• 한국균학회지
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• 제51권3호
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• pp.219-227
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• 2023

This study was conducted to analyze the distribution and characteristics of fungal species in meju using the traditional method. Fungal distribution in meju was investigated using metagenomic and morphological analyses, based on which Aspergillus flavus/oryzae strains were identified as the dominant fungi in all meju samples, followed by Pichia, Rhizopus and Lichtheimia spp. As A. flavus/oryzae was dominant, we further evaluated the aflatoxin production ability and enzymatic activity of the isolates. Thin-layer chromatography and polymerase chain reaction revealed that the A. flavus/oryzae strains isolated from meju are non-aflatoxigenic fungi. Based on the analyses of amylase and protease activities, strains with high activities of amylase or protease were identified, which are proposed to be used as starters for meju fermentation.

• Asian-Australasian Journal of Animal Sciences
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• 제19권11호
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• pp.1617-1622
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• 2006

Long-term storage of feeds or feedstuffs in high temperature and humid conditions can be difficult because of microbial contamination. Essential oil isolated from industrial waste citrus peel could be used as a preservative because it is likely to have anti-bacterial and anti-fungal activity. Our objective was to determine whether different levels (0.028, 0.056 and 0.112 g/kg) of citrus essential oil (CEO) would provide anti-microbial activity and enhance preservation of animal feed without influencing rumen fermentation. At 0.112 g/kg, CEO inhibited growth of Escherichia coli (ATCC 25922) and Salmonela enteritidis (IFO 3313). Growth of E. coli recovered after 24 h of incubation, but S. enteritidis continued to be inhibited for 72 h. Preservation of antibiotic-free diets for swine was assessed by observing anti-aflatoxin activity. Aflatoxin was detected in control feed samples on days 16 (8 ppb) and 21 (8 ppb) and in anti-fungal agent (AA) treated samples on days 16 (2 ppb) and 21 (4 ppb). However, aflatoxin was not detected in feed samples treated with CEO. Treatment with CEO and AA did not influence ruminal pH, dry matter digestibility (DMD) or organic matter digestibility (OMD) over 48 h of incubation in rumen fluid. Acetate and propionate were slightly higher with CEO treatment (p<0.05), but total concentration of volatile fatty acid (VFA) was not significantly affected by treatment. Ammonia-N concentration was slightly higher for the control treatment (p<0.05). This study showed that treating feed with CEO enhances preservation of animal feed without influencing in vitro rumen fermentation.

• 한국균학회지
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• 제23권2호통권73호
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• pp.161-175
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• 1995

메주는 간장과 된장의 원료로 우리나라의 식물성 단백질인 조선 전통식품으로 중요하다. 조선 전통식으로 농가에서 만들어진 23종류의 메주덩어리를 수거하여, 29종의 균과 한 종의 세균을 채집하여 동정하였다. 이러한 중에서 다만 몇개의 미생물만이 메주발효과정에 작용하는 것을 발견하였고, 나머지 미생물은 메주발효에서 잘못 발효로 일어나는 오염 미생물로 밝혀졌다. 메주발효과정에서는 물리적인 변화로 건조과정(수분활성도)과 열방생과정이 메주발효 중에 일어나며, 이러한 과정이 미생물(대부분의 경우 메주 표면에서는 균)의 천이를 유도시켜 메주의 생화학적인 변화를 유도하는 것으로 나타났다. 균의 천이 과정에서 수분이 많았을 때는 물곰팡이인 접합균이 첨 서식한 것이 발견되었으며, 메주발효를 유도하는 것으로 나타났다. 흰포자를 방출하는 Scopulariopsis brevicaulis는 메주표면에서 고초세균인 Bacillus megatrium와 함께 후기 발열반응과정에서 발견되고 있었다. 미생물들이 분비하는 단백질 분해효소에 관한 조사에서, 각각의 미생물들은 콩 단백질 분해에 서로 상호보안적인 역할을 하였다. 또한, 접합균들은 조선 전통의 메주발효과정에서 후기 메주발효를 유도하는 중요한 균으로 관찰되었다.

• 한국의류산업학회지
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• 제15권4호
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• pp.635-641
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• 2013

This study examined the dye-properties of natural fabrics dyed with Coptis chinensis and Curcuma longa root fermented with fungi. The optimum culture conditions for the fermentation of microorganisms, the relationship between natural dye color and fermentation conditions were investigated. Two different medical herbs (ground to 80-100 mesh in size) were used as a natural dyeing source. Phellinus linteus (P. linteus), which can grow in different media, such as Agarmedium (only agar containing medium), maltose extract agar (MA) and potato dextrose extract agar (PDA) culture media, were isolated from the medium. P. linteus was confirmed to be the optimum microorganism for the fermentation of Coptis chinensis and Curcuma longa, and the MA medium was confirmed to be the best for culturing. When using the microorganism as the fermenting agent, $32^{\circ}C$ was found to be the optimum fermenting temperature for both natural colorants. Regarding the dyeing property of the fermented natural dye, silk was dyed quite darkly in an appearance by naked eye estimation and the K/S value in the color strength of silk reached a high level of 16 after the fermenting process. The washing fastness of dyed silk after treatment washing was reduced from 4 to under4 and indicates that dyed silk with fermented plant was not unsubstantial. The light fastness was 1 to 2, showing intended to maintain due to the fermentation process.

