Optimal growth condition of earthworms and their vermicompost features during recycling of five different fresh fruit and vegetable wastes

This study aimed to promote vermicomposting performance for recycling fresh fruit and vegetable wastes (FVWs) and to assess microbial population and community of final products. Five fresh FVWs including banana peels, cabbage, lettuce, potato, and watermelon peels were chosen as earthworms' food. The fate test of earthworms showed that 30 g fresh FVWs/day was the optimal loading and the banana peels was harmful for the survival of Eisenia fetida. The followed vermicomposting test revealed lower contents of total carbon and weaker microbial activity in final vermicomposts, relative to those in compared systems without earthworms worked. The leachate from FVWs carried away great amounts of nutrients from reactors. Additionally, different fresh FVWs displayed dissimilar stabilization process. Molecular biological approaches revealed that earthworms could broaden bacterial diversity in their products, with significant greater populations of actinobacteria and ammonia oxidizing bacteria than in control. This study evidences that vermicomposting efficiency differs with the types and loadings of fresh FVWs and vermicomposts are rich in agricultural probiotics.