• 한국균학회지
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• 제42권2호
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• pp.144-149
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• 2014

본 연구에서는 효율적으로 표고 액체종균을 생산하기 위하여, 액체배지에 폭기방법으로 산소를 공급하고, 대두박을 첨가하여 표고균사체 생장량과 잔존 배양액의 유리당함량을 조사하였다. 그 결과 폭기방법은 균질화된 표고균사가 생장하면서 서로 뭉치지 않고 균질하게 증식하고, 대두박 첨가는 대수기 이후에도 지효성 질소영양원이 공급되도록 하는 효과가 있었다. 배양 중 침전 균사체의 중량은 13일째에 가장 많았으며, 배양용기의 배출구에서 이산화탄소 농도는 13일째에 가장 높았다. 상층 수용액에서 환원당은 폭기 12일째에 거의 소비되었다. 그리고 배양균사체에서 총질소(T-N)량은 폭기 배양 13일째에 최고 수준이며, 키틴함량과 5종의 유리당 중에서 수크로즈함량은 폭기 배양 18일째에 가장 높았으나, 에르고스테롤 함량은 폭기 배양 22일째에 가장 높았다. 이와 같은 결과를 종합적으로 판단할 경우 표고액체 종균으로서 사용 적기는 균사활력이 가장 왕성하고 균체량이 많은 배양 18일째로 판단되었다.

• 한국균학회지
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• 제32권2호
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• pp.95-100
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• 2004

목질진흙버섯의 균사생육에 적합한 배지로는 MYA(malt yeast agar)와 SMS(soybean flour malt extract sugar)이며, MYA를 기본배지로 사용하였다. 균사생육은 $30^{\circ}C$의 온도와 pH는 5.0에서 생장이 양호하였다. 영양원으로는 malt extract 2%, yeast extract 0.2%와 $KH_{2}PO_{4}$ 0.1% 상태에서 균사생장 및 밀도가 양호하였다. C/N비는 10 : 1의 비율이 가장 적합하였다. 삼각플라스크배양을 위해서는 용기부피 300 ml Shake flask에 100 ml의 배양액을 넣고 $5{\sim}6$개 균사체 절편을 접종하여 20일간 배양하면 높은 고립상의 균체를 양호하게 증식시킬 수 있었다. 대량 액체종균 배양을 위해 접종원을 균질기로 분쇄하여 통기량 2.0 vvm의 조건에서 12일 배양하면 높은 균사의 생장을 보였고 접종에도 수월하였다.

• Journal of Microbiology
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• 제44권2호
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• pp.233-242
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• 2006

The objectives of this study were to optimize submerged culture conditions of a new fungal isolate, Ganorderma resinaceum, and to enhance the production of bioactive mycelial biomass and exopolysaccharides (EPS) by fed-batch culture. The maximum mycelial growth and EPS production in batch culture were achieved in a medium containing 10 g/l glucose, 8 g/l soy peptone, and 5 mM $MnCl_2$ at an initial pH 6.0 and temperature $31^{\circ}C$. After optimization of culture medium and environmental conditions in batch cultures, a fed-batch culture strategy was employed to enhance production of mycelial biomass and EPS. Five different EPS with molecular weights ranging from 53,000 to 5,257,000 g/mole were obtained from either top or bottom fractions of ethanol precipitate of culture filtrate. A fed-batch culture of G. resinaceum led to enhanced production of both mycelial biomass and EPS. The maximum concentrations of mycelial biomass (42.2 g/l) and EPS (4.6 g/l) were obtained when 50 g/l of glucose was fed at day 6 into an initial 10 g/l of glucose medium. It may be worth attempting with other mushroom fermentation processes for enhanced production of mushroom polysaccharides, particularly those with industrial potential.

