• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.3
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• pp.184-190
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• 2004

The influences of impeller types on morphology and protein expression were investigated in a submerged culture of Aspergillus oryzae. The impeller types strongly affected mycelial morphology and protein production in batch and fed-batch fermentations. Cells that were cultured by propeller agitation grew in the form of a pellet, whereas cells that were cultured by turbine agitation grew in a freely dispersed-hyphal manner and in a clumped form. Pellet-grown cells showed high levels of protein production for both the intracellularly heterologous protein (${\beta}$-glucuronidase) and the extracellularly homologous protein (${\alpha}$-amylase). The feeding mode of the carbon source also influenced the morphological distribution and protein expression in fed-batch fermentation of A. oryzae. Pulsed-feeding mainly showed high protein expression and homogeneous distribution of pellet whereas continuous feeding resulted in less protein expression and heterogeneous distribution with pellet and dispersed-hyphae. The pellet growth with propeller agitation paralleling with the pulsed-feeding of carbon source showed a high level of protein production in the submerged fed-batch fermentation of recombinant A. oryzae.

• Journal of Microbiology and Biotechnology
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• v.10 no.4
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• pp.482-487
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• 2000

Optimization of submerged culture conditions for the production of exo-biopolymer from Paecilomyces japonica ws studied. Maltose, yeast extract, and potassium phosphate were the most suitable sources of carbon, nitrogen, and inorganic salt, respectively, for both production of the exo-biopolymer and mycelial growth. The optimal culture conditions in a flask culture were pH 5.0, $25^{\circ}C$, and 150 rpm in a medium containing (as in g/l) 30 maltose, 6 yeast extruct, 2 polypeptone, $0.5{\;}K_3HPO_4,{\;}0.2{\;}KH_2PO_4,{\;}0.2{\;}MnSO_4{\cdot}5H_2O,{\;}0.2{\;}MgSO_4{\cdot}7H_2O$. Exo-biopolymer production and mycelial growth in the above suggested medium were significantly increased in a 2.5-1 jar fermentor, where the maximum biopolymer concentration was 8 g/l. The morphological changes of the mycelium in the submerged culture were observed within pH ranges from 4.0 to 9.0; i.e., growth of the filamentous form was optimal at culture pHs of 5.0 and 6.0, whereas pellet was formed at other pHs.

• The Korean Journal of Mycology
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• v.15 no.3
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• pp.158-168
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• 1987

Several species of the fungi were isolated from cassava(Manihot esculenta Gruntz) starch which had formed into pellet, those had been stored for a while in southern part of Thailand. The species of Rhizopus, Aspergillus niger, and Aspergillus fumigatus were identified. The experimental results are as follows; Dry weight increases were checked during the static liquid culture with modified Czapek Dox medium to which cassava starch was partly replaced to sugar, Aspergillus niger and Aspergillus fumigatus had grown more than Rizopus species when 6% cassava starch was replaced to sugar and had been cultured for 72 hours. Amounts of mycelial protein of Aspergillus niger were checked, the highest amount was shown in 6% cassava starch involved medium. When nitrogen sources were varied such as ammonium sulfate or urea against sodium nitrate, there was no significant difference in mycelial production. Alpha amylase activity of each fungus isolated here was checked, those of Aspergillus niger have shown the highest peak at 72 hours.

• The Korean Journal of Mycology
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• v.33 no.2
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• pp.59-63
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• 2005

Altogether twenty isolates were collected from Wakayama, Japan. The optimum mycelial growth of I. obliquus was observed in BMYA and MCM. The optimum temperature and pH for the mycelial growth were $25^{\circ}C\;and\;6.0{\sim}7.0$, respectively. The optimum carbon and nitrogen sources were dextrose and yeast extract, respectively. Similarly, the optimum mineral salt was $K_{2}HPO_{4}$. The optimum number of mycelial discs for the mycelial growth was $6{\sim}7$ per 100 ml. Similarly, the optimum culture period was $21{\sim}22$ days in liquid broth. The optimum brown rice : water ratio was 1 : 1. No difference in mycelial growth was observed in all the four types of tree stumps used.

