The Experts below are selected from a list of 363 Experts worldwide ranked by ideXlab platform
Yifa Zhou - One of the best experts on this subject based on the ideXlab platform.
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ginsenoside re impacts on biotransformation products of ginsenoside rb1 by Cellulosimicrobium cellulans sp 21 and its mechanisms
Process Biochemistry, 2019Co-Authors: Yanbo Hu, Ye Yuan, Nan Wang, Zhuyun Jiang, Yifa ZhouAbstract:Abstract Ginsenoside Rg3, a known anti-cancer agent, is usually prepared by enzyme-mediated and acid hydrolysis of ginsenoside Rb1 and Rd. In this study, we used the bacterium Cellulosimicrobium cellulans sp. 21 to transform Rb1 into Rg3. When Rb1 was used as the sole substrate, the transformation products included Rg3, Rh2, C-K and PPD. However, when Rb1 and Re were mixed, the yield of Rg3 was significantly higher, indicating that Re attenuates the activity of β-1,2-glucosidase secreted by C. cellulans sp. 21. β-1,2-glucosidase hydrolyzes the β-1,2-glucose moiety at the C-3 position of Rb1, but Re dose not modify enzymes that produce Rg3 by hydrolyzing glucose at the C-20 position in aglycon. We also tested the inhibitory effects from various ginsenosides on β-1,2-glucosidase, and discovered that sugar chains played key roles in inhibiting β-1,2 glucosidase activity, whereas aglycones of protopanaxadiol and protopanaxatriol had little inhibitory effects. Some sugar chains with different linkages, such as C-20, C-3 and C-6, exhibited different inhibitory effects. Overall, our findings demonstrate that a combination of substrates, in addition to microorganism-secreted enzymes, can be used for selective biotransformation. This approach provides a novel strategy for natural product preparations via microbial transformation.
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cloning expression and biochemical characterization of a gh1 β glucosidase from Cellulosimicrobium cellulans
Biocatalysis and Biotransformation, 2018Co-Authors: Ye Yuan, Fenghua Xu, Yanho Hu, Jiao Wang, Tianjiao Zhao, Yifa ZhouAbstract:Abstractβ-Glucosidase plays an important role in the degradation of cellulose. In this study, a novel β-glucosidase ccbgl1b gene for a glycosyl hydrolase (GH) family 1 enzyme was cloned from the genome of Cellulosimicrobium cellulans and expressed in Escherichia coli BL21 cells. The sequence contained an open reading frame of 1494 bp, encoded a polypeptide of 497 amino acid residues. The recombinant protein CcBgl1B was purified by Ni sepharose fastflow affinity chromatography and had a molecular weight of 57 kDa, as judged by SDS-PAGE. The optimum β-glucosidase activity was observed at 55 °C and pH 6.0. Recombinant CcBgl1B was found to be most active against aryl-glycosides p-nitrophenyl-β-D-glucopyranoside (pNPβGlc), followed by p-nitrophenyl-β-D-galactopyranoside (pNPβGal). Using disaccharides as substrates, the enzyme efficiently cleaved β-linked glucosyl-disaccharides, including sophorose (β-1,2-), laminaribiose (β-1,3-) and cellobiose (β-1,4-). In addition, a range of cello-oligosaccharides including...
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high yield preparation of ganglioside gm1 using recombinant sialidase from Cellulosimicrobium cellulans
Process Biochemistry, 2017Co-Authors: Ye Yuan, Li Ji, Yanbo Hu, Chenxing Hu, Honglei Chen, Yifa ZhouAbstract:Abstract Cellulosimicrobium cellulans employs extracellular sialidase to selectively convert polysialogangliosides to ganglioside GM1. We cloned this novel sialidase gene (ccsia) from C. cellulans sp. 21, and overexpressed recombinant sialidase (CcSia) protein in E. coli BL21 (DE3) by high cell density fermentation. The presence of an N-terminal hexa-His tag allowed for purification using nickel affinity chromatography (2.3-fold, specific activity 41.5 U/mg). As determined by gel electrophoresis and gel filtration chromatography, the molecular weight of CcSia was found to be about 75 kDa, consistent with sequence analysis (75,271 Da). CcSia transformed polysialogangliosides GD1a, GD1b and GT1b into GM1. For this reaction, the response surface approach showed that optimal conditions in a 1-L system were 2 h incubation at 32.5 °C and pH 5.2, with substrate concentrations of 10 g/L and crude enzyme concentration 1 g/L, respectively. Under above conditions, 10 g/L of ganglioside was completely converted to the product GM1 with a yield of 52%. Our studies demonstrate CcSia could be used for industrial preparation of ganglioside GM1 by the pharmaceutical industry.