• 한국미생물·생명공학회지
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• 제23권5호
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• pp.602-608
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• 1995

The aim of the present research program was to construct an optimum fermentation system and to characterize the properties of cathepsin B inhibitor from Streptomyces chromofuscus SMF28. Glucose and casitone were proved to be good carbon source and nitrogen source, respectively. The production of inhibitor was high at lower concentration than 10 mM of inorganic phosphate. The optimum temperature and pH for the production of inhibitor were 30$\circ$C and pH 7, respectively. The production of inhibitor was related to mycelial growth and was affected by medium composition. The inhibitor in culture filtrate of S. chromofuscus SMF28 was purified by butanol extraction, silica gel chromatography, Amberlite IRC-50 (H$^{+}$ form) chromatography, preparative TLC, and preparative HPLC. From amino acid analysis and UV, IR, $^{1}$H-NMR spectroscopic analysis, the inhibitor was identified as a peptide containing valine and phenylalanine derivative.

• 산업기술연구
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• 제8권
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• pp.13-21
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• 1988

For the improvement of productivity of Pleurotus ostreatus, the production of liquid spawn was studied. The highest liquid spawn production was obtained after shaking culture for 4 days in the culture medium containing 5%(W/V) wheat flour, 0.2%(W/V) yeast extract, 0.1%(W/V)$KNO_3$ 0.05% (W/V) $MgSO_4{\cdot}7H_2O$, 0.05%(W/V) $KH_2PO_4$. The optimum pH and temperature was 7.0 ana $30^{\circ}C$. The period required to complete the mycelial growth after spawning were 28, 22, 10 and 9 days, respectively, when the 2%(V/V) of solid spawn and 2%(V/V), 5% (V/V) and 10%(V/V) of liquid spawn were inoculated. The days required from spawning to fruiting bodies were 38, 34, 28 and 27 days.

• 식물병연구
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• 제15권3호
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• pp.222-229
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• 2009

기계유가 심하게 오염된 토양으로부터 생물계면활성제를 생산하고 항균활성과 살충활성을 보이는 Pseudomonas sp. SG3 균주를 분리하였다. 이 길항세균은 시험한 8개의 식물병원곰팡이 모두에 대하여 균사생육저해활성을 보였다. 또한 in vivo assay에서는 SG3 액체 배양액 처리시 벼도열병, 토마토 잿빛곰팡이병, 토마토 역병, 밀 붉은녹병, 보리 흰가루병 및 고추 탄저병에 강한 항균 효과를 보였다. 액체배양액으로부터 ethyl acetate 추출, silica gel column chromatography 및 preparative HPLC 등을 통하여 한 개의 항균물질을 분리하였다. 질량분석과 핵자기공명분석을 통해 분리한 물질의 구조를 동정한 결과 rhamnolipid B로 동정되었다. Rhamnolipid B는 토마토 잿빛곰팡이병과 토마토 역병에 높은 방제활성을 보였다. 그리고 토마토 잿빛곰팡이병균인 B. cinerea의 균사 생장과 토마토 역병균인 P. infestans의 유주자 발아 및 균사 생장을 효과적으로 억제하였다. Rhamnolipid B를 생산하는 Pseudomonas sp. SG3는 토마토에서 발생하는 식물병을 방제하는 새로운 생물방제제로서 이용이 가능할 것으로 기대된다.

• 한국식품조리과학회지
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• 제29권3호
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• pp.267-274
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• 2013

Demand for a rice cake, a popular traditional food in Korea, is rising, but its industrial-scale production is extremely difficult due to its short shelf-life caused by starch retrogradation and microbial spoilage. By means of the sourdough fermentation technique, we attempt to develop rice cakes with a longer shelf-life. Heterofermentative lactic acid bacteria (Weissella koreensis HO20, Weissella kimchii HO22) isolated from kimchi were used to ferment wet-milled rice flour for their abilities to produce exopolysaccharides and to inhibit the microbial spoilage of rice cakes. After 24 hr of fermentation at $25^{\circ}C$, viable cell counts in rice dough increased from $10^6$ CFU/g to $10^8$ CFU/g and total titratable acidity increased from 0.05% to 0.20%, whereas pH decreased from 6.5 to 5.1. Fermented rice flour showed significantly lower peak, trough, and final viscosities as well as breakdown and setback viscosities measured by rapid viscoanalyzer. Both lactic acid bacteria showed in vitro antifungal activity against Penicillium crustosum isolated from rice cakes. The antifungal activity remained constant after the treatments with heat, proteinase K and trypsin, but fell significantly by increase of pH. Rice cakes made of fermented rice flour were found to retard mycelial growth of P. crustosum. The degree of retrogradation as measured by the hardness of the rice cake was significantly reduced by the use of fermented rice flour. The results suggest that use of fermented rice flour has a beneficial role in retarding starch retrogradation and in preventing fungal growth, hence extending the shelf-life of rice cakes.

