• 한국식품과학회지
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• 제21권6호
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• pp.808-814
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• 1989

Mortierella isabellina IFO 8183을 이용하여 ${\gamma}-linolenic$ acid를 생산하기 위한 최적 배양조건을 검토한 결과, 최적 탄소원과 최적 질소원은 각각 glucose와 $NH_4NO_3$이었으며, 지질 생산배지내의 최적 C/N율은 40이었다. 또한, 최적 초기 pH와 배양온도는 각각 6.0과 $30^{\circ}C$이었으며, 균체내에 축적된 지질의 지방산 조성은 pH와 온도에 의해 변화되었다. Sodium acetate를 배양 초기에 0.5%(w/v) 첨가하였을 때 대조구에 비해 ${\gamma}-linolenic$ acid 함량과 ${\gamma}-linolenic$ acid 생성량이 각각 15.4%와 37.8% 증가되었다. 최적 조건하에서 8일간 진탕배양하였을 때 균체수율, 지질수율, 지질함량, ${\gamma}-linolenic$ 함량 및 ${\gamma}-linolenic$생성량은 각각 0.347g/g, 0.18g/g, 0.52g/g, 60mg/g 및 347mg/l이었다.

• 한국식품과학회지
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• 제24권4호
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• pp.326-329
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• 1992

${\gamma}-linolenic$ acid를 함유한 유지를 생산하기 위해 포도당을 주기적으로 첨가하면서 Mucor sp. KCTC 8405P를 유가배양하였다. 배양 시작 후 2일까지 효모 모양으로 배양한 후 배지의 pH를 높여 균사체 모양으로 유도하여 배양하면, 지방질은 포도당이 고갈되는 배양 7일째까지 축적되었다. 본 배양조건에 의하여 건조 균체량 99.3 g/l, 총지방질 38.0 g/l와 3.5 g/l의 ${\gamma}-linolenic$ acid를 얻을 수가 있었다.

• Journal of Microbiology and Biotechnology
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• 제18권3호
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• pp.539-544
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• 2008

A mutant of Arthrospira platensis PCC 9108, strain M9108, obtained by mutagenesis with UV treatment, was able to mixotrophically grow in an SOT medium containing 40 g of glucose/l. The biomass and specific growth rate of strain M9108 (4.10 g/l and 0.70/d) were 1.9-fold and 1.4-fold higher, respectively, than those of the wild type (2.21 g/l and 0.58/d) under mixotrophic culture condition. In addition, when compared with the wild type, the content of ${\gamma}$-linolenic acid (GLA) in the mutant was increased when glucose concentration was increased. Compared with the wild type, the GLA content of the mutant was 2-fold higher in autotrophic culture and about 3-fold higher in mixotrophic culture. Thus, the mutant appears to possess more efficient facility to assimilate and metabolize glucose and to produce more GLA than its wild-type strain.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권6호
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• pp.506-513
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• 2004

Spirulina produces $\gamma$-linolenic acid (GLA), an important pharmaceutical substance, in a relatively low level compared with fungi and plants, prompting more research to improve its GLA yield. In this study, metabolic flux analysis was applied to determine the cellular metabolic flux distributions in the GLA synthetic pathways of two Spiru/ina strains, wild type BP and a high­GLA producing mutant Z19/2. Simplified pathways involving the GLA synthesis of S. platensis formulated comprise of photosynthesis, gluconeogenesis, the pentose phosphate pathway, the anaplerotic pathway, the tricarboxylic cycle, the GLA synthesis pathway, and the biomass syn­thesis pathway. A stoichiometric model reflecting these pathways contains 17 intermediates and 22 reactions. Three fluxes - the bicarbonate (C-source) uptake rate, the specific growth rate, and the GLA synthesis rate - were measured and the remaining fluxes were calculated using lin­ear optimization. The calculation showed that the flux through the reaction converting acetyl­CoA into malonyl-CoA in the mutant strain was nearly three times higher than that in the wild­type strain. This finding implies that this reaction is rate controlling. This suggestion was sup­ported by experiments, in which the stimulating factors for this reaction $(NADPH\;and\;MgCl_{2})$ were added into the culture medium, resulting in an increased GLA-synthesis rate in the wild type strain.

• Journal of Microbiology and Biotechnology
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• 제20권3호
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• pp.609-614
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• 2010

The effluent from anaerobic digestion contains organic nitrogen and phosphorus, which are both required for growth of Spirulina platensis. Effluent (20%) from the upflow anaerobic sludge blanket (UASB) from a pig farm, supplemented with 4.5 g/l sodium bicarbonate ($NaHCO_3$) and 0.2 g/l urea fertilizer (46:0:0, N:P:K), was found to be not only a suitable medium for the growth of Spirulina platensis but also a low-cost alternative. Cost calculation showed that this medium is 4.4 times cheaper than modifized Zarrouk's medium. The average productivities of a semi-continuous culture grown under outdoor conditions in a 6-1 scale and a 100-1 pilot scale were 19.9 $g/m^2/d$ and 12 $g/m^2/d$, respectively. In addition, the biomass of organisms grown in UASB effluent contained approximately 57.9% protein, 1.12% $\gamma$-linolenic acid, and 19.5% phycocyanin. The average rates of bicarbonate, total nitrogen, and phosphorus removal were 380 mg/l/d, 34 mg/l/d, and 4 mg/l/d, respectively.