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Gao Z, Wu C, Wu J, Zhu L, Gao M, Wang Z, Li Z, Zhan X. Antioxidant and anti-inflammatory properties of an aminoglycan-rich exopolysaccharide from the submerged fermentation of Bacillus thuringiensis. Int J Biol Macromol 2022; 220:1010-1020. [PMID: 36030974 DOI: 10.1016/j.ijbiomac.2022.08.116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 08/11/2022] [Accepted: 08/16/2022] [Indexed: 11/05/2022]
Abstract
Proteins from Bacillus thuringiensis are widely used as biopesticides but little is known about its exopolysaccharides. The exopolysaccharide BPS-2 was extracted from B. thuringiensis IX-01 after high-cell-density fermentation. BPS-2 is a heteropolysaccharide (molecular weight 29.36 kDa) composed of D-galactosamine, arabinose, glucosamine, glucose, and mannose in molar ratios 5.53: 1.77:4.74:3.24:1. In vitro upper gastrointestinal simulations showed that BPS-2 has strong anti-digestive capacity, with scavenging of DPPH, hydroxyl, ABTS, and superoxide anions radicals of 31.34 ± 1.67 %, 32.43 ± 3.01 %, 34.31 ± 2.12 %, and 48.53 ± 3.55 %, respectively, after BPS-2 entered the colon. It significantly inhibited production of lipopolysaccharide-induced nitric oxide and multiple pro-inflammatory cytokines and had proliferative effects on RAW 264.7 cells. BPS-2 inhibited malondialdehyde secretion and elevated activities of glutathione peroxidase, superoxide dismutase, and total antioxidants, significantly improving the antioxidant status of inflammation model cells. This first report of the in vitro anti-inflammation and antioxidant properties of BPS-2 from B. thuringiensis provides a basis for biopharmaceutical applications.
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Affiliation(s)
- Zexin Gao
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, PR China
| | - Chuanchao Wu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, PR China
| | - Jianrong Wu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, PR China
| | - Li Zhu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, PR China; A & F Biotech. Ltd., Burnaby, BC V5A3P6, Canada
| | - Minjie Gao
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, PR China
| | - Zichao Wang
- College of Biological Engineering, Henan University of Technology, Zhengzhou 450001, China
| | - Zhitao Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, PR China
| | - Xiaobei Zhan
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, PR China.
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Zhang Q, Wang X, Luo H, Wang Y, Wang Y, Tu T, Qin X, Su X, Huang H, Yao B, Bai Y, Zhang J. Metabolic engineering of Pichia pastoris for myo-inositol production by dynamic regulation of central metabolism. Microb Cell Fact 2022; 21:112. [PMID: 35659241 PMCID: PMC9166411 DOI: 10.1186/s12934-022-01837-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 05/25/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The methylotrophic budding yeast Pichia pastoris GS115 is a powerful expression system and hundreds of heterologous proteins have been successfully expressed in this strain. Recently, P. pastoris has also been exploited as an attractive cell factory for the production of high-value biochemicals due to Generally Recognized as Safe (GRAS) status and high growth rate of this yeast strain. However, appropriate regulation of metabolic flux distribution between cell growth and product biosynthesis is still a cumbersome task for achieving efficient biochemical production. RESULTS In this study, P. pastoris was exploited for high inositol production using an effective dynamic regulation strategy. Through enhancing native inositol biosynthesis pathway, knocking out inositol transporters, and slowing down carbon flux of glycolysis, an inositol-producing mutant was successfully developed and low inositol production of 0.71 g/L was obtained. The inositol production was further improved by 12.7% through introduction of heterologous inositol-3-phosphate synthase (IPS) and inositol monophosphatase (IMP) which catalyzed the rate-limiting steps for inositol biosynthesis. To control metabolic flux distribution between cell growth and inositol production, the promoters of glucose-6-phosphate dehydrogenase (ZWF), glucose-6-phosphate isomerase (PGI) and 6-phosphofructokinase (PFK1) genes were replaced with a glycerol inducible promoter. Consequently, the mutant strain could be switched from growth mode to production mode by supplementing glycerol and glucose sequentially, leading to an increase of about 4.9-fold in inositol formation. Ultimately, the dissolved oxygen condition in high-cell-density fermentation was optimized, resulting in a high production of 30.71 g/L inositol (~ 40-fold higher than the baseline strain). CONCLUSIONS The GRAS P. pastoris was engineered as an efficient inositol producer for the first time. Dynamic regulation of cell growth and inositol production was achieved via substrate-dependent modulation of glycolysis and pentose phosphate pathways and the highest inositol titer reported to date by a yeast cell factory was obtained. Results from this study provide valuable guidance for engineering of P. pastoris for the production of other high-value bioproducts.
