• 동아시아식생활학회지
• /
• 제22권1호
• /
• pp.103-108
• /
• 2012

밀, 쌀 및 녹두를 분쇄 후 밀기울을 첨가하여 일정 비율(15:1:1:3)로 혼합한 곡물에 양조용 곰팡이의 균종을 달리하여 제조한 누룩의 품질 특성을 알아보고자 발효 시기별 일반성분 및 효소활성과 유기산 분석을 하였다. 누룩의 pH는 발효 시기별 큰 차이는 보이지 않았으며, 산도와 아미노산도는 두균을 혼합하여 제조한 누룩(AO-AK)이 가장 높게 나타났다. 전반적으로 두 균을 혼합한 누룩이 단일 균을 접종한 누룩보다 ${\alpha}$-amylase 및 acidic protease의 효소활성이 높게 나타났다. 누룩의 유기산은 acetic, citric, formic, fumaric, lactic, malic 및 oxalic acid 등이 확인되었다. 전체 유기산 총량은 혼용누룩(2,116.3 mg%), A. kawachii SC60 단용누룩(1,608.5 mg%), A. oryzae RIB1353 단용누룩(1,146.7 mg%) 순으로 혼용누룩의 유기산 생성량이 가장 높게 나타났다. 따라서 두 균주를 혼용하여 제조한 누룩이 단일균주를 사용한 누룩보다 유기산 함량, 효소활성 등 품질 특성이 우수한 것으로 여겨진다.

• Journal of Microbiology and Biotechnology
• /
• 제34권3호
• /
• pp.654-662
• /
• 2024

To investigate the effect of the predominant fungal species from Korean traditional meju and doenjang on soybean fermentation, the enzymatic activity and amino acid production of twenty-two fungal strains were assessed through solid- and liquid-state soybean fermentation. Enzymatic activity analyses of solid-state fermented soybeans revealed different enzyme activities involving protease, leucine aminopeptidase (LAP), carboxypeptidase (CaP), glutaminase, γ-glutamyl transferase (GGT), and amylase, depending on the fungal species. These enzymatic activities significantly affected the amino acid profile throughout liquid-state fermentation. Strains belonging to Mucoromycota, including Lichtheimia, Mucor, Rhizomucor, and Rhizopus, produced smaller amounts of total amino acids and umami-producing amino acids, such as glutamic acid and aspartic acid, than strains belonging to Aspergillus subgenus circumdati. The genera Penicillium and Scopulariopsis produced large amounts of total amino acids and glutamic acid, suggesting that these genera play an essential role in producing umami and kokumi tastes in fermented soybean products. Strains belonging to Aspergillus subgenus circumdati, including A. oryzae, showed the highest amino acid content, including glutamic acid, suggesting the potential benefits of A. oryzae as a starter for soybean fermentation. This study showed the potential of traditional meju strains as starters for soybean fermentation. However, further analysis of processes such as the production of G-peptide for kokumi taste and volatile compounds for flavor and safety is needed.

• Journal of Microbiology and Biotechnology
• /
• 제34권4호
• /
• pp.863-870
• /
• 2024

Meju, a fermented soybean brick, is a key component in soybean foods like doenjang and ganjang, harboring a variety of microorganisms, including bacteria and fungi. These microorganisms significantly contribute to the nutritional and sensory characteristics of doenjang and ganjang. Amplicon-based next-generation sequencing was applied to investigate how the microbial communities of meju fermented at low and high temperatures differ and how this variation affects the microbial communities of doenjang, a subsequently fermented soybean food. Our metagenomic data showed distinct patterns depending on the fermentation temperature. The microbial abundance in the bacterial community was increased under both temperatures during the fermentation of meju and doenjang. Weissella was the most abundant genus before the fermentation of meju, however, it was replaced by Bacillus at high temperature-fermented meju and lactic acid bacteria such as Weissella and Latilactobacillus at low temperature-fermented meju. Leuconostoc, Logiolactobacillus, and Tetragenococcus gradually took over the dominant role during the fermentation process of doenjang, replacing the previous dominant microorganisms. Mucor was dominant in the fungal community before and after meju fermentation, whereas Debaryomyces was dominant under both temperatures during doenjang fermentation. The dominant fungal genus of doenjang was not affected regardless of the fermentation temperature of meju. Strong correlations were shown for specific bacteria and fungi linked to specific fermentation temperatures. This study helps our understanding of meju fermentation process at different fermentation temperatures and highlights different bacteria and fungi associated with specific fermentation periods which may influence the nutritional and organoleptic properties of the final fermented soybean foods doenjang.

