• 한국미생물·생명공학회지
• /
• 제23권1호
• /
• pp.6-11
• /
• 1995

In order to screen microorganism producing lactic acid with high productivity from nature, we used a medium containing 100 g/l glucose and selected several microorganisms producing more than 80 g/l L-lactic acid. We investigated their physiological characteristics and compared them. The best microorganism was identified as Lactobacillus casei subsp. rhamnosus. The optimum pH for growth and production of lactic acid was 6.0 and this strain showed the highest growth rate at around 30$\circ$C , but the optimum temperature for lactic acid production was 45$\circ$C . The growth was inhibited proportionally from 50 g/l to 300 g/l of glucose and the maximal cell mass increased according to increasing the concentration of corn steep liquor (CSL) protein up to 30 g/l. In batch fermentation for lactic acid production, we produced 128 g/l L-lactic acid with 20 g/l CSL protein and 150 g/l glucose in 35 hours. In pH-stat fed-batch fermentation, we were able to produce 183 g/l L-lactic acid.

• 한국미생물·생명공학회지
• /
• 제17권6호
• /
• pp.533-538
• /
• 1989

S. uvarum KFCC 32021의 발효여액은 10% 농도에서 L. acidophilus KFCC 12731의 산생성 및 생육을 촉진하였으나 촉진작용은 10$0^{\circ}C$에서 10분간의 열처리에 의해 실활되었다. 또한 이 여액은 두유의 sucrose, raffinose 및 stachyose 등의 과당류를 분해하여 단당류의 함량을 증가시켰다. L. acidophilus KFCC 12731의 24시간 단독배양에서 두유의 단당류는 전량 소비되었으나 과당류는 거의 선량 잔존하였다. S. uvarum KFCC 32021의 단독배양에서는 단당류, sucrose 및 vaffinose는 완전 소비되었고, stachyose는 일부 잔존되고 manninotriose가 축적되었다. 혼합발효에서의 당소비유형은 S. uvarum의 단독배양에서와 유사하였다. 이상의 결과로 혼합배양에서 S. uvarum KFCC 32021은 두유의 과당류를 L. acidophilus KFCC 12731이 이용할 수 있는 단당류로 분해시켜 줌으로써 발효액의 산생성을 촉진시키는 것으로 보인다.

• 한국식품저장유통학회지
• /
• 제5권1호
• /
• pp.81-87
• /
• 1998

Antimicrobial activities of the extracts from spices microorganisms related to kimchi fermentation were investigated. 32 kinds of spices such as allspice, mount, basil, bay leaves, caraway, cardamon, celery, chilli powder, chives, cinnamon, clover, coriander, cumin, dill, fennel, garlic, horseradish, marjorarm, mugwort, mustard, nutmeg, onion, oregano, paprika, parsely, pepper, peppermint, rosemary, sage, tarragon, thyme and tumeric were extracted with water, ethyl ether, ethyl acetate and ethanol. Fractions were tested for antimicrobial activities against Lactobacillus plantarum and Leuconostoc mesenteroides, The extracts of 28 kinds of spices except caraway, cardamon, paprika and tarragon by water extraction, those of 29 kinds except arrowroot, paprika and tarragon by ethyl ether extraction, those of 30 kinds except paprika and tarragon by ethyl acetate extraction, and those of 29 kinds except clover, paprika and tarragon by ethanol extraction showed strong antimicrobial activities against Lactobacillus plantarum. On the other hand, the extracts of 28 kinds of spices except caraway, cardamon, paprika and thyme by water extraction, those of 27 kinds except cardamon, cumin, paprika, tarragon and thyme by ethyl ether extraction, thou of 30 kinds except paprika and thyme by ethyl acetate extraction, and those of 28 kinds except cardamon, cumin, paprika and thyme by ethanol extraction showed strong antimicrobial activities against Leuconostoc mesenteroides.

• Journal of Microbiology and Biotechnology
• /
• 제25권1호
• /
• pp.26-32
• /
• 2015

Four types of straw, namely, soybean, wheat, corn, and rice, were investigated for use in lactic acid production. These straws were mainly composed of cellulose, hemicellulose, and lignin. After pretreatment with ammonia, the cellulose content increased, whereas the hemicellulose and lignin contents decreased. Analytical results also showed that the liquid enzymatic hydrolysates were primarily composed of glucose, xylose, and cellobiose. Preliminary experiments showed that a higher lactic acid concentration could be obtained from the wheat and soybean straw. However, soybean straw was chosen as the substrate for lactic acid production owing to its high protein content. The maximum lactic acid yield (0.8 g/g) and lactic acid productivity (0.61 g/(l/h)) were obtained with an initial reducing sugar concentration of 35 g/l at 30℃ when using Lactobacillus casei (10% inoculum) for a 42 h fermentation period. Thus, the experimental results demonstrated the feasibility of using a soybean straw enzymatic hydrolysate as a substrate for lactic acid production.

