Clostridium vitabionis sp. nov., isolated from the large intestine of a mini-pig

An obligately anaerobic, Gram-stain-negative, spore-forming, short rod-shaped bacterium, designated strain YH- T4B42^T, was isolated from the large intestine of a mini-pig. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate belongs to the genus Clostridium and is most closely related to Clostridium aminophilum KCTC 5424^T, Clostridium symbiosum KCTC 15329^T and Clostridium butyricum KCTC 1871^T, with 95.5, 92.4 and 83.0 % sequence similarity, respectively. The average nucleotide identity values for strain YH-T4B42^T and the closest related strains were lower than 72 %. The G+C content of the isolate was 55.8 mol%. The cell-wall peptidoglycan was A1γ type and contained meso-diaminopimelic acid. The predominant fatty acids were C_16 : 0, C_18 : 1 cis 9, C_14 : 0 and C_18 : 0. The major end products of glucose fermentation were lactate, formate and acetate, with a minor amount of butyrate. Based on its phenotypic, phylogenetic and chemotaxonomic properties, a novel species, Clostridium vitabionis sp. nov., is proposed for strain YH-T4B42^T (=KCTC 25105^T=NBRC 114767^T).

The effect of fly maggot in pig feeding diets on growth performance and gut microbial balance in Ningxiang pigs

Fly maggot meal has been regarded as one of the substitutes of fish meal and soybean meal in pig feed. However, its effects on pig growth performance and faecal micro-organism remain unclear. The purpose of this study was to investigate the effect of dietary fly maggot meal on fattening performance, plasma indices related to gut hormones, immunity and faecal microbial communities composition of finishing pigs. A total of 40 Ningxiang fattening pigs were randomly allocated to two dietary treatments and pigs in each group were arranged by control group (CK) diet or 8% maggot meal group (MMG) diet for 45 days respectively. Growth performance, indices of gut hormones and immunity in plasma were evaluated. Microbiota composition in faeces was determined using 16S rDNA Amplicon Sequencing. The results showed that dietary MMG did not affect gut hormones and immune proteins in the trial compared with CK group (p > .05). However, dietary MMG significantly increased average daily gain (ADG). The population of the Firmicutes in MMG treatment was increased, while the percentage of the Bacteroidetes was decreased (p < .05). In particular, the number of Clostridiales related to hydrolyzed sugar and protein were increased (p < .05). It can inhibit the growth of harmful intestinal bacteria, promote the proliferation of beneficial bacteria and effectively improve the ability of digestion and absorption of nutrients. In conclusion, a diet containing 8% MMG changed the proportion of intestinal micro-organisms in finishing pigs, especially the higher richness of Firmicutes, and promoted the fattening ability of pigs to a certain extent. These changes should benefit finishing pig production during fattening period.

Isolation of Clostridium from Yunnan-Tibet hot springs and description of Clostridium thermarum sp. nov. with lignocellulosic ethanol production

Lignocellulose is considered a major source of renewable energy that serve as an alternative to the fossil fuels. Members of the genus Clostridium are some of the many microorganisms that have the ability to degrade lignocellulose efficiently to sugar, which can be further converted to biofuel. In this study, we isolated twelve Clostridium strains from hot spring samples of Yunnan and Tibet, of which isolates SYSU GA15002^T and SYSU GA17076 showed low 16S rRNA gene sequence identity profiles to any of the validly named Clostridium strains (<94.0%). Studies using a polyphasic taxonomy approach concluded that the two isolates represent one novel species of the genus Clostridium, for which we propose the name Clostridium thermarum sp. nov., with SYSU GA15002^T as the type strain of the species. Isolate SYSU GA15002^T has an optimum growth temperature at 45°C. Fermentation of the substrates cellobiose, cellulose, xylan and untreated straw powder by this strain results in the production of ethanol, along with acetate and formate. The complete pathways for the conversion of cellulose and xylan to ethanol is also predicted from the genome of isolate SYSU GA15002^T, which revealed a single step conversion of lignocellulosic biomass through consolidated bioprocessing. This paper is a comprehensive study encompassing isolation, polyphasic taxonomy, lignocellulose biodegradation and the genomic information of Clostridium in Yunnan-Tibet hot springs.

Mechanism of gut butyric acid producing bacteria for prevention and treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) represents a group of intestinal disorders with uncontrolled and chronic inflammation which include Crohn¡¯s disease (CD) and ulcerative colitis (UC). The incidence of IBD is increasing dramatically in Asian countries, especially in China. Recent studies have observed changes in the amount and structure of the gut butyrate-producing bacteria in IBD patients, which suggested that butyrate-producing bacteria might be related to the occurrence and development of IBD. This review will focus on the anti-inflammatory effects of butyrate-producing bacteria by producing butyric acid and butyrate and inhibiting inflammation as well as the immune characteristics of three species of butyrate-producing bacteria: Roseburia intestinalis, Faecalibacterium prausnitzii, and Clostridium butyricum. These mechanisms provide some new ideas and clues for IBD prevention and treatment.