Clostridium cellabutyricum sp. nov., isolated from a Chinese liquor mud cellar, exhibiting probiotic potential and antibacterial activity against Pseudomonas aeruginosa

Abstract

Abstract Clostridium spp., which can produce short-chain fatty acids, represents potential probiotic candidates as promising adjuvant therapy against immune-associated disease via modulating host gut microbiome disorder. However, as obligate anaerobic bacteria, the strain resource of Clostridium spp. remains limited. A novel Clostridium bacterium, designated strain YQ-FP-027T, was isolated from a Chinese liquor mud cellar with the highest 16S rRNA gene sequence similarity (97.24%) with Clostridium intestinale DSM6191T. Characterization based on phylogenetic, phenotypic, chemotaxonomic, and genomic evidence was conducted. The probiotic profiles were determined both in vitro and in vivo. While its in vitro resistance to bile salts and acid was limited, the strain produced significant quantities of butyric acid (2001.92µg/g), and acetic acid (458.17µg/g). Its supernatant exhibited inhibitory effects on Pseudomonas aeruginosa bacterial cell growth. To evaluate its in vivo probiotic capacity, two chronic Pseudomonas aeruginosa Biofilm lung infection mouse models for both the preventative (pre-treatment) and therapeutic (post-treatment) applications of strain YQ-FP-027T were constructed. Treatment with YQ-FP-027T substantially reduced bacterial loads in lung tissue by 44.4% and 34.9% for the prevention and treatment models, respectively. Notably, upregulation of interleukin-10 expression and a significant increase in gut flora diversity were observed during YQ-FP-027T treatment. Further analysis of gut microbial diversity indicated an increase in beneficial genera such as Lachnospira and Prevotella, with a potential uptick in Lactobacillus abundance post-treatment in the prevention model, indicating the modulating ability of strain YQ-FP-027T on the gut microbiome as underlying mechanisms against Pseudomonas aeruginosa Biofilm infections. Characterization based on phylogenetic, phenotypic, chemotaxonomic, and genomic evidence demonstrated that strain YQ-FP-027T represents a novel species of the genus Clostridium, for which the name Clostridium cellabutyricum sp. nov., is proposed. Our results showed that strain holds great potential to provide a therapeutic alternative to alleviate the negative impacts of current infectious disease treatments.