Isolation and application of pH- and salt-resistant Bacillus strains to reduce ammonia emission from pig manure during the storage period

Aim Ammonia released during the storage period from pig manure causes severe air pollution and odor issues, ultimately leading to nitrogen loss in the manure. In this study, we investigated the application of 13 Bacillus spp. strains isolated from paddy soil and their potential to minimize reactive nitrogen loss during pig manure storage at 28 & DEG;C and initial moisture content at 76.45%. Methods and results We selected five strains of Bacillus spp. named H3-1, H4-10, H5-5, H5-9, and Y3-28, capable of reducing ammonia emissions by 23.58%, 24.65%, 25.58%, 25.36%, and 26.82% in pig manure over 60 days compared to control. We further tested their ability on various pH, salinity, and ammonium-nitrogen concentrations for future field applications. Our investigation revealed that certain bacteria could survive and grow at pH 6, 8, and 10; 4, 8, and 10% salinity and up to 8 g l(-1) of ammonium-nitrogen concentration. Conclusions The results from our study show that saline and ammonium-nitrogen tolerant Bacillus strains isolated from soil can potentially reduce ammonia emissions in pig manure, even at high moisture content during their storage period.

Automated summary

This study investigated the potential of 13 Bacillus spp. strains isolated from paddy soil to reduce ammonia emissions during pig manure storage. Five strains were found to significantly reduce ammonia emissions by 23.58% to 26.82% over 60 days. The strains also showed tolerance to different pH levels, salinity, and ammonium-nitrogen concentrations.