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Affiliation(s)
- Qiquan Zhang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, No.2 Yuanmingyuan West Road, Haidian district, Beijing, 100193, China
| | - Xiaolu Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, No.2 Yuanmingyuan West Road, Haidian district, Beijing, 100193, China
| | - Huiying Luo
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, No.2 Yuanmingyuan West Road, Haidian district, Beijing, 100193, China
| | - Yaru Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, No.2 Yuanmingyuan West Road, Haidian district, Beijing, 100193, China
| | - Yuan Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, No.2 Yuanmingyuan West Road, Haidian district, Beijing, 100193, China
| | - Tao Tu
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, No.2 Yuanmingyuan West Road, Haidian district, Beijing, 100193, China
| | - Xing Qin
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, No.2 Yuanmingyuan West Road, Haidian district, Beijing, 100193, China
| | - Xiaoyun Su
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, No.2 Yuanmingyuan West Road, Haidian district, Beijing, 100193, China
| | - Huoqing Huang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, No.2 Yuanmingyuan West Road, Haidian district, Beijing, 100193, China
| | - Bin Yao
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, No.2 Yuanmingyuan West Road, Haidian district, Beijing, 100193, China
| | - Yingguo Bai
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, No.2 Yuanmingyuan West Road, Haidian district, Beijing, 100193, China.
| | - Jie Zhang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, No.2 Yuanmingyuan West Road, Haidian district, Beijing, 100193, China.
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Wang H, Zhang BY, Gong T, Chen TJ, Chen JJ, Yang JL, Zhu P. Construction of acetyl-CoA and DBAT hybrid metabolic pathway for acetylation of 10-deacetylbaccatin III to baccatin III. Acta Pharm Sin B 2021; 11:3322-3334. [PMID: 34729319 PMCID: PMC8546859 DOI: 10.1016/j.apsb.2021.03.029] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 03/05/2021] [Accepted: 03/11/2021] [Indexed: 01/01/2023] Open
Abstract
10-Deacetylbaccatin III (10-DAB) C10 acetylation is an indispensable procedure for Taxol semi-synthesis, which often requires harsh conditions. 10-Deacetylbaccatin III-10-β-O-acetyltransferase (DBAT) catalyzes the acetylation but acetyl-CoA supply remains a key limiting factor. Here we refactored the innate biosynthetic pathway of acetyl-CoA in Escherichia coli and obtained a chassis with acetyl-CoA productivity over three times higher than that of the host cell. Then, we constructed a microbial cell factory by introducing DBAT gene into this chassis for efficiently converting 10-DAB into baccatin III. We found that baccatin III could be efficiently deacetylated into 10-DAB by DBAT with CoASH and K+ under alkaline condition. Thus, we fed acetic acid to the engineered strain both for serving as a substrate of acetyl-CoA biosynthesis and for alleviating the deacetylation of baccatin III. The fermentation conditions were optimized and the baccatin III titers reached 2, 3 and 4.6 g/L, respectively, in a 3-L bioreactor culture when 2, 3 and 6 g/L of 10-DAB were supplied. Our study provides an environment-friendly approach for the large scale 10-DAB acetylation without addition of acetyl-CoA in the industrial Taxol semi-synthesis. The finding of DBAT deacetylase activity may broaden its application in the structural modification of pharmaceutically important lead compounds.
