• 한국토양비료학회지
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• 제48권4호
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• pp.262-270
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• 2015

The scientific information between microbial community and chemical properties of reclaimed tidal soil is not enough to understand the land reclamation process. This study was conducted to investigate the relation between chemical properties and microbial activities of soils from reclaimed tidal lands located at south-western coastal area (42 samples from Goheuong, Samsan, Bojun, Kunnae, Hwaong and Yeongsangang sites). Most of the reclaimed soils showed chemical characteristics as salinity soil based on EC. Only $Na^+$ in exchangeable cation was dependent on EC of reclaimed soil, whereas other cations such as $K^+$, $Ca^{2+}$, and $Mg^{2+}$ were independent on EC. The mesophilic bacteria decreased with an increase in EC of soil. Microbial population increased with soil organic content in the range of $0{\sim}10g\;kg^{-1}$ and dehydrogenase activity less than $100{\mu}g-TPF\;g^{-1}h^{-1}$. Microbial population of soils from reclaimed tidal lands was closely related to the microbial community containing hydrolytic enzyme activities of cellulase, amylase, protease, and lipase.

• The Plant Pathology Journal
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• 제30권2호
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• pp.117-124
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• 2014

The plant pathogenic bacterial genus Pectobacteirum consists of heterogeneous strains. The P. carotovorum species is a complex strain showing divergent characteristics, and a new subspecies named P. carotovorum subsp. brasiliensis has been identified recently. In this paper, we re-identified the P. carotovorum subsp. brasiliensis isolates from those classified under the subspecies carotovorum and newly isolated P. carotovorum subsp. brasiliensis strains. All isolates were able to produce plant cell-wall degrading enzymes such as pectate lyase, polygalacturonase, cellulase and protease. We used genetic and biochemical methods to examine the diversity of P. carotovorum subsp. brasiliensis isolates, and found genetic diversity within the brasiliensis subsp. isolates in Korea. The restriction fragment length polymorphism analysis based on the recA gene revealed a unique pattern for the brasiliensis subspecies. The Korean brasiliensis subsp. isolates were divided into four clades based on pulsed-field gel electrophoresis. However, correlations between clades and isolated hosts or year could not be found, suggesting that diverse brasiliensis subsp. isolates existed.

• Journal of Microbiology and Biotechnology
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• 제10권2호
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• pp.181-186
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• 2000

MAPI (microbial alkaline protease inhibitor) was isolated from cultrue broth of Streptomyces chromofuscus SMF28. The Ki values of MAPI for the representative serine proteases such as chymotrypsin and proteinase K were 0.28 and $0.63{\;}\mu\textrm{M}$, respectively, and for the cysteine proteases cathepsin B and papain were 0.66 and $0.28{\;}\mu\textrm{M}$, respectively. These data indicate that MAPI is not a potent selective inhibitor of serine or cysteine proteases. Progress curves for the inhibition of three proteases by MAPI exhibithe characteristic patterns; MAPI exhibited slow-binding inhibition of cathepsin B. It was rapidly associated with chymotrypsin before the addition of substrate and then reactivation of MAPI-inhibited enzyme was investigated in the presence of substrate. On the other hand, MAPI-proteinase K interaction was typical for those classical inhibitors. When MAPI was incubated with trypsin, there was an extensive reduction in the ingibitory activities of MAPI corresponding to 66.5% inactivation of MAPI, indicating that trypsin-like protease may play a role in the decrease of the inhibitory activity during cultivation.

• Journal of Microbiology and Biotechnology
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• 제31권8호
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• pp.1163-1174
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• 2021

Casein-derived antioxidant peptides by using microbial proteases have gained increasing attention. Combination of two microbial proteases, Protin SD-NY10 and Protease A "Amano" 2SD, was employed to hydrolyze casein to obtain potential antioxidant peptides that were identified by LC-MS/MS, chemically synthesized and characterized in a oxidatively damaged HepG2 cell model. Four peptides, YQLD, FSDIPNPIGSEN, FSDIPNPIGSE, YFYP were found to possess high 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging ability. Evaluation with HepG2 cells showed that the 4 peptides at low concentrations (< 1.0 mg/ml) protected the cells against oxidative damage. The 4 peptides exhibited different levels of antioxidant activity by stimulating mRNA and protein expression of the antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px), as well as nuclear factor erythroid-2-related factor 2 (Nrf2), but decreasing the mRNA expression of Kelch-like ECH-associated protein 1 (Keap1). Furthermore, these peptides decreased production of reactive oxygen species (ROS) and malondialdehyde (MDA), but increased glutathione (GSH) production in HepG2 cells. Therefore, the 4 casein-derived peptides obtained by using microbial proteases exhibited different antioxidant activity by activating the Keap1-Nrf2 signaling pathway, and they could serve as potential antioxidant agents in functional foods or pharmaceutic preparation.