• 한국버섯학회지
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• 제6권1호
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• pp.27-31
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• 2008

현재까지 연구로는 흰목이 균사체에서 EPS 생산과 균사생장에 대한 적정 정치배양 조건이 연구되었다. 본 연구로부터 탄소원과 질소원의 처음 농도, 균사 형태와 발효조의 타입의 선택은 흰목이 균사체 EPS 생산에 가장 영향을 미친다는 것을 알게 되었다. 이들 결과는 공기주입식 반응기에서 EPS 생산성은 진탕탱크 반응기 보다 더 높았다는 점을 증명하였다. 또한 흰목이 균사의 정치배양의 생리적 생장에 대한 지식은 아직도 제한적이다.

• Journal of Microbiology and Biotechnology
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• 제20권4호
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• pp.844-851
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• 2010

Controlling the dissolved oxygen (DO) in the fed-batch culture of the medicinal mushroom Ganoderma lucidum led to a 2-fold increase of the maximum biomass productivity compared with uncontrolled DO conditions. By contrast, extracellular polysaccharide (EPS) production was two times higher under oxygen limitation (uncontrolled DO) than under increased oxygen availability (controlled DO). Morphologically, dispersed mycelium was predominant under controlled DO conditions, with highly branched hyphae, consistent with the enhanced culture growth noted under these conditions, whereas in the uncontrolled DO process mycelial clumps were the most common morphology throughout the culture. However, in both cultures, clamp connections were found. This is an exciting new finding, which widens the applicability of this basidiomycete in submerged fermentation. In rheological terms, broths demonstrated shear-thinning behavior with a yield stress under both DO conditions. The flow curves were best described by the Herschel-Bulkley model: flow index down to 0.6 and consistency coefficient up to 0.2 and 0.6 Pa $s^n$ in uncontrolled and controlled cultures DO, respectively. The pseudoplastic behavior was entirely due to the fungal biomass, and not to the presence of EPS (rheological analysis of the filtered broth showed Newtonian behavior). It is clear from this study that dissolved oxygen tension is a critical process parameter that distinctly influences G. lucidum morphology and rheology, affecting the overall performance of the process. This study contributes to an improved understanding of the process physiology of submerged fermentation of G. lucidum.

• Journal of Microbiology and Biotechnology
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• 제34권5호
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• pp.1040-1050
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• 2024

To isolate and analyze bacteria with Verticillium wilt-resistant properties from the fermentation residue of kitchen wastes, as well as explore their potential for new applications of the residue. A total of six bacterial strains exhibiting Verticillium wilt-resistant capabilities were isolated from the biogas residue of kitchen waste fermentation. Using a polyphasic approach, strain ZL6, which displayed the highest antagonistic activity against cotton Verticillium wilt, was identified as belonging to the Pseudomonas aeruginosa. Bioassay results demonstrated that this strain possessed robust antagonistic abilities, effectively inhibiting V. dahliae spore germination and mycelial growth. Furthermore, P. aeruginosa ZL6 exhibited high temperature resistance (42℃), nitrogen fixation, and phosphorus removal activities. Pot experiments revealed that P. aeruginosa ZL6 fermentation broth treatment achieved a 47.72% biological control effect compared to the control group. Through activity tracking and protein mass spectrometry identification, a neutral metalloproteinase (Nml) was hypothesized as the main virulence factor. The mutant strain ZL6ߡNml exhibited a significant reduction in its ability to inhibit cotton Verticillium wilt compared to the strain P. aeruginosa ZL6. While the inhibitory activities could be partially restored by a complementation of nml gene in the mutant strain ZL6CMߡNml. This research provides a theoretical foundation for the future development and application of biogas residue as biocontrol agents against Verticillium wilt and as biological preservatives for agricultural products. Additionally, this study presents a novel approach for mitigating the substantial amount of biogas residue generated from kitchen waste fermentation.