• Animal Bioscience
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• 제36권8호
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• pp.1209-1220
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• 2023

Objective: The use of probiotics as an alternative to antibiotics in animal feed has received considerable attention in recent decades. Lactic acid bacteria (LAB) have remarkable functional properties promoting host health and are major microorganisms for probiotic purposes. The aim of this study was to characterize LAB strains of the chicken digestive tract and to determine their functional properties for further use as potential probiotics in poultry. Methods: A total of 2,000 colonies were isolated from the ileum and cecal contents of the chickens based on their phenotypic profiles and followed by a preliminary detection for acid and bile tolerance. The selected 200 LAB isolates with exhibited well-tolerance in acid and bile conditions were then identified by sequencing the 16S rDNA gene, followed by acid and bile tolerance, antimicrobial activity, adhesion to epithelial cells and additional characteristics on the removal of cholesterol. Then, the two probiotic strains (L. ingluviei and L. salivarious) which showed the greatest advantage in vitro testing were selected to assess their efficacy in broiler chickens. Results: It was found that 200 LAB isolates that complied with all measurement criteria belonged to five strains, including L. acidophilus (63 colonies), L. ingluviei (2 colonies), L. reuteri (58 colonies), L. salivarius (72 colonies), and L. saerimneri (5 colonies). We found that the L. ingluviei and L. salivarius can increase the population of LAB and Bifidobacterium spp. while reducing Enterobacteria spp. and Escherichia coli in the cecal content of chickens. Additionally, increased concentrations of valeric acid and short chain fatty acids were also observed. Conclusion: This study indicates that all five Lactobacillus strains isolated from gut contents of chickens are safe and possess probiotic properties, especially L. ingluviei and L. salivarius. Future studies should evaluate the potential for growth improvement in broilers.

• 한국미생물·생명공학회지
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• 제44권2호
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• pp.201-207
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• 2016

건강한 닭의 맹장에서 분리한 Lactobacillus sakei LAB 2와 LAB 8의 생균제로 이용을 알아보기 위해 기본적인 특성과 면역활성을 시험하였다. LAB 2와 LAB 8은 높은 내산성과 내담즙성을 가지고 있으며, 1차 대사산물인 유기산에 기인한 항균활성을 보였다. Salmonella 종을 병원성균으로 이용하여 최대 항균력을 나타내는 시간을 시험한 결과 48시간으로 나타났으며, 생성된 유기산 중 젖산의 생산량은 다른 Lactobacillus 균주보다 높게 조사되었다. In vitro 모델로 알아본 면역증진효과는 면역관련 세포의 증식과 사이토카인의 생산량 증가로 확인하였다. 이에 Lactobacillus sakei LAB 2와 LAB 8은 유용한 생균제로 개발할 수 있는 균으로 생각된다.

• Journal of Microbiology and Biotechnology
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• 제32권1호
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• pp.64-71
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• 2022

The discarding of wastes into the environment is a significant problem for many communities. Still, food waste can be used for lactic acid bacteria (LAB) growth. Here, we evaluated three growth media equivalent to de Mann Rogosa Sharpe (MRS), using apple bagasse, yeast waste, fish flour, forage oats, and cheese whey. Cell-free supernatants of eight LAB strains were tested for antimicrobial activity against nine indicator microorganisms. The supernatants were also evaluated for protein content, reducing sugars, pH, and lactic acid concentration. Cell-free supernatants from fish flour broth (FFB) LAB growth were the most effective. The strain Leuconostoc mesenteroides PIM5 presented the best activity in all media. L. mesenteroides CAL14 completely inhibited L. monocytogenes and strongly inhibited Bacillus cereus (91.1%). The strain L. mesenteroides PIM5 consumed more proteins (77.42%) and reducing sugars (56.08%) in FFB than in MRS broth (51.78% and 30.58%, respectively). Culture media formulated with agroindustrial wastes positively improved the antimicrobial activity of selected LAB, probably due to the production of antimicrobial peptides or bacteriocins.

