Study of heterotrophic nitrifying bacteria from wastewater treatment systems treating acrylonitrile, butadiene and styrene resin wastewater

In this study we investigated the population of heterotrophic nitrifying bacteria in three biological wastewater treatment systems treating acrylonitrile, butadiene and styrene (ABS) resin wastewater. In addition to isolating and identifying these bacteria, we examined the physiological properties of the isolates, particularly utilization of acrylonitrile and its derivatives. An enrichment process was employed to isolate heterotrophic nitrifying bacteria from sludge samples taken from three biological wastewater treatment systems. Thirteen isolates were obtained and four strains were identified as Alcaligenes sp., Acinetobacter sp., Xanthomonas sp. and Corynebacterium sp. Alcaligenes sp. and Corynebacterium sp. have already been reported as heterotrophic nitrifiers. To our knowledge, this is the first time Acinetobacter sp. and Xanthomonas sp. have been reported as heterotrophic nitrifiers. The heterotrophic nitrifying isolates used acrylonitrile and acrylamide as the sole carbon and nitrogen sources. Moreover, adding an extra carbon source enhanced the nitrification rate.