Promising Antimicrobial Compounds from an Endophytic Fungus Penicillium daleae EF 4 Isolated from the Seaweed Enteromorpha flexuosa Linn.

B. Iswarya; K. Vijaya Ramesh

Abstract

AbstractThe present aim of the study is to isolate the endophytic fungi from various seaweeds and to screen their bioactivity, to analyze the β-lactamase inactivator and to evaluate the interactions between the crude extract of Endophytic fungi Penicillium daleae EF 4 and two antibiotics (penicillin G and tetracycline), against some antibiotic resistant bacterial strains. Seaweeds collected from various places of Bay of Bengal coast was subjected to Endophytic fungal isolation. The antibacterial susceptibility of the intracellular and extracellular extracts of all isolates was tested against antibiotic resistant bacterial strains. The minimum inhibitory concentration was determined. The synergistic effect of the crude extracts and antibiotics were assessed and evaluated by adopting the checkerboard methods. Inactivation of β-lactamase enzyme by the extracts was assessed by the Iodiometric method and agar plate assay. Active metabolites were detected using Thin Layer Chromatography. The endophytic isolates EF 4 and KOