락토바실러스 존소니 PF01 균주 유래 항균 활성

김상훈 ( Sang Hoon Kim ),박혜균 ( Hye Kyun Park ),황인찬 ( In-chan Hwang ),강대경 ( Dae-kyung Kang ) 한국낙농식품응용생물학회(구 한국유가공학회) 2020 한국유가공기술과학회지 Vol.38 No.1

장관 흡착능 등을 비롯한 프로바이오틱 활성이 우수한 Lactobacillus johnsonii PF01의 배양상 등액을 황산암모늄으로 70% 농축한 후에 항균능을 조사한 결과, 황색포도상구균을 억제하는 활성을 나타내었다. PF01 균주가 분비하는 항균물질은 단백질분해효소 proteinase K에 의해 항균활성이 소실되지 않는 특성을 나타냄으로써, 항균물질이 박테리오신일 가능성을 시사하였다. L. johnsonii PF01 유전체에서 박테리오신을 코딩하는 유전자를 검색한 결과, helveticin과 상동성이 높은 유전자가 존재함을 확인하였다. Culture concentrate of probiotic Lactobacillus johnsonii PF01 inhibited the growth of Staphylococcus aureus, which was confirmed by agar well diffusion method. Protease treatment of PF01 culture concentrate indicated that the antimicrobial substance of PF01 was a bacteriocin. Investigation of PF01 genome revealed the existence of a gene similar to that of helveticin, which showed 34.9% and 41.0% identity with those of L. helveticus 481 and L. crispatus K313, respectively, thereby suggesting that the bacteriocin produced by strain PF01 is a helveticin homolog.

Antimicrobial Activity of Hibiscus sabdariffa L. (Roselle) Powder against Food-Borne Pathogens Present in Dairy Products: Preliminary Study

( Hyun-woo Lim ),( Kun-ho Seo ),( Jung-whan Chon ),( Kwang-young Song ) 한국낙농식품응용생물학회(구 한국유가공학회) 2020 한국유가공기술과학회지 Vol.38 No.1

The antimicrobial activity of the ethanol extract of Hibiscus sabdariffa L. (Roselle) powder against various food-borne pathogens was tested using the lawn diffusion assay. The results showed that the ethanol extract exhibited antimicrobial activities against Staphylococcus aureus (total inhibition), Salmonella enteritidis (partial inhibition), Listeria monocytogenes (partial inhibition), Escherichia coli (partial inhibition), Cronobacter sakazakii (partial inhibition), and Bacillus cereus (partial inhibition). Therefore, it is strongly recommended that Hibiscus sabdariffa L. (Roselle) should be considered for use as a natural food-grade additive for the inhibition of various food-borne pathogens, including both gram-positive and gram-negative pathogens, and the improvement of the overall quality of various dairy products, including milk.

Chemical and Organoleptic Properties of Some Dairy Products Supplemented with Various Concentration of Propolis: A Preliminary Study

( Jung-whan Chon ),( Kun-ho Seo ),( Hyungsuk Oh ),( Dongkwan Jeong ),( Kwang-young Song ) 한국낙농식품응용생물학회(구 한국유가공학회) 2020 한국유가공기술과학회지 Vol.38 No.2

This study was conducted to evaluate the chemical and organoleptic properties of some dairy products supplemented with different concentrations of propolis (0%, 0.5%, 1.0%, 1.5%, and 2.0%). There was no significant difference between pH values of the treated and control groups. All samples were tested using 20 evaluators divided in five categories. Compared to the control, the best organoleptic test results were obtained for market milk, yoghurt, and Kefir supplemented with 0.5% propolis. Statistical difference was observed in the taste, flavor, color, texture, and overall acceptability of market milk, yoghurt, and Kefir between the treated and control groups (p<0.05). However, as propolis has a strong aromatic flavor, it should be supplemented in small amounts, so as not to affect the organoleptic properties of the product. In conclusion, this study provides useful information for the development of functional dairy products using propolis.

한국전통식품 김치로부터 분리한 유산균주의 항산화 활성

김다영 ( Da-young Kim ),김홍석 ( Hong Seok Kim ),유정식 ( Jung Sik Yoo ),조윤아 ( Yoon Ah Cho ),김철현 ( Cheol-hyun Kim ) 한국낙농식품응용생물학회(구 한국유가공학회) 2020 Journal of Dairy Science and Biotechnology (JMSB) Vol.38 No.2

