天山一号冰川沉积层低温脂肪酶产生菌的筛选及初步鉴定

Isolation and identification of a cold-adapted lipase producing strains from the Glacier No.1 in the Tianshan

从新疆天山一号冰川西支尾部的底部沉积层中分离筛选出高产低温脂肪酶菌株,进行初步鉴定及产酶探讨。使用罗丹明-B、吐温80、维多利亚蓝选择培养基以及三丁酸甘油酯酶活检测板,结合棕榈酸对硝基苯酯(p-NPP)比色法,筛选出产低温脂肪酶酶活较高的菌株,研究其生长特性及常规生理生化实验,并根据16S rRNA基因序列初步确定其所属菌属。共分离筛选到5株产低温脂肪酶酶活较高的菌株,经初步鉴定其中4株为假单胞菌属(Pseudomonas sp.),1株为芽孢杆菌属(Bacillus sp.)。该芽孢杆菌属产脂肪酶的能力略高于其余菌株。分离得到的5株菌均属于耐冷菌,有较好的耐盐性,能在低温条件下发酵产酶,其中4株在36h左右达到产酶高峰,为开发冰川环境下丰富的低温酶资源奠定了基础。

The purpose of this study was to isolate high-yield lipase-producing strains from Sediments of the bottom layer of the Glacier No. 1 in Tianshan Mountains,China. And preliminary identification and investigation on activity of cold-adapted lipase had been carried out. Using the screening medium such as Rhodamine-B,Tween-80,Vitoria blue and glyceryl tributyrate activity assay plate,alkaline cold-adapted strains producing lipase were screened. The growth characteristic of the strains had been studied and the related physiological and biochemical experiments were carried out. Taxonomic identities of isolated strains were determined according to the 16S rRNA gene sequences. 5high-yield lipase- producing strains were obtained. Primary identification showed that 1 strain belonged to the genus Bacillus,4 strains belonged to the genus Pseudomonas. The lipase production capacity of Bacillus was slightly higher than the rest of the strains. 5 high-yield lipase-producing strains were psychrophilic. These 5 strains could tolerate high salinities and be fermented under relative low temperature. 4 strains of them could reach the peak production of enzyme after fermentation for 36 h. The research herein had provided foundation for the development of abundant resources of cold-adapted enzymes.