The rapid advancement of molecular biology and biochemical techniques has revolutionised microbial biotechnology, enabling precise genetic modifications for enhanced industrial applications. This chapter provides an overview of genetic engineering methods and their role in strain improvement for innovative bioproducts. We discuss fundamental techniques such as gene cloning, DNA library construction, DNA amplification (PCR and RT-PCR), and genome mapping strategies (RFLPs, RAPD, AFLP, and FISH). The chapter also covers genome expression analysis through microarrays, expressed sequence tags (ESTs), and next-generation sequencing methods (RNA-seq). This chapter also explores gene knock-down and gene knock-out strategies by providing an overview of gene silencing via RNA interference (RNAi) and genome editing by CRISPR technology. We discuss post-transcriptional gene silencing mechanisms by comparing siRNA- and miRNA-mediated mechanisms and their applications. We also explain advances with regard to CRISPR gene editing as well as CRISPR-mediated gene activation or repression. We will also briefly discuss applications and ethical concerns associated with CRISPR. These strategies are likely revolutionising the bioprocess industry by enabling precise genetic modifications and innovative as well as efficient product development.