Patent GB-401284-A (GB)
Title: Improvements in carrying out fermentations
IPC: C12P1/00
Filed: 1932-04-01
Abstract: Fermentations with bacteria, especially such as are capable of forming alcohols, carboxylic acids and/or ketones, for example, Bacillus butylicus, macerans, and butyricus, are carried out by directly inoculating large amounts, i.e. about 1 cubic metre or preferably more of a sterile, sugar containing liquid with spores of pure cultures, preferably on a sterile carrier such as clay, kieselguhr, or earth, and fermenting, instead of working with a series of intermediate cultures of increasing size.  The spores of the bacteria are formed in the usual manner, in a suitable carbohydrate mash, the mash exhausted of nutrients, if desired, after partial evaporation in vacuo at temperatures not exceeding 60 or 70 DEG  C., being decanted from the sludge of spores settling at the bottom of the vessel employed for their formation.  The ratio of the volume of the culture thus obtained to that of the sugar containing liquid to be fermented may range from 1 : 100 to 1 : 3000. Alternatively, to the cultivation mash as soon as it has reached the maximum degree of fermentation, or to the exhausted mash, or to a sludge of spores obtained as above, there is added a quantity of sterile, neutral adsorbent such as charcoal, active carbon, silica gel, alumina, bleaching earths, sawdust, peat or the like sufficient to adsorb the spores.  In carrying out the main fermentation, the temperature of the liquid should first be raised to 60-95 DEG  C., to kill any bacteria not forming spores introduced with the spore culture, and only reduced to the normal fermentation temperature about an hour after the inoculation. After about 45 hours the liquid may be transferred to a final fermentation vessel 10 or 20 times as large, the mash in which need not be sterilized.  A further quantity of more concentrated sugar containing liquid may be added to this final fermentation vessel after fermentation has commenced therein, and the addition may be repeated.  Examples are given, according to one of which an aqueous solution of molasses is treated in the manner described above with Bacillus macerans, or a butyl or a butyric bacillus, the products obtained in the three cases being respectively a mixture of butanol, isopropanol, and acetone, a mixture of acetone and ethanol, and a mixture of volatile fatty acids.  In a second example a liquid obtained by the saccharification of wood with dilute sulphuric acid is brought by an addition of calcium hydroxide to a pH value of 7,2 to 7,4, additions of secondary sodium and ammonium phosphate and of malt germs are made, and the fermentation is carried out with a culture of the spores of Bacillus butylicus as before. The methods of preparing the spore cultures used in the examples are described in detail. Specifications 20942/13, 278,307, [both in Class 14 (ii), Beverages &c.], and 349,490 are referred to.ALSO:Fermentations with bacteria, especially such as are capable of forming alcohols, carboxylic acids and/or ketones, for example, Bacillus butylicus, macerans, and butyricus, are carried out by directly inoculating large amounts, i.e. about 1 cubic metre or preferably more, of a sterile, sugar containing liquid with spores of pure cultures, preferably on a sterile carrier such as clay, kieselguhr, or earth, and fermenting, instead of working with a series of intermediate cultures of increasing size.  The spores of the bacteria are formed in the usual manner, in a suitable carbohydrate mash, the mash exhausted of nutrients, if desired after partial evaporation in vacuo at temperatures not exceeding 60 or 70 DEG  C., being decanted from the sludge of spores settling on the bottom of the vessel employed for their formation.  The ratio of the volume of the culture thus obtained to that of the sugar containing liquid to be fermented may range from 1 : 100 to 1 : 3000. Alternatively, to the cultivation mash as soon as it has reached the maximum degree of fermentation, or to the exhausted mash, or to a sludge of spores obtained as above, there is added a quantity of sterile, neutral adsorbent such as charcoal, active carbon, silica gel, alumina, bleaching earths, sawdust, peat, or the like sufficient to adsorb the spores.  In carrying out the main fermentation, the temperature of the liquid should first be raised to 60-95 DEG  C. to kill any bacteria not forming spores introduced with the spore culture, and only reduced to the normal fermentation temperature about an hour after the inoculation. After about 45 hours the liquid may be transferred to a final fermentation vessel 10 or 20 times as large, the mash in which need not be sterilized.  A further quantity of more concentrated sugar containing liquid may be added to this final fermentation vessel after fermentation has commenced therein, and the addition may be repeated.  Examples are given, according to one of which an aqueous solution of molasses is treated in the manner described above with Bacillus macerans, or a butyl or a butyric bacillus, the products obtained in the three cases being respectively a mixture of butanol, isopropanol, and acetone, a mixture of acetone and ethanol, and a mixture of volatile fatty acids.  In a second example a liquid obtained by the saccharification of wood with dilute sulphuric acid is brought by an addition of calcium hydroxide to a pH value of 7.2 to 7.4, additions of secondary sodium and ammonium phosphate and of malt germs are made, and the fermentation is carried out with a culture of the spores of bacillus butylicus as before. The methods of preparing the spore cultures used in the examples are described in detail. Specifications 20942/13, 278,307, [both in Class 14 (ii), Beverages &c.], and 349,490 are referred to.