Organomercury lyase (MerB) overexpressed in Escherichia coli captured and decomposed organomercury compounds, and it has been detected by radioactive analysis with neutron irradiation. Genetically modified E. coli captures a lot of mercury from a cultivation solution with about 80% recovery, when the bacteria are growing during 24 to 72 hours. Since the modified E. coli has no additive gene for mercury metabolism, the bacteria could hold mercury tightly by the MerB enzyme in their cell and do not release them into medium. In the later, 72 hours after, bacteria have less recovery ratio; it may be affected by undecompsed mercury compounds in bacteria growth. The recovery ability of the bacteria would not be changed by addition of the MerB producing reagent (IPTG). A quantitative value of mercury atom is estimated by an emission of γ-ray by reactor neutron from a dried cell or solution on a filter paper, which is available for nondestructive testing of bacteria holding mercury atoms. In this method an efficient recovery system of toxic mercury from a polluted solution has been archived without destruction of samples, so called in-cell analysis.
{"title":"Organomercury Captured by Lyase Overexpressed Escherichia coli and Its Evaluation by In-Cell Radiometry*","authors":"Y. Morimoto, K. Takamiya","doi":"10.4236/aer.2020.82002","DOIUrl":"https://doi.org/10.4236/aer.2020.82002","url":null,"abstract":"Organomercury lyase (MerB) overexpressed in Escherichia coli captured and decomposed organomercury compounds, and it has been detected by radioactive analysis with neutron irradiation. Genetically modified E. coli captures a lot of mercury from a cultivation solution with about 80% recovery, when the bacteria are growing during 24 to 72 hours. Since the modified E. coli has no additive gene for mercury metabolism, the bacteria could hold mercury tightly by the MerB enzyme in their cell and do not release them into medium. In the later, 72 hours after, bacteria have less recovery ratio; it may be affected by undecompsed mercury compounds in bacteria growth. The recovery ability of the bacteria would not be changed by addition of the MerB producing reagent (IPTG). A quantitative value of mercury atom is estimated by an emission of γ-ray by reactor neutron from a dried cell or solution on a filter paper, which is available for nondestructive testing of bacteria holding mercury atoms. In this method an efficient recovery system of toxic mercury from a polluted solution has been archived without destruction of samples, so called in-cell analysis.","PeriodicalId":65616,"journal":{"name":"酶研究进展(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49652252","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 medical herb Phyllanthus amarus play a crucial role in indigenous medicine. Therapeutically, these plants’ extract acts as potential players that inhibits several digestive enzymes that are relevant to the management of Peptic ulcers and Diabetes Mellitus, which occur due to the overproduction of such enzymes. Evaluation of inhibitory effect of this extract was carried out against Pepsin, α-amylase, Trypsin enzymes along with the effect of thermal stability and ammonium sulphate precipitation on these inhibitory assays. P. amarus leave’s extract with different concentration gradients were used in this research analysis. Results obtained along with the literature analysis revealed photochemical compounds such as polyphenols causes inhibitory nature in the extract. Maximal percentage of inhibition of amylase, pepsin and trypsin were found to be 71% (0.32 mg/ml), 85% (0.08 mg/ml) and 87% (1.28 mg/ml) respectively. In thermal stability assay the maximum percentage of inhibition for amylase, pepsin and trypsin was observed at 30% (80°C), 68% (4°C) and 5% (37°C). Enzymes inhibitory assays on ammonium sulphate precipitation elicited maximum percentage of inhibition for amylase, pepsin and trypsin as 42% (at 45% of (NH4)2SO4), 58% (at 15% of (NH4)2SO4) and 40% (at 30% of (NH4)2SO4) respectively. This research concluded that Phyllanthus amarus leave extracts are potential inhibitors of α-amylase, pepsin and trypsin enzymes. Ammonium sulphate precipitation was helpful to purify the polyphenols the active compounds to a good extend. Also, thermal stability was helpful to check the stability of these active photochemical compounds present in the extract. Thus, P. amarus is an effective inhibitor to be used as supplements in the disease management.
