Dental caries is an infectious disease accompanied by the destruction of teeth. It is a multifactorial disease caused by the interaction between microbes in dental plaque and food, with cariogenic Streptococcus mutans being one of the primary causes. In this study, the antimicrobial and antibiofilm activities of Lactiplantibacillus plantarum THK-j112 isolated from Kimchi, a traditional fermented food, against S. mutans were investigated. Furthermore, this paper also showed the possibility of developing this strain. After analyzing the 16S rRNA sequence, strain THK-j112 was named L. plantarum THK-j112 as it shared 99.93% similarity with L. plantarum ATCC 14917T. Both L. plantarum THK-j112 and L. plantarum ATCC 14917T demonstrated MIC values of 5 mg/mL and MBC values of 10 mg/mL against S. mutans KACC 16833T. The study confirmed that L. plantarum THK-j112 exhibited significant concentration-dependent inhibitory effects on biofilm formation, acid production, and glucosyltransferases(GTFs) production. Regarding hemolytic activity, Bacillus cereus ATCC 14579T, used as a positive control, was confirmed to cause hemolysis, whereas L. plantarum THK-j112 did not cause this phenomenon. Additionally, except for gentamicin, the antibiotic resistance test revealed a lower value than the MIC cut-off value for each antibiotic, indicating no resistance. Based on the findings, L. plantarum THK-j112 is expected to be useful in the food industry, such as functional food, as a lactic acid bacterium with antimicrobial and antibiofilm effects.

This mini-review focused on the current advances in the development and the application of the antibacterial agents produced from probiotics strains against foodborne pathogens. Inhibitory activity of the pathogen growth could be achieved by co-culture with probiotics and/or the treatment of metabolites extracted from probiotics culture, whereas strain-dependent efficacy was mainly reported according to the bacterial species of the target pathogens. To overcome the limited antibacterial spectrum and the efficacy of the metabolites from probiotics, the recent research highlight the discovery of novel bioactive substances with broad range of the inhibitory activity of foodborne pathogens and mode-of-action which has not been reported as the major research goal. Moreover, understanding the distribution of functional and regulation genes coding the production of the antibacterial metabolites based on the bacterial genome analysis can provide the clues for the mechanisms of the pathogen control by using probiotics. Major strategies on the application of the genomics in this research area can be represented as follows: 1) functional annotation specialized for antimicrobial proteins, 2) assessment of the antibacterial effects followed by the general/functional annotation, 3) genome and metabolites analysis for the purification of antimicrobial proteins, 4) comparative genomics and the characterization of antimicrobial potential. Especially the relationship between phenotype-genotype based on genomic bioinformation with the results of the practical efficacy tests of bacterial metabolites as an active substance of disinfectants and/or preservatives can be expected to act as supportive research for broadening our knowledge regarding the key metabolic pathways associated with the production of antibacterials from probiotics.

본 연구에서는 선행연구를 통해 병원성 박테리아의 억제효과가 입증된 kefir 유래 유산균 L. pentosus BMSE-K006과 L. pentosus BMSE-K009의 다제내성 균주를 포함하는 Staphylococcus spp., Escherichia spp. 등 총 7주에 대한 억제효과를 확인하고자 하였 다. L. pentosus BMSE-K006과 L. pentosus BMSE-K009는 대 체로 다제내성 균주 중 그람 음성균에 대한 억제효과가 더 큰 것으 로 확인되었으며, E. coli 1507 CCARM 0236을 제외한 모든 지 시 균주에서 L. pentosus BMSE-K009보다 L. pentosus BMSEK006의 항균효과가 더 우수한 것으로 확인되었다. 본 연구는 kefir 유래 유산균의 다제내성 균주에 대한 우수한 항균효과를 입 증할 수 있는 기초자료가 될 수 있으며, 추후 probiotics 특성 및 안전성에 대한 추가적인 연구가 필요할 것으로 판단된다.

