摘要
[目的]减少堆肥过程中碳氮损失,提高堆肥质量.[方法]本研究通过添加5株外源嗜热固氮菌株,设置6个处理分别为:CK(不添加外源固氮菌)、A1(根癌异根瘤菌)、A2(亮杆菌)、A3(头状葡萄菌)、B1(液化沙雷菌)和B2 (蜡样芽孢杆菌)进行堆肥,研究外源嗜热固氮菌对堆肥碳氮损失、养分含量和细菌微生物群落的影响.[结果]5株外源嗜热固氮菌均减少了堆肥中碳氮损失,提高了养分含量.A1、A2、A3、B1、B2与CK相比碳氮损失分别减少了38.74％、26.99％、33.09％、28.75％、34.35％和 25.23％、11.20％、22.58％、20.77％、20.51％,氮含量增加了279.15％、42.74％、344.31％、277.51％、1.42％;磷含量增加了49.21％、16.19％、51.33％、24.26％、58.90％;全钾含量增加了27.76％、17.41％、16.35％、11.80％、29.12％;有机质增加了31.41％、20.56％、27.15％、30.19％、26.61％,总体上A1>A3>B1>A2>B2.细菌群落结构演替表明,A1和B1菌株的丰度在堆肥过程中始终高于对照处理.外源固氮菌均显著提高了堆肥中土著固氮细菌Pseudomonas(假单胞菌属),Sphingobacterium(鞘氨醇杆菌属)、Saccharomonospora(糖单孢菌属)、Planifilum(直丝菌属)和Bacillus(芽孢杆菌属)等的相对丰度,降低具有反硝化能力的Acinetobacter(不动杆菌属)、Corynebacterium(棒状杆菌属)和Halomonas(盐单胞菌属)等的丰度.KEGG分析表明,外源固氮菌剂影响氨基酸代谢、碳水化合物代谢和次生代谢产物的生物合成功能基因.[结论]A1和B1菌株能够较好地在堆肥中定殖,具有开发固氮菌生物有机肥的潜力;添加外源固氮菌均可通过影响优势微生物群落及氨基酸代谢、碳水化合物代谢等功能基因抑制堆肥过程中的碳氮代谢,提高养分含量,减少堆肥过程中碳氮损失.
Abstract
[Objective]To reduce the loss of carbon and nitrogen during composting and improve the quality of the compost.[Method]This study investigated the effects of 5 strains of exogenous thermophilic nitrogen-fixing bacteria on carbon and nitrogen losses,nutrient content and the bacterial microbial commu-nity of composting using 6 treatments:CK(without exogenous nitrogen-fixing bacteria),A1(Allorhizobium tumefaciens),A2(Leucobacter sp.4J7B1),A3(Staphylococcus capitis),B1(Serratia liquefaciens)and B2(Ba-cillus cereus).[Result]5 strains of exogenous thermophilic nitrogen-fixing bacteria reduced the carbon and nitrogen losses in compost and increased the nutrient content.A1,A2,A3,B1,B2 compared with the control,the losses of carbon and nitrogen decreased by 38.74%,26.99%,33.09,28.75,32.25%and 25.33%,11.20%,22.25%,20.77%,20.51%,respectively;the nitrogen content increased by 279.15%,42.74%,344.31%,277.51%,1.42%;phosphorus increased by 49.21%,16.19%,51.33%,242.26%,58.90%;potassium increased by 27.76%,17.14%,15.36%,11.80%,29.12%;and organic matter increased by 31.41%,20.56%,27.15%,30.19%,25.61%.In general,A1>A3>B1>A2>B2.The succession of the bacterial community showed that the abundance of A1 and B1 strains was always higher than that of the con-trol.Exogenous nitrogen-fixing bacterial agents significantly increased the relative abundance of indigenous nitrogen-fixing bacteria in composting,such as Pseudomonas,Sphingobacterium,Saccharomonospora,Pl-anifilum and Bacillus,and decreased the relative abundance of denitrifying bacteria,such as Acinetobacter,Corynebacterium and Halomonas.KEGG analysis showed that exogenous nitrogen-fixing bacteria affected functional genes involved in amino acid metabolism,carbohydrate metabolism and biosynthesis of secondary metabolite biosynthesis.[Conclusion]It can be seen that A1 and B1 strains can colonize well in composting,which has the potential to develop nitrogen-fixing bacteria as bioorganic fertilizer.The addition of exog-enous nitrogen-fixing bacteria can inhibit carbon and nitrogen metabolism during composting by influencing dominant microbial communities and functional genes such as amino acid metabolism and carbohydrate me-tabolism,improve nutrient content and reduce carbon and nitrogen loss during composting.
基金项目
甘肃农业大学研究生导师基金项目(GAU-QDFC-2021-20)
甘肃农业大学学科建设基金项目(GAU-XKJS-2018-212)
甘肃省自然科学基金项目(18JR3RA180)
维普
万方数据