• Journal of the Korean Society of Food Science and Nutrition
• /
• v.25 no.1
• /
• pp.157-162
• /
• 1996

A. oryzas 의 밀가루 누룩과 R. japonicus의 밀가루 누룩으로 탁주를 제조할 때에는 두 누룩의 혼합 비율이 탁주의 품질에 미치는 영향을 알아조기 위하여 두 누룩의 혼합 비율을 달리하여 7종의 탁주시료를 제조하고, 탁주의 이화학적 및 관능적 특성들을 조사하였다. R. japonicus는 누룩의 사용 비율이 높을 때에는 술덧의 산도와 유리당 함량이 높았고, 제성주의 부유물 함량과 부유물의 현탁 안정성도 높았다. 그러나 A. oryzas 누룩의 사용 비율이 높을 때에는 술덧의 산도와 유리당 함량이 낮았고, 제성주의 부유물 함량과 부유물의 현탁 안정성도 낮았다. R. japonicus 누룩과 A. oryzas 누룩을 2 : 1~5 : 1의 비율로 병용했을때에는 주박의 양이 크게 줄어들었고, 아미노산 함량이 증가하였으며, 기호성도 더 좋아졌다. 탁주의 전반적이 특성으로 볼 때 각 누룩의 단용시에는 R. japonicus 누룩이 A. oryzas 누룩보다 좋았다. 그러나 R. japonicus 누룩과 A. oryzas 누룩을 병용했을때에는 탁주의 전반적인 품질이 더욱 개선되어졌는데, 이때 두 누룩의 최적 혼합 비율은 대략 5 : 1이었다.

• Mycobiology
• /
• v.33 no.2
• /
• pp.109-112
• /
• 2005

The internal transcribed spacer (ITS) regions including the 3'-end of 18S rRNA gene, 5.8S rRNA gene and the 5'-end of the 28S rRNA gene of Rhizopus spp. were amplified by PCR and analyzed by DNASIS program. Length polymorphism of these region ranged from 564 bp in R. oryzae to 789bp in R. stolonifer. The length and sequence of 5.8S was very conserved with $154{\sim}155\;bp$. The sequence of ITS2 was more variable than that of ITS1. The base substitution rates were ranged from 0 to 0.6069 per site, and higher rate was found in R. stolonifer. In general, transition was usually more frequent than transversion. On the basis of sequencing results, four groups were clustered with value of 61.9% similarity; R. oryzae, R. micros pores, R. homothallicus, and R. stolonifer groups.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.1
• /
• pp.72-79
• /
• 2016

The fungal morphologies and pellet sizes were controlled in acetophenone reduction by Rhizopus oryzae. The acetophenone conversion and (S)-phenylethanol enantiomeric excesses (e.e.) reached the peak after 72 h of incubation when using pellets with 0.54 mm diameter, which showed an excellent performance compared with suspended mycelia, clumps, and pellets with 0.65 or 0.75 mm diameter. Furthermore, nano-sized acetophenone was used as a substrate to improve the performances of biotransformation work. The results showed that the conversion of nanometric acetophenone and (S)-phenylethanol e.e. reached the maximum (both >99%) after 32 h of incubation when using 0.54 mm diameter pellets, at least 24 h in advance of the control group. On the other hand, Tween 80 and 1, 2-propylene glycol showed low or no toxicity to cells. In conclusion, pellets and acetophenone nanoemulsions synergistically result in superior performances of acetophenone reduction.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.9 no.4
• /
• 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.

• Microbiology and Biotechnology Letters
• /
• v.26 no.5
• /
• pp.456-464
• /
• 1998

For the standardization and quality improvement of traditional Korean Nuruk, 10 strains of fungi, which were isolated from Nuruks and showed good productivity of the saccharogenic and dextrinogenic enzymes, acid and flavor, were selected and their enzymological characteristics and identification were carried out. Aspergillus spp. and Rhizopus sp. showed a high liquefying activity without regard to cultivation time, whereas the majority of strains except for Rhizopus sp. had decreasing saccharifying activity in proportion to the increase in cultivation time. Aspergillus spp. No.17-2, No.17-6 and Rhizopus sp. No.18-1 showed high liquefying and saccharifying activity after 15 and 30 day cultivation. The optimum temperature of most of these saccharogenic and dextrinogenic enzymes was from 40$^{\circ}C$ to 60$^{\circ}C$, and their optimum pH was extensive between pH 3 and pH 11. But Penicillium spp.(2 strains) and Rhizopus sp. showed low activity under the alkalic and acidic conditions. Among these isolated strains, 5 strains which had shown the high productivity of materials were identified as Aspergillus oryzae NR3-6 and Aspergillus oryzae NR17-6, Aspergillus penicilloides NR12-1, Penicillium expansum NR7-7 and Rhizopus oryzee NRl8-1, respectively. Five kinds of mixed culture were carried out and all of them showed a better productivity of saccharogenic and dextrinogenic enzymes than single culture. These results indicate that it is possible to make traditional Korean liquors of good quality by using these fungi.

