高产丁二酮乳球菌的选育及发酵条件优化  

Screening and Breeding of a High Diacetyl-producing Lactococcus lactis Strain and Optimization of Fermentation Conditions

作　　者：丁海兵[1] 潘道东[1,2] 周配东[2] 

机构地区：[1]南京师范大学国家乳品加工技术研发分中心,江苏南京210097 [2]宁波大学生命科学与生物工程学院,浙江宁波315211

出　　处：《食品科学》2011年第21期142-147,共6页Food Science

基　　金：江苏省科技支撑计划项目(BE2009366);国家农业科技成果转化基金项目(2009GB2C220412);浙江省重大科技专项(2010C12015);宁波市科技创新基金项目(2010C92024)

摘　　要：从收集到的6株乳酸菌中筛选得到一株高产丁二酮菌株DX。经过16S rDNA测序和构建系统发育树,结果表明菌株DX的16S rDNA基因序列同Lactococcus lactis的同源性为99%,综合系统发育树结果表明该菌株为乳酸乳球菌。通过单因素试验和中心组合试验确定菌株DX的最佳发酵条件为:脱脂乳质量浓度10g/100mL、接种量2%、发酵培养基初始pH6.5、培养温度37℃、静置培养,丁二酮产量达到22.383mg/L。A strain of Lactobacillus lactis highly capable of producing diacetyl,named as DX,was screened out of 6 lactic acid bacterial isolates and the fermentation conditions for diacetyl production by strain DX were optimized.The 16S rDNA sequence analysis and phylogenetic tree indicated that the 16S rDNA gene sequence of strain DX revealed 99% homology with Lactococcus lctis.Therefore,this strain was identified as Lactococcus lctis.Using central composite experimental design combined with response surface methodology,the optimal fermentation conditions for diacetyl production by strain DX were determined as follows： skim milk concentration 10 g/100 mL,inoculum amount 2%,fermentation medium initial pH 6.5,and fermentation temperature 37 ℃.Under these conditions,the diacetyl production was up to 22.383 mg/L.

关 键 词：乳酸菌 产丁二酮 筛选 发酵条件 优化 

分 类 号：TQ920.1[轻工技术与工程—发酵工程]