{"title":"Evaluation of the Inhibitory Effect of a Medicinal Herb Phyllanthus amarus on the Activity of α-Amylase, Pepsin and Trypsin","authors":"Chanjugaa Uthayakumar, Santhosh Rupert","doi":"10.4236/aer.2020.81001","DOIUrl":"https://doi.org/10.4236/aer.2020.81001","url":null,"abstract":"The medical herb Phyllanthus amarus play a crucial role in indigenous medicine. Therapeutically, these plants’ extract acts as potential players that inhibits several digestive enzymes that are relevant to the management of Peptic ulcers and Diabetes Mellitus, which occur due to the overproduction of such enzymes. Evaluation of inhibitory effect of this extract was carried out against Pepsin, α-amylase, Trypsin enzymes along with the effect of thermal stability and ammonium sulphate precipitation on these inhibitory assays. P. amarus leave’s extract with different concentration gradients were used in this research analysis. Results obtained along with the literature analysis revealed photochemical compounds such as polyphenols causes inhibitory nature in the extract. Maximal percentage of inhibition of amylase, pepsin and trypsin were found to be 71% (0.32 mg/ml), 85% (0.08 mg/ml) and 87% (1.28 mg/ml) respectively. In thermal stability assay the maximum percentage of inhibition for amylase, pepsin and trypsin was observed at 30% (80°C), 68% (4°C) and 5% (37°C). Enzymes inhibitory assays on ammonium sulphate precipitation elicited maximum percentage of inhibition for amylase, pepsin and trypsin as 42% (at 45% of (NH4)2SO4), 58% (at 15% of (NH4)2SO4) and 40% (at 30% of (NH4)2SO4) respectively. This research concluded that Phyllanthus amarus leave extracts are potential inhibitors of α-amylase, pepsin and trypsin enzymes. Ammonium sulphate precipitation was helpful to purify the polyphenols the active compounds to a good extend. Also, thermal stability was helpful to check the stability of these active photochemical compounds present in the extract. Thus, P. amarus is an effective inhibitor to be used as supplements in the disease management.","PeriodicalId":65616,"journal":{"name":"酶研究进展(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44080864","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}
Combinatorial chemistry involves the chemical or biological synthesis of diverse variation of the structures of a target molecule and the library is then screened for variants of desirable target properties. The approach has been a focus of research activity in drug discovery and biotechnology. This report is to demonstrate the application of enzyme technology using the concept of combinatorial chemistry as a novel approach for the bioconversion of plant fibers. Wheat insoluble fiber was subjected to combinatorial enzyme digestion to create structural variants of feruloyl oligosaccharides (FOS). Fractionation and screening resulted in the isolation of a fraction of bioactive FOS species showing antimicrobial activity. These results demonstrate the feasibil-ity and usefulness of the combinatorial enzyme technique in the transforma-tion of plant biomass to value-added products.
{"title":"Combinatorial Enzyme Approach for Production and Screening of Libraries of Feruloyl Oligosaccharides","authors":"D. Wong, S. Batt, W. Orts","doi":"10.4236/aer.2020.83003","DOIUrl":"https://doi.org/10.4236/aer.2020.83003","url":null,"abstract":"Combinatorial chemistry involves the chemical or biological synthesis of diverse variation of the structures of a target molecule and the library is then screened for variants of desirable target properties. The approach has been a focus of research activity in drug discovery and biotechnology. This report is to demonstrate the application of enzyme technology using the concept of combinatorial chemistry as a novel approach for the bioconversion of plant fibers. Wheat insoluble fiber was subjected to combinatorial enzyme digestion to create structural variants of feruloyl oligosaccharides (FOS). Fractionation and screening resulted in the isolation of a fraction of bioactive FOS species showing antimicrobial activity. These results demonstrate the feasibil-ity and usefulness of the combinatorial enzyme technique in the transforma-tion of plant biomass to value-added products.","PeriodicalId":65616,"journal":{"name":"酶研究进展(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70485776","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 aim of the present work was to isolate Bacillus spp. With high lipase activity; to characterize the isolates using both biochemical and molecular methods; to produce lipase using Bacillus isolates and to study the biochemical and biophysical characteristics of the produced lipase. Sixty five Bacillus isolates were isolated from soil 20 isolates from guar field soil (G), 15 isolates from Abusabein field soil (B), 15 isolates from sun flower field soil (S) and 15 isolates from oil effluent (O). Lipase producing isolates were screened; a Chromogenic plate’s method was used. Enzyme activity was quantitatively assayed. Lipase production under submerged fermentation (SMF) conditions using a production medium that contained metal salts, Tween-20 and olive oil as substrate at different period 24, 48, 72 and 96 h, the optimum pH, temperature for lipase activity was determinated and kinetics as well. The isolates showed the highest lipase activity which was identified as Bacillus sp. The optimum pH, temperature, thermostability and kinetic of the produced enzymes were found in three isolates G14, O1 and B10 with the highest enzyme activity and best stability. The isolates G14, O1 and B10 revealed the highest lipase activity of 63.4, 41.2 and 28.3 U/ml, respectively. The results showed optimum pH of the lipase activity from isolates G14, O1 and B10 8.0, 6.0 and 6.0 and the optimum temperature 40, 60 and 75˚C, respectively. Lipase enzymes from isolates O1 and B10 were found to be more thermostable after incubation time for 120 min at 90˚C. The Vmax and Km values of lipase for isolates G14, OI and B10 were 17.6, 135 and 24.4 μmole∙min and 1.3, 1.6 and 0.681 mM, respectively. According to these results Bacillus spp. with high lipase activity and thermostability can be used to promote food, pharmaceuticals, paper, detergents agrochemicals industries and pollution control in Sudan.
