产油脂纤维素降解菌株的分离鉴定与特性初探OA

As a major global energy consumer,China is confronting the dual severe challenges of fossil fuel depend-ence and ecological environmental pollution.The development and utilization of renewable clean energy has emerged as a crucial pathway to address this developmental dilemma.In recent years,the conversion of cellulose by functional microorganisms for microbial lipid synthesis,which is regarded as a promising feedstock for biodiesel production,has been recognized as a viable alternative to fossil fuels.In the present study,three functional strains with both lipid-producing and cellulose-degrading capacities were isolated and screened from cow dung,using sodium carboxymethyl-cellulose(CMC-Na)as the sole carbon source.Their cellulose degradation efficiency,corresponding enzymes activi-ties,lipid accumulation,and taxonomic identity were systematically determined and analyzed.The results demon-strated that all three strains effectively promoted straw degradation.After 5 days of treatment,the straw weight loss rates induced by strains 42,47a,and 59a were 18.30%,18.34%,and 18.79%,respectively.The maximum filter paper enzyme activities of these strains were 10.35,8.84,3.67 U·mL-1;the maximum carboxymethyl cellulase ac-tivities were 12.78,14.23,5.24 U·mL-1;and the maximum β-glucosidase activities were 4.36,16.48,4.45 U·mL-1,respectively.Notably,the cellulose-to-lipid conversion capacity of all three strains peaked on the 4th day,with lipid contents reaching 34.94%,69.82%,and 39.25%for strains 42,47a,and 59a,respectively.Based on 16S rRNA gene sequence analysis,strains 42,47a,and 59a showed the highest phylogenetic similarity to Calidifon-tibacillus erzurumensis P2,Bacillus stercoris D7XPN1,and Bacillus safensis NBRC,respectively.