一株高效凤眼莲脱胶菌的筛选及鉴定

Screening and Identification of an Efficient Strain of Bacteria Degumming Eichhornia crassipes

预处理是生物质能源产品制备中最昂贵、最关键的环节,生物预处理因环境友好和能耗低而受到广泛关注。为获得较好的生物预处理菌株,以脱胶效率为出发点筛选菌株,从凤眼莲(Eichhornia crassipes)生长环境介质中分离菌株,通过富集培养、刚果红平板染色法初筛,获得一株对凤眼莲脱胶效果较好的A_1菌株。在最佳条件下A_1菌株分泌的果胶酶活性、木聚糖酶活性和纤维素酶活性分别为3 925.00、8 331.67和4 883.62 nmol·s^(-1)·mL^(-1);A_1菌株对凤眼莲的1次脱胶减重率为33.37%,3次连续脱胶的累计减重率为49.26%。通过16S rRNA序列鉴定,构建系统发育树分析,该菌株为解淀粉芽孢杆菌(Bacillus amyloliquefaciens)。

Pretreatment is the most expensive and critical step of converting biomass into energy,while biological pretreatment has attracted extensive attention for its environmental friendliness and low energy consumption.In order to find a bacteria efficient for use in biological pretreatment,degumming efficiency was chosen as the scale for strain screening.A strain,coded as A1,was isolated from the environmental media where Eichhornia crassipes grew through enrichment culture and primary screening with the Congo red plate staining method,and tested to be a strain quite efficient in degumming water hyacinth.Under the optimal conditions,Strain A1 could secrete pectinase,xylanase and cellulase as high as3 925.00,8 331.67 and 4 883.62 nmol·s^-1·mL^-1,respectively,in activity.When used in pretreatment,it could reduce the weight of water hyacinth by 33.37% through one round of degumming,and cumulatively by 49.26% after three rounds of degumming.The strain was identified as Bacillus amyloliquefaciens by means of 16 S rRNA sequencing and phylogenetic tree analysis.