分解秸秆纤维素菌群的发酵及保存方法

    Fermentation and preservation of cellulose-degrading microbial community

    • 摘要: 探索一种简洁、高效的秸秆纤维素分解菌的发酵及保存方法,便于后续的秸秆沼气开发应用。将中国农业大学生物质工程中心前期工作中筛选到的一组纤维素分解菌(ADS-3)作为供试菌种,分别用5种培养基分别进行菌种发酵,通过测定各发酵液总DNA浓度,并采用基于16Sr RNA基因的变性梯度凝胶电泳(DGGE)技术比较其微生物组成,综合评定最优培养基;将最适培养基发酵后的产物分别用“秸秆粉吸附风干”、“秸秆粉吸附冷冻干燥”和“直接冷冻干燥”3种方法保存,在6个月的保存过程中,通过测定各产物保存的pH值和复壮后对秸秆的降解效果,及比较处理间微生物组成,评定适宜的保存方法。结果表明:改良Czapek培养基的发酵质量最好,其微生物组成和供试菌种的相似率最高;保存方法“秸秆吸附冷冻干燥”的保存效果最好,其pH值在7.2和7.4之间与供试菌种最接近、复壮后分解能力和原供试菌种无显著差异,微生物组成和供试菌种相似率最高,且和“直接冷冻干燥”相比具有成本低的优势。该研究为纤维素菌群的进一步利用提供了研究基础。

       

      Abstract: To explore easy and effective methods for fermentation and preservation of a cellulose-degrading microbial community (ADS-3) with high capacity of straw degradation, two experiments for selecting effective culture medium and preservation method were carried out. Five culture mediums were used for the fermentation experiment, and the best culture medium was determined by DNA based method of PCR-DGGE (Polymerase Chain Reaction Denaturing Gradient Gel Electrophoresis). Three preservations of freeze-directly, absorb-drying and absorb-freezing were carried out, and pH value, wheat straw degrading capacity to assess the effect of six months preservation were tested. In addition, the method of DGGE was also used to analyze the microbial component of the cellulose-degrading microbial community. The results showed that the modified Czapek’s medium was superior to other mediums, after cultivation the fermentation with the most similarity microbial component compared with control of the initial ADS-3; preservation method of absorb-freezing had similar pH changes, degrading capacity for wheat straw after rejuvenation and microbial component compared with control of the initial ADS-3. Furthermore, it had cost advantage over the other methods. This study supports technical parameters for the further use of the straw-degrading microbial community.

       

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