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Sample records for autolysis

  1. [Overexpression of FKS1 to improve yeast autolysis-stress].

    Science.gov (United States)

    Li, Jia; Wang, Jinjing; Li, Qi

    2015-09-01

    With the development of high gravity brewing, yeast cells are exposed to multiple brewing-associated stresses, such as increased osmotic pressure, enhanced alcohol concentration and nutritional imbalance. These will speed up yeast autolysis, which seriously influence beer flavor and quality. To increase yeast anti-autolytic ability, FKS1 overexpression strain was constructed by 18S rDNA. The concentration of β-1,3-glucan of overexpression strain was 62% higher than that of wild type strain. Meantime, FKS1 overexpression strain increased anti-stress ability at 8% ethanol, 0.4 mol/L NaCl and starvation stress. Under simulated autolysis, FKS1 showed good anti-autolytic ability by slower autolysis. These results confirms the potential of FKS1 overexpression to tackle yeast autolysis in high-gravity brewing. PMID:26955712

  2. Autolysis and extension of isolated walls from growing cucumber hypocotyls

    Science.gov (United States)

    Cosgrove, D. J.; Durachko, D. M.

    1994-01-01

    Walls isolated from cucumber hypocotyls retain autolytic activities and the ability to extend when placed under the appropriate conditions. To test whether autolysis and extension are related, we treated the walls in various ways to enhance or inhibit long-term wall extension ('creep') and measured autolysis as release of various saccharides from the wall. Except for some non-specific inhibitors of enzymatic activity, we found no correlation between wall extension and wall autolysis. Most notably, autolysis and extension differed strongly in their pH dependence. We also found that exogenous cellulases and pectinases enhanced extension in native walls, but when applied to walls previously inactivated with heat or protease these enzymes caused breakage without sustained extension. In contrast, pretreatment of walls with pectinase or cellulase, followed by boiling in methanol to inactivate the enzymes, resulted in walls with much stronger expansin-mediated extension responses. Crude protein preparations from the digestive tracts of snails enhanced extension of both native and inactivated walls, and these preparations contained expansin-like proteins (assessed by Western blotting). Our results indicate that the extension of isolated cucumber walls does not depend directly on the activity of endogenous wall-bound autolytic enzymes. The results with exogenous enzymes suggest that the hydrolysis of matrix polysaccharides may not induce wall creep by itself, but may act synergistically with expansins to enhance wall extension.

  3. Autolysis of Lactococcus lactis is influenced by proteolysis

    NARCIS (Netherlands)

    Buist, G; Venema, G; Kok, J.

    1998-01-01

    The autolysin AcmA of Lactococcus lactis was shown to be degraded by the extracellular Lactococcal proteinase PrtP. Autolysis, as evidenced by reduction in optical density of a stationary-phase culture and concomitant release of intracellular proteins, was greatly reduced when L. lactis MG1363 cells

  4. Acinar autolysis and mucous extravasation in human sublingual glands: a microscopic postmortem study

    Directory of Open Access Journals (Sweden)

    Luciana Reis AZEVEDO-ALANIS

    2015-10-01

    Full Text Available Although some morphological investigations on aged human sublingual glands (HSG found eventual phenomena identified as autolysis and mucous extravasation, the exact meaning of these findings has not been elucidated.Objective The aim of this work is to investigate whether acinar autolysis and mucous extravasation are related to the aging process in human sublingual glands. We also speculate if autolytic changes may assist forensic pathologists in determining time of death.Material and Methods 186 cadavers’ glands were allocated to age groups: I (0–30 years; II (31–60, and III (61–90. Time and mode of death were also recorded. Acinar autolysis and mucous extravasation were classified as present or absent. Ultrastructural analysis was performed using transmission electron microscopy (TEM. Data were compared using Mann-Whitney U, Spearman’s correlation coefficient, Kruskal-Wallis, and Dunn tests (p<0.05.Results There was correlation between age and acinar autolysis (r=0.38; p=0.0001. However, there was no correlation between autolysis and time of death. No differences were observed between genders. TEM showed mucous and serous cells presenting nuclear and membrane alterations and mucous cells were more susceptible to autolysis.Conclusion Acinar autolysis occurred in all age groups and increased with age while mucous extravasation was rarely found. Both findings are independent. Autolysis degrees in HSG could not be used to determine time of death.

  5. Absence of correlation between rates of cell wall turnover and autolysis shown by Bacillus subtilis mutants.

    OpenAIRE

    Vitković, L; Cheung, H. Y.; Freese, E

    1984-01-01

    Bacillus subtilis mutants with reduced rates of cell wall autolysis reached a constant rate of wall turnover after a longer lag than the standard strain but eventually showed the same turnover rate. In reverse, a turnover-deficient mutant autolysed at a slightly higher rate than the standard strain. Consequently, there is no correlation between the rates of cell wall turnover and autolysis.

  6. Death of Prorocentrum donghaiense May Be a Programmed Autolysis

    Institute of Scientific and Technical Information of China (English)

    YANG Guanpin; LIU Yongjian; LI Bingjun

    2008-01-01

    Prorocentrum donghaiense, one of the dinoflagellate, has continuously caused large scale red tides along the Chinese coast in recent years. These red tides have brought tremendous loss to the local economy and serious impacts to the local environ- ment. Unfortunately, little was known about the mechanism of the fast appearance and extinction of the red tide caused by this alga. In this study, the full-length cDNA of a caspase encoding gene ofP donghaiense was cloned and characterized, and the transcription of this gene during the senescence of the alga was semi-quantitatively determined. The cDNA was 520bp in length. It contained a 258bp open reading frame (ORF) which encoded a peptide of 85 amino acids. The amount of transcripts of the caspase encoding gene increased with the senescence of P. donghaiense and started to decrease gradually when the autolysis of P. donghaiense cells took place. We proposed that the death of P. donghaiense may be a caspase mediated programmed autolysis.

  7. The role of autolysis loop in determining the specificity of coagulation proteases

    Directory of Open Access Journals (Sweden)

    L. Yang

    2007-08-01

    Full Text Available We recently demonstrated that the substitution of the autolysis loop (residues 143 to 154 in the chymotrypsin numbering system of activated protein C (APC with the corresponding loop of factor Xa (fXa renders the APC mutant (APC/fX143-154 susceptible to inhibition by antithrombin (AT in the presence of pentasaccharide. Our recent results further indicated, that in addition to an improvement in the reactivity of APC/fX143-154 with AT, both the amidolytic and anti-factor Va activities of the mutant APC have also been significantly increased. Since the autolysis loop of APC is five residues longer than the autolysis loop of fXa, it could not be ascertained whether this loop in the mutant APC specifically interacts with the activated conformation of AT or if a shorter autolysis loop is responsible for a global improvement in the catalytic activity of the mutant protease. To answer this question, we prepared another APC mutant in which the autolysis loop of the protease was replaced with the corresponding loop of trypsin (APC/Tryp143-154. Unlike an ~500-fold improvement in the reactivity of APC/fX143-154 with AT in the presence of pentasaccharide, the reactivity of APC/Tryp143-154 with the serpin was improved ~10-fold. These results suggest that both the length and structure of residues of the autolysis loop are critical for the specificity of the coagulation protease interaction with AT. Further factor Va inactivation studies with the APC mutants revealed a similar role for the autolysis loop of APC in the interaction with its natural substrate.

  8. Apoptosis induction is involved in UVA-induced autolysis in sea cucumber Stichopus japonicus.

    Science.gov (United States)

    Qi, Hang; Fu, Hui; Dong, Xiufang; Feng, Dingding; Li, Nan; Wen, Chengrong; Nakamura, Yoshimasa; Zhu, Beiwei

    2016-05-01

    Autolysis easily happens to sea cucumber (Stichopus japonicus, S. japonicus) for external stimulus like UV exposure causing heavy economic losses. Therefore, it is meaningful to reveal the mechanism of S. japonicas autolysis. In the present study, to examine the involvement of apoptosis induction in UVA-induced autolysis of S. japonicas, we investigated the biochemical events including the DNA fragmentation, caspase-3 activation, mitogen-activated protein kinases (MAPKs) phosphorylation and free radical formation. Substantial morphological changes such as intestine vomiting and dermatolysis were observed in S. japonicus during the incubation after 1-h UVA irradiation (10W/m(2)). The degradation of the structural proteins and enhancement of cathepsin L activity were also detected, suggesting the profound impact of proteolysis caused by the UVA irradiation even for 1h. Furthermore, the DNA fragmentation and specific activity of caspase-3 was increased up to 12h after UVA irradiation. The levels of phosphorylated p38 mitogen activated protein kinase (MAPK) and phosphorylated c-Jun.-N-terminal kinase (JNK) were significantly increased by the UVA irradiation for 1h. An electron spin resonance (ESR) analysis revealed that UVA enhanced the free radical formation in S. japonicas, even through we could not identify the attributed species. These results suggest that UVA-induced autolysis in S. japonicas at least partially involves the oxidative stress-sensitive apoptosis induction pathway. These data present a novel insight into the mechanisms of sea cucumber autolysis induced by external stress. PMID:26971278

  9. Biochemical changes in the mycelium of two Rhizoctonia solani isolates during autolysis

    Directory of Open Access Journals (Sweden)

    M. N. Reddy

    2014-08-01

    Full Text Available Some biochemical changes occurring in the mycelium of two isolates (one pathogenic FR and another non-pathogenic GD2 of R. solani during autolytic phase of their growth were studied, by growing the fungi for periods longer than 210 days. During autolysis a decrease of 76.4% and 78.5% in mycelial dry weight occurred in pathogenic and non-pathogenic isolates respectively, compared to that at the beginning of autolysis. The mycelium of non-pathogenic isolate was more affected during autolytic phase of growth than that of the pathogenic isolate.

  10. FUNCTION OF THE ACTIVATED PROTEIN C (APC) AUTOLYSIS LOOP IN ACTIVATED FVIII INACTIVATION

    OpenAIRE

    Cramer, Thomas J.; Gale, Andrew J.

    2011-01-01

    Activated protein C (APC) binds to its substrates activated factor V (FVa) and activated factor VIII (FVIIIa) with a basic exosite that consists of loops 37, 60, 70 and the autolysis loop. These loops have a high density of basic residues, resulting in a positive charge on the surface of APC. Many of these residues are important in the interaction of APC with FVa and FVIIIa. The current study focused on the function of the autolysis loop in the interaction with FVIIIa. This loop was previousl...

  11. Induced autolysis of fungus Aspergillus terreus AT-490 grown on agricultural and food industry wastes

    International Nuclear Information System (INIS)

    Autolysis of the biomass of fungus Aspergillus terreus AT-490 grown on citrus meal and tomato residues was studied. The optimal conditions of conducting it were determined: preliminary ultrasonic treatment for 5 min, temperature 55 degrees C, concentration of dry materials 50 g/liter, duration 23 hr, inducer 3% ethanol. The amino acid composition of the biomass of A. terreus AT-490 was determined

  12. Screening of lactic acid bacteria with high autolysis rate by N+-implantation

    International Nuclear Information System (INIS)

    In order to obtain lactic acid bacteria with high autolysis rate, Streptococcus salivarius ssp. thermophilus GS1 and Lactobacillus delbrueckii ssp. bulgaricus LD3 were mutated by 50 keV N+ ions implantation. The results indicated that the survival rate curve took a saddle shape in the range of 1 x 2.6 x 1013 ∼ 6 x 2.6 x 1013 and the total mutation rate was 57% ∼ 74%. The survival rate were 25% ∼ 33% on the suitable dose 4 x 2.6 x 1013 ion/cm2. Among the mutated strains with mutation rate in the range of 127.98% ∼-51.96%, the highest autolysis rate mutation strains were named LD3-A3 and GS1-B13. Compare with original strains, autolysis rates of LD3-A3 and GS1-B13 increased by 127.98% and 115.11% respectively. Fermentation properties of LD3-A3 and GS1-B13 were stable after 5 generation transfer inoculation. It indicates that the ion implantation technique is a feasible method in lactic acid bacteria breeding. (authors)

  13. Effect of autolysis on the specificity of bovine spongiform encephalopathy rapid tests

    Directory of Open Access Journals (Sweden)

    Caramelli Maria

    2010-07-01

    Full Text Available Abstract Background Routine rapid testing for Bovine Spongiform Encephalopathy (BSE has highlighted some problems with BSE rapid test performance, the most significant being the number of initially reactive samples and the false positive results on autolyzed tissue. This point is important for BSE active surveillance in risk populations, because tissue autolysis is often unavoidable in routine cases. A robust test suitable for use on field material is therefore needed. To date, very limited information regarding the effect of autolysis on the robustness of rapid tests has been documented; therefore, the National Reference Centre for Animal Encephalopathies (CEA rapid test laboratory selected 450 autolyzed and negative brain stem samples from fallen stock bovines older than 24 months to assess the specificity of four tests approved for BSE active surveillance: Biorad TeSeE, Enfer TSE version 2.0, Prionics® Check LIA, and IDEXX Herd Check BSE Antigen Kit EIA. The samples were graded according to the degree of autolysis and then dissected into five portions, four of which randomly assigned to processing by rapid tests and one to be available for confirmatory Western blot analysis. Findings The specificity of the four systems was 100% for all three grades of autolysis, while the percentage of initially reactive results was 0.00 (95%CI 0.00-0.82, 0.22 (95%CI 0.006-1.23, 0.44 (95%CI 0.05-1.60, and 0.89 (95%CI 0.24-2.26 for the Biorad TeSeE, the Prionics® Check LIA, the IDEXX Herd Check BSE and the Enfer TSE tests, respectively. No association with the degree of autolysis could be drawn. Conclusions The present study demonstrates that the four rapid tests can be considered well-running diagnostic tools regardless of tissue quality; nevertheless, the number of initial reactive samples reported for some systems must not be underestimated in routine testing. Furthermore the compliance with the reported performance can be guaranteed only when an ongoing

  14. Identification of key peptidoglycan hydrolases for morphogenesis, autolysis, and peptidoglycan composition of Lactobacillus plantarum WCFS1

    Directory of Open Access Journals (Sweden)

    Rolain Thomas

    2012-10-01

    Full Text Available Abstract Background Lactobacillus plantarum is commonly used in industrial fermentation processes. Selected strains are also marketed as probiotics for their health beneficial effects. Although the functional role of peptidoglycan-degrading enzymes is increasingly documented to be important for a range of bacterial processes and host-microbe interactions, little is known about their functional roles in lactobacilli. This knowledge holds important potential for developing more robust strains resistant to autolysis under stress conditions as well as peptidoglycan engineering for a better understanding of the contribution of released muramyl-peptides as probiotic immunomodulators. Results Here, we explored the functional role of the predicted peptidoglycan hydrolase (PGH complement encoded in the genome of L. plantarum by systematic gene deletion. From twelve predicted PGH-encoding genes, nine could be individually inactivated and their corresponding mutant strains were characterized regarding their cell morphology, growth, and autolysis under various conditions. From this analysis, we identified two PGHs, the predicted N-acetylglucosaminidase Acm2 and NplC/P60 D,L-endopeptidase LytA, as key determinants in the morphology of L. plantarum. Acm2 was demonstrated to be required for the ultimate step of cell separation of daughter cells, whereas LytA appeared to be required for cell shape maintenance and cell-wall integrity. We also showed by autolysis experiments that both PGHs are involved in the global autolytic process with a dominant role for Acm2 in all tested conditions, identifying Acm2 as the major autolysin of L. plantarum WCFS1. In addition, Acm2 and the putative N-acetylmuramidase Lys2 were shown to play redundant roles in both cell separation and autolysis under stress conditions. Finally, the analysis of the peptidoglycan composition of Acm2- and LytA-deficient derivatives revealed their potential hydrolytic activities by the

  15. Transcriptomic and functional analysis of an autolysis-deficient, teicoplanin-resistant derivative of methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Renzoni, Adriana; Barras, Christine; François, Patrice; Charbonnier, Yvan; Huggler, Elzbieta; Garzoni, Christian; Kelley, William L; Majcherczyk, Paul; Schrenzel, Jacques; Lew, Daniel P; Vaudaux, Pierre

    2006-09-01

    The molecular basis of glycopeptide-intermediate S. aureus (GISA) isolates is not well defined though frequently involves phenotypes such as thickened cell walls and decreased autolysis. We have exploited an isogenic pair of teicoplanin-susceptible (strain MRGR3) and teicoplanin-resistant (strain 14-4) methicillin-resistant S. aureus strains for detailed transcriptomic profiling and analysis of altered autolytic properties. Strain 14-4 displayed markedly deficient Triton X-100-triggered autolysis compared to its teicoplanin-susceptible parent, although microarray analysis paradoxically did not reveal significant reductions in expression levels of major autolytic genes atl, lytM, and lytN, except for sle1, which showed a slight decrease. The most important paradox was a more-than-twofold increase in expression of the cidABC operon in 14-4 compared to MRGR3, which was correlated with decreased expression of autolysis negative regulators lytSR and lrgAB. In contrast, the autolysis-deficient phenotype of 14-4 was correlated with both increased expression of negative autolysis regulators (arlRS, mgrA, and sarA) and decreased expression of positive regulators (agr RNAII and RNAIII). Quantitative bacteriolytic assays and zymographic analysis of concentrated culture supernatants showed a striking reduction in Atl-derived, extracellular bacteriolytic hydrolase activities in 14-4 compared to MRGR3. This observed difference was independent of the source of cell wall substrate (MRGR3 or 14-4) used for analysis. Collectively, our results suggest that altered autolytic properties in 14-4 are apparently not driven by significant changes in the transcription of key autolytic effectors. Instead, our analysis points to alternate regulatory mechanisms that impact autolysis effectors which may include changes in posttranscriptional processing or export. PMID:16940101

  16. The Effect of Different Temperatures on Autolysis of Baker’s Yeast for the Production of Yeast Extract

    OpenAIRE

    TANGÜLER, Hasan; Erten, Hüseyin

    2009-01-01

    This study aimed to determine the optimum autolysis conditions for the production of yeast extract, which is used to give a meaty flavor to food products and to increase their nutritional value. Autolysis was induced by incubating baker’s yeast cell suspensions at different temperatures (45, 50, 55, and 60 °C) with a reaction time ranging from 8 to 72 h. Content and yield of total solids, a-amino nitrogen (a-AN), and protein were determined. Yeast extract powder was obtained by dryi...

  17. Yeast adapted to wine: nitrogen compounds released during induced autolysis in a model wine.

    Science.gov (United States)

    Perrot, L; Charpentier, M; Charpentier, C; Feuillat, M; Chassagne, D

    2002-09-01

    As important as the blend of base wines before bottling, one of the most important steps in the champagne-making process is the long ageing on lees. Two yeast strains of Saccharomyces cerevisiae MC001 and MC002, used in champagne wine production, were allowed to autolyse. After 8 days of autolysis, active dry yeasts adapted to wine released 1.7- to 1.8-fold more nitrogen compounds than nonadapted active dry yeast. The nitrogen content (total, proteins, peptides and amino) present in autolysates was measured for yeasts adapted to wine. The composition of free amino acids and amino acids constituting peptides showed no difference between the two strains of yeast used. Studies of intracellular proteolytic activity and release of peptides showed no correlation between these two phenomena. These results indicate that yeasts adapted to wine give results similar to those that occur in wine during ageing. PMID:12242635

  18. Evidence for specific secretion rather than autolysis in the release of some Helicobacter pylori proteins.

    Science.gov (United States)

    Vanet, A; Labigne, A

    1998-03-01

    We investigated whether Helicobacter pylori cells actively secrete proteins such as the urease subunits UreA and UreB and the GroES and GroEL homologs HspA and HspB or whether these proteins were present in the extracellular compartment as a consequence of autolysis. Using a subcellular fractionation approach associated with quantitative Western blot analyses, we showed that the supernatant protein profiles were very different from those of the cell pellets, even for bacteria harvested in the late growth phase; this suggests that the release process is selective. A typical cytoplasmic protein, a beta-galactosidase homolog, was found exclusively associated with the pellet of whole-cell extracts, and no traces were found in the supernatant. In contrast, UreA, UreB, HspA, and HspB were mostly found in the pellet but significant amounts were also present in the supernatant. HspA and UreB were released into the supernatant at the same rate throughout the growth phase (3%), whereas large portions of HspB and UreA were released during the stationary phase (over 30 and 20%, respectively) rather than during the early growth phase (20% and 6, respectively). The profiles of protein obtained after water extraction of the bacteria with those of the proteins naturally released within the liquid culture supernatants demonstrated that water extraction led to the release of a large amount of protein due to artifactual lysis. Our data support the conclusion that a specific and selective mechanism(s) is involved in the secretion of some H. pylori antigens. A programmed autolysis process does not seem to make a major contribution. PMID:9488391

  19. A newly discovered ubiquitin-conjugating enzyme E2 correlated with the cryogenic autolysis of Volvariella volvacea.

    Science.gov (United States)

    Gong, Ming; Wang, Hong; Chen, Mingjie; Bao, Dapeng; Zhu, Qiuming; Tan, Qi

    2016-05-25

    In Volvariella volvacea, a species of edible mushroom, cryogenic autolysis is a typical part of abnormal metabolism. Previous functional annotation cluster analyses of cold-induced gene expression profiles have shown that the ubiquitin-conjugating enzyme E2 (UBE2), rather than the cyclin-like F-box domain alone, forms the functional cluster. In this study, analysis of gene expression profiling showed that only one type of UBE2 in V. volvacea (UBEV2) was significantly up-regulated. Further quantitative real-time PCR analysis confirmed that the expression of UBEV2 was significantly up-regulated (Pnatural selection showed that there has been recent positive selection after HGT in UBEV2. Molecular modeling and logo analysis showed that the cysteine-cysteine motif is the characteristic of the UBEV2 family. These observations indicate that UBEV2 is a new type of UBE2 correlated with the cryogenic autolysis of V. volvacea. PMID:26927519

  20. Transcriptomic and Functional Analysis of an Autolysis-Deficient, Teicoplanin-Resistant Derivative of Methicillin-Resistant Staphylococcus aureus†

    OpenAIRE

    Renzoni, Adriana; Barras, Christine; François, Patrice; Charbonnier, Yvan; Huggler, Elzbieta; Garzoni, Christian; Kelley, William L; Majcherczyk, Paul; Schrenzel, Jacques; Lew, Daniel P.; Vaudaux, Pierre

    2006-01-01

    The molecular basis of glycopeptide-intermediate S. aureus (GISA) isolates is not well defined though frequently involves phenotypes such as thickened cell walls and decreased autolysis. We have exploited an isogenic pair of teicoplanin-susceptible (strain MRGR3) and teicoplanin-resistant (strain 14-4) methicillin-resistant S. aureus strains for detailed transcriptomic profiling and analysis of altered autolytic properties. Strain 14-4 displayed markedly deficient Triton X-100-triggered autol...

  1. Effect of protein S-nitrosylation on autolysis and catalytic ability of μ-calpain.

    Science.gov (United States)

    Liu, Rui; Li, Yupin; Wang, Mengqin; Zhou, Guanghong; Zhang, Wangang

    2016-12-15

    The effect of S-nitrosylation on the autolysis and catalytic ability of μ-calpain in vitro in the presence of 50μM Ca(2 +) was investigated. μ-Calpain was incubated with different concentrations of nitric oxide donor S-nitrosoglutathione (GSNO) and subsequently reacted with purified myofibrils. Results showed that the amount of 80kDa μ-calpain subunit significantly decreased as GSNO increased from 0 to 300μM, but increases of GSNO to 300, 500 and 1000μM did not result in further inhibition. The catalytic ability of nitrosylated μ-calpain to degrade titin, nebulin, troponin-T and desmin was significantly reduced when the GSNO concentration was higher than 300μM. The cysteine residues of μ-calpain at positions 49, 351, 384, and 592 in the catalytic subunit and at 142 in small subunit were S-nitrosylated, which could be responsible for decreased μ-calpain activity. Thus, S-nitrosylation can negatively regulate the activation of μ-calpain resulting in decreased proteolytic ability on myofibrils. PMID:27451206

  2. A novel screening system based on VanX-mediated autolysis-Application to Gaussia luciferase.

    Science.gov (United States)

    Wu, Nan; Kamioka, Tetsuya; Kuroda, Yutaka

    2016-07-01

    We report a novel bacterial screening protocol based on co-expressing the target protein with VanX, an enzyme which mediates Escherichia coli's autolysis and the release of the target protein into the culture medium, thereby facilitating activity measurement and screening from crude medium. This protocol as assessed with 19 Gaussia luciferase (GLuc) expressing colonies, was able to detect bioluminescence wavelength shift as small as 1.5 nm. We demonstrate the performance and versatility of this protocol by applying it to a semi-rational search for GLuc variants with red-shifted bioluminescence. Six GLuc's sites, F113, I114, W143, L144, A149, and F151, were randomly mutated, and for each site, 50 colonies were cultivated in 3 mL samples, from which bioluminescence was measured without purification. We identified two GLuc single mutation red-shifted variants: W143V and L144A. Their red shifted bioluminescence and biophysical/biochemical properties were confirmed using HPLC purified variants. Biotechnol. Bioeng. 2016;113: 1413-1420. © 2015 Wiley Periodicals, Inc. PMID:26694096

  3. Autolysis at the disintegrin domain of patagonfibrase, a metalloproteinase from Philodryas patagoniensis (Patagonia Green Racer; Dipsadidae) venom.

    Science.gov (United States)

    Peichoto, María E; Paes Leme, Adriana F; Pauletti, Bianca A; Batista, Isabel Correia; Mackessy, Stephen P; Acosta, Ofelia; Santoro, Marcelo L

    2010-09-01

    Patagonfibrase is a 57.5-kDa hemorrhagic metalloproteinase isolated from the venom of Philodryas patagoniensis (Patagonia Green Racer), a South American rear-fanged snake. Herein we demonstrate that patagonfibrase undergoes autolysis at its pH optimum (7.5) and at 37 degrees C, primarily producing a approximately 32.6 kDa fragment composed of disintegrin-like and cysteine-rich domains, as identified by mass spectrometry and N-terminal sequencing. The autolysis site for production of this fragment is similar to that observed for metalloproteinases from front-fanged Viperidae snake venoms. In the presence of Ca(2+), patagonfibrase was only partially autolysed, giving rise mainly to one fragment of approximately 52.2 kDa. In addition, calcium markedly enhanced the azocaseinolytic activity of patagonfibrase. Our findings contribute to the understanding of the structural and mechanistic bases of this family of metalloenzymes that are widely distributed among snake venoms, demonstrating that important post-translational modifications such as proteolysis can also contribute to the diversity and complexity of proteins found in rear-fanged snake venoms. PMID:20538077

  4. Effects of yogurt starters autolysis on quality of yogurt%发酵剂菌体自溶对酸乳品质的影响

    Institute of Scientific and Technical Information of China (English)

    孙洁; 沈瑾; 王希卓; 田亚洲; 吕加平; 刘鹭

    2012-01-01

    通过研究发酵剂自溶对菌株产酸、凝乳能力,及对酸乳黏度、持水率、风味物质、后酸化程度等理化指标的影响.结果表明:自溶度较高的乳酸菌菌株在酸乳发酵过程中产酸性能更优,凝乳时间较短;菌株的自溶度对酸乳的黏度、持水率、风味物质成分及含量影响不大,但对酸乳的后酸化程度有着显著影响,高自溶度菌株发酵而成的酸乳在模拟货架期储藏条件下(10~15℃)后酸化程度相对较低.该文为开发新型复合发酵剂提供了理论依据.%For developing new composite yogurt starters and finding new lactic acid bacteria strains for starters, the effects of yogurt starters autolysis on quality of yogurt, such as acid producing ability and curd ability of strains, yogurt viscosity, water-holding ratio, flavor compounds, acidification in shelf-life were studied. The results showed that coagulation time decreased significantly by using high autolysis rate lactic acid bacteria strains fermented yogurt, were positively related to acid producing ability of lactic acid bacteria starters. There was no relative correlation between autolysis rate of strains and water-holding ratio, viscosity and flavor compounds of yogurt. However, yogurt acidities were significant influenced by autolysis rate of lactic acid bacteria starters, especially in the simulated shelf life of 10-15°C storage conditions. High autolysis rate starters could decrease acidification level of yogurt.

  5. Selective autolysis of protoplasmic components during development of secondary-phloem sieve-tube elements in Populus deltoides

    Institute of Scientific and Technical Information of China (English)

    Zengfang YIN; Ruwen FAN

    2008-01-01

    Observing changes in plasma components dur-ing the development of sieve-tube elements (SE) in sec-ondary-phloem is very important in the study of their physiological function. We investigated the development of SE in the secondary-phloem of Populus deltoides with the aid of an electron microscope. The developmental process of SE in secondary-phloem can be divided into three stages: immature, mature and degenerated, based on the changes of plasma components and cell structures. The immature stage is the development period before the vacuole membrane was ruptured. The radial extension of cells, cell wall incrassation and generation of plastid sieve elements and P-protein occurred during this period. The mature stage started when the vacuole membrane was ruptured. Selective autolysis of protoplasmic components formed mature SEs, with the characteristics that the orga-nelles, such as dissociative ribosome, Golgi body, endo-plasmic reticulum and nuclei were disassembled quickly. Two distinctive ways of nuclear degeneration occur. One is an early degenerated nuclear membrane, with dispersed karyoplasms, joined by P-protein. The other is early agglomerated chromatin and subsequently degenerate karyotin with two clear layer structures in the nuclear membrane. One sign in the degenerated stage is the dis-assembled plasma membrane. During this stage, plastid membranes become disorganized, the starch grains are dispersed in the chamber of SE and the mitochondria dissembled. The callose appears synchronously in sieve plates and P-protein disaggregates. Opened sieve plates are then formed because of callose autolysis, after the protoplasm disappears completely. Finally, the physio-logical function of SE is lost.

  6. 虾蛋白自溶与外源酶促水解作用研究%Study on the Autolysis and Enzymatic Hydrolysis of Shrimp Protein

    Institute of Scientific and Technical Information of China (English)

    叶伟娟; 吴少辉; 于新

    2012-01-01

    目的:研究虾蛋白的自溶与外源酶促水解作用,为开发新型虾味高档调味品提供实验依据.方法:以基围虾为原料,氨基态氮含量、水解度(DH)为指标,研究pH、温度、时间、料液比对基围虾自溶水解效果的影响,并在最优条件下添加不同外源酶,探讨其对虾蛋白的酶促作用.结果:通过单因素和L9(33)正交试验获得基围虾自溶的最佳工艺参数是:料液比1:8(g/mL),温度60℃,pH 6.5,时间8h.结论:在此条件下,氨基态氮含量1.7 g/L,水解度45.88%.外源木瓜蛋白酶具有较好的酶促水解作用,菠萝蛋白酶、中性蛋白酶、胰蛋白酶对虾蛋白的酶促水解作用不显著.%Objective:This paper studied on the autolysis and enzymatic hydrolysis of shrimp protein in order to provide experimental basis for a development of new and high-grade sauce. Method:In an autolysis experiment with Metapenaeus ensis as the main raw material, amino nitrogen content and DH were taken as indicators to determine the effects of pH, temperature, hydrolysis time and solid-liquid ratio on hydrolysis. And the effect of different exogenous enzymes on autolysis was investigated. Results: Using single-factor and L9(33) orthogonal experiments, the conditions for Metapenae us ensis autolysis were optimized, the best technological parameters being solid—liquid ratio l:8(g/mL), reaction temperature 60 ℃, pH 6.5 and reaction time 8 h. Conclusion:Under the optimized, amino nitrogen was 1.7 g/L, DH was 45.88%. The exogenous enzymes of papain promoted the autolysis of the shrimp protein preferably, while bromelain, neutral protease and trypsin were not significant.

  7. Influences of food addictive on protein autolysis of Euphausia superba%食品添加剂对南极大磷虾蛋白自溶的影响

    Institute of Scientific and Technical Information of China (English)

    迟海; 李学英; 杭虞杰; 杨宪时; 郭全友

    2011-01-01

    以氨基态氮、可溶性蛋白质含量和可溶性固形物含量为指标,研究了食品添加剂对南极大磷虾(Euphausia superba)蛋白自溶的影响.结果显示,氯化镁和柠檬酸对南极大磷虾蛋白的自溶有一定的促进作用,两者作用显著的添加量分别为2%和0.2%,结合可溶性蛋白质和可溶性固形物指标,促进作用最显著的为添加0.2%柠檬酸;葡萄糖和氯化钙对南极大磷虾蛋白的自溶影响不大;氯化钾、氯化钠、EDTA-2Na对南极大磷虾蛋白的自溶有一定的抑制作用,氯化钠和EDTA-2Na的抑制作用相近,但优于氯化钾,三者作用显著的添加量分别为2%、4%、0.05%,考虑到可溶性蛋白质含量,抑制作用最显著为添加0.05% EDTA-2Na.%Based on the testing indexes of Amino Nitrogen Contents (ANC), Soluble Protein Concentration ( SPC) and Total Soluble Solids (TSS), influences of food addictive on protein autolysis of Euphausia superba were studied. Results showed that effects of magnesium chloride and citric acid on protein autolysis of Euphausia superba had certain simulative effect. Both optimum substitutabilities were 2% and 0. 2% , respectively. Combined soluble protein concentration and total soluble solid indexes, the optimum was adding 0.2% citric acid. Glucose and calcium chloride protein autolysis of Euphausia superba had little impact on protein autolysis; Potassium chloride, sodium chloride and EDTA-2Na had certain inhibition on protein autolysis of Euphausia superba, and inhibition of sodium chloride and EDTA-2Na was similar, both better than potassium chloride. The most suitable adding amount of for the three were 2% , 4% , and 0. 05%. Considering the soluble protein concentration, the best for autolysis was adding 0.05% EDTA-2Na.

  8. Impact of NaCl reduction in Danish semi-hard Samsoe cheeses on proliferation and autolysis of DL-starter cultures.

    Science.gov (United States)

    Søndergaard, Lise; Ryssel, Mia; Svendsen, Carina; Høier, Erik; Andersen, Ulf; Hammershøj, Marianne; Møller, Jean R; Arneborg, Nils; Jespersen, Lene

    2015-11-20

    Reduction of sodium chloride (NaCl) in cheese manufacturing is a challenge for the dairy industry. NaCl has a profound role on microbial development influencing cheese sensory and technological properties. The purpose of this work was to investigate how proliferation, distribution and autolysis of two commercial DL-starter cultures (C1 and C2) used in the production of Danish semi-hard Samsoe cheeses were affected by reduced NaCl levels. Cheeses containing <0.3% (unsalted), 2.3% (reduced-salt) and 3.4% (normal-salted) (w/v) NaCl in moisture were produced and analyzed during 12 weeks of ripening. Lactic acid bacteria (LAB), distribution of bacteria as single cells or microcolonies, their viability in the cheeses and cell autolysis were monitored during ripening, as well as the impact of NaCl content and autolysis on the formation of free amino acids (FAA). Reduction of NaCl resulted in higher LAB counts at the early stages of ripening, with differences between the two DL-starter cultures. The unsalted cheeses produced with C1 had retained a significantly higher number of the initial LAB counts (cfu/g) after 1 and 2 weeks of ripening (i.e. 58% and 71%), compared to the normal-salted cheeses (i.e. 22% and 21%), whereas no significant difference was found between the reduced-salt (i.e. 31% and 35%) and normal-salted cheeses. At the later stages of ripening (i.e. 7 and 11 weeks) NaCl had no significant influence. For cheeses produced with C2, a significant influence of NaCl was only found in cheeses ripened for 7 weeks, where the unsalted and reduced-salt cheeses had retained a significantly higher number of the initial LAB counts (cfu/g) (i.e. 39% and 38%), compared to the normal-salted cheeses (i.e. 21%). In the Samsoe cheeses, bacteria were organized as single cells, in groups of 2-3 cells or in groups of ≥4 cells. During ripening the decrease in the number of viable bacteria was mainly due to a reduction in the number of viable bacteria organized in groups of ≥4

  9. A comparison for acid production, proteolysis, autolysis and inhibitory properties of lactic acid bacteria from fresh and mature Feta PDO Greek cheese, made at three different mountainous areas.

    Science.gov (United States)

    Bozoudi, Despina; Kotzamanidis, Charalambos; Hatzikamari, Magdalini; Tzanetakis, Nikolaos; Menexes, George; Litopoulou-Tzanetaki, Evanthia

    2015-05-01

    Isolates of NSLAB were obtained from fresh (58 isolates) and mature (38) Feta cheese made at household level in three different mountainous areas, in order to study the effect of the area of production on NSLAB composition and their technological characteristics. Results obtained by SDS-PAGE of whole-cell proteins indicated that the microflora of the fresh cheese was composed of either lactococci (areas 1, 2), or lactococci and enterococci (area 3). The NSLAB microflora of mature cheese was composed almost entirely of lactobacilli species, differing according to the area of production. Species allocation by the SDS-PAGE method was confirmed by sequencing representative strains. Lactococci of cheese made in area 1 exhibited a narrow spectrum of antibacterial activity compared to isolates from areas 2 and 3, while for lactobacilli from all three areas a similar spectrum was noticed. Lactococci from area 2 exhibited higher (P2=1. The strains from areas 1 and 3 degraded preferentially αs-CN, while a clear preference towards β-CN was noticed for strains of area 2; their mean proteolytic activity was for strains of area 1 higher (Ptechnological properties. Principal component analysis of results on acidifying and proteolytic activities as well as autolysis allowed the distinction of lactococci according to their derivation area enabling the selection of appropriate strains as starters for cheese production in each area. PMID:25702882

  10. Discrimination of three mutational events that result in a disruption of the R122 primary autolysis site of the human cationic trypsinogen (PRSS1 by denaturing high performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    Férec Claude

    2001-11-01

    Full Text Available Abstract Background R122, the primary autolysis site of the human cationic trypsinogen (PRSS1, constitutes an important "self-destruct" or "fail-safe" defensive mechanism against premature trypsin activation within the pancreas. Disruption of this site by a missense mutation, R122H, was found to cause hereditary pancreatitis. In addition to a c.365G>A (CGC>CAC single nucleotide substitution, a c.365~366GC>AT (CGC>CAT gene conversion event in exon 3 of PRSS1 was also found to result in a R122H mutation. This imposes a serious concern on the genotyping of pancreatitis by a widely used polymerase chain reaction-restriction fragment length polymorphism assay, which could only detect the commonest c.365G>A variant. Materials and methods DNA samples containing either the known c.365G>A or c.365~366GC>AT variant in exon 3 of PRSS1 were used as positive controls to establish a denaturing high performance liquid chromatography (DHPLC assay. Results DHPLC could readily discriminate the two known different mutational events resulting in the R122H mutation. More importantly, under the same experimental conditions, it identified a further mutational event that also occurs in the R122 primary autolysis site but results in a different amino acid substitution: c.364C>T (CGC>TGC; R122C. Conclusions A rapid, simple, and low-cost assay for detecting both the known and new mutations occuring in the R122 primary autolysis site of PRSS1 was established. In addition, the newly found R122C variant represents a likely pancreatitis-predisposing mutation.

  11. Protease production during growth and autolysis of submerged Metarhizium anisopliae cultures Produção de protease durante o crescimento e análise de culturas submersas de Metarhizium anisopliae

    Directory of Open Access Journals (Sweden)

    Gilberto U.L. Braga

    1999-04-01

    Full Text Available The growth and autolysis of two strains of the entomopathogenic deuteromycete fungus Metarhizium anisopliae var. anisopliae were evaluated in medium containing casein or glucose as carbon source. Parameters such as economic coefficient and degree of autolysis were determined for each strain. Protease production was determined throughout the growth and autolysis phases of the cultures on medium under conditions of protease induction (in the presence of casein as sole source of carbon and nitrogen. The fungus was shown to utilize casein as a carbon/energy source in a more efficient manner than glucose. The autolysis shown by the strains was intense under both types of growth conditions, reaching up to 62.7% of the dry mass produced and started soon after the depletion of the exogenous carbon source. The relationship between the proteolytic activities of the two strains evaluated varied significantly (a maximum of 19.78 on the 5th day and a minimum of 2.03 on the 16th day of growth during the various growth and autolysis phases, clearly showing that the difference between the growth curves and the difference in the kinetics of enzyme production may decisively affect the process of strain selection for protease production.O crescimento e a autólise de duas linhagens do deuteromiceto entomopatogênico Metarhizium anisopliae var. anisopliae foram avaliados em meio contendo caseína ou glicose como fonte de carbono. Foram determinados parâmetros como o coeficiente econômico e o grau de autólise apresentado pelas linhagens. A produção de protease foi determinada durante todas as fases do crescimento e da autólise das culturas, em meio indutor da produção de proteases (meio contendo caseína como única fonte de carbono e de nitrogênio. Pôde-se verificar que o fungo foi capaz de utilizar a caseína como fonte de carbono/energia de maneira mais eficiente do que a glicose. A autólise apresentada pelas linhagens foi intensa em ambas as condi

  12. Inactivation of the Autolysis-Related Genes lrgB and yycI in Staphylococcus aureus Increases Cell Lysis-Dependent eDNA Release and Enhances Biofilm Development In Vitro and In Vivo.

