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

F Muhammad,H.M Yakasai,F.A Ahmad,U Shehu,F Yusuf

doi:10.4314/njb.v38i2.10

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.

Highlights

Worldwide, several anthropogenic activities have resulted in high increase of environmental pollution, and its effect has affect almost all components of the ecosystem (Izabel et al, 2020)
This paper reports the efficiency of Bacillus safensis strain BUK_BCH_BTE6 in the degradation of atrazine in mineral salt media (MSM) media
Isolation, Identification and Screening of Atrazine-Degrading Bacteria After inoculation of the culture with MSM agar and incubating at 37 °C for 48 hours and further sub culturing for 24 hours at 37 °C resulted in the appearance of white, round, slimy shape colonies with raised elevation and rough edge which look like fried egg

Summary

Introduction

Several anthropogenic activities have resulted in high increase of environmental pollution, and its effect has affect almost all components of the ecosystem (Izabel et al, 2020). As an important constituent of the terrestrial ecosystem is exposed to pollution from various sources, including industrialization and various agricultural practices. High growth in demand and use of agricultural and industrial products have lead to rapid increases in polluted soils and waters (Zhao et al, 2018). Isopropylamino-1, 3, 5- triazine) is a s-triazine herbicide with a molecular formula C8H14ClN5 (He et al, 2019). It is a nonpolar, nonvolatile and low soluble compound (Olu-arotiowa et al, 2019). It is powdery white substance that is unstable at high temperature.

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