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characterization of a recombinant multifunctional glycoside hydrolase family 3 β xylosidase α l arabinofuranosidase β glucosidase from Cellulosimicrobium cellulans sp 21
Journal of Molecular Catalysis B-enzymatic, 2016Co-Authors: Ye Yuan, Yanbo Hu, Jiayi Leng, Xuesong Zhao, Han Zhang, Fan Li, Yifa ZhouAbstract:Abstract A multifunctional β-xylosidase/α- l -arabinofuranosidase/β-glucosidase gene ( ccxyl3a ) belonging to glycoside hydrolase family 3 (GH3) was cloned from Cellulosimicrobium cellulans sp. 21 and expressed in Escherichia coli BL21 (DE3). The molecular mass of recombinant CcXyl3A was estimated to be approximately 95 kDa. With p -nitrophenyl-β- d -xyloside ( p NPβXyl) as a substrate, the purified protein presented an optimal pH of 8.5 and an optimal temperature of 45 °C. Moreover, CcXyl3A was activated in the presence of the metals K + and Na + . Purified CcXyl3A demonstrated multifunctional activities on p NPβXyl, p -nitrophenyl-β- d -glucoside ( p NPβGlc), and p -nitrophenyl-α- l -arabinofuranoside ( p NPαAraf). The greatest catalytic activity were found on p NPβXyl followed by p NPαAra f and p NPβGlc, respectively. Using xylooligosaccharides as substrate, CcXyl3A completely hydrolyzed xylobiose, xylotriose, xylotetraose and xylohexaose, xylose was the sole product. In addition, CcXyl3A synergistically acted with Thermomyces lanuginosus xylanase in the degradation of beechwood xylan, released xyloses from intermediate xylooligosaccharides produced by T. lanuginosus xylanase. To date, this is the first report to demonstrate the cloning and characterization of a multifunctional GH3 enzyme in C. cellulans that may have applications in hemicellulose degradation.
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Characterization of a recombinant multifunctional glycoside hydrolase family 3 β-xylosidase/α-l-arabinofuranosidase/β-glucosidase from Cellulosimicrobium cellulans sp. 21
Journal of Molecular Catalysis B-enzymatic, 2016Co-Authors: Ye Yuan, Yanbo Hu, Jiayi Leng, Xuesong Zhao, Han Zhang, Fan Li, Yifa ZhouAbstract:Abstract A multifunctional β-xylosidase/α- l -arabinofuranosidase/β-glucosidase gene ( ccxyl3a ) belonging to glycoside hydrolase family 3 (GH3) was cloned from Cellulosimicrobium cellulans sp. 21 and expressed in Escherichia coli BL21 (DE3). The molecular mass of recombinant CcXyl3A was estimated to be approximately 95 kDa. With p -nitrophenyl-β- d -xyloside ( p NPβXyl) as a substrate, the purified protein presented an optimal pH of 8.5 and an optimal temperature of 45 °C. Moreover, CcXyl3A was activated in the presence of the metals K + and Na + . Purified CcXyl3A demonstrated multifunctional activities on p NPβXyl, p -nitrophenyl-β- d -glucoside ( p NPβGlc), and p -nitrophenyl-α- l -arabinofuranoside ( p NPαAraf). The greatest catalytic activity were found on p NPβXyl followed by p NPαAra f and p NPβGlc, respectively. Using xylooligosaccharides as substrate, CcXyl3A completely hydrolyzed xylobiose, xylotriose, xylotetraose and xylohexaose, xylose was the sole product. In addition, CcXyl3A synergistically acted with Thermomyces lanuginosus xylanase in the degradation of beechwood xylan, released xyloses from intermediate xylooligosaccharides produced by T. lanuginosus xylanase. To date, this is the first report to demonstrate the cloning and characterization of a multifunctional GH3 enzyme in C. cellulans that may have applications in hemicellulose degradation.