• Journal of Microbiology and Biotechnology
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• 제8권5호
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• pp.427-440
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• 1998

• 한국균학회소식:학술대회논문집
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• 한국균학회 2009년도 춘계학술대회 및 임시총회
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• pp.38-40
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• 2009

• Journal of Microbiology and Biotechnology
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• 제30권11호
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• pp.1670-1679
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• 2020

The substantial use of fungal enzymes to degrade lignocellulosic plant biomass has widely been attributed to the extensive requirement of powerful enzyme-producing fungal strains. In this study, a two-step screening procedure for finding cellulolytic fungi, involving a miniaturized culture method with shake-flask fermentation, was proposed and demonstrated. We isolated 297 fungal strains from several cellulose-containing samples found in two different locations in Thailand. By using this screening strategy, we then selected 9 fungal strains based on their potential for cellulase production. Through sequence-based identification of these fungal isolates, 4 species in 4 genera were identified: Aspergillus terreus (3 strains: AG466, AG438 and AG499), Penicillium oxalicum (4 strains: AG452, AG496, AG498 and AG559), Talaromyces siamensis (1 strain: AG548) and Trichoderma afroharzianum (1 strain: AG500). After examining their lignocellulose degradation capacity, our data showed that P. oxalicum AG452 exhibited the highest glucose yield after saccharification of pretreated sugarcane trash, cassava pulp and coffee silverskin. In addition, Ta. siamensis AG548 produced the highest glucose yield after hydrolysis of pretreated sugarcane bagasse. Our study demonstrated that the proposed two-step screening strategy can be further applied for discovering potential cellulolytic fungi isolated from various environmental samples. Meanwhile, the fungal strains isolated in this study will prove useful in the bioconversion of agricultural lignocellulosic residues into valuable biotechnological products.

• 미생물학회지
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• 제19권4호
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• pp.154-162
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• 1981

서울근교 역곡동과 신원동의 논토양 시료들 중에서 계절별 균류의 수직분포를 조사하였다. 평판회석법을 사용하여 토양 1g중 총균류의 평균수는 상층부(5cm 깊이)에서 $10^4$ 이상을 나타내었으며 그 다음이 중충부(15cm 깊이), 하층부(25cm 깊이)의 순서였다. 가장 많은 총 균류의 분포는 가을토양의 상층부로 평균 $11.0\;{\times}\;10^4$ 이었다. 또한 균류의 수는 논 토양의 깊이가 깊어질 수록 감소하였다. 균 분포의 계절적 변이는 겨울에는 낮으나 가을에는 가장 높았으며, 이 사실로 가을이 균 생장에 가장 좋은 환경조건임을 알 수 있었다. 일반적으로, 논 토양에서의 Talaromyces의 수는 겨울에 적은 반면에 특히 가을에 현저하게 많으며, 역곡동의 가을 시료의 경우에는 토양 g당 $6.5\;{\times}\;10^4$ propagules로 최고수를 나타냈고, 신원동의 겨울시료가 $0.5\;{\times}\;10^4$으로 최저의 수를 나타내었다.

• Journal of Microbiology and Biotechnology
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• 제18권3호
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• pp.545-551
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• 2008

When cultivated aerobically, Aspergillus niger hyphae produced extracellular glucoamylase, which catalyzes the saccharification of unliquified potato starch into glucose, but not when grown under anaerobic conditions. The $K_m\;and\;V_{max}$ of the extracellular glucoamylase were 652.3 mg/l of starch and 253.3 mg/l/min of glucose, respectively. In mixed culture of A. niger and Saccharomyces cerevisiae, oxygen had a negative influence on the alcohol fermentation of yeast, but activated fungal growth. Therefore, oxygen is a critical factor for ethanol production in the mixed culture, and its generation through electrolysis of water in an electrochemical bioreactor needs to be optimized for ethanol production from starch by coculture of fungal hyphae and yeast cells. By applying pulsed electric fields (PEF) into the electrochemical bioreactor, ethanol production from starch improved significantly: Ethanol produced from 50 g/l potato starch by a mixed culture of A. niger and S. cerevisiae was about 5 g/l in a conventional bioreactor, but was 9 g/l in 5 volts of PEF and about 19 g/l in 4 volts of PEF for 5 days.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.529-532
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• 2001

Korean food waste, one of the abundantly available but environmentally problematic organic wastes in Korea, was utilized as solid-substrate by fungal strain Aspergillus niger ATcC 6275 for the production of enzymemixture containing amylase, cellulase and xylanase. The enzyme mixture can be used as high value-added animal feed. Solid-state fermentation method yielded a 84-fold enhancement in xylanase activity compared with submerged fermentation method. The effect of incubation period, incubation temperature, pH of medium, moisture content, inoculum size and enrichment of the medium with nitrogen and carbon sources were observed for optimal production of these enzymes The optimal amylase activity of 33.10 U/g, cellulase activity of 24.41 U/g, xylanase activity of 328.84 U/g were obtained at 8 days incubation with 50%(w/w) soy bean flake, with incubation temperature of $25^{\circ}C$, pH of 6.38, optimal moisture content of 55% and with inoculum size of $3.8{\times}10^6$spore/g. Enzyme activities were enhanced when ImM $CaSO_4$, 2% Malt extract and 2% galactose were added as mineral, nitrogen and carbon enrichment respectively.