본 연구의 목적은 한국 전통 음식 김치에서 분리한 유산균의 특성을 연구하기 위해 형태학적, 생화학적 특성을 조사하였다. 한국의 전통 발효 식품에서 젖산균을 확인하기 위해 분리된 균주의 그람염색을 수행한 후 Macrogen에서 16S rRNA 분석 결과, DKGF9(Lactobacillus plantarum), DKGF1(Lactobacillus paracasei ), DKGF8(Lactobacillus casei ), DK207(Lactobacillus casei ), DK211(Lactobacillus casei )이 확인되었다. 우리는 한국의 전통 발효 식품인 김치에서 분리된 5가지 LAB의 기본 생물학적 활성에 대한 실험을 수행했다. 37℃, 55℃, 65℃, 75℃에서 각각 5분, 15분 5균주의 내열성 확인 결과, 상업 균주인 Lactobacillus acidophilus LA-5의 내열성과 유사하거나 더 높음을 보여주었다. 장내부착능에서는 선발균주 모두 상용균주와 비교했을 때 10⁷ CFU/mL 이상으로 우수한 결합능을 보여주었고, KCTC(한국생명공학연구원 생물자원센터)에서 분양받은 Escherichia coli KCTC1682, Salmonella enterica KCTC2054, Bacillus cereus KCTC3624 3종을 활용한 항균활성 결과, 모든 균주는 상업용 균주인 L. acidophilus LA-5와 비교하여 유사하거나 더 높은 항균 활성을 나타냈다. 단백질분해능력 실험에서, 5개의 균주는 clear-zone의 직경이 24시간에서 72시간으로 갈수록 점차 증가하고, L. paracasei DKGF1이 가장 큰 직경을 갖고 있어 단백질분해능력이 가장 우수한 것으로 나타났다. 5개의 균주로부터 선택된 3개의 균주는 ABTS, DPPH, FRAP, Hydroxyl radical scanenging 활성을 포함하여 다양한 항산화활성 효과를 나타냈다. 결과적으로, 5가지 균주 중에서 우수한 기능성을 갖는 L. paracasei DKGF1이 잠재적인 프로바이오틱스 활성을 나타내며, 건강 관련 제품의 개발에 유용한 균주라고 판단된다. The purpose of this study was to investigate the probiotic properties of lactic acid bacteria (LAB) isolated from a Korean traditional food kimchi. Gram staining was performed by Macrogen (Macrogen, Inc.) for identification of the LAB. Five strains of LAB were identified, including DKGF9 (Lactobacillus plantarum), DKGF1 (L. paracasei ), DKGF8 (L. casei ), DK207 (L. casei ), and DK211 (L. casei ). The biological activities of the isolated strains were assessed. The results showed that heat resistance of the strains was similar to or higher than the commercial strain L. acidophilus LA-5. Indirect testing of the ability of the strains to attach to the mucin layer revealed that DKGF9, DKGF1, and DKGF8 have high binding affinities for the mucous layer. All strains showed antimicrobial activity similar to or higher than the commercial strain LA-5. In proteolysis experiments, the diameters of proteolysis zones of the five strains increased in the period of 24-72 h, with DKGF1 exhibiting the largest zone diameter. Three strains were selected based on their antioxidant activities. Among the five isolated strains, L. paracasei DKGF1 showed potential probiotic activity, and thus, it may be useful for the development of health-promoting products.

항생제 내성을 가진 유산균의 현황과 전망

천정환 ( Jung-whan Chon ),서건호 ( Kun-ho Seo ),배동렬 ( Dongryeoul Bae ),정동관 ( Dongkwan Jeong ),송광영 ( Kwang-young Song ) 한국낙농식품응용생물학회(구 한국유가공학회) 2020 Journal of Dairy Science and Biotechnology (JMSB) Vol.38 No.2

