• 농업과학연구
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• 제26권1호
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• pp.31-38
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• 1999

한국인의 기호에 맞으며 약리적인 효능을 가지고 있는 인삼을 인삼 extract, 백삼분 및 미삼분의 형태로 요구르트 제조시에 첨가하고 제품의 산생성도, 유산균수, 점도, 관능검사 및 보존성 등을 시험한 결과는 다음과 같다. 1. 인삼 extract, 백삼분 및 미삼분을 첨가한 호상 요구르트의 시험제조 결과 산도는 무첨가구의 0.95%에 비하여 인삼첨가구 특히 미삼 첨가구가 1.13%로서 가장 높았다. 2. 유산균수에 있어서는 무첨가구의 $6.5{\times}10^8/ml$에 비하여 첨가구 특히 미삼첨가구가 $9.8{\times}10^8/ml$로서 가장 높았다. 3. 제품의 점성은 무첨가구에 비하여 첨가구 특히 백삼첨가구가 가장 높았다. 4. 제품의 관능검사 결과 맛과 향취에 있어서는 인삼첨가구가 우수하였고 조직에 있어서는 무첨가구가 우수하였으며 전체적인 기호도에 있어서는 미삼첨가구가 우수하였다. 5. 제품의 보존시험에 있어서는 $5^{\circ}C$, 10일간 보존에서 pH, 산도 및 유산균수의 변화가 크게 나타나지 않았다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.125-128
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• 2000

본 연구에서는 순환식 돈분 폐수 처리 시스템에서의 미생물 분포에 따른 폐수 처리 효과를 모델링하기 위해 신경회로망과 PCA를 이용하는 새로운 방법을 제안하였다. PCA 분석 결과를 바탕으로 신경회로망의 최적 입력 조건을 찾고, 실측 데이터를 이용하여, 폐수 처리 시스템의 각 탱크를 별도로 학습함으로써 비교적 적은 수의 데이터에도 불구하고 정확한 모델링 결과를 얻었다. 제안한 시스템은 폐수 처리 시스템의 효과적인모니터링 시스템으로 사용할 수 있으며, 향후 실제 돈분 처리 시스템에서 원하는 기준의 방류수를 얻기 위한 최적의 입력조건 (미생물밀도 등)을 결정하는데 있어서 에뮬레이터로 사용될 수 있을 것으로 기대된다.

• Journal of Microbiology and Biotechnology
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• 제30권10호
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• pp.1510-1515
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• 2020

Trimethylamine (TMA) is a well-known off-odor compound in fish and fishery products and is a metabolic product of trimethylamine N-oxide (TMAO) generated by the enzymatic action of microorganisms. The off-odor is a factor that can debase the value of fish and fishery products. The present study aimed to remove TMA using lactic acid bacteria (LAB). A total of fifteen isolates exhibiting the TMA reduction efficacy were isolated from Korean traditional fermented foods. Among these isolates, five LAB isolates (Lactobacillus plantarum SKD 1 and 4; Lactobacillus paraplantarum SKD 15; Pediococcus stilesii SKD 11; P. pentosaceus SKD 14) were selected based on their high TMA reduction efficacy. In situ reduction of TMA efficacy by the LAB cell-free supernatant was evaluated using a spoiled fish sample. The results showed effective TMA reduction by our selected strains: SKD1 (45%), SKD4 (62%), SKD11 (60%), SKD14 (59%), and SKD15 (52%), respectively. This is the first study on TMA reduction by the metabolic activity of LAB and in situ reduction of TMA using cell-free supernatant of LAB. The present finding suggests an economically useful and ecofriendly approach to the reduction of TMA.

• Asian-Australasian Journal of Animal Sciences
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• 제28권5호
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• pp.620-631
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• 2015