{"title":"Biochemical Characterization of Lipase Produced by Bacillus spp. Isolated from Soil and Oil Effluent","authors":"Afaf O. B. Shart, E. Elkhalil","doi":"10.4236/aer.2020.84004","DOIUrl":"https://doi.org/10.4236/aer.2020.84004","url":null,"abstract":"The aim of the present work was to isolate Bacillus spp. With high lipase activity; to characterize the isolates using both biochemical and molecular methods; to produce lipase using Bacillus isolates and to study the biochemical and biophysical characteristics of the produced lipase. Sixty five Bacillus isolates were isolated from soil 20 isolates from guar field soil (G), 15 isolates from Abusabein field soil (B), 15 isolates from sun flower field soil (S) and 15 isolates from oil effluent (O). Lipase producing isolates were screened; a Chromogenic plate’s method was used. Enzyme activity was quantitatively assayed. Lipase production under submerged fermentation (SMF) conditions using a production medium that contained metal salts, Tween-20 and olive oil as substrate at different period 24, 48, 72 and 96 h, the optimum pH, temperature for lipase activity was determinated and kinetics as well. The isolates showed the highest lipase activity which was identified as Bacillus sp. The optimum pH, temperature, thermostability and kinetic of the produced enzymes were found in three isolates G14, O1 and B10 with the highest enzyme activity and best stability. The isolates G14, O1 and B10 revealed the highest lipase activity of 63.4, 41.2 and 28.3 U/ml, respectively. The results showed optimum pH of the lipase activity from isolates G14, O1 and B10 8.0, 6.0 and 6.0 and the optimum temperature 40, 60 and 75˚C, respectively. Lipase enzymes from isolates O1 and B10 were found to be more thermostable after incubation time for 120 min at 90˚C. The Vmax and Km values of lipase for isolates G14, OI and B10 were 17.6, 135 and 24.4 μmole∙min and 1.3, 1.6 and 0.681 mM, respectively. According to these results Bacillus spp. with high lipase activity and thermostability can be used to promote food, pharmaceuticals, paper, detergents agrochemicals industries and pollution control in Sudan.","PeriodicalId":65616,"journal":{"name":"酶研究进展(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70485812","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}
Proteases are important industrial enzymes that account for about 60% of the total enzyme market globally due to their large application in food, feed, textile and pharmaceutical industries. The effect of salt stress on protease production was evaluated on Aspergillus flavus and Aspergillus niger. The enzyme production was enhanced by stepwise optimization of the culture parameters, notably, carbon source, nitrogen source, pH, and temperature of the submerged fermentation process while using a minimal salt media and casein as substrate for the protease activity. The fungi species were found to be good producers of both acid and alkaline proteases under 4% salt stress condition. The optimum culture conditions for alkaline protease production by Aspergillus flavus were sucrose 4%, peptone 1%, pH 8 at 40°C with maximum enzymatic activities of 8.85 mM/min/mg protein, 5.22 mM/min/mg protein, 3.75 mM/min/mg protein, and 1.64 mM/min/mg protein, respectively. Lactose 4%, peptone 1%, pH 6 at 50°C were the optimum culture conditions for acid protease production by Aspergillus flavus with maximum enzymatic activities of 4.59 mM/min/mg protein, 2.06 mM/min/mg protein, 1.24 mM/min/mg protein, and 1.23 mM/min/mg protein, respectively. For Aspergillus niger, the optimum culture conditions for alkaline protease production were corn starch 4%, yeast extract 1%, pH 6 at 40°C with maximum enzymatic activities of 5.99 mM/min/mg protein, 3.85 mM/min/mg protein, 6.18 mM/min/mg protein, and 3.72 mM/min/mg protein, respectively. While lactose 4%, yeast extract 1%, pH 6 at 50°C were the best culture conditions for acid protease production by Aspergillus niger with maximum enzymatic activities of 4.81 mM/min/mg protein, 0.93 mM/min/mg protein, 5.71 mM/min/mg protein, and 3.34 mM/min/mg protein, respectively.