• 한국식생활문화학회지
• /
• 제26권2호
• /
• pp.190-197
• /
• 2011

Chungtaejeon is a traditional tea introduced in the age of the Three States and is the only "Don-cha" culture in the world that survived on the southwestern shore of Korea. To restore Chungtaejeon and to make the tea with consistent quality, the microorganisms involved in traditional type fermentation of Chungtaejeon were isolated, and the tea was prepared with high fermentation ability starters. The sensuous characteristics of Chungtaejeon were also examined. Only Bacilli were found in 3 and 5 year aged Chungtaejeon samples. The Lactobacilli were isolated from properly fermented kimchi and one of them showed high growth capability in media containing green tea extract and also showed strong antagonistic activity against methicillin-resistant Staphylococcus aureus, S. aureus, Salmonella, and E. coli. It was identified and named Lactobacillus plantarum CHO25. Chungtaejeon was fermented with a single starter of L. plantarum CHO25 and with a mixed starter (L. plantarum CHO25, Saccharomyces cerevisiae and Bacillus amyloliquefaciens CHO104). The single fermented sample had the highest cell growth after 5 days of inoculation and the level decreased slowly thereafter. The mixed fermented sample showed strong growth of S. cerevisiae. The highest hunter values were the a value of the single fermented sample and the b value of the mixed sample. The single fermented tea showed the best incense score.

• 한국미생물·생명공학회지
• /
• 제23권4호
• /
• pp.461-471
• /
• 1995

The heterofermentative Leuconostoc mesenteroides, which is propagated from the initial to the intermediate stage of Kimchi fermentation, produces organic acids and carbon dioxide to impart refreshment, weak acid taste to Kimchi. But owing to lactic acid production by the homofermentative Lactobacillus Plantarum, Kimchi finally reaches its acidified state. So, Leu. mesenteroides was isolated from Kimchi and identified and was improved by mutation for carbon dioxide production at low pH, and for the high total acceptability. We tested with a wild-type strain K-1 and its improved mutant strain M-10 of Leu. mesenteroides. The wild-type strain K-1 could grow in pH 4.2 at 30$\circ$C or 20$\circ$C, and in pH 5.0 at 10$\circ$C. But the mutant strain M-10 could grow in pH 3.3 at 10$\circ$C. In the respect of total acceptability, mutant strain M-10 inoculated Kimchi was ever better than any others. Mutant M-10 inoculated Kimchi prolonged the optimum ripening period of Kimchi up to two times as compared with the control group.

• Preventive Nutrition and Food Science
• /
• 제9권3호
• /
• pp.206-212
• /
• 2004

Prickly pear extract (PPE) was fermented by Lactobacillus rhamnosus LS at 3$0^{\circ}C$ for 2 days. To improve the physicochemical properties of fermented PPE, it was fortified with food polysaccharides (0.2 %) or seaweed calcium before lactic acid fermentation. The viable cell counts, flow behavior, titratable acidity and color stability of fermented PPE were evaluated during 4 weeks of cold storage. Addition of xanthan gum or glucomannan increased the apparent viscosity and acid production, viable cell counts and red color of PPE were also well maintained during the cold storage. However, fermenting PPE with gellan gum resulted in a decrease in relative absorbance, indicating lower color stability. In particular, PPE fortified with carrageenan or alginic acid showed reduced acid production and lower viable cell counts. Addition of seaweed calcium at a 0.1 % level had positive effects on color stability, and helped maintain viable cell counts of 4.1 ${\times}$ 10$^{9}$ CFU/mL. This study demonstrated that xanthan gum could be used as a good thickening agent and stabilizer for retaining viable cell counts and red color during the cold storage in PPE fermented by lactic acid bacteria.

• Quantitative Bio-Science
• /
• 제37권2호
• /
• pp.125-132
• /
• 2018

In this study, noble strains of lactic acid bacteria were isolated and identified by genetic analysis of 16s rRNA. Also, pH-dependent growth curve, cholesterol assimilation ability and sugar production efficiency were measured. Lactic acid bacteria were identified to inhabit in the milks from various animals. Results of sequence analysis showed that there were differences in 16S rRNA sequence among strains and part of gene deletion was also recognized. Growth rates were varied, too, depending on the pH of the medium. Lactobacillus rhamnosus LOCK908 isolated from cow milk showed the highest growth rate and high cholesterol assimilation ability. Results of sugar fermentation tests were relatively consistent with the sequencing results. So, we propose newly isolated Lactobacillus rhamnosus LOCK908 as useful candidate for a starter of fermented beverage and probiotics. Results of this study will contribute to the isolation and identification of noble Lactic acid bacteria and to the public health.

