• 한국미생물·생명공학회지
• /
• 제51권4호
• /
• pp.441-448
• /
• 2023

Penicillium spp. are frequently found in meju, a Korean traditional fermented soybean brick. We isolated and identified 96 Penicillium spp. from 22 traditional meju, and their β-tubulin genes were sequenced for the genetic and taxonomic study. Penicillium Section Viridicata was the most commonly isolated group. Notably, we also isolated and identified Penicillium roqueforti, a crucial industrial strain employed in the fermentation of blue cheese. Additionally, certain strains exhibited relatively high protease and γ-glutamyl transpeptidase activities, suggesting that they might contribute to the development of kokumi flavor during meju fermentation. Interestingly, all eight Penicillium spp., including P. roqueforti, were found to possess both types of MAT1 genes. This intriguing finding suggests the feasibility of strain improvement through mating, thereby offering opportunities for industrial applications. Therefore, these studies pave the way for a deeper exploration of Penicillium's role in meju fermentation, potentially leading to the development of starters for producing plant-based cheese-flavored condiments.

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

• 한국미생물·생명공학회지
• /
• 제24권2호
• /
• pp.247-253
• /
• 1996

Changes in microorganisms, enzyme activities and major components of two types of Doenjang prepared with spring Meju and autumn Meju and Kochujang were investigated during 4 months of fermentation. The viable cell counts of aerobic bacteria in Doenjang and Kochujang were increased up to 60 days of fermentation, but viable cell counts of anaerobic bacteria did not show remarkable changes during fermentation. Viable cell count of yeast showed a rapid increase up to 15 days of fermentation in Doenjang and 60 days in Kochujang. It was found that $\alpha$-amylase activity of autumn Meju Doenjang and glucoamylase activity of Kochujang were higher than the other. Acidic and neutral protease showed the highest activity during 15-30 days of fermentation. The pH of Doenjang was increased up to pH 7.0 until 60 days of fermentation, but pH of Kochujang gradually decreased during fermentation. Moisture content of spring Meju Doenjang and Kochujang decreased to 40% during ferme- ntation and reducing sugar content of Kochujang increased up to 15 days of fermentation, but decreased after that.

• 한국식품영양학회지
• /
• 제33권5호
• /
• pp.524-531
• /
• 2020

The purpose of this study was to evaluate the quality properties of Meju prepared by inoculating two strains of Bacillus amyloliquefaciens HJ5-2, and Aspergillus oryzae PS03. The three soybean varieties that include Daewonkong, Daechan, and Saedanbaek were used in this experiment. The fermentation temperature during the Meju aging varied at 20℃, 30℃, and 40℃, respectively. The physicochemical analysis of the soybeans, showed that the cured protein and fat contents were 34.83~43.49% and 12.91~18.90%, respectively. The pH and total acidity were 6.47~6.93 and 0.11~1.22%, respectively. The change in appearance of the Meju was that the yellow-green mold was well formed on seven days at fermentation temperature of 20℃ and 30℃, but at 40℃, there was minimal mold formation and cracking of the surface. The amino nitrogen content was highest on the Daechan Meju at 621.83 mg% for seven days. The amylase increased as the fermentation period increased in all samples, and the protease increased rapidly until the first day of the fermentation, and then gradually increased thereafter. The total number of bacteria increased or decreased as the fermentation proceeded to 6.66~10.07 log CFU/g. The mold counts increased with increasing fermentation period in the range of 6.38~8.79 log CFU/g.

• Food Science and Biotechnology
• /
• 제17권3호
• /
• pp.527-533
• /
• 2008

For preparation of high quality kochujang by the traditional fermentation method, 4 types of kochujang were prepared with brick- or grain-shaped meju fermented with different strains (Aspergillus sojae, Aspergillus oryzae+Bacillus subtilis). After 100 days of fermentation at $25^{\circ}C$, the moisture, pH, salt, and ethanol content of kochujang were 40.52-43.20%, 4.71-4.82, 8.7-9.1%, and 0.75-0.94%, respectively, showing slight differences according to the strains and shapes of meju. Titratable acidities were slightly increased for up to 60 days of fermentation. The amino-type nitrogen content of kochujang prepared with brick-shaped meju (A. oryzae+B. subtilis) was the highest (164.20 mg%) among all of the kochujang types. The redness (a) value of kochujang prepared with brick-shaped meju (A. sojae) were higher (19.08) than those of other treatments (18.37-18.59). Sensory evaluation of kochujang prepared with grain-shaped meju (A. sojae) showed the highest scores for color and overall acceptability, 'at $6.43{\pm}1.87$ and $6.29{\pm}1.44$, respectively. It was estimated that high quality kochujang could be made by using meju fermented with selected strains.

