• Journal of Life Science
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• v.25 no.6
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• pp.673-679
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• 2015

The culture conditions needed to maximize the production of laccase from Pholiota highlandensis mycelia were investigated. Among the tested media for laccase production, Coriolus versicolor medium (CVM; 2% dextrose, 0.4% peptone, 0.6% yeast extract, 0.046% KH₂PO₄, 0.1% K₂HPO₄, 0.05% MgSO₄·7H₂O) showed the highest activity for the enzyme. Then, to optimize culture conditions for laccase activity, the influences of various carbon, nitrogen, phosphorus, and inorganic salt sources in CVM were investigated. The optimum culture medium was 2% fructose, 0.4% peptone with 0.6% yeast extract, 0.05% NaH₂PO₄, and 0.05% MgSO₄·7H₂O as carbon, nitrogen, phosphorus, and inorganic salt sources, respectively. Several aromatic compounds in the medium enhanced laccase activity to varying degrees. Guaiacol induced maximum laccase production, yielding 114.1 U/ml laccase activity after cultivation for 11 days at 25℃. The optimum pH and temperature for laccase production were 8.0 and 35℃, respectively. Native polyacrylamide-gel electrophoresis (PAGE) followed by laccase-activity staining with 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) as the substrate was performed to identify the presence of laccase under the optimum conditions studied. Zymogram analysis of the supernatant culture showed an enzymatic band with a molecular mass of about 90 kDa.

• Korean Chemical Engineering Research
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• v.52 no.3
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• pp.402-406
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• 2014

The present study was carried out to evaluate the potential of lignocellulosic byproducts for the production of citric acid through solid-state fermentation by Aspergillus niger NRRL 567. A sequential optimization based on one-factor-at-a-time method was applied to optimize fermentation conditions and media constituents. The results obtained from the optimization indicated that $30^{\circ}C$, 70% moisture content, 0.5~1.0 mm particle size, pH 5.5 and 4% methanol were found to be the optimum condition at 72 hr fermentation. The application the optimization resulted in an improvement of maximum citric acid production from 74.5 to 206.0 g/kg dry material (DM) from wheat straw. The optimal condition was used to produce citric acid from A. niger grown on different lignocellulosic byproducts, including wheat straw, corn stover and peat moss. A. niger produced the highest citric acid levels of 231.8, 213.8 and 240.2 g/kg DM at 120 hr fermentation, respectively.

• Journal of Life Science
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• v.22 no.2
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• pp.200-208
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• 2012

The characteristics of mycelium growth of Sparassis crispa KGFS08 and KFRI746 in liquid culture were investigated. The optimum growth of the mycelium of S. crispa was observed in the KTM medium. The best carbon source was starch. In terms of nitrogen sources, tryptone affected mycelial growth in the liquid culture. The optimal culture conditions were pH 4.0-5.0 in STK medium [3% (w/v) starch, 0.3% (w/v) tryptone, 0.1% (w/v) $KH_2PO_4$, and 0.1% (w/v) folic acid].

• KSBB Journal
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• v.14 no.2
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• pp.188-191
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• 1999

We have investigated the fortifying effect of amino acids on the cell growth and productivity during the perfusion culture of hybridoma vR8 cells in serum-free media. Through the quantitative analysis of amino acids and metabolites in perfusion culture, we found that many amino acids(glutamine, histidine, arginine, methionine, isoleucine, leucine, phenylalanine, tryptophane) were heavily consumed at cell density of $1.06{\times}10^7$cells/mL. Due to amino acid depletion, cells died suddenly. So we supplemented the media with those amino acids by 30-170%. As a result, were could increase maximum cell density by 270%, average specific productivity by 175%, and average volumetric productivity by 560% in this fortified media, GC-HY-S2.

• Microbiology and Biotechnology Letters
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• v.29 no.2
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• pp.78-83
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• 2001

Phytase (myo-inositol hexakisphosphate phosphohydrolase: EC 3.1.3.8) hydrolyzes phytic acid (myo-inositol hexakisphosphate) to myo-inositol and monophosphates. In order to obtain phytase producing bacteria, many samples were collected from various soils. Among thirty-five phytase-producing strains, YH100 showed the highest phytase activity. In order to identify the selected YHlOO strain, the morphological and physiological characteristics were examined according to the method of Bergey's manual by 168 rRNA sequence, cellular fatty acids profile, O+C contents and physiological test using API 20E kit. The strain YH100 identified to be a genus of Enterobacter cloacae and was named as Enterobacter cloacae YHlOO. Optimum medium for the phytase production by the Entemhacter c!o([we YHlOO was composed of 2.0%(w/v) glucose, 1.0%(w/v) peptone, 1.0%(w/v) beef extract, 0.1 %(w/v) KCI. and 0.1 %( w/v) sodium phytate.

• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.383-388
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• 2003

A bacterium producing the extracellular xylanase and CMCase was isolated from soil and has been identified as Bacillus sp. The isolate, named Bacillus sp. A-7, was shown to be very similar to Bacillus licheniformis on the basis of its biochemical and physiological properties. The maximum xylanase and CMCase production were obtained when 2.0% (w/v) glucose and 0.3% (w/v) yeast extract were used as carbon source and nitrogen source, respectively. The best mineral conditions for xylanase and CMCase production were 0.1%(w/v) $CaC1_2$. Among the various feedstuffs, 1.0%(w/v) soybean meal was selected for the best xylanase and CMCase production.

• KSBB Journal
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• v.16 no.4
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• pp.365-369
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• 2001

Chitinase producing microorganism, Serratia marcescens KY, was isolated from seashore mud around Beobseongpo in Chunnam province by selective enrichment culture. As the colloidal chitin concentration increased, chitinase production was increased. But chitinase production with addition of other carbon sources (glucose, fructose, galactose, maltose, sucrose, starch) was decreased. The effect of nitrogen sources on the chitinase production with serratia marcescens KY was as fellows. The opitimum mineral concentration for chitinase production was K$_2$HPO$_4$ 0.2 g/L and MgSO$_4$ 0.20 ∼ 0.25 g/L, respectively. The effect of nitrogen sources on chitinase production by Serratia marcescens KY was increased as follows, tryptone > yeast extract > beef extract > asparagine.

• The Korean Journal of Mycology
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• v.31 no.3
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• pp.187-191
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• 2003

Armillaria mellea, honey mushroom is well known as a symbiotic fungus with Gastodia elata, The mycelial yields of the fungus were compared when cultured with various broth media. The highest yield of cell mass, 2.31 g dry weight/50mL, was obtained on germinated-malt extract broth (GMEB). The optimal broth concentration which was measured hand refractometer for mycelium production was $15\;Brix^{\circ}$. The optimal conditions estimated with response surface methodology under temperature, pH and incubation period were $25.9^{\circ}C$, pH 5.72, 15.22 days, respectively, on GMEB having $15\;Brix^{\circ}$ concentration for mycelial production of A. mellea.

• Korean Journal of Medicinal Crop Science
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• v.15 no.1
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• pp.46-50
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• 2007

Transformed hairy roots were induced from in vitro grown plantlets of Trichosanthes kirilowii by infection with Agrobacterium rhizogenes strain ATCC15834. Transformed hairy roots exhibited active growth with high branching of roots on plant growth regulators-free medium. Cloned line (TR-03) of hairy root was tested for its growth and extracellular protein accumulation in medium under various culture conditions. Among the culture media tested, a full-strength MS medium had a pronounced effect on root biomass and extracelluar protein accumulation in medium. The maximum root biomass (2.4 g DRW/flask) and extracellular total protein contents $(28.3ug/m\ell)$ in medium was obtained at inoculum size of 2 g (FRW) and in MS medium supplemented with 4% sucrose. In addition, the optimal shaking speed for root growth and extracellular protein accumulation in medium were 100 rpm. The total extracellualr protein concentration reached a maximum of $28.3ug/m\ell$ at 4 weeks and decreased thereafter. Protein translation inhibitory activity was observed in culture broths and reached levels of 21.3 unit. These studies demonstrate that the transformed hairy roots can be utilized for the in vitro production of ribosome-inactivating proteins.

• Journal of Life Science
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• v.19 no.8
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• pp.1033-1038
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• 2009

Maximal productions of gellan by Sphingomnas paucibilis NK2000 from 20 g/l glucose and 10 g/l soybean pomace were 7.46 g/l in a flask and 7.35 g/l in a 7 l bioreactor, when the initial pH of media was 6.8. Maximal production of gellan in a 7 l bioreactor under pH control by sodium hydroxide was 8.42 g/l, whereas that under control by potassium phosphate was 8.50 g/l. The optimal concentration of potassium phosphate in a medium for production of gellan by S. paucibilis NK2000 was found to be 5.0 g/l. Maximal production of gellan in a medium containing 5.0 g/l potassium phosphate without pH control was 8.93 g/l in a 7 l bioreactor. In this study, a simple process without pH control was developed to enhance the production of gellan, with optimized concentration of potassium phosphate in the medium.