Lignocellulosic residues as supports for enzyme immobilization, and biocatalysts with potential applications

Growing demand for agricultural production means a higher quantity of residues produced. The reuse and recycling of agro-industrial wastes reduce worldwide greenhouse emissions. New opportunities are derived from this kind of residuals in the biotechnological field generating valuable products in growing sectors such as transportation, bioenergy, food, and feedstock. The use of natural macromolecules towards biocatalysts offers numerous advantages over free enzymes and friendliness with the environment. Enzyme immobilization improves enzyme properties (stability and reusability), and three types of supports are discussed: inorganic, organic, and hybrid. Several examples of agro-industrial wastes such as coconut wastes, rice husks, corn residues and brewers spent grains (BSG), their properties and potential as supports for enzyme immobilization are described in this work. Before the immobilization, biological and non-biological pretreatments could be performed to enhance the waste potential as a carrier. Additionally, immobilization methods such as covalent binding, adsorption, cross-linking and entrapment are compared to provide high efficiency. Enzymes and biocatalysts for industrial applications offer advantages over traditional chemical processes with respect to sustainability and process efficiency in food, energy, and bioremediation fields. The wastes reviewed in this work demonstrated a high affinity for lipases and laccases and might be used in biodiesel production and textile wastewater treatment, among other applications.