摘要
菌黄素的存在使得野油菜黄单胞菌产生的黄原胶发酵液呈现黄色,并显著影响了黄原胶的性状、产量及提取工艺。研究过程中得到一株自然突变的不产生菌黄素的黄原胶生产菌株XW,测序发现该菌株xanK基因的一处碱基突变使相应编码的天冬氨酸突变为甘氨酸。为探究xanK基因突变对菌黄素合成的影响,通过回补试验将野生型菌株的xanK基因导入到突变菌株中,发现突变菌株的菌黄素合成恢复,说明该突变导致菌黄素合成受阻。此外,对两种黄原胶产物进行分析,结果显示突变菌株产生的黄原胶在黏度和丙酮酸含量上均高于野生型菌株,而分子量和乙酰基含量要低于野生型菌株,说明菌黄素对黄原胶的合成可能具有复杂的影响。
The fermentation broth of Xanthomonas campestris pv.campestris containing xanthan gum has a yellow color in the presence of xanthomonadin.This significantly affects the properties,yield,and extraction process of xanthan gum.Previous research obtained a naturally mutated strain of X.campestris,in which the synthesis of xanthomonadin was suppressed.Genome sequencing indicated that a mutation in the xanK gene altered the corresponding encoded aspartic acid to glycine.To investigate the effect of this mutation on the synthesis of xanthomonadin,wild-type xanK was introduced to the mutant strain for complementary expression.This resulted in the restoration of the synthesis of xanthomonadin,indicating that this mutation was responsible for the impaired xanthomonadin synthesis.Furthermore,it was found that the xanthan gum produced by the mutant strain exhibited higher viscosity and pyruvate content,but lower molecular weight and acetyl content compared with that produced by the wild-type strain.These results suggest xanthomonadin may have complex interactions in xanthan gum synthesis.
作者
梁佳园
刘洋
韩鸿宇
张艳敏
张永刚
伏广好
董学前
LIANG Jia-yuan;LIU Yang;HAN Hong-yu;ZHANG Yan-min;ZHANG Yong-gang;FU Guang-hao;DONG Xue-qian(Division of Food Science and Engineering,Qilu University of Technology(Shandong Academy of Sciences),Jinan 250353,Shandong,China;Shandong Food Ferment Industry Research&Design Institute,Jinan 250013,Shandong,China;Inner Mongolia Fufeng Biotechnologies Co.,Ltd.,Hohhot 010070,Inner Mongolia,China)
出处
《食品研究与开发》
CAS
北大核心
2022年第24期7-13,共7页
Food Research and Development
基金
国家重点研发计划(2021YFC2103200)
齐鲁工业大学(山东科学院)科教产“揭榜制”项目(2022JBZ01-08)。
关键词
黄原胶
xanK
菌黄素
野油菜黄单胞菌
基因工程
xanthan gum
xanK
xanthomonadin
Xanthomonas campestris pv.campestris
genetic engineering