• Food Science and Biotechnology
• /
• v.18 no.6
• /
• pp.1423-1429
• /
• 2009

Rhizopus oryzae KSD-815 was isolated from nuruk that has been used to make Korean traditional wines. This study was performed to investigate the effect of cultures of R. oryzae KSD-815 on cardiovascular disorders and cancer metastasis. Firstly, these cultures were sequentially fractionationed with n-hexane (TAHe), ethylacetate (TAE), n-butanol (TAB), and $H_2O$ (TAW). The TAE inhibited the activity of angiotensin-converting enzyme (ACE) and TAB suppressed platelet aggregation in vitro. TAE and TAB inhibited cell motility of human breast cancer cells. Furthermore, TAW interrupted the formation of neovasculature and tube-like structure, and down-regulated the expression of angiogenic factors, basic fibroblast growth factor (bFGF), tumor necrosis factor-$\alpha$ (TNF-$\alpha$), and hypoxia-inducible factor-$1{\alpha}$ (HIF-$1{\alpha}$) in breast cancer cells. These results indicated that cultures of R. oryzae KSD-815 display the inhibitory activities on hypertension, platelet aggregation, and metastasis, and suggest that these cultures might be further probed for the purposes as therapeutic agents or dietary supplements.

• Korean Journal of Food Science and Technology
• /
• v.16 no.3
• /
• pp.322-328
• /
• 1984

These experiments were conducted to purify the glucoamylase produced by Rhizopus oryzae. Two forms of glucoamylase (GI and GII) from Phizopus oryzae were purified by $(NH_2)_2SO_4$ fractionation, acetone fractionation and successive column chromatography on DEAE-cellulose and CM-cellulose. The specific activities of GI and GII toward soluble starch were 157.6 U/㎎. protein (37.5 fold of crude extract), and 164.7 U/㎎. protein (39.2 fold of curde extract), respectively, and the yields of them were 4.3% and 3.8%, respectively. The two purified enzymes have shown a single band by polyacrylamide disc gel electrophoresis and SDS-polyacrylamide gel electrophoresis. The protein bands of their electrophoresis gel were revealed to have glucoamylase activity by iodine staining and were proved to be glycoprotein by periodic acid Schiff's staining.

• Microbiology and Biotechnology Letters
• /
• v.40 no.4
• /
• pp.319-324
• /
• 2012

Production of liquid starters using wheat bran as a medium for Rhizopus oryzae N174 and the changes in their characteristics noted during storage were investigated in this study. The optimal culture conditions of the liquid starters were determined to be 5~15% (w/v) wheat bran and 48~72 hrs of incubation. The effects of liquid starters with different storage periods and temperatures (-18, 4, 10 and $25^{\circ}C$) on the quality of wheat nuruk were evaluated. According to the results of the pH, acidity, reducing sugar and enzyme activities, it was found that liquid starter using wheat bran preserved for one day, at any temperature, is the best method of storage for seed cultures for R. oryzae N174.

• Mycobiology
• /
• v.43 no.4
• /
• pp.415-422
• /
• 2015

The study aimed to evaluate the probiotic properties, antioxidant activity and fermentative capacity of Acremonium charticola and Rhizopus oryzae isolated from the Indonesian fermented dried cassava, with particular application on poultry. A. charticola inhibited the growth of Escherichia coli and Aspergillus flavus. A. charticola and R. oryzae grew in potato dextrose agar (PDA) adjusted to pH 3 and 8 or in PDA supplemented with bile salt up to 0.8%. After soaking for 8 hr, the survival rate of A. charticola in the simulated gastric juice (pH 2) and bile solutions (2% bile salt) was lower than that of R. oryzae. A. charticola and R. oryzae exhibited strong antioxidant activities. Compared to unfermented cassava pulp (control), the fibre content of cassava pulp tended to be lower after fermentation with A. charticola for 14 days. The populations of A. charticola and R. oryzae were significantly higher in fermented cassava pulp than in unfermented one. Coliform was higher in cassava pulp fermented with R. oryzae or A. charticola + R. oryzae compared to control after 7 days of fermentation, however, the bacteria were not different between A. charticola-fermented cassava pulp and control. Lactic acid bacteria (LAB) were higher in A. charticola- and R. oryzae-fermented cassava pulp than those in control, however, no difference of LAB was observed between A. charticola + R. oryzae-fermented cassava pulp and control. In conclusion, A. charticola exhibited antibacterial, antifungal and antioxidant activity, gastrointestinal persistence and fermentative capacity that may be beneficial for poultry industry.

• Korean Journal of Microbiology
• /
• v.48 no.2
• /
• pp.147-155
• /
• 2012

To improve of the quality of Korea traditional wheat-rice wine (makgeolli) production, we used a rice fermentation starter (rice nuruk) made by inoculation of Rhizopus oryzae CCS01 which was isolated and selected from commercial nuruk. Amylase activity of a rice nuruk was 1.8-2.4 times higher than those of commercial nuruks. The best acceptability of wheat-rice wine in a sensory test was observed at 4 : 6 ratio of wheat-rice mash at experimental condition. During the fermentation period, pH of wheat-rice makgeolli made with a rice nuruk was higher compared to those made with commercial nuruks such as Sanseong, Jinju, and Songhak. Acidity of makgeolli mash was lower in case of using a rice nuruk and birx and alcohol production were higher compared to those of makgeolli mash using commercial nuruks. Highest alcohol production was observed at makgeolli mash using a rice nuruk and 12% of alcohol was produced at fermentation end. These results suggest that production of a new type of wheat-rice makgeolli using a rice nuruk was possible.