IN SILICO CHARACTERIZATION OF BACILLUS SP. Tct6, PLANT GROWTH PROMOTER AND BIOCONTROL AGENT.

PISTORIO, M; DI MARZIO, G

Congreso; CONGRESO CONJUNTO SAIB-SAMIGE 2021; 2021

SAIB-SAMIGE

In a previous study, we obtained 169 isolates of grapevine rhizospheres from the three main wine-growing regions of Argentina. The isolates were characterized in vitro in different properties of plant growth promotion and of inhibition of phytopathogenic fungi such as Alternaria alternata and Botrytis cinerea. The isolate Bacillus sp. Tct6 showed a powerful inhibition of phytopathogenic fungi, for this reason it was chosen for genomic and functional characterization. Since there are pathogenic species within the genus Bacillus, it is necessary, before continuing with the study of the Tct6 isolate, to achieve its taxonomic classification. The objective of this work was to sequence, characterize genetically and taxonomically the strain Bacillus sp. Tct6. The genome was sequenced through Illumina's 2×150 pair-end technology, obtaining 602,237 reads with approximately 180 Mb reads. After assembly, 54 contigs greater than 500 bp were obtained with a total size of 5,874,226 bp and a G+C percentage of 34.79%. The annotation identified 5,867 CDS, rRNA: 16, tRNA: 88, tmRNA: 1. The predicted functions of the protein-coding genes reveal a metabolically versatile bacterium with an abundance of genes for carbohydrate and amino acid metabolisms. In addition, using antiSMASH (version 5.1.32), 16 clusters were identified for the synthesis of secondary metabolites and correspond to non-ribosomal synthesis peptides, sactipedtide, lanthipeptide, terpenes, bacteriocins, betalactones and siderophores. The search for genes related to resistance to antibiotics and toxic compounds identified different groups of genes, such as: beta-lactamases and genes for resistance to Co, Cd and Zn, among others. For the taxonomic assignment we used different approaches, first through the 16S we identified the closest species to calculate the ANIm values using the type strains. Bacillus sp. Tct6 presented the highest values of ANIm with Bacillus thuringiensis serovar berliner ATCC 10792 [T] (96.51) and with Bacillus cereus ATCC 14579 [T] (96.04). The use of the BToxin program made it possible to identify the presence of a protein with 36% identity with the Cyt2Ca1 toxin. Using the Placnet platform, the presence of 4 plasmids was detected, 3 smaller than 12 kb and one larger. In the future, it will be characterized phenotypically to know its attributes as a growth promoter in plants and its biological control mechanisms.