Metagenome Based Analysis of Aflatoxin Degrading Bacteria in Poultry Farms

Abstract

This study aimed to screen aflatoxin degrading bacteria by using both traditional techniques and metagenome based methods and also screen possible genes involved in the biodegradation mechanisms. • A total of 119 biological samples which included 41 soil samples, 32 feed samples and 42 fecal swaps were collected from the examined localities from Giza, Cairo and Sharikya Governorates. Screening of potential degraders was conducted on coumarin media with gradual increase to coumarin concentrations from 0.01-0.5%. • Ten isolates that showed strong visible growth on 0.1% coumarin were furthermore chosen as candidates to be tested against 150ppb AFB1, 150ppb AFG1, 100ppb AFB2, and 100ppb AFG2 simultaneously in liquid media for 3 days at 37°C and analyses were conducted using HPLC. These isolates degradation rates ranged from (25-100%) against the aflatoxins mentioned. One special degrader could almost degrade all four types of aflatoxins in just 72hrs, this strain was identified by molecular and biochemical methods as pseudomonas fluorescens strain and submitted to GenBank under Accession No. MT019826. • The other nine isolates when identified belonged to four genera Bacillus spp(6), Pseudomonas spp(2), Enterococcus spp(1) and Stenotrophomonas spp(1). • Isolates, B. haynesii, Enterococcus casseliflavus, B. tequilensis and B. amyloliquefaciens were reported for the first time to have aflatoxin degradation activity.