆草为试验栽培模式,探讨不同栽培模式对油茶、土壤微生物及土壤酶活性的影响。结果表明:5种栽培模式对油茶新梢生长、单株产果量及出油率有显著影响,但对鲜出籽率影响不明显;对土壤微生物数量和酶活性均存在显著差异,根际土壤微生物数量和酶活性比非根际土壤高;综合分析得出在油茶林下套种毛豆和绿豆2种模式最好。细菌与真菌、各种土壤酶活性以及出油率均有显著或极显著相关关系,说明土壤细菌可作用为判断土壤肥力状况的生物学指标。

  19. Microorganisms Resistant to Free-Living Amoebae

    OpenAIRE

    Greub, Gilbert; Raoult, Didier

    2004-01-01

    Free-living amoebae feed on bacteria, fungi, and algae. However, some microorganisms have evolved to become resistant to these protists. These amoeba-resistant microorganisms include established pathogens, such as Cryptococcus neoformans, Legionella spp., Chlamydophila pneumoniae, Mycobacterium avium, Listeria monocytogenes, Pseudomonas aeruginosa, and Francisella tularensis, and emerging pathogens, such as Bosea spp., Simkania negevensis, Parachlamydia acanthamoebae, and Legionella-like amoe...

  20. Effect of Different Fertilizers on Continuous Tobacco Cropping Rhizospheric Soil Microorganisms and Enzyme Activities%不同肥料对连作烟草根际土壤微生物及酶活性的影响

    Institute of Scientific and Technical Information of China (English)

    段玉琪; 陈冬梅; 晋艳; 王海斌; 杨宇虹; 尤垂淮; 田卫霞; 林文雄

    2012-01-01

    烟草连作障碍是制约烟草产量与品质的关键因素.以连作12年的烟草土壤为对象,通过施用不同肥料,研究了不同肥料对连作烟草产量、根际土壤微生物量、土壤酶活性的影响.结果表明:不同施肥处理对连作烟草产量及土壤微生物及酶活性的影响存在一定差异,施用农家肥有利于提高连作烟草产量.土壤微生物量分析结果显示,不同施肥处理后烟草根际土壤微生物量碳、氮及微生物呼吸强度依次为:农家肥>有机肥>氮肥>复合肥.与土壤营养循环相关酶活性的分析结果表明,不同施肥处理后烟草根际土壤中性磷酸酶、碱性磷酸酶、脲酶、蔗糖酶活性以有机肥处理后活性最大,而酸性磷酸酶则以农家肥处理后活性最高.与土壤生物抗逆性相关的多酚氧化酶、过氧化物酶、过氧化氢酶、脱氢酶活性分析的结果显示,不同施肥处理后烟草根际土壤抗性相关酶活性大小依次为:农家肥>有机肥>氮肥>复合肥.%Problems caused by continuous tobacco cropping were critical obstacles restricting the yield and quality of tobacco leaf. The trial was conducted in a filed,where tobacco was continuously planted for 12 years. By applying different fertilizers,we studied the effect of different fertilizers on the yield,quality and rhizospheric soil microbial biomass,enzyme activity of the rhizosphere. The results indicated that different fertilization treatments had different effects on leaf yield,soil microorganism and enzyme activity in continuous cropping,and farmyard manure application was favorable to improve the leaf yield. The result of soil microbial biomass analysis showed that microbial biomass C and N,and microbial respiration intensity ranked as farmyard manure > organic fertilizer > nitrogen fertilizer > compound fertilizer after different fertilizer treatments. Furthermore,the activity of neutral phosphatase,alkaline phosphatase,urease and

  1. Spoilage microorganisms in milk and dairy products

    Directory of Open Access Journals (Sweden)

    Andrea Skelin

    2007-12-01

    Full Text Available Spoilage microorganisms cause changes of primary characteristics and properties of milk and dairy products. The product defects depends on the specific species and number of microorganisms involved in pre- and post- technological processing. Most often, these changes are related to single undesirable sensory characteristic, smell, flavour or conistency. However, in the case of heavier microbial contamination all these undesirable characteristics can occur simultaneously. Besides, even small changes caused by presence of spoilage microorganisms lead to decreased quality of milk and various dairy products. Despite of the importance for the overall quality, the control of spoilage microorganisms for dairy industry is not obligated and therefore, only a few producers control them. Therefore, the present study describes the undesirable effect of spoilage microorganisms on quality of raw, pasteurized and sterilized milk, fermented milk, butter, sour cream and cheeses with the intention to emphasize the importance and significance of their control in the dairy industry.

  2. Systems biology of industrial microorganisms.

    Science.gov (United States)

    Papini, Marta; Salazar, Margarita; Nielsen, Jens

    2010-01-01

    The field of industrial biotechnology is expanding rapidly as the chemical industry is looking towards more sustainable production of chemicals that can be used as fuels or building blocks for production of solvents and materials. In connection with the development of sustainable bioprocesses, it is a major challenge to design and develop efficient cell factories that can ensure cost efficient conversion of the raw material into the chemical of interest. This is achieved through metabolic engineering, where the metabolism of the cell factory is engineered such that there is an efficient conversion of sugars, the typical raw materials in the fermentation industry, into the desired product. However, engineering of cellular metabolism is often challenging due to the complex regulation that has evolved in connection with adaptation of the different microorganisms to their ecological niches. In order to map these regulatory structures and further de-regulate them, as well as identify ingenious metabolic engineering strategies that full-fill mass balance constraints, tools from systems biology can be applied. This involves both high-throughput analysis tools like transcriptome, proteome and metabolome analysis, as well as the use of mathematical modeling to simulate the phenotypes resulting from the different metabolic engineering strategies. It is in fact expected that systems biology may substantially improve the process of cell factory development, and we therefore propose the term Industrial Systems Biology for how systems biology will enhance the development of industrial biotechnology for sustainable chemical production.

  3. [Genome editing of industrial microorganism].

    Science.gov (United States)

    Zhu, Linjiang; Li, Qi

    2015-03-01

    Genome editing is defined as highly-effective and precise modification of cellular genome in a large scale. In recent years, such genome-editing methods have been rapidly developed in the field of industrial strain improvement. The quickly-updating methods thoroughly change the old mode of inefficient genetic modification, which is "one modification, one selection marker, and one target site". Highly-effective modification mode in genome editing have been developed including simultaneous modification of multiplex genes, highly-effective insertion, replacement, and deletion of target genes in the genome scale, cut-paste of a large DNA fragment. These new tools for microbial genome editing will certainly be applied widely, and increase the efficiency of industrial strain improvement, and promote the revolution of traditional fermentation industry and rapid development of novel industrial biotechnology like production of biofuel and biomaterial. The technological principle of these genome-editing methods and their applications were summarized in this review, which can benefit engineering and construction of industrial microorganism.

  4. Systems Biology of Industrial Microorganisms

    Science.gov (United States)

    Papini, Marta; Salazar, Margarita; Nielsen, Jens

    The field of industrial biotechnology is expanding rapidly as the chemical industry is looking towards more sustainable production of chemicals that can be used as fuels or building blocks for production of solvents and materials. In connection with the development of sustainable bioprocesses, it is a major challenge to design and develop efficient cell factories that can ensure cost efficient conversion of the raw material into the chemical of interest. This is achieved through metabolic engineering, where the metabolism of the cell factory is engineered such that there is an efficient conversion of sugars, the typical raw materials in the fermentation industry, into the desired product. However, engineering of cellular metabolism is often challenging due to the complex regulation that has evolved in connection with adaptation of the different microorganisms to their ecological niches. In order to map these regulatory structures and further de-regulate them, as well as identify ingenious metabolic engineering strategies that full-fill mass balance constraints, tools from systems biology can be applied. This involves both high-throughput analysis tools like transcriptome, proteome and metabolome analysis, as well as the use of mathematical modeling to simulate the phenotypes resulting from the different metabolic engineering strategies. It is in fact expected that systems biology may substantially improve the process of cell factory development, and we therefore propose the term Industrial Systems Biology for how systems biology will enhance the development of industrial biotechnology for sustainable chemical production.

  5. Genome-Based Studies of Marine Microorganisms to Maximize the Diversity of Natural Products Discovery for Medical Treatments

    Directory of Open Access Journals (Sweden)

    Xin-Qing Zhao

    2011-01-01

    Full Text Available Marine microorganisms are rich source for natural products which play important roles in pharmaceutical industry. Over the past decade, genome-based studies of marine microorganisms have unveiled the tremendous diversity of the producers of natural products and also contributed to the efficiency of harness the strain diversity and chemical diversity, as well as the genetic diversity of marine microorganisms for the rapid discovery and generation of new natural products. In the meantime, genomic information retrieved from marine symbiotic microorganisms can also be employed for the discovery of new medical molecules from yet-unculturable microorganisms. In this paper, the recent progress in the genomic research of marine microorganisms is reviewed; new tools of genome mining as well as the advance in the activation of orphan pathways and metagenomic studies are summarized. Genome-based research of marine microorganisms will maximize the biodiscovery process and solve the problems of supply and sustainability of drug molecules for medical treatments.

  6. Nitrogen utilization pathways of soil microorganisms

    Science.gov (United States)

    Pinggera, J.; Geisseler, D.; Merbach, I.; Ludwig, B.

    2012-04-01

    Nitrogen (N) is an essential nutrient for all organisms. In terrestrial ecosystems N occurs predominantly in the form of organic matter. Here, soil microorganisms can use two possible mechanisms for the uptake of organic N: the direct route and the mobilization-immobilization-turnover (MIT) route. In the direct route simple organic molecules are taken up directly into the cell. The deamination occurs inside the cell and only the surplus N is released into the soil solution. In the second route, the deamination occurs outside the cell and all N is mineralized before assimilation. To determine the importance of the different N uptake pathways of soil microorganisms an incubation experiment (21 days, 20°C) is currently being carried out. Corn leaves with different C to N ratios (20, 40) and (NH4)2SO4 have been added to three soils (Haplic Chernozem, FAO) with different fertilization histories (300dt/ha farmyard manure every second year, mineral NPK fertilizer, no fertilization) from the long-term experiment at Bad Lauchstädt. Contents of NH4+, NO3- and microbial biomass C (Cmic) and N (Nmic), CO2 production, potential protease activity, gross N mineralization and mineralization of added amino acids will be determined after 3, 7 and 21 days. Preliminary results show that the protease activity (without addition of corn residues) decreased in the order manure-fertilized soil (18.26 mg tyrosine kg-1 soil h-1) > Soil with mineral NPK fertilizer (17.45 mg tyrosine kg-1 soil h-1) > unfertilized soil (11.34 mg tyrosine kg-1 oven dry soil h-1). The turnover of amino acids after 24h was higher for the manure-fertilized soil (99.5% of the added amino acids were consumed) than for the NPK- fertilized and unfertilized soils (76%). The effects of the fertilization histories on the temporal dynamics of the different biological properties (Cmic, Nmic), CO2 production, protease activity and N mineralization rates will be presented.

  7. L-methionine degradation potentialities of cheese-ripening microorganisms.

    Science.gov (United States)

    Bonnarme, P; Lapadatescu, C; Yvon, M; Spinnler, H E

    2001-11-01

    Volatile sulphur compounds are major flavouring compounds in many traditional fermented foods including cheeses. These compounds are products of the catabolism of L-methionine by cheese-ripening microorganisms. The diversity of L-methionine degradation by such microorganisms, however, remains to be characterized. The objective of this work was to compare the capacities to produce volatile sulphur compounds by five yeasts, Geotrichum candidum, Yarrowia lipolytica, Kluyveromyces lactis, Debaryomyces hansenii, Saccharomyces cerevisiae and five bacteria, Brevibacterium linens, Corynebacterium glutamicum, Arthrobacter sp., Micrococcus lutens and Staphylococcus equorum of technological interest for cheese-ripening. The ability of whole cells of these microorganisms to generate volatile sulphur compounds from L-methionine was compared. The microorganisms produced a wide spectrum of sulphur compounds including methanethiol, dimethylsulfide, dimethyldisulfide, dimethyltrisulfide and also S-methylthioesters, which varied in amount and type according to strain. Most of the yeasts produced methanethiol, dimethylsulfide, dimethyldisulfide and dimethyltrisulfide but did not produce S-methylthioesters, apart from G. candidum that produced S-methyl thioacetate. Bacteria, especially Arth. sp. and Brevi. linens, produced the highest amounts and the greatest variety of volatile sulphur compounds includling methanethiol, sulfides and S-methylthioesters, e.g. S-methyl thioacetate, S-methyl thiobutyrate, S-methyl thiopropionate and S-methyl thioisovalerate. Cell-free extracts of all the yeasts and bacteria were examined for the activity of enzymes possibly involved in L-methionine catabolism, i.e. L-methionine demethiolase, L-methionine aminotransferase and L-methionine deaminase. They all possessed L-methionine demethiolase activity, while some (K. lactis, Deb. hansenii, Arth. sp., Staph. equorum) were deficient in L-methionine aminotransferase, and none produced L-methionine deaminase

  8. Advancing oleaginous microorganisms to produce lipid via metabolic engineering technology.

    Science.gov (United States)

    Liang, Ming-Hua; Jiang, Jian-Guo

    2013-10-01

    With the depletion of global petroleum and its increasing price, biodiesel has been becoming one of the most promising biofuels for global fuels market. Researchers exploit oleaginous microorganisms for biodiesel production due to their short life cycle, less labor required, less affection by venue, and easier to scale up. Many oleaginous microorganisms can accumulate lipids, especially triacylglycerols (TAGs), which are the main materials for biodiesel production. This review is covering the related researches on different oleaginous microorganisms, such as yeast, mold, bacteria and microalgae, which might become the potential oil feedstocks for biodiesel production in the future, showing that biodiesel from oleaginous microorganisms has a great prospect in the development of biomass energy. Microbial oils biosynthesis process includes fatty acid synthesis approach and TAG synthesis approach. In addition, the strategies to increase lipids accumulation via metabolic engineering technology, involving the enhancement of fatty acid synthesis approach, the enhancement of TAG synthesis approach, the regulation of related TAG biosynthesis bypass approaches, the blocking of competing pathways and the multi-gene approach, are discussed in detail. It is suggested that DGAT and ME are the most promising targets for gene transformation, and reducing PEPC activity is observed to be beneficial for lipid production.

  9. Application of flow cytometry to wine microorganisms.

    Science.gov (United States)

    Longin, Cédric; Petitgonnet, Clément; Guilloux-Benatier, Michèle; Rousseaux, Sandrine; Alexandre, Hervé

    2017-04-01

    Flow cytometry (FCM) is a powerful technique allowing detection and enumeration of microbial populations in food and during food process. Thanks to the fluorescent dyes used and specific probes, FCM provides information about cell physiological state and allows enumeration of a microorganism in a mixed culture. Thus, this technique is increasingly used to quantify pathogen, spoilage microorganisms and microorganisms of interest. Since one decade, FCM applications to the wine field increase greatly to determine population and physiological state of microorganisms performing alcoholic and malolactic fermentations. Wine spoilage microorganisms were also studied. In this review we briefly describe FCM principles. Next, a deep revision concerning enumeration of wine microorganisms by FCM is presented including the fluorescent dyes used and techniques allowing a yeast and bacteria species specific enumeration. Then, the last chapter is dedicated to fluorescent dyes which are used to date in fluorescent microscopy but applicable in FCM. This chapter also describes other interesting "future" techniques which could be applied to study the wine microorganisms. Thus, this review seeks to highlight the main advantages of the flow cytometry applied to wine microbiology.

  10. Bactericidal Activities of Spicy Essential Oils on Microorganisms in Crude Food%香辛料精油成分对生鲜食品中有害菌杀灭活性研究

    Institute of Scientific and Technical Information of China (English)

    段雪娟; 吴克刚; 柴向华

    2012-01-01

    Bactericidal activities of seven spicy essential oil components on five microorganisms (Escherichia Coli, Staphylococcus Awrous, Saimonella, Listcria monocytogenes, Vibrio Parahemolyticus) were studied by plate dilution method and transferring substrate cob method. Results showed that salicylaldehyde had the best bactericidal activity,followed successively by thymol, cin-namic aldehyde, anethole, eugenol, citral, vanillin. The optimal composite essential oil ( salicylaldehyde: cinnamic aldehyde: thymol: anethole 2:5: 20: 5. ) was obtained through orthogonal test. The minimum bactericidal mass concentration of the composite essential oil for killing five pathogens was 0.25 mg/L, only 1/2 of that of salicylaldehyde. Synergistic sterilization effects of composite essential oil was analyzed. The composite essential oil showed a strong synergistic effect on Listeria monocytogenes, an additive effect on Staphylococcus Aurous , Escherichia Coli and Vibrio Parahemolyticus, and unrelated effect on Salmonella.%采用平板稀释法和菌块转移法研究了百里香酚、丁香酚、肉桂醛、茴香脑、水杨醛、柠檬醛、香兰素7种食用植物精油组分对大肠杆菌、金黄色葡萄球菌、沙门氏菌、单增李斯特菌、副溶血性弧菌等生鲜食品常见5种有害菌的杀灭活性.实验结果表明,水杨醛对5种有害菌的综合杀灭能力最强,然后依次是百里香酚、肉桂醛、茴香脑、丁香酚、柠檬醛、香兰素.通过正交试验将水杨醛、肉桂醛、百里香酚、茴香脑复配,得到最佳组合是为:水杨醛、肉桂醛、百里香酚、茴香脑的质量比为2:5:20:5,其杀灭所有供试菌的最低质量浓度为0.25 mg/L,仅为杀菌效果最好的单一水杨醛浓度的1/2.通过对香辛料精油成分杀菌作用协同效应分析得出,复配的香辛精油对单增李斯特菌的杀灭表现出很强的协同增效作用效果,对金黄色葡萄球菌、大肠杆菌和副溶血性弧菌的杀灭

  11. Impact of Transgenic Bt+CpTI Cotton on Soil Enzyme Activities and Soil Microorganisms%转双价棉种植对土壤酶活性及土壤微生物的影响

    Institute of Scientific and Technical Information of China (English)

    刘红梅; 宋晓龙; 皇甫超河; 张贵龙; 杨殿林; 赵建宁

    2013-01-01

    Due to its strong and effective insecticidal properties, transgenic Bt+CpTI cotton has witnessed an expanding planting area in recent years, and the impact of its cultivation on soil ecosystem becomes an important part of environmental risk assessment. Using transgenic Bt+CpTI cotton sGK321 and its parental homologous conventional cotton Shiyuan 321 as the study objects, a comparative analysis was conducted on the changes in enzyme activities (urease, alkaline phosphatase, and catalase) of the rhizosphere soil and changes in the number of culturable microor-ganisms (bacteria, fungi, and actinomycetes) at different growth stages (seedling stage, budding stage, flower and bol stage, and bol opening stage) of sGK321 and Shiyuan 321 under the condition of 13 years field plantings. The results showed that, the populations of bacteria, fungi, and actinomycete and the soil enzyme activi-ties of urease, alkaline phosphatase and catalase had a similar variation trend along with the cotton growing process for transgenic cotton and conventional cotton. Some occasional and inconsistent effects on soil enzyme activities and soil fungi composi-tion in the rhizosphere soil of transgenic Bt+CpTI cotton were found at the seedling stage, budding stage, flower and bol stage as compared with that of conventional cotton. The amount of bacteria and actinomycetes were not significantly different during a certain stage; however, the activities of urease, catalase, alkaline phos-phatase, also with the number of fungi were significantly different, e.g. the urease activities at seedling stage, the alkaline phosphatase at seedling and budding stages, and the soil culturable fungi at flower and bol stage were less than that of conven-tional cotton, while the soil alkaline phosphatase activities at flower and bol stage were higher. Cluster analysis showed that soil enzyme activities and microbial popu-lation changed mainly along the growth processes, suffering little from the planting of

  12. Preparation and characterization of gelatin scaffold containing microorganism fermented cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Youn Mook; Gwon, Hui Jeong; Park, Jong Seok; Nho, Young Chang; Lee, Byeong Heon [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Kim, Mi Yeong; Lee, Jong Dae; Song, Sung Gi [Quegenbiotech, Co., Incheon (Korea, Republic of)

    2010-12-15

    Cellulose, chitin, chitosan and hyaluronic acid are well known as polysaccharides. These polysaccharides have many effects on cell growth and differentiation. Cell activation increases with increasing the polysaccharides concentration. In this study, gelatin scaffold containing microorganism fermented cellulose, citrus gel were prepared by using irradiation technique. Physical properties of the scaffolds were investigated as a function of the concentrations of gelatin and citrus gel and the cell attachment, cell morphology and inflammation of the scaffolds also were characterized for regeneration of skin tissue.

  13. Detection of microorganisms using terahertz metamaterials.

    Science.gov (United States)

    Park, S J; Hong, J T; Choi, S J; Kim, H S; Park, W K; Han, S T; Park, J Y; Lee, S; Kim, D S; Ahn, Y H

    2014-05-16

    Microorganisms such as fungi and bacteria cause many human diseases and therefore rapid and accurate identification of these substances is essential for effective treatment and prevention of further infections. In particular, contemporary microbial detection technique is limited by the low detection speed which usually extends over a couple of days. Here we demonstrate that metamaterials operating in the terahertz frequency range shows promising potential for use in fabricating the highly sensitive and selective microbial sensors that are capable of high-speed on-site detection of microorganisms in both ambient and aqueous environments. We were able to detect extremely small amounts of the microorganisms, because their sizes are on the same scale as the micro-gaps of the terahertz metamaterials. The resonant frequency shift of the metamaterials was investigated in terms of the number density and the dielectric constants of the microorganisms, which was successfully interpreted by the change in the effective dielectric constant of a gap area.

  14. Mass Spectrometry for Rapid Characterization of Microorganisms

    Science.gov (United States)

    Demirev, Plamen A.; Fenselau, Catherine

    2008-07-01

    Advances in instrumentation, proteomics, and bioinformatics have contributed to the successful applications of mass spectrometry (MS) for detection, identification, and classification of microorganisms. These MS applications are based on the detection of organism-specific biomarker molecules, which allow differentiation between organisms to be made. Intact proteins, their proteolytic peptides, and nonribosomal peptides have been successfully utilized as biomarkers. Sequence-specific fragments for biomarkers are generated by tandem MS of intact proteins or proteolytic peptides, obtained after, for instance, microwave-assisted acid hydrolysis. In combination with proteome database searching, individual biomarker proteins are unambiguously identified from their tandem mass spectra, and from there the source microorganism is also identified. Such top-down or bottom-up proteomics approaches permit rapid, sensitive, and confident characterization of individual microorganisms in mixtures and are reviewed here. Examples of MS-based functional assays for detection of targeted microorganisms, e.g., Bacillus anthracis, in environmental or clinically relevant backgrounds are also reviewed.

  15. NEW LIPASE-PRODUCERS MICROORGANISMS FROM PERUVIAN AMAZONIA WHICH HYDROLYZE PALM OIL AND DERIVATIVES

    OpenAIRE

    Roxana Trujillo; Pedro Peláez; Josep-Vicent Sinisterra

    2014-01-01

    Two yeasts: Cryptococcus uchicensis TMY9 and Pichia uchicensis TMY10 and one fungus Verticillium tingalensis TMFMB are described for the first time as lipase producer microorganisms. The strains have been isolated after an ecological screening in a palm oil industry. The yeasts- C. uchicensis and Pichia uchicensis - mainly produce extracellular lipases as active as those produced by traditional lipase producing microorganisms. The extracellular lipases are active in the hydrolysis of crude pa...

  16. Alkaliphilic Micro-organisms and Habitats

    OpenAIRE

    Ulukanli, Zeynep

    2002-01-01

    Alkaline environments are typical extreme environments which include naturally occurring soda lakes, deserts, soils and artificially occurring industrial-derived waters. Micro-organisms that occupy extreme pH environments have resulted in the definition of an unusual group, termed alkaliphiles. In this review, the current status of the biodiversity of alkaliphilic micro-organisms in various environments and aspects of their biotechnological potential are summarised briefly.

  17. Reactions of fish to microorganisms in wastewater.

    OpenAIRE

    1985-01-01

    Fish were inoculated with various microorganisms present in wastewater. A threshold concentration was determined over which these microorganisms were recovered from the muscles. The threshold concentrations were different for bacteria, bacteriophages, and polio 1 LSc virus. The threshold values were lower when fish were inoculated than when they were immersed in water containing these organisms. Depuration experiments were efficient when the fish did not contain high concentrations of bacteri...

  18. Autonomous support for microorganism research in space

    Science.gov (United States)

    Fleet, Mary L.; Miller, Mark S.; Shipley, Derek, E.; Smith, Jeff D.

    1992-01-01

    A preliminary design for performing on orbit, autonomous research on microorganisms and cultured cells/tissues is presented. An understanding of gravity and its effects on cells is crucial for space exploration as well as for terrestrial applications. The payload is designed to be compatible with the Commercial Experiment Transporter (COMET) launch vehicle, an orbiter middeck locker interface, and with Space Station Freedom. Uplink/downlink capabilities and sample return through controlled reentry are available for all carriers. Autonomous testing activities are preprogrammed with in-flight reprogrammability. Sensors for monitoring temperature, pH, light, gravity levels, vibrations, and radiation are provided for environmental regulation and experimental data collection. Additional experimental data acquisition includes optical density measurement, microscopy, video, and film photography. On-board full data storage capabilities are provided. A fluid transfer mechanism is utilized for inoculation, sampling, and nutrient replenishment of experiment cultures. In addition to payload design, representative experiments were developed to ensure scientific objectives remained compatible with hardware capabilities. The project is defined to provide biological data pertinent to extended duration crewed space flight including crew health issues and development of a Controlled Ecological Life Support System (CELSS). In addition, opportunities are opened for investigations leading to commercial applications of space, such as pharmaceutical development, modeling of terrestrial diseases, and material processing.

  19. Preparation of Seeding Type Immobilized Microorganisms and Their Degradation Characteristics on Di-n-Butyl Phthalate

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    To study the preparation of seeding type immobilized microorganisms and their degradation characteristics on di-n-butyl phthalate (DBP). Methods Diatomite, clinoptilolite, silk zeolite, and coal fly ash were chosen as reserved materials and modified. Their adsorption capacity and intensity in the bacteria were determined and the best carrier was picked out. The seeding type immobilized microorganisms were prepared by the best carrier and then it degraded DBP under different primary concentration, vibration rate, pH, temperature in the presence of metal compounds. Results The adsorption capacity of the modified coal fly ash, silk zeolite, clinoptilolite and zeolite was 44.2%, 71.6%, 84.0%, and 94.4%, respectively, which was 1.66, 1.49, 1.37, and 1.16 times as high as that of their natural state. Their adsorption intensity was 72.1%, 90.5%, 90.1%,and 91.1% in turn. The modified diatomite was selected to prepare the seeding type immobilized microorganisms. When the primary DBP concentration was 100 to 500 mg/L, the DBP-degraded rate of the immobilized microorganisms could be above 80%. The degradation activity of both the dissociative and immobilized microorganisms was higher in vibration than in stillness.When pH was 6.0 to 9.0, the DBP-degraded rate of the immobilized microorganisms was above 82%, which was higher than the dissociative microorganisms. When the temperature was between 20℃ and 40℃, the DBP-degraded rate could reach 84.5% in 24 h. The metal compounds could inhibit the degradation activity of both the dissociative and immobilized microorganisms. The degradation process of the immobilized microorganisms could be described by the first-order model.Conclusion The adsorption capacity of the diatomite, clinoptilolite, silk zeolite and coal fly ash on DBP-degrading bacteria can be improved obviously after they are modified. The modified diatomite is best in terms of its adsorption capacity and intensity. Its seeding type immobilized microorganisms could

  20. Detection of extracellular proteases from microorganisms on agar plates

    Directory of Open Access Journals (Sweden)

    Alane Beatriz Vermelho

    1996-12-01

    Full Text Available We present herein an improved assay for detecting the presence of extracellular proteases from microorganisms on agar plates. Using different substrates (gelatin, BSA, hemoglobin incorporated into the agar and varying the culture medium composition, we were able to detect proteolytic activities from Pseudomonas aeruginosa, Micrococcus luteus and Serratia marcescens as well as the influence that these components displayed in the expression of these enzymes. For all microorganisms tested we found that in agar-BHI or yeast extract medium containing gelatin the sensitivity of proteinase detection was considerably greater than in BSA-agar or hemoglobin-agar. However, when BSA or hemoglobin were added to the culture medium, there was an increase in growth along with a marked reduction in the amount of proteinase production. In the case of M. luteus the incorporation of glycerol in BHI or yeast extract gelatin-agar induced protease liberation. Our results indicate that the technique described here is of value for detecting extracellular proteases directly in the culture medium, by means of a qualitative assay, simple, inexpensive, straight forward method to assess the presence of the proteolytic activity of a given microorganism colony with great freedom in substrate selection.

