ABSTRACT
Different local active yeasts were isolated from air, soils, and muddy sludges. Potentialities and capabilities of 67 yeasts isolates for formation of SCP (single-cell protein) were evaluated by their cultivation on the fermentation medium, containing diesel oil as sole carbon source to select the most efficient yeast isolates. Identification of the most active organisms revealed that Candida tropicalis and Yarrowia lipolytica were the most efficient yeasts, having potentialities for SCP production. Biochemical changes which occurred during the fermentative production of SCP by Candida tropicalis revealed that during the fermentation process a deep in pH towards the acid side was recorded, and this might be due to the formation of certain organic acids with the beginning of fermentation. Yields of yeast cell biomass increased with the increase of fermentation period, reaching its optimum at 168 h, above which a decline in SCP was observed. High diesel oil concentrations in the fermentation medium harmed yeast growth and consequently a decrease in cell biomass was observed, while low diesel oil concentrations, especially in the range of 40--60 ml/litre, gave high titres of SCP. Addition of diesel oil at different intervals of the fermentation process-promoted yield of SCP.
Subject(s)
Candida/metabolism , Dietary Proteins , Fungal Proteins/biosynthesis , Protein Biosynthesis , Yeasts/metabolism , Candida/growth & development , Fermentation , Petroleum , Yeasts/growth & developmentABSTRACT
Carbomycin is produced by Streptomyces halstedii. It was produced in a medium containing the following ingredients (g/l): soybean meal, 30.0; glucose, 22.0; NaCl, 1.0; CaCO3, 5.0; CoCl2 . 6 H2O, 0.005; and lard oil, 4.0. Influence of trace elements on the biosynthesis of carbomycin was recorded. Methods of extraction and purification were given in the review article. Chemical and physical properties of carbomycin were also described. A microbiological assay method for carbomycin determination was described. Biosynthesis of carbomycin was reported. Mechanism of action of carbomycin on micro-organisms was also given in the review article.
Subject(s)
Leucomycins/biosynthesis , Streptomyces/metabolism , Bacteria/drug effects , Chemical Phenomena , Chemistry , Culture Media , Eukaryota/drug effects , Leucomycins/isolation & purification , Leucomycins/pharmacology , Microbial Sensitivity Tests , Protein BiosynthesisABSTRACT
Results are presented for the atomic-absorption spectrophotometric determination of zinc in aluminium and aluminium-silicon alloys, and aluminium, antimony and tin in steels, by means of solid samples dropped into an induction-heated graphite-well furnace to produce the atomic vapour.
