Abstract
Background
Antibiotic resistance and dearth of novel compounds from natural sources warrants the need to search other environments for potential antibiotic-producing microbial species. The study investigated isolation and identification of antibiotic-producing fungi from pharmaceutical waste sludge.
Results
Seven hundred and ninety-seven isolates obtained from sludge of seven pharmaceutical industries in Sango Ota, Ogun State using several growth media, with mould isolates highest (696). Isolated species were from genera Aspergillus (28.55%), Penicillium (18.35%), Trichoderma (13.44%), Rhizopus (10.21%) and Geotrichum (4.01%), and Stachybotrys (0.13%). The CFS of strains named Geotrichum candidum OMON-1, Talaromyces pinophilus OKHAIN-12, and Penicillium citrinum PETER-OOA1 had high reproducible bioactivity against Staphylococcus aureus (32 ± 0.12 mm) and Klebsiella pneumoniae (29 ± 0.12 mm) while P. citrinum MASTER-RAA2 had activity against K. pneumoniae only. Active metabolites were successfully extracted using Diaion HP-20 and methanol:iso-propanol:acetone (6:3:1 v/v). Antibacterial-active fractions of fungal extract successfully eluted with 40–60% NaCl on ion-exchange chromatography using a cation column.
Conclusions
The study successfully screened antibiotic-producing fungal species from pharmaceutical waste storage facilities. Study also showed that similar species from same toxic environment could potentially produce different metabolites.
Application of pharmaceutical waste sludge compost alters the antibiotic resistome in soil under the Chinese cabbage system