    Directory of Open Access Journals (Sweden)

    Cristiana Ossaille Beltrame

    Full Text Available Staphylococcus aureus ica-independent biofilms are multifactorial in nature, and various bacterial proteins have been associated with biofilm development, including fibronectin-binding proteins A and B, protein A, surface protein SasG, proteases, and some autolysins. The role of extracellular DNA (eDNA has also been demonstrated in some S. aureus biofilms. Here, we constructed a Tn551 library, and the screening identified two genes that affected biofilm formation, lrgB and yycI. The repressive effect of both genes on the development of biofilm was also confirmed in knockout strains constructed by allelic recombination. In contrast, the superexpression of either lrgB or yycI by a cadmium-inducible promoter led to a decrease in biofilm accumulation. Indeed, a significant increase in the cell-lysis dependent eDNA release was detected when lrgB or yycI were inactivated, explaining the enhanced biofilm formed by these mutants. In fact, lrgB and yycI genes belong to distinct operons that repress bacterial autolysis through very different mechanisms. LrgB is associated with the synthesis of phage holin/anti-holin analogues, while YycI participates in the activation/repression of the two-component system YycGF (WalKR. Our in vivo data suggest that autolysins activation lead to increased bacterial virulence in the foreign body animal model since a higher number of attached cells was recovered from the implanted catheters inoculated with lrgB or yycI knockout mutants.

  13. Efecto de tres ambientes de transporte sobre el tiempo de aparición de la autólisis en muestras de alevines de trucha arcoíris (Oncorhynchus mykiss Effect of three transport conditions on the appearance time of autolysis in samples of rainbow trout fry (Oncorhynchus mykiss

    Directory of Open Access Journals (Sweden)

    AR Ortloff

    2011-01-01

    C. Every hour from 0 to 24 hours, groups of 4 fry per condition were fixed in 10% formalin and processed using the conventional hematoxylin and eosin stain technique (H&E. The appearance time of the autolytic changes in the different segments of the kidney and liver were determined in each group, classifying the changes as early autolytic, advanced autolytic and complete autolysis. It was observed that the autolytic changes appeared first in the livers of the corpses at 4 °C under dry condition while last ones to be affected were the corpses submerged in water at 4 °C (1 and 6 hours, respectively. The first autolytic changes appeared in the kidneys of the corpses at 4 °C in the dry atmosphere and the last in the corpses submerged in water at 4 °C (3 and 9 hours, respectively. It was concluded that out of the three transport conditions studied, the one preserving for longer the histological and cytological structure of the fish tissue for histological analysis was water preservation at 4 °C, demonstrating the key role of the temperature and atmospheric humidity in the progress of fish autolysis.

  14. A defect in cell wall recycling triggers autolysis during the stationary growth phase of Escherichia coli.

    OpenAIRE

    Templin, M F; Ursinus, A; Höltje, J V

    1999-01-01

    The first gene of a family of prokaryotic proteases with a specificity for L,D-configured peptide bonds has been identified in Escherichia coli. The gene named ldcA encodes a cytoplasmic L, D-carboxypeptidase, which releases the terminal D-alanine from L-alanyl-D-glutamyl-meso-diaminopimelyl-D-alanine containing turnover products of the cell wall polymer murein. This reaction turned out to be essential for survival, since disruption of the gene results in bacteriolysis during the stationary g...

  15. Targeting the autolysis loop of urokinase-type plasminogen activator with conformation-specific monoclonal antibodies

    DEFF Research Database (Denmark)

    Bøtkjær, Kenneth Alrø; Fogh, Sarah; Bekes, Erin C;

    2011-01-01

    Tight regulation of serine proteases is essential for their physiological function, and unbalanced states of protease activity have been implicated in a variety of human diseases. One key example is the presence of uPA (urokinase-type plasminogen activator) in different human cancer types...... to harbour the epitopes for three conformation-specific monoclonal antibodies, two with a preference for the zymogen form pro-uPA, and one with a preference for active uPA. All three antibodies were shown to have overlapping epitopes, with three common residues being crucial for all three antibodies...

  16. msaABCR operon positively regulates biofilm development by repressing proteases and autolysis in Staphylococcus aureus

    OpenAIRE

    Sahukhal, Gyan S; Batte, Justin L.; Elasri, Mohamed O.

    2015-01-01

    Staphylococcus aureus is an important human pathogen that causes nosocomial and community-acquired infections. One of the most important aspects of staphylococcal infections is biofilm development within the host, which renders the bacterium resistant to the host’s immune response and antimicrobial agents. Biofilm development is very complex and involves several regulators that ensure cell survival on surfaces within the extracellular polymeric matrix. Previously, we identified the msaABCR op...

  17. Effect of Bovine Plasma Protein on Autolysis and Gelation of Protein Extracted from Giant Squid (Dosidicus gigas Mantle

    Directory of Open Access Journals (Sweden)

    Laura Raquel Marquez-Alvarez

    2015-01-01

    Full Text Available The effect of bovine plasma protein (BPP on the inhibition of autolytic activity and its effect on the gelling properties of a protein concentrate (PC obtained from jumbo squid (Dosidicus gigas mantle were investigated. Sols and gels were prepared from the PC by adding different amounts of BPP (0, 1, and 2%. Dynamic oscillatory measurements indicated that systems with 1% BPP had a higher elastic modulus (G′, in which hydrophobic interactions were favored. Concerning the technological and textural quality of the gels, BPP caused a greater water holding capacity (WHC, force, cohesiveness, and elasticity, probably due to improvement of the electrostatic and hydrophobic interactions during gel formation. Scanning electron microscopy (SEM allowed visualization of the formation of more rigid and ordered gels with less porosity when BPP was added. Therefore, the addition of BPP improved the gelling capacity of proteins extracted from giant squid.

  18. Effect of Bovine Plasma Protein on Autolysis and Gelation of Protein Extracted from Giant Squid (Dosidicus gigas) Mantle

    OpenAIRE

    Laura Raquel Marquez-Alvarez; Wilfrido Torres-Arreola; Victor Manuel Ocano-Higuera; Benjamin Ramirez-Wong; Enrique Marquez-Rios

    2015-01-01

    The effect of bovine plasma protein (BPP) on the inhibition of autolytic activity and its effect on the gelling properties of a protein concentrate (PC) obtained from jumbo squid (Dosidicus gigas) mantle were investigated. Sols and gels were prepared from the PC by adding different amounts of BPP (0, 1, and 2%). Dynamic oscillatory measurements indicated that systems with 1% BPP had a higher elastic modulus (G′), in which hydrophobic interactions were favored. Concerning the technological and...

  19. Staphylococcus aureus Alters Growth Activity, Autolysis, and Antibiotic Tolerance in a Human Host-Adapted Pseudomonas aeruginosa Lineage

    DEFF Research Database (Denmark)

    Frydenlund Michelsen, Charlotte; Christensen, Anne-Mette; Bojer, Martin Saxtorph;

    2014-01-01

    Interactions among members of polymicrobial infections or between pathogens and the commensal flora may determine disease outcomes. Pseudomonas aeruginosa and Staphylococcus aureus are important opportunistic human pathogens and are both part of the polymicrobial infection communities in human...... hosts. In this study, we analyzed the in vitro interaction between S. aureus and a collection of P. aeruginosa isolates representing different evolutionary steps of a dominant lineage, DK2, that have evolved through decades of growth in chronically infected patients. While the early adapted P....... aeruginosa DK2 strains outcompeted S. aureus during coculture on agar plates, we found that later P. aeruginosa DK2 strains showed a commensal-like interaction, where S. aureus was not inhibited by P. aeruginosa and the growth activity of P. aeruginosa was enhanced in the presence of S. aureus. This effect...

  20. Can the development and autolysis of lactic acid bacteria influence the cheese volatile fraction? The case of Grana Padano.

    Science.gov (United States)

    Lazzi, Camilla; Povolo, Milena; Locci, Francesco; Bernini, Valentina; Neviani, Erasmo; Gatti, Monica

    2016-09-16

    In this study, the relationship between the dynamics of the growth and lysis of lactic acid bacteria in Grana Padano cheese and the formation of the volatile flavor compounds during cheese ripening was investigated. The microbial dynamics of Grana Padano cheeses that were produced in two different dairies were followed during ripening. The total and cultivable lactic microflora, community composition as determined by length heterogeneity-PCR (LH-PCR), and extent of bacterial lysis using an intracellular enzymatic activity assay were compared among cheeses after 2, 6 and 13months of ripening in two dairies. The evolution of whole and lysed microbiota was different between the two dairies. In dairy 2, the number of total cells was higher than that in dairy 1 in all samples, and the number of cells that lysed during ripening was lower. In addition, at the beginning of ripening (2months), the community structure of the cheese from dairy 2 was more complex and was composed of starter lactic acid bacteria (Lactobacillus helveticus and Lactobacillus delbrueckii) and NSLAB, possibly arising from raw milk, including Lactobacillus rhamnosus/Lactobacillus casei and Pediococcus acidilactici. On the other hand, the cheese from dairy 1 that ripened for 2months was mainly composed of the SLAB L. helveticus and L. delbrueckii. An evaluation of the free-DNA fraction through LH-PCR identified those species that had a high degree of lysis. Data on the dynamics of bacterial growth and lysis were evaluated with respect to the volatile profile and the organic acid content of the two cheeses after 13months of ripening, producing very different results. Cheese from dairy 1 showed a higher content of free fatty acids, particularly those deriving from milk fat lipolysis, benzaldehyde and organic acids, such as pGlu and citric. In contrast, cheese from dairy 2 had a greater amount of ketones, alcohols, hydrocarbons, acetic acid and propionic acid. Based on these results, we can conclude that in the first cheese, the intracellular enzymes that were released from lysis were mainly involved in aroma formation, whereas in the second cheese, the greater complexity of volatile compounds may be associated with its more complex microbial composition caused from SLAB lysis and NSLAB (mainly L. rhamnosus/L. casei) growth during ripening. PMID:27299670

  1. Detection of Lawsonia intracellularis in formalinfixed Porcine Intestinal Tissue Samples: Comparison of Immunofluorescense and In-situ Hybridization, and Evaluation of the Effectf of Controlled Autolysis

    DEFF Research Database (Denmark)

    Jensen, Tim Kåre; Boesen, H. T.; Vigre, Håkan;

    2010-01-01

    (the cause of porcine proliferative enteritis [PE]) in formalin-fixed samples of intestinal tissue. Of 69 intestinal samples with gross lesions of PE, 63 were positive by both FISH and IFA, but six were positive only by IFA. This indicated that the sensitivity of FISH was 91% that of IFA. However, both...

  2. Impact of NaCl reduction in Danish semi-hard Samsoe cheeses on development and autolysis of DL-starter cultures

    DEFF Research Database (Denmark)

    Søndergaard, Lise; Ryssel, Mia; Svendsen, Carina;

    2015-01-01

    of two commercial DL-starter cultures (C1 and C2) used in the production of Danish semi-hard Samsoe cheeses were affected by reduced NaCl levels. Cheeses containing reduced-salt) and 3.4% (normal-salted) (w/v) NaCl in moisture were produced and analyzed during 12weeks of ripening.......e. 22% and 21%), whereas no significant difference was found between the reduced-salt (i.e. 31% and 35%) and normal-salted cheeses. At the later stages of ripening (i.e. 7 and 11weeks) NaCl had no significant influence. For cheeses produced with C2, a significant influence of NaCl was only found...... in cheeses ripened for 7weeks, where the unsalted and reduced-salt cheeses had retained a significantly higher number of the initial LAB counts (cfu/g) (i.e. 39% and 38%), compared to the normal-salted cheeses (i.e. 21%). In the Samsoe cheeses, bacteria were organized as single cells, in groups of 2-3 cells...

  3. Induction and control of the autolytic system of Escherichia coli.

    OpenAIRE

    Leduc, M.; Kasra, R; van Heijenoort, J

    1982-01-01

    Various methods of inducing autolysis of Escherichia coli cells were investigated, some being described here for the first time. For the autolysis of growing cells only induction methods interfering with the biosynthesis of peptidoglycan were taken into consideration, whereas with harvested cells autolysis was induced by rapid osmotic or EDTA shock treatments. The highest rates of autolysis were observed after induction by moenomycin, EDTA, or cephaloridine. The different autolyses examined s...

  4. Chymotrypsin C (caldecrin) promotes degradation of human cationic trypsin: Identity with Rinderknecht's enzyme Y

    OpenAIRE

    Szmola, Richárd; Sahin-Tóth, Miklós

    2007-01-01

    Digestive trypsins undergo proteolytic breakdown during their transit in the human alimentary tract, which has been assumed to occur through trypsin-mediated cleavages, termed autolysis. Autolysis was also postulated to play a protective role against pancreatitis by eliminating prematurely activated intrapancreatic trypsin. However, autolysis of human cationic trypsin is very slow in vitro, which is inconsistent with the documented intestinal trypsin degradation or a putative protective role....

  5. Ethanol-Glycerin Fixation with Thymol Conservation: A Potential Alternative to Formaldehyde and Phenol Embalming

    Science.gov (United States)

    Hammer, Niels; Loffler, Sabine; Feja, Christine; Sandrock, Mara; Schmidt, Wolfgang; Bechmann, Ingo; Steinke, Hanno

    2012-01-01

    Anatomical fixation and conservation are required to prevent specimens from undergoing autolysis and decomposition. While fixation is the primary arrest of the structures responsible for autolysis and decomposition, conservation preserves the state of fixation. Although commonly used, formaldehyde has been classified as carcinogenic to humans. For…

  6. Evolution of Bacterial Suicide

    Science.gov (United States)

    Tchernookov, Martin; Nemenman, Ilya

    2013-03-01

    While active, controlled cellular suicide (autolysis) in bacteria is commonly observed, it has been hard to argue that autolysis can be beneficial to an individual who commits it. We propose a theoretical model that predicts that bacterial autolysis is evolutionarily advantageous to an individualand would fixate in physically structured environments for stationary phase colonies. We perform spatially resolved agent-based simulations of the model, which predict that lower mixing in the environment results in fixation of a higher autolysis rate from a single mutated cell, regardless of the colony's genetic diversity. We argue that quorum sensing will fixate as well, even if initially rare, if it is coupled to controlling the autolysis rate. The model does not predict a strong additional competitive advantage for cells where autolysis is controlled by quorum sensing systems that distinguish self from nonself. These predictions are broadly supported by recent experimental results in B. subtilisand S. pneumoniae. Research partially supported by the James S McDonnell Foundation grant No. 220020321 and by HFSP grant No. RGY0084/2011.

  7. Treatment of Leptothrix Cells with Ultrapure Water Poses a Threat to Their Viability

    Directory of Open Access Journals (Sweden)

    Tatsuki Kunoh

    2015-01-01

    Full Text Available The genus Leptothrix, a type of Fe/Mn-oxidizing bacteria, is characterized by its formation of an extracellular and microtubular sheath. Although almost all sheaths harvested from natural aquatic environments are hollow, a few chained bacterial cells are occasionally seen within some sheaths of young stage. We previously reported that sheaths of Leptothrix sp. strain OUMS1 cultured in artificial media became hollow with aging due to spontaneous autolysis within the sheaths. In this study, we investigated environmental conditions that lead the OUMS1 cells to die. Treatment of the cells with ultrapure water or acidic buffers (pH 6.0 caused autolysis of the cells. Under these conditions, the plasma membrane and cytoplasm of cells were drastically damaged, resulting in leakage of intracellular electrolytes and relaxation of genomic DNA. The autolysis was suppressed by the presence of Ca2+. The hydrolysis of peptidoglycan by the lysozyme treatment similarly caused autolysis of the cells and was suppressed also by the presence of Ca2+. However, it remains unclear whether the acidic pH-dependent autolysis is attributable to damage of peptidoglycan. It was observed that L. discophora strain SP-6 cells also underwent autolysis when suspended in ultrapure water; it is however, uncertain whether this phenomenon is common among other members of the genus Leptothrix.

  8. Changes in collagenous tissue microstructures and distributions of cathepsin L in body wall of autolytic sea cucumber (Stichopus japonicus).

    Science.gov (United States)

    Liu, Yu-Xin; Zhou, Da-Yong; Ma, Dong-Dong; Liu, Yan-Fei; Li, Dong-Mei; Dong, Xiu-Ping; Tan, Ming-Qian; Du, Ming; Zhu, Bei-Wei

    2016-12-01

    The autolysis of sea cucumber (Stichopus japonicus) was induced by ultraviolet (UV) irradiation, and the changes of microstructures of collagenous tissues and distributions of cathepsin L were investigated using histological and histochemical techniques. Intact collagen fibers in fresh S. japonicus dermis were disaggregated into collagen fibrils after UV stimuli. Cathepsin L was identified inside the surface of vacuoles in the fresh S. japonicus dermis cells. After the UV stimuli, the membranes of vacuoles and cells were fused together, and cathepsin L was released from cells and diffused into tissues. The density of cathepsin L was positively correlated with the speed and degree of autolysis in different layers of body wall. Our results revealed that lysosomal cathepsin L was released from cells in response to UV stimuli, which contacts and degrades the extracellular substrates such as collagen fibers, and thus participates in the autolysis of S. japonicus. PMID:27374541

  9. Optimisation of the Method for the Quantitative Determination of Sulforaphane in Broccoli

    International Nuclear Information System (INIS)

    Consumption of vegetables, especially crucifers, reduces the risk of developing cancer. Sulforaphane [l-isothiocyanato-4- (methylsulfinyl)-butane], a compound with the ability to inhibit carcinogenesis, is one of the degradation products of glucosinolates in cruciferous vegetables. Among available extraction methods, autolysis at room temperature is the most effective for Sulforaphane extraction (relatively higher purity and better yield). The research work undertaken at Federal Research Centre for Nutrition, Institute of Biology and Chemistry, Karlsruhe, Germany was isolation of Sulforaphane based on cruciferous vegetables like Broccoli (Brassica oleracea L. Cv. italica) employing autolysis - the yield being higher. The extracted Sulforaphane compound's purity and yield were accordingly examined with gas chromatography. (author)

  10. FEATURES OF TECHNOLOGY OF WINE SUCH AS PORT FROM PERSPECTIVE RED AND WHITE GRAPE Особенности технологии вина типа портвейн из перспективных красных и белых сортов винограда

    Directory of Open Access Journals (Sweden)

    Hristjuk V. T.

    2011-09-01

    Full Text Available Features of technology of port from perspective red grape of Negro, Podlesniy, 40 let Pobedy, Dostoyniy and white - Bianka and First-born Magaracha are investigated. The organoleptic characteristics of re-ceived ports is given. Positive influence is established and explained at en-tering in researched strong wine materials the autoly-sis of yeast processed by electromagnetic fields VLF or the MICROWAVE. Experimental results are shown and optimum parameters of a fermentation, thermal processing and conditions of entering of an autolysis of yeast, MICROWAVES - EXTRACTS are determined.

  11. 16 CFR 1702.9 - Relevant experimental data.

    Science.gov (United States)

    2010-01-01

    ... seven day observation period of test animals. Good pharmacological practice provides that test animals... observation period. Documentation of non-lethal effects occurring during these observation periods should be... onset of autolysis. Results of microscopic examinations, when indicated by the nature or results of...

  12. Manipulating the autolytic pathway of a Bacillus protease

    NARCIS (Netherlands)

    VandenBurg, B; Eijsink, VGH; Vriend, G; Veltman, OR; Venema, G; HopsuHavu, VK; Jarvinen, M; Kirschke, H

    1997-01-01

    Autolytic degradation of Bacillus subtilis thermolysin-like proteinase (TLP-sub) is responsible for the irreversible inactivation of the enzyme at elevated temperatures. Previously, we reported five autolysis sites in B. subtilis neutral protease (Van den Burg et al., 1990, Biochem. J. 272:93-97). I

  13. SarA is a negative regulator of Staphylococcus epidermidis biofilm formation

    DEFF Research Database (Denmark)

    Martin, Christer; Heinze, C.; Busch, M.;

    2012-01-01

    contributed to biofilm formation in mutant 1585ΔsarA. Increased eDNA amounts indirectly resulted from up-regulation of metalloprotease SepA, leading to boosted processing of major autolysin AtlE, in turn inducing augmented autolysis and release of chromosomal DNA. Hence, this study identifies sarA as a...

  14. sarA negatively regulates Staphylococcus epidermidis biofilm formation by modulating expression of 1 MDa extracellular matrix binding protein and autolysis‐dependent release of eDNA

    DEFF Research Database (Denmark)

    Christner, Martin; Heinze, Constanze; Busch, Michael;

    2012-01-01

    biofilm formation in mutant 1585ΔsarA. Increased eDNA amounts indirectly resulted from upregulation of metalloprotease SepA, leading to boosted processing of autolysin AtlE, in turn inducing augmented autolysis and release of eDNA. Hence, this study identifies sarA as a negative regulator of Embp‐ and e...

  15. Monovalent cations enable cell wall turnover of the turnover-deficient lyt-15 mutant of Bacillus subtilis.

    OpenAIRE

    Cheung, H. Y.; Freese, E

    1985-01-01

    A lyt-15 mutant reported to be unable to turn over the cell wall exhibited the same rate of wall turnover as the standard strain if the medium contained 0.2 M NaCl, which did not affect growth. Cell wall autolysis was also optimal at 0.2 M NaCl.

  16. Biodiversity of autolytic ability in flocculent Saccharomyces cerevisiae strains suitable for traditional sparkling wine fermentation.

    Science.gov (United States)

    Perpetuini, Giorgia; Di Gianvito, Paola; Arfelli, Giuseppe; Schirone, Maria; Corsetti, Aldo; Tofalo, Rosanna; Suzzi, Giovanna

    2016-07-01

    Yeasts involved in secondary fermentation of traditional sparkling wines should show specific characteristics, such as flocculation capacity and autolysis. Recently it has been postulated that autophagy may contribute to the outcome of autolysis. In this study, 28 flocculent wine Saccahromyces cerevisiae strains characterized by different flocculation degrees were studied for their autolytic and autophagic activities. Autolysis was monitored in synthetic medium through the determination of amino acid nitrogen and total proteins released. At the same time, novel primer sets were developed to determine the expression of the genes ATG1, ATG17 and ATG29. Twelve strains were selected on the basis of their autolytic rate and ATG gene expressions in synthetic medium and were inoculated in a base wine. After 30, 60 and 180 days the autolytic process and ATG gene expressions were evaluated. The obtained data showed that autolysis and ATG gene expressions differed among strains and were independent of the degree of flocculation. This biodiversity could be exploited to select new starter stains to improve sparkling wine production. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26804203

  17. [Effect of proteolysis inhibitors on the incorporation of labelled amino acids into proteins].

    Science.gov (United States)

    Konikova, A S; Korotkina, R N

    1975-01-01

    Role of peptide bond breaks in the incorporation of amino acids into proteins in a "protein--amino acid" system is investigated. For this purpose the incorporation of labelled amino acids into trypsin under the inhibition of its autolysis by a specific inhibitor from soybean and epsilon-amino-caproic acid is studied. The trypsin inhibitor from soybean is found to suppress considerably the incorporation of 14C-glycine, 14C-lysine and 14C-methionine into crystal trypsin and not to affect the incorporation of labelled amino acids into chomotrypsin, papain and carboxypeptidase. Epsilon-Aminocaproic acid inhibited 14C-glycine incorporation into crystal trypsin by 40% and did not change its incorporation level into serum albumin. The dependency of amino acid incorporation level into trypsin on the activity of autolysis in the "protein--amino acid" system is demonstrated. PMID:1212456

  18. Two-component signal transduction system SaeRS is involved in competence and penicillin susceptibility in Staphylococcus epidermidis.

    Science.gov (United States)

    Lou, Qiang; Ma, Yuanfang; Qu, Di

    2016-04-01

    Staphylococcus epidermidis, which is a causative pathogen of nosocomial infection, expresses its virulent traits such as biofilm and autolysis regulated by two-component signal transduction system SaeRS. In this study, the S. epidermidis SaeRS was identified to negatively regulate the expression of genes involved in competence (comF, murF), cytolysis (lrgA), and autolysis (lytS) by DNA microarray or real-time RT-PCR analysis. In addition, saeRS mutant showed increased competence and higher susceptibility to antibiotics such as penicillin and oxacillin than the wild-type strain. The study will be helpful for understanding the characterization of the SaeRS in S. epidermidis. PMID:26898187

  19. The effect of cambial zone isolation upon the autolytic system in maturing tracheids of pine (Pinus silvestris L.

    Directory of Open Access Journals (Sweden)

    Jacek Zakrzewski

    2014-02-01

    Full Text Available The autolytic protease system in maturing tracheids of the main stem of Pinus silvestris was investigated after separation (using surgical methods of the cambial zone from the layer of differentiating xylem, in combination with decapitation and IAA application. Separation of the cambium prevented autolysis of the protoplast in maturing tracheids, although the specific activity of proteases was little reduced. It was found that a radial or longitudinal concentration gradient of exogenously applied auxin was not responsible for autolysis, but that it could influence the level of extracted protein, and proteolytic activity. Similarly, decapitation modified, only to small degree, the effects of the cambium separation. Thus, the data from this experiment lead to the conclusion that integration of all cells in the region of xylem formation is a crucial factor for the start of autolytic protoplast breakdown. Possible involvement of auxin waves in the transfer of the positional information for this process is suggested.

  20. Dynamic capsule restructuring by the main pneumococcal autolysin LytA in response to the epithelium.

    Science.gov (United States)

    Kietzman, Colin C; Gao, Geli; Mann, Beth; Myers, Lance; Tuomanen, Elaine I

    2016-01-01

    Bacterial pathogens produce complex carbohydrate capsules to protect against bactericidal immune molecules. Paradoxically, the pneumococcal capsule sensitizes the bacterium to antimicrobial peptides found on epithelial surfaces. Here we show that upon interaction with antimicrobial peptides, encapsulated pneumococci survive by removing capsule from the cell surface within minutes in a process dependent on the suicidal amidase autolysin LytA. In contrast to classical bacterial autolysis, during capsule shedding, LytA promotes bacterial survival and is dispersed circumferentially around the cell. However, both autolysis and capsule shedding depend on the cell wall hydrolytic activity of LytA. Capsule shedding drastically increases invasion of epithelial cells and is the main pathway by which pneumococci reduce surface bound capsule during early acute lung infection of mice. The previously unrecognized role of LytA in removing capsule to combat antimicrobial peptides may explain why nearly all clinical isolates of pneumococci conserve this enzyme despite the lethal selective pressure of antibiotics. PMID:26924467

  1. A non-catalytic histidine residue influences the function of the metalloprotease of Listeria monocytogenes

    OpenAIRE

    Forster, Brian M.; Bitar, Alan Pavinski; Marquis, Hélène

    2014-01-01

    Mpl, a thermolysin-like metalloprotease, and PC-PLC, a phospholipase C, are synthesized as proenzymes by the intracellular bacterial pathogen Listeria monocytogenes. During intracellular growth, L. monocytogenes is temporarily confined in a membrane-bound vacuole whose acidification leads to Mpl autolysis and Mpl-mediated cleavage of the PC-PLC N-terminal propeptide. Mpl maturation also leads to the secretion of both Mpl and PC-PLC across the bacterial cell wall. Previously, we identified neg...

  2. Utilization of baker's yeast (Saccharomyces cerevisiae) for the production of yeast extract: effects of different enzymatic treatments on solid, protein and carbohydrate recovery

    OpenAIRE

    TATJANA VUKASINOVIC MILIC; MARICA RAKIN; SLAVICA SILER-MARINKOVIC

    2007-01-01

    Yeast extract (YE) was produced from commercial pressed baker's yeast (active and inactivated) using two enzymes: papain and lyticase. The effects of enzyme concentration and hydrolysis time on the recovery of solid, protein and carbohydrate were investigated. Autolysis, as a basic method for cell lysis was also used and the results compared. The optimal extraction conditions were investigated. The optimal concentrations of papain and lyticase were found to be 2.5 % and 0.025 %, respectively.

  3. Improvement of Omega-3 Docosahexaenoic Acid Production by Marine Dinoflagellate Crypthecodinium cohnii Using Rapeseed Meal Hydrolysate and Waste Molasses as Feedstock

    OpenAIRE

    Yangmin Gong; Jiao Liu; Mulan Jiang; Zhuo Liang; Hu Jin; Xiaojia Hu; Xia Wan; Chuanjiong Hu

    2015-01-01

    Rapeseed meal and waste molasses are two important agro-industrial by-products which are produced in large quantities. In this study, solid state fermentation and fungal autolysis were performed to produce rapeseed meal hydrolysate (RMH) using fungal strains of Aspergillus oryzae, Penicillium oxalicum and Neurospora crassa. The hydrolysate was used as fermentation feedstock for heterotrophic growth of microalga Crypthecodinium cohnii that produce docosahexaenoic acid (DHA). The addition of wa...

  4. INCAPABILITY OF FORMALIN BASED FIXATIVE TO KILL MAGGOT IN MUTILATED HUMAN CARRION

    OpenAIRE

    Oladele, A.A.; Sanya, J.O.; Raji, M.O; Ekundina, V.O

    2015-01-01

    Background: Embalming is a process used to temporarily preserve a human cadaver to forestall decomposition and make it suitable for display at funerals; thus, are agents that prevent autolysis and putrefaction. The outbreak of maggots from a heap of inadequately embalmed bodies due to deep cuts and bodies involved in inferno, necessitated the need to re-investigate the efficacy of formalin based embalming fluid and its inability to kill maggots. Methodology: Various strength of Formaldehy...

  5. Toxin ζ Reversible Induces Dormancy and Reduces the UDP-N-Acetylglucosamine Pool as One of the Protective Responses to Cope with Stress

    OpenAIRE

    Mariangela Tabone; Silvia Ayora; Alonso, Juan C.

    2014-01-01

    Toxins of the ζ/PezT family, found in the genome of major human pathogens, phosphorylate the peptidoglycan precursor uridine diphosphate-N-acetylglucosamine (UNAG) leading to unreactive UNAG-3P. Transient over-expression of a PezT variant impairs cell wall biosynthesis and triggers autolysis in Escherichia coli. Conversely, physiological levels of ζ reversibly induce dormancy produce a sub-fraction of membrane-compromised cells, and a minor subpopulation of Bacillus subtilis cells become tol...

  6. Cleaning out the Litterbox of Proteomic Scientists’ Favorite Pet: Optimized Data Analysis Avoiding Trypsin Artifacts

    OpenAIRE

    Schittmayer, Matthias; Fritz, Katarina; Liesinger, Laura; Griss, Johannes; Birner-Gruenberger, Ruth

    2016-01-01

    Chemically modified trypsin is a standard reagent in proteomics experiments but is usually not considered in database searches. Modification of trypsin is supposed to protect the protease against autolysis and the resulting loss of activity. Here, we show that modified trypsin is still subject to self-digestion, and, as a result, modified trypsin-derived peptides are present in standard digests. We depict that these peptides commonly lead to false-positive assignments even if native trypsin i...

  7. Alanine Esters of Enterococcal Lipoteichoic Acid Play a Role in Biofilm Formation and Resistance to Antimicrobial Peptides

    OpenAIRE

    Fabretti, Francesca; Theilacker, Christian; Baldassarri, Lucilla; Kaczynski, Zbigniew; Kropec, Andrea; Holst, Otto; Huebner, Johannes

    2006-01-01

    Enterococcus faecalis is among the predominant causes of nosocomial infections. Surface molecules like d-alanine lipoteichoic acid (LTA) perform several functions in gram-positive bacteria, such as maintenance of cationic homeostasis and modulation of autolytic activities. The aim of the present study was to evaluate the effect of d-alanine esters of teichoic acids on biofilm production and adhesion, autolysis, antimicrobial peptide sensitivity, and opsonic killing. A deletion mutant of the d...

  8. Utilization of baker's yeast (Saccharomyces cerevisiae for the production of yeast extract: effects of different enzymatic treatments on solid, protein and carbohydrate recovery

    Directory of Open Access Journals (Sweden)

    TATJANA VUKASINOVIC MILIC

    2007-05-01

    Full Text Available Yeast extract (YE was produced from commercial pressed baker's yeast (active and inactivated using two enzymes: papain and lyticase. The effects of enzyme concentration and hydrolysis time on the recovery of solid, protein and carbohydrate were investigated. Autolysis, as a basic method for cell lysis was also used and the results compared. The optimal extraction conditions were investigated. The optimal concentrations of papain and lyticase were found to be 2.5 % and 0.025 %, respectively.

  9. Metody prodloužení skladovatelnosti strojně děleného rybího masa

    OpenAIRE

    Kubík, Michal

    2015-01-01

    The initial part of this work sums up the methods of mechanical mincing of fish meat and food safety. The fish meat processing methods are described in detail and supplemented with the respective legislative. The primary factors affecting the quality and usability of the product are the changes caused by proteolysis and autolysis, the occurrence of microorganisms and biogenic amines. These processes are natural; they may only be delayed or reduced in intensity. Despite the possibility of usin...

  10. The effect of cambial zone isolation upon the autolytic system in maturing tracheids of pine (Pinus silvestris L.)

    OpenAIRE

    Jacek Zakrzewski; Krzysztof Rakowski

    2014-01-01

    The autolytic protease system in maturing tracheids of the main stem of Pinus silvestris was investigated after separation (using surgical methods) of the cambial zone from the layer of differentiating xylem, in combination with decapitation and IAA application. Separation of the cambium prevented autolysis of the protoplast in maturing tracheids, although the specific activity of proteases was little reduced. It was found that a radial or longitudinal concentration gradient of exogenously ap...

  11. Adenovirus: an emerging factor in red squirrel Sciurus vulgaris conservation

    OpenAIRE

    Everest, David J; Shuttleworth, Craig M.; Stidworthy, Mark F.; Grierson, Sylvia S.; Duff, J. Paul; Kenward, Robert E.

    2014-01-01

    1. Adenovirus is an emerging threat to red squirrel Sciurus vulgaris conservation, but confirming clinically significant adenovirus infections in red squirrels is challenging. Rapid intestinal autolysis after death in wild animals frequently obscures pathology characteristic of the disease in animals found dead. 2. We review the available literature to determine current understanding of both subclinical and clinically significant adenovirus infections in free-living wild and captive red sq...

  12. Hepatocyte vacuolation and autolytic changes in the liver of pilot whales, Globicephala melas, stranded on Cape Cod, MA, USA.

    Science.gov (United States)

    Moore, M J; Stegeman, J J

    1996-07-16

    Most cetacea available for internal sampling in recent times have died through mass or single stranding events. It is important to know how the time elapsed between death and sampling affect quality of tissues. This study evaluated histological quality in the liver of long-finned pilot whales that either died or were euthanased after mass stranding events. Histological detection of significant autolysis was found in animals when 2 or more hours elapsed between death and sampling. In addition, hepatocytes often had marked idiopathic cytoplasmic vacuolation that did not stain with hematoxylin and eosin. The extent of this vacuolation did not show any correlation with time between death and sampling, but did appear more often in animals of greater total length. These observations suggest that when animals die or are euthanased at a single or mass stranding, every effort should be made to obtain samples as soon as possible, although meaningful histological observations can still be made in the presence of significant autolysis. These data also suggest that a multi-disciplinary study should be conducted to determine whether increasing autolysis is associated with changes in the organic chemical residues, molecular biology, histopathology and microbiology of those tissues. PMID:8685702

  13. Structural studies of the cell wall polysaccharides from three strains of Lactobacillus helveticus with different autolytic properties: DPC4571, BROI, and LH1.

