Characteristics and functions of Limosilactobacillus reuteri(Lactobacillus reuteri)from the intestine of mice supplemented with three dietary components based on genome resequencing and metabolite analysis

Limosilactobacillus reuteri is a resident probiotic in the intestines of animals with strong environmental adaptability.In the current study,to elucidate the adaptation strategies of L.reuteri to the intestine of mice supplemented with three dietary components(oil,peptide and cellulose),whole genome resequencing and determination of intracellular metabolites were carried out.The resequencing results showed that L.reuteri TO60(LR-TO)from the intestines of mice supplemented with high docosahexaenoic acid(DHA)tuna oil,or fermented Benincasa hispida culture(L.reuteri FB151,abbreviated as LR-FB)had relatively consistent single nucleotide polymorphisms(SNPs)and insertions and deletions(InDels),and those of L.reuteri from the intestines of mice supplemented with Rhopilema esculentum polypeptides(L.reuteri RE225,abbreviated as LR-RE)were quite different from them.The KEGG functional annotation of resequencing and the intracellular metabolites suggested that in all of the L.reuteri adapted to the intestinal environment mainly by regulating carbohydrate metabolism and membrane transport metabolic pathways.However,there were still some differences in their genes and metabolites,which may be related to the changes in the intestinal environment caused by three different types of dietary interventions.Our study analyzed the adaptation mechanism of L.reuteri to different isolated sources at the genetic level and metabolic level,which is helpful to clarify the adaptation strategies of probiotics to the intestinal environment,and provide supplementary information for the use of dietary nutritional supplements.

Delignification of disposable wooden chopsticks waste for fermentative hydrogen production by an enriched culture from a hot spring

Hydrogen （H2） production from lignocellulosic materials may be enhanced by removing lignin and increasing the porosity of the material prior to enzymatic hydrolysis. Alkaline pretreatment conditions, used to delignify disposable wooden chopsticks （DWC） waste, were investigated. The effects of NaOH concentration, temperature and retention time were examined and it was found that retention time had no effect on lignin removal or carbohydrate released in enzymatic hydrolysate. The highest percentage of lignin removal （41%） was obtained with 2% NaOH at 100℃, correlated with the highest carbohydrate released （67 mg/gpretreated DWC） in the hydrolysate. An enriched culture from a hot spring was used as inoculum for fermentative H2 production, and its optimum initial pH and temperature were determined to be 7.0 and 50℃, respectively. Furthermore, enzymatic hydrolysate from pretreated DWC was successfully demonstrated as a substrate for fermentative H2 production by the enriched culture. The maximum H2 yield and production rate were achieved at 195 mL H2/g total sugarsconsumed and 1 16 mL Hz/（L.day）, respectively.