• Biotechnology and Bioprocess Engineering:BBE
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• 제11권4호
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• pp.313-318
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• 2006

A two-stage process of nanofiltration and water-splitting electrodialysis was investigated for lactic acid recovery from fermentation broth. In this process, sodium lactate is isolated from fermentation broth in the first stage of nanofiltration by using an NTR-729HF membrane, and then is converted to lactic acid in the second stage by water-splitting electrodialysis. To determine the optimal operating conditions for nanofiltration, the effects of pressure, lactate concentration, pH, and known added impurities were studied. Lactate rejection was less than 5%, magnesium rejection approximated 45%, and calcium rejection was at 40%. In subsequent water-splitting electrodialysis, both the sodium lactate conversion to lactic acid and sodium hydroxide recovery, were about 95%, with a power requirement of $0.9{\sim}1.0\; kWh$ per kg of lactate.

• KSBB Journal
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• 제18권1호
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• pp.14-18
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• 2003

본 연구에서는 제지 슬러지를 이용한 SSF 공정에 L..paracasei KLB58을 적용하여 젖산과 더불어 생균제용 균체를 경제적으로 대량 생산하고자 하였다. KLB58의 배양온도와 섬유소 가수분해 효소인 $\beta$-glucosidase의 농도를 조절하여 최적의 생산 조건을 확인해 본 결과, 37$^{\circ}C$ 에서 2 unit/ml의 $\beta$-glucosidase를 첨가하여 배양하였을 때 최대의 젖산과 균체를 생산하였다. 또한 $\beta$-glucosidase를 포함하지 않아도 상대적으로 많은 양의 젖산과 균체를 생산하였으므로, 이에 대한향후 연구가 기대된다.

• 한국초지조사료학회지
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• 제39권3호
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• pp.127-131
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• 2019

The effects of lactic acid bacteria (LAB) mixtures on low moisture Italian ryegrass (IRG) silage fermentation was evaluated in field conditions. The experiment was categorized into two groups: Un-inoculated (Control) and Inoculated with LAB mixture for four storage periods (45, 90, 180, and 365 days, respectively). Silage inoculated with the LAB mixture had the lowest pH with highest lactic acid production than the control from beginning at 45-365 days at all moistures. Higher LAB counts were observed in inoculated silages than the control silages at whole experimental periods. It is a key reason for the rapid acidification and higher lactic acid production in silages during the storage periods. Overall results suggest that an adding of LAB mixture had positive effects on the increasing aerobic stability of silage and preserved its quality for an extended duration.

• 한국미생물·생명공학회지
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• 제23권1호
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• pp.6-11
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• 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.

• 한방비만학회지
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• 제16권1호
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• pp.11-18
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• 2016

Objectives: To confirm microbiological change and cytoprotective effect of Samjung-hwan (SJH) which fermented by Lactic acid bacteria from natural fermented SJH. Methods: SJH was fermented by Lactobacillus brevis and Lactococcus lactis subsp. lactis from natural fermented SJH. After 1 week of fermentation, we analysed pH and microbial profiling. We also performed measuring total polyphenol total flavonoid contents and 1,1-Diphenyl-2-picryhydrazyl (DPPH) free radical scavenging activity to investigate antioxidant ability. Cell viability was performed by using HepG2 cell. Results: pH of lactic acid bacteria inoculated group and non-inoculated group was decreased and total counts of lactic acid bateria for both group was increased after fermentation of SJH. Total polyphenol and flavonoid contents and DPPH free radical scavenging activity was increased in both group. Total polyphenol contents of lactic acid bacteria Inoculated group is more increased than non-inoculated group. HepG2 cell viability was increased in both group. Conclusions: SJH fermentd by Lactobacillus brevis and Lactococcus lactis subsp. lactis shows change in microbiological character and has cytoprotective effect. Further studies are required for investigating function of lactic acid bacteria during fermentation of SJH.

• KSBB Journal
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• 제21권3호
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• pp.199-203
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• 2006

본 연구에서는 에탄올 농도에 따른 모델용액과 발효액에서 여러 유기산들의 침전거동을 조사하였다. 발효액에서 에탄올의 농도가 높을수록 Ca(LA)2의 침전양이 많았다. Ca(LA)2의 침전효과는 발효액 내에서도 비슷하게 관찰되었다. 모델용액이나 발효액과의 혼합물 대비 30%(v/v)로 에탄올을 첨가하였을 때 젖산분리 공정의 불순물로 존재하는 다른 organic salt들의 침전율도 높았다. 따라서 전체 젖산회수공정의 효율에 대한 연구에서는 에탄올과 발효액의 혼합비율을 20%로 하였다. 반응증류시 일정 온도 이상에서는 젖산회수율이 차이나지 않았다. 에탄올이 첨가된 발효액에서는 대조군과 비교하여 최종젖산 회수율이 38.9% 증가하였다. 또한, 다른 유기산들을 포함한 회수액에서의 순도도 99.7%에 달하였다. 이러한 젖산 회수율의 증가는 owning-out crystallization에 의한 Ca(LA)2의 용해도 감소에 기인한 것으로 판단한다. 본 실험 이후에 더 높은 젖산 회수와 정제 효율을 얻기 위해서는 에탄올의 첨가에 따른 유기산의 거동과, 반응증류에서 사용되는 triethylamine의 양과 반응시간에 대한 검토가 필요할 것으로 사료된다.

