Fermentations glucose

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

Enzymatic hydrolysis with glucose fermentation, but without the fermentation of pentoses. 

It did not deviate from the values found with pure cultures (Freudenreich and Orla-Jensen 1906 van Niel 1928). The analytical methods allowed the determination of the products of glucose fermentation by Escherichia coli, and the general equation calculated (Harden 1901) does not differ from that accepted today. Harden even correctly deduced that hydrogen arises from formic acid the Aerobacter modihcation was recognized by Harden in 1906. Thus the methods for the analysis of fermentation products were completed within the nineteenth century. 

Conversion of glucose (fermentation) Ethanol + Lactic acid... 

Fig. 5. Possible products from glucose fermentation in different microorganisms (modified after [80])...

More carboxyl groups and C02 molecules are formed in this fermentation (22/3 per glucose molecule) than in the regular lactic acid fermentation. The yield of ATP (also 2 2/3 mol/mol of glucose fermented) is correspondingly greater and AG is more negative. 

Some lactic acid bacteria of the genus Lactobacillus, as well as Leuconostoc mesenteroides and Zymomonas mobilis, carry out the heterolactic fermentation (Eq. 17-33) which is based on the reactions of the pentose phosphate pathway. These organisms lack aldolase, the key enzyme necessary for cleavage of fructose 1,6-bisphosphate to the triose phosphates. Glucose is converted to ribulose 5-P using the oxidative reactions of the pentose phosphate pathway. The ribulose-phosphate is cleaved by phosphoketolase (Eq. 14-23) to acetyl-phosphate and glyceraldehyde 3-phosphate, which are converted to ethanol and lactate, respectively. The overall yield is only one ATP per glucose fermented. 

Use the pyruvate formate-lyase reaction. What yield of ATP do you expect per molecule of glucose fermented ... 

Reichstein-Griissner Sorbitol Fermentation Glucose Fermentation synthesis... 

M Anderlund, TL Nissen, J Nielsen, J Villadsen, J Rydstrom, B Hahn-Hagerdal, MC Kielland-Brandt. Expression of the Escherichia coli pntA and pntB genes, encoding nicotinamide nucleotide transhydrogenase, in Saccharomyces cerevisiae and its effect on product formation during anaerobic glucose fermentation. Appl Environ Microbiol 65 2333-2340, 1999. 

Index Entries Succinic acid sorbent adsorption hot water regeneration glucose fermentation broth. 

When cellulose is used as a raw material, the activity of cellulase (the enzyme catalyzing cellulose hydrolysis) is inhibited by glucose and short cellulose chains. One way to overcome this inhibition is to combine enzymatic hydrolysis with glucose fermentation to ethanol, as the accumulation of ethanol in fermenter does not inhibit cellulase. 

Schroder, C., Selig, M., and Schonheit, P. 1994. Glucose fermentation to acetate, C02 and H2 in the anaerobic hyperthermophilic eubacterium Thermotoga maritima involvement of the Embden-Meyerhof pathway. Arch. Microbiol., 767,460-470. 

Using Brettanomyces claussenii, Custers showed glucose fermentation is inhibited under anaerobic conditions. Glucose was fermented more rapidly under aerobic than anaerobic conditions. He named this inhibitory effect a negative Pasteur effect". Aerobic conditions activated the fermentation of glucose to produce ethyl alcohol, carbon dioxide, and "a considerable amount of acetic acid". Only ethanol and carbon dioxide were produced under anaerobic conditions acetic acid was not. 

TABLE 11.11 Moles of Product per 100 Mol of Glucose Fermented by Various Species of Clostridia"... 

Xanthan Made primarily of linear glucose chain with side chains based on mannose and glucuronic acid residues A microbial gum made by glucose fermentation, forms viscous pseudoplastic solutions Emulsifying or suspending agent, particularly in toothpaste and ointments... 

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