Ye Yuan - One of the best experts on this subject based on the ideXlab platform.
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ginsenoside re impacts on biotransformation products of ginsenoside rb1 by Cellulosimicrobium cellulans sp 21 and its mechanisms
Process Biochemistry, 2019Co-Authors: Yanbo Hu, Ye Yuan, Nan Wang, Zhuyun Jiang, Yifa ZhouAbstract:Abstract Ginsenoside Rg3, a known anti-cancer agent, is usually prepared by enzyme-mediated and acid hydrolysis of ginsenoside Rb1 and Rd. In this study, we used the bacterium Cellulosimicrobium cellulans sp. 21 to transform Rb1 into Rg3. When Rb1 was used as the sole substrate, the transformation products included Rg3, Rh2, C-K and PPD. However, when Rb1 and Re were mixed, the yield of Rg3 was significantly higher, indicating that Re attenuates the activity of β-1,2-glucosidase secreted by C. cellulans sp. 21. β-1,2-glucosidase hydrolyzes the β-1,2-glucose moiety at the C-3 position of Rb1, but Re dose not modify enzymes that produce Rg3 by hydrolyzing glucose at the C-20 position in aglycon. We also tested the inhibitory effects from various ginsenosides on β-1,2-glucosidase, and discovered that sugar chains played key roles in inhibiting β-1,2 glucosidase activity, whereas aglycones of protopanaxadiol and protopanaxatriol had little inhibitory effects. Some sugar chains with different linkages, such as C-20, C-3 and C-6, exhibited different inhibitory effects. Overall, our findings demonstrate that a combination of substrates, in addition to microorganism-secreted enzymes, can be used for selective biotransformation. This approach provides a novel strategy for natural product preparations via microbial transformation.
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cloning expression and biochemical characterization of a gh1 β glucosidase from Cellulosimicrobium cellulans
Biocatalysis and Biotransformation, 2018Co-Authors: Ye Yuan, Fenghua Xu, Yanho Hu, Jiao Wang, Tianjiao Zhao, Yifa ZhouAbstract:Abstractβ-Glucosidase plays an important role in the degradation of cellulose. In this study, a novel β-glucosidase ccbgl1b gene for a glycosyl hydrolase (GH) family 1 enzyme was cloned from the genome of Cellulosimicrobium cellulans and expressed in Escherichia coli BL21 cells. The sequence contained an open reading frame of 1494 bp, encoded a polypeptide of 497 amino acid residues. The recombinant protein CcBgl1B was purified by Ni sepharose fastflow affinity chromatography and had a molecular weight of 57 kDa, as judged by SDS-PAGE. The optimum β-glucosidase activity was observed at 55 °C and pH 6.0. Recombinant CcBgl1B was found to be most active against aryl-glycosides p-nitrophenyl-β-D-glucopyranoside (pNPβGlc), followed by p-nitrophenyl-β-D-galactopyranoside (pNPβGal). Using disaccharides as substrates, the enzyme efficiently cleaved β-linked glucosyl-disaccharides, including sophorose (β-1,2-), laminaribiose (β-1,3-) and cellobiose (β-1,4-). In addition, a range of cello-oligosaccharides including...
