Mannitol from fructose

Mannitol is produced by some lactic acid bacteria (Section 2.4.4) as per 

The formation of mannitol is detected by growing the bacterium in the fructose-enriched medium described by Pilone etal. (1991). Formation of mannitol salt crystals in the dried medium are detected visually as large rosettes without further magnification. It is essential to allow a few days for crystal formation at 25°C/77°F after evaporating the water at 37°C/99 F because crystals are often not seen prior to the final drying time. 

Place 9mL of the HFA broth into 18 x 150mm test tubes and autoclave at 121°C/250°F for 15 min. 

Inoculate tubes with 0.1 mL of an actively growing culture from apple juice Rogosa broth. 

After incubation, pour approximately 8 mL of the broth culture into a 90 mm plastic Petri dish. 

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Several heterofermentative LAB belonging to the genera Lactobacillus, Leu-conostoc, and Oenococcus can produce mannitol from fructose effectively (Saha, 2003). In addition to mannitol, these bacteria may produce lactic acid, acetic acid, carbon dioxide, and ethanol. The process is based on the ability of the LAB to use fructose as an electron acceptor and reduce it to mannitol with the participation of the enzyme mannitol 2-dehydrogenase (EC 1.1.1.38). 

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... 

PiLONE, G.J., M.G. Clayton, and RJ. van Duivenboden. 1991. Characterization of wine lactic acid bacteria Single broth culture for tests of heterofermentation. Mannitol from fructose and ammonia from arginine. Am. J. Enol Vitic. 42(2) 153-157. 

It should not produce dextran from sucrose or mannitol from fructose. If mannitol appears, it should be able to ferment it rapidly. 

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)... 

Busse et al. (1961) and Erten (1998) found a lower mannitol yield from fructose in Leu. mesenteroides. In these cases, the enzyme reaction proceeds by the following equation ... 

U.S. 6,649,754 (to Merck) describes a process for making mannitol by hydrogenation of a mixture of glucose and fructose. U.S. 3,632,656 (to Atlas Chemical) describes recovery of mannitol from a mixture with sorbitol by crystallization from aqueous solution. U.S. 4,456,774 (to Union Carbide) describes an adsorptive separation of mannitol from sorbitol. U.S. 6,235,947 (to Takeda Chemical Industries) describes a process for recrystallizing mannitol to improve the crystal morphology and hence make a more compressible product that can be used in making tablets. Estimate the cost of production of Mannitol by the Merck route and determine which separation is most economical. What is the additional cost of making the recrystallized product via the Takeda route ... 

A multi-step process has also been developed for the preparation of mannitol from D-glucose [31,32]. D-Glucose is first epimerized to D-mannose by molybdate and D-glucose remaining in the mixture is then treated with glucose isomerase to establish equilibrium with D-fructose. Finally, the glucose-mannose-fructose mixture is hydrogenated to yield 40 % mannitol. 

Mannitol salt formation is also used as a laboratory diagnostic test for the separation of homofermenters (which do not reduce fructose in formation of mannitol) from heterofermenters, which utilize the pathway described above. From the winemaker s perspective, the importance of mannitol formation, by itself, is uncertain except to increase the potential for acetic acid production. Sponholz (1993) reports that it is associated with bacterially mediated deterioration in high-pH sweet wines. He concludes that the best technique for the prevention is acidulation, whereby the pH is lowered to the point (<3.5) at which the likelihood of growth of most spoilage lactics is precluded. 

Veiga-da-Gunha et al. (1993) observed that O. oeni produced another sugar alcohol, erythritol, anaerobically from glucose but not from fructose or ribose. In the presence of oxygen, synthesis of this sugar alcohol was absent. In agreement, Firme et al. (1994) reported erythritol production by this bacterium under N2 or COg environments. As with the formation of mannitol, synthesis of erythritol is probably related to the cell s need to reoxidize NADPH under anaerobic conditions. 

Fig. 11.2 (a-c) Growth of G. oxydans deletion strains (open symbols) and the parent strain G. oxydans hupp (filled symbols) on mannitol hgnd (a) hgnd zwf (b) hedd-eda (c). (d-f) Substrate consumption and product formation of G. oxydans deletion strains (dashed lines) and the reference strain hupp (closed lines) hgnd (d) hgnd zwj (e) hedd-eda (f). Cells were cultivated in mannitol medium at 15 % dissolved oxygen at pH 6. Mean values and standard deviations of three independent cultures are shown. Mannitol (red), fructose (green), 5-ketofructose (blue), acetate (yellow). (Modified from Richhardt et al. 2012)... 

D-Mannitol i-phosphate has been isolated from Lactobacillus arabinosus and is formed enzymically from fructose 6-phosphate . It may be prepared by borohydride reduction of fructose 6-phosphate or mannose 6-phosphate . ... 

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