Enzymes derived from extremophiles, or extremozymes, possess unique properties that enable them to function under extreme environmental conditions. Microbial communities in subterranean ecosystems have evolved specialized metabolic pathways to survive, leading to the discovery of bioactive molecules with diverse biotechnological and industrial applications as well as the development of sustainable methods for habitat restoration. This study aimed to identify cultivable microorganisms producing industrially relevant enzymes, such as laccases, proteases, and urethanases, from extremophiles in the Dinaric Karst subterranean ecosystems, which are known as biodiversity hotspot. A total of 40 samples were collected from six caves and an abandoned railway tunnel, now a key roost for a large Myotis myotis maternity colony. Cave samples were taken from the entrance, twilight, and dark zones, including soil, sediments, moonmilk, mineral deposits, bedrock deposits, insect remains, entomophagous fungi, wall biofilm, and guano from various bat species. Following microbial cultivation, 207 colonies were screened for enzymatic activity using substrate‐specific assays. Functional analysis identified one microorganism exhibiting strong laccase activity, seven capable of degrading polyurethane, and numerous protease‐producing colonies. Notably, this study constitutes the inaugural report on discovering polyurethane‐degrading microorganisms in karst caves. Molecular identification revealed microbial genera, including Bacillus, Pseudomonas, Serratia, Paenibacillus, and Priestia. These findings underscore the biotechnological potential of subterranean extremophiles and highlight the importance of conserving these ecosystems. Further characterization of these enzymes may drive advancements in environmental remediation, waste recycling, and sustainable industrial processes.

The need for a systematic approach in developing new metal-based drugs with dual anticancer-antimicrobial properties is emphasized by the vulnerability of cancer patients to bacterial infections. In this context, a novel organometallic assembly was designed, featuring ruthenium(II) coordination with p-cymene, one chlorido ligand, and a bidentate neutral Schiff base derived from 4-methoxybenzaldehyde and N,N-dimethylethylenediamine. The compound was extensively characterized in both solid-state and solution, employing single crystal X-ray diffraction, nuclear magnetic resonance, infrared, ultraviolet-visible spectroscopy, and density functional theory, alongside Hirshfeld surface analysis. The hydrolysis kinetic was thoroughly investigated, revealing the important role of the chloro-aqua equilibrium in the dynamics of binding with deoxyribonucleic acid and bovine serum albumin. Notably, the aqua species exhibited a pronounced affinity for deoxyribonucleic acid, engaging through electrostatic and hydrogen bonding interactions, while the chloro species demonstrated groove-binding properties. Interaction with albumin revealed distinct binding mechanisms. The aqua species displayed covalent binding, contrasting with the ligand-like van der Waals interactions and hydrogen bonding observed with the chloro specie. Molecular docking studies highlighted site-specific interactions with biomolecular targets. Remarkably, the compound exhibited wide spectrum moderate antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans, coupled with low micromolar cytotoxic activity against human colorectal adenocarcinoma cells and significant activity against human leukemic monocyte lymphoma cells. The presented findings encourage further development of this compound, promising avenues for its evolution into a versatile therapeutic agent targeting both infectious diseases and cancer.