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high yield preparation of ganglioside gm1 using recombinant sialidase from Cellulosimicrobium cellulans
Process Biochemistry, 2017Co-Authors: Ye Yuan, Li Ji, Yanbo Hu, Chenxing Hu, Honglei Chen, Yifa ZhouAbstract:Abstract Cellulosimicrobium cellulans employs extracellular sialidase to selectively convert polysialogangliosides to ganglioside GM1. We cloned this novel sialidase gene (ccsia) from C. cellulans sp. 21, and overexpressed recombinant sialidase (CcSia) protein in E. coli BL21 (DE3) by high cell density fermentation. The presence of an N-terminal hexa-His tag allowed for purification using nickel affinity chromatography (2.3-fold, specific activity 41.5 U/mg). As determined by gel electrophoresis and gel filtration chromatography, the molecular weight of CcSia was found to be about 75 kDa, consistent with sequence analysis (75,271 Da). CcSia transformed polysialogangliosides GD1a, GD1b and GT1b into GM1. For this reaction, the response surface approach showed that optimal conditions in a 1-L system were 2 h incubation at 32.5 °C and pH 5.2, with substrate concentrations of 10 g/L and crude enzyme concentration 1 g/L, respectively. Under above conditions, 10 g/L of ganglioside was completely converted to the product GM1 with a yield of 52%. Our studies demonstrate CcSia could be used for industrial preparation of ganglioside GM1 by the pharmaceutical industry.
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characterization of a recombinant multifunctional glycoside hydrolase family 3 β xylosidase α l arabinofuranosidase β glucosidase from Cellulosimicrobium cellulans sp 21
Journal of Molecular Catalysis B-enzymatic, 2016Co-Authors: Ye Yuan, Yanbo Hu, Jiayi Leng, Xuesong Zhao, Han Zhang, Fan Li, Yifa ZhouAbstract:Abstract A multifunctional β-xylosidase/α- l -arabinofuranosidase/β-glucosidase gene ( ccxyl3a ) belonging to glycoside hydrolase family 3 (GH3) was cloned from Cellulosimicrobium cellulans sp. 21 and expressed in Escherichia coli BL21 (DE3). The molecular mass of recombinant CcXyl3A was estimated to be approximately 95 kDa. With p -nitrophenyl-β- d -xyloside ( p NPβXyl) as a substrate, the purified protein presented an optimal pH of 8.5 and an optimal temperature of 45 °C. Moreover, CcXyl3A was activated in the presence of the metals K + and Na + . Purified CcXyl3A demonstrated multifunctional activities on p NPβXyl, p -nitrophenyl-β- d -glucoside ( p NPβGlc), and p -nitrophenyl-α- l -arabinofuranoside ( p NPαAraf). The greatest catalytic activity were found on p NPβXyl followed by p NPαAra f and p NPβGlc, respectively. Using xylooligosaccharides as substrate, CcXyl3A completely hydrolyzed xylobiose, xylotriose, xylotetraose and xylohexaose, xylose was the sole product. In addition, CcXyl3A synergistically acted with Thermomyces lanuginosus xylanase in the degradation of beechwood xylan, released xyloses from intermediate xylooligosaccharides produced by T. lanuginosus xylanase. To date, this is the first report to demonstrate the cloning and characterization of a multifunctional GH3 enzyme in C. cellulans that may have applications in hemicellulose degradation.
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Characterization of a recombinant multifunctional glycoside hydrolase family 3 β-xylosidase/α-l-arabinofuranosidase/β-glucosidase from Cellulosimicrobium cellulans sp. 21
Journal of Molecular Catalysis B-enzymatic, 2016Co-Authors: Ye Yuan, Yanbo Hu, Jiayi Leng, Xuesong Zhao, Han Zhang, Fan Li, Yifa ZhouAbstract:Abstract A multifunctional β-xylosidase/α- l -arabinofuranosidase/β-glucosidase gene ( ccxyl3a ) belonging to glycoside hydrolase family 3 (GH3) was cloned from Cellulosimicrobium cellulans sp. 21 and expressed in Escherichia coli BL21 (DE3). The molecular mass of recombinant CcXyl3A was estimated to be approximately 95 kDa. With p -nitrophenyl-β- d -xyloside ( p NPβXyl) as a substrate, the purified protein presented an optimal pH of 8.5 and an optimal temperature of 45 °C. Moreover, CcXyl3A was activated in the presence of the metals K + and Na + . Purified CcXyl3A demonstrated multifunctional activities on p NPβXyl, p -nitrophenyl-β- d -glucoside ( p NPβGlc), and p -nitrophenyl-α- l -arabinofuranoside ( p NPαAraf). The greatest catalytic activity were found on p NPβXyl followed by p NPαAra f and p NPβGlc, respectively. Using xylooligosaccharides as substrate, CcXyl3A completely hydrolyzed xylobiose, xylotriose, xylotetraose and xylohexaose, xylose was the sole product. In addition, CcXyl3A synergistically acted with Thermomyces lanuginosus xylanase in the degradation of beechwood xylan, released xyloses from intermediate xylooligosaccharides produced by T. lanuginosus xylanase. To date, this is the first report to demonstrate the cloning and characterization of a multifunctional GH3 enzyme in C. cellulans that may have applications in hemicellulose degradation.
