Showing papers on "Pichia pastoris published in 1983"

Serological differences between the multiple amine oxidases of yeasts and comparison of the specificities of the purified enzymes from Candida utilis and Pichia pastoris.

Abstract: 1. Antiserum to purified methylamine oxidase of Candida boidinii formed precipitin lines (with spurs) in double-diffusion tests with crude extracts of methylamine-grown cells of the following yeast species: Candida nagoyaensis, Candida nemodendra, Hansenula minuta, Hansenula polymorpha and Pichia pinus. No cross-reaction was observed with extracts of Candida lipolytica, Candida steatolytica, Candida tropicalis, Candida utilis, Pichia pastoris, Sporobolomyces albo-rubescens, Sporopachydermia cereana or Trigonopsis variabilis. Quantitative enzyme assays enabled the relative titre of antiserum against the various methylamine oxidases to be determined. 2. The amine oxidases from two non-cross-reacting species, C. utilis and P. pastoris, were purified to near homogeneity. 3. The methylamine oxidases, despite their serological non-similarity, showed very similar catalytic properties to methylamine oxidase from C. boidinii. Their heat-stability, pH optima, molecular weights, substrate specificities and sensitivity to inhibitors are reported. 4. The benzylamine oxidases of C. utilis and P. pastoris both oxidized putrescine, and the latter enzyme failed to show any cross-reaction with antibody to C. boidinii methylamine oxidase. Benzylamine oxidase from C. boidinii itself also did not cross-react with antibody to methylamine oxidase. The heat-stability, molecular weights, substrate specificities and sensitivity to inhibitors of the benzylamine/putrescine oxidases are reported. 5. The benzylamine/putrescine oxidase of C. utilis differed only slightly from that of C. boidinii. 6. Benzylamine/putrescine oxidase from P. pastoris differed from the Candida enzymes in heat-stability, subunit molecular weight and substrate specificity. In particular it catalysed the oxidation of the primary amino groups of spermine, spermidine, lysine, ornithine and 1,2-diaminoethane, which are not substrates for either of the Candida benzylamine oxidases that have been purified. 7. Spermine and spermidine were oxidized at both primary amino groups; in the case of spermidine this is a different specificity from that of plasma amine oxidase. 8. Under appropriate conditions, P. pastoris benzylamine/putrescine oxidase (which is very easy to purify) can be a useful analytical tool in measuring polyamines.

A continuous culture study of methanol and formate utilization by the yeast Pichia pastoris

Abstract: Quantitative aspects of C1 metabolism by chemostat cultures of Pichia pastoris have been studied. Under methanol limitation the maximum growth yield was 0.41 (g/g), the maintenance energy was 9.1 mg CH3OH/g.h and the μmax was estimated to be 0.18 h−1. Formate was utilized by methanol-limited cultures, and increased the cell yield approx. 20% as compared to that on methanol alone.

Oxidation of Methanol by the Yeast, Pichia pastoris, Purification and Properties of the Formaldehyde Dehydrogenase

Abstract: The formate dehydrogenase from the yeast Pichia pastoris IFP 206 was purified to homogeneity. The protein showed a molecular weight of 68,000 daltons and was composed of two identical subunits. Its amino acid composition was similar to those of other formate dehydrogenases and was characterized by a high content of acidic residues. The N-terminal end of the molecule was probably blocked.The enzyme activity was NAD+ dependent (NADP+ could not replace NAD+). Its optimum temperature was 47°C and the activation energy 10.8 kcal/mol. The enzyme was active from pH 3.5 to 10.5 with a maximum at pH 7.5. The Michaelis constant for NAD+ and formate were respectively 0.27 and 15mM. The purified enzyme had no S-formylglutathione hydrolase activity, strongly suggesting that the true substrate was formate. NADH, cyanide and azide were strong inhibitors of the enzyme.

Treatment of yeast cells with proteolytic enzymes

Abstract: Functional protein having reduced nucleic acid content is produced without initial denaturation of the protein by contacting undenatured yeast cells with an alkaline protease at a temperature of about 20° C. to 40° C. for about 2 minutes to 2 hours at a pH of about 8 to 11. The yeast cells are preferably Pichia pastoris and the alkaline protease is preferably from Bacillus lichenformis.

Isolation and characterization of a methanol utilizing yeast with high cell yield

Abstract: A yeast (Pichia pastoris strain CMB 10) growing on methanol as sole carbon and energy source was isolated. The high growth rate (0.235·h−1 at pH 5) and high cell yield (0.41 g cell per g methanol at pH 3.5) of this strain are of interest for production of single cell protein (SCP). Other advantages of the strain are: low maintenance coefficient (m=9.5 mg·g−1·h−1), high affinity for methanol (Ks=100 mg·l−1), possibility of non aseptic culture at low pH (pH 3.5), equilibrated amino acid profile and flocculating properties.