• 미생물학회지
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• 제47권3호
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• pp.231-240
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• 2011

숙성된 갓김치에서 분리된 유산균을 pH 2.5에서 2시간 반응시킨 후 0.3% oxgall 존재 하에서 3시간 배양시킨 결과 MLK11, MLK22, MLK27, MLK41 및 MLK67 균주들은 $10^5$ CFU/ml 이상의 균수를 유지하여 높은 저항성을 보인 반면, MLK53 균주는 대부분의 균수가 사멸되어 매우 민감한 것으로 나타났다. 담즙산에 대한 내성이 강한 균주들 대부분은 복합 담즙산의 탈포합능이 있었으며, MLK22와 MLK67 균주는 sodium glycocholate로부터 3.5 mM 이상의 cholic acid을 유리시켜 가장 높은 탈포합능을 보인 반면, MLK13과 MLK41은 각각 1.35와 1.16 mM 정도 낮은 양의 cholic acid를 유리시켰다. 특히, MLK22와 MLK67의 탈포합능은 sodium taurocholate 혹은 포합담즙산 혼합물 보다는 sodium glycoholate 존재 하에서 더 높게 나타났다. 게다가 sodium glycocholate와 sodium taurocholate으로부터 MLK22와 MLK67이 생산하는 bile salt hydrolase (BSH)의 활성은 정지기 초기에 최대를 이르렀고 MLK67 보다는 MLK22의 BSH 활성이 다소 높았다. 한편, 실험 균주들의 콜레스테롤 제거능은 5.22-39.16 ${\mu}g$/ml로 균주별 유의적인 차이가 있었으며(p<0.05), 그 중에서 MLK67 균주는 0.3% oxgall, cholic acid 및 taurocholic acid로부터 가장 높은 콜레스테롤 동화능을 나타내었다. 따라서 실험 균주 중 높은 내산성과 내담즙성을 가지며, 담즙산 탈포합능 및 콜레스테롤 동화능이 유의하게 높은 MLK67 균주는 probiotic 균주로서의 가능성이 있는 것으로 간주되어 이를 생화학적 특성과 당분해능 및 염기서열 분석에 의해 동정한 결과 Pediococcus pentosaceus MLK67로 확인되었다.

• 한국식품영양과학회지
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• 제41권9호
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• pp.1191-1196
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• 2012

주박 추출물을 열수 및 에탄올로 추출하여 tyrosinase와 xanthine oxidase, ACE, 아질산염 소거능을 실험하였다. 주박 열수 및 에탄올 추출물의 tyrosinase 저해 효과는 85% 이상이었다. 아질산염의 경우에는 pH 4.2과 pH 6.0보다 pH 1.2가 높았으며, pH 1.2에서 열수 및 에탄올 추출물 모두 90% 이상의 소거능을 가지고 있었다. 주박 열수 및 에탄올 추출물의 xanthine oxidase 저해 효과는 매우 낮았고, 효과는 열수와 에탄올에 의해 차이가 없었다. 주박 열수와 에탄올 추출물의 ACE 저해 효과는 각각 약 43~53%와 36~47%를 보였다. 전체적으로 주박의 열수 및 에탄올 추출물은 tyrosinase저해, ACE 저해 그리고 아질산염 소거 효과를 가지고 있었으나, xanthine oxidase 저해 효과는 없는 것으로 나타났다. 따라서 주박은 화장품 원료로 가능성이 있으며, 추가적으로 식품 첨가물로써 사용 가능성이 있을 것으로 사료된다.

