• ALGAE
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• v.28 no.1
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• pp.101-109
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• 2013

Some Chlorella species grow heterotrophically with organic substrate in dark condition. However, heterotrophic Chlorella species are limited and their optimum culture conditions are not fully known. In this study, three heterotrophic Chlorella species, two strains (C4-3 and C4-4) of C. vulgaris and one Chlorella sp. (C4-8) were examined on optimum culture conditions such as carbon source, temperature, and concentrations of nitrogen and phosphorus in Jaworski's medium (JM). And the growth and fatty acid composition of Chlorella were analyzed. For three heterotrophic Chlorella species, glucose (1-2%) as a carbon source only increased the growth and the range of optimum culture temperature was $26-28^{\circ}C$. Doubled concentrations of the nitrogen or phosphorus in JM medium also improved the growth of Chlorella. Chlorella cultured heterotrophically showed significantly higher growth rate and bigger cell size than those autotrophically did. C. vulgaris (C4-3) cultured heterotrophically showed the highest biomass in dry weight ($0.8g\;L^{-1}$) among three species. With respect to fatty acid composition, the contents of C16:0 and n-3 highly unsaturated fatty acid (HUFA) were significantly higher in autotrophic Chlorella than in heterotrophic one and those of total lipid were not different between different concentrations of nitrogen and phosphorus in JM medium. Among three Chlorella species in this study, C. vulgaris (C4-3) appeared to be the most ideal heterotrophic Chlorella species for industrial application since it had a high biomass and lipid content.

• Microbiology and Biotechnology Letters
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• v.22 no.5
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• pp.557-560
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• 1994

The optimum medium composition for the production of L-tryptophan with Klebsiella pnuemoniae pheA tyrA trpE trpR/pSC 101-trp$^{+}$ and the effect of precusors in the optimum medium were studied. The specific growth rate in the optimum medium was almost the same as that in the basal medium, the former showing 1.01 and the latter 1.07 hr $$^{-1}$, but the produced tryptophan was increased 45% in the optimum medium. The maximum amount of produced tryptophan was 159 mg/l within 14 hours. Tryptophan production was ceased by casamino acid addition over 4 g/l in medium, but cell maSS increased with its addition. Indole and anthranilate as precusors had toxic effect on growth and tryptophan production at experimented concentration range (over 20 mg/l), but L-serine had good effect on tryptophan production, resulting in 175 mg/l tryptophan within 14 hours.

• KSBB Journal
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• v.14 no.2
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• pp.167-173
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• 1999

A new synthetic medium was developed for the submerged mycelial cultures of Phellinus linteus. The medium for maximum mycelial growth of Phellinus linteus (3 days incubation, 28$^{\circ}C$, pH 5) consisted of (per 1 L): glucose, 90 g peptone, 10 g soluble starch, 10 g yeast extract, 3 g KH2PO4, 1 g MgSO4.7H2O, 1 g and CaCl2, 0.1 g. The concentrations of glucose, peptone, yeast extract, KH2PO4, MgSO4.7H2O, and CaCl2 were examined in the ranges of 10~90 g/L, 0~10 g/L, 0~15 g/L, 0~2 g/L, 0~1 g/L, and 0~0.5 g/L, respectively. The dry weight of mycelium in 3 days increased to 16.79 mg/mL using the new synthetic medium. The optimum temperature for mycelial growth of Phellinus linteus was 28$^{\circ}C$. The concentrations of KH2OP4, CaCl2, and yeast extract, which gave the maximum mycelial growth of Phellinus linteus, existed in the concentration ranges examined in this study. But, in the cases of other compositions (MgSO4.7H2O, peptone, and glucose), the mycelial growth of Phellinus linteus increased with the concentration in the ranges.

