一株野生竹黄菌的鉴定及其萃取发酵产竹红菌甲素发酵条件的优化  

Phylogenetic Identification and Extractive Fermentation of A Shiraia bambusicola Strain for Improved Hypocrellin A Production

作　　者：胡梦花 闫晓晓 黄志贤 吴振强[1] 田霄飞[1] HU Menghua;YAN Xiaoxiao;HUANG Zhixian;WU Zhenqiang;TIAN Xiaofei(School of Biology and Biological Engineering,South China University of Technology,Guangzhou,Guangdong 510006,China)

机构地区：[1]华南理工大学生物科学与工程学院,广东广州510006

出　　处：《食用菌学报》2020年第1期49-62,共14页Acta Edulis Fungi

基　　金：中央高校基本科研业务费(D2172840);企业横向委托项目(D8178730)。

摘　　要：通过内转录间隔区测序和序列比对的方法,对1株高产竹红菌甲素(hypocrellin A,HA)的菌株进行分子鉴定;以HA得率为目标,对种子液培养时间、接种量以及发酵产HA的培养基碳氮源进行优化,并对萃取发酵的表面活性剂种类、添加量和时间进行筛选和优化。通过形态和荧光染色观察,研究菌丝体形态、细胞膜成分和活性氧分布对萃取发酵的响应。结果表明:该菌株属于竹黄菌,命名为Shiraia bambusicola(GDMCC 60438)。在实验范围内,以10 g·L^-1甘油、4 g·L^-1马铃薯浸出粉和12 g·L^-1牛肉膏为培养基,经72 h液态发酵,单位碳源HA生物转化率(得率)达到13.98 mg·g^-1。在1%~10%(V∶V)范围内,增加接种量可以提升HA得率。Triton X-100为萃取发酵的优选表面活性剂。与常规发酵相比,在第70小时添加0.2%(V∶V)Triton X-100启动萃取发酵,HA的得率提高37.02%,达到了16.70 mg·g^-1碳源。萃取发酵时,菌丝表面发生褶皱,呈现收缩或聚集状态;菌丝体内活性氧得到诱导。A culture of Shiraia bambusicola(GDMCC 60438)with a high hypocrellin A(HA)productivity was isolated and identified through phylogenetic analysis using its internal transcription spacer(ITS)rRNA gene.Targeting towards high HA yield,this strain was then subjected to optimization of fermentation conditions in terms of carbon and nitrogen sources,type of surfactant,and time and quantity of surfactant addition.By morphological and fluorescent staining observation,mycelium morphology,cell membrane components,and intracellular reactive oxygen content were monitored during extractive fermentations.The results showed that GDMCC 60438 is a S.bambusicola strain.The HA conversion yield reached 13.98 mg·g^-1 carbon source using the optimal medium comprising 10 g·L^-1 glycerol,4 g·L^-1 potato powder and 12 g·L^-1 beef extract and 72-h submerged fermentation.HA yield increased as the seed inoculum increased from 1%to 10%(V∶V).Triton X-100 was selected as the optimal surfactant to facilitate releasing the intracellular HA to the fermentation broth.Compared with normal fermentation,triggering extraction fermentation at 70 h with 0.2%(V∶V)Triton X-100 promoted HA yield by 37.02%,reaching a yield of 16.70 mg·g^-1 carbon source.During the extraction fermentation,the mycelia showed wrinkled surface with contracted or aggregated morphology.The fluorescence staining observation result showed that the extraction fermentation stimulated reactive oxygen species(ROS)production by which the HA biosynthesis was promoted.

关 键 词：竹红菌甲素得率 菌丝体生物量 Shiraia bambusicola(GDMCC 60438) TRITON X-100 

分 类 号：TQ920.6[轻工技术与工程—发酵工程]