• Asian-Australasian Journal of Animal Sciences
• /
• 제32권3호
• /
• pp.357-365
• /
• 2019

Objective: The experiment was conducted to evaluate the effects of four fungal pretreatments on the nutritional value of Camellia seed residues, and to evaluate the feeding value of pretreated Camellia seed residues for ruminants. Methods: Camellia seed residues were firstly fermented by four lignin degrading fungi, namely, Phanerochaete chrysosporium (P. chrysosporium)-30942, Trichoderma koningiopsis (T. koningiopsis)-2660, Trichoderma aspellum (T. aspellum)-2527, or T. aspellum-2627, under solid-state fermentation (SSF) conditions at six different incubation times. The nutritional value of each fermented Camellia seed residues was then analyzed. The fermentation profiles, organic matter degradability and metabolizable energy of each pre-treated Camellia seed residue were further evaluated using an in vitro rumen fermentation system. Results: After 5 days of fermentation, P. chrysosporium-30942 had higher degradation of lignin (20.51%), consumed less hemicellulose (4.02%), and the SSF efficiency reached 83.43%. T. koningiopsis-2660 degraded more lignin (21.54%) and consumed less cellulose (20.94%) and hemicellulose (2.51%), the SSF efficiency reached 127.93%. The maximum SSF efficiency was 58.18% for T. aspellum-2527 and 47.61% for T. aspellum-2627, appeared at 30 and 15 days respectively. All the fungal pretreatments significantly improved the crude protein content (p<0.05). The Camellia seed residues pretreated for 5 days were found to possess significantly increased organic matter degradability, volatile fatty acid production and metabolizable energy (p<0.05) after the treatment of either P. chrysosporium-30942, T. koningiopsis-2660 or T. aspellum-2527. The fungal pretreatments did not significantly change the rumen fermentation pattern of Camellia seed residues, with an unchanged ratio of acetate to propionate. Conclusion: The fungi showed excellent potential for the solid-state bioconversion of Camellia seed residues into digestible ruminant energy feed, and their shorter lignin degradation characteristics could reduce loss of the other available carbohydrates during SSF.

• Fisheries and Aquatic Sciences
• /
• 제13권1호
• /
• pp.12-17
• /
• 2010

This study was conducted to evaluate the potential of a microbial fermentation procedure to improve the functional qualities of seaweeds. Aspergillus oryzae, which has been used in traditional Korean fermented foods, was inoculated and cultivated in an aqueous extract of sea tangle (Laminaria japonica). Fermentation of the sea tangle extract by A. oryzae for 4 days resulted in a 3-fold increase in $\gamma$-aminobutyric acid (GABA) content. GABA is known to be a bioactive compound. Fungal fermentation of the extract also enhanced its antioxidant activity and increased its total content of phenolic compounds. It was assumed that these changes stemmed from the biodegradation of active compounds of the sea tangle packaged within its rigid structural matrix or occurred as result of fungal fermentation. These results suggested that the application of microbial fermentation to the processing of seaweeds will help in the development of processed foods to meet consumer demands.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제9권4호
• /
• pp.245-251
• /
• 2004

The fungal species of Rhizopus oryzae 2062 has the capacity to carry out a single stage fermentation process for lactic acid production from potato starch wastewater. Starch hydrolysis, reducing sugar accumulation, biomass formation, and lactic acid production were affected with variations in pH, temperature, and starch source and concentration. A growth condition with starch concentration approximately 20 g/ L at pH 6.0 and 30$^{\circ}C$ was favourable for starch fermentation, resulting in a lactic acid yield of 78.3%∼85.5% associated with 1.5∼2.0 g/L fungal biomass produced in 36 h of fermentation.

• Asian-Australasian Journal of Animal Sciences
• /
• 제20권2호
• /
• pp.214-219
• /
• 2007

A $3{\times}3$ factorial design experiment was conducted to investigate the effect of temperature and duration of storage on the fermentation quality of potato pulp ensiled with two fungal inoculants under laboratory conditions. The inoculants, Rhizopus oryzae (R) and Amylomyces rouxii (A) were each added to potato pulp material to contain at least $1{\times}10^6$ CFU/g fresh matter, and silages without additives served as controls. The silages were stored under three temperature regimes; 4, 12 and $25^{\circ}C$. Three silos per treatment from every temperature regime were opened on days 7, 24 and 40 days after ensiling to investigate treatment effects on fermentation quality, starch and sugar concentrations. Increase in temperature and duration of storage had a positive significant effect (p<0.01) on the fermentation quality of potato pulp silage (PPS). The inoculants had little effect (p>0.05) on the fermentation quality of the silages. Sugar concentration in the silages decreased with increase in temperature (p<0.01) but increased (p<0.05) with progression of duration of storage. The fungal inoculants had no effect on starch degradation in PPS. The results suggest that storage temperature and duration of storage are more important in determining the rate of fermentation than addition of the fungal inoculants in PPS.

