β-glucosidase is an enzyme that hydrolyzes glycosidic bonds to generate terminal non-reducing residues in β-D-glucosides and oligosaccharides. These enzymes are used to degrade the plant cell walls of plant biomass. The 170 lactic acid bacteria isolated from beachu kimchi were examined for their β-glucosidase activity(E.C. 3.2.1.21.). Among the tested lactic acid bacteria, 48 strains utilized cellobiose as a carbon source. The highest β-glucosidase activity was 0.0537±0.0021(U/mg protein) in MSE129. MSE129 was identified to be Weissella koreenisis using 16S rRNA gene sequence analysis.

Glucansucrase is an enzyme classified as a glycoside hydrolase (GH) 70 family, which catalyzes the synthesis of glucooligosaccharides with a low molecular weight using sucrose as a donor of D-glucopyranose and maltose as a carbohydrate acceptor. In this study, glucansucrase-producing lactic acid bacteria strain was isolated from the fermented foods collected in traditional markets, and the optimum conditions for the oligosaccharide production were investigated. The strain CCK940 isolated from Chinese cabbage kimchi was selected as an oligosaccharide-producing strain due to its high glucansucrase activity, with 918.2 mU/mL, and identified as Leuconostoc lactis. The optimum conditions for the production of oligosaccharides using Leu. lactis CCK940 were to adjust the initial pH to 6.0, add 5% (w/v) sucrose and 10% (w/v) maltose as a donor and acceptor molecules, respectively, and feed 5% (w/v) sucrose at 4 and 8 h of cultivation. When Leu. lactis CCK940 was cultured for 12 h at optimum conditions, at least four oligosaccharides with a polymerization degree of 2-4 were produced.

Gastrodia elata Blume often has been used for the treatment of headaches, convulsions, hypertension, and neurodegenerative diseases. The main active constituents are gastrodin, 4-hydroxybenzyl alcohol, vanillyl alcohol, 4-hydroxybenzylaldehyde and parishin A, B, C and E. Because Gastrodia elata has also unacceptable off-odor (swine barnyard-like) for food, there is a need to reduce it as well as allow for greater utilization as a functional food materials. In this study, a major off-odor producing substance of Gastrodia elata was fractionated by steam distillation and silica gel column chromatography. The substance was identified as p-cresol(4-methyl phenol) by GC-MS analysis and comparison of the retention time with that of an authentic compound in GC. The content of p-cresol in fermented Gastrodia elata was decreased. A fermented sample of Latobacillus sakei for 2 days was reduced to 54.7%, when compared with a unfermented sample. The five parishin derivatives in Gastrodia elata were identified by HPLC-MS analyses, and a comparison of HPLC retention times with those of authentic compounds. When compared with parishin derivatives of an unfermented Gastrodia elata, those of Gastrodia elata fermented by L. sakei, increased to 18.3% for 2 days. Increases of about 14.0~38.4% of the total phenolic compounds and 57.4~77.3% total flavonoids were found in fermented extracts, by 3 lactic acid bacteria strains. They were compared with 97.1±2.9 μg/g and 40.9±2.0 μg/g in the unfermented control, respectively. The extracts of Gastrodia elata Blume that were fermented by lactic acid bacteria had higher DPPH free radical scavenging activity and FRAP reducing power than the unfermented control.

The acidity of soy curd fermented by lactic acid bacteria is a major factor degrading the sensory properties of soy curd. For preparation of soy curd with low sour taste, lactic acid bacteria were separated from kimchi. The lactic acid bacteria which showed yellow-clear zone around the colonies on BCP plate and formed soy curd with low level of acidity were selected. The selected strain was analyzed by 16S rDNA sequence and named as Pediococcus inopinatus Y2. The maximum viable cell number of the soy curd fermented by P. inopinatus Y2 was obtained at 10.73 log CFU/mL at 25°C for 24 h of fermentation. By the results of panel test, the overall sensory quality of the soy curd produced by P. inopinatus Y2 was higher than that of Leuconostoc mesenteroides No. 4395 and Lactobacillus sakei strain No. 383.

