Responses of ammonia-oxidizing bacteria community composition to temporal changes in physicochemical parameters during food waste composting

Abstract

Chemoautotrophic ammonia-oxidizing bacteria (AOB) serve an important function in ecological nitrogen transformation because of their great potential to alleviate ammonia emissions during aerobic composting. However, studies on the influence of specific environmental factors on AOB community dynamics in the food waste composting field are scarce. Hence, this study aimed to identify and prioritize some environmental parameters that affect AOB community composition during food waste composting. The composition and diversity of the AOB community were determined using polymerase chain reaction–denaturing gradient gel electrophoresis (PCR–DGGE). Relationships between the obtained parameters and AOB community composition were simultaneously evaluated by multivariate analysis. Phylogenetic analysis indicated that large amounts of Nitrosomonas-like and Nitrosospira-like lineages existed in different periods. The Nitrosomonas europaea/eutropha were the most dominant AOB species in the thermophilic stage. Redundancy analysis revealed that the dynamics of the AOB community was mainly attributed to temporal changes in nitrate and the pH of the compost material (p < 0.05). Variations (54.7% for AOB species data) were statistically explained by nitrate and pH, suggesting that these parameters were the most likely to influence, or be influenced by AOB community composition, and may further influence nitrogen cycle in the food waste composting ecosystem.