Mannitol fermentation

Conditions are slightly different during the so-called mannitol fermentation of sugars, especially of D-fructose. The process, which has been known for a long time, has recently been investigated more thoroughly by Bolcato. He found that 3 moles of D-fructose yield 2 moles of carbon dioxide, 2 moles of acetic acid and 2 moles of D-mannitol. Up to now, a maximum of 60% of the theoretically possible amount of D-mannitol has been isolated. The mechanism of the reaction may be assumed to be as follows ... 

Topinambur tubers Helianthus tvberoms, L.), which contain the D-fructose polysaccharide inulin, can undergo a mannitol fermentation through microorganisms which adhere to the nodules. Similar observations have been made with clamped beets (that is, beets which have been conserved by covering with earth), the sucrose of which can become inverted and partially reduced to D-mannitol. ... 

Additional yeast spoilage is induced by species of the genera Candida Mycoderma), Pischia and Hansenula (Willia). Other microorganisms are involved in the formation of viscous, moldy and ropy wine flavor defects. Bacterial spoilage may involve acetic acid and lactic acid bacteria. In this case vinegar or lactic acid souring is detectable. It has usually been associated with mannitol fermentation which may result in considerable amounts of mannitol. 

Deoxy-4-fluoro-D-fructose (552) was prepared (59%) by fermentation of 3-deoxy-3-fluoro-D-mannitol with Gluconobacter oxydans. The structure of 552 (fi-T) form) was confirmed by the n.m.r. spectrum, which resembles that of 4-deoxy-4-fluoro-Q -D-sorbopyranose (553) 552 was identical with one of the products obtained from the oxirane-ring opening of 3,4-anhy-dro-l,2-0-isopropylidene- -D-tagatopyranose with KHFj. 

The third group is that of compounds which may potentially be transported by the PTS and inhibit cAMP production. Cellulase synthesis is initiated after these compounds are consumed for cell growth. This group includes D-glucose, D-fructose, maltose, mannitol, glycerol, sorbitol, and -methyl glucoside. The presence of these compounds in Solka Floe fermentations, enhanced enzyme yields (132 to 254%) but the time required to complete cellulase synthesis took longer (106 to 148%) than the control. 

Osmotic laxative effects are also produced by the polyhydric alcohols, mannitol and sorbitol, which unlike glucose cannot be transported through the intestinal mucosa, as well as by the non-hydrolyzable disaccharide, lactubse. Fermentation of lactulose by colon bacteria results in acidification of bowel contents and microfloral damage. Lactulose is used in hepatic failure in order to prevent bacterial production of ammonia and its subsequent absorption (absorbable NH3 nonabsorbable NH4+), so as to forestall hepatic coma. 

More than seventy years ago the impressive discovery was made that bioreduction of mannitol, glycerol and starch yields butanol. Fermentations in which butyric acid, butanol and acetone are formed from carbohydrates by different bacilli (butyl bacteria) belong in this group. The term butyl bacteria as a generic name for microbes producing the genetically related substances of the four-carbon series was proposed in 1921" and has been applied since then. The approximate course of these reactions is shown by the following formulations which, however, do not explain the mechanism ... 

D-mannitol/ although normal molasses contains only a negligible amount. It apparently arises from anaerobic fermentation. D-Manni-tol is also present in silage and sauerkraut. 

D-Mannitol is not only a product of the hydrogenation of sucrose or of D-glucose but it is also a by-product of the fermentation of sugar to lactic acid and other special fermentations and is a by-product in the extraction of alginic acid from seaweeds. It is found in the sugar cane... 

Clements,33 it may be no accident that phaeophytes, which contain large amounts of the difflcult-to-digest mannitol, tend to be eaten by fish species such as Kyphosus, Odea, and Naso that contain elevated levels of fermentation products in their posterior intestines. 

Bacteriological culture media, dulcitol, mannitol and sorbitol in, I, 192 Bacterium amylobacter, in fermentation of wood sugars, IV, 184 Bacterium dysenteries, antigens, II, 199 Bacterium xylinoides, cellulose formation by, II, 206... 

Richter, H., Hamann, I., and Unden, G. 2003. Use of the mannitol pathway in fructose fermentation of Oenococcus oeni due to limiting redox regeneration capacity of the ethanol pathway. Arch. Microbiol., 179,227-233. 

Some microorganisms can specifically produce mannitol from glucose or fructose without making a sorbitol byproduct (Smiley et al., 1967 Song et al., 2002 Wisselink et al, 2002 Saha, 2003). Mannitol, at 180g/L, can be easily recovered from the fermentation broth by cooling crystallization. Thus, research efforts have been directed toward production of mannitol by fermentation and enzymatic means (Vandamme and Soetaert, 1995). In this paper, the authors review the production of mannitol by lactic acid bacteria. 

Martinez et al. (1963) reported that L. brevis fermented lmol fructose to 0.67 mol mannitol and 0.33 mol lactate and 0.33 mol acetate. Soetaert et al. (1995) reported a fed batch fermentation method with automatic feeding strategy for very fast and rapid production of mannitol and D-lactic acid from fructose or glucose/fructose mixture (1 2) by using Leu. pseudomesenteroides. The maximal volumetric productivity of mannitol was 11.1 g/L-h with a final concentration of 150 g/L in 24 h and a conversion efficiency of 94%. By using a special mutant strain, quantitative conversion and a further concentration increase up to 185 g mannitol per L could be obtained. Grobben et al. (2001)... 

The net gain is 1.25 mol of ATP per mol of fructose fermented. The typical pathway for mannitol production by a heterofermentative LAB from glucose and fructose mixture (1 2) is shown in Figure 21.2. 

Heterofermentative LAB have the capability to utilize high concentrations of fructose such that the mannitol concentration in the fermentation broth could reach more than 180g/L, which is enough to be separated from the cell-free fermentation broth by cooling crystallization. Lactic and acetic acids can be recovered by electrodialysis (Soetaert et al., 1995). The enzyme mannitol dehydrogenase responsible for catalyzing the conversion of fructose to mannitol requires NADPH (NADH) as cofactor. Thus, it is possible to develop a one-pot enzymatic process for production of mannitol from fructose if a cost-effective cofactor regeneration system can be developed (Saha, 2004). The heterofermentative LAB cells can be immobilized in a suitable support, and... 

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