Department of Environmental Science, Tezpur University, Assam 784028, India.
Department of Molecular Biology and Biotechnology, Tezpur University, Assam 784028, India.
Bioresour Technol. 2016 Dec;222:165-174. doi: 10.1016/j.biortech.2016.09.115. Epub 2016 Sep 30.
Vermicomposting is a dependable waste recycling technology which greatly augments N and P levels mainly through microbial action. This paper aims to identify efficient N-fixing (NFB) and P-solubilizing (PSB) bacteria from earthworm intestines. Various combinations of vegetable market waste, rice straw, and cowdung were fed to two earthworm species (Eisenia fetida and Perionyx excavatus). Total organic C decreased, pH shifted towards neutrality, and NPK availability, and microbial (NFB, PSB, and total bacteria) population increased remarkably during vermicomposting with E. fetida. Therefore, 45 NFB and 34 PSB strains isolated from Eisenia gut were initially screened, their inter-dominance assessed, and 8 prolific strains were identified through 16SrRNA sequencing. Interestingly, two novel N-fixing strains of Kluyvera ascorbata emerged as an efficient biofertilizer candidate. Moreover, both N-fixing and P-solubilizing strains of Serratia and Bacillus were isolated from earthworm gut. All the isolated strains significantly improved soil health and facilitated crop growth as compared to commercial biofertilizers.
蚯蚓堆肥是一种可靠的废物回收技术，主要通过微生物作用极大地增加了氮和磷水平。本文旨在从蚯蚓肠道中筛选出高效的固氮（NFB）和溶磷（PSB）细菌。将不同比例的菜市场废物、稻草和牛粪喂给两种蚯蚓（赤子爱胜蚓和威廉环毛蚓）。在赤子爱胜蚓的作用下，蚯蚓堆肥过程中总有机碳减少，pH 值向中性偏移，NPK 有效性和微生物（NFB、PSB 和总细菌）种群显著增加。因此，从赤子爱胜蚓肠道中分离出 45 株固氮菌和 34 株溶磷菌，对其优势度进行了评估，并通过 16SrRNA 测序鉴定出 8 株高产菌株。有趣的是，两种新型的可利用抗坏血酸的固氮菌 Kluyvera ascorbata 作为一种有效的生物肥料候选菌株出现。此外，还从蚯蚓肠道中分离出了固氮和溶磷的沙雷氏菌和芽孢杆菌。与商业生物肥料相比，所有分离出的菌株都显著改善了土壤健康状况并促进了作物生长。