• 한국미생물·생명공학회지
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• 제48권4호
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• pp.556-563
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• 2020

본 연구는 단풍잎돼지풀 발효 추출물의 항산화 및 미백 효과를 검증하여 화장품 소재로서 활용가능성을 확인하고자 하였다. 항산화 효과를 측정하기 위해 전자공여능 측정과 ABTS 라디칼 소거능을 측정하였다. 단풍잎돼지풀 발효 추출물의 전자공여능 측정 결과 1,000 ㎍/ml 농도에서 68.4%의 효과를 보였으며, ABTS 라디칼 소거능 측정 결과 같은 농도에서 58.7%의 효과를 나타내었다. 미백효과를 Tyrosinase의 효소 억제 활성에 의해 측정한 결과, 1,000 ㎍/ml 농도에서 32.4%의 저해활성 효과를 보였다. 세포 차원에서 미백효과를 측정하기 위해 단풍잎돼지풀 발효추출물의 세포 생존율을 멜라노마 세포에서 측정하였다. 그 결과, 100 ㎍/ml 농도에서 85.2%의 생존율을 보였으며, 독성을 보이지 않는 농도인 100 ㎍/ml 농도 이하에서 western blot을 진행하였다. 단풍잎돼지풀 발효 추출물의 단백질 발현억제 효과를 25, 50, 100 ㎍/ml의 농도에서 western blot으로 측정하였으며, 양성대조군으로 β-actin을 사용하였다. 그 결과, 100 ㎍/ml 농도에서 MITF, TRP-1, TRP-2, Tyrosinase인자들은 각각 51.14%, 55.4%, 38.6%, 83.77%의 효과를 나타내었다. 결론적으로 단풍잎돼지풀 발효 추출물의 항산화 및 미백효과가 검증되었으며, 화장품 천연물 소재로서 활용가능성을 확인하였다.

• 대한화장품학회지
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• 제48권3호
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• pp.235-244
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• 2022

본 연구는 비타민나무열매, 아사이팜열매, 망고, 레몬, 살구 및 블루베리의 혼합 발효물이 화장품 소재로서의 가능성을 확인하기 위하여 세포독성, 라디칼 소거 능력, 엘라스타아제, 보습, 항균 활성 측정을 수행 및 확인하였다. 혼합 발효추출물의 세 농도(0.5 / 1.5 / 2%)에서 세포독성을 보이지 않아 해당 농도로 실험을 수행하였다. 이를 바탕으로 항산화 소재의 대표적 원료인 L-ascorbic acid와 비교하는 라디칼 소거능 실험을 실시하였다. 그 결과 1,1-diphenyl-2-picrylhydrazyl (DPPH) 라디칼 소거능력은 혼합 발효추출물의 농도가 2%일 때, Sample 1 ~ 7은 각각 95.1 ± 0.6%, 94.3 ± 0.7%, 95.3 ± 0.6%, 95.1 ± 0.7%, 95.1 ± 0.3%, 95.5 ± 0.3%, 그리고 95.4 ± 0.4% 로 우수한 항산화 능력을 확인하였다. 세 농도(0.5 / 1.5 / 2%)에서 농도의 증가와 블루베리추출물의 함량이 증가함에 따라 sample 7은 2% 농도에서 대조예인 retinol crystal과 같은 0.9 cm로 엘라스타제 활성이 우수함을 알 수 있었으며, 보습 활성 또한 HAS-3 증가율이 세 농도에서 각각 71.5%, 75.6%, 81.6%로 우수한 결과를 확인하였다. 항균 활성은 혼합 발효추출물의 농도가 0.5%에서 2%로 증가, 블루베리 함량의 증가에 따라서 우수한 항균 활성을 확인하였다. 특히, 혼합 발효추출물의 농도가 2%에서 sample 7에서 프로피오니박테리움(Propionibacterium)에 대한 항균 활성 효과가 매우 우수한 것을 확인하였다. 따라서 혼합 발효추출물 2%의 농도에서 항산화, 보습, 항균성을 가지는 화장품 성분으로서 개발가치가 충분하다고 사료된다.