  1. Selection of potential microorganism for sago starch fermentation

    Directory of Open Access Journals (Sweden)

    RUTH MELLIAWATI

    2006-02-01

    Full Text Available Fermentation process of sago starch for the production of bioproduct requires potential microorganism that have ability to hydrolyze sago starch. The purpose of this research was to get the potential of amylolytic microorganisms for their capability of amyloglucosidase activity and to know the sugar strains of the fermentation result. Eleven amylolytic microorganisms (9 strains of mold and 2 strains of yeast were obtained from the collection Research Centre for Biotechnology – Indonesian Institute of Sciences (LIPI, Cibinong-Bogor were used. The selection step was carried out based on their capability of starch hydrolysis to reducing sugar. The best result indicates that the production of reducing sugar reached the highest 18.485 ppm and amyloglucosidase activities was 3.583 units by KTU-1 strain. The highest total acid obtained was 5.85 mg/mL by Rhizopus IFO.R5442. The cell biomass was obtained between 0.5 to 1.74 g dry weight/100 mL and pH of the final fermentation (72 h were 3.57 to 8.38.

  2. Microorganisms: Good or Evil, MIRRI Provides Biosecurity Awareness.

    Science.gov (United States)

    Smith, David; Martin, Dunja; Novossiolova, Tatyana

    2017-03-01

    The life-science community is a key stakeholder in the effort to ensure that the advances in biotechnology are not misused. Unfortunately, to date, the engagement of life scientists with issues of biosecurity has been limited. Microorganisms have been harnessed for the benefit of humankind but in the wrong hands could be used in direct or indirect acts against humans, livestock, crops, food, water infrastructure and other economically valuable entities. The Microbial Resources Research Infrastructure in its preparatory phase has addressed the topic implementing a code of conduct as part of its programme of prevention of malicious use and continues to work with the international community to raise awareness of best practice to avoid misuse of microorganisms. Biosecurity has become a major concern for several countries creating numerous activities to put in place counter measures, risk assessment, legislation and emergency response. The goal is to implement measures to protect us against malicious use of microorganisms, their products, information and technology transfer. Through this paper, we wish to discuss some of the activities that are underway, mention key educational tools and provide scientists with information on addressing biosecurity issues.

  3. Bioprospection of marine microorganisms: biotechnological applications and methods.

    Science.gov (United States)

    Dionisi, Hebe M; Lozada, Mariana; Olivera, Nelda L

    2012-01-01

    Environmental microorganisms constitute an almost inexhaustible reserve of genetic and functional diversity, accumulated during millions of years of adaptive evolution to various selective pressures. In particular, the extent of microbial biodiversity in marine habitats seems to grow larger as new techniques emerge to measure it. This has resulted in novel and more complex approaches for the screening of molecules and activities of biotechnological interest in these environments. In this review, we explore the different partially overlapping biotechnological fields that make use of microorganisms and we describe the different marine habitats that are particularly attractive for bioprospection. In addition, we review the methodological approaches currently used for microbial bioprospection, from the traditional cultivation techniques to state of the art metagenomic approaches, with emphasis in the marine environment.

  4. Ecological aspects of microorganisms inhabiting uranium mill tailings.

    Science.gov (United States)

    Miller, C L; Landa, E R; Updegraff, D M

    1987-09-01

    Numbers and types of microorganisms in uranium mill tailings were determined using culturing techniques.Arthrobacter were found to be the predominant microorganism inhabiting the sandy tailings, whereasBacillus and fungi predominated in the slime tailings. Sulfate-reducing bacteria, capable of leaching radium, were isolated in low numbers from tailings samples but were isolated in significantly high numbers from topsoil in contact with the tailings. The results are placed in the context of the magnitude of uranium mill tailings in the United States, the hazards posed by the tailings, and how such hazards could be enhanced or diminished by microbial activities. Patterns in the composition of the microbial population are evaluated with respect to the ecological variables that influence microbial growth.

  5. Synthesis of biosurfactants and their advantages to microorganisms and mankind.

    Science.gov (United States)

    Cameotra, Swaranjit Singh; Makkar, Randhir S; Kaur, Jasminder; Mehta, S K

    2010-01-01

    Biosurfactants are surface-active compounds synthesized by a wide variety of microorganisms. They are molecules that have both hydrophobic and hydrophilic domains and are capable of lowering the surface tension and the interfacial tension of the growth medium. Biosurfactants possess different chemical structures--lipopeptides, glycolipids, neutral lipids and fatty acids. They are nontoxic biomolecules that are biodegradable. Biosurfactants also exhibit strong emulsification of hydrophobic compounds and form stable emulsions. The low water solubility of these hydrophobic compounds limits their availability to microorganisms, which is a potential problem for bioremediation of contaminated sites. Microbially produced surfactants enhance the bioavailability of these hydrophobic compounds for bioremediation. Therefore, biosurfactant-enhanced solubility of pollutants has potential applications in bioremediation. Not only are the biosurfactants useful in a variety of industrial processes, they are also of vital importance to the microbes in adhesion, emulsification, bioavailability, desorption and defense strategy. These interesting facts are discussed in this chapter.

  6. Biotechnologies for Marine Oil Spill Cleanup: Indissoluble Ties with Microorganisms.

    Science.gov (United States)

    Mapelli, Francesca; Scoma, Alberto; Michoud, Grégoire; Aulenta, Federico; Boon, Nico; Borin, Sara; Kalogerakis, Nicolas; Daffonchio, Daniele

    2017-09-01

    The ubiquitous exploitation of petroleum hydrocarbons (HCs) has been accompanied by accidental spills and chronic pollution in marine ecosystems, including the deep ocean. Physicochemical technologies are available for oil spill cleanup, but HCs must ultimately be mineralized by microorganisms. How environmental factors drive the assembly and activity of HC-degrading microbial communities remains unknown, limiting our capacity to integrate microorganism-based cleanup strategies with current physicochemical remediation technologies. In this review, we summarize recent findings about microbial physiology, metabolism and ecology and describe how microbes can be exploited to create improved biotechnological solutions to clean up marine surface and deep waters, sediments and beaches. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Functional microorganisms for functional food quality.

    Science.gov (United States)

    Gobbetti, M; Cagno, R Di; De Angelis, M

    2010-09-01

    Functional microorganisms and health benefits represent a binomial with great potential for fermented functional foods. The health benefits of fermented functional foods are expressed either directly through the interactions of ingested live microorganisms with the host (probiotic effect) or indirectly as the result of the ingestion of microbial metabolites synthesized during fermentation (biogenic effect). Since the importance of high viability for probiotic effect, two major options are currently pursued for improving it--to enhance bacterial stress response and to use alternative products for incorporating probiotics (e.g., ice cream, cheeses, cereals, fruit juices, vegetables, and soy beans). Further, it seems that quorum sensing signal molecules released by probiotics may interact with human epithelial cells from intestine thus modulating several physiological functions. Under optimal processing conditions, functional microorganisms contribute to food functionality through their enzyme portfolio and the release of metabolites. Overproduction of free amino acids and vitamins are two classical examples. Besides, bioactive compounds (e.g., peptides, γ-amino butyric acid, and conjugated linoleic acid) may be released during food processing above the physiological threshold and they may exert various in vivo health benefits. Functional microorganisms are even more used in novel strategies for decreasing phenomenon of food intolerance (e.g., gluten intolerance) and allergy. By a critical approach, this review will aim at showing the potential of functional microorganisms for the quality of functional foods.

  8. Production of fats and oils by microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Osamu

    1987-10-20

    This paper describes the production of fats and oils by microorganisms. Various fat-productive bacteria have been found to produce the fats and oils by microorganisms which are roughly classified into enzyme and filiform fungus. The cells do not proliferate under the conditions adequate for producing the cells with the high content of lipid. A cell with high content of fat belonging to Mortierella filamentas fungi has been recently obtained at high density in the high concentration culture medium. The productivity of the fat similar to cocoa butter seems to be also high. A lot of microorganisms producing various functional fatty acids have been found. The microorganismic production methods of esters of longer-chain dicarboxylic acids and alcohols than C/sub 11/ hardly produced in nature form n-alkane also have been recently developed. Squalene has been able to produce by a cell from the other raw materials than the shark oil. Various sterols exist in microorganisms. The high-productivity manufacturing method of the fats containing gamma-linoleic acid by Mortierella filiform fungi has been developed and commercialized as the first production process of the fat by the microorganism. (5 figs, 7 tabs, 128 refs

  9. Host gut microorganisms' cues mediate orientation behaviour in the larva of the parasitoid Mallophora ruficauda.

    Science.gov (United States)

    Groba, H F; Castelo, M K

    2016-02-01

    The robber fly Mallophora ruficauda is one of the most important apicultural pests in the Pampas region of Argentina. This species is a parasitoid of scarab beetle larvae. Females lay eggs away from the host, and the larvae perform active search behaviour toward Cyclocephala signaticollis third instar larvae, parasitoid's preferred host. This behaviour is mediated by host-related chemical cues produced in hosts' fermentation chamber. Also, C. signaticollis larvae are attracted to fermentation chamber extracts. As scarab larvae have microbe-rich fermentation chamber, it has been suggested that microorganisms could be involved in the production of these semiochemicals. The aims of this work were first to ascertain the presence of microorganisms in the fermentation chamber of C. signaticollis larvae and second to determine the role of microorganisms in the orientation response of parasitoid and host larvae. We found that microorganisms-free C. signaticollis larvae showed deterioration in their development and did not produce the attractive semiochemicals. Therefore, we isolated fermentation chamber microorganisms of host larvae by means of different cultures media, and then, assayed different microorganisms' stimuli by binary choice tests. We were able to isolate microorganisms and determine that M. ruficauda larvae are attracted to semiochemicals from protein degradation in the fermentation chamber. However, C. signaticollis larvae were not attracted to any semiochemicals associated with microorganisms' activity in the fermentation chamber. Although we were unable to elucidate the exact role of gut microorganisms in host behaviour, we discuss their relevance in parasitoid host-seeking behaviour and host conspecific interaction in M. ruficauda-C. signaticollis system.

  10. PRESENCE OF MICROORGANISMS AT VARIOUS STAGES OF POULTRY WASTES MANAGEMENT. PART I. KERATINOLYTIC MICROORGANISMS

    Directory of Open Access Journals (Sweden)

    Ilona Wrońska

    2016-11-01

    Based on the study, the presence of keratinolytic microorganisms was found in all materials. The slime was the most numerously inhabited waste, while proper compost the least. Predominant group of microorganisms, regardless of the tested material type, was composed of bacteria.

  11. Anti-Candida and anti-Cryptococcus antifungal produced by marine microorganisms.

    Science.gov (United States)

    El Amraoui, B; El Amraoui, M; Cohen, N; Fassouane, A

    2014-12-01

    In order to search for antifungal from biological origin, we performed a screening of marine microorganisms isolated from seawater, seaweed, sediment and marine invertebrates collected from different coastal areas of the Moroccan Atlantic Ocean. The antifungal activities of these isolates were investigated against the pathogenic yeasts involved in medical mycology. Whole cultures of 34 marine microorganisms were screened for antifungal activities using the method of agar diffusion against four yeasts. The results showed that among the 34 isolates studied, 13 (38%) strains have antifungal activity against at least one out of four yeast species, 11 isolates have anti-Candida albicans CIP 48.72 activity, 12 isolates have anti-C. albicans CIP 884.65 activity, 13 isolates have anti-Cryptococcus neoformans activity and only 6 isolates are actives against Candida tropicalis R2 resistant to nystatin and amphotericin B. Nine isolates showed strong fungicidal activity. Fourteen microorganisms were identified and assigned to the genera Acinetobacter, Aeromonas, Alcaligenes, Bacillus, Chromobacterium, Enterococcus, Pantoea, and Pseudomonas. Due to a competitive role for space and nutrient, the marine microorganisms could produce more antimicrobials; therefore these marine microorganisms were expected to be potential resources of natural products such as those we research: anti-Candida and anti-Cryptococcus fungicides.

  12. Uric acid in plants and microorganisms: Biological applications and genetics - A review.

    Science.gov (United States)

    Hafez, Rehab M; Abdel-Rahman, Tahany M; Naguib, Rasha M

    2017-09-01

    Uric acid increased accumulation and/or reduced excretion in human bodies is closely related to pathogenesis of gout and hyperuricemia. It is highly affected by the high intake of food rich in purine. Uric acid is present in both higher plants and microorganisms with species dependent concentration. Urate-degrading enzymes are found both in plants and microorganisms but the mechanisms by which plant degrade uric acid was found to be different among them. Higher plants produce various metabolites which could inhibit xanthine oxidase and xanthine oxidoreductase, so prohibit the oxidation of hypoxanthine to xanthine then to uric acid in the purine metabolism. However, microorganisms produce group of degrading enzymes uricase, allantoinase, allantoicase and urease, which catalyze the degradation of uric acid to the ammonia. In humans, researchers found that several mutations caused a pseudogenization (silencing) of the uricase gene in ancestral apes which exist as an insoluble crystalloid in peroxisomes. This is in contrast to microorganisms in which uricases are soluble and exist either in cytoplasm or peroxisomes. Moreover, many recombinant uricases with higher activity than the wild type uricases could be induced successfully in many microorganisms. The present review deals with the occurrence of uric acid in plants and other organisms specially microorganisms in addition to the mechanisms by which plant extracts, metabolites and enzymes could reduce uric acid in blood. The genetic and genes encoding for uric acid in plants and microorganisms are also presented.

  13. Recovery of germanium from lignite by microorganism

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The recovery of Ge from lignite by microorganism includes two stages: (1) the breaking-down of Ge complex of humus in lignite into simple compounds assisted by microorganism; (2) the desorption of Ge compounds from the lignite. The recovery rate of Ge has been enhanced by 14% since the discovery of adsorption and desorption of Ge from coal. The effects of pH, leaching agents, and coal size on the recovery of Ge were experimentally investigated, and the optimized process parameters were obtained. The reaction heat of Ge adsorption and desorption in lignite was determined. It is about 23-53 kJ/mol, which reveals that the adsorption belongs to physical process. The recovery rate of Ge from lignite with direct microorganism leaching can reach about 85%, which is higher than that of 60% reported elsewhere. A potential process for leaching Ge in lignite was suggested.

  14. Selective enumeration of probiotic microorganisms in cheese.

    Science.gov (United States)

    Karimi, Reza; Mortazavian, Amir M; Amiri-Rigi, Atefeh

    2012-02-01

    Cheese is a dairy product which has a good potential for delivery of probiotic microorganisms into the human intestine. To be considered to offer probiotic health benefits, probiotics must remain viable in food products above a threshold level (e.g., 10(6) cfu g(-1)) until the time of consumption. In order to ensure that a minimal number of probiotic bacteria is present in the cheese, reliable methods for enumeration are required. The choice of culture medium for selective enumeration of probiotic strains in combination with starters depends on the product matrix, the target group and the taxonomic diversity of the bacterial background flora in the product. Enumeration protocol should be designed as a function of the target microorganism(s) to be quantified in the cheese. An overview of some series of culture media for selective enumeration of commercial probiotic cultures is presented in this review.

  15. Microorganism Utilization for Synthetic Milk Production

    Science.gov (United States)

    Birmele, Michele; Morford, Megan; Khodadad, Christina; Spencer, Lashelle; Richards, Jeffrey; Strayer, Richard; Caro, Janicce; Hummerick, Mary; Wheeler, Ray

    2014-01-01

    A desired architecture for long duration spaceflight, such as aboard the International Space Station (ISS) or for future missions to Mars, is to provide a supply of fresh food crops for the astronauts. However, some crops can create a high proportion of inedible plant waste. The main goal of this project was to produce the components of milk (sugar, lipid, protein) from inedible plant waste by utilizing microorganisms (fungi, yeast, bacteria). Of particular interest was utilizing the valuable polysaccharide, cellulose, found in plant waste, to naturally fuel- through microorganism cellular metabolism- the creation of sugar (glucose), lipid (milk fat), and protein (casein) to produce a synthetic edible food product. Environmental conditions such as pH, temperature, carbon source, aeration, and choice microorganisms.

  16. Effective role of indigenous microorganisms for sustainable environment.

    Science.gov (United States)

    Kumar, Baduru Lakshman; Gopal, D V R Sai

    2015-12-01

    Environmental protection has the foremost importance in the present day life of mankind. Scientists have been researching for technologies naturally available for enhancement of agriculture, management of agricultural waste, etc. Indigenous Microorganisms (IMO's)-based technology is one such great technology which is applied in the eastern part of world for the extraction of minerals, enhancement of agriculture and waste management. Indigenous microorganisms are a group of innate microbial consortium that inhabits the soil and the surfaces of all living things inside and outside which have the potentiality in biodegradation, bioleaching, biocomposting, nitrogen fixation, improving soil fertility and as well in the production of plant growth hormones. Without these microbes, the life will be wretched and melancholic on this lively planet for the survival of human race. That is why, environmental restoration and safeguarding target via the indigenous microbes in a native manner to turn out the good-for-nothing and useless waste into productive bioresources is the primary concern of this review. Based on the collection sites, the process of collection and isolation methods are different as they may vary from place to place. Ultimately, in this way to a meaningful and significant extent, we can bridge the gap between the horrifying environmental distress and the hostile activities that have been constantly provoked by human kind-by getting these indigenous microorganisms into action.

  17. Functional Properties of Microorganisms in Fermented Foods

    Directory of Open Access Journals (Sweden)

    Jyoti Prakash Tamang

    2016-04-01

    Full Text Available Fermented foods have unique functional properties imparting some health benefits to consumers due to presence of functional microorganisms, which possess probiotics properties, antimicrobial, antioxidant, peptide production, etc. Health benefits of some global fermented foods are synthesis of nutrients, prevention of cardiovascular disease, prevention of cancer, gastrointestinal disorders, allergic reactions, diabetes, among others. The present paper is aimed to review the information on some functional properties of the microorganisms associated with fermented foods and beverages, and their health-promoting benefits to consumers.

  18. Risk Assessment of Genetically Modified Microorganisms

    DEFF Research Database (Denmark)

    Jacobsen, B. L.; Wilcks, Andrea

    2001-01-01

    the industry, national administration and research institutions were gathered to discuss which elements should be considered in a risk assessment of genetically modified microorganisms used as food or food ingredients. The existing EU and national regulations were presented, together with the experiences......The rapid development of recombinant DNA techniques for food organisms urges for an ongoing discussion on the risk assessment of both new as traditional use of microorganisms in food production. This report, supported by the Nordic Council of Ministers, is the result of a workshop where people from...

  19. [Metagenomics in studying gastrointestinal tract microorganism].

    Science.gov (United States)

    Xu, Bo; Yang, Yunjuan; Li, Junjun; Tang, Xianghua; Mu, Yuelin; Huang, Zunxi

    2013-12-01

    Animal gastrointestinal tract contains a complex community of microbes, whose composition ultimately reflects the co-evolution of microorganisms with their animal host. The gut microbial community of humans and animals has received significant attention from researchers because of its association with health and disease. The application of metagenomics technology enables researchers to study not only the microbial composition but also the function of microbes in the gastrointestinal tract. In this paper, combined with our own findings, we summarized advances in studying gastrointestinal tract microorganism with metagenomics and the bioinformatics technology.

  20. Antibiosis of vineyard ecosystem fungi against food-borne microorganisms.

    Science.gov (United States)

    Cueva, Carolina; Moreno-Arribas, M Victoria; Bartolomé, Begoña; Salazar, Óscar; Vicente, M Francisca; Bills, Gerald F

    2011-12-01

    Fermentation extracts from fungi isolated from vineyard ecosystems were tested for antimicrobial activities against a set of test microorganisms, including five food-borne pathogens (Staphylococcus aureus EP167, Acinetobacter baumannii (clinically isolated), Pseudomonas aeruginosa PAO1, Escherichia coli O157:H7 (CECT 5947) and Candida albicans MY1055) and two probiotic bacteria (Lactobacillus plantarum LCH17 and Lactobacillus brevis LCH23). A total of 182 fungi was grown in eight different media, and the fermentation extracts were screened for antimicrobial activity. A total of 71 fungi produced extracts active against at least one pathogenic microorganism, but not against any probiotic bacteria. The Gram-positive bacterium S. aureus EP167 was more susceptible to antimicrobial fungi broth extracts than Gram-negative bacteria and pathogenic fungi. Identification of active fungi based on internal transcribed spacer rRNA sequence analysis revealed that species in the orders Pleosporales, Hypocreales and Xylariales dominated. Differences in antimicrobial selectivity were observed among isolates from the same species. Some compounds present in the active extracts were tentatively identified by liquid chromatography-mass spectrometry. Antimicrobial metabolites produced by vineyard ecosystem fungi may potentially limit colonization and spoilage of food products by food-borne pathogens, with minimal effect on probiotic bacteria.

  1. Modelling the morphology of filamentous microorganisms

    DEFF Research Database (Denmark)

    Nielsen, Jens Bredal

    1996-01-01

    The rapid development in image analysis techniques has made it possible to study the growth kinetics of filamentous microorganisms in more detail than previously, However, owing to the many different processes that influence the morphology it is important to apply mathematical models to extract...

  2. Food fermentations: Microorganisms with technological beneficial use

    DEFF Research Database (Denmark)

    Bourdichon, François; Casaregola, Serge; Farrokh, Choreh

    2012-01-01

    Microbial food cultures have directly or indirectly come under various regulatory frameworks in the course of the last decades. Several of those regulatory frameworks put emphasis on “the history of use”, “traditional food”, or “general recognition of safety”. Authoritative lists of microorganisms...

  3. Engineered microorganisms having resistance to ionic liquids

    Science.gov (United States)

    Ruegg, Thomas Lawrence; Thelen, Michael P.

    2016-03-22

    The present invention provides for a method of genetically modifying microorganisms to enhance resistance to ionic liquids, host cells genetically modified in accordance with the methods, and methods of using the host cells in a reaction comprising biomass that has been pretreated with ionic liquids.

  4. Ecophysiology of microorganisms in microbial elctrolysis cells

    NARCIS (Netherlands)

    Croese, E.

    2012-01-01

    One of the main challenges for improvement of the microbial electrolysis cell (MEC) has been the reduction of the cost of the cathode catalyst. As catalyst at the cathode, microorganisms offer great possibilities. Previous research has shown the principle possibilities for the biocathode for H2

  5. Microorganisms as Indicators of Soil Health

    DEFF Research Database (Denmark)

    Nielsen, M. N.; Winding, A.; Binnerup, S.;

    Microorganisms are an essential part of living soil and of outmost importance for soil health. As such they can be used as indicators of soil health. This report reviews the current and potential future use of microbial indicators of soil health and recommends specific microbial indicators for soil...... indicators into soil monitoring programmes as they become applicable....

  6. 40 CFR 725.85 - Microorganism identity.

    Science.gov (United States)

    2010-07-01

    ... information confidential in a TERA submission and wishes the same information to remain confidential in a subsequent TERA or MCAN submission, the person must reassert and resubstantiate the claim in the subsequent... under paragraph (a) of this section in any TERA submitted for the microorganism, but subsequently...

  7. Ecophysiology of microorganisms in microbial elctrolysis cells

    NARCIS (Netherlands)

    Croese, E.

    2012-01-01

    One of the main challenges for improvement of the microbial electrolysis cell (MEC) has been the reduction of the cost of the cathode catalyst. As catalyst at the cathode, microorganisms offer great possibilities. Previous research has shown the principle possibilities for the biocathode for H2 prod

  8. Attaching substances to micro-organisms

    NARCIS (Netherlands)

    Buist, Girbe; Leenhouts, Cornelis Johannes; Venema, Gerard; Kok, Jan

    1999-01-01

    The invention relates to surface display of proteins on micro-organisms via the targeting and anchoring of heterologous proteins to the outer surface of cells such as yeast, fungi, mammalian and plant cells, and bacteria. The invention provides a proteinaceous substance comprising a reactive group a

  9. Airborne microorganisms and dust from livestock houses

    NARCIS (Netherlands)

    Zhao, Y.; Aarnink, A.J.A.; Jong, de M.C.M.; Groot Koerkamp, P.W.G.

    2011-01-01

    The objective of this study was to evaluate the efficiencies and suitability of samplers for airborne microorganisms and dust, which could be used in practical livestock houses. Two studies were performed: 1) Testing impaction and cyclone pre-separators for dust sampling in livestock houses; 2) Dete

  10. Biodiversity of deep-sea microorganisms

    Directory of Open Access Journals (Sweden)

    Fengping Wang

    2013-07-01

    Full Text Available The oceans, with an average depth of 3,800 meters and an average pressure about 38 MPa, cover about 70% of the surface of the Earth. Geological structures under the seawater, such as marine sediments, oceanic crust, hydrothermal vents, and the cold seeps, vary significantly with regard to physical and chemical properties. In combination, these diverse environments contain the largest microbial ecosystem in the world. In deep seawater, the major microorganism groups are Alpha-& Gammaproteobacteria, and Marine Group I. In deep-sea sediments, the abundance of microbes is related to the content of organic matter and distance from land. Methane Oxidizing Archaea (ANME and sulfate reducing bacteria (Deltaproteobacteria are common in deep-sea cold seep environments; while in hydrothermal vents, the richness and dynamics of chemical substances have led to highly diversified archaeal and bacterial groups. In contrast, the oceanic crust is mainly composed of basic and ultrabasic rocks rich in minerals, and as a result houses microorganisms that are mainly autotrophic, utilizing iron, manganese and sulfur. Because more than 99% of deep-sea microorganisms cannot be cultured, an understanding of their diversity, physiological features, and biogeochemical roles remains to be fully achieved. In this article, we review and summarize what is known about the distribution and diversity of deep-sea microorganisms in diverse habitats. It is emphasized that there is much to learn about these microbes.

  11. Artifical Microorganism Infection in Aviation Kerosene

    Directory of Open Access Journals (Sweden)

    Dušan Vallo

    2004-12-01

    Full Text Available The fuel used in the aviation engineering has to be clean and dry, it may not contain mechanical impurities and water. Water inaviation kerosene may occur in soluble and insoluble form. The danger inheres in the insoluble form, which may drop out in the crystallineform and cause various failures, such as those caused by mechanical impurities. The water assists in the biological matter formation createdby various species of microorganisms (bacteria, mould fungi and yeast. The microorganisms, present in water phase occurring on thebottom of tanks or on the interface water phase – kerosene, grow and reproduce and subsequently may pollute (impair the fuel by thebiomass or by the products of their metabolism. There is a possibility to infect the fuel artificially by a selected reference microorganismstrain, which usually occur in contaminated fuel, or by microorganisms which cause a biological contamination of aviation kerosene.Out of the selected reference strains used in the experiments, the reference strains of Proteus vulgaris, Sacharamyces cerevisiae andClostridium perfringens were not cultivated in the sterile aviation kerosene and the propagating nutrient medium. The aviation kerosene actsas a biocide medium for the presented reference microorganism strains.

  12. Photosynthetic microorganisms in cold environments

    Science.gov (United States)

    Kviderova, Jana; Hajek, Josef; Elster, Josef; Bartak, Milos; Vaczi, Peter; Nedbalova, Linda

    and their physiological processes are inactive. If hydrated, they are physiologically active even at subzero temperatures (Kappen et al., 1996). Although living in cold environments, the growth optimum temperature of typical phycobiont Trebouxia (Chlorophyta) sp. is above 15 ° C, so these algae are considered to be rather psychrotolerant. Acknowledgement The work was supported from projects GA AS CR Nos. KJB 601630808 and KJ KJB600050708, CAREX and long-term institutional research plan of the Institute of Botany AS CR AV0Z600050516 and the Masaryk University. Prof. Martin Backor (Safarik University in Kosice) is kindly ac-knowledged for providing the strains Trebouxia erici and T. glomerata (Backor). References Elster, J. , Benson, E.E. Life in the polar terrestrial environment with a focus on algae and cyanobacteria, in Fuller, B.J., Lane, N. , Benson, E.E. (Eds), Life in the Frozen State. CRC Press, pp. 111-150, 2004. Kappen, L., Schroeter, B., Scheidegger, C., Sommerkorn, M. , Hestmark, G. Cold resistance and metabolic activity of lichens below 0 ° C. Adv. Space Res. 18, 119-128, 1996. Kviderova, J. Characterization of the community of snow algae and their photochemical performance in situ in the Giant Mountains, Czech Republic. Arct. Antarct. Alp. Res. accepted, 2010. Nedbalova, L., Kocianova, M. , Lukavsky, J. Ecology of snow algae in the Giant Mountains and their relation to cryoseston in Europe. Opera Corcontica 45, 59-68, 2008.

