Wenjie Gu1, Fabao Zhang, Peizhi Xu, Kaizhi Xie, Shuanhu Tang. 1. Soil and Fertilizer Institute, Guangdong Academy of Agricultural Sciences, Key Laboratory of Plant Nutrition and Fertilizer in South Region/Guangdong Key Laboratory of Nutrient Cycling and Farmland Conservation, Guangzhou, 510640 China. irisgu0818@yahoo.com.cn
Abstract
OBJECTIVE: The aim of this study was to screen microorganisms that could degrade rice straw. METHODS: We used selective medium to screen strains and determined straw fracture tension strength, weight loss, lignocellulose decomposition rate and extracellular enzyme activity as re-screening methods after 10 days shake flask culture. RESULTS: We isolated two antinomycetes (A3 and A6), the highest cellulose enzyme activity of holoenzyme, beta3-Glucosidase, endonuclease and exonclease for A3 were 12.84, 6.23, 24.56 and 14.00 U/mL, and for A6 12.85, 6.53, 17.80 and 18.80 U/mL. The hemicelluloses enzyme activity was 83.05 for A3 and 52.98 U/mL for A6. Both strains belonged to Streptomyces. With 10 days' treatment, inoculated straws showed a decrease of straw fracture tension strength by 62.67% (A3) and 66.67% (A6), while weight loss of straw was 31.50% (A3) and 35.83% (A6). A3's decomposition rate of cellulose, hemicellulose and lignin was 38.73% , 33.16% and 20.68% , and 47.69% , 28.64% and 22.59% for A6. CONCLUSION: Antinomycetes A3 and A6 could degrad cellulose, hemicellulose and lignin.
OBJECTIVE: The aim of this study was to screen microorganisms that could degrade rice straw. METHODS: We used selective medium to screen strains and determined straw fracture tension strength, weight loss, lignocellulose decomposition rate and extracellular enzyme activity as re-screening methods after 10 days shake flask culture. RESULTS: We isolated two antinomycetes (A3 and A6), the highest cellulose enzyme activity of holoenzyme, beta3-Glucosidase, endonuclease and exonclease for A3 were 12.84, 6.23, 24.56 and 14.00 U/mL, and for A6 12.85, 6.53, 17.80 and 18.80 U/mL. The hemicelluloses enzyme activity was 83.05 for A3 and 52.98 U/mL for A6. Both strains belonged to Streptomyces. With 10 days' treatment, inoculated straws showed a decrease of straw fracture tension strength by 62.67% (A3) and 66.67% (A6), while weight loss of straw was 31.50% (A3) and 35.83% (A6). A3's decomposition rate of cellulose, hemicellulose and lignin was 38.73% , 33.16% and 20.68% , and 47.69% , 28.64% and 22.59% for A6. CONCLUSION: Antinomycetes A3 and A6 could degrad cellulose, hemicellulose and lignin.