• Journal of Microbiology and Biotechnology
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• 제26권3호
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• pp.483-487
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• 2016

The triglyceride-lowering effect of probiotics Lactobacillus plantarum KY1032 and Lactobacillus curvatus HY7601 were investigated. Male SD Wistar rats were randomly divided into three groups and fed high-fat diet (HFD), HFD and probiotics (5 × 10⁹ CFU/day of L. plantarum KY1032 and 5 × 10⁹ CFU/day of L. curvatus HY7601), or normal diet for 6 weeks. Probiotic treatment significantly lowered the elevated plasma triglyceride and increased plasma free fatty acid, glycerol, and plasma apolipoprotein A-V (ApoA-V) levels. The probiotic-treated group showed elevated hepatic mRNA expression of PPARα, bile acid receptor (FXR), and ApoA-V. These results demonstrate that L. plantarum KY1032 and L. curvatus HY7601 lower triglycerides in hypertriglyceridemic rats by upregulating ApoA-V, PPARα, and FXR.

• Journal of Microbiology and Biotechnology
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• 제4권4호
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• pp.305-315
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• 1994

Nineteen strains of bacteriocin-producing lactic acid bacteria were isolated from 432 Kimchi samples, and identified by the comprehensive biochemical and morphological tests verifying their cellular fatty acid composition. Using partially purified bacteriocins from these isolates, their inhibitory activities against other lactic acid bacteria and some pathogens, and sensitivity to enzyme and heat treatments were tested. The isolates were identified as Lactobacillus plantarum (2 strains), L curvatus (2 starins), L brevis (2 strains), Enterococcus faecium (6 strains), Leuconostoc mesenteroides subsp. mesenteroides (1 strain) and Lactobacillus sp. (6 strains). The bacteriocins produced by E. faecium strains provided the broadest spectrum of inhibition, affecting against other Gram-positive bacteria including lactic acid bacteria and health-threatening bacteria such as Clostridium perfringens and Listeria monocytogenes. The bacteriocins of Lactobacillus sp., L plantarum and L brevis strains were capable of inhibiting many strains of the lactic acid bacteria, whereas those of L curvatus and L mesenteroides subsp. mesenteroides strains were only inhibitory to a few strains. Generally, the inhibitory activities of both E. faecium and Lactobacillus sp. strains were greater than those of other producer strains. The bacteriocins from the isolates were sensitive to several proteolytic enzymes, and those of L curvatus and L mesenteroides subsp. mesenteroides were also sensitive to lipase and $\alpha$-amylase as well as to proteolytic enzymes. The bacteriocins from the strains of Lactobacillus sp. and a strain of L. brevis were resistant to autoclaving.

• Journal of Microbiology and Biotechnology
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• 제8권6호
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• pp.588-594
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• 1998

Lactic acid bacteria were isolated from Kimchi and screened for bacteriocin production. Strain SE1, identified as Lactobacillus curvatus sp., showed the strongest inhibitory activity against Lactobacillus delbrueckii subsp. delbrueckii. The bacteriocin was inactivated by amyloglucosidase, trypsin, or protease K treatment. However, it maintained its activity under heat treatment at $100^{\circ}C$ for 60 min. The production of the bacteriocin had a growth-related mode and decreased around the early-stationary phase. The optimum temperature for the growth of L. curvatus SE1 was $37^{\circ}C$; however, the optimum temperature for bacteriocin production was $30^{\circ}C$. The bacteriocin activity was decreased by treatment with methanol, butanol, acetone, or chloroform, however, it was not affected by treatment with ethanol, iso-propanol, or cyclohexane. The inhibitory activity of bacteriocin was stable over a wide range of pHs (2 to 11). The bacteriocin from L. curvatus SE1 killed the indicator strain by a bactericidal mode of action. The bacteriocin from L. curvatus SE1 was partially purified by ethanol precipitation and ion exchange chromatography. SDS-polyacrylamide gel electrophoresis was used to determine the molecular weight of the bacteriocin by the bacteriocin activity test. The apparent molecular mass of the bacteriocin produced by L. curvatus SE1 was about 14 kDa.

