Catalyzes the conversion of pentalenene to pentalen-13-al by stepwise oxidation via pentalen-13-ol, a precursor of neopentalenolactone antibiotic. 4 H(+) + 2 O2 + pentalenene + 4 reduced [2Fe-2S]-[ferredoxin] = 3 H2O + 4 oxidized [2Fe-2S]-[ferredoxin] + pentalen-13-al kcat is 0.503 min(-1) with active enantiomer of pentalenene as substrate. Optimum pH is 8.0. Antibiotic biosynthesis; neopentalenolactone biosynthesis. S.avermitilis does not produce pentalenolactone itself in vivo but instead a group of new metabolites that are neopentalenolactone derivatives. Belongs to the cytochrome P450 family.