• Journal of Microbiology and Biotechnology
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• v.11 no.4
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• pp.552-557
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• 2001

By UV-irradiation of Eremothecium ashbyii DTl, a higWy flavinogenic mutant (UV-18-57) and a nonflavinogenic mutant (UV -85) were obtained. The physio-morphological characteristics of these three strains were studied on glucose medium in submerged fermentation. Glucose utilization and mycelial growth occurred in 0 - 2 days of fermentation. By the third day, the biomass had declined. Extracellular riboflavin excretion was distinct from the second day, reaching a maximum rate by the fourth day. The hyphae of the highly flavinogenic mutant UV-18-57 were broader than DTl, while the nonflavinogenic UV-85 hyphae were very thin. Riboflavin accumulation was high in UV-18-57 (extracellular riboflavin,$825\mu\textrm{g}/ml$ , and intracellular, $490\mu\textrm{g}/ml$) and caused the mycelia to swell into bulbous forms. Riboflavin accumulation was less in DTl ($108\mu\textrm{g}/ml$ extracellular and $24\mu\textrm{g}/ml$ intracellular) and correspondingly its hyphae were thinner than those of UV-18-57 and swollen bulbous mycelia were not prominent. UV-85 was nonflavinogenic and, accordingly, its mOlphological characteristics included long thin filaments with no intracellular riboflavin accumulation. A large number of greenish fluorescence spores were seen in UV-18-57, whereas DTI had less spores and UV-85 was nonsporulating. Sporulation is correlated with riboflavin production. UV-18-57 had better mycelial integrity and lysis started only by the seventh day, whereas DTI and UV -85 started to lyze earlier by 4 -5 days. By the late stage of fermentation (eighth day), DTl had a few long, thin filaments indicating some secondary growth, whereas UV -85 showed a compact pellet form of mycelia. Most mycelia of UV-18-57 still appeared intact.

• Research in Plant Disease
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• v.25 no.1
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• pp.29-32
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• 2019

Burcucumber (Sicyos angluatus) is a representative ecosystem-disturbing plant in Korea and currently widely spread throughout the country. A sclerotia-forming fungus with moderate host selectivity, Sclerotinia trifoliorum BWC98-105, was tested in the laboratory, green house and natural habitat for its pathogenicity to burcucumber. When mycelial culture fragment was inoculated to burcucumber seedlings under the green house condition, mycelial growth was observed in the following day, and then resulted in the onset of wilting from 5 days after inoculation (DAI). Its characteristic sclerotia as a sign was observed from 7 DAI, and thus plants turned into dark-brown color at the bottom of stem of burcucumber that was eventually blighted at 14 DAI. Similar visible symptoms were observed in natural habitat. Based on the results of showing typical blight symptom to burcucumber and the sign of sclerotia, we report S. trifoliorum BWC98-105 causing stem blight against burcucumber. Its globular pellet was considered of having quite potential as a bioherbicide to control burcucumber in Korea.

• Journal of Mushroom
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• v.12 no.1
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• pp.12-16
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• 2014

This study was carried out to develop the new mushroom cultivation medium for Pleurotus ostreatus using by EFB. Two strains of Pleurotus ostreatus were used for this study and the difference in productivity was observed in each strain. There was not confirmed a mycelial growth inhibition by addition of Empty Fruit Bunch which is palm tree waste. In the productivity test of the mixed medium, In Suhan 1ho, yield of T2 treatment was highest as 90.6 g per bottle, It was 14.9% higher than control. In Kimje variety which is Chunchu strain, Yield of T2 treatment was highest as 139.8 g per bottle. It was 25.2% higher than control. In Kimje variety, as amount of 6mm diameter PEFB pellet is increased in medium, yield of mushroom was decreased. When 8mm diameter EFB was used for 532 medium, yield of both 50% EFB(T3) and 100% EFB (T5) treatment was better than other treatments. Therefore, it is suggested that 8 mm diameter EFB pellet is good material for mushroom cultivation medium and T5 treatment was showed a potential possibility as an alternative medium.

• Journal of Microbiology and Biotechnology
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• v.18 no.1
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• pp.128-134
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• 2008

The kinetics of cell growth and Cyclosporin A (Cyc A) production by Tolypocladium inflatum were studied in shake flasks and bioreactors under controlled and uncontrolled pH conditions. In the case of the shake flask, the production time was extended to 226 h and the maximal antibiotic concentration was 76 mg/l. When scaling up the cultivation process to a bioreactor level, the production time was reduced to only 70h with a significant increase in both the cell growth and the antibiotic production. The maximal dry cell weights in the case of the controlled pH and uncontrolled pH cultures in the bioreactor were 22.4g/l and 14.2g/l, respectively. The corresponding maximal dry cell weight values did not exceed 7.25g/l with the shake flask cultures. The maximal values for Cyc A production were 144.72 and 131.4 mg/l for the controlled and uncontrolled pH cultures, respectively. It is also worth noting that a significant reduction was observed in both the dry cell mass and the antibiotic concentration after the Cyc A production phase, whereas the highest rate of antibiotic degradation was observed in the stirred tank bioreactor with an uncontrolled pH. Morphological characterization of the micromorphological cell growth (mycelial/pellet forms) was also performed during cultivation in the bioreactor.