    Science.gov (United States)

    Vinogradov, Evgeny; Valence, Florence; Maes, Emmanuel; Jebava, Iva; Chuat, Victoria; Lortal, Sylvie; Grard, Thierry; Guerardel, Yann; Sadovskaya, Irina

    2013-09-20

    Lactobacillus helveticus is traditionally used in dairy industry as a starter or an adjunct culture for manufacture of cheese and some types of fermented milk. Its autolysis releases intracellular enzymes which is a prerequisite for optimum cheese maturation, and is known to be strain dependent. Autolysis is caused by an enzymatic hydrolysis of the cell wall peptidoglycan (PG) by endogenous peptidoglycan hydrolases (PGHs) or autolysins. Origins of differences in autolytic properties of different strains are not fully elucidated. Regulation of autolysis possibly depends on the structure of the cell wall components other than PG, particularly polysaccharides. In the present work, we screened six L. helveticus strains with different autolytic properties: DPC4571, BROI and LH1. We established, for the first time, that cell walls (CWs) of these strains contained polysaccharides, different from their CW teichoic acids. Cell wall polysaccharides of three strains were purified, and their chemical structures were established by 2D NMR spectroscopy and methylation analysis. The structures of their repeating units are presented. PMID:23831635

  14. 反刍动物瘤胃原虫自溶现象的初步研究

    Institute of Scientific and Technical Information of China (English)

    王欢莉; 王洪荣; 徐爱秋; 赵庆新; 姜小波

    2014-01-01

    瘤胃原虫自溶的初步研究,可为反刍动物瘤胃内微生物蛋白循环的研究及相关调控技术的开展提供基础资料。本试验采用氧诱导自溶的方法,在体外培养条件下研究原虫形态、自溶度、蛋白酶活性及脂肪酶活性的变化。结果表明,氧诱导处理原虫形态变化明显,表现出自溶特征。前期(0~4 h)自溶速度较快,4 h胞内蛋白释放达50%。自溶组蛋白酶活性较对照组降低9.92%(P<0.05);而脂肪酶活性较对照组提高41.01%(P<0.01)。胞外蛋白酶活性与原虫自溶度相关性最高(r=0.703)。脂肪酶活性对于原虫自溶度的直接效应最强(P=0.586)。综上所述,氧诱导处理使瘤胃原虫发生自溶,据此建立自溶模型。脂肪酶的作用是瘤胃原虫自溶的关键因素。%The purpose of this article is to find out the autolytic characteristic of rumen protozoa,and to provide some basic information for the study of microbial protein circulation and correlating regulation technique.The following parameters in vitro including conformation of protozoa,protein content,degree of autolysis,activity of protease and lipase were studied, with the method of oxygen inducement.The conformation change of protozoa conformation was evident induced by oxygen. There existed a sharp increase in the rate of autolysis during the prophase(0~4 h).The release of protein got 50%in 4 h.The protease activity outside of protozoa in oxygen-induced group was 9.92%lower than that of control group(P<0.05).The lipase activity outside of protozoa in oxygen-induced group was 41.01%higher than that of control group (P<0.01).There existed positive correlation between the protease activity outside of protozoa and autolysis degree of protozoa (r=0.703).The direct effect of the lipase activity on autolysis degree of protozoa was the strongest (P=0.586).The autolysis model of rumen protozoa was established in this study induced by oxygen

  15. Estrogen and pure antiestrogen fulvestrant (ICI 182 780) augment cell–matrigel adhesion of MCF-7 breast cancer cells through a novel G protein coupled estrogen receptor (GPR30)-to-calpain signaling axis

    International Nuclear Information System (INIS)

    Fulvestrant (ICI 182 780, ICI) has been used in treating patients with hormone-sensitive breast cancer, yet initial or acquired resistance to endocrine therapies frequently arises and, in particular, cancer recurs as metastasis. We demonstrate here that both 17-beta-estradiol (E2) and ICI enhance cell adhesion to matrigel in MCF-7 breast cancer cells, with increased autolysis of calpain 1 (large subunit) and proteolysis of focal adhesion kinase (FAK), indicating calpain activation. Additionally, either E2 or ICI induced down-regulation of estrogen receptor α without affecting G protein coupled estrogen receptor 30 (GPR30) expression. Interestingly, GPR30 agonist G1 triggered calpain 1 autolysis but not calpain 2, whereas ER agonist diethylstilbestrol caused no apparent calpain autolysis. Furthermore, the actions of E2 and ICI on calpain and cell adhesion were tremendously suppressed by G15, or knockdown of GPR30. E2 and ICI also induced phosphorylation of extracellular regulated protein kinases 1 and 2 (ERK1/2), and suppression of ERK1/2 phosphorylation by U0126 profoundly impeded calpain activation triggered by estrogenic and antiestrogenic stimulations indicating implication of ERK1/2 in the GPR30-mediated action. Lastly, the E2- or ICI-induced cell adhesion was dramatically impaired by calpain-specific inhibitors, ALLN or calpeptin, suggesting requirement of calpain in the GPR30-associated action. These data show that enhanced cell adhesion by E2 and ICI occurs via a novel GPR30-ERK1/2-calpain pathway. Our results indicate that targeting the GPR30 signaling may be a potential strategy to reduce metastasis and improve the efficacy of antiestrogens in treatment of advanced breast cancer. - Highlights: • Estrogen and ICI augment adhesion to matrigel with calpain activation in MCF-7 cells. • GPR30 mediates cell–matrigel adhesion and calpain activation via ERK1/2. • Calpain is required in the cell–matrigel adhesion induced by E2 and ICI

  16. Estrogen and pure antiestrogen fulvestrant (ICI 182 780) augment cell–matrigel adhesion of MCF-7 breast cancer cells through a novel G protein coupled estrogen receptor (GPR30)-to-calpain signaling axis

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yan; Li, Zheng; He, Yan; Shang, Dandan; Pan, Jigang; Wang, Hongmei; Chen, Huamei; Zhu, Zhuxia [Department of Physiology/Cancer Research Group, Guiyang Medical University School of Basic Medicine, 9 Beijing Road, Guiyang 550004, Guizhou (China); Wan, Lei [Department of Pharmacology, Guiyang Medical University School of Basic Medicine, 9 Beijing Road, Guiyang 550004, Guizhou (China); Wang, Xudong, E-mail: xdwang@gmc.edu.cn [Department of Physiology/Cancer Research Group, Guiyang Medical University School of Basic Medicine, 9 Beijing Road, Guiyang 550004, Guizhou (China)

    2014-03-01

    Fulvestrant (ICI 182 780, ICI) has been used in treating patients with hormone-sensitive breast cancer, yet initial or acquired resistance to endocrine therapies frequently arises and, in particular, cancer recurs as metastasis. We demonstrate here that both 17-beta-estradiol (E2) and ICI enhance cell adhesion to matrigel in MCF-7 breast cancer cells, with increased autolysis of calpain 1 (large subunit) and proteolysis of focal adhesion kinase (FAK), indicating calpain activation. Additionally, either E2 or ICI induced down-regulation of estrogen receptor α without affecting G protein coupled estrogen receptor 30 (GPR30) expression. Interestingly, GPR30 agonist G1 triggered calpain 1 autolysis but not calpain 2, whereas ER agonist diethylstilbestrol caused no apparent calpain autolysis. Furthermore, the actions of E2 and ICI on calpain and cell adhesion were tremendously suppressed by G15, or knockdown of GPR30. E2 and ICI also induced phosphorylation of extracellular regulated protein kinases 1 and 2 (ERK1/2), and suppression of ERK1/2 phosphorylation by U0126 profoundly impeded calpain activation triggered by estrogenic and antiestrogenic stimulations indicating implication of ERK1/2 in the GPR30-mediated action. Lastly, the E2- or ICI-induced cell adhesion was dramatically impaired by calpain-specific inhibitors, ALLN or calpeptin, suggesting requirement of calpain in the GPR30-associated action. These data show that enhanced cell adhesion by E2 and ICI occurs via a novel GPR30-ERK1/2-calpain pathway. Our results indicate that targeting the GPR30 signaling may be a potential strategy to reduce metastasis and improve the efficacy of antiestrogens in treatment of advanced breast cancer. - Highlights: • Estrogen and ICI augment adhesion to matrigel with calpain activation in MCF-7 cells. • GPR30 mediates cell–matrigel adhesion and calpain activation via ERK1/2. • Calpain is required in the cell–matrigel adhesion induced by E2 and ICI.

  17. Botulinum toxin: The Midas touch.

    Science.gov (United States)

    Shilpa, P S; Kaul, Rachna; Sultana, Nishat; Bhat, Suraksha

    2014-01-01

    Botulinum Toxin (BT) is a natural molecule produced during growth and autolysis of bacterium called Clostridium botulinum. Use of BT for cosmetic purposes has gained popularity over past two decades, and recently, other therapeutic uses of BT has been extensively studied. BT is considered as a minimally invasive agent that can be used in the treatment of various orofacial disorders and improving the quality of life in such patients. The objective of this article is to review the nature, mechanism of action of BT, and its application in various head and neck diseases. PMID:24678189

  18. Potential for irradiation of marine foods in New Zealand

    International Nuclear Information System (INIS)

    The potential for treatment of fish with ionising radiation to extend the useful shelf life lies with low dose pasteurization methods. A practical extension of 1 week or more under optimal refrigeration conditions can be achieved although a background loss of quality due to autolysis continues throughout storage. Of New Zealands markets for fish products only Australia could be serviced by sea freight with irradiated fresh fish. Two difficulties are forseen: firstly a market advantage for fresh over frozen fish is unproven; secondly the industry is dispersed and does not lend itself to a central irradiation facility. Some possibilities for irradiation may arise in future. (auth.)

  19. Production of yeast extract from whey using Kluyveromyces marxianus

    OpenAIRE

    Revillion Jean P. de Palma; Brandelli Adriano; Ayub Marco A. Záchia

    2003-01-01

    The yeast Kluyveromyces marxianus CBS 6556 was grown on whey to produce nucleotide-rich yeast extracts. Thermal treatments of cells at 35 or 50ºC for 15-30h resulted in yeast extracts containing about 20 g/L protein, with only the second treatment resulting in the presence of small amounts of RNA. In contrast, autolysis in buffered solution was the unique treatment that resulted in release of high amounts of intracellular RNA, being, therefore, the better procedure to produce 5'-nucletide ric...

  20. Production of yeast extract from whey using Kluyveromyces marxianus

    Directory of Open Access Journals (Sweden)

    Revillion Jean P. de Palma

    2003-01-01

    Full Text Available The yeast Kluyveromyces marxianus CBS 6556 was grown on whey to produce nucleotide-rich yeast extracts. Thermal treatments of cells at 35 or 50ºC for 15-30h resulted in yeast extracts containing about 20 g/L protein, with only the second treatment resulting in the presence of small amounts of RNA. In contrast, autolysis in buffered solution was the unique treatment that resulted in release of high amounts of intracellular RNA, being, therefore, the better procedure to produce 5'-nucletide rich extract with K. marxianus.

  1. Detection of Chlamydia in postmortal formalin-fixed tissue

    DEFF Research Database (Denmark)

    Lundemose, AG; Lundemose, JB; Birkelund, Svend;

    1989-01-01

    A procedure to detect Chlamydia in postmortal formalin-fixed tissue is described. Monoclonal antibodies against a genus specific chlamydia epitope were used in immunofluorescence to detect chlamydia inclusions in formalin-fixed tissue sections. Lung sections from chlamydia-infected mice were...... retrospective investigations in formalin-fixed tissues....... examined and the effect of autolysis and tetracycline treatment was evaluated. Furthermore, lung tissue from two patients who died of ornithosis was examined. Inclusions detected in lung sections showed a bright apple-green fluorescence, and had a characteristic and easily recognizable morphology...

  2. A p53-like transcription factor similar to Ndt80 controls the response to nutrient stress in the filamentous fungus, Aspergillus nidulans [v1; ref status: indexed, http://f1000r.es/y2

    Directory of Open Access Journals (Sweden)

    Margaret E Katz

    2013-03-01

    Full Text Available The Aspergillus nidulans xprG gene encodes a putative transcriptional activator that is a member of the Ndt80 family in the p53-like superfamily of proteins. Previous studies have shown that XprG controls the production of extracellular proteases in response to starvation. We undertook transcriptional profiling to investigate whether XprG has a wider role as a global regulator of the carbon nutrient stress response. Our microarray data showed that the expression of a large number of genes, including genes involved in secondary metabolism, development, high-affinity glucose uptake and autolysis, were altered in an xprGΔ null mutant. Many of these genes are known to be regulated in response to carbon starvation. We confirmed that sterigmatocystin and penicillin production is reduced in xprG- mutants. The loss of fungal mass and secretion of pigments that accompanies fungal autolysis in response to nutrient depletion was accelerated in an xprG1 gain-of-function mutant and decreased or absent in an xprG- mutant. The results support the hypothesis that XprG plays a major role in the response to carbon limitation and that nutrient sensing may represent one of the ancestral roles for the p53-like superfamily. Disruption of the AN6015 gene, which encodes a second Ndt80-like protein, showed that it is required for sexual reproduction in A. nidulans.

  3. A simple method for the formalin fixation of lungs in toxicological pathology studies.

    Science.gov (United States)

    Qu, Wen-Sheng; Yin, Ji-Ye; Wang, He-Mei; Dong, Yan-Sheng; Ding, Ri-Gao

    2015-10-01

    Optimized lung preparation for detailed structural evaluation is required to improve consistency in preclinical safety evaluation, differences of opinion exist among regulatory agency personnel regarding the optimal methods for routine formalin fixation of lungs from rodent toxicology studies. The simple tracheal ligation fixation method emphasizes tracheal ligation before opening the thorax instead of attempting to re-inflate after lung collapse when opening the thorax. Photomicrographs of this method demonstrated an unprecedented ability to maintain the natural lung architecture, in contrast to the unavoidable changes in the alveolar environment by the intratracheal instillation and vascular perfusion methods. In addition, a comparison of fixation methods on lung morphology in a rodent model of LPS-induced acute lung injury demonstrated that the tracheal ligation fixation method may provide a standard approach for morphometry. Additionally, a TUNEL assay was used to determine the degree of autolysis, which revealed that the autolysis was insignificant in the central areas of each lobe of the lung compared to the lung periphery by tracheal ligation fixation. In conclusion, our novel modified method, which avoids the disadvantages of generating artifacts, fulfills the requirement of preserving the clear, natural morphology of the lung making it suitable and worthy of recommendation for toxicological studies in a good laboratory practice (GLP) lab. PMID:26388042

  4. Enhancing the value of nitrogen from rapeseed meal for microbial oil production.

    Science.gov (United States)

    Uçkun Kiran, Esra; Salakkam, Apilak; Trzcinski, Antoine P; Bakir, Ufuk; Webb, Colin

    2012-05-10

    Rapeseed meal, a major byproduct of biodiesel production, has been used as a low-cost raw material for the production of a generic microbial feedstock through a consolidated bioconversion process. Various strategies were tested for the production of a novel fermentation medium, rich in free amino nitrogen (FAN): commercial enzymes (CEs) (2.7 mg g⁻¹ dry meal), liquid state fungal pre-treatment (LSF) using Aspergillus oryzae (4.6 mg g⁻¹), liquid state fungal pre-treatment followed by fungal autolysis (LSFA) (9.13 mg g⁻¹), liquid state pre-treatment using fungal enzymatic broth (EB) (2.1 mg g⁻¹), but the best strategy was a solid state fungal pre-treatment followed by fungal autolysis (34.5 mg g⁻¹). The bioavailability of the nitrogen sources in the novel medium was confirmed in fed-batch bioreactor studies, in which 82.3g dry cell L⁻¹ of the oleaginous yeast Rhodosporidium toruloides Y4 was obtained with a lipid content of 48%. The dry cell weight obtained was higher than that obtained using conventional yeast extract, due to a higher total nitrogen content in the novel biomedium. The fatty acids obtained from the microbial oil were similar to those derived from rapeseed oil. PMID:22500902

  5. The uptake of 14C-glycine to Bufo vulgaris formosus (Boulenger) larva at metamorphosis

    International Nuclear Information System (INIS)

    With the eggs of Bufo vulgaris formosus (Boulenger) immediately after fertilization, the larvae in the 50 ml solution containing 1 ml of 14C-glycine were developed to the end of metamorphosis. Measurements were made on the length of body, tail, fore limb and hind leg through the stages of tail degeneration and vestige. The radioactivity of the cut off fore limbs, hind legs, tails and head trunks was measured with a scintillation counter, and the 10 μ sections of the samples were used for autoradiography. The larvae uptook orally 14C-glycine to the organs of cell tissues. On the basis of the reports of the autolysis of tails and the activation of lysosome enzyme in metamorphosis and on the uptake of 14C-leucine and 14C-proline to four legs by other workers, and on the present results, the free amino acids formed from the autolysis of tails were utilized for the recomposition of organ protein synthesis in the metamorphosis of the amphibians. (J.P.N.)

  6. A non-catalytic histidine residue influences the function of the metalloprotease of Listeria monocytogenes.

    Science.gov (United States)

    Forster, Brian M; Bitar, Alan Pavinski; Marquis, Hélène

    2014-01-01

    Mpl, a thermolysin-like metalloprotease, and PC-PLC, a phospholipase C, are synthesized as proenzymes by the intracellular bacterial pathogen Listeria monocytogenes. During intracellular growth, L. monocytogenes is temporarily confined in a membrane-bound vacuole whose acidification leads to Mpl autolysis and Mpl-mediated cleavage of the PC-PLC N-terminal propeptide. Mpl maturation also leads to the secretion of both Mpl and PC-PLC across the bacterial cell wall. Previously, we identified negatively charged and uncharged amino acid residues within the N terminus of the PC-PLC propeptide that influence the ability of Mpl to mediate the maturation of PC-PLC, suggesting that these residues promote the interaction of the PC-PLC propeptide with Mpl. In the present study, we identified a non-catalytic histidine residue (H226) that influences Mpl secretion across the cell wall and its ability to process PC-PLC. Our results suggest that a positive charge at position 226 is required for Mpl functions other than autolysis. Based on the charge requirement at this position, we hypothesize that this residue contributes to the interaction of Mpl with the PC-PLC propeptide. PMID:24140648

  7. Influence of early pH decline on calpain activity in porcine muscle.

    Science.gov (United States)

    Pomponio, Luigi; Ertbjerg, Per; Karlsson, Anders H; Costa, Leonardo Nanni; Lametsch, René

    2010-05-01

    This study investigated the influence of post-mortem pH decline on calpain activity and myofibrillar degradation. From 80 pigs, 30 Longissimus dorsi (LD) muscles were selected on the basis of pH values at 3h post-mortem and classified into groups of 10 as fast, intermediate and slow pH decline. The rate of pH decline early post-mortem differed between the three groups, but the ultimate pH values were similar at 24h. Calpain activity and autolysis from 1 to 72h post-mortem were determined using casein zymography and studied in relation to myofibrillar fragmentation. Colour and drip loss were measured. A faster decrease in pH resulted in reduced level of mu-calpain activity and increased autolysis of the enzyme, and hence an earlier loss of activity due to activation of mu-calpain in muscles with a fast pH decline. Paralleling the mu-calpain activation in muscles with a fast pH decline a higher myofibril fragmentation at 24h post-mortem was observed, which was no longer evident in the later phase of the tenderization process. In conclusion, the rate of early pH decline influenced mu-calpain activity and the rate but not the extent of myofibrillar degradation, suggesting an early effect of proteolysis on myofibril fragmentation that is reduced during ageing due to an earlier exhaustion of mu-calpain activity. PMID:20374873

  8. Preparation of inocula for experimental infection of blood with Streptococcus pneumoniae

    Science.gov (United States)

    Vivas-Alegre, Santiago; Fernández-Natal, Isabel; López-Fidalgo, Eduardo; Rivero-Lezcano, Octavio Miguel

    2015-01-01

    Experimental infections of either cells or animals require the preparation of good quality inocula. Unfortunately, the important pulmonary pathogen Streptococcus pneumoniae is a fastidious microorganism that suffers an autolysis process when cultured in vitro. Supplementation of Todd–Hewitt broth with a biological buffer (20 mM Tris–HCl, pH = 7.8) promotes a six hours delay in the beginning of the autolysis process. Additional improvements include washing bacteria before freezing, avoiding manipulations after thawing, and the use of glycerol (70% of the frozen bacteria was viable after 28 weeks at −80 °C, and aliquots were highly homogeneous. We have tested their utility in a whole blood infection model and have found that human plasma exhibits a higher microbicidal activity than whole blood, a result that we have not found previously reported. Additionally, we have also observed significant variations in the antimicrobial activity against different strains, which might be related to their virulence.•Media culture buffering extends S. pneumoniae viability for 6 h.•Washing before freezing of single use aliquots minimizes manipulation after thawing.•Experimental infection with the frozen inocula has shown that plasma has higher bactericidal activity than blood. PMID:26844211

  9. Identification and functional characterization of AclB, a novel cell-separating enzyme from Lactobacillus casei.

    Science.gov (United States)

    Xu, Yi; Wang, Ting; Kong, Jian; Wang, Hui-Li

    2015-06-16

    Autolysis of nonstarter lactic acid bacteria (NSLAB) was favorable for the development of flavor compounds during cheese manufacture. Among these bacteria, Lb. casei was regarded as the most important microbiota involved in cheese processes. In this study, a novel autolysin named AclB was identified in the genome of Lb. casei BL23 and its modular structure was predicted through bioinformatic approaches. Subsequently, its transcription profile in the exponential phase, hydrolytic activities against cell walls, enzymatic properties under different conditions, physiological function via gene inactivation and upregulation assays, as well as potential applications to NSLAB's autolysis were fully investigated. According to the results, AclB was recognized as a species-specific cell-separating enzyme, responsible for cell separation after cell division in Lb. casei BL23. The purified AclB showed considerable hydrolyzing activities towards cell walls, indicating its enzymatic nature as peptidoglycan hydrolase, or autolysin. The highest activity of AclB was determined at pH5.0 and 37°C, and the expression vector constructed based on AclB was shown to facilitate the controlled lysis of Lb. casei BL23 hosts. In summary, this study provided insight into the enzymatic properties of a novel autolysin involved in cell separation of Lb. casei BL23, which is promising to accelerate cheese ripening and improve cheese quality. PMID:25797034

  10. Release of UV-absorbing substances from maize coleoptiles during auxin-, fusicoccin- and acid-mediated elongation growth

    International Nuclear Information System (INIS)

    Isolated cell walls from maize coleoptiles prepared under conditions that preserve the ability for enzymatic hemicellulose autolysis release UV-absorbing substances into the incubation medium in a time-dependent reaction with an optimal rate at pH 6–7. The reaction can be inhibited by low temperature and protein-denaturing treatments, indicating an enzymatic process. Spectroscopic and chromatographic analyses showed that the liberated substances represent a complex mixture of free and bound (alkali-hydrolyzable) phenolic compounds with similar absorption spectra restricted to the range below 300 nm and thus excluding hydroxycinnamic acids from cell-wall esters. A spectroscopically and chromatographically similar mixture of soluble UV-absorbing substances is released if living (abraded) maize coleoptiles or coleoptile segments are incubated in water or buffer, suggesting that insoluble phenolic materials in the cell wall are metabolized also in vivo. This reaction can be promoted by anaerobic conditions and application of fusicoccin whereas auxin had a slightly inhibitory effect. No clear relationship to elongation growth could be demonstrated. We conclude from these results that polymeric phenolic constituents of the cell wall are subject to enzymatic degradation in muro similar to polysaccharide autolysis and that this process is under metabolic control

  11. Toxin ζ Reversible Induces Dormancy and Reduces the UDP-N-Acetylglucosamine Pool as One of the Protective Responses to Cope with Stress

    Directory of Open Access Journals (Sweden)

    Mariangela Tabone

    2014-09-01

    Full Text Available Toxins of the ζ/PezT family, found in the genome of major human pathogens, phosphorylate the peptidoglycan precursor uridine diphosphate-N-acetylglucosamine (UNAG leading to unreactive UNAG-3P. Transient over-expression of a PezT variant impairs cell wall biosynthesis and triggers autolysis in Escherichia coli. Conversely, physiological levels of ζ reversibly induce dormancy produce a sub-fraction of membrane-compromised cells, and a minor subpopulation of Bacillus subtilis cells become tolerant of toxin action. We report here that purified ζ is a strong UNAG-dependent ATPase, being GTP a lower competitor. In vitro, ζ toxin phosphorylates a fraction of UNAG. In vivo, ζ-mediated inactivation of UNAG by phosphorylation does not deplete the active UNAG pool, because expression of the toxin enhances the efficacy of genuine cell wall inhibitors (fosfomycin, vancomycin or ampicillin. Transient ζ expression together with fosfomycin treatment halt cell proliferation, but ε2 antitoxin expression facilitates the exit of ζ-induced dormancy, suggesting that there is sufficient UNAG for growth. We propose that ζ induces diverse cellular responses to cope with stress, being the reduction of the UNAG pool one among them. If the action of ζ is not inhibited, e.g., by de novo ε2 antitoxin synthesis, the toxin markedly enhances the efficacy of antimicrobial treatment without massive autolysis in Firmicutes.

  12. Toxin ζ reversible induces dormancy and reduces the UDP-N-acetylglucosamine pool as one of the protective responses to cope with stress.

    Science.gov (United States)

    Tabone, Mariangela; Ayora, Silvia; Alonso, Juan C

    2014-09-01

    Toxins of the ζ/PezT family, found in the genome of major human pathogens, phosphorylate the peptidoglycan precursor uridine diphosphate-N-acetylglucosamine (UNAG) leading to unreactive UNAG-3P. Transient over-expression of a PezT variant impairs cell wall biosynthesis and triggers autolysis in Escherichia coli. Conversely, physiological levels of ζ reversibly induce dormancy produce a sub-fraction of membrane-compromised cells, and a minor subpopulation of Bacillus subtilis cells become tolerant of toxin action. We report here that purified ζ is a strong UNAG-dependent ATPase, being GTP a lower competitor. In vitro, ζ toxin phosphorylates a fraction of UNAG. In vivo, ζ-mediated inactivation of UNAG by phosphorylation does not deplete the active UNAG pool, because expression of the toxin enhances the efficacy of genuine cell wall inhibitors (fosfomycin, vancomycin or ampicillin). Transient ζ expression together with fosfomycin treatment halt cell proliferation, but ε2 antitoxin expression facilitates the exit of ζ-induced dormancy, suggesting that there is sufficient UNAG for growth. We propose that ζ induces diverse cellular responses to cope with stress, being the reduction of the UNAG pool one among them. If the action of ζ is not inhibited, e.g., by de novo ε2 antitoxin synthesis, the toxin markedly enhances the efficacy of antimicrobial treatment without massive autolysis in Firmicutes. PMID:25238046

  13. Ultraviolet induced lysosome activity in corneal epithelium

    International Nuclear Information System (INIS)

    A 5.000 W Xe-Hg high pressure lamp and a double monochromator were used to produce a 3.3 nm half-bandpass ultraviolet radiation at 295 nm. Pigmented rabbit eyes were irradiated with radiant exposures from 140 Jm-2 to 10.000 Jm-2 and evaluated by slit-lamp biomicroscopy, light and electron microscopy. Corneal threshold (Hsub(c) was 200 Jm-2 and lens threshold (Hsub(L)) was 7.500 Jm-2. The most repeatable and reliable corneal response to these levels of UV was the development of corneal epithelial granules. Histological changes included a loss of superficial epithelial cells and selective UV induced autolysis of the wing cells. It is suggested that the biomicroscopically observed granules are the clinical manifestation of the secondary lysosomes revealed by light and electron microscopy. It is proposed that UV breaks down the primary lysosome membranes to release hydrolytic enzymes which in turn form the secondary lysosomes during autolysis. Extreme levels of radiant exposure at 295 nm result in indiscriminate destruction of all layers of the corneal epithelium, but the posterior cornea was spared. (orig.)

  14. An investigation of the shedding of macromolecules from the Ehrlich mouse ascites tumor cell

    International Nuclear Information System (INIS)

    The spontaneous release, or shedding, of cell surface components into the extracellular medium may be important in the determination of several features of the cancer cell phenotype. The release of macromolecules from the Erhlich mouse ascites tumor cell was studied under a variety of experimental conditions to elucidate the origin and the underlying mechanisms of release. The extrinsic macromolecules are a diverse group with apparent molecular weights ranging from 13,500 to 400,000 daltons. External labeling of the cell surface with tritiated 4,4'-diisothiocyano-1,2-diphenylethane-2,2-disulfonic acid ([3H]H2DIDS) reveals a slow loss of labeled components at 4 degrees C, while at 21 degrees C and 37 degrees C an initial rapid loss is followed by a slower release. In vitro metabolic labeling with [1-14C]-D-glucosamine hydrochloride, D-[2-3H]-mannose and various [3H]-L-amino acids results in the appearance of labeled macromolecules in the medium suggesting tumor, not mouse, origin. These data suggest that the extrinsic macromolecules originate from the cell surface. Macromolecules are shed by a temperature and pH sensitive process. These results suggest that a limited proteolytic digestion, or sublethal autolysis, of the cell surface may occur in this system. The macromolecules shed by the Ehrlich cell originate from the surface and are probably released by sublethal autolysis, direct secretion and a passive process

  15. Using mixed inocula of Saccharomyces cerevisiae killer strains to improve the quality of traditional sparkling-wine.

    Science.gov (United States)

    Velázquez, Rocío; Zamora, Emiliano; Álvarez, Manuel; Álvarez, María L; Ramírez, Manuel

    2016-10-01

    The quality of traditional sparkling-wine depends on the aging process in the presence of dead yeast cells. These cells undergo a slow autolysis process thereby releasing some compounds, mostly colloidal polymers such as polysaccharides and mannoproteins, which influence the wine's foam properties and mouthfeel. Saccharomyces cerevisiae killer yeasts were tested to increase cell death and autolysis during mixed-yeast-inoculated second fermentation and aging. These yeasts killed sensitive strains in killer plate assays done under conditions of low pH and temperature similar to those used in sparkling-wine making, although some strains showed a different killer behaviour during the second fermentation. The fast killer effect improved the foam quality and mouthfeel of the mixed-inoculated wines, while the slow killer effect gave small improvements over single-inoculated wines. The effect was faster under high-pressure than under low-pressure conditions. Wine quality improvement did not correlate with the polysaccharide, protein, mannan, or aromatic compound concentrations, suggesting that the mouthfeel and foaming quality of sparkling wine are very complex properties influenced by other wine compounds and their interactions, as well as probably by the specific chemical composition of a given wine. PMID:27375256

  16. Effects of vancomycin versus nafcillin in enhancing killing of methicillin-susceptible Staphylococcus aureus causing bacteremia by human cathelicidin LL-37.

    Science.gov (United States)

    Le, J; Dam, Q; Schweizer, M; Thienphrapa, W; Nizet, V; Sakoulas, G

    2016-09-01

    Recent studies have demonstrated that anti-staphylococcal beta-lactam antibiotics, like nafcillin, render methicillin-resistant Staphylococcus aureus (MRSA) more susceptible to killing by innate host defense peptides (HDPs), such as cathelicidin LL-37. We compared the effects of growth in 1/4 minimum inhibitory concentration (MIC) of nafcillin or vancomycin on the LL-37 killing of 92 methicillin-susceptible S. aureus (MSSA) isolates. For three randomly selected strains among these, we examined the effects of nafcillin, vancomycin, daptomycin, or linezolid on LL-37 killing and autolysis. Growth in the presence of subinhibitory nafcillin significantly enhanced LL-37 killing of MSSA compared to vancomycin and antibiotic-free controls. Nafcillin also reduced MSSA production of the golden staphylococcal pigment staphyloxanthin in 39 % of pigmented strains vs. 14 % for vancomycin. Among the antibiotics tested, only nafcillin resulted in significantly increased MSSA autolysis. These studies point to additional mechanisms of anti-staphylococcal activity of nafcillin beyond direct bactericidal activity, properties that vancomycin and other antibiotic classes do not exhibit. The ability of nafcillin to enhance sensitivity to innate HDPs may contribute to its superior effectiveness against MSSA, as suggested by studies comparing clinical outcomes to vancomycin treatment. PMID:27234592

  17. Assessment of freshness and freeze-thawing of sea bream fillets (Sparus aurata) by a cytosolic enzyme: Lactate dehydrogenase.

    Science.gov (United States)

    Diop, Mamadou; Watier, Denis; Masson, Pierre-Yves; Diouf, Amadou; Amara, Rachid; Grard, Thierry; Lencel, Philippe

    2016-11-01

    The evaluation of freshness and freeze-thawing of fish fillets was carried out by assessment of autolysis of cells using a cytosolic enzyme lactate dehydrogenase. Autolysis plays an important role in spoilage of fish and postmortem changes in fish tissue are due to the breakdown of the cellular structures and release of cytoplasmic contents. The outflow of a cytosolic enzyme, lactate dehydrogenase, was studied in sea bream fillets and the Sparus aurata fibroblasts (SAF-1) cell-line during an 8day storage period at +4°C. A significant increase of lactate dehydrogenase release was observed, especially after 5days of storage. The ratio between the free and the total lactate dehydrogenase activity is a promising predictive marker to measure the quality of fresh fish fillets. The effect of freeze-thawing on cytosolic lactate dehydrogenase and lysosomal α-d-glucosidase activities was also tested. Despite the protecting effect of the tissue compared to the cell-line, a loss of lactate dehydrogenase activity, but not of α-d-glucosidase, was observed. In conclusion, lactate dehydrogenase may be used as a marker to both assess freshness of fish and distinguish between fresh and frozen-thawed fish fillets. PMID:27211667

  18. Experimental taphonomy of Artemia reveals the role of endogenous microbes in mediating decay and fossilization.

    Science.gov (United States)

    Butler, Aodhán D; Cunningham, John A; Budd, Graham E; Donoghue, Philip C J

    2015-06-01

    Exceptionally preserved fossils provide major insights into the evolutionary history of life. Microbial activity is thought to play a pivotal role in both the decay of organisms and the preservation of soft tissue in the fossil record, though this has been the subject of very little experimental investigation. To remedy this, we undertook an experimental study of the decay of the brine shrimp Artemia, examining the roles of autolysis, microbial activity, oxygen diffusion and reducing conditions. Our findings indicate that endogenous gut bacteria are the main factor controlling decay. Following gut wall rupture, but prior to cuticle failure, gut-derived microbes spread into the body cavity, consuming tissues and forming biofilms capable of mediating authigenic mineralization, that pseudomorph tissues and structures such as limbs and the haemocoel. These observations explain patterns observed in exceptionally preserved fossil arthropods. For example, guts are preserved relatively frequently, while preservation of other internal anatomy is rare. They also suggest that gut-derived microbes play a key role in the preservation of internal anatomy and that differential preservation between exceptional deposits might be because of factors that control autolysis and microbial activity. The findings also suggest that the evolution of a through gut and its bacterial microflora increased the potential for exceptional fossil preservation in bilaterians, providing one explanation for the extreme rarity of internal preservation in those animals that lack a through gut. PMID:25972468

  19. Effect of varying the salt and fat content in Cheddar cheese on aspects of the performance of a commercial starter culture preparation during ripening.

    Science.gov (United States)

    Yanachkina, Palina; McCarthy, Catherine; Guinee, Tim; Wilkinson, Martin

    2016-05-01

    Production of healthier reduced-fat and reduced-salt cheeses requires careful selection of starter bacteria, as any substantial alterations to cheese composition may prompt changes in the overall performance of starters during cheese ripening. Therefore, it is important to assess the effect of compositional alterations on the individual strain response during cheese ripening for each optimised cheese matrix. In the current study, the effect of varying fat and salt levels in Cheddar cheese on the performance of a commercial Lactococcus lactis culture preparation, containing one L. lactis subsp. lactis strain and one L. lactis subsp. cremoris strain was investigated. Compositional variations in fat or salt levels did not affect overall starter viability, yet reduction of fat by 50% significantly delayed non-starter lactic acid bacteria (NSLAB) populations at the initial ripening period. In comparison to starter viability, starter autolysis, as measured by release of intracellular lactate dehydrogenase (LDH) or post-proline dipeptidyl aminopeptidase (Pep X) into cheese juices, decreased significantly with lower salt addition levels in full-fat Cheddar. Conversely, reducing fat content of cheese resulted in a significantly higher release of intracellular Pep X, and to a lesser extent intracellular LDH, into juices over ripening. Flow cytometry (FCM) indicated that the permeabilised and dead cell sub-populations were generally lower in juices from cheeses with reduced salt content, however no significant differences were observed between different salt and fat treatments. Interestingly, fat reductions by 30 and 50% in cheeses with reduced or half added salt contents appeared to balance out the effect of salt, and enhanced cell permeabilisation, cell death, and also cell autolysis in these variants. Overall, this study has highlighted that alterations in both salt and fat levels in cheese influence certain aspects of starter performance during ripening, including

  20. Northern and Southern blot analysis of human RNA and DNA in autopsy material

    DEFF Research Database (Denmark)

    Larsen, S; Rygaard, K; Asnaes, S; Spang-Thomsen, M

    1992-01-01

    21-118 h postmortem. Extracted RNA and DNA were examined by Northern and Southern blot analysis using oligo-labelled human DNA probes recognizing gene transcripts of 2-5 kb. The results indicated that, in general, Northern blot analysis was feasible with the applied probes when the tissue was......Fresh biopsy material for molecular biological investigations is not obtainable from all relevant normal human tissues. We studied the feasibility of using RNA and DNA from autopsies for Northern and Southern blot analysis. Tissue samples from seven organs were obtained from 10 autopsies performed...... obtained less than two days postmortem. Histological examination showing slight or no autolysis and the presence of ribosomal bands after gel electrophoresis were both indicative parameters of RNA preservation. DNA was appropriate for Southern blotting when the tissue was obtained less than three to five...

  1. SarA is a negative regulator of Staphylococcus epidermidis biofilm formation

    DEFF Research Database (Denmark)

    Martin, Christer; Heinze, C.; Busch, M.; Franke, G.; Hentschke, M.; Dühring, Sara Bayard; Buettner, H.; Kotasinska, M.; Wischnewski, V.; Buck, F.; Molin, Søren; Otto, Michael; Rohde, Henning

    2012-01-01

    the existence of superimposed regulatory systems suppressing a multi-cellular biofilm life style in vitro. Transposon mutagenesis of clinical significant but biofilm-negative S. epidermidis 1585 was used to isolate a biofilm positive mutant carrying a Tn917 insertion in sarA,chief regulator of...... contributed to biofilm formation in mutant 1585ΔsarA. Increased eDNA amounts indirectly resulted from up-regulation of metalloprotease SepA, leading to boosted processing of major autolysin AtlE, in turn inducing augmented autolysis and release of chromosomal DNA. Hence, this study identifies sarA as a...... negative regulator of Embp- and eDNA dependent biofilm formation. Given the importance of SarA as a positive regulator of polysaccharide mediated cell aggregation, the regulator enables S. epidermidis to switch between mechanisms of biofilm formation, ensuring S. epidermidis adaptation to hostile...

  2. Adsorption at the air-water interface and emulsification properties of grain legume protein derivatives from pea and broad bean.

    Science.gov (United States)

    Tsoukala, A; Papalamprou, E; Makri, E; Doxastakis, G; Braudo, E E

    2006-12-01

    Functional properties of native and modified (through induced autolysis) pea (Pisum sativum L.) and broad bean (Vicia faba L.) protein derivatives are studied. In specific, protein solubility and behavior at the air-water interface through surface pressure measurements are investigated. Furthermore the ability of the protein products to act as emulsifying agents and to stabilize emulsions is studied through oil droplet size distribution measurements and by the protein adsorbed at the oil-water interface. The data reveal that the ability of the proteins to act as surfactants and build up a rigid film around the oil droplets, mainly depends on their suitable molecular configuration and structure. Hydrolysis did not promote the functionality of the legume proteins. Broad bean exhibited better functionality than pea, before and after hydrolysis. Some comparisons were also made with lupin (Lupinus albus L.) protein isolate. PMID:17049437

  3. Combination of Maldi-tof mass spectrometry with immobilized enzyme microreactor for peptide mapping

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) has been combined with immobilized enzyme microreactor for the rapid, sensitive, and accurate tryptic mapping of protein and polypeptides. The technique utilizes the trypsin microreactor by immobilized enzyme on the glycidyl methacrylate (GMA)-modified cellulose membrane. The membrane microreactor was used for the tryptic mapping of cytochrome C and the results were compared with those obtained by using free trypsin. A significant increase in the overall sensitivity of the process was observed using the membrane microreactor, as well as the elimination of background signals due to the autolysis of the trypsin. Further, membrane microreactor digestions were found to be rapid and convenient.

  4. Combination of MALDI-TOF mass spectrometry with immobilized enzyme microreactor for peptide mapping

    Institute of Scientific and Technical Information of China (English)

    姜泓海; 邹汉法; 汪海林; 张强; 倪坚毅; 张清春; 郭忠; 陈小明

    2000-01-01

    Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) has been combined with immobilized enzyme microreactor for the rapid, sensitive, and accurate tryptic mapping of protein and polypeptides. The technique utilizes the trypsin microreactor by immobilized enzyme on the glycidyl methacrylate (GMA)-modified cellulose membrane. The membrane micro-reactor was used for the tryptic mapping of cytochrome C and the results were compared with those obtained by using free trypsin. A significant increase in the overall sensitivity of the process was observed using the membrane microreactor, as well as the elimination of background signals due to the autolysis of the trypsin. Further, membrane microreactor digestions were found to be rapid and convenient.

  5. Living bacteria rheology: population growth, aggregation patterns and cooperative behaviour under different shear flows

    CERN Document Server

    Patricio, P; Portela, R; Sobral, R G; Grilo, I R; Cidade, T; Leal, C R

    2014-01-01

    The activity of growing living bacteria was investigated using real-time and in situ rheology -- in stationary and oscillatory shear. Two different strains of the human pathogen Staphylococcus aureus -- strain COL and its isogenic cell wall autolysis mutant -- were considered in this work. For low bacteria density, strain COL forms small clusters, while the mutant, presenting deficient cell separation, forms irregular larger aggregates. In the early stages of growth, when subjected to a stationary shear, the viscosity of both strains increases with the population of cells. As the bacteria reach the exponential phase of growth, the viscosity of the two strains follow different and rich behaviours, with no counterpart in the optical density or in the population's colony forming units measurements. While the viscosity of strain COL keeps increasing during the exponential phase and returns close to its initial value for the late phase of growth, where the population stabilizes, the viscosity of the mutant strain ...

