The partition behaviors of β-1,3-1,4-glucanase, α-amylase and neutral proteases from clarified and whole fermentation broths of Bacillus subtilis ZJF-1A5 were investigated. An aqueous two-phase system (polyethylene...The partition behaviors of β-1,3-1,4-glucanase, α-amylase and neutral proteases from clarified and whole fermentation broths of Bacillus subtilis ZJF-1A5 were investigated. An aqueous two-phase system (polyethylene glycol (PEG)/MgSO4) was examined with regard to the effects of PEG molecular weight (MW) and concentration, MgSO4 concentration, pH and NaC1 concentration on enzyme partition and extraction. The MW and concentration of PEG were found to have significant effects on enzyme partition and extraction with low MW PEG showing the greatest benefit in the partition and extraction of β-glucanase with the PEG/MgSO4 system. MgSO4 concentration influenced the partition and extraction of β-glucanase significantly, pH had little effect on β-glucanase or proteases partition but affected a-amylase partition when pH was over 7.0. The addition of NaCl had little effect on the partition behavior of β-glucanase but had very significant effects on the partitioning of α-amylase and on the neutral proteases. The partition behaviors of β-glucanase, α-amylase and proteases in whole broth were also investigated and results were similar to those obtained with clarified fermentation broth. A two-step process for purifying β-glucanase was developed, which achieved β-glucanase recovery of 65.3% and specific activity of 14027 U/mg, 6.6 times improvement over the whole broth.展开更多
Gene encoding endo-β-1,4-glucanase(TM1525)is derived from Thermotoga maritima(T.maritima),which has an open reading frame of 825 bp and encodes a 274 amino acid endo-β-1,4-glucanase.This enzyme has the same high tem...Gene encoding endo-β-1,4-glucanase(TM1525)is derived from Thermotoga maritima(T.maritima),which has an open reading frame of 825 bp and encodes a 274 amino acid endo-β-1,4-glucanase.This enzyme has the same high temperature resistance as thermophilic bacteria,which is an ideal property for industrial applications.By molecular biological means,TM1525 was cloned into pHT43 vector and introduced into Bacillus subtilis(B.subtilis)WB800N by electroporation.The results showed that the WB800N expression system was successfully constructed,and extracellular expression of the recombinant gene was achieved.Cellulose hydrolyzed activity of the protein was exhibited.展开更多
In order to improve the thermostability of β- 1,3-1,4-glucanase, evolutionary molecular engineering was used to evolve the β-1,3-1,4-glucanase from Bacillus subtilis ZJF-1A5. The process involves random mutation by ...In order to improve the thermostability of β- 1,3-1,4-glucanase, evolutionary molecular engineering was used to evolve the β-1,3-1,4-glucanase from Bacillus subtilis ZJF-1A5. The process involves random mutation by error-prone PCR and DNA shuffling followed by screening on the filter-based assay. Two mutants, EGsl and EGs2, were found to have four and five amino acid substitutions, respectively. These substitutions resulted in an increase in melting temperature from Tm=62.5℃ for the wild-type enzyme to Tm=65.5℃ for the mutant EGsl and 67.5℃ for the mutant EGs2. However, the two mutated enzymes had opposite approaches to produce reducing sugar from lichenin with either much higher (28%) for the former or much lower (21.6%) for the latter in comparison with their parental enzymes. The results demonstrate that directed evolution is an effective approach to improve the thermostability of a mesophilic enzyme.展开更多
Trichomes are specialized structures that originate from epidermal cells of organs in higher plants.The cotton fiber is a unique single-celled trichome that elongates from the seed coat epidermis.Cotton(Gossypium hirs...Trichomes are specialized structures that originate from epidermal cells of organs in higher plants.The cotton fiber is a unique single-celled trichome that elongates from the seed coat epidermis.Cotton(Gossypium hirsutum)fibers and trichomes are models for cell differentiation.In an attempt to elucidate the intercellular factors that regulate fiber and trichome cell development,we identified a plasmodesmal β-1,3-glucanase gene(designated GhPdBG)controlling the opening and closing of plasmodesmata in cotton fibers.Structural and evolutionary analysis showed haplotypic variation in the promoter region of the GhPdBG gene among 352 cotton accessions,but high conservation in the coding region.GhPdBG was expressed predominantly in cotton fibers and localized to plasmodesmata(PD).Expression patterns of PdBG that corresponded to PD permeability were apparent during fiber development in G.hirsutum and G.barbadense.The PdBG-mediated opening-closure of PD appears to be involved in fiber development and may account for the contrasting fiber traits of these two species.Ectopic expression of GhPdBG revealed that it functions in regulating fiber and trichome length and/or density by modulating plasmodesmatal permeability.This finding suggests that plasmodesmal targeting of GhPdBG,as a switch of intercellular channels,regulates single-celled fiber and trichome development in cotton.展开更多
