两株黄单胞菌多糖生产菌的鉴定

IDENTIFICATION OF TWO XANTHAN-PRODUCING STRAINS

黄单胞菌多糖(Xanthan gum)是由野油菜黄单胞菌(Xanthomonas campestris)以糖质原料为底物产生的。这种多糖溶液具有高粘度、假塑性,对广范围的盐浓度、pH、温度、二价离子和剪切降解作用等比较稳定,可配伍性较好,且可被生物降解而无污染环境的特点,因而常作为增稠剂、悬浮剂和稳定剂等广泛地应用于食品、农业、消防、造纸、摄影、制药、化工、印染和陶瓷等方面。

Two xanthan-producing strains were selected: the strain L4 uses sucrose as a better Csource for xanthan production, while the strain L5 tends to utilize starch. Their cell morphological and cultural characters, physiological and biochemical properties, as well as G+C mol% contents of DNA are almost all consistent with the differentiating characteristics of Xanthomonas campestris described in 'Bergey's Manual of Systematic Bacteriology' and other papers published in China. Therefore, both the strain L4 and L5 are identified as X. campostris L4 and X. campestris L5, respectively.