• Journal of Microbiology and Biotechnology
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• 제26권12호
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• pp.2148-2158
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• 2016

To investigate the effects of Lactobacillus curvatus and Leuconostoc mesenteroides on suan cai (pickled Chinese cabbage) fermentation, L. curvatus and/or Ln. mesenteroides were inoculated into suan cai. Physicochemical indexes were measured, and the microbial dynamics during the fermentation were analyzed by Illumina MiSeq sequencing and quantitative polymerase chain reaction (qPCR). The results showed that inoculation with lactic acid bacteria (LAB) lowered the pH of the fermentation system more rapidly. The decrease in water-soluble carbohydrates in the inoculated treatments occurred more rapidly than in the control. The LAB counts in the control were lower than in other inoculated treatments during the first 12 days of fermentation. According to the Illumina MiSeq sequencing analyses, Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteria, Cyanobacteria, Fusobacteria, and Verrucomicrobia were present in the fermentations, along with other unclassified bacteria. Generally, Firmicutes was predominant during the fermentation in all treatments. At the genus level, 16 genera were detected. The relative abundance of Lactobacillus in all inoculated treatments was higher than in the control. The relative abundance of Lactobacillus in the treatments containing L. curvatus was higher than in the Ln. mesenteroides-only treatment. The relative abundance of Leuconostoc in the Ln. mesenteroides-containing treatments increased continuously throughout the fermentation. Leuconostoc was highest in the Ln. mesenteroides-only treatment. According to the qPCR results, L. curvatus and/or Ln. mesenteroides inoculations could effectively inhabit the fermentation system. L. curvatus dominated the fermentation in the inoculated treatments.

• 한국식품영양과학회지
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• 제43권7호
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• pp.1009-1016
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• 2014

묵은지 스타터로 개발된 Lb. curvatus ML17의 생균제적 특성 및 기능성 조사를 통하여 기능성 소재로서의 개발 가능성을 검토하였다. Lb. curvatus ML17은 용혈현상을 일으키지 않았으며 ${\beta}$-glucosidase와 ${\beta}$-glucuronidase의 발암효소 활성이 없는 것으로 나타나 균주에 대한 안전성을 확인하였다. 장내 생존성 확인 실험에서는 인공위액에서 2시간 처리한 다음 인공담즙에서 24시간 처리한 결과 초기 균수 대비 12.30%의 생존율을 나타내었다. Caco-2 cell에 대한 부착율은 초기 접종균수가 많을수록 높게 나타났으며, $5.66{\times}10^9$ CFU/mL로 처리 시 17.31%의 부착율을 나타냈는데 20.78%의 부착율을 나타낸 양성 대조군 Lb. rhamnosus GG에 근접하게 높은 부착율을 나타내어 장내환경에서 바람직한 작용을 할 수 있음을 보여주었다. 유해균주에 대한 생육저해 활성 측정에서는 Micrococcus luteus, Bacillus cereus, Salmonella enterica subsp. enterica, Pseudomonas aeruginosa에 대하여 우수한 항균 활성을 나타내었다. DPPH radical 소거능을 이용한 항산화 활성 측정 결과 72.88%로 양성 대조군인 0.1 mg/mL ascorbic acid보다 높은 free radical 소거능을 나타내었다. AGS 위암세포 및 HT-29 결장암세포에 대한 성장 억제 효과에서는 Lb. curvatus ML17의 배양 상등액 $80{\mu}L/mL$ 처리 시 각각 82.91% 및 79.35%의 암세포 성장 억제 효과를 나타내었다. 이와 같은 결과로 Lb. curvatus ML17이 묵은지를 포함한 발효스타터로 사용되었을 경우 식품의 보존성 향상과 품질 유지 및 균주에 의한 건강 기능성을 부여할 수 있으며 식품, 사료, 의약 분야의 다양한 산업적 활용이 기대된다.

• 한국미생물·생명공학회지
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• 제37권3호
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• pp.238-242
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• 2009

분자생물학적 방법에 의한 김치유산균 연구의 진행으로 Leuconostoc, Lactobacillus, Weissella 속 유산균의 김치발효 과정 중 생육에 대한 새로운 결과들이 도출되었지만, Pediococcus속의 생육에 대한 새로운 결과는 거의 보고되지 않았다. 본 연구에서는 김치에 존재하는 Pediococcus 속 유산균의 존재에 대한 재조명을 위하여 ampicillin (A)의 첨가로 pediococci의 선발 유효성이 향상된 것으로 보고된 pediococci selective medium(PSM)+A를 이용하여 pediococci 선택적 검출의 유효성을 검토한 결과, 기존에 보고된 결과와는 달리 Pediococcus pentosaceus 외에도 leuconostocs, Lactobacillus casei, Lactobacillus curvatus, Oenococcus oeni, Streptococcus thermophilus에 대한 생육저해가 발생하지 않았다. PSM+A 한천배지를 이용하여 김치에 생육하는 미생물을 검출한 경우, leuconostocs, P. pentosaceus, Weissella koreensis, Lb. curvatus, Lactobacillus brevis, Lactobacillus sakei가 생육하여 김치와 같은 발효침채류의 발효에 관여하는 pediococci의 선택적 선발에는 PSM+A가 유효하지 않은 것으로 확인되었다.

