不同纤维素降解菌对玉米秸秆的降解效果

该研究旨在探索不同纤维素降解菌对玉米秸秆降解效果的差异性,为秸秆资源化利用提供参考。利用筛选自宁夏秸秆堆、畜粪和土壤中的四株纤维素降解菌,分别为黄曲霉(Aspergillusflavus)Z5-3菌株,非洲哈茨木霉(Trichoderma afroharzianum)Z6-4菌株,藤黄单胞菌(Luteimonas sp.)X11-1菌株,施氏假单胞菌(Pseudomonas stutzeri)X3-5-1菌株,通过室内控温秸秆堆肥发酵试验,研究添加不同纤维素降解菌后堆肥温度、pH值、碳损失、氮损失、有效养分含量的变化规律。试验结果表明,与对照(不加菌处理)比较,加菌处理提前1-2 d进入高温期,最高温度提高了0.3-1.3℃,且细菌处理较真菌处理提前1 d进入高温期,最高温度提高了0.5-0.7℃。pH值总体呈先增加后降低的趋势,且在高温期达到最大值。与对照相比,加菌处理NH3和CO2累积释放量具有降低趋势。以全氮含量变化计,细菌X11-1、X3-5-1处理的氮损失分别为26.14%和26.57%,真菌Z5-3、Z6-4处理分别为36.49%和34.19%,表明添加不同纤维素降解菌可不同程度地降低堆肥物料中的碳损失和氮损失,其中细菌处理保氮效果显著优于真菌处理。与对照相比,细菌X11-1、X3-5-1处理、真菌Z5-3、Z6-4处理分别提前腐熟5、2、2、2d,表明添加纤维素降解菌可减少堆肥物腐熟时间,促进物料养分浓缩。综合判断,玉米秸秆堆肥中加入纤维素降解菌,有利于降低物料的碳、氮损失,且细菌的保氮效果优于真菌,其藤黄单胞菌X11-1处理最先达到腐熟,为最佳处理。

Effects of Different Cellulose-degrading Microorganism on Corn Straw Degradation

The purpose of this study was to explore the degradation effects on corn straw compos with different cellulose-degrading microorganisms, and to provide a understanding for the utilization of straw resources. Four indigenous strains of cellulose-degrading microorganisms were Aspergillus flavus Z5-3, Trichoderma afroharzianum Z6-4, Luteimonas sp. X11-1, Pseudomonas stutzeri X3-5-1 which were selected from the stover pile, livestock manure and soil in Ningxia. Fermentation experiments were conducted outdoors, the change of temperature, pH value, carbon loss, nitrogen loss and available nutrient content within corn straw compost with different cellulose-degrading microorganisms were screened. The results showed that compared with CK(no microorganism processed), the treatments with microorganism entered the high temperature stage 1-2 d in advance, the maximum temperature increased by 0.3-1.3 ℃, and the bacteria treatments entered the high temperature stage 1 day earlier than fungi treatments, the maximum temperature increased by 0.5-0.7 ℃. The pH value generally increased first and then decreased a little, and reached the peak within temperature peaking period. Compared with the control, the cumulative release of NH3 and CO2 had a decreasing trend when processed with bacteria. The loss of total nitrogen content in corn straw compost were 26.14% and 26.57% processed by bacteria X11-1 and X3-5-1, and 36.49% and 34.19% with fungi Z5-3 and Z6-4 treatment, respectively. The experimental data showed that the loss of carbon and nitrogen in compost materials could be declined with the treatment of different cellulose-degrading microorganisms. The nitrogen retention in compost materials processed by bacteria treatments were significantly better than that by fungi treatments. Compared with control without cellulose-degrading microorganisms, the treatments of bacteria X11-1, X3-5-1, fungi Z5-3 and Z6-4 were prematurely decomposed for 5, 2, 2, 2 days in advance, respectively. The results showed that cellulose-degrading microorganisms could reduce the maturity time and promote the nutrient concentration in corn straw compost. However, the addition of cellulose-degrading microorganisms to the corn straw compost is beneficial to reduce the loss of carbon and nitrogen. The effect of nitrogen retention in corn straw compost with bacteria is better than that with fungus. The best treatment is to add Luteimonas sp. X11-1.