Microbial Lipase Production: From Fermentation Strategies (SSF/SmF) to Novel Bioreactor Designs & Substrate Optimization using Agro-Industrial Wastes

Microbial Lipases (triacylglycerol acylhydrolases; EC 3.1.1.3) are one of the most important enzymes bioproducts of biotechnology worldwide, covering diverse biotecnological applications such as food processing, pharmaceuticals, biodiesel manufacture, detergent formulation, and fine chemical synthesis. This review aims to cover profoundly the present status of microbial lipase production processes on a comparison basis between Submerged Fermentation (SmF) and Solid-State Fermentation (SSF), optimization approaches using agro-industry residuals as cost-effective substrates, and novel bioreactor designs and developments. This review critically overviews lipase-producing microbes such as bacteria (Bacillus, Pseudomonas), yeasts (Candida, Yarrowia), and fungal taxa (Aspergillus, Rhizopus), and Thermomyces lanuginosus), along with their kinetics of bioproduction under diverse bioprocess strategies of batch, fed-batch, repeated batch, and continuous culture processes. Due priority is given for sustainable bioprocess development strategies using agricultural and industrial residuals such as oil cakes, animal fats, vegetable oils processing residuals, and ligneous biowaste biorefineries as agro-waste biomass bioproducts. Advances on novel bioreactor designs such as Packed Bed Bioreactors (PBB), Fluidized Bed Bioreactors (FBB), Airlift Bioreactors (AL), and Membrane Bioreactors (MB), for intensification of bioprocess on scale-up principles are covered. Notions on critical bioprocess factors for improvement of microbial lipase bioproduction such as carbon source materials and rates of bioproduction of N-source materials (bioreactor biotopology), pH-range biologically suitable temperatures of bioproduction process (range of critical temperatures), influence of Dissolved Oxygen (DO biocomponent), and supplemental bioproducts of bacterial agro-industry residues (inducers), eventually provide a collective biocomprehensive framework on economically productive bioprocess strategies on biotechnology for biocommercially sustainable bioproduction of microbial lipase.