  6. FindPept, a tool to identify unmatched masses in peptide mass fingerprinting protein identification.

    Science.gov (United States)

    Gattiker, Alexandre; Bienvenut, Willy V; Bairoch, Amos; Gasteiger, Elisabeth

    2002-10-01

    FindPept (http://www.expasy.org/tools/findpept.html) is a software tool designed to identify the origin of peptide masses obtained by peptide mass fingerprinting which are not matched by existing protein identification tools. It identifies masses resulting from unspecific proteolytic cleavage, missed cleavage, protease autolysis or keratin contaminants. It also takes into account post-translational modifications derived from the annotation of the SWISS-PROT database or supplied by the user, and chemical modifications of peptides. Based on a number of experimental examples, we show that the commonly held rules for the specificity of tryptic cleavage are an oversimplification, mainly because of effects of neighboring residues, experimental conditions, and contaminants present in the enzyme sample. PMID:12422360

  7. Postmortal incorporation of 3H-thymidine into human oral mucosa at +40C ambient temperature

    International Nuclear Information System (INIS)

    The postmortal behaviour of the skin was studied under the conditions of 'normal' autolysis. Skin samples with a diameter of 3 mm were taken every 2 or 4 hours in the period between 1 and 56 h p.m. or between 48 and 100 h p.m. The incorporation of 3H-thymidine, represented by the quotient of labelled germ layer cells per 100μ length of basal membrane, was studied in situ as a function of the time interval between death and sampling, using histoautoradiographs. Postmortal incorporation into the oral mucosa was higher by a factor 3 to 5 than incorporation into the epidermis; similar results were obtained in vivo. Experiments on refrigerated skin showed a strong temperature influence on the decrease of epithelial DNA synthesis activity. At +40C, it continued for more than 4 days in the oral mucosa, showing an undulating course of the 'proliferation activities'. (orig./MG)

  8. Protein degradation in Euglena gracilis: Purification and characterization of the major proteinase

    International Nuclear Information System (INIS)

    Protolysis in a crude extract of Euglena gracilis was characterized by autolysis and the hydrolysis of 125I-labeled bovine serum albumin (125I-BSA). Both procedures showed similar properties: stimulation by dithiothreitol, inhibition by leupeptin, and the same pH optima. Hydrolysis of 125I-BSA increased with growth stage and with the depletion of nutrient in the medium. The major proteolytic enzyme was purified to near homogeneity from extracts of dark-grown, stationary-phase Euglena gracilis by acid treatment, and by chromatography on CM-cellulose, DEAE-cellulose, Sephadex G-75, and hydroxyapatite using 125I-BSA as substrate. The molecular weight of the proteinase was 30,000 when determined by gel filtration on Sephadex G-75 and 15,000 when estimated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The enzyme therefore appears to be composed of two subunits

  9. A dual role of extracellular DNA during biofilm formation of Neisseria meningitidis

    DEFF Research Database (Denmark)

    Lappann, M.; Claus, H.; van Alen, T.;

    2010-01-01

    -acetylmuramyl-l-alanine amidase genes. In late biofilms, outer membrane phospholipase A-dependent autolysis, which was observed in most cc, but not in ST-8 and ST-11 strains, was required for shear force resistance of microcolonies. Taken together, N. meningitidis evolved two different biofilm formation strategies, an e......DNA-dependent one yielding shear force resistant microcolonies, and an eDNA-independent one. Based on the experimental findings and previous epidemiological observations, we hypothesize that most meningococcal cc display a settler phenotype, which is eDNA-dependent and results in a stable interaction with the host....... On the contrary, spreaders (ST-11 and ST-8 cc) are unable to use eDNA for biofilm formation and might compensate for poor colonization properties by high transmission rates....

  10. Stimulation of Egg Production in Japanese Quails by Enriching Feed with Residual Yeast

    Directory of Open Access Journals (Sweden)

    Letitia Oprean

    2010-05-01

    Full Text Available Quail eggs are more and more approved for consumers because they bring many benefits to the human body. Therefore, quails breeding for eggs production have become a very profitable business. Residual yeast may be a nutritional supplement, especially rich in vitamins and proteins. This article studies the influence of residual beer yeast on egg laying in Japanese quails. In order to be integrated into the diet of quails the yeast has undergone a process of autolysis; its influence has been examined on separate groups. The results were reported as a percentage compared with the control group, where the feed does not contain this supplement. Due to its content rich in vitamins and proteins, the residual beer yeast used in feeding the quails bred for eggs stimulates egg laying.

  11. Untargeted Metabolic Profiling of Winery-Derived Biomass Waste Degradation by Penicillium chrysogenum.

    Science.gov (United States)

    Karpe, Avinash V; Beale, David J; Godhani, Nainesh B; Morrison, Paul D; Harding, Ian H; Palombo, Enzo A

    2015-12-16

    Winery-derived biomass waste was degraded by Penicillium chrysogenum under solid state fermentation over 8 days in a (2)H2O-supplemented medium. Multivariate statistical analysis of the gas chromatography-mass spectrometry (GC-MS) data resulted in the identification of 94 significant metabolites, within 28 different metabolic pathways. The majority of biomass sugars were utilized by day 4 to yield products such as sugars, fatty acids, isoprenoids, and amino acids. The fungus was observed to metabolize xylose to xylitol, an intermediate of ethanol production. However, enzyme inhibition and autolysis were observed from day 6, indicating 5 days as the optimal time for fermentation. P. chrysogenum displayed metabolism of pentoses (to alcohols) and degraded tannins and lignins, properties that are lacking in other biomass-degrading ascomycetes. Rapid fermentation (3-5 days) may not only increase the pentose metabolizing efficiency but also increase the yield of medicinally important metabolites, such as syringate. PMID:26611372

  12. Model ecosystem approach to estimate community level effects of radiation

    International Nuclear Information System (INIS)

    Mathematical computer model is developed to simulate the population dynamics and dynamic mass budgets of the microbial community realized as a self sustainable aquatic ecological system in the tube. Autotrophic algae, heterotrophic protozoa and sapro-trophic bacteria live symbiotically with inter-species' interactions as predator-prey relationship, competition for the common resource, autolysis of detritus and detritus-grazing food chain, etc. The simulation model is the individual-based parallel model, built in the demographic stochasticity, environmental stochasticity by dividing the aquatic environment into patches. Validity of the model is checked by the multifaceted data of the microcosm experiments. In the analysis, intrinsic parameters of umbrella endpoints (lethality, morbidity, reproductive growth, mutation) are manipulated at the individual level, and tried to find the population level, community level and ecosystem level disorders of ecologically crucial parameters (e.g. intrinsic growth rate, carrying capacity, variation, etc.) that related to the probability of population extinction. (author)

  13. Problems encountered in searching for new strains of toxic planktonic syanobacteria

    International Nuclear Information System (INIS)

    In 1979 and 1980, four blooms from Lac La Nonne (80 km NW of Edmonton, Alberta) dominated 67 to 95 percent by Aphanizomenon flos-aquae L., were found to be type-c-toxic to mice and agglutinated red blood cells. A search for type-c-toxic strains of Aphanizomenon in this lake was undertaken in 1980 and 1981 by making 128 colony isolates and testing the unialgal cultures obtained from five blooms which varied in composition from 10 to 95 precent Aphanizomenon. The following problems were encountered in this search and in attempts to obtain axenic clones of different species: 1)a high precentage of isolation failures caused by the gradual but complete take-over of most of the Aphanizomenon cultures by a purple-brown species of Pseudanabaena, 2)stasis or lysis caused by pH and/or composition of the medium or the agar, 3)stasis or lysis caused by bacteria in liquid microculture, on agar streaks or in agar pour-plates, 4) autolysis triggered by tensile stress during transfer of trichomes with loop or needle, 5)inability of graded dosages of gamma rays of sodium sulphide selectively to eliminate or reduce numbers of bacteria to a satisfactory level for plating, 6)autolysis and growth inhibition caused by gentle washing to reduce numbers of bacteria for plating, and 7)discovery that haemagglutination is not perfectly correlated with type-c-toxicity. The search produced no type-c toxic strains of Aphanizomenon but two heterogeneous take-over cultures of Pseudanabaena sp. were found that produced violent convulsions when injected intraperitoneally into mice

  14. Formula optimization of high autolytic complex microbial agents for yogurt%酸乳高自溶度复合发酵剂配方优化

    Institute of Scientific and Technical Information of China (English)

    孙洁; 王希卓; 刘鹭; 文一; 张书文; 吕加平

    2014-01-01

    乳酸菌的自溶特性可对发酵乳制品品质产生影响,发酵剂菌体快速自溶不仅缩短酸乳发酵周期、降低了生产成本,同时菌体自溶之后释放的胞内物质又决定着酸乳的风味和感官特性。为了复配出一种高质量的复合型酸乳发酵剂,该文对前期研究筛选出的3株高度自溶的酸乳发酵剂菌株:德氏乳杆菌保加利亚亚种(Lactobacillus delbrueckii ssp. Bulgaricus)LD3-A3、唾液链球菌嗜热亚种(Streptococcus salivarius ssp.)GS1-A8和乳酸乳杆菌(Lactobacillus lactis)S15-A3进行复配,运用二次正交旋转组合设计复合发酵剂中各菌株比例,并讨论了3株菌株之间的共生关系和交互作用,根据所建模型优选结果,最后确定3种菌株最优组合方案为:GS1∶LD3-A3∶S15-A3为45∶1∶3。使用该复合发酵剂制作的酸乳感官性状优良,具有较好的风味和质地,在货架期贮藏条件下(10~15℃)后酸化程度小,可极好的满足生产需要。该文所得高自溶度复合发酵剂具有很好的生产实践指导和应用价值。%Cell autolysis could be induced by bacterial peptidoglycan hydrolases (autolysins) degrading the peptidoglycan structure of cell walls. Autolysis of lactobic acid bacteria shows direct influence on the characteristics of fermented milk products. Three high autolysis rate lactic acid bacteria, Lactobacillus delbrueckii ssp. Bulgaricus LD3-A3, Streptococcus salivarius ssp. and Thermophilus GS1-A8, and Lactobacillus lactis S15-A3 were tested to obtain a good yogurt starter. The three-factors quadratic regression orthogonal rotational composite experiment was designed to determine the effects of the three high autolysis strains on yogurt characteristics during fermentation, and the effects of mixed symbiosis and interactions were also analyzed. Quadratic orthogonal rotation combination design was used to compare differences among 23 yogurt samples that were

  15. Meat Spoilage Mechanisms and Preservation Techniques: A Critical Review

    Directory of Open Access Journals (Sweden)

    D. Dave

    2011-01-01

    Full Text Available Problem statement: Extremely perishable meat provides favorable growth condition for various microorganisms. Meat is also very much susceptible to spoilage due to chemical and enzymatic activities. The breakdown of fat, protein and carbohydrates of meat results in the development of off-odors, off-flavor and slim formation which make the meat objectionable for human consumption. It is, therefore, necessary to control meat spoilage in order to increase its shelf life and maintain its nutritional value, texture and flavor. Approach: A comprehensive literature review was performed on the spoliage mechanisms of meat and meat products and preservation techniques. Results: Historical data reveals that salting, drying, smoking, fermentation and canning were the traditional methods used to prevent meat spoilage and extend its shelf life. However, in order to prevent wholesomeness, appearance, composition, tenderness, flavor, juiciness and nutritive value, new methods were developed. These included: cooling, freezing and chemical preservation. Wide range of physical and chemical reactions and actions of microorganisms or enzymes are responsible for the meat spoilage. Microbial growth, oxidation and enzymatic autolysis are three basic mechanisms responsible for spoilage of meat. Microbial growth and metabolism depends on various factors including: pre-slaughter husbandry practices, age of the animal at the time of slaughtering, handling during slaughtering, evisceration and processing, temperature controls during slaughtering, processing and distribution, preservation methods, type of packaging and handling and storage by consumer. Microbial spoilage causes pH change, slime formation, structural components degradation, off odors and appearance change. Autoxidation of lipids and the production of free radicals are natural processes which affect fatty acids and lead to oxidative deterioration of meat and off-flavour development. Lipid hydrolysis can take

  16. A smallest 6 kda metalloprotease, mini-matrilysin, in living world: a revolutionary conserved zinc-dependent proteolytic domain- helix-loop-helix catalytic zinc binding domain (ZBD

    Directory of Open Access Journals (Sweden)

    Yu Wei-Hsuan

    2012-05-01

    Full Text Available Abstract Background The Aim of this study is to study the minimum zinc dependent metalloprotease catalytic folding motif, helix B Met loop-helix C, with proteolytic catalytic activities in metzincin super family. The metzincin super family share a catalytic domain consisting of a twisted five-stranded β sheet and three long α helices (A, B and C. The catalytic zinc is at the bottom of the cleft and is ligated by three His residues in the consensus sequence motif, HEXXHXXGXXH, which is located in helix B and part of the adjacent Met turn region. An interesting question is - what is the minimum portion of the enzyme that still possesses catalytic and inhibitor recognition?” Methods We have expressed a 60-residue truncated form of matrilysin which retains only the helix B-Met turn-helix C region and deletes helix A and the five-stranded β sheet which form the upper portion of the active cleft. This is only 1/4 of the full catalytic domain. The E. coli derived 6 kDa MMP-7 ZBD fragments were purified and refolded. The proteolytic activities were analyzed by Mca-Pro-Leu-Gly-Leu-Dpa-Ala-Arg-NH2 peptide assay and CM-transferrin zymography analysis. SC44463, BB94 and Phosphoramidon were computationally docked into the 3day structure of the human MMP7 ZBD and TAD and thermolysin using the docking program GOLD. Results This minimal 6 kDa matrilysin has been refolded and shown to have proteolytic activity in the Mca-Pro-Leu-Gly-Leu-Dpa-Ala-Arg-NH2 peptide assay. Triton X-100 and heparin are important factors in the refolding environment for this mini-enzyme matrilysin. This minienzyme has the proteolytic activity towards peptide substrate, but the hexamer and octamer of the mini MMP-7 complex demonstrates the CM-transferrin proteolytic activities in zymographic analysis. Peptide digestion is inhibited by SC44463, specific MMP7 inhibitors, but not phosphorimadon. Interestingly, the mini MMP-7 can be processed by autolysis and producing ~ 6

  17. Systems approaches to predict the functions of glycoside hydrolases during the life cycle of Aspergillus niger using developmental mutants ∆brlA and ∆flbA.

    Directory of Open Access Journals (Sweden)

    Jolanda M van Munster

    Full Text Available BACKGROUND: The filamentous fungus Aspergillus niger encounters carbon starvation in nature as well as during industrial fermentations. In response, regulatory networks initiate and control autolysis and sporulation. Carbohydrate-active enzymes play an important role in these processes, for example by modifying cell walls during spore cell wall biogenesis or in cell wall degradation connected to autolysis. RESULTS: In this study, we used developmental mutants (ΔflbA and ΔbrlA which are characterized by an aconidial phenotype when grown on a plate, but also in bioreactor-controlled submerged cultivations during carbon starvation. By comparing the transcriptomes, proteomes, enzyme activities and the fungal cell wall compositions of a wild type A. niger strain and these developmental mutants during carbon starvation, a global overview of the function of carbohydrate-active enzymes is provided. Seven genes encoding carbohydrate-active enzymes, including cfcA, were expressed during starvation in all strains; they may encode enzymes involved in cell wall recycling. Genes expressed in the wild-type during starvation, but not in the developmental mutants are likely involved in conidiogenesis. Eighteen of such genes were identified, including characterized sporulation-specific chitinases and An15g02350, member of the recently identified carbohydrate-active enzyme family AA11. Eight of the eighteen genes were also expressed, independent of FlbA or BrlA, in vegetative mycelium, indicating that they also have a role during vegetative growth. The ΔflbA strain had a reduced specific growth rate, an increased chitin content of the cell wall and specific expression of genes that are induced in response to cell wall stress, indicating that integrity of the cell wall of strain ΔflbA is reduced. CONCLUSION: The combination of the developmental mutants ΔflbA and ΔbrlA resulted in the identification of enzymes involved in cell wall recycling and sporulation

  18. Growth physiology and fate of diatoms in the ocean: a review

    Science.gov (United States)

    Sarthou, Géraldine; Timmermans, Klaas R.; Blain, Stéphane; Tréguer, Paul

    2005-01-01

    Diatoms are a major component of phytoplankton community. They tend to dominate under natural high-nutrient concentrations, as well as during artificial Fe fertilisation experiments. They are main players in the biogeochemical cycle of carbon (C), as they can account for 40% of the total primary production in the Ocean and dominate export production, as well as in the biogeochemical cycles of the other macro-nutrients, nitrogen (N), phosphorus (P), and silicon (Si). Another important nutrient is Fe, which was shown to have a direct or indirect effect on nearly all the biogeochemical parameters of diatoms. In the present paper, an inventory is made of the growth, physiology and fate of many diatom species, including maximum growth rate, photosynthetic parameters (maximum specific rate of photosynthesis, photosynthetic efficiency and light adaptation parameter), nutrient limitation (half-saturation constant for growth/uptake), cellular elemental ratios, and loss terms (sinking rates, autolysis rates and grazing rates). This is a first step for improvement of the parameterisation of physiologically based phytoplankton growth and global 3D carbon models. This review is a synthesis of a large number of published laboratory experiments using monospecific cultures as well as field data. Our compilation confirms that size is an important factor explaining variations of biogeochemical parameters of diatoms (e.g. maximum growth rate, photosynthesis parameters, half-saturation constants, sinking rate, and grazing). Some variations of elemental ratios can be explained by adaptation of intracellular requirements or storage of Fe, and P, for instance. The important loss processes of diatoms pointed out by this synthesis are (i) sinking, as single cells as well as through aggregation which generally greatly increases sinking rate, (ii) cell autolysis, which can significantly reduce net growth rates, especially under nutrient limitation when gross growth rates are low, and (iii

  19. Diagnostic accuracy and limitations of post-mortem MRI for neurological abnormalities in fetuses and children

    International Nuclear Information System (INIS)

    Aim: To compare the diagnostic accuracy of non-invasive cerebral post-mortem magnetic resonance imaging (PMMRI) specifically for cerebral and neurological abnormalities in a series of fetuses and children, compared to conventional autopsy. Materials and methods: Institutional ethics approval and parental consent was obtained. Pre-autopsy cerebral PMMRI was performed in a sequential prospective cohort (n = 400) of fetuses (n = 277; 185 ≤ 24 weeks and 92 > 24 weeks gestation) and children <16 years (n = 123) of age. PMMRI and conventional autopsy findings were reported blinded and independently of each other. Results: Cerebral PMMRI had sensitivities and specificities (95% confidence interval) of 88.4% (75.5 to 94.9), and 95.2% (92.1 to 97.1), respectively, for cerebral malformations; 100% (83.9 to 100), and 99.1% (97.2 to 99.7) for major intracranial bleeds; and 87.5% (80.1 to 92.4) and 74.1% (68 to 79.4) for overall brain pathology. Formal neuropathological examination was non-diagnostic due to maceration/autolysis in 43/277 (16%) fetuses; of these, cerebral PMMRI imaging provided clinically important information in 23 (53%). The sensitivity of PMMRI for detecting significant ante-mortem ischaemic injury was only 68% (48.4 to 82.8) overall. Conclusions: PMMRI is an accurate investigational technique for identifying significant neuropathology in fetuses and children, and may provide important information even in cases where autolysis prevents formal neuropathological examination; however, PMMRI is less sensitive at detecting hypoxic–ischaemic brain injury, and may not detect rarer disorders not encountered in this study. -- Highlights: •Post mortem MRI (PMMRI) has a sensitivity of >87% for detecting cerebral malformations, intracranial bleeds and neurological cause of death. •PMMRI provides important diagnostic information in >50% of fetuses where conventional brain autopsy is non-diagnostic. •PMMRI is currently poor at reliably identifying

  20. Optimization of RNA Extraction from Rat Pancreatic Tissue

    Directory of Open Access Journals (Sweden)

    Sanaz Dastgheib

    2014-05-01

    Full Text Available Background: Optimized RNA extraction from tissues and cell lines consists of four main stages regardless of the method of extraction: 1 homogenizing, 2 effective denaturation of proteins from RNA, 3 inactivation of ribonuclease, and 4 removal of any DNA, protein, and carbohydrate contamination. Isolation of undamaged intact RNA is challenging when the related tissue contains high levels of RNase. Various technical difficulties occur during extraction of RNA from pancreatic tissue due to spontaneous autolysis. Since standard routine protocols yield unacceptable results in pancrease, we have designed a simple method for RNA extraction by comparing different protocols. Methods: We obtained 20-30 mg pancreatic tissues in less than 2 min from 30 rats. Several methods were performed to extract RNA from pancreatic tissue and evaluate its integrity. All methods were performed three times to obtain reproducible results. Results: Immersing pancreatic tissue in RNA-later for 24 h at -80ºC yielded high quality RNA by using the TriPure reagent which was comparable to the commercial RNeasy Micro Kit. The quality of RNA was evaluated by spectrophotometer, electrophoresis and RT-PCR. We separated intact 28S and 18S ribosomal RNA (rRNA when our procedure was compared with the RNeasy Micro Kit. Finally, full length of the actin gene was amplified by RT-PCR. Conclusion: We designed a simple, fast, cost-effective method for complete RNA extraction from the least amount of quantitatively intact pancreatic tissue

  1. Mini-Review: Novel Therapeutic Strategies to Blunt Actions of Pneumolysin in the Lungs

    Directory of Open Access Journals (Sweden)

    Martin Leustik

    2013-07-01

    Full Text Available Severe pneumonia is the main single cause of death worldwide in children under five years of age. The main etiological agent of pneumonia is the G+ bacterium Streptococcus pneumoniae, which accounts for up to 45% of all cases. Intriguingly, patients can still die days after commencing antibiotic treatment due to the development of permeability edema, although the pathogen was successfully cleared from their lungs. This condition is characterized by a dramatically impaired alveolar epithelial-capillary barrier function and a dysfunction of the sodium transporters required for edema reabsorption, including the apically expressed epithelial sodium channel (ENaC and the basolaterally expressed sodium potassium pump (Na+-K+-ATPase. The main agent inducing this edema formation is the virulence factor pneumolysin, a cholesterol-binding pore-forming toxin, released in the alveolar compartment of the lungs when pneumococci are being lysed by antibiotic treatment or upon autolysis. Sub-lytic concentrations of pneumolysin can cause endothelial barrier dysfunction and can impair ENaC-mediated sodium uptake in type II alveolar epithelial cells. These events significantly contribute to the formation of permeability edema, for which currently no standard therapy is available. This review focuses on discussing some recent developments in the search for the novel therapeutic agents able to improve lung function despite the presence of pore-forming toxins. Such treatments could reduce the potentially lethal complications occurring after antibiotic treatment of patients with severe pneumonia.

  2. Application of microbial electrolysis cells to treat spent yeast from an alcoholic fermentation.

    Science.gov (United States)

    Sosa-Hernández, Ornella; Popat, Sudeep C; Parameswaran, Prathap; Alemán-Nava, Gibrán Sidney; Torres, César I; Buitrón, Germán; Parra-Saldívar, Roberto

    2016-01-01

    Spent yeast (SY), a major challenge for the brewing industry, was treated using a microbial electrolysis cell to recover energy. Concentrations of SY from bench alcoholic fermentation and ethanol were tested, ranging from 750 to 1500mgCOD/L and 0 to 2400mgCOD/L respectively. COD removal efficiency (RE), coulombic efficiency (CE), coulombic recovery (CR), hydrogen production and current density were evaluated. The best treatment condition was 750mgCOD/LSY+1200mgCOD/L ethanol giving higher COD RE, CE, CR (90±1%, 90±2% and 81±1% respectively), as compared with 1500mgCOD/LSY (76±2%, 63±7% and 48±4% respectively); ethanol addition was significantly favorable (p value=0.011), possibly due to electron availability and SY autolysis. 1500mgCOD/LSY+1200mgCOD/L ethanol achieved higher current density (222.0±31.3A/m(3)) and hydrogen production (2.18±0.66 [Formula: see text] ) but with lower efficiencies (87±2% COD RE, 71.0±.4% CE). Future work should focus on electron sinks, acclimation and optimizing SY breakdown. PMID:26512857

  3. Studying of Phototransformation of Light Signal by Photoreceptor Pigments - Rhodopsin, Iodopsin and Bacteriorhodopsin

    Directory of Open Access Journals (Sweden)

    Ignat Ignatov

    2014-09-01

    Full Text Available This review article views predominately the structure and function of animal and bacterial photoreceptor pigments (rhodopsin, iodopsin, bacteriorhodopsin and their aspects of nano- and biotechnological usage. On an example of bacteriorhodopsin is described the method of its isolation from purple membranes of photo-organotrophic halobacterium Halobacterium halobium by cellular autolysis by distilled water, processing of bacterial biomass by ultrasound at 22 KHz, alcohol extraction of low and high-weight molecular impurities, cellular RNA, carotenoids and lipids, the solubilization with 0,5 % (w/v SDS-Na and subsequent fractionation by methanol and gel filtration chromatography on Sephadex G-200 Column balanced with 0.09 M Tris-borate buffer (pH = 8,35 with 0,1 % (w/v SDS-Na and 2,5 mM EDTA. Within the framework of the research the mechanism of color perception by the visual analyzer having the ability to analyze certain ranges of the optical spectrum, as colors was studied along with an analysis of the additive mixing of two colors. It was shown that at the mixing of electromagnetic waves with different wavelengths, the visual analyzer perceive them as separate or average wave length corresponding to mix color.

  4. Studying the Mechanism of Phototransformation of Light Signal by Various Mammal and Bacterial Photoreceptor Pigments  Rhodopsin, Iodopsin and Bacteriorhodopsin

    Directory of Open Access Journals (Sweden)

    Ignat Ignatov

    2015-06-01

    Full Text Available This review article outlines the structure and function of mammal and bacterial photoreceptor pigments (rhodopsin, iodopsin, bacteriorhodopsin and their aspects of bio-nanotechnological usage. On an example of bacteriorhodopsin is described the method of its isolation from purple membranes of photo-organotrophic halobacterium Halobacterium halobium ET 1001 by cellular autolysis by distilled water, processing of bacterial biomass by ultrasound at 22 KHz, alcohol extraction of low and high-weight molecular impurities, cellular RNA, carotenoids and lipids, the solubilization with 0,5 % (w/v SDS-Na and subsequent fractionation by methanol and gel filtration chromatography on Sephadex G-200 Column balanced with 0,09 M Tris-buffer (pH = 8,35 with 0,1 % (w/v SDS-Na and 2,5 mM EDTA. Within the framework of the research the mechanism of color perception by the visual retina analyzer having the ability to analyze certain ranges of the optical spectrum as colors, was studied along with an analysis of the additive mixing of two or more colors. It was shown that at the mixing of electromagnetic waves with different wavelengths, the visual analyzer perceives them as the separate or average wave length corresponding to the mixing color.

  5. Improvement of Omega-3 Docosahexaenoic Acid Production by Marine Dinoflagellate Crypthecodinium cohnii Using Rapeseed Meal Hydrolysate and Waste Molasses as Feedstock.

    Science.gov (United States)

    Gong, Yangmin; Liu, Jiao; Jiang, Mulan; Liang, Zhuo; Jin, Hu; Hu, Xiaojia; Wan, Xia; Hu, Chuanjiong

    2015-01-01

    Rapeseed meal and waste molasses are two important agro-industrial by-products which are produced in large quantities. In this study, solid state fermentation and fungal autolysis were performed to produce rapeseed meal hydrolysate (RMH) using fungal strains of Aspergillus oryzae, Penicillium oxalicum and Neurospora crassa. The hydrolysate was used as fermentation feedstock for heterotrophic growth of microalga Crypthecodinium cohnii that produce docosahexaenoic acid (DHA). The addition of waste molasses as a supplementary carbon source greatly increased the biomass and DHA yield. In the batch fermentations using media composed of diluted RMH (7%) and 1-9% waste molasses, the highest biomass concentration and DHA yield reached 3.43 g/L and 8.72 mg/L, respectively. The algal biomass produced from RMH and molasses medium also had a high percentage of DHA (22-34%) in total fatty acids similar to that of commercial algal biomass. RMH was shown to be rich in nitrogen supply comparable to the commercial nitrogen feedstock like yeast extract. Using RMH as sole nitrogen source, waste molasses excelled other carbon sources and produced the highest concentration of biomass. This study suggests that DHA production of the marine dinoflagellate C. cohnii could be greatly improved by concomitantly using the cheap by-products rapeseed meal hydrolysate and molasses as alternative feedstock. PMID:25942565

  6. Improvement of Omega-3 Docosahexaenoic Acid Production by Marine Dinoflagellate Crypthecodinium cohnii Using Rapeseed Meal Hydrolysate and Waste Molasses as Feedstock.

    Directory of Open Access Journals (Sweden)

    Yangmin Gong

    Full Text Available Rapeseed meal and waste molasses are two important agro-industrial by-products which are produced in large quantities. In this study, solid state fermentation and fungal autolysis were performed to produce rapeseed meal hydrolysate (RMH using fungal strains of Aspergillus oryzae, Penicillium oxalicum and Neurospora crassa. The hydrolysate was used as fermentation feedstock for heterotrophic growth of microalga Crypthecodinium cohnii that produce docosahexaenoic acid (DHA. The addition of waste molasses as a supplementary carbon source greatly increased the biomass and DHA yield. In the batch fermentations using media composed of diluted RMH (7% and 1-9% waste molasses, the highest biomass concentration and DHA yield reached 3.43 g/L and 8.72 mg/L, respectively. The algal biomass produced from RMH and molasses medium also had a high percentage of DHA (22-34% in total fatty acids similar to that of commercial algal biomass. RMH was shown to be rich in nitrogen supply comparable to the commercial nitrogen feedstock like yeast extract. Using RMH as sole nitrogen source, waste molasses excelled other carbon sources and produced the highest concentration of biomass. This study suggests that DHA production of the marine dinoflagellate C. cohnii could be greatly improved by concomitantly using the cheap by-products rapeseed meal hydrolysate and molasses as alternative feedstock.

  7. Transfer, composition and technological characterization of the lactic acid bacterial populations of the wooden vats used to produce traditional stretched cheeses.

    Science.gov (United States)

    Scatassa, Maria Luisa; Gaglio, Raimondo; Macaluso, Giusi; Francesca, Nicola; Randazzo, Walter; Cardamone, Cinzia; Di Grigoli, Antonino; Moschetti, Giancarlo; Settanni, Luca

    2015-12-01

    The biofilms of 12 wooden vats used for the production of the traditional stretched cheeses Caciocavallo Palermitano and PDO Vastedda della valle del Belìce were investigated. Salmonella spp. and Listeria monocytogenes were never detected. Total coliforms were at low numbers with Escherichia coli found only in three vats. Coagulase-positive staphylococci (CPS) were below the enumeration limit, whereas lactic acid bacteria (LAB) dominated the surfaces of all vats. In general, the dominance was showed by coccus LAB. Enterococci were estimated at high numbers, but usually between 1 and 2 Log cycles lower than other LAB. LAB populations were investigated at species and strain level and for their technological properties relevant in cheese production. Eighty-five strains were analysed by a polyphasic genetic approach and allotted into 16 species within the genera Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Pediococcus and Streptococcus. Enterococcus faecium was found in all wooden vats and the species most frequently isolated were Enterococcus faecalis, Lactococcus lactis, Leuconostoc mesenteroides, Pediococcus acidilactici and Streptococcus thermophilus. The study of the quantitative data on acidification rate, autolysis kinetics, diacetyl production, antibacterial compound generation and proteolysis by cluster and principal component analysis led to the identification of some strains with promising dairy characteristics. Interestingly, a consistent percentage of LAB was bacteriocin-like inhibitory substances (BLIS) producer. Thus, the microbial biofilms of the wooden vats analysed in this study might contribute actively to the stability of the final cheeses. PMID:26338114

  8. [Spectral characteristics of soluble metabolites during endogenous respiration].

    Science.gov (United States)

    Li, Zhi-hua; Zhang, Qin; Bai, Xu-li; Liu, Yi

    2014-09-01

    Endogenous respiration phase plays an important role in the sewage treatment process. In order to clearly understand the endogenous respiration process of the activated sludge process, three-dimensional fluorescence spectroscopy, ultraviolet spectroscopy and respirogram were employed for the analysis of endogenous respiration process. Results showed that the three-dimensional fluorescence spectroscopy and UV spectroscopy could identify all stages significantly. The following conclusions could be drawn: (1) Rapid decline phase of endogenous respiration:the excitation wavelength (EX) and emission wavelength (Em) of humic peak showed blue shift of 5 nm and 6 nm, respectively, the fluorescence index f450/500 and HIX (humification index) were reduced by 9. 3% and 0.2%, respectively, UV253/203 and UV254 increased by 37.5% and 200%, respectively. These results indicated the presence of bioavailable organics; (2)Slow decline phase of endogenous respiration: f450/500 was increased by 0. 5% , HIX was reduced by 0. 2% , UV253/203 was reduced by 20% , UV254 was increased by 16. 7%. These results indicated that hydrolysis or autolysis of cells might occur; (3)Stable phase of endogenous respiration: humic acid peak remained unchanged, indicating the adaption of microorganisms to starving environment. The analysis of the endogenous respiration process from the perspective of metabolites provides a new way for control of microbial wastewater treatment process. PMID:25518670

  9. Hematodinium sp. infection in Norway lobster Nephrops norvegicus and its effects on meat quality.

    Science.gov (United States)

    Albalat, Amaya; Gornik, Sebastian G; Beevers, Nicholas; Atkinson, R James A; Miskin, David; Neil, Douglas M

    2012-08-27

    Hematodinium and Hematodinium-like species have emerged in the last 3 decades as important parasitic pathogens of crustaceans worldwide, causing a significant economic loss to fisheries and related markets. In some species (notably the Tanner crab Chionoecetes bairdi), the parasite reportedly causes the cooked meat to taste bitter and aspirin-like. The bitter taste, together with the gross pathology of the infection, renders these crabs unmarketable. Surprisingly, no organoleptic tests have ever been conducted to date, and the cause for the bitter taste is still unknown. Nevertheless, it is generally assumed that the bitter taste occurs widely in cooked meats and products derived from crustaceans infected with Hematodinium. In the present study, we analysed the meat quality and organoleptic attributes after capture and during storage of Norway lobsters Nephrops norvegicus from Scottish waters that were either asymptomatic or symptomatic of patent Hematodinium infection. Results from the sensory evaluation of the cooked product indicate that tail meat from symptomatic N. norvegicus is bland in flavour and aftertaste, and more friable or sloppier in texture than meat from asymptomatic animals. As a consequence, infected meat tends to be less palatable, although surprisingly no bitter taste is reported. From an analytical point of view, tail meat from patently infected animals is at an advanced stage of autolysis, while no difference in microbial load is detected. These results suggest that Norway lobsters heavily infected with Hematodinium are of inferior marketing quality even after the tails have been cooked. PMID:23186698

  10. Identification and Characterization of a New Alkaline Thermolysin-Like Protease, BtsTLP1, from Bacillus thuringiensis Serovar Sichuansis Strain MC28.

    Science.gov (United States)

    Zhang, Zhenghong; Hao, Helong; Tang, Zhongmei; Zou, Zhengzheng; Zhang, Keya; Xie, Zhiyong; Babe, Lilia; Goedegebuur, Frits; Gu, Xiaogang

    2015-08-01

    Thermolysin and its homologs are a group of metalloproteases that have been widely used in both therapeutic and biotechnological applications. We here report the identification and characterization of a novel thermolysin-like protease, BtsTLP1, from insect pathogen Bacillus thuringiensis serovar Sichuansis strain MC28. BtsTLP1 is extracellularly produced in Bacillus subtilis, and the active protein was purified via successive chromatographic steps. The mature form of BtsTLP1 has a molecule mass of 35.6 kDa as determined by mass spectrometry analyses. The biochemical characterization indicates that BtsTLP1 has an apparent Km value of 1.57 mg/ml for azocasein and is active between 20°C and 80°C. Unlike other reported neutral gram-positive thermolysin homologs with optimal pH around 7, BtsTLP1 exhibits an alkaline pH optimum around 10. The activity of BtsTLP1 is strongly inhibited by EDTA and a group of specific divalent ions, with Zn(2+) and Cu(2+) showing particular effects in promoting the enzyme autolysis. Furthermore, our data also indicate that BtsTLP1 has potential in cleaning applications. PMID:25824434

  11. Characterization of the aodA, dnmA, mnSOD and pimA genes in Aspergillus nidulans.

    Science.gov (United States)

    Leiter, Éva; Park, Hee-Soo; Kwon, Nak-Jung; Han, Kap-Hoon; Emri, Tamás; Oláh, Viktor; Mészáros, Ilona; Dienes, Beatrix; Vincze, János; Csernoch, László; Yu, Jae-Hyuk; Pócsi, István

    2016-01-01

    Mitochondria play key roles in cellular energy generation and lifespan of most eukaryotes. To understand the functions of four nuclear-encoded genes predicted to be related to the maintenance of mitochondrial morphology and function in Aspergillus nidulans, systematic characterization was carried out. The deletion and overexpression mutants of aodA, dnmA, mnSOD and pimA encoding alternative oxidase, dynamin related protein, manganese superoxide dismutase and Lon protease, respectively, were generated and examined for their growth, stress tolerances, respiration, autolysis, cell death, sterigmatocystin production, hyphal morphology and size, and mitochondrial superoxide production as well as development. Overall, genetic manipulation of these genes had less effect on cellular physiology and ageing in A. nidulans than that of their homologs in another fungus Podospora anserina with a well-characterized senescence. The observed interspecial phenotypic differences can be explained by the dissimilar intrinsic stabilities of the mitochondrial genomes in A. nidulans and P. anserina. Furthermore, the marginally altered phenotypes observed in A. nidulans mutants indicate the presence of effective compensatory mechanisms for the complex networks of mitochondrial defense and quality control. Importantly, these findings can be useful for developing novel platforms for heterologous protein production, or on new biocontrol and bioremediation technologies based on Aspergillus species. PMID:26846452

  12. Vancomycin susceptibility in methicillin-resistant Staphylococcus aureus is mediated by YycHI activation of the WalRK essential two-component regulatory system.

    Science.gov (United States)

    Cameron, David R; Jiang, Jhih-Hang; Kostoulias, Xenia; Foxwell, Daniel J; Peleg, Anton Y

    2016-01-01

    The treatment of infections caused by methicillin-resistant Staphylococcus aureus is complicated by the emergence of strains with intermediate-level resistance to vancomycin (termed VISA). We have characterised a molecular pathway involved in the in vivo evolution of VISA mediated by the regulatory proteins YycH and YycI. In contrast to their function in other bacterial species, we report a positive role for these auxiliary proteins in regulation of the two-component regulator WalRK. Transcriptional profiling of yycH and yycI deletion mutants revealed downregulation of the 'WalRK regulon' including cell wall hydrolase genes atlA and sle1, with functional autolysis assays supporting these data by showing an impaired autolytic phenotype for each deletion strain. Using bacterial-two hybrid assays, we showed that YycH and YycI interact, and that YycHI also interacts with the sensor kinase WalK, forming a ternary protein complex. Mutation to YycH or YycI associated with clinical VISA strains had a deleterious impact on the YycHI/WalK complex, suggesting that the interaction is important for the regulation of WalRK. Taken together, we have described a novel antibiotic resistance strategy for the human pathogen S. aureus, whereby YycHI mutations are selected for in vivo leading to reduced WalRK activation, impaired cell wall turnover and ultimately reduced vancomycin efficacy. PMID:27600558

  13. Purification, cDNA cloning, and recombinant expression of chymotrypsin C from porcine pancreas

    Institute of Scientific and Technical Information of China (English)

    Haibo Wang; Duoduo Yuan; Rong Xu; Cheng-Wu Chi

    2011-01-01

    Chymotrypsin C is a bifunctional secretory-type serine protease in pancreas; besides proteolytical activity, it also exhibits a calcium-decreasing activity in serum, In this study, we purified activated chymotrypsin C from porcine pancreas, and identified its three active forms. Active chymotrypsin C was found to be different in the length of its 13-residue activation peptide due to carboxydipeptidase (present in the pancreas) degradation or autolysis of the activated chymotrypsin C itself, resulting in the removal of several C-terminus residues from the activation peptide. After limited chymotrypsin C cleavage with endopeptidase Lys C, several purified peptides were partially sequenced, and the entire cDNA sequence for porcine chymotrypsin C was cloned. Recombinant chymotrypsinogen C was successfully expressed in Escherichia coli cells as inclusion bodies. After refolding and activation with trypsin, the comparison of the recombinant chymotrypsin C with the natural form showed that their proteolytic and calcium-decreasing activities were at the same level. The successful expression of chymotrypsin C gene paves the way to further mutagenic structurefunction studies.

  14. Recombinant immobilized rhizopuspepsin as a new tool for protein digestion in hydrogen/deuterium exchange mass spectrometry.

    Science.gov (United States)

    Rey, Martial; Man, Petr; Brandolin, Gérard; Forest, Eric; Pelosi, Ludovic

    2009-11-01

    Hydrogen/deuterium (H/D) exchange coupled to mass spectrometry is nowadays routinely used to probe protein interactions or conformational changes. The method has many advantages, e.g. very low sample consumption, but offers limited spatial resolution. One way to higher resolution leads through the use of different proteases or their combinations. In the present work we describe recombinant production, purification and use of aspartic protease zymogen from Rhizopus chimensis, protease type XVIII (EC 3.4.23.6), commonly referred to as rhizopuspepsinogen (Rpg). The enzyme was expressed in Escherichia coli, refolded and purified to homogeneity. A typical yield was approximately 100 mg of pure enzyme per 1 L of original bacterial culture. The kinetics of protease activation, i.e. removal of the propeptide achieved by autolysis in an acidic environment, was followed by mass spectrometry. The digestion efficiency was tested for the protease in solution as well as for the immobilized enzyme. Apomyoglobin was successfully digested under all conditions tested and the protease displayed very low or no autodigestion. The results outperformed those obtained with commercial protease where the digestion of apomyoglobin was incomplete and accompanied by many contaminating peptides. Taken together, the recombinant protease type XVIII can be considered as a new and highly efficient tool for H/D exchange followed by mass spectrometry. PMID:19827048

  15. Light and electron microscopic observations in connection with the developing pistil and seed-appendix (caruncle of Ricinus communis L.