In this study, we investigated the effects of indole on biofilm formation inhibition in Pantoea agglomerans (P. agglomerans). In the biofilm growth assay, indole inhibited biofilm formation across all the growth time. Depending on biofilm growth stage, indole exhibited biofilm inhibition and anti-bacterial effects on planktonic cells. Through the analysis of the proportion rate between biofilm and Colony Forming Units (CFU) and inhibition rate of indole, we confirmed that depending on the biofilm stage of P. agglomerans, indole treatment timing was more important than the treatment duration. By comparing gene expression rates through rt-qPCR P.agglomerans affected by indole was found to significantly change quorum sensing (pagI/R) and indole transportation (bssS) gene expressions. Throughout all, indole exhibited both antimicrobial and anti-biofilm effects on P. agglomerans. In addition, we confirmed the anti-biofilm effects of indole on mature biofilm. In conclusion, indole as a signal molecule, can exhibit anti-biofilm effects through bacterial quorum sensing inhibition and indole affects. Therefore, indole can regulate biofilm bacteria especially gram-negative opportunistic pathogens.

Fermented foods of Korean temple are vegetable-based foods and their seasonings are limited to five pungent herbs. The aim of this study was to investigate cell-free supernatants (CFS) of lactic acid bacteria isolated from the fermented foods of Korean temples. Three selected CFS significantly inhibited the biofilm formation of Escherichia coli O157:H7 at 24 h, while one of the selected CFS markedly inhibited the biofilm formation at 72 h. However, only one CFS significantly attenuated the biofilm formation of Staphylococcus aureus at 24 h, but these CFS failed to inhibit the biofilm formation. Moreover, selected CFS effectively inhibited the growth of E. coli O157:H7, whereas the growth of S. aureus was not affected in the presence of CFS. These results suggest that CFS of lactic acid bacteria isolated from fermented foods of Korean temples shows antimicrobial activity agasint Gram-negative E. coli O157:H7, but not at Gramd-positive S. aureus .

본 연구에서는 당근 지상부 추출물 및 용매 분획물의 항염, 항균 활성을 확인하고 유효성분을 분리하여 화학구조를 동정하였다. 당근 지상부 에탄올 추출물 및 용매 분획물의 항염 활성을 측정하기 위해 LPS로 자극된 RAW 264.7 세포를 이용하여 NO 생성 억제 활성을 확인하였다. 그 중 에틸아세테이트 분획물이 NO의 생성을 농도 의존적으로 감소시키는 효과가 나타났고, 추가적인 항염 기전 연구를 위해 에틸아세테이트 분획물에 대해 PGE2, 전염증성 사이토카인의 생성량 및 iNOS, COX-2 단백질의 발현량을 측정하였다. 그 결과, 에틸아세테이트 분획물이 PGE2, IL-1β, IL-6의 생성을 감소시키고, iNOS, COX-2 단백질의 발현도 억제 시키는 효과가 있음을 확인하였다. 또한 표피포도상구균과 여드름균을 이용한 활성 실험 결과, 헥산 및 에틸아세테이트 분획물에서 항균 활성이 나타났다. 이와 같은 결과를 바탕으로 에틸아세테이트 분획물에 대해 컬럼 크로마토그래피를 수행하여 3개의 화합물을 분리하였으며, 1H 및 13C NMR 데이터 분석과 문헌을 통하여 화학구조를 동정하였다; diosmetin (1), disomin (2), cynaroside (3). 분리된 화합물 1-3에 대해 항염 및 항균 활성을 측정하였으며, 그 결과 화합물 1-3 모두 NO의 생성을 저해시키는 효과가 있음을 확인하였다. 또한 화합물 3은 여드름균에 대해 항균 활성이 우수하였다. 이상의 연구 결과를 바탕으로 당근 지상부 추출물을 이용한 항염 및 항균 효과를 갖는 천연 화장품 소재로의 개발이 가능할 것이라 사료된다.