• 한국한의학연구원논문집
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• 제17권3호
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• pp.115-121
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• 2011

Objective : The purpose of this study was to investigate the changes in the contents of constituents in Socheongryong-tang (CY) and its fermentations (FCY) with 10 species of lactic acid bacteria. Methods : Ten strains of lactic acid bacteria, Lactobacillus casei 127, L. acidophilus 128, L. casei 129, L. plantarum 144, L. amylophilus 161, L. curvatus 166, L. delbruekil subsp. lactis 442, L. casei 693, B. breve 744, and B. thermophilum 748, were used for the fermentation of Socheongryong-tang. The increased and decreased constituents were identified using HPLC/DAD and various liquid chromatographic techniques, and the structure was elucidated using NMR and MS. These compounds were quantitatively analyzed using an HPLC/DAD system. Results : The increased constituents were identified to be liquiritigenin (1) and cinnamyl alcohol (2), and the decreased constituent was determined to be liquiritin (3). Liquiritigenin (1) and cinnamyl alcohol (2) were increased in all of the FCYs, while liquiritin (3) was decreased. The fermentation of the ten lactic acid bacteria demonstrated that the decomposable rate of these three compounds in FCYs were different. Socheongryong-tang fermented by L. plantarum 144 and L. amylophilus 161 showed the most remarkable changes. Conclusions : CY could be increased antibacterial, neuroprotective, or antiinflammatory effect by fermentation with lactic acid bacteria, especially with L. plantarum and L. amylophilus, considering their known biological activities. In addition, it is expected that this study will help to establish quality control parameters for FCY.

• 한방비만학회지
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• 제18권2호
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• pp.64-73
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• 2018

Objectives: This study investigated the effect on microbial ecology, fermentation characteristics and anti-obesity of Platycodon grandiflorum (PG) fermentation with salt. Methods: PG was fermented for four weeks with 2.5% salt and the characteristics of fermented PG were performed by measuring pH, total sugar content, viable bacteria number and microbial profiling. Also, we measured total polyphenol, flavonoid and the percent of inhibition of lipase activity and lipid accumulation. Results: Salt added to PG for fermentation had an effect on pH, total sugar, total and the number of lactic acid bacteria. Total sugar and pH were reduced and number of total and lactic acid bacteria were increased after fermentation. The majority of bacteria for fermentation were Lactobacillus plantarum, Leuconostoc psedomesenteroides and Lactococcus lactis subspecies lactis regardless of salt addition. However, microbial compositions were altered by added salt and additional bacteria including Weissella koreensis, W. viridescens, Lactobacillus sakei and Lactobacillus cuvatus were found in fermented PG with salt. Total flavonoid was increased in fermented PG and lipid accumulation on HepG2 cells treated with fermented PG was reduced regardless of salt addition. Moreover, fermented PG without salt suppressed lipase activity. Conclusions: Addition of salt for PG fermentation had influence on fermentation characteristics including pH and sugar content as well as number of bacteria and microbial composition. In addition, fermented PG showed anti-obesity effect by increasing flavonoid content and inhibition of lipase activity and lipid accumulation.

• Korean Chemical Engineering Research
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• 제53권1호
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• pp.1-5
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• 2015

Lactic acid(젖산)는 가장 널리 사용되는 Hydroxy-carboxylic acid로서 일반적으로 식품, 화장품, 의약품 및 화학산업의 원료로 사용된다. 하지만 다양한 분야의 적용과 대량생산의 광범위한 잠재력에도 불구하고 원재료의 높은 가격으로 인하여 Lactic acid 생산의 주된 문제가 된다. Lactic acid는 발효 또는 화학적 합성에 의하여 얻어진다. 최근, 자연적으로 생산되는 Lactic acid의 시장 수요가 증가하여 미생물 발효 방법에 의한 Lactic acid 생산을 일반적으로 사용한다. 일반적으로 Lactic acid 생산의 원재료는 순수한 전분 또는 글루코오스를 이용한다. 이의 경제적인 원재료의 대안으로, 지구상에서 가장 풍부한 재생가능 자원인 바이오매스를 가수분해물로 전환하여 이용한다. 본 연구에서는 Lactobacillus rhamnosus ATCC 10863을 이용하여 전처리 된 가수분해물로부터 발효 방법에 의해 L(+)-Lactic acid를 생산하였다. 전처리 된 가수분해물은 암모니아 침출 공정(AP) 후 효소 당화에 의하여 얻었다. 효과적으로 Lactic acid 생산 수율과 전환율을 높이기 위하여 순수 글루코오스 조건에서 배지, 온도, 글루코오스 농도를 조절하여 수행하였다. 발효 최적조건에서 순수 글루코오스와 가수분해물의 Lactic acid 생산을 비교하였다.

• Food Science and Biotechnology
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• 제15권5호
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• pp.664-671
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• 2006

Modeling the growth kinetics of lactic acid bacteria (LAB), one of the most valuable microbial groups in the food industry, has been actively pursued in order to understand, control, and optimize the relevant fermentation processes. Most modeling approaches have focused on the development of single population models. Primary single population models provide fundamental kinetic information on the proliferation of a primary LAB species, the effects of biological factors on cell inhibition, and the metabolic reactions associated with cell growth. Secondary single population models can evaluate the dependence of primary model parameters, such as the maximum specific growth rate of LAB, on the initial external environmental conditions. This review elucidates some of the most important single population models that are conveniently applicable to the LAB fermentation analyses. Also, a well-defined mixed population model is presented as a valuable tool for assessing potential microbial interactions during fermentation with multiple LAB species.