[Isolation and Nitrogen Removal Characteristics of Salt-tolerant Heterotrophic Nitrification and Aerobic Denitrification Bacteria Zobellella sp. B307].

ABSTRACT

A heterotrophic nitrification and aerobic denitrification strain, B307, was isolated from the sediment of Jiaozhou Bay. The strain was identified by 16S rRNA sequence analysis, and its optimization condition and salt-tolerance characteristics were studied by single factor experiment. The denitrification effect in single or mixed nitrogen sources was investigated under optimum conditions. The results allowed the strain to be identified as Zobellella sp., based on 16S rRNA sequence analysis. The best carbon source was sodium succinate, and the optimum C/N was 5, the optimal initial pH was 9, and the optimal temperature was 35-40℃ respectively. After 12 hours, the NH4+-N and the NO3--N removal efficiencies were 98.35% and 99.75% in a mixed nitrogen source system. The removal efficiencies for NH4+-N and NO3--N were 97.67% and 94.39% within 24 hours when salinity was 75 g·L-1. The strain has highly efficient heterotrophic nitrification-aerobic denitrification ability and strong salt tolerance, which demonstrated that the strain has potential for extensive application for nitrogen removal in high salt wastewater.