Probiotics may be defined as microbial agents that can benefit humans and have been used primarily by mankind in fermented foods. A representative of probiotics is lactic acid bacteria (LAB), which has received attention recently due to its perceived health benefits. We reviewed research papers about Bifidobacerium and Lactobacillus, which are two of the most known of the LAB. Bifidobacerium alleviates diarrhea from various causes by improving intestinal microflora, and it has been reported that it reduces Helicobacter pylori bacteria known as the cause of gastric ulcer and stomach cancer. Bifidobacerium has also reported to be effective on immunization and allergy, reduce blood cholesterol, cancer, lactose intolerance. Lactobacillus alleviates diarrhea but has not fully demonstrated its effectiveness relative to other health issues. Several lactic acid bacteria and yeast are expected to act as probiotics, so, in the future, more research on the health benefits of lactic acid bacteria is needed.

For preliminary molecular typing, PCR-based fingerprinting using random amplified polymorphic DNA (RAPD) is the method of choice. In this study, 14 bacterial strains were isolated from different Korean food sources, identified using 16S rRNA gene sequencing, and characterized through RAPD-PCR. Two PCR primers (239 and KAY3) generated a total of 130 RAPD bands, 14 distinct PCR profiles, 10 polymorphic bands, one monomorphic band, and four unique bands. Dendrogram-based analysis with primer 239 showed that all 14 strains could be divided into seven clades out of which clade VII had the maximum of seven. In contrast, dendrogram analysis with the primer KAY3 divided the 14 L. citreum strains into four clades out of which clade IV consisted of a maximum of 10 strains out of 14. This research identified and characterized bacterial populations associated with different Korean foods. The proposed RAPD-PCR method, based on sequence amplification, could easily identify and discriminate the lactic acid bacteria species at the strain-specific level and could be used as a highly reliable genomic fingerprinting tool.

For preliminary molecular typing, PCR-based fingerprinting using random amplified polymorphic DNA (RAPD) is the method of choice. In this study, 14 bacterial strains were isolated from different Korean food sources, identified using 16S rRNA gene sequencing, and characterized through RAPD-PCR. Two PCR primers (239 and KAY3) generated a total of 130 RAPD bands, 14 distinct PCR profiles, 10 polymorphic bands, one monomorphic band, and four unique bands. Dendrogram-based analysis with primer 239 showed that all 14 strains could be divided into seven clades out of which clade VII had the maximum of seven. In contrast, dendrogram analysis with the primer KAY3 divided the 14 L. citreum strains into four clades out of which clade IV consisted of a maximum of 10 strains out of 14. This research identified and characterized bacterial populations associated with different Korean foods. The proposed RAPD-PCR method, based on sequence amplification, could easily identify and discriminate the lactic acid bacteria species at the strain-specific level and could be used as a highly reliable genomic fingerprinting tool.

This study was conducted to investigate the effect of microbial inoculation as additive consisting of novel lactic acid bacteria on quality and fermentation characterization of Miscanthus sinnensis silages.The contents of crude protein, acid detergent fiber, neutral detergent fiber in treatments of additive of lactic acid bacteria (ALAB) inoculation had similar to control. pH of Miscanthus sinnensis (MS) silage in treatments of ALAB inoculation significantly decreased as compared to control (p<0.05). The content of lactic acid in in treatments of ALAB inoculation significantly increased (p<0.05), but the content of acetic acid in treatments of ALAB inoculation decreased. In addition, number of lactic acid bacteria in treatments of ALAB inoculation significantly increased as compared to control (p<0.05). Therefor, we suggest that MS silage improved by inoculation of additive consisting of novel lactic acid bacteria.

Probiotic functional foods are known to have various functional effects such as intestinal regulation, modulation of immune system, reduction of allergies, and lowering of cholesterol. The purpose of this study was to select probiotic strain that is most suitable for freeze-dried coffee for the development of functional coffee products. The survival rate of probiotics, at drinking condition of coffee, at acid, at bile and after freeze-dried in coffee were measured on 1 strain isolated from commercial freeze-dried coffee, 8 strains used as fermented milk starter, 1 Bifidobacterium and 1 Bacillus coagulans. Bacillus coagulans showed the highest survival rate from 2.4×107 cfu/g to 2.0×107 cfu/g especially after freeze-drying. The results at drinking condition of coffee, at acid tolerance, at bile tolerance and at storage test showed significantly better survival rate of Bacillus coagulans than that of control (Lactobacillus casei). Especially, Bacillus coagulans showed 3.8-fold higher survival rate at acid tolerance (pH 1, 120 minutes) than control. Thus, the lactic acid-producing Bacillus coagulans is characterized as a probiotic strain suitable for functional coffee formulation and commercialization.

