From cultural and natural heritage to reservoir of biomedicine: Prospection of bioactive com-pounds produced by bacterial isolates from caves

Abstract

Caves, with distinctive features and specialized ecosystems, harbour microorganisms that have adapted metabolically to survive in seemingly harsh conditions with limited essential elements. Despite the potential threat of biodeterioration to subterranean heritage due to microbial proliferation, caves serve as vital reservoirs of bioactive compounds produced by subsurface-adapted microorganisms. These microorganisms form biofilms, producing diverse bioactive compounds with properties such as antimicrobial, antioxidant, and anticancer capabilities. We conducted a comprehensive study with different bacterial strains isolated from terrestrial and marine caves (Escoural cave and in different caves on the Lanzarote island and on Selvagem Grande island). Extracts from these strains demonstrated potential in inhibiting the growth of pathogenic bacteria, showed robust antioxidant effects, and exhibited antiproliferative activity against breast cancer cells, moreover some of these extracts (Knoellia sp. CI04-s2.2, Brevibacillus sp. MR02B-s3, Bacillus sp. CK03-s2 and Bacillus sp. SD03-s6) present more than one bioactivity. This study unveiled the potential of cave bacterial strains as valuable sources of bioactive compounds, with implications for the development of novel biocides and pharmaceuticals. Bioprospecting within these unique environments offers a distinct opportunity not only to explore and safeguard these ecosystems but also to promote the development of eco-friendly, safe, and sustainable solutions.