• Toxicological Research
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• 제29권2호
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• pp.99-106
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• 2013

Clostridium difficile infection (CDI) has become a significant threat to public health. Although broad-spectrum antibiotic therapy is the primary treatment option for CDI, its use has evident limitations. Probiotics have been proved to be effective in the treatment of CDI and are a promising therapeutic option for CDI. In this study, 4 strains of lactic acid bacteria (LAB), namely, Lactobacillus rhamnosus (LR5), Lactococcuslactis (SL3), Bifidobacterium breve (BR3), and Bifidobacterium lactis (BL3) were evaluated for their anti-C. difficile activity. Co-culture incubation of C. difficile ($10^6$ and $10^{10}$ CFU/ml) with each strain of LAB indicated that SL3 possessed the highest antimicrobial activity over a 24-hr period. The cell-free supernatants of the 4 LAB strains exhibited $MIC_{50}$ values between 0.424 mg/ml (SL3) and 1.318 (BR3) mg/ml. These results may provide a basis for alternative therapies for the treatment of C. difficile-associated gut disorders.

• Journal of Dairy Science and Biotechnology
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• 제37권2호
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• pp.83-93
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• 2019

Food spoilage by fungi is responsible for considerable food waste and economical losses. Among the food products, fermented dairy products are susceptible to deterioration due to the growth of fungi, which are resistant to low pH and can proliferate at low storage temperatures. For controlling fungal growth in dairy products, potassium sorbate and natamycin are the main preservatives used, and natamycin is approved by most countries for use in cheese surface treatment. However, a strong societal demand for less processed and preservative-free food has emerged. In the dairy products, lactic acid bacteria (LAB) are naturally present or used as cultures and play a key role in the fermentation process. Fermentation is a natural preservation technique that improves food safety, nutritional value, and specific organoleptic features. Production of organic acids is one of the main features of the LAB used for outcompeting organisms that cause spoilage, although other mechanisms such as antifungal peptides obtained from the cleavage of food proteins and competition for nutrients also play a role. More studies for better understanding these mechanisms are required to increase antifungal LAB available in the market.

• Journal of Microbiology and Biotechnology
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• 제26권6호
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• pp.1035-1045
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• 2016

To evaluate the effects of lactic acid bacteria (LAB) on Peyer's patch cells, mice were treated with a high dose of kanamycin to disturb the gut microbial environment. The overarching goal was to explore the potential of LAB for use as a dietary probiotic that buffers the negative consequences of antibiotic treatment. In vitro, LAB stimulated the production of immunoglobulin A (IgA) from isolated Peyer's patch cells. Inflammation-related genes (TNF-α, IL-1β, and IL-8) were up-regulated in Caco-2 cells stimulated with lipopolysaccharide (LPS), while tight-junction-related genes (ZO-1 and occludin) were down-regulated; the effects of LPS on inflammatory gene and tight-junction gene expression were reversed by treatment with LAB. Mice treated with a high dose of kanamycin showed increased serum IgE levels and decreases in serum IgA and fecal IgA levels; the number of Peyer's patch cells decreased with kanamycin treatment. However, subsequent LAB treatment was effective in reducing the serum IgE level and recovering the serum IgA and fecal IgA levels, as well as the number of Peyer's patch cells. In addition, ZO-1 and occludin mRNA levels were up-regulated in the ileum tissues of mice receiving LAB treatment. Lactic acid bacteria can enhance the intestinal immune system by improving the integrity of the intestinal barrier and increasing the production of IgA in Peyer's patches. Lactic acid bacteria should be considered a potential probiotic candidate for improving intestinal immunity, particularly in mitigating the negative consequences of antibiotic use.

• Food Science and Biotechnology
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• 제16권6호
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• pp.994-998
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• 2007

Changes in microflora, pH, reducing sugar content, lactic acid content, and ethanol content during Korean rice wine fermentation were investigated. Typical quality characteristics of Korean rice wine fermentation including pH, reducing sugar content, lactic acid content, and ethanol content were evaluated. While a fungus was not detected in our Korean rice wine mash, yeast was found to be present at fairly high quantities (1.44-4.76\;{$\times}\;10^8\;CFU/mL$) throughout the fermentation period. It is assumed that lactic acid bacteria (LAB) had effects on the variations of fragrance and flavor for traditional Korean rice wine. The main LAB during the Korean rice wine fermentation was determined and identified as a Gram-positive, straight rod-shaped cell. Genotypic identification of the isolated strain by amplification of its 16S rRNA sequence revealed that the isolated strain was most closely related to Lactobacillus plantarum (99%) strains without any other comparable Lactobacillus strains. Therefore, we designated the major LAB identified from traditional Korean rice wine fermentation as L. plantarum RW.

