Natural Bioactive Products from Marine Fungi Against Bacterial Infection

In spite of the different antibiotics available in the market, the need for new antibacterial agents is still in high demand. This is because of continuously increasing antimicrobial resistance which makes treatment ineffective to control superficial and invasive bacterial infections and has become a primary cause of global issues. These global issues appealed to us to find out a novel drug discovery against these infections. For the last decades, marine microorganisms especially marine-derived fungi have been considered to be a rich source of therapeutic agents and helpful for humankind to produce a multitude of bioactive secondary metabolites, important for preventing different ailments. These marine fungal natural products possess cytotoxic, anticancer, antiviral, antibacterial, or antifungal activities. Marine fungal-derived bioactive compounds can broadly belong to alkaloids, polyketides, coumarins, polyphenols, acetophenones, and xanthones groups. A number of anti-infective agents derived from different microbial sources are currently used for the treatment of different ailments. As antifungal- Helicascolide C, isolated from Daldinia eschscholzii KT32, anticancer-meroterpenes from Penicillium sp., and antibacterial as Cephalosporin C, from a Cephalosporium sp., diketopiperazine produced by Aspergillus sp., ascochital from marine ascomycete Kirschsteiniothelia maritima., amino lipopeptides trichoderins A, A1, and B from a marine Trichoderma sp., pestalon from marine Pestalotia sp. The present chapter is focused on describing different antimicrobial secondary metabolites originating from marine-derived fungal sources and synthesis and regulatory conditions and action mechanisms in response to drug-sensitive and resistant bacteria pathogens.