• Journal of Animal Science and Technology
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• 제44권6호
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• pp.801-808
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• 2002

상업적 단백질 분해 효소에 0.02% $CaCl_2$를 첨가하여 응유 활성화를 시킨 탈지유에 대한 분해 작용의 결과를 요약하면 다음과 같다. 다양한 효소별 가수분해 시간에 따른 가수분해도는 미생물 유래 효소와 trypsin은 pepsin과 papain W-40보다 높은 분해도를 나타냈다. 12% TCA 용액에 가용성인 NPN의 양은 trypsin이 가장 높은 분해도를 나타내었고 rennet과 pepsin이 가장 낮은 분해도를 보였다. 전기영동에 있어서 trypsin과 protease S는 $\alpha$- lactalbumin을 분해하였고 papain w-40은 $\beta$- lactoglobulin을 미약하게 분해하였으며 neutrase 1.5는 90분 이후부터 $\alpha$-lactalbumin과 $\beta$-lactoglobulin을 분해하였다. Rennet과 비교한 전기영동상에서는 rennet에 의해 분해 되지 않은 ${\alpha}_s$- casein과 $\beta$-casein을 trypsin과 protease S가 다량 분해하였고 $\kappa$-casein은 rennet에 비해 papain W-40이 상당 수준의 분해상을 나타내었다. 이상의 결과 가수분해도 및 NPN 양은 trypsin, neutrase 1.5 및 protease S가 다른 효소에 비해 높게 나타났으며, 전기영동상에서는 pepsin과 neutrase 1.5가 rennet과 유사한 경향을 나타내었다.

• Applied Biological Chemistry
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• 제51권4호
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• pp.281-287
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• 2008

저식염 고추장 제조시 알콜 또는 알콜에 겨자나 키토산을 혼합 첨가한 고추장을 1년간 숙성시켜, $30^{\circ}C$에서 12주간 저장하면서 미생물상과 이화학적 특성 변화를 비교하였다. 고추장의 amylase 활성은 저장 중에 급격히 감소하였고, 저온살균 처리구에서 낮았다. 산성 protease 활성은 저장 중에 증가하였으나 중성 protease는 저장 4주 이후에 서서히 감소하였다. 고추장 중의 효모수는 저장 중에 조금 증가하였으나 세균수는 감소하는 경향이었고, 시험구간의 차이는 없었다. 고추장의 색은 저장 중에 a값은 감소하였으나 L-과 b-값은 저장 4주에 증가한 후에 감소하였고, ${\Delta}E$값의 변화는 4주에 제일 심하였다. 고추장의 수분과 수분활성도는 저장 중에 감소하였으며 수분활성도는 부원료 첨가구들에서 높았다. 고추장의 pH는 저장 중에 저하하였으나, 적정산도는 저장 4주 이후에는 감소하였으며 알콜에 겨자나 키토산을 혼합 첨가한 고추장에서 높았다. 산화환원전위는 저장 4주에 증가하였으나 그 이후에는 감소하였고 부원료 첨가구에서 낮았다. 총당과 환원당은 저장 중에 감소하였으나 부원료 첨가구에서 높았다. 알콜은 저장 중에 증가하나 알콜 첨가구들은 감소하였다. 아미노태 질소와 암모니아태 질소 함량은 저장 중에 감소하였으며 부원료 첨가 고추장에서 아미노태 질소 함량이 낮았다. 따라서 부원료를 첨가한 저식염 고추장을 장기간 숙성시키면 저장 중에 가스 발생이 없어 유통 중에 포장용기의 파열이나 변색이 적고, 환원당과 아미노태 질소의 감소가 적어 품질저하 요인이 상대적으로 적은 것으로 판단되었다.

• 한국환경농학회지
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• 제18권3호
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• pp.272-279
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• 1999

