Showing papers on "Pichia pastoris published in 1981"
Patent•
29 Oct 1981TL;DR: In this paper, the characteristics of Pichia pastoris NRRL Y-11430 and mutants of it have been revealed, as well as methods of culturing the strains, and biochemical conversions employing the strains.
Abstract: Novel yeasts are disclosed including Pichia pastoris NRRL Y-11430, yeasts having the characteristics of Pichia pastoris NRRL Y-11430, mutants of Pichia pastoris NRRL Y-11430, and strains derived therefrom. Also disclosed are methods of culturing the strains, and biochemical conversions employing the strains.
86 citations
TL;DR: The secondary-alcohol dehydrogenase activity was inhibited by metal-chelating agents and by strong thio reagents such as p-hydroxymercuribenzoate and 5,5'-dithiobis(2-nitrobenzoic acid).
Abstract: NAD-dependent alcohol dehydrogenase from the methanol-grown Methylcoccus sp. CRL M1 (type I membrane), Methylosinus trichosporium OB3b (type II membrane), Methylobacterium organophillum CRL 26 (type II membrane, facultative methylotroph). Pseudomonas sp. ATCC 21439, and Pichia pastoris Y-55 are secondary-alcohol-specific and that from P. pastoris Y-7556 is not. This novel secondary-alcohol-specific alcohol dehydrogenase (secondary-alcohol dehydrogenase) has been purified from methanol-grown Pseudomonas sp. ATCC 21439. Secondary-alcohol dehydrogenase shows a single protein band on acrylamide gel electrophoresis and has a molecular weight of 95000. It consists of two subunits of Mr 48000 daltons and two atoms of zinc per molecule of enzyme protein. It oxidizes secondary alcohols, notably 2-propanol and 2-butanol. Primary alcohols are not oxidized. The pH and temperature optima for secondary-alcohol dehydrogenase are 8--9, and 30--35 degrees C, respectively. The activation energy calculated is 82.8 kJ. Secondary-alcohol dehydrogenase also catalyzes the reduction of methyl ketones to their corresponding 2-alcohols in the presence of NADH (a reverse reaction). The Km values at 25 degrees C in the forward reaction for 2-butanol, (2R)-(-)-butan-2-ol, and NAD, and in the reverse reaction for 2-butanone and NADH are 2.5 x 10(-4) M, 1.6 x 10(-4) M, 11 x 10(-5) M, 1.98 x 10(-4) M, and 2.1 x 10(-6) M, respectively. The secondary-alcohol dehydrogenase activity was inhibited by metal-chelating agents and by strong thio reagents such as p-hydroxymercuribenzoate and 5,5'-dithiobis(2-nitrobenzoic acid). The substrate specificity, and mobility on gel electrophoresis of secondary-alcohol dehydrogenase and primary-alcohol dehydrogenases are compared. Secondary-alcohol dehydrogenase oxidizes preferentially the (-)-2-butanol. This is different from primary-alcohol dehydrogenase from bakers' yeast which oxidizes only the (+)-2-butanol. This may be explained in terms of the structure of the enzymes.
28 citations
Patent•
09 Sep 1981TL;DR: Mutant yeasts of the strain Pichia pastoris have been developed which contain relatively high levels of methionine as mentioned in this paper, which can be used to produce improved amino acid balance single-cell protein product eliminating or reducing the need to supplement singlecell protein with methionines when used as food supplements.
Abstract: Mutant yeasts of the strain Pichia pastoris have been developed which contain relatively high levels of methionine These high methionine content Pichia pastoris mutants grow on an oxygenated hydrocarbon such as methanol, to produce improved amino acid balance single-cell protein product eliminating or reducing the need to supplement single-cell protein with methionine when used as food supplements
16 citations