• 한국미생물·생명공학회지
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• 제22권5호
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• pp.544-549
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• 1994

Lactobacilli proliferating in fermented sausages of the specific ripening conditions were isolated from fermented sausages, manufactured in the absence of an added starter, during ripening under controlled temperature-humidity conditions. Based on morphological, physiological and bio- chemical characteristics and carbohydrate fermentation of isolated strains, three strains of isolates were identified as Lactobacillus curvatus, two strains as Lactobacillus sake. Optimal temperature and pH for growth of isolated strains were 30$\circ$C and pH 6.0~7.0, respectively. These strains were salt tolerant, multiplying in the presense of 6~8% NaCl.

• Asian-Australasian Journal of Animal Sciences
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• 제31권4호
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• pp.585-594
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• 2018

Objective: This study was to determine the bacterial diversity and monitor the community dynamic changes during storage of vacuum-packaged sliced raw beef as affected by Lactobacillus sakei and Lactobacillus curvatus. Methods: L. sakei and L. curvatus were separately incubated in vacuumed-packaged raw beef as bio-protective cultures to inhibit the naturally contaminating microbial load. Dynamic changes of the microbial diversity of inoculated or non-inoculated (control) samples were monitored at $4^{\circ}C$ for 0 to 38 days, using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Results: The DGGE profiles of DNA directly extracted from non-inoculated control samples highlighted the order of appearance of spoilage bacteria during storage, showing that Enterbacteriaceae and Pseudomonas fragi emerged early, then Brochothrix thermosphacta shared the dominant position, and finally, Pseudomonas putida showed up became predominant. Compared with control, the inoculation of either L. sakei or L. curvatus significantly lowered the complexity of microbial diversity and inhibited the growth of spoilage bacteria (p<0.05). Interestingly, we also found that the dominant position of L. curvatus was replaced by indigenous L. sakei after 13 d for L. curvatus-inoculated samples. Plate counts on selective agars further showed that inoculation with L. sakei or L. curvatus obviously reduced the viable counts of Enterbacteraceae, Pseudomonas spp. and B. thermosphacta during later storage (p<0.05), with L. sakei exerting greater inhibitory effect. Inoculation with both bio-protective cultures also significantly decreased the total volatile basic nitrogen values of stored samples (p<0.05). Conclusion: Taken together, the results proved the benefits of inoculation with lactic acid bacteria especially L. sakei as a potential way to inhibit growth of spoilage-related bacteria and improve the shelf life of vacuum-packaged raw beef.

• Journal of Microbiology and Biotechnology
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• 제32권3호
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• pp.348-354
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• 2022

Recent studies have shown that probiotics have health-promoting effects, particularly intestinal immune modulation. In this study, we focused on the immunomodulatory properties of Latilactobacillus curvatus BYB3, formerly called Lactobacillus curvatus, isolated from kimchi. In a mouse model of 14-day dextran sulfate sodium (DSS)-induced colitis, treatment with L. curvatus BYB3 significantly decreased the disease activity index, colon length, and weight loss. Moreover, histological analyses showed that L. curvatus BYB3 protected the structural integrity of the intestinal epithelial layer and mucin-secreting goblet cells from DSS-induced damage, with only slight infiltration by immune cells. To evaluate the molecular mechanisms underlying L. curvatus BYB3-driven inhibition of interleukin 6 production, possible in vivo anti-inflammatory effects of L. curvatus BYB3 were examined in the same mouse model. In addition, significantly lower levels of IL-6 and tumor necrosis factor receptor 1 upregulation were seen in the DSS+BYB3 group (compared to that in the DSS group). These results indicate that L. curvatus BYB3 exhibits health-promoting effects via immune modulation; and therefore, it can be used to treat various inflammatory diseases.

• 한국식품영양과학회지
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• 제42권11호
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• pp.1872-1877
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• 2013

본 연구는 경기도 일대의 배추김치로부터 젖산 생성능이 우수한 젖산균주 분리 및 두유 발효 특성에 대해 조사하였다. 먼저 0.01% bromocresol green이 첨가된 MRS 한천 배지에서 clear zone의 size 측정을 통하여 우수한 젖산 생성능을 갖는 균주를 선발 후 탄수화물 이용성 조사 및 16S rRNA 염기서열 분석으로 L. plantarum Gk04, Ped. pentosaceus Gk07, L. brevis Gk35 및 L. curvatus Gk36이 동정되었으며 특히 99%의 상동성을 갖는 L. curvatus Gk36을 두유발효를 위한 최종균주로 사용하였다. L. curvatus Gk36과 시판 균주 L. actobacillus에 의한 두유 발효 결과 pH는 L. actobacillus에서 유의적으로 더 낮은 것으로 나타났으나 생균수 및 산도 측정 결과 두 균주간에 유의적 차이가 없는 것으로 나타나 L. curvatus Gk36 균주는 두유발효 등 발효제품 제조를 위한 젖산균 균주로 이용이 가능할 것으로 판단되었다.