Lipases from thermophiles have gained interest in recent years as it has various applications in industries. It plays a significant role in industries as it has high stability and resistant to chemical denaturation. Its extensive application in industries requires its production in a large scale. In this study, thermostable lipase production by Geobacillus thermodenitrificans in a 5-L stirred tank bioreactor was evaluated. The cultivation was carried out for 96 hours at 55 oC in a cultivation medium containing (%; w/v or v/v): glucose 1.0; yeast extract 1.25; NaCl 0.45 and olive oil 0.1. Optimization of physical parameters in the bioreactor will improve the production of the thermosatble lipase. Different physical parameters affecting enzyme production and biomass concentration such as agitation rate (100, 200, 300, 400 and 500 rpm), aeration rate (1, 2, 3 and 4 lpm) and inoculum concentration [0.5, 1.0, 1.5, 2.0, and 2.5% (v/v; 5 x 10 cell/ml)] were evaluated. Thermostable lipase activity was enhanced by 53% in the bioreactor and the biomass concentration increased by 23% after optimizing the physical parameters in the stirred tank bioreactor. Maximum lipase activity of 180 U/ml was obtained at 72 hours of cultivation at 2 lpm, 400 rpm and 2% (v/v; 5 x 10 cell/ml) inoculum with a specific activity of 3.62 U/mg. Thermostable lipase production in the bioreactor was about six-fold higher than that attained in a shake flasks culture. From the results obtained in this study, it is possible of producing thermostable lipase in a large-scale which has an extensive application in industry.
{"title":"Thermostable Lipase Production By Geobacillus Thermodenitrificans In A 5-L Stirred-Tank Bioreactor","authors":"A. Balan, Nisha Magalinggam, D. Ibrahim, R. Rahim","doi":"10.5580/240","DOIUrl":"https://doi.org/10.5580/240","url":null,"abstract":"Lipases from thermophiles have gained interest in recent years as it has various applications in industries. It plays a significant role in industries as it has high stability and resistant to chemical denaturation. Its extensive application in industries requires its production in a large scale. In this study, thermostable lipase production by Geobacillus thermodenitrificans in a 5-L stirred tank bioreactor was evaluated. The cultivation was carried out for 96 hours at 55 oC in a cultivation medium containing (%; w/v or v/v): glucose 1.0; yeast extract 1.25; NaCl 0.45 and olive oil 0.1. Optimization of physical parameters in the bioreactor will improve the production of the thermosatble lipase. Different physical parameters affecting enzyme production and biomass concentration such as agitation rate (100, 200, 300, 400 and 500 rpm), aeration rate (1, 2, 3 and 4 lpm) and inoculum concentration [0.5, 1.0, 1.5, 2.0, and 2.5% (v/v; 5 x 10 cell/ml)] were evaluated. Thermostable lipase activity was enhanced by 53% in the bioreactor and the biomass concentration increased by 23% after optimizing the physical parameters in the stirred tank bioreactor. Maximum lipase activity of 180 U/ml was obtained at 72 hours of cultivation at 2 lpm, 400 rpm and 2% (v/v; 5 x 10 cell/ml) inoculum with a specific activity of 3.62 U/mg. Thermostable lipase production in the bioreactor was about six-fold higher than that attained in a shake flasks culture. From the results obtained in this study, it is possible of producing thermostable lipase in a large-scale which has an extensive application in industry.","PeriodicalId":22514,"journal":{"name":"The Internet journal of microbiology","volume":"78 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2009-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82327995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The antimicrobial effectiveness of extracts of garlic, ginger and lime on Escherichia coli, Salmonella spp., Shigella spp. and Bacillus cereus were ascertained and compared with that of the conventional antibiotics of Amoxicillin and Ampicillin using the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). The plant extracts showed varied activity on the test organisms with garlic showing a stronger antimicrobial activity of 150mg/ml, 50mg/ml and 100mg/ml on Salmonella, Shigella and Bacillus respectively compared to MIC of 250mg/ml of lime extracts on both Salmonella and Shigella and 150mg/ml on Bacillus spp. whilst ginger was totally ineffective at the highest concentration of 500mg/ml on all test organisms. MBC’s of garlic extract on Shigella and Bacillus cereus was generally lower compared with Lime. The lowest and highest MBC’s was shown by garlic on Shigella (150mg/ml) and Salmonella (500mg/ml) respectively. Generally, the MIC’s and MBC’s of the conventional antibiotics were lower compared with the plant extracts. However, garlic exhibited similar antimicrobial activity as Amoxicillin on Shigella (MIC=50mg/ml) and Bacillus cereus (MIC=100mg/ml) with no difference in Least Significant Difference (M1-M3=78.6254). Garlic also retained the same MIC activity with Ampicillin on Shigella (50mg/ml). The MBC’s of garlic and Amoxicillin were the same (200mg/ml). This study confirms the antimicrobial potential of these plants extracts especially garlic on the test bacteria and suggests the possibility of employing them as household remedies to some bacterial infections.
