Bacillus megaterium (B. megaterium)

Bacillus megaterium (recently reclassified as Priestia megaterium) is a large, Gram-positive, rod-shaped bacterium that is widely recognized as one of the largest known prokaryotes, with cells often reaching 4 micrometers in length (Vary et al., 2007). It is a ubiquitous soil saprophyte that plays a significant role in nutrient cycling and bioremediation, but it is most prominently known for its extensive use in the biotechnology industry (Biedendieck et al., 2011). The organism is a preferred host for the industrial-scale production of recombinant proteins, vitamins, and enzymes, such as penicillin amidase, due to its high capacity for protein secretion and the absence of alkaline proteases (Vary et al., 2007). While generally classified as a non-pathogenic organism with "Generally Recognized as Safe" (GRAS) status, it has been documented as an opportunistic pathogen in rare clinical cases involving immunocompromised individuals (Dib et al., 2003). In the context of pharmacology, Bacillus megaterium is not a specific molecular target like a receptor or enzyme; rather, it is an organism targeted by broad-spectrum antibiotics or utilized as a source of model enzymes like Cytochrome P450 BM3 for drug metabolism studies (Gupta et al., 2020). Antibiotics such as penicillins and vancomycin are effective against it by disrupting cell wall synthesis, while others like tetracyclines inhibit its protein synthesis (Vary et al., 2007).

Other names

Priestia megateriumBacillus megatherium

As a bacterial organism, it is targeted by antibiotics that inhibit cell wall synthesis, inhibit protein synthesis by binding to ribosomal subunits, or inhibit DNA replication by targeting topoisomerases.