Screening and characteristics analysis of degradation of cellulose degrading bacteria from waste edible fungus residue

【Objective】 To study the influence of carboxymethyl cellulose sodium(CMC-Na) and cellulose powder on the screening results of cellulose degrading bacteria, and provide a basis for the comprehensive utilization of waste edible fungus residue.【Method】 In this study, CMC-Na and cellulose powder were used as the only carbon sources, the cellulose degrading bacteria were screened from the edible mushroom slag by Congo red staining method, which were identified by morphology and molecular biology, and the cellulose degradation characteristics of each strain were compared and analyzed by enzyme vitality determination and filter paper disintegrate test.【Result】 The results showed that 34 bacteria were isolated and purified from the CMC-Na, 7 of them had good cellulose degradation performance, which were mainly identified as Bacillus sp., B. subtilis, B. amyloliquefaciens. While 36 strains were isolated and purified from the cellulose powder solid medium, 7 of them had good cellulose degradation performance, there were mainly identified as B. altitudinis, B. methylotrophicus, B. amyloliquefacien, B. amyloliquefaciens subsp. plantarum, B. vallismortis, Bacillus sp. Through the enzyme activity determination test and the filter paper strip disintegration test, it was found that the g31 strain could disintegrate the filter paper into a paste within 7 d, and this strain had the highest filter paper enzyme(FPase) activityand endoglucanase(CMCase) activity, the enzyme activities reached 33.14 and 394.41 U/mL, while the C23 strain had a higher β-glucosidase(β-Gase) activity, which was 118.12 U/mL, g29 strain had a higher exo-glucanaanaose carbohydrase(Cex) activity, which was 1.22 U/mL.【Conclusion】 The study shows that the cellulose degrading bacteria isolated and screened with cellulose powder as carbon source are more abundant, have better filter paper disintegration effect and higher enzyme activity, which can provide high-quality strain resources for cellulose degradation.