    Directory of Open Access Journals (Sweden)

    Katherine Liszt

    2014-02-01

    Full Text Available The development of the particularly organized stigma and obturator, their fine structure, their function as well as the histological differentiation and the role of the seed-appendix i.e. the caruncle of Ricinus communis L. have been investigated in several developmental phases from the so called "gynoecial primordium" state to the ripe state, 'using the terminology introduced by S a t t 1 e r (1974. The stigma cells are characterized by dens cytoplasm, numerous vesicles mostly of ER origin, ribosomes and negatively stained mitochondria. Dilatation of ER, the appearance of electron opaque substances in it and between the plasmamembran and cell wall are frequent. The degenerating process of some stigma cells will start before the pollination because of autolysis. In the cells of the obturator and young caruncle however dictyosomes can be found more frequently than in stigma cells and the starch content of the ;plastids is remarkable. The thickening of the cell wall is connected with the function of these tissues.

  16. Structure determination and analysis of a haemolytic gingipain adhesin domain from Porphyromonas gingivalis

    Energy Technology Data Exchange (ETDEWEB)

    Li, N.; Yun, P.; Nadkarni, M.A.; Ghadikolaee, N.B.; Nguyen, K.A.; Lee, M.; Hunter, N.; Collyer, C.A. (Sydney)

    2010-08-27

    Porphyromonas gingivalis is an obligately anaerobic bacterium recognized as an aetiological agent of adult periodontitis. P. gingivalis produces cysteine proteinases, the gingipains. The crystal structure of a domain within the haemagglutinin region of the lysine gingipain (Kgp) is reported here. The domain was named K2 as it is the second of three homologous structural modules in Kgp. The K2 domain structure is a 'jelly-roll' fold with two anti-parallel {beta}-sheets. This fold topology is shared with adhesive domains from functionally diverse receptors such as MAM domains, ephrin receptor ligand binding domains and a number of carbohydrate binding modules. Possible functions of K2 were investigated. K2 induced haemolysis of erythrocytes in a dose-dependent manner that was augmented by the blocking of anion transport. Further, cysteine-activated arginine gingipain RgpB, which degrades glycophorin A, sensitized erythrocytes to the haemolytic effect of K2. Cleaved K2, similar to that found in extracted Kgp, lacks the haemolytic activity indicating that autolysis of Kgp may be a staged process which is artificially enhanced by extraction of the protein. The data indicate a functional role for K2 in the integrated capacity conferred by Kgp to enable the porphyrin auxotroph P. gingivalis to capture essential haem from erythrocytes.

  17. Evidence for the presence of phospholipase A1 in Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    The cause of the autolysis of pressed Baker's yeast was examined. Softened pressed yeast cells (Saccharomyces cerevisiae), after about 10 days of storage at 30 deg C, was subjected to a series of extraction: the extraction with acetone was made to the supernatant after the centrifugation of the water-suspended yeast cell at 1000 x g for 10 min, and the obtained precipitation was mechanically (with a Potter teflon homogenizer) homogenized. After removing the residues by centrifugation, the protein was salted out with ammonium sulfate up to 0.6 saturation. An enzyme, phospholipase A1 was thus obtained from the softened yeast cells. The activity of the enzyme thus obtained was assayed using L-α-phosphatidylethanolamine as the substrate. It was previously found that 14C-labelled free fatty acids liberated from phosphatidylcholine (PC) accumulated in the softened yeast packed cake. The enzyme was identified as phospholipase A1 having the optimal pH at around 8. Another evidence, obtained previously, together with the present finding suggest that the softening of the pressed Baker's yeast may be caused by the degradation of phospholipid by the combined action of phospholipase A1 and lysophospholipase L2. (Yamashita, S.)

  18. Morbidity and mortality in stranded Cook Inlet beluga whales Delphinapterus leucas.

    Science.gov (United States)

    Burek-Huntington, Kathleen A; Dushane, Jennifer L; Goertz, Caroline E C; Measures, Lena N; Romero, Carlos H; Raverty, Stephen A

    2015-05-11

    The endangered Cook Inlet (Alaska, USA) stock of beluga whales Delphinapterus leucas declined 47% between 1994 and 1998, from an estimated 653 whales to 347 whales, with a continued decline to approximately 312 in 2012. Between 1998 and 2013, 164 known dead strandings were reported by the National Marine Fisheries Service. Only 38 of these animals, or 23% of the known stranded carcasses, were necropsied. Carcasses were found between April and October. The majority of animals necropsied were adults (n=25), followed by juveniles (n=6), calves (n=3), and aborted fetuses (n=4). Eight of the 11 mature females were pregnant, post-partum, or lactating. Many (82%) of these belugas were in moderate to advanced autolysis, which hampered determination of a cause of death (COD). Each animal had a single primary COD assigned within a broad set of categories. The CODs were unknown (29%), trauma (18%), perinatal mortality (13%), mass stranding (13%), single stranding (11%), malnutrition (8%), or disease (8%). Other disease processes were coded as contributory or incidental to COD. Multiple animals had mild to moderate verminous pneumonia due to Stenurus arctomarinus, renal granulomas due to Crassicauda giliakiana, and ulcerative gastritis due to Anisakis sp. Each stranding affords a unique opportunity to obtain natural history data and evidence of human interactions, and, by long-term monitoring, to characterize pathologies of importance to individual and population health. PMID:25958805

  19. Production and functional evaluation of a protein concentrate from giant squid (Dosidicus gigas) by acid dissolution and isoelectric precipitation.

    Science.gov (United States)

    Cortés-Ruiz, Juan A; Pacheco-Aguilar, Ramón; Elena Lugo-Sánchez, M; Gisela Carvallo-Ruiz, M; García-Sánchez, Guillermina

    2008-09-15

    A protein concentrate from giant squid (Dosidicus gigas) was produced under acidic conditions and its functional-technological capability evaluated in terms of its gel-forming ability, water holding capacity and colour attributes. Technological functionality of the concentrate was compared with that of squid muscle and a neutral concentrate. Protein-protein aggregates insoluble at high ionic strength (I=0.5M), were detected in the acidic concentrate as result of processing with no preclusion of its gel-forming ability during the sol-to-gel thermal transition. Even though washing under acidic condition promoted autolysis of the myosin heavy chain, the acidic concentrate displayed an outstanding ability to gel giving samples with a gel strength of 455 and 1160gcm at 75% and 90% compression respectively, and an AA folding test grade indicative of high gel strength, elasticity, and cohesiveness. The process proved to be a good alternative for obtaining a functional protein concentrate from giant squid muscle. PMID:26049243

  20. Trophosome of the Deep-Sea Tubeworm Riftia pachyptila Inhibits Bacterial Growth

    Science.gov (United States)

    Klose, Julia; Aistleitner, Karin; Horn, Matthias; Krenn, Liselotte; Dirsch, Verena; Zehl, Martin; Bright, Monika

    2016-01-01

    The giant tubeworm Riftia pachyptila lives in symbiosis with the chemoautotrophic gammaproteobacterium Cand. Endoriftia persephone. Symbionts are released back into the environment upon host death in high-pressure experiments, while microbial fouling is not involved in trophosome degradation. Therefore, we examined the antimicrobial effect of the tubeworm’s trophosome and skin. The growth of all four tested Gram-positive, but only of one of the tested Gram-negative bacterial strains was inhibited by freshly fixed and degrading trophosome (incubated up to ten days at either warm or cold temperature), while no effect on Saccharomyces cerevisiae was observed. The skin did not show antimicrobial effects. A liquid chromatography-mass spectrometric analysis of the ethanol supernatant of fixed trophosomes lead to the tentative identification of the phospholipids 1-palmitoleyl-2-lyso-phosphatidylethanolamine, 2-palmitoleyl-1-lyso-phosphatidylethanolamine and the free fatty acids palmitoleic, palmitic and oleic acid, which are known to have an antimicrobial effect. As a result of tissue autolysis, the abundance of the free fatty acids increased with longer incubation time of trophosome samples. This correlated with an increasing growth inhibition of Bacillus subtilis and Listeria welshimeri, but not of the other bacterial strains. Therefore, the free fatty acids produced upon host degradation could be the cause of inhibition of at least these two bacterial strains. PMID:26730960

  1. Development of an enzymatic fish hydrolysate and its use in instant soup bases.

    Science.gov (United States)

    Gálvez, A; Morales de Léon, J; Bourges Rodríguez, H

    1985-12-01

    The successful conservation of fish products, at low costs, is a subject of special interest in the developing countries. Conscious of this fact, our group has been studying several fish conservation methods, such as autolysis with high salt concentrations, and has obtained a sauce of high nutritive value and long shelf life. Nevertheless, the reaction process takes from four to six months. In the study herein reported, the hydrolysis was accelerated and controlled by using the following enzymes: papain, HT proteolytic, and Brew (N) zyme. The hydrolysate was then mixed with cereals to prepare instant soups. As results indicated, the best hydrolysate was obtained with Brew (N) zyme at 50 degrees C and 8.30 hours. This hydrolysate contains 93.0 g/100 g crude protein with a protein efficiency ratio (PER) and a net protein utilization (NPU) of 60% that of casein's NPU as well as a content of 0.8% ether extract. The lowest-cost mixtures with the highest nutritive value were: hydrolysate-wheat-soymeal, and hydrolysate-rice-soymeal, with 38.3 and 29.7 protein per 100 g of mixture, respectively, and a NPU of 79.0 and 79.8% in relation to casein, respectively. The soups prepared had a satisfactory acceptance rating. There were no significant differences in flavor and aroma at a confidence level of 95%. The cost per gram of protein is about US$ 0.22 per kg. PMID:3842931

  2. Histopathologic ear findings of syphilis: a temporal bone study.

    Science.gov (United States)

    Hızlı, Ömer; Hızlı, Pelin; Kaya, Serdar; Monsanto, Rafael da Costa; Paparella, Michael M; Cureoglu, Sebahattin

    2016-09-01

    To the best of our knowledge, histopathologic studies of syphilitic ears have generally focused on hydropic changes; so far, no such studies have investigated peripheral vestibular otopathology using differential interference contrast microscopy, in patients with syphilis. For this study, we examined 13 human temporal bone samples from 8 patients with a history of syphilis. Using conventional light microscopy, we performed qualitative histopathologic assessment. In addition, using differential interference contrast microscopy, we performed type I and type II vestibular hair cell counts on each vestibular sense organ with minimal autolysis; in which the neuroepithelium was oriented perpendicular to the plane of section. We then compared vestibular hair cell densities (cells per 0.01 mm² surface area) in the syphilis group vs. the control group. In the syphilis group, we observed precipitate in the endolymphatic or perilymphatic spaces in 1 (7.7 %) of the samples and endolymphatic hydrops in eight (61.5 %) of the samples. Hydrops involved the cochlea (four samples) and/or saccule (four samples). In addition, the syphilis group experienced a significant loss of type II vestibular hair cells in the maculae of the utricle and saccule, and in the cristae of the lateral and posterior semicircular canals, as compared with the control group (P < 0.05). PMID:26573155

  3. AKTIVITAS ANTIBAKTERI DAN ANTIOKSIDAN HIDROLISAT HASIL HIDROLISIS PROTEIN SUSU KAMBING DENGAN EKSTRAK KASAR BROMELIN [Antibacterial and Antioxidant Activity of Hydrolysate from Goat Milk Protein Hydrolized by Crude Bromelain Extract

    Directory of Open Access Journals (Sweden)

    Eni Kusumaningtyas

    2015-12-01

    Full Text Available Goat milk is highly nutritious foodstuffs that beneficial for improving health. The milk contains bioactive peptides which produced by hydrolysis process. The aim of this study was to evaluate antibacterial and antioxidant activities of hydrolisate produced from hydrolysis of goat milk protein by crude bromelain extract. Hydrolysis of goat milk protein was conducted using crude bromelain (0.1 U/mL at pH 6, 50°C for 60 min. Hydrolysate was fractionated by using membrane molecular weight cut off 10 kDa. hydrolysate before and after fractionation were assayed for antibacterial and antioxidant activities. Toxicity of the Hydrolysate was determined by hemolysis assay. The result showed that the hydrolysate before and after fractionation inhibited growth of E. coli, S. Typhimurium and L. monocytogenes. Hydrolysate after fractionation has higher antibacterial activity indicated that fractionation was able to improve antibacterial activities of the hydrolysate fraction. The hydrolysate showed scavenging activity to ABTS and DPPH radicals. Fraction 10 kDa not only showed absence of hemolysis but also they were able to reduce autolysis of red blood cells. The result showed that hydrolysate from goat milk hydrolyzed by bromelain were able to be antibacterial and antioxidant.

  4. METACASPASE9 modulates autophagy to confine cell death to the target cells during Arabidopsis vascular xylem differentiation

    Directory of Open Access Journals (Sweden)

    Sacha Escamez

    2016-02-01

    Full Text Available We uncovered that the level of autophagy in plant cells undergoing programmed cell death determines the fate of the surrounding cells. Our approach consisted of using Arabidopsis thaliana cell cultures capable of differentiating into two different cell types: vascular tracheary elements (TEs that undergo programmed cell death (PCD and protoplast autolysis, and parenchymatic non-TEs that remain alive. The TE cell type displayed higher levels of autophagy when expression of the TE-specific METACASPASE9 (MC9 was reduced using RNAi (MC9-RNAi. Misregulation of autophagy in the MC9-RNAi TEs coincided with ectopic death of the non-TEs, implying the existence of an autophagy-dependent intercellular signalling from within the TEs towards the non-TEs. Viability of the non-TEs was restored when AUTOPHAGY2 (ATG2 was downregulated specifically in MC9-RNAi TEs, demonstrating the importance of autophagy in the spatial confinement of cell death. Our results suggest that other eukaryotic cells undergoing PCD might also need to tightly regulate their level of autophagy to avoid detrimental consequences for the surrounding cells.

  5. Characterization of an extensin-modifying metalloprotease: N-terminal processing and substrate cleavage pattern of Pectobacterium carotovorum Prt1

    DEFF Research Database (Denmark)

    Feng, Tao; Nyffenegger, Christian; Højrup, Peter;

    2014-01-01

    (EDTA) treatment abolished activity; Zn2+ addition caused regain of the activity, but Zn2+addition decreased the thermal stability of the Prt1 enzyme presumably as a result of increased proteolytic autolysis. In addition to casein, the enzyme catalyzed degradation of collagen, potato lectin, and plant......Compared to other plant cell wall-degrading enzymes, proteases are less well understood. In this study, the extracellular metalloprotease Prt1 from Pectobacterium carotovorum (formerly Erwinia carotovora) was expressed in Escherichia coli and characterized with respect to N-terminal processing......) fingerprinting and N-terminus analysis. The optimal reaction conditions for the activity of Prt1 on azocasein were at pH 6.0, 50 °C. At these reaction conditions, KM was 1.81 mg/mL and kcat was 1.82 × 107 U M-1. The enzyme was relatively stable at 50 °C with a half-life of 20 min. Ethylenediaminetetraacetic acid...

  6. The chemical nature of the carbon-14- labelled organic matter released into soil from growing wheat roots. Effects of soil micro-organisms

    International Nuclear Information System (INIS)

    Individual wheat plants were grown in a sandy soil under an atmosphere of 14CO2 for 21 days with the plant roots maintained under sterile or non-sterile conditions. A comparison has been made of the chemical nature of the 14C-labelled organic matter present in root-free soil from the sterile and non-sterile treatments, based on solubility, molecular size and ion-exchange chromatography of soil extracts and acid hydrolysates of whole soil. There was little difference between sterile and non-sterile soils for the values from any of these determinations. It is proposed that a major part of the organic 14C present in soils from both treatments resulted from autolysis of root tissue, particularly in localized zones where low water availability may have limited microbial decomposition of sugars and amino acids released from the roots. About 15% of the 14C in both soil treatments was present in humic acid fractions with a molecular weight, estimated from ultrafiltration of >5X104. These experiments show that there can be a significant formation of soil organic matter during active root growth, much of it directly from root tissue without the intervention of soil microflora or microfauna. Such reactions would be important in nutrient cycling in permanent pastures and forests, and in the interchange of nutrients in grass/legume associations. (author)

  7. Multimodal Raman-fluorescence spectroscopy of formalin fixed samples is able to discriminate brain tumors from dysplastic tissue

    Science.gov (United States)

    Anand, Suresh; Cicchi, Riccardo; Giordano, Flavio; Buccoliero, Anna Maria; Pavone, Francesco Saverio

    2014-05-01

    In the recent years, there has been a considerable surge in the application of spectroscopy for disease diagnosis. Raman and fluorescence spectra provide characteristic spectral profile related to biochemical and morphological changes when tissues progress from normal state towards malignancy. Spectroscopic techniques offer the advantage of being minimally invasive compared to traditional histopathology, real time and quantitative. In biomedical optical diagnostics, freshly excised specimens are preferred for making ex-vivo spectroscopic measurements. With regard to fresh tissues, if the lab is located far away from the clinic it could pose a problem as spectral measurements have to be performed immediately after dissection. Tissue samples are usually placed in a fixative agent such as 4% formaldehyde to preserve the samples before processing them for routine histopathological studies. Fixation prevents the tissues from decomposition by arresting autolysis. In the present study, we intend to investigate the possibility of using formalin fixed samples for discrimination of brain tumours from dysplastic tissue using Raman and fluorescence spectroscopy. Formalin fixed samples were washed with phosphate buffered saline for about 5 minutes in order to remove the effects of formalin during spectroscopic measurements. In case of fluorescence spectroscopy, changes in spectral profile have been observed in the region between 550-670 nm between dysplastic and tumor samples. For Raman measurements, we found significant differences in the spectral profiles between dysplasia and tumor. In conclusion, formalin fixed samples can be potentially used for the spectroscopic discrimination of tumor against dysplastic tissue in brain samples.

  8. Storage stability and improved quality of fish products by enzyme suppression and gamma-irradiation

    International Nuclear Information System (INIS)

    The occurrence and distribution of lysosomal hydrolases in the skeletal muscle and skin of a variety of fish species have been demonstrated. As compared with the skeletal muscle, the skin contained two to ten times more activity of hydrolytic enzymes. In the case of Bombay duck (Harpodon nehereus), the drip represented a rich source of lysosomal enzymes. The involvement of these hydrolases in accentuating fish spoilage was examined by measuring the release of cathepsin D and accumulated hydrolytic end-products during progressive autolysis. The data showed that the shelf-life of fresh-water fish Tilapia mossambica could be extended by removing the skin, while that of Bombay duck by eliminating drip. Sodium tripolyphosphate (NaTPP) dip treatment was shown to inhibit the activity of lysosomal hydrolases of Bombay duck. Combination treatment consisting of NaTPP dip and irradiation (100 krad) resulted in a two-week extension in the shelf-life of Bombay duck fillets when stored at 0-40C. (author)

  9. Storage Stability and Improved Quality of Fish Products by Enzyme Suppression and Gamma Irradiation

    International Nuclear Information System (INIS)

    The occurrence and distribution of lysosomal hydrolases in the skeletal muscle and skin of a variety of fish species have been demonstrated. As compared with the skeletal muscle, the skin contained two to ten times more activity of hydrolytic enzymes. In the case of Bombay duck (Harpodon nehereus), the drip represented a rich source of lysosomal enzymes. The involvement of these hydrolases in accentuating fish spoilage was examined by measuring the release of cathepsin D and accumulated hydrolytic end-products during progressive autolysis. The data showed that the shelf-life of fresh-water fish Tilapia mossambica could be extended by removing the skin, while that of Bombay duck by eliminating drip. Sodium tripolyphosphate (NaTPP) dip treatment was shown to inhibit the activity of lysosomal hydrolases of Bombay duck. Combination treatment consisting NaTPP dip and irradiation (100 krad) resulted in a two-week extension in the shelf-life of Bombay duck fillets when stored at 0-4°C. (author)

  10. Population dynamics of mixed cultures of yeast and lactic acid bacteria in cider conditions

    Directory of Open Access Journals (Sweden)

    Leila Roseli Dierings

    2013-10-01

    Full Text Available The objective of this work was to study the malolactic bioconversion in low acidity cider, according Brazilian conditions. The apple must was inoculated with Saccharomyces cerevisiae or S. cerevisiae with Oenococcus oeni. The control contained the indigenous microorganisms. Fermentation assays were carried out with clarified apple must from the Gala variety. At the beginning of fermentation, there was a fast growth of the non-Saccharomyces yeast population. Competitive inhibition occurred in all the assays, either with inoculated or indigenous populations of the yeast. The lactic acid bacteria count was ca. 1.41·10²CFU/mL at the beginning and 10(6CFU/mL after yeast cells autolysis. The lactic bacteria O. oeni reached the highest population (10(7CFU/mL when added to the apple must after the decline of the yeast. The malic acid was totally consumed during the alcoholic fermentation period (80.0 to 95.5 % and lactic acid was still synthesized during the 35 days of malolactic fermentation. These results could be important in order to achieve a high quality brut, or sec cider obtained from the dessert apple must.

  11. Sea Cucumber-Inspired Autolytic Hydrogels Exhibiting Tunable High Mechanical Performances, Repairability, and Reusability.

    Science.gov (United States)

    Gao, Fei; Zhang, Yinyu; Li, Yongmao; Xu, Bing; Cao, Zhiqiang; Liu, Wenguang

    2016-04-13

    Inspired by stimuli-responsive remarkable changes in consistency (hardening, softening, autolysis) of sea cucumbers, we synthesized a supramolecular polymer(SP) hydrogel directly by photoinitiated aqueous polymerization of N-acryloyl 2-glycine monomer bearing one amide and one carboxyl group on the side chain. The SP hydrogels doped with Ca(2+) demonstrated excellent mechanical properties-high tensile strength (∼1.3 MPa), large stretchability (up to 2300%), high compressive strength (∼10.8 MPa), and good toughness (∼1000 J m(-2)) due to cooperative hydrogen bonding interactions from amide and carboxyl together with Ca(2+) cross-linking. Responding to the change in pH and Ca(2+) concentration, the hydrogels could modulate their network stability and mechanical properties: at pH3.0 and higher Ca(2+) content, the hydrogel formed low swelling network which was stiff and stable; in alkaline or neutral buffer with lower content of or without Ca(2+), the hydrogel formed a highly swollen transient network, which was soft and eventually autolyzed. The reversible multiple noncovalent bonds enabled the hydrogels to achieve thermoplasticity, self-healability, and reusability. Notably, distinct formulations of hydrogels could be welded together under heating to form a gradient hydrogel. In vitro cytotoxicity assay and subcutaneous implantation indicated that the SP hydrogels were biocompatible and autolytic in vivo. The SP hydrogels may find applications as temporary biodevices for intestinal drug delivery or for injectable filling in assisting suturing small vessels. PMID:27014865

  12. Thermostable trypsin conjugates immobilized to biogenic magnetite show a high operational stability and remarkable reusability for protein digestion

    International Nuclear Information System (INIS)

    In this work, magnetosomes produced by microorganisms were chosen as a suitable magnetic carrier for covalent immobilization of thermostable trypsin conjugates with an expected applicability for efficient and rapid digestion of proteins at elevated temperatures. First, a biogenic magnetite was isolated from Magnetospirillum gryphiswaldense and its free surface was coated with the natural polysaccharide chitosan containing free amino and hydroxy groups. Prior to covalent immobilization, bovine trypsin was modified by conjugating with α-, β- and γ-cyclodextrin. Modified trypsin was bound to the magnetic carriers via amino groups using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysulfosuccinimide as coupling reagents. The magnetic biomaterial was characterized by magnetometric analysis and electron microscopy. With regard to their biochemical properties, the immobilized trypsin conjugates showed an increased resistance to elevated temperatures, eliminated autolysis, had an unchanged pH optimum and a significant storage stability and reusability. Considering these parameters, the presented enzymatic system exhibits properties that are superior to those of trypsin forms obtained by other frequently used approaches. The proteolytic performance was demonstrated during in-solution digestion of model proteins (horseradish peroxidase, bovine serum albumin and hen egg white lysozyme) followed by mass spectrometry. It is shown that both magnetic immobilization and chemical modification enhance the characteristics of trypsin making it a promising tool for protein digestion. (paper)

  13. Conformational flexibility in the catalytic triad revealed by the high-resolution crystal structure of Streptomyces erythraeus trypsin in an unliganded state

    International Nuclear Information System (INIS)

    This work reports the first sub-angstrom resolution structure of S. erythraeus trypsin. The detailed model of a prototypical serine protease at a catalytically relevant pH with an unoccupied active site is presented and is compared with other high-resolution serine protease structures. With more than 500 crystal structures determined, serine proteases make up greater than one-third of all proteases structurally examined to date, making them among the best biochemically and structurally characterized enzymes. Despite the numerous crystallographic and biochemical studies of trypsin and related serine proteases, there are still considerable shortcomings in the understanding of their catalytic mechanism. Streptomyces erythraeus trypsin (SET) does not exhibit autolysis and crystallizes readily at physiological pH; hence, it is well suited for structural studies aimed at extending the understanding of the catalytic mechanism of serine proteases. While X-ray crystallographic structures of this enzyme have been reported, no coordinates have ever been made available in the Protein Data Bank. Based on this, and observations on the extreme stability and unique properties of this particular trypsin, it was decided to crystallize it and determine its structure. Here, the first sub-angstrom resolution structure of an unmodified, unliganded trypsin crystallized at physiological pH is reported. Detailed structural analysis reveals the geometry and structural rigidity of the catalytic triad in the unoccupied active site and comparison to related serine proteases provides a context for interpretation of biochemical studies of catalytic mechanism and activity

  14. Conformational flexibility in the catalytic triad revealed by the high-resolution crystal structure of Streptomyces erythraeus trypsin in an unliganded state

    Energy Technology Data Exchange (ETDEWEB)

    Blankenship, Elise; Vukoti, Krishna [Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106 (United States); Miyagi, Masaru, E-mail: mxm356@cwru.edu [Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106 (United States); Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106 (United States); Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106 (United States); Lodowski, David T., E-mail: mxm356@cwru.edu [Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106 (United States); Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106 (United States)

    2014-03-01

    This work reports the first sub-angstrom resolution structure of S. erythraeus trypsin. The detailed model of a prototypical serine protease at a catalytically relevant pH with an unoccupied active site is presented and is compared with other high-resolution serine protease structures. With more than 500 crystal structures determined, serine proteases make up greater than one-third of all proteases structurally examined to date, making them among the best biochemically and structurally characterized enzymes. Despite the numerous crystallographic and biochemical studies of trypsin and related serine proteases, there are still considerable shortcomings in the understanding of their catalytic mechanism. Streptomyces erythraeus trypsin (SET) does not exhibit autolysis and crystallizes readily at physiological pH; hence, it is well suited for structural studies aimed at extending the understanding of the catalytic mechanism of serine proteases. While X-ray crystallographic structures of this enzyme have been reported, no coordinates have ever been made available in the Protein Data Bank. Based on this, and observations on the extreme stability and unique properties of this particular trypsin, it was decided to crystallize it and determine its structure. Here, the first sub-angstrom resolution structure of an unmodified, unliganded trypsin crystallized at physiological pH is reported. Detailed structural analysis reveals the geometry and structural rigidity of the catalytic triad in the unoccupied active site and comparison to related serine proteases provides a context for interpretation of biochemical studies of catalytic mechanism and activity.

  15. Thermostable trypsin conjugates immobilized to biogenic magnetite show a high operational stability and remarkable reusability for protein digestion

    Science.gov (United States)

    Pečová, M.; Šebela, M.; Marková, Z.; Poláková, K.; Čuda, J.; Šafářová, K.; Zbořil, R.

    2013-03-01

    In this work, magnetosomes produced by microorganisms were chosen as a suitable magnetic carrier for covalent immobilization of thermostable trypsin conjugates with an expected applicability for efficient and rapid digestion of proteins at elevated temperatures. First, a biogenic magnetite was isolated from Magnetospirillum gryphiswaldense and its free surface was coated with the natural polysaccharide chitosan containing free amino and hydroxy groups. Prior to covalent immobilization, bovine trypsin was modified by conjugating with α-, β- and γ-cyclodextrin. Modified trypsin was bound to the magnetic carriers via amino groups using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysulfosuccinimide as coupling reagents. The magnetic biomaterial was characterized by magnetometric analysis and electron microscopy. With regard to their biochemical properties, the immobilized trypsin conjugates showed an increased resistance to elevated temperatures, eliminated autolysis, had an unchanged pH optimum and a significant storage stability and reusability. Considering these parameters, the presented enzymatic system exhibits properties that are superior to those of trypsin forms obtained by other frequently used approaches. The proteolytic performance was demonstrated during in-solution digestion of model proteins (horseradish peroxidase, bovine serum albumin and hen egg white lysozyme) followed by mass spectrometry. It is shown that both magnetic immobilization and chemical modification enhance the characteristics of trypsin making it a promising tool for protein digestion.

  16. Lysis of tubercle bacilli in fresh and stored sputum specimens: implications for diagnosing tuberculosis in stored and paucibacillary specimens by PCR

    Directory of Open Access Journals (Sweden)

    Chakravorty Soumitesh

    2007-09-01

    Full Text Available Abstract Background Nucleic acid amplification techniques are being used increasingly in diagnosing tuberculosis. In developing countries clinical samples are often stored for subsequent analysis since molecular tests are conducted at only a limited number of laboratories. This study was conducted to assess the speed at which mycobacteria undergo autolysis and free DNA is detected in the supernatant during low-temperature storage. Results Eighty-seven smear positive sputa from tuberculosis patients were analysed immediately and after storage at -20°C. Timelines of 1 and 2 months were selected to assess the maximum extent of DNA loss that occurred during storage. All samples remained PCR- and smear-positive at 1 month and only 1 sample turned negative after 2 months. Bacterial lysis in the specimens was demonstrated by PCR analysis of supernatant fractions; 53% of the freshly analysed samples contained mycobacterial DNA in supernatants. PCR positivity increased significantly during storage (to 69% and 77% after 1 and 2 months of storage, respectively, P Conclusion We conclude that (i freshly isolated sputum contains both intact and lysed mycobacteria, (ii lysis increased during storage and (iii supernatant fractions routinely discarded during sample processing contain mycobacterial DNA. We propose that supernatant is a valuable sample for PCR for both fresh and stored specimens, particularly those with a low bacterial load in addition to conventional sediment.

  17. Food irradiation and sterilization

    Science.gov (United States)

    Josephson, Edward S.

    Radiation sterilization of food (radappertization) requires exposing food in sealed containers to ionizing radiation at absorbed doses high enough (25-70 kGy) to kill all organisms of food spoilage and public health significance. Radappertization is analogous to thermal canning is achieving shelf stability (long term storage without refrigeration). Except for dry products in which autolysis is negligible, the radappertization process also requires that the food be heated to an internal temperature of 70-80°C (bacon to 53°C) to inactivate autolytic enzymes which catalyze spoilage during storage without refrigeration. To minimize the occurence of irradiation induced off-flavors and odors, undesirable color changes, and textural and nutritional losses from exposure to the high doses required for radappertization, the foods are vacuum sealed and irradiated frozen (-40°C to -20°C). Radappertozed foods have the characteristic of fresh foods prepared for eating. Radappertization can substitute in whole or in part for some chemical food additives such as ethylene oxide and nitrites which are either toxic, carcinogenic, mutagenic, or teratogenic. After 27 years of testing for "wholesomeness" (safety for consumption) of radappertized foods, no confirmed evidence has been obtained of any adverse effecys of radappertization on the "wholesomeness" characteristics of these foods.

  18. Food irradiation and sterilization

    International Nuclear Information System (INIS)

    Radiation sterilization of food (radappertization) requires exposing food in sealed containers to ionizing radiation at absorbed doses high enough (25 to 70 kGy) to kill all organisms of food spoilage and public health significance. Radappertization is analogous to thermal canning in achieving shelf stability (long term storage without refrigeration). Except for dry products in which autolysis is negligible, the radappertization process also requires that the food be heated to an internal temperature of 70 to 800C (bacon to 530C) to inactivate autolytic enzymes which catalyze spoilage during storage without refrigeration. To minimize the occurrence of irradiation induced off-flavors and odors, undesirable color changes, and textural and nutritional losses from exposure to the high doses required for radappertization, the foods are vacuum sealed and irradiated frozen (-400C to -200C). Radappertized foods have the characteristic of fresh foods prepared for eating. Radappertization can substitute in whole or in part for some chemical food additives such as ethylene oxide and nitrites which are either toxic, carcinogenic, mutagenic, or teratogenic. After 27 years of testing for 'wholesomeness' (safety for consumption) of radappertized foods, no confirmed evidence has been obtained of any adverse effects of radappertization on the 'wholesomeness' characteristics of these foods. (author)

  19. Ionizing radiation effect on enzymes. III

    International Nuclear Information System (INIS)

    A decrease in the efficacy of trypsin (determination according to PhBs 3 with the use of L-lysine ethyl ester chloride) was investigated in pancreatin obtained by enzyme precipitation from a pancreas extraction after autolysis, in the identical sample with an additionally increased content of lipids, in pancreatin containing parts of the pancreatic tissue, in crystalline trypsin, and in crystalline salt-free and lyophilized trypsine after irradiation with gamma rays from 60Co, doses ranging from 1x104 Gy to 12x104 Gy. The results were statistically evaluated and after the conversion to dried or lipid-free substance expressed in graphs. The dependence of the efficacy on the radiation dose has a linear course in semi-logarithmic arrangement, similarly as it occurred in chymotrypsin and in the total proteolytic efficacy. The decrease in the efficacy of trypsin in the samples of pancreatin in percentage maintains the same sequence in the samples under study as it was in the decrease in the efficacy of chymotrypsin and the total proteolytic efficacy, but it is smaller. The decrease in the efficacy of pure enzyme is, similarly to chymotrypsin, greater than the decrease in the efficacy of the enzyme in pancreatin. The present ballast substances thus significantly influence stability. (author)

  20. Ionizing radiation effect on enzymes. IV

    International Nuclear Information System (INIS)

    The effect was studied of 60Co gamma radiation on the total proteolytic efficacy of pancreatin with gradually differentiated humidity, both in a preparation obtained by separating the active ingredients from an extract from the pancreas destroyed by autolysis, and in a preparation containing the remains of the pancreatic tissue, where the basic operation of manufacture was drying of the ground pancreas. The samples were irradiated with doses of 2.5x104 and 12x104, or 14.2x104 Gy. The mean values found of the residual proteolytic efficacy expressed in the units of PhBs 3, calculated to the dried substance, are tabulated. At the same time the efficacy of samples before irradiation was tested. The evaluation of results included in the individual tables by variance analysis and Lord's u-test shows that there is no statistically significant difference between the mean values of the efficacy of samples with the initial humidity and the samples with increased humidity (maximally 16.20%). (author)

  1. Growth phase-dependent composition of the Helicobacter pylori exoproteome.

    Science.gov (United States)

    Snider, Christina A; Voss, Bradley J; McDonald, W Hayes; Cover, Timothy L

    2016-01-01

    Helicobacter pylori colonizes the human stomach and is associated with an increased risk of gastric cancer and peptic ulcer disease. Analysis of H. pylori protein secretion is complicated by the occurrence of bacterial autolysis. In this study, we analyzed the exoproteome of H. pylori at multiple phases of bacterial growth and identified 74 proteins that are selectively released into the extracellular space. These include proteins known to cause alterations in host cells, antigenic proteins, and additional proteins that have not yet been studied in any detail. The composition of the H. pylori exoproteome is dependent on the phase of bacterial growth. For example, the proportional abundance of the vacuolating toxin VacA in culture supernatant is higher during late growth phases than early growth phases, whereas the proportional abundance of many other proteins is higher during early growth phases. We detected marked variation in the subcellular localization of putative secreted proteins within soluble and membrane fractions derived from intact bacteria. By providing a comprehensive view of the H. pylori exoproteome, these results provide new insights into the array of secreted H. pylori proteins that may cause alterations in the gastric environment. PMID:26363098

  2. Supercritical fluid chromatography as a method of analysis for the determination of 4-hydroxybenzylglucosinolate degradation products.

    Science.gov (United States)

    Buskov, S; Hasselstrøm, J; Olsen, C E; Sørensen, H; Sørensen, J C; Sørensen, S

    2000-07-01

    In the present study analytical and preparative supercritical fluid chromatography (SFC) were used for investigation of myrosinase catalysed degradation of 4-hydroxybenzylglucosinolate (sinalbin). Sinalbin occurs as a major glucosinolate in seeds of Sinapis alba L., in various mustards and other food products. The degradation products were identified and quantified by analysis based on a developed SFC method using a bare silica column. Determinations comprised transformation products of sinalbin, produced both during degradation of isolated sinalbin, and during autolysis of meal from S. alba seeds. The conditions in the developed SFC method were used as basis for the preparative SFC procedure applied for isolation of the components prior to their identification by nuclear magnetic resonance (NMR) spectroscopy. Myrosinase catalysed sinalbin hydrolysis resulted in the reactive 4-hydroxybenzyl isothiocyanate as an initial product at pH values from 3.5 to 7.5 whereas 4-hydroxybenzyl cyanide was one of the major products at low pH values. 4-Hydroxybenzyl isothiocyanate was found to disappear from the aqueous reaction mixtures in a few hours, as it reacted easily with available nucleophilic reagents. 4-Hydroxybenzyl alcohol was found as the product from reaction with water, and with ascorbic acid, 4-hydroxybenzylascorbigen was produced. PMID:10869674

  3. The Thanatomicrobiome: A Missing Piece of the Microbial Puzzle of Death.

    Science.gov (United States)

    Javan, Gulnaz T; Finley, Sheree J; Abidin, Zain; Mulle, Jennifer G

    2016-01-01

    Death is a universal phenomenon; however, is there "life after death?" This topic has been investigated for centuries but still there are gray areas that have yet to be elucidated. Forensic microbiologists are developing new applications to investigate the dynamic and coordinated changes in microbial activity that occur when a human host dies. There is currently a paucity of explorations of the thanatomicrobiome (thanatos-, Greek for death) and epinecrotic communities (microbial communities residing in and/or moving on the surface of decomposing remains). Ongoing studies can help clarify the structure and function of these postmortem microbiomes. Human microbiome studies have revealed that 75-90% of cells in the body prior to death are microbial. Upon death, putrefaction occurs and is a complicated process encompassing chemical degradation and autolysis of cells. Decomposition also involves the release of contents of the intestines due to enzymes under the effects of abiotic and biotic factors. These factors likely have predictable effects on postmortem microbial communities and can be leveraged for forensic studies. This mini review provides a critical examination of emerging research relating to thanatomicrobiome and epinecrotic communities, how each is studied, and possible strategies of stochastic processes. PMID:26941736

  4. The Thanatomicrobiome: A Missing Piece of the Microbial Puzzle of Death

    Directory of Open Access Journals (Sweden)

    Gulnaz T Javan

    2016-02-01

    Full Text Available Death is a universal phenomenon; however, is there life after death? This topic has been investigated for centuries but still there are grey areas that have yet to be elucidated. Forensic microbiologists are developing new applications to investigate the dynamic and coordinated changes in microbial activity that occur when a human host dies. There is currently a paucity of explorations of the thanatomicrobiome (thanatos-, Greek for death and epinecrotic communities (microbial communities residing in and/or moving on the surface of decomposing remains. Ongoing studies can help clarify the structure and function of these postmortem microbiomes. Human microbiome studies have revealed that 75-90% of cells in the body prior to death are microbial. Upon death, putrefaction occurs and is a complicated process encompassing chemical degradation and autolysis of cells. Decomposition also involves the release of contents of the intestines due to enzymes under the effects of abiotic and biotic factors. These factors likely have predictable effects on postmortem microbial communities and can be leveraged for forensic studies. This mini review provides a critical examination of emerging research relating to thanatomicrobiome and epinecrotic communities, how each is studied, and possible strategies of stochastic processes.

