• 한국식품영양과학회지
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• 제27권1호
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• pp.51-56
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• 1998

A bacteium, KP-6408, capable of hydrolyzing fibrin was isolated from Chungkook-jang, which was possibly identified as a strain of Bacillus sp. The effects of culture condition and medium composition on the enzyme production were investigated. Among nitrogen sources tested, yeast extract was the most effective for the enzyme production, and the level of the concentration for the optimal enzyme production was 0.2%(w/v). For carbon sources, glucose was the best for the enzyme production with the level of 2.0%(w/v). The enzyme was maximally produced by cultivating the enzyme production with the level of 2.0%(w/v). The enzyme was maximally produced by cultivating the organism at the liquid medium of the initial pH 8.0 and temperature of 4$0^{\circ}C$. In Chungkook-jang fermentation, the enzyme was maximally produced when incubated at 35$^{\circ}C$ for 24 hrs using soybean as a solid medium. The addition of various rice starch to the soybean in Chungkook-jang fermentation lowered the enzyme production.

• Food Science and Biotechnology
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• 제18권6호
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• pp.1342-1350
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• 2009

This paper investigates the production and optimization of $\beta$-galactosidase enzyme using synthetic medium by Kluyveromyces lactis NRRL Y-8279 in stirred tank bioreactor. Response surface methodology was used to investigate the effects of fermentation parameters on $\beta$-galactosidase enzyme production. Maximum specific enzyme activity of 4,622.7 U/g was obtained at the optimum levels of process variables (aeration rate 2.21 vvm, agitation speed 173.4 rpm, initial sugar concentration 33.8 g/L, incubation time 24.0 hr). The optimum temperature and pH of the $\beta$-galactosidase enzyme produced under optimized conditions were $37^{\circ}C$ and pH 7.0, respectively. The enzyme was stable over a pH range of 6.0-7.5 and a temperature range of $25-37^{\circ}C$. The $K_m$ and $V_{max}$ values for O-nitrophenol-$\beta$-D-galactopyranoside (ONPG) were 1.20 mM and $1,000\;{\mu}mol/min{\cdot}mg$ protein, respectively. The response surface methodology was found to be useful in optimizing and determining the interactions among process variables in $\beta$-galactosidase enzyme production. Hence, this study fulfills the lack of using mathematical and statistical techniques in optimizing the $\beta$-galactosidase enzyme production in stirred tank bioreactor.

• Asian-Australasian Journal of Animal Sciences
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• 제25권8호
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• pp.1184-1189
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• 2012

White spot syndrome virus (WSSV) is one of the major viral pathogens affecting shrimp aquaculture. Four proteins, WSSV199, WSSV 222, WSSV 249 and WSSV 403, from WSSV are predicted to encode a RING-H2 domain, which in presence of ubiquitin conjugating enzyme (E2) in shrimp can function as viral E3 ligase and modulate the host ubiquitin proteasome pathway. Modulation of host ubiquitin proteasome pathway by viral proteins is implicated in viral pathogenesis. In the present study, a time course expression profile analysis of WSSV Open Reading Frame (ORF) 199 and Penaeus monodon ubiquitin conjugating enzyme (PmUbc) was carried out at 0, 3, 6, 12, 24, 48 and 72 h post WSSV challenge by semi-quantitative RT-PCR as well as Real Time PCR. EF1${\alpha}$ was used as reference control to normalize the expression levels. A significant increase in PmUbc expression at 24 h post infection (h.p.i) was observed followed by a decline till 72 h.p.i. Expression of WSSV199 was observed at 24 h.p.i in WSSV infected P. monodon. Since the up-regulation of PmUbc was observed at 24 h.p.i where WSSV199 expression was detected, it can be speculated that these proteins might interact with host ubiquitination pathway for viral pathogenesis. However, further studies need to be carried out to unfold the molecular mechanism of interaction between host and virus to devise efficient control strategies for this chaos in the shrimp culture industry.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 추계학술대회
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• pp.109-109
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• 2018