Yanbo Hu - One of the best experts on this subject based on the ideXlab platform.
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ginsenoside re impacts on biotransformation products of ginsenoside rb1 by Cellulosimicrobium cellulans sp 21 and its mechanisms
Process Biochemistry, 2019Co-Authors: Yanbo Hu, Ye Yuan, Nan Wang, Zhuyun Jiang, Yifa ZhouAbstract:Abstract Ginsenoside Rg3, a known anti-cancer agent, is usually prepared by enzyme-mediated and acid hydrolysis of ginsenoside Rb1 and Rd. In this study, we used the bacterium Cellulosimicrobium cellulans sp. 21 to transform Rb1 into Rg3. When Rb1 was used as the sole substrate, the transformation products included Rg3, Rh2, C-K and PPD. However, when Rb1 and Re were mixed, the yield of Rg3 was significantly higher, indicating that Re attenuates the activity of β-1,2-glucosidase secreted by C. cellulans sp. 21. β-1,2-glucosidase hydrolyzes the β-1,2-glucose moiety at the C-3 position of Rb1, but Re dose not modify enzymes that produce Rg3 by hydrolyzing glucose at the C-20 position in aglycon. We also tested the inhibitory effects from various ginsenosides on β-1,2-glucosidase, and discovered that sugar chains played key roles in inhibiting β-1,2 glucosidase activity, whereas aglycones of protopanaxadiol and protopanaxatriol had little inhibitory effects. Some sugar chains with different linkages, such as C-20, C-3 and C-6, exhibited different inhibitory effects. Overall, our findings demonstrate that a combination of substrates, in addition to microorganism-secreted enzymes, can be used for selective biotransformation. This approach provides a novel strategy for natural product preparations via microbial transformation.
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high yield preparation of ganglioside gm1 using recombinant sialidase from Cellulosimicrobium cellulans
Process Biochemistry, 2017Co-Authors: Ye Yuan, Li Ji, Yanbo Hu, Chenxing Hu, Honglei Chen, Yifa ZhouAbstract:Abstract Cellulosimicrobium cellulans employs extracellular sialidase to selectively convert polysialogangliosides to ganglioside GM1. We cloned this novel sialidase gene (ccsia) from C. cellulans sp. 21, and overexpressed recombinant sialidase (CcSia) protein in E. coli BL21 (DE3) by high cell density fermentation. The presence of an N-terminal hexa-His tag allowed for purification using nickel affinity chromatography (2.3-fold, specific activity 41.5 U/mg). As determined by gel electrophoresis and gel filtration chromatography, the molecular weight of CcSia was found to be about 75 kDa, consistent with sequence analysis (75,271 Da). CcSia transformed polysialogangliosides GD1a, GD1b and GT1b into GM1. For this reaction, the response surface approach showed that optimal conditions in a 1-L system were 2 h incubation at 32.5 °C and pH 5.2, with substrate concentrations of 10 g/L and crude enzyme concentration 1 g/L, respectively. Under above conditions, 10 g/L of ganglioside was completely converted to the product GM1 with a yield of 52%. Our studies demonstrate CcSia could be used for industrial preparation of ganglioside GM1 by the pharmaceutical industry.
