Whole Genome Sequencing and Analysis of Benzo(a)pyrene Degrading Bacteria Bacillus cereus M72-4.

Abstract

Benzo (a) pyrene produced by food during high-temperature process enters the body through ingestion, which causes food safety issues to the human body. In order to alleviate the harm of foodborne benzo (a) pyrene to human health, a strain that can degrade benzo (a) pyrene was screened from Kefir, a traditional fermented product in Xinjiang. Bacillus cereus M72-4 is a Gram-positive bacteria sourced from Xinjiang traditional fermented product Kefir, under Benzo(a)pyrene stress conditions, there was 69.39% degradation rate of 20 mg/L Benzo(a)pyrene by strain M72-4 after incubation for 72 h. The whole genome of M72-4 sequenced using PacBio sequencing technology in this study. The genome size was 5754801 bp and a GC content was 35.24%, a total of 5719 coding genes were predicted bioinformatically. Through functional database annotation, it was found that the strain has a total of 219 genes involved in the transportation and metabolism of hydrocarbons, a total of 9 metabolic pathways related to the degradation and metabolism of exogenous substances, and a total of 67 coding genes.According to the KEGG database annotation results, a key enzyme related to Benzo(a)pyrene degradation, catechol 2,3-dioxygenase, was detected in the genome data of Bacillus cereus M72-4, encoding genes dmpB and xylE, respectively; There are also monooxygenases and dehydrogenases. Therefore, it can be inferred that this strain mainly degrades Benzo(a)pyrene through Benzoate metabolic.