• 한국식품영양학회지
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• 제13권2호
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• pp.146-151
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• 2000

To evaluate anticaries and antiinflammation of Aloe vera peel, antimicrobial substances were extracted from Aloe vera peel and identified. The antimicrobial active substances of water extract were successfully purified with solvent fractionation, silica gel column chromatography, preparative thin layer chromatography and UV spectrophotometer. Two purified active substances were identified as aloe-emodin and barbaloin by Mass Spectrometer, 1H-NMR and FT-IR.

• 급식외식위생학회지
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• 제1권1호
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• pp.27-35
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• 2020

Salt is a common seasoning agent used in various processed foods, especially in kimchi and salted seafood (jeotgal). This study was conducted to investigate the efficacy of salt with antimicrobial substances (acetic acid, garlic extract, carvacrol, nisin, thymol, and their combination (acetic acid+nisin+thymol)) on improvement of antibacterial effects of salt against foodborne pathogens. Salt (10%) was prepared using six different types of 0.2% natural antimicrobial substances. The antibacterial effect of salt combined with natural antimicrobial substances was evaluated against foodborne pathogens using the broth micro-dilution method and growth curve plotted using absorbance measurements. For the five foodborne pathogens, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of salt without antimicrobial substances as control were in the range of 24~>50,000 ㎍/mL and >50,000 ㎍/mL, respectively. Salt with nisin, thymol, or garlic extract showed strong inhibitory effects and their MIC against L. monocytogenes were 49, 12,500, and 24 ㎍/mL, respectively. In particular, salt with nisin showed inhibitory activities against Gram-positive bacteria. However, all the antimicrobial substances were less effective against Gram-negative bacteria such as E. coli O157:H7 and S. Typhimurium than Gram-positive bacteria. These results could be used for the development of salt with natural antimicrobial substances especially targeted against L. monocytogenes. This would enable the lowering of saline concentration while improving the storability of food.

• Food Science and Biotechnology
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• 제16권5호
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• pp.778-782
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• 2007

This study assessed the effects of the antimicrobial substances sulforaphane, grapefruit seed extracts (GSE), and reuterin on the expression of Salmonella HilA and InvF virulence gene using a LacZY assay (${\beta}$-galactosidase assay) with hilA:lacZY and invF:lacZY fusion strains of Salmonella typhimurium SL1344. Salmonella was grown for 8 hr at $37^{\circ}C$ in the presence of diluted antimicrobial substances ($2\;{\mu}g/mL$ sulforaphane, $20\{\mu}g/mL$ GSE, and 0.26 mM reuterin) at concentrations that did not inhibit the cellular growth of Salmonella. Sulforaphane inhibited the expression of HilA and InvF by 50-90 and 20-80%, respectively. GSE also inhibited the expression of both genes, but to a lesser degree. Among the 3 antimicrobial substances, reuterin showed the least inhibition, which was abolished after 3-4 hr. None of the antimicrobial substances inhibited the ${\beta}$-galactosidase enzyme activity of S. typhimurium. The assay used in this study represents a very sensitive method for screening bioactive substances that inhibit the expression of virulence genes in Salmonella.

• 미생물학회지
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• 제51권3호
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• pp.288-299
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• 2015

숙성된 백김치로부터 얻은 Lactobacillus brevis BK11의 증식과 항균물질 생산에 대한 배양용 배지 종류, 공기 조성, 초기 pH, 배양온도 및 시간과 프리바이오틱스의 영향을 조사하였다. L. brevis BK11의 증식과 항균물질 활성은 BHI와 M17 배지 보다는 MRS 배지 상에서 더 높게 나타났으며, 배지의 초기 pH 6.0에서 생산량이 최대에 이르렀다. 혐기적 조건보다는 호기적 및 미호기적 조건에서 배양했을 때와 $25^{\circ}C$ 보다는 $30^{\circ}C$와 $37^{\circ}C$ 온도에서 배양했을 때 균 성장과 항균물질 생산에 유리하였다. BK11 균주는 배양 24시간 만에 정지기에 도달하였고, 36시간 후부터는 생균수가 감소되었고, 배양상등액과 박테리오신 용액의 항균 활성은 $37^{\circ}C$, 24-30시간 배양했을 때 가장 높았다. 세포수와 유산 및 박테리오신 생산은 프락토올리고당 1-2% 첨가한 경우에 가장 높았으나, 이뉼린과 라피노오스는 균 증식에 별다른 도움을 주지 못했다. 결과적으로 L. brevis BK11의 항균물질 생산은 세포수와 관계 있었으며, 이러한 최적 조건 하에서 배양한 경우 Helicobacter pylori ATCC 43504의 성장을 효과적으로 저해할 수 있다.