• 한국축산식품학회지
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• 제34권1호
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• pp.106-114
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• 2014

Folic acid, one of the B group of vitamins, is an essential substance for maintaining the functions of the nervous system, and is also known to decrease the level of homocysteine in plasma. Homocysteine influences the lowering of the cognitive function in humans, and especially in elderly people. In order to determine the strains with a strong capacity to produce folic acid, 190 bacteria were isolated from various kinds of jeotgal and chungkuk-jang. In our test experiment, JA71 was found to contain $9.03{\mu}g/mL$ of folic acid after 24 h of incubation in an MRS broth. This showed that JA71 has the highest folic acid production ability compared to the other lactic acid bacteria that were isolated. JA71 was identified as Lactobacillus plantarum by the result of API carbohydrate fermentation pattern and 16s rDNA sequence. JA71 was investigated for its physiological characteristics. The optimum growth temperature of JA71 was $37^{\circ}C$, and the cultures took 12 h to reach pH 4.4. JA71 proved more sensitive to bacitracin when compared with fifteen different antibiotics, and showed most resistance to neomycin and vancomycin. Moreover, it was comparatively tolerant of bile juice and acid, and displayed resistance to Escherichia coli, Salmonella Typhimurium, and Staphylococcus aureus with restraint rates of 60.4%, 96.7%, and 76.2%, respectively. These results demonstrate that JA71 could be an excellent strain for application to functional products.

• Journal of Microbiology
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• 제38권3호
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• pp.160-168
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• 2000

A-factor I a microbial hormone that can positively control cell differentiation leading to spore formation and secondary metabolite formation in Streptomyces griseus. to identify a protease that is deeply involved in the morphological and physiological differentiation of Streptomyces, the proteases produced by Streptomyces griseus IFO 13350 and its A-factor deficient mutant strain, Streptomyces griseus HH1, as well as Streptomyces griseus HH1 transformed with the afsA gene were sturdied. In general Streptomyces griseus showed a higher degree of cell growth and protease activity in proportion to its ability to produce a higher amount of A-factor. In particular, the specific activity of the trypsin of Streptomyces griseus IFO 13350 was greatly enhanced more than twice compared with that of Streptomyces griseus HH1 in the later stage of growth. The specific activity of the metalloprotease of Streptomyces griseus HH1 was greatly enhanced more than twice compared with that of Streptomyces griseus IFO 13350, and this observation was reversed in the presence of thiostreptione, However, Streptomyces griseus HH1 transformed with the afsA gene showed a significantly decreased level of trypsin and metalloprotease activity compared with that of the HH1 strain. There was no significant difference between Streptomyces griseus IFO 13350 and HH1 strain in their chymotrypsin and thiol protease activity, yet the level of leu-amionpeptidase activity was 2 times higher in Streptomyces griseus HH1 than in strain IFO 13350 . Streptomyces griseus HH1 harboring afsA showed a similar level of enzyme activity , however, all the three protease activities sharply increased and the thiol protease activity was critically increased at the end of the fermentation. When a serine protease inhibitor, pefabloc SC, and metalloprotease inhibitor, EDTA, were applied to strain IFO 13350 to examine the in vivo effects of the protease inhibitors on the morpholofical differentiation, the formation of aerial meycelium and spores was delayed by two or three days.

• 한국버섯학회지
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• 제14권4호
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• pp.162-167
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• 2016

Lactic acid bacteria (LAB) producing phenyllactic acid (PLA), which is known as antimicrobial compound, was isolated from button mushroom bed and the isolated LAB was identified to Lactobacillus casei by 16 rRNA gene sequence analysis. Cell-free supernatant (CFS) from L. casei was assessed for both the capability to produce the antimicrobial compound PLA and the antifungal activity against three fungal pathogens (Rhizoctonia solani, Botrytis cinerea, and Collectotricum aculatum). PLA concentration was investigated to be 3.23 mM in CFS when L. casei was grown in MRS broth containing 5 mM phenylpyruvic acid as precursor for 16 h. Antifungal activity demonstrated that all fungal pathogens were sensitive to 5% CFS (v/v) of L. casei with average growth inhibitions ranging from 34.58% to 65.15% (p < 0.005), in which R. solani was the most sensitive to 65.15% and followed by C. aculatum, and B. cinerea. The minimum inhibitory concentration (MIC) for commercial PLA was also investigated to show the same trend in the range of 0.35 mg mL-1 (2.11 mM) to 0.7 mg mL-1 (4.21 mM) at pH 4.0. The inhibition ability of CFS against the pathogens were not affected by the heating or protease treatment. However, pH modification in CFS to 6.5 resulted in an extreme reduction in their antifungal activity. These results may indicate that antifungal activities in CFS was caused by acidic compounds like PLA or organic acids rather than protein or peptide molecules.