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Key Words
- 10-Deacetylbaccatin III-10-β-O-acetyltransferase
- ACS, acetyl-CoA synthetase
- Bioconversion of 10-deacetylbaccatin III to baccatin III
- Biosynthetic pathway of acetyl-CoA
- DBAT, 10-deacetylbaccatin III-10-β-O-acetyltransferase
- Deacetylation of baccatin III
- E. coli, Escherichia coli
- GAPD, glyceraldehyde-3-phosphate dehydrogenase
- High-cell-density fermentation
- Microbial cell factory
- PANK, pantothenate kinase
- PDH, pyruvate dehydrogenase complex
- PGK, 1,3-bisphosphoglycerate kinase
- Se/acsL641P, acetyl-CoA synthetaseL641P of Salmonella enterica
- Taxol semi-synthesis
- aceE, pyruvate decarboxynase
- aceF, dihydrolipoamide transacetylase
- lpdA, lipoamide dehydrogenase
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Affiliation(s)
| | | | | | | | | | | | - Ping Zhu
- Corresponding author. Tel.: +86 10 63165197; fax: +86 10 63017757.
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Yao D, Su L, Li N, Wu J. Enhanced extracellular expression of Bacillus stearothermophilus α-amylase in Bacillus subtilis through signal peptide optimization, chaperone overexpression and α-amylase mutant selection. Microb Cell Fact 2019; 18:69. [PMID: 30971250 PMCID: PMC6458788 DOI: 10.1186/s12934-019-1119-8] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 04/03/2019] [Indexed: 01/14/2023] Open
Abstract
Background Our laboratory has constructed a Bacillus stearothermophilus α-amylase (AmyS) derivative with excellent enzymatic properties. Bacillus subtilis is generally regarded as safe and has excellent protein secretory capability, but heterologous extracellular production level of B. stearothermophilus α-amylase in B. subtilis is very low. Results In this study, the extracellular production level of B. stearothermophilus α-amylase in B. subtilis was enhanced by signal peptide optimization, chaperone overexpression and α-amylase mutant selection. The α-amylase optimal signal peptide (SPYojL) was obtained by screening 173 B. subtilis signal peptides. Although the extracellular α-amylase activity that was produced by the resulting recombinant strain was 3.5-fold greater than that of the control, significant quantities of inclusion bodies were detected. Overexpressing intracellular molecular chaperones significantly reduced inclusion body formation and further increased α-amylase activity. Error-prone PCR produced an amylase mutant K82E/S405R (AmySA) with enzymatic activity superior to that of AmyS. Expression of the amySA gene with the SPYojL while overexpressing molecular chaperones resulted in a 7.1-fold improvement in α-amylase activity. When the final expression strain (WHS11YSA) was cultivated in a 3-L fermenter for 92 h, the α-amylase activity of the culture supernatant was 9201.1 U mL−1, which is the highest level that has been reported to date. Conclusions This is the first report that describes an improvement of B. stearothermophilus α-amylase extracellular production levels in B. subtilis using these strategies, and this represents the highest extracellular production level ever reported for α-amylase from B. stearothermophilus in B. subtilis. This high-level production provides a basis for enhanced industrial production of α-amylase. These extracellular production level improvement approaches are also expected to be valuable in the expression of other enzymes in B. subtilis. Electronic supplementary material The online version of this article (10.1186/s12934-019-1119-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Dongbang Yao
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, Jiangsu, China.,School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
| | - Lingqia Su
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, Jiangsu, China.,School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
| | - Na Li
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, Jiangsu, China.,School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
| | - Jing Wu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, Jiangsu, China. .,School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China. .,International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.
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Su L, Sun F, Liu Z, Zhang K, Wu J. Highly efficient production of Clostridium cellulolyticum H10 D-psicose 3-epimerase in Bacillus subtilis and use of these cells to produce D-psicose. Microb Cell Fact 2018; 17:188. [PMID: 30486886 PMCID: PMC6260708 DOI: 10.1186/s12934-018-1037-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 11/23/2018] [Indexed: 01/08/2023] Open
Abstract
Background d-Psicose 3-epimerase (DPEase) catalyzes the isomerization of d-fructose to the rare sugar d-psicose, which may help prevent obesity, reduce blood sugar and blood fat, and inhibit intra-abdominal fat accumulation. Results In this study, the DPEase of Clostridium cellulolyticum H10 was expressed in the food-grade host Bacillus subtilis. Optimization of the culture medium during shake-flask experiments yielded a DPEase activity of 314 U/mL. The optimal medium included 20 g/L peptone, 15 g/L corn steep powder, 5 g/L glycerol, and 1 mM Ca2+. Controlling the carbon source concentration was important because elevated concentrations can result in catabolite metabolic suppression (CCR). To avoid CCR and increase DPEase expression, we developed a fed-batch strategy in a 3.6-L fermenter. We altered the ratio of carbon source to nitrogen source (C/N) in the feeding medium and employed a constant feeding rate (6 g/L/h). This strategy improved the DPEase activity to 2246 U/mL (7.8 g/L), which is almost 15 times higher than that observed in the original shake-flask cultures. Finally, we used the DPEase-expressing B. subtilis cells to produce d-psicose from d-fructose, and a 28% conversion yield was achieved with these cells, demonstrating their potential use in d-psicose production. Conclusions This is the first report to enhance recombinant DPEase production in B. subtilis using efficient and convenient fermentation strategy, and the DPEase yield is three times higher than the highest yield reported to date. The recombinant B. subtilis cells were further used in the efficient synthesis of d-psicose. This study provides a basis for the industrial production of d-psicose.
