Isolation, identification, and deamination characterization of a strain of Alcaligenes aquatilis

Abstract:

[Background] With the rapid development of animal husbandry, it becomes a challenging task to utilize animal manure and reduce the pollution caused by it. Aerobic composting, as an effective way to utilize manure, has become the focus of research. [Objective] By screening microorganisms with efficient nitrogen conversion capabilities for use in reducing nitrogen losses in aerobic composting, thus improving fertility and reducing pollution. [Methods] We isolated and identified the strain NS-1 with strong ammonia-oxidizing capacity from the heterotrophic nitrifying bacteria in cow dung. Furthermore, we cultured the strain NS-1 under different conditions to investigate its ammonia-oxidizing capacity. [Results] The strain NS-1 was identified as Alcaligenes aquatilis based on morphological characteristics and 16S rRNA sequence. When being cultured in the medium with sodium succinate as the carbon source, the C/N ratio of 15, and pH 7.0 at 35℃, strain NS-1 demonstrated significantly improved ammonia-oxidizing capacity. The validation experiment showed that strain NS-1 completely removed 1 230.694 7 mg/L ammonia nitrogen within 32 h, with the removal efficiency of 100% and the removal rate of 38.46 mg/(L·h).[Conclusion] The strain NS-1 with excellent ammonia-oxidizing capacity is of great significance for reducing nitrogen loss in the composting process. This study provides microbial materials and technical support for the production of high-quality bio-organic fertilizer.

Key words:nitrifying bacteria;nitrogen transformation;heterotrophic nitrification;Alcaligenes aquatilis