• 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.

• Journal of Applied Biological Chemistry
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• 제56권3호
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• pp.157-163
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• 2013

알로에의 유효성분인 다당의 효율적 생산연구일환으로 수행되었던 aloe callus의 현탁배양과 관련하여, 본 연구에서는 이의 배양생성물(세포외 다당)과 callus의 용매추출물에 대한 항염증 활성을 조사하였다. 세포외 다당(ACP)과 callus (AC)의 물 및 에탄올 추출물의 대식세포(Raw 264.7) 세포생존율을 MTT assay로 조사한 결과, AC-DMSO의 $400{\mu}g/mL$ 첨가구에서 97%로 미미한 증식저해를 보였으나 나머지 시료처리구는 모두 증식 촉진효과를 나타내었다. 또, LPS에 의해 활성화된 Raw 264.7 세포 배양액의 알로에 추출물 처리에 따른 NO 생성 저해효과를 조사한 결과, AC-DW와 AC-DMSO는 오히려 양성대 조구인 LPS 단독보다 더 많은 NO를 생성하였다. 특히, 세포외 다당 분획인 ACP-DW는 NO 생성을 강력히 억제하여 $80-100{\mu}g/mL$의 비교적 낮은 농도의 첨가로 대조구 수준까지 억제하였다. 또, Raw 264.7 세포에 LPS로 자극을 주고 알로에 현탁 배양 생성물의 처리에 따른 COX-2단백질의 발현정도를 조사한 결과, ACP-DW 처리구는 단독으로 COX-2 단백질을 발현시키지 않았으며, LPS 자극에 따른 COX-2의 발현감소는 미미하였다. 아울러, 활성화된 대식세포로부터 생성된 염증 사이토카인인 IL-$1{\beta}$와 TNF-${\alpha}$의 발현량을 RT-PCR로 조사한 결과, ACPDW 처리구에서 TNF-${\alpha}$의 발현이 강력하게 억제되었다. 이상의 결과들은 알로에 현탁배양 유래의 생성물들이 비교적 우수한 항염증활성을 나타냄을 보여주는 결과로, 그동안 삽목번식의 재배방법에 의존하였던 알로에 유효성분의 생산을 대체할 수 있는 효율적이고, 새로운 방법으로서의 알로에 callus의 현탁배양 가능성을 보여주었다.

• 한국식품과학회지
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• 제48권3호
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• pp.231-240
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• 2016

김치에서 분리된 Leuconosotc종과 Weissella종의 프로바이오틱스 특성시험과 요구르트에 접종하여 그 특성에 대해 알아보았다. 김치에서 분리한 균주들 대부분 85% 이상의 생존율을 보이며 산에 대한 높은 저항성을 보였다. 내담즙성 시험에서는 쓸개즙산을 0.3% 첨가한 MRS broth에 분리균주를 접종하여 측정한 결과 한 균주를 제외한 나머지 분리균주들의 생존율이 60% 이상으로 우수한 내성을 보였다. 내산성과 내담즙성 모두 우수한 Leuconostoc 6종, Weissella 3종을 E. coli와 S. Typimurium에 대한 생육억제 능력에 대한 시험을 진행하였다. 최종적으로 Leuconostoc 종인 KC. 5과 Weissella 종인 KC. 10을 최종 선발하였다. 선별된 김치분리균주 KC. 10의 덱스트란슈크레이스 활성 및 EPS 수율은 각각 15.91 DSU/mg protein 및 48.81%으로 일반 type 균주보다도 높았다. 선별 김치분리 균주를 이용하여 제조한 요구르트를 제조한 뒤 측정한 pH는 발효 6시간 때 pH 4.5에 도달하였으며 12일 저장기간 동안에 pH의 큰 변화는 없었다. 산도는 1.2-1.3%로 1.1-1.15% 사이인 대조군에 비해 산도가 높았다. $4^{\circ}C$ 저장기간 동안, 요구르트의 점도는 펙틴을 첨가한 대조군과 비교하였을 때 A12, KC. 5, KC. 10을 접종한 요구르트 중 슈크로스 함량이 4%인 첨가하고 선별된 김치 Leuconostoc 및 Wissella 접종 실험군이 12일째까지 유의적인 차이의 높은 점도를 나타내었다(p<0.05). 요구르트 저장 종료일에 시너레시스 측정값과 EPS수율 결과는 선별 김치균주를 이용한 4% 슈크로스첨가 요구르트는 대조군에 비해 시너레시스가 적은 값을 나타냈으며(p<0.05), EPS수율 또한 시료간 유의적인 차이를 나타내었다(p<0.05). 프로바이오틱 및 요구르트 특성시험을 종합해본 결과 선별 김치균주들을 요구르트 제조 시 혼합균주로 첨가할 경우 EPS 생성으로 인해 프로바이오틱 특성과 프리바이오틱 특성을 동시에 가져 신바이오틱 발효유의 생산이 가능하였다.