본 연구에서는 하수오를 이용하여 50% 에탄올 추출물과 에틸아세테이트 분획물을 제조하고, 추출물 및 분획물의 항산화, 세포 보호 및 항균 효능을 평가하여 기능성 소재로서의 가능성을 확인하였다. 또한, 하수오에 주요하게 존재하는 성분의 활성도 검증하였다. HPLC-DAD, LC-EIS-MS를 통해 분석한 결과, 하수오의 주성분은 2, 3, 5, 4'-tetrahydroxystilbene 2-O-β-D-glucoside (THSG)이었다. 페놀류 및 THSG 함량은 에틸아세테이트 분획물이 에탄올 추출물 보다 각각 11.1 및 3.0배 높게 나타났다. DPPH 자유 라디칼 및 Fe3+-EDTA/H2O2 시스템에서 생성된 ROS에 대한 소거 활성 평가에서, 에틸 아세테이트 분획물은 에탄올 추출물 보다 뛰어난 소거 활성을 나타냈다. 특히 ROS 소거 활성 평가에서 에틸 아세테이트 분획물과 THSG은 L-ascorbic acid와 동등한 소거 활성을 나타냈다. 이러한 결과를 바탕으로 수행된 광증감 반응으로 유도된 적혈구의 산화적 손상에 대한 세포 보호 활성은 에틸아세테이트 분획물, 에탄올 추출물, THSG 순서로 나타났으며, 모든 실험군이 양성 대조군으로 사용한 (+)-α-tocopherol보다 우수한 활성을 나타냄을 확인하였다. 항균 활성 평가는 S. aureus, E. coli, P. aeruginosa, C. albicans 균주를 대상으로, disc diffusion assay와 broth microdilution assay를 이용하여 수행하였다. 그 결과 추출물, 분획물 및 THSG 모두 모든 균주에 대해 항균 활성을 나타냈으며, 특히 그람 양성균인 S. aureus에 대해 methyl paraben보다 우수한 항균력을 나타냄을 확인하였다. 본 연구의 결과는 하수오가 항산화, 세포 보호 및 항균력에 관한 천연 소재로의 활용될 수 있는 가능성을 시사한다.

This study was performed to develop a new natural antimicrobial materials by analyzing the effect of extracts obtained from Ten Lauraceae Species on the inhibitory activity against Propionibacterium acnes. The plant materials were collected from Wando and Jeju islands, and the antimicrobial activity of the crude extracts was examined by the agar diffusion method with different part (i.e., leaf and branch), solvents (i.e., distilled water, 80% ethanol, and 100% methanol) and at different ultrasonic extracting times (i.e., 15, 30, and 45 minutes). The control agents used were synthetic antimicrobials, methylparaben and phenoxyethanol, at concentrations of 0.4, 1, 2, and 4 ㎎/disc. Altogether, extracts of 10 species used in the study showed inhibitory activity, which confirmed their antimicrobial action against acnes. Among these, leaves of Laurus nobilis L. which was extracted in 80% ethanol for 45 min showed the largest clear zone (19.8 ㎜). Leaves of L. nobilis L., showing highest antimicrobial activities among 10 species, were successively reextracted with n-hexane, chloroform, ethylacetate and n-butanol. As a results, in all fractions except butanol, clear zone above 10 ㎜ were formed. The ethyl acetate fraction showed the highest inhibitory activity (13.3 ㎜) and the inhibitory activity was significantly higher than that of crude extract (10.2 ㎜) and phenoxyethanol as a control (12.5 ㎜).

