Hansenula anomala

Hansenula anomala has both fermentative (albeit limited) and oxidative capabilities (growing as a film yeast). When growing fermentatively, Hansenula is capable of producing from 0.2% to 4.5% (vol/vol) alcohol along with potentially large amounts of acetic acid (1-2 g/L) and ethyl acetate (2150 mg/L) and isoamyl acetate (Shimazu and Watanabe, 1981  

Sponholz and Dittrich, 1974). Ester production, at much lower concentrations, before and during the early stages of alcoholic fermentation may play a positive sensory role in wine complexity. 

In wine, Hansenula exists as part of the film yeast community, where it utilizes ethanol, glycerol, and wine acids in the production of acetic acid and acetaldehyde as well as esters of which ethyl acetate and 3-methylbu-tylacetate may be the most notable (Sponholz and Dittrich, 1974). Acid utilization by H. anomala may be substantial, resulting in measurable decreased titritable acidity and upward pH shifts (Sponholz, 1993). 

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Hansenula anomala Pichia miso Pichia farinosa Candida polymorpha Candida tropicalis Torulopsis versatilis... 

Hammett s-constants, of astatophenols, 31 66 Hansenula anomala, flavocytochrome bj from, 36 260-261... 

Ihn GS, Park KH, Pek UH, Moo Jeong (1992) Microbial sensor of biochemical oxygen demand using Hansenula anomala. Bull Korean Chem Soc 13 145-148 Sohn M-J, Hong D (1993) Comprehension of the response time in a microbial BOD sensor (II). Bull Korean Chem Soc 14 666-668... 

Hansenula anomala -inhibited by sorbates [SORBIC ACID] (Vol 22)... 

Pectinolysis Saccharnmyces khiyxeri Kluyveromyces fragilis, Hansenula anomala Softening of nlives and cherries in brines, followed by formation of gas pockets in fin it. Strains of wine yeasts contain polygalacturonases which, during fermentation of grape juice, participate in the solubilization of pec tin... 

The yeasts used in the production of mead are usually strains of Saccharo-myces cerevisiae, similar to that used in wine, beer, and champagne productions. These yeasts metabolize sugars, such as glucose and fructose, resulting in the formation of ethanol and carbon dioxide. Nevertheless, the yeast Hansenula anomala had also given good results (Qureshi and Tamhane, 1987). 

Chromophores free in solution and bound to macromolecules do not display identical s values and absorption peaks. For example, free hemin absorbs at 390 nm. However, in the cytochrome b2 core extracted from the yeast Hansenula anomala, the absorption maximum of heme is located at 412 nm with a molar extinction coefficient equal to 120 mM-1 cm-1 (Albani 1985). In the same way, protoporphyrin IX dissolved in 0.1 N NaOH absorbs at 510 nm, whereas when it is bound to apohemoglobin, it absorbs in the Soret band at around 400 nm. 

Albani, J. (1985). Fluorescence studies on the interaction between two cytochromes extracted from the yeast Hansenula anomala. Archives of Biochemistry and Biophysics, 243, 292-297. 

Equations (11.10) and (11.11) do not yield exactly the same value for protein with a molecular mass of 235 kDa, such as flavocytochrome b2extracted from the yeast Hansenula anomala, the rotational correlation times calculated from Equations (11.10) and (11.11) are 97 and 90 ns, respectively. 

The cytochrome b2 core from the yeast Hansenula anomala has a molecular mass of 14 kDa, and its sequence shows the presence of two tryptophan residues. Their fluorescence intensity decay can be adequately described by a sum of three exponentials. Lifetimes obtained from the fitting are equal to 0.054,0.529, and 2.042 ns, with fractional intensities equal to 0.922, 0.068, and 0.010. The mean fluorescence lifetime, r0, is 0.0473 ns. 

Binding experiments have been performed between the fluorophore TNS and a flavodeshydrogenase extracted from the yeast Hansenula anomala. The fluorescence spectrum of the Trp residues of the protein was recorded from 320 to 370 nm, in the absence and presence of different concentrations of TNS. Two sets of experiments were... 

