GB337153A - Improvements in or relating to the production of aliphatic acids by fermentation - Google Patents

Abstract

337,153. Distillers Co., Ltd., and Hutchinson, H. B. Sept. 30, 1929. Volatile fatty acids; acetic acid; butyric acid; propionic acid.-These acids are produced by the fermentation with thermophilic organisms of a sugar solution of low concentration, to which stronger sugar solution is added in such a way that the concentration remains sufficiently low to prevent the formation of non-volatile fatty acids. The thermophilic organisms may be obtained, for example, from animal excrements or from decomposing cellulosic material. They are characterized, first, by their capacity to decompose and ferment cellulose in the entire absence of other sources of carbon nutrient, secondly, by the very high optimum temperature of their growth, e.g. 60- 65‹ C., and thirdly, by the formation of terminal spores which render them resistant to temperatures of 100‹ C. or over for short periods. The hydrogen ion concentration is maintained at the optimum for the organisms employed, i.e. between pH5 and pH9, by addition of neutralizing agents' such as sodium bicarbonate, ammonia, lime water, and calcium carbonate. Nutrients such as ammonia, ammonium sulphate, and ammonium phosphate may be added. The sugar solution used may be diluted molasses from cane or beet sugar manufacture, solutions from crude sucrose, from glucose, sorghum, carob beans and other plant products containing sugar, from products of hydrolysis of cellulose such as those obtained by treating sawdust with acid, or obtained in the sulphite treatment of wood, or solutions from the hydrolysis of starch and starchcontaining materials. In this way, an economic concentration of fatty acid salts, especially acetates, but including butyrates and sometimes propionates, may be obtained. The acid can then be recovered by any known means. In the example, a fermenter of 600 gallons capacity is used, and on each of 7 days, 80 lbs, of molasses in 80 gallons of water is added. The fermenter has already been charged with a thermophilic cellulose-fermenting organism. A temperature of 60' C. is maintained, and the hydrogen ion concentration is kept between pH6 and pH7.5 by the usual means. Having thus built up a wash of low sugar concentration suitable for further additions and corresponding withdrawals, 80 gallons of wash may be withdrawn per day and 80 gallons of 10 per cent molasses added. Using beet molasses, the addition of nutrients will not, in general, be necessary, Specification 316,287 is referred to.