• Journal of Microbiology and Biotechnology
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• 제19권12호
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• pp.1644-1649
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• 2009

This study investigates the buffering effects of calcium salts in kimchi on the total acidity, microbial population, and dextransucrase activity. Calcium chloride or calcium carbonate was added to dongchimi-kimchi, a watery radish kimchi, and the effects on various biochemical attributes were analyzed. The addition of 0.1% calcium chloride produced a milder decrease in the pH after 24 days of incubation, which allowed the lactic acid bacteria to survive longer than in the control. In particular, the heterofermentative Leuconostoc genus population was 10-fold higher than that in the control. When sucrose and maltose were also added along with the calcium salts, the dextransucrase activity in the kimchi was elevated and a higher concentration of isomaltooligosaccharides was synthesized when compared with the control. Calcium chloride was determined as a better activator compound of dextransucrase than calcium carbonate, probably because of its higher solubility. Therefore, the results of this study confirm the ability of the proposed approach to modulate the kimchi fermentation process and possibly enhance the quality of kimchi based on the addition of dietary calcium salts.

• Journal of Microbiology and Biotechnology
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• 제20권1호
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• pp.117-126
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• 2010

A chitinase (CHT) and a protease (PRO) were purified from the culture supernatant of Serratia sp. TKU017, with shrimp shell as the sole carbon/nitrogen source. The molecular masses of CHT and PRO determined by SDS-PAGE were approximately 65 kDa and 53 kDa, respectively. CHT was inhibited by $Mn^{2+}$ and $Cu^{2+}$, and PRO was inhibited by most tested divalent metals and EDTA. The optimum pH, optimum temperature, pH stability, and thermal stability of CHT and PRO were pH 5, $50^{\circ}C$, pH 5-7, and <$50^{\circ}C$, and pH 9, $40^{\circ}C$, pH 5-11, and <$40^{\circ}C$, respectively. PRO retained 95% of its protease activity in the presence of 0.5 mM SDS. The result demonstrates that PRO is an SDS-resistant protease and probably has a rigid structure. The $4^{th}$-day supernatant showed the strongest antioxidant activity (70%, DPPH scavenging ability) and the highest total phenolic content ($196{\pm}6.2\;{\mu}g$ of gallic acid equiv./ml). Significant associations between the antioxidant potency and the total phenolic content, as well as between the antioxidant potency and free amino groups, were found for the supernatant. With this method, we have shown that shrimp shell wastes can be utilized and it is effective in the production of enzymes and antioxidants, facilitating its potential use in industrial applications and functional foods.

• Journal of Microbiology and Biotechnology
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• 제23권5호
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• pp.587-601
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• 2013

During the last few decades, it has become evident that the compatibility of the yeast biochemical environment with the ability to process and translate the RNA transcript, along with its capacity to modify a translated protein, are relevant requirements for selecting this host cell for protein expression in several pharmaceutical and clinical applications. In particular, Pichia pastoris is used as an industrial host for recombinant protein and metabolite production, showing a powerful capacity to meet required biomolecular target production levels in high-throughput assays for functional genomics and drug screening. In addition, there is a great advantage to using P. pastoris for protein secretion, even at high molecular weights, since the recovery and purification steps are simplified owing to relatively low levels of endogenous proteins in the extracellular medium. Clearly, no single microexpression system can provide all of the desired properties for human protein production. Moreover, chemical and physical bioprocess parameters, including culture medium formulation, temperature, pH, agitation, aeration rates, induction, and feeding strategies, can highly influence product yield and quality. In order to benefit from the currently available wide range of biosynthesis strategies using P. pastoris, this mini review focuses on the developments and technological fermentation achievements, providing both a comparative and an overall integration analysis. The main aim is to highlight the relevance and versatility of the P. pastoris biosystem to the design of more cost-effective microfactories to meet the increasing demands for recombinant membrane proteins and clinical antibodies for several therapeutic applications.