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Gao M, Liu Z, Zhao Z, Wang Z, Hu X, Jiang Y, Yan J, Li Z, Zheng Z, Zhan X. Exopolysaccharide synthesis repressor genes (exoR and exoX) related to curdlan biosynthesis by Agrobacterium sp. Int J Biol Macromol 2022; 205:193-202. [PMID: 35181324 DOI: 10.1016/j.ijbiomac.2022.02.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 01/20/2022] [Accepted: 02/12/2022] [Indexed: 11/25/2022]
Abstract
Curdlan is a neutral, water-insoluble, unbranched, linear β-(1,3)-glucan. This study explored the roles of exoR and exoX in curdlan biosynthesis in Agrobacterium sp. ATCC 31749. The microcapsule biosynthesis of ΔexoR strain was reduced, and the motility of this strain increased remarkably compared with the wild-type (WT) strain during the cell growth phase. The curdlan yields of ΔexoR and ΔexoX strains enhanced by 19% and 17%, and the glucose utilization increased by 12% and 11%, respectively, compared with the WT strain during batch fermentation. By contrast, the curdlan yields of exoR and exoX overexpression strains decreased by 28% and 33%, respectively. The gel strength produced by ΔexoR and exoX overexpression strains decreased compared with the WT strain. RT-qPCR analysis at the transcriptional level revealed that key genes in exopolysaccharide synthesis and central metabolic pathways were up-regulated in ΔexoX and ΔexoR strains during gel production. Metabolomics analysis of ΔexoR and ΔexoX mutants proved the rates of central metabolic and electron transport chain were accelerated.
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Affiliation(s)
- Minjie Gao
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, PR China
| | - Zhilei Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, PR China
| | - Zhongsheng Zhao
- 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, PR China
| | - Xiuyu Hu
- China Biotech Fermentation Industry Association, Beijing 100833, PR China
| | - Yun Jiang
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, PR China
| | - Jiajun Yan
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, PR China
| | - Zhitao Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, PR China
| | - Zhiyong Zheng
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, PR China; Jiangsu Key Laboratory of Anaerobic Biotechnology, 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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Biosynthesis and applications of curdlan. Carbohydr Polym 2021; 273:118597. [PMID: 34560997 DOI: 10.1016/j.carbpol.2021.118597] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 08/18/2021] [Accepted: 08/19/2021] [Indexed: 01/01/2023]
Abstract
Curdlan is widely applied in the food and pharmaceutical industries. This review focuses on the biosynthetic pathways, regulatory mechanisms and metabolic engineering strategies for curdlan production. Firstly, curdlan biosynthesis is discussed. Furthermore, various strategies to increase curdlan production are summarized from four aspects, including the overexpression of genes for curdlan biosynthesis, weakening/knockdown of genes from competing pathways, increasing the supply of curdlan precursors, and optimization of fermentation conditions. Moreover, the emerging and advanced applications of curdlan are introduced. Finally, the challenges that are frequently encountered during curdlan biosynthesis are noted with a discussion of directions for curdlan production.