  5. Metarhizium anisopliae pathogenesis of mosquito larvae: a verdict of accidental death.

    Science.gov (United States)

    Butt, Tariq M; Greenfield, Bethany P J; Greig, Carolyn; Maffeis, Thierry G G; Taylor, James W D; Piasecka, Justyna; Dudley, Ed; Abdulla, Ahmed; Dubovskiy, Ivan M; Garrido-Jurado, Inmaculada; Quesada-Moraga, Enrique; Penny, Mark W; Eastwood, Daniel C

    2013-01-01

    Metarhizium anisopliae, a fungal pathogen of terrestrial arthropods, kills the aquatic larvae of Aedes aegypti, the vector of dengue and yellow fever. The fungus kills without adhering to the host cuticle. Ingested conidia also fail to germinate and are expelled in fecal pellets. This study investigates the mechanism by which this fungus adapted to terrestrial hosts kills aquatic mosquito larvae. Genes associated with the M. anisopliae early pathogenic response (proteinases Pr1 and Pr2, and adhesins, Mad1 and Mad2) are upregulated in the presence of larvae, but the established infection process observed in terrestrial hosts does not progress and insecticidal destruxins were not detected. Protease inhibitors reduce larval mortality indicating the importance of proteases in the host interaction. The Ae. aegypti immune response to M. anisopliae appears limited, whilst the oxidative stress response gene encoding for thiol peroxidase is upregulated. Cecropin and Hsp70 genes are downregulated as larval death occurs, and insect mortality appears to be linked to autolysis through caspase activity regulated by Hsp70 and inhibited, in infected larvae, by protease inhibitors. Evidence is presented that a traditional host-pathogen response does not occur as the species have not evolved to interact. M. anisopliae retains pre-formed pathogenic determinants which mediate host mortality, but unlike true aquatic fungal pathogens, does not recognise and colonise the larval host. PMID:24349111

  6. Evaluation of Streptococcus pneumoniae in bile samples: A case series review.

    Science.gov (United States)

    Itoh, Naoya; Kawamura, Ichiro; Tsukahara, Mika; Mori, Keita; Kurai, Hanako

    2016-06-01

    Although Streptococcus pneumoniae is an important pathogen of humans, pneumococcal cholangitis is rare because of the rapid autolysis of S. pneumoniae. The aim of this case series was to review patients with bile cultures positive for S. pneumoniae. This study was a single center retrospective case series review of patients with S. pneumoniae in their bile at a tertiary-care cancer center between September 2002 and August 2015. Subjects consisted of all patients in whom S. pneumoniae was isolated in their bile during the study period. Bile specimens for culture were obtained from biliary drainage procedures such as endoscopic retrograde biliary drainage, endoscopic nasobiliary drainage, and percutaneous transhepatic biliary drainage. There were 20 patients with bile cultures positive for S. pneumoniae during the study period. All patients presented with extrahepatic obstructive jaundice due to hepatopancreatobiliary tumors. Nineteen of 20 patients underwent the placement of plastic intrabiliary tubes. The mean time between the first-time drainage and the positive culture was 26 days (range 0-313 days). Although 12 of 20 patients met our definition of cholangitis, 5 were clinically treated with antibiotics based on a physician's assessment of whether there was a true infection. The present study is the largest case series of patients with S. pneumoniae in their bile. Based on our findings, the isolation of S. pneumoniae from bile may be attributed to the placement of biliary drainage devices. PMID:27025902

  7. Expression of ogu cytoplasmic male sterility in cybrids of Brassica napus.

    Science.gov (United States)

    Gourret, J P; Delourme, R; Renard, M

    1992-03-01

    A light and electron microscopic investigation revealed that ogu cytoplasmic male sterility (CMS) in cybrids of Brassica napus is primarily a deficiency of the tapetum and clearly time and site specific. Three patterns of ogu CMS were found, and specific conclusions drawn. First, the partially male fertile cybrid 23 was highly variable. It sometimes produced heterogeneous stamens with an endothecium formed exclusively around the fertile locules, thus delineating each microsporangium as a functional unit. The second type, including cybrids 27, 58 and 85, on the contrary, was stable and completely male sterile. In the four locules of normal length, microspores were observed to die at the vacuolate polarized stage while the tapetum disappeared prematurely through excessive vacuolization by the end of meiosis followed by a rapid autolysis during the tetrad or early free microspore stage. The subepidermal layer of the locule wall failed to form characteristic thickenings. The male-sterile stamens were completely indehiscent. At the time of anthesis they contained only collapsed empty exines adhering to each other. These cybrids, 27, 58 and 85, were closest to the ogu CMS trait of radish and seemed to be the best suited for further use in plant breeding. The third pattern was found in cybrids 77 and 118, which besides showing abortion of the microsporangia also showed a feminization of the stamens. We suggest that this feminization might be due to an alloplasmic situation associating Brassica napus nuclear genes with the mitochondrial DNA of radish. PMID:24202671

  8. Experimentally caused proliferation of lysosomes in cultured BHK cells involving an increase of biphosphatidic acids and triglycerides.

    Science.gov (United States)

    Brotherus, J; Niinioja, T; Sandelin, K; Renkonen, O

    1977-05-01

    When cultured hamster fibroblasts (BHK 21 cells) were incubated in a synthetic serum-free medium up to 4 days, they developed signs of a progressive proliferation of lysosomes. The cells became filled with vacuoles that contained polymorphic debris and showed acid phosphatase activity. The specific activities of acid protease and acid phosphatase in the cell cultures increased three- to fourfold. The process was accompanied by a marked decrease in the contents of protein, deoxyribonucleic acid, and total phospholipids of the cultures. The concentration of lysobisphosphatidic acid increased during the incubation from about 1.5% to 3-6% of the cellular phospholipids. The concentrations of two related lipids, bisphosphatidic acid and semilysobisphosphatidic acid also increased substantially. The triglyceride content of the cells increased several fold, whereas the concentration of phosphatidylcholine decreased markedly. Lysobisphosphatidic acid did not increase upon induction of vacuolization by exogenous sucrose, nor when there was an accumulation of triglyceride due to addition of oleic acid to the growth medium. These findings suggest that the formation of the bisphosphatidic acids may be specifically linked to the autolysis of the phospholipids of the cellular membranes and the formation of triglycerides associated with this process. PMID:864326

  9. Potential of lees from wine, beer and cider manufacturing as a source of economic nutrients: An overview.

    Science.gov (United States)

    Pérez-Bibbins, B; Torrado-Agrasar, A; Salgado, J M; Oliveira, R Pinheiro de Souza; Domínguez, J M

    2015-06-01

    Lees are the wastes generated during the fermentation and aging processes of different industrial activities concerning alcoholic drinks such as wine, cider and beer. They must be conveniently treated to avoid uncontrolled dumping which causes environmental problems due to their high content of phenols, pesticides, heavy metals, and considerable concentrations of nitrogen, phosphate and potassium as well as high organic content. The companies involved must seek alternative environmental and economic physicochemical and biological treatments for their revalorization consisting in the recovery or transformation of the components of the lees into high value-added compounds. After describing the composition of lees and market of wine, beer and cider industries in Spain, this work aims to review the recent applications of wine, beer and cider lees reported in literature, with special attention to the use of lees as an endless sustainable source of nutrients and the production of yeast extract by autolysis or cell disruption. Lees and/or yeast extract can be used as nutritional supplements with potential exploitation in the biotechnological industry for the production of natural compounds such as xylitol, organic acids, and biosurfactants, among others. PMID:25824282

  10. Biochemical analysis of granzyme H and elucidation of its structurally important residues involved in substrate and inhibitor binding

    Institute of Scientific and Technical Information of China (English)

    Naheed Z Razwi; Rukhshan Khurshid; Mahjabeen Saleem; Sabiha Karim; Saeed Ahmad Nagra; Asmat Salim

    2012-01-01

    Apoptotic cell death plays an important role in the maintenance of the normal physiological state and in the pathogenesis of diseases.Granule exocytosis is the main pathway for the immune elimination of virus-infected cells and tumor cells by cytotoxic T lymphocytes and natural killer cells.In recent study,we have investigated the level of granzyme H in patients with breast cancer and in control subjects using enzymatic method.Our study also included the prediction of different sites of granzyme H that play a role in substrate and inhibitor recognition in apoptosis process by using 3D structural model of the enzyme.The research described the possible post-translational modification sites that may help the enzyme in immune elimination of tumor cells.Our study shows that the level of granzyme H was reduced in patients when compared to normal control subjects.There are a number of amino acids that function as substrate recognition sites in granzyme H.However,inhibitors may inhibit their activity and affect the process of autolysis.

  11. A fungal biofilm reactor based on metal structured packing improves the quality of a Gla::GFP fusion protein produced by Aspergillus oryzae.

    Science.gov (United States)

    Zune, Q; Delepierre, A; Gofflot, S; Bauwens, J; Twizere, J C; Punt, P J; Francis, F; Toye, D; Bawin, T; Delvigne, F

    2015-08-01

    Fungal biofilm is known to promote the excretion of secondary metabolites in accordance with solid-state-related physiological mechanisms. This work is based on the comparative analysis of classical submerged fermentation with a fungal biofilm reactor for the production of a Gla::green fluorescent protein (GFP) fusion protein by Aspergillus oryzae. The biofilm reactor comprises a metal structured packing allowing the attachment of the fungal biomass. Since the production of the target protein is under the control of the promoter glaB, specifically induced in solid-state fermentation, the biofilm mode of culture is expected to enhance the global productivity. Although production of the target protein was enhanced by using the biofilm mode of culture, we also found that fusion protein production is also significant when the submerged mode of culture is used. This result is related to high shear stress leading to biomass autolysis and leakage of intracellular fusion protein into the extracellular medium. Moreover, 2-D gel electrophoresis highlights the preservation of fusion protein integrity produced in biofilm conditions. Two fungal biofilm reactor designs were then investigated further, i.e. with full immersion of the packing or with medium recirculation on the packing, and the scale-up potentialities were evaluated. In this context, it has been shown that full immersion of the metal packing in the liquid medium during cultivation allows for a uniform colonization of the packing by the fungal biomass and leads to a better quality of the fusion protein. PMID:25935344

  12. Correlative and dynamic imaging of the hatching biology of Schistosoma japonicum from eggs prepared by high pressure freezing.

    Directory of Open Access Journals (Sweden)

    Malcolm K Jones

    Full Text Available BACKGROUND: Schistosome eggs must traverse tissues of the intestine or bladder to escape the human host and further the life cycle. Escape from host tissues is facilitated by secretion of immuno-reactive molecules by eggs and the formation of an intense strong granulomatous response by the host which acts to exclude the egg into gut or bladder lumens. Schistosome eggs hatch on contact with freshwater, but the mechanisms of activation and hatching are poorly understood. In view of the lack of knowledge of the behaviour of egg hatching in schistosomes, we undertook a detailed dynamic and correlative study of the hatching biology of Schistosoma japonicum. METHODOLOGY/PRINCIPAL FINDINGS: Hatching eggs of S. japonicum were studied using correlative light and electron microscopy (EM. The hatching behaviour was recorded by video microscopy. EM preparative methods incorporating high pressure freezing and cryo-substitution were used to investigate ultrastructural features of the miracidium and extra-embryonic envelopes in pre-activated and activated eggs, and immediately after eggshell rupture. Lectin cytochemistry was performed on egg tissues to investigate subcellular location of specific carbohydrate groups. CONCLUSIONS/SIGNIFICANCE: The hatching of S. japonicum eggs is a striking phenomenon, whereby the larva is liberated explosively while still encapsulated within its sub-shell envelopes. The major alterations that occur in the egg during activation are scission of the outer envelope-eggshell boundary, autolysis of the cellular inner envelope, and likely hydration of abundant complex and simple polysaccharides in the lacunal space between the miracidial larva and surrounding envelopes. These observations on hatching provide insight into the dynamic activity of the eggs and the biology of schistosomes within the host.

  13. Developing a sustainable bioprocessing strategy based on a generic feedstock.

    Science.gov (United States)

    Webb, C; Koutinas, Wang R; Wang, R

    2004-01-01

    Based on current average yields of wheat per hectare and the saccharide content of wheat grain, it is feasible to produce wheat-based alternatives to many petrochemicals. However, the requirements in terms of wheat utilization would be equivalent to 82% of current production if intermediates and primary building blocks such as ethylene, propylene, and butadiene were to be produced in addition to conventional bioproducts. If only intermediates and bioproducts were produced this requirement would fall to just 11%, while bioproducts alone would require only 7%. These requirements would be easily met if the global wheat yield per hectare of cultivated land was increased from the current average of 2.7 to 5.5 tonnes ha(-1) (well below the current maximum). Preliminary economic evaluation taking into account only raw material costs demonstrated that the use of wheat as a generic feedstock could be advantageous in the case of bioproducts and specific intermediate petrochemicals. Gluten plays a significant role considering the revenue occurring when it is sold as a by-product. A process leading to the production of a generic fermentation feedstock from wheat has been devised and evaluated in terms of efficiency and economics. This feedstock aims at providing a replacement for conventional fermentation media and petrochemical feedstocks. The process can be divided into four major stages--wheat milling; fermentation of whole wheat flour by A. awamori leading to the production of enzymes and fungal cells; glucose enhancement via enzymatic hydrolysis of flour suspensions; and nitrogen/micronutrient enhancement via fungal cell autolysis. Preliminary costings show that the operating cost of the process depends on plant capacity, cereal market price, presence and market value of added-value by-products, labour costs, and mode of processing (batch or continuous). PMID:15217108

  14. INCAPABILITY OF FORMALIN BASED FIXATIVE TO KILL MAGGOT IN MUTILATED HUMAN CARRION

    Directory of Open Access Journals (Sweden)

    Oladele, A.A.

    2015-03-01

    Full Text Available Background: Embalming is a process used to temporarily preserve a human cadaver to forestall decomposition and make it suitable for display at funerals; thus, are agents that prevent autolysis and putrefaction. The outbreak of maggots from a heap of inadequately embalmed bodies due to deep cuts and bodies involved in inferno, necessitated the need to re-investigate the efficacy of formalin based embalming fluid and its inability to kill maggots. Methodology: Various strength of Formaldehyde, Xylene, Kerosene, and, Lime fluid, Isopropanol, Gamalin 20, Potassium ferrocyanide, and Physiological saline as control were used in the investigation. In the present investigation, Two maggots under the same atmospheric condition were put in each of the ten selected chemical reagents/solutions, including Lime, Kerosene, and the Gamalin 20 that are naturally available were initially dispensed into ten glass universal containers. Maggot movements in each reagent solution were critically observed. Result: Maggots death occurred within the first ten minutes in test number three groups III that contains Concentrated Formalin and Xylene and Maggots died after fifteen minute of the experiment, but maggots did not died until about eight hours after the test in two of the experiment. Discussion: Results of this investigation showed clearly that Maggots were not killed as soon as expected by the embalmer when ordinary ten percent alcoholic formalin embalming fluid is used. Equal volume of concentrated formalin plus Xylene was found out to be effective at killing maggot instantly. Conclusion: It is therefore advisable to use Xylene plus Conc. Formalin when preserving cadaver infested with Maggot and this could at the same time prevent the occurrence of Maggots Infestation and better preservation of mass of burnt mutilated corpses in our Mortuary.

  15. Phosphodiesterase MoPdeH targets MoMck1 of the conserved mitogen-activated protein (MAP) kinase signalling pathway to regulate cell wall integrity in rice blast fungus Magnaporthe oryzae.

    Science.gov (United States)

    Yin, Ziyi; Tang, Wei; Wang, Jingzhen; Liu, Xinyu; Yang, Lina; Gao, Chuyun; Zhang, Jinlong; Zhang, Haifeng; Zheng, Xiaobo; Wang, Ping; Zhang, Zhengguang

    2016-06-01

    In the rice blast fungus Magnaporthe oryzae, the high-affinity cyclic adenosine monophosphate (cAMP) phosphodiesterase MoPdeH is important not only for cAMP signalling and pathogenicity, but also for cell wall integrity (CWI) maintenance through an unknown mechanism. By utilizing affinity purification, we found that MoPdeH interacts with MoMck1, one of the components of the mitogen-activated protein (MAP) kinase cascade that regulates CWI. Overexpression of MoMCK1 suppressed defects in autolysis and pathogenicity of the ΔMopdeH mutant, although partially, suggesting that MoPdeH plays a critical role in CWI maintenance mediated by the MAP kinase pathway. We found that MoMck1 and two other MAP kinase cascade components, MoMkk1 and MoMps1, modulate intracellular cAMP levels by regulating the expression of MoPDEH through a feedback loop. In addition, disruption of MoMKK1 resulted in less aerial hyphal formation, defective asexual development and attenuated pathogenicity. Moreover, MoMkk1 plays a role in the response to osmotic stress via regulation of MoOsm1 phosphorylation levels, whereas endoplasmic reticulum (ER) stress enhances MoMps1 phosphorylation and loss of the MAP kinase cascade component affects the unfolded protein response (UPR) pathway. Taken together, our findings demonstrate that MoPdeH functions upstream of the MoMck1-MoMkk1-MoMps1 MAP kinase pathway to regulate CWI, and that MoPdeH also mediates crosstalk between the cAMP signalling pathway, the osmotic sensing high osmolarity glycerol (HOG) pathway and the dithiothreitol (DTT)-induced UPR pathway in M. oryzae. PMID:27193947

  16. Novel Use of PIT Tags in Sea Cucumbers: Promising Results with the Commercial Species Cucumaria frondosa.

    Science.gov (United States)

    Gianasi, Bruno L; Verkaik, Katie; Hamel, Jean-François; Mercier, Annie

    2015-01-01

    The lack of a reliable and innocuous mark-recapture method has limited studies that would provide essential information for the management of commercial sea cucumbers. Tagging sea cucumbers is notoriously difficult because of their plastic nature and autolysis capacities. The markers that have so far been tested, mainly on or through the body wall, were either lost rapidly or had major drawbacks (e.g. suitable only for batch identification, requiring complex analysis, causing infections, necrosis, behavioural changes and mortality). The present study explored the efficacy of passive integrated transponder (PIT) tags for individually marking sea cucumbers by assessing retention rates and long-term side effects of tags inserted in previously unstudied tissues/organs. Individuals of the species Cucumaria frondosa were tagged in the body wall, aquapharyngeal bulb and at the base of the oral tentacles. They were monitored closely for evidence of stress, infection, change in feeding and spawning behaviour and tag retention rate. Implanting the tag in an oral tentacle to reach the hydrovascular system of the aquapharyngeal bulb achieved the best retention rates in full-size individuals: from a maximum of 92% after 30 days to 68% at the end of the experimental period (300 days). Efficacy was lower in smaller individuals (84% after 30 d and 42% after 300 d). Following a slight increase in cloacal movements for 15 h post tagging, no side effect was noted in sea cucumbers tagged in the aquapharyngeal bulb via the tentacles. Feeding and spawning behaviours were not affected and no signs of infections or abnormal cell development in the vicinity of the tags were observed. This study indicates that marking sea cucumbers with 8.2 mm long PIT tags implanted via the oral tentacle is an effective technique, yielding relatively high retention rates over long periods without any detectable physiological or behavioural effects. PMID:26011165

  17. Novel Use of PIT Tags in Sea Cucumbers: Promising Results with the Commercial Species Cucumaria frondosa.

    Directory of Open Access Journals (Sweden)

    Bruno L Gianasi

    Full Text Available The lack of a reliable and innocuous mark-recapture method has limited studies that would provide essential information for the management of commercial sea cucumbers. Tagging sea cucumbers is notoriously difficult because of their plastic nature and autolysis capacities. The markers that have so far been tested, mainly on or through the body wall, were either lost rapidly or had major drawbacks (e.g. suitable only for batch identification, requiring complex analysis, causing infections, necrosis, behavioural changes and mortality. The present study explored the efficacy of passive integrated transponder (PIT tags for individually marking sea cucumbers by assessing retention rates and long-term side effects of tags inserted in previously unstudied tissues/organs. Individuals of the species Cucumaria frondosa were tagged in the body wall, aquapharyngeal bulb and at the base of the oral tentacles. They were monitored closely for evidence of stress, infection, change in feeding and spawning behaviour and tag retention rate. Implanting the tag in an oral tentacle to reach the hydrovascular system of the aquapharyngeal bulb achieved the best retention rates in full-size individuals: from a maximum of 92% after 30 days to 68% at the end of the experimental period (300 days. Efficacy was lower in smaller individuals (84% after 30 d and 42% after 300 d. Following a slight increase in cloacal movements for 15 h post tagging, no side effect was noted in sea cucumbers tagged in the aquapharyngeal bulb via the tentacles. Feeding and spawning behaviours were not affected and no signs of infections or abnormal cell development in the vicinity of the tags were observed. This study indicates that marking sea cucumbers with 8.2 mm long PIT tags implanted via the oral tentacle is an effective technique, yielding relatively high retention rates over long periods without any detectable physiological or behavioural effects.

  18. Fish protein hydrolysate production from sardine solid waste by crude pepsin enzymatic hydrolysis in a bioreactor coupled to an ultrafiltration unit

    International Nuclear Information System (INIS)

    The aims of the study were to optimize the production a fish protein hydrolysate (FPH) by enzymatic hydrolysis of sardine solid waste using crude pepsin, and to scale up the process in a bioreactor coupled to an ultrafiltration unit for product recovery. Results showed that the crude pepsin prepared by autolysis of the mucous membranes of a sheep stomach at optimal conditions (i. e. pH = 1.5–2 and incubation time of 6 h) could be satisfactory used for the enzymatic hydrolysis of fish solid waste. The optimal conditions for enzymatic reaction were: temperature 48 °C, and pH 1.5. The scale up of the enzymatic hydrolysis and the coupling of the reactor an ultrafiltration unit to concentrate the hydrolysate gave good results with a rejection coefficient for the protein hydrolysate product in the range of 90%. The volumetric concentration factor was 2.5, with a permeate flux of 200 L m−2 bar−1. However, the results also suggest that the ultrafiltration product concentration process may be operating beyond the critical flux at which point irreversible membrane fouling occurs. - Highlights: ► Evaluating to produce a (FPH) by enzymatic hydrolysis of sardine solid wastes was achieved. ► Investigation of key parameters for optimal conditions for enzymatic hydrolysis have been studied. ► Valorization of sardine waste was realized by enzymatic hydrolysis process. ► Performances of this enzyme gave comparable results to those obtained with commercial pepsin. ► The nutritional quality of the FPH produced appears to be satisfactory.

  19. Cell wall structure and function in lactic acid bacteria.

    Science.gov (United States)

    Chapot-Chartier, Marie-Pierre; Kulakauskas, Saulius

    2014-08-29

    The cell wall of Gram-positive bacteria is a complex assemblage of glycopolymers and proteins. It consists of a thick peptidoglycan sacculus that surrounds the cytoplasmic membrane and that is decorated with teichoic acids, polysaccharides, and proteins. It plays a major role in bacterial physiology since it maintains cell shape and integrity during growth and division; in addition, it acts as the interface between the bacterium and its environment. Lactic acid bacteria (LAB) are traditionally and widely used to ferment food, and they are also the subject of more and more research because of their potential health-related benefits. It is now recognized that understanding the composition, structure, and properties of LAB cell walls is a crucial part of developing technological and health applications using these bacteria. In this review, we examine the different components of the Gram-positive cell wall: peptidoglycan, teichoic acids, polysaccharides, and proteins. We present recent findings regarding the structure and function of these complex compounds, results that have emerged thanks to the tandem development of structural analysis and whole genome sequencing. Although general structures and biosynthesis pathways are conserved among Gram-positive bacteria, studies have revealed that LAB cell walls demonstrate unique properties; these studies have yielded some notable, fundamental, and novel findings. Given the potential of this research to contribute to future applied strategies, in our discussion of the role played by cell wall components in LAB physiology, we pay special attention to the mechanisms controlling bacterial autolysis, bacterial sensitivity to bacteriophages and the mechanisms underlying interactions between probiotic bacteria and their hosts. PMID:25186919

  20. Prokaryotic Caspase Homologs: Phylogenetic Patterns and Functional Characteristics Reveal Considerable Diversity

    Science.gov (United States)

    Asplund-Samuelsson, Johannes; Bergman, Birgitta; Larsson, John

    2012-01-01

    Caspases accomplish initiation and execution of apoptosis, a programmed cell death process specific to metazoans. The existence of prokaryotic caspase homologs, termed metacaspases, has been known for slightly more than a decade. Despite their potential connection to the evolution of programmed cell death in eukaryotes, the phylogenetic distribution and functions of these prokaryotic metacaspase sequences are largely uncharted, while a few experiments imply involvement in programmed cell death. Aiming at providing a more detailed picture of prokaryotic caspase homologs, we applied a computational approach based on Hidden Markov Model search profiles to identify and functionally characterize putative metacaspases in bacterial and archaeal genomes. Out of the total of 1463 analyzed genomes, merely 267 (18%) were identified to contain putative metacaspases, but their taxonomic distribution included most prokaryotic phyla and a few archaea (Euryarchaeota). Metacaspases were particularly abundant in Alphaproteobacteria, Deltaproteobacteria and Cyanobacteria, which harbor many morphologically and developmentally complex organisms, and a distinct correlation was found between abundance and phenotypic complexity in Cyanobacteria. Notably, Bacillus subtilis and Escherichia coli, known to undergo genetically regulated autolysis, lacked metacaspases. Pfam domain architecture analysis combined with operon identification revealed rich and varied configurations among the metacaspase sequences. These imply roles in programmed cell death, but also e.g. in signaling, various enzymatic activities and protein modification. Together our data show a wide and scattered distribution of caspase homologs in prokaryotes with structurally and functionally diverse sub-groups, and with a potentially intriguing evolutionary role. These features will help delineate future characterizations of death pathways in prokaryotes. PMID:23185476

  1. Staphylococcus aureus Colonization of the Mouse Gastrointestinal Tract Is Modulated by Wall Teichoic Acid, Capsule, and Surface Proteins.

    Directory of Open Access Journals (Sweden)

    Yoshiki Misawa

    2015-07-01

    Full Text Available Staphylococcus aureus colonizes the nose, throat, skin, and gastrointestinal (GI tract of humans. GI carriage of S. aureus is difficult to eradicate and has been shown to facilitate the transmission of the bacterium among individuals. Although staphylococcal colonization of the GI tract is asymptomatic, it increases the likelihood of infection, particularly skin and soft tissue infections caused by USA300 isolates. We established a mouse model of persistent S. aureus GI colonization and characterized the impact of selected surface antigens on colonization. In competition experiments, an acapsular mutant colonized better than the parental strain Newman, whereas mutants defective in sortase A and clumping factor A showed impaired ability to colonize the GI tract. Mutants lacking protein A, clumping factor B, poly-N-acetyl glucosamine, or SdrCDE showed no defect in colonization. An S. aureus wall teichoic acid (WTA mutant (ΔtagO failed to colonize the mouse nose or GI tract, and the tagO and clfA mutants showed reduced adherence in vitro to intestinal epithelial cells. The tagO mutant was recovered in lower numbers than the wild type strain in the murine stomach and duodenum 1 h after inoculation. This reduced fitness correlated with the in vitro susceptibility of the tagO mutant to bile salts, proteases, and a gut-associated defensin. Newman ΔtagO showed enhanced susceptibility to autolysis, and an autolysin (atl tagO double mutant abrogated this phenotype. However, the atl tagO mutant did not survive better in the mouse GI tract than the tagO mutant. Our results indicate that the failure of the tagO mutant to colonize the GI tract correlates with its poor adherence and susceptibility to bactericidal factors within the mouse gut, but not to enhanced activity of its major autolysin.

  2. Fish protein hydrolysate production from sardine solid waste by crude pepsin enzymatic hydrolysis in a bioreactor coupled to an ultrafiltration unit

    Energy Technology Data Exchange (ETDEWEB)

    Benhabiles, M.S.; Abdi, N. [National Polytechnic school of Algiers, B.P. 182-16200, El Harrach, Algiers (Algeria); Drouiche, N., E-mail: nadjibdrouiche@yahoo.fr [National Polytechnic school of Algiers, B.P. 182-16200, El Harrach, Algiers (Algeria); Silicon Technology Development Unit (UDTS) 2, Bd Frantz Fanon BP140, Alger-7 Merveilles, 16000 (Algeria); Lounici, H. [National Polytechnic school of Algiers, B.P. 182-16200, El Harrach, Algiers (Algeria); Pauss, A. [University of Technology of Compiegne, Departement Genie chimique,B.P. 20.509, 60205 Compiegne cedex (France); Goosen, M.F.A. [Alfaisal University, Riyadh (Saudi Arabia); Mameri, N. [University of Technology of Compiegne, Departement Genie chimique,B.P. 20.509, 60205 Compiegne cedex (France)

    2012-05-01

    The aims of the study were to optimize the production a fish protein hydrolysate (FPH) by enzymatic hydrolysis of sardine solid waste using crude pepsin, and to scale up the process in a bioreactor coupled to an ultrafiltration unit for product recovery. Results showed that the crude pepsin prepared by autolysis of the mucous membranes of a sheep stomach at optimal conditions (i. e. pH = 1.5-2 and incubation time of 6 h) could be satisfactory used for the enzymatic hydrolysis of fish solid waste. The optimal conditions for enzymatic reaction were: temperature 48 Degree-Sign C, and pH 1.5. The scale up of the enzymatic hydrolysis and the coupling of the reactor an ultrafiltration unit to concentrate the hydrolysate gave good results with a rejection coefficient for the protein hydrolysate product in the range of 90%. The volumetric concentration factor was 2.5, with a permeate flux of 200 L m{sup -2} bar{sup -1}. However, the results also suggest that the ultrafiltration product concentration process may be operating beyond the critical flux at which point irreversible membrane fouling occurs. - Highlights: Black-Right-Pointing-Pointer Evaluating to produce a (FPH) by enzymatic hydrolysis of sardine solid wastes was achieved. Black-Right-Pointing-Pointer Investigation of key parameters for optimal conditions for enzymatic hydrolysis have been studied. Black-Right-Pointing-Pointer Valorization of sardine waste was realized by enzymatic hydrolysis process. Black-Right-Pointing-Pointer Performances of this enzyme gave comparable results to those obtained with commercial pepsin. Black-Right-Pointing-Pointer The nutritional quality of the FPH produced appears to be satisfactory.

  3. Assembly and development of the Pseudomonas aeruginosa biofilm matrix.

    Directory of Open Access Journals (Sweden)

    Luyan Ma

    2009-03-01

    Full Text Available Virtually all cells living in multicellular structures such as tissues and organs are encased in an extracellular matrix. One of the most important features of a biofilm is the extracellular polymeric substance that functions as a matrix, holding bacterial cells together. Yet very little is known about how the matrix forms or how matrix components encase bacteria during biofilm development. Pseudomonas aeruginosa forms environmentally and clinically relevant biofilms and is a paradigm organism for the study of biofilms. The extracellular polymeric substance of P. aeruginosa biofilms is an ill-defined mix of polysaccharides, nucleic acids, and proteins. Here, we directly visualize the product of the polysaccharide synthesis locus (Psl exopolysaccharide at different stages of biofilm development. During attachment, Psl is anchored on the cell surface in a helical pattern. This promotes cell-cell interactions and assembly of a matrix, which holds bacteria in the biofilm and on the surface. Chemical dissociation of Psl from the bacterial surface disrupted the Psl matrix as well as the biofilm structure. During biofilm maturation, Psl accumulates on the periphery of 3-D-structured microcolonies, resulting in a Psl matrix-free cavity in the microcolony center. At the dispersion stage, swimming cells appear in this matrix cavity. Dead cells and extracellular DNA (eDNA are also concentrated in the Psl matrix-free area. Deletion of genes that control cell death and autolysis affects the formation of the matrix cavity and microcolony dispersion. These data provide a mechanism for how P. aeruginosa builds a matrix and subsequently a cavity to free a portion of cells for seeding dispersal. Direct visualization reveals that Psl is a key scaffolding matrix component and opens up avenues for therapeutics of biofilm-related complications.

  4. Nepenthesin from monkey cups for hydrogen/deuterium exchange mass spectrometry.

    Science.gov (United States)

    Rey, Martial; Yang, Menglin; Burns, Kyle M; Yu, Yaping; Lees-Miller, Susan P; Schriemer, David C

    2013-02-01

    Studies of protein dynamics, structure and interactions using hydrogen/deuterium exchange mass spectrometry (HDX-MS) have sharply increased over the past 5-10 years. The predominant technology requires fast digestion at pH 2-3 to retain deuterium label. Pepsin is used almost exclusively, but it provides relatively low efficiency under the constraints of the experiment, and a selectivity profile that renders poor coverage of intrinsically disordered regions. In this study we present nepenthesin-containing secretions of the pitcher plant Nepenthes, commonly called monkey cups, for use in HDX-MS. We show that nepenthesin is at least 1400-fold more efficient than pepsin under HDX-competent conditions, with a selectivity profile that mimics pepsin in part, but also includes efficient cleavage C-terminal to "forbidden" residues K, R, H, and P. High efficiency permits a solution-based analysis with no detectable autolysis, avoiding the complication of immobilized enzyme reactors. Relaxed selectivity promotes high coverage of disordered regions and the ability to "tune" the mass map for regions of interest. Nepenthesin-enriched secretions were applied to an analysis of protein complexes in the nonhomologous end-joining DNA repair pathway. The analysis of XRCC4 binding to the BRCT domains of Ligase IV points to secondary interactions between the disordered C-terminal tail of XRCC4 and remote regions of the BRCT domains, which could only be identified with a nepenthesin-based workflow. HDX data suggest that stalk-binding to XRCC4 primes a BRCT conformation in these remote regions to support tail interaction, an event which may be phosphoregulated. We conclude that nepenthesin is an effective alternative to pepsin for all HDX-MS applications, and especially for the analysis of structural transitions among intrinsically disordered proteins and their binding partners. PMID:23197791

  5. Microbiological and microscopic analysis of the pulp of non-vital traumatized teeth with intact crowns

    Directory of Open Access Journals (Sweden)

    Kely Firmino Bruno

    2009-10-01

    Full Text Available OBJECTIVE: This study evaluated the presence of microorganisms and analyzed microscopically the pulp of 20 traumatized human teeth with intact crowns and clinical diagnosis of pulp necrosis, based on the association of at least three of the clinical criteria: crown discoloration, negative response to thermal and electric pulp vitality tests, positive response to vertical and horizontal percussion, pain on palpation or mobility. MATERIAL AND METHODS: Microbiological collection was performed from the root canals to evaluate the presence of microorganisms. The pulp samples were stained with hematoxylin and eosin (H.E. for histological evaluation of possible morphological alterations. RESULTS: Analysis of results was performed by statistical tests (linear regression test and diagnostic analysis and subjective analysis of the sections stained with H.E. and revealed that only 15% of the sample did not exhibit microbial development. The time elapsed between dental trauma and onset of endodontic intervention ranged from 15 days to 31 months; the percussion test presented high sensitivity (80% for detection of microorganisms in the root canal of traumatized teeth; 3 teeth (15% did not present pulp tissue, being characterized as complete autolysis; analysis of pulp samples was performed on the other 17 cases, among which 3 (15% exhibited partial necrosis without possibility of repair and 14 presented complete necrosis; none of the clinical criteria employed for the diagnosis of pulp necrosis in traumatized teeth was pathognomonic. CONCLUSIONS: The present results allowed the following conclusions: with regard to microbiological findings, 85% of teeth presented microorganisms in the root canal, despite the presence of an intact crown. Concerning the microscopic findings, 100% of traumatized teeth presented pulp necrosis; the pulp vitality tests based on pulp response to heat, cold and vertical percussion were the most reliable to diagnose pulp necrosis in

  6. Improvement of L-arginine production by overexpression of a bifunctional ornithine acetyltransferase in Corynebacterium crenatum.

    Science.gov (United States)

    Dou, Wenfang; Xu, Meijuan; Cai, Dongmei; Zhang, Xiaomei; Rao, Zhiming; Xu, Zhenghong

    2011-10-01

    Ornithine acetyltransferase (EC 2.3.1.35; OATase) gene (argJ) from the L-arginine-producing mutant Corynebacterium crenatum SYPA5-5 was cloned, sequenced, and expressed in Escherichia coli BL21 (DE3). Analysis of the argJ sequence revealed that the argJ coded a polypeptide of 388 amino acids with a calculated molecular weight of 39.7 kDa. In this study, the function of the OATase (argJ) of C. crenatum SYPA5-5 has been identified as a conserved ATML sequence for the autolysis of the protein to α- and β-subunits. When the argJ regions corresponding to the α- and β-subunits were cloned and expressed separately in E. coli BL21, OATase activities were abolished. At the same time, a functional study revealed that OATase from C. crenatum SYPA5-5 was a bifunctional enzyme with the functions of acetylglutamate synthase (EC 2.3.1.1, NAGS) and acetylornithine deacetylase (EC 3.5.1.16, AOase) activities. In order to investigate the effects of the overexpression of the argJ gene on L: -arginine production, the argJ gene was inserted into pJCtac to yield the recombinant shuttle plasmid pJCtac-argJ and then transformed into C. crenatum SYPA5-5. The results showed that the engineered strains could not only express more OATase (90.9%) but also increase the production of L: -arginine significantly (16.8%). PMID:21785983

  7. Improved utilization of marine species of low commercial value through the elaboration of hydrolysates.

    Science.gov (United States)

    Morales de León, J C; Bourges, R H; Necoechea, H

    1985-03-01

    Although Mexico is a country with a great fishing potential, fish consumption remains very low. An important reason for this situation is the difficulty faced in regard to its preservation and distribution, a factor which notably increases the final price of the product. As is known, in some countries fish preservation is carried out through autolysis, using high concentrations of sodium chloride. This was the type of work carried out by us, in an effort to adapt the procedure to the species and conditions prevalent in Mexico. The raw material was selected according to its availability and cost. The selected species were mojarra (Archosargus unimaculatus) and sardine (Sardinops caerula). Three different fish-to-salt ratios were tested (1.5:1, 4:1 and 6:1), with incubation periods ranging from 4 to 24 weeks, at both 20 to 23 degrees C, and 37 to 39 degrees C. Results indicated that a fish-to-salt ratio of 4:1, at a temperature of 37 degrees C and an incubation period of 12 weeks, represent the optimun conditions for obtaining a fish sauce which is acceptable in flavor, with a protein content of 12% per 100 ml, and a storage life of at least 90 days. The recovery of the final product was 22%, reaching 35% in a second extraction. Sensory evaluation tests were undertaken by adding the sauce to cooked unsalted rice. According to the results, there was a favorable acceptance of the final product. The price calculated for the elaboration of the sauce at the household or rural level was lower, as compared with the price of protein from meat or egg which is 3-to-4-fold higher. PMID:3834870

  8. Living bacteria rheology: Population growth, aggregation patterns, and collective behavior under different shear flows

    Science.gov (United States)

    Patrício, P.; Almeida, P. L.; Portela, R.; Sobral, R. G.; Grilo, I. R.; Cidade, T.; Leal, C. R.

    2014-08-01

    The activity of growing living bacteria was investigated using real-time and in situ rheology—in stationary and oscillatory shear. Two different strains of the human pathogen Staphylococcus aureus—strain COL and its isogenic cell wall autolysis mutant, RUSAL9—were considered in this work. For low bacteria density, strain COL forms small clusters, while the mutant, presenting deficient cell separation, forms irregular larger aggregates. In the early stages of growth, when subjected to a stationary shear, the viscosity of the cultures of both strains increases with the population of cells. As the bacteria reach the exponential phase of growth, the viscosity of the cultures of the two strains follows different and rich behaviors, with no counterpart in the optical density or in the population's colony-forming units measurements. While the viscosity of strain COL culture keeps increasing during the exponential phase and returns close to its initial value for the late phase of growth, where the population stabilizes, the viscosity of the mutant strain culture decreases steeply, still in the exponential phase, remains constant for some time, and increases again, reaching a constant plateau at a maximum value for the late phase of growth. These complex viscoelastic behaviors, which were observed to be shear-stress-dependent, are a consequence of two coupled effects: the cell density continuous increase and its changing interacting properties. The viscous and elastic moduli of strain COL culture, obtained with oscillatory shear, exhibit power-law behaviors whose exponents are dependent on the bacteria growth stage. The viscous and elastic moduli of the mutant culture have complex behaviors, emerging from the different relaxation times that are associated with the large molecules of the medium and the self-organized structures of bacteria. Nevertheless, these behaviors reflect the bacteria growth stage.

