Enzyme Composites in Catalytic Conversion of Biomass

Enzymes have attracted attention for well over a century and continues to expand in the industry applications [66]. Interest in the enzymes 

Novozym 435 is already a famous biocomposite containing Candida antarctica lipase B (CAL-B) as the bioactive part. Novozym 435 is commercially available immobilized enzyme with CAL-B physically adsorbed on a macroporous resin of poly(methylmethacrylate) [82]. The enzyme versatility and the substrate affinity recommended Novozym 435 for many applications, including the biomass valorization. An example is the production of the fatty acid esters used as emollient in the cosmetic industry (ex. myristyl myristate) [83,84], 

Biocatalytic transformation of glycerol has been accomplished via a lipase-catalyzed process using tetrahydrofuran as solvent, [85] but solvent-free conditions using dimethyl carbonate in excess may be also efficient 

Another example of lipase application in biomass valorization is the synthesis of monoester derivatives of 6-azauridine via one-step regioselec-tive acylation. It is catalyzed by immobilized lipase (CAL-B) where 99% of the substrate was converted with 99% selectivity into target product 

Another practical example is glucose isomerase. It is connected to 5-HMF, another platform molecule, that has been synthesized using a chemo-enzymatic route [95]. Accordingly, glucose isomerase immobilized on a solid support catalyzed the glucose isomerization into fructose followed by the catalytic dehydration (oxalic acid catalyst) step to the target compound (5-HMF). The reaction was carried out in seawater since high salt concentration enhanced the efficiency of the whole process. 5-HMF product is continuously extracted from the reaction medium into 

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