• 한국미생물·생명공학회지
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• 제38권1호
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• pp.19-23
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• 2010

Recently, marine organisms are emerging as a leading group for identifying and extracting novel bioactive substances. These substances are known to possess a potential regarding not only as a source of pharmaceutical products but also their beneficial effects on humans. Among the substances, antimicrobial peptides (AMPs) specifically have attracted considerable interest for possible use in the development of new antibiotics. AMPs are characterized by relatively short cationic peptides containing the ability to adopt a structure in which cationic or hydrophobic amino acids are spatially scattered. Although a few reports address novel marine organisms-derived AMPs, their antimicrobial mechanism(s) are still remain unknown. In this review, we summarized the peptides previously investigated, such as Pleurocidin, Urechistachykinins, Piscidins and Arenicin-1. These peptides exhibited significant antimicrobial activities against human microbial pathogens without remarkable hemolytic effects against human erythrocytes, and their mode of actions are based on permeabilization of the plasma membrane of the pathogen. Therefore, the study of antimicrobial peptides derived from marine organisms may prove to be useful in the design of future therapeutic antimicrobial drugs.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2016년도 춘계학술대회 및 임시총회
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• pp.13-13
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• 2016

Insects constitute the largest and most diverse group of animals in the world. They also serve as the hosts or nutrient sources for an immense assemblage of pathogens, parasites, and predators. More than 700 fungal species from 100 genera have adopted an entomopathogenic lifestyle. Although entomopathogenic fungi were studied as only biocontrol agents against a variety of pests in various countries, it has been recently focused their additional roles in nature. They are antagonists to/against plant pathogens, endophytes, and possibly even plant growth promoting agents. The potential antimicrobial effect against fungal plant pathogens by an isolate of entomopathogenic fungi including Beauveria bassiana, Lecanicillium spp., and Isaria fumosorosea have been reported since late 1990s, but wasn't reported pathogenicity of the isolate against pests. Later, a Canadian Lecanicillium sp. isolate and L. longisporium isolated from Vertalec$^{(R)}$ showed simultaneous control effect against both aphid and cucumber powder mildew. Therefore, the antimicrobial activities of 342 fungi isolates collected from various regions and conditions in Korea were evaluated against plant pathogenic fungus Botrytis cinerea using dual culture technique on agar plate. As a result, 186 isolates (54.4%) shown the antifungal activity against B. cinerea. The culture filtrates of selected fungi completely suppressed the growth of the microorganisms, indicating that suppression was due to the presence of antimicrobial substances in the culture filtrate. Mode of action of these fungi against insect involves the attachment of conidia to the insect cuticle, followed by germination, cuticle penetration, and internal dissemination throughout the insect. During infection process, secreted enzymes, proteinous toxins, and/or secondary metabolites secreted by entomopathogenic fungi can be used to overcome the host immune system, modify host behavior, and defend host resources. Recently, secondary metabolites isolated from entomopathogenic fungi have been reported as potential bioactive substances. Generally, most of bioactive substances produced by entomopathogenic fungi have reported low molecular weight (lower than 1,000 g/mol) as peptide and, in contrast the high molecular weight fungal bioactive substances are rare. Most substances based on entomopathogenic fungi were shown antimicrobial activity with narrow control ranges. In our study we analyzed the antimicrobial substances having antagonistic effects to B. cinerea. Antimicrobial substances in our fungal culture filtrates showed high thermostability, high stability to proteolytic enzymes, and hydrophilicity and their molecular weights were differed from substance. In conclusion, entomopathogenic fungi showed pathogenicity against insect pests and culture filtrate of the fungi also shown to antimicrobial activity. In the future, we can use the entomopathogenic fungi and its secondary metabolites to control both insect pest control and plant pathogenic fungi simultaneously.