{"title":"A Comparison of the Antimicrobial Effectiveness of Aqueous Extracts of Garlic, Ginger and Lime and Two Conventional Antibiotics on Escherichia coli, Salmonella spp., Shigella spp. and Bacillus cereus.","authors":"D. Tagoe, F. Gbadago","doi":"10.5580/34f","DOIUrl":"https://doi.org/10.5580/34f","url":null,"abstract":"The antimicrobial effectiveness of extracts of garlic, ginger and lime on Escherichia coli, Salmonella spp., Shigella spp. and Bacillus cereus were ascertained and compared with that of the conventional antibiotics of Amoxicillin and Ampicillin using the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). The plant extracts showed varied activity on the test organisms with garlic showing a stronger antimicrobial activity of 150mg/ml, 50mg/ml and 100mg/ml on Salmonella, Shigella and Bacillus respectively compared to MIC of 250mg/ml of lime extracts on both Salmonella and Shigella and 150mg/ml on Bacillus spp. whilst ginger was totally ineffective at the highest concentration of 500mg/ml on all test organisms. MBC’s of garlic extract on Shigella and Bacillus cereus was generally lower compared with Lime. The lowest and highest MBC’s was shown by garlic on Shigella (150mg/ml) and Salmonella (500mg/ml) respectively. Generally, the MIC’s and MBC’s of the conventional antibiotics were lower compared with the plant extracts. However, garlic exhibited similar antimicrobial activity as Amoxicillin on Shigella (MIC=50mg/ml) and Bacillus cereus (MIC=100mg/ml) with no difference in Least Significant Difference (M1-M3=78.6254). Garlic also retained the same MIC activity with Ampicillin on Shigella (50mg/ml). The MBC’s of garlic and Amoxicillin were the same (200mg/ml). This study confirms the antimicrobial potential of these plants extracts especially garlic on the test bacteria and suggests the possibility of employing them as household remedies to some bacterial infections.","PeriodicalId":22514,"journal":{"name":"The Internet journal of microbiology","volume":"61 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2009-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80575746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Objective: In this study 20 Lactobacillus strains isolated from different sources were selected for an account of their high bile-salt hydrolase (BSH) activity, bile-salt resistance, and tolerance to the toxicity of bile salts. Method: Bile salt hydrolase and resistance to toxic effects of bile salts were checked by assay for Deconjugation of bile salts and by toxicity of conjugated bile salt assay Results: A total of 20 isolates were tested for hydrolase activity of conjugated bile salts sodium salt taurocholic acid and glycocholic acid while toxicity of bile salts was in MRS broth supplemented various concentrations of bile salts. Out of 20 strains 2 strains displayed the largest precipitation zones were selected for toxicity assay. . Conclusion: The present study suggested that the finally two indigenous isolated of Lactobacillus from Pakistan has an excellent hypocholesterolemic effects. They will be used as a Probiotics to prevent hypercholesterolemia from human health while the mechanisms of regulating serum cholesterol and the effect on serum cholesterol level in vivo needs further extensive investigations.
