• Korean Journal of Food Science and Technology
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• v.15 no.2
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• pp.170-176
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• 1983

Starchy single cell protein produced by a starch-utilizing yeast, Sporobolomyces holsaticus FRI Y-5 was analyzed for its composition such as intracellular protein, amino acids, fatty acids, minerals, vitamins and pigments. It was shown that it contained 33.08% of total carbohydrate, 45.63% of crude protein, 20.01% of crude lipid, 3.24% of ash and 4.46% of pigment. Whole cell extracted by cold and hot NaOH method contained 40.89% of soluble protein and the estimated nucleic acid content from crude and soluble protein contents was about 7.6%. The sulphur-containing amino acids, threonine, isoleucine and valine were analyzed to be the limiting amino acids in the starchy SCP, and the protein score was calculated as 89.4. It was shown from its fatty acid analysis that it contained $6.5%\;of\;C_{16:0}$, $2.4%\;of\;C_{18:0}$, $81.9%\;of\;C_{18:1}$, $3.2%\;of\;C_{18:2}$, and $6.0%\;of\;C_{18:3}$. Also it was observed that it contained, per 100 g of dry cell, 365.33mg of Mg and 282.75mg of K more than Fe and Ca. The content of Vit. $B_2$ was 3.7mg per 100 g of dry cell, but niacin was not detected under this experimental condition. The UV-visible scanning result of pigment extract showed that the yeast contained carotenoid and unknown pigments.

• Korean Journal of Food Science and Technology
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• v.25 no.2
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• pp.142-147
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• 1993

For the purpose of fixing solar energy and utilizing water wastes from food industries for SCP(single cell protein), 170 strains of photosynthetic bacteria were isolated from 56 samples. Among 170 strains, B-Ps-106 strain was selected as the most suitable strain and identified as a variant or a relation of Rhodopseudomonas sphaeroides and its growth was better under anaerobic light condition than aerobic condition. The optimum conditions of the cell growth of B-Ps-106 were investigated on soybean-curd whey media. The optimum pH for cell growth was $8.5{\sim}9.0$. The optimum temperature was $30^{\circ}C$ and the optimum light density was above $0.72\;cal/cm^2/min$. The most favorable concentration of $K_2HPO_4\;and\;(NH_4)_2SO_4$ was both 0.9 g/l when added to soybean-curd whey media.

• Microbiology and Biotechnology Letters
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• v.4 no.3
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• pp.99-104
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• 1976

Experiments were carried out to establish the effects of acids in neutralization after alkaline treatment of rice straw, with which cellulosic single cell protein can be produced by cellulose utilizing bacteria, Cellulomonas flavigena KIST 321, previously isolated by authors. Following results were obtained. 1. Rice straw as carbon source was pretreated with 10 volumes of 1 normality of NH$_4$OH or NaOH(NaOH/substrate：40％, and then washed with water or neutralized with H$_3$PO$_4$, H$_2$SO$_4$, HCl and CH$_3$COOH. Among the above mentioned methods, neutralization with H$_3$PO$_4$after alkaline treatment was proved to be the most effective on its digestibility and SCP production. Dry cell 12.28g/$\ell$ and 78％ digestibility were obtained. 2. When rice straw was treated with NaOH solution, the result suggested that the productibity of cell-mass was attained on treatment of rice straw with 6％ of NaOH (NaOH/substrate ratio) for 15～24hrs at room temperature. 3. When rice straw was treated with NaOH, a volume of water to substrate is adequate by two or three fold and the amount of NaOH can be economized up to 5％ for the weight of rice straw. 4. The steaming of rice straw at 121$^{\circ}C$ for 30min. in alkaline treatment of rice straw gave the similiar effectiveness to that at room temperature for 15～24hrs. and accelerated the sterilization of the substrate. 5. Finally, the level of inorganic phosphate in a medium was investigated. 11.2g of dry cell was produced at the concentration of 0.2％, phosphate (phosphorous level 0.04％) in medium even though treated rice straw was neutralized with HCI instead of H$_3$PO$_4$, and 12.2g/$\ell$ at the concentration of 0.3％ phosphate (phosphorous 0.04％) on neutralization with H$_2$SO$_4$.