• Mycobiology
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• v.29 no.3
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• pp.176-178
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• 2001

A soft rot of fruits caused by Rhizopus stolonifer occurred on cherry tomato in Jinju City Agricultural Products Wholesale Market, Korea. The disease infection usually started from wounding after cracking of fruits. At first, the lesions started with water soaked and were rapidly softened and diseased lesion gradually expanded. The mycelia grew vigorously on the surface of fruits and formed stolons. Colonies on potato dextrose agar at $25^{\circ}C$ were white cottony at first, becoming heavily speckled by the presence of sporangia and the browinish black, and spreading rapidly by means of stolons fired at various points to the substrate by rhizoids. Sporangia were $82.7{\times}196.7{\mu}m$ in size and globose or sub-globose with somewhat flattened base. The color of sporangia was white at first and then turned black with many spores, and never overhanging. Sporangiophores were $2.6{\sim}5.8{\times}12.3{\sim}24.2{\mu}m$ in width, smooth-walled, non-septate, tight brown, simple, long, arising in groups of $3{\sim}5$ from stolons opposite rhizoids. Sporangiospores were $8.2{\sim}18.8{\mu}m$ long, irregular, round, oval, elongate, angular, and browinish-black streaked. Columella was $64.1{\times}136.3{\mu}m$. brownish gray, and umberella-shaped when dehisced. The causal organism was identified to be R. stolonifer. This is the first report of Rhizopus soft rot on cherry tomato caused by R. stolonifer in Korea.

• Journal of Microbiology and Biotechnology
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• v.27 no.3
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• pp.514-523
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• 2017

Carbon catabolite repression is a crucial regulation mechanism in microorganisms, but its characteristic in Rhizopus is still unclear. We extracted a carbon regulation gene, cre, that encoded a carbon catabolite repressor protein (CRE) from Rhizopus stolonifer TP-02, and studied the regulation of CRE by real-time qPCR. CRE responded to glucose in a certain range, where it could significantly regulate part of the cellulase genes (eg, bg, and cbh2) without cbh1. In the comparison of the response of cre and four cellulase genes to carboxymethylcellulose sodium and a simple carbon source (lactose), the effect of CRE was only related to the concentration of reducing sugars. By regulating the reducing sugars to range from 0.4% to 0.6%, a glucose-containing medium with lactose as the inducer could effectively induce cellulases without the repression of CRE. This regulation method could potentially reduce the cost of enzymes produced in industries and provide a possible solution to achieve the largescale synthesis of cellulases.

• The Korean Journal of Mycology
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• v.37 no.1
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• pp.117-119
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• 2009

Rhizopus soft rot caused by Rhizopus stolonifer occurred on strawberry (Fragaria ${\times}$ ananassa) in the plastic boxes in Jinju City Wholesale Market of Agricultural Products at Gyeongnam province in Korea on April 2008. The infected fruits were rapidly softened, water soaked and finally rotted. The symptoms were mainly occurred through wounds at harvest time. The colony color was white, cottony to brownish black after fully matured and numerous sporangiospores were formed on sporangia. The optimum growth temperature of the fungus was $30^{\circ}C$ on potato dextrose agar. Sporangia were globose or hemispheric shape of white color at initial stage and gradually changed with black color of $82{\sim}195{\mu}m$ in size. Sporangiophores were $12{\sim}25{\mu}m$ in width. Columella were hemispheric in shape, and $70{\sim}92{\mu}m$ in size. Sporangiospores were irregular round or oval in shape, brownish-black in color and $9{\sim}21\;{\times}\;7{\sim}8{\mu}m$ in size. This fungus formed stolones and rhizoid on PDA. On the basis of symptom, mycological characteristics and pathogenicity of the fungus, the causal fungus was identified as Rhizopus stolonifer (Ehrenb.) Vuill.

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

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.757-763
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• 1999

Based on the previous studies, R. stolonifer was selected for the model system of Korean soy sauce preparation process, using the fermented soybean. The system of meju fermentation was refined; the optimal conditions of temperature and relative humidity were $25^{\circ}C$ and 90%, respectively. The optimal temperature for soy sauce fermentation was evaluated to the $25^{\circ}C$ and, in the latter half of the fermentation, some aeration was observed to positively affect the sensory evaluation of soy sauce. In the sensory evaluation, the soy sauce fermented with B. subtilis and A. sojae was showed to be better than one fermented with R. stolonifer. Conditions of the pasteurization and ultrafiltration process were also established for industrialization of the soy sauce. Finally, the standard systems using the soybean fermented was, by the industrial scales, proposed for Korean traditional soy sauces.

