• Microbiology and Biotechnology Letters
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• v.47 no.3
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• pp.364-371
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• 2019

The use of GRAS microorganisms isolated from fermented foods during amylase production using an economical food-waste medium provides more opportunities to produce amylase with a wider range of applications. Hence, this study aimed to isolate a good amylase-producing fungi from the traditional Indonesian fermented cassava, gatot, and to identify the amylase-producing capability of the isolate in a potato peel waste (PPW) medium. Black-colored fungi isolated from gatot was morphologically identified and the amylase produced was characterized using SDS-PAGE and Native PAGE. The isolate was then grown on PPW medium, and the amylase produced was further characterized. Morphological identification and enzyme characterization revealed that the Aspergillus niger aggregate F isolated from gatot secreted an active extracellular ${\alpha}$-amylase with an optimum pH of 5-6. In conclusion, Aspergillus niger aggregate F isolated from gatot can be used to produce ${\alpha}$-amylase using PPW as a medium.

• The Korean Journal of Mycology
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• v.32 no.2
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• pp.95-100
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• 2004

The main objectives of the study were to investigate cultural characteristics of Phellinus linteus. The optimum culture media for mycelial growth of P. linteus were MYA (malt yeast agar) and SMS (soybean powder malt Sucrose). Similarly, optimum temperature and pH were $30^{\circ}C$ and 6.0, respectively. Malt extract (2%, v/v) and yeast extract (0.2%, v/v) were optimum carbon and nitrogen sources. Similarly, 0.1% $KH_2PO_4$ was optimum mineral salt. Highest mycelial growth was observed when C/N ratio was 10 : 1. Optimum inoculum amount for flask culture was $5{\sim}6$ mycelial discs (6 mm diameter) per 100 ml of liquid medium, Highest mycelial dry weight was obtained when cultured in 100 ml liquid medium in 300 ml shaking flask after 20 days of shaking culture, For mass liquid culture (8 l), flask culture was homogenized and used as an inoculum. Optimum culture period and aeration rate for 8l fermentation culture were 12 days and 2.0 vvm, respectively.

• KSBB Journal
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• v.14 no.5
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• pp.561-565
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• 1999

Optimum conditions for vacuum-drying ad cultivation of yeast cells for the production of active dry yeast were examined. At lower temperature, more drying time was required to dry the yeast pellet to reach the desirable water content(8%). Optimum temperature of vaccum oven and time for drying was 63$^{\circ}C$ and 90 min, respectively. Optimum medium composition for flask culture using cane molasses as the substrate were 0.25% sugar, 0.013% $K_2$HPO$_4$, 0.1% $K_2$HPO$_4$. and 0.125% (NH$_4$)$_2$SO$_4$. Culture temperature $25^{\circ}C$ gave the highest survival rate of dired yeast. After finishing fed-batch culture and the culture was left in the fermentor without adding any sugar or nutrient, survival of the dried yeast harvested from the fermentor increased to 86.0% after 36 hr. It was also observed that the yeast cells with higher budding rates showed lower survival rate.

• Journal of Aquaculture
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• v.19 no.1
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• pp.40-46
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• 2006

Bacillus subtilis strain with highly active chitosanase was isolated from the intestine of Sebastiscus marmoratus (scorpion fish). It was named as Bacillus subtilis CH1 by morphological, biochemical and 165 rRNA gene analysis. The optimal conditions for chitosanase production were investigated. The optimum carbon and nitrogen sources for Bacillus stibtilis CH1 were 2% starch and 1% yeast extract respectively. Unlike other chitosanases, the expression of this chitosanase was not induced or slightly induced with chitosan. The chitosanase secreted into the medium were concentrated with ammonium sulfate precipitation and purified by gel permeation chromatography. The molecular weight of purified chitosanase was 30 kDa. The optimum pH and temperature of purified chitosanase were 5.5 and $60^{\circ}C$ respectively. The purified chitosanase was continuously thermostable at $40^{\circ}C$ and showed stable activity between pH 6.0 and 8.0. Chitosanase activity of Bacillus subtilis CH1 under optimum condition was 4.1 units/ml.

