牛瘤胃产纤维二糖磷酸化酶细菌的筛选及产酶条件研究

为了获得产新型纤维二糖磷酸化酶(CBP)的菌株,利用选择性培养基从牛瘤胃液中逐步分离纯化,筛选能以纤维二糖为唯一碳源生长的菌株,分别检测所筛选菌株的β-葡萄糖苷酶(βG)和CBP活力,并对其纤维二糖的利用方式(水解途径或磷解途径)进行鉴定,获得产CBP的菌株,命名为BY-a。采用形态学观察、生理生化试验,结合16S r DNA序列分析,鉴定菌株BY-a为克雷伯氏菌属(Klebsiella)。对菌种产CBP的温度、时间、最适装液量和溶氧量进行初步优化,结果显示,BY-a菌株在装液量为30mL(250mL)、37℃振荡培养24 h时,产CBP活力最高。

Screening and Fermentation Conditions of Cellobiose Phosphory-lase-producing Bacteria from Bovine Rumen

To obtain a novel CBP-producing strain,the bovine rumen fluid was screened using selective culture for the strains which could grow with cellobiose as the sole carbon source.The mode i.e.,hydrolysis or phosphorolysis that the strains degrade cellobiose was further identified.The CBP-producing strain named BY-a was obtained.The targeted strain's taxonomic status was identified as Klebsiella based on its physiological,biochemical characteristics,and 16S rDNA phylogenetic analysis.Then the fermentation conditions of the strain for enzyme production were optimized.The highest enzyme activity was obtained under 37 ℃ at 24 h,with 30 mL liquid in 250 mL flask.