  13. Imprinting of Microorganisms for Biosensor Applications

    Science.gov (United States)

    Idil, Neslihan; Mattiasson, Bo

    2017-01-01

    There is a growing need for selective recognition of microorganisms in complex samples due to the rapidly emerging importance of detecting them in various matrices. Most of the conventional methods used to identify microorganisms are time-consuming, laborious and expensive. In recent years, many efforts have been put forth to develop alternative methods for the detection of microorganisms. These methods include use of various components such as silica nanoparticles, microfluidics, liquid crystals, carbon nanotubes which could be integrated with sensor technology in order to detect microorganisms. In many of these publications antibodies were used as recognition elements by means of specific interactions between the target cell and the binding site of the antibody for the purpose of cell recognition and detection. Even though natural antibodies have high selectivity and sensitivity, they have limited stability and tend to denature in conditions outside the physiological range. Among different approaches, biomimetic materials having superior properties have been used in creating artificial systems. Molecular imprinting is a well suited technique serving the purpose to develop highly selective sensing devices. Molecularly imprinted polymers defined as artificial recognition elements are of growing interest for applications in several sectors of life science involving the investigations on detecting molecules of specific interest. These polymers have attractive properties such as high bio-recognition capability, mechanical and chemical stability, easy preparation and low cost which make them superior over natural recognition reagents. This review summarizes the recent advances in the detection and quantification of microorganisms by emphasizing the molecular imprinting technology and its applications in the development of sensor strategies. PMID:28353629

  14. Atividade antimicrobiana de bactérias lácticas isoladas de queijo-de-minas artesanal do Serro (MG frente a microrganismos indicadores Antimicrobial activity of lactic acid bacteria from artisanal minas cheese against indicator microorganisms

    Directory of Open Access Journals (Sweden)

    D.P. Alexandre

    2002-08-01

    Full Text Available Isolaram-se 192 cepas de bactérias lácticas de cinco amostras de queijo-de-minas artesanal, oriundos da região do Serro, MG. Os resultados da prova de inibição direta indicaram que 48 cepas isoladas (25% foram capazes de inibir o crescimento in vitro de microrganismos indicadores, dentre os quais Staphylococcus aureus e Listeria monocytogenes. As 48 cepas foram submetidas à prova de inibição indireta. Verificou-se que 20,8% (10/48 das cepas demonstraram amplo espectro antimicrobiano frente a microrganismos como: Salmonella enteritidis var. typhimurium, Staphylococcus aureus, Listeria monocytogenes e Listeria innocua. Nenhuma das cepas isoladas foi capaz de inibir Escherichia coli.A total of 192 strains of lactic acid bacteria were isolated from five samples of artisanal minas cheese, from Serro region - Minas Gerais State. The results of direct inhibition test indicated that 48 strains (25% inhibited the in vitro growth of the indicator microorganisms: Staphylococcusaureus and Listeriamonocytogenes. Those 48 strains were tested by the indirect inhibition test, and 10 strains (20.8% showed a wide antimicrobial spectrum against Salmonellaenteritidisvar. typhimurium, Staphylococcusaureus, Listeria monocytogenes and Listeria innocua. None of the isolated strains was able to inhibit Escherichia coli.

  15. Analysis of bioremediation of pesticides by soil microorganisms

    Science.gov (United States)

    Ruml, Tomas; Klotz, Dietmar; Tykva, Richard

    1995-10-01

    The application of new pesticides requires careful monitoring of their distribution in the environment. The effect of the soil microflora on the stability of the [14C]- labelled juvenoid hormone analogue W-328 was estimated. The micro-organisms from two different soil samples were isolated and tested for their ability to decompose W-328. One bacterial strain, yeast and mold isolates, exhibited the degradation activity. The growth characteristics such as pH and temperature optima were determined. The degradation products were estimated using HPLC.

  16. Effects of Hangeshashinto on Growth of Oral Microorganisms

    Directory of Open Access Journals (Sweden)

    Haruka Fukamachi

    2015-01-01

    Full Text Available Oral mucositis (OM in cancer patients induced by chemotherapy or radiotherapy has a significant impact on quality of life, and causes considerable morbidity. Oral microorganisms are likely to intensify the inflammatory process and aggravate the formation of ulcers. Hangeshashinto (HST, a Japanese kampo medicine, has been reported to be effective when used as a gargle for the treatment of OM. To clarify the effects of HST on oral microorganisms, we assessed its antimicrobial activity against 27 microbial species, including 19 oral bacteria and one fungus. HST extract inhibited the growth of Gram-negative bacteria, including Fusobacterium nucleatum, Porphyromonas gingivalis, Porphyromonas endodontalis, Prevotella intermedia, Prevotella melaninogenica, Tannerella forsythia, Treponema denticola, and Porphyromonas asaccharolytica, though inhibitory effects were less pronounced for Gram-positive bacteria and the fungal strain. We then investigated the effects of antibacterial activities on 15 purified ingredients of HST and determined that baicalein, berberine, coptisine, [6]-shogaol, and homogentisic acid actively inhibited the growth of these bacteria. These findings showed that HST inhibits the growth of specific Gram-negative periodontopathogenic bacteria, which are significant pathogens in OM, without disturbing the normal oral flora. Our data suggest that HST may be a useful treatment for OM in patients undergoing anticancer treatment.

  17. In vitro minocycline activity on superinfecting microorganisms isolated from chronic periodontitis patients Atividade in vitro de minociclina sobre microrganismos superinfectantes isolados de pacientes com periodontite crônica

    Directory of Open Access Journals (Sweden)

    Luciana Fernandes de Oliveira

    2006-09-01

    Full Text Available Chronic periodontitis is the most common type of periodontitis and it is associated with various species of microorganisms. Enteric rods, Pseudomonas, Staphyloccocus and Candida have been retrieved from periodontal pockets of patients with chronic periodontitis and correlated to cases of superinfection. Local or systemic antibiotic therapy is indicated to reinforce the effects of the conventional mechanical therapy. Minocycline has been suggested as one of the most effective drugs against periodontal pathogens. The aim of this work was to evaluate the minimal inhibitory concentration (MIC of minocycline on superinfecting microorganisms isolated from the periodontal pocket and the oral cavity of individuals with chronic periodontitis. Isolates of Enterobacteriaceae (n = 25, Staphylococcus spp. (n = 25, Pseudomonas aeruginosa (n = 9 and Candida spp. (n = 25 were included in the study. Minimal inhibitory concentrations (MIC of minocycline were determined using the Müeller-Hinton agar dilution method. Staphylococcus spp. isolates were the most sensitive to minocycline with a MIC of 8 µg/mL, followed by Enterobacteriaceae with a MIC of 16 µg/mL. The concentration of 16 µg/mL inhibited 96% of Candida spp. isolates. The MIC for 88.8% of the isolates of Pseudomonas aeruginosa was 128 µg/mL. A concentration of 1,000 µg/mL was not enough to inhibit 100% of the tested isolates.Periodontite crônica é a forma mais comum de periodontite e está associada a diversas espécies de microrganismos. Enterobactérias, Pseudomonas, Staphyloccocus e Candida têm sido recuperados de bolsas periodontais de indivíduos com periodontite crônica e implicados em casos de superinfecção. A terapia antimicrobiana local ou sistêmica pode ser utilizada para reforçar os efeitos da terapia mecânica convencional, e a minociclina tem sido sugerida como antimicrobiano eficaz frente a periodontopatógenos. O objetivo deste trabalho foi avaliar a concentração inibit

  18. Effects of Humus Fertilizer from Fermented Branches on Microorganisms and Enzyme Activity in the Soil under Dracontomelon duperreranum Trees%树枝发酵肥对人面子林下土壤微生物和酶活性的影响

    Institute of Scientific and Technical Information of China (English)

    宫彦章; 王丽; 吴彩琼; 刘中奇; 钟彦山

    2012-01-01

    [Objective] This study aimed to explore the effect of humus fertilizer from fermented branches on pH, total porosity, contents of organic matter, alkaline hy- drolysable nitrogen, available phosphorus, rapidly available potassium, the number of microorganisms and the activity of enzymes in the soil under Dracontomelon duper- reranum trees. [Method] Experiments were carried out to study the physical and chemical properties of soil under Dracontomelon duperreranum trees, and soil with- out any fertilizer treatment was used as control. [Result] The results showed that application of humus fertilizer from fermented branches raised the total porosity of soil, and improved the contents of soil organic matter, available phosphorus, rapidly available potassium, the number of soil microorganisms and the activity of soil en- zymes. In addition, the number of soil microorganisms was positively related to the activity of soil enzymes. [Conclusion] Application of humus fertilizer from fermented branches markedly raised the ratio of the number of bacteria to the number of fungi, and promoted the transformation of fungi-rich soil into bacteria-rich soil, which thus significantly enhanced the soil fertility and improved the soil environment under Dracontomelon duperreranum trees.%[目的]研究树枝发酵腐殖质肥对人面子林下土壤pH、总孔隙度、有机质含量、碱解氮、有效磷、速效钾、土壤微生物数量以及土壤酶活性的影响。[方法]以不施任何肥料为对照,对人面子林下土壤进行理化性质分析。【结果】树枝发酵腐殖质肥能增加总孔隙度,能显著增加土壤有机质、碱解氮、有效磷、速效钾含量、土壤微生物数量和土壤酶活性,土壤微生物数量与土壤酶活性显著正相关。[结论】施用树枝发酵腐殖质肥能提高人面子林下细菌同真菌数量的比值,促使土壤由真菌型向细菌型方向转化,且提高了微生物数量和土壤酶活性,

  19. Effects of Humus Fertilizer from Fermented Branches on Microorganisms and Enzyme Activity in the Soil under Dracontomelon duperreranum Trees%树枝发酵腐殖质肥对人面子林下土壤微生物和酶活性的影响

    Institute of Scientific and Technical Information of China (English)

    宫彦章; 吴彩琼; 王丽; 刘中奇; 钟彦山

    2013-01-01

    [目的]研究树枝发酵腐殖质肥对人面子林下土壤pH、总孔隙度、有机质含量、碱解氮含量、有效磷含量、速效钾含量、土壤微生物数量以及土壤酶活性的影响.[方法]以不施任何肥料为对照,对人面子林下土壤理化性质进行分析.[结果]树枝发酵腐殖质肥能增加总孔隙度,显著增加土壤有机质、碱解氮、有效磷、速效钾含量、土壤微生物数量和土壤酶活性,土壤微生物数量与土壤酶活性呈显著正相关.[结论]施用树枝发酵腐殖质肥能提高人面子林下细菌数量与真菌数量的比值,促使土壤由真菌型向细菌型方向转化,且提高微生物数量和土壤酶活性,从而显著提高人面子林下土壤肥力,改善土壤环境.%[Objective]This study aimed to explore the effect of humus fertilizer from fermented branches on pH, total porosity, contents of organic matter, alkaline hydrolysable nitrogen, available phosphorus, rapidly available potassium, the number of microorganisms and the activity of enzymes in the soil under Dracontomelon duperreranum trees. [ Method] Experiments were carried out to study the physical and chemical properties of soil under Dracontomelon duperreranum trees, and soil without any fertilizer treatment was used as control. [ Result] The results showed that application of humus fertilizer from fermented branches raised the total porosity of soil, and improved the contents of soil organic matter, available phosphorus, rapidly available potassium, the number of soil microorganisms and the activity of soil enzymes. In addition, the number of soil microorganisms was positively related to the activity of soil enzymes. [ Conclusion] Application of humus fertilizer from fermented branches markedly raised the ratio of the number of bacteria to the number of fungi, and promoted the transformation of fungi-rich soil into bacteria-rich soil, which thus significantly enhanced the soil fertility and improved the

  20. UV inactivation of pathogenic and indicator microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Chang, J.C.; Ossoff, S.F.; Lobe, D.C.; Dorfman, M.H.; Dumais, C.M.; Qualls, R.G.; Johnson, J.D.

    1985-06-01

    Survival was measured as a function of the dose of germicidal UV light for the bacteria Escherichia coli, Salmonella typhi, Shigella sonnei, Streptococcus faecalis, Staphylococcus aureus, and Bacillus subtilis spores, the enteric viruses poliovirus type 1 and simian rotavirus SA11, the cysts of the protozoan Acanthamoeba castellanii, as well as for total coliforms and standard plate count microorganisms from secondary effluent. The doses of UV light necessary for a 99.9% inactivation of the cultured vegetative bacteria, total coliforms, and standard plate count microorganisms were comparable. However, the viruses, the bacterial spores, and the amoebic cysts required about 3 to 4 times, 9 times, and 15 times, respectively, the dose required for E. coli. These ratios covered a narrower relative dose range than that previously reported for chlorine disinfection of E. coli, viruses, spores, and cysts.

  1. Interactions of chromium with microorganisms and plants.

    Science.gov (United States)

    Cervantes, C; Campos-García, J; Devars, S; Gutiérrez-Corona, F; Loza-Tavera, H; Torres-Guzmán, J C; Moreno-Sánchez, R

    2001-05-01

    Chromium is a highly toxic non-essential metal for microorganisms and plants. Due to its widespread industrial use, chromium (Cr) has become a serious pollutant in diverse environmental settings. The hexavalent form of the metal, Cr(VI), is considered a more toxic species than the relatively innocuous and less mobile Cr(III) form. The presence of Cr in the environment has selected microbial and plant variants able to tolerate high levels of Cr compounds. The diverse Cr-resistance mechanisms displayed by microorganisms, and probably by plants, include biosorption, diminished accumulation, precipitation, reduction of Cr(VI) to Cr(III), and chromate efflux. Some of these systems have been proposed as potential biotechnological tools for the bioremediation of Cr pollution. In this review we summarize the interactions of bacteria, algae, fungi and plants with Cr and its compounds.

  2. Microorganisms detection on substrates using QCL spectroscopy

    Science.gov (United States)

    Padilla-Jiménez, Amira C.; Ortiz-Rivera, William; Castro-Suarez, John R.; Ríos-Velázquez, Carlos; Vázquez-Ayala, Iris; Hernández-Rivera, Samuel P.

    2013-05-01

    Recent investigations have focused on the improvement of rapid and accurate methods to develop spectroscopic markers of compounds constituting microorganisms that are considered biological threats. Quantum cascade lasers (QCL) systems have revolutionized many areas of research and development in defense and security applications, including his area of research. Infrared spectroscopy detection based on QCL was employed to acquire mid infrared (MIR) spectral signatures of Bacillus thuringiensis (Bt), Escherichia coli (Ec) and Staphylococcus epidermidis (Se), which were used as biological agent simulants of biothreats. The experiments were carried out in reflection mode on various substrates such as cardboard, glass, travel baggage, wood and stainless steel. Chemometrics statistical routines such as principal component analysis (PCA) regression and partial least squares-discriminant analysis (PLS-DA) were applied to the recorded MIR spectra. The results show that the infrared vibrational techniques investigated are useful for classification/detection of the target microorganisms on the types of substrates studied.

  3. Consolidated bioprocessing method using thermophilic microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Mielenz, Jonathan Richard

    2016-02-02

    The present invention is directed to a method of converting biomass to biofuel, and particularly to a consolidated bioprocessing method using a co-culture of thermophilic and extremely thermophilic microorganisms which collectively can ferment the hexose and pentose sugars produced by degradation of cellulose and hemicelluloses at high substrate conversion rates. A culture medium therefor is also provided as well as use of the methods to produce and recover cellulosic ethanol.

  4. Mass Spectrometer for Airborne Micro-Organisms

    Science.gov (United States)

    Sinha, M. P.; Friedlander, S. K.

    1986-01-01

    Bacteria and other micro-organisms identified continously with aid of new technique for producing samples for mass spectrometer. Technique generates aerosol of organisms and feeds to spectrometer. Given species of organism produces characteristic set of peaks in mass spectrum and thereby identified. Technique useful for monitoring bacterial makeup in environmental studies and in places where cleanliness is essential, such as hospital operating rooms, breweries, and pharmaceutical plants.

  5. Biology Students’ Initial Mental Model about Microorganism

    Science.gov (United States)

    Hamdiyati, Y.; Sudargo, F.; Redjeki, S.; Fitriani, A.

    2017-02-01

    The purpose of this study was to identify biology students’ initial mental model about microorganism. This research used descriptive method with 32 sixth semester biology students at Biology Education Departement-Universitas Pendidikan Indonesia as its respondents. Data was taken at the beginning of the 6th semester before respondents endure microbiology course. Instrument used to assess mental model was drawing-writing test in which it contains concepts such as structure of bacteria, archaea, virus, and fungi. Students were asked to describe their imagination about the structure of microorganisms and subsequently asked to explain the structure of microorganisms in writing through open-ended questions. Students’ response was then compared to scientists or experts’ mental models as the targeted mental model. Student mental models were categorized into five levels (levels 1-5), namely “there is no drawing/writing,” “wrong or irrelevant drawing/writing of question,” “partially correct drawing/writing,” “the drawing/writing that has some deficiencies,” and “completely correct and complete drawing/writing.” Results showed that the level of mental models through drawing or writing about the four concepts were varied. The highest level of mental models through drawing (D5) was found in the concept of bacteria, while the highest level of mental models through writing (W3) was found in the concept of bacteria, virus, and fungi. Mental model levels most commonly found in each concept through drawing-writing tests (D/W) were bacteria (D2/W2), Archaea (D1/W1 and D2/W2), virus (D3/W3), and fungi (D2/W1). From these results it is advisable to improve lectures and assessment strategy to enhance or complement students’ mental models about microorganisms.

  6. MODELING THE FATE OF MICROORGANISMS IN WATER, WASTEWATER, AND SOIL

    Science.gov (United States)

    The natural environment is filled with microorganisms, most of which are natural residents and colonize various ecological niches. These microorganisms either live independently within the environment, or live in association with various host organisms. There also are places and ...

  7. Histamine and tyramine degradation by food fermenting microorganisms.

    Science.gov (United States)

    Leuschner, R G; Heidel, M; Hammes, W P

    1998-01-06

    Microorganisms suitable for food fermentation were examined with regard to their potential to degrade histamine and tyramine. Out of 64 lactic acid bacteria evaluated in this study, 27 degraded histamine and one tyramine, respectively, with low activity. Among 32 strains of Brevibacterium linens and coryneform bacteria, 21 exhibited histamine and tyramine oxidase activity. None of 20 strains of Staphylococcus carnosus tested degraded histamine or tyramine. One strain out of nine strains of Geotrichum candidum degraded tyramine slightly. Among 44 strains of Micrococcus sp. examined, 17 degraded either one or two biogenic amines. In this study Micrococcus varians (M. varians) LTH 1540 exhibited the highest tyramine oxidase activity of all strains tested and was therefore investigated in detail. The enzyme was found to be located in the cytoplasm and was not membrane bound. The reaction end product p-hydroxyphenyl acetic acid was detected by HPLC analysis. An activity staining for the amine oxidase in a native polyacrylamide gel based on the formation of H2O2 during amine oxidation was developed. Resting cells of the strain exhibited optimal tyramine oxidase activity at a pH of 7 at 37-40 degrees C. The enzyme in the cell free extract had a pH optimum between 7-8. The enzyme activity was decreased by NaCl, glucose and hydralazine. Phenylethylamine and tryptamine were oxidized at lower concentrations than tyramine. The potential for amine degradation was not found to be associated with that of formation of biogenic amines, as 23 microorganisms with the ability to metabolise biogenic amines exhibited no decarboxylase activity toward histidine, tyrosine, phenylalanine, lysine or ornithine.

  8. Antimicrobial characteristics of chitosans against food spoilage microorganisms in liquid media and mayonnaise.

    Science.gov (United States)

    Oh, H I; Kim, Y J; Chang, E J; Kim, J Y

    2001-11-01

    Four different kinds of chitosans were prepared by treating crude chitin with various NaOH concentrations. The antimicrobial activities of the chitosans were tested against four species of food spoilage microorganisms (Lactobacillus plantarum, Lactobacillus fructivorans, Serratia liquefaciens, and Zygosaccharomyces bailii). The initial effect of the chitosans was biocidal, and counts of viable cells were significantly reduced. After an extended lag phase, some strains recovered and resumed growth. The activities of chitosan against these microorganisms increased with the concentration. Chitosan-50 was most effective against L. fructivorans, but inhibition of L. plantarum was greatest with chitosan-55. There was no significant difference among the chitosans in their antimicrobial activity against S. liquefaciens and Z. bailii. The addition of chitosan to mayonnaise significantly decreased the viable cell counts of L. fructivorans and Z. bailii during storage at 25 degrees C. These results suggest that chitosan can be used as a food preservative to inhibit the growth of spoilage microorganisms in mayonnaise.

  9. Stress-tolerant P-solubilizing microorganisms.

    Science.gov (United States)

    Vassilev, N; Eichler-Löbermann, B; Vassileva, M

    2012-08-01

    Drought, high/low temperature, and salinity are abiotic stress factors accepted as the main reason for crop yield losses in a world with growing population and food price increases. Additional problems create nutrient limitations and particularly low P soil status. The problem of phosphate fertilizers, P plant nutrition, and existing phosphate bearing resources can also be related to the scarcity of rock phosphate. The modern agricultural systems are highly dependent on the existing fertilizer industry based exclusively of this natural, finite, non-renewable resource. Biotechnology offers a number of sustainable solutions that can mitigate these problems by using plant beneficial, including P-solubilizing, microorganisms. This short review paper summarizes the current and future trends in isolation, development, and application of P-solubilizing microorganisms in stress environmental conditions bearing also in mind the imbalanced cycling and unsustainable management of P. Special attention is devoted to the efforts on development of biotechnological strategies for formulation of P-solubilizing microorganisms in order to increase their protection against adverse abiotic factors.

  10. Biomining: metal recovery from ores with microorganisms.

    Science.gov (United States)

    Schippers, Axel; Hedrich, Sabrina; Vasters, Jürgen; Drobe, Malte; Sand, Wolfgang; Willscher, Sabine

    2014-01-01

    Biomining is an increasingly applied biotechnological procedure for processing of ores in the mining industry (biohydrometallurgy). Nowadays the production of copper from low-grade ores is the most important industrial application and a significant part of world copper production already originates from heap or dump/stockpile bioleaching. Conceptual differences exist between the industrial processes of bioleaching and biooxidation. Bioleaching is a conversion of an insoluble valuable metal into a soluble form by means of microorganisms. In biooxidation, on the other hand, gold is predominantly unlocked from refractory ores in large-scale stirred-tank biooxidation arrangements for further processing steps. In addition to copper and gold production, biomining is also used to produce cobalt, nickel, zinc, and uranium. Up to now, biomining has merely been used as a procedure in the processing of sulfide ores and uranium ore, but laboratory and pilot procedures already exist for the processing of silicate and oxide ores (e.g., laterites), for leaching of processing residues or mine waste dumps (mine tailings), as well as for the extraction of metals from industrial residues and waste (recycling). This chapter estimates the world production of copper, gold, and other metals by means of biomining and chemical leaching (bio-/hydrometallurgy) compared with metal production by pyrometallurgical procedures, and describes new developments in biomining. In addition, an overview is given about metal sulfide oxidizing microorganisms, fundamentals of biomining including bioleaching mechanisms and interface processes, as well as anaerobic bioleaching and bioleaching with heterotrophic microorganisms.

  11. Protein languages differ depending on microorganism lifestyle.

    Directory of Open Access Journals (Sweden)

    Joseph J Grzymski

    Full Text Available Few quantitative measures of genome architecture or organization exist to support assumptions of differences between microorganisms that are broadly defined as being free-living or pathogenic. General principles about complete proteomes exist for codon usage, amino acid biases and essential or core genes. Genome-wide shifts in amino acid usage between free-living and pathogenic microorganisms result in fundamental differences in the complexity of their respective proteomes that are size and gene content independent. These differences are evident across broad phylogenetic groups-a result of environmental factors and population genetic forces rather than phylogenetic distance. A novel comparative analysis of amino acid usage-utilizing linguistic analyses of word frequency in language and text-identified a global pattern of higher peptide word repetition in 376 free-living versus 421 pathogen genomes across broad ranges of genome size, G+C content and phylogenetic ancestry. This imprint of repetitive word usage indicates free-living microorganisms have a bias for repetitive sequence usage compared to pathogens. These findings quantify fundamental differences in microbial genomes relative to life-history function.

  12. Food fermentations: microorganisms with technological beneficial use.

    Science.gov (United States)

    Bourdichon, François; Casaregola, Serge; Farrokh, Choreh; Frisvad, Jens C; Gerds, Monica L; Hammes, Walter P; Harnett, James; Huys, Geert; Laulund, Svend; Ouwehand, Arthur; Powell, Ian B; Prajapati, Jashbhai B; Seto, Yasuyuki; Ter Schure, Eelko; Van Boven, Aart; Vankerckhoven, Vanessa; Zgoda, Annabelle; Tuijtelaars, Sandra; Hansen, Egon Bech

    2012-03-15

    Microbial food cultures have directly or indirectly come under various regulatory frameworks in the course of the last decades. Several of those regulatory frameworks put emphasis on "the history of use", "traditional food", or "general recognition of safety". Authoritative lists of microorganisms with a documented use in food have therefore come into high demand. One such list was published in 2002 as a result of a joint project between the International Dairy Federation (IDF) and the European Food and Feed Cultures Association (EFFCA). The "2002 IDF inventory" has become a de facto reference for food cultures in practical use. However, as the focus mainly was on commercially available dairy cultures, there was an unmet need for a list with a wider scope. We present an updated inventory of microorganisms used in food fermentations covering a wide range of food matrices (dairy, meat, fish, vegetables, legumes, cereals, beverages, and vinegar). We have also reviewed and updated the taxonomy of the microorganisms used in food fermentations in order to bring the taxonomy in agreement with the current standing in nomenclature.

  13. Screening and flocculating properties of bioflocculant-producing microorganisms

    Institute of Scientific and Technical Information of China (English)

    Yanling Sheng; Qiang Zhang; Yanru Sheng; Chengbin Li; Huajun Wang

    2006-01-01

    Screening of bioflocculant-producing microorganisms was carried out. A strain that secreted excellent bioflocculant was isolated from municipal sewage using the spread plate technique, identified as Klebsiella sp. by the analytical profile index (API) identification system, and named A9. Several important factors that had an effect on A9's bioflocculant-producing and flocculating activity were studied. A total of 4 g/L Kaolin suspension was used to measure the flocculating activity of the bioflocculant from A9. It was found that maltose and urea were A9's best carbon and nitrogen sources, respectively, and the flocculating activity of the flocculating agent from A9 was markedly increased by the addition of trivalent cations such as Fe3+ and Al3+; furthermore, the bioflocculant produced by A9 was most effective when the pH value was 6.0.

  14. Antimicrobial Effects of Garcinia Mangostana on Cariogenic Microorganisms

    Science.gov (United States)

    Janardhanan, Sunitha; Girija, A. S. Smiline; Mahendra, Little; Priyadharsini, Vijayashree

    2017-01-01

    Introduction Garcinia mangostana commonly called as Mangosteen fruit has been used as an antibacterial agent since age old times. The mangosteen pericarp has proven to have antibacterial effect, but the effect of the same on cariogenic organisms has not been explored. The present study was an attempt to gain a better understanding of the antibacterial effect of mangosteen pericarp on the cariogenic bacteria, to unravel the therapeutic potential for the same. Aim The aim of the study was to assess the antibacterial efficacy of the crude chloroform extract of mangosteen pericarp against cariogenic bacteria. Materials and Methods The study was done under laboratory settings using an in vitro design. The microorganisms namely Streptococcus mutans, Streptococcus sanguis, Streptococcus salivarius, Streptococcus oralis and Lactobacillus acidophilus were procured from American Type Cell Culture (ATCC) and Microbial Type Culture Collection (MTCC) were revived and lawn cultured. The antibacterial effect of mangosteen pericarp was tested using agar well diffusion method on Trypticase Soy Agar-Blood Agar (TSA-BA) and de Man, Rogosa and Sharpe (MRS) agar media. The standard antiplaque agent chlorhexidine was used as the positive control. This cross-sectional, experimental study was done in Central Research laboratory, Meenakshi Ammal Dental College for period of eight weeks. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values were determined by microbroth dilution method. Statistical analysis was done by calculating the mean of the zones of inhibition on tested microorganisms. Mann-Whitney test was done to compare the zones of inhibition of mangosteen and chlorhexidine. Results The antibacterial bioassay showed the highest activity for Lactobacillus acidophilus (13.6 mm) and Streptococcus sanguis (13.6 mm), whereas, it showed a medium and low activity for Streptococcus oralis (11.3 mm), Streptococcus mutans (10.6 mm) and Streptococcus

  15. Influence of microorganisms on the alteration of glasses; Influence des microorganismes sur l'alteration des verres

    Energy Technology Data Exchange (ETDEWEB)

    Besnainou, B.; Libert, M.F. [CEA Cadarache, 13 - Saint Paul lez Durance (France). Dept. d' Entreposage et de Stockage des Dechets

    1997-07-01

    Under specific conditions, microorganisms may enhance the alteration process of basaltic glass. However bacterial activity in the near field of a glass container would be possible only in environmental conditions provide nutrients and energetic substrates for bacterial growth. Depending of these conditions, microorganisms can: - modify the pH or the medium, - consume or produce soluble organic acids. To qualify the long term behaviour of glass, in presence of microorganisms, a qualitative and quantitative estimation of microbial activity potentialities and their consequences is needed. This must be achieved in studying the availability of the chemical species in the environment. (authors)

  16. Ocean acidification and marine microorganisms: responses and consequences

    Directory of Open Access Journals (Sweden)

    Surajit Das

    2015-10-01

    Full Text Available Ocean acidification (OA is one of the global issues caused by rising atmospheric CO2. The rising pCO2 and resulting pH decrease has altered ocean carbonate chemistry. Microbes are key components of marine environments involved in nutrient cycles and carbon flow in marine ecosystems. However, these marine microbes and the microbial processes are sensitive to ocean pH shift. Thus, OA affects the microbial diversity, primary productivity and trace gases emission in oceans. Apart from that, it can also manipulate the microbial activities such as quorum sensing, extracellular enzyme activity and nitrogen cycling. Short-term laboratory experiments, mesocosm studies and changing marine diversity scenarios have illustrated undesirable effects of OA on marine microorganisms and ecosystems. However, from the microbial perspective, the current understanding on effect of OA is based mainly on limited experimental studies. It is challenging to predict response of marine microbes based on such experiments for this complex process. To study the response of marine microbes towards OA, multiple approaches should be implemented by using functional genomics, new generation microscopy, small-scale interaction among organisms and/or between organic matter and organisms. This review focuses on the response of marine microorganisms to OA and the experimental approaches to investigate the effect of changing ocean carbonate chemistry on microbial mediated processes.