Each possible pair of residues inβ-1,4 glucanase for disulfide formation was assessed using online websites,and four pairs L28C-S256C,Q41C-P278C,S122C-N163C and A184C-A215C were selected.Accordingly,four recombinant ...Each possible pair of residues inβ-1,4 glucanase for disulfide formation was assessed using online websites,and four pairs L28C-S256C,Q41C-P278C,S122C-N163C and A184C-A215C were selected.Accordingly,four recombinant plasmids pET28a(+)EccslH28,pET28a(+)EccslH41,pET28a(+)EccslH122 and pET28a(+)EccslH184 were prepared and transformed into E.coli to express the recombinant enzymes.Then analysis on enzymatic properties showed that T50 of the recombinant enzymes was increased from 10 min for EccslHt2 to 90 min for EccslH28 and 40 min for EccslH41 at 70℃,while their optimum pH value and pH stability were not affected,which proved that the introduction of disulfide bond improved the thermal stability ofβ-1,4 glucanase.展开更多
In order to reveal which role the callose played in R. rugosa pollination incompatibility, the full-length cDNA sequence of β-1,3-glucanase gene was cloned for the first time from the stylus of Rosa rugosa “Tanghong...In order to reveal which role the callose played in R. rugosa pollination incompatibility, the full-length cDNA sequence of β-1,3-glucanase gene was cloned for the first time from the stylus of Rosa rugosa “Tanghong” with RT-PCR and RACE methods and named as RrGlu. The full-length cDNA is 1380 bp with an open reading frame of 1041 bp, encoding 346 amino acids. The derived protein has a molecular weight of 37.85 kD, a calculated pI of 9.12, a pfam00332 conserved domain at position 36 - 345, and belongs to glycosyl hydrolase family 17. The derived protein is a hydrophilic protein secreted into the vacuole. There is a signal peptide cleavage site at position 34 - 35, a transmembrane domain at position 13 - 32, six Ser phosphorylation sites, three Thr phosphorylation sites, three Tyr phosphorylation sites, one N-glycosylation site, and five O-glycosylation sites. There are 31.50% α-helixes, 30.92% random coil, 25.14% extended peptide chain, and 12.43% β-corner structure. This protein and the Glu protein from eight other species, including Prunus persica, share a sequence homology of greater than 72%;all of the proteins contain a pfam00332 conserved domain and a β-1,3-glucanase active center sequence (LIVM)-X-(LIVMFYW)3-(STAG)-E-(ST)-G-W-P-(ST)-X-G. Furthermore, their phylogenetic relationships are consistent with their traditional classifications. These results were meaningful to reveal the molecular mechanism of R. rugosa pollination incompatibility and improve the theory and techniques of breeding ornamental R. rugosa.展开更多
The aim of this work was to construct a novel food-grade industrial arming yeast displaying β-1,3-1,4-glucanase and to evaluate the thermal stability of the glucanase for practical application. For this purpose, a bi...The aim of this work was to construct a novel food-grade industrial arming yeast displaying β-1,3-1,4-glucanase and to evaluate the thermal stability of the glucanase for practical application. For this purpose, a bi-directional vector containing galactokinase (GALl) and phosphoglycerate kinase 1 (PGK1) promoters in different orientations was constructed. The β-1,3-1,4-glucanase gene from Bacillus subtilis was fused to α-agglutinin and ex- pressed under the control of the GALl promoter, α-galactosidase induced by the constitutive PGK1 promoter was used as a food-grade selection marker. The feasibility of the α-galactosidase marker was confirmed by the growth of transformants harboring the constructed vector on a medium containing melibiose as a sole carbon source, and by the clear halo around the transformants in Congo-red plates owing to the expression of β-1,3-1,4-glucanase. The analysis of β-1,3-1,4-glucanase activity in cell pellets and in the supernatant of the recombinant yeast strain revealed that β-1,3-1,4-glucanase was successfully displayed on the cell surface of the yeast. The displayed β-1,3-1,4-glucanase activity in the recombinant yeast cells increased immediately after the addition of galactose and reached 45.1 U/ml after 32-h induction. The thermal stability of β-1,3-1,4-glucanase displayed in the recombinant yeast cells was en- hanced compared with the free enzyme. These results suggest that the constructed food-grade yeast has the potential to improve the brewing properties of beer.展开更多