Background : Panos extract is a mixture of four Panax plant extracts namely Dendropanax morbifera, Panax ginseng, Acanthopanax senticosus and Kalopanax septemlobus. We intended to use Panos extract for ZnO nanoparticles(NPs) synthesis and application for waste water treatment. Methods and Results : In the present study, we have synthesized Panos ZnO nanoparticles via co precipitation method. Characterization of the NPs has been done using X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR) and UV-Visible spectroscopy. An average of 75% efficacy in degrading the methylene blue dye has been observed. The nanoparticles showed antibacterial activity against E. coli and S. aureus. Conclusion : The results shows that Panos ZnO NPs can be a potential eco-friendly and economical tool for waste water management in the current scenario where there an intense urge to remediate the polluted environment through novel approaches such as Nanobiotechnology.

한련초는 열대 및 아열대 지방에 서식하는 국화과 한련초속에 속하는 한해살이풀로 간 손상에 대한 보호 효과, 살무사 독에 대한 해독효과, 항산화효과, 발모효과, 상처치유효과 등의 효능들이 확인된 바 있다. 더 나아가 본 연구에서는 한련초의 항산화 및 항노화효과를 확인하여 피부보호 소재로써의 가능성을 검토하고자 하였다. 이를 위해 한련초를 50% 에탄올로 추출한 추출물과 이를 다시 에틸아세테이트로 분획하여 얻은 분획물을 실험에 사용하였다. 항산화 지표인 FSC50과 OSC50을 측정한 결과, 에틸아세테이트 분획물의 OSC50은 항산화제로 잘 알려진 L-ascorbic acid 보다 2.7배 이상 뛰어난 것으로 나타났다. 이와 더불어 시료의 세포 내 활성산소 종 소거능과 H2O2로 유도된 세포손상에 대한 보호효과가 확인되었으며, 특히 1O2으로 유도된 사람 적혈구 광용혈에 대한 지연효과의 평가에서 64 μ g/mL의 에틸아세테이트 분획물이 적혈구 광용혈의 소요시간을 6배 이상 지연시켜 한련초의 우수한 항산화능을 반영해주었다. 한련초의 항노화 효과를 검증하기 위해 Hs68에서 추출한 엘라스타제에 대한 저해활성을 평가한 결과, 16 μ g/mL의 두 시료 모두 엘라스타제의 활성을 각각 6.8%와 14.0% 억제한 것을 확인하였다. 마지막으로 한련초가 식품 또는 화장품 등의 소재로 사용됨에 있어 화학적 방부제의 역할을 대체할 수 있을 가능성을 확인하기 위한 항균실험의 결과, 에틸아세테이트 분획물이 그람 양성 균주 인 Staphylococcus aureus에 대해 mehyl paraben과 동등하거나 더 뛰어난 항균활성을 가진 것을 확인하였다. 이상의 실험결과들을 통해 한련초는 피부보호 소재 또는 천연방부제로서의 가능성을 가진 천연소재라 생각되며, 식품 또는 화장품 소재로서의 이용이 기대된다.

This study was performed to investigate and measure the antimicrobial activity of evergreen woody species extracts on Trichophyton mentagrophytes. To do this, leaves and stems were collected from Wando and Jeju islands, and were used for the extraction with different solvents (i.e., distilled water, 80% ethanol, and 100% methanol), and at different ultrasonic extracting times (i.e., 15, 30, and 45 minutes). The experiment was conducted by using the agar diffusion method. The clear zone was measured after incubating the paper disc containing the plant extract in a bacterial culture medium. The controls were synthetic antimicrobials, methylparaben and phenoxyethanol, at concentrations of 0.4, 1, 2, and 4 mg/disc. Altogether, extracts of 56 out of 64 species used in this study had inhibitory activity, which confirmed their antimicrobial activity against Athlete’s foot. Among them, the crude ethanolic extract of Elaeocarpus sylvestris in 45 min showed a zone of inhibition < 20.2 ㎜, while the clear zone of Actinodaphne lancifolia ethanolic extraction for 30 min was 23.5 ㎜. Also, Quercus acuta, Dendropanax morbiferus and Daphne odora showed clear zones of 28.0 ㎜ (45 minutes ethanolic extraction), 20.5 ㎜ (45 minutes crude methanolic extraction) and 19.7 ㎜ (45 minutes methanolic extraction), respectively. Thus, these results confirm that the extracts of evergreen woody species have therapeutic potential against Athlete’s foot, and suggest that in order to extract adequate amounts of antimicrobial substance from the plant sources, ideal extraction condition has to be considered.

