• The Korean Journal of Mycology
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• v.40 no.1
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• pp.65-68
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• 2012

In July and August 2011, a disease suspected to be Rhizopus soft rot was observed on peach (Prunus persica var. vulgaris) at the Wholesale Market for Agricultural Products, Jinju, Korea. The first symptom of soft rot on peach is a water-soaked appearance of the affected tissue. The infected parts later disintegrated into a mushy mass of disorganized cells followed by rapid softening of the diseased tissue. The lesion on peach was rapidly softened and rotted, then became brown or dark brown. Optimum temperature for mycelial growth of the causal fungus on PDA was $30^{\circ}C$and growth was still apparent at $37^{\circ}C$Sporangiophores were 6~20 ${\mu}m$ in diameter. Sporangia were globose and 35~200 ${\mu}m$ in size. The color of sporangia was brownish-grey to blackish-grey at maturity. Sporangiospores were sub-globose, brownish- black streaked and 5~10 ${\mu}m$ in size. Columella were globose to sub-globose and 85~120 ${\mu}m$ in size. On the basis of mycological characteristics, pathogenicity test, and molecular identification, the causal fungus was identified as Rhizopus oryzae Went & Prinsen Geerligs. To our knowledge, this is the first report of soft rot caused by R. oryzae on peach in Korea.

• Korean Journal of Food Science and Technology
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• v.35 no.2
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• pp.291-296
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• 2003

Effects of Bacillus subtilis and Rhizopus oryzae on chitooligosaccharides (COS) content of doenjang (soybean paste) and kanjang (soy sauce) were investigated using kojis made with the two strains. Competitive direct enzyme-linked immunosorbent assay (cdELISA) system using anti-COS mixture (COSM) antibody was applied for COS detection ranging from 0.001 to $1{\mu}g/mL$, and the recoveries of COSM spiked to doenjang and kanjang were 102 and 115%, respectively. Doenjang and kanjang products made with a mixture of B. subtilis and R. oryzae kojis showed COS contents of 171 and $29{\mu}g/mL$, respectively, during two-month aging period, much higher than those of Japanese and Korean commercial ones.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.2
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• pp.195-200
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• 1992

Rhizopus oryzae CJ-2114 was selected for its strong polygalacturonase activity among various strains of mold found in soil. The optimum pH for the enzyme activity was 4.0 and optimum temperature was 4$0^{\circ}C$. The activation energy for the polygalacturonase was calculated by Arrhenius equation was 2.048㎉/㏖. The reaction of this enzyme followed typical Michaelis-Menten kinetics with the Km value of 54.05mM with the $V_{max}$ of 13.9m mole/min. The enzyme is relatively stable in acidic condition. The activity of polygalactur-onase was inhibited completely by C $u^{2+}$, P $b^{2+}$ and Z $n^{2+}$, $_Mn^{2+}$ at concentration of 1 mM. The enzyme can be inactivated by the treatment with maleic anhydride and iodine. The results indicate the possible involvement of histidine at active site. When polygalacturonase from Rhizopus oryzae CJ-2114 was reacted with poly-galacturonic acid as a substrate mono-, di-, and oligogalacturonic acid were produced at early and mono-, digalacturonic acid produced at late incubation time. time.

• The Korean Journal of Food And Nutrition
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• v.35 no.6
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• pp.435-444
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• 2022

In vitro digestibility and protein digestibility corrected amino acid scores (PDCAAS) were investigated to verify the availability of protein in various Rhizopus oligosporus fermented products of domestic soybean (Glycine max L.) cultivars. Danbaegkong (DBK), Daepung (DP), Daewonkong (DWK), Saedanbaek (SDB), Seonyu (SY), and Cheongja4ho (CJ4) were used as raw samples, which were fermented using commercially available Rhizopus oligosporus for 48 h. All cultivars showed increased crude protein content after fermentation. The crude protein content of DBK and SDB was significantly higher than that of the other samples (55.12% in DBK and 54.22% in SDB) (p<0.001). CJ4 had the highest alanine content of 28.88 mg/g (p<0.001), and no significant difference in cysteine content was detected among the cultivars. In most of the fermented samples, the in vitro digestibility was 0.9 or higher, indicating high protein in the fermented samples. However, it is considered that restrictions on digestion are low. In DWK, the amino acid content and PDCAAS, which together indicate protein quality, were 0.917 and 0.855, respectively, confirming that it was the best cultivar to provide the raw material for fermentation. In conclusion Rhizopus oligosporus fermented soybean products can be considered a prospective source of protein with high utility value.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.402-405
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• 2001

The production of fumaric acid in shaken flask cultures by Rhizopus oryzae KCTC 6946 was studied. The effects of various carbon and nitrogen sources on fumaric acid production were investigated. The strain fermented starch (or glucose) and corn steep liquor (or polypepton) better than other carbon and nitrogen sources to fumaric acid. When C/N ratio of carbon and nitrogen source was 41.7, the concentration of fumaric acid produced with 2N NaGH as a neutralizing agent was more than 10 g/L after 3 days.

