几种不同来源酵母抽提物性质及其对典型工程宿主菌生长的比较研究

本实验选取五种来源于国内外著名厂家生产的酵母抽提物(国内两种，国外3 种)，从理化性质和微生物培养特性方面进行比较研究。结果表明，国内厂家的啤酒酵母抽提物溶解性不如国外的3 种面包酵母抽提物，但国内生产厂家的面包酵母抽提物在总氮和氨基氮含量等方面与国外产品无明显差别。供试的几种酵母抽提物中，国内酵母抽提物有利于大肠杆菌DH5α生长，国外酵母抽提物有利于大肠杆菌DH10B 生长，而对于大肠杆菌BL21 生长而言，国内外酵母抽提物无明显差异。这说明在微生物发酵实验中，必须根据微生物生长与代谢特性，选择合适的酵母抽提物。由于国内酵母抽提物价格低于国外，为节约成本，可优先选择国内酵母抽提物。

Comparison of Physico-chemical Characteristics among Yeast Extracts from Different Sources and Their Effects on Growth of Typical Engineering Strains

Two kinds of yeast extracts including 1 brewer＇s yeast extract produced by a Chinese company and 4 baker＇s yeast extracts produced by the Chinese company, a UK company, two French companies were selected to compare their characteristics and the effects on the growth of typical engineering bacteria such as E.coli BL21, DH5 αand DH10B. The results showed that the clarity of brewer＇s yeast extract from the Chinese domestic producer was lower than those of the 3 baker＇s yeast extracts from overseas producers while no differences in the contents of total nitrogen and amino nitrogen were observed between the bakers＇yeast extract from the domestic producer and from the overseas producers. E.coli DH5 α showed better growth in the domestic yeast extracts while E.coli DH10B in the yeast extracts from the overseas producers. No significant effect, however, was observed on the growth of E.coli BL21 between the domestic and overseas products. Therefore, a suitable yeast extract is one of the key factors affecting the microbial fermentation according to the growth and metabolism of different strains.