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Yang H, Li W, Chen S, Guo X, Huang F, Zhu P. Optimization and Modeling of Curdlan Production under Multi-physiological-parameters Process Control by Agrobacterium radiobacter Mutant A-15 at High Initial Glucose. BIOTECHNOL BIOPROC E 2021. [DOI: 10.1007/s12257-021-0028-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Chu X, Li S, Wang S, Luo D, Luo H. Gene loss through pseudogenization contributes to the ecological diversification of a generalist Roseobacter lineage. ISME JOURNAL 2020; 15:489-502. [PMID: 32999421 DOI: 10.1038/s41396-020-00790-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 09/13/2020] [Accepted: 09/21/2020] [Indexed: 12/11/2022]
Abstract
Ecologically relevant genes generally show patchy distributions among related bacterial genomes. This is commonly attributed to lateral gene transfer, whereas the opposite mechanism-gene loss-has rarely been explored. Pseudogenization is a major mechanism underlying gene loss, and pseudogenes are best characterized by comparing closely related genomes because of their short life spans. To explore the role of pseudogenization in microbial ecological diversification, we apply rigorous methods to characterize pseudogenes in the 279 newly sequenced Ruegeria isolates of the globally abundant Roseobacter group collected from two typical coastal habitats in Hong Kong, the coral Platygyra acuta and the macroalga Sargassum hemiphyllum. Pseudogenes contribute to ~16% of the accessory genomes of these strains. Ancestral state reconstruction reveals that many pseudogenization events are correlated with ancestral niche shifts. Specifically, genes related to resource scavenging and energy acquisition were often pseudogenized when roseobacters inhabiting carbon-limited and energy-poor coral skeleton switched to other resource-richer niches. For roseobacters inhabiting the macroalgal niches, genes for nitrogen regulation and carbohydrate utilization were important but became dispensable upon shift to coral skeleton where nitrate is abundant but carbohydrates are less available. Whereas low-energy-demanding secondary transporters are more favorable in coral skeleton, ATP-driven primary transporters are preferentially kept in the energy-replete macroalgal niches. Moreover, a large proportion of these families mediate organismal interactions, suggesting their rapid losses by pseudogenization as a potential response to host and niche shift. These findings illustrate an important role of pseudogenization in shaping genome content and driving ecological diversification of marine roseobacters.
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Affiliation(s)
- Xiao Chu
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Siyao Li
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Sishuo Wang
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Danli Luo
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Haiwei Luo
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR. .,Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, 518000, China.
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Wang XYZ, Dong JJ, Xu GC, Han RZ, Ni Y. Enhanced curdlan production with nitrogen feeding during polysaccharide synthesis by Rhizobium radiobacter. Carbohydr Polym 2016; 150:385-91. [DOI: 10.1016/j.carbpol.2016.05.036] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 04/19/2016] [Accepted: 05/11/2016] [Indexed: 01/12/2023]
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Wu D, Li A, Ma F, Yang J, Xie Y. Genetic control and regulatory mechanisms of succinoglycan and curdlan biosynthesis in genus Agrobacterium. Appl Microbiol Biotechnol 2016; 100:6183-6192. [DOI: 10.1007/s00253-016-7650-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 05/18/2016] [Accepted: 05/21/2016] [Indexed: 12/15/2022]
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Zheng ZY, Jiang Y, Zhan XB, Ma LW, Wu JR, Zhang LM, Lin CC. An increase of curdlan productivity by integration of carbon/nitrogen sources control and sequencing dual fed-batch fermentors operation. APPL BIOCHEM MICRO+ 2013. [DOI: 10.1134/s000368381401013x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Wu JR, Yu LJ, Zhan XB, Zheng ZY, Lu J, Lin CC. NtrC-dependent regulatory network for curdlan biosynthesis in response to nitrogen limitation in Agrobacterium sp. ATCC 31749. Process Biochem 2012. [DOI: 10.1016/j.procbio.2011.11.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Zhan XB, Lin CC, Zhang HT. Recent advances in curdlan biosynthesis, biotechnological production, and applications. Appl Microbiol Biotechnol 2011; 93:525-31. [PMID: 22124723 DOI: 10.1007/s00253-011-3740-2] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2011] [Revised: 11/01/2011] [Accepted: 11/15/2011] [Indexed: 12/18/2022]
Abstract
Curdlan is a water-insoluble β-(1,3)-glucan produced by Agrobacterium species under nitrogen-limited condition. Its heat-induced gelling properties render curdlan to be very useful in the food industry initially. Recent advances in the understanding of the role curdlan plays in both innate and adaptive immunity lead to its growing applications in biomedicine. Our review focuses on the recent advances on curdlan biosynthesis and the improvements of curdlan fermentation production both from our laboratory and many others as well as the latest advances on the new applications of curdlan and its derivatives particularly in their immunological functions in biomedicine.
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Affiliation(s)
- Xiao-Bei Zhan
- Key Laboratory of Carbohydrate Chemistry and Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, 1800, Lihu Road, Wuxi, 214122, China.
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