• Natural Product Sciences
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• v.1 no.1
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• pp.10-16
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• 1995

A number of microorganisms have been screened for growth on sunflower oil as a sale carbon source for production of useful chemicals. Rhizopus stolonifer NRRL 1478 was found to transform the lipid contents of sunflower oil into dodecyl ${\beta}$-D-glucopyranoside and dodecanedioic acid in 15 and 25% yield respectively. The produced compounds were isolated and purified by column chromatography and its chemical identity were established using MS, IR, $^1H\;and\;^{13}C\;NMR$ spectroscopy.

• Korean Journal of Microbiology
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• v.11 no.1
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• pp.31-50
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• 1973

151 strains which belong to the gens Rhizopus were isolated from 750 specimens collected through all over South Korea, and 19 species of the genus, all of which are unrecorded in Korea, were identified according to the modified Takeda-Yamamoto's classification key. The species identified are as follows ; R. nigricans, R.formosaensis, R.achlamydosporus, R.tritici, R.javanicus, R.cuiuniang, R liquefaciens, R.chungruoensis, R.acidus, R.chinensis, R.delemar, R.hangchow, R.japonicus, R.arrhizus, R.bahrnenesis, R.tonrinensis, and R.shanghaiensis.

• The Korean Journal of Mycology
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• v.39 no.1
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• pp.88-89
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• 2011

To investigate liver toxicity of traditional rice wine, traditional rice wine was prepared by using cooked rice, Rhizopus stolonifier No. 17 nuruk and Saccharomyces cerevisiae. After concentrated the traditional rice wine, it was orally administered into Sprague-Dawley(SD) rats and then changes of its body weight and biochemical parameters of the blood were investigated. All of male and female SD rats did not show any changes in its body weight during two weeks after administering the traditional rice wine concentrates and also biochemical parameters such as aspartate aminotransferase (AST or GOT), alanine aminotransferase (ALT of GOT) and alkaline phosphatase activity were not different compared to control. This results indicated that the traditional rice wine has not any toxicity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.4
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• pp.708-714
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• 1996

Ethanol production from raw starch was performed using the co-immobilized culture system of Rhizopu japonicus and zymomonas mobilis(R-Z). Glucose Production in immobilized R. japonicus culture was 2-fold higher than that in free cell culture. Ethanol production was 1.67g/L(Yp/s, 0.094) and 6.549/L(Yp/s, 0.38) in R-Z and R-Z 24 culture system, respectively. R-Z system was modified and designated as R-Z 24 system by replacing cotton plug with silicon check valve after 24h fermentation with R-Z system. Optimal substrate concentration for ethanol production in batch culture was 5%(w/v) and ethanol concentration produced was 15.02g/L(Yp/s, 0.36). Ethanol yield(Yp/s, 0.38) in fed-batch culture of 5 times with 2%(w/v) substrate was equal to that in batch culture of 2%(w/v) substrate.

• The Korean Journal of Mycology
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• v.15 no.1
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• pp.23-28
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• 1987

Physicochemical factors influencing the $11{\alpha}$, hydroxylation of progesterone by Rhizopus nigricans Ehrenberg were studied. The higher is the concentration of progesterone. the shorter time is need to attain maximum yield in the $11{\alpha}-hydroxyprogesterone$. High concentration in progesterone was supposed to inhibit the hydroxylation reaction of the $11{\alpha}-hydroxyprogesterone$. The range of optimum pH and temperature appeared to be rather broad and these conditions were similar to those of optimum growth of the mycelia. Agitation at a higher speed than a certain limit, and the presence of sugars accelerated the $11{\alpha}-hydroxyprogesterone$ reaction. Glucose was found to be more effective for the reaction using spores rather than mycelia as enzyme sources. Organic solvents were proved to supress the enzyme activity, which decreased with increase in the concentration of the organic solvents and in the time for pretreatment with the solvents.