The objective of this study was to investigate characteristics and functionality of yogurt applied red ginseng extract. Yogurts added with red ginseng extract (0.5, 1, 1.5, and 2%) were produced using Lactobacillus acidophilus and Streptococcus thermophilus and stored at refrigerated temperature. During fermentation, pH was decreased whereas titratable aicidity and viable cell counts of L. acidophilus and S. thermophilus were increased. The composition of yogurt samples was measured on day 1, an increase of red ginseng extract content in yogurt resulted in an increase in lactose, protein, total solids, and ash content, whereas fat and moisture content decreased. The pH value and cell counts of L. acidophilus and S. thermophilus were declined, however titratable acidity was increased during storage period. The antioxidant capacity was measured as diverse methods. During refrigerated storage time, the value of antioxidant effect was decreased, however, yogurt fortified with red ginseng extract had higher capacity than plain yogurt. The antioxidant effect was improved in proportion to concentration of red ginseng extract. These data suggests that red ginseng extract could affect to reduce fermentation time of yogurt and enhance antioxidant capacity.

BackgroundGinsenosides, which are bioactive components in ginseng, can be converted to smaller compounds for improvement of their pharmacological activities. The conversion methods include heating; acid, alkali, and enzymatic treatment; and microbial conversion. The aim of this study was to determine the bioconversion of ginsenosides in fermented red ginseng extract (FRGE).MethodsRed ginseng extract (RGE) was fermented using Lactobacillus plantarum KCCM 11613P. This study investigated the ginsenosides and their antioxidant capacity in FRGE using diverse methods.ResultsProperties of RGE were changed upon fermentation. Fermentation reduced the pH value, but increased the titratable acidity and viable cell counts of lactic acid bacteria. L. plantarum KCCM 11613P converted ginsenosides Rb2 and Rb3 to ginsenoside Rd in RGE. Fermentation also enhanced the antioxidant effects of RGE. FRGE reduced 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and reducing power; however, it improved the inhibition of β-carotene and linoleic acid oxidation and the lipid peroxidation. This suggested that the fermentation of RGE is effective for producing ginsenoside Rd as precursor of ginsenoside compound K and inhibition of lipid oxidation.ConclusionThis study showed that RGE fermented by L. plantarum KCCM 11613P may contribute to the development of functional food materials.

Lactobacillus brevis KU15153 was isolated from kimchi and probiotic characterization was performed including analysis of its antimicrobial and antioxidant effects. Lactobacillus rhamnosus GG (LGG) was used as a probiotic control. L. brevis KU15153 survived under artificial gastric conditions and was non-hemolytic, showed antibiotic susceptibility, and did not produce carcinogenic b-glucuronidase. L. brevis KU15153 adhered strongly to HT-29 cells in the direct adherent assay and showed high cell surface hydrophobicity. Particularly, L. brevis KU15153 showed antimicrobial activity against the foodborne pathogens Escherichia coli ATCC 25922, Listeria monocytogenes ATCC 15313, Salmonella Typhimurium P99, and Staphylococcus aureus KCCM 11335. Antioxidant activity was assessed using the DPPH radical scavenging assay and b-carotene and linoleic acid inhibition assay. L. brevis KU15153 showed higher antioxidant activity than LGG. These results suggest that L. brevis KU15153 has potential for use as a probiotic organism.

The purpose of this study was to determine the probiotic properties of Lactobacillus brevis KCCM 12203P isolated from the Korean traditional food kimchi and to evaluate the antioxidative activity and immune-stimulating potential of its heat-killed cells to improve their bio-functional activities. Lactobacillus rhamnosus GG, which is a representative commercial probiotic, was used as a comparative sample. Regarding probiotic properties, L. brevis KCCM 12203P was resistant to 0.3% pepsin with a pH of 2.5 for 3 h and 0.3% oxgall solution for 24 h, having approximately a 99% survival rate. It also showed strong adhesion activity (6.84%) onto HT-29 cells and did not produce β-glucuronidase but produced high quantities of leucine arylamidase, valine arylamidase, β-galactosidase, and N-acetyl-βglucosaminidase. For antioxidant activity, it appeared that viable cells had higher radical scavenging activity in the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay, while in the 2azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assay, heat-killed cells had higher antioxidant activity. Additionally, L. brevis KCCM 12203P showed higher lipid oxidation inhibition ability than L. rhamnosus GG; however, there was no significant difference (p < 0.05) between heat-killed cells and control cells. Furthermore, heat-killed L. brevis KCCM 12203P activated RAW 264.7 macrophage cells without cytotoxicity at a concentration lower than 10 8 CFU/ml and promoted higher gene expression levels of inducible nitric oxide synthase, interleukin-1β, and interleukin-6 than L. rhamnosus GG. These results suggest that novel L. brevis KCCM 12203P could be used as a probiotic or applied to functional food processing and pharmaceutical fields for immunocompromised people.

