Utilization of cattle manure for Torula yeast production from straw hydrolysates

Good growth of Torula (Candida utilis) was obtained from mixtures of anaerobically fermented cattle manure liquor and barley straw acid hydrolysate. Relatively good growth of this yeast was also obtained from mixtures of acid- or alkali-pretreated cattle manure and barley straw acid hydrolysate. However, a significant amount of reducing sugars (30–40%) was usually left unutilized, indicating the need for a better strain of C. utilis capable of utilizing such sugars as galactose and arabinose which are released (in additon to glucose and xylose) from the hemicellulose during the acid hydrolysis of barley straw. These experiments demonstrate the practicability of using these nutrient sources, obtainable from abundant waste materials, to produce useful single cell protein (SCP) products. In particular, an integrated two stage anaerobic—aerobic fermentation process for the co-production of methane fuel gas and SCP offers an economically attractive option.     

Redox ribonucleosides. Isolation and characterization of 5-hydroxyuridine, 8-hydroxyguanosine, and 8-hydroxyadenosine from Torula yeast RNA.

Three hydroxyribonucleosides catalyzing the oxido-reduction of NADH and K3F3(CN)6 were purified from Torula yeast RNA by a series of steps including sodium dodecyl sulfate/phenol extraction, nuclease P1 digestion, alkaline phosphatase digestion, anion-exchange chromatography, and high performance liquid chromatography on an ODS column. Analysis by fast atom bombardment-mass spectrometry and 1H and 13C NMR spectroscopy led to identification of the redox ribonucleosides as 5-hydroxyuridine, 8-hydroxyguanosine, and 8-hydroxyadenosine. Their mass spectra, chromatographic behavior, UV spectra, NMR spectra, and IR spectra were identical to those from natural and synthetic sources. Oxidoreduction activities were specific for K3Fe(CN)6 as the oxidant and NADH as the reductant; and their magnitudes decreased in the order 5-hydroxycytidine, 5-hydroxyuridine, 8-hydroxyguanosine, and 8-hydroxyadenosine. The fact that these nucleosides have redox activities suggests new functional roles for RNAs as catalysts.     

Novel minimum ribozymes with oxidoreduction activity: 5-hydroxyuridine, 8-hydroxyguanosine, and 8-hydroxyadenosine isolated from Torula yeast RNA.

Three nucleosides catalyzing the oxidoreduction of NADH and K3Fe(CN)6 were isolated from Torula yeast RNA and also obtained by a series of steps: SDS-phenol extraction, nuclease P1 digestion, alkaline phosphatase digestion, anion exchange chromatography, and HPLC on an ODS column. Their chemical structures were clearly determined as 5-hydroxyuridine, 8-hydroxyguanosine, and 8-hydroxyadenosine from the results of FAB-MS, 1H and 13C-NMR spectroscopies.     

A general method for characterizing naturally occurring folate compounds, illustrated by characterizing Torula yeast (Candida utilis) folates

A method previously found suitable for the chromatographic separation and identification of simpler folates has been extended and found suitable for separating and characterizing all the complex polyglutamyl folyl derivatives occurring naturally. Folates were characterized employing the combined use of analytical DEAE-cellulose chromatography, folylpoly-γ-glutamyl carboxypeptidase digestion, and differential microbiological growth response studies. An observed relation between the log phosphate concentration of the eluting buffer and the number of γ-glutamyl residues in successive pteroylpoly-γ-glutamyl derivatives provides a simple tool for a rapid and accurate identification of folate compounds from their elution profile. Twelve folate compunds present in Torula yeast (Candida utilis) were characterized employing this method; 80% of the total folates appeared to be pteroylpolyglutamates. The method characterizes not only the number of γ-glutamyl residues but also the state of reduction of the pteridine ring and the nature of the 1-C substituents attached.     

The fine structure of conidial development in the genus Torula. III. T. graminis Desm.

Torula graminis produced blastoconidia in acropetalous chains after the evagination of a characteristic conidiogenous cell. Conidia consisted of up to 15 cells and their cell wall was differentiated into an outer melanized zone and an inner hyaline zone. A consistent cytoplasmic feature of conidial cells was the presence of dictyosomal-like membranous stacks often closely associated with the nucleus. Vesicles that developed from the dictyosomal-like cisternae were probably involved in conidial wall synthesis.     

Preliminary Studies of Some Physiological Properties of Torula jeanselmei

The morphological characteristics of pathogenic and saprophytic strains of Torula jeanselmei (Fungi Imperfecti) are indistinguishable. Some basic physiological properties of T. jeanselmei were investigated in the hope of separating the human pathogenic strain from common saprophytes in a clinical laboratory. Nitrogen and carbon assimilation tests were not useful for distinguishing the pathogen, since all strains, pathogenic and saprophytic, were able to assimilate nitrogen from ammonium, nitrate, and nitrite sources, and all were able to utilize glucose, fructose, galactose, cellobiose, lactose, glycerol, and starch. It appeared that temperature range for growth might be useful in the identification of the pathogen. All pathogenic strains grew well at 37 C but poorly at 10 C; in contrast, all saprophytes could grow at 10 C but were unable to grow at 37 C (with two exceptions).     

Increased erythritol production in Torula sp. with inositol and phytic acid

Of the vitamins tested, inositol was the most effective for erythritol production. To increase erythritol production by Torula sp., inositol and a related compound, phytic acid (myoinositol hexaphosphate), were added to the culture media. Erythritol production in the presence of phytic acid was greater than that in the presence of inositol, due to the synergistic effects of phosphate and inositol. Supplementation with phosphate and inositol increased cell growth, erythritol production, and the activity of erythrose reductase in cells. Inositol was a more effective stimulator of cell growth and erythritol production than was phosphate.     

Increased erythritol production in fed-batch cultures of Torula sp. by controlling glucose concentration

The effect of glucose concentration on erythritol production by Torula sp. was investigated. The maximum volumetric productivity of erythritol was obtained at an initial glucose concentration of 300 g l⁻¹ in batch culture. The volumetric productivity was maximal at a controlled glucose concentration of 225 g l⁻¹, reducing the lag time of the erythritol production. A fed-batch culture was established with an initial glucose concentration of 300 g l⁻¹ and with a controlled glucose concentration of 225 g l⁻¹ in medium containing phytic acid as a phosphate source. In this fed-batch culture, a final erythritol production of 192 g l⁻¹ was obtained from 400 g l⁻¹ glucose in 88 h. This corresponded to a volumetric productivity of 2.26 g l⁻¹ h⁻¹ and a 48% yield. Journal of Industrial Microbiology & Biotechnology (2001) 26, 248–252. Received 26 September 2000/ Accepted in revised form 16 January 2001     

A new name for Torula glutinosa in Heteroconium

Torula glutinosa, a sooty mold on living leaves and stems of Eriodictyon spp. from California is illustrated and described. It shares, with the type species of Heteroconium, H. citharexyli, acropetal conidiogenesis of chains of conidia of variable length and acropetal transseptation. An unnamed synanamorph is recognized and described.