Exploring oil cakes in the production of proteases: a systematic review

Oil cakes are valuable co-products of the oil industries, rich in bioactive and nutritional compounds, whose use in biotechnological processes can reduce costs and minimize their environmental impact. Recognized as versatile raw materials, they are often used as substrate in the optimized production of microbial enzymes, aiming for a cheaper and more sustainable approach. In this context, the objective of this review was to carry out a survey of the use of oil cakes as substrates for the production of microbial proteases. The search focused on the ScienceDirect, PubMed, Web of Science and Scopus databases, taking into account the last 10 years (2013-2023). After applying the inclusion and exclusion criteria, 1602 articles were discarded and around 30 studies were considered eligible. The results showed 19 different types of oil cakes, resulting from different production processes, with soybean cake being the main residue used. The ability of oil cakes to promote the production of microbial proteases stands out due to the great diversity of microorganisms reported in studies, with species belonging to the genera Aspergillus and Bacillus being the most utilized among fungi and bacteria, respectively. Despite the considerable number of articles found, few of them provided information on the composition of these co-products. Nonetheless, this review reveals a growing trend towards exploring oil cakes as a viable and economical source of nutrients for protease-producing microorganisms.