  9. The irradiation effects of ultraviolet rays on Leptospira cells

    International Nuclear Information System (INIS)

    The irradiation effects of ultraviolets rays (UV) on leptospira cells were investigated. Four serovar strains of Genus Leptospira ; L. copenhageni, L. canicola, L. biflexa and L. illini were used. A sterilization lamp (Toshiba-GL-15) were lighted at intervals of 90mm on the sample fluid for several minutes. Loss of motility, survival growth and morphological damages were recognized under several conditions. The medium conditions were important, that is, the Korthof's medium was less effective than phosphate buffered saline (PBS). The irradiation time was also important, that is, L. canicola cells in PBS lost their motility and survive ability within 300sec. of irradiation, however, much more time, such as 1.200sec. was necessary in Korthof's medium. This phenomenon may be depended upon defensibility of albumin in the latter. Among the strains, L. biflexa cells showed the highest resistance in loss of motility and survive ability, and other three strains were inferior. The remarkable efects of cellular structures were also seen in the materials with 30 min. of irradiation, in both immediate time or after 24h incubation. The damages observed after 24th of irradiation were much more drastic than those of immediate time. No effect could be seen on the cells suspended in the Korthof's medium irradiated for 24h. Regarding morphological effect, there appeared relaxation of helical body, spherical body and semighost as the immediate changes. Structural damages were recognized as the collapse of cell body, such as scattering of capsule, release of axial flagella, loss or change of cytoplasmic density and break down of wall membrane complex. These phenomena were regarded as the indirect effects of UV-irradiation and autolysis in a post-mortem change. (author)

  10. Irradiation effects of ultraviolet rays on Leptospira cells. Loss of motility, survive ability, and damages of cell structures

    Energy Technology Data Exchange (ETDEWEB)

    Maeda, Hidezo (Yamaguchi Univ., Ube (Japan). School of Medicine)

    1982-12-01

    The irradiation effects of ultraviolets rays (UV) on leptospira cells were investigated. Four serovar strains of Genus Leptospira ; L. copenhageni, L. canicola, L. biflexa and L. illini were used. A sterilization lamp (Toshiba-GL-15) was lighted at intervals of 90mm on the sample fluid for several minutes. Loss of motility, survival growth and morphological damages were recognized under several conditions. The medium conditions were important, that is, the Korthof's medium was less effective than phosphate buffered saline (PBS). The irradiation time was also important, that is, L. canicola cells in PBS lost their motility and survive ability within 300sec. of irradiation, however, much more time, such as 1.200sec. was necessary in Korthof's medium. This phenomenon may be depended upon defensibility of albumin in the latter. Among the strains, L. biflexa cells showed the highest resistance in loss of motility and survive ability, and other three strains were inferior. The remarkable efects of cellular structures were also seen in the materials with 30 min. of irradiation, in both immediate time or after 24h incubation. The damages observed after 24th of irradiation were much more drastic than those of immediate time. No effect could be seen on the cells suspended in the Korthof's medium irradiated for 24h. Regarding morphological effect, there appeared relaxation of helical body, spherical body and semighost as the immediate changes. Structural damages were recognized as the collapse of cell body, such as scattering of capsule, release of axial flagella, loss or change of cytoplasmic density and break down of wall membrane complex. These phenomena were regarded as the indirect effects of UV-irradiation and autolysis in a post-mortem change.

  11. Plasmin enzymatic activity in the presence of actin

    Directory of Open Access Journals (Sweden)

    Yusova E. I.

    2015-10-01

    Full Text Available Aim. To study the changes in the plasmin activity towards substrates with high and low molecular mass in the presence of actin. Methods. The proteins used for this investigation were obtained by affinity chromatography and gel-filtration. The plasmin enzymatic activity was determined by a turbidimetric assay and a chromogenic substrate-based assay. The enzyme linked immunosorbent assay and biotin-avidin-phosphatase system were used to study the interaction of plasminogen and its fragments with actin. Results. It was shown that G-actin causes 1.5-fold decrease in the rate of polymeric fibrin hydrolysis by plasmin and Glu-plasminogen activated by the tissue plasminogen activator. However, actin did not impede plasmin autolysis and had no influence on its amidase activity. We have studied an interaction of biotinylated Glu-plasminogen and its fragments (kringle 1-3, kringle 4 and mini-plasminogen with immobilized G-actin. Glu-plasminogen and kringle 4 had a high affinity towards actin (C50 is 113 and 117 nM correspondingly. Mini-plasminogen and kringe 4 did not bind to actin. A similar affinity of Glu-plasminogen and kringle 1-3 towards actin proves the involvement of the kringle 1-3 lysine-binding sites of the native plasminogen form in the actin interaction. Conclusions. Actin can modulate plasmin specificity towards high molecular mass substrates through its interaction with lysine-binding sites of the enzyme kringle domains. Actin inhibition of the fibrinolytic activity of plasmin is due to its competition with fibrin for thelysine binding sites of plasminogen/plasmin.

  12. Fish Spoilage Mechanisms and Preservation Techniques: Review

    Directory of Open Access Journals (Sweden)

    Abdel E. Ghaly

    2010-01-01

    Full Text Available Problem statement: Spoilage of food products is due to chemical, enzymatic or microbial activities One-fourth of the worlds food supply and 30% of landed fish are lost through microbial activity alone. With the ever growing world population and the need to store and transport the food from one place to another where it is needed, food preservation becomes necessary in order to increase its shelf life and maintain its nutritional value, texture and flavor. The freshness and quality of fish have always gained the attention by Food Regulatory Agencies and Food Processing Industry. Proper handling, pretreatment and preservation techniques can improve the quality fish and fish products and increase their shelf life. Methodology: Historically salting, drying, smoking, fermentation and canning were the methods to prevent fish spoilage and extend its shelf life. In response to consumer demand for texture, appearance and taste, new methods were developed including: Cooling, freezing and chemical preservation. A comprehensive review of the literature on the subject of fish spoilage and modern preservation techniques was carried out. Conclusion: Fish spoilage results from three basic mechanisms: Enzymatic autolysis, oxidation, microbial growth. Low temperature storage and chemical techniques for controlling water activity, enzymatic, oxidative and microbial spoilage are the most common in the industry today. A process involving the addition of an EDTA (1 mM-TBHQ (0.02% combination and ascorbic acid and storage at refrigerated temperatures (5°C in darkness can be the most positive for controlling the spoilage of fish and fish product. The suggested process would address antimicrobial activity as well as destructive oxidation of the desired lipids and fats. However, more efforts are required to understand the role of proximate composition of fish, post harvest history, environmental conditions, initial microbial load, type and nature of bacteria and their

  13. Postmortem biochemistry: Current applications.

    Science.gov (United States)

    Belsey, S L; Flanagan, R J

    2016-07-01

    The results of biochemical analyses in specimens obtained postmortem may aid death investigation when diabetic and alcoholic ketoacidosis is suspected, when death may have been the result of drowning, anaphylaxis, or involved a prolonged stress response such as hypothermia, and in the diagnosis of disease processes such as inflammation, early myocardial infarction, or sepsis. There is often cross-over with different disciplines, in particular with clinical and forensic toxicology, since some endogenous substances such as sodium chloride, potassium chloride, and insulin can be used as poisons. The interpretation of results is often complicated because of the likelihood of postmortem change in analyte concentration or activity, and proper interpretation must take into account all the available evidence. The unpredictability of postmortem changes means that use of biochemical measurements in time of death estimation has little value. The use of vitreous humour is beneficial for many analytes as the eye is in a physically protected environment, this medium may be less affected by autolysis or microbial metabolism than blood, and the assays can be performed with due precaution using standard clinical chemistry analysers. However, interpretation of results may not be straightforward because (i) defined reference ranges in life are often lacking, (ii) there is a dearth of knowledge regarding, for example, the speed of equilibration of many analytes between blood, vitreous humour, and other fluids that may be sampled, and (iii) the effects of post-mortem change are difficult to quantify because of the lack of control data. A major limitation is that postmortem vitreous glucose measurements are of no help in diagnosing antemortem hypoglycaemia. PMID:27131037

  14. AbaA and WetA govern distinct stages of Aspergillus fumigatus development.

    Science.gov (United States)

    Tao, Li; Yu, Jae-Hyuk

    2011-02-01

    The opportunistic human pathogen Aspergillus fumigatus produces a massive number of asexual spores (conidia) as the primary means of dispersal, survival, genome protection and infection of hosts. In this report, we investigate the functions of two developmental regulators, AfuAbaA and AfuWetA, in A. fumigatus. The AfuabaA gene is predicted to encode an ATTS/TEA DNA-binding domain protein and is activated by AfuBrlA during the middle stage of A. fumigatus asexual development (conidiation). The deletion of AfuabaA results in the formation of aberrant conidiophores exhibiting reiterated cylinder-like terminal cells lacking spores. Furthermore, the absence of AfuabaA causes delayed autolysis and cell death, whereas the overexpression of AfuabaA accelerates these processes, indicating an additional role for AfuAbaA. The AfuwetA gene is sequentially activated by AfuAbaA in the late phase of conidiation. The deletion of AfuwetA causes the formation of defective spore walls and a lack of trehalose biogenesis, leading to a rapid loss of spore viability and reduced tolerance to various stresses. This is the first report to demonstrate that WetA is essential for trehalose biogenesis in conidia. Moreover, the absence of AfuwetA causes delayed germ-tube formation and reduced hyphal branching, suggesting a role of AfuWetA in the early phase of fungal growth. A genetic model depicting the regulation of conidiation in A. fumigatus is proposed. PMID:20966095

  15. Amino acid composition and functional properties of giant red sea cucumber ( Parastichopus californicus) collagen hydrolysates

    Science.gov (United States)

    Liu, Zunying; Su, Yicheng; Zeng, Mingyong

    2011-03-01

    Giant red sea cucumber ( Parastichopus californicus) is an under-utilized species due to its high tendency to autolysis. The aim of this study was to evaluate the functional properties of collagen hydrolysates from this species. The degree of hydrolysis (DH), amino acid composition, SDS-PAGE, emulsion activity index (EAI), emulsion stability index (ESI), foam expansion (FE), and foam stability (FS) of hydrolysates were investigated. The effects of pH on the EAI, ESI FE and FS of hydrolysates were also investigated. The results indicated that the β and α 1 chains of the collagen were effectively hydrolyzed by trypsin at 50°c with an Enzyme/Substrate (E/S) ration of 1:20 (w:w). The DH of collagen was up to 17.3% after 3 h hydrolysis with trypsin. The hydrolysates had a molecular weight distribution of 1.1-17 kDa, and were abundant in glycine (Gly), proline (Pro), glutamic acid (Glu), alanine (Ala) and hydroxyproline (Hyp) residues. The hydrolysates were fractionated into three fractions ( 10 kDa), and the fraction of 3-10 kDa exhibited a higher EAI value than the fraction of > 10 kDa ( P 10 kDa had higher FE and FS values than other fractions ( P4.0. Under pH 7.0 and pH 10.0, the 3-10 kDa fraction showed higher EAI value and the fraction of > 10 kDa showed higher FE value, respectively. They are hoped to be utilized as functional ingredients in food and nutraceutical industries.

  16. Fitness of isogenic colony morphology variants of Pseudomonas aeruginosa in murine airway infection.

    Directory of Open Access Journals (Sweden)

    Elza Rakhimova

    Full Text Available Chronic lung infections with Pseudomonas aeruginosa are associated with the diversification of the persisting clone into niche specialists and morphotypes, a phenomenon called 'dissociative behaviour'. To explore the potential of P. aeruginosa to change its morphotype by single step loss-of-function mutagenesis, a signature-tagged mini-Tn5 plasposon library of the cystic fibrosis airway isolate TBCF10839 was screened for colony morphology variants under nine different conditions in vitro. Transposon insertion into 1% of the genome changed colony morphology into eight discernable morphotypes. Half of the 55 targets encode features of primary or secondary metabolism whereby quinolone production was frequently affected. In the other half the transposon had inserted into genes of the functional categories transport, regulation or motility/chemotaxis. To mimic dissociative behaviour of isogenic strains in lungs, pools of 25 colony morphology variants were tested for competitive fitness in an acute murine airway infection model. Six of the 55 mutants either grew better or worse in vivo than in vitro, respectively. Metabolic proficiency of the colony morphology variant was a key determinant for survival in murine airways. The most common morphotype of self-destructive autolysis did unexpectedly not impair fitness. Transposon insertions into homologous genes of strain PAO1 did not reproduce the TBCF10839 mutant morphotypes for 16 of 19 examined loci pointing to an important role of the genetic background on colony morphology. Depending on the chosen P. aeruginosa strain, functional genome scans will explore other areas of the evolutionary landscape. Based on our discordant findings of mutant phenotypes in P. aeruginosa strains PAO1, PA14 and TBCF10839, we conclude that the current focus on few reference strains may miss modes of niche adaptation and dissociative behaviour that are relevant for the microevolution of complex traits in the wild.

  17. Cilia-associated bacteria in fatal Bordetella bronchiseptica pneumonia of dogs and cats.

    Science.gov (United States)

    Taha-Abdelaziz, Khaled; Bassel, Laura L; Harness, Melanie L; Clark, Mary Ellen; Register, Karen B; Caswell, Jeff L

    2016-07-01

    Bordetella bronchiseptica frequently causes nonfatal tracheobronchitis, but its role in fatal pneumonia is less recognized. Our study evaluated histologic identification of cilia-associated bacteria as a method for diagnosis of B. bronchiseptica pneumonia. Cases of fatal bronchopneumonia were studied retrospectively, excluding neonates and cases of aspiration pneumonia, minor lung lesions, or autolysis. The study population comprised 36 canine and 31 feline cases of bronchopneumonia. B. bronchiseptica was identified in 8 of 36 canine and 14 of 31 feline cases based on immunohistochemistry (IHC) using serum from a rabbit hyperimmunized with pertactin, PCR testing (Fla2/Fla12), and/or bacterial culture data when available. Of these, IHC was positive in 4 canine and 7 feline cases, PCR was positive in 8 canine and 14 feline cases, and B. bronchiseptica was isolated in 2 of 5 canine and 3 of 9 feline cases tested. Examination of histologic sections stained with hematoxylin and eosin revealed bronchial cilia-associated bacteria in 4 of 36 canine and 5 of 31 feline cases; these were all positive by IHC and PCR. The presence of cilia-associated bacteria had been noted in the pathology report for only 2 of these 9 cases. Thus, the presence of cilia-associated bacteria seems frequently overlooked by pathologists, but is a diagnostically significant feature of B. bronchiseptica pneumonia. A specific diagnosis of B. bronchiseptica pneumonia is important because it suggests primary or opportunistic bacterial pneumonia rather than aspiration pneumonia, and because of the risk of animal-to-animal transmission of B. bronchiseptica, the availability of vaccines for disease prevention, and the potential zoonotic risk to immunocompromised pet owners. PMID:27178716

  18. Microbiological, physico-chemical, and sensorial modifications during the useful life of the shrimps (Penaeus brasiliensis e Penaeus Paulensis) submitted to gamma radiation

    International Nuclear Information System (INIS)

    During the last years, there has been an increase in the consumption of seafood and freshwater fish as a healthier diet option. Shrimps are the most important product in the international trade market. This kind of food easily deteriorates due to autolysis, oxidation and microbial action. This research was carried out in order to study the effectiveness of radiation in preserving shrimps. Samples of shrimps (Penaeus brasiliensis and P. paulensi) were submitted to gamma radiation doses of O kGy, 1 kGy, 2 kGy, 2.5 kGy, 3 kGy and 3.5 kGy and stored under refrigeration. The microbiological analysis was performed on days O, 2, 4, 7 10 and 14 post processing. Simultaneously, the pH and total, volatile bases (TVBN) were determined. The psychotropic population varied from <2.0 log to 8.08 log CFU/g while the mesophilic ranged from <1.0 109 to 6.03 log CFU/g; pH varied from 7.52 to 8.33 and TVBN from 28.47 to 56.00 mg N/100g, according to the radiation dose and the day of analysis. Black spots, changes in the characteristic odour and TVBN levels showed the beginning of a chemical deterioration as of the 4 th day of analysis. Doses of 3 kGy and 3.5 kGy presented the best results. Pseudomonas spp. showed the highest sensitivity to radiation. Due to the lapse of time between capturing shrimps and returning to land together with inadequate manipulation and storage in the boat, the quality of raw material is prejudiced which makes the radiation process unfeasible. (author)

  19. Microbiological, physico-chemical, and sensorial modifications during the useful life of the shrimps (Penaeus brasiliensis e Penaeus Paulensis) submitted to gamma radiation.; Alteracoes microbiologicas, fisico-quimicas e sensoriais durante a vida util do camarao-rosa (Penaeus brasiliensis e Penaeus Paulensis) submetido a radiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, Mariana Del Ben

    2000-07-01

    During the last years, there has been an increase in the consumption of seafood and freshwater fish as a healthier diet option. Shrimps are the most important product in the international trade market. This kind of food easily deteriorates due to autolysis, oxidation and microbial action. This research was carried out in order to study the effectiveness of radiation in preserving shrimps. Samples of shrimps (Penaeus brasiliensis and P. paulensi) were submitted to gamma radiation doses of O kGy, 1 kGy, 2 kGy, 2.5 kGy, 3 kGy and 3.5 kGy and stored under refrigeration. The microbiological analysis was performed on days O, 2, 4, 7 10 and 14 post processing. Simultaneously, the pH and total, volatile bases (TVBN) were determined. The psychotropic population varied from <2.0 log to 8.08 log CFU/g while the mesophilic ranged from <1.0 109 to 6.03 log CFU/g; pH varied from 7.52 to 8.33 and TVBN from 28.47 to 56.00 mg N/100g, according to the radiation dose and the day of analysis. Black spots, changes in the characteristic odour and TVBN levels showed the beginning of a chemical deterioration as of the 4 th day of analysis. Doses of 3 kGy and 3.5 kGy presented the best results. Pseudomonas spp. showed the highest sensitivity to radiation. Due to the lapse of time between capturing shrimps and returning to land together with inadequate manipulation and storage in the boat, the quality of raw material is prejudiced which makes the radiation process unfeasible. (author)

  20. Amino Acid Composition and Functional Properties of Giant Red Sea Cucumber (Parastichopus californicus) Collagen Hydrolysates

    Institute of Scientific and Technical Information of China (English)

    LIU Zunying; SU Yicheng; ZENG Mingyong

    2011-01-01

    Giant red sea cucumber (Parastichopus californicus) is an under-utilized species due to its high tendency to autolysis.The aim of this study was to evaluate the functional properties of collagen hydrolysates from this species. The degree of hydrolysis (DH), amino acid composition, SDS-PAGE, emulsion activity index (EAI), emulsion stability index (ESI), foam expansion (FE), and foam stability (FS) of hydrolysates were investigated. The effects of pH on the EAI, ESI FE and FS of hydrolysates were also investigated. The results indicated that the β and α1 chains of the collagen were effectively hydrolyzed by trypsin at 500C with an Enzyme/Substrate (E/S) ration of 1:20 (w:w). The DH of collagen was up to 17.3% after 3 h hydrolysis with trypsin. The hydrolysates had a molecular weight distribution of 1.1-17kDa, and were abundant in glycine (Gly), proline (Pro), glutamic acid (Glu), alanine (Ala) and hydroxyproline (Hyp) residues. The hydrolysates were fractionated into three fractions (<3kDa, 3-10kDa, and > 10 kDa),and the fraction of 3-10 kDa exhibited a higher EAI value than the fraction of > 10 kDa (P<0.05). The fraction of > 10 kDa had higher FE and FS values than other fractions (P<0.05). The pH had an important effect on the EAI, ESI, FE and FS. All the fractions showed undesirable emulsion and forming properties at pH 4.0. Under pH 7.0 and pH 10.0, the 3-10kDa fraction showed higher EAI value and the fraction of > 10 kDa showed higher FE value, respectively. They are hoped to be utilized as functional ingredients in food and nutraceutical industries.

  1. Effect of nutrient restriction and re-feeding on calpain family genes in skeletal muscle of channel catfish (Ictalurus punctatus.

    Directory of Open Access Journals (Sweden)

    Elena Preziosa

    Full Text Available BACKGROUND: Calpains, a superfamily of intracellular calcium-dependent cysteine proteases, are involved in the cytoskeletal remodeling and wasting of skeletal muscle. Calpains are generated as inactive proenzymes which are activated by N-terminal autolysis induced by calcium-ions. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we characterized the full-length cDNA sequences of three calpain genes, clpn1, clpn2, and clpn3 in channel catfish, and assessed the effect of nutrient restriction and subsequent re-feeding on the expression of these genes in skeletal muscle. The clpn1 cDNA sequence encodes a protein of 704 amino acids, Clpn2 of 696 amino acids, and Clpn3 of 741 amino acids. Phylogenetic analysis of deduced amino acid sequences indicate that catfish Clpn1 and Clpn2 share a sequence similarity of 61%; catfish Clpn1 and Clpn3 of 48%, and Clpn2 and Clpn3 of only 45%. The domain structure architectures of all three calpain genes in channel catfish are similar to those of other vertebrates, further supported by strong bootstrap values during phylogenetic analyses. Starvation of channel catfish (average weight, 15-20 g for 35 days influenced the expression of clpn1 (2.3-fold decrease, P<0.05, clpn2 (1.3-fold increase, P<0.05, and clpn3 (13.0-fold decrease, P<0.05, whereas the subsequent refeeding did not change the expression of these genes as measured by quantitative real-time PCR analysis. Calpain catalytic activity in channel catfish skeletal muscle showed significant differences only during the starvation period, with a 1.2- and 1.4- fold increase (P<0.01 after 17 and 35 days of starvation, respectively. CONCLUSION/SIGNIFICANCE: We have assessed that fasting and refeeding may provide a suitable experimental model to provide us insight into the role of calpains during fish muscle atrophy and how they respond to changes in nutrient supply.

  2. Dynamics of Streptococcus mutans transcriptome in response to starch and sucrose during biofilm development.

    Directory of Open Access Journals (Sweden)

    Marlise I Klein

    Full Text Available The combination of sucrose and starch in the presence of surface-adsorbed salivary α-amylase and bacterial glucosyltransferases increase the formation of a structurally and metabolically distinctive biofilm by Streptococcus mutans. This host-pathogen-diet interaction may modulate the formation of pathogenic biofilms related to dental caries disease. We conducted a comprehensive study to further investigate the influence of the dietary carbohydrates on S. mutans-transcriptome at distinct stages of biofilm development using whole genomic profiling with a new computational tool (MDV for data mining. S. mutans UA159 biofilms were formed on amylase-active saliva coated hydroxyapatite discs in the presence of various concentrations of sucrose alone (ranging from 0.25 to 5% w/v or in combination with starch (0.5 to 1% w/v. Overall, the presence of sucrose and starch (suc+st influenced the dynamics of S. mutans transcriptome (vs. sucrose alone, which may be associated with gradual digestion of starch by surface-adsorbed amylase. At 21 h of biofilm formation, most of the differentially expressed genes were related to sugar metabolism, such as upregulation of genes involved in maltose/maltotriose uptake and glycogen synthesis. In addition, the groEL/groES chaperones were induced in the suc+st-biofilm, indicating that presence of starch hydrolysates may cause environmental stress. In contrast, at 30 h of biofilm development, multiple genes associated with sugar uptake/transport (e.g. maltose, two-component systems, fermentation/glycolysis and iron transport were differentially expressed in suc+st-biofilms (vs. sucrose-biofilms. Interestingly, lytT (bacteria autolysis was upregulated, which was correlated with presence of extracellular DNA in the matrix of suc+st-biofilms. Specific genes related to carbohydrate uptake and glycogen metabolism were detected in suc+st-biofilms in more than one time point, indicating an association between presence of starch

  3. Genetic pathway in acquisition and loss of vancomycin resistance in a methicillin resistant Staphylococcus aureus (MRSA strain of clonal type USA300.

    Directory of Open Access Journals (Sweden)

    Susana Gardete

    2012-02-01

    Full Text Available An isolate of the methicillin-resistant Staphylococcus aureus (MRSA clone USA300 with reduced susceptibility to vancomycin (SG-R (i.e, vancomycin-intermediate S. aureus, VISA and its susceptible "parental" strain (SG-S were recovered from a patient at the end and at the beginning of an unsuccessful vancomycin therapy. The VISA phenotype was unstable in vitro generating a susceptible revertant strain (SG-rev. The availability of these 3 isogenic strains allowed us to explore genetic correlates of antibiotic resistance as it emerged in vivo. Compared to the susceptible isolate, both the VISA and revertant strains carried the same point mutations in yycH, vraG, yvqF and lspA genes and a substantial deletion within an intergenic region. The revertant strain carried a single additional frameshift mutation in vraS which is part of two component regulatory system VraSR. VISA isolate SG-R showed complex alterations in phenotype: decreased susceptibility to other antibiotics, slow autolysis, abnormal cell division and increased thickness of cell wall. There was also altered expression of 239 genes including down-regulation of major virulence determinants. All phenotypic properties and gene expression profile returned to parental levels in the revertant strain. Introduction of wild type yvqF on a multicopy plasmid into the VISA strain caused loss of resistance along with loss of all the associated phenotypic changes. Introduction of the wild type vraSR into the revertant strain caused recovery of VISA type resistance. The yvqF/vraSR operon seems to function as an on/off switch: mutation in yvqF in strain SG-R turns on the vraSR system, which leads to increase in vancomycin resistance and down-regulation of virulence determinants. Mutation in vraS in the revertant strain turns off this regulatory system accompanied by loss of resistance and normal expression of virulence genes. Down-regulation of virulence genes may provide VISA strains with a "stealth

  4. PBP1a-deficiency causes major defects in cell division, growth and biofilm formation by Streptococcus mutans.

    Directory of Open Access Journals (Sweden)

    Zezhang T Wen

    Full Text Available Streptococcus mutans, a key etiological agent of human dental caries, lives almost exclusively on the tooth surface in plaque biofilms and is known for its ability to survive and respond to various environmental insults, including low pH, and antimicrobial agents from other microbes and oral care products. In this study, a penicillin-binding protein (PBP1a-deficient mutant, strain JB467, was generated by allelic replacement mutagenesis and analyzed for the effects of such a deficiency on S. mutans' stress tolerance response and biofilm formation. Our results so far have shown that PBP1a-deficiency in S. mutans affects growth of the deficient mutant, especially at acidic and alkaline pHs. As compared to the wild-type, UA159, the PBP1a-deficient mutant, JB467, had a reduced growth rate at pH 6.2 and did not grow at all at pH 8.2. Unlike the wild-type, the inclusion of paraquat in growth medium, especially at 2 mM or above, significantly reduced the growth rate of the mutant. Acid killing assays showed that the mutant was 15-fold more sensitive to pH 2.8 than the wild-type after 30 minutes. In a hydrogen peroxide killing assay, the mutant was 16-fold more susceptible to hydrogen peroxide (0.2%, w/v after 90 minutes than the wild-type. Relative to the wild-type, the mutant also had an aberrant autolysis rate, indicative of compromises in cell envelope integrity. As analyzed using on 96-well plate model and spectrophotometry, biofilm formation by the mutant was decreased significantly, as compared to the wild-type. Consistently, Field Emission-SEM analysis also showed that the PBP1a-deficient mutant had limited capacity to form biofilms. TEM analysis showed that PBP1a mutant existed primarily in long rod-like cells and cells with multiple septa, as compared to the coccal wild-type. The results presented here highlight the importance of pbp1a in cell morphology, stress tolerance, and biofilm formation in S. mutans.

  5. The effect of radioecological condition to earthworms and the problems of ecosystems related with them

    International Nuclear Information System (INIS)

    The soil and fertility was evident and breathe regarding to living materials which are composed of billions of microorganisms and pedobionts also earthworms; throughout of it plants get all chemical elements. Living materials inhabit in lamella of soil, essentially within the scope of 5 to 15 cm of depth. Soil is a main source of carbon in nature. There is for about 10 times more carbone dioxide here (the breath product of soil biota) than in atmosphere. From carbonic acid of air, plants by its terrestrial part extract carbone and by the help of photosynthesis transform it to carbohydrates and tissues. Nowadays investigations about earthworms which live in strongly polluted soils has appeared that earthworms have found a way of a survival even in such extreme conditions. Earthworms have adapted to the polluted soils. However, bait attractive in appearance to dig in such places it is not necessary: in such a way the worm accumulates heavy metals in the organism. Though earthworms aren't so attractive, and for many are simply unpleasant, for an ecosystem they are invaluable. Thus even dying they don't leave after itself any traces, and digest itself by means of cages containing in them - lysis. This process is called autolysis. Thereby for investigation of strongly polluted areas of Ramana iodine plant as an ecosystem and there is significant point to determine the effect of radiation on earthworms as one of the most important chain of soil bionetwork. So, in this way it was investigated an effect of radioactive pollution to earthworms aboriginal for Absheron peninsula. By the experimentation of earthworms in contaminated soil (with 226Ra, 228Ra, U) in respectively 1 percent, 2,5 percent, 5 percent and 10 percent soil examples during a month, it was established that the earthworms so sensible to the high level of radioactive pollution. Regarding to the data received it has a point that usage of earthworms as bio indicators, in future should help people to apply this

  6. 食用油提取番茄中番茄红素的研究%Edible Oil Extraction of Lycopene from Tomato Research

    Institute of Scientific and Technical Information of China (English)

    李莉民; 李金星

    2012-01-01

    番茄红素是一种脂溶性的天然色素,具有较强的抗氧化和防癌、抗癌作用。文章采用自溶法利用植物油脂将番茄中的番茄红索提取出来,提取效率是传统提取方法4倍。并通过实验研究了时间、料液比、浸提次数、搅拌等因素对番茄红素提取效果的影响,确定了最佳的提取工艺条件。用豆油作溶剂,在pH为8的条件下,反应温度35℃,料液比1:1,在0i断搅拌下,浚捉3h,分次进行浸提、过滤、合并浸提液,且进行2级浸捉效果最好。这种方法解决了传统有机溶剂提取番茄红素产率低,并且存在溶剂存昭的问题.简椎方便,适用于工业化生产。%Lycopene is a kind of fat-soluble natural pigment, has strong antioxidant and anti-cancer, anti-cancer effect. The paper adopts the autolysis method using plant oil to tomato lycopene extraction, the extraction efficiency was 4 times of the traditional extraction method. And through experimental study time, ratio of material to liquid, extraction times, mixing and other factors on lycopene extraction effect, the optimum extraction conditions. Using soybean oil as solvent, at pH 8 under the condition of 35 DEG C, reaction temperature, liquid ratio 1:1, constantly stirring, extracting for 3 hours, conducted leaching, filtering, and extract, and 2 stage leaching effect best. This method has solved the traditional organic solvent extraction of lycopene yield is low, and the presence of solvent retention problems, is simple and convenient, suitable for industrialized production.

  7. Alpha-2 Heremans Schmid Glycoprotein (AHSG) Modulates Signaling Pathways in Head and Neck Squamous Cell Carcinoma Cell Line SQ20B

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Pamela D.; Sakwe, Amos [Department of Biochemistry and Cancer Biology, Meharry Medical College, Nashville, TN 37208 (United States); Koumangoye, Rainelli [Division of Surgical Oncology and Endocrine Surgery, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Yarbrough, Wendell G. [Division of Otolaryngology, Departments of Surgery and Pathology and Yale Cancer Center, Yale University, New Haven, CT 06520 (United States); Ochieng, Josiah [Department of Biochemistry and Cancer Biology, Meharry Medical College, Nashville, TN 37208 (United States); Marshall, Dana R., E-mail: dmarshall@mmc.edu [Department of Pathology, Anatomy and Cell Biology, Meharry Medical College, Nashville, TN 37208 (United States)

    2014-02-15

    This study was performed to identify the potential role of Alpha-2 Heremans Schmid Glycoprotein (AHSG) in Head and Neck Squamous Cell Carcinoma (HNSCC) tumorigenesis using an HNSCC cell line model. HNSCC cell lines are unique among cancer cell lines, in that they produce endogenous AHSG and do not rely, solely, on AHSG derived from serum. To produce our model, we performed a stable transfection to down-regulate AHSG in the HNSCC cell line SQ20B, resulting in three SQ20B sublines, AH50 with 50% AHSG production, AH20 with 20% AHSG production and EV which is the empty vector control expressing wild-type levels of AHSG. Utilizing these sublines, we examined the effect of AHSG depletion on cellular adhesion, proliferation, migration and invasion in a serum-free environment. We demonstrated that sublines EV and AH50 adhered to plastic and laminin significantly faster than the AH20 cell line, supporting the previously reported role of exogenous AHSG in cell adhesion. As for proliferative potential, EV had the greatest amount of proliferation with AH50 proliferation significantly diminished. AH20 cells did not proliferate at all. Depletion of AHSG also diminished cellular migration and invasion. TGF-β was examined to determine whether levels of the TGF-β binding AHSG influenced the effect of TGF-β on cell signaling and proliferation. Whereas higher levels of AHSG blunted TGF-β influenced SMAD and ERK signaling, it did not clearly affect proliferation, suggesting that AHSG influences on adhesion, proliferation, invasion and migration are primarily due to its role in adhesion and cell spreading. The previously reported role of AHSG in potentiating metastasis via protecting MMP-9 from autolysis was also supported in this cell line based model system of endogenous AHSG production in HNSCC. Together, these data show that endogenously produced AHSG in an HNSCC cell line, promotes in vitro cellular properties identified as having a role in tumorigenesis. Highlights: • Head

  8. 杂交鲍苗种“病毒性萎缩症(AbSV)”病理学研究%Studies on Pathology of “Shriveling Syndrome Associated Virus(AbSV)” in Juvenile Hybrid Abalone

    Institute of Scientific and Technical Information of China (English)

    杨小强

    2013-01-01

    从福州地区患病杂交鲍苗种组织中分离到一种球形病毒用以感染健康鲍,通过对感染发病的鲍苗进行光镜和电镜观察,发现:病毒主要在消化腺嗜碱性细胞的细胞核中发生;消化腺消化细胞和嗜碱性细胞细胞核异形、染色质固缩,内质网扩张,线粒体嵴断裂、消失;消化腺小叶基膜肌纤维断裂、消失;消化道肠道具微绒毛的柱状细胞和纤毛柱状细胞发生自溶现象;足部肌细胞核浓缩,染色质固缩、边集,肌纤维断裂出现空泡.据此推测,病毒以鲍消化腺嗜碱性细胞为靶细胞,造成消化腺和胃、肠道等消化系统病变,机体因长期营养不良而萎缩,最后因全身性感染出现死亡.%Pathological analysis was done on juvenile hybrid abalone (Haliotisdiscus discus Haliotis discus hannai)artificially infected by a spherical virus isolated from the diseased ones in Fuzhou.Examination of artificially infected juvenile hybrid abalone by optical and electron microscopy showed that the virion mainly developed in nucleus of basophilic cells in digestive gland,and led to nuclear heteromorphosis,chromatin condensation,endoplasmic reticulum expansion,and mitochondria cristae breakage in digestive gland cell and basophilic cell.Meanwhile,broken digestive gland lobule basal lamina muscle fibers,autolysis and pyknosis of microvillus and cilium columnar cell in digestive gland intestinal tract were observed.In foot muscle cells,muscle fibers were broken and vesicles emerged,together with chromatin condensation and margination.These results suggested that the digestive gland basophilic cells maybe the special target cell of this virus,the infection could cause lesion in digestive gland and digestive organs such as stomach,intestines.Atrophy due to long-term malnutrition and systemic infection would finally led to death.

  9. The impact of ColRS two-component system and TtgABC efflux pump on phenol tolerance of Pseudomonas putida becomes evident only in growing bacteria

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    Kivisaar Maia

    2010-04-01

    Full Text Available Abstract Background We have recently found that Pseudomonas putida deficient in ColRS two-component system is sensitive to phenol and displays a serious defect on solid glucose medium where subpopulation of bacteria lyses. The latter phenotype is significantly enhanced by the presence of phenol in growth medium. Here, we focused on identification of factors affecting phenol tolerance of the colR-deficient P. putida. Results By using transposon mutagenesis approach we identified a set of phenol-tolerant derivatives of colR-deficient strain. Surprisingly, half of independent phenol tolerant clones possessed miniTn5 insertion in the ttgABC operon. However, though inactivation of TtgABC efflux pump significantly enhanced phenol tolerance, it did not affect phenol-enhanced autolysis of the colR mutant on glucose medium indicating that phenol- and glucose-caused stresses experienced by the colR-deficient P. putida are not coupled. Inactivation of TtgABC pump significantly increased the phenol tolerance of the wild-type P. putida as well. Comparison of phenol tolerance of growing versus starving bacteria revealed that both ColRS and TtgABC systems affect phenol tolerance only under growth conditions and not under starvation. Flow cytometry analysis showed that phenol strongly inhibited cell division and to some extent also caused cell membrane permeabilization to propidium iodide. Single cell analysis of populations of the ttgC- and colRttgC-deficient strains revealed that their membrane permeabilization by phenol resembles that of the wild-type and the colR mutant, respectively. However, cell division of P. putida with inactivated TtgABC pump seemed to be less sensitive to phenol than that of the parental strain. At the same time, cell division appeared to be more inhibited in the colR-mutant strain than in the wild-type P. putida. Conclusions ColRS signal system and TtgABC efflux pump are involved in the phenol tolerance of P. putida. However, as

  10. Advances in Diagnosis of Rabies

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    Shankar B.P.

    2009-04-01

    Full Text Available Rabies is a major zoonosis for which diagnostic techniques have been standardised internationally. Laboratory techniques are preferably conducted on central nervous system (CNS tissue removed from the cranium. Agent identification is preferably done using the fluorescent antibody test. A drop of purified immunoglobulin previously conjugated with fluorescein isothiocyanate is added to an acetone-fixed brain tissue smear, preferably made from several parts of the brain, including the hippocampus, cerebellum and medulla oblongata. For a large number of samples, as in an epidemiological survey, the immunoenzyme technique can provide rapid results (the rapid rabies enzyme immunodiagnosis. FAT provides a reliable diagnosis in 98-100% of cases for all genotypes if a potent conjugate is used, while RREID detects only genotype 1 virus. Infected neuronal cells have been demonstrated by histological tests and these procedures will reveal aggregates of viral material (the Negri bodies in the cytoplasm of neurones. However, the sensitivity of histological techniques is much less than that of immunological methods, especially if there has been some autolysis of the specimen. Consequently, histological techniques can no longer be recommended. As a single negative test on fresh material does not rule out the possibility of infection, inoculation tests, or other tests, should be carried out simultaneously. Newborn or 3-4-week-old mice are inoculated intracerebrally with a pool of several CNS tissues, including the brain stem, and then kept under observation for 28 days. For any mouse that dies between 5 and 28 days, the cause of death should be confirmed by FAT. Alternatively, a monolayer culture of susceptible cells is inoculated with the same material as used for mice. FAT carried out after appropriate incubation will demonstrate the presence or absence of viral antigen. Wherever possible, virus isolation in cell culture should replace mouse inoculation tests

  11. 功能性麦精的生物提取技术的研究%Research of biological extraction technology of functional malt extract

    Institute of Scientific and Technical Information of China (English)

    段胜林; 王雪; 刘炎桥; 刘士伟; 刘杰

    2012-01-01

    以麦芽、糙米、废弃啤酒酵母为原料,采用生物技术富集γ-氨基丁酸,定向降解生成所需要的糖原和蛋白原,通过一定的配比研究,控制美拉德反应,然后采用连续微波真空干燥技术开发功能性麦精.本文通过单因素实验研究了淀粉酶、蛋白酶定向酶解麦芽的参数,确定蛋白酶的添加量为0.2%、反应温度为50℃、反应时间为1h以及淀粉酶的添加量为0.2%、反应温度为60℃、反应时间为1h;研究了通过促进糙米中谷氨酸脱羧酶的活性富集γ-氨基丁酸,确定添加VB6以及硫酸钙提高γ-氨基丁酸含量;研究了促进啤酒酵母自溶的条件:pH6.0、食盐添加量0.8%、50℃条件下提取4.5h.%In this article, we took malt, brown rice, waste beer yeast as raw materials, using biological technology to enrich γ - Aminobutyric acid, and directional enzyme digestion technology to get the required sugar source and protein source, through the ratio research to control the maillard reaction, and the continuous microwave vacuum drying technology to produce functional malt extract. Through single - factor experiments, the directional degradation parameters of malt were studied, and the best reaction conditions were decided as followings, the protease addition amount was 0. 2% , at temperatur 50℃, reaction for lh; and the amylase addition amount was 0. 2% , at temperature 60℃ , reaction for lh. γ -Aminobutyric acid can be enriched by promoting the activity of glutamic acid decarboxylase catalase in the brown rice, and the contents can be raised by adding VB6 and calcium sulfate. The conditions of accelerating beer yeast autolysis were also studied as followings : pH6, the addition of NaCl was 0. 8% , at temperature 50℃ and extraction for 4. 5hs.

