Exploring Cave Microbiota: Microbial Diversity, Activity, and Biotechnological Potential in Pristine Parts of Temnata Dupka Cave, Bulgaria

Due to their natural isolation and limited accessibility, sections of caves that are extremely difficult to reach provide an ideal setting for studying unique and diverse microbial communities. This microbial diversity represents a potential reservoir of microorganisms with biosynthetic capabilities including the production of bioactive compounds with potential applications in biotechnology and medicine. Seven swab samples collected from wall surfaces in hard-to-reach galleries in Temnata Dupka Cave, Vratsa Karst Re¬gion, Bulgaria were subjected to quantitative and qualitative analysis. Quantitative air sample analysis was conducted at seven different locations within the cave. A total of 49 pure cultures were isolated under aerobic conditions from different galleries in Temnata Dupka Cave. The temperature growth patterns of the isolates were determined. Bacterial isolates from Temnata Dupka Cave were investigated for hydrolytic enzyme production, antimicrobial activity, and antibiotic resistance. A higher prevalence of protease-pro¬ducing microorganisms (59%) was detected, followed by those exhibiting amylase activity (16%). A total of 53% of the bacterial isolates displayed resistance to at least one of the four antibiotics tested. Around 30% of the tested bacteria demonstrated antimicrobial potential. The results suggest that microorganisms isolated from pristine parts of Temnata Dupka Cave could be a valuable source of different psychrotolerant enzymes and bioactive metabolites. This study represents the first comprehensive report on microbial diver¬sity and biosynthetic potential in hard-to-reach locations within a Temnata Dupka Cave.