• Korean Journal of Food Science and Technology
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• v.24 no.4
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• pp.326-329
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• 1992

Mucor sp. KCTC 8405P was cultivated in a jar fermentor for the production of fungal lipid containing ${\gamma}-linolenic$ acid with feeding the glucose solution periodically. The transition of the fungal growth into the mycelial phase from yeast-like growth was achieved by pH shift after the first two day of cultivation in the low pH medium and then lipid accumulation was accelerated until the seven day of cultivation, when the glucose in the culture broth was almost consumed. With the culture conditions applied in this experiment, biomass of 99.3 g/l by the dry cell weight and the total extractable lipid of 38.0 g containing 3.5 g/l ${\gamma}-linolenic$ acid were obtained.

• Journal of Microbiology and Biotechnology
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• v.1 no.2
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• pp.126-129
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• 1991

In order to produce ${\gamma}-linolenic$ acid by Mucor sp. KCTC 8405P. the fungus was cultivated in fed-batch culture with two phases. i.e., growth in yeast-like form and induction to hyphal growth by pH shift of the culture medium during cultivation. The synchronous growth of the fungus into the appropriate sizes was important for the high density cell culture of this dimorphic fungus. Dissolved oxygen concentration in the medium did not affect degree of unsaturation of fatty acids and ${\gamma}-linolenic$ acid content. Under the culture conditions applied in this experiment. the fungus was found to produce 100 g/l dry mycelia containing 40% of the lipids, where ${\gamma}-linolenic$ acid comprised about 9% of the total extractable fatty acids.

• Microbiology and Biotechnology Letters
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• v.19 no.1
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• pp.64-69
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• 1991

- The effects of sodium acetate on the production of $\gamma$-linolenic acid (GLA) and the secretion of the mycelial lipid into the culture medium with noninnic surfactants were studied with Mucor sp. KCTC 8405P. In the addition of 2.0%) sodium acetate to the basal medium, dry cell weight and total lipid content were increased from 7.8 g/l and 2.46 g/l to 16.0 g/1 and 4.77 g/l, but GLA content was decreased from 18.6% to 13.85%. The growth of Mucor sp. KCTC 8405P was greatly dependent on both the initial pH and the concentration of sodium acetate of culture medium, which was considered as the results of the formation of acetic acid because the fungal growth was completely inhibited at the concentration of acetic acid higher than 22 mM. With the decrease of the oxygen supply, the cell growth, total lipid, and GLA content were sharply decreased in the presence of 2.0% sodium acetate. For the secretion of mycelial lipid into the culture medium, the effects of the various nonionic surfactants were examined. In the addition of 0.5% Tween 80 or Span 80 to the basal medium, 194 mg/l or 263 mg/l of GLA was obtained in the culture medium.

• Microbiology and Biotechnology Letters
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• v.17 no.6
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• pp.568-573
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• 1989

As a way to determine the optimal culture conditions for the production of ${\gamma}$-linolenic acid by Mucor sp. KCTC 8405P, the influence of different carbon and nitrogen sources, initial pH, and C/N ratio of medium was investigated. Glucose was found to be the best carbon source in terms of lipid content and ${\gamma}$-linolenic acid yield. Ammonium sulfate and organic nitrogen sources such as urea and peptone resulted in relatively increased lipid and ${\gamma}$-linolenic acid production. The highest accumulation of lipid was obtained at a C/N ratio of 56.6 using glucose and (NH$_4$)$_2$SO$_4$ as carbon and nitrogen source, respectively. It was found that the lipid content increased significantly with increasing initial pH of medium up to pH 9.0. The influence of mixed carbon source on the ${\gamma}$-linolenic acid yield was also investigated. High accumulation of lipids, 315 mg/100 ml medium, and 13-14% of ${\gamma}$-linolenic acid content in the cellular lipid were obtained in a shaking culture containing 3% of glucose and 2% sodium acetate as carbon source and 0.1% of (NH$_4$)$_2$SO$_4$ as nitrogen source at pH 8.0.