title: Activation of glycerol metabolism in Xanthomonas campestris by adaptive evolution to produce a high-transparency and low-viscosity xanthan gum from glycerol.
abstract: Many studies have focused on using crude glycerol from biodiesel to obtain valuable products, but few of these studies have focused on obtaining polysaccharides. A mutant strain of Xanthomonas campestris CCTCC M2015714 that could use glycerol to produce high-transparency and low-viscosity xanthan gum was obtained by adaptive evolution, and the yield of xanthan gum reached 11.0g/L. We found that transcriptional levels of genes related to glycerol metabolism (glpF, glpK, glpD, and fbp) in the mutant strain were all higher than those from the parent strain. Using 5g/L sucrose or glucose as starter substrate, cell growth time decreased from 36h to 24h and xanthan gum yield increased. Moreover, the mutant strain can tolerate high titer glycerol, and its activity was not affected by the impurities in crude glycerol. All these results proved that crude glycerol from biodiesel industries can be used for xanthan gum production.
authors.affiliation: Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China.
authors.forename: Zichao
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China.
authors.forename: Jianrong
authors.initials: J
authors.lastname: Wu
authors.affiliation: Wuxi Galaxy Biotech Co. Ltd., Wuxi, Jiangsu 214125, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China. Electronic address: xbzhan@yahoo.com.
authors.forename: Xiaobei
authors.initials: X
authors.lastname: Zhan
mesh_terms: D050260:Carbohydrate Metabolism; D005947:Glucose / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism*; D011135:Polysaccharides, Bacterial / Q000737:chemistry / Q000378:metabolism*; D014783:Viscosity; D016959:Xanthomonas campestris / Q000378:metabolism*
chemical_list: D011135:Polysaccharides, Bacterial; D005947:Glucose; D005990:Glycerol; C002563:xanthan gum
keywords: Adaptive evolution; Glycerol; Starter substrate; X. campestris; Xanthan gum