본 연구는 마늘의 물추출물(AGE)의 E. coli O157:H7,S. typhimurium, 그리고 S. aureus에 대한 항균효과를 조사하였다. AGE의 E. coli O157:H7, S. typhimurium, and S.aureus에 대한 최소억제농도(MIC)는 각각 24, 48 그리고 24 mg/mL이었으며, 최소살균농도(MBC)는 모든 균에 대하여 96 mg/mL이었다. AGE 24 mg/mL을 E. coli O157:H7에 투여하고 배양 24시간 후에, 균의 증식이 무처리 대조군과 비교하여 유의성 있게 감소하였다(p < 0.01). 그러나 AGE 24 mg/mL을 S. aureus에 투여하고 배양 24시간 후에, 대조군과 비교하여 유의성 있는 균의 증식억제 효과가 나타나지 않았으나, AGE 96 mg/mL을 투여한 경우에서는 배양 24시간 후에 대조군과 비교하여 유의성 있는 균의 증식억제가 나타났다(p < 0.01). AGE 48 (p < 0.05)과 96 mg/mL (p < 0.001)을 S. typhimurim에 투여하고 24시간배양 후에, 대조군과 비교하여 통계적으로 유의성 있는 균의 증식억제 효과가 나타났다. 본 연구의 결과로부터, 마늘의 물추출물은 항생제와 화학적 식품보존제의 대체제로서 사용이 가능할 것으로 사료된다.

본 연구는 자몽종자추출물이 도포 포장지의 항균활성에 미치는 영향을 알아보았다. 저장 안전성 중 항균력을 확인 하기 위하여 그람 양성균(B. cereus, L. monocytogenes) 2종 과 그람 음성균(E. coli, S. enteritidis) 2종을 선택하였다. 자몽종자추출물의 농도별(60-5,000 ppm)에 따른 그람 양성 균의 투명환 크기는 최저 5 mm에서 최고 21 mm로 나타내 었다. 또한 그람 음성균의 투명환 크기는 최저 0 mm에서 최고 7 mm로 나타내었다. 자몽종자추출물을 농도별(60- 5,000 ppm)로 도포 포장시킨 경우 그람 양성균의 투명환 크기는 최저 5 mm에서 최고 19 mm로 나타내었다. 또한 그람 음성균의 투명환 크기는 최저 7 mm에서 최고 11 mm 로 나타내었다. 자몽종자추출물을 처리한 도포 포장지를 이용하여 즉석섭취 식품에 대한 저장 안정성을 알아본 결 과, GFSE의 농도(1,000, 5,000, 10,000 ppm) 차이에 따라 각각 11시간, 16시간, 18시간 동안 신선도가 유지 되었고, 일반 세균수 측정 결과, 1,000, 5,000 ppm 및 10,000 ppm 에서 각각 4.5 log CFU/g, 4.8 log CFU/g, 4.2 log CFU/g로 측정되어 저장성을 증가 시킴을 알 수 있었다.

Apolipophorin III (apoLp-III) is a multifunctional protein that is involved in lipid transport and innate immunity in insects. In this study, an apoLp-III protein that exhibits antibacterial activity was identified in honeybees (Apis cerana). A. cerana apoLp-III cDNA consists of 193 amino acids that share high protein sequence identity to other members of the hymenoptran insect apoLp-III family. A. cerana apoLp-III is expressed constitutively in the fat body, epidermis, and venom gland and is detected as a 23-kDa protein. A. cerana apoLp-III expression is induced in the fat body after injection with Escherichia coli, Bacillus thuringiensis, or Beauveria bassiana. However, recombinant A. cerana apoLp-III (expressed in baculovirus-infected insect cells) binds directly to E. coli and B. thuringiensis but not to B. bassiana. Consistent with these findings, A. cerana apoLp-III exhibited antibacterial activity against Gram-negative and Gram-positive bacteria. These results provide insight into the role of A. cerana apoLp-III during the innate immune response following bacterial infection.

본 연구에서는 곤약 가공을 위한 응고제와 침지액을 선정하고, 침지액 농도에 따른 식중독균에 대한 항균 활성을 확인하였다. 응고제 종류에 따른 곤약의 응고시간별 물성 변화는 응고액의 종류에 관계없이 응고시간이 진행될수록 경도, 검성 및 씹힘성이 증가하였다. 응고제 종류에 따른 곤약의 무기질 함량은 응고제가 Ca(OH)2일 경우, NaOH를 이용한 곤약보다 유의적으로 높은 Ca 함량을 나타내었으며, 응고제가 NaOH일 경우에는 Ca(OH)2보다 유의적으로 높은 Na 함량을 나타내었다. Mg와 P의 경우에는 응고제의 종류에 따른 유의적 차이는 보이지 않았다. 관능검사에서 색, 향, 맛, 조직감 및 전반적인 기호도는 응고제의 종류에 따른 유의적 차이는 없었다. 곤약의 제조과정 중 식중독균인 Staphylococcus aureus, E. coli, Salmonella typhimurium을 접종하여 Ca(OH)2 농도에 따른 항균 활성을 본 결과, 1.0×10－4 N 용액에 저장한 곤약이 가장 항균 활성이 적었으며, 1.0×10－2 N 농도가 가장 항균 활성이 높았다. 즉, 응고액의 농도에 비례하여 균 성장이 억제됨을 확인할 수 있었다. 제조 공정 별 미생물 변화는 구약감자 분말을 입고하여 저장시켰을 때 미생물 수가 약간 증가하지만, 그 이후 공정부터는 미생물 수가 급격하게 감소되며, 성형 이후부터는 검출되지 않는 것으로 확인되었다.

