Expressão diferencial de genes ao longo do crescimento de quatro bactérias em meio com glicose, petróleo e sem fonte de carbono

Abstract

Environmental microbiology plays a crucial role in understanding the interactions between microorganisms and the environment. How these interactions can contribute to mitigating environmental contamination, a growing concern around the world. This work aimed to study the fluctuation in diversity and gene expression of four bacteria throughout the three bacterial growth phases (lag, log and stationary), in a laboratory-produced environment. In order to identify functional patterns, these bacteria were subjected to growth in three different situations: having the only source of carbon, either glucose, or oil, or no carbon source. The total RNA of bacteria present in these environments was sequenced, and the data was subjected to bioinformatics and statistical analysis. The negative binomial distribution was used to model the RNA fragment count data. For differential expression analyses, TMM normalization, the exact test and generalized linear models with the likelihood ratio test were used. The four bacteria were identified in all samples, with a predominance of bacteria of the genus Acinetobacter, regardless of the carbon source used and the growth phase. One of the functional categories with the greatest abundance among the samples was genes involved in RNA metabolism and genes without defined hierarchical classification. Differentially expressed genes were identified between samples for functions involved in stress response metabolism, cell mobility, and phenol degradation and oxidation of quinol, a benzene derivative. Furthermore, among the genes with significant differential expression are hypothetical proteins. Although they do not provide information on biological function, they indicate potential for describing unknown metabolic pathways when there is the presence of oil in the bacteria's environment.