Mannitol enzymatic production

Enzymatic enantioselective reduction of 2-octanone Fungal decolourisation of a waste sludge Technetium Tc (VII) reduction with E. coli cells Enzymatic production of mannitol and gluconic acid Enzymatic production of L-glutamate Enzymatic production of oligodextrans Lipolysis of olive oil Cell-free protein synthesis Enzymatic synthesis of aspartame precursor Enzymatic resolution of amino acids... 

The molecular weight (94,000) was smaller than that of other microbial P-mannosidases such as Aspergillus o/jCTe( 120,000-135,000) and Tremella fuciformis (160,000-200,000). The final product from the oligosaccharides with the enzyme was mainly D-mannose and the enzymatic activity was not inhibited by D-mannose or mannose-derivatives such as D-mannosamine, D-mannonic acid and D-mannitol. 

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. 

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... 

Saha, B. C. 2006c. Production of mannitol from inuhn by simultaneous enzymatic saccharification and fermentation with Lactobacillus intermedius NRRL B-3693. Enz. Microb. Technol., 39, 991-995. 

Excipients derived from bacterial transformation or enzymatic processes, such as sugars (e.g., mannitol or dextrose), pose special concerns due to potential contamination by endotoxins. Endotoxins, or pyrogens, are lipopolysaccharides from gram-negative bacteria that can induce severe fever upon parenteral administration. Parenteral products have different limits for allowable endotoxin levels.57... 

The enzymatic conversion of 6-azido-6-deoxy-D-glucose into its D-fructose isomer was utilised as a key step in a five-step synthesis from sucrose [80] of the natural product and powerful D-mannosidase inhibitor 1-deoxymannojirimycin (l,5-dideoxy-l,5-imino-D-mannitol, 66) [81]. Subsequently, it was shown that the immobilised enzyme from Streptomyces murinus sp. (Sweetzyme T from Novo A/S) was able to isomerise D-glucose derivatives with modifications at C-3 and C-6 such as 6-azido-6-deoxy-3-0-methyl-D-glucose (67) as well as the corresponding 3-deoxy derivative 69 (Scheme 24) [64,82]. 

Further structural diversification of FruA products has been investigated by enzymatic reduction to corresponding alditols using stereochemically complementary alditol dehydrogenases (Figure 5.40). Indeed, stereospecific (2S)- and (2R)-specific reduction of simple derivatives of o-fructose could be achieved by NADH-dependent catalysis of sorbitol dehydrogenase (EC 1.1.1.14) [209] or mannitol dehydrogenase (EC 1.1.1.67), respectively [26]. 

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