{"title":"Enhanced Production of Salinity-Induced Proteases from Aspergillus flavus and Aspergillus niger","authors":"M. Okpara, O. Bamidele, J. Ajele","doi":"10.4236/aer.2019.74004","DOIUrl":"https://doi.org/10.4236/aer.2019.74004","url":null,"abstract":"Proteases are important industrial enzymes that account for about 60% of the total enzyme market globally due to their large application in food, feed, textile and pharmaceutical industries. The effect of salt stress on protease production was evaluated on Aspergillus flavus and Aspergillus niger. The enzyme production was enhanced by stepwise optimization of the culture parameters, notably, carbon source, nitrogen source, pH, and temperature of the submerged fermentation process while using a minimal salt media and casein as substrate for the protease activity. The fungi species were found to be good producers of both acid and alkaline proteases under 4% salt stress condition. The optimum culture conditions for alkaline protease production by Aspergillus flavus were sucrose 4%, peptone 1%, pH 8 at 40°C with maximum enzymatic activities of 8.85 mM/min/mg protein, 5.22 mM/min/mg protein, 3.75 mM/min/mg protein, and 1.64 mM/min/mg protein, respectively. Lactose 4%, peptone 1%, pH 6 at 50°C were the optimum culture conditions for acid protease production by Aspergillus flavus with maximum enzymatic activities of 4.59 mM/min/mg protein, 2.06 mM/min/mg protein, 1.24 mM/min/mg protein, and 1.23 mM/min/mg protein, respectively. For Aspergillus niger, the optimum culture conditions for alkaline protease production were corn starch 4%, yeast extract 1%, pH 6 at 40°C with maximum enzymatic activities of 5.99 mM/min/mg protein, 3.85 mM/min/mg protein, 6.18 mM/min/mg protein, and 3.72 mM/min/mg protein, respectively. While lactose 4%, yeast extract 1%, pH 6 at 50°C were the best culture conditions for acid protease production by Aspergillus niger with maximum enzymatic activities of 4.81 mM/min/mg protein, 0.93 mM/min/mg protein, 5.71 mM/min/mg protein, and 3.34 mM/min/mg protein, respectively.","PeriodicalId":65616,"journal":{"name":"酶研究进展(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42120870","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}
S. V. Stovbun, K. Ermakov, A. Bukhvostov, A. S. Vedenkin, D. Kuznetsov
A conventionally synthesized thio- and cyano-modified single-stranded poly(dNTP) sequences of different molecular sizes (20n - 200n) and the same lengths routine poly(dNTP) and poly(NTP) species were obtained through the good services provided by the Russian Federal Bioorganic Products Group and by the ThermoFischer, Inc., and then tested for their impact on catalytic activities of β-like DNA polymerases from chromatin of HL-60, WERI-1A and Y-79 cells as well as for the affinity patterns in DNApolβ-poly(dNTP)/ (NTP) pairs, respectively. An essential link between the lengths of ultrashort (50n - 100n) single-stranded poly(dNTP) sequences of different structures and their inhibitory effects towards the cancer-specific DNA polymerases β has been found. A possible significance of this phenomenon for both DNA repair suppression in tumors and a consequent anti-cancer activity of the DNA repair related short poly(dNTP) fragments has been for the first time emphasized with a respect to their pharmacophore revealing potential. Thus, this work presents an experimental attempt to upgrade a contemporary attitude towards the DNA derived products applied for anti-cancer agenda, particularly, for acute myeloid leukemia and retinoblastoma cell DNA repair machinery breakdown. In this study, tumor specific DNA polymerases β were found of being the targets for attack promoted with the primer-like single-stranded DNA fragments followed by consequent cytostatic phenomena. A novel concept of the DNA related anti-cancer medicines is under discussion.
