ABSTRACT
Three isolates viz. Lysinibacillus sp. HT13, Alcaligenes sp. HT15 and Proteus sp. HT37 isolated from fish processing effluent and having a C/N ratio of 2, removed 218, 169, and 400 µg cell(-1) day(-1) NH4(+)-N, respectively without subsequent build up of nitrite or nitrate. Ability of the selected isolates in removing NH4(+)-N, NO2(-)-N, and NO3(-)-N was checked in the presence of four commonly reported and tested effluent carbon sources viz. pyruvate, glycerol, methanol, and acetate. Further, when supplemented to fish processing wastewater containing 234 ppm total Kjeldahl's nitrogen, Lysinibacillus sp. HT13, Alcaligenes sp. HT15, and Proteus sp. HT37 could remediate 95.74, 86.17, and 76.6% nitrogen, respectively in 48 h. This is the first report of a Lysinibacillus sp. carrying out aerobically the process of simultaneous nitrification and denitrification. The results demonstrate the potential of the isolates for use in treatment of fish processing effluents and demonstrating the efficient removal of ammonia.