The aim of this study was to evaluate the probiotic properties of Ln1 isolated from kimchi and the antioxidant activities of live and heat-killed cells. KCTC 3108, which has been used as a commercial probiotic strain, was used as a control. strains (Ln1 and KCTC 3108) can survive under artificial gastric conditions (pH 2.5 in 0.3% pepsin for 3 h and 0.3% oxgall for 24 h), and adhere strongly to HT-29 cells. In addition, Ln1 did not produce carcinogenic β-glucuronidase, whereas it showed a higher β-galactosidase production of 3067.42 mU/mL. The antioxidant activity of . Ln1 was assessed using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging, β-carotene and linoleic acid inhibition, and reducing power assays. In all these methods, live . Ln1 showed a higher antioxidant activity than the control strain. In heat-killed cells of . Ln1, β-carotene bleaching inhibitory activity and reducing power was higher than DPPH and ABTS radical scavenging activity. These results suggested that live or heat-killed Ln1 isolated from kimchi might be useful as an antioxidant probiotic.

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Random mutagenesis was performed on beta-agarase, AgaB, from Zobellia galactanivorans to improve its catalytic activity and thermostability. The activities of three mutants E99K, T307I and E99K-T307I were approx. 140, 190 and 200%, respectively, of wild type beta-agarase (661 U/mg) at 40 degrees C. All three mutant enzymes were stable up to 50 degrees C and E99K-T307I had the highest thermostability. The melting temperature (Tm) of E99K-T307I, determined by CD spectra, was increased by 5.2 degrees C over that of the wild-type enzyme (54.6 degrees C). Activities of both the wild-type and E99K-T307I enzymes, as well as their overall thermostabilities, increased in 1 mM CaCl2. The E99K-T307I enzyme was stable at 55 degrees C with 1 mM CaCl2, reaching 260% of the activity the wild-type enzyme held at 40 degrees C without CaCl2.

Lactic acid bacteria (LAB) are widely known probiotics and para-probiotics used to improve gut condition, barrier function, and immunity [1][2][3][4]. LAB is reported to improve the immune system and decrease the risk of infection by bacteria, viruses, and other pathogens [5]. Although the mechanisms of immune system stimulation by LAB has not yet been fully understood, heat-killed probiotics as well as live probiotics are reported to have immune-stimulating effects [6]. Thus, the aim of this study was to evaluate the immune-stimulating effect of heatkilled Lactobacillus plantarum Ln1 (HK-Ln1) isolated from kimchi.L. plantarum Ln1 isolated from kimchi and L. rhamnosus GG (LGG) were grown in lactobacilli MRS broth (BBL, BD Biosciences, USA) at 37°C for 15 h. LGG, used as the control strain, was obtained from Korean Collection for Type Cultures (Korea). To obtain heat-killed Lactobacillus, the cells were heated at 80°C for 30 min. The final concentration of heat-killed Lactobacillus was adjusted to 10 7 and 10 8 CFU/ml, respectively. To investigate the immune-stimulating effects of HK-Ln1, nitric oxide (NO) assay, semi-quantitative real time RCR, and Western blot assay were performed with some modifications [7,8]. In addition, we used specific inhibitors such as MAPKs inhibitors (ERK 1/2, PD98059; JNK, SP600125; p38, SB203580) and NF-кB inhibitor (PDTC). NO is known to be involved in various physiological processes, such as nerve growth, neurotransmission, and regulation of cardiovascular pressure; furthermore, NO has been used for treatment of vascular disorders [9, 10]. It has been reported that NO plays an important role in immune response and host defense against invading pathogenic bacteria and viruses, as well as tumor cells [11]. NO produced by iNOS plays a physiological role in immune function after LPS stimulation to protect host cells [12]. This study demonstrated immune-stimulatory effect of HK-Ln1 compared to 10 ng/ml LPS. Generally, in order to evaluate the immune-stimulating other LAB, LPS concentration was performed at 1-10 ng/ml to minimize the cytotoxic effect [7,12,13]. NO production was examined in RAW 264.7 cells by NO assay. HK-Ln1 (10 8 CFU/ml) showed the highest NO production (5.31 μM) compared to that of cell non-treated LPS (3.74 μM). NO production was higher in HK-Ln1 (10 8 CFU/ml) at 5.30 μM than in LGG (Fig. 1A). NO assay is convenient tool for detection of immune response. Many studies have reported that probiotics can also stimulate the immune system, resulting in modulation of inflammatory mediators through cytokines that are responsible for the maintenance of the pathological process or immune response in a regulatory sense [14]. In a previous study, NO production of Lactobacillus brevis KCCM 12203P,