• Korean Journal of Microbiology
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• v.16 no.4
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• pp.170-179
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• 1978

By the successive enrichment culture, more than 250 methanol-utilizing bacteria were isolated from various samples such as soil, waste water and sewage. Two strains of which were selected and tentatively identified as Acinetobacter sp. and Pseudomonas sp. experiments were carried out to determine the growth conditions for the higher biomass yield and to demonstrate the difference to protein composition dependent upon carbon sources of these two species. the results were as follows ; 1. the optimum pH was determined as 8 in the both species. The optimum temperature in Acinetobacter sp. was $25^{\circ}C{\sim}30^{\circ}C$ and pseudomonas sp. was $30^{\circ}C-35^{\circ}C$. The optimum initial concentration of mthanol was determined as 1-2% in Acinetobacter sp. and 2-3% in pseudomonas sp. 2. The optimum concnetrations of nitrogen source, micro-elements, and vitamins such as biotin and thiamine-HCl in Acnetobactar sp. were 1g $(NH_4)_3SO4,\;1{\sim}3mg\;Mn^{++},\;4mg\;Fe^{++},\;10{\mu}g\;biotin,\;and\;100{\mu}g$ thiamine-HCl per liter medium. In the Pseudomonas sp., 2g $(NH_4)_3SO4,\;1mg\;Mn^{++},\;trace\;amounts\;of\;Fe^{++},\;5{\mu}g\;biotin,\;and\;100{\mu}g$ thiamine HCl per liter were effective. Maximum biomass yield was 2.5g/l in Acinetobacter sp. and 4.8g/l in Pseudomonas sp. 3. Protein composition of the two strains exhibited that alkai-labile protein was higher than alkali-stable protein. In Pseudomonas sp., the contents of acid soluble fraction and alkali-stable protein of the cells grown in the methanol medium were higher than in sucrose medium. On the other hand, in Acinetobacter sp., alkalilabile protein of the cells grown in sucrose medium was higher than in methanol medium.

• Journal of Microbiology and Biotechnology
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• v.12 no.3
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• pp.449-456
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• 2002

The objective of this study was to optimize medium composition of initial pH, tryptone, glucose, yeast extract, and mineral mixture for production of bacteriocin by Lactobacillus acidophilus ATCC 4356, using response surface methodology. A response surface approach including new statistical and plotting methods was employed for design and analysis of the experiment. An interiorly augmented central composite design was used as an experimental design. A normal-distribution log-link generalized linear model based on a subset fourth-order polynomial ($R^2$=0.94, Mean Error Deviance=0.0065) was used as an analysis model. This model was statistically superior to the full second-order polynomial-based generalized linear model ($R^2$=0.80, Mean Error Deviance=0.0140). Nonlinear programming determined the optimum composition of the medium as initial pH 6.35, typtone $1.21\%$, glucose $0.9\%$, yeast extract $0.65\%$, and mineral mixture $1.17\%$. A validation experiment confirmed that the optimized medium was comparable to the MRS medium in bacteriocin production, having the advantage of economy and practicality.

• Journal of Animal Science and Technology
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• v.63 no.3
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• pp.603-613
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• 2021

This research improved the growth potential of Bifidobacterium animalis subsp lactis strain JNU306, a commercial medium that is appropriate for large-scale production, in yeast extract, soy peptone, glucose, L-cysteine, and ferrous sulfate. Response surface methodology (RSM) was used to optimize the components of this medium, using a central composite design and subsequent analyses. A second-order polynomial regression model, which was fitted to the data at first, significantly lacked fitness. Thus, through further analyses, the model with linear and quadratic terms plus two-way, three-way, and four-way interactions was selected as the final model. Through this model, the optimized medium composition was found as 2.8791% yeast extract, 2.8030% peptone soy, 0.6196% glucose, 0.2823% L-cysteine, and 0.0055% ferrous sulfate, w/v. This optimized medium ensured that the maximum biomass was no lower than the biomass from the commonly used blood-liver (BL) medium. The application of RSM improved the biomass production of this strain in a more cost-effective way by creating an optimum medium. This result shows that B. animalis subsp lactis JNU306 may be used as a commercial starter culture in manufacturing probiotics, including dairy products.