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characterization of a recombinant multifunctional glycoside hydrolase family 3 β xylosidase α l arabinofuranosidase β glucosidase from Cellulosimicrobium cellulans sp 21
Journal of Molecular Catalysis B-enzymatic, 2016Co-Authors: Ye Yuan, Yanbo Hu, Jiayi Leng, Xuesong Zhao, Han Zhang, Fan Li, Yifa ZhouAbstract:Abstract A multifunctional β-xylosidase/α- l -arabinofuranosidase/β-glucosidase gene ( ccxyl3a ) belonging to glycoside hydrolase family 3 (GH3) was cloned from Cellulosimicrobium cellulans sp. 21 and expressed in Escherichia coli BL21 (DE3). The molecular mass of recombinant CcXyl3A was estimated to be approximately 95 kDa. With p -nitrophenyl-β- d -xyloside ( p NPβXyl) as a substrate, the purified protein presented an optimal pH of 8.5 and an optimal temperature of 45 °C. Moreover, CcXyl3A was activated in the presence of the metals K + and Na + . Purified CcXyl3A demonstrated multifunctional activities on p NPβXyl, p -nitrophenyl-β- d -glucoside ( p NPβGlc), and p -nitrophenyl-α- l -arabinofuranoside ( p NPαAraf). The greatest catalytic activity were found on p NPβXyl followed by p NPαAra f and p NPβGlc, respectively. Using xylooligosaccharides as substrate, CcXyl3A completely hydrolyzed xylobiose, xylotriose, xylotetraose and xylohexaose, xylose was the sole product. In addition, CcXyl3A synergistically acted with Thermomyces lanuginosus xylanase in the degradation of beechwood xylan, released xyloses from intermediate xylooligosaccharides produced by T. lanuginosus xylanase. To date, this is the first report to demonstrate the cloning and characterization of a multifunctional GH3 enzyme in C. cellulans that may have applications in hemicellulose degradation.
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Characterization of a recombinant multifunctional glycoside hydrolase family 3 β-xylosidase/α-l-arabinofuranosidase/β-glucosidase from Cellulosimicrobium cellulans sp. 21
Journal of Molecular Catalysis B-enzymatic, 2016Co-Authors: Ye Yuan, Yanbo Hu, Jiayi Leng, Xuesong Zhao, Han Zhang, Fan Li, Yifa ZhouAbstract:Abstract A multifunctional β-xylosidase/α- l -arabinofuranosidase/β-glucosidase gene ( ccxyl3a ) belonging to glycoside hydrolase family 3 (GH3) was cloned from Cellulosimicrobium cellulans sp. 21 and expressed in Escherichia coli BL21 (DE3). The molecular mass of recombinant CcXyl3A was estimated to be approximately 95 kDa. With p -nitrophenyl-β- d -xyloside ( p NPβXyl) as a substrate, the purified protein presented an optimal pH of 8.5 and an optimal temperature of 45 °C. Moreover, CcXyl3A was activated in the presence of the metals K + and Na + . Purified CcXyl3A demonstrated multifunctional activities on p NPβXyl, p -nitrophenyl-β- d -glucoside ( p NPβGlc), and p -nitrophenyl-α- l -arabinofuranoside ( p NPαAraf). The greatest catalytic activity were found on p NPβXyl followed by p NPαAra f and p NPβGlc, respectively. Using xylooligosaccharides as substrate, CcXyl3A completely hydrolyzed xylobiose, xylotriose, xylotetraose and xylohexaose, xylose was the sole product. In addition, CcXyl3A synergistically acted with Thermomyces lanuginosus xylanase in the degradation of beechwood xylan, released xyloses from intermediate xylooligosaccharides produced by T. lanuginosus xylanase. To date, this is the first report to demonstrate the cloning and characterization of a multifunctional GH3 enzyme in C. cellulans that may have applications in hemicellulose degradation.