  17. Influence of salinity and water content on soil microorganisms

    Directory of Open Access Journals (Sweden)

    Nan Yan

    2015-12-01

    Full Text Available Salinization is one of the most serious land degradation problems facing world. Salinity results in poor plant growth and low soil microbial activity due to osmotic stress and toxic ions. Soil microorganisms play a pivotal role in soils through mineralization of organic matter into plant available nutrients. Therefore it is important to maintain high microbial activity in soils. Salinity tolerant soil microbes counteract osmotic stress by synthesizing osmolytes which allows them to maintain their cell turgor and metabolism. Osmotic potential is a function of the salt concentration in the soil solution and therefore affected by both salinity (measured as electrical conductivity at a certain water content and soil water content. Soil salinity and water content vary in time and space. Understanding the effect of changes in salinity and water content on soil microorganisms is important for crop production, sustainable land use and rehabilitation of saline soils. In this review, the effects of soil salinity and water content on microbes are discussed to guide future research into management of saline soils.

  18. Bioprospecting of lipolytic microorganisms obtained from industrial effluents.

    Science.gov (United States)

    Peil, Greice H S; Kuss, Anelise V; Rave, Andrés F G; Villarreal, José P V; Hernandes, Yohana M L; Nascente, Patrícia S

    2016-01-01

    The lipases have ability to catalyze diverse reactions and are important in different biotechnological applications. The aim of this work was to isolate and characterize microorganisms that produce lipases, from different food industry effluents localized in Pelotas, RS/Brazil. Bacteria were identified using Gram stain and biochemical tests (Vitek 2(r)). Fungi were identified according to macro and micromorphology characteristics. The extracellular lipase production was evaluated using the Rhodamine B test and the enzymatic activity by titration. Twenty-one bacteria were isolated and identified as Klebsiella pneumoniae ssp. pneumoniae, Serratia marcescens, Enterobacter aerogenes, Raoultella ornithinolytica and Raoultella planticola. Were characterized isolated filamentous fungi by the following genera: Alternaria sp., Fusarium sp., Geotrichum sp., Gliocladium sp., Mucor sp., Paecilomyces sp. and Trichoderma sp. Extracellular lipase production was observed in 71.43% of the bacteria and 57.14% of the fungi. The bacterium that presented better promising enzymatic activity was E. aerogenes (1.54 U/ml) however between fungi there was not significant difference between the four isolates. This study indicated that microorganisms lipase producers are present in the industrial effluents, as well as these enzymes have potential of biodegradation of lipid compounds.

  19. Bioprospecting of lipolytic microorganisms obtained from industrial effluents

    Directory of Open Access Journals (Sweden)

    GREICE H.S. PEIL

    2016-01-01

    Full Text Available ABSTRACT The lipases have ability to catalyze diverse reactions and are important in different biotechnological applications. The aim of this work was to isolate and characterize microorganisms that produce lipases, from different food industry effluents localized in Pelotas, RS/Brazil. Bacteria were identified using Gram stain and biochemical tests (Vitek 2(r. Fungi were identified according to macro and micromorphology characteristics. The extracellular lipase production was evaluated using the Rhodamine B test and the enzymatic activity by titration. Twenty-one bacteria were isolated and identified as Klebsiella pneumoniae ssp. pneumoniae, Serratia marcescens, Enterobacter aerogenes, Raoultella ornithinolytica and Raoultella planticola. Were characterized isolated filamentous fungi by the following genera: Alternaria sp., Fusarium sp., Geotrichum sp., Gliocladium sp., Mucor sp., Paecilomyces sp. and Trichoderma sp. Extracellular lipase production was observed in 71.43% of the bacteria and 57.14% of the fungi. The bacterium that presented better promising enzymatic activity was E. aerogenes (1.54 U/ml however between fungi there was not significant difference between the four isolates. This study indicated that microorganisms lipase producers are present in the industrial effluents, as well as these enzymes have potential of biodegradation of lipid compounds.

  20. Inhibition of Staphylococcus aureus by antimicrobial biofilms formed by competitive exclusion microorganisms on stainless steel.

    Science.gov (United States)

    Son, Hyeri; Park, Sunhyung; Beuchat, Larry R; Kim, Hoikyung; Ryu, Jee-Hoon

    2016-12-05

    The goal of this study was to develop a desiccation resistant antimicrobial surface using biofilm of competitive exclusion (CE) microorganism inhibitory to Staphylococcus aureus. We isolated 161 microorganisms from soils, foods, and food-contact surfaces that are inhibitory to S. aureus. Among them, three CE microorganisms (Streptomyces spororaveus strain Gaeunsan-18, Bacillus safensis strain Chamnamu-sup 5-25, and Pseudomonas azotoformans strain Lettuce-9) exhibiting strong antibacterial activity and high growth rates were selected for evaluation. These isolates formed biofilms within 24h on stainless steel coupons (SSCs) immersed in Bennet's broth and tryptic soy broth at 25°C. Cells in these biofilms showed significantly (P≤0.05) enhanced resistance to a desiccation (43% relative humidity [RH]) compared to those attached to SSCs but not in biofilms. The antimicrobial activities of biofilms formed by these isolates on SSCs against S. aureus at 25°C and 43% RH were determined. Compared to SSCs lacking biofilms formed by CE microorganisms, populations of S. aureus on SSCs harboring CE biofilms were significantly lower (P≤0.05). Results indicate that persistent antimicrobial activity against S. aureus on stainless steel surfaces can be achieved by the presence of biofilms of CE microorganisms. This information will be useful when developing strategies to improve the microbiological safety of foods during storage, processing, and distribution by facilitating the development of effective antimicrobial food-contact surfaces.

  1. 21 CFR 866.2660 - Microorganism differentiation and identification device.

    Science.gov (United States)

    2010-04-01

    ... § 866.2660 Microorganism differentiation and identification device. (a) Identification. A microorganism differentiation and identification device is a device intended for medical purposes that consists of one or more... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Microorganism differentiation and identification...

  2. Antibacterial Effect of Copper on Microorganisms Isolated from Bovine Mastitis

    Science.gov (United States)

    Reyes-Jara, Angelica; Cordero, Ninoska; Aguirre, Juan; Troncoso, Miriam; Figueroa, Guillermo

    2016-01-01

    The antimicrobial properties of copper have been recognized for several years; applying these properties to the prevention of diseases such as bovine mastitis is a new area of research. The aim of the present study was to evaluate in vitro the antimicrobial activity of copper on bacteria isolated from subclinical and clinical mastitis milk samples from two regions in Chile. A total of 327 microorganisms were recovered between March and September 2013, with different prevalence by sample origin (25 and 75% from the central and southern regions of Chile, respectively). In the central region, Escherichia coli and coagulase negative Staphylococci (CNS) were the most frequently detected in clinical mastitis cases (33%), while in the southern region S. uberis, S. aureus, and CNS were detected with frequencies of 22, 21, and 18%, respectively. Antibiotic susceptibility studies revealed that 34% of isolates were resistant to one or more antibiotics and the resistance profile was different between bacterial species and origins of isolation of the bacteria. The minimum inhibitory concentration of copper (MIC-Cu) was evaluated in all the isolates; results revealed that a concentration as low as 250 ppm copper was able to inhibit the great majority of microorganisms analyzed (65% of isolates). The remaining isolates showed a MIC-Cu between 375 and 700 ppm copper, and no growth was observed at 1000 ppm. A linear relationship was found between the logarithm of viable bacteria number and time of contact with copper. With the application of the same concentration of copper (250 ppm), CNS showed the highest tolerance to copper, followed by S. uberis and S. aureus; the least resistant was E. coli. Based on these in vitro results, copper preparations could represent a good alternative to dipping solutions, aimed at preventing the presence and multiplication of potentially pathogenic microorganisms involved in bovine mastitis disease. PMID:27199953

  3. Antibacterial effect of copper on microorganisms isolated from bovine mastitis

    Directory of Open Access Journals (Sweden)

    Angelica eReyes-Jara

    2016-04-01

    Full Text Available The antimicrobial properties of copper have been recognized for several years; applying these properties to the prevention of diseases such as bovine mastitis is a new area of research. The aim of the present study was to evaluate in vitro the antimicrobial activity of copper on bacteria isolated from subclinical and clinical mastitis milk samples from two regions in Chile. A total of 327 microorganisms were recovered between March and September 2013, with different prevalence by sample origin (25% and 75% from the central and southern regions of Chile, respectively. In the central region, E. coli and coagulase negative Staphylococci (CNS were the most frequently detected in clinical mastitis cases (33%, while in the southern region S. uberis, S. aureus and CNS were detected with frequencies of 22%, 21% and 18%, respectively. Antibiotic susceptibility studies revealed that 34% of isolates were resistant to one or more antibiotics and the resistance profile was different between bacterial species and origins of isolation of the bacteria.The minimum inhibitory concentration of copper (MIC-Cu was evaluated in all the isolates; results revealed that a concentration as low as 250 ppm copper was able to inhibit the great majority of microorganisms analyzed (65% of isolates. The remaining isolates showed a MIC-Cu between 375 and 700 ppm copper, and no growth was observed at 1000 ppm. A linear relationship was found between the logarithm of viable bacteria number and time of contact with copper. With the application of the same concentration of copper (250 ppm, CNS showed the highest tolerance to copper, followed by S. uberis and S. aureus; the least resistant was E.coli. Based on these in vitro results, copper preparations could represent a good alternative to dipping solutions, aimed at preventing the presence and multiplication of potentially pathogenic microorganisms involved in bovine mastitis disease.

  4. Surfactant producing TNT-degrading microorganisms for bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Vorobyov, A.; Marchenko, A.; Rudneva, O.; Borovick, R. [Research Center for Toxicology and Hygienic Regulation of Biopreparations, Serpukhov, Moscow region (Russian Federation); Radosevich, M. [Univ. of Delaware, Newark (United States). Dept. of Plant and Soil Sciences

    2003-07-01

    In general the biodegradation of nitroaromatic hydrocarbons is influenced by their bioavailability. 2,4,6-trinitrotoluene is very poorly soluble in water. TNT is easily adsorbed to clay or humus fractions in the soil, and pass very slowly to the aqueous phase, where microorganisms metabolize it. Biosurfactants that increase TNT solubility and improve its bioavailability can thereby accelerate degradation. Pure cultures of microorganisms-TNT degraders were isolated by the method of enrichment cultures from samples of different-type soil contaminated by TNT (soddy-podzol, black earth, and gray forest ones). From 28 soil samples 35 isolates of microorganisms degrading TNT were taken. The isolated soil samples had been tested for availability of microbial activity towards TNT. By10 g of air-dried soil, 10 ml of distilled water, and 2 mg of TNT were placed into 750 ml shaken flasks. The flasks were incubated at 150 rev/min and 24 C. Glucose, sodium succinate or sodium acetate had been used as co-substrates. The ability of the strains to produce surfactants was studied by drop collapsing test and direct measuring of surface tension of cultural liquid after cultivation with TNT. Cells of the strains were cultivated on solid and liquid nutrient media. For drop collapsing test the cells were cultivated on solid nutrient media; the separated colonies were suspended in distilled water. Drop sustainability test ws conducted on a standard 96-well plates coated with a thin layer of vaseline oil. Surface tension of cultural liquid ws measured after cultivation of strains in the presence of TNT with the use of a ring tensiometer. Before measuring of surface tension microbial cells were collected from liquid culture by centrifugation. (orig.)

  5. Extracellular electron transfer mechanisms between microorganisms and minerals

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Liang; Dong, Hailiang; Reguera, Gemma; Beyenal, Haluk; Lu, Anhuai; Liu, Juan; Yu, Han-Qing; Fredrickson, James K.

    2016-08-30

    Electrons can be transferred from microorganisms to multivalent metal ions that are associated with minerals and vice versa. As the microbial cell envelope is neither physically permeable to minerals nor electrically conductive, microorganisms have evolved strategies to exchange electrons with extracellular minerals. In this Review, we discuss the molecular mechanisms that underlie the ability of microorganisms to exchange electrons, such as c-type cytochromes and microbial nanowires, with extracellular minerals and with microorganisms of the same or different species. Microorganisms that have extracellular electron transfer capability can be used for biotechnological applications, including bioremediation, biomining and the production of biofuels and nanomaterials.

  6. Real-time detection of viable microorganisms by intracellular phototautomerism

    Directory of Open Access Journals (Sweden)

    Schuren Frank

    2010-06-01

    Full Text Available Abstract Background To date, the detection of live microorganisms present in the environment or involved in infections is carried out by enumeration of colony forming units on agar plates, which is time consuming, laborious and limited to readily cultivable microorganisms. Although cultivation-independent methods are available, they involve multiple incubation steps and do mostly not discriminate between dead or live microorganisms. We present a novel generic method that is able to specifically monitor living microorganisms in a real-time manner. Results The developed method includes exposure of cells to a weak acid probe at low pH. The neutral probe rapidly permeates the membrane and enters the cytosol. In dead cells no signal is obtained, as the cytosolic pH reflects that of the acidic extracellular environment. In live cells with a neutral internal pH, the probe dissociates into a fluorescent phototautomeric anion. After reaching peak fluorescence, the population of live cells decays. This decay can be followed real-time as cell death coincides with intracellular acidification and return of the probe to its uncharged non-fluorescent state. The rise and decay of the fluorescence signal depends on the probe structure and appears discriminative for bacteria, fungi, and spores. We identified 13 unique probes, which can be applied in the real-time viability method described here. Under the experimental conditions used in a microplate reader, the reported method shows a detection limit of 106 bacteria ml-1, while the frequently used LIVE/DEAD BacLight™ Syto9 and propidium iodide stains show detection down to 106 and 107 bacteria ml-1, respectively. Conclusions We present a novel fluorescence-based method for viability assessment, which is applicable to all bacteria and eukaryotic cell types tested so far. The RTV method will have a significant impact in many areas of applied microbiology including research on biocidal activity, improvement of

  7. Effects of Different Straw Returning Modes on the Soil Microorganism and Enzyme Activity in Corn Field%不同秸秆还田方式对玉米根际土壤微生物及酶活性的影响

    Institute of Scientific and Technical Information of China (English)

    于寒; 梁烜赫; 张玉秋; 孙杨; 吴春胜; 谷岩

    2015-01-01

    为了探明不同秸秆还田方式对玉米根际土壤微生物及酶活性的影响,设置秸秆覆盖和深埋2种秸秆还田方式,研究了不同处理(秸秆覆盖于玉米长期连作土壤CT1、秸秆深埋于玉米长期连作土壤CT2、秸秆覆盖于米麦轮作土壤T1、秸秆深埋于米麦轮作土壤T2)对下茬玉米根际土壤微生物及土壤酶活性的影响。结果表明:(1)相同的秸秆还田方式下,T1和T2玉米根际土壤微生物生物量碳、主要微生物及生理类群和土壤酶活性均高于CT1和CT2处理。(2)在玉米长期连作土壤中,秸秆深埋更能提高下茬玉米根际土壤微生物生物量碳含量,增加土壤细菌、放线菌、主要微生物生理类群(氨化细菌、好气性固氮菌、硝化细菌)和降低土壤真菌数量,提高土壤脲酶和转化酶活性。而在米麦轮作土壤中,秸秆还田方式对玉米根际土壤真菌和主要微生物生理类群(氨化细菌、好气性固氮菌、硝化细菌)、土壤脲酶和过氧化氢酶活性影响不大。在吉林省玉米长期连作种植区,秸秆深埋比秸秆覆盖更能有效改善土壤微生物结构。%Straws contain a large amount of organic matter and nitrogen, phosphous, potassium and different microelements. Straw-returning becomes one of the most important measures to replace the traditional organic fertilizer and increase the soil organic matter. As the bond be-tween next stubble crops and soil microorganism, returned straws play an important role in underground rhizosphere microorganisms environ-ment. In this study, the effects of different straw returning modes on the soil microorganism and enzyme activity were investigated. The experi-ment included four different treatment:the soil of continuous-cropping with straw mulching(CT1), the soil of continuous-cropping with straw buried(CT2), the soil of alternate-cropping with straw mulching(T1), the soil of alternate-cropping with

  8. Antimicrobial activity of Lactobacillus and Bifidobacterium strains against pathogenic microorganisms “in vitro”Atividade antimicrobiana de Lactobacillus e Bifodobacterium frente a microrganismos patogênicos “in vitro”

    Directory of Open Access Journals (Sweden)

    Giselle Nobre Costa

    2012-10-01

    Full Text Available Lactobacilli and bifidobacteria have a long history of safe use in foods. These bacteria have biotechnological characteristics of interest such as the inhibition of pathogens. In this work, two lactobacilli strain and a bifidobacterium strain isolated from human gut were evaluated concerning to their ability to inhibit pathogenic microorganisms in foods by diffusion agar tests. Moreover, we assessed the metabolites produced in culture broth under static and shaking growth to simulate anaerobiosis and aerobiosis conditions, respectively. L. acidophilus LA5, L. plantarum DCTA 8420 and B. lactis DCTA 8724 showed ability to inhibit S. aureus FRI 196, strains producer toxins A and D, as well as B. cereus ATCC 25923, E. coli ATCC 25922 and S. Enteritidis, whose inhibition halos reached, on average, 24 mm in diameter. In the agar diffusion method with concentrated culture medium, it was possible to observe the effect of oxygen on the production of toxic substances. This result showed that cultivation of Lactobacillus under aerobic conditions seems to exert greater inhibitory effect, whereas for Bifidobacterium strain the effect was the opposite.Lactobacilos e bifidobactérias apresentam um longo histórico de uso seguro em alimentos, além de apresentarem características de interesse biotecnológico como a inibição de patógenos. Neste trabalho duas linhagens de lactobacilos e uma de bifidobactéria, isoladas do intestino humano, foram avaliadas em testes de difusão em ágar, quanto à capacidade de inibição de microrganismos patogênicos de ocorrência comuns em toxinfecções alimentares. Adicionalmente, foram avaliados os metabólitos produzidos em caldo de cultivo estático e em agitação para simular condições de anaerobiose a aerobiose, respectivamente. As três bactérias, L. acidophilus LA5, L. plantarum DCTA 8420 e B. lactis DCTA 8724 apresentaram capacidade de inibição para S. aureus FRI 196 linhagem produtora de toxinas A e D

  9. Screening of biosurfactants from cloud microorganisms

    Science.gov (United States)

    Sancelme, Martine; Canet, Isabelle; Traikia, Mounir; Uhliarikova, Yveta; Capek, Peter; Matulova, Maria; Delort, Anne-Marie; Amato, Pierre

    2015-04-01

    The formation of cloud droplets from aerosol particles in the atmosphere is still not well understood and a main source of uncertainties in the climate budget today. One of the principal parameters in these processes is the surface tension of atmospheric particles, which can be strongly affected by trace compounds called surfactants. Within a project devoted to bring information on atmospheric surfactants and their effects on cloud droplet formation, we focused on surfactants produced by microorganisms present in atmospheric waters. From our unique collection of microorganisms, isolated from cloud water collected at the Puy-de-Dôme (France),1 we undertook a screening of this bank for biosurfactant producers. After extraction of the supernatants of the pure cultures, surface tension of crude extracts was determined by the hanging drop technique. Results showed that a wide variety of microorganisms are able to produce biosurfactants, some of them exhibiting strong surfactant properties as the resulting tension surface decreases to values less then 35 mN.m-1. Preliminary analytical characterization of biosurfactants, obtained after isolation from overproducing cultures of Rhodococcus sp. and Pseudomonas sp., allowed us to identify them as belonging to two main classes, namely glycolipids and glycopeptides. 1. Vaïtilingom, M.; Attard, E.; Gaiani, N.; Sancelme, M.; Deguillaume, L.; Flossmann, A. I.; Amato, P.; Delort, A. M. Long-term features of cloud microbiology at the puy de Dôme (France). Atmos. Environ. 2012, 56, 88-100. Acknowledgements: This work is supported by the French-USA ANR SONATA program and the French-Slovakia programs Stefanik and CNRS exchange.

  10. Application of microorganisms towards synthesis of chiral terpenoid derivatives.

    Science.gov (United States)

    Kuriata-Adamusiak, Renata; Strub, Daniel; Lochyński, Stanisław

    2012-09-01

    Biotransformations are a standard tool of green chemistry and thus are following the rules of sustainable development. In this article, we describe the most common types of reactions conducted by microorganisms applied towards synthesis of chiral terpenoid derivatives. Potential applications of obtained products in various areas of industry and agriculture are shown. We also describe biological activity of presented compounds. Stereoselective hydroxylation, epoxidation, Baeyer-Villiger oxidation, stereo- and enantioselective reduction of ketones, and various kinetic resolutions carried out by bacteria and fungi have been reviewed. Mechanistic considerations regarding chemical and enzymatic reactions are presented. We also briefly describe modern approaches towards enhancing desired enzymatic activity in order to apply modified biocatalysts as an efficient tool and green alternative to chemical catalysts used in industry.

  11. 农用抗真菌海洋微生物的筛选及放线菌T19-07活性代谢产物的初步研究%Screening of marine microorganisms with agricultural antifungal activities and preliminary study on the bioactive metabolites produced by strain T19-07

    Institute of Scientific and Technical Information of China (English)

    胡杨; 张道敬; 李元广; 陶黎明; 田黎; 李淑兰

    2011-01-01

    Objective To screen the active strains with agricultural antifungal activity from marine microorganisms as well as the bioactive metabolites produced by marine actinomyces Streptomyces nodosus T19-07. Methods Using phytopathogenic fungi as targets, the active strains were screened out by pairing culture assay. Based on the index of antifungal activity, the characteristics of fermentation of strain T19-07 in 5 L fermentor were studied, and the bioactive substances were extracted by macro-porous resin XAD-16, and TLC bioautography combined with HPLC was used to separate the active compound Results Twelve antagonistic strains against phytopathogenic fungi were screened out from 31 marine microorganisms. The main antifungal substance of strain T19-07 was isolated with relative molecular mass of 214 Da, and its antifungal activity in vitro against Alternaria solani was similar with iprodione registrated as a chemical pesticide, MIC below 12. 5 μg · Ml-1. Conclusion Marine microorganisms are important resources to find agricultural antibiotics. The bioactive substances produced by marine actinomyces S. nodosus T19-07 exhibit potent antifungal activity in vitro, and it has the potential for further study.%通过筛选获得具有拮抗植物病原真菌活性的海洋微生物菌株,并对其中一株海洋生境的结节链霉菌(Streptomyces nodosus)T19-07的活性代谢产物进行初步研究.方法 以植物病原真菌为靶标,采用平板对峙培养法筛选出活性菌株;再以抑菌活性为指标,考察较强活性菌株T19-07在5L发酵罐中的培养过程特征,并通过大孔吸附树脂XAD-16柱层析对活性物质进行分离提取,结合TLC生物自显影和HPLC快速确定代谢产物中的活性组分.结果 从31株海洋微生物中筛选出12株对多种植物病原真菌具有拮抗作用的菌株;确定了菌株T19-07的代谢产物中的主要抑菌活性物质,其相对分子质量为214,并且它对茄交链格孢霉的

  12. Microorganisms as Indicators of Soil Health

    DEFF Research Database (Denmark)

    Nielsen, M. N.; Winding, A.; Binnerup, S.

    Microorganisms are an essential part of living soil and of outmost importance for soil health. As such they can be used as indicators of soil health. This report reviews the current and potential future use of microbial indicators of soil health and recommends specific microbial indicators for soil...... ecosystem parameters representing policy relevant end points. It is further recommended to identify a specific minimum data set for specific policy relevant end points, to carefully establish baseline values, to improve scientific knowledge on biodiversity and modelling of soil data, and to implement new...... indicators into soil monitoring programmes as they become applicable....

  13. Resistance of soil microorganisms to starvation.

    Science.gov (United States)

    Chen, M.; Alexander, M.

    1972-01-01

    Most groups of soil microorganisms died when exposed to prolonged starvation in a carbon-free solution, but the relative abundance of Bacillus and actinomycetes increased with time. Certain nonspore-forming bacteria also persisted. The ability of individual soil isolates to endure starvation in solution was not correlated with their glycogen content or rate of endogenous respiration. However, cells of the resistant populations were rich in poly-beta-hydroxybutyrate, whereas the starvation-susceptible bacteria generally contained little of this substance. Poly-beta-hydroxybutyrate was used rapidly in cells deprived of exogenous sources of carbon.

  14. Lead resistance in micro-organisms.

    Science.gov (United States)

    Jarosławiecka, Anna; Piotrowska-Seget, Zofia

    2014-01-01

    Lead (Pb) is an element present in the environment that negatively affects all living organisms. To diminish its high toxicity, micro-organisms have developed several mechanisms that allow them to survive exposure to Pb(II). The main mechanisms of lead resistance involve adsorption by extracellular polysaccharides, cell exclusion, sequestration as insoluble phosphates, and ion efflux to the cell exterior. This review describes the various lead resistance mechanisms, and the regulation of their expression by lead binding regulatory proteins. Special attention is given to the Pbr system from Cupriavidus metallidurans CH34, which involves a unique mechanism combining efflux and lead precipitation.

  15. Microorganisms and biomolecules in space hard environment

    Science.gov (United States)

    Horneck, G.

    1981-01-01

    Microorganisms and biomolecules exposed to space vacuum and to different intensities of selected wavelengths of solar ultraviolet radiation is studied. The influence of these factors, applied singly or simultaneously, on the integrity of microbial systems and biomolecules is measured. Specifically, this experiment will study in Bacillus subtilis spores (1) disturbances in subsequent germination, outgrowth, and colony formation; (2) photochemical reactions of the DNA and protein in vivo and in vitro and their role in biological injury; and (3) the efficiency of repair processes in these events.

  16. Mixing by microorganisms in stratified fluids

    CERN Document Server

    Wagner, Gregory L; Lauga, Eric

    2014-01-01

    We examine the vertical mixing induced by the swimming of microorganisms at low Reynolds and P\\'eclet numbers in a stably stratified ocean, and show that the global contribution of oceanic microswimmers to vertical mixing is negligible. We propose two approaches to estimating the mixing efficiency, $\\eta$, or the ratio of the rate of potential energy creation to the total rate-of-working on the ocean by microswimmers. The first is based on scaling arguments and estimates $\\eta$ in terms of the ratio between the typical organism size, $a$, and an intrinsic length scale for the stratified flow, $\\ell = \\left ( \

  17. Microorganisms and radionuclides in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Yoshitomo [Central Research Inst. of Electric Power Industry, Abiko, Chiba (Japan)

    2002-11-01

    The influence of microorganisms on the behavior of radionuclides in the subsurface environment is one of the factors to be concerned with for the safety assessment of the geological disposal of radioactive waste. It is considered that the important microbiological aspects with respect to radionuclide behavior are biological adsorption, oxidation-reduction and complex formation between organic matter and radionuclides. These phenomena with respect to radionuclides, especially actinides, in the environment should be understood. A description of two studies, illustrating these points are presented. (author)

  18. Engineering photosynthesis in plants and synthetic microorganisms.

    Science.gov (United States)

    Maurino, Veronica G; Weber, Andreas P M

    2013-01-01

    Photosynthetic organisms, such as cyanobacteria, algae, and plants, sustain life on earth by converting light energy, water, and CO(2) into chemical energy. However, due to global change and a growing human population, arable land is becoming scarce and resources, including water and fertilizers, are becoming exhausted. It will therefore be crucial to design innovative strategies for sustainable plant production to maintain the food and energy bases of human civilization. Several different strategies for engineering improved photosynthesis in crop plants and introducing novel photosynthetic capacity into microorganisms have been reviewed.

  19. Microorganisms in human milk: lights and shadows.

    Science.gov (United States)

    Civardi, Elisa; Garofoli, Francesca; Tzialla, Chryssoula; Paolillo, Piermichele; Bollani, Lina; Stronati, Mauro

    2013-10-01

    Human milk has been traditionally considered germ free, however, recent studies have shown that it represents a continuous supply of commensal and potentially probiotic bacteria to the infant gut. Mammary microbioma may exercise anti-infective, anti-inflammatory, immunomodulatory and metabolic properties. Moreover human milk may be a source of pathogenic microorganism during maternal infection, if contaminated during expression or in case of vaccination of the mother. The non-sterility of breast milk can, thus, be seen as a protective factor, or rarely, as a risk factor for the newborn.

  20. Fossil micro-organisms evidenced by electronic microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Prashnowsky, A.A.; Oberlies, F.; Burger, K.

