农业废弃物柑橘皮渣堆肥工艺优化及其微生物群落结构演替规律研究

Optimization of Citrus Peel Composting Process and Its Succession Patterns of Microbial Community Structure

重庆柑橘加工业每年产生大量皮渣,不及时有效地处理将污染三峡库区生态环境。堆肥是一种可行的皮渣资源化利用方式。通过正交试验获得了柑橘皮渣堆肥的最优工艺参数,即原料含水率55%、碳氮比(C/N) 25、石灰量10 g/kg、加菌量3%。基于最优参数的中试试验结果表明,中试效果较小试有显著提升,总养分含量达到6.48%。堆肥过程中微生物群落结构分析表明,芽孢杆菌(Bacillus)、青霉(Penicillium)及喜热裂孢菌(Thermobifida)在堆肥前期占据优势,鞘氨醇单胞菌(Sphingobium)、嗜热子囊菌(Thermoascus)及拟诺卡菌(Nocardiopsis)则在后期占优势。Bacillus及Penicillium对堆肥前期果胶的快速降解起主要作用,木质纤维素在不同时期均存在降解,是多种优势菌属共同作用的结果。试验数据为柑橘皮渣堆肥处理的产业化提供了充足的理论与技术支撑。

Chongqing’s citrus processing industries produce a large number of citrus peels every year.Without effective treatment,the peels would pollute the environment.Composting is a feasible method for reusing citrus peels.The optimum parameters of peel composting were obtained by the orthogonal experiments,that is,water content of the raw material is 55%,carbon nitrogen ratio 25,lime 10 g/kg,and microorganism dosage 3%.The pilot-scale experiment based on the optimum conditions shows that the pilot test results have been improved dramatically compared with bench-scale test.Moreover,the content of total nutrients reaches up to 6.48%.Microbial community structure analysis was conducted during the course of composting,and the result showes that the abundance of Bacillus,Penicillium and Thermobifida dominated in the initial period,and Sphingobium,Thermoascus and Nocardiopsis dominates later.Bacillus and Penicillium play a critical role in the rapid decomposition of pectin at early stage,and lignocellulose is degraded by the cooperation of multiple dominant bacteria throughout the whole process.These results provide theoretical and technical support for compost industrialization of citrus peel.