Isolation, identification and primary application of bacteria from putrid alkaline silica sol  

作　　者：Lijie REN Ye HAN Shuwen YANG Xiqian TAN Jin WANG Xin ZHAO Jie FAN Ting DONG Zhijiang ZHOU 

机构地区：[1]School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China

出　　处：《Frontiers of Chemical Science and Engineering》2014年第3期330-339,共10页化学科学与工程前沿（英文版）

摘　　要：The putrefaction of alkaline silica sol was investigated in this paper. The total colony numbers in three alkaline silica sol samples were 1.47 ×^ 105, 1.25× 10^4, and 9.45 × 10^4 cfu. mL 1, respectively. The salt- and alkalitolerant strains were isolated and selected using nutrient agar medium at 2.5% salinity and pH 9.5. Basic morphological, physiological and biochemical tests were conducted to confirm the preliminary characterizations of the strains. Based on API 50 CH test and 16S rDNA gene sequence analysis, the isolated strains were finally identified as Exiguobacterium aurantiacum, Cyclobacteriaceae bacterium, Microbacterium sp., Acinetobacter sp., Stenotrophomonas maltophilia and Bacillus thuringiensis. The survivability of the strains under different conditions such as salinities, acidities and temperatures was also studied. Some suitable methods for degerming, such as product pipe steam sterilization and regular canister cleaning, were proposed. To explore the possibility of isolates in industrial application, their alkaline protease and amylase production abilities were preliminarily studied. Five strains produced alkaline protease, whereas two strains produced alkaline amylase. Thus, understanding of the putrefaction on alkaline silica sol would be beneficial for improving industrial production.The putrefaction of alkaline silica sol was investigated in this paper. The total colony numbers in three alkaline silica sol samples were 1.47 ×^ 105, 1.25× 10^4, and 9.45 × 10^4 cfu. mL 1, respectively. The salt- and alkalitolerant strains were isolated and selected using nutrient agar medium at 2.5% salinity and pH 9.5. Basic morphological, physiological and biochemical tests were conducted to confirm the preliminary characterizations of the strains. Based on API 50 CH test and 16S rDNA gene sequence analysis, the isolated strains were finally identified as Exiguobacterium aurantiacum, Cyclobacteriaceae bacterium, Microbacterium sp., Acinetobacter sp., Stenotrophomonas maltophilia and Bacillus thuringiensis. The survivability of the strains under different conditions such as salinities, acidities and temperatures was also studied. Some suitable methods for degerming, such as product pipe steam sterilization and regular canister cleaning, were proposed. To explore the possibility of isolates in industrial application, their alkaline protease and amylase production abilities were preliminarily studied. Five strains produced alkaline protease, whereas two strains produced alkaline amylase. Thus, understanding of the putrefaction on alkaline silica sol would be beneficial for improving industrial production.

关 键 词：putrid alkaline silica sol ALKALIPHILE isolationand identification STERILIZATION alkaline protease and alkaline amylase 

分 类 号：TQ925.2[轻工技术与工程—发酵工程] TQ127.2