    1983-04-01

    Fossil microorganisms in colonies and in the form of isolated cells (iron bacteria, fungi, actinomycetes etc.) were detected by electron microscopy of rocks containing remains of plant roots, carbonaceous substance, and strata of clay iron stone with ooids. These findings suggest an environment favourable to bacterial activity during sedimentation in the Upper Carboniferous and during the later processes of peat and coal formation. They also suggest that bacterial processes are an important factor in coal formation. Accurate data on coal formation can only be obtained by systematic biochemical studies. Analyses of the defined organic substances provide a better understanding of the conversion processes of the original substances. For example, the results of sterine analysis provide information on the mycoplancton, phytoplancton and zooplancton of the Upper Carboniferous. For some types of rock, the ratio of saponifiable to non-saponifiable constituents of the organic compounds yield information on stability under various geochemical conditions. The interactions between the various groups of microorganisms also play a major role in the solution of ecological problems.

  1. Scanning respirometer for toxicity tests using micro-organisms

    Science.gov (United States)

    Zhang, Min-Quan; Li, Xiang-Ming; Wong, Yuk-Shan; Kwan, FolkYear

    1995-09-01

    A novel respirometer is developed for microbial toxicity tests. The respirometer is based on luminescent quenching of oxygen to measure the concentration of dissolved oxygen in cell vessels and evaluate the toxicity of chemicals by monitoring the effect of toxicants on cell respiration of micro-organisms. The oxygen sensing element is ruthenium complex absorbed on the surface of silica particles followed by immobilizing on a silicone rubber film. The oxygen sensing film is coated on the inner bottom of a transparent cell vessel. A sensing device scanning under the cell vessel is used for remote monitoring of the oxygen concentration inside the cell vessels so that a large number of samples can be handled in one batch. The sensing device includes the excitation light sources and an optical cable connected to a filter and a photomultiplier tube for detecting the luminescence in the cell vessel which can then be related to the dissolved oxygen concentration inside the cell vessel. The movement of the sensing device and data acquisition are controlled by a personal computer. The toxicity of heavy metals to activated sludge, soil bacteria and E. coli were tested using the present device. The scanning respirometer provides a new alternative for fast and large scale screening and monitoring of toxicants using micro-organisms.

  2. Yeasts in table olive processing: desirable or spoilage microorganisms?

    Science.gov (United States)

    Arroyo-López, F N; Romero-Gil, V; Bautista-Gallego, J; Rodríguez-Gómez, F; Jiménez-Díaz, R; García-García, P; Querol, A; Garrido-Fernández, A

    2012-11-01

    Yeasts are unicellular eukaryotic microorganisms isolated from many foods, and are commonly found in table olive processing where they can play a double role. On one hand, these microorganisms can produce spoilage of fruits due to the production of bad odours and flavours, the accumulation of CO(2) leading to swollen containers, the clouding of brines, the softening of fruits and the degradation of lactic acid, which is especially harmful during table olive storage and packaging. But on the other hand, fortunately, yeasts also possess desirable biochemical activities (lipase, esterase, β-glucosidase, catalase, production of killer factors, etc.) with important technological applications in this fermented vegetable. Recently, the probiotic potential of olive yeasts has begun to be evaluated because many species are able to resist the passage through the gastrointestinal tract and show beneficial effects on the host. In this way, yeasts may improve consumers' health by decreasing cholesterol levels, inhibiting pathogens, degrading non assimilated compounds, producing antioxidants and vitamins, adhering to intestinal cells or by maintaining epithelial barrier integrity. Many yeast species, usually also found in table olive processing, such as Wicherhamomyces anomalus, Saccharomyces cerevisiae, Pichia membranifaciens and Kluyveromyces lactis, have been reported to exhibit some of these properties. Thus, the selection of the most appropriate strains to be used as starters, alone or in combination with lactic acid bacteria, is a promising research line to develop in a near future which might improve the added value of the commercialized product.

  3. [The solubilization of four insoluble phosphates by some microorganisms].

    Science.gov (United States)

    Zhao, Xiaorong; Lin, Qimei; Li, Baoguo

    2002-04-01

    Four insoluble phosphates of ferric phosphate (Fe-P), aluminum phosphate (Al-P), fluorapatite (FAP) and rock phosphate (RP) were used as a sole phosphorus resource for some phosphate-solubilizing microorganisms. It was found that there was significant difference in solubilizing these phosphates by the tested isolates. The fungi normally were more powerful than the bacteria in dissolving the phsophates. The microorganisms generally solubilized more phosphate when supplied with NO3- than with NH4+. However, the isolates of 2TCiF2 and 4TCiF6 had much higher capacity to solubilize FAP and Al-P respectively in NH4+ medium. Most of the isolates solubilized readily FAP and RP, and then Al-P. Ferric phosphate was the least soluble to these isolates. Only isolate 2TCiF2 showed strong ability to solubilize Fe-P. In particular, two Aspergillus sp. had much higher capacity of dissolving Fe-P when suppled with NO3-. The isolates of Evwinia sp. 4TCRi22 and Enterobacter sp. 1TCRi15 had higher capacity of solubilizing FAP. But two Arthrobacter sp. showed the highest activity in RP medium. It is supposed that complexion of organic acids with metals may be the main reason for these isolates to solubilize the phosphates. However, other chelant substances may be much more important for Enterobacter sp. and Erwinia sp. to release phosphorus from the phsphates.

  4. Evolution, Metabolism and Biotechnological Usage of Methylotrophic Microorganisms

    Directory of Open Access Journals (Sweden)

    Oleg Mosin

    2014-09-01

    Full Text Available Methylotrophs – aerobic chemoheterotrophic microorganisms submitted by cocci and bacilli mobile forms, are inhabitants of reservoirs and soils of various type, where there are going on various processes of decomposition of organic substances with formation of the one-carbon С1-compounds and some С2-, and С3-compounds, capable to be assimilated by methylotrophs. These microorganisms assimilating carbon on ribuloso-5-monophospate and serine pathways, are allocated from soil ground, the sewage containing decomposing vegetative remainss, from ruminant paunch and other sources. Methylotrophic bacteria recently draw the increasing attention of biotechnology as feasible sources of natural biologically active compounds – fodder fibers and irreplaceable amino acids, carotenoid pigments, lipids and policarbohydrates. For preparation of these compounds are used genetically marked strains of methylotrophic bacteria, obtained via genetic engineering approaches and selection. Recently developed gene-engineering methods of manipulation with the methylotrophic genom allow create on the basis of microbic DNA of methylotrophs expression vectors of eukaryotic proteins for medical and veterinary purposes, as human insulins. In this review article there are submitted data including the results of the authors’ own research on evolution of methylotrophic bacteria, the metabolism and their biotechnological usage

  5. Studies on the radiation sensitivity of food microorganism by high dose irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Han Joon; Lee, Eun Jung; Yu, Hyun Hee; Lee, Jae Ho [Korea University, Seoul (Korea, Republic of)

    2010-04-15

    We investigated the radio resistance of pathogenic microorganisms (Bacillus cereus, Staphylococcus aureus, Methicillin resistant Staphylococcus aureus(MRSA) and Escherichia coli O157) in irradiating environments. Their radiation conditions of pathogenic microorganisms varied with pH(3-10), salt concentration(1-15%), temperature(-20, 4 and 25 .deg. C) and atmospheric condition. In addition, the effect of {gamma}-irradiation on the inactivation of pathogenic microorganisms inoculated into food (saengsik, sliced ham, chopped beef) was investigated. The radiation dose ranged from 0 to 3 kGy. The {gamma}--irradiated B.cereus({gamma}--BC) St.aureus({gamma}--SA), MRSA({gamma}--MRSA) and E.coli O157({gamma}--EC) were then cultured and the viable cell count on plate count agar and D10-values(dose required to inactivate 90% of a microbial population) were calculated. The number of pathogenic microorganisms at pH(3-10) and salt concentration(1-15%), temperature(-20, 4 and 25 .deg. C) and atmospheric condition decreased by 1 log CFU/ml after irradiation. The D{sub 10}-value of {gamma}--SA in the optimum condition was 0.152 kGy, and these of {gamma}--MRSA and {gamma}--EC were 0.346 and 0.240 kGy, respectively. The initial cell counts of pathogenic microorganisms in culture broth were slightly decreased as the decrease of pH and the increase of salt concentration. However, radiation resistance of pathogenic microorganisms was increased at frozen state. Moreover, D{sub 10}-values of these is test strains in saengsik, sliced ham and chopped beef were 0.597, 0.226 , 0.398 and 0.416 kGy, respectively. These results provide the basic information for the in activation of pathogenic microorganisms in foods by irradiation

  6. SCREENING OF THERMOPHYLIC MICROORGANISM FROM IJEN CRATER BANYUWANGI AS PHYTASE ENZYME PRODUCER

    Directory of Open Access Journals (Sweden)

    Aline Puspita Kusumadjaja

    2010-06-01

    Full Text Available Phytase is enzyme which hydrolysis phytic acid to anorganic phosphate and myo-inositol pentakis-, tetrakis-, tris-, bis-, and monophosphate. The use of phytase in feed industry can overcome environment and nutrition problems which were arisen from unmetabolism phytic acid or its salt by poultry, swine and fish. The feed industry needs a thermostable enzyme due to the need of high temperature in pelleting process, i.e. 81 °C. By using thermostabile phytase, the pelleting process will not affect the enzyme activity. Thermostabile phytase can be isolated from microorganism live in hot spring water or volcano crater. In this study, the screening of thermophylic microorganism having thermostabile phytase activity in Ijen Crater, Banyuwangi, has been done. From this process, it was obtained 33 isolates that produce phytase enzyme. Isolate was code by AP-17 yields highest phytase activity, that is 0.0296 U/mL, so this isolate was choosen for further study. The activity of crude phytase enzyme was measured based on the amount of anorganic phosphate that was produced in enzymatic reaction using UV-VIS spectrophotometer at 392 nm. Based on morphology test to identify the gram type of microorganism, isolate AP-17 has a bacill cell type and identified as positive gram bacteria. This isolate was assumed as Bacillus type.   Keywords: Phytase, thermophilic microorganism, phytase activity

  7. Soil:An Extreme Habitat for Microorganisms?

    Institute of Scientific and Technical Information of China (English)

    M.BOLTER

    2004-01-01

    The question is asked whether soils can be regarded as extreme environments with respect to microorganisms. After defining some extreme environments in a general sense, special properties of extreme environments are compared to soil habitats, with special emphasis laid on time frame and localities. In relation to water availability, nutrients and other properties, such places as aggregates can show properties of extreme habitats. These features, which can act at different levels of the system from the community level down to the cellular level, are summarized as stress factors. The latter,where many switches are located leading to different strategies of survival, is described as the most important one. This raises the question of how organisms have adapted to such conditions. The soil system demands a broad spectrum of adaptations and/or adjustments for a highly variable environment.The soil microorganisms'adaptation can thus be seen as the highest kind of flexibility and is more useful than any other special adaptation.

  8. [Sensitivity of surface microorganisms to disinfectants].

    Science.gov (United States)

    Krzywicka, H; Janowska, J; Tadeusiak, B

    1991-01-01

    The influence of humidity and temperature on survival of S. aureus and P. aeruginosa on the surfaces of titles, glass and blanket carriers has been estimated. The number of CFU was examined after exposure time 6 and 24 hours in temperatures of 21 degrees C, 37 degrees C and RH 35%, 95%. It was observed: 1. The important reduction of numbers of both microorganisms at temperature 37 degrees C and RH 95%, 2. The relatively high number of survival cells of P. aeruginosa on the surface of blankets at temp. 21 degrees C and RH 95%. The microorganisms on the carriers were previously kept for 24 h at temp. 21 degrees C, RH 35% and 95% and then exposed to solutions of chloramine, formalin, lysol and Sterinol (QAC). It was observed that there was a great dependence of the disinfecting effect on the degree of dessication of the surfaces. In all cases the resistance of contaminated carriers stored 24 h was higher at 95% RH than at 35% RH.

  9. Identification of periodontopathogen microorganisms by PCR technique

    Directory of Open Access Journals (Sweden)

    Milićević Radovan

    2008-01-01

    Full Text Available INTRODUCTION Periodontitis is an inflammatory disease of the supporting tissues of teeth and is a major cause of tooth loss in adults. The onset and progression of periodontal disease is attributed to the presence of elevated levels of a consortium of pathogenic bacteria. Gram negative bacteria, mainly strict anaerobes, play the major role. OBJECTIVE The present study aimed to assess the presence of the main types of microorganisms involved in the aetiopathogenesis of periodontal disease: Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Eikenella corrodens, Treponema denticola, Tanerella forsythia and Prevotella intermedia in different samples collected from the oral cavity of 90 patients diagnosed with periodontitis. METHOD Bacterial DNA detection was performed in diverse biological materials, namely in dental plaque, gingival tissue and saliva, by means of multiplex PCR, a technique that allows simultaneous identification of two different bacterial genomes. RESULTS In the dental plaque of the periodontitis patients, Treponema denticola dominated. In the gingival tissue, Tannerella forsythia and Treponema denticola were the microbiota most frequently detected, whilst in saliva Treponema denticola and Eikenella corrodens were found with the highest percentage. CONCLUSION The identification of microorganisms by multiplex PCR is specific and sensitive. Rapid and precise assessment of different types of periodontopathogens is extremely important for early detection of the infection and consequently for the prevention and treatment of periodontal disease. In everyday clinical practice, for routine bacterial evaluation in patients with periodontal disease, the dental plaque is the most suitable biological material, because it is the richest in periodontal bacteria.

  10. Bioremediation of trinitrotolulene by a ruminal microorganism

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Taejin; Williamson, K.J.; Craig, A.M. [Oregon State Univ., Corvallis, OR (United States)

    1995-10-01

    2,4,6-trinitrotoluene (TNT) has been widely used for the production of explosives because of its low boiling point, high stability, low impact sensitivity, and safe manufacture. More than 1,100 military facilities, each potentially contaminated with munitions waste, are expected to require treatment of more than one million cubic yards of contaminated soils. The cost associated with remediation of these sites has been estimated to be in excess of $1.5 billion. Recently, researchers have studied ruminal microorganisms in relation to their ability to degrade xenobiotic compounds. Many of these organisms are strict anaerobes with optimal redox potentials as low as -420 mV. Ruminal organisms have been shown capable of destroying some pesticides, such as parathion, p-nitrophenol, and biphenyl-type compounds; thiono isomers, and nitrogen-containing heterocyclic plant toxins such as the pyrrolizidine alkaloids. Many of these compounds have structures similar to TNT. A TNT-degrading ruminal microorganism has been isolated from goat rumen fluid with successive enrichments on triaminotoluene (TAT) and TNT. The isolate, designated G.8, utilizes nitrate and lactate as the primary energy source. G.8 was able to tolerate and metabolite levels of TNT up to the saturation point of 125 mg/l.

  11. From chemosensing in microorganisms to practical biosensors.

    Science.gov (United States)

    Ghosh, Surya K; Kundu, Tapanendu; Sain, Anirban

    2012-11-01

    Microorganisms like bacteria can sense concentrations of chemoattractants in their medium very accurately. They achieve this through interaction between the receptors on their cell surfaces and chemoattractant molecules (like sugar). Physical processes like diffusion set some limits on the accuracy of detection, which was discussed by Berg and Purcell in the late seventies. We re-examine their work in order to assess what insight it may offer for making efficient, practical biosensors. We model the functioning of a typical biosensor as a reaction-diffusion process in a confined geometry. Using available data first we characterize the system by estimating the kinetic constants for the binding and unbinding reactions between the chemoattractants and the receptors. Then we compute the binding flux for this system, which Berg and Purcell had discussed. Unlike in microorganisms where the interval between successive measurements determines the efficiency of the nutrient searching process, it turns out that biosensors depend on long time properties like signal saturation time, which we study in detail. We also develop a mean field description of the kinetics of the system.

  12. Treatment of landfill leachate by immobilized microorganisms

    Institute of Scientific and Technical Information of China (English)

    YE ZhengFang; YU HongYan; WEN LiLi; NI JinRen

    2008-01-01

    This paper focuses on the outcome and the main performance of the immobilized microbial that treats landfill leachate. Based on the analysis of COD and ammonia-nitrogen of the influent and effluent, research was done on the high removal efficiency of COD and ammonium nitrogen by immobilized microbial. The leachate composition was analyzed qualitatively using GC-MS before and after being treated. Biological loading of efficient microbial flora on the carrier was measured by Kjeldahl's method. Finally, the patterns of immobilized microbe were observed through scanning electron microscopy (SEM). The results showed that in immobilized microorganisms system, the efficiencies of COD and nitrogen were 98.3% and 99.9%, respectively. There was a great reduction of organic components in effluent. When the immobilized biomass on the carrier was 38 g·L-1 (H2O), the filamentous microorganism was highly developed. There was no inhibitory effect on the nitrobacteria and nitrococcus, when ammonia was over 200 mg·L-1 and NH3 over 150 mg·L-1, At a high organic loading, it still had good nitrification. This paper also compares the performance of immobilized microbial with free microbial under the same condition. The immobilized microbial technology demonstrated better than the latter in all aspects.

  13. Treatment of landfill leachate by immobilized microorganisms

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper focuses on the outcome and the main performance of the immobilized microbial that treats landfill leachate. Based on the analysis of COD and ammonia-nitrogen of the influent and effluent, research was done on the high removal efficiency of COD and ammonium nitrogen by immobilized microbial. The leachate composition was analyzed qualitatively using GC-MS before and after being treated. Biological loading of efficient microbial flora on the carrier was measured by Kjeldahl’s method. Finally, the patterns of immobilized microbe were observed through scanning electron microscopy (SEM). The results showed that in immobilized microorganisms system, the efficiencies of COD and nitrogen were 98.3% and 99.9%, respectively. There was a great reduction of organic components in effluent. When the immobilized biomass on the carrier was 38 g·L?1 (H2O), the filamentous microorganism was highly developed. There was no inhibitory effect on the nitrobacteria and nitrococcus, when ammonia was over 200 mg·L?1 and NH3 over 150 mg·L?1. At a high organic loading, it still had good nitrification. This paper also compares the performance of immobilized microbial with free microbial under the same condition. The immobilized microbial technology demonstrated better than the latter in all aspects.

  14. Microorganisms resistant to free-living amoebae.

    Science.gov (United States)

    Greub, Gilbert; Raoult, Didier

    2004-04-01

    Free-living amoebae feed on bacteria, fungi, and algae. However, some microorganisms have evolved to become resistant to these protists. These amoeba-resistant microorganisms include established pathogens, such as Cryptococcus neoformans, Legionella spp., Chlamydophila pneumoniae, Mycobacterium avium, Listeria monocytogenes, Pseudomonas aeruginosa, and Francisella tularensis, and emerging pathogens, such as Bosea spp., Simkania negevensis, Parachlamydia acanthamoebae, and Legionella-like amoebal pathogens. Some of these amoeba-resistant bacteria (ARB) are lytic for their amoebal host, while others are considered endosymbionts, since a stable host-parasite ratio is maintained. Free-living amoebae represent an important reservoir of ARB and may, while encysted, protect the internalized bacteria from chlorine and other biocides. Free-living amoebae may act as a Trojan horse, bringing hidden ARB within the human "Troy," and may produce vesicles filled with ARB, increasing their transmission potential. Free-living amoebae may also play a role in the selection of virulence traits and in adaptation to survival in macrophages. Thus, intra-amoebal growth was found to enhance virulence, and similar mechanisms seem to be implicated in the survival of ARB in response to both amoebae and macrophages. Moreover, free-living amoebae represent a useful tool for the culture of some intracellular bacteria and new bacterial species that might be potential emerging pathogens.

  15. A new thermophilic nitrilase from an antarctic hyperthermophilic microorganism.

    Directory of Open Access Journals (Sweden)

    Geraldine V. Dennett

    2016-02-01

    Full Text Available Several environmental samples from Antarctica were collected and enriched to search for microorganisms with nitrilase activity. A new thermostable nitrilase from a novel hyperthermophilic archaea Pyrococcus sp. M24D13 was purified and characterized. The activity of this enzyme increased as the temperatures rise from 70 up to 85 °C. Its optimal activity occurred at 85 °C and pH 7.5. This new enzyme shows a remarkable resistance to thermal inactivation retaining more than 50% of its activity even after 8 h of incubation at 85 °C.In addition, this nitrilase is highly versatile demonstrating activity towards different substrates such as benzonitrile (60 mM, aromatic nitrile and butyronitrile (60 mM, aliphatic nitrile, with a specific activity of 3286.7 U mg-1 of protein and 4008.2 U mg-1 of protein respectively. Moreover the enzyme NitM24D13 also presents cyanidase activity.The apparent Michaelis-Menten constant (Km and Vmáx of this Nitrilase for benzonitrile were 0.3 mM and 333.3 µM min-1, respectively, and the specificity constant (kcat/Km for benzonitrile was 2.05×105 s-1 M-1.

  16. Susceptibility of microorganism to selected medicinal plants in Bangladesh

    Institute of Scientific and Technical Information of China (English)

    S M Masud Rana; Md Mustahsan Billah; Mohammad Salim Hossain; A K M Saifuddin; S K M Azizul Islam; Sujan Banik; Zannatul Naim; Golam Sarwar Raju

    2014-01-01

    Objective: To analyze in-vitro antimicrobial activities of some ethno-pharmacologically significant medicinal plants (methanol extract) against the pathogenic microorganisms (Escherichiacoli, Salmonella spp., Bacillus cereus, Staphylococcus aureus, Aspergillus niger and Candida albicans).Methods:The disc diffusion method was applied for antibacterial test and the poisoned food technique was applied for antifungal test.Results:The methanol extract of Terminalia chebula (bark), Phyllanthus acidus (fruits), Sarcochlamys pulcherrima (leaves) and Abelmoschus esculentus (fruits) had significant in vitro antibacterial activity angainst the entire test samples in comparison to standard drug ciprofloxacin. Most of the plant extracts showed low activity against Gram negative bacteria while potential activity against Gram positive bacteria. The antifungal activities of methanol extracts of these plants and standard drug griseofulvin were determined against two pathogenic fungi, andPolygonum lapathifolium (leaves) and Cinnamomum tamala (leaves) showed maximum activity, while Erioglossum rubiginosum (leaves) showed no antifungal activity.Conclusions:Further chemical and pharmacological investigations are required to identify and isolate chemical constituents responsible for these potential bioactivities and thus to determine their full spectrum of efficacy.

  17. Susceptibility of microorganism to selected medicinal plants in Bangladesh

    Institute of Scientific and Technical Information of China (English)

    S.M.Masud; Rana; Md.Mustahsan; Billah; Mohammad; Salim; Hossain; A.K.M.Saifuddin; S.K.M.Azizul; Islam; Sujan; Banik; Zannatul; Nairn; Golam; Sarwar; Raju

    2014-01-01

    Objective:To analyze in-vitro antimicrobial activities of some ethno-pharmacologically significant medicinal plants(methanol extract) against the pathogenic microorganisms(Escherichia coli,Salmonella spp..Bacillus cereus.Staphylococcus aureus.Aspergillus niger and Candida albicans).Methods:The disc diffusion method was applied for antibacterial test and the poisoned food technique was applied for antifungal test.Results:The methanol extract of Terminalia chebula(bark),Fhyllanthus acidus(fruits).Sarcochlamys pulcherrima(leaves) and Abelmoschus esculcntus(fruits) had significant in vitro antibacterial activity angainst the entire test samples in comparison to standard drug ciprofloxacin.Most of the plant extracts showed low activity against Gram negative bacteria while potential activity against Gram positive bacteria.The antifungal activities of methanol extracts of these plants and standard drug griseofulvin were determined against two pathogenicfungi,and Polygonum Iapathifolium(leaves) and Cinnamomum tamala(leaves) showed maximum activity,while Erioglossum rubiginosum(leaves) showed no antifungal activity.Conclusions:Further chemical and pharmacological investigations are required to identify and isolate chemical constituents responsible for these potential bioactivities and thus to determine their full spectrum of efficacy.

  18. 不同解磷菌剂对美国山核桃根际微生物和酶活性的影响%Effects of Different Phosphate-Solubilizing Bacteria on Rhizosphere Microorganism and Enzyme Activities of Pecan Seedlings

    Institute of Scientific and Technical Information of China (English)

    余旋; 朱天辉; 刘旭

    2012-01-01

    A potting experiment was conducted to evaluate effects of three phosphate-solubilizing bacteria ( PSB) (Pseudomonas chlororaphis, P. Fluorescens, Bacillus cereus) and their mixture on rhizosphere soil microorganism and enzyme activities at three growth stages of pecan ( Carya illinoensis) seedlings subjected to three application levels of calcium-superphosphate. Results showed that; Inoculation of the three PSB and their mixture increased the amounts of rhizosphere bacteria and actinomyces, reduced the amounts of rhizosphere fungi, and enhanced activities of phosphatase and urease. However, the effects on rhizosphere microorganism and enzyme activities decreased progressively with increase of calcium-superphosphate content. The bacteria mixture was stronger effects than that of any single bacterium, and brought about the most rhizosphere bacteria and actinomyces, the lest rhizosphere fungi, and the highest activities of phosphatase and urease in all three application levels of calcium-superphosphate compared to inoculation with any single bacteria.%通过盆栽试验研究3种施P水平下绿针假单胞菌、荧光假单胞菌、蜡样芽孢杆菌3种细菌及其混合菌群对美国山核桃苗3个生长时期根际微生物数量和酶活性的影响.结果表明:施加4种细菌菌剂后山核桃根际土壤中的细菌和放线菌数量增加,真菌数量减少,土壤磷酸酶和脲酶活性上升;3种施P水平下,随着施P水平的提高,各种菌剂对根际微生物数量和酶活性的影响逐渐降低,且3种细菌的混合菌剂较单一菌种对根际微生物数量及土壤磷酸酶和脲酶活性的影响更大.

  19. Aerobic activation of endogenous microorganisms in middle and high temperature reservoir%中高温油藏内源微生物好氧激活技术研究

    Institute of Scientific and Technical Information of China (English)

    王静; 段传慧; 李彩风; 高光军

    2016-01-01

    In order to study the endogenous microbial aerobic activation characteristics in middle and high temperature reservoir,12 typical blocks in high temperature reservoirs in Shengli Oilfield were selected to carry out the aerobic activation evaluation.Three reservoir temperature range were selected,namely from 55 to 65 ℃,65 to 79 ℃ and 79 to 95 ℃.6 different carbon sources were selected as the main activator:different activator formulation was prepared.Under the simulated reservoir conditions of aerobic activation evaluation,we found that the additional nutrient agent of corn syrup, molasses and yeast powder could effectively activate the functional strain below 79 ℃ oil reservoir blocks,the cell density could reach 3× 109 cell/mL.The emulsifying and dispersing effect of crude oil was obvious. In oil reservoir blocks above 79 ℃,the activation effect and emulsifying effect of crude oil were generally worse than that in 79 ℃ oil reservoir blocks.The cell density and emulsifying effect after activation show a positive correlation in each block center,whereas the surface tension and emulsifying effect had no obvious correlation. The surface tension of the solution after aerobic activation was reduced from 65 mN/m to 47 mN/m. The dominant bacteria after aerobic activation were mainly Geobacillus and Bacillus thermoamylovorans.%为了掌握中高温油藏内源微生物好氧激活特征,在胜利油田选取12个中高温油藏典型区块开展了好氧激活评价:在所选油藏温度范围分别为55~65℃、65~79℃、79~95℃,通过模拟油藏条件下好氧激活评价发现:在小于79℃油藏区块中,以玉米浆干粉、糖蜜、酵母粉等作为外加营养剂能够有效激活水样中的功能菌株,激活后菌密度最高能够达到3×109个/mL,原油乳化分散作用明显;在大于79℃的油藏区块中,激活效果和原油乳化效果普遍比小于79℃的油藏区块差。各区块中心井激活后的菌

  20. Catabolism of volatile sulfur compounds precursors by Brevibacterium linens and Geotrichum candidum, two microorganisms of the cheese ecosystem.

    Science.gov (United States)

    Arfi, Kenza; Amárita, Felix; Spinnler, Henry-Eric; Bonnarme, Pascal

    2003-11-01

    Two Brevibacterium linens strains and the cheese-ripening yeast Geotrichum candidum were compared with regard to their ability to produce volatile sulfur compounds (VSCs) from three different precursors namely L-methionine, 4-methylthio-2-oxobutyric acid (KMBA) and 4-methylthio-2-hydroxybutyric acid (HMBA). All microorganisms were able to convert these precursors to VSCs. However, although all were able to produce VSCs from L-methionine, only G. candidum accumulated KMBA when cultivated on this amino acid, contrary to B. linens suggesting that the transamination pathway is not active in this microorganism. Conversely, a L-methionine gamma-lyase activity--which catalyses the one step L-methionine to methanethiol (MTL) degradation route--was only found in B. linens strains. Several other enzymatic activities involved in the catabolism of the precursors tested were investigated. KMBA transiently accumulated in G. candidum cultures, and was then reduced to HMBA by a KMBA dehydrogenase (KDH) activity. This activity was not detected in B. linens. Despite no HMBA dehydrogenase (HDH) was found in G. candidum, a strong HMBA oxidase (HOX) activity was measured in this microorganism. This latter activity was weakly active in B. linens. KMBA and HMBA demethiolating activities were found in all the microorganisms. Our results illustrate the metabolic diversity between cheese-ripening microorganisms of the cheese ecosystem.

