First Evidence on Genomic Potential of Stenotrophomonas Rhizophila Strain Is26 Able to Reduce Aflatoxin B1 Produced by Aspergillus Flavus in a Solid-based Medium

Abstract

Abstract This work aimed to study the interaction between Stenotrophomonas rhizophila strain IS26 and an isolate of Aspergillus flavus NRRL 62477 able to synthesize aflatoxin B1. Our results demonstrated that, when co-cultivated with A. flavus on ISP2 medium, the strain IS26 reduced the aflatoxin B1 residual concentration by 47%. The assembly of 5189077 Illumina's paired-end sequencing reads resulted in 42 contigs for a total genome assembly size of 4.09 Mb with 66.4% GC content. An overall total of 3624 genes was predicted using the NCBI Prokaryotic Genome Automatic Annotation Pipeline (NCBI-PGAAP). A total of 304 subsystems with 27% subsystem coverage was predicted using RAST annotation of the S. rhizophila strain IS26 genome. The genome sequence analysis of the strain IS26 detected the presence of genes involved in inhibition of aflatoxins (Afs) biosynthesis as well as genes involved in the degradation of AFs. Thus, these results suggest that S. rhizophila IS26 decreased aflatoxin B1 via down-regulated gene expression in terms of aflatoxin B1 biosynthesis and/or degradation of Afs. In summary, S. rhizophila IS26 can be employed for the biological reduction of aflatoxin B1 produced by A. flavus NRRL 62477.