{"title":"Bile Salt Hydrolase Activity Screening and Resistance to the Toxicity of Bile Salt by Indigenous Lactobacillus Isolates of Pakistan; A Research Article","authors":"N. Ahmed, Sadaf Ajmal, S. Pervez","doi":"10.5580/10b2","DOIUrl":"https://doi.org/10.5580/10b2","url":null,"abstract":"Objective: In this study 20 Lactobacillus strains isolated from different sources were selected for an account of their high bile-salt hydrolase (BSH) activity, bile-salt resistance, and tolerance to the toxicity of bile salts. Method: Bile salt hydrolase and resistance to toxic effects of bile salts were checked by assay for Deconjugation of bile salts and by toxicity of conjugated bile salt assay Results: A total of 20 isolates were tested for hydrolase activity of conjugated bile salts sodium salt taurocholic acid and glycocholic acid while toxicity of bile salts was in MRS broth supplemented various concentrations of bile salts. Out of 20 strains 2 strains displayed the largest precipitation zones were selected for toxicity assay. . Conclusion: The present study suggested that the finally two indigenous isolated of Lactobacillus from Pakistan has an excellent hypocholesterolemic effects. They will be used as a Probiotics to prevent hypercholesterolemia from human health while the mechanisms of regulating serum cholesterol and the effect on serum cholesterol level in vivo needs further extensive investigations.","PeriodicalId":22514,"journal":{"name":"The Internet journal of microbiology","volume":"58 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2009-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74791799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An indigenously isolated strain of Aspergillus tubingensis NIICC-08155 from soil of teak dominated vegetation of kusmi forest at Gorakhpur was subjected to neutral protease production and its partial characterization. The maximum production of neutral protease i.e. 68.50 U/ml was attained after 96h of incubation. The crude preparation of protease showed reasonable activity at temperature range of 40 to 60 °C with maximum activity at 40 oC and had a maximum enzyme activity at pH 6.4. The Km value of the enzyme was found to be 45.0 mg/ml and the molecular weight as determined by SDS-PAGE was approximately 45 kDa. The enzyme was completely inhibited by DTT and EDTA.
{"title":"Production and partial characterization of neutral protease by an indigenously isolated strain of Aspergillus tubingensis NIICC-08155","authors":"V. Morya, D. Yadav","doi":"10.5580/1b13","DOIUrl":"https://doi.org/10.5580/1b13","url":null,"abstract":"An indigenously isolated strain of Aspergillus tubingensis NIICC-08155 from soil of teak dominated vegetation of kusmi forest at Gorakhpur was subjected to neutral protease production and its partial characterization. The maximum production of neutral protease i.e. 68.50 U/ml was attained after 96h of incubation. The crude preparation of protease showed reasonable activity at temperature range of 40 to 60 °C with maximum activity at 40 oC and had a maximum enzyme activity at pH 6.4. The Km value of the enzyme was found to be 45.0 mg/ml and the molecular weight as determined by SDS-PAGE was approximately 45 kDa. The enzyme was completely inhibited by DTT and EDTA.","PeriodicalId":22514,"journal":{"name":"The Internet journal of microbiology","volume":"80 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2009-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75813210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A soil isolate of Lactic acid bacteria (LAB), strain LR/6 was identified as Enterococcus faecium on the basis of its morphological, biochemical, and 16S rDNA analysis. Strain LR/6 is a potential producer of an antimicrobial compound that followed the kinetic pattern typical of a primary metabolite synthesis and is released extracellularly. The antimicrobial action remained unaffected when treated with β-glycerophosphate and catalase suggesting that the activity is neither based on acid nor H2O2 production. This antimicrobial compound was highly stable over a wide range of pH (2.0 to 8.0), high temperature (boiling and autoclaving) and could be stored stably at a range of temperature (-20oC to 37oC) at least upto one year. The proteinaceous nature of the antimicrobial compound was ascertained by its sensitivity to many proteolytic enzymes confirming it to be a bacteriocin. Strain LR/6 bacteriocin was also insensitive to the presence of α-amylase, lipase, surfactants, organic solvents, and showed a bactericidal mode of action. Crude bacteriocin exhibited broad inhibition spectrum both against related as well as some foodborne pathogenic bacteria including Listeria monocytogenes. Tricine SDS-PAGE analysis and bacteriocin activity assay corresponded to a protein of an apparent molecular mass of ~6.0 kDa.
