Vc二步发酵一株新产酸菌的分子生物学特性

Biological and Molecular Characteristics of a Novel Strain for Production of 2-KGA in Two-step Fermentation of Vitamin C

对最近分离到的一株能合成维生素C前体 - 2 -酮基 -L -古龙酸 (2 -KGA)的新产酸菌V6生物学和分子生物学特性进行了初步研究。该菌株为革兰氏阴性菌 ,细胞为短杆状 ,菌体大小为 0 .8- 1.0× 0 .4 - 0 .6 μm ,菌落为淡黄色 ,好氧 ,最适生长温度为 2 8～ 30℃ ,最适pH为 7.0～ 7.8,GCmol%含量为 5 3.1% ,不含质粒 ,能氧化葡萄糖、山梨醇和山梨糖合成 2 -KGA。 16SrDNA同源性分析发现 ,该产酸菌与以前报道的能合成 2 -KGA的三个属Ketogulonigenium属、Gluconobacter属和Acetobacter属的同源性分别是 98.9～ 99.3%、82～ 83%和 81～ 82 %。基于以上特性分析 ,该产酸菌在分类发育学上宜归为Ketogulonigenium属。

A novel bacterial strain V6 that can produce 2-keto-L-gulonic acid(2-KGA),a key precursor of Vitamin C,was screened recently.It was Gram-negtive,aerobic,short rods,no plasmid;its size was 0.8-1.0x0.4-0.6μm.The optimum growth temperature was from 28℃ to 30℃,and the optimum pH was from 7.0 to 7.8.The GC mol% content was about 53.1%.Comparative analysis revealed that the identical 16srDNA sequence with Ketogulonigenium gen.,Gluconobacter gen.and Acetobacter gen.was 98.9～99.3%,82～83% and 81～82% respectively.On the basis of phenotypic and genotypic analyses,this strain should belong to Ketogulonigenium gen.,but it still need further study to identify and name this strain.