Protein-enriched feedstuff from beet pulp.

Of five moulds that were cultivated in a medium containing beet pulp, Trichoderma reesel was superior in protein production (34%) and in conversion of pulp to proteins (18% w/w). Protein ylelds were improved by up to 49% by pre-treatment of the beet pulp, adjustment of the solld/llquid and liquld/solid ratios, the incubation period, nitrogen level and addition of some trace elements as well as with inoculum size. The protein obtained contained all essential amino acids and compared favourably with those of the FAO guldeline and of soy bean oll meal.

Utilization of beet molasses for sterol production by some moulds.

Different moulds were cultivated in beet molasses (BM)-containing medium. Penicillium crustosum Thom was superior to the other moulds in total sterols production (4% on dry weight basis), efficiency of convertibility of the BM sugars to sterols (2%), total lipids (19.4%) and unsaponified lipids (13.4%). The treatment of BM with H2SO4- followed by centrifugation allowed maximum fermentation yields. The highest unsaponified lipids (16.5%) and total sterols level (7.4%) were obtained with a medium composed of (g/1): NaNO3, 3; K2HPO4, 3; MgSO4.7H2O, 1.5; K2SO4, 0.11; ZnSO4.7H2O, 0.05; FeCl3.6H2O, 0.16; H2SO4-treated BM, 60. Maximal sterol yields (8.4%) and high growth rate were achieved at the accelerated growth phase (8 days old cultures), when the initial pH value of the medium was adjusted to 7.0.

Production of riboflavin (vitamin B2) by hydrocarbon-utilizing yeasts.

Candida guilliermondii Wickerham was found to be superior to the other yeasts tested for growth yields and riboflavin production when cultivated on different carbohydrate and hydrocarbon-containing media. Among the refined petroleum fractions and cheap hydrocarbons tested, solar was selected as a carbon source best suited for the fermentation process. The highest growth yield and riboflavin output (10.64 mg/100 ml) by C. guilliermondii Wickerham were achieved by placing aliquots of 20 ml medium (pH 6.0) in 100 ml Erlenmeyer flasks and incubating the inoculated medium at 30 degrees C for 14 days in the dark.

Riboflavin formation by mould fungi cultivated on hydrocarbon-containing media.

The potentiality of some mould fungi, isolated from petroleum sludge to produce riboflavin when grown on hydrocarbon-containing media was tested. Aspergillus terreus was found to be distinguished by its capacity to produce riboflavin when cultivated on the different culture media tested. It was able to grow more luxuriantly and produce good riboflavin output on solar-containing medium. A solar concentration of 5% v/v favoured high riboflavin productivity. The maximal vitamin B2 yields were achieved after 20 days incubation at 30 degrees C. An initial pH value of 5.5-6.0 was found to be the optimum for growth of A. terreus and for riboflavin production.

Formation and some factors influencing the activity of progesterone hydroxylases by Aspergillus niger.

The formation of progesterone hydroxylases by Aspergillus niger 173 was investigated. The constitution of the fermentation medium influenced both the yield and the type of enzymes catalyzing the transformation of progesterone. The enzyme yield also varied with the pH value at which induction was performed as well as with the buffer used. The transformation activity of progesterone was more pronounced with mycelia induced in citrate-phosphate than in phosphate buffer. The results demonstrated that induction of 6beta-hydroxylase was favoured at pH values near neutrality while that of 11alpha-hydroxylase in the presence of citrate ions. The transformation activity of progesterone was optimal at pH 5.0. The action of 11alpha-hydroxylase was also optimal at pH 5.0, but other hydroxylase showed pH optima between 2.2 and 4.0. Progesterone concentrations higher than 6 mg in 50 ml reaction mixture was a limiting factor for the rate of transformation activity.

Some biochemical aspects of the enzymic transformation of cortisol with Bacillus cereus.

The role of a variety of compounds including organic acids, vitamins, growth promoting substances, purines and pyrimidines in the bioconversion of cortisol with Bacillus cereus was investigated. The transformation of cortisol to prednisolone and pregn-4-en-11beta, 17alpha,20beta, 21-tetrol-3-one was affected by these compounds in different manners. The enzymatic delta1-dehydrogenation reaction was greatly induced with fumarate, menadione, and xanthine treatments. However, the enzymic reduction of the 20-carbonyl to the 20beta-ol was specifically stimulated with fumarate, nicotinic acid amide, and uracil treatments.