Liquorilactobacillus satsumensis from water kefir yields α-glucan polysaccharides with prebiotic and synbiotic qualities.

Exopolysaccharides from water kefir grains are a potential source of novel, food-safe and functional materials. Herein, prebiotic properties of polysaccharides produced by water kefir-derived Liquorilactobacillus satsumensis bacteria were explored. Strains were cultured in sucrose-supplemented media for exopolysaccharides production, and partial hydrolysis was performed to yield shorter chain polysaccharides. Structural characterization revealed that hydrolyzed polysaccharides were branched glucans comprising α-1,6 bonds and α-1,3/α-1,4 branching, with molecular weight of ~10 kDa. Hydrolyzed polysaccharides demonstrated selective utilization by probiotics, but not by pathogens, and were non-digestible by human digestive enzymes. Particularly, hydrolyzed polysaccharides were fermentable by kefir-derived probiotics, and these were combined in a novel kefir synbiotic formulation. Using large bowel simulated conditions, it was demonstrated that hydrolyzed polysaccharides and kefir synbiotics promoted Bacteroidetes abundance, and increased acetate, propionate, and butyrate concentrations. Overall, hydrolyzed glucans from Liquorilactobacillus satsumensis have prebiotic properties with enhanced benefits in a synbiotic when combined with kefir probiotics.

Genetic Diversity Analysis of Sapindus in China and Extraction of a Core Germplasm Collection Using EST-SSR Markers.

Sapindus is an important forest tree genus with utilization in biodiesel, biomedicine, and it harbors great potential for biochemical engineering applications. For advanced breeding of Sapindus, it is necessary to evaluate the genetic diversity and construct a rationally designed core germplasm collection. In this study, the genetic diversity and population structure of Sapindus were conducted with 18 expressed sequence tag-simple sequence repeat (EST-SSR) markers in order to establish a core germplasm collection from 161 Sapindus accessions. The population of Sapindus showed high genetic diversity and significant population structure. Interspecific genetic variation was significantly higher than intraspecific variation in the Sapindus mukorossi, Sapindus delavayi, and combined Sapindus rarak plus Sapindus rarak var. velutinus populations. S. mukorossi had abundant genetic variation and showed a specific pattern of geographical variation, whereas S. delavayi, S. rarak, and S. rarak var. velutinus showed less intraspecific variation. A core germplasm collection was created that contained 40% of genetic variation in the initial population, comprising 53 S. mukorossi and nine S. delavayi lineages, as well as single representatives of S. rarak and S. rarak var. velutinus. These results provide a germplasm basis and theoretical rationale for the efficient management, conservation, and utilization of Sapindus, as well as genetic resources for joint genomics research in the future.