  1. Investigations of subterranean microorganisms. Their importance for performance assessment of radioactive waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, K. [Goeteborg Univ. (Sweden). General and Marine Microbiology; Karlsson, Fred [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    1995-06-01

    This report presents a broad and thorough description of how microorganisms may influence safety of repositories for radioactive waste. First, an overview of the Swedish concepts for disposal is given, including a discussion of the geological, chemical and hydrological conditions in repositories. Then the limiting and stimulating factors for life of microorganisms are reviewed, such as relations to oxygen, temperature, pH, radiation, pressure, water and nutrients availability. Bacteria in the cycles of carbon, nitrogen, sulfur, iron, manganese and hydrogen are also discussed. A literature review of subterranean bacteria is given in chapter 4. Chapter 5 treats investigations of microorganisms in repository-like environments, and microbial corrosion and redox processes relevant for materials in the repository and for the mobility of radionuclides. Possibilities to predict the activity and presence of microorganisms through mathematical models are discussed in chapter 6. Chapter 7 summarizes the conclusion drawn in the report, how microorganisms may influence performance safety assessment of radioactive waste disposal, and also identifies research needs. 293 refs, 43 figs, 36 tabs.

  2. A HYBRID METHOD FOR AUTOMATIC COUNTING OF MICROORGANISMS IN MICROSCOPIC IMAGES

    Directory of Open Access Journals (Sweden)

    P.Kalavathi

    2016-03-01

    Full Text Available Microscopic image analysis is an essential process to enable the automatic enumeration and quantitative analysis of microbial images. There are several system are available for numerating microbial growth. Some of the existing method may be inefficient to accurately count the overlapped microorganisms. Therefore, in this paper we proposed an efficient method for automatic segmentation and counting of microorganisms in microscopic images. This method uses a hybrid approach based on morphological operation, active contour model and counting by region labelling process. The colony count value obtained by this proposed method is compared with the manual count and the count value obtained from the existing method

  3. Effect of Dettol® on viability of some microorganisms associated with ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    May 16, 2008 ... The efficacy of the liquid disinfectant Dettol®®®® against nosocomial Staphylococcus aureus, Escherichia coli and Candida ... activity of this disinfectant on microorganisms causing ..... On the other hand, a non-logarithmic order of death has also .... antimicrobial agent by reducing effective concentration of.

  4. The rhizosphere: a playground and battlefield for soilborne pathogens and beneficial microorganisms

    NARCIS (Netherlands)

    Raaijmakers, J.M.; Paulitz, T.C.; Steinberg, C.; Alabouvette, C.; Moënne-Loccoz, Y.

    2009-01-01

    The rhizosphere is a hot spot of microbial interactions as exudates released by plant roots are a main food source for microorganisms and a driving force of their population density and activities. The rhizosphere harbors many organisms that have a neutral effect on the plant, but also attracts orga

  5. Dynamical patterns and regime shifts in the nonlinear model of soil microorganisms growth

    Science.gov (United States)

    Zaitseva, Maria; Vladimirov, Artem; Winter, Anna-Marie; Vasilyeva, Nadezda

    2017-04-01

    Dynamical model of soil microorganisms growth and turnover is formulated as a system of nonlinear partial differential equations of reaction-diffusion type. We consider spatial distributions of concentrations of several substrates and microorganisms. Biochemical reactions are modelled by chemical kinetic equations. Transport is modelled by simple linear diffusion for all chemical substances, while for microorganisms we use different transport functions, e.g. some of them can actively move along gradient of substrate concentration, while others cannot move. We solve our model in two dimensions, starting from uniform state with small initial perturbations for various parameters and find parameter range, where small initial perturbations grow and evolve. We search for bifurcation points and critical regime shifts in our model and analyze time-space profile and phase portraits of these solutions approaching critical regime shifts in the system, exploring possibility to detect such shifts in advance. This work is supported by NordForsk, project #81513.

  6. Cell surface engineering of industrial microorganisms for biorefining applications.

    Science.gov (United States)

    Tanaka, Tsutomu; Kondo, Akihiko

    2015-11-15

    In order to decrease carbon emissions and negative environmental impacts of various pollutants, biofuel/biochemical production should be promoted for replacing fossil-based industrial processes. Utilization of abundant lignocellulosic biomass as a feedstock has recently become an attractive option. In this review, we focus on recent efforts of cell surface display using industrial microorganisms such as Escherichia coli and yeast. Cell surface display is used primarily for endowing cellulolytic activity on the host cells, and enables direct fermentation to generate useful fuels and chemicals from lignocellulosic biomass. Cell surface display systems are systematically summarized, and the drawbacks/perspectives as well as successful application of surface display for industrial biotechnology are discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Mutual Dynamics of Swimming Microorganisms and Their Fluid Habitat

    Science.gov (United States)

    Kessler, John O.; Burnett, G. David; Remick, Katherine E.

    "Organisms alter their material environment, and their environment constrains and naturally selects organisms." Lenton's [17] statement applies especially well to populations of swimming micro-organisms. The mutual dynamic of themselves and their fluid habitat orders and constrains them, generates concentration-convection patterns [12], [15], enhances transport of metabolites and, at all scales, guides many of their interactions. Our objective is to describe mathematical models sufficient for reaching insights that can further guide theory and experiment. These models necessarily include nonlinear and stochastic features. To illustrate self-organization and the type of experimental statistical inputs available, we present some rather astonishing data concerning the motile bacteria Bacillus subtilis and hydrodynamics associated with their activity. The inescapable interdependence of physics and biology emerges from the analysis.

  8. Pentachlorophenol (PCP) degradation microorganism community structure under microaeration condition

    Institute of Scientific and Technical Information of China (English)

    Chen Yuancai; Hao Yuan; Fu Shiyu; Zhan Huaiyu

    2007-01-01

    The comparison of pentachlorophenol (PCP)degradation was conducted under micro-aeration and anaerobic condition with three series of batch experiment,results of which indicated that during micro-aeration condition co-immobilized of anaerobic granular sludge and isolated aerobic bacterial species could enhance the efficiency of PCP reduction through the synergism of aerobes and anaerobes reductive dechlorination and exchange of metabolites within the co-immobilized granular sludge.While during anaerobic condition,there was no great difference in the three series.The specific activities experiment further confirmed that strict anaerobes were not affected over the presence of micro aeration environment.Microorganism community construction of co-immobilized anaerobic granular sludge and the mixed isolated aerobic community was also deduced.By the efficient cooperation of aerobes and anaerobes,the high efficiency removal rate of PCP was implemented.

  9. Factors determining rock phosphate solubilization by microorganisms isolated from soil.

    Science.gov (United States)

    Nahas, E

    1996-11-01

    Forty two soil isolates (31 bacteria and 11 fungi) were studied for their ability to solubilize rock phosphate and calcium phosphate in culture medium. Eight bacteria and 8 fungi possessed solubilizing ability. Pseudomonas cepacia and Penicillium purpurogenum showed the highest activity. There was a correlation between final pH value and titratable acidity (r=-0.29 to -0.87) and between titratable acidity and soluble phosphate (r=0.22 to 0.99). Correlation values were functions of insoluble phosphate and of the group of microorganisms considered. A high correlation was observed between final pH and soluble phosphate only for the rock phosphates inoculated with the highest concentration of solubilizing bacteria (r=-0.73 to -0.98).

  10. Dynamics of microorganism populations in recirculating nutrient solutions

    Science.gov (United States)

    Strayer, R. F.

    1994-11-01

    This overview covers the basic microbial ecology of recirculating hydroponic solutions. Examples from NASA and Soviet CELSS tests and the commercial hydroponic industry will be used. The sources of microorganisms in nutrient solutions include air, water, seeds, plant containers and plumbing, biological vectors, and personnel. Microbial fates include growth, death, and emigration. Important microbial habitats within nutrient delivery systems are root surfaces, hardware surfaces (biofilms), and solution suspension. Numbers of bacteria on root surfaces usually exceed those from the other habitats by several orders of magnitude. Gram negative bacteria dominate the microflora with fungal counts usually much lower. Trends typically show a decrease in counts with increasing time unless stressed plants increase root exudates. Important microbial activities include carbon mineralization and nitrogen transformations. Important detrimental interactions include competition with plants, and human and plant pathogenesis.

  11. System for identification of microorganism and detection of infectious disorder

    DEFF Research Database (Denmark)

    2013-01-01

    Methods for the identification of microorganisms or infectious disorders are disclosed, comprising obtaining a suitable sample from sources such as persons, animals, plants, food, water or soil. The methods also comprise providing tailored nucleic acid substrate(s) designed to react with a type 1...... topoisomerase from one or more microorganism(s) or infectious agent(s), and incubating said substrate with said sample, or extracts or preparations from the sample, so that the substrate is processed by said topoisomerase if said microorganism(s) or infectious agent(s) is present in the sample. Finally......, processed substrates are identified and potentially quantified by one or more of a range of standard molecular biology methods and read-out systems. The identification and potential quantification of microorganisms and infectious agents, including but not limited to Plasmodium falciparum and Mycobacterium...

  12. Itaconic Acid Production by Microorganisms: A Review

    Directory of Open Access Journals (Sweden)

    Helia Hajian

    2015-04-01

    Full Text Available Itaconic acid (C5H6O4 is an organic acid with unique structure and characteristics. In order to promote the bio-based economy, the US-Department of Energy (DOE assigned a “top-12” of platform chemicals, which include numerous of organic acids. In particular di-carboxylic acids, like itaconic acid, can be used as monomers for bio-polymers. Thus the need to produce itaconic acid attracts much attention. The favored production process is fermentation of carbohydrates by fungi and Aspergillus terreus is the mostly frequently employed commercial producer of itaconic acid. This review reports the current status of use of microorganisms in enhancing productivity.

  13. Laboratory studies of ocean mixing by microorganisms

    Science.gov (United States)

    Martinez-Ortiz, Monica; Dabiri, John O.

    2011-11-01

    Ocean mixing plays a major role in nutrient and energy transport and is an important input to climate models. Recent studies suggest that the contribution of fluid transport by swimming microorganisms to ocean mixing may be of the same order of magnitude as winds and tides. An experimental setup has been designed in order to study the mixing efficiency of vertical migration of plankton. To this end, a stratified water column is created to model the ocean's density gradient. The vertical migration of Artemia Salina (brine shrimp) within the water column is controlled via luminescent signals on the top and bottom of the column. By fluorescently labelling portions of the water column, the stirring of the density gradient by the animals is visualized and quantified. Preliminary results show that the vertical movement of these organisms produces enhanced mixing relative to control cases in which only buoyancy forces and diffusion are present.

  14. POLYPEPTIDE AND POLYSACCHARIDE PROCESSING IN HYPERTHERMOPHILIC MICROORGANISMS

    Energy Technology Data Exchange (ETDEWEB)

    KELLY, ROBERT M.

    2008-12-22

    This project focused on the microbial physiology and biochemistry of heterotrophic hyperthermophiles with respect to mechanisms by which these organisms process polypeptides and polysaccharides under normal and stressed conditions. Emphasis is on two model organisms, for which completed genome sequences are available: Pyrococcus furiosus (growth Topt of 98°C), an archaeon, and Thermotoga maritima (growth Topt of 80°C), a bacterium. Both organisms are obligately anaerobic heterotrophs that reduce sulfur facultatively. Whole genome cDNA spotted microarrays were used to follow transcriptional response to a variety of environmental conditions in order to identify genes encoding proteins involved in the acquisition, synthesis, processing and utilization of polypeptides and polysaccharides. This project provided new insights into the physiological aspects of hyperthermophiles as these relate to microbial biochemistry and biological function in high temperature habitats. The capacity of these microorganisms to produce biohydrogen from renewable feedstocks makes them important for future efforts to develop biofuels.

  15. Microorganism billiards in closed plane curves

    CERN Document Server

    Krieger, Madison S

    2016-01-01

    Recent experiments have shown that many species of microorganisms leave a solid surface at a fixed angle determined by steric interactions and near-field hydrodynamics. This angle is completely independent of the incoming angle. For several collisions in a closed body this determines a unique type of billiard system, an aspecular billiard in which the outgoing angle is fixed for all collisions. We analyze such a system using numerical simulation of this billiard for varying tables and outgoing angles, and also utilize the theory of one-dimensional maps and wavefront dynamics. When applicable we cite results from and compare our system to similar billiard systems in the literature. We focus on examples from three broad classes: the ellipse, the Bunimovich billiards, and the Sinai billiards. The effect of a noisy outgoing angle is also discussed.

  16. Role of effective microorganism in unfertile soil

    Directory of Open Access Journals (Sweden)

    Yasotha Chandramohan

    2014-03-01

    Full Text Available The present study was conducted to evaluvate the effect of Effective microorganisms (EM.The EM isolation is very important for agricultural fields. For this study used the different kinds of natural ingrediends such as banana, papaya, pumpkin, egg, cane molasses and neem powder to added and mixed and wait for the fermentation. After 45 days the samples were collected.The collected sample were identified using plating technique, microscopic studies and Biochemical test. The identified effective organism was Bacillus megaterium. These Effective organisms acting against the pathogen. The results concluded miximum zone of inhibition against the pathogen Such as E.coil (16mm, P.aeruginosa (18mm, K.pneumoniae (19mm, S.aureus (17mm, S.epidermis (16mm

  17. Pathogenic microorganisms of medicinal herbal drugs

    Directory of Open Access Journals (Sweden)

    Stević Tatjana

    2012-01-01

    Full Text Available All the parts of plants (root, leaf, flower naturally have a high level of microorganisms, bacteria and fungi, especially molds. Microbial contamination could be a result of inappropriate harvesting, cleaning of the raw plant material, unhygienic processing of the plants, unsuitable transport and storage. After examination of over 40 dried medicinal plant species, the lowest microbial quality was determined for Maydis stigma, Mentha leaf and herb, Equisetum herb, Calendula flower, Urtica leaf, Melissa leaf, Serpylli herb, Chamomilla flower etc. Although mixed infections are recorded with different types of fungus, Fusarium was observed as the most dominant genus in most of the tested drugs, followed by Aspergillus and Alternaria. In addition to these fungi species from the following genera were identified: Phoma, Cephalosporium, Nigrospora, Cladosporium, Epicoccum, Gliocladium, Myrothecium, Cercospora, Phomopsis, Verticillium, Dreschlera (=Bipolaris, Rhizoctonia, Septoria, Trichoderma, Curvularia, Stachybotrys, Trichothecium, Puccinia, Botrytis, Mucor and Rhizopus sp., depending on plant species.

  18. Genetic engineering of microorganisms for biodiesel production.

    Science.gov (United States)

    Lin, Hui; Wang, Qun; Shen, Qi; Zhan, Jumei; Zhao, Yuhua

    2013-01-01

    Biodiesel, as one type of renewable energy, is an ideal substitute for petroleum-based diesel fuel and is usually made from triacylglycerides by transesterification with alcohols. Biodiesel production based on microbial fermentation aiming to establish more efficient, less-cost and sustainable biodiesel production strategies is under current investigation by various start-up biotechnology companies and research centers. Genetic engineering plays a key role in the transformation of microbes into the desired cell factories with high efficiency of biodiesel production. Here, we present an overview of principal microorganisms used in the microbial biodiesel production and recent advances in metabolic engineering for the modification required. Overexpression or deletion of the related enzymes for de novo synthesis of biodiesel is highlighted with relevant examples.

  19. Petroleum pollutant degradation by surface water microorganisms.

    Science.gov (United States)

    Antić, Malisa P; Jovancićević, Branimir S; Ilić, Mila; Vrvić, Miroslav M; Schwarzbauer, Jan

    2006-09-01

    It is well known that the composition of petroleum or some of its processing products changes in the environment mostly under the influence of microorganisms. A series of experiments was conducted in order to define the optimum conditions for an efficient biodegradation of petroleum pollutant, or bioremediation of different segments of the environment. The aim of these investigations was to show to what extent the hydrocarbons of a petroleum pollutant are degraded by microbial cultures which were isolated as dominant microorganisms from a surface water of a wastewater canal of an oil refinery and a nitrogen plant. Biodegradation experiments were conducted on one paraffinic, and one naphthenic type of petroleum during a three month period under aerobic conditions, varying the following parameters: Inorganic (Kp) or an organic medium (Bh) with or without exposition to light. Microorganisms were analyzed in a surface water sample from a canal (Pancevo, Serbia), into which wastewater from an oil refinery and a nitrogen plant is released. The consortia of microorganisms were isolated from the water sample (most abundant species: Phormidium foveolarum--filamentous Cyanobacteria, blue-green algae and Achanthes minutissima, diatoms, algae). The simulation experiments of biodegradation were conducted with the biomass suspension and crude oils Sirakovo (Sir, paraffinic type) and Velebit (Ve, naphthenic type). After a three month period, organic substance was extracted by means of chloroform. In the extracts, the content of saturated hydrocarbons, aromatic hydrocarbons, alcohols and fatty acids was determined (the group composition). n-Alkanes and isoprenoid aliphatic alkanes, pristane and phytane, in the aliphatic fractions, were analyzed using gas chromatography (GC). Total isoprenoid aliphatic alkanes and polycyclic alkanes of sterane and triterpane types were analyzed by GC-MS. Paraffinic type petroleums have a significant loss of saturated hydrocarbons. For naphthenic

  20. Putative ancient microorganisms from amber nuggets.

    Science.gov (United States)

    Veiga-Crespo, Patricia; Blasco, Lucía; Poza, Margarita; Villa, Tomás G

    2007-06-01

    Evolutionary microbiology studies based on the isolation of ancient DNA and/or microbial samples are scarce due to the difficulty of finding well preserved biological specimens. However, amber is a fossil resin with natural preserving properties for microbial cells and DNA. The visualization by transmission electron microscopy of different microorganism-like specimens found in amber nuggets from both the Miocene and the Cretaceous periods was accompanied by studies of ancient DNA obtained from the nuggets. After the design of specific primers based on the present sequences of both genes in Saccharomyces cerevisiae, the ancestral AGP2 sequence from the Miocene, as well as the 18S rRNA from the Cretaceous, were amplified.

  1. Climate change effects on beneficial plant-microorganism interactions

    OpenAIRE

    Compant, Stéphane; van der Heijden, Marcel G. A.; Sessitsch, Angela

    2017-01-01

    It is well known that beneficial plant-associated microorganisms may stimulate plant growth and enhance resistance to disease and abiotic stresses. The effects of climate change factors such as elevated CO2, drought and warming on beneficial plant-microorganism interactions are increasingly being explored. This now makes it possible to test whether some general patterns occur and whether different groups of plant-associated microorganisms respond differently or in the same way to climate chan...

  2. Safety Assessment of Foods Derived from Genetically Modified Microorganisms

    OpenAIRE

    Schlundt, J.

    2011-01-01

    Microorganisms have a long history of use in food production, e.g. in the production of sausages, cheeses, etc. Roughly one quarter of all food products rely on microbiological processes, and the safe use of microorganisms for food production is essential. The transfer of novel traits to food microorganisms through recombinant gene technology will result in new potential food safety issues. This requires the elaboration of criteria for safety assessment of foods derived from genetic microorga...

  3. Enhancement of uranium-accumulating ability of microorganisms by irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sakaguchi, Takashi; Nakajima, Akira; Tsuruta, Takehiko [Miyazaki Medical Coll., Kiyotake (Japan)

    1998-01-01

    Some microorganisms having excellent ability to accumulate uranium were isolated, from soil and water systems in and around the Ningyo-toge Station of Power Reactor and Nuclear Fuel Development Corporation. The enhancement of uranium-accumulating ability of microorganisms by electron-beam irradiation was examined, and the ability of JW-046 was increased 3-5% by the irradiation. The irradiation affect the growth of some of microorganisms tested. (author)

  4. [Screening and identification of hemicellulose degrading microorganisms in acid soil].

    Science.gov (United States)

    Gu, Wenjie; Xu, Youquan; Xu, Peizhi; Xie, Kaizhi; Lu, Yusheng; Tang, Shuanhu; Zhang, Fabao

    2012-10-04

    The aim of this study was to screen hemicellulose degrading microorganisms. The methods used to screen the effective strains included hydrolysis spot diameter measurement of hemicellulose plate and extracellular enzyme activity. The methods used to identify the strains included culture characteristics, morphological, physiological-biochemical characteristics and molecular biological methods. We isolated 4 actinomycetes (NA9, NA10, NA12 and NA13), 2 fungi (NF1 and NF7) with hemicellulose degrading ability and no antagonistic effect among them. The hemicellulose degrading activity of 4 actinomyces (NA9, NA10, NA12 and NA13) was 217.6, 229.8, 221.1 and 211.8 U/mL. The hemicellulose degrading activity of 2 fungi (NF1 and NF7) was 217.7 and 244.2 U/mL. The hemicellulose degrading activity of complex microbial system was 299.0 U/mL. NA9, NA10, NA12 and NA13 were Streptomyces costaricanus; NF1 was Aspergillus candidus and NF7 was Tarlaromyces flavus. the 4 actinomyces and 2 fungi screened have high hemicelluloses enzyme activity. These strains have good application value and more research value.

  5. Accumulation of metals by microorganisms — processes and importance for soil systems

    Science.gov (United States)

    Ledin, Maria

    2000-08-01

    Metal accumulation by solid substances can counteract metal mobilization in the environment if the solid substance is immobile. Microorganisms have a high surface area-to-volume ratio because of their small size and therefore provide a large contact area that can interact with metals in the surrounding environment. Microbial metal accumulation has received much attention in the last years due to the potential use of microorganisms for cleaning metal-polluted water. However, considerably less attention has been paid to the role of microorganisms for metal mobility in soil even though the same processes may occur there. Therefore, this paper highlights this area. The different accumulation processes that microorganisms perform are analyzed and their potential significance in soil systems is discussed. Different kinds of mechanisms can be involved in the accumulation of metals by microorganisms, e.g. adsorption, precipitation, complexation and active transport into the cell. Physicochemical parameters like pH and ionic composition, as well as biological factors are of importance for the magnitude of accumulation. Often large amounts of metals can be accumulated with varying specificity, and microorganisms may provide nucleation sites for mineral formation. Several studies of microbial metal accumulation have been made with different methods and aims. Most of these studies concern single-component systems with one organism at a time. Data from accumulation experiments with pure cultures of microorganisms have been used to model the overall metal retention in soil. A further development is experimental model systems using various solid soil components in salt medium. Microbial metal accumulation is difficult to study in situ, but some experimental methods have been applied as tools for studying real soil systems, e.g. litter bags buried in soil containing microorganisms, a method where discs with microorganisms have been put onto agar plates with soil extracts, and

  6. Radiation resistance of microorganisms on unsterilized infusion sets

    DEFF Research Database (Denmark)

    Christensen, E. Ahrensburg; Kristensen, H.; Hoborn, J.;

    1991-01-01

    Three different methods were used for detecting and isolating microorganisms with high radiation resistance from the microbial contamination on infusion sets prior to sterilization. By all three methods, microorganisms with a radiation resistance high enough to be a critical factor in a steriliza......Three different methods were used for detecting and isolating microorganisms with high radiation resistance from the microbial contamination on infusion sets prior to sterilization. By all three methods, microorganisms with a radiation resistance high enough to be a critical factor...

  7. Biosynthesis of Nanoparticles by Microorganisms and Their Applications

    National Research Council Canada - National Science Library

    Li, Xiangqian; Xu, Huizhong; Chen, Zhe-Sheng; Chen, Guofang

    2011-01-01

    .... Nowadays, a variety of inorganic nanoparticles with well-defined chemical composition, size, and morphology have been synthesized by using different microorganisms, and their applications in many...

  8. Collective motion of micro-organisms from field theoretical viewpoint

    CERN Document Server

    Kawamura, M; Kawamura, Masako; Sugamoto, Akio

    1995-01-01

    We analyze the collective motion of micro-organisms in the fluid and consider the problem of the red tide. The red tide is produced by the condensation of the micro-organisms, which might be a similar phenomenon to the condensation of the strings. We propose a model of the generation of the red tide. By considering the interaction between the micro-organisms mediated by the velocity fields in the fluid, we derive the Van der Waals type equation of state, where the generation of the red tide can be regarded as a phase transition from the gas of micro-organisms to the liquid.

  9. The ecology of micro-organisms in a closed environment

    Science.gov (United States)

    Fox, L.

    1971-01-01

    Microorganisms under closed environmental ecological conditions with reference to astronauts infectious diseases, discussing bacteria growth in Biosatellite 2 and earth based closed chamber experiments

  10. Analysis of Membrane Lipids of Airborne Micro-Organisms

    Science.gov (United States)

    MacNaughton, Sarah

    2006-01-01

    A method of characterization of airborne micro-organisms in a given location involves (1) large-volume filtration of air onto glass-fiber filters; (2) accelerated extraction of membrane lipids of the collected micro-organisms by use of pressurized hot liquid; and (3) identification and quantitation of the lipids by use of gas chromatography and mass spectrometry. This method is suitable for use in both outdoor and indoor environments; for example, it can be used to measure airborne microbial contamination in buildings ("sick-building syndrome"). The classical approach to analysis of airborne micro-organisms is based on the growth of cultureable micro-organisms and does not provide an account of viable but noncultureable micro-organisms, which typically amount to more than 90 percent of the micro-organisms present. In contrast, the present method provides an account of all micro-organisms, including cultureable, noncultureable, aerobic, and anaerobic ones. The analysis of lipids according to this method makes it possible to estimate the number of viable airborne micro-organisms present in the sampled air and to obtain a quantitative profile of the general types of micro-organisms present along with some information about their physiological statuses.

  11. Assessment of soil properties by organic matter and EM-microorganism incorporation

    Directory of Open Access Journals (Sweden)

    Valarini P. J.

    2003-01-01

    Full Text Available Properties of a claim loam soil, collected in Aranjuez (Madrid and enriched with organic matter and microorganisms, were evaluated under controlled temperature and moisture conditions, over a period of three months. The following treatments were carried out: soil (control; soil + 50 t ha-1 of animal manure (E50; soil + 50 t ha-1 of animal manure + 30 L ha-1 of effective microorganisms (E50EM; soil + 30 t ha-1 of the combination of various green crop residues and weeds (RC30 and soil + 30 t ha-1 of the combination of various green crop residues and weeds + 30 L ha-1 of effective microorganisms (RC30EM. Soil samples were taken before and after incubation and their physical, chemical, and microbiological parameters analyzed. Significant increase was observed in the production of exopolysaccharides and basic phosphatase and esterase enzyme activities in the treatments E50EM and RC30EM, in correlation with the humification of organic matter, water retention at field capacity, and the cationic exchange capacity (CEC of the same treatments. The conclusion was drawn that the incorporation of a mixture of effective microorganisms (EM intensified the biological soil activity and improved physical and chemical soil properties, contributing to a quick humification of fresh organic matter. These findings were illustrated by the microbiological activities of exopolysaccharides and by alkaline phosphatase and esterase enzymes, which can be used as early and integrated soil health indicators.

  12. EFFECTS OF FEEDING MICROORGANISMS ON GROWTH PERFORMANCE AND THE ACTIVITIES DIGESTIVE ENZYMES OF OREOCHROMIS NILOTICUS×O.AUREUS%微生物制剂对奥尼罗非鱼生长及消化酶活性的影响

    Institute of Scientific and Technical Information of China (English)

    江永明; 付天玺; 张丽; 许国焕; 吴月嫦; 龚全

    2011-01-01

    In the present experiment, the effects of Debaryomyces hanseni, Bacillus subtilis and Bacillus coagulans (3.0×l011 cfu/kg feed) on growth and the digestive enzyme activities of Oreochromis niloticus×O. Aureus[average initial weight about (34.50±0.25) g] for 56 days were studied. The results showed that compared with the control group (non-supplemented), the weight gain rates of Bacillus subtilis and Bacillus coagulans were 12.27% and 8.18%, which were higher than that of the control (P<0.05). The feed coefficients of Bacillus subtilis and Bacillus coagulans were 10.92% and 8.18%, which were lower than that of the control respectively (P<0.05). Compared with the control group, the apparent digestibility on dry matter of Bacillus subtilis and Bacillus coagulans increased by 10.54% and 10.07%, and the protein apparent digestibility increased by 4.18% and 3.65% (P<0.05). Bacillus subtilis and Bacillus coagulans adding to the diets could significantly improve the activities of proteinase in intestine, hepatopancreas and stomach of Oreochromis niloticus×O. Aureus (P<0.05) compared to the control group and Debaryomyces hanseni group, but three Micoecologics adding to the diets showed no significant difference with the activities of amylase and lipase in intestine, hepatopancreas and stomach of Oreochromis niloticus/O. Aureus (P>0.05). The results suggested that diet with 3.0×l011 cfu/kg feed of Bacillus subtilis supplement could significantly promote the growth of Oreochromis niloticus×O. Aureus and the activities of proteinase in intestine, hepatopancreas and stomach of Oreochromis niloticus×O. Aureus.%选用192 尾初始体重(34.50±0.25) g 的健康奥尼罗非鱼(Oreochromis niloticus×O.aureu),研究在基础饲料中分别添加相同剂量(活菌含量为3.0×1011 cfu/kg 饲料)的汉逊德巴利酵母、枯草芽孢杆菌和凝结芽孢杆菌对奥尼罗非鱼生长及消化酶活性的影响,试验期56d.试验结果表明,与对照组相比,添

  13. Protein expression on Cr resistant microorganism using electrophoresis method

    Directory of Open Access Journals (Sweden)

    SAJIDAN

    2009-01-01

    Full Text Available Fatmawati U, Suranto, Sajidan. 2009. Protein expression on Cr resistant microorganism using electrophoresis method. Nusantara Bioscience 1: 31-37. Hexavalent chromium (Cr(VI is known as toxic heavy metals, so the need is reduced to Cr(III is much less toxicity. Pseudomonas aeruginosa, Pseudomonas putida, Klebsiella pneumoniae, Pantoea sp. and Saccharomyces cerevisiae are resistant Cr(VI microorganism and have ability to reduce Cr(VI. The aim of this research is to know ability of microorganism to reduce Cr(VI and to know protein band pattern between Cr(VI resistant microorganism and non resistant microorganism which inoculated on LB broth. SDS-PAGE was used to indentify protein expression. While, Cr(VI concentration was identified by 1.5 diphenylcarbazide method. The quantitative data was analyzed by two factorial ANOVA that continued with DMRT at 1% level test. The qualitative data i.e. protein expression analyzed by relative mobility (Rf. The results showed that the ability of microorganisms to reduce Cr(VI at initial concentration of 0.5 ppm, 1 ppm, 5 ppm and 10 ppm may vary, the average percentage of the ability of each microorganism in reducing Cr(VI is P. putida (65% > S. cerevisiae (64.45% >. P. aeruginosa (60.73% > Pantoea sp. (50.22% > K. pneumoniae (47.82% > without microorganisms (34.25%. The adding microorganisms have significantly influenced toward reduction of Cr(VI. The SDS-PAGE shows that protein expression between resistant and not resistant microorganisms are no different, but resistant microorganisms have more protein (protein band is thicker.