  12. Identification of genes for small non-coding RNAs that belong to the regulon of the two-component regulatory system CiaRH in Streptococcus

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    Hakenbeck Regine

    2010-11-01

    Full Text Available Abstract Background Post-transcriptional regulation by small RNAs (sRNAs in bacteria is now recognized as a wide-spread regulatory mechanism modulating a variety of physiological responses including virulence. In Streptococcus pneumoniae, an important human pathogen, the first sRNAs to be described were found in the regulon of the CiaRH two-component regulatory system. Five of these sRNAs were detected and designated csRNAs for cia-dependent small RNAs. CiaRH pleiotropically affects β-lactam resistance, autolysis, virulence, and competence development by yet to be defined molecular mechanisms. Since CiaRH is highly conserved among streptococci, it is of interest to determine if csRNAs are also included in the CiaRH regulon in this group of organisms consisting of commensal as well as pathogenic species. Knowledge on the participation of csRNAs in CiaRH-dependent regulatory events will be the key to define the physiological role of this important control system. Results Genes for csRNAs were predicted in streptococcal genomes and data base entries other than S. pneumoniae by searching for CiaR-activated promoters located in intergenic regions that are followed by a transcriptional terminator. 61 different candidate genes were obtained specifying csRNAs ranging in size from 51 to 202 nt. Comparing these genes among each other revealed 40 different csRNA types. All streptococcal genomes harbored csRNA genes, their numbers varying between two and six. To validate these predictions, S. mitis, S. oralis, and S. sanguinis were subjected to csRNA-specific northern blot analysis. In addition, a csRNA gene from S. thermophilus plasmid pST0 introduced into S. pneumoniae was also tested. Each of the csRNAs was detected on these blots and showed the anticipated sizes. Thus, the method applied here is able to predict csRNAs with high precision. Conclusions The results of this study strongly suggest that genes for small non-coding RNAs, csRNAs, are part of

  13. Insights into Substrate Specificity of NlpC/P60 Cell Wall Hydrolases Containing Bacterial SH3 Domains

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Qingping; Mengin-Lecreulx, Dominique; Liu, Xueqian W.; Patin, Delphine; Farr, Carol L.; Grant, Joanna C.; Chiu, Hsiu-Ju; Jaroszewski, Lukasz; Knuth, Mark W.; Godzik, Adam; Lesley, Scott A.; Elsliger, Marc-André; Deacon, Ashley M.; Wilson, Ian A.

    2015-09-15

    ABSTRACT

    Bacterial SH3 (SH3b) domains are commonly fused with papain-like Nlp/P60 cell wall hydrolase domains. To understand how the modular architecture of SH3b and NlpC/P60 affects the activity of the catalytic domain, three putative NlpC/P60 cell wall hydrolases were biochemically and structurally characterized. These enzymes all have γ-d-Glu-A2pm (A2pm is diaminopimelic acid) cysteine amidase (ordl-endopeptidase) activities but with different substrate specificities. One enzyme is a cell wall lysin that cleaves peptidoglycan (PG), while the other two are cell wall recycling enzymes that only cleave stem peptides with an N-terminall-Ala. Their crystal structures revealed a highly conserved structure consisting of two SH3b domains and a C-terminal NlpC/P60 catalytic domain, despite very low sequence identity. Interestingly, loops from the first SH3b domain dock into the ends of the active site groove of the catalytic domain, remodel the substrate binding site, and modulate substrate specificity. Two amino acid differences at the domain interface alter the substrate binding specificity in favor of stem peptides in recycling enzymes, whereas the SH3b domain may extend the peptidoglycan binding surface in the cell wall lysins. Remarkably, the cell wall lysin can be converted into a recycling enzyme with a single mutation.

    IMPORTANCEPeptidoglycan is a meshlike polymer that envelops the bacterial plasma membrane and bestows structural integrity. Cell wall lysins and recycling enzymes are part of a set of lytic enzymes that target covalent bonds connecting the amino acid and amino sugar building blocks of the PG network. These hydrolases are involved in processes such as cell growth and division, autolysis, invasion, and PG turnover and recycling. To avoid cleavage of unintended substrates, these enzymes have very selective substrate specificities. Our biochemical and structural

  14. Alpha-2 Heremans Schmid Glycoprotein (AHSG) Modulates Signaling Pathways in Head and Neck Squamous Cell Carcinoma Cell Line SQ20B

    International Nuclear Information System (INIS)

    This study was performed to identify the potential role of Alpha-2 Heremans Schmid Glycoprotein (AHSG) in Head and Neck Squamous Cell Carcinoma (HNSCC) tumorigenesis using an HNSCC cell line model. HNSCC cell lines are unique among cancer cell lines, in that they produce endogenous AHSG and do not rely, solely, on AHSG derived from serum. To produce our model, we performed a stable transfection to down-regulate AHSG in the HNSCC cell line SQ20B, resulting in three SQ20B sublines, AH50 with 50% AHSG production, AH20 with 20% AHSG production and EV which is the empty vector control expressing wild-type levels of AHSG. Utilizing these sublines, we examined the effect of AHSG depletion on cellular adhesion, proliferation, migration and invasion in a serum-free environment. We demonstrated that sublines EV and AH50 adhered to plastic and laminin significantly faster than the AH20 cell line, supporting the previously reported role of exogenous AHSG in cell adhesion. As for proliferative potential, EV had the greatest amount of proliferation with AH50 proliferation significantly diminished. AH20 cells did not proliferate at all. Depletion of AHSG also diminished cellular migration and invasion. TGF-β was examined to determine whether levels of the TGF-β binding AHSG influenced the effect of TGF-β on cell signaling and proliferation. Whereas higher levels of AHSG blunted TGF-β influenced SMAD and ERK signaling, it did not clearly affect proliferation, suggesting that AHSG influences on adhesion, proliferation, invasion and migration are primarily due to its role in adhesion and cell spreading. The previously reported role of AHSG in potentiating metastasis via protecting MMP-9 from autolysis was also supported in this cell line based model system of endogenous AHSG production in HNSCC. Together, these data show that endogenously produced AHSG in an HNSCC cell line, promotes in vitro cellular properties identified as having a role in tumorigenesis. Highlights: • Head

  15. Complete Reconstitution of the Vancomycin-Intermediate Staphylococcus aureus Phenotype of Strain Mu50 in Vancomycin-Susceptible S. aureus.

    Science.gov (United States)

    Katayama, Yuki; Sekine, Miwa; Hishinuma, Tomomi; Aiba, Yoshifumi; Hiramatsu, Keiichi

    2016-06-01

    Complete reconstitution of the vancomycin-intermediate Staphylococcus aureus (VISA) phenotype of strain Mu50 was achieved by sequentially introducing mutations into six genes of vancomycin-susceptible S. aureus (VSSA) strain N315ΔIP. The six mutated genes were detected in VISA strain Mu50 but not in N315ΔIP. Introduction of the mutation Ser329Leu into vraS, encoding the sensor histidine kinase of the vraSR two-component regulatory (TCR) system, and another mutation, Glu146Lys, into msrR, belonging to the LytR-CpsA-Psr (LCP) family, increased the level of vancomycin resistance to that detected in heterogeneous vancomycin-intermediate S. aureus (hVISA) strain Mu3. Introduction of two more mutations, Asn197Ser into graR of the graSR TCR system and His481Tyr into rpoB, encoding the β subunit of RNA polymerase, converted the hVISA strain into a VISA strain with the same level of vancomycin resistance as Mu50. Surprisingly, however, the constructed quadruple mutant strain ΔIP4 did not have a thickened cell wall, a cardinal feature of the VISA phenotype. Subsequent study showed that cell wall thickening was an inducible phenotype in the mutant strain, whereas it was a constitutive one in Mu50. Finally, introduction of the Ala297Val mutation into fdh2, which encodes a putative formate dehydrogenase, or a 67-amino-acid sequence deletion into sle1 [sle1(Δ67aa)], encoding the hydrolase of N-acetylmuramyl-l-alanine amidase in the peptidoglycan, converted inducible cell wall thickening into constitutive cell wall thickening. sle1(Δ67aa) was found to cause a drastic decrease in autolysis activity. Thus, all six mutated genes required for acquisition of the VISA phenotype were directly or indirectly involved in the regulation of cell physiology. The VISA phenotype seemed to be achieved through multiple genetic events accompanying drastic changes in cell physiology. PMID:27067329

  16. Sperm ultrastructure in the nudibranch genus Halgerda with reference to other Discodorididae and to Chromodorididae (Mollusca: Opisthobranchia).

    Science.gov (United States)

    Fahey, Shireen J; Healy, John M

    2003-07-01

    nucleus of Asteronotus. Sperm features alone do not provide a means of defining the genus Halgerda or the family Discodorididae nor do they support the monophyletic status of the caryophyllidia-bearing dorids. Important sperm characters such as the acrosome, nucleus, and midpiece can often still be determined from specimens that have been initially fixed in formalin, then stored in ethanol for extended periods of time (i.e., museum material). Of all sperm features, the mitochondrial derivative of the midpiece is the most resistant to long-term fixation : the survival of acrosomal, nuclear, and axonemal components is variable, presumably a factor of prefixation autolysis, varied primary fixation times and temperatures, formalin quality, and duration of alcohol storage. PMID:12740892

  17. Human decomposition and the reliability of a 'Universal' model for post mortem interval estimations.

    Science.gov (United States)

    Cockle, Diane L; Bell, Lynne S

    2015-08-01

    Human decomposition is a complex biological process driven by an array of variables which are not clearly understood. The medico-legal community have long been searching for a reliable method to establish the post-mortem interval (PMI) for those whose deaths have either been hidden, or gone un-noticed. To date, attempts to develop a PMI estimation method based on the state of the body either at the scene or at autopsy have been unsuccessful. One recent study has proposed that two simple formulae, based on the level of decomposition humidity and temperature, could be used to accurately calculate the PMI for bodies outside, on or under the surface worldwide. This study attempted to validate 'Formula I' [1] (for bodies on the surface) using 42 Canadian cases with known PMIs. The results indicated that bodies exposed to warm temperatures consistently overestimated the known PMI by a large and inconsistent margin for Formula I estimations. And for bodies exposed to cold and freezing temperatures (less than 4°C), then the PMI was dramatically under estimated. The ability of 'Formulae II' to estimate the PMI for buried bodies was also examined using a set of 22 known Canadian burial cases. As these cases used in this study are retrospective, some of the data needed for Formula II was not available. The 4.6 value used in Formula II to represent the standard ratio of time that burial decelerates the rate of decomposition was examined. The average time taken to achieve each stage of decomposition both on, and under the surface was compared for the 118 known cases. It was found that the rate of decomposition was not consistent throughout all stages of decomposition. The rates of autolysis above and below the ground were equivalent with the buried cases staying in a state of putrefaction for a prolonged period of time. It is suggested that differences in temperature extremes and humidity levels between geographic regions may make it impractical to apply formulas developed in

  18. Homology Modeling Study of Bovine μ-Calpain Inhibitor-Binding Domains

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    Han-Ha Chai

    2014-05-01

    Full Text Available The activated mammalian CAPN-structures, the CAPN/CAST complex in particular, have become an invaluable target model using the structure-based virtual screening of drug candidates from the discovery phase to development for over-activated CAPN linked to several diseases, such as post-ischemic injury and cataract formation. The effect of Ca2+-binding to the enzyme is thought to include activation, as well as the dissociation, aggregation, and autolysis of small regular subunits. Unfortunately, the Ca2+-activated enzyme tends to aggregate when provided as a divalent ion at the high-concentration required for the protease crystallization. This is also makes it very difficult to crystallize the whole-length enzyme itself, as well as the enzyme-inhibitor complex. Several parameters that influence CAPN activity have been investigated to determine its roles in Ca2+-modulation, autoproteolysis, phosphorylation, and intracellular distribution and inhibition by its endogenous inhibitor CAST. CAST binds and inhibits CAPN via its CAPN-inhibitor domains (four repeating domains 1–4; CAST1–4 when CAPN is activated by Ca2+-binding. An important key to understanding CAPN1 inhibition by CAST is to determine how CAST interacts at the molecular level with CAPN1 to inhibit its protease activity. In this study, a 3D structure model of a CAPN1 bound bovine CAST4 complex was built by comparative modeling based on the only known template structure of a rat CAPN2/CAST4 complex. The complex model suggests certain residues of bovine CAST4, notably, the TIPPKYQ motif sequence, and the structural elements of these residues, which are important for CAPN1 inhibition. In particular, as CAST4 docks near the flexible active site of CAPN1, conformational changes at the interaction site after binding could be directly related to CAST4 inhibitory activity. These functional interfaces can serve as a guide to the site-mutagenesis in research on bovine CAPN1 structure

  19. Application of oxygen vectors in xanthan gum production%氧载体在黄原胶发酵中的应用

    Institute of Scientific and Technical Information of China (English)

    林琳; 邓春; 龙柯; 程蓉; 张永奎

    2011-01-01

    In xanthan gum fermentation process,the level of dissolved oxygen drops with the viscosity increasing,and the synthesis of xanthan gum is inhibited.Adding oxygen vectors to the system of xanthan gum fermentation is a method to improve oxygen supply.The optimal soybean oil concentration and adding time was 6%(v/v)and 0h,and the optimal n-hexane concentration and adding time was 1%(v/v)and 12h.The addition of soybean oil and n-hexane significantly improved xanthan gum yield to 2.977% and 2.927%,respectively(increased by 49% and 47%,respectively).Although partial autolysis occurred in the soybean oil group,synthesis could still continue in most normal cells by 72h,which made it possible to extend fermentation period.Prolonging fermentation with n-hexane had little effect on the yield,however the capsule around the cell was obviously much thicker than that of control group after 72h fermentation.%黄原胶发酵过程中因发酵液粘度逐渐增加,系统供氧不足,导致黄原胶产率受到影响。为改善发酵系统供氧情况,提高黄原胶产率,本实验研究添加氧载体(大豆油、正己烷、正十二烷)对黄原胶发酵的影响。实验结果表明:发酵初期添加6%(v/v)大豆油、发酵12h添加1%(v/v)正己烷,发酵72h,可分别显著提高黄原胶产率至2.347%和2.927%,相对于空白组分别提高18%和47%;另外,实验发现:大豆油组细胞干重有明显提高,发酵72h后,仍能观察到部分形态正常的细胞,延长发酵周期至84h,黄原胶产率显著提高至2.977

  20. Experimental intoxication of pregnant goats with Tetrapterys multiglandulosa A. Juss. (Malpighiaceae Intoxicação experimental por Tetrapterys multiglandulosa A. Juss. (Malpighiaceae em cabras gestantes

    Directory of Open Access Journals (Sweden)

    M.M. Melo

    2001-02-01

    Full Text Available Green leaves of Tetrapterys multiglandulosa A. Juss were fed to pregnant goats from day 35 of pregnancy. Five goats received 10g/kgBW (group I, five received 20g/kgBW (group II and five were used as control (group III, and received only hay, fresh grass and commercial ration. All animals were clinically examined daily and submitted to ultrasonography every three days. Fetal death and vulvar catarrhal discharge with subsequent abortion were observed at the end of the second month of pregnancy in group II and at the third month of pregnancy in group I. Animals from groups I and II were slaughtered after abortion and necropsied. Goats from the control group were necropsied at the same time. The main lesions in the aborted goats were focal placentitis with early involution (apoptosis and placentary coagulation necrosis, acute focal endometritis and vulvo-vaginal petechiae. All aborted fetuses were underdeveloped when compared to control fetuses, probably due to fetal malnutrition, since no congenital malformations could be noted. The majority of aborted fetuses showed some degree of autolysis, as fetal death occurred five and three days before abortion, in groups I and II, respectively. The most remarkable fetal lesions were focal or diffuse hemorrhages in the skin, meninges and visceral serosae.Com o objetivo de investigar a toxicidade da Tetrapterys multiglandulosa A. Juss. foram utilizadas 15 cabras gestantes, divididas aleatoriamente em três grupos (GI, GII e GIII com cinco animais cada. Após estabelecer o diagnóstico de gestação no tempo médio de 35 dias, eram oferecidas diariamente doses de 10 e 20g/kg PV das folhas (jovens e maduras de Tetrapterys multiglandulosa para os grupos I e II, respectivamente, junto ao capim picado, feno e concentrado. Para o grupo III, usado como controle, foram fornecidos somente capim picado, feno e concentrado. Todos os animais foram submetidos a exames clínicos diários e a ultra-sonografia a cada tr

  1. Estudio epidemiológico del suicidio en Sevilla en 2004 Epidemiological study of suicide in Seville in 2004

    Directory of Open Access Journals (Sweden)

    L. Miguel

    2005-01-01

    previous autolysis intents. Hanging was the most frequent mechanism to commit suicide in men (50.9% while in women was jumping (41,5%. In 57,1% of cases there were antecedents of mental disorder mainly depression of depressive symptoms (65,5% followed by schizophrenia (15,5%. Toxicological analyses were performed in 78,2% of cases with positive results in 69,6%. Ethanol was the toxic most detected (24,3% followed by benzodiazepines (18,3% and antidepressants (11,3%. According to the results of the study, we observe a certain stabilization of the suicide rates in Seville from the middle of the XXth century up to now.

  2. 石蜡包埋乳腺癌组织DNA提取方法%Paraffin-embedded Breast Cancer Tissue DNA Extraction Method

    Institute of Scientific and Technical Information of China (English)

    康毓芝; 王永兴; 杨宝珍; 韩恩善

    2012-01-01

    Objective Explore DNA extraction methods of the paraffin-embedded tissue in breast cancer patients and verified it. Methods 70 cases of large areas of bleeding in 10 ml/dl formalin fixed paraffin-embedded breast cancer tissue with avoid autolysis , degeneration, or organizational structure was unclear, and prevent cross-contamination. After TES solution water bathed dewaxing,successively with PBS buffer (pH7. 2) and 100 ml/dl,95 ml/dl,75 ml/dl ethanol concentration gradient of 60°C incubation of 4 hours,Phenol-chloroform extraction DNA. By polymerase chain reaction (PCR) ,agarose gel electropho-resis and ultraviolet spectrophotometry to measured the A260nm /A280nm value analysis of the quality of the extracted DNA. Results 62 cases (88.57%) paraffin tissue specimen DNA successfully extracted obtained DNA samples from the A260nm/ A280nm ratio (1. 78 + 0. 16) ,This condition of the sample availability of a sufficient number of complete DNA extraction rate, to meet the follow-up clinical research needs. Conclusions The method improved extracting DNA from paraffin-embedded simple,economic and it is ideal means to extract DNA from paraffin-embedded tissues,%目的 探讨一种乳腺癌患者石蜡包埋组织乳腺癌组织DNA提取方法并进行验证.方法 选择无自溶、退变或组织结构不清、大片出血的70例10 ml/dl甲醛固定石蜡包埋乳腺癌组织,在避免交叉污染的情况下,经过TES溶液水浴脱蜡后,先后用PBS缓冲液(pH7.2)及无水、95 ml/dl,75 ml/dl浓度梯度的乙醇60℃温浴4 h;加入含蛋白酶K的裂解液56℃消化72 h后,酚氯仿法抽提DNA.通过聚合酶链反应(PCR)、琼脂糖凝胶电泳及紫外分光光度仪测定A260nm/A280nm值,分析所提取DNA的质量.结果 62例(88.57%)石蜡组织标本DNA获得成功提取,所得DNA样本A260nm/A280nm比值为1.78±0.16,采用此条件处理的样本可获得足够数量的完整DNA,抽提率高,可满足后续临床研究需要.结论 改进的石蜡包埋

  3. Fatores que interferem na qualidade do DNA extraído de amostras biológicas armazenadas em blocos de parafina Factors that affect the quality of DNA extracted from biological samples stored in paraffin blocks

    Directory of Open Access Journals (Sweden)

    Anderson Paulo Scorsato

    2011-10-01

    attempt to prevent cell autolysis, may be a limiting factor at the time of DNA extraction. The quality of DNA obtained in the first two phases is regarded important for post-fixation procedures (DNA extraction and purification. In the literature there are several protocols whose steps can be modified to obtain DNA from paraffin embedded material. Therefore, the understanding of reactions at each stage is important in order to solve or minimize problems that interfere in the quality of DNA macromolecules.

  4. Modelo experimental de tumor na cavidade oral de ratos com carcinossarcoma de Walker 256 Experimental model of Walker 256 carcinosarcoma developed in the oral cavity of rats

    Directory of Open Access Journals (Sweden)

    Ana Paula Negreiros Nunes Alves

    2004-08-01

    Full Text Available OBJETIVO: Estabelecer um modelo experimental de desenvolvimento tumoral na cavidade oral de ratos, permitindo, assim, o estudo da osteólise induzida pelo tumor nos ossos do complexo maxilomandibular como também nas estruturas dentais, através da caracterização histomorfológica da reabsorção óssea e dentária. MÉTODOS: Uma suspensão de células tumorais (0,1mL do Carcinossarcoma de Walker 256, na concentração de 10(6 células/mL foi implantado na cavidade alveolar de ratos previamente aberta por exodontia. Os animais foram observados durante 12 (doze dias consecutivos para determinação da curva de peso corpóreo, sendo posteriormente sacrificados e as mandíbulas removidas para exames radiográfico e histológico. RESULTADOS: No exame radiográfico foi verificada área lítica, sem evidência de reparo, na região dos alvéolos. No exame microscópico foi identificada infiltração óssea, periférica e central, de pequenas células hipercromáticas e pleomórficas, com leve infiltrado inflamatório mononuclear associado e áreas de necrose. O índice de pega foi de 100%. CONCLUSÃO: O modelo animal de invasão óssea, do tumor de Walker na cavidade oral, possibilita a avaliação in vivo de drogas antitumorais e esquemas terapêuticos no tratamento do câncer bucal.PURPOSE: To estabilish an experimental model of tumor development in the oral cavity of rats, that would enable to study the tumor-induced autolysis in the maxillomandibular bone complex as well as of the dental structures, through histomorphological characterization of bone and dental resorption. METHODS: Walker 256 carcinossarcoma cell suspension (0,1 mL containing 10(6 cell/mL was implanted in the alveoli of first and second molars. The animals were observed during twelve consecutive days and the body weigth were determined. Later, the animals were sacrificed and their mandibles removed to radiographic and hystologic analysis. RESULTS: The radiographic image

  5. NUTRITIONAL COMPOSITION AND APPARENT DIGESTIBILITY COEFFICIENT OF WHOLE YEAST, AUTOLYZED YEAST AND YEAST CELL WALL BY NILE TILAPIA COMPOSIÇÃO NUTRICIONAL E DIGESTIBILIDADE APARENTE DALEVEDURA ÍNTEGRA, DA LEVEDURA AUTOLISADA E DA PAREDE CELULAR PELA TILÁPIA-DO-NILO

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    Luiz Edivaldo Pezzato

    2008-04-01

    Full Text Available Nutritional composition and apparent digestibility coefficient of dry matter, crude protein, ether extract, gross energy, essential amino acids and no essential amino acids of spray dried whole yeast, autolyzed yeast and yeast cell wall were evaluated to Nile tilapia. Eighty juveniles (83.0±8.5g were placed in eight 250L aquaria for feeding and four aquaria of the same volume for collecting faecal samples. Both sets were equipped with flow-trough recirculating system provided with mechanical and biological filter. The results were analyzed through comparative relative index and the 100% value corresponded to the whole yeast nutrients. It can be concluded that the whole yeast contains high protein level and good apparent digestibility to nutrients and amino acids; autolysis process improves the dry matter, crude protein, gross energy and the most of essential and no essential amino acids apparent digestibility. Moreover yeast cell wall must not be used as protein source but is suggested as functional foodstuff in Nile tilapia diets.KEY WORDS: Amino acids, Oreochromis niloticus, Saccharomyces cerevisiae A composição nutricional e os coeficientes de digestibilidade aparente para matéria seca, proteína bruta, extrato etéreo, energia bruta, aminoácidos essenciais e aminoácidos não essenciais da levedura de álcool íntegra, levedura autolisada e parede celular spray dried foram avaliados para tilápia-do-nilo. Utilizou-se um total de oitenta peixes (83,0±8,5g, alojados em oito aquários de 250 L para alimentação e quatro de mesmo volume para a coleta de fezes, todos eles dotados de sistema de recirculação contínua de água, com filtro físico-biológico e temperatura controlada. Procedeu-se à avaliação dos resultados por meio do índice relativo de compara

  6. Composição centesimal e valor protéico de levedura residual da fermentação etanólica e de seus derivados Centesimal composition and protein nutritive value of yeast from ethanol fermentation and of yeast derivatives

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    Eunice Akemi Yamada

    2003-12-01

    Full Text Available Este trabalho teve por objetivo promover a autólise e o fracionamento da levedura (Saccharomyces sp. para produção de autolisado e extrato, bem como para produção de concentrado protéico fosforilado, a partir da levedura residual das destilarias de álcool etílico. Foram estudados a composição centesimal, o perfil de aminoácidos essenciais e o valor protéico dos três derivados comparativamente à levedura íntegra não processada. Proteína e carboidrato (fibra alimentar foram os principais componentes da levedura íntegra e do autolisado. No extrato e no concentrado protéico predominaram proteína e minerais (cinzas. O autolisado e a levedura íntegra apresentaram os melhores índices de aminoácidos essenciais, seguidos pelo concentrado protéico e pelo extrato. A digestibilidade da proteína variou de 68% para a levedura íntegra a 91% para o extrato. Os índices de quociente de utilização líquida da proteína variaram de 2,1 para a levedura íntegra a 4,3 para a caseína (referência. Não houve diferença estatística no quociente de utilização líquida da proteína entre o autolisado (4,1, o extrato (3,9 e o concentrado protéico (4,2. O concentrado protéico promoveu o maior crescimento no período (21 dias, seguido do extrato e o autolisado. As células íntegras apresentaram a menor capacidade para promover crescimento em rato.The objective of this work was to promote the autolysis and the fractionation of the yeast (Saccharomyces sp. for the production of autolysate and extract, as well as phosphorylated protein concentrate, from ethanol distillery yeast. Comparative studies of centesimal composition, essential amino acid profiles and protein nutritive value were performed for the unprocessed integral cells, and for autolysate, extract and phosphorylated protein concentrate. Protein and carbohydrate (dietary fiber were the main components for the integral cells and autolysate. For the extract and the protein

  7. Análise imuno-histoquímica de cães naturalmente infectados pelo parvovírus canino Immunohistochemical analysis of dogs infected naturally by canine parvovirus

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    Eduardo C. Oliveira

    2009-02-01

    immunohistochemistry test was performed in tissues of small intestine, mesenteric lymph nodes, thymus, spleen, tonsils, tongue, and bone marrow in all the 96 selected cases. Parvovirus antigen was detected in 91.6% (88/96 of the dogs necropsied. The best result of the IHC test was seen in samples of small intestine which was positive in 77% (74/96 of the cases. The statistical analysis (Fisher test showed a weak association between intestinal autolysis and positive result of the IHC test. The chance of the autolysed intestine showing a positive result in the immunohistochemistry test was 0.33 less (OR=0.33, 95% CI:0.10-1.17 when compared with small intestine not autolysed.

  8. 溴隐亭治疗垂体腺瘤后超微结构改变和相关基因表达的研究%Medical management of pituitary adenomas: a study of ultrastructural changes and receptor expressions

    Institute of Scientific and Technical Information of China (English)

    吴哲褒; 诸葛启钏; 张亚卓; 孙异临; 陈勇; 王成德; 苏志鹏; 吕庆平; 吴近森; 郑伟明

    2011-01-01

    otroph adenomas,8 sparsely granulated lactotroph adenomas showed that cytoplasm was shrunken and the karyoplasmic ratio was enlarged.Ultrastructural analysis confirmed a series of changes including nuclear chromatin aggregation and margination,marked reduction of rough endoplasmic reticulum and Golgi complexes, vascular degenerations, necrosis and autolysis of tumor cells with dark cell or naked nuclear cell Compared to prolactinomas,NFPAs had little changes in cell size and cytoplasmic apparatus but also had chromatin aggregation, cytoplasmic vacuolization and unconspicuous necrosis of tumor cell.Conclusions This study shows the differential expression of ER mRNA and D2R mRNA isoforms between prolactinomas and NFPAs.Comparinb to prolactinomas,NFPAs with medical treatment also have some ultrastructural changes according to their exression levels of D2R isoforms.Ultrastructural changes in those adenomas are closely correlated with the expression levels of D2R isoforms.

  9. Release rules of phosphorus and relevant indicator of excess sludge under anaerobic condition%厌氧条件下剩余污泥中磷及相关指标的释放和变化规律

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    孙连鹏; 谭锦欣; 郭五珍; 叶挺进; 欧伟松

    2014-01-01

    the system. Through analysis of the system parameters changes under anaerobic conditions, total phosphorus concentration and ammonia concentration in the supernatant were got, that is very important to provide conditions for the following sludge phosphorus recovery. The results show that, in the system of 5 days SRT under anaerobic conditions, microbial decay autolysis or decomposed in residual sludge, and intracellular substances was released, so the solid matter was changed into liquid, phosphorus, nitrogen and other related substances have been released. The concentration of total phosphorus and ammonia nitrogen in supernatant could reach 100 mg·L-1 and 40 mg·L-1, respectively. The concentration of nitrogen and phosphorus released was demanded to the minimum required to meet the economic requirements of struvite recovery method. The results provide important basis for nitrogen and phosphorus recovery using struvite method. SS and VSS were all found decreased, that were reduced more than 8.34% and 10.14%, respectively. The reduced mass of VSS was accounted for about 65%of the SS reduced mass. In additional, initial sludge concentration in anaerobic reaction system was great influence for releasing mass of nitrogen and phosphorus. Releasing mass of phosphorus and nitrogen was reached most under 6 300-7 200 mg·L-1of SS, that is 0.015 mg·mg-1 and 0.006 mg·mg-1 per unit dry sludge, respectively. The research results provide an important basis for the recovery of nitrogen and phosphorus in sludge.

  10. Development of a local baiting system for the control of the Africa invader fly, (Bactrocera invadens) Drew, Tsuruta and White (Diptera: Tephritidae) in mango orchards at Somanya, Eastern Ghana

    International Nuclear Information System (INIS)

    Fruit production plays an important role in Africa's economy. In Ghana, mango is targeted as one of the next non-traditional export crop that is expected to fetch the highest foreign exchange for the country and replace cocoa. Ghana's current production is said to have increased from 6,800 tonnes in 2007 to about 7000 tonnes in 2010. However, the African invader fruit fly, Bactrocera invadens, is causing high yield losses as an important quarantine pest and has brought some setback in the mango trade between Ghana and their exporting destinations. Imported commercial protein hydrolysate bait for controlling the flies constitutes the highest cost component of the control programme, excluding cost of labour. The baits are exhorbitant for local farmers and seldom available. This setback has called for the need to design and implement efficient and cost-effective control regimes for managing this pest. The objective of the study was to explore the development of locally produced, cheap and efficient baiting system using brewery yeast wastes and coloured cylinder traps to attract and control this quarantine pest. A 1 ha study area was selected within DORMEHSCO FARM, a mango orchard at Somanya in the Eastern region of Ghana with the Keith mango variety for the study. Local sources of Guiness, Beer and Pito yeast wastes were collected into Winchester bottles and subjected to pasteurisation. Papain enzyme was added to maximize yeast cell autolysis at 70 degrees celcius for 9 hours. The Micro-Kjeldahl apparatus was used to determine the percentage protein in each waste. Transparent cylinder traps with three different colours of lids (red, yellow and green) and three 3cm diameter round holes referred to as coloured traps were used to dispense the baits. The traps were labelled according to the type of bait and trap colour combination. The trials were conducted in two successive peak fruiting seasons fron October to November, 2011 (minor season and then from April to June

  11. Progesterone levels in the ovarian uterine and systematic venous blood in alpacas with embryo mortality

    International Nuclear Information System (INIS)

    important, because it means that several females that can be diagnosed as pregnant at the middle or final part of breeding season will result open in delivery period, without opportunity to be breed, in order to improve birth rate in the flock. The process can be explained in ultrasound images, embryo degeneration, which it is suggested an autolysis process, that occur after cardiac beat suspension, gradual decreasing of placental fluids volume, that finish with the presence of remnants, as reported by Ginther (1985). This process would not involucrate the progesterone secretion of CL, because in the 3 cases, it is evident that serum hormone levels are higher than 1 ng/ml in ovarian vein blood, and that is considered as functional corpus luteum (Raggi, 1999). When comparing progesterone levels in Case 1 with gestation and diestrus serum progesterone concentrations, values were similar, but highly different from serum progesterone levels originated from ovaric vein in alpacas 1 and 13 days post breeding, where values for progesterone were basal, and that is coincident with follicles in ovaries (Echevarria, 2007). Progesterone level in ovarian vein sample is in relation to ovarian progesterone secretion as was showed by Stefanczyk-Krzymowska (1998), because this blood vessel has its origin in the ovary, later it receives affluent from uterus. Progesterone levels in uterine vein sample resulted similar with jugular vein, possibly because a dilution of progesterone concentration with blood from uterus. Progesterone secretion from ovary is compatible with a functional corpus luteum in these cases of embryo mortality in alpacas, so it would not be involved in the origin of the process. (author)

  12. Intoxicação aguda e abortos em cobaias pelas favas de Enterolobium contortisiliquum (Leg. Mimosoideae Acute poisoning and abortions in guinea pigs by the pods of Enterolobium contortisiliquum (Leg. Mimosoideae

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    Josiane Bonel-Raposo

    2008-12-01

    properties of Enterolobium contortisiliquum pods in guinea pigs. Pods of E. contortisiliquum were administered orally to 4 groups of 3 guinea pigs each. Another group of 3 guinea-pigs was used as control. Group 1 and 2 were fed with one dose of 5 and 10g of pods for kg body weight, respectively. The guinea pigs of Group 3 and 4 received 10 and 15g/kg, respectively, divided into daily doses of 5g/kg. One guinea pig from Group 2 and one from Group 4 died 12 and 18 hours after the end of the administration. Gross lesions were hemorrhages of the stomach and of the large and small gut, enlarged liver, and dilated gall bladder. Histologically, the liver had severe vacuolation and necrosis of periportal hepatocytes. In another experiment a ration containing 4% of pods of E. contortisiliquum was fed to 2 groups of 4 guinea-pigs, 35 days after mating. Four of the 8 guinea pigs aborted 6-15 days after the beginning of ingestion. The other 4 guinea pigs were not pregnant. All guinea pigs were euthanized after abortion or at the end of the experiment. Histologically all animals had mild to severe periportal hemorrhagic necrosis. All fetuses had variable degree of autolysis. In 4 fetuses studied no significant histologic lesions were observed. The acute lesions observed in guinea-pigs are similar than those observed in the spontaneous poisoning by Enterolobium spp. in cattle. Similar lesions are observed in guinea-pigs poisoned experimentally with saponins from E. gummiferum. The results of the experiments in pregnant guinea pigs suggest that E. contortisiliquum can be used to study the abortive effect of its pods or its toxic compounds.

  13. Predictive factors of breast cancer evaluated by immunohistochemistry Fatores preditivos do câncer de mama avaliados pela imuno-histoqu��mica

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    Helenice Gobbi

    2008-04-01

    Full Text Available Hormone receptor and Her2 protein overexpression evaluated by immunohistochemistry (IHC is widely validated as a predictive factor in breast cancer. The quality of the IHC reaction is influenced by tissue fixation and processing. Over- and underfixation deeply affect IHC results. Antigen retrieval may improve IHC but it does not recover tissue from autolysis or overfixation. The choice of primary antibody for IHC as to its sensitivity and specificity in relation to therapeutic response represents an important stage. Apart from mouse monoclonal antibodies, new rabbit monoclonal antibodies are commercially available, such as clones anti-ER SP1 and B644, anti-PR SP2 and B645 and anti-Her2 SP3 and 4B5. They represent an alternative to hormone receptor and Her2 evaluation by IHC. New polymeric non-biotinylated detection systems are also available and allow accurate and strong marking with no stromal and no non-specific cytoplasmic staining due to endogenous biotin. The most recommended cut off for estrogen and progesterone receptors (ER and PR is more than 1% of positive cells with moderate or strong staining intensity (Allred's scoring system. New guidelines for Her2 evaluation by IHC show a cut off of more than 30% of positive cells with strong intensity (3+ that correlates better with gene amplification. The 2+ cases are now considered indeterminate and should be confirmed by fluorescence in situ hybridisation (FISH or chromogenic in situ hybridisation CISH. A quality control of pre-analytical, analytical and post-analytical phases of IHC is recommended in order to optimize results.A superexpressão de receptores hormonais e Her2 avaliada pela imuno-histoquímica (IHQ é amplamente validada como fator preditivo em câncer de mama. A qualidade da reação imuno-histoquímica é influenciada pela fixação do tecido e seu processamento. A fixação insuficiente ou demasiada afeta profundamente os resultados da IHQ. A reativação antigênica pode

  14. Doenças de bovinos no Sul do Brasil: 6.706 casos Diseases of cattle in southern Brazil: 6.706 cases

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    Ricardo B. Lucena

    2010-05-01

    exams 29.9% were necropsies performed at the LPV-UFSM and 79.1% were mailed-in organ fragments from necropsies performed at the field by veterinary practitioners. Autolysis and non-representative sampling o mailed in organs were the main reasons for non-conclusive diagnosis. Poisoning by Senecio spp. was the main cause of death in cattle in this study and poisonous plants together with toxi-infections accounted for 22.8% of the cases with conclusive diagnosis. Inflammatory diseases together with parasitic diseases accounted for more than 30% of cattle diseases and babesiosis and anaplasmosis were the main diseases in this category. Other categories were distributed in the following order: neoplasms and tumor-like lesions (13.87%, diseases caused by physical agents (2.7%, metabolic and nutritional diseases (2.46%, circulatory disturbances (1.4%, degenerative diseases (1.1%, developmental disorders (0.54%, iatrogenic diseases and sundry lesions. The high prevalence of tumors in cattle in this study was attributed to the chronic ingestion of Pteridium aquilinum, a common toxicosis in the region. The main diseases in cattle from the studied region are related to environmental factors associated to the predominantly husbandry practices adopted in the region.

  15. Quantitative synaptic alterations in human brain during normal aging and in patients with Alzheimer disease%正常增龄及阿尔茨海默病患者脑组织中突触密度改变的定量观察

    Institute of Scientific and Technical Information of China (English)

    许丹; 胡亚卓; 桂秋萍; 朱明伟; 张红红; 王鲁宁

    2005-01-01

    particularly strong over layers Ⅱ and Ⅲ in frontal lobe, and layer ⅣV in occipital lobe. ② Synaptophysin density was negatively correlated with age, which was -0.688 in frontal lobe, -0.592 in occipital lobe, -0.458 in putamen and -0.619 in hippocampal CA2 area,respectively (P = 0.000, 0.001, 0.014, and 0.000). ③ Significant difference in synaptic density in CA3 area was found between AD patients (0.031 3±0.003 0)and normal subjects over the age of 75 (0.040 7±0.005 3) (Z=-2.997, P=0.001)in nonparametric test.CONCLUSION: ① Synaptic density was found to decrease in frontal lobe, occipital lobe, CA3 area of hippocampus and putamen with age; the changes had significant correlation with age. ② Synaptic density of AD patients was lower than that of normal subjects, and their cognitive hypofunction was related to synaptic loss. ③ All tissues were obtained after 8-72 hours of death and fixed over 6 weeks, which to the greatest extent reduced the effects of tissue autolysis and formalin fixation on the results.