A total of 59 lactic acid bacteria (LAB) strains were isolated from corn stover silage. According to phenotypic and chemotaxonomic characteristics, 16S ribosomal DNA (rDNA) sequences and recA gene polymerase chain reaction amplification, these LAB isolates were identified as five species: Lactobacillus (L.) plantarum subsp. plantarum, Pediococcus pentosaceus, Enterococcus mundtii, Weissella cibaria and Leuconostoc pseudomesenteroides, respectively. Those strains were also screened for antimicrobial activity using a dual-culture agar plate assay. Based on excluding the effects of organic acids and hydrogen peroxide, two L. plantarum subsp. plantarum strains ZZU 203 and 204, which strongly inhibited Salmonella enterica ATCC $43971^T$, Micrococcus luteus ATCC $4698^T$ and Escherichia coli ATCC $11775^T$ were selected for further research on sensitivity of the antimicrobial substance to heat, pH and protease. Cell-free culture supernatants of the two strains exhibited strong heat stability (60 min at $100^{\circ}C$), but the antimicrobial activity was eliminated after treatment at $121^{\circ}C$ for 15 min. The antimicrobial substance remained active under acidic condition (pH 2.0 to 6.0), but became inactive under neutral and alkaline condition (pH 7.0 to 9.0). In addition, the antimicrobial activities of these two strains decreased remarkably after digestion by protease K. These results preliminarily suggest that the desirable antimicrobial activity of strains ZZU 203 and 204 is the result of the production of a bacteriocin-like substance, and these two strains with antimicrobial activity could be used as silage additives to inhibit proliferation of unwanted microorganism during ensiling and preserve nutrients of silage. The nature of the antimicrobial substances is being investigated in our laboratory.

• 한국축산식품학회지
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• 제37권4호
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• pp.561-570
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• 2017

This study examined the laxative effects of mulberry leaf extract (MLE) fermented by lactic acid bacteria (LAB), which contains high levels of polyphenolic and flavonoid compounds, against loperamide-induced constipation in rats. Sprague-Dawley rats were divided into a normal group (N) and three experimental groups; loperamide treated group (C), loperamide and LAB-fermented MLE 300 mg/kg treated group (MLEL), and loperamide and LAB-fermented MLE 600 mg/kg treated group (MLEH). After 33 d, fecal pellet amount, fecal weight, water content of fecal, gastrointestinal transit time and length, and serum lipid profiles were measured. Constipation was induced via subcutaneous injection of loperamide (2.0 mg/kg b. w., twice a day) for the final 5 d of the experiment. After loperamide administration, the LAB-fermented MLE groups showed a significantly increase in the fecal pellets number, wet weight, and water content in rats compared with the C group. Moreover, increases in the intestinal length and viable Lactobacillus numbers in the feces were observed in the LAB-fermented MLE groups. The intestinal transit time was shorter in the LAB-fermented MLE groups than in the C group. In addition, the LAB-fermented MLE groups showed a significant decrease in triglyceride and total cholesterol levels and an increase in HDL-cholesterol level. These results indicated that oral administration of LAB-fermented MLE shows laxative effect in loperamide-induced constipated rats.

• 한국식품과학회지
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• 제43권4호
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• pp.446-452
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• 2011

항균활성을 나타내는 야생형 유산균을 분리 동정하기 위하여 김치에서 480종의 유산균을 분리하였으며, S. enterica serovar Typhimurium, P. aeruginosa, B. subtilis에 대한 항균활성을 agar diffusion 법을 사용하여 검사하였다. 이들 중 항균활성을 나타내는 균주 340종에 대하여 multiplex PCR과 API 50CHL Kit을 이용한 생화학적 특성검사 및 16S rDNA sequencing을 통해 Lb. plantarum 169균주, Lb. fermentum 20균주, Lb. paracasei spp. paracasei 2균주, Lactobacillus 속 2균주와 Pediococcus 속 15균주를 동정하였다. 이들 균주 중 Lb. fermentum의 경우는 프로바이오틱스로서의 활성이 보고되고 있는 균으로 추가적인 연구가 필요하다고 사료된다.

• Journal of Applied Biological Chemistry
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• 제55권2호
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• pp.135-140
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• 2012

양식의 성공으로 생산되는 다량의 홍해삼의 이용도를 다양화하기 위해 홍해삼 김치를 개발 연구하였다. 김치 숙성 정도의 지표인 총산도와 pH는 7일째 까지 감소현상이 심하였으나, 숙성후기에는 pH의 변화가 느려지고, 적정 pH인 4-4.5에 머물렀다. 환원당 함량은 초기에 다소 높게 나타났다가 저장기간 동안 지속적인 감소를 보였다. 생홍해삼을 넣은 김치와 삶은 홍해삼을 넣은 김치의 발효과정에 따른 유산균 변화는 저장초기에 급속히 증가하였고 삶은 해삼보다는 생해삼에서 더 많은 유산균 발육을 확인 할 수 있었다. 생해삼과 삶은 해삼 그리고 젓갈이 홍해삼 김치의 기호도에 미치는 영향을 측정한 결과 해삼을 첨가한 김치는 일반 김치에 비하여 색, 향, 질감, 맛, 뒷맛, 기호도 모두 뒤떨어짐이 없었다.