• 한국응용과학기술학회지
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• 제32권4호
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• pp.758-766
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• 2015

Dextran is a generic term for a bacterial exopolysaccharide synthesized from sucrose and composed of chains of D-glucose units connected by ${\alpha}$-1,6-linkages by using dextransucrases. Dextran could be used as vicosifying, stabilizing, emulsifying, gelling, bulking, dietary fiber, prebiotics, and water holding agents. We isolated new strain capable of producing dextran from Korean traditional kimchi and identified as Leuconostoc sp. strain JYY4. Batch fermentation was conducted in bioreactor with a working volume of 3 L. The media was MMY and 15% (w/v) sucrose. Mineral medium consisted of $3.0g\;KH_2PO_4$, $0.01g\;FeSO_4$, $H_2O$, $0.01g\;MnSO_4$, $4H_2O$, $0.2g\;MgSO_4\;7H_2O$, 0.01 g NaCl, $0.05g\;CaCl_2$ per 1 liter deionized water. The pH of media was initially adjusted to 6.0. The inoculation rate was 1.0% (v/v) of the working volume. Temperature was maintained at $28^{\circ}C$. The agitation rate was 100 rpm. The production pattern of dextran was associated with the cell growth. After 24 hr dextran reached its highest concentration of 59.4 g/L. The sucrose was consumed completely after 40 hr. Growth reached stationery phase when sucrose became limiting, regardless of the presence of fructose or mannitol. When the specific growth rate was 0.54 hr-1, utilization averaged 5.8 g/L-hr. The yield and productivity of dextran were 80% and 2.0 g/L-hr, respectively. Dextrans produced by were separated to two different size by an alcohol fraction method. The size of high molecular weight dextran (45% alcohol, v/v), less soluble dextran, was between MW 500,000 and 2,000,000. Soluble dextran (55% alcohol, v/v) was between 70,000 and 150,000. The molecular weight average of total dextran (70% alcohol, v/v) was between 150,000 to 500,000. The enzymatic hydrolyzates of total dextran of ATCC 13146 showed branched dextrans by Penicillium dextranase contained of glucose, isomaltose, isomaltotriose, and isomaltooligosaccharides greater than DP4 (degree of polymerization) that had branch points. Compounds greater than DP4 were branched isomaltooligosaacharides. Hydrolysates by the Lipomyces dextranase produced the same composition of oligosaccharides as those by Penicillin dextranase.

