Abstract:

In order to obtain high efficient degumming strain for fiber crops, the strain CXJZU-120 was screened by UV mutagenesis treatment of CXJZ95-198 for 120 s. By studying the biological characteristics and function of degumming, the results showed that strain CXJZU-120 with stable characters, could finish ramie degumming within 5.5~6.0 h. The removal rate of non-cellulose materials was 87.22%. The strain had a high activity of pectinase, β-mannanase and xylanase in fermentation liquid after cultivation for 10 h, which reached 211.2 U/mL, 3748 U/mL and 96.6 U/mL, respectively. It showed dark brown after cultivation for 16.0~17.0 h in slant medium, bluish green appeared after cultivation for 5.0~5.5 h in fermentation liquid, and it began to present blue color when inoculating on ramie for 5.0~5.5 h. These results indicated that the ability of degumming and performance of enzyme production of the mutant strain CXJZU-120 were increased compared with the original strain. And because of the characteristics of rapid-reproduction and presentation of special colors in ramie fermentation, the strain CXJZU-120 has important significance in degumming application for fiber crops.

Key words: Erwinia carotovora, ramie, degumming, UV mutagenesis, enzyme activity

摘要：

为寻求更适宜于生产应用的麻类生物脱胶高效菌株,对苎麻脱胶菌株CXJZ95-198进行紫外诱变,存活菌株的生理特性研究和脱胶功能实验发现:紫外线处理120 s获得的变异菌株CXJZU-120性状稳定;在5.5~6.0 h完成苎麻脱胶,总胶质脱除率达87.22%;该菌经10.0 h培养,发酵液中的果胶酶、β-甘露聚糖酶和木聚糖酶活分别为211.2 U/mL、374.8 U/mL和96.6 U/mL;该菌株在固态培养基中培养16.0~17.0 h开始显棕褐色,液态发酵培养基中培养5.0~5.5 h开始显蓝绿色,接种到苎麻上发酵5.0~5.5 h开始显蓝色。该结果表明,变异菌株CXJZU-120与出发菌比较,不仅在脱胶功能和产酶性能上有所提高,而且繁殖速度快,发酵时具有特别的显色现象,对于该菌在生产中的应用具有重要意义。

关键词: 胡萝卜软腐欧文氏菌;苎麻;脱胶;紫外诱变;酶活