• Korean Journal of Microbiology
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• v.28 no.2
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• pp.145-150
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• 1990

The effects of environmental factors on degradation of Aroclor 1242 were investigated with four Gram-negative bacterial isolates. Their biodegradabilities of the Aroclor were well correlated to their growth rates on the Aroclor added as a sole carbon and energy source. The optimum concentration of the Aroclor for biodegradation of the substrate in MM2 medium was 0.5mg/ml in HK-100, HK-123, and MS-1003 strains, but 1 mg/ml in DJ-26 strain. The optimum temperature and pH were $30^{\circ}C$ and 7.0, respectively, for all the strains. On the basis of the results which the strain of DJ-26 showed the highest degradability of the Aroclor as well as the highest growth rate under the optimum environmental conditions, the bacterial isolate identified as Pseudomonas sp. was found to be a strain usable for treatment of the toxic and recalcitrant chemical pollutants, such as polychlorinated aromatic hydrocarbons.

• Structural Engineering and Mechanics
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• v.68 no.1
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• pp.121-130
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• 2018

This study deals with optimum geometry design of laterally loaded piles in a Winkler's medium through the Fully Stressed Design (FSD) method. A numerical algorithm distributing the mass by means of the FSD method and updating the moment by finite elements is implemented. The FSD method is implemented here using a simple procedure to optimise the beam length using an approach based on the calculus of variations. For this aim two conditions are imposed, one transversality condition at the bottom end, and a one sided constraint for moment and mass distribution in the lower part of the beam. With this approach we derive a simple condition to optimise the beam length. Some examples referred to different fields are reported. In particular, the case of laterally loaded piles in Geotechnics is faced.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.9 no.2
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• pp.16-24
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• 2013

A multi-heat pump provides the benefits of comfort, energy conservation and easy maintenance. Recently, the multi-heat pump has been widely employed in small and medium-sized buildings. However, the control algorithm of the multi-heat pump are limited in the open literature due to complicated operating conditions. In this study, the MIMO control algorithm using integral optimum regulator was designed and the control performance of it was analyzed. In addition, system model of the control plant was developed by PRBS system identification scheme. The MIMO controller adopting the integral optimum regulator yielded satisfactory control performance results.

• Applied Biological Chemistry
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• v.49 no.4
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• pp.266-269
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• 2006

For the purpose of application for biomass of Tricholoma matsutake, the optimum culture condition were determined. It was found that the optimum culture condition for spot culture of Tricholoma matsutake were pH 5.5 and 3% brown rice meal at $24^{\circ}C$ for 35 days with MMN medium. And the optimum culture condition of bioreactor for biomass were $18^{\circ}C$ and 60 days with PDMP broth.

• Mycobiology
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• v.37 no.2
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• pp.89-93
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• 2009

The effect of fermentation parameters and medium composition on the simultaneous mycelial growth and exo-polymer production from submerged cultures of Ganoderma applanatum was investigated in shake-flask cultures. The optimum initial pH for mycelial growth and exo-polymer production was 5.0 and 6.0, respectively. The optimum temperature was $25^{\circ}C$ and the optimum inoculum content was 3.0% (v/v). The optimal carbon and nitrogen sources were glucose and corn steep powder, respectively. After 12 days fermentation under these conditions, the highest mycelial growth was 18.0 g/l and the highest exo-polymer production was 3.9 g/l.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.217-222
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• 2010

Bark is a general medium for potted Cymbidium in Korea, but it is difficult to shake off or eliminate the medium from the roots before exporting the potted plants. This working process can injure the roots and then deteriorate plant marketability. This study was carried out to select the optimum medium easier to eliminate from the roots instead of bark and the optimum amount of applied fertilizer to improve the plant growth. Cymbidium young plants 'Honey Hot' and 'Desert Look' were planted in pots with bark, cocochip, and peatmoss. The plants were treated with 2, 4, and 6 g of slow release fertilizer. The plant growth characteristics were investigated in the first and second years during production period of three years. The medium characteristics and mineral nutrient content of the leaves were also examined in the second year. In the first year, the plant growth of 'Desert Look' was improved in all peatmoss treatments more than bark. 'Honey Hot' showed the highest plant growth values in the bark treatment. In the second year, the plant growth of the two cultivars was improved in peatmoss. Cocochip treatments showed the lower plant growth values than bark and peatmoss in the first and second year. There was no significant difference among fertilizer amounts in all the media. The higher CEC values of peatmoss medium resulted to higher capacity to hold more nutrients than bark, and the nutrient retention of the peatmoss improved the plant growth. The higher K and Ca contents in the leaves would contribute to improve the plant growth. Consequently, it would be possible to use peatmoss instead of bark for Cymbidium young plants, but there must be always attention to appropriately water the medium and manage the moisture.