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 acid from ethanol, The racemic resolution of amino acids via the acylase method is regarded as one of the first industrial processes using isolated enzymes (Tanabe, Japan, 1969), Presently, approximately 100 different biotransformations are carried out in industry, mostly for the production of pharmaceutical and agrochemical precursors. In most cases, chiral compounds (fine chemicals) are obtained. Biotransformations are also successful for the production of commodities such as acryl amide, Until now, mainly hydrolases are used industrially with water as solvent. A lot of additional processes are presently under development where oxidreductases are also employed. Another important reaction type is the C-C-bond formation using the reverse reaction of lyases, In the future, we will see a transition from degrading reactions via transforming reactions to synthetic reactions. We will also see more biotransformations in the presence of organic solvents, Probably, there will be a renaissance of whole cell biotransformations where undesired side 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 possibility to combine such enzymes in one strain can be of great importance for biocatalysis 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 will see enzymes, which have been adapted to industrial biocatalysis by means of evolution under non-natural conditions. On the other hand, homogeneous catalysts sill show up, which will mimic principles of enzyme catalysis (synzymes).