一株高产乳酸菌株的分离鉴定及特性研究  

The Screening and Characterization of A Lactic Acid-producting Bacterium

作　　者：李剑[1] 唐赟[1] 梁凤来[1] 张心平[1] 刘如林[1] 马挺[1] 

机构地区：[1]南开大学生命科学学院,天津300071

出　　处：《南开大学学报（自然科学版）》2008年第3期79-83,共5页Acta Scientiarum Naturalium Universitatis Nankaiensis

基　　金：教育部天津大学-南开大学两校共建合作项目

摘　　要：从青贮饲料中筛选到一株能在48℃条件下生产乳酸的乳酸菌.该菌株革兰氏染色呈阳性,细胞呈杆状,菌体大小为(0.4～0.8)μm×(1.8～6.4)μm,无芽孢和鞭毛;兼性厌氧,接触酶阴性,不运动,同型乳酸发酵,产 D 型和 L 型乳酸.该菌株16SrDNA 序列与异型乳酸发酵的 Lactobacillus hilgardii 相似性达到98%,但在发酵类型上差异显著.通过非变性聚丙烯酰胺凝胶电泳表明该菌株具有 D 型和 L 型两种乳酸脱氢酶.菌株 MD-1在适宜发酵条件下,乳酸产量可达约140 g/L,是一株性能优良的乳酸生产菌,可用作乳酸发酵生产.Lactobacillus sp. MD-1 was isolated from maize silage. The strain could yield lactic acid under condition of 48 ℃. Cells are facultatively anaerobic, non-spore-forming, non-flagellum, catalase negative, Gram-postive, non-motile lactic acid homofermentative rods that were （0. 4-0. 8） μm× （1.8-6.4） μm The fermentation products from glucose were D- and L- lactic acid. The strain could ferment glucose, arabinose, robese, galactose, melibiase, maltose and xylose. The phylogenetic analysis based on 16S rDNA suggested strain MD-1 was closest relative of Lactobacillus hilgardii with 98 % sequence similarity, but its type of fermentation was distinctly different from L. hilgardii Native-PAGE of LDH stained for activity on D/L lactate showed the strain had D- and L-lactate dehydrogenase. The lactic acid yield of strain MD-1 was about 140 g/L on condition of the optimum fermentation, so MD-1 could be used to lactic acid fermentation.

关 键 词：乳杆菌(Lactobacillus sp.)MD-1 16S RDNA 系统发育分析 乳酸脱氢酶 

分 类 号：Q93[生物学—微生物学]