• 한국식품과학회지
• /
• 제32권4호
• /
• pp.889-895
• /
• 2000

자일로스와 자일리톨을 첨가하여 제조한 김치 발효시 pH, 적정산도 등의 이화학적 특성과 젖산 및 유기산의 함량을 측정하였으며, 김치에서 분리된 미생물의 당 이용도와 자일로스와 자일리톨를 첨가한 배지에서의 젖산균수를 측정하였다. 김치 미생물의 당 이용도를 보면 김치에서 분리한 젖산균 6종류 중 자일로스의 경우는 5균주가, 자일리톨의 경우에는 6균주 모두를 이용하지 못하는 것으로 볼 때 발효성 당이 아닌 자일로스와 당알코올인 자일리톨의 첨가가 김치의 숙성을 억제시켜 저장성을 향상시킬 수 있었다. 자일로스와 자일리톨을 첨가하여 제조한 김치의 pH는 시료간의 큰 차이는 없었으나, 자일리톨 첨가구의 경우가 다른 시료보다 높게 나타났으며, 적정산도의 경우는 자일로스와 자일리톨 첨가구의 경우가 다른 실험구보다 낮게 나타난 것으로 보아 산 생성속도를 억제시켜 가식기간을 연장시킬 수 있었다. 유기산의 측정 결과를 보면 자일로스와 자일리톨을 첨가한 실험구의 경우 설탕을 첨가한 실험구보다 젖산과 다른 유기산의 생성이 느리게 나타나는 것을 볼 수 있었으며, 당류를 첨가하지 않은 대조구와는 거의 비슷하거나 다소 생성이 저해되었다. 따라서 김치 제조 시 자일로스와 자일리톨을 첨가하면 발효 미생물 등의 성장을 억제하여 김치의 저장기간 동안 숙성을 억제함으로써 유통기간을 연장시켜 김치의 가식기간을 연장시킬 수 있다.

• 한국식품저장유통학회지
• /
• 제23권3호
• /
• pp.326-334
• /
• 2016

오미자 열매를 이용하여 기능성물질인 GABA를 강화시킨 오미자 젖산발효음료를 개발하기 위해서 L. plantarum EJ2014에 의한 젖산발효 최적화를 수행하였다. 오미자 열매 추출액을 젖산 발효시킨 경우 발효 2일 동안 생균수 $4.0{\times}10^7CFU/mL$수준을 유지하면서 젖산균 증식이 미비하였지만 영양성분 YE와 MSG를 함께 첨가한 경우 50배 정도 증가된 $2.2{\times}10^9CFU/mL$생균수를 나타내었다. 특히 젖산발효 3일 동안에 대조군, MSG, YE를 각각 첨가군에서 초기 pH 3-4 수준에서 유지되었다. 반면에 YE와 MSG를 함께 첨가한 발효물은 pH가 증가되면서 pH 5.0 이상을 나타내었으며, 초기 산도 1.74%에서 발효 3일에 0.56% 수준으로 감소하였다. 오미자 열매 추출물인 대조군과 2% MSG 또는 0.5% YE만을 첨가한 조건에서는 GABA로 소량 전환되는 것으로 나타났다. 반면에 MSG와 YE를 함께 첨가한 경우 젖산발효 1일째부터 GABA가 생성되면서 3일째에는 MSG 2%를 거의 소진하는 것으로 나타났으며, HPLC 정량분석으로 0.92% GABA 생성이 확인되었다. MSG와 YE함께 첨가한 발효조건에서는 젖산발효 1일째부터 발효물은 붉은 색이 퇴색되면서 황색으로 변화하였으며, 발효 초기에 적색을 나타내는 a값이 15.74에서 발효 후에 5.39로 크게 감소하는 것으로 나타났다. 색, 맛, 향 등을 포함한 전반적인 기호도를 나타낸 관능평가에서 오미자 착즙 원액과 발효물 100%인 실험군에서 점수가 각각 4.50, 4.33을 기록하여 상대적으로 낮은 기호도를 나타낸 반면에 발효물 50% 첨가한 실험군이 6.33으로 가장 높은 기호도 점수를 나타내었다. 오미자 열매 추출액에 오미자 발효물을 50% 첨가함으로서 기호성이 우수하며 고농도 GABA와 probiotic을 함유한 오미자 발효음료의 제조가 가능하였다.