Recombinant Enzymes From Marine Actinomycetes: Genome Mining, Cloning, Expression Systems, and Biotechnological Significance

Marine actinomycetes represent a unique and underexplored reservoir of novel enzymes with valuable properties. However, their cultivation and low enzyme yield often hinder commercial applications. This book chapter reviews strategies for overcoming these limitations by producing recombinant enzymes. Modern genome mining has led to the discovery of promising biocatalytic genes directly from microbial genomic data. Subsequently, we discuss cloning strategies, including restriction-based, ligation-independent, and Gibson assembly methods, emphasizing the critical role of codon optimization for heterologous expression. A comparative analysis of various expression systems—including Escherichia coli, Streptomyces, Bacillus, and Pichia pastoris—is presented to highlight their respective advantages and suitability for different enzyme types. Finally, the properties and diverse biotechnological applications of recombinant enzymes from marine actinomycetes, from pharmaceuticals to bioremediation, are described.