{"title":"Production and characterization of a bacteriocin produced by Enterococcus faecium LR/6","authors":"Manoj Kumar, N. Ghosh, S. Srivastava","doi":"10.5580/1530","DOIUrl":"https://doi.org/10.5580/1530","url":null,"abstract":"A soil isolate of Lactic acid bacteria (LAB), strain LR/6 was identified as Enterococcus faecium on the basis of its morphological, biochemical, and 16S rDNA analysis. Strain LR/6 is a potential producer of an antimicrobial compound that followed the kinetic pattern typical of a primary metabolite synthesis and is released extracellularly. The antimicrobial action remained unaffected when treated with β-glycerophosphate and catalase suggesting that the activity is neither based on acid nor H2O2 production. This antimicrobial compound was highly stable over a wide range of pH (2.0 to 8.0), high temperature (boiling and autoclaving) and could be stored stably at a range of temperature (-20oC to 37oC) at least upto one year. The proteinaceous nature of the antimicrobial compound was ascertained by its sensitivity to many proteolytic enzymes confirming it to be a bacteriocin. Strain LR/6 bacteriocin was also insensitive to the presence of α-amylase, lipase, surfactants, organic solvents, and showed a bactericidal mode of action. Crude bacteriocin exhibited broad inhibition spectrum both against related as well as some foodborne pathogenic bacteria including Listeria monocytogenes. Tricine SDS-PAGE analysis and bacteriocin activity assay corresponded to a protein of an apparent molecular mass of ~6.0 kDa.","PeriodicalId":22514,"journal":{"name":"The Internet journal of microbiology","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2009-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76439488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cold-active enzymes have recently received great attention due to their potential applications in a broad range of industrial, agricultural and medical processes. One of the enzymes is lipase (triacyglycerol acylhydrolases E.C 3.1.1.3) which is unique in catalyzing the hydrolysis of triacylglycerols into free fatty acids and glycerol. In this particular research, an obligate psychrophilic microorganism was isolated from Casey Station, Antarctica. The growth of this microorganism has been tested at different temperatures, 4C, 27C and 37C. At 4C, the microorganism was able to grow whereas at 27C and 37C, there was no growth at all. The presence of lipase enzyme in this microorganism was detected by halo zone on palm oil (substrate) agar plates. Identification of this microorganism was done based on its morphological, biochemical and molecular characteristics. For the morphology analysis, two types of microscopy observation were carried out: phase contrast microscopy and Scanning Electron Microscopy (SEM). Both observations showed budding structures. This suggested that this particular microorganism is psychrophilic yeast. Biochemical tests were done based on its capability to ferment and assimilate sugar. In addition, assimilation of nitrate was also tested. In molecular approach, the genomic DNA (gDNA) of this microorganism was successfully extracted and the extracted gDNA was used for amplification via polymerase chain reaction (PCR) technique using Internal Transcribed Spacer (ITS) primers. The PCR product obtained was sequenced and submitted for Basic Local Alignment Search Tool (BLAST) at National Center for Biotechnological Information (NCBI). The analysis showed that this microorganism contained ITS sequences (highest identity with Leocosporidium sp.).
{"title":"Identification Of Lipase – Producing Psychrophilic Yeast, Leucosporidium Sp.","authors":"F. Rashid, R. Rahim, D. Ibrahim","doi":"10.5580/1215","DOIUrl":"https://doi.org/10.5580/1215","url":null,"abstract":"Cold-active enzymes have recently received great attention due to their potential applications in a broad range of industrial, agricultural and medical processes. One of the enzymes is lipase (triacyglycerol acylhydrolases E.C 3.1.1.3) which is unique in catalyzing the hydrolysis of triacylglycerols into free fatty acids and glycerol. In this particular research, an obligate psychrophilic microorganism was isolated from Casey Station, Antarctica. The growth of this microorganism has been tested at different temperatures, 4C, 27C and 37C. At 4C, the microorganism was able to grow whereas at 27C and 37C, there was no growth at all. The presence of lipase enzyme in this microorganism was detected by halo zone on palm oil (substrate) agar plates. Identification of this microorganism was done based on its morphological, biochemical and molecular characteristics. For the morphology analysis, two types of microscopy observation were carried out: phase contrast microscopy and Scanning Electron Microscopy (SEM). Both observations showed budding structures. This suggested that this particular microorganism is psychrophilic yeast. Biochemical tests were done based on its capability to ferment and assimilate sugar. In addition, assimilation of nitrate was also tested. In molecular approach, the genomic DNA (gDNA) of this microorganism was successfully extracted and the extracted gDNA was used for amplification via polymerase chain reaction (PCR) technique using Internal Transcribed Spacer (ITS) primers. The PCR product obtained was sequenced and submitted for Basic Local Alignment Search Tool (BLAST) at National Center for Biotechnological Information (NCBI). The analysis showed that this microorganism contained ITS sequences (highest identity with Leocosporidium sp.).","PeriodicalId":22514,"journal":{"name":"The Internet journal of microbiology","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2009-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89007337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Spores of a Streptomyces lividans strain (donor) bearing the recombinant conjugative plasmid pIJ303, which codes for thiostrepton resistance, and spores of a plasmid-free Streptomyces parvulus strain (recipient) were added together to finelysieved, sterile silt loam soil. This bulk soil was adjusted to either 20%, 35% or 45% of the soil’s water holding capacity. To this inoculated bulk soil were added sterile, nutrientamended, artificial soil aggregates. After incubation to allow streptomycete growth and aggregate colonization, both the sieved bulk soil and the aggregates were assayed for numbers of transconjugants by spreadplanting on a thiostrepton – agar selective medium. This allowed estimation of parental ability to colonize nutrient – rich soil sites at different soil moisture levels, and comparison of plasmid exchange frequency in the nonamended bulk soil versus the nutrient – rich soil aggregates. Plasmid exchange was detected only on aggregates of about 20% water holding capacity or less (4.2% wt/wt H20). The soil moisture threshold for heterotrophic streptomycete activity appeared to lie between 2.87% and 4.2% wt/wt H20 for the nutrientamended soil aggregates.
