Identification of substituent groups and related genes involved in salecan biosynthesis in Agrobacterium sp. ZX09

• Published in: Applied microbiology and biotechnology Vol. 101; no. 2; pp. 585 - 598
• Main Authors: Xu, Linxiang, Cheng, Rui, Li, Jing, Wang, Yang, Zhu, Bin, Ma, Shihong, Zhang, Weiming, Dong, Wei, Wang, Shiming, Zhang, Jianfa
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.01.2017; Springer; Springer Nature B.V
• Subjects: Agrobacterium; Agrobacterium - genetics; Agrobacterium - metabolism; Analysis; Bacteria; beta-Glucans - chemistry; beta-Glucans - metabolism; bioactive properties; Biomedical and Life Sciences; Biosynthesis; Biosynthetic Pathways - genetics; Biotechnological Products and Process Engineering; Biotechnology; Cellular biology; Chromatography, High Pressure Liquid; Cloning; Cloning, Molecular; enzymatic hydrolysis; Enzymes; Gene Deletion; Gene expression; Genes; Genetic aspects; Genetic Complementation Test; Genetic engineering; Glucans; high performance liquid chromatography; Life Sciences; Liquid chromatography; Magnetic Resonance Spectroscopy; Mass Spectrometry; Microbial Genetics and Genomics; Microbiology; Molecular weight; Multigene Family; mutants; NMR; Nuclear magnetic resonance; nuclear magnetic resonance spectroscopy; Observations; Physiological aspects; plasmids; Proteobacteria; Pyruvates - chemistry; Pyruvates - metabolism; Rheology; salt tolerance; Studies; Succinates - chemistry; Succinates - metabolism; Transferases - genetics; Viscosity; Gene cluster; Substituent; sp. ZX09; Salecan; Rheology; Agrobacterium sp. ZX09
• DOI: 10.1007/s00253-016-7814-z
• ISSN: 0175-7598

Salecan, a soluble β-1,3- d -glucan produced by a salt-tolerant strain Agrobacterium sp. ZX09, has been the subject of considerable interest in recent years because of its multiple bioactivities and unusual rheological properties in solution. In this study, both succinyl and pyruvyl substituent groups on salecan were identified by an enzymatic hydrolysis following nuclear magnetic resonance (NMR), HPLC, and MS analysis. The putative succinyltransferase gene ( sleA ) and pyruvyltransferase gene ( sleV ) were determined and cloned. Disruption of the sleA gene resulted in the absence of succinyl substituent groups on salecan. This defect could be complemented by expressing the sleA cloned in a plasmid. Thus, the sleA and sleV genes located in a 19.6-kb gene cluster may be involved in salecan biosynthesis. Despite the lack of succinyl substituents, the molecular mass of salecan generated by the sleA mutant did not substantially differ from that generated by the wild-type strain. Loss of succinyl substituents on salecan changed its rheological characteristics, especially a decrease in intrinsic viscosity.