The Complete Genome Sequence Analysis Of Gram-Positive Bacterium Bacillus Nematocida B16

Bacillus nematocida B16is screening from more than40different soil samples in Yunnan forest areas,it showed the strongest capability of infestation Nematode,which to kill95percent of the nematode within84hours.Bacillus nematocida B16belongs to a new species of Bacillus,and it has a high commercial exploitation value.So exploring B16’s the genetic basis and the biological significance of genetics is showed the more relatively important and meaningful.In my study,I use B16’s Gene splicing sketch which completed sequencing, and mainly analyze B16’s the genetic basis and molecular mechanisms of nematode infestation through analyzing the genetic composition of B16, the evolutionary position, gene function annotation,predict virulence factor and B16’s comparative genomics, and dig its potential biological value.The completed genome sequencing of B16has352contigs, the total length is4358509bp, the percentage of GC is46.05%. There are3,856open reading frames （Open Reading Frame, ORF） in the B16, rRNA operon numbers are8, tRNA numbers are82,B16shows an independent branch in NJ phylogenetic tree. The study reached the following conclusions:①B16is a new species of Bacillus, which the strongest ability to kill nematodes. Its genome is the moderate size, second only to the genome of actinomycetes, so it makes the B16genome has a relatively strong metabolism and stress tolerance,adapt to different ecological environment;②Made a detailed annotation of protein and genome annotation to B16,so we can understand the special function of each B16’s gene and protein. In the COG’s classification and annotation features, the most enriched showed metabolic process, it described that the soil saprophytes have the highest degree of enrichment in the energy production and conversion （C）, amino acid transport and metabolism （E）, carbohydrate transport and metabolism of （G）, transcription （K）, high inorganic ion transport and metabolism （P） and so on, it concluded that "the genome is relatively large strains typically have relatively strong metabolism and stress tolerance" is consistent. The presumed reasons of such result is that the most soil saprophytes dependent on soil and plants, they are primarily ingestion some carbs and organic compounds which from soil and plants produce on their daily lives as the main nutrients, so the soil saprophytes have the highly sensitive to energy production and transport, carbohydrate transport and metabolism process, and have a higher environmental adaptability saprophytic life;③By VFDB predict the B16’s virulence factors, the predict of result joint shows that74protein sequences are virulence factors. Most of virulence factors are involved in the regulate transcription process, control the replication and recombination of DNA and some metabolic processes; the partly is the RNA polymerase which to regulate transcription; some protein sequences can regulate signal transduction, they are the reactor and the receiver, and as a transcription factor involved in this process, so they can regulate bacterial QS systems; The mostly predicted virulence factors are pancreatic proteolytic enzymes which can hydrolyze the cell wall, they are the enzyme catalytic center, so we concluded that these virulence factors are involved in the infection process of killing nematodes;④By the method of comparative genomics, we predict the relative presence of various bacteria-specific genes and total genes of various bacteria in the B16and the rest of the five height homology Bacillus. It predicted that the unique genes are28in the B16, the unique genes are14in the Bacillus subtilis168; the unique genes are2in the Bacillus amyloliquefaciens FZB42, the unique genes are46in the Bacillus amyloliquefaciens DSM7, the unique genes are4in the Bacillus atrophaeus1942, the unique genes are71in the Bacillus licheniformis DSMI3. Among them, the most unique gene of B16is acyl transferase enzymes. Coenzyme A, trypsin and some protein domains and so on. It predicted that the common genes are15,311in the six strains, most of these genes are ATP synthetase, ATP ligase, carrier protein, and Amino acid adenylation domain and so on. They are mainly involved in the basic sugars, amino acids, peptide synthesis and transport, the synthesis of ATP, in the various strains itself required. the synthesis of ATP provide a lot of energy for the various strains’biological processes. The Part of gene is also involved in regulation of transcription processes.⑤Through Cluster analysis of B16’s gene families, we predict that spread genes and reduced genes in the B16. Obviously amplified genes are:OrthoMCL2family: BN₀834, BN₁260, BN₁601, BN₂223, BN₃342; OrthoMCL3family:BN₀835, BN₁259, BN₁602, BN₂224, BN₃341; OrthoMCL25family:BN₁388, BN₂016, BN₂281; OrthoMCL63family:BN₃028; BN₃029. The amplified genes were detailed annotation again, we can find that these genes are mainly the domain of protein structure and function and active center, the most genes are some acyltransferase and some of the coenzyme A. So we speculate that these obviously amplified genes may be have related to the stronger ability of B16’s kill the nematodes, and participate in the process of nematode infestation B16.