{"title":"Exchange of a Conjugative Plasmid At Different Soil Moisture Levels Between Streptomyces Species Colonizing Artificial Soil Aggregates","authors":"B. Bleakley, D. Crawford","doi":"10.5580/215a","DOIUrl":"https://doi.org/10.5580/215a","url":null,"abstract":"Spores of a Streptomyces lividans strain (donor) bearing the recombinant conjugative plasmid pIJ303, which codes for thiostrepton resistance, and spores of a plasmid-free Streptomyces parvulus strain (recipient) were added together to finelysieved, sterile silt loam soil. This bulk soil was adjusted to either 20%, 35% or 45% of the soil’s water holding capacity. To this inoculated bulk soil were added sterile, nutrientamended, artificial soil aggregates. After incubation to allow streptomycete growth and aggregate colonization, both the sieved bulk soil and the aggregates were assayed for numbers of transconjugants by spreadplanting on a thiostrepton – agar selective medium. This allowed estimation of parental ability to colonize nutrient – rich soil sites at different soil moisture levels, and comparison of plasmid exchange frequency in the nonamended bulk soil versus the nutrient – rich soil aggregates. Plasmid exchange was detected only on aggregates of about 20% water holding capacity or less (4.2% wt/wt H20). The soil moisture threshold for heterotrophic streptomycete activity appeared to lie between 2.87% and 4.2% wt/wt H20 for the nutrientamended soil aggregates.","PeriodicalId":22514,"journal":{"name":"The Internet journal of microbiology","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2009-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86563211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Production of protease via submerged fermentation using Rhizopus microsporus var oligospous was studied using shake flask cultures. After 96 h of growth on a BOD shaker revolving at 150 rpm, protease was partially purified using the isopropanol. Factors affecting the enzyme production viz incubation temperature, initial pH of the shake flask medium. and inoculum size were optimized. Protease having the maximum enzyme activity of 521.739 IU was obtained at an incubation temperature of 30oC, an initial pH of the basal medium as 5.5 and an inoculum size of to 1x10 spores ml of Tween-80. Protease deactivated at 80 oC.
{"title":"Production Of Protease By Submerged Fermentation Using Rhizopus Microsporus Var Oligospous","authors":"L. Sarao, M. Arora, V. Sehgal, S. Bhatia","doi":"10.5580/2582","DOIUrl":"https://doi.org/10.5580/2582","url":null,"abstract":"Production of protease via submerged fermentation using Rhizopus microsporus var oligospous was studied using shake flask cultures. After 96 h of growth on a BOD shaker revolving at 150 rpm, protease was partially purified using the isopropanol. Factors affecting the enzyme production viz incubation temperature, initial pH of the shake flask medium. and inoculum size were optimized. Protease having the maximum enzyme activity of 521.739 IU was obtained at an incubation temperature of 30oC, an initial pH of the basal medium as 5.5 and an inoculum size of to 1x10 spores ml of Tween-80. Protease deactivated at 80 oC.","PeriodicalId":22514,"journal":{"name":"The Internet journal of microbiology","volume":"69 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2009-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74329274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bacterial exopolysaccharides have wide applications in various industries. In this perspective, it is essential to explore the natural biodiversity for novel strains of exopolysaccharide synthesizing lactic acid bacteria (LAB). Two novel isolates of lactic acid bacteria with higher enzyme activity were screened and characterized based on a battery of microscopic, staining, metabolic, physiological and antibiotic sensitivity tests. The two isolates of LAB named SPO and SPA were cocci shaped, Gram Positive, catalase negative, heterofermentative, vancomycin resistant, broad spectrum carbohydrate fermentating with exopolysaccharide synthesizing activity. EPS synthesizing activity was confirmed by activity staining of EPS using sucrose as substrate. This confirmed that the EPS produced was dextran and the enzyme responsible for its synthesis is dextransucrase. The enzyme activity of SPO was 3.8 U/ml and that of SPA was 3.4 U/ml. For strain improvement, the isolates were subjected to UV radiation. The isolate SPO did not give promising results. However, SPA after UV-mutagenesis, generated two novel mutants, SPAm1 and SPAm2. The enzyme activity of SPAm1 was 4.9 U/ml and that of SPAm2 was 4.7 U/ml. The mutants possessed about 40% enhanced enzyme activity over the wild type strain.