음식물 쓰레기 자체미생물에 의한 퇴비화 가능성을 검토하기 위해 음식물 쓰레기 자체 미생물의 분포 및 수를 조사한 결과 $30^{\circ}C$에서 세균은 전 시료구에서 $10^5-10^7CFU/g$, $50^{\circ}C$에서 $10^5-10^6\;CFU/g$이 검출되었다. 효소생산 미생물은 $30^{\circ}C$와 $50^{\circ}C$에서 amylase, protease 생산균주는 계절에 관계없이 $10^3-10^7\;CFU/g$로 검출되었다. 한편 30일간의 퇴비화 실험결과 $50^{\circ}C$ 항온에서 음식물 쓰레기만을 이용한 시험구(FW1)는$30^{\circ}C$(FW2) 시험구와 유사하였으나 온도구배 적용구(FW3) 그리고 미생물 부숙제첨가구(FM1, FM2)에 비해 가장 많은 $CO_2$ gas 발생율을 보였고 유기물 분해율, 조단백함량 변화에 있어서 가장 우수한 것으로 나타났다. 또한 퇴비화 과정중 미생물과 효소생산 균주의 변화를 조사한 결과 FW1의 경우 $30^{\circ}C$, $50^{\circ}C$, $60^{\circ}C$의 전배양 온도에서 $10^5-10^9\;CFU/ml$의 세균과 Amylase 및 Protease 생산균주가 검출되어 미생물 부숙제를 첨가한 시험구에 비해 우수하였다. 이상의 결과로 음식물 쓰레기 자체 총균수 및 효소 생산균주 그리고 퇴비과정중의 성분 변화를 고려할 때 $50^{\circ}C$의 부숙온도가 가장 효율적이며 음식물 쓰레기 퇴비화에 별도의 미생물 부숙제 사용은 불필요한 것으로 추측된다.

• Journal of Microbiology and Biotechnology
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• 제9권6호
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• pp.861-869
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• 1999

An extracellular protease was purified to homogeneity from the culture supernatant of psychrotrophic bacteria Bacillus sp. JH 108 using procedures including ammonium sulfate fractionation, anion exchange chromatography, gel filtration chromatography, and cation exchange chromatography. The enzyme exhibited a molecular weight of 36 kDa, an optimum pH of 8 to 9, and optimum temperature of $60^{\circ}C$. The enzyme preferentially hydrolyzed leucine at the N-terminus of peptides and thus can be classified as an aminopeptidase. It was strongly inhibited by metal chelating agents such as EDTA and l, l0-phenanthroline. The activity lost by EDTA was restored with $Zn^{2+}{\;}or{\;}Co^{2+}$. These divalent cations also stimulated the native enzyme. This suggests that the enzyme is a metalloprotease acting as a leucine aminopeptidase.

• Journal of Microbiology
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• 제41권1호
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• pp.58-62
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• 2003

An extracellular pretense of Bacillus amyloliquefaciens S94 was purified to apparent homogeneity. The enzyme activity was strongly inhibited by general inhibitor for serine protease, PMSF, suggesting that the enzyme is a serine pretense. The purified enzyme activity was inhibited by leucine peptidase inhibitor, bestatin, suggesting that the enzyme is a leucine endopeptidase. The maximum proteolytic activity against different protein substrates occurred at pH 10, 45$^{\circ}C$ (protein substrate) and pH 8, 45$^{\circ}C$ (synthetic substrate). The purified enzyme was specific in that it readily hydrolyBed substrates with Leu or Lys residues at P$_1$ site. The pretense had characteristics of a cold-adapted protein, which was more active for the hydrolysis of synthetic substrate in the range of 15$^{\circ}C$ to 45$^{\circ}C$, specially at low temperature.

• 한국미생물·생명공학회지
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• 제27권4호
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• pp.311-319
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• 1999

Leaves of Aloe vera Linne and bloods of domestic animal were composted in a soild state fermentation reactor (SSFR) by using microbial additive including a bulking and moisture controlling agent. From solid-culture of microbial additive, 10 species of bacteria and 10 species of fungi were isolated and, their enzyme activities including amylase, carboxy methyl cellulase CMCase, lipase and protease were detected. Optimum fermentation conditions of Aloe leaves and domestic animal bloods in SSFR were obtained from the studies of response surface analysis employing microbial additive content, initial moisture content, and fermentation temperature as the independent variables. The optimum conditions for SSFR using Aloe leaves were obtained at 9.45$\pm$73%(w/w) of microbial additives, 62.73$\pm$4.54%(w/w) of initial moisture content and 55.32$\pm$3.14$^{\circ}C$ of fermentation temperature while those for SSFR using domestic animal bloods were obtained at 10.25$\pm$2.04%, 58.68$\pm$4.97% and 57.85$\pm$5.$65^{\circ}C$, respectively. Composting process in SSFR was initially proceeded through fermentation and solid materials were decomposed within 24 hours by maintaining higher moisture level, and maturing and drying steps are followed later. After the fermentation step, the concentrations of solid phase inorganic components were increased while that of organic components were decreased. Also, concentrations of total organic carbon(TOC), peptides, amino acids, polysaccharides, and low fatty acids in water extracts were increased. As fermentation in composting process depends on initial C/N ratios in water extracts of two samples were increased because of increased water-soluble TOC. From these results, it was revealed that solid state fermentation reactor using microbial additives can be used in composting process of organic wastes with broad C/N ratio.