Bacillus subtilis B22, a chemotrophic and aerobic bacterial strain was isolated from homemade kimchi, identified by 16S rRNA gene sequencing. B22 was primarily screened by biochemical, carbon source utilization tests. B22 was used to produce pectinase and ${\beta}$-glucosidase by submerged fermentation under different light sources. B22 was incubated in pectin media and basal media (pH 7.0) under blue, green, red and white light-emitting diodes (LEDs), fluorescent white light, and in darkness at $37^{\circ}C$, orbital shaker 150 rpm for 24 hours. Fermentation under blue LEDs maximized pectinase production ($71.59{\pm}1.6U/mL$ at 24 h) and ${\beta}$-glucosidase production ($56.31{\pm}1.6U/mL$ at 24 h). Further, the production of enzyme increased to pectinase ($156{\pm}1.28U/mL$) and ${\beta}$-glucosidase ($172{\pm}1.28U/mL$) with 3% glucose as a carbon source. Activity and stability of the partially purified enzymes were higher at pH 6.0 to 8.0 and $25-55^{\circ}C$. The effect on the metal ions $Na^+$ and $K^+$ and (moderateactivity) $Mn^{2+}$ and $Ni^{2+}$ increased activity, while $Hg^{2+}$, $Cu^{2+}$, $Fe^{2+}$, and $Fe^{2+}$ inhibited activity. EDTA, phenylmethylsulfonyl fluoride and 5,5-dithiobis (2-nitrobenzoicacid) reduced activity, while tetrafluoroethylene and 1,10-phenanthroline inhibited activity. The amylase was highly tolerant of the surfactants TritonX-100, Tween-20, Tween-80 and compatible with organic solvents methanol, ethanol, isoamylalcohol, isopropanol, t-butylalcohol and the oxidizing agents hydrogen peroxide, sodium perborate and sodium hypochlorite, although potassium iodide and ammonium persulfate reduced activity. These properties suggest utility of pectinase and ${\beta}$-glucosidase produced by B. subtilis B22 under blue LED-mediated fermentation for industrial applications.

• 한국미생물·생명공학회지
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• 제24권2호
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• pp.143-148
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• 1996

Thousand actinomycetes and 50 soil samples were used for the isolation of microorganisms producing yeast cell wall lytic enzymes. Among 493 strains producing large clear zones on autolysed washed yeast (AWY), 117 strains were selected on living yeast cell agar plates. With the method of lytic activity, one strain (St-1702) was selected, which was temporarily identified as Streptomyces eurythermus. The optimal condition for enzyme production of this strain was partially determined as follows: incubation of the strain for 3 days at 30$\circ$C in the medium containing 2% freeze dried yeast cell, 1% glucose, 1% K$_{2}$HPO$_{4}$, 0.01% MgSO$_{4}$'7H$_{2}$O, 0.5% peptone, and 0.2% (NH$_{4}$)$_{2}$CO$_{3}$ with pH 7.0. The protoplast formation of yeast by using the enzyme produced by this strain was compared with commercial enzymes.

• 한국미생물·생명공학회지
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• 제18권4호
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• pp.417-422
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• 1990

선발균의 효소생산성 향상을 위해 배양과정의 특징을 조사하였다. 효소생산을 위한 최적의 탄소원은 sucrose (35)이고, 질소원은 ammonium oxalate와 yeast extract를 함께 넣어 주었을 때이었다. 5l jar fermentor에서 선발균의 배양형태를 조사한 결과 2-3일 배양기간에는 pH가 4 이하로 현저하게 감소하는 것을 관찰하였고 4일 이후 다시 pH가 5-6 사이로 증가하였다. 균의 성장은 4일까지 증가하였다. 균체내 효소의 생성은 2일까지는 현저한 증가를 보이고 3-4일 정도 큰 변화를 나타내지 않으며 5일 이후 감소하였다. 균체외 효소는 5-6 일까지 계속 증가하는 형태를 나타내었다. Glucose로 24시간 동안 미리 배양한 후 surcose를 첨가하여 배양했을 때 균체내 효소의 생산이 현저히 증가하는 것을 알 수 있었다.

