GB1224172A - Improvements in or relating to the production of nitrogenous material - Google Patents

Abstract

1,224,172. Extracting protein. BRITISH PETROLEUM CO. Ltd. 2 May, 1968 [6 June, 1967], No. 26093/67. Heading C3H. [Also in Division C6] In the recovery of a nitrogenous product from the cells of micro-organisms, the cells are extracted with a solvent which consists of or contains formic acid, the extraction being carried out under conditions such that a substantial proportion of the free protein content of the cells and of compounds present in the cells having carbohydrate-to-protein bonds pass into the extract phase and such that a substantial proportion of the free carbohydrate content of the cells remains in solid phase, thereafter the extract phase is separated from the solid phase, the extract phase, which contains compounds having carbohydrate-to-protein bonds, is maintained at such temperatures for such a period of time that the bonds are disrupted, and there is recovered from the treated extract phase a nitrogenous product. The micro-organism cells are typically obtained by the aerobic culture of specified normal paraffin-consuming yeasts, moulds or bacteria on a hydrocarbon substrate. Under preferred conditions of operation the micro-organism is in a dry state when subjected to the extraction, formic acid is employed in the anhydrous state or in aqueous dilution containing at least 30% of formic acid and the extraction is carried out at a temperature below 60‹ C. with a contact time of at least 2 hours. Disruption of the carbohydrate-to-protein bonds may be achieved by subjecting the extract to elevated temperature (60-100‹ C.) or maintaining the extract for a prolonged period (2-50 hours) at ambient temperature. According to the examples, dry Candida yeast was treated with 85% w./w. aqueous formic acid at 20‹ C. for 16 hours. The extract phase was maintained under stirring at 20‹ C. for 48 hours (or at 80‹ C. for 2 hours) and the formic acid was then removed by vacuum distillation. From the solid residue there was obtained an aqueous phase containing 18% by weight of the original nitrogen of the yeast and a solid phase from which there was obtained by further extraction and precipitation proteinaceous material (12.5% by wt. of nitrogen) constituting 52% by wt. of the original nitrogen of the yeast.