GB572642A - Improvements in and relating to the production of aliphatic acids by the fermentation of difficultly fermentable materials - Google Patents

Abstract

Cellulosic and hemicellulosic materials such as wood, maize leaves and cobs or other leaves or products of hydrolysis of these substances, are fermented with cultures prepared from soils in which beetroots, sugar beets or carrots have been cultivated, and yield mixtures of acetic, propionic and butyric acids. The cultures may be prepared by adding fresh soil to a mash of rice bran which has been heated to 120 DEG C. and cooled. The mixture may be heated for two minutes at 100 DEG C. and is incubated at 37 DEG C. Pure cultures may be prepared by isolating single colonies growing on a solid medium, and propagating these colonies. A culture resembling Clostridium pectinororum, but without its proteolytic power, may be obtained. The cellulosic material may be hydrolysed by heating with dilute sulphuric acid at about 140 DEG C. and fermented, after neutralization, without removing the suspended matter at 37-43 DEG C. The neutralization is effected, preferably incompletely, with ammonia and the fermentation effected in presence of calcium carbonate in amount 1 to 3 times that sufficient to neutralize the amount of acid expected. The acids are separated by distilling the fermented product after acidifying with sulphuric acid and filtering. An actively fermenting rice bran mash containing calcium carbonate may be used for inoculating the liquid to be fermented. The residues from the fermentation of rice or wheat bran or maize by Clostridium acetobutylicum may be hydrolysed and fermented. Specification 249,833, [Class 2 (iii)], is referred to.