• 한국식품저장유통학회지
• /
• 제18권3호
• /
• pp.397-406
• /
• 2011

메주의 산업화를 위해, 종균으로서는 A. oryze와 A. sojae 그리고 B. subtilis를 병용하고, 습도조절과 함께 $28^{\circ}C$에서 12일간 발효하면서 메주의 품질특성 변화를 조사하였다. 그리고 이들 종균 접종 메주와 순창 고추장 민속마을에서 입수한 된장용 전통메주의 효소 활성도를 비교하였다. 즉, A. oryzae를 접종한 메주(=AO메주), A. oryze와 B. subtilis를 접종한 메주(AOBS메주), A. sojae를 접종한 메주(=AS메주), A. sojae와 B. subtilis를 접종한 메주(=ASBS메주)를 12일 동안 발효시키면서 메주별로 품질 변화를 관찰하였다. 세균수와 곰팡이수는 각각 발효초기 6.48~6.69 log cfu/g, 5.00~5.71 log cfu/g에서 발효 2일에 8 log cfu/g 이상, 6 log cfu/g 이상으로 증가한 후 발효 12일 까지 세균수는 유지되었고, 곰팡이수는 감소 경향을 보였다. 아미노태 질소 함량은 발효 2일에 430.5~577.5 mg% 범위를 나타내었다. 중성 protease 활성도는 전통메주 $1,258.0{\pm}38.8$, AS메주 $1,238.3{\pm}38.6$, AO메주 $1,204.1{\pm}24.1$, ASBS메주 $1,040.6{\pm}10.6$, AOBS메주 $1,033.5{\pm}11.2$ unit/g순으로 나타났다. 산성 protease활성도는 AO메주 $1,030.1{\pm}19.1$, 전통메주 $1007.7{\pm}30.5$, AS메주 $990.9{\pm}25.0$, AOBS메주 $910.9{\pm}15.3$, ASBS메주 $888.2{\pm}15.7$ unit/g 순이었다.

• Journal of Microbiology and Biotechnology
• /
• 제23권12호
• /
• pp.1654-1663
• /
• 2013

Rice straw is closely associated with meju fermentation and it is generally known that the rice straw provides meju with many kinds of microorganisms. In order to elucidate the origin of meju fungi, the fungal diversity of rice straw was examined. Rice straw was collected from 12 Jang factories where meju are produced, and were incubated under nine different conditions by altering the media (MEA, DRBC, and DG18), and temperature ($15^{\circ}C$, $25^{\circ}C$, and $35^{\circ}C$). In total, 937 strains were isolated and identified as belonging to 39 genera and 103 species. Among these, Aspergillus, Cladosporium, Eurotium, Fusarium, and Penicillium were the dominant genera. Fusarium asiaticum (56.3%), Cladosporium cladosporioides (48.6%), Aspergillus tubingensis (37.5%), A. oryzae (31.9%), Eurotium repens (27.1%), and E. chevalieri (25.0%) were frequently isolated from the rice straw obtained from many factories. Twelve genera and 40 species of fungi that were isolated in the rice straw in this study were also isolated from meju. Specifically, A. oryzae, C. cladosporioides, E. chevalieri, E. repens, F. asiaticum, and Penicillium polonicum (11.8%), which are abundant species in meju, were also isolated frequently from rice straw. C. cladosporioides, F. asiaticum, and P. polonicum, which are abundant in the low temperature fermentation process of meju fermentation, were frequently isolated from rice straw incubated at $15^{\circ}C$ and $25^{\circ}C$, whereas A. oryzae, E. repens, and E. chevalieri, which are abundant in the high temperature fermentation process of meju fermentation, were frequently isolated from rice straw incubated at $25^{\circ}C$ and $35^{\circ}C$. This suggests that the mycobiota of rice straw has a large influence in the mycobiota of meju. The influence of fungi on the rice straw as feed and silage for livestock, and as plant pathogens for rice, are discussed as well.

• 한국조리학회지
• /
• 제6권3호
• /
• pp.357-371
• /
• 2000

Changes of Microflora, enzyme activity, and contents of several taste compounds in traditional Kanjang(Korean Soy Sauce) with the variation of fermentation jars and Meju(fermented soybean brick)concentration were studied. Substitution possibilities of clay jar with glass jar and improvement possibilities of taste and nutritional value with increased Meju concentration were examined. (1) Aerobic bacteria and lactic acid bacteria were enumerated during fermentation and ripening period. But yeast and molds were hardly isolated. The number of viable cells showed small changes during fermentation and ripening period. (2) Isolated Aerobic bacteria were identified as Bacillus subtilis, Bacillus lichenformis, and lactic acid bacteria were identified as Lactlbacillus lactis lactis and lactobacillus brevis. (3) The activities of $\alpha$-amylase and $\beta$-amylase increased during fermentation period, but did not show any trend by fermentation jars or Meju concentrations. Protense activity showed small difference among four samples, and increased during the fermentation period.

• 한국식품과학회지
• /
• 제32권1호
• /
• pp.125-131
• /
• 2000

고추장의 품질 향상 및 제품 다양화를 목적으로 메주, 고오지 및 메주와 고오지의 혼용으로 담금한 고추장의 숙성과정 중 품질은 아래와 같다. 고추장 숙성과정 중 수분은 $53.4{\sim}66.5%$, 식염 $8.3{\sim}10.1%$, 조단백질 $8.3{\sim}19.3%$, pH $4.6{\sim}5.4$의 범위였다. 아미노태질소는 숙성 중 증가하여 150일에 $230{\sim}270mg%$로 나타났고 담금 직후에는 혼용고추장에서, 숙성 30일 이후는 고오지 고추장에서 높았다. 환원당은 숙성 60일에 $15.0{\sim}19.5%$로 최대함량을 보였다. 고추장의 아미노산 함량은 glutamic acid가 $1.38{\sim}3.66%$로 아미노산 중 함량이 가장 높았고 이외 aspartic acid, leucine, arginine, alanine, phenylalanine의 함량이 높은 편에 속하였다. 색도의 밝기는 30일까지 혼용고추장에서, 이후는 메주 고추장에서 높았으며 적색도는 60일까지 메주 고추장에서, $90{\sim}120$일에는 고오지 고추장에서 높았다.

• 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.