• Food Science and Biotechnology
• /
• 제15권4호
• /
• pp.647-649
• /
• 2006

Mevinolin, a fungal metabolite, is a potent inhibitor of 3-hydroxy-methyl-3-glutaryl-coenzyme A (HMG-CoA) reductase, the rate-controlling enzyme in cholesterol biosynthesis. In this investigation, the optimum factors for mevinolin production by Monascus pilosus IFO 480 in soymeal fermentation were studied. The highest yield of mevinolin, 2.82 mg mevinolin per g dry weight, without citrinin (a toxic fungal secondary metabolite) was obtained after 21 days of fermentation at $30^{\circ}C$ at 65% moisture content, particle size 0.6-0.9 mm, and initial substrate pH of 6.0. Mevinolin was present in the fermentation substrate predominantly in the hydroxycarboxylate form (open lactone, 92.1-97.3%), which is currently being used as a hypocholesterolemic agent.

• Journal of Microbiology and Biotechnology
• /
• 제27권1호
• /
• pp.1-8
• /
• 2017

The production of high-value chemicals from natural resources as an alternative for petroleum-based products is currently expanding in parallel with biorefinery. The use of lignocellulosic biomass as raw material is promising to achieve economic and environmental sustainability. Filamentous fungi, particularly Aspergillus species, are already used industrially to produce organic acid as well as many enzymes. The production of lignocellulose-degrading enzymes opens the possibility for direct fungal fermentation towards organic acids such as itaconic acid (IA) and fumaric acid (FA). These acids have wide-range applications and potentially addressable markets as platform chemicals. However, current technologies for the production of these compounds are mostly based on submerged fermentation. This work showed the capacity of two Aspergillus species (A. terreus and A. oryzae) to yield both acids by solid-state fermentation and simultaneous saccharification and fermentation. FA was optimally produced at by A. oryzae in simultaneous saccharification and fermentation (0.54 mg/g wheat bran). The yield of 0.11 mg IA/g biomass by A. oryzae is the highest reported in the literature for simultaneous solid-state fermentation without sugar supplements.

• 농업과학연구
• /
• 제31권1호
• /
• pp.15-25
• /
• 2004

균류발효물질의 사료가치를 평가하고 착유우 사료에 대한 발효물질 첨가가 in vitro 반추위액 발효상태 증진 효과를 규명하기 위하여 비발효(Unfermented; UF)구와 Formitella flaxinea(FF)와 Sarcodon aspratus(SA)에 의한 톱밥+소맥피 배양물 성분변화와 48시간 발효 후 소화율을 측정하고 기본유우사료 (Basal diet)에 이들 발효물을 0, 1, 3 및 5%를 첨가하여 in vitro 건물소화율, pH 및 용해성 당류의 변화 등을 규명하여 다음과 같은 결과를 얻었다. 1. 발효물의 영양소 함량변화는 Neutral detergent fiber(NDF)에서 차이가 크게 나타났는데 SA와 UF(80.4와 82.2%)가 FF(88.3%)에 비해 낮게 나타났다(P<0.05). In vitro 반추위 소화시험(48시간)에서는 SA(21.2%)가 UF와 FF(17.9 및 12.2%)보다 높게 나타났다(P<0.05). 2. 균류 첨가 사료에 대한 건물소화율을 발효 24시간에서 기본사료(44.98%)에 비하여 FF 1%(49.18%)에서 높게 나타났으며(P<0.05), 기타 균류첨가사료에서는 높게 나타나는 경향을 보였다. 그러나 발효 48 및 72시간에서는 기본사료와 첨가사료간에 유의차가 나타나지 않았다. 3. 반추위 pH는 발효 24시간 및 48시간에서 기본사료(6.64 및 6.91)에 비하여 첨가사료가 낮은 경향(5.37~6.01 및 6.04~6.07)을 보였으며 (P<0.05), 발효 72시간에서는 SA 1%(6.74)가 기본사료(6.41)에 대하여 높게 나타났으나(P<0.05) 기타 첨가구에서는 유의차가 나타나지 않았다. 4. 가용성당 함량은 발효 24시간에서는 기본사료 첨가구에서 유의차가 보이지 않았으나 48시간은 기본사료(1.44%)에 비하여 SA 5%(1.71)에서 높게 나타났고 발효72시간에서는 기본사료(1.44%)에 비하여 첨가구사료(1.64~1.74%)가 모두 높게 나타났다(P<0.05). 5. 이상의 결과로 보아 균류발효물질의 사료나 사료 첨가제로서 in vitro 반추위 소화율 증진 효과가 나타났고 가용성당함량 증가효과도 보였다. 따라서 앞으로 첨가제를 순수한 균사로만 분리 제조하면 효과가 더욱 증진될 것으로 기대되며 톱밥균류 발효물질 전체를 사료의 5%내에서 이용효과도 기대된다고 판단되었다.