대부분의 스타터 배양균은 유산균(LAB)군(group)에 속하며 미국 식품의약국(FDA)과 유럽식품안전청(EFSA)에 의해 안전하다고 인정받고 있다. 그러나, LAB는 항생제 내성(antibiotic resistance) 유전자를 위한 내적 또는 외적 저장소로 작용할 수 있다. 하지만 저항 유전자 전달이 수직이기 때문에 이 사실은 그 자체가 안전상의 문제가 아닐 수도 있다. 그럼에도 불구하고 외부 유전적 요소는 심각한 안전 문제를 나타내는 인체 장내 미생물뿐만 아니라 병원균의 저항성 수평 전달에 유리한 변화를 유도할 수 있다. 항생제 내성을 가진 유산균의 일부 속(genus)에는 발효육 및 유제품에서 분리된 Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Pediococcus, Streptococcus 등이 포함된다. 현재 WHO는 식품산업에서 사용되는 LAB는 저항이 없어야 한다고 권고하고 있다. 다행히도 한국의 식품의약품안전처가 인정한 프로바이오틱스 균주 중 Enterococcus 에 해당되는 균주는 E. faecium과 E. faecalis인데, 2019년 4월 1일부터 E. faecium과 E. faecalis의 독성인자와 항생제 내성전달인자 모두 없다고 인정된 경우에면 사용이 허가된다. 따라서 LAB의 산업적 중요성을 고려할 때 앞으로 인체와 동물장관 유래의 LAB은 체계적인 탐색 및 동정, 병원성 및 항생제 내성 유전자의 확인, 식품 및 가축사료 첨가제로의 활용, 안전성 평가연구는 계속 필요하다고 사료된다. Lactic acid bacteria (LAB) form an essential part of the intestinal microbiota of the human body and possess the ability to stabilize the intestinal microbiota, strengthen immunity, and promote digestion as well as intestinal synthesis of vitamins, amino acids, and proteins. Hence, LAB are currently widely used in various products. However, due to the indiscriminate overuse of antibiotics in humans and livestock, bacterial resistance to antibiotics has been increasing rapidly, which has led to serious problems in the treatment of bacterial infections. Additionally, several reports have revealed that antibiotic-resistant LAB may infect people whose immune systems are not fully developed or whose immune systems are temporarily weakened. Therefore, it is imperative to consider the possibility of antibioticresistant LAB causing diseases in humans and animals, investigate the mechanism of action between antibiotics and LAB, and determine the relevant regulations for the safe use of LAB.

박테리오신 생성 Pediococcus acidilactici 를 적용한 요거트 특성 및 항균성 연구

현인경 ( In Kyung Hyun ),김민영 ( Min Young Kim ),김서연 ( Seo-yeon Kim ),이지수 ( Jee-su Lee ),최아랑 ( Ah-rang Choi ),강석성 ( Seok-seong Kang ) 한국낙농식품응용생물학회(구 한국유가공학회) 2020 Journal of Dairy Science and Biotechnology (JMSB) Vol.38 No.3

본 연구에서는 박테리오신을 생성하는 P. acidilactici를 적용한 기능성 요거트를 제조하여 항균활성과 프로바이오틱스로서의 품질을 평가하였다. Yogurt starter로는 시판되는 요거트에서 분리한 혼합 균주 3종(S. thermophilus, Lb. bulgaricus, Lb. rhamnosus GG)을 사용하였으며, 혼합 균주와 P. acidilactici HW01, P. acidilactici JM01, P. acidilactici K10을 각각 혼합 접종하여 각각의 요거트를 제조한 다음 유산균의 생균수, pH, brix를 측정한 결과, 유산균의 생균수는 모두 8.0 Log CFU/mL 이상의 생균수가 검출되어 유산균 발효유로서 기준에 적합하였다. 또한 pH와 brix를 측정한 결과, 발효 후 시간이 지남에 따라 모두 감소하였다. 우유나 유제품의 오염에 있어서 유의해야 할 병원성 균인 L. monocytogenes를 통해 병원성 저해능을 측정하였으며 L. monocytogenes가 발효 후 3일째부터 모두 저해되는 것이 확인되었다. 본 연구 결과를 통해 박테리오신 생성 균주인 P. acidilactici HW01, P. acidilactici JM01, P. acidilactici K10이 발효유제품 제조에 있어서 요거트 제품의 변화 없이 프로바이오틱 효과를 지닌 균주로 기대되며, 식품안정성 및 새로운 프로바이오틱스 유제품 개발에 도움을 줄 것이라 예상된다. 그리고 L. monocytogenes 외의 다른 병원성 균의 저해효과에 대한 연구 및 요거트의 저장온도에 따른 병원성 저해효과 차이에 대한 연구도 기대된다. 따라서 박테리오신 생성 균주를 활용한 기능성 식품을 실제 식품산업에 적용한다면 안전성 및 신제품 개발에 대한 연구가 더 이루어져야 될 것으로 보인다. Physical and sensory characteristics of commercial yogurts are important aspects for consumer acceptability. In addition, beneficial functions of commercial yogurts are also emphasized for the probiotic dairy products. The aim of this study was to investigate the functional properties of yogurts with the combination of bacteriocin-producing Pediococcus acidilactici. Yogurts fermented with commercial starter culture (control yogurt) and control yogurt together with P. acidilactici HW01 (yogurt+HW01), P. acidilactici JM01 (yogurt+JM01), or P. acidilactici K10 (yogurt+K10) were prepared. During 28 days after fermentation, the viability of lactic acid bacteria, pH, and brix, in the yogurt samples were assessed with standard methods. Moreover, to investigate the antilisterial activity of the yogurt samples, Listeria monocytogenes was simultaneously inoculated when the yogurts were prepared with lactic acid bacteria, and the viability of L. monocytogenes was determined. Although yogurt+K10 did not completely remove L. monocytogenes, control yogurt, yogurt+HW01, and yogurt+JM01 eradicated L. monocytogenes at day 2 after fermentation. However, yogurt+K10 also removed L. monocytogenes at day 3 after fermentation. Taken together, these findings suggest that the combination of yogurt with P. acidilactici does not affect its quality and they may consequently aid in the development of new probiotic yogurt.