• 한국식생활문화학회지
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• 제34권2호
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• pp.142-158
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• 2019

Kimchi is a traditional Korean fermented vegetable probiotic food. The use of high quality ingredients and predominant LAB (lactic acid bacteria)-whether it be ambient bacteria or adding starters, low temperature and facultative anaerobic condition for the fermentation are important factors for preparing kimchi with better taste and functionality. The predominated LAB genera are Leuconostoc, Lactobacillus, and Weissella in kimchi fermentation. The representative species are Leu. mesenteroides, Leu. citrium, Lab. plantarum, Lab. sakei, and Wei. koreensis. Kimchi, especially the optimally fermented kimchi, has various health benefits, including control of colon health, antioxidation, antiaging effects, cancer preventive effect, antiobesity, control of dyslipidemic and metabolic syndrome, etc.; due to the presence of LAB, various nutraceuticals, and metabolites from the ingredients and LAB. The kimchi LAB are good probiotics, exhibiting antimicrobial activity, antioxidant, antimutagenic and anticancer effects, as well as immunomodualatory effect, antiobesity, and cholesterol and lipid lowering effects. Thus, kimchi ingredients, LAB, fermentation methods, and metabolites are important factors that modulate various functionalities. In this review, we introduced recent information showing kimchi and its health benefits in Korean Functional Foods (Park & Ju 2018).

• 한국식품과학회지
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• 제49권4호
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• pp.377-382
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• 2017

본 연구에서는 한국 전통식품인 김치에서 분리된 LAB를 이용하여 콜레스테롤 감소능을 가지고 있는 LAB를 분리하고 그 특성을 규명하였다. 23 종의 분리 LAB 중에서 L. plantarum FMB 31 균주가 99.4%의 높은 콜레스테롤 감소 활성을 나타내었고, 프로바이오틱스로서 활용하기 위한 중요한 특성인 내담즙성, 내산성 그리고 내염성 등이 대조구로 사용된 L. rhamnosus KCTC 5033 균주보다 우수하거나 동등하였다. 또한 L. plantarum FMB 31 균주는 인체 안전성과 관련된 용혈독성 및 생체아민 생성능 실험에서도 안전성에 문제가 없는 것으로 분석되었다. 향후, 이 분리균은 콜레스테롤 저하 기능을 가지는 다양한 건강 기능 식품 개발에 이용될 수 있을 것으로 기대된다.

• Journal of Applied Biological Chemistry
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• 제63권4호
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• pp.375-385
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• 2020

본 연구의 목적은 발효 기간 동안 멸치 액젓과 새우젓으로 담근 배추 김치로부터 분리 동정된 바이오제닉 아민(biogenic amines, BA) 생성 유산균 단독 스타터 혹은 BA 분해 유산균과의 혼합 스타터로 제조한 김치의 품질 특성을 조사하고자 하였다. 발효가 진행될수록 새우젓 보다 멸치 액젓을 첨가하여 제조한 김치에서 유산균수, 산도 및 BA 함량이 높게 나타났다. 유산균이 생산하는 BA의 종류 및 생성량은 균종 보다는 균주에 의존적이었다. 분리 균주 중에서 가장 많은 양의 카다베린, 히스타민, 푸트레신 및 티라민은 각각 Leuconostoc mesenteroides MBK32, Lactobacillus brevis MBK34, Lactobacillus curvatus MBK31 및 Enterococcus faecalis SBK31로부터 생산되었다. BA 생성능과 분해능이 있는 스타터는 김치 내 유산균의 증식 속도와 산 생성능에 중요한 역할을 하였다. BA 생성균 단독 스타터에 의해 증가된 김치의 BA 함량은 BA 분해균과의 혼합 스타터에 의해 효과적으로 감소되었다.