• Applied Biological Chemistry
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• v.36 no.5
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• pp.332-338
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• 1993

For the production of riboflavin, strain development of Ashbya gossypii NRRL Y-1056 was attempted by NTG(N-methyl-N'-nitro-N-nitrosoguanidne) treatment. The optimum composition of culture medium and other culture conditions for the production of riboflavin by selected mutant Ashbya gossypii JAG-13 were determined. The optimum composition of medium was 9% of corn oil, 3% of gellatone, 4% of CSL, 0.3% of glycine, 0.2% of S770. The optimum culture temperature and initial pH of medium was $28^{\circ}C$ and 6.5, respectively. oxygen was essential for the production of riboflavin, but excess oxygen inhibit the production of riboflavin. When Ashbya gossypii JAG-13 was cultured under above conditions for 12 days with a bioreactor, 6.9 mg/ml of riboflavin was produced.

• YAKHAK HOEJI
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• v.36 no.4
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• pp.390-396
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• 1992

Streptomyces minoensis DMCJ-144 isolated from soil produces the ${\alpha}-amylase$ inhibitor. Optimum culture conditions for ${\alpha}-amylase$ inhibitor production of the strain were determined in this experiment. The optimum composition of the culture medium was studied by supplementing various carbon sources, nitrogen sources, vitamins, and metal salts to the basal medium containing 1% glucose, 0.1% asparagine, 0.005% $MgSO_4{\cdot}7H_2O$, 0.005% $K_2HPO_4$, 0.005% NaCl. Other culture conditions such as the culture temperature, initial pH of the medium, aeration, and culture time were also investigated. When the strain was cultured in a 100 ml flask containing 20 ml of 2% glucose, 0.5% beef extract, 0.0002% riboflavin, 0.0002% thiamine HCI, 0.01% $ZnCl_2$, 0.005% $MgSO_4{\cdot}7H_2O$, 0.005% $CuSO_4{\cdot}5H_2O$, 0.005% NaCl, pH 7.2, 180 rpm at $30^{\circ}C$, the maximum production of the ${\alpha}-amylase$ inhibitor was observed after 5 days of the cultivation.

• Korean Journal of Plant Resources
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• v.19 no.2
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• pp.265-272
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• 2006

This study was conducted to investigate the efficient propagation method of Cyrtomium caryoptideum var. coreanum by sporophyte culture. The influence of origin of explant sources (rhizome, blade, or stipe) and homogenization of culture materials on shoot regeneration were investigated. As a result, only rhizome explant exhibited the organogenic capacity and the shoot regeneration was promoted by homogenization of culture material. Vigorous and excellent growth of multiple shoots was induced on the half-strength of inorganic salts containing MS medium. It was appeared that optimum nitrogen content of shoot regeneration was half-strength of nitrogen containing MS medium (30mM) and optimum sucrose concentration was 1%. Addition of $NaH_2PO_4$ to culture medium generally enhanced shoot multiplication and promoted growth of the regenerants. The organogenic capacity of homogenized rhizomes was especially promoted on medium supplemented with $5{\mu}M$ kinetin plus $5{\mu}M$ IBA. The incorporation of $0.1\sim0.2%$ activated charcoal on medium supplemented with growth regulators prevented the formation of multiple bud primordia - nodule-like bud clusters and improved the normal morphogenesis of sporophytes.

• Journal of Microbiology and Biotechnology
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• v.16 no.9
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• pp.1338-1346
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• 2006

Ansamitocin P-3 is a potent antitumor agent produced by A. pretiosum. A deletion mutant of A. pretiosum was constructed by deleting the asm2 gene, a putative transcriptional repressor. The deletion mutant showed a 9-fold enhanced ansamitocin P-3 productivity. The response surface method with central composite design was employed to further optimize the culture medium composition for ansamitocin P-3 production by the deletion mutant. The concentrations of four medium ingredients, dextrin, maltose, cotton seed flour, and yeast extract, which have been reported as major components for ansamitocin production, were optimized through a series of flask culture experiments. The optimum concentrations of the selected factors were found to be dextrin 6.0%; maltose 3.0%; cotton seed flour 0.53%; and yeast extract 0.45%. The maximum titer of ansamitocin P-3 was 78.3 mg/l with the optimized composition, about 15-folds higher than the unoptimized titer of 5.0 mg/l obtained with YMG medium.