본 연구에서는 다양한 식품유해미생물에 대한 길항작용 및 항산화활성이 우수한 B. subtilis SRCM102046 균주를 식품보존 소재로서 이용하기 위해 반응표면분석법을 이용하여 균체 증량을 통한 항균활성 및 항산화활성 증대를 도모하고자 하였다. SRCM102046의 산업적 활용을 위한 성장조건을 최적화하기 위해 배양시간에 따른 균체 성장을 조사하였으며, 통계학적 기법인 반응표면분석법을 사용하였다. SRCM102046의 최적 성장을 위한 배지 성분을 선별하기 위해 Plackett-Burman design을 이용하였으며, PBD 결과 선별된 배지 성분으로 molasses, sucrose, peptone으로 예측되었다. 각 배지 성분의 최적농도를 결정하기 위한 방법으로 central composite design을 이용하였으며, 최종적으로 예측된 각 배지 성분의 농도는 molasses 7 g/L, sucrose 7 g/L, peptone 2 g/L로 예측되었다. 이때의 균체량은 22.03±1.30 g/L로 예측되었으며, 통계분석을 통해 실험모델의 적합성을 확인하였다. 또한, 실험 모델을 수행하여 건조균체량을 측정한 결과 22.02±0.35 g/L로 측정되어 실험모델에 의해 예측된 값이 오차범위 내에 존재하여 모델의 신뢰성이 매우 높음을 확인하였으며, 이는 실험모델에 의해 예측된 최적배지 사용시 최적화 이전의 LB 배지에서의 균체량(2.47±0.03 g/L)대비 약 9배의 균체량이 증가함을 확인하였다. 또한 최적배지에서 B. subtilis SRCM102046 배양 시 항균활성은 대조구로 사용된 LB 배지에서의 항균활성 대비 최대 140% 향상되었으며, 항산화활성은 약 100.41% 증가함을 확인하였다. 본 연구를 통하여 식품보존제로서B. subtilis SRCM102046의 산업화를 위한 배지최적화를 수행하였으며, 추후 박테리오신의 정제 및 특성 등에 대한 세부적인 연구가 필요하지만 본 연구를 통해 확립된 배양조건을 기반으로 식품보존 소재의 측면에서 매우 유용한 자료로 활용될 수 있을 것으로 기대된다.

Background : Endophytes are generally regarded as beneficial microorganisms that live in plant tissues without disease symptoms. The endophytic species may differ depending on the plant age, the sampled time, the plant genotype, and the tissue. Although numerous endophytes have been identified from various plants, little is known about the endophytic bacteria of Panax quinquefolius, a useful herb plant. Therefore, the aim of this study is to investigate diversity and distribution of endophytic bacteria from 2-years-old to 6-years-old P. quinquefolius and to evaluate antimicrobial activity of isolates. Methods and Results : Initially, 2-years-old to 6-years-old plants were collected and sterilized with 70% ethanol and sodium hypochlorite, subsequently we prepared individual suspensions which were mixed with sample and sterile distilled water. A total of 88 single colonies were obtained from the LB agar plates spreading suspension. Using 16S rDNA sequencing, the taxonomic status of the isolates were determined consequently 42 species were identified. The 42 species were classified into 4 phylum; Proteobacteria (64%), Firmicute (27%), Actinobacteria (8%), and Bacteroidetes (1%). Based on age, the isolates of 5-years-old plant showed highest diversity. Moreover, Actinomycetales, Bacillales, and Pseudomonadales were equally dispersed as predominant orders in 5-years-old plant. The antagonistic activities of isolates against a phytopathogen, Pseudomonas syringae pv. tomato DC3000 : GFP (Pst : GFP) were performed using dual culture assays. We measured antibacterial activity by quantifying fluorescence of Pst:GFP which representing pathogen growth. As a result, 36 isolates inhibited growth of Pst:GFP. Interestingly, all species belonging Pseudomonas in this study showed strong antibacterial activity against Pst : GFP. Conclusion : These results improve our understanding of the structure and diversity of the endophytic bacteria of P. quinquefolius. Furthermore, we suggest that bacterial endophytes with antimicrobial activity might have useful as materials for biocontrol agents.

