Kluyveromyces

Saccharomyces cerevisiae is well characterized biochemically and genetically and was the organism of choice for most of the eady experiments. However, heterologous expression seems to be better in some of the industrial strains of yeasts such as Pichiapastoris Hansenulapolymorpha Kluyveromyces lactis and Yarrowia lipolytica (25—28). 

Figure 4.4 The production of whey protein and Kluyveromyces lactis from whey.

All foe organisms listed would grow on foe sucrose in molasses. Candida utUis or Kluyveromyces fragilis would be foe best organisms to use, as they are food-grade yeasts with high growth rates. 

A series of 2-(4-chlorophenoxy)-3-oxoalkanoate were reduced by baker s yeast, and Kluyveromyces marxianus. Yeast reduction of ethyl 2-(4-chlorophenoxy)-3-oxo-3-phenylpropanoate (R=Ph) afforded enantiomerically pure ethyl 2R, 3S)-2-(4-chlorophenoxy)-3-hydroxy-3-phenylpropanoate out of the four possible stereoisomers in >99% de [29h]. Although baker s yeast reduction of butanoate (R = CFl3) was not selective (92% de), the use of K. marxianus afforded (2R, 3S)-isomer selectively [29i]. The products are intermediates for potential peroxisome prolifera-tor-activated receptor isoform a-agonists (Figure 8.39a). 

Endo-polygalacturonase of the yeast Kluyveromyces marxianus is constitutive, highly active on native pectin and is the main extracellular protein... 

Kluyveromyces marxianus CCT 3172 was isolated from cocoa fermentations in Bahia, Brazil and has been deposited in the culture collection of the Funda ao Tropical de Pesquisas e Tecnologia "Andre Tosello" (CCT), Campinas, Sao Paulo, Brazil. 

A commercial pectinase, immobilised on appropriately functionalised y-alumina spheres, was loaded in a packed bed reactor and employed to depolymerise the pectin contained in a model solution and in the apple juice. The activity of the immobilized enzyme was tested in several batch reactions and compared with the one of the free enzyme. A successful apple juice depectinisation was obtained using the pectinase immobilised system. In addition, an endopolygalacturonase from Kluyveromyces marxianus, previously purified in a single-step process with coreshell microspheres specifically prepared, was immobilised on the same active support and the efficiency of the resulting catalyst was tested. 

The endopolygalacturonase obtained from a Kluyveromyces marxianus culture broth was purified through the addition of specifically designed core-shell microspheres consisting of an inner polystyrene core and an outer shell constituted by a poly(methacrylic acid-co-ethylacrylate) statistical copolymer. These microspheres were previously found very effective in purifying the pectinlyase within a commercial pectinase sample [15]. 

Several scouting experiments were performed to find the best pH conditions. Figure 3 reports the ratio between the PG specific activity measured after the purification procedure (ASf) and the initial PG specific activity (ASi). At pH 3.5, the microspheres are able to remove from the broth the major part of the protein without PG activity, thus providing a four time increase of the enzyme specific activity. The purified PG from Kluyveromyces marxianus was immobilised following the above procedure. Batch reactions in the packed bed reactor were done to evaluate the biocatalyst stability. After an initial loss, due to enzyme release, the residual PG activity reaches a plateau value corresponding to about 40% of the initial activity. Probably, some broth component interfered during the immobilisation reaction weakening the protein-carrier interactions. 

Recovery of inulinase from Kluyveromyces marxianus fermentation broth [16]... 

Artolozaga, M. J., Jonas, R., Schneider, A. L., Furlan, S. A., and Carvalho-Jones, M. F., One step partial purification of fi-D-ga lactosidase from Kluyveromyces marxianus CDB 002 using STREAMLINE-DEAE, Bioseparation, 7, 137, 1998. 

Morlino, G.B., Tizzani, L., Fleer, R. et al. (1999) Inducible amplification of gene copy number and heterologous protein production in the yeast Kluyveromyces lactis. Applied and Environmental Microbiology, 65 (11), 4808 1813. 

