Optimizing the Effect of pH and Temperature on Atrazine Degradation by Bacillus safensis strain BUK_BCH_BTE6 an Efficient Atrazine Tolerating Bacteria from an Agricultural Soil in Kura Local Government Area of Kano State, Nigeria

Abstract

The widespread and long term use of atrazine results in high residue levels of atrazine in soil, which further causes water contamination, it is considered as an endocrine disruptor and is potentially carcinogenic. Microbial degradation of herbicide represents a time cost effective way of eco-restoration. This research was aimed at isolating and characterizing bacteria capable of degrading and utilizing atrazine as a sole carbon source. An enrichment method was used to isolate the bacteria on mineral salt media (MSM) following serial dilution. The isolate was identified morphologically, biochemically and molecularly as Bacillus safensis strain BUK_BCH_BTE6 based on 16S rRNA gene sequence and molecular phylogenetic analysis. The effect of pH and temperature on the degradation of atrazine was studied in MSM medium supplemented with atrazine as sole carbon source. Growth and degradation of atrazine in this isolate was optimal at pH 7.5 and temperature of 35 °C. Bacillus safensis is highly efficient in atrazine degradation with an optimum range of pH and temperature. Bacillus safensis could be a suitable candidate for bioremediation of atrazine polluted sites.