Kloeckera

Methyl-5-hepten-2-one is a valuable precursor for microbial epoxidations and hence the production of chiral ethers with high optical purities. The biotransformation of 6-methyl-5-hepten-2-one (33) by Botryodiplodia malorum CBS 13450 to (/ )-sulcatol (84) was described [61], which is then epoxidised to the (55)-epoxide (85) and opened intramolecularly to cis-(2R,5R)-2-(2 -hydroxyisopropyl)-5-methyltetra-hydrofuran (86) and c/s-(35,67 )-3-hydroxy-2,2,6-trimethyltetrahydropyran (87). Reduction of 6-methyl-5-hepten-2-one (33) with baker s yeast to (5)-sulcatol (88) which was used as substrate for Kloeckera corticis... 

Decarboxylation 21 Malic acid to lactic acid (in wines) amino acids to amines (histamine and tyramine accumulate in soft cheeses because of surface growth of lorulopsis Candida and Debaryomvces kloeckera). 

Yeasts and fungi Actidione agar (PM118) (e.g. Kloeckera and Brettanomyces spp.) contains 10 ppm actidione (cycloheximide)... 

Enantioselective reduction of the prochiral cyclic acylsilane 42 with growing cells of the yeast Kloeckera corticis (ATCC 20109) yielded the optically active reduction product (R)-43 (Scheme 8)53. On a preparative scale, the l-silacyclohexan-2-ol (R)-43 was isolated in 60% yield with an enantiomeric purity of 92% ee. Repeated recrystallization of the biotransformation product from n-hexane raised the enantiomeric purity to 99% ee. 

Indeed, grapes are a primary source of microorganism, and many studies have shown that natural fermentation starts with those species predominant on grapes at harvest time (Fleet et ah, 2002). These can include the apiculate yeasts (Hanseniaspora uvarum and Kloeckera apicu-lata), Metschnikozvia, Candida, Pichia, Khodotorula, and Kluyveromyces. In contrast, although it is the main wine fermentation yeast, Saccharomyces have only rarely been isolated from vineyards (Martini, 1993 Martini et ah, 1996 Pretorius, 2000 Sabate et ah, 1998), since it is closely associated with the winery environment (Ciani et ah, 2004). 

Erten, H. (2002). Relations between elevated temperatures and fermentation behaviour of Kloeckera apiculata and Saccharomyces cerevisiae associated with winemaking in mixed cultures. World J. Microbiol. Biotechnol. 18, 373-378. 

Gao, C. and Fleet, G. H. (1988). The effects of temperature and pH on the ethanol tolerance of the wine yeasts, Saccharomyces cerevisiae, Candida stellata and Kloeckera apiculata. ]. Appl. Bacteriol. 65,405-410. 

Alexandre, H., Rousseaux, I., Charpentier, C. (1994) Relationship between ethanol tolerance, hpid composition and plasma membrane fluidity in Saccharomyces cerevisiae and Kloeckera apiculata. FEMS Microbiol. Lett., 124, 17-22... 

Metschnikowia pulcherrima (Candida pulcherrima) Hanseniaspora uvarum (Kloeckera apiculata)... 

Hanseniaspora uvarum (anamorph Kloeckera apiculata) is commonly the major yeast present on the grape berry and in musts and juices, but due to low tolerance to ethanol, populations decline quickly in the presence of Saccharomyces cerevisiae. Strains are typically characterised by low fermentative ability and high production of acetic acid, ethyl acetate and acetaldehyde, which render such strains more suitable to vinegar production. Nevertheless, Ciani and Maccarelli (1998) surveyed 37 isolates and found considerable variability, with some strains producing concentrations of these compounds approaching concentrations present in wines made with Saccharomyces cerevisiae (Table 8D.6). Cofermentation fermentation with Saccharomyces cerevisiae can produce wines with an acceptable balance of volatile and non-volatile compounds and sensory scores (Ciani et al. 2006 Jemec and Raspor 2005 Jolly et al. 2003b Zohre and Erten 2002). 

Zironi, R., Romano, P., Suzzi, G., Battistutta, R, Comi, G. (1993) Volatile metabolites produced in wine by mixed and sequential cultures of Hanseniaspora guilliermondii or Kloeckera apic-ulata and Saccharomyces cerevisiae. Biotechnology Letters, 15, 235-238. 

Zohre, D. E., Erten, H. (2002) The influence of Kloeckera apiculata and Candida pulcherrima yeasts on wine fermentation. Process Biochemistry, 38, 319-324. 

Angioni, A., Caboni, R, Garau, A., Farris, A., Orro, D., Budroni, M., Cabras, P. (2007). In Vitro Interaction Ochratoxin A and Different Strains of Saccharomyces cerevisiae and Kloeckera apiculata. J. Agric. Food Chem., 55, 2043-2048. 

Yeast differ in sensitivity to SO2 treatment in fruit juices and wines. Brettanomyces spp. can resist 500 mg/L SO2 while Pichia membranefaciens Kloeckera apiculata are less resistant (63). In general, many yeast and bacteria are inhibited by 100 mg/L and less SO2 (64). Beech and Carr (65) found low concentrations of molecular SO2 (0.625 mg/L) were toxic to species of the genera Brettanomyces and Saccharomyces. 

Air is another source for Brettanomyces dispersion, although few articles have been written (66, 75). In fruit orchards, Adams (76) exposed agar plates at ground level and isolated mainly molds (95%) and a few yeasts (5%) from fruit orchard air samples. Isolation of yeast colonies was hindered by early mold growth. Adams identified 6 genera from 180 yeast isolates, the order in decreasing frequency Kloeckera, Cryptoccus, Torulopsis, Rhodotorula, Candida, and Brettanomyces (66). ... 

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