Biolog代谢表型技术解析小菜蛾肠道细菌河生肠杆菌的生物学特性

Biological characterization of gut bacterium Enterobacter amnigenus of the diamondback moth analyzed with Biolog Metabolic Phenomics

河生肠杆菌Enterobacter amnigenus为小菜蛾Plutella xylostella幼虫肠道优势可培养格兰氏阴性细菌,本文系统地阐述了河生肠杆菌在养分需求和环境适应力上的生物学特性。采用Biolog代谢表型技术,系统地研究了E.amnigenus的碳、氮、磷、硫需求及其在各种环境下的适应力。河生肠杆菌具有广泛的营养需求,可代谢38.42%的供试碳源、98.42%的供试氮源,以及100%的硫源和100%的磷源;高效代谢的碳源和氮源分别为有机酸类和糖类、及氨基酸类和肽类化合物。它表现出95种生物合成途径。河生肠杆菌具有广泛的环境适应力,能分别在高达6.5%氯化钠、5%硫酸钠、6%氯化钾、20%乙二醇、6%甲酸钠、4%尿素、10%乳酸钠、50 mmol/L苯甲酸钠(pH5.2)、200 mmol/L磷酸钠(pH7.0)、100 mmol/L硫酸铵(pH8.0)、100 mmol/L亚硝酸钠和100 mmol/L硝酸钠的渗透溶液中生长,而不能在11%~12%的乳酸钠渗透溶液中生长;其适应pH值范围为4.5~10.0,最适约为9.0。在多种氨基酸的作用下,河生肠杆菌具有脱羧酶和脱氨酶活性。小菜蛾肠道细菌河生肠杆菌具有广泛营养需求特性、渗透压与pH环境适应力。

Enterobacter amnigenus is a predominant Gram-negative cultivated bacterial species in the larval gut of the diamondback moth,Plutella xylostella.The objective of the current study was to explore the biological properties of this bacterium.The ability of E.amnigenu s to metabolize different sources of carbon,nitrogen,sulphur and phosphorus and its adaptability to different environments were investigated using the Biolog Phenotype MicroArray(PM).The nutritional requirements of E.amnigenus were wide.It was capable of metabolizing 38.42%of the carbon sources that we tested,98.42%of nitrogen sources,100%of sulphur sources and 100%of phosphorus sources.Organic acids and carbohydrates were the most informative utilization patterns for carbon sources of E.amnigenu,whereas diverse amino acids and peptides were the most informative utilization patterns for nitrogen.The bacterium showed 95 different biosynthetic pathways.It displayed a broad range of adaptability and metabolized in osmolytes with up to 6.5%sodium chloride,5%sodium sulphate,6%potassium chloride,20%ethylene glycol,6%sodium formate,4%urea,10%sodium lactate,50 mmol/L sodium benzoate(pH5.2),200 mmol/L sodium phosphate(pH7.0),100 mmol/L ammonium sulphate(pH8.0),100 mmol/L sodium nitrite and 100 mmol/L sodium nitrate.In comparison,it was unable to survive under the pressure of 11%to 12%sodium lactate.It also showed active metabolism at pH values ranging from 4.5 to 10.0,with an optimum pH of around 9.0.In the presence of different amino acids,E.amnigenus exhibited both decarboxylase and deaminase activity.The larval intestinal bacterium E.amnigenus showed a wide adaptability to nutritional,osmotic and pH environments.