Patent GB-1110999-A (GB)
Title: Growing increased yields of microorganisms
IPC: C12N1/38
Filed: 1967-02-06
Abstract: <PICT:1110999/C6-C7/1> <PICT:1110999/C6-C7/2> <PICT:1110999/C6-C7/3> A method of securing increased cell growth of an aerobic, hydrocarbonutilizing micro-organism comprises growing the cells in a fermenter or an aqueous mineral nutrient in a first zone in the presence of oxygen and a hydrocarbon as the sole source of carbon, thereby forming a culture mixture comprising nutrient, cells and cell products including growth-inhibiting products, removing the growth-inhibiting products from the first zone by dialyzing (or electrodialyzing) the culture mixture against an aqueous liquid (prefarably against an aqueous mineral medium) in a second zone. The method can, if desired, be carried out intermittently by resorting to the dialysis only when the cells stop growing.  Many genera and species of micro-organisms (bacteria, fungi, yeasts and moulds) are particularly mentioned.  Suitable hydrocarbons, mineral salts and trace elements are discussed at length.  The dialysis material may consist of flat or zigzag sheets, tubes or coils of Cellophane (Trade Mark), parchment, collodion, regenerated cellulose, cellulose derivatives (nitrate, acetate and mixed nitrate-acetate) and nylon. Referring to Fig. 4, a portion of the culture mixture in the fermenter 10c is sent along a plate and frame type dialysis membrane 14c to permit dialysis to take place against non-fermented mineral medium 15c circulated from a tank 16c either in cocurrent flow (as shown) or in counter current flow.  The portion of the culture mixture is circulated past the membrane alternately clockwise (as shown) and anti-clockwise so that any cell material deposited in or on the pores of filters 11c and 18c, respectively, is washed away when the direction of circulation is reversed.  The growth-inhibiting materials collected in the tank 16c through the dialysis may be recovered as follows: (1) by adsorption on adsorbent material dispersed by agitation throughout a relatively small quantity of mineral medium in a tank (30e, Fig. 7, not shown); (2) by adsorption upon adsorbent granules 37, Fig. 6, held by glass wool 39 within an adsorber 30, which can be mounted on the floor of the tank 16c, Fig. 4, at the top above the liquid level or on an outer wall, the aqueous liquid being sucked through apertures 41, Fig. 6, of the adsorber either by an air aspirator (as shown) or by a circulation of the mineral medium produced by a pump, many suitable adsorbent materials being mentioned; or (3) by solvent extraction with specified solvents in a unit 61, Fig. 8, the flow directions of the aqueous medium and solvent into the unit 61 are reversed when employing a solvent lighter than the mineral medium. Examples are directed to the cultivation of: (1) Norcardia salmonicolor employing butane as the sole source of carbon: (2) Candida lipolytica employing a paraffinic kerosene as the sole source of carbon.  After 16 days of cultivation the dialysate had an orange-red colour and a yeasty odour.  The coloured material was adsorbed on granules of carbon black and then, after acidification, was recovered with chloroform to give a viscous liquid and some crystals: (3) Pseudomonas aeruginosa employing p-cymene as the sole source of carbon. In this case the fermenter was disposed over a dialysis tank containing aqueous mineral salts medium with a sheet of dialysis membrane between. After 8 days of the cultivation the medium in the dialysis tank was acidified and extracted with ethyl acetate to give a mixture of crystals-one of the products was identified as p-isopropylbenzoic acid: (4) Achromobacter sp. employing decane as the sole source of carbon and a fermenter disposed over a dialysis tank as in Example 3.ALSO:A method of securing increased cell growth of an aerobic, hydrocarbon-utilizing microorganism comprises growing the cells in a fermenter on an aqueous mineral nutrient in a first zone in the presence of oxygen and a hydrocarbon as the sole source of carbon, thereby forming a culture mixture comprising nutrient, cells and cell products including growth-inhibiting products, removing the growth-inhibiting products from the first zone by dialysing (or electrodialysing) the culture mixture against an aqueous liquid (preferably against an aqueous mineral medium) in a second zone.  Example 3 is directed to the cultivation of pseudomonas aeruginosa employing p-cymene as the sole source of carbon.  In this case the fermenter was disposed over a dialysis tank containing aqueous mineral salts medium with a sheet of dialysis membrane between.  After eight days of the cultivation the medium in the dialysis tank was acidified and extracted with ethyl acetate to give a mixture of crystals-of the products was identified as p-isopropylbenzoic acid.