基金Project (No. 20276064) supported by the National Nature ScienceFoundation of China
文摘The partition behaviors of β-1,3-1,4-glucanase, α-amylase and neutral proteases from clarified and whole fermentation broths of Bacillus subtilis ZJF-1A5 were investigated. An aqueous two-phase system (polyethylene glycol (PEG)/MgSO4) was examined with regard to the effects of PEG molecular weight (MW) and concentration, MgSO4 concentration, pH and NaC1 concentration on enzyme partition and extraction. The MW and concentration of PEG were found to have significant effects on enzyme partition and extraction with low MW PEG showing the greatest benefit in the partition and extraction of β-glucanase with the PEG/MgSO4 system. MgSO4 concentration influenced the partition and extraction of β-glucanase significantly, pH had little effect on β-glucanase or proteases partition but affected a-amylase partition when pH was over 7.0. The addition of NaCl had little effect on the partition behavior of β-glucanase but had very significant effects on the partitioning of α-amylase and on the neutral proteases. The partition behaviors of β-glucanase, α-amylase and proteases in whole broth were also investigated and results were similar to those obtained with clarified fermentation broth. A two-step process for purifying β-glucanase was developed, which achieved β-glucanase recovery of 65.3% and specific activity of 14027 U/mg, 6.6 times improvement over the whole broth.
基金National Natural Science Foundation of China(Regional Fund)(No.51863020)
文摘Gene encoding endo-β-1,4-glucanase(TM1525)is derived from Thermotoga maritima(T.maritima),which has an open reading frame of 825 bp and encodes a 274 amino acid endo-β-1,4-glucanase.This enzyme has the same high temperature resistance as thermophilic bacteria,which is an ideal property for industrial applications.By molecular biological means,TM1525 was cloned into pHT43 vector and introduced into Bacillus subtilis(B.subtilis)WB800N by electroporation.The results showed that the WB800N expression system was successfully constructed,and extracellular expression of the recombinant gene was achieved.Cellulose hydrolyzed activity of the protein was exhibited.
基金Project supported by the National Natural Science Foundation of China (No. 20276064) and Natural Science Foundation of ZhejiangProvince (No. Z304076), China
文摘In order to improve the thermostability of β- 1,3-1,4-glucanase, evolutionary molecular engineering was used to evolve the β-1,3-1,4-glucanase from Bacillus subtilis ZJF-1A5. The process involves random mutation by error-prone PCR and DNA shuffling followed by screening on the filter-based assay. Two mutants, EGsl and EGs2, were found to have four and five amino acid substitutions, respectively. These substitutions resulted in an increase in melting temperature from Tm=62.5℃ for the wild-type enzyme to Tm=65.5℃ for the mutant EGsl and 67.5℃ for the mutant EGs2. However, the two mutated enzymes had opposite approaches to produce reducing sugar from lichenin with either much higher (28%) for the former or much lower (21.6%) for the latter in comparison with their parental enzymes. The results demonstrate that directed evolution is an effective approach to improve the thermostability of a mesophilic enzyme.
基金the State Key Laboratory of Cotton Biology Open Fund(CB2021A04)the Agricultural Seed Project of Shandong Province(2020LZGC002)the Science Foundation of Shandong Province(ZR2020MC107)。
文摘Trichomes are specialized structures that originate from epidermal cells of organs in higher plants.The cotton fiber is a unique single-celled trichome that elongates from the seed coat epidermis.Cotton(Gossypium hirsutum)fibers and trichomes are models for cell differentiation.In an attempt to elucidate the intercellular factors that regulate fiber and trichome cell development,we identified a plasmodesmal β-1,3-glucanase gene(designated GhPdBG)controlling the opening and closing of plasmodesmata in cotton fibers.Structural and evolutionary analysis showed haplotypic variation in the promoter region of the GhPdBG gene among 352 cotton accessions,but high conservation in the coding region.GhPdBG was expressed predominantly in cotton fibers and localized to plasmodesmata(PD).Expression patterns of PdBG that corresponded to PD permeability were apparent during fiber development in G.hirsutum and G.barbadense.The PdBG-mediated opening-closure of PD appears to be involved in fiber development and may account for the contrasting fiber traits of these two species.Ectopic expression of GhPdBG revealed that it functions in regulating fiber and trichome length and/or density by modulating plasmodesmatal permeability.This finding suggests that plasmodesmal targeting of GhPdBG,as a switch of intercellular channels,regulates single-celled fiber and trichome development in cotton.
