In this study, probiotic properties such as acid resistance, bile tolerance, intestinal adhesion and fat accumulation inhibition of lactic acid bacteria isolated from kimchi were investigated in order to develop probiotics effective anti-adipogenic effects. Among the 120 types of lactic acid bacteria isolated from kimchi, 42 types of lactic acid bacteria being to acid resistance, 35 types of lactic acid bacteria being to bile resistance, and 24 types of lactic acid bacteria being to both acid resistance and bile resistance were selected. These 24 types were tested for the intestinal adhesion ability which is an essential factor of probiotics’ function and L. rhamnosus GG was used as a positive control in this test. 10 types of lactic acid bacteria having the intestinal adhesion ability were selected. The selected 10 types of lactic acid bacteria were treated in 3T3-L1 cells and intracellular fat was stained with Oil Red O reagent to measure fat accumulation. As a result, in the group treated with lactic acid bacteria OS-15, 48, 102 and 120, fat accumulation was significantly decreased compared with the non-treated group. And the strain OS-48 showed the greatest inhibitory effect on fat accumulation. The lactic acid bacterium OS-48 was identified as Lactiplantibacillus plantarum by analysis based on 16S rRNA sequencing and was named Lactiplantibacillus plantarum OS-48. Therefore, based on the results of this study, L. plantarum OS-48 is expected to be very useful as probiotics with anti-obesity effect in the food industry such as fermented food and functional food.

The aim of this study was to evaluate the probiotic properties of lactic acid bacteria (LAB) isolated from kimchi and antioxidant and anti-inflammatory activities of heat-killed LAB strains. Regarding probiotic properties, Lactiplantibacillus plantarum SMF398 and L. plantarum SMF470 isolated from kimchi can survive under artificial gastric condition and adhere strongly to HT-29 cells. The SMF398 and SMF470 strains showed strong antimicrobial activity and co-aggregation against pathogenic bacteria. The heat-killed cells of LAB (1 mg/mL) were prepared by heating at 121℃ for 15 min. MTT assay revealed that the heat-killed cells (1 mg/mL) of SMF398 and SMF470 were not toxic to HT-29 cells. The heat-killed SMF398 and SMF470 showed significantly higher DPPH and ABTS radical scavenging activities as well as β- carotene bleaching inhibitory activity than the heat-killed L. plantarum ATCC14917, a control probiotic strain (p<0.05). In lipopolysaccharide-induced RAW264.7 cells, the heat-killed SMF398 and SMF470 significantly reduced the nitric oxide production by 30.92% and 22.81%, respectively (p<0.05). Furthermore, the heat-killed SMF398 and SMF470 significantly decreased the gene expression levels of tumor necrosis factor-α, interleukin-6, inducible nitric oxide synthase, cyclooxygenase-2 up to 58.02%, 67.70%, 53.44%, 45.90%, respectively (p<0.05). These results suggest that the heat-killed L. plantarum SMF398 and L. plantarum SMF470 might be useful as antioxidant and anti-inflammatory agents.

Liquid-state fermentation (LSF) and solid-state fermentation (SSF) were carried out to produce enzymes and β-glucan. The modified synthetic medium composition in liquid-state fermentation (LSF) was determined to be 5% (w/v) whole oat flour, 2% (w/v) tryptone, and 2% (w/v) rice bran. The different humidity conditions of oat by solid-state fermentation were evaluated in terms of maximum production of fungal biomass, amylase, protease, and β-glucan, which were 0.23 mg/g, 7,157.38 U/g, 413.67 U/g, and 8.26% (w/w), respectively, at 60% of humidity condition. Moreover, α-glucosidase inhibition activities of fermented oat with 60% humidity at 48 h were shown to be high 49.08% (w/w). Therefore, liquid- and solid-state fermentation processes were found to enhance the overall fermentation yields of oat to produce enzymes and β-glucan.

This study aimed to isolate and identify the new strains which can be utilized in fermentation process for the production of functional materials. Isolation of the new microorganism in wood vinegar, natural liquid material generated from the carbonization of various trees was studied. Marine agar medium was used for the isolation of halo-tolerant bacteria. Using a sterilized toothpick, transfer same shape colonies to agar plates and continuous cultivation of colonies at 37℃ for several days, 2 colonies were isolated. Through the 16S-based ID service, isolated strains were identified as Cytobacillus species. Verifying the industrial values of the two isolated strains, the productivities of various enzymes such as amylase, lipase, and protease were confirmed. As a result, isolated 2 strains showed amylase and protease activities which means the possibility of applying to biological processes in the food and cosmetic industries.

After liquid culture of Phellinus baumii (P. baumii) mycelium (LPBM) was prepared, LPBM was fractionated into A∼E fraction (A; hot-water extract of liquid culture including mycelia, B; crude polysaccharide of A, C; hot-water extract of mycelia, D; crude polysaccharide of C, and E; crude polysaccharide of culture broth) to evaluate for possibility as functional materials with immunostimulatory activity. In macrophage stimulatory activity, E fraction as postbiotics significantly increased secretion of NO and IL-12 from RAW 264.7 cells. Next, when the splenocytes of C3H/HeN mice were primary cultured, E fraction showed significantly mitogenic activity with enhancing mitogen-related cytokines (IFN-γ and TNF-α) production from splenocyte. E fraction also potently stimulated GM-CSF production from Peyer’s patch cells as well as Peyer’s patch-mediated bone marrow cell proliferation. In addition, the immunostimularoy E fraction contained neutral sugar (73.8%), uronic acid (10.6%), protein (7.8%), and polyphenol (7.5%), and mainly consisted of glucose (39.1%), galactose (21.7%), mannose (11.1%), galacturonic acid (9.9%), and arabinose (8.9%) as component sugars. In conclusion, it was demonstrated that postbiotics including exopolysaccharide fractionated from liquid culture of the P. baumii mycelium could enhanced immunostimulatory activity.

Grapefruit extract rich in functional substances adjusting pH 5.0 and adding sucrose (final concentration, 2%) was fermented by Leuconostoc mesenteroides CJNU 0147 strain, consequently prepared a fermented grapefruit extract containing dextran. As a result of analyzing the growth inhibitory effect on gut harmful bacterium Clostridium difficile strain using the prepared fermented grapefruit extract, the viable cell count was significantly reduced (p<0.05 vs. control for 0.5 brix as a final concentration; p<0.001 vs. control for 1.0 brix). On the other hand, the proliferative ability of the extract for Bifidobacterium breve strain, which is one of the species of the genus Bifidobacterium well known as human gut beneficial bacteria, was confirmed (p<0.001 vs. control for both 0.5 and 1.0 brix). These results indicate fermented grapefruit extract with Leu. mesenteroides CJNU 0147 strain inhibits the growth of gut harmful bacterium C. difficile and promotes the proliferation of beneficial bacterium B. breve and is expected to be used as a functional food material for gut health.