• Mycobiology
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• v.34 no.3
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• pp.128-130
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• 2006

The solid waste of sago industry using cassava was fermented by Aspergillus niger, Aspergillus terreus and Rhizopus stolonifer in solid state fermentation. Cassava waste contained 52 per cent starch and 2.9 per cent protein by dry weight. The amylase activity was maintained at a high level and the highest amylase activity was observed on the $8^{th}$ day in R. stolonifer mediated fermentation. R. stolonifer was more efficient than Aspergillus niger and Aspergillus terreus in bioconverting cassava waste into fungal protein (90.24 mg/g) by saccharifying 70% starch and releasing 44.5% reducing sugars in eight days of solid state fermentation.

• The Plant Pathology Journal
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• v.36 no.6
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• pp.570-578
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• 2020

Rhizopus rot is a serious postharvest disease of various crops caused by Rhizopus spp. and controlled mainly by synthetic fungicides. We detected the antifungal activity of a culture extract of Setosphaeria rostrata F3736 against Rhizopus oryzae. The active ingredient was identified as moriniafungin, a known sordarin derivative, which showed minimum inhibitory concentrations of 1-8 ㎍/ml against Colletotrichum spp. and 0.03-0.13 ㎍/ml against Rhizopus spp. in vitro. Moriniafungin showed protective control efficacies against Rhizopus rot on apple and peach fruits. Treatment with 25 ㎍/ml moriniafungin delimited the lesion diameter significantly by 100% on R. oryzae-inoculated apple fruits compared with the non-treated control. Treatment with 0.04 ㎍/ml of moriniafungin reduced the lesion diameter significantly by 56.45%, and treatment with higher concentrations of 0.2-25 ㎍/ml reduced the lesion diameter by 70-90% on Rhizopus stolonifer var. stolonifer-inoculated peach fruit. These results suggest moriniafungin has potential as a control agent of postharvest diseases caused by Rhizopus spp.

• 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.

• The Plant Pathology Journal
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• v.16 no.6
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• pp.321-324
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• 2000

season of 2000. The disease infection usually started from flower, peduncle and young fruits, then moved to flower stalk, stem and leaves. At first, the lesions started with water-soaked, rapidly softened, and then the area gradually expanded. In severely affected film house, the rate of infected fruits reached to 28.6%. Numerous sporangiospores were formed on the diseased fruits, flower stalk, stem and leaves. Most of the sporangiospores were appeare to be rapidly dispersed in the air. The mycelia grew on the surface of host and formed stolons. Colonies on potato dextrose agar were cottony at first brownish black at maturity. Sporangia were 125.3${\times}$294.2 ${\mu}$m. globose or sub-globose with somewhat flattened base. White at first the black, many spored, and are never overhanging. Sporangiophores were 2.7-6.8${\times}$12.9-33.9 ${\mu}$m, smooth-walled, non-septate, light brown, simple, long, arising in groups of 3-5 from stolons opposite rhizoids. Sporangiophores were 8.6-21.1${\times}$6.41-1.7 ${\mu}$m, irregular, round, oval, elongate, angular and brownish-black streaked. Columella were 63.8${\times}$140.4 ${\mu}$m. brownish gray, umberella-shaped when dehisced. The causal organism was identified as Rhizopus stolonifer Lind on the basis of the morphological characteristics of the fungus. Rhizopus soft rot on squash (Cucurbita moschata) caused by the fungi has not been previously reported in Korea.

• Korean Journal of Microbiology
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• v.22 no.3
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• pp.197-205
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• 1984

After the previous paper, this chromosomal studies on the fungi were dealt with 17 species in genus of Rhizopus. The results are sumarized as the followings; The haploid chromosome number of 17 species were confirmed as of 6(Rh. oligosporus), 8(Rh. homothallicus, Rh. liquefaciens, Rh. shanghaiensis, Rh, acetorinus), 12(Rh. microsporus, Rh. pseudochinensis, Rh, rhizopodiformis, Rh, thermosus, and Rh. kazanensis), 14(Rh. stolonifer), and 16(Rh. suinus), respectively. Referring to the above fact and the previous paper, it is strongly presumed that the basic chromosome number of Rhizopus are 4.