Figure 17.3 Fluorescence spectra of Trp residues of Hansenula anomala flavodehydrogenase, in the absence (spectrum 1) and presence (spectra 2-14) with increasing concentrations of TNS. The spectra obtained are from Experiment 1.

Halogenacetic acids, glyceraldehyde-3-phosphate dehydrogenase and, 2 Hansenula anomala, L-lactate dehydrogenase of, 265, 268, 269 Heart... 

Gervais, M., Risler, J., and Corazzin, S., 1983, Proteolytic cleavage of Hansenula anomala flav-ocytochrome b2 into its two functional domains. Isolation of a highly active flavodehy-drogenase and a cytochrome h2 core, Eur. J. Biochem. 130 253n259. 

Flavocytochromes 2 2-hydroxyacid dehydrogenases found in the inter-membrane space of yeast mitochondria where they couple oxidation of the substrate to reduction of cytochrome c. Examples include the enzymes from Saccharomyces cerevisiae and Hansenula anomala, both of which are l-lactate dehydrogenases (Chapman et al., 1998), and the enzyme from Rhodotorula graminis which is a L-mandelate dehydrogenase (Ilias et al., 1998). This article will concentrate on the flavocytochrome 2 (L-lactate cytochrome c oxidoreductase) from S. cerevisiae (Bakersi yeast), since this is by far the most studied of these enzymes (Chapman et al., 1991). Therefore, throughout this article, the term flavocytochrome 2 will refer specifically to the enzyme from S. cerevisiae unless otherwise stated. 

Mutation. For industrial applications, mutations are induced by x-rays, uv irradiation or chemicals (nitrosoguanidine, EMS, MMS, etc). Mutant selections based on amino acid or nucleotide base analogue resistance or treatment with Nystatin or 2-deoxyglucose to select auxotrophs or temperature-sensitive mutations are easily carried out. Examples of useful mutants are strains of Candida membranefaciens, which produce L-threonine Hansenula anomala, which produces tryptophan or strains of Candida lipofytica that produce citric acid. An auxotrophic mutant of S. cerevisiae that requires leucine for growth has been produced for use in wine fermentations (see also Wine). This yeast produces only minimal quantities of isoamji alcohol, a fusel oil fraction derived from leucine by the Ehrlich reaction (10,11). A mutant strain of bakers yeast with cold-sensitive metabolism shows increased stability and has been marketed in Japan for use in doughs stored in the refrigerator (12). 

Fig. 4. Sequence alignment of flavocytochromes 62 and glycollate oxidase. The amino acid sequences of the mature forms of flavocytochromes 62 from Saccharomyces cerevisiae (Scb2) and Hansenula anomala (Hab2) and of glycollate oxidase from spinach (SpGO) are shown along with a consensus (Con) wherein all three sequences are identical. The interdomain hinge region and the proteinase-sensitive loop of flavocytochromes are boxed.

Under aerobic conditions, certain yeasts can convert 20 to 40% of the D-galactose they take up into galactitol, which is excreted and can be isolated from the culture medium.643 These yeasts include strains of Hansenula anomala, Pichia farinosa, Candida diddensii (polymorpha), and Torulopsis versatilis, not one of which species,... 

Besides sensors using isolated enzymes, cell-based lactate sensors using cytochrome b2-containing yeast (Hansenula anomala, Saccharo-myces cerevisiae) (Kulys and Kadziauskiene, 1978 Vincke et al., 1985a Hauptmann, 1985 Racek and Musil, 1987) and erythrocytes (Racek, 1987) have also been proposed. 

Cytochrome b2 (EC 1.1.2.3) is a tetrameric protein in which each subunit contains one molecule of flavin mononucleotide and one molecule of heme. The molecular weight is 238 000. The enzyme is contained in Saccharomyces cerevisiae and Hansenula anomala, where it transfers electrons in the respiratory chain from lactate to cytochrome c. With the artificial electron acceptor hexacyanoferrateflll) the respective Km values are 0.4 and 1.3 mmol/1. The pH optimum is between 6.5 and 8. 

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