본 연구는 여러 종류의 수액에서 lactobacillus brevis CFM20에 의한 γ-aminobutyricacid(GABA) 생산을 증가시키기 위해 수행되었다. 수액은 0.22㎛의 membrane filter로 여과하고 유산균으로 발효시켰다. 분리 된 L. brevis CFM20은 MRS 배지에서 pH 6.5, 37℃의 최적 조건에서 GABA를 276.42㎍/mL의 농도로 생산하였다. 0.8%(w/v) MSG를 함유 한 MRS 배지에서 배양된 L. brevis CFM20은1011.86㎍/mL의 농도에서 가장 높은 GABA 생산을 보였다. 0.8%(w/v) MSG와 5%(w/v) 동결건조 시킨 미강추출물을 수액에 첨가하여 얻은 GABA 량은 835.409㎍/mL였다. 결론적으로 5%(w/v) 동결건조된 미강추출물을 수액에 첨가하면 GABA 함량이 증가 된 발효 수액 음료를 개발 할 수 있을 것이라고 사료된다.

Asparagus cochinchinensis is known to ameliorate respiratory disease. We evaluated the antimicrobial activity of non-fermented and fermented A. cochinchinensis using lactic acid bacteria and investigated the physicochemical characteristics of the fermented A.cochinchinensis. Non-fermented A.cochinchinensis showed lower levels of antimicrobial activity than the fermented A.cochinchinensis. Ethyl acetate (EtOAc) extracts of the fermented A. cochinchinensis showed antimicrobial activities against the indicator strains at lower minimum inhibitory concentration (MIC). The MIC of the EtOAc extract of non-fermented A. cochinchinensis against Escherichia coli, Staphylococcus epidermidis, and Stphylococcus aureus were 100, 75, and 100 mg/ml. In contrast, the MIC of the EtOAc extract of ACLM was 25 mg/mL against E. coli. The MIC of the EtOAc extract of ACLS was 12.5 mg/mL against S.epidermidis, and the MIC of the EtOAc extract ofACLP was 12.5 mg/mL against S.aureus. The viable cell number, pH, and acidity of A. cochinchinensis fermented by Lactobacillussakei 383 were similar to those of A. cochinchinensis fermented by Leuconostocmesenteroides 4395, but were different from those of A. cochinchinensis fermented by Lactobacillus.plantarum KCCM 11322. These results suggested that the fermented A. cochinchinensis by lactic acid bacteria may be a good candidate for application to ameliorate respiratory disease.

In Western countries, kimchi, the Korean traditional fermented cabbage, is considered to be a healthy. However, it is one of the main sources of the high sodium content of the Korean diet. In order to decrease the sodium content, we manufactured a low-sodium kimchi (LK, salinity 1.0%) and 4 additional low-sodium kimchi starters in which each of 4 lactic acid bacteria (Lb. sakei 1, Lb. sakei 2, Lb. palntarum and W. koreensis) were added. The LKL1 to LKL4 samples were prepared by adding 4 single LAB starters, each with an inoculum size of 106 CFU/g, when the cabbage was mixed with kimchi sauce. The kimchi starters were fermented at 10℃ until reaching 0.5% acidity, and then stored at －1.5℃ until reaching 0.75% acidity. The pH and acidity of the starter kimchi changed more rapidly in the early phase of fermentation (up to 0.75% acidity) than control low-sodium kimchi. After the acidity of the kimchi starters reached 0.75% it remained constant. As the fermentation progressed, the total aerobic and lactic acid bacteria concentrations in the kimchi starter with added Lb. sakei 1 were the same as in the control low-sodium kimchi. The low-sodium kimchi fermentation of the kimchi starter with added Lb. palntarum progressed differently due to a difference in acid resistance. The kimchi starter with added Lb. sakei 2 had an overall liking score that was slightly higher than that of the control low-sodium kimchi due to a lower off-flavor

