Abstract:
A great deal of concern has been aroused among the scientific community about the extensive use of carbamate pesticides represented by carbofuran and their residues in soil. Strain KJ82 was isolated from the carbofuran degradation bacterial flora, which enriched in the saline alkali soil of the continuous cropping cotton field in Aksu area for more than 10 years. Now, the whole genome of this strain was sequenced by PacBio Sequel Ⅱthird-generation sequencing platform. Microbial assembly, HGAP4, Canu, Glimmer and other software were used to perform assembly, encoding gene prediction, gene function annotation, species collinear analysis and prediction of the strain KJ82 secondary metabolite synthesis gene cluster. The genome-wide analysis showed that the strain KJ82 genome was composed of one circular chromosome without plasmid. The total sequence length of the strain KJ82 genome was 3 754 440 bp, GC content of 41.41%, and 3 896 coding genes were annotated. There were twenty-four 16 S-23 S-5 S rRNAs, 81 tRNAs and 77 other RNAs, 9 CRISPR sequences, 4 genomic islands, and 1 prophage structure were predicted. The protein sequences of 3 005, 2 214, and 2 162 genes can be matched with annotation information in the COG, GO and KEGG/KOG databases, respectively. According to comparative genomics analysis, the ANI(Average nucleotide identity) value between the strain KJ82 and highest similarity strain Bacillus altitudinis GQYP101 was 97.59% to 97.89%, and the dDDH(Digital DNA-DNA hybridization) value was 81%. Therefore, all the ANI and dDDH values were higher than the cut-off point recommended for delineating species. Through antiSMASH prediction, it was found that there were 11 secondary metabolite synthesis gene clusters in the genome of strain KJ82, of which 6 gene clusters had low similarity with the known synthetic gene clusters, and 4 gene clusters had unknown functions, respectively. One possible hydrolase gene and two monooxygenase genes were found in the genome of this strain, which were located on Cluster 8, Cluster 4 and Cluster 3, respectively, and the similarity with known synthetic gene clusters was 6% and 50%, respectively, and a gene cluster functional location. This study provides a scientific basis for the study of the gene function of the strain involved in the degradation of carbofuran under alkaline conditions and the novel active natural products that may be encoded by its gene cluster.