• Mycobiology
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• 제28권1호
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• pp.33-38
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• 2000

Mycelium of Hericium erinaceum isolate KU-1 was cultured in liquid medium (HL medium) and solid medium (Ko medium) at pH 4.0 in $28^{\circ}C$. 1.0% glucose or fructose was the most favorable carbon source, and 0.2% amonium acetate or $NaNO_3$ was an exellent nitrogen source for mycelial growth as well as production of antimicrobial substances. The mixture of saw dust 70% with rice bran 30% (SR medium) was the substrate for formation of sporophores. The active substrates in extracts from mycelium, culture filtrate and fruiting body were separated by TLC. The solvent for TLC was EtOAc: Chloroform: MeOH (10 : 5 : 10). Phenol-like substances appeared at Rf $0.5{\sim}0.9$, and fatty acid-like substances appeared at Rf $0.1{\sim}0.2$. The purified materials from the extracts showed antimicrobial effects to Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Aspergillus niger, Candida albicans and Microsporum gypseum. The S. aureus was the most inhibited. Minimal inhibitory concentration (MIC) of purified white powder and the Hercenone derivatives against S. aureus were $5.65\;{\mu}g/ml$ and $1.85\;{\mu}g/ml$, respectively.

• 한국식품영양과학회지
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• 제24권6호
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• pp.948-955
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• 1995

겨자의 항균성을 조사하기 의하여 추출용매에 따른 겨자의 항균성을 비교하고, 항균물질을 동정한 결과물, 메탄올 및 헥산에 대한 겨자 추출물의 항균성은 물 및 메탄올 추출물이 실험균주 모두에서 나타났으나 헥산에 의한 겨자 추출물은 항균활성이 거의 나타나지 않았다. SDE장치를 이용한 겨자 추출물의 항균성은 증류성분에서 항균활성이 아주 크게 나타났고, 메탄올에 의한 잔사 추출물도 항균활성이 조금 나타났으나 물층은 항균활성이 거의 나타나지 않았다. 겨자로 부터 3-iso-thiocynate-1-propene, 4-isothiocyanato-1-butene 및 4-ios-thiocyanatoethyl benzene과 같은 3종류의 isothiocyanate를 포함하여 30여종의 증류성분이 동정되었다.

• 생약학회지
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• 제42권4호
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• pp.329-335
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• 2011

Antimicrobial studies on reproductive organs have been scarcely reported. Candida albicans and Neisseria gonorrhoea test to find out the natural substances of various concentrations in the antimicrobial experiments have been made. Antimicrobial effect of biopole as the natural compound biosynthesis matter that contain anti-inflammatory material, catechin polyphenols and lactic acid as a single natural substance on C. albicans were of great significance. Also the results of antimicrobial effects of biopole, catechin and lactic acid as a single natural substance on N. gonorrhoea, respectively, showed lower concentration than those of the antimicrobial effects on C. albicans. Through the survival of Lactobacillus acidofillus that acts for the protection of the genital tissue the importance of lactic acid was confirmed. Lactobacillus acidofillus protection and C. albicans firmly into disinfected to low concentrations of the natural mixture from biopole and catechin with lactic acid were found and the antimicrobial effects of this natural mixture on N. gonorrhoea were perfect. C. albicans and N. gonorrhoea to disinfect the optimal natural mixture from 2% concentration biopole, 0.2% concentration of catechin and 2% lactic acid were obtained. Through the survival of Lactobacillus acidofillus in the reproductive organs protectable effects were acquired to prevent the infections of reproductive tissue and the recurrence.

• 한국축산식품학회지
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• 제36권4호
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• pp.547-557
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• 2016

This review discusses the status, antimicrobial mechanisms, application, and regulation of natural preservatives in livestock food systems. Conventional preservatives are synthetic chemical substances including nitrates/nitrites, sulfites, sodium benzoate, propyl gallate, and potassium sorbate. The use of artificial preservatives is being reconsidered because of concerns relating to headache, allergies, and cancer. As the demand for biopreservation in food systems has increased, new natural antimicrobial compounds of various origins are being developed, including plant-derived products (polyphenolics, essential oils, plant antimicrobial peptides (pAMPs)), animal-derived products (lysozymes, lactoperoxidase, lactoferrin, ovotransferrin, antimicrobial peptide (AMP), chitosan and others), and microbial metabolites (nisin, natamycin, pullulan, ε-polylysine, organic acid, and others). These natural preservatives act by inhibiting microbial cell walls/membranes, DNA/RNA replication and transcription, protein synthesis, and metabolism. Natural preservatives have been recognized for their safety; however, these substances can influence color, smell, and toxicity in large amounts while being effective as a food preservative. Therefore, to evaluate the safety and toxicity of natural preservatives, various trials including combinations of other substances or different food preservation systems, and capsulation have been performed. Natamycin and nisin are currently the only natural preservatives being regulated, and other natural preservatives will have to be legally regulated before their widespread use.