{"title":"Primer-Like Inhibitors for DNA Repair Enzymes of the AML-HL60 and WERI-1A/Y79 Malignant Cells","authors":"S. V. Stovbun, K. Ermakov, A. Bukhvostov, A. S. Vedenkin, D. Kuznetsov","doi":"10.4236/aer.2019.73003","DOIUrl":"https://doi.org/10.4236/aer.2019.73003","url":null,"abstract":"A conventionally synthesized thio- and cyano-modified \u0000single-stranded poly(dNTP) sequences of different molecular sizes \u0000(20n - 200n) and the same lengths routine poly(dNTP) and poly(NTP) species were \u0000obtained through the good services provided \u0000by the Russian Federal Bioorganic Products Group and by the \u0000ThermoFischer, Inc., and then tested for their impact on catalytic activities \u0000of β-like DNA polymerases from chromatin of HL-60, WERI-1A and Y-79 cells as well as for the affinity patterns in \u0000DNApolβ-poly(dNTP)/ (NTP) pairs, respectively. An essential link between the lengths of \u0000ultrashort (50n - 100n) single-stranded poly(dNTP) sequences of different structures and their \u0000inhibitory effects towards the cancer-specific DNA polymerases β has been found. A possible significance of this phenomenon for both DNA \u0000repair suppression in tumors and a consequent anti-cancer activity of the DNA \u0000repair related short poly(dNTP) fragments has been for the first time \u0000emphasized with a respect to their pharmacophore revealing potential. Thus, \u0000this work presents an experimental attempt to upgrade a contemporary attitude \u0000towards the DNA derived products applied for anti-cancer agenda, particularly, for acute myeloid leukemia and \u0000retinoblastoma cell DNA repair machinery breakdown. In this study, tumor \u0000specific DNA polymerases β were found \u0000of being the targets for attack promoted with the primer-like single-stranded DNA fragments followed by consequent \u0000cytostatic phenomena. A novel concept of the DNA related anti-cancer medicines \u0000is under discussion.","PeriodicalId":65616,"journal":{"name":"酶研究进展(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48144030","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}
K. Ishihara, Natsumi Adachi, Takumu Mishima, C. Kuboki, Ayaka Shuto, K. Okamoto, Manami Inoue, H. Hamada, Daisuke Uesugi, N. Masuoka, N. Nakajima
We screened 15 Agromyces strains from the Microbacteriaceae family and 16 Gordonia strains from the Gordoniaceae family to investigate their biocatalytic ability to reduce carbonyl compounds. Two Agromyces strains (A. soli NBRC109063 and A. humatus NBRC109085) and two Gordonia strains (G. hydrophobica NBRC16057 and G. malaquae NBRC108250) grew well in 230 medium. The stereoselective reduction of various carbonyl compounds using these four strains was investigated. We discovered that these strains can reduce aliphatic and aromatic α-keto esters and an aromatic α-keto amide. On the basis of the conversion rate and stereoselectivity of the alcohols produced, G. hydrophobica NBRC16057 is a potential biocatalyst for the stereoselective reduction of α-keto esters and an aromatic α-keto amide to the corresponding chiral alcohols. Our results also suggest that the reduction of ethyl 2-methylacetoacetate by wet G. hydrophobica NBRC16057 cells in the presence of L-glutamate is useful for the production of chiral ethyl 3-hydroxy-2-methylbutanoate.