• Journal of Microbiology and Biotechnology
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• 제33권4호
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• pp.500-510
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• 2023

In this study, lactic acid bacteria were isolated from 21 top-selling probiotic products on Korean market and their antimicrobial resistance were analyzed. A total 152 strains were claimed to be contained in these products and 70 isolates belonging to three genera (Bifidobacterium, Lactobacillus, and Lactococcus) were obtained from these products. RAPD-PCR showed diversity among isolates of the same species except for two isolates of Lacticaibacillus rhamnosus from two different products. The agar dilution method and the broth dilution method produced different MICs for several antimicrobials. With the agar dilution method, five isolates (three isolates of Bifidobacterium animalis subsp. lactis, one isolate of B. breve, one isolate of B. longum) were susceptible to all nine antimicrobials and 15 isolates were multi-drug resistant. With the broth microdilution method, only two isolates (one isolate of B. breve and one isolate of B. longum) were susceptible while 16 isolates were multi-drug resistant. In this study, only two AMR genes were detected: 1) lnu(A) in one isolate of clindamycin-susceptible and lincomycin-resistant Limosilactobacillus reuteri; and 2) tet(W) in one tetracycline-susceptible isolate of B. longum B1-1 and two tetracycline-susceptible isolates and three tetracycline resistant isolates of B. animalis subsp. lactis. Transfer of these two genes via conjugation with a filter mating technique was not observed. These results suggest a need to monitor antimicrobial resistance in newly registered probiotics as well as probiotics with a long history of use.

• 한국미생물·생명공학회지
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• 제51권2호
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• pp.157-166
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• 2023

Three lactic acid bacteria (LAB) producing exopolysaccharides (EPSs) were isolated from Pa (green onion)-kimchi, and identified as Weissella confusa (SKP 173), Weissella cibaria (SKP 182), and Leuconostoc citreum (SKP 281), respectively by 16S rRNA gene sequencing. The yields of EPS were 21.27, 18.53, and 15.4 g/l for EPS from SKP 173, 182, and 281, respectively when grown in MRS broth containing sucrose (5%, w/v). Total sugar contents were 64.39, 62.84, and 65.16% (w/w) for EPS from SKP 173, 182, and 281, respectively while the protein contents were 0.33, 0.31, and 0.25% (w/w), respectively. EPSs from W. confusa SKP 173 and W. cibaria SKP 182 contained glucose only but EPS from L. citreum SKP 281 contained glucose and glucitol. Viscosities of the 2% (w/w) freeze-dried EPS solution were 9.60, 8.00, and 8.20 centipoise (cP) for EPS from SKP 173, 182, and 281, respectively. Viscosities of culture grown in MRS broth with 5% sucrose (no glucose) were 92.98, 57.19, and 18.8 cP, respectively. The average molecular weights of EPSs were larger than 2 × 10⁷ Da. Fourier transform infrared spectroscopy (FT-IR) analyses of EPSs showed typical carbohydrate peaks, suggesting that the EPSs consisted of pyranose saccharides with α-(1,6) and α-(1,3) glycosidic linkages. L. citreim SKP 281 was used as the starter for yogurt fermentation, and EPS production was confirmed.

• 한국식품과학회지
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• 제36권2호
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• pp.365-367
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• 2004

절임 배추의 저장 기간을 연장하기 위하여 배추를 절인 다음 전해산화수로 세척하고 저장하면서 품질 특성의 변화를 측정한 결과는 다음과 같았다. 즉 절임 배추를 전해산화수로 세척한 처리구가 대조구보다 낮은 pH를 보였으며, 저장 8일까지는 대조구에 비하여 낮은 pH를 나타내었다. 적정산도는 저장기간 동안 0.11-0.15%로 큰 변화를 나타내지 않았으며, 대도구와 처리구간에도 큰 차이가 없었다. 절임 배추를 전해산화수로 세척한 직후에는 대조구에 비하여 총균수가 $10^3\;CFU/mL$ 정도 낮았으나 처리구의 총균수는 저장 6일에 대조구와 비슷하였다. 유산균수도 세척 직후에는 처리구가 대조구보다 낮았으며, 저장 4일에는 대조구와 처리구의 차이가 가장 현저하였다. 저장 2일까지는 국물의 밝은 정도(L)에 있어서 대조구와 처리구간에 차이가 없었으나 그 이후에는 처리구가 대조구보다 높은 값을 나타내었다.