  14. Atrazine degradation by aerobic microorganisms isolated from the rhizosphere of sweet flag (Acorus calamus L.).

    Science.gov (United States)

    Marecik, Roman; Króliczak, Paweł; Czaczyk, Katarzyna; Białas, Wojciech; Olejnik, Anna; Cyplik, Paweł

    2008-04-01

    In presented study the capability of microorganisms isolated from the rhizosphere of sweet flag (Acorus calamus) to the atrazine degradation was assessed. Following isolation of the microorganisms counts of psychrophilic bacteria, mesophilic bacteria and fungi were determined. Isolated microorganisms were screened in terms of their ability to decompose a triazine herbicide, atrazine. Our results demonstrate that within the rhizosphere of sweet flag there were 3.8x10(7) cfu of psychrophilic bacteria, 1.8x10(7) cfu of mesophilic bacteria, and 6x10(5) cfu of fungi per 1 g of dry root mass. These microorganisms were represented by more than 20 different strains, and at the first step these strains were grown for 5 days in the presence of atrazine at a concentration of 5 mg/l. In terms of the effect of this trial culture, the bacteria reduced the level of atrazine by an average of about 2-20%, but the average level of reduction by fungi was in the range 18-60%. The most active strains involved in atrazine reduction were then selected and identified. These strains were classified as Stenotrophomonas maltophilia, Bacillus licheniformis, Bacillus megaterium, Rahnella aquatilis (three strains), Umbelopsis isabellina, Volutella ciliata and Botrytis cinerea. Culturing of the microorganisms for a longer time resulted in high atrazine degradation level. The highest degradation level was observed at atrazine concentrations of 5 mg/l for S. maltophilia (83.5% after 15 days of culture) and for Botrytis sp. (82% after 21 days of culture). Our results indicate that microorganisms of the sweet flag rhizosphere can play an important role in the bioremediation of atrazine-contaminated sites.

  15. Biotransformation of Spanish coals by microorganisms; Biotransformacion de Carbones Espanoles por Microorganismos

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    some newly isolated microorganisms could solubilized different kinds of Spanish coals (hard coal, subbituminous coal and lignite). Certain fungi and bacteria could solubilized lignite when growing in a mineral medium. However, to solubilized higher rank coals (hard coal and subbituminous coal) microorganisms require a complete medium. Microorganisms, which showed higher capacity to solubilized coal, were incubated in the presence of coal (hard coal, subbituminous coal and lignite) at the optimal conditions to get coal liquefaction/solubilization. The resultant products were analysed by IR and UV/visible spectrometry. No major differences among the original coal, solubilized/liquefied coal and residual coal were detected. However, an increase in metallic carboxylate and a decrease in OH'- carboxylic groups were observed in the liquefied lignite. Humic acids derived from original lignite residual lignite and liquefied/solubilized lignite by microorganisms were analysed. Several differences were observed in the humic acids extracted from the liquefied lignite, such as an increase in the total acidity and in the proportion of the phenolic groups. Differences on the humic acid molecular weight were observed too. Several fungal and bacterial strains were able to grow using humic acids as sole carbon source. Microorganisms growing in humic acid were observed by Scanning Electron Microscopy. Besides, the coal solubilization capacity of several fungal strains (M2, m$ and AGI) growing in different culture media was assayed. In order to get some insight into the mechanisms of the liquefaction/solubilization of Spanish coals (hard coal, subbituminous coal and lignite) by these microorganisms, some features in the culture supernatants were studied: pH values; extracellular specific proteins; enzyme activities possibly related with coal solubilization and the presence of oxalate. M2 and M4 fungal strains grown in the presence of coal produced some specific extracellular

  16. In vitro antimicrobial activity of irreversible hydrocolloid impressions against 12 oral microorganisms Atividade antimicrobiana in vitro de moldes de hidrocolóide irreversível contra 12 microrganismos orais

    Directory of Open Access Journals (Sweden)

    Luciana Assirati Casemiro

    2007-12-01

    Full Text Available This study evaluated in vitro the antimicrobial activity of irreversible hydrocolloids (one containing an antimicrobial agent prepared with water or with a 0.2% chlorhexidine digluconate solution against 12 strains of the oral microbiota. Twenty specimens (0.5 x 1.0 cm for each group (1. Jeltrate mixed with water; 2. Jeltrate mixed with 0.2% chlorhexidine digluconate solution; 3. Greengel mixed with water; 4. Greengel mixed with 0.2% chlorhexidine digluconate solution were prepared under sterile conditions and placed in culture media inoculated with the indicator strains. After incubation in aerobiosis or microaerophilia, inhibition of the microbial growth was measured and the results were interpreted. The normal adherence curve revealed a non-normal distribution of the data, so the non-parametric Friedman Test was performed (p Este trabalho avaliou in vitro a atividade antimicrobiana de alginatos (um deles contendo agente antimicrobiano manipulados com água ou solução de digluconato de clorexidina a 0,2% contra 12 cepas da microbiota oral. Vinte espécimes (0,5 x 1,0 cm para cada grupo (1. Jeltrate manipulado com água, 2. Jeltrate manipulado com solução de digluconato de clorexidina a 0,2%; 3. Greengel manipulado com água; 4. Greengel manipulado com solução de digluconato de clorexidina a 0,2% foram confeccionados sob condições estéreis e semeados em meios de cultura inoculados com as cepas indicadoras. Após incubação em aerobiose ou microaerofilia, a inibição do crescimento microbiano foi medida e os resultados foram interpretados. A curva normal de aderência revelou uma distribuição não-normal dos dados, então o teste não paramétrico de Friedman (p < 0,05 foi realizado. A atividade antimicrobiana dos grupos foi classificada na seguinte ordem crescente: 1, 3, 4 e 2. Os resultados sugerem que a manipulação de alginatos com solução de digluconato de clorexidina a 0,2% é um método efetivo para reduzir a contamina

  17. "Petit suisse" cheese from kefir: an alternative dessert with microorganisms of probiotic activity Queijo "Petit suisse" de kefir: uma alternativa de sobremesa com microorganismos de ação probiótica

    Directory of Open Access Journals (Sweden)

    Thanise Sabrina Souza Santos

    2012-09-01

    Full Text Available "Petit Suisse" is a creamy cheese. Kefir is a symbiotic mixture of lactic acid bacteria and yeasts with probiotic activity including immunomodulation and balance of intestinal microflora. The present study aims to develop "Petit Suisse" cheese from kefir. Kefir grains were grown in pasteurized cow milk, and after the separation of kefir the serum was discarded and the "Petit Suisse" cheese was prepared using strawberry, mangaba, herbs, and dried tomatoes. The acceptance of the different preparations was evaluated using a nine-point hedonic scale followed by ANOVA. The sweet and salty products were compared by the Student's t-test. Purchase intent was evaluated by the means test and frequency distribution. All products were well accepted by the judges. The product was characterized by low yield, but it can be prepared at home at low cost. The nutritional composition analyses and the variety of flavors as well as the range of age of the judges are alternatives for further studies.Petit suisse é um queijo de consistência pastosa. O kefir é um produto resultante da simbiose entre bactérias ácido-láticas e leveduras, e apresenta ação probiótica, como imunomodulação e balanço da microbiota intestinal. O presente estudo buscou desenvolver petit suisse de kefir. Os grãos foram cultivados no leite de vaca pasteurizado e, após separação do kefir, seguiu-se para dessoragem e preparo do petit suisse nos sabores morango, mangaba, ervas e tomate seco. Com escala hedônica estruturada de nove pontos, avaliou-se aceitação pela ANOVA. As amostras doces e salgadas foram comparadas por meio do teste t de Student e a intenção de compra foi avaliada por meio do teste de médias e de distribuição das frequências. As amostras apresentaram boa aceitação pelos julgadores. O produto pronto apresentou baixo rendimento, mas pode ser reproduzido em nível domiciliar com baixo custo. A análise da composição nutricional e a variação dos sabores e

  18. Scientific Opinion on the substantiation of health claims related to various microorganisms and reduction of gastro-intestinal discomfort (ID 1030, 2956, 2958, 2961, 2963, 2966, 2970, decreasing potentially pathogenic gastro-intestinal microorganisms (ID 1030, 2956, 2958, 2961, 2963, 2966, 2970, improved lactose digestion (ID 1030, 2956, 2958, 2961, 2963, 2966, 2970, “intestinal flora/digestive health” (ID 4231, defence against vaginal pathogens (ID 2950, 2957, 2967 and increasing IL-10 production and/or enhancing the activity of natural killer cells (ID 2960, 2962, 2971 (further assessment pursuant to Article 13(1 of Regulation (EC No 1924/2006

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Dietetic Products, Nutrition and Allergies

    2012-08-01

    Full Text Available

    Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies (NDA was asked to provide a scientific opinion on health claims pursuant to Article 13 of Regulation (EC No 1924/2006 in the framework of further assessment related to various microorganisms and reduction of gastro-intestinal discomfort, decreasing potentially pathogenic gastro-intestinal microorganisms, improved lactose digestion, “intestinal flora/digestive health”, defence against vaginal pathogens and increasing IL-10 production and/or enhancing the activity of natural killer cells. The food constituents Lactobacillus crispatus BCCM/LMG P-17631, Lactobacillus gasseri BCCM/LMG P-17632, Lactobacillus gasseri BCCM/LMG P-18137, Lactobacillus paracasei CNCM I-1687, Lactobacillus paracasei CNCM I-1688, Lactobacillus plantarum BCCM/LMG P-17630, Lactobacillus salivarius CNCM I-1794 and a combination of Bifidobacterium animalis ssp. lactis Bf-6 and Lactobacillus johnsonii La-1 (ACD-1(CLbA22 are sufficiently characterised. The evidence provided did not establish that the proposed claimed effect, increasing IL-10 production and/or enhancing the activity of natural killer cells, is a beneficial physiological effect. The claimed effect “intestinal flora/digestive health” is general and non-specific, and does not refer to any specific health claim as required by Regulation (EC No 1924/2006. The references provided in relation to the claims evaluated in this opinion included studies which assessed the effects of food constituents other than the food constituents which are the subject of the claims and/or investigated health outcomes unrelated to the claimed effects. No human studies which investigated the effects of the food constituents on appropriate measures of the claimed effects were provided. On the basis of the data presented, the Panel

  19. Sensory Transduction in Microorganisms 2008 Gordon Research Conference (January 2008)

    Energy Technology Data Exchange (ETDEWEB)

    Ann M. Stock

    2009-04-08

    Research into the mechanisms involved in the sensing and responses of microorganisms to changes in their environments is currently very active in a large number of laboratories worldwide. An increasingly wide range of prokaryotic and eukaryotic species are being studied with regard to their sensing of diverse chemical and physical stimuli, including nutrients, toxins, intercellular signaling molecules, redox indicators, light, pressure, magnetic fields, and surface contact, leading to adaptive responses affecting motile behavior, gene expression and/or development. The ease of manipulation of microorganisms has facilitated application of a broad range of techniques that have provided comprehensive descriptions of cellular behavior and its underlying molecular mechanisms. Systems and their molecular components have been probed at levels ranging from the whole organism down to atomic resolution using behavioral analyses; electrophysiology; genetics; molecular biology; biochemical and biophysical characterization; structural biology; single molecule, fluorescence and cryo-electron microscopy; computational modeling; bioinformatics and genomic analyses. Several model systems such as bacterial chemotaxis and motility, fruiting body formation in Myxococcus xanthus, and motility and development in Dictyostelium discoideum have traditionally been a focus of this meeting. By providing a basis for assessment of similarities and differences in mechanisms, understanding of these pathways has advanced the study of many other microbial sensing systems. This conference aims to bring together researchers investigating different prokaryotic and eukaryotic microbial systems using diverse approaches to compare data, share methodologies and ideas, and seek to understand the fundamental principles underlying sensory responses. Topic areas include: (1) Receptor Sensing and Signaling; (2) Intracellular Signaling (two-component, c-di-GMP, c-AMP, etc.); (3) Intracellular Localization and

  20. Screening of lipid degrading microorganisms for wastewater treatment

    Directory of Open Access Journals (Sweden)

    Sarmurzina, Z. S.

    2013-01-01

    Full Text Available Aims: Fats, oils and greases (FOG are poorly removable materials in wastewater treatment systems. The aim of this work is to find the most suitable strain(s for a biological treatment technology of FOGs polluted wastewaters. Methodology and results: The 142 microorganisms from polluted environment were screened for lipase activity (LA by sequentially using assays on agar-Tween 80, agar-fats, and turbidimetrically measuring the quantity of calcium salts with fatty acids. The isolates G23, G30, and Zb32 showed highest units of LA and were identified by sequence analysis of 16S rRNA genes. Lipid masses were determined gravimetrically after chloroform/ethyl alcohol extraction. In the model solutions with animal fats the strain Pseudomonas aeruginosa G23 reduced mass fractions of mutton fat, beef tallow, and lard by 79±5%, 88±4%, and 80±6% respectively. Under the same conditions Aeromonas punctata G30 reduced: 65±3%, 60±8%, and 75±4%, and P. aeruginosa Zb32 reduced: 47±5%, 52±6% and 73±7%. In the model solutions with FOGs trap specimens as a carbon source from the local cafeteria the strains P. aeruginosa G23, A. punctata G30, and P. aeruginosa Zb32 reduced a lipid mass fraction by 61.5±7%, 45.2±5%, and 37.5±3% respectively.Conclusion, significance and impact of study: The strain P. aeruginosa G23 is the most effective lipid-degrading microorganism and the best candidate to use in biological treatment technology of FOGs polluted wastewater in Kazakhstan.

  1. 5-Fluorouracil sensitivity varies among oral micro-organisms.

    Science.gov (United States)

    Vanlancker, Eline; Vanhoecke, Barbara; Smet, Rozel; Props, Ruben; Van de Wiele, Tom

    2016-08-01

    5-Fluorouracil (5-FU), a commonly used chemotherapeutic agent, often causes oral mucositis, an inflammation and ulceration of the oral mucosa. Micro-organisms in the oral cavity are thought to play an important role in the aggravation and severity of mucositis, but the mechanisms behind this remain unclear. Although 5-FU has been shown to elicit antibacterial effects at high concentrations (>100 µM), its antibacterial effect at physiologically relevant concentrations in the oral cavity is unknown. This study reports the effect of different concentrations of 5-FU (range 0.1-50 µM) on the growth and viability of bacterial monocultures that are present in the oral cavity and the possible role in the activity of dihydropyrimidine dehydrogenase (DPD), an enzyme involved in 5-FU resistance. Our data showed a differential sensitivity among the tested oral species towards physiological concentrations of 5-FU. Klebsiellaoxytoca, Streptococcus salivarius, Streptococcus mitis, Streptococcus oralis, Pseudomonas aeruginosa and Lactobacillus salivarius appeared to be highly resistant to all tested concentrations. In contrast, Lactobacillusoris, Lactobacillus plantarum, Streptococcus pyogenes, Fusobacterium nucleatum and Neisseria mucosa showed a significant reduction in growth and viability starting from very low concentrations (0.2-3.1 µM). We can also provide evidence that DPD is not involved in the 5-FU resistance of the selected species. The observed variability in response to physiological 5-FU concentrations may explain why certain microbiota lead to a community dysbiosis and/or an overgrowth of certain resistant micro-organisms in the oral cavity following cancer treatment.

  2. Microbiology and atmospheric processes: research challenges concerning the impact of airborne micro-organisms on the atmosphere and climate

    Directory of Open Access Journals (Sweden)

    C. E. Morris

    2011-01-01

    Full Text Available For the past 200 years, the field of aerobiology has explored the abundance, diversity, survival and transport of micro-organisms in the atmosphere. Micro-organisms have been explored as passive and severely stressed riders of atmospheric transport systems. Recently, an interest in the active roles of these micro-organisms has emerged along with proposals that the atmosphere is a global biome for microbial metabolic activity and perhaps even multiplication. As part of a series of papers on the sources, distribution and roles in atmospheric processes of biological particles in the atmosphere, here we describe the pertinence of questions relating to the potential roles that air-borne micro-organisms might play in meteorological phenomena. For the upcoming era of research on the role of air-borne micro-organisms in meteorological phenomena, one important challenge is to go beyond descriptions of abundance of micro-organisms in the atmosphere toward an understanding of their dynamics in terms of both biological and physico-chemical properties and of the relevant transport processes at different scales. Another challenge is to develop this understanding under contexts pertinent to their potential role in processes related to atmospheric chemistry, the formation of clouds, precipitation and radiative forcing. This will require truly interdisciplinary approaches involving collaborators from the biological and physical sciences, from disciplines as disparate as agronomy, microbial genetics and atmosphere physics, for example.

  3. Integrated evaluation of soil quality after the incorporation of organic matter and microorganisms

    Directory of Open Access Journals (Sweden)

    Valarini Pedro J.

    2002-01-01

    Full Text Available The soil quality was evaluated following the addition of organic matter and microorganisms to a clay loam soil collected in Aranjuez (Madrid under controlled conditions of temperature and moisture, and over a period of three months. The following treatments were carried out: soil (control; soil + 50 t/ha of animal manure (E50; soil + 50 t/ha of animal manure + 30l/ha of effective microorganisms (E50EM; soil + 30 t/ha of combination of various green crop residues and weeds (RC30 and soil + 30 t/ha of combination of various green crop residues and weeds + 30l/ha of effective microorganisms (RC30EM. The soil samples were taken before and after the incubation and analysed using physical, chemical and microbiological parameters. A significant increase in the production of polysaccharides and alkaline phosphatase and esterase enzymes in the treatments E50EM and RC30EM was observed, being in direct correlation with the humification of the organic matter, with the water retention at field capacity, and with the cationic exchange capacity (CEC. It can be concluded that the incorporation of microorganisms EM potentialized the soil biological activity and improved physico-chemical soil properties, contributing to a quick humification of fresh organic matter. Those findings were proved by microbiological activities of exopolysaccharides by alcaline phosphatase and esterase enzymes, which can be used as earlier and integral soil health indicators.

  4. Effect of gamma irradiation on hyperthermal composting microorganisms for feasible application in space

    Science.gov (United States)

    Yoon, Minchul; Choi, Jong-il; Yamashita, Masamichi

    2013-05-01

    The composting system is the most efficient method for processing organic waste in space; however, the composting activity of microorganisms can be altered by cosmic rays. In this study, the effect of ionizing irradiation on composting bacteria was investigated. Sequence analyses of amplified 16S rRNA, 18S rRNA, and amoA genes were used to identify hyperthermal composting microorganisms. The viability of microorganisms in compost soil after gamma irradiation was directly determined using LIVE/DEAD BacLight viability kit. The dominant bacterial genera were Weissella cibaria and Leuconostoc sp., and the fungal genera were Metschnikowia bicuspidata and Pichia guilliermondii. Gamma irradiation up to a dose of 10 kGy did not significantly alter the microbial population. Furthermore, amylase and cellulase activities were maintained after high-dose gamma irradiation. Our results show that hyperthermal microorganisms can be used to recycle agricultural and fermented material in space stations and other human-inhabiting facilities on the Moon, Mars, and other planets.

  5. Magnesium Fertilizer-Induced Increase of Symbiotic Microorganisms Improves Forage Growth and Quality.

    Science.gov (United States)

    Chen, Jihui; Li, Yanpeng; Wen, Shilin; Rosanoff, Andrea; Yang, Gaowen; Sun, Xiao

    2017-04-26

    Magnesium (Mg) plays important roles in photosynthesis and protein synthesis; however, latent Mg deficiencies are common phenomena that can influence food quality. Nevertheless, the effects of Mg fertilizer additions on plant carbon (C):nitrogen (N):phosphorus (P) stoichiometry, an important index of food quality, are unclear and the underlying mechanisms unexplored. We conducted a greenhouse experiment using low-Mg in situ soil without and with a gradient of Mg additions to investigate the effect of Mg fertilizer on growth and stoichiometry of maize and soybean and also measure these plants' main symbiotic microorganisms: arbuscular mycorrhizal fungi (AMF) and rhizobium, respectively. Our results showed that Mg addition significantly improved both plant species' growth and also increased N and P concentrations in soybean and maize, respectively, resulting in low C:N ratio and high N:P ratio in soybean and low C:P and N:P ratios in maize. These results presumably stemmed from the increase of nutrients supplied by activation-enhanced plant symbiotic microorganisms, an explanation supported by statistically significant positive correlations between plant stoichiometry and plants' symbiotic microorganisms' increased growth with Mg addition. We conclude that Mg supply can improve plant growth and alter plant stoichiometry via enhanced activity of plant symbiotic microorganisms. Possible mechanisms underlying this positive plant-soil feedback include an enhanced photosynthetic product flow to roots caused by adequate Mg supply.

  6. Microorganisms in processes of the destruction of oil in reservoirs

    Directory of Open Access Journals (Sweden)

    A. A. Kurapov

    2010-01-01

    Full Text Available Pollution by oil has negative influence on all ecosystem of the sea. The main role in decomposing of hydrocarbons belongs to microorganisms. Influence emulsion and water repellencies of cellular walls of microorganisms on an oil destruction is noted.

  7. Potential applications of plant probiotic microorganisms in agriculture and forestry

    OpenAIRE

    Luciana Porto de Souza Vandenberghe; Lina Marcela Blandon Garcia; Cristine Rodrigues; Marcela Cândido Camara; Gilberto Vinícius de Melo Pereira; Juliana de Oliveira; Carlos Ricardo Soccol

    2017-01-01

    Agriculture producers, pushed by the need for high productivity, have stimulated the intensive use of pesticides and fertilizers. Unfortunately, negative effects on water, soil, and human and animal health have appeared as a consequence of this indiscriminate practice. Plant probiotic microorganisms (PPM), also known as bioprotectants, biocontrollers, biofertilizers, or biostimulants, are beneficial microorganisms that offer a promising alternative and reduce health and environmental problems...

  8. Composting MSW and sewage sludge with effective complex microorganisms

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The effects of complex microorganisms in composting process of the municipal solid waste (MSW) and sludge were examined through inspecting biomass, temperature, oxygen consumption, organic mater, and C/N (the ratio of carbon and nitrogen). The experimental results shows: complex microorganisms are effective to compose organic matter and speedup composting change into humus.

  9. Climate change effects on beneficial plant-microorganism interactions.

    Science.gov (United States)

    Compant, Stéphane; van der Heijden, Marcel G A; Sessitsch, Angela

    2010-08-01

    It is well known that beneficial plant-associated microorganisms may stimulate plant growth and enhance resistance to disease and abiotic stresses. The effects of climate change factors such as elevated CO(2), drought and warming on beneficial plant-microorganism interactions are increasingly being explored. This now makes it possible to test whether some general patterns occur and whether different groups of plant-associated microorganisms respond differently or in the same way to climate change. Here, we review the results of 135 studies investigating the effects of climate change factors on beneficial microorganisms and their interaction with host plants. The majority of studies showed that elevated CO(2) had a positive influence on the abundance of arbuscular and ectomycorrhizal fungi, whereas the effects on plant growth-promoting bacteria and endophytic fungi were more variable. In most cases, plant-associated microorganisms had a beneficial effect on plants under elevated CO(2). The effects of increased temperature on beneficial plant-associated microorganisms were more variable, positive and neutral, and negative effects were equally common and varied considerably with the study system and the temperature range investigated. Moreover, numerous studies indicated that plant growth-promoting microorganisms (both bacteria and fungi) positively affected plants subjected to drought stress. Overall, this review shows that plant-associated microorganisms are an important factor influencing the response of plants to climate change.

  10. Process for selecting polyhydroxyalkanoate (PHA) producing micro-organisms

    NARCIS (Netherlands)

    Van Loosdrecht, M.C.M.; Kleerebezem, R.; Jian, Y.; Johnson, K.

    2009-01-01

    The invention relates to a process for selecting a polyhydroxyalkanoate (PHA) producing micro-organism from a natural source comprising a variety of micro-organisms, comprising steps of preparing a fermentation broth comprising the natural source and nutrients in water; creating and maintaining

  11. Process for selecting polyhydroxyalkanoate (PHA) producing micro-organisms

    NARCIS (Netherlands)

    Van Loosdrecht, M.C.M.; Kleerebezem, R.; Jian, Y.; Johnson, K.

    2009-01-01

    The invention relates to a process for selecting a polyhydroxyalkanoate (PHA) producing micro-organism from a natural source comprising a variety of micro-organisms, comprising steps of preparing a fermentation broth comprising the natural source and nutrients in water; creating and maintaining aero

  12. Microorganisms in Food--Their Significance and Methods of Enumeration.

    Science.gov (United States)

    Andrews, S.

    1980-01-01

    Described are laboratory methods for enumerating microorganisms in food. These methods are utilized to determine if foods are potentially hazardous to the consumer due to high concentrations of microorganisms. Discussed are indicator organisms, including coliforms, interococci, yeasts, and molds; food poisoning organisms (staphylococci and…

  13. Resistance of aerobic microorganisms and soil enzyme response to soil contamination with Ekodiesel Ultra fuel.

    Science.gov (United States)

    Borowik, Agata; Wyszkowska, Jadwiga; Wyszkowski, Mirosław

    2017-09-10

    This study determined the susceptibility of cultured soil microorganisms to the effects of Ekodiesel Ultra fuel (DO), to the enzymatic activity of soil and to soil contamination with PAHs. Studies into the effects of any type of oil products on reactions taking place in soil are necessary as particular fuels not only differ in the chemical composition of oil products but also in the composition of various fuel improvers and antimicrobial fuel additives. The subjects of the study included loamy sand and sandy loam which, in their natural state, have been classified into the soil subtype 3.1.1 Endocalcaric Cambisols. The soil was contaminated with the DO in amounts of 0, 5 and 10 cm(3) kg(-1). Differences were noted in the resistance of particular groups or genera of microorganisms to DO contamination in loamy sand (LS) and sandy loam (SL). In loamy sand and sandy loam, the most resistant microorganisms were oligotrophic spore-forming bacteria. The resistance of microorganisms to DO contamination was greater in LS than in SL. It decreased with the duration of exposure of microorganisms to the effects of DO. The factor of impact (IFDO) on the activity of particular enzymes varied. For dehydrogenases, urease, arylsulphatase and β-glucosidase, it had negative values, while for catalase, it had positive values and was close to 0 for acid phosphatase and alkaline phosphatase. However, in both soils, the noted index of biochemical activity of soil (BA) decreased with the increase in DO contamination. In addition, a positive correlation occurred between the degree of soil contamination and its PAH content.

