• Journal of Microbiology
• /
• v.40 no.1
• /
• pp.20-25
• /
• 2002

An extracellular PHB depolymerase was purified from P. simplicissimum LAR13 cultural medium by Sepharose CL-6B chromatography. When the fungus was grown in a basal salt medium with poly(3-hydroxybutyrate) (PHB) as the sole carbon source, PHB depolymerase production reached maximum at its stationary phase. The mycelial growth rate was higher at 37$^{\circ}C$ than at 30$^{\circ}C$ and even higher than at 25$^{\circ}C$, However, the enzyme production was lower at 37$^{\circ}C$ than 30$^{\circ}C$ or 25$^{\circ}C$. The isolated enzyme is composed of a single polypeptide chain with a molecular mass of about 36 kDa as determined by SDS-PAGE. The optimum conditions for the enzyme activity are pH 5.0 and 45$^{\circ}C$. The enzyme was stable for 30 min at a temperature lower than 50$^{\circ}C$, and stable at pH higher than 2.0 but it was unstable at pH 1.0.1 mM Fe$\^$2+/ reduced the enzyme activity by 56% and the enzyme was inhibited almost completely by 4 mM Fe$\^$2+/ . The enzyme was partially inhibited by phenylmethylsulfonyl fluoride and was very sensitive to diazo-DL-norleucine methyl esters dithiothreitol and mercuric ion. However, N-p - tosyl - L - Iysinechloromethyl ketone, p -hydroxymercuricbenzoate and N- acetylimidazole had no influence upon its activity.

• Journal of Industrial Technology
• /
• v.7
• /
• pp.59-68
• /
• 1987

In order to obtain a strain of producing lipase which has resistance against alkaline and detergent, a screening test was carried out. Among 500 strains isolated from soil samples, the strain J-19 was selected for this study. The composition of the optimum medium for the highest lipase production was 2.0% glycerin, 1.0% corn steep liquor, 2.0% yeast extract, 0.1% $MgSO_4$ $7H_2O$, 0.2% $K_2HPO_4$, 1.5% soybean oil and 0.1% LAS(linear alkylbenzene sulfonate) with initial pH value of 10.0 and 3-day cultivation at $25^{\circ}C$. The lipase activity of the strain J-19 under optimal condition was 3.3. units/ml, which was increased about 1.3-fold than that of basal medium.

• Korean Journal of Agricultural Science
• /
• v.18 no.2
• /
• pp.157-163
• /
• 1991

The cultural conditions in shake flasks were investigated under which maximum amounts of laccase produced by a strain of white-rot fungus Coriolus versicolor CV3. The enzyme yields on potato-malt extract medium by the fungus were higher than on other media consisted of onion infusion or malt extract, with maximum activity of $1.50unit/m{\ell}$ culture or 119.5 unit/g mycelium at 11 days of incubation. Maximum yields of laccase and growth were obtained by supplementation of yeast extract or potassium nitrate to the potato-malt extract medium. Addition of 2.5-xylidine at $4{\times}10^{-4}M$ concentration to the medium induced the laccase production 3.1-fold higher than the basal level, while the mycelial growth was somewhat repressed. The pH optimum for the growth and laccase formation by the fungus was between pH 4 to 4.5.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.8
• /
• pp.1369-1378
• /
• 2007

