ABSTRACT
The industrial revolution, increasing market demands for chemicals and fuels, and soaring levels of greenhouse gases (GHGs) accumulation have made humans change the trajectory of industrial production processes towards green and sustainable options. Industrial production of chemicals and fuels incurs a toll on nature via releasing harmful by-products as a result of the use of harsh chemicals but also cost and labor-intensive processes, and thus alternative methods are now developed and pursued. Catalysis plays an important role in any industrial chemical reaction involved in a significant production process. Using enzymes as a biocatalyst is a usual option but imposes an economic burden as the cost of purified enzymes is high, and also, they are non-renewable in nature. Whereas, when a whole-cell is considered as a biocatalyst, it could surpass the technical difficulties and provides much longer sustaining enzymatic activity as it is protected by the cellular wall from harsh environment of the reaction condition. The cofactor regeneration capability, optimal micro- and macro-environment for 4the enzymatic reactions, and many more advantages of whole-cells when used as biocatalysts are discussed in this introductory chapter, including the history of origin and concepts of selecting and designing the whole-cell biocatalyst.