{"title":"Microbial Production of Chiral Hydroxy Esters and Their Analogs: Biocatalytic Reduction of Carbonyl Compounds by Actinobacteria, Agromyces and Gordonia Strains","authors":"K. Ishihara, Natsumi Adachi, Takumu Mishima, C. Kuboki, Ayaka Shuto, K. Okamoto, Manami Inoue, H. Hamada, Daisuke Uesugi, N. Masuoka, N. Nakajima","doi":"10.4236/AER.2019.72002","DOIUrl":"https://doi.org/10.4236/AER.2019.72002","url":null,"abstract":"We screened 15 Agromyces strains from the Microbacteriaceae family and 16 Gordonia strains from the Gordoniaceae family to investigate their biocatalytic ability to reduce carbonyl compounds. Two Agromyces strains (A. soli NBRC109063 and A. humatus NBRC109085) and two Gordonia strains (G. hydrophobica NBRC16057 and G. malaquae NBRC108250) grew well in 230 medium. The stereoselective reduction of various carbonyl compounds using these four strains was investigated. We discovered that these strains can reduce aliphatic and aromatic α-keto esters and an aromatic α-keto amide. On the basis of the conversion rate and stereoselectivity of the alcohols produced, G. hydrophobica NBRC16057 is a potential biocatalyst for the stereoselective reduction of α-keto esters and an aromatic α-keto amide to the corresponding chiral alcohols. Our results also suggest that the reduction of ethyl 2-methylacetoacetate by wet G. hydrophobica NBRC16057 cells in the presence of L-glutamate is useful for the production of chiral ethyl 3-hydroxy-2-methylbutanoate.","PeriodicalId":65616,"journal":{"name":"酶研究进展(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46416587","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}
Sulfatases which cleave sulfate esters in biological systems are key enzymes that deserve special attention due to their significant roles in organic sulfur (OS) mineralization and inorganic sulfur () release. In this study, in-vitro experiments were conducted to evaluate S bonded substrate hydrolysis by a commercially available arylsulfatase (EC 3.1.6.1) from Aerobacter aerogenes. The enzyme-substrate interactions were assessed to determine: 1) rate of hydrolysis, 2) catalytic efficiency, 3) thermal stability, and 4) optimal pH of this enzyme. Arylsulfatase exhibited substrate hydrolysis with a high affinity for p-nitrophenyl sulfate (potassium 4-nitrophenyl sulfate (pNPS)). The optimum activity for the enzyme was observed to occur at a pH of 7.1. The optimal temperature was 37°C but ranged from 35°C - 45°C. The apparent Km and Kcat of the enzyme for pNPS hydrolysis at the optimal pH, and temperature were determined to be 1.03 mM and 75.73 μM/min, respectively. This work defines the catalytic and kinetic properties of arylsulfatase (EC 3.1.6.1) and confirms the optimal conditions for sulfatase activity testing. The resulting information is useful in elucidating the contributions that individual enzymes have for specific reactions rather than relying on traditional total enzyme activity measurements.
{"title":"Enzymatic Hydrolysis of an Organic Sulfur Compound","authors":"T. Gardner, Z. Senwo","doi":"10.4236/AER.2019.71001","DOIUrl":"https://doi.org/10.4236/AER.2019.71001","url":null,"abstract":"Sulfatases which cleave sulfate esters in biological systems are key enzymes that deserve special attention due to their significant roles in organic sulfur (OS) mineralization and inorganic sulfur () release. In this study, in-vitro experiments were conducted to evaluate S bonded substrate hydrolysis by a commercially available arylsulfatase (EC 3.1.6.1) from Aerobacter aerogenes. The enzyme-substrate interactions were assessed to determine: 1) rate of hydrolysis, 2) catalytic efficiency, 3) thermal stability, and 4) optimal pH of this enzyme. Arylsulfatase exhibited substrate hydrolysis with a high affinity for p-nitrophenyl sulfate (potassium 4-nitrophenyl sulfate (pNPS)). The optimum activity for the enzyme was observed to occur at a pH of 7.1. The optimal temperature was 37°C but ranged from 35°C - 45°C. The apparent Km and Kcat of the enzyme for pNPS hydrolysis at the optimal pH, and temperature were determined to be 1.03 mM and 75.73 μM/min, respectively. This work defines the catalytic and kinetic properties of arylsulfatase (EC 3.1.6.1) and confirms the optimal conditions for sulfatase activity testing. The resulting information is useful in elucidating the contributions that individual enzymes have for specific reactions rather than relying on traditional total enzyme activity measurements.","PeriodicalId":65616,"journal":{"name":"酶研究进展(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45212140","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}
Phytase is a kind of enzyme that hydrolyzes phytic acid and its salts to produce inositol and phosphoric acid. As a new feed additive, phytase has great potential in animal nutrition and environmental protection. Because of its good stability, large-scale production and high activity, microbial phytase has become a hot spot in industrial application. Here, we reported the predicted structure and enzymatic properties of a phytase from Bacillus subtilis, which was named as phyS. It was clear that the optimal temperature is 35°C, and the optimal pH is 8. Meanwhile, the enzyme activity was kept at above 90% in the range of pH 8 - 9, this result demonstrated that phyS is an alkaline phytase. This study lays a foundation for the extensive application of phyS.
