Isolation and Identification of a Bacterium from Marine Shrimp Digestive Tract:A New Degrader of Starch and Protein

作     者：LI Jiqiu TAN Beiping MAI Kangsen 

作者机构：The Key Laboratory of Mariculture Ministry Education of China Fisheries College Ocean University of China Qingdao 266003 P. R. China College of Life Science South China Normal University Guangzhou 510631 P. R. China Fisheries College Guangdong Ocean University Zhanjiang 524025P. R. China 

出 版 物：《Journal of Ocean University of China》 (中国海洋大学学报（英文版）)

年 卷 期：2011年第10卷第3期

页      面：287-292页

学科分类：0832[工学-食品科学与工程（可授工学、农学学位）] 090502[农学-动物营养与饲料科学] 0905[农学-畜牧学] 08[工学] 09[农学] 0836[工学-生物工程] 082203[工学-发酵工程] 0822[工学-轻工技术与工程] 083203[工学-农产品加工及贮藏工程] 

基　　金：financially supported by the National High Technology Research and Development Project of China(863 Project No.2001AA622060 and No.2003A-A622060) 

主　　题：candidate probiotic selection identification marine shrimp 

摘      要：It is a practical approach to select candidate probiotic bacterial stains on the basis of their special traits. Production of digestive enzyme was used as a trait to select a candidate probiotic bacterial strain in this study. In order to select a bacterium with the ability to degrade both starch and protein, an ideal bacterial strain STE was isolated from marine shrimp (Litopenaeus vannamei) intestines by using multiple selective *** selected isolate STE was identified on the basis of its morphological, physiological,and biochemical characteristics as well as molecular analyses. Results of degradation experiments confirmed the ability of the selected isolate to degrade both starch and casein. The isolate STE was aerobic, Gram-negative, rod-shaped, motile and non-spore-forming, and had catalase and oxidase activities but no glucose fermentation activity. Among the tested carbon/nitrogen sources, only Tween40, alanyl-glycine, aspartyl-glycine, and glycyl-l-glutamic acid were utilized by the isolate STE. Results of homology comparison analyses of the 16S rDNA sequences showed that the isolate STE had a high similarity to several Pseudoalteromonas species and, in the phylogenetic tree, grouped with P. ruthenica with maximum bootstrap support (100%). In conclusion, the isolate STE was characterized as a novel strain belonging to the genus *** study provides a further example of a probiotic bacterial strain with specific characteristics isolated from the host gastrointestinal tract.