基金Supported by the National Key Research and Development Plan of China(2019YFC1905902,2019YFC1905900)Key Research and Development Plan in Shandong Province(2020CXGC010603,2021ZDSYS10,2022CXGC020206)+2 种基金"Open Competition Mechanism"Project of Qilu University of Technology(Shandong Academy of Sciences)(2022JBZ01-06)Taishan Industry Leading Talent Program(tscy20180103)National Natural Science Foundation of China(31801527)。
文摘Each possible pair of residues inβ-1,4 glucanase for disulfide formation was assessed using online websites,and four pairs L28C-S256C,Q41C-P278C,S122C-N163C and A184C-A215C were selected.Accordingly,four recombinant plasmids pET28a(+)EccslH28,pET28a(+)EccslH41,pET28a(+)EccslH122 and pET28a(+)EccslH184 were prepared and transformed into E.coli to express the recombinant enzymes.Then analysis on enzymatic properties showed that T50 of the recombinant enzymes was increased from 10 min for EccslHt2 to 90 min for EccslH28 and 40 min for EccslH41 at 70℃,while their optimum pH value and pH stability were not affected,which proved that the introduction of disulfide bond improved the thermal stability ofβ-1,4 glucanase.
文摘In order to reveal which role the callose played in R. rugosa pollination incompatibility, the full-length cDNA sequence of β-1,3-glucanase gene was cloned for the first time from the stylus of Rosa rugosa “Tanghong” with RT-PCR and RACE methods and named as RrGlu. The full-length cDNA is 1380 bp with an open reading frame of 1041 bp, encoding 346 amino acids. The derived protein has a molecular weight of 37.85 kD, a calculated pI of 9.12, a pfam00332 conserved domain at position 36 - 345, and belongs to glycosyl hydrolase family 17. The derived protein is a hydrophilic protein secreted into the vacuole. There is a signal peptide cleavage site at position 34 - 35, a transmembrane domain at position 13 - 32, six Ser phosphorylation sites, three Thr phosphorylation sites, three Tyr phosphorylation sites, one N-glycosylation site, and five O-glycosylation sites. There are 31.50% α-helixes, 30.92% random coil, 25.14% extended peptide chain, and 12.43% β-corner structure. This protein and the Glu protein from eight other species, including Prunus persica, share a sequence homology of greater than 72%;all of the proteins contain a pfam00332 conserved domain and a β-1,3-glucanase active center sequence (LIVM)-X-(LIVMFYW)3-(STAG)-E-(ST)-G-W-P-(ST)-X-G. Furthermore, their phylogenetic relationships are consistent with their traditional classifications. These results were meaningful to reveal the molecular mechanism of R. rugosa pollination incompatibility and improve the theory and techniques of breeding ornamental R. rugosa.
基金Project (No.2006AA10Z316) supported by the Hi-Tech Research and Development Program (863) of China
文摘The aim of this work was to construct a novel food-grade industrial arming yeast displaying β-1,3-1,4-glucanase and to evaluate the thermal stability of the glucanase for practical application. For this purpose, a bi-directional vector containing galactokinase (GALl) and phosphoglycerate kinase 1 (PGK1) promoters in different orientations was constructed. The β-1,3-1,4-glucanase gene from Bacillus subtilis was fused to α-agglutinin and ex- pressed under the control of the GALl promoter, α-galactosidase induced by the constitutive PGK1 promoter was used as a food-grade selection marker. The feasibility of the α-galactosidase marker was confirmed by the growth of transformants harboring the constructed vector on a medium containing melibiose as a sole carbon source, and by the clear halo around the transformants in Congo-red plates owing to the expression of β-1,3-1,4-glucanase. The analysis of β-1,3-1,4-glucanase activity in cell pellets and in the supernatant of the recombinant yeast strain revealed that β-1,3-1,4-glucanase was successfully displayed on the cell surface of the yeast. The displayed β-1,3-1,4-glucanase activity in the recombinant yeast cells increased immediately after the addition of galactose and reached 45.1 U/ml after 32-h induction. The thermal stability of β-1,3-1,4-glucanase displayed in the recombinant yeast cells was en- hanced compared with the free enzyme. These results suggest that the constructed food-grade yeast has the potential to improve the brewing properties of beer.