Glucansucrases are members of GH70 family of glycoside hydrolases and mainly produced by lactic acid bacteria such as Leuconostoc, Lactobacillus, and Weisella species. Glucansucrases use sucrose as a substrate to synthesize glucans as well as to produce oligosaccharides by transferring glucose moiety from sucrose onto acceptor carbohydrate molecules. It is known that some oligosaccharides produced by the reaction of glucansucrase show functional properties such as prebiotics and immunostimulatory activities. In this study, lactic acid bacteria which produce glucansucrase were screened from a variety of fermented foods, vegetables, and fruits collected from various area of Korea. Among 149 lactic acid bacteria strains which were isolated using BCP agar plates, 8 strains were selected which showed high glucansucrase activities. By nucleotide sequence analysis of 16S rRNA gene, strain no. 26-4 and 109-4 were identified as Leuconostoc mesenteroides, strain no. 95-4 strain was L. lactis, strain no. 92-4 and 112-1 were Weissella kimchii, strain no. 94-1 and 95-1 strains were W. confusa, and strain no. 113 was W. cibaria. When the oligosaccharides produced by the reaction of glucansucrase were analyzed using Bio-LC after these lactic acid bacteria were cultured into sucrose-containing media, the chromatograms of all bacterial showed unidentified peaks which implied the newly synthesized oligosaccharides

Aims: The objective of this study was to demonstrate the possible use of the psycrhotrophic, acid producing, and non-pathogenic microflora of the target chilled food (e.g. imitation crab sticks, ICSs) as time-temperature integrator-based materials for a quality indicator of the food. Methods and Results: Three strains out of four hundred and twelve psychrotrophic LAB colonies isolated from the ICSs were selected and identified as the genus Weissella (16S rDNA gene sequences), Gram-positive, catalase-negative, acid producing, and not hemolytic. Three prototype TTIs were correspondingly developed. A modified imitation crab medium was used as the bacterial nutrient source. The color change of a particular TTI in response to the experimental static and dynamic temperature conditions well represented the microbial growth and spoilage points of the Pseudomonas spp. and LAB which were justified as the spoilage microorganisms of thirty-three commercial ICSs. Conclusions: The psychrotrophic LAB based TTI is likely to be an effective tool for monitoring ICSs shelf life during storage and distribution. Significance and Impact of the Study: This finding suggests that the indigenous microflora of target food can be considered as potential materials for customizing a new TTI particularly for the target food. The food analog is potentially used as the microbial medium.

For several decades, lactic acid bacterium (Lactobacillus graminis: LAB) has been generally recognized as safe. To develop the pan-environmental bio-control agent, algicidal activity of the live LAB cell and its culture filtrate (CF) was examined against Microcystis aeruginosa. LAB cells perfectly lysed M. aeruginosa within 3 days, while the CF had a less effect than the live cells, approximately 78% inhibition of algal growth during a same culture period. The concentration of microcystin in alone culture of M. aeruginosa was 7.1 μg L-1, but gradually increased and leach 158.5 μg L-1 on 10 days. However, LAB cells clearly decreased the microcystin by 10.3 μg L-1 in the same period, approximately 93.5%. CF of LAB showed a strong algicidal activity over 75% between pH 2-7, 91.3% by the treatment of proteinase K, 87.8% by below 3 kDa in particle size, and 75.3% by heat treatment, respectively. Of five solvents, fractions of CF passed through solvents diethyl ether and ethyl acetate showed an obvious algicidal activity in the algal-lawn test. Among 5 fractions purified by silica-gel TLC plate, two spots showed a most strong removal activity on M. aeruginosa. Another analysis of GC indicate that CF contained six representative fatty acids. Even though most of these substance have been known as an anti-algal substance against M. aeruginosa, oleic acid is the most effective. These results suggested that the culture filtrate or specific substances, like a fatty acids, in comparison with live L. graminis can be a successful and eco-friendly agent to control Microcystis bloom.