R V Velho1, D G G Caldas, L F C Medina, S M Tsai, A Brandelli. 1. Laboratório de Bioquímica e Microbiologia Aplicada, Departamento de Ciência de Alimentos, Universidade Federal do Rio Grande do Sul, 91501-970 Porto Alegre, Brasil.
Abstract
AIMS: To investigate the expression of sboA and ituD genes among strains of Bacillus spp. at different pH and temperature. METHODS AND RESULTS: Different Bacillus strains from the Amazon basin and Bacillus subtilis ATCC 19659 were investigated for the production of subtilosin A and iturin A by qRT-PCR, analysing sboA and ituD gene expression under different culture conditions. Amazonian strains presented a general gene expression level lower than B. subtilis ATCC 19659 for sboA. In contrast, when analysing the expression of ituD gene, the strains from the Amazon, particularly P40 and P45B, exhibited higher levels of expression. Changes in pH (6 and 8) and temperature (37 and 42 °C) caused a decrease in sboA expression, but increased ituD expression among strains from Amazonian environment. CONCLUSIONS: Temperature and pH have an important influence on the expression of genes sboA (subtilosin A) and ituD (iturin A) among Bacillus spp. The strains P40 and P45B can be useful for the production of antimicrobial peptide iturin A. SIGNIFICANCE AND IMPACT OF THE STUDY: Monitoring the expression of essential biosynthetic genes by qRT-PCR is a valuable tool for optimization of the production of antimicrobial peptides.
AIMS: To investigate the expression of sboA and ituD genes among strains of Bacillus spp. at different pH and temperature. METHODS AND RESULTS: Different Bacillus strains from the Amazon basin and Bacillus subtilis ATCC 19659 were investigated for the production of subtilosin A and iturin A by qRT-PCR, analysing sboA and ituD gene expression under different culture conditions. Amazonian strains presented a general gene expression level lower than B. subtilis ATCC 19659 for sboA. In contrast, when analysing the expression of ituD gene, the strains from the Amazon, particularly P40 and P45B, exhibited higher levels of expression. Changes in pH (6 and 8) and temperature (37 and 42 °C) caused a decrease in sboA expression, but increased ituD expression among strains from Amazonian environment. CONCLUSIONS: Temperature and pH have an important influence on the expression of genes sboA (subtilosin A) and ituD (iturin A) among Bacillus spp. The strains P40 and P45B can be useful for the production of antimicrobial peptide iturin A. SIGNIFICANCE AND IMPACT OF THE STUDY: Monitoring the expression of essential biosynthetic genes by qRT-PCR is a valuable tool for optimization of the production of antimicrobial peptides.