RESUMO
Vibrio alginolyticus is one of the most common opportunistic pathogens in marine animals and humans. In this study, A transposon mutation library of the V. alginolyticus E110 was used to identify motility-related genes, and we found three flagellar and one capsular polysaccharide (CPS) synthesis-related genes were linked to swarming motility. Then, gene deletion and complementation further confirmed that CPS synthesis-related gene ugd is involved in the swarming motility of V. alginolyticus. Phenotype assays showed that the Δugd mutant reduced CPS production, decreased biofilm formation, impaired swimming ability, and increased cytotoxicity compared to the wild-type strain. Transcriptome analysis showed that 655 genes (15%) were upregulated and 914 genes (21%) were downregulated in the Δugd strain. KEGG pathway and heatmap analysis revealed that genes involved in two-component systems (TCSs), chemotaxis, and flagella assembly pathways were downregulated in the Δugd mutant. On the other hand, genes involved in pathways of human diseases, biosynthesis ABC transporters, and metabolism were upregulated in the Δugd mutant. The RT-qPCR further validated that ugd-regulated genes are associated with motility, biofilm formation, virulence, and TCSs. These findings imply that ugd may be an important player in the control of some physiological processes in V. alginolyticus, highlighting its potential as a target for future research and potential therapeutic interventions.
Assuntos
Cápsulas Bacterianas , Proteínas de Bactérias , Biofilmes , Flagelos , Regulação Bacteriana da Expressão Gênica , Vibrio alginolyticus , Vibrio alginolyticus/genética , Vibrio alginolyticus/fisiologia , Vibrio alginolyticus/metabolismo , Biofilmes/crescimento & desenvolvimento , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Flagelos/genética , Flagelos/metabolismo , Flagelos/fisiologia , Cápsulas Bacterianas/metabolismo , Cápsulas Bacterianas/genética , Polissacarídeos Bacterianos/biossíntese , Polissacarídeos Bacterianos/metabolismo , Polissacarídeos Bacterianos/genética , Virulência , Animais , Perfilação da Expressão Gênica , Deleção de Genes , Humanos , Vibrioses/microbiologiaRESUMO
Recently, using microalgae to remediate heavy metal polluted water has been attained a huge attention. However, heavy metals are generally toxic to microalgae and consequently decrease biomass accumulation. To address this issue, the feasibility of adding exogenous glucose, employing algae-bacteria system and algae-bacteria-activated carbon consortium to enhance microalgae growth were evaluated. The result showed that Cd2+ removal efficiency was negatively correlated with microalgal specific growth rate. The exogenous glucose alleviated the heavy metal toxicity to algal cells and thus increased the microalgae growth rate. Among the different treatments, the algae-bacteria-activated carbon combination had the highest biomass concentration (1.15 g L-1) and lipid yield (334.97 mg L-1), which were respectively 3.03 times of biomass (0.38 g L-1) and 4.92 times of lipid yield (68.08 mg L-1) in the single microalgae treatment system. Additionally, this algae-bacteria-activated carbon consortium remained a high Cd2+ removal efficiency (91.61%). In all, the present study developed an approach that had a great potential in simultaneous heavy metal wastewater treatment and microalgal lipid production.