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overexpression and characterization of a glycoside hydrolase family 1 enzyme from Cellulosimicrobium cellulans sp 21 and its application for minor ginsenosides production
Journal of Molecular Catalysis B-enzymatic, 2015Co-Authors: Ye Yuan, Yanbo Hu, Chenxing Hu, Honglei Chen, Jiayi Leng, Xuesong Zhao, Yifa ZhouAbstract:Abstract A novel β-glucosidase gene (ccbgl1a) was cloned from the ginsenosides-transforming strain Cellulosimicrobium cellulans sp. 21. This enzyme was overexpressed in Escherichia coli, the recombinant β-glucosidase (CcBgl1A) containing N-terminal His-tag was sufficiently purified by nickel metal affinity chromatography with purification factor of 1.9-fold and specific activity of 31.5 U/mg. The molecular mass of recombinant CcBgl1A was estimated to be approximately 46 kDa. CcBgl1A exhibited optimal activity at 35 °C and pH 5.5. However, above 40 °C, the enzyme stability significantly decreased. The enzyme showed high bioconversion ability on protopanaxadiol-type ginsenosides mixture (PPDGM), which could hydrolyze the outer C-3 glucose moieties of ginsenosides Rb1, Rb2, Rc and Rd into the rare ginsenosides Gypenoside XVII (Gyp XVII), compound O, ginsenoside Mb and ginsenoside F2. Scaled-up production using 1 g of the PPDGM resulted in 292 mg Gyp XVII, 134 mg CO, 184 mg Mb, and 62 mg F2, with chromatographic purities. These results suggest that CcBgl1A would be potentially useful in the preparation of pharmacologically active minor ginsenosides Gyp XVII, CO, Mb and F2.
Yuguang Du - One of the best experts on this subject based on the ideXlab platform.
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Cellulosimicrobium cellulans strain e4 5 enzymatic hydrolysis of curdlan for production of 1 3 linked β d glucan oligosaccharides
Carbohydrate Polymers, 2015Co-Authors: Yunbin Fu, Likun Cheng, Yanyu Meng, Shuguang Li, Xiaoming Zhao, Yuguang DuAbstract:In order to find an efficient enzymatic tool for curdlan degradation to produce (1 -> 3)-linked beta-D-glucan oligosaccharides, strain E4-5 (registration number JN089883, Genbank) was isolated from seaside soil. The 16S rRNA gene sequencing classified it as Cellulosimicrobium cellulans. It was the first reported microorganism that succeeded in degrading high-set heated curdlan blocks. The ferments of strain E4-5 also showed good degradation effects on laminaran and alkali-neutralized curdlan. Due to the products with less amount of glucose, it was assumed that endo-1,3-beta-glucanases of strain E4-5 had a greater hydrolyzing effect than exo-1,3-beta-glucanases. This indicated that strain E4-5 was a promising microorganism to hydrolyze (1 -> 3)-linked beta-D-glucan. Moreover, alkali-neutralization pretreatment was effective for promoting a more diversified degree of polymerization (DP) of (1 -> 3)-linked beta-D-glucan oligosaccharides under enzymatic hydrolysis and will pave the way for making full use of curdlan for production of glucan oligosaccharides. (C) 2015 Elsevier Ltd. All rights reserved.
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Cellulosimicrobium cellulans strain E4-5 enzymatic hydrolysis of curdlan for production of (1 → 3)-linked β-D-glucan oligosaccharides.
Carbohydrate Polymers, 2015Co-Authors: Yunbin Fu, Likun Cheng, Yanyu Meng, Shuguang Li, Xiaoming Zhao, Yuguang DuAbstract:In order to find an efficient enzymatic tool for curdlan degradation to produce (1 -> 3)-linked beta-D-glucan oligosaccharides, strain E4-5 (registration number JN089883, Genbank) was isolated from seaside soil. The 16S rRNA gene sequencing classified it as Cellulosimicrobium cellulans. It was the first reported microorganism that succeeded in degrading high-set heated curdlan blocks. The ferments of strain E4-5 also showed good degradation effects on laminaran and alkali-neutralized curdlan. Due to the products with less amount of glucose, it was assumed that endo-1,3-beta-glucanases of strain E4-5 had a greater hydrolyzing effect than exo-1,3-beta-glucanases. This indicated that strain E4-5 was a promising microorganism to hydrolyze (1 -> 3)-linked beta-D-glucan. Moreover, alkali-neutralization pretreatment was effective for promoting a more diversified degree of polymerization (DP) of (1 -> 3)-linked beta-D-glucan oligosaccharides under enzymatic hydrolysis and will pave the way for making full use of curdlan for production of glucan oligosaccharides. (C) 2015 Elsevier Ltd. All rights reserved.
Zhi Li - One of the best experts on this subject based on the ideXlab platform.
