Isolation and 16S rRNA-Based Identification of Benomyl-Degrading Bacteria
Adil A. El-Hussein *
Department of Botany, Faculty of Science, University of Khartoum, Sudan
Randa H. Elsalahi
Environmental and Natural Resources Research Institute, National Center for Research, Khartoum, Sudan
Awad G. Osman
Department of Botany, Faculty of Science, University of Khartoum, Sudan
Ashraf M. Sherif
Environmental and Natural Resources Research Institute, National Center for Research, Khartoum, Sudan
Marmar A. El Siddig
Environmental and Natural Resources Research Institute, National Center for Research, Khartoum, Sudan
*Author to whom correspondence should be addressed.
Abstract
Laboratory experiments were conducted to isolate and identify Benlate- (Benomyl) degrading microorganisms from two soil types collected from different locations in Khartoum State, Sudan. Benomyl degradation was studied at two temperatures (28 and 40ºC) in soil treated with three Benomyl concentrations (0.032, 3.2 and 8.0mg Benomyl/g soil) and incubated for 360 days. Potential degraders were also tested in mineral salt liquid medium using Benomyl as a sole carbon source. Degradation percentages were then determined and the most efficient Benomyl degraders were identified by amplification with 16S rRNA gene, sequencing and alignment with deposited sequences in the international gene bank. A total of 64 isolates were recovered from the two soil types, with 59 (92.2%) isolates recovered from the clay soil. Thirty four isolates were recovered from clay soil treated with 8.0mg Benomyl/g soil and incubated at 28ºC. The most efficient Benomyl degraders, with degradation percentages in the range of 44-59, were identified as Pseudomonas stutzeri (Two different isolates), Pseudomonas putida, Acinetobacter johnsonii, Brevibacillus invocatus, Bacillus clausii, Lysinibacillus sp. and Agrobacterium radiobacter.
Keywords: Benlate, MSM, Biodegradation, clay soil, bacteria