{"title":"Structure Prediction and Enzymatic Properties of Phytase phyS","authors":"Yueming Li, Hongqing Xu, Jian-cheng Xu, Ruilian Pang, Xu Bingzheng","doi":"10.4236/aer.2019.74005","DOIUrl":"https://doi.org/10.4236/aer.2019.74005","url":null,"abstract":"Phytase is a kind of enzyme that hydrolyzes phytic acid and its salts to produce inositol and phosphoric acid. As a new feed additive, phytase has great potential in animal nutrition and environmental protection. Because of its good stability, large-scale production and high activity, microbial phytase has become a hot spot in industrial application. Here, we reported the predicted structure and enzymatic properties of a phytase from Bacillus subtilis, which was named as phyS. It was clear that the optimal temperature is 35°C, and the optimal pH is 8. Meanwhile, the enzyme activity was kept at above 90% in the range of pH 8 - 9, this result demonstrated that phyS is an alkaline phytase. This study lays a foundation for the extensive application of phyS.","PeriodicalId":65616,"journal":{"name":"酶研究进展(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70485763","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}
R. A. Abdulrauf, F. Dawud, N. S. Emmanuel, H. D. Muhammad, A. Dange, B. David, A. Ogweje, A. Alexander, M. Yahuza
This study was designed to assess the effect to apple cider vinegar (ACV) on oxidative stress biomarkers in male and female Wistar rats exposed to chronic restraint stress. Severe and persistent stress elevates reactive oxygen species (ROS) production by metabolic and physiological processes; causing cellular damage. Thirty (30) Adult Wistar rats of both sexes weighing about 150 - 200 g were divided into 3 groups each consisting of a male and female subgroup and given the following treatments once a day for 21 days: Normal control group received 0.5 ml distilled water orally, the restraint stress (RS) group was exposed to chronic restraint stress 6 hours daily while the Apple cider vinegar (ACV)-treated group received 4 ml/kg of apple cider vinegar orally in addition to chronic restraint stress 6 hours daily. The rats were sacrificed after the experimental period and blood was collected via cardiac puncture for assessing oxidative stress biomarkers. ACV (4 ml/kg) treatment decreased lipid peroxidation (MDA) and serum catalase (CAT) activity while upregulating endogenous superoxide dismutase (SOD) activity. The findings of this study show that the female Wistar rats are more predisposed to the antioxidant effect of ACV than the males.
{"title":"Lipid Peroxidation and Some Antioxidant Enzymes Evaluation in Apple Cider Vinegar (ACV) Treated Male and Female Wistar Rats Exposed to Chronic Restraint Stress","authors":"R. A. Abdulrauf, F. Dawud, N. S. Emmanuel, H. D. Muhammad, A. Dange, B. David, A. Ogweje, A. Alexander, M. Yahuza","doi":"10.4236/AER.2018.63003","DOIUrl":"https://doi.org/10.4236/AER.2018.63003","url":null,"abstract":"This study was designed to assess the effect to apple cider vinegar (ACV) on oxidative stress biomarkers in male and female Wistar rats exposed to chronic restraint stress. Severe and persistent stress elevates reactive oxygen species (ROS) production by metabolic and physiological processes; causing cellular damage. Thirty (30) Adult Wistar rats of both sexes weighing about 150 - 200 g were divided into 3 groups each consisting of a male and female subgroup and given the following treatments once a day for 21 days: Normal control group received 0.5 ml distilled water orally, the restraint stress (RS) group was exposed to chronic restraint stress 6 hours daily while the Apple cider vinegar (ACV)-treated group received 4 ml/kg of apple cider vinegar orally in addition to chronic restraint stress 6 hours daily. The rats were sacrificed after the experimental period and blood was collected via cardiac puncture for assessing oxidative stress biomarkers. ACV (4 ml/kg) treatment decreased lipid peroxidation (MDA) and serum catalase (CAT) activity while upregulating endogenous superoxide dismutase (SOD) activity. The findings of this study show that the female Wistar rats are more predisposed to the antioxidant effect of ACV than the males.","PeriodicalId":65616,"journal":{"name":"酶研究进展(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45370424","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}
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