• 한국식품영양학회지
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• 제34권5호
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• pp.487-497
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• 2021

To investigate the industrial availability of liquid fermentation (PL-ferment) by Phellinus linteus mycelium as a postbiotics for the inhibition of inflammation, PL-ferment was fractionated into culture supernatant (CS), hot-water extract (HW) from PL-ferment, EtOH-precipitate (CP) fractionated from HW, and the dialysate (DCP) of CP. Compared to the other fractions, DCP which is expected to contain exopolysaccharide (EPS) as the major component, significantly decreased the production of NO, IL-6, and MCP-1 in LPS-induced RAW 264.7 cells, and IL-6 and IL-8 in TNF-α and IFN-γ-induced HaCaT cells. The general component analysis results showed that no significant difference in components was observed between the fractions, whereas sugar composition analysis revealed that DCP had decreased glucose and increased mannose contents compared to the other fractions. This suggests that mannose played an important role in the anti-inflammatory activity of the active fraction, DCP. Molecular weight distribution analysis revealed that DCP was mainly composed of low-molecular-weight material-removed high-molecular-weight polysaccharides of 18-638 kDa, suggesting that EPS originated from P. linteus EPS. In conclusion, our results suggest that the DCP of P. linteus mycelium fermentation using the anti-inflammatory activity could be used industrially as postbiotic material.

• 식물병연구
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• 제25권3호
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• pp.136-142
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• 2019

식물 근권과 내생에서 분리한 447 균주 중 식물 생장 촉진특성과 건조 내성이 있는 28 균주를 일차적으로 스크리닝 하였으며, PEG에 의한 인위적 건조 스트레스 조건에서 잎의 상대수분함량과 MDA를 기반으로 GLC02와 KJ40을 선발하였다. 이 두 균주의 효과를 검증하기 위해 밭흙을 사용한 자연 건조에서 식물 포트 검정을 하였으며, 기공전도도와 지상부(줄기와 잎) 무게가 유의하게 증가한 반면 MDA가 감소하였다. 병 억제 효과에서는 GLC02를 처리할 경우 역병의 병진전도가 감소하였으며, KJ40을 처리할 경우 세균성 점무늬병에 대한 억제효과가 있었다. 이를 토대로, GLC02와 KJ40을 처리할 경우 건조 스트레스를 경감시켜주며 식물생장의 증진, 병 억제효과를 유도하여 생물비료의 소재로 사용할 수 있을 것으로 생각된다.

• Animal Bioscience
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• 제35권2호
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• pp.281-289
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• 2022

Objective: The aim of this study was to characterize the exopolysaccharides (EPS)-producing lactic acid bacteria from Taiwanese ropy fermented milk (TRFM) for developing a clean label low-fat fermented milk. Methods: Potential isolates from TRFM were selected based on the Gram staining test and observation of turbid suspension in the culture broth. Random amplified polymorphic DNA-polymerase chain reaction, 16S rRNA gene sequencing, and API CHL 50 test were used for strain identification. After evaluation of EPS concentration, target strains were introduced to low-fat milk fermentation for 24 h. Fermentation characters were checked: pH value, acidity, viable count, syneresis, and viscosity. Sensory evaluation of fermented products was carried out by 30 volunteers, while the storage test was performed for 21 days at 4℃. Results: Two EPS-producing strains (APL15 and APL16) were isolated from TRFM and identified as Lactococcus (Lc.) lactis subsp. cremoris. Their EPS concentrations in glucose and lactose media were higher than other published strains of Lc. lactis subsp. cremoris. Low-fat fermented milk separately prepared with APL15 and APL16 reached pH 4.3 and acidity 0.8% with a viable count of 9 log colony-forming units/mL. The physical properties of both products were superior to the control yogurt, showing significant improvements in syneresis and viscosity (p<0.05). Our low-fat products had appropriate sensory scores in appearance and texture according to sensory evaluation. Although decreasing viable cells of strains during the 21-day storage test, low-fat fermented milk made by APL15 exhibited stable physicochemical properties, including pH value, acidity, syneresis and sufficient viable cells throughout the storage period. Conclusion: This study demonstrated that Lc. lactis subsp. cremoris APL15 isolated from TRFM had good fermentation abilities to produce low-fat fermented milk. These data indicate that EPS-producing lactic acid bacteria have great potential to act as natural food stabilizers for low-fat fermented milk.