摘要 辅酶Q10(CoQ10)是天然存在的抗氧化剂和细胞代谢激活剂,具有消除自由基、维持细胞膜通透性、提高机体免疫功能等多种生理作用。选育CoQ10高产菌株并通过发酵法实现该功能化合物的高效合成具有重要价值。作者从污水处理厂的淤泥中分离纯化获得了一株CoQ10高产菌株YLL-13,通过形态观察、生化特性分析及16S rDNA序列比对,鉴定为类球红细菌(Rhodobacter sphaeroides),命名为R.sphaeroides YLL-13。随后,以R.sphaeroides YLL-13为出发菌株,以维生素K3和4-羟基苯甲酸(p-hydroxybenzoic acid,pHBA)为复合筛选标记,通过亚硝基胍化学诱变,筛选高产突变菌株,并初步研究了其生产CoQ10特性。结果显示,经诱变选育获取了一株遗传稳定的CoQ10高产突变株R.sphaeroides YLL-13-T,其具有相对低类胡萝卜素合成、高生长速率和高CoQ10积累特性。在所考察的发酵体系中,发酵120 h后突变菌株YLL-13-T的生物量、CoQ10产量和CoQ10产率达到83.5、1.04 g/L和12.46 mg/g,比出发菌株分别提高了12.3%、42.5%和23.6%,展现出良好的工业化应用前景。 Coenzyme Q10(CoQ10)is a natural antioxidant and cell metabolic activator,possessing several important biological properties,such as eliminating free radicals,maintaining cell membrane permeability,and improving immune function.It is of great value to develop high-yield CoQ10strain and realize high-efficient synthesis of functional compounds by fermentation.In this work,a potent CoQ10-producing strain YLL-13 was isolated from the silt of a sewage treatment plant.based on the morphological observation,biochemical characteristics analysis and 16S rDNA sequence alignment,the strain was identified as Rhodobacter sphaeroides and named as R.sphaeroides YLL-13.In further,a high-yield mutant strain was screened by nitrosoguanidine chemical mutagenesisusing R.sphaeroides Yll-13 as the starting strainand Vitamin K3 and p-hydroxybenzoic acid(pHBA)as the compound screening markers.A genetically stable CoQ10mutant with high yield of CoQ10,R.sphaeroides YLL-13-T,was achieved by mutagenesis.This strain had relatively low carotenoid synthesis,high growth rate and high CoQ10accumulation characteristics.In the studied fermentation system,the biomass,CoQ10concentration and specific CoQ10content of the mutant strain YLL-13-T after 120 h fermentation were 83.5 g/L,1.04 g/L and 12.46 mg/g(DCW)respectively,which were 12.3%,42.5%and 23.6%higher than those of original wild-type strain,showing a good prospect of industrial application.
出处 《食品与生物技术学报》 CAS CSCD 北大核心 2021年第2期32-40,共9页 Journal of Food Science and Biotechnology
基金 国家自然科学基金项目(31670804,31971372) 江苏省博士后基金资助项目(2020Z074) 浙江省自然科学基金青年基金项目(LQ18B060002)。
分类号 Q815 [生物学—生物工程]
