摘要
根据微生物菌株生物合成L-色氨酸代谢途径的特性,设计了产色氨酸的细菌选择性分离筛选培养基,对从土壤中分离得到的832株细菌通过初筛和复筛,筛选到6株L-色氨酸产生菌株,并对其进行了初步分类鉴定,确定了这6株菌均为为谷氨酸棒杆菌(Corynebacterium glutanicum)。其中1株可产L-色氨酸0.85g/L,进一步通过NTG以及紫外线照射多重诱变育种得到苯丙氨酸和酪氨酸双重营养缺陷型与多种色氨酸结构类似物抗性突变株,遗传性状稳定,产酸量达到10.82g/L。
Based on the properties of metabolic pathway of L-tryptophan in microorganisms, a bacterial selective cuh＇ure medium to isolate L-tryptophan-producing bacterial strains from soil samples was designed and used to isolate out 832 strains. Through the primary isolation and the secondary screening, six potential strains were selected and they were generally identified as Corynebacteriurn glutanicurn. One of the most productive strain, SYS3-17 could produce L-tryptophan 0.85 g/L at first, and used for genetic mutation breeding with simple or combined NTG treatment and UV irradiation. Finally, a high effective strain with the stable genetic phynotypes of double auxotrophes of phenylalanine and tyrosine and multiple high resistances to L-tryptophan structural analogues was obtained, which could stably produce 10.82 g/L L-tryptophan.
出处
《食品与发酵工业》
CAS
CSCD
北大核心
2007年第7期37-41,共5页
Food and Fermentation Industries
