Abstract:

【Objective】 In order to accelerate decay of cornstalks returned to fields in Northern China, the complex microbial system CSS-1 with high efficiency and stable degrading ability for corn stalks was constructed and its microbial composition was analyzed. 【Method】 The CSS-1 was domesticated from the soils which had been treated with cornstalks for a long time in Shanxi, Shandong and Beijing using the methods of nutrition-restricted cultivation combined with gradient-temperature induction. Its decomposition ability was determined by weight-loss percentage, C/N and CMC enzyme activity of the treated corn stalks. The stability of CSS-1 was confirmed by comparing the curves of weight-loss percentage, CMC enzyme activity, xylanase activity, as well as PCR-DGGE analysis of CSS-1’s different generations. The microbial composition of CSS-1 was analyzed by cloning library method. 【Result】 The average of cellulase activity and the maximum cellulase activity produced by CSS-1 were 79% and 82% higher respectively than those of the widely used inoculant A in corn stalk decomposition experiments. The weight-loss of the corn stalks treated with CSS-1 increased by 62.62% and 173.65 % compared with that of blank control and the inoculant A, respectively. The CSS-1 had high decomposition efficiency for corn stalks and microbial composition stability was confirmed by determining and evaluating the subculture of 22 generations. The results of cloning library method showed that the dominant bacteria of CSS-1 belonged to Enterobacter sp., Cellulomonas sp., Streptomyces sp., Bacillaceae sp., Pantoea sp. and Cellvibrio sp. and the dominant fungi were Trichoderma sp. and Gibberella sp. 【Conclusion】 The complex microbial system CSS-1 has high efficiency corn-stalk decaying ability under natural conditions, and its microbial component and decomposition function are suitable for corn stalks returned to fields in Northern China.

Key words: corn stalk')">corn stalk, complex microbial system, decomposition, composition analysis, cloning library