Saccharomyces cerevisiae production

Torulaspora delbrueckii (anamorp Candida colliculosa formerly Saccharomyces rosei) has a moderate tolerance to ethanol (<12.5 vol.% Table 8D.6) and produces wines which resemble those made with Saccharomyces cerevisiae. Production of higher alcohols is however highly variable and strain dependent. Because this yeast produces comparatively low concentrations of acetic acid, ethyl acetate, acetaldehyde and acetoin, its potential suitability for wine production has been suggested by several studies (Cabrera et al. 1988 Ciani and Ferraro 1998 Herraiz et al. 1990 ... 

Glycerol Saccharomyces cerevisiae Production of explosives (nitroglycerin, dynamite)... 

Yeast. The advantages of expression in yeast include potentially high level production of proteins, the abiUty to have expressed proteins secreted into the media for ease of purification, and relatively low cost, easy scale-up. A disadvantage is that plasmid instabiUty may be a problem which can lead to low product yield. Whereas post-translational modification occurs in yeast, proteins are quite often hyperglycosylated. This is generally a problem with expression in Saccharomyces cerevisiae but not for the more recently used yeast host Pichiapastoris (25) (see Yeasts). 

Trehalose is particularly well-suited for this purpose and has been shown to be superior to other polyhydroxy compounds, especially at low concentrations. Support for this novel idea comes from studies by P. A. Attfield, which show that trehalose levels in the yeast Saccharomyces cerevisiae increase significandy during exposure to high salt and high growth temperatures—the same conditions that elicit the production of heat-shock proteins ... 

Fermentation of sugar by Saccharomyces cerevisiae, for production of ethanol in an immobilised cell reactor (ICR), was successfully carried out to improve the performance of the... 

Owing to diminishing fossil fuel reserves, alternative energy sources need to be renewable, sustainable, efficient, cost-effective, convenient and safe.1 In recent decades, microbial production of ethanol has been considered as an alternative fuel for the future because fossil fuels are depleting. Several microorganisms, including Clostridium sp. and yeast, the well-known ethanol producers Saccharomyces cerevisiae and Zymomonas mobilis, are suitable candidates to produce ethanol.2,3... 

Example 12.7 Develop a model for the anaerobic batch fermentation of glucose to ethanol and coproduct CO2 using Saccharomyces cerevisiae. The starting mixture contains 10% glucose. The inoculum is 0.0005 w/w. Product inhibition stops cell growth at 14% ethanol. Assume ka = 0 but include the cannibalization of cellular material beginning when the substrate is completely consumed. 

In current industrial practice, benzaldehyde is added to fermenting baker s yeast Saccharomyces cerevisiae) with resultant PAC production occurring from the yeast-derived pyruvate. Typically PAC concentrations of 12-15 g F are produced at yields of 65-70% theoretical in a 10-12 h biotransformation process. [2], Appreciable concentrations of benzyl alcohol are produced as by-product due to oxidoreductase activity in the fermentative yeast. 

The proline transport protein prnB of Aspergillus nidulans [47] is very similar to the above-mentioned family of Saccharomyces cerevisiae amino acid transporters (about 42% identity with the PUT4 gene product and 30% identity with the CANl and the HIP I gene products). So is the AroP general aromatic amino acid transporter protein of Escherichia coli K-12, which has about 30% identity with the HIPI gene product [48]. Both hydrophilic ends are very different from one transporter to another (see Fig. 2). 

A cytochrome P450 has been purified from Saccharomyces cerevisiae that has benzo[a]pyrene hydroxylase activity (King et al. 1984), and metabolizes benzo[fl]pyrene to 3- and 9-hydroxybenzo[fl]pyrene and benzo[fl]pyrene-7,8-dihydrodiol (Wiseman and Woods 1979). The transformation of PAHs by Candida Upolytica produced predominantly monohydroxyl-ated products naphth-l-ol from naphthalene, 4-hydroxybiphenyl from biphenyl and 3- and 9-hydroxybenzo[fl]pyrene from benzo[fl]pyrene (Cerniglia and Crow 1981). The transformation of phenanthrene was demonstrated in a number of yeasts isolated from littoral sediments and of these, Trichosporumpenicillatum was the most active. In contrast, biotransformation of benz[fl]anthracene by Candida krusei and Rhodotorula minuta was much slower (MacGillivray and Shiaris 1993). 

The enantiomeric reduction of 2-nitro-l-phenylprop-l-ene has been studied in a range of Gram-positive organisms including strains of Rhodococcus rhodochrous (Sakai et al. 1985). The enantiomeric purity of the product depended on the strain used, the length of cultivation, and the maintenance of a low pH that is consistent with the later results of Meah and Massey (2000). It has been shown that an NADPH-linked reduction of a,p-unsaturated nitro compounds may also be accomplished by old yellow enzyme via the flcf-nitro form (Meah and Massey 2000). This is formally analogous to the reduction and dismutation of cyclic enones by the same enzyme (Vaz et al. 1995), and the reductive fission of nitrate esters by an enzyme homologous to the old yellow enzyme from Saccharomyces cerevisiae (Snape et al. 1997). 

Continuous extraction loop reactor Ethanol production with glucose fermentation Saccharomyces cerevisiae 126... 

R)- and ( -selective HNLs. A number of recombinant HNLs have also been expressed in E. coli, Saccharomyces cerevisiae, and Pichia pastoris. Recently, protein engineering has been successfully applied to the development of a tailor-made HNL for large-scale production of specific cyanohydrins [69,70]. 

Traditional and well-established yeast species are Saccharomyces cerevisiae, Hansenula polymorpha, Klyveromyces lactis, Pichia pastoris and Schizosaccharomyces pombe. With every year that passes they are increasingly being used in industrial and pharmaceutical enzyme production on a large scale. Many further yeasts present interesting features (e.g. Arxula adeninivorans and Yarrowia lipolytica), but are not that widely used. 

Despite the higher selectivity of enzymatic methyl transfer over chemical methylation, where toxic or hazardous reagents are often employed, such as methyl sulfonate and diazomethane, the synthetic applications of these enzymes have been largely ignored primarily as a result of high costs associated with the cofactor SAM. Recent efforts have been directed to in vivo methylation, where SAM may be regenerated inside cells. For example, methyl benzoate production was engineered in recombinant Saccharomyces cerevisiae and in vivo... 

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