一株植物乳杆菌乳糖酶性质的研究  

Properties of the Lactase Isolated from Lactobacillus plantarum

作　　者：高晓峰[1] 周颖[1] 霍贵成[1] 

机构地区：[1]东北农业大学乳品科学教育部重点实验室,哈尔滨150030

出　　处：《食品工业》2014年第11期260-264,共5页The Food Industry

基　　金：国家"863"项目(2011AA100902)食品安全与营养协同创新中心

摘　　要：为了对植物乳杆菌的乳糖酶性质进行研究,以乳糖为唯一碳源,邻硝基苯酚-β-D-半乳糖苷（ONPG）为底物,从10株植物乳杆菌中筛选出了一株乳糖酶活力最高的菌株KLDS1.0628,并进行酶学性质的研究。结果表明：该菌种所产乳糖酶活性达1.91U/mL,乳糖酶的最适温度和最适pH分别为50℃和7.0,且在45℃以下和pH5.0-8.0范围内具有较好的稳定性。另外,金属离子Mg^2＋、Mn^2＋对该酶的活性具有显著的激活作用,而Cu^2＋、EDTA对酶活有较强的抑制作用。最终采用Linew eaver-Burk做图法测得乳糖酶的Km为6.88mmol/L。试验结果为进一步研究应用乳糖酶生产低乳糖乳制品及合成低聚半乳糖提供了一定的理论基础。10 Lactobacillus plantarum strains which produced lactase were screened using lactose as sole carbon source and strain KLDS 1.062 8 produced highest lactase, which was subsequently subjected to research enzymatic characterization with o-nitrophenyl-β-D-galactopyranoside（ONPG） as a substrate. The results showed that the activity oflactase could reach up to 1.91 U/mL, the optimal temperature and pH of the reaction of this enzyme were 50 ℃ and 7.0, respectively. The enzyme was stable at temperatures below 45 ℃ and in a pH range between 5.0-8.0. Its activity was notably promoted by Mg^2＋, Mn^2＋, whereas Cu^2＋, EDTA had high inhibition to the enzyme. Km was calculated by using Lineweaver-Burk and determined to be 6.88 mmol/L. The research provides theoretical basis for further study on application oflactase to produce low-lactose dairy products and synthesize galacto-oligosaccharides.

关 键 词：植物乳杆菌 乳糖酶 性质 

分 类 号：TS201.25[轻工技术与工程—食品科学]