Although not well understood, demethiolation has been noted in some fungi.38 Moreover, evidence for a required enzyme activity was obtained for lactococci (used in cheddar cheese production)40 and a relatively high level of demethiolase activity was present in Kluyveromyces lactis, a cheese-ripening yeast (see below).41... 

In addition to bacterial conversion of L-methionine to cheese aroma compounds, certain cheese-ripening yeasts have been implicated. They include De-baromyces hansenii, Geotrichum candidum, and Yarrowia lipolytica, in addition to Kluyveromyces lactis and Saccharomyces cerevisiae (previously noted). Of these yeasts, Geotrichum candidum was most effective at producing sulfur compounds with the major product being S-methyl thioacetate, with smaller amounts of MT, DMS, DMDS, and DMTS. Kluyveromyces lactis had a similar profile, but produced a much smaller amount of S-methyl thioacetate than did G. candidum. S-Methyl thioacetate is formed by a reaction of MT and acetyl-CoA (Equation 7) ... 

Meehan C, Banat IM, McMullan G et al (2000) Decolorization of remazol black-B using a thermotolerant yeast, Kluyveromyces marxianus IMB3. Environ Int 26 75-79... 

Phenylethanol L-Phenylalanine Diverse yeasts e.g. Saccharomyces and Kluyveromyces >10gL , 30 h, 0.5-1 tyear Fed-batch cultivation in situ product recovery by two-phase system with more than 25 g L in the organic phase possible [109,120]... 

Lactose may be hydrolysed to glucose and galactose by enzymes (fi-galactosidases, commonly called lactase) or by adds. Commercial sources of / -galactosidase are moulds (especially Aspergillus spp.), the enzymes from which have acid pH optima, and yeasts (Kluyveromyces spp.) which produce enzymes with neutral pH optima. /S-Galactosidases were considered to have... 

Lactose is readily fermented by lactic acid bacteria, especially Lactococcus spp. and Lactobacillus spp., to lactic acid, and by some species of yeast, e.g. Kluyveromyces spp., to ethanol (Figure 2.27). Lactic acid may be used as a food acidulant, as a component in the manufacture of plastics, or converted to ammonium lactate as a source of nitrogen for animal nutrition. It can be converted to propionic acid, which has many food applications, by Propionibacterium spp. Potable ethanol is being produced commercially from lactose in whey or UF permeate. The ethanol may also be used for industrial purposes or as a fuel but is probably not cost-competitive with ethanol produced by fermentation of sucrose or chemically. The ethanol may also be oxidized to acetic acid. The mother liquor remaining from the production of lactic acid or ethanol may be subjected to anaerobic digestion with the production of methane (CH4) for use as a fuel several such plants are in commercial use. 

The gene for calf chymosin has been cloned in Kluyveromyces marxianus var. lactis, Aspergillus niger and E. coli. Microbial (cloned) chymosins have... 

Kefir Kefir grains - thermophilic lactobacilli and Kluyveromyces marxianus... 

Kefir and Koumiss contain about 1 and 6% ethanol, respectively, which is produced by lactose-fermenting yeasts, usually Kluyveromyces marxianus. The ethanol modifies the flavour of the products and the C02 produced in the fermentation affects both their flavour and texture. Koumiss, which is produced traditionally from mares milk, mainly in Russia and surrounding areas of Asia, is not in fact coagulated. 

Hansenula petersonii Kluyveromyces bulgaricus Kluyveromyces marxianus Lipomyces kononenkoae Lipomyces starkeyi Lipomyces tetrasporus Pichia guilliermondii... 

Snyder and Phaff74 classified their enzyme from Kluyveromyces marxianus as inulinase (EC 3.2.1.7) rather than /3-D-fructofuranosidase (EC 3.2.1.26). Their inulinase hydrolyzed inulin from the D-fruc-tosyl end of the polymer, by an endwise action.81,82 Release of the en-... 

---