Advanced Methods for Isolating from and Confirming Campylobacter spp. in Milk and Dairy Products: Review

( Jung-whan Chon ),( Kun-ho Seo ),( Binn Kim ),( Dongkwan Jeong ),( Kwang-young Song ) 한국낙농식품응용생물학회(구 한국유가공학회) 2020 Journal of Dairy Science and Biotechnology (JMSB) Vol.38 No.3

Campylobacter spp. are a type of microaerophilic bacteria that cause human foodborne illnesses worldwide. Among the various types of Campylobacter spp., Campylobacter jejuni and Campylobacter coli account for 90% of foodborne campylobacteriosis. Generally, poultry meats are known to be a primary cause of campylobacteriosis; however, several other types of foods have also been reported to cause campylobacteriosis. Particularly, raw milk has been directly linked to Campylobacter infections among many foodborne illnesses, and cases of campylobacteriosis caused because of the ingestion of unpasteurized raw milk have been recorded worldwide. This review reports (1) general information, history, and nomenclature of Campylobacter spp., (2) epidemiology of Campylobacter spp., (3) detection of Campylobacter spp. from foods including milk and dairy products, and (4) review of methods for controlling the growth Campylobacter spp.

프로바이오틱스에 의한 알레르기 질환 제어 및 안전성

이예원 ( Yewon Lee ),윤요한 ( Yohan Yoon ) 한국낙농식품응용생물학회(구 한국유가공학회) 2020 Journal of Dairy Science and Biotechnology (JMSB) Vol.38 No.1

Allergic diseases, including atopic dermatitis, asthma, allergic rhinitis, and food allergies, could be caused by dysbiosis that results in an immune system imbalance. The incidence of allergic diseases has been increasing and they are now one of the most common diseases throughout the world. Recently, probiotics have been suggested as an alternative intervention for the prevention and treatment of allergic diseases. Probiotics are endogenous microflora with functional effects within hosts. They have various clinical and immunological capacities and have recently been considered as a supplement for the treatment and prevention of allergic diseases. Probiotic bacteria modulate immune cells such as Th1, Th2, and regulatory T cells that are correlated with protection against atopic dermatitis, however, safety concerns for the use of probiotics have been raised. Therefore, further research is needed to clarify the efficacy and safety of probiotics in the treatment of allergic diseases.

유제품 및 식품 분석 업무의 중요성 (분석학자의 관점)

곽병만 ( Byung-man Kwak ) 한국낙농식품응용생물학회(구 한국유가공학회) 2020 Journal of Dairy Science and Biotechnology (JMSB) Vol.38 No.4

Processes that products we consume that contain dairy foods comprise planning → design → production → quality/suitability assessment → safety verification → launch → distribution → consumption. Analysis of nutrients and potential toxins at each stage in the production process is essential to verify food quality, suitability, and safety. Products display ingredient lists and nutrient content to help consumers choose healthy foods. These products should also be fully assessed for microbes and toxins before reaching consumers. Products require verification through test inspections. However, this step has reduced value from a food manufacturer's viewpoint, because it does not visibly impact real economic trends. The most important first step in determining the quality and suitability of products is the inspection capability of food companies.

Complete Genome Sequence of Enterococcus faecalis CAUM157 Isolated from Raw Cow’s Milk

( Arxel G. Elnar ),( Sang-dong Lim ),( Geun-bae Kim ) 한국낙농식품응용생물학회(구 한국유가공학회) 2020 Journal of Dairy Science and Biotechnology (JMSB) Vol.38 No.3

Enterococcus faecalis CAUM157, isolated from raw cow’s milk, is a Gram-positive, faculta-tively anaerobic, and non-spore-forming bacterium capable of inhabiting a wide range of environmental niches. E. faecalis CAUM157 was observed to produce a two-peptide bacteriocin that had a wide range of activity against several pathogens, including Listeria monocytogenes, Staphylococcus aureus, and periodontitis-causing bacteria. The whole genome of E. faecalis CAUM157 was sequenced using the PacBio RS II platform, revealing a genome size of 2,972,812 bp with a G+C ratio of 37.44%, assembled into two contigs. Annotation analysis revealed 2,830 coding sequences, 12 rRNAs, and 61 tRNAs. Further, in silico analysis of the genome identified a single bacteriocin gene cluster.