For effective exopolysaccharide production and mycelial growth by a liquid culture of Fomitopsis pinicola in an air-lift bioreactor, the culture temperature, pH, carbon source, nitrogen source, and mineral source were initially investigated in a flask. The optimal temperature and pH for mycelial growth and exopolysaccharide production were $25^{\circ}C$ and 6.0, respectively. Among the various carbon sources tested, glucose was found to be the most suitable carbon source. In particular, the maximum mycelial growth and exopolysaccharide production were achieved in 4% glucose. The best nitrogen sources were yeast extract and malt extract. The optimal concentrations of yeast extract and malt extract were 0.5 and 0.1%, respectively. $K_2HPO_4\;and\;MgSO_4{\cdot}7H_2O$ were found to be the best mineral sources for mycelial growth and exopolysaccharide production. In order to investigate the effect of aeration on mycelial growth and exopolysaccharide production in an air-lift bioreactor, various aerations were tested for 8 days. The maximum mycelial growth and exopolysaccharide production were 7.9 g/l and 2.6 g/l, respectively, at 1.5 vvm of aeration. In addition, a batch culture in an air-lift bioreactor was carried out for 11 days under the optimal conditions. The maximum mycelial growth was 10.4 g/l, which was approximately 1.7-fold higher than that of basal medium. The exopolysaccharide production was increased with increased culture time. The maximum concentration of exopolysaccharide was 4.4 g/l, which was about 3.3-fold higher than that of basal medium. These results indicate that exopolysaccharide production increased in parallel with the growth of mycelium, and also show that product formation is associated with mycelial growth. The developed model in an air-lift bioreactor showed good agreement with experimental data and simulated results on mycelial growth and exopolysaccharide production in the culture of F. pinicola.

• KSBB Journal
• /
• v.5 no.4
• /
• pp.355-363
• /
• 1990

Methanol-utilizing bacterium isolated from sewage samples in Seoul showed optimal temperature and pH of $33^{\circ}C$ and 7.1 for growth, respectively. The maximum specific growth rate was $0.42hr^{-1}$. The minimum medium composition was reconstituted depending on the surplus and the deficit of each component in the basal medium at steady state. The optimal composition was given as(g/l); Methanol 40, $(NH_4)_2\;SO_42, \;KH_2PO_4\;1.5, \;K_2HPO_4\;0.2, \;H_3PO_4\;0.79, \;Na_2HPO_4{\cdot}12H_2O\;0.15, \;MgSO_4{\cdot}7H_2O\;1.5, \;FeSO_4{\cdot}7H_2O\;0.034, \;MnSO_4{\cdot}4H_2O\;0.005, \;CuSO_4{\cdot}5H_2O\;0.0027, \;CaCl_2{\cdot}2H_2O\;0.25, \;ZnSO_4{\cdot}7H_2O\;0.007, \;(NH_4)_6\;Mo_7O_{24}{\cdot}4H_2O\;0.00048, \;H_3BO_3\;0.00068, \;CoCl_2\; 0.00024$ Under the continuous culture with optimum medium the maximum cell productivity was 3.8g/1/hr at dilution rate $0.23hr^{-1}$. Maximum cell concentration and its protein content were 19.5g/l and 70% at dilution rate of $0.1hr^{-1}$, respectively.

• Mycobiology
• /
• v.33 no.4
• /
• pp.230-234
• /
• 2005

Oudemansiella radicata, one of edible mushrooms belonging to Tricholomataceae of Basidiomycota, has been known to exhibit outstanding therapeutic effects on the hypertension caused by high blood pressure and inhibitory effects on the sarcoma 180 and Erhrlich carcinoma of mice. As one of preliminary experiments for producing fruiting-body of O. radicata, this study was carried out to obtain the basic information for culture conditions of mycelial growth of the fungus. The optimal temperature and pH for the mycelial growth were $25^{\circ}C$ and pH 6, respectively. The medium for favorable mycelial growth of O. radicata was shown in the Lilly medium, whereas compact mycelial density was found in Hamada medium. The carbon and nitrogen sources promoting for mycelial growth of O. radicata were xylose and alanine, respectively. The optimum C/N ratio was about 20 : 1 in case that 3% glucose was supplimented to the basal medium as a carbon source.

