Biological decomposition of chemical lignin: II. Studies on the decomposition of calcium lignosulphonate by wood destroying and soil fungi

The growth and lignin decomposing properties of 106 cultures of wood destroying and soil fungi have been studied on a synthetic calcium lignosulphonate medium. Certain species of Fusarium and Alternaria, decomposing a maximum of 12 and 18% lignin, respectively, were the most effective in utilizing the lignosulphonate. Although a few species of wood destroyers were equally effective, in general this group of fungi showed great variation and was more difficult to cultivate on the medium employed. A slight positive correlation was found between the Bavendamm tannic acid reaction for identifying lignin decomposing fungi and the lignosulphonate breakdown after 60 days' growth.Peer reviewed: YesNRC publication: Ye

Biological decomposition of chemical lignin: III. Application of a new ultra-violet spectrographic method to the estimation of sodium lignosulphonate in culture media

An ultra-violet spectrographic method has been developed for estimating the amount of sodium lignosulphonate present in solutions. The method has been applied to the measurement of lignosulphonate losses in liquid media after fungous growth and the results are compared with those obtained under similar conditions by the \u3b2-naphthylamine precipitation method. The spectrographic method gave slightly lower values but was free from certain errors present in the chemical method. The results confirmed previous observations that fungi are capable of decomposing lignosulphonates.Peer reviewed: YesNRC publication: Ye

Production and properties of 2,3-butanediol II. Strains of Aerobacillus polymyxa in relation to filterability and butanediol production

Under laboratory conditions it has been found that most strains of Aerobacillus polymyxa split off variants that differ substantially in: colony formation; appearance of wheat mashes after fermentation; filterability of these mashes; and their ability to produce 2,3-butanediol and ethanol. It has been impossible to demonstrate a close correlation between particular colony types and their usefulness for commercial 2,3-butanediol production. By selection it has been possible to obtain strains that are excellent both from the standpoint of mash filterability and product yield. Preservation of cultures in lyophile tubes prevents further variation during storage.Peer reviewed: YesNRC publication: Ye

Production and properties of 2,3-butanediol: I. Fermentation of wheat mashes by Aerobacillus polymyxa

Isolation of Aerobacillus strains with desirable fermentative characteristics was facilitated by pasteurization of the original inoculum. Both cultural characteristics and fermentative capacity of the original isolates were extremely variable. Dissociation into more variant types occurred in later generations giving rise to further differences in fermentative characteristics.In the preparation of mashes particle size of wheat is unimportant in relation to yield provided the kernel has been broken. Since prolonged cooking is harmful, a standard procedure of sterilization for 1\u2002hr. at 121 \ub0C. has been adopted. Mashes containing over 15% wheat by weight are inefficiently fermented. Acid production in the mash may be controlled by the addition of excess calcium carbonate at the beginning of the fermentation, or by the addition of ammonia as required. The most satisfactory fermentation temperature is about 32.5 \ub0C.The addition of yeast extract, malt extract, dried yeast, or corn steep liquor is essential for the preparation of an active inoculum. Fermentation of whole wheat mashes may also be enhanced by yeast extract. Removal of the gluten has little effect, but the bran, shorts, germ, and soluble nitrogenous constituents are necessary for a normal fermentation. Pure wheat starch with inorganic supplements can be only partially utilized.Under anaerobic conditions fermentation of a 15% mash is complete in 60\u2002hr., but continuous removal of the carbon dioxide reduces this time to 48\u2002hr. The diol\u2013ethanol ratio for anaerobic fermentations is of the order of 1.3: 1.0. Aerobic conditions inhibit the fermentation, particularly ethanol formation, and 120\u2002hr. are required for completion. The diol\u2013ethanol ratio, however, may be raised to 3: 1 or higher.Peer reviewed: YesNRC publication: Ye

Separation of starch and gluten I. Development of mechanical equipment and washing methods for separation of wheat flour

Starch and gluten were separated from wheat flour in a washing vessel, hemicylindrical in shape, oscillated 48 times per minute through 45\ub0, accommodating 15\u2002kgm. of water plus the dough prepared from 3\u2002kgm. of patent hard spring flour. Washing action was provided by the combined movements of the vessel and an adjustable free-swinging rubber-covered roller. The starch suspension was continuously pumped into a settling tray, from which the overflow was recycled to the washing machine. Under these conditions 45\u2002min. of washing with 40\u2002kgm. of water effected a recovery of about 95% of the starch and gluten present in the dough. About 70% of the starch was extracted in the first 10\u2002min. washing period.Washing was more efficient at 37 \ub0C. than at lower temperatures, and dough mixing times of nine minutes gave better results than three minutes. The washing equipment provided results of a precision that permitted demonstration of statistically significant differences between starch yields differing by as little as 3%.Peer reviewed: YesNRC publication: Ye