一组可抗抗生素干扰的木质纤维素分解菌复合系ADC-6的筛选

Screening of a group of antibiotics resistance interference lignocellulosic decomposition microbial consortium ADC-6

以高温期堆肥样为菌源,在含0.025 mg·mL-1四环素的培养基内以秸秆作为唯一碳源,经多代驯化筛选到一组能够分解木质纤维素和抗生素的ADC-6复合系.该复合系能够在6 d内分解四环素0.0194 mg,在14 d内使稻秆减重32%.ADC-6纤维素内切酶酶活、半纤维素酶活、总纤维素酶活在第4 d、2 d和2 d达到最大值分别为15.85 U·mL-1、62.97 U·mL-1和15.56 U·mL-1.用变性梯度凝胶电泳检测驯化过程中菌种的动态变化,并用克隆文库对稳定阶段的菌种多样性分析,发现该菌群中含Bacteroidetes、Sphingobacteriales、Bacillaceae、Clostridiales和Proteobacteria等5个属的微生物,其中,Clostridiales对木质纤维素的转化能力较强,很可能是菌群中分解木质纤维素的关键菌,而Bacteroidetes很可能是分解抗生素的关键菌.

A new microbial consortium ADC-6 was constructed in medium with 0.025 mg·mL^-1 tetracycline and straw as the sole carbon source from high temperature stage compost. After many generations of domestication and screening, ADC-6 can degrade the lignocellulose and antibiotics steadily. The microbial consortium ADC-6 could degrade the tetracycline 0.0194 mg within 6 days, and 32% of straw within 14 days. The peak values of CMCase activity, hemicellulase activity and the Filter Paper activity of ADC-6 reached 15.85 U·mL^-1, 62.97 U·mL^-1 and 15.56 U·mL^-1 at 4 d, 2 d and 2 d, respectively. Denatured gradient gel electrophoresis was used to domesticate the dynamic change of ADC-6 during the degradation, and clone library was used to analyze the microbial diversity. It was found that the consortium contained the Bacteroidetes, Sphingobacteriales, Bacillaceae, Clostridiales and Proteobacteria. Clostridiales had strong ability to degrade lignocellulose, and might be the key bacteria in ADC-6. Bacteroidetes was probably the key bacteria for antibiotics degradation.