{"title":"Isolation, characterization and mutagenesis of exopolysaccharide synthesizing new strains of lactic acid bacteria","authors":"Seema Patel, A. Goyal","doi":"10.5580/1bbb","DOIUrl":"https://doi.org/10.5580/1bbb","url":null,"abstract":"Bacterial exopolysaccharides have wide applications in various industries. In this perspective, it is essential to explore the natural biodiversity for novel strains of exopolysaccharide synthesizing lactic acid bacteria (LAB). Two novel isolates of lactic acid bacteria with higher enzyme activity were screened and characterized based on a battery of microscopic, staining, metabolic, physiological and antibiotic sensitivity tests. The two isolates of LAB named SPO and SPA were cocci shaped, Gram Positive, catalase negative, heterofermentative, vancomycin resistant, broad spectrum carbohydrate fermentating with exopolysaccharide synthesizing activity. EPS synthesizing activity was confirmed by activity staining of EPS using sucrose as substrate. This confirmed that the EPS produced was dextran and the enzyme responsible for its synthesis is dextransucrase. The enzyme activity of SPO was 3.8 U/ml and that of SPA was 3.4 U/ml. For strain improvement, the isolates were subjected to UV radiation. The isolate SPO did not give promising results. However, SPA after UV-mutagenesis, generated two novel mutants, SPAm1 and SPAm2. The enzyme activity of SPAm1 was 4.9 U/ml and that of SPAm2 was 4.7 U/ml. The mutants possessed about 40% enhanced enzyme activity over the wild type strain.","PeriodicalId":22514,"journal":{"name":"The Internet journal of microbiology","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2009-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81364158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A screen of the commercially available collection of haploid deletion mutants of Saccharomyces cerevisiae for spontaneous mutator mutants newly identified a deletion of SRL3. This gene had been previously isolated as a suppressor of lethality of checkpoint kinase deletions if overexpressed. We found DNA damage sensitivity and extended checkpoint arrests to be associated with this strain. However, when crossed to wild-type, a mutant gene conferring these phenotypes was found to segregate from the SRL3 deletion. The mutation was identified as a C-terminal truncation of Mms2, an E2 ubiquitin conjugating enzyme involved in error-free replicative bypass of lesions. This confirmed an earlier report that Mms2 may be required to restrain error-prone polymerase ζ activity and underscored that residues of the C-terminus are necessary for Mms2 function. Srl3, on the other hand, does not appear to influence DNA damage sensitivity or spontaneous mutability if deleted. However, the absence of these phenotypes does not contradict its likely role as a positive regulator of dNTP levels.
{"title":"The available <i>SRL3</i> deletion strain of <i>Saccharomyces cerevisiae</i> contains a truncation of DNA damage tolerance protein Mms2: Implications for Srl3 and Mms2 functions.","authors":"Eunmi Kim, Wolfram Siede","doi":"10.5580/42c","DOIUrl":"10.5580/42c","url":null,"abstract":"<p><p>A screen of the commercially available collection of haploid deletion mutants of <i>Saccharomyces cerevisiae</i> for spontaneous mutator mutants newly identified a deletion of <i>SRL3</i>. This gene had been previously isolated as a suppressor of lethality of checkpoint kinase deletions if overexpressed. We found DNA damage sensitivity and extended checkpoint arrests to be associated with this strain. However, when crossed to wild-type, a mutant gene conferring these phenotypes was found to segregate from the <i>SRL3</i> deletion. The mutation was identified as a C-terminal truncation of Mms2, an E2 ubiquitin conjugating enzyme involved in error-free replicative bypass of lesions. This confirmed an earlier report that Mms2 may be required to restrain error-prone polymerase ζ activity and underscored that residues of the C-terminus are necessary for Mms2 function. Srl3, on the other hand, does not appear to influence DNA damage sensitivity or spontaneous mutability if deleted. However, the absence of these phenotypes does not contradict its likely role as a positive regulator of dNTP levels.</p>","PeriodicalId":22514,"journal":{"name":"The Internet journal of microbiology","volume":"8 1","pages":"8"},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4008323/pdf/nihms238834.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32315447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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