Salmonella species is one of the major bacterial agents that causes gastrointestinal disease in pigs. Natural antimicrobials derived from plants may be alternative therapeutics that could replace currently used antibiotics in the control of infectious disease. In this study, we assessed the antibacterial activity of Oenothera biennis L. extract against Salmonella Typhimurium both in vitro and in vivo. O. biennis L. extract had a strong inhibitory effect on S. Typhimurium in vitro, reducing bacterial growth by 87%. For the in vivo experiment, 16 post-weaned pigs were divided into 4 groups consisting of 4 pigs each: an uninfected, untreated negative control group; an untreated positive control group that was infected with S. Typhimurium; and two groups that were infected with S. Typhimurium and treated with either 0.1% or 0.5% O. biennis L. extract. Pigs were followed for 21 days after infection, and their body weight, daily gains, feed conversion ratio (FCR), and feed efficiency (FE) were monitored. The pigs treated with O. biennis L. extract had significantly higher daily gains than the positive control group (p<0.05). The O. biennis L. extract-treated pigs also exhibited better weight gain and FE, as well as a lower FCR and less severe diarrhea, than the positive controls but these results were not statistically significant. Our study demonstrates that O. biennis L. extract has antibacterial effects against S. Typhimurium, both in vitro and in vivo, and that these antibacterial effects may produce better growth performance in pigs infected with S. Typhimurium.

김치 과숙에 관여하는 균주와 대장균의 성장을 억제하는항균활성을 지닌 균주를 김치로부터 선발하고자 하였다. 전국 6개도의 배추김치 10종으로부터 분리한 500여개의 균주를 대상으로 김치의 과도한 산생성에 관여할 것으로 예상되는 P. pentosaceus, Lb. sakei, Lb. plantarum과 원·부재로로부터 초기에 유입되는 대장균군의 저감화를 위하여 E.coli에 대한 항균활성을 살펴본 결과, 2-7 30 균주가 모든지시균주에 대해 뚜렷한 생육저지환을 나타내었다. 지시균주들에 대해 일부 항균활성을 나타낸 15균주를 최종적으로선발하여 동정한 결과, Lb. sakei, Lb. plantarum, Lb. brevis,Lb. paraplantarum, Leu. citreum으로 각각 동정되었다.

Larvae black soldier fly, Hermetia illucens, is beneficial because its larvae feed on organic materials derived from plants, animals and humans and promote the recycling of food waste and organic materials. Chymotrypsin serine protease is one of the main digestive proteases in the midgut of and is involved in various essential processes. In a previous study, a gene encoding a chymotrypsin-like protease, Hi-SP1, was cloned from the larvae of Hermetia illucens and characterized. The objective of this study was to compare the digestive enzyme activity with various enzymes such as papain, protease and α-chymotrypsin. And also, we investigated the antimicrobial activity of the Hi-SP1 against the spoilage relate bacteria. The growth of the bacteria was inhibited in nutrient broth containing the Hi-SP1.

There are estimated to be about 700 species of bacteria in the oral cavity. Based on epidemiological investigations, some of these strains have been proposed as the pathogens responsible for oral diseases such as dental caries, gingivitis and periodontitis. Since electrolyzed hydrogen-rich water has been shown to have beneficial effects on human im- munity, its use has increased. In our study, the antibacterial activity of hydrogen-rich water for oralagainst bacteria asso- ciated with oral disease was evaluated. The bacterial strains Streptococcus mutans, Fusobacterium nucleatum, Porphy- romonas gingivalis and Tannerella forsythia were cultured in specific growth medium. S. mutans, F. nucleatum and P. gingivalis were soaked to thein both hydrogen water and tap water for 30 sec and then inoculated onto mitis-sali- varius agar and brain heart infusion agar including supple- mented withvitamin K and hemin, respectively. The num- bers of bacterial colonies were then measured after cultiva- tion for 48 hours. In the case of T. forsythia, which does not grow well on agar plates, inoculations into modified new oral spirochete (NOS) broth were performed and growth curve analysis was undertaken every day with a spectrophotometer. Hydrogen water showed antibacterial activity against all four bacterial strains in comparison with tap-water. We conclude from this that hydrogen water may have a positive impact on oral hygiene by helping to remove cariogenic bacteria and periodontopathogens.