• Korean Journal of Plant Resources
• /
• v.27 no.1
• /
• pp.43-50
• /
• 2014

This study was carried out to determine the optimal medium composition and growth regulators for the micropropagation of Platycodon grandiflorum (Jacq.) A. DC. Nodes containing yellow green petals were used as plant materials to execute the study. The best performance of adventitious root development was found in 1/4 strength of MS basal salt and the growth was satisfactory in the concentration of 1/2 MS medium. The best condition for adventitious root development and growth was observed in the higher concentration (5%) of sucrose and activated charcoal free 1/4MS medium respectively. Adventitious roots were developed at the controlled culture medium at pH 4.8 with a tendency of suppression with higher levels of pH. However, it was prevailed that the development and growth depended on the concentration of agar. The lower concentration of agar (0.4%) was performed better than that of higher concentration (1.2%), whereas the agar concentration (0.4%) showed the best performance for the development and growth of adventitious roots. For the development of shoots containing node, BA combined with IAA was more effective than kinetin with IAA or NAA. The highest shoot development (3.9 shoots per explant) was performed on MS medium supplemented with 0.1 mg/L BA and 0.5 mg/L IAA.

• KSBB Journal
• /
• v.21 no.2
• /
• pp.96-102
• /
• 2006

Recently, it has been known that Hericium erinaceum is a one of the very useful functional materials with great attention in mushroom processing industry. In present study, a liquid culture which was not studied systematically until now, was conducted as a method of cultivation for H. erinaceum, and also examined the characteristics of the liquid culture and conditions of process optimization. A good basal medium was selected through the cultivation of 16 species mushroom media and the optimum condition for medium and cultivation were chosen by response surface method. From these results, the optimum condition of medium for mushroom was 3% glucose, 0.2% yeast extract/peptone(1:1) and 0.1% $KH_2PO_4/MgSO_4$(1:1) and also the optimal culture condition was obtained at inoculum of 13.42%, temperature of $22.3^{\circ}C$ and pH of 5.7. The mycelial dry weight of 9 g/I was obtained under these conditions and this amount was about 1.7 times higher than that which were cultivated in basal medium for 8 days.

• Journal of Microbiology and Biotechnology
• /
• v.15 no.4
• /
• pp.716-721
• /
• 2005

The role of an effective microbial species is critical to the successful application of biological processes to remove sulfur compounds. A bacterial strain was isolated from the soil of a malodorous site and identified as Burkholderia spp. This isolate was able to oxidize thiosulfate to sulfate, with simultaneous pH decrease and accumulation of elemental sulfur. The specific growth rate and the sulfate oxidation rate using the thiosulfate basal medium were $0.003 h^{-1}\;and\;3.7 h^{-1}$, respectively. The isolated strain was mixotrophic, and supplementation of $0.2\%$ (w/v) of yeast extract to the thiosulfate-basal medium increased the specific growth rate by 50-fold. However, the rate of sulfate oxidation was more than ten times higher without yeast extract. The isolate grew best at pH 7.0 and $30^{\circ}C$, and the sulfate oxidation rate was the highest at 0.12 M sodium thiosulfate. In an upflow biofilter, the isolated strain was able to degrade $H_2S\;with\;88\%$ efficiency at 8 ppm and 121/h of incoming gas concentration and flow rate, respectively. The cell density at the bottom of the column reached $3.2{\times}10^8$ CFU/(g bead) at a gas flow rate of 121/h.

• Food Science and Preservation
• /
• v.22 no.2
• /
• pp.251-255
• /
• 2015

To optimize the medium composition of Undaria pinnatifida as a pH modulator the growth of Lactobacillus plantarum industrial scale, we analyzed the pH and growth characteristics of L. plantarum in basal medium. Subsequently, the medium compositions addition of carbon, nitrogen sources and buffering agents were optimized. When 0.5% yeast extract and 2% glucose, L. plantarum grew to maximum cell density in experimental condition. However, the growth of L. plantarum rapidly pH 4.0 in basal medium. A high alkali-ash value and low cost-effective utilization n the waste part as examined. ddition of U. pinnatifida extract alleviated the serious decrease. Among them, juice of U. pinnatifida was most helpful for the growth of L. plantarum ($36.3{\pm}1.810^8CFU/mL$). These results show that U. pinnatifida be large-scale cultivation of L. plantarum. This optimized U. pinnatifida medium can be used for safe and economical production of Lactobacillus.