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Affiliation(s)
- Lingqia Su
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
| | - Fan Sun
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
| | - Zhanzhi Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
| | - Kang Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
| | - Jing Wu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China. .,School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China. .,International Joint Laboratory on Food Safety, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.
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Abstract
Pichia pastoris has been one of the most successful heterologous overexpression systems in generating proteins for large-scale production through high-cell-density fermentation. However, optimizing conditions of the large-scale high-cell-density fermentation for biochemistry and industrialization is usually a laborious and time-consuming process. Furthermore, it is often difficult to produce authentic proteins in large quantities, which is a major obstacle for functional and structural features analysis and industrial application. For these reasons, we have developed a protocol for efficient demonstration-scale high-cell-density fermentation of P. pastoris, which employs a new methanol-feeding strategy-biomass-stat strategy and a strategy of increased air pressure instead of pure oxygen supplement. The protocol included three typical stages of glycerol batch fermentation (initial culture phase), glycerol fed-batch fermentation (biomass accumulation phase), and methanol fed-batch fermentation (induction phase), which allows direct online-monitoring of fermentation conditions, including broth pH, temperature, DO, anti-foam generation, and feeding of glycerol and methanol. Using this protocol, production of the recombinant β-xylosidase of Lentinula edodes origin in 1000-L scale fermentation can be up to ~900 mg/L or 9.4 mg/g cells (dry cell weight, intracellular expression), with the specific production rate and average specific production of 0.1 mg/g/h and 0.081 mg/g/h, respectively. The methodology described in this protocol can be easily transferred to other systems, and eligible to scale up for a large number of proteins used in either the scientific studies or commercial purposes.
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Affiliation(s)
- Wan-Cang Liu
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences, Peking Union Medical College, 1 Xian Nong Tan Street, Beijing, 100050, People's Republic of China
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences, Peking Union Medical College, 1 Tian Tan Xi Li, Beijing, 100050, People's Republic of China
- Biotechnology Core Laboratory, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Ping Zhu
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences, Peking Union Medical College, 1 Xian Nong Tan Street, Beijing, 100050, People's Republic of China.
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Guan C, Cui W, Cheng J, Zhou L, Liu Z, Zhou Z. Development of an efficient autoinducible expression system by promoter engineering in Bacillus subtilis. Microb Cell Fact 2016; 15:66. [PMID: 27112779 PMCID: PMC4845504 DOI: 10.1186/s12934-016-0464-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 04/13/2016] [Indexed: 11/11/2022] Open
Abstract
Background Bacillus subtilis, a Gram-positive organism, has been developed to be an attractive expression platform to produce both secreted and cytoplasmic proteins owing to its prominent biological characteristics. We previously developed an auto-inducible expression system containing the srfA promoter (PsrfA) which was activated by the signal molecules acting in the quorum-sensing pathway for competence. The PsrfA promoter exhibited the unique property of inducer-free activity that is closely correlated with cell density. Results To improve the PsrfA-mediated expression system to the high-cell-density fermentation for industrial production in the B. subtilis mutant strain that is unable to sporulate, a spore mutant strain BSG1682 was developed, and the PsrfA promoter was enhanced by promoter engineering. Using green fluorescent protein (GFP) as the reporter, higher fluorescent intensity was observed in BSG1682 with expression from either plasmid or chromosome than that of the wild type B. subtilis 168. Thereafter, the PsrfA was engineered, yielding a library of PsrfA derivatives varied in the strength of GFP expression. The P23 promoter exhibited the best performance, almost twofold stronger than that of PsrfA. Two heterologous proteins, aminopeptidase (AP) and nattokinase (NK), were successfully overproduced under the control of P23 in BSG1682. Finally, the capacity of the expression system was demonstrated in batch fermentation in a 5-L fermenter. Conclusions The expression system demonstrates prominence in the activity of the auto-inducible promoter. Desired proteins could be highly and stably produced by integrating the corresponding genes downstream of the promoter on the plasmid or the chromosome in strain BSG1682. The expression system is conducive to the industrial production of pharmaceuticals and heterologous proteins in high-cell-density fermentation in BSG1682.