  14. Physiological ecology of microorganisms in Subglacial Lake Whillans

    Directory of Open Access Journals (Sweden)

    Trista J Vick-Majors

    2016-10-01

    Full Text Available Subglacial microbial habitats are widespread in glaciated regions of our planet. Some of these environments have been isolated from the atmosphere and from sunlight for many thousands of years. Consequently, ecosystem processes must rely on energy gained from the oxidation of inorganic substrates or detrital organic matter. Subglacial Lake Whillans (SLW is one of more than 400 subglacial lakes known to exist under the Antarctic ice sheet; however, little is known about microbial physiology and energetics in these systems. When it was sampled through its 800 m thick ice cover in 2013, the SLW water column was shallow (~2 m deep, oxygenated, and possessed sufficient concentrations of C, N, and P substrates to support microbial growth. Here, we use a combination of physiological assays and models to assess the energetics of microbial life in SLW. In general, SLW microorganisms grew slowly in this energy-limited environment. Heterotrophic cellular carbon turnover times, calculated from 3H-thymidine and 3H-leucine incorporation rates, were long (60 to 500 days while cellular doubling times averaged 196 days. Inferred growth rates (average ~0.006 d-1 obtained from the same incubations were at least an order of magnitude lower than those measured in Antarctic surface lakes and oligotrophic areas of the ocean. Low growth efficiency (8% indicated that heterotrophic populations in SLW partition a majority of their carbon demand to cellular maintenance rather than growth. Chemoautotrophic CO2-fixation exceeded heterotrophic organic C-demand by a factor of ~1.5. Aerobic respiratory activity associated with heterotrophic and chemoautotrophic metabolism surpassed the estimated supply of oxygen to SLW, implying that microbial activity could deplete the oxygenated waters, resulting in anoxia. We used thermodynamic calculations to examine the biogeochemical and energetic consequences of environmentally imposed switching between aerobic and anaerobic metabolisms

  15. Cybernetic modeling of adaptive prediction of environmental changes by microorganisms.

    Science.gov (United States)

    Mandli, Aravinda R; Modak, Jayant M

    2014-02-01

    Microorganisms exhibit varied regulatory strategies such as direct regulation, symmetric anticipatory regulation, asymmetric anticipatory regulation, etc. Current mathematical modeling frameworks for the growth of microorganisms either do not incorporate regulation or assume that the microorganisms utilize the direct regulation strategy. In the present study, we extend the cybernetic modeling framework to account for asymmetric anticipatory regulation strategy. The extended model accurately captures various experimental observations. We use the developed model to explore the fitness advantage provided by the asymmetric anticipatory regulation strategy and observe that the optimal extent of asymmetric regulation depends on the selective pressure that the microorganisms experience. We also explore the importance of timing the response in anticipatory regulation and find that there is an optimal time, dependent on the extent of asymmetric regulation, at which microorganisms should respond anticipatorily to maximize their fitness. We then discuss the advantages offered by the cybernetic modeling framework over other modeling frameworks in modeling the asymmetric anticipatory regulation strategy.

  16. Influence of type of microorganism, food ingredients and food properties on high-pressure carbon dioxide inactivation of microorganisms.

    Science.gov (United States)

    Garcia-Gonzalez, L; Geeraerd, A H; Elst, K; Van Ginneken, L; Van Impe, J F; Devlieghere, F

    2009-02-28

    High pressure carbon dioxide (HPCD) treatment is currently considered as an attractive non-thermal process for preserving food. Industrial application of this technique requires, among others, systematic (quantitative) data on the inactivation of food relevant pathogenic and spoilage microorganisms, and in-depth information on the effect that the composition and the properties of a food matrix have on the inactivation efficacy. The first objective of this study, therefore, is to evaluate and compare the HPCD susceptibility of several food pathogens and spoilage microorganisms under the same treatment conditions. In the second part, the influence of different food components (NaCl, oil, starch, whey protein and emulsifier) and food properties (pH, fluid viscosity and water activity) on the inactivation efficacy of HPCD was determined. For the first aim, a range of Gram-negative and Gram-positive bacteria, yeasts and spores were treated with pressurized CO(2) at 10.5 MPa and 35 degrees C during 20 min. Bacterial susceptibility towards HPCD treatments followed the sequence Gram-negative approximately Gram-positive>yeasts>spores and appeared to be related to the acid resistance of the organisms. To study the effect of different food compounds on HPCD inactivation, the reduction degree of Pseudomonas fluorescens was determined in media with and without these components at 10.5 MPa and 35 degrees C after 5 or 20 min, depending on the tested component. NaCl and the emulsifiers Tween 80 and sucrose stearate enhanced bacterial reduction, while oil reduced the bactericidal efficacy of HPCD. Starch and whey proteins did not influence inactivation. Finally, the influence of pH, fluid viscosity and water activity was investigated by determining the reduction of P. fluorescens at 10.5 MPa and 35 degrees C in suspensions from which the pH, viscosity and water activity were adjusted with respectively NaOH or HCl, gelatin or polyethylene glycol, and sucrose, NaCl or glycerol

  17. Effectiveness of ozone against periodontal pathogenic microorganisms.

    Science.gov (United States)

    Huth, Karin C; Quirling, Martina; Lenzke, Stefanie; Paschos, Ekaterini; Kamereck, Klaus; Brand, Korbinian; Hickel, Reinhard; Ilie, Nicoleta

    2011-06-01

    Ozone has been proposed as an adjunct antiseptic in periodontitis therapy. The aim of this study was to investigate the antimicrobial effectiveness of gaseous/aqueous ozone, in comparison with that of the established antiseptic chlorhexidine digluconate (CHX), against periodontal microorganisms. Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, and Parvimonas micra in planktonic or biofilm cultures were exposed, for 1 min, to gaseous ozone, aqueous ozone, CHX, or phosphate-buffered saline (control). None of the agents was able to substantially reduce the A. actinomycetemcomitans count in biofilm cultures. In contrast, P. gingivalis, T. forsythia, and P. micra could be eliminated by 2% CHX or by ozone gas at 53 gm(-3) . Significantly greater antimicrobial effects were observed against planktonic cultures than against biofilm-associated bacteria. The rate of killing was influenced by the species of bacteria, and by the type and concentration of agent. There were no significant differences in the effectiveness of aqueous ozone (20 μg ml(-1) ) or gaseous ozone (≥ 4 gm(-3) ) compared with 2% CHX but they were more effective than 0.2% CHX. Therefore, high-concentrated gaseous and aqueous ozone merit further investigation as antiseptics in periodontitis therapy. A safe system for applying gaseous ozone into the periodontal pocket that avoids inhalation still needs to be developed.

  18. Rapidly evolving microorganisms with high biofuel tolerance

    Science.gov (United States)

    Vyawahare, Saurabh; Zhang, Qiucen; Lang, Wendy; Austin, Robert

    2012-02-01

    Replacing non-renewable energy sources is one of the biggest and most exciting challenges of our generation. Algae and bacteria are poised to become major renewable biofuels if strains can be developed that provide a high,consistent and robust yield of oil. One major stumbling block towards this goal is the lack of tolerance to high concentrations of biofuels like isobutanol. Using traditional bioengineering techniques to remedy this face the hurdle of identifying the correct pathway or gene to modify. But the multiplicity of interactions inside a cell makes it very hard to determine what to modify a priori. Instead, we propose a technology that does not require prior knowledge of the genes or pathways to modify. In our approach that marries microfabrication and ecology, spatial heterogeneity is used as a knob to speed up evolution in the desired direction. Recently, we have successfully used this approach to demonstrate the rapid emergence of bacterial antibiotic resistance in as little as ten hours. Here, we describe our experimental results in developing new strains of micro-organisms with high oil tolerance. Besides biofuel production, our work is also relevant to oil spill clean-ups.

  19. Snow as a habitat for microorganisms

    Science.gov (United States)

    Hoham, Ronald W.

    1989-01-01

    There are three major habitats involving ice and snow, and the microorganisms studied from these habitats are most eukaryotic. Sea ice is inhabited by algae called diatoms, glacial ice has sparse populations of green algai cal desmids, and the temporary and permanent snows in mountainous regions and high latitudes are inhabited mostly by green algal flagellates. The life cycle of green algal flagellates is summarized by discussing the effects of light, temperature, nutrients, and snow melts. Specific examples of optimal conditions and environmental effects for various snow algae are given. It is not likely that the eukaryotic snow algae presented are candidated for life on the planet Mars. Evolutionally, eukaryotic cells as know on Earth may not have had the opportunity to develop on Mars (if life evolved at all on Mars) since eukaryotes did not appear on Earth until almost two billion years after the first prokaryotic organisms. However, the snow/ice ecosystems on Earth present themselves as extreme habitats were there is evidence of prokaryotic life (eubacteria and cyanbacteria) of which literally nothing is known. Any future surveillances of extant and/or extinct life on Mars should include probes (if not landing sites) to investigate sites of concentrations of ice water. The possibility of signs of life in Martian polar regions should not be overlooked.

  20. Evaluation of actinide biosorption by microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Happel, A.M.

    1996-06-01

    Conventional methods for removing metals from aqueous solutions include chemical precipitation, chemical oxidation or reduction, ion exchange, reverse osmosis, electrochemical treatment and evaporation. The removal of radionuclides from aqueous waste streams has largely relied on ion exchange methods which can be prohibitively costly given increasingly stringent regulatory effluent limits. The use of microbial cells as biosorbants for heavy metals offers a potential alternative to existing methods for decontamination or recovery of heavy metals from a variety of industrial waste streams and contaminated ground waters. The toxicity and the extreme and variable conditions present in many radionuclide containing waste streams may preclude the use of living microorganisms and favor the use of non-living biomass for the removal of actinides from these waste streams. In the work presented here, we have examined the biosorption of uranium by non-living, non-metabolizing microbial biomass thus avoiding the problems associated with living systems. We are investigating biosorption with the long term goal of developing microbial technologies for the remediation of actinides.

  1. Heavy metal removal and recovery using microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Wilde, E.W. (Westinghouse Savannah River Co., Aiken, SC (United States)); Benemann, J.R. (Benemann (J.R.), Pinole, CA (United States))

    1991-02-01

    Microorganisms -- bacteria, fungi, and microalgae -- can accumulate relatively large amounts of toxic heavy metals and radionuclides from the environment. These organisms often exhibit specificity for particular metals. The metal content of microbial biomass can be a substantial fraction of total dry weight with concentration factors (metal in dry biomass to metal in solution) exceeding one million in some cases. Both living and inert (dead) microbial biomass can be used to reduce heavy metal concentrations in contaminated waters to very low levels -- parts per billion and even lower. In many respects (e.g. specificity, residual metal concentrations, accumulation factors, and economics) microbial bioremoval processes can be superior to conventional processes, such as ion exchange and caustic (lime or hydroxide) precipitation for heavy metals removal from waste and contaminated waters. Thus, bioremoval could be developed to contribute to the clean-up of wastes at the Savannah River Site (SRS) and other DOE facilities. However, the potential advantages of bioremoval processes must still be developed into practical operating systems. A detailed review of the literature suggests that appropriate bioremoval processes could be developed for the SRS. There is great variability from one biomass source to another in bioremoval capabilities. Bioremoval is affected by pH, other ions, temperature, and many other factors. The biological (living vs. dead) and physical (immobilized vs. dispersed) characteristics of the biomass also greatly affect metal binding. Even subtle differences in the microbial biomass, such as the conditions under which it was cultivated, can have major effects on heavy metal binding.

  2. Prospects of effective microorganisms technology in wastes treatment in Egypt

    Institute of Scientific and Technical Information of China (English)

    Emad A Shalaby

    2011-01-01

    Sludge dewatering and treatment may cost as much as the wastewater treatment. Usually large proportion of the pollutants in wastewater is organic. They are attacked by saprophytic microorganisms, i.e. organisms that feed upon dead organic matter. Activity of organisms causes decomposition of organic matter and destroys them, where the bacteria convert the organic matter or other constituents in the wastewater to new cells, water, gases and other products. Demolition activities, including renovation/remodeling works and complete or selective removal/demolishing of existing structures either by man-made processes or by natural disasters, create an extensive amount of wastes. These demolition wastes are characterized as heterogeneous mixtures of building materials that are usually contaminated with chemicals and dirt. In developing countries, it is estimated that demolition wastes comprise 20% to 30% of the total annual solid wastes. In Egypt, the daily quantity of construction and demolition (C&D) waste has been estimated as 10 000 tones. That is equivalent to one third of the total daily municipal solid wastes generated per day in Egypt. The zabbaliin have since expanded their activities and now take the waste they collect back to their garbage villages where it is sorted into recyclable components: paper, plastics, rags, glass, metal and food. The food waste is fed to pigs and the other items are sold to recycling centers. This paper summarizes the wastewater and solid wastes management in Egypt now and future.

  3. Methods for identifying lipoxygenase producing microorganisms on agar plates.

    Science.gov (United States)

    Nyyssölä, Antti; Heshof, Ruud; Haarmann, Thomas; Eidner, Jasmin; Westerholm-Parvinen, Ann; Langfelder, Kim; Kruus, Kristiina; de Graaff, Leo; Buchert, Johanna

    2012-03-26

    Plate assays for lipoxygenase producing microorganisms on agar plates have been developed. Both potassium iodide-starch and indamine dye formation methods were effective for detecting soybean lipoxygenase activity on agar plates. A positive result was also achieved using the β-carotene bleaching method, but the sensitivity of this method was lower than the other two methods. The potassium iodide-starch and indamine dye formation methods were also applied for detecting lipoxygenase production by Trichoderma reesei and Pichia pastoris transformants expressing the lipoxygenase gene of the fungus Gaeumannomyces graminis. In both cases lipoxygenase production in the transformants could be identified. For detection of the G. graminis lipoxygenase produced by Aspergillus nidulans the potassium iodide-starch method was successful. When Escherichia coli was grown on agar and soybean lipoxygenase was applied on the culture lipoxygenase activity could clearly be detected by the indamine dye formation method. This suggests that the method has potential for screening of metagenomic libraries in E. coli for lipoxygenase activity.

  4. Myeloperoxidase: a front-line defender against phagocytosed microorganisms.

    Science.gov (United States)

    Klebanoff, Seymour J; Kettle, Anthony J; Rosen, Henry; Winterbourn, Christine C; Nauseef, William M

    2013-02-01

    Successful immune defense requires integration of multiple effector systems to match the diverse virulence properties that members of the microbial world might express as they initiate and promote infection. Human neutrophils--the first cellular responders to invading microbes--exert most of their antimicrobial activity in phagosomes, specialized membrane-bound intracellular compartments formed by ingestion of microorganisms. The toxins generated de novo by the phagocyte NADPH oxidase and delivered by fusion of neutrophil granules with nascent phagosomes create conditions that kill and degrade ingested microbes. Antimicrobial activity reflects multiple and complex synergies among the phagosomal contents, and optimal action relies on oxidants generated in the presence of MPO. The absence of life-threatening infectious complications in individuals with MPO deficiency is frequently offered as evidence that the MPO oxidant system is ancillary rather than essential for neutrophil-mediated antimicrobial activity. However, that argument fails to consider observations from humans and KO mice that demonstrate that microbial killing by MPO-deficient cells is less efficient than that of normal neutrophils. We present evidence in support of MPO as a major arm of oxidative killing by neutrophils and propose that the essential contribution of MPO to normal innate host defense is manifest only when exposure to pathogens overwhelms the capacity of other host defense mechanisms.

  5. DENTINE CARIES: ACID-TOLERANT MICROORGANISMS AND ASPECTS ON COLLAGEN DEGRADATION.

    Science.gov (United States)

    Lager, Anders Hedenbjörk

    2014-01-01

    . Key findings: Each investigated lesion harbored a unique microbiota in terms of both species composition and numbers of microorganisms. This indicates that various combinations of aciduric microorganisms can colonize, survive in and probably also propagate dentine carious lesions. We also found that solid pH-selective agars can be used successfully to select acid-tolerant microorganisms in caries lesions. This would preserve their phenotypic traits for further study. In Paper III, the relation between salivary levels of matrix metalloproteinase-8 (MMP-8), salivary levels of tissue inhibitor of MMP (TIMP-1), and the presence of manifest caries lesions in a large number of subjects was investigated. Saliva samples were collected and analyzed for concentrations of MMP-8, TIMP-1 and total protein using immunofluorometric assays, enzyme linked immunosorbent assays and Bradford assays, respectively. Key findings: Subjects with manifest caries lesions had significantly elevated levels of salivary MMP-8 compared to subjects without caries lesions. TIMP-1 was not significant in any case. In Paper IV, a new method for generating bioactive demineralized dentine matrix substrate (DDM) was developed using a dialysis system and two different demineralization approaches (acetic acid or EDTA). The generated DDM was subsequently analyzed for the presence of type 1 collagen, active MMP-8 and hydroxyproline (HYP) levels using SDS-PAGE, ELISA or immunofluorescence assay. Key findings: Both demineralization methods produced a substrate rich in collagen and with preserved MMP-8 activity. This report presents new knowledge on the composition of the acid tolerant dentine caries microbiota from three levels in dentine carious lesions and on the efficacy of operative caries removal on the numbers of viable microorganisms in the caries free cavity using two operative methods. Moreover, the basic mechanisms behind collagen degradation in the dentine caries process are studied from both a

  6. ANTIMICROBIAL ACTIVITY OF ROSA CANINA FLOWERS AGAINST SELECTED MICROORGANISMS

    Directory of Open Access Journals (Sweden)

    Katarína Rovná

    2015-02-01

    Full Text Available Rosa canina flowers were screened against various plant pathogenic microbial strains to study the antimicrobial properties of the plant. Ethanolic and methanolic extracts of flowers were screened applying agar well diffusion method against two Gram-negative bacteria including Escherichia coli CCM 3988 and Pseudomonas aeruginosa CCM 1960 and three microscopic filamentous fungi strains Aspergillus niger, Fusarium culmorum and Alternaria alternata, respectively. The best antimicrobial effect of ethanolic extract of Rosa canina flowers was found against Pseudomonas aeruginosa and the best antimicrobial effect of methanolic extract of Rosa canina flowers was found against Escherichia coli.

  7. Isolation of porphyran-degrading marine microorganisms from the surface of red alga, Porphyra yezoensis.

    Science.gov (United States)

    Yoshimura, Takashi; Tsuge, Keisuke; Sumi, Toshihisa; Yoshiki, Masahiro; Tsuruta, Yumi; Abe, Shin-ichi; Nishino, Shiduo; Sanematsu, Seigo; Koganemaru, Kazuyoshi

    2006-04-01

    Marine microorganisms degrading porphyran (POR) were found on the surface of thalli of Porphyra yezoensis. Fifteen crude microorganism groups softened and liquefied the surface of agar-rich plate medium. Among these, 11 microorganism groups degraded porphyran that consisted of sulfated polysaccharide in Porphyra yezoensis. Following isolation, 7 POR-degradable microorganisms were isolated from the 11 POR-degradable microorganism groups.

  8. Detection of antibacterial substances in some plant residues and their effect on certain micro-organisms.

    Science.gov (United States)

    Abdel-Nasser, M; Safwat, M S; Ali, M Z

    1983-01-01

    The effect of dry residues from several plants, belonging to different families on certain microorganisms in vitro and in vivo, was studied. Dry residues of paprica leaves, tomato tops, egg plant leaves, guava leaves, onion peels, garlic tops, wheat straw, sugar cane leaves, cotton leaves, Egyptian clover tops, field bean tops or pea tops were examined for the presence of antibacterial substances, using successive extractions with hexane, ethyl ether, ethanol, and water, respectively, for each plant residue. On culture media, the antibacterial effect, expressed as width of inhibition zones, differed according to the type of plant, type of micro-organism, and extraction medium, used for each plant. Water extract from each of the studied plants showed no effect on any of the studied micro-organisms, while the other extracts indicated the presence of antibacterial substances in all the used plants. In most cases, ether extract showed the highest incidence of antimicrobial activities against the majority of test micro-organisms. In general, the antibacterial substances seemed to be more inhibitory to Gram-positive bacteria than to Gram-negative ones. Ethyl-ether extract of the residues of most of these plants markedly affected the growth of more than one of the different Rhizobium species when grown on culture medium, as indicated by the presence of wide zones of inhibition.

  9. Application of molecular techniques for the assessment of microorganism diversity on cultural heritage objects.

    Science.gov (United States)

    Otlewska, Anna; Adamiak, Justyna; Gutarowska, Beata

    2014-01-01

    As a result of their unpredictable ability to adapt to varying environmental conditions, microorganisms inhabit different types of biological niches on Earth. Owing to the key role of microorganisms in many biogeochemical processes, trends in modern microbiology emphasize the need to know and understand the structure and function of complex microbial communities. This is particularly important if the strategy relates to microbial communities that cause biodeterioration of materials that constitute our cultural heritage. Until recently, the detection and identification of microorganisms inhabiting objects of cultural value was based only on cultivation-dependent methods. In spite of many advantages, these methods provide limited information because they identify only viable organisms capable of growth under standard laboratory conditions. However, in order to carry out proper conservation and renovation, it is necessary to know the complete composition of microbial communities and their activity. This paper presents and characterizes modern techniques such as genetic fingerprinting and clone library construction for the assessment of microbial diversity based on molecular biology. Molecular methods represent a favourable alternative to culture-dependent methods and make it possible to assess the biodiversity of microorganisms inhabiting technical materials and cultural heritage objects.

  10. Single cell genomics of subsurface microorganisms

    Science.gov (United States)

    Stepanauskas, R.; Onstott, T. C.; Lau, C.; Kieft, T. L.; Woyke, T.; Rinke, C.; Sczyrba, A.; van Heerden, E.

    2012-12-01

    Recent studies have revealed unexpected abundance and diversity of microorganisms in terrestrial and marine subsurface, providing new perspectives over their biogeochemical significance, evolution, and the limits of life. The now commonly used research tools, such as metagenomics and PCR-based gene surveys enabled cultivation-unbiased analysis of genes encoded by natural microbial communities. However, these methods seldom provide direct evidence for how the discovered genes are organized inside genomes and from which organisms do they come from. Here we evaluated the feasibility of an alternative, single cell genomics approach, in the analysis of subsurface microbial community composition, metabolic potential and microevolution at the Sanford Underground Research Facility (SURF), South Dakota, and the Witwaterstrand Basin, South Africa. We successfully recovered genomic DNA from individual microbial cells from multiple locations, including ultra-deep (down to 3,500 m) and low-biomass (down to 10^3 cells mL^-1) fracture water. The obtained single amplified genomes (SAGs) from SURF contained multiple representatives of the candidate divisions OP3, OP11, OD1 and uncharacterized archaea. By sequencing eight of these SAGs, we obtained the first genome content information for these phylum-level lineages that do not contain a single cultured representative. The Witwaterstrand samples were collected from deep fractures, biogeochemical dating of which suggests isolation from tens of thousands to tens of millions of years. Thus, these fractures may be viewed as "underground Galapagos", a natural, long-term experiment of microbial evolution within well-defined temporal and spatial boundaries. We are analyzing multiple SAGs from these environments, which will provide detailed information about adaptations to life in deep subsurface, mutation rates, selective pressures and gene flux within and across microbial populations.

  11. [Metagenomics as a Tool for the Investigation of Uncultured Microorganisms].

    Science.gov (United States)

    Ravin, N V; Mardanova, A V; Skryabin, K G

    2015-05-01

    Uncultured microorganisms represent a significant part of the Earth's biodiversity. Natural ecosystems contain less than 0.1-1% of the microorganisms that can be cultured in the laboratory. Therefore, new methodological approaches are required for the identification and description of uncultured microorganisms, for studies of their genetic diversity and the structure of microbial associations, and for an understanding of their ecological importance in the biosphere. Metagenomics, a method of analyzing the collective genome.of a microbial community without cultivation, makes it possible to unravel fundamental matters of the microbiology and ecology of microorganisms. Another efficient method of analysis of uncultured forms of microorganisms is "single cell genomics," which involves the isolation of single cells from microbial communities and the sequencing of their genomes. Developed in the last decade, the high throughput technologies of next-generation sequencing provide important input into the investigation of genome reconstruction for all of the microorganisms residing and interacting within ecosystems. This review describes the major methodological approaches used in metagenomic analysis of microbial communities, as well as accomplishments in the search for new uncultured microorganism, the unraveling of their genomes, and an elucidation of their role in ecosystems.

  12. 调节茶园土壤pH对土壤养分、酶活性及微生物数量的影响%Effects of Adjusting pH of Tea Plantation Soil on Its Soil Nutrients, Enzyme Activity and Microorganisms

    Institute of Scientific and Technical Information of China (English)

    刘炳君; 杨扬; 李强; 呼广雷; 陈向阳; 方建新; 王世强

    2011-01-01

    [目的]考察酸化和碱化作用对茶园土壤主要养分、土壤酶活性及微生物数量的影响,进而探讨pH值变化与三者之间关系.[方法]用石灰调节茶园土壤pH进行不同天数培养后研究土壤养分、酶活性及微生物.[结果]酸性土壤经石灰调节提高pH 1 ~2,引起土壤中速效磷、可交换性酸降低,土壤细菌、放线菌数量增加近10倍,真菌随pH增加而减少;土壤过氧化氢酶、多酚氧化酶、脲酶活性随pH调节而增高.[结论]随着培养天数的增加茶园土壤pH呈降低趋势;土壤中速效磷、交换性酸、真菌数量及转化酶活性与pH之间呈负相关;土壤中细菌、放线菌数量及过氧化氢酶、多酚氧化酶、脲酶的酶活性与pH呈正相关.%[Objective] The research aimed to investigate the effects of acidification and alkalization on soil nutrients, soil enzyme activity and microbial quantity in tea plantation soil so as to further explore the mutual relationship between them and the change of pH. [ Method] The study was conducted by regulating the soil pH of the tea plantation soil with lime on the soil nutrients, enzyme activity and microorganism. [ Result ] Acid soil, with its pH improved by 1 - 2 units would cause the soil available phosphorus and soil exchangeable acid to reduce. And the quantity of bacteria and aetinomyces in the soil would increase by about 10 times. With pH increasing, the fungi decreased. The activity of catalase, polyphenol oxidase, the urease in the soil increased with pH regulation. [ Conclusion ] As the days went on, soil pH decreased. The available phosphorus, exchangeable acid, the number of fungi and invertase activity in the soil were negatively correlated with pH. The quantity of bacteria and actinomyces in the soil and the activity of catalase, polyphenol oxidase, urease were positively correlated with pH.

  13. Lipase-producing microorganisms from a Kenyan alkaline soda lake.

    Science.gov (United States)

    Vargas, Virginia A; Delgado, Osvaldo D; Hatti-Kaul, Rajni; Mattiasson, Bo

    2004-01-01

    Lipolytic enzyme production of 150 isolated strains from samples of Lake Bogoria (Kenya) was examined. Among these, fifteen isolates were selected on the basis of their lipolytic activities and subjected to morphological and 16S rRNA gene sequencing analyses for their identification. All the microorganisms have been selected under culture conditions with pH ranges between 7-10 and temperatures of 37-55 degrees C. Most of them showed optimal growth at 37 degrees C and tolerated salinity up to 10% (w/v). Ten of the isolates were Gram-negative, nine of which were closely related to the Pseudomonas cluster and one to the Halomonas cluster sharing high similarity profile with Halomonas desiderata. The remaining Gram-positive isolates were closely related to the Bacillus cluster, and were grouped with Bacillus halodurans, Bacillus alcalophilus and Bacillus licheniformis. Four members of the Bacillus cluster and the Halomonas sp. produced lipolytic activity under alkaline conditions, while others did so at neutral pH values.

  14. Glycolic acid production using ethylene glycol-oxidizing microorganisms.

    Science.gov (United States)

    Kataoka, M; Sasaki, M; Hidalgo, A R; Nakano, M; Shimizu, S

    2001-10-01

    Screening for microorganisms oxidizing ethylene glycol to glycolic acid was carried out. Among stock cultures, several yeasts and acetic acid bacteria showed high glycolic acid producing activity. Pichia naganishii AKU 4267 formed the highest concentration of glycolic acid, 35.3 g/l, from 10% (v/v) ethylene glycol (molar conversion yield, 26.0%). Among soil isolates, Rhodotorula sp. 3Pr-126, isolated using propylene glycol as a sole carbon source, formed the highest concentration of glycolic acid, 25.1 g/l, from 10% (v/v) ethylene glycol (molar conversion yield, 18.5%). Rhodotorula sp. 3Pr-126 showed higher activity toward 20% (v/v) ethylene glycol than P. naganishii AKU 4267. Optimization of the conditions for glycolic acid production was investigated using P. naganishii AKU 4267 and Rhodotorula sp. 3Pr-126. Under the optimized conditions, P. naganishii AKU 4267 and Rhodotorula sp. 3Pr-126 formed 105 and 110 g/l of glycolic acid (corrected molar conversion yields, 88.0 and 92.2%) during 120 h of reaction, respectively.

  15. Effect on microorganisms of volatile compounds released from germinating seeds.

    Science.gov (United States)

    Schenck, S; Stotzky, G

    1975-10-01

    Volatile compounds evolved from germinating seeds of slash pine, bean, cabbage, corn, cucumber, and pea were evaluated for their ability to support growth of microorganisms in liquid mineral salts media lacking a carbon source. Growth of eight bacteria was measured turbidimetrically and of six fungi as dry weight of mycelium. Volatiles caused increased growth of Pseudomonas fluorescens, Bacillus cereus, Erwinia carotovora, Agrobacterium tumefaciens, A. radiobacter, Rhizobium japonicum, Mucor mucedo, Fusarium oxysporum f. conglutinans, Trichoderma viride, and Penicillium vermiculatum but not of Sarcina lutea, Serratia marcescens, Chaetomium globosum, or Schizophyllum commune. Spores of Trichoderma viride showed higher germination in the presence of volatiles. Effects on growth were apparent only during the first 3 or 4 days after planting the seeds. Killed or dried seeds had no effect. The volatiles did not support microbial growth in the absence of nitrogen nor did they supply growth factors. Passing volatiles through KMnO4 or hydrazone reduced growth of the bacteria, indicating that oxidizable organic compounds, prima