不同Xenorhabdus spp菌株培养物游离氨基酸的含量分析

FREE AMINO ACID COMPOSITIONS AND CONCENTRATIONS of XENORHABDUS SPP.CULTURES

本文测定了在加入六个 Xenorhabdus luminescens 菌株和 X.nematophilus A24菌株后,一种豆粉鸡蛋线虫培养基游离氨基酸含量的变化.Xenorhabdus luminesces 菌株和 X.nematophilus A24菌株培养物中游离氨基酸的含量差别明显,后者未测出谷氨酸,苯丙氨酸极微;而这两种氨基酸在 X.luminescens 菌株中都占很大比例,Xenorhabdus luminescens不同的菌株培养物中游离氨基酸的含量变化很大,这可能反映出各菌株含氮代谢的差别.但这些变化与线虫对细菌的营养专化性未见直接的相关.

In an attempt to establish the nutrient roles played by Xenorhobdus app.in the nitrogen metabolism,the changes of free amino acid compositions and concen- trations of six X.luminesccns isolates and X.nematophilns A24 in a soy flour -egg medium were determined.In X.nematophilus A24 cultures markedly lower concentration of phenylalanine,and even no glutamic acid or proline were detec- ted.All these three amino acids were predominant in X.,luminescens cultures. Free amino acid concentrations of different X.luminesccns isolates were varied,whi- ch mighty reflect the differences in metabolic activities of bacterial isolates.It is difficult,however,to correlate the alteration in free amino acids with the specific nutrient supply of the bacterial isolates for Heterorhabditis app.nematodes.