Background : In this study, we have examined antioxidative effects and antimicrobial activity of methanol extracts of several plant resources (three varieties of Asimina triloba L., Momordica charantia L., Psidium guajava L. and Alium ampeloprasum L.) Methods and Results : The antioxidant activities were assayed by five methods based on total polyphenol and flavonoid contents, scavenging of DPPH, ABTS and reducing power analysis. Total polyphenol contents was the highest in Psidium guajava and Mango, the varieties of Asimina triloba as the contents of 95.85, 95.81 ㎎/g, respectively. Total flavonoid content was the highest in Psidium guajava (54.3 ㎎/g). DPPH free radical scavening activity of all extracts was ranged from 10.5 - 85.8%, and significantry great activities was found at Psidium guajava leaf. Methanol extracts of Psidium guajava and Asimina triloba showed showed greater ABTS scavening activities compared to others. Reducing power of all extracts was linearly proportional to the concentration. Especially, the extracts of Psidium guajava and three varieties of Asimina triloba showed greater reducing power than that of other resources. The antimicrobial activities of extracts were tested by paper disc assay and minimum inhibitory concentration test. Antimicrobial activity of Psidium guajava leaf extract was shown relatively high activity against all investigated strains. Conclusion : The results suggest that Psidium guajava leaf extract be a new functional cosmetic ingredient with antioxidant effect and antimicrobial activity.

Background : Schisandrae Fructus (Omija) has been widely used for medicinal herbs because it is known for its various medical functions and antimicrobial activities. This study was conducted to investigate the antimicrobial activities of extracts from Schisandrae Fructus against six foodborne pathogens (Bacillus cereus, E. coli, Listeria monocytogenes, Salmonella enteritidis, Staphylococcus aureus, Vibrio parahaemolyticus) and figured out the efficient extraction methods. Methods and Results : Traditionally, Schisandrae Fructus is soaked or boiled in water when people drink it like tea. In this study, we extracted Schisandrae Fructus by soaking in water and ethyl alcohol for 24 hours, ultrasonicating in methyl alcohol and water for 60 minutes, and boiling in water for 30, 60, 90, 120 minutes. Each extract used for paper disc test that estimates antimicrobial activities by measuring the inhibition zone. The blank discs that absorbed with extracts were placed on the agar plates that smeared with each foodborne pathogen, then incubated overnight at 37℃ incubator. Then, antibacterial extracts formed clear zones around the disc. In this study, Vibrio parahaemolyticus was the most sensitive to the all kinds of extracts and methyl alcohol extracts that were obtained by ultrasonicating showed the most strong antimicrobial activities against six foodborne pathogens (23, 12, 29, 18, 23, 28 ㎜). Hot water extracts and soaking extracts in water showed the similar results, and the extracts that was boiled for 60 minutes was the best results (13, 8, 21, 10, 13, 17 ㎜) against all the pathogens. Conclusion : The extracts from Schisandrae Fructus inhibited the growth of six foodborne pathogens. Soaking and boiling in water are good methods for drinking Schisandrae Fructus like tea because they showed antimicrobial activities in the paper disc test. According to this study, the best boiling time for effective antimicrobial activity is 60 minutes.