This study was performed to evaluate the quality characteristics of sourdough bread with addition of lactic acid bacteria (LAB) in the antibacterial activity. The starter cultures were used for sourdough bread to increase bread shelf-life: Lactobacillus fermentum, Lactobacillus paracasei KB28, and Pediococcus pentosaceus MJK7. The results showed that the viable counts of lactic acid bacteria were increased in 8.1~9.2 log cfu/㎖, respectively. The pH of the three sourdoughs was lower than that of control. In the texture characteristics, hardness, gumminess, and chewiness were tended to increase on the sourdough bread. Among the three sourdough breads, bread volume and retrogradation of bread were not significantly different. According to the results from preservation period, the sourdough breads with addition of Lb. paracasei KB28, Ped. pentosaceus MJK7 were showed the appearance of mold and bacteria growth in 5~6 days, whereas the control were showed in 3 days. As a result, a sensory evaluation indicated the highest overall acceptance in order of Lb. fermentum, Lb. paracasei KB28, Ped. pentosaceus MJK7. Based on these results, Lb. paracasei KB28 can be applicable to improve the quality of sourdough bread.

We sought to study the qualities and scientific benefits of Dongchimi, a traditional Korean food. We compared and analyzed ingredients used for the appearance and storability of dongchimi - honggot (Brassica juncea czerniak et coss), cockscomb (Celosia cristata L.), and beet Beta vulgaris L.). We specifically examined the antioxidative and antibacterial activity of pigments from extracts of these ingredients. Distilled water (H2O) and 1% citric acid were used to safely extract pigments. The antioxidative activity of the pigments was then measured for total phenolic compounds, SOD (Super Oxide Dismutase), and EDA (Electron Donation Ability) by DPPH. The antibacterial activity of was also assessed by a Paper disc solution. Our results show that the pigments had sufficient antioxidative activity and had antibacterial properties against Gram positive and negative bacteria. In particular, Cockscomb (used for enhancing color) contained the highest amount of polyphenol compounds and had the most efficient antioxidative activity.

Peptidoglycan recognition proteins (PGRPs) are pattern recognition molecules of the innate immune system that recognize peptidoglycan, a unique cell wall component of bacteria. Here we cloned and characterized PGRP-S from the bumblebee Bombus ignitus (BiPGRP-S). The BiPGRP-S gene consists of four exons encoding 194 amino acid residues. Comparative analysis indicates that the predicted amino acid sequence of BiPGRP-S shares high identity with enzymatically active PGRP-S proteins and contains the amino acids required for amidase activity. BiPGRP-S in B. ignitus worker bees is constitutively expressed in boththe fat body and epidermis, and it is secreted into the hemolymph. Quantitative real-time PCR assays revealed that in both the fat body and epidermis, the BiPGRP-S gene is highly induced by an injection of Bacillus thuringiensis. In addition, recombinant BiPGRP-S expressed as a 19-kDa protein in baculovirus-infected insect cells can bind to B. megaterium and B. thuringiensis but not to Staphylococcus aureus, Escherichia coli or Beauveria bassiana. Consistent with these data, BiPGRP-S shows antibacterial activity against B. megaterium and B. thuringiensis. These results indicate that BiPGRP-S is an inducible protein that may be involved in the immune response against bacterial infection of the genus Bacillus as an amidase-type PGRP-S.

Thrombin-induced platelet microbicidal protein (tPMP) is a small cationic peptide that exerts potent in vitro microbicidal activity against a broad spectrum of human pathogens, including Staphylococcus aureus and Streptococcus rattus BHT. Earlier evidence has suggested that tPMP targets and disrupts the bacterial membrane. However, it is not yet clear whether membrane disruption itself is sufficient to kill the bacteria or whether subsequent, presumably intracellular, events are also involved in this process. In this study, we investigated the microbicidal activity of rabbit tPMP toward S. rattus BHT cells in the presence or absence of a pretreatment with antibiotics that differ in their mechanisms of action. The streptocidal effects of tPMP on control cells (no antibiotic pretreatment) were rapid and concentration-dependent. Pretreatment of S. rattus BHT cells with either penicillin or amoxicillin (inhibitors of bacterial cell wall synthesis) significantly enhanced the anti-S. rattus BHT effects of tPMP compared with the effects against the respective control cells over most tPMP concentration ranges tested. On the other hand, pretreatment of S. rattus BHT cells with tetracycline or doxycycline (30S ribosomal subunit inhibitors) significantly decreased the streptocidal effects of tPMP over a wide peptide concentration range. Furthermore, pretreatment with rifampin (an inhibitor of DNA-dependent RNA polymerase) essentially blocked the killing of S. rattus BHT by tPMP at most concentrations compared with the respective control cells. These results suggest that tPMP exerts anti-S. rattus BHT activity through mechanisms involving both the cell membrane and intracellular targets.