| 摘要 |
1284799 Yeast &c. INSTITUT FRANCAIS DU PETROLE DES CARBURANTS ET LUBRIFIANTS 26 June 1970 [7 July 1969] 31238/70 Heading C6F A monocellular micro-organism e. g. a Candida lipolytica yeast is grown in the presence of an oxygen-containing gas preferably at 1À2-2À0 atmospheres pressure, an aqueous nutrition medium and a hydrocarbon feedstock containing at least 70% by weight of straight-chain paraffinic hydrocarbons (dewaxed gas, fuel and lubricating oils) until the total content of straight-chain paraffinic hydrocarbons has decreased to 0À2-5% with respect to the total weight of the initial hydrocarbon feedstock, a micro-organism enriched phase, after separation from at least the major part of the aqueous nutrient medium and from any unconverted or unabsorbed hydrocarbons, is washed in the presence of oxygen with a hydrocarbon feedstock containing at least 70% by weight of straight-chain paraffinic hydrocarbons to replace absorbed hydrocarbons which consist mainly of branched chain isomers, by hydrocarbons having a higher content of straight-chain paraffins, the washed micro-organisms are separated from the hydrocarbon feedstock which is recycled for use as at least 10% of the hydrocarbon feedstock in the original growing step, and then are grown in the presence of an oxygen-containing gas and an aqueous nutrition medium but in the absence of hydrocarbons other than the absorbed hydrocarbons, and the micro-organism enriched phase is separated from the aqueous nutrition medium. The washing step is carried out in a column type liquid - liquid extractor or in a centrifuge.
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