Industrial biocatalysis: Past, present, and future

Industrial biocatalysis is older than one might think. In the past, entire microorganisms have been used, for instance, for the production of acetic a cid from ethanol, The racemic resolution of amino acids via the acylase met hod is regarded as one of the first industrial processes using isolated enz ymes (Tanabe, Japan, 1969), Presently, approximately 100 different biotrans formations are carried out in industry, mostly for the production of pharma ceutical and agrochemical precursors. In most cases, chiral compounds (fine chemicals) are obtained. Biotransformations are also successful for the pr oduction of commodities such as acryl amide, Until now, mainly hydrolases a re used industrially with water as solvent. A lot of additional processes a re presently under development where oxidreductases are also employed. Anot her important reaction type is the C-C-bond formation using the reverse rea ction of lyases, In the future, we will see a transition from degrading rea ctions via transforming reactions to synthetic reactions. We will also see more biotransformations in the presence of organic solvents, Probably, ther e will be a renaissance of whole cell biotransformations where undesired si de activities and further metabolising steps (besides the desired reaction) are avoided by means of gene-disruption. Work is going on to establish non -natural cofactor-regenerating systems in whole cells ("designer strains"). Especially the methods of non-natural evolution of enzymes and the possibi lity to combine such enzymes in one strain can be of great importance for b iocatalysis in future, With respect to isolated enzymes it can be predicted that the cost of enzymes will further drop due to an efficient production with genetically engineered microorganisms or higher cells. The gap between enzyme catalysis and homogeneous catalysis will narrow. On one hand we wil l see enzymes, which have been adapted to industrial biocatalysis by means of evolution under non-natural conditions. On the other hand, homogeneous c atalysts sill show up, which will mimic principles of enzyme catalysis (syn zymes).