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highly chemo and regio selective hydroxylations of o and m substituted toluenes to benzyl alcohols with Cellulosimicrobium cellulans eb 8 4
Tetrahedron, 2010Co-Authors: Jinchuan Wu, Zunsheng Wang, Yongzheng Chen, Zhi LiAbstract:Abstract Highly chemo- and regio-selective benzylic hydroxylations of o- and m-substituted toluenes were achieved with the easily available and easy-to-handle resting cells of Cellulosimicrobium cellulans EB-8-4 as biocatalysts, giving the corresponding benzyl alcohols as single product. Benzyl alcohols were obtained in 78–94% yield, demonstrating the first green, clean, and simple method for the preparation of benzyl alcohols via hydroxylations. Biotransformation of 4-methylbenzyl chloride with the same strain gave 4-methylbenzyl alcohol in 67–81% yield, suggesting a novel dehalogenation activity of the cells and providing a novel, green, and efficient method for the preparation of 4-methylbenzyl alcohol as well as the application potential in biodegradation of chlorine-containing aromatics.
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regio and stereoselective allylic hydroxylation of d limonene to trans carveol with Cellulosimicrobium cellulans eb 8 4
Advanced Synthesis & Catalysis, 2009Co-Authors: Zunsheng Wang, Keyang Li, Zhi LiAbstract:Cellulosimicrobium cellulans EB-8-4 was discovered by screening of microorganisms as a powerful catalyst for the regio- and stereoselective allylic hydroxylation of D -limonene to (+)-trans-carveol that is a useful and valuable fragrance and flavour compound. Cells of strain EB-8-4 were easily obtained, demonstrated more than 99% regio- and stereoselectivity, showed a specific hydroxylation activity of 4.0 U/g cdw (cell dry weight), and accepted 62 mM D -limonene without inhibition. The hydroxylation was possibly catalyzed by an nicotinamide adenine dinucleotide (NADH)-dependent oxygenase involved in the degradation of aromatic ring during cell growth. 13.4 mM of (+)-trans-carveol were obtained by biohydroxylation of D -limonene with resting cells of C. cellulans EB-8-4, thus being 11 times higher than that obtained with the best biocatalyst known thus far. High conversion and high yield were obtained in the biohydroxylation of 11.6 mM of D -limonene with the resting cells as catalyst in a closed shaking flask, giving 10 mM of (+)-trans-carveol, and 0.30 mM of carvone as the only by-product. Thus, a unique biocatalyst for the regio- and stereoselective allylic hydroxylation of D -limonene and an efficient synthesis of natural identical (+)-trans-carveol by biohydroxylation have been developed.
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Regio- and Stereoselective Allylic Hydroxylation of D-Limonene to (+)-trans-Carveol with Cellulosimicrobium cellulans EB-8-4
Advanced Synthesis & Catalysis, 2009Co-Authors: Zunsheng Wang, Keyang Li, Zhi LiAbstract:Cellulosimicrobium cellulans EB-8-4 was discovered by screening of microorganisms as a powerful catalyst for the regio- and stereoselective allylic hydroxylation of D -limonene to (+)-trans-carveol that is a useful and valuable fragrance and flavour compound. Cells of strain EB-8-4 were easily obtained, demonstrated more than 99% regio- and stereoselectivity, showed a specific hydroxylation activity of 4.0 U/g cdw (cell dry weight), and accepted 62 mM D -limonene without inhibition. The hydroxylation was possibly catalyzed by an nicotinamide adenine dinucleotide (NADH)-dependent oxygenase involved in the degradation of aromatic ring during cell growth. 13.4 mM of (+)-trans-carveol were obtained by biohydroxylation of D -limonene with resting cells of C. cellulans EB-8-4, thus being 11 times higher than that obtained with the best biocatalyst known thus far. High conversion and high yield were obtained in the biohydroxylation of 11.6 mM of D -limonene with the resting cells as catalyst in a closed shaking flask, giving 10 mM of (+)-trans-carveol, and 0.30 mM of carvone as the only by-product. Thus, a unique biocatalyst for the regio- and stereoselective allylic hydroxylation of D -limonene and an efficient synthesis of natural identical (+)-trans-carveol by biohydroxylation have been developed.