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Affiliation(s)
- Chengran Guan
- School of Biotechnology, Key Laboratory of Industrial Biotechnology (Ministry of Education), Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, Jiangsu, China
| | - Wenjing Cui
- School of Biotechnology, Key Laboratory of Industrial Biotechnology (Ministry of Education), Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, Jiangsu, China.
| | - Jintao Cheng
- School of Biotechnology, Key Laboratory of Industrial Biotechnology (Ministry of Education), Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, Jiangsu, China
| | - Li Zhou
- School of Biotechnology, Key Laboratory of Industrial Biotechnology (Ministry of Education), Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, Jiangsu, China
| | - Zhongmei Liu
- School of Biotechnology, Key Laboratory of Industrial Biotechnology (Ministry of Education), Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, Jiangsu, China
| | - Zhemin Zhou
- School of Biotechnology, Key Laboratory of Industrial Biotechnology (Ministry of Education), Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, Jiangsu, China.
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Cordova LT, Long CP, Venkataramanan KP, Antoniewicz MR. Complete genome sequence, metabolic model construction and phenotypic characterization of Geobacillus LC300, an extremely thermophilic, fast growing, xylose-utilizing bacterium. Metab Eng 2015; 32:74-81. [PMID: 26391740 DOI: 10.1016/j.ymben.2015.09.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 08/26/2015] [Accepted: 09/11/2015] [Indexed: 02/07/2023]
Abstract
We have isolated a new extremely thermophilic fast-growing Geobacillus strain that can efficiently utilize xylose, glucose, mannose and galactose for cell growth. When grown aerobically at 72 °C, Geobacillus LC300 has a growth rate of 2.15 h(-1) on glucose and 1.52 h(-1) on xylose (doubling time less than 30 min). The corresponding specific glucose and xylose utilization rates are 5.55 g/g/h and 5.24 g/g/h, respectively. As such, Geobacillus LC300 grows 3-times faster than E. coli on glucose and xylose, and has a specific xylose utilization rate that is 3-times higher than the best metabolically engineered organism to date. To gain more insight into the metabolism of Geobacillus LC300 its genome was sequenced using PacBio's RS II single-molecule real-time (SMRT) sequencing platform and annotated using the RAST server. Based on the genome annotation and the measured biomass composition a core metabolic network model was constructed. To further demonstrate the biotechnological potential of this organism, Geobacillus LC300 was grown to high cell-densities in a fed-batch culture, where cells maintained a high xylose utilization rate under low dissolved oxygen concentrations. All of these characteristics make Geobacillus LC300 an attractive host for future metabolic engineering and biotechnology applications.
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Affiliation(s)
- Lauren T Cordova
- Department of Chemical and Biomolecular Engineering, Metabolic Engineering and Systems Biology Laboratory, University of Delaware, 150 Academy St, Newark, DE 19716, USA
| | - Christopher P Long
- Department of Chemical and Biomolecular Engineering, Metabolic Engineering and Systems Biology Laboratory, University of Delaware, 150 Academy St, Newark, DE 19716, USA
| | - Keerthi P Venkataramanan
- Department of Chemical and Biomolecular Engineering, Metabolic Engineering and Systems Biology Laboratory, University of Delaware, 150 Academy St, Newark, DE 19716, USA
| | - Maciek R Antoniewicz
- Department of Chemical and Biomolecular Engineering, Metabolic Engineering and Systems Biology Laboratory, University of Delaware, 150 Academy St, Newark, DE 19716, USA.
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