5株纤维菌属菌株的分离、鉴定及产酶活性研究

Five Strains of Cellulosimicrobium:Isolation,Identification and Enzymatic Activity

旨在将贵州的玉米秸秆生物质资源通过微生物降解还田,应用到烤烟轮作生产上。以植烟土壤为材料,采用刚果红染色法以及CMCase活性测定进行菌株的筛选,通过失重法测定秸秆降解率。实验共获得44株分解纤维素菌株;初筛获得20株纤维素分解菌。选择D/d较大的5株菌株,通过拮抗实验共获得复合菌剂10株。5株高效纤维素分解菌初步鉴定为Cellulosimicrobium cellulans与Cellulosimicrobium funkei(同源性都达100%);通过CMCase活性测定,复合菌剂酶活高于单一菌剂,选择酶活高(314.39 U/mL)且作用时间短(5天)的菌剂进行秸秆降解实验,25天降解率达53.35%,是对照的1.87倍。因此,5株菌株可作为贵州烟区玉米秸秆还田的潜在开发菌种,这对于资源有效利用、环境友好和植烟土壤连作障碍改良具有重要意义。

The aim is to apply the corn stalk biomass resources of Guizhou in tobacco crop rotation by using the microbial degradation method.The tobacco planting soil was used as material,the Congo red staining method and CMCase enzyme activity determination were used to screen the bacteria strains,and the straw degradation rate of corn stalk was determined by weight loss method.The results showed that 44 cellulose decomposing bacteria strains were obtained in the experiment,20 cellulose decomposing bacteria strains were obtained in the preliminary screening.Five strains with larger D/d value were selected and 10 compound bacteria strains were obtained through antagonistic experiment.In addition,the five high efficient cellulose decomposing bacterial strains were preliminarily identified as Cellulosimicrobium cellulans or Cellulosimicrobium funkei(100%homology).The CMCase enzyme activity of the compound bacteria strains was higher than that of the single bacteria strain,and the bacteria with high enzyme activity value(i.e.,314.39 U/mL)and short time of achieving the enzyme activity(i.e.,5 days)were selected to do corn stalk degradation experiments.The degradation rate of corn stalk was about 53.35%after 25 days,which was 1.87 times of the control group.Therefore,the five strains can be used as potential developing strains for corn stalk returning to field in tobacco growing areas of Guizhou Province,and could play a significant role in the effective utilization of resources,environmental protection and improvement of continuous cropping obstacles in tobacco-growing soil.