• 한국미생물·생명공학회지
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• 제47권4호
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• pp.555-564
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• 2019

Biodiesel is produced through the transesterification process in the presence of alcohol and a catalyst that catalyzes the conversion of triglycerides to esters and glycerol compounds. A more optimal product conversion can be achieved using enzymes, such as lipase. Lipase is reported to be produced in osmophilic yeasts due to the low water content in their natural habitats. Wild forest honey is one of the osmophilic natural habitats in Indonesia. However, lipase-producing yeast has not been reported in the Indonesian honey. In this study, we screened the lipase-producing yeasts isolated from wild forest honey collected from Central Sulawesi. The production profile and activity of lipase were determined at different pH values and temperatures. One promising yeast was isolated from the honey, which was identified as Zygosaccharomyces mellis SG 1.2 based on ITS sequence. The maximum lipase production (24.56 ± 1.30 U/mg biomass) was achieved by culturing the strain in a medium containing 2% olive oil as a carbon source at pH 7 and 30℃ for 40 h. The optimum pH and temperature for lipase activity were 6 and 55℃, respectively. The enzyme maintained 80% of its activity upon incubation at 25℃ for 4 h. However, the enzyme activity decreased by more than 50% upon incubation at 35 and 40℃ for 2 h. This is the first study to report the lipase producing capability of Z. mellis. Further studies are needed to optimize the enzyme production.

• 한국미생물·생명공학회지
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• 제24권3호
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• pp.299-303
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• 1996

Isolation, identification, and culture conditions of a lytic enzyme producing microorganism against Lacto- bacillus plantarum were investigated. The selected strain was gram-positive, rod (0.7 $\times$ 2.7 $\mu$m in size), and non-motile. The strain did not have any flagella and spores. According to its cultural and physiological characteristics, the strain was identified as Bacillus sp. The optimal pH and temperature for the production of lytic enzyme were 8.0 and 30$\circ$C, respectively. The maximum enzyme activity showed 1.5 units/ml in the medium composed of 1% peptone and 0.1% NaCl.

• 한국염색가공학회지
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• 제24권1호
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• pp.18-26
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• 2012

In this work, colorants extraction process from gromwell was studied for making powder form of colorants by solving the high viscosity problem of gromwell extracts. In order to do that, sugar extracted together with colorants must be pre-extracted. For sugar decomposition, gromwell roots were pretreated with various enzyme solutions. The total sugar content of pre-extract with enzyme solution was measured. Accordingly, the effects of enzyme type and pretreatment condition on sugar decomposition were investigated to find appropriate enzyme(amylase, hemicellulase, pectinase) and enzyme activity (100~1000unit), pre-extracted time(3~24hr). Color characteristics and dye uptake of dyed fabrics were evaluated. Gromwell colorants were assessed for their potential antimicrobial activities, which possibly expand their end use as functional pigments. The efficiency of removing sugar was increased in the order of hemicellulase, pectinase, amylase, $H_2O$. Gromwell colorants powder yield was in the range of 4.4% to 9.8% depending on pretreatment enzyme. Gromwell colorants produced RP color on the silk and wool fabrics with good dye uptake. Antimicrobial activity of gromwell colorants will greatly increase its potentiality for applying as functional natural colorants in the future.

• Applied Biological Chemistry
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• 제35권6호
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• pp.501-506
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• 1992

두유박 단백질을 시료로 하여 pepsin을 사용한 가수분해와 plastein 합성의 최적조건을 조사하였다. 가수분해의 최적 기질농도는 3%이었으며, 기질에 대한 최적의 효소 농도는 2%이었고, 최적 pH, 반응온도 및 반응시간은 각각 pH 1.7, $45^{\circ}C$ 및 24시간이었다. Plastein 합성 조건으로 기질농도 40%, pH 4.0, 반응온도 $45^{\circ}C$, 반응시간 18시간, (효소/기질) 농도 1%를 설정하였다. 생성된 plastein은 반응시간 및 기질농도 별로 전기영동으로 확인하였다.