Genomic insights into Penicillium chrysogenum adaptation to subseafloor sedimentary environments

Penicillium chrysogenum is a filamentous fungal species with diverse habitats, yet little is known about its genetics in adapting to extreme subseafloor sedimental environments.

Here, we report the discovery of P. chrysogenum strain 28R-6-F01, isolated from deep coal-bearing sediments 2306 m beneath the seafloor. This strain possesses exceptional characteristics, including the ability to thrive in extreme conditions such as high temperature (45 °C), high pressure (35 Mpa), and anaerobic environments, and exhibits broad-spectrum antimicrobial activity, producing the antibiotic penicillin at a concentration of 358 μg/mL. Genome sequencing and assembly revealed a genome size of 33.19 Mb with a GC content of 48.84%, containing 6959 coding genes. Comparative analysis with eight terrestrial strains identified 88 unique genes primarily associated with penicillin and aflatoxins biosynthesis, carbohydrate degradation, viral resistance, and three secondary metabolism gene clusters. Furthermore, significant expansions in gene families related to DNA repair were observed, likely linked to the strain's adaptation to its environmental niche.

Our findings provide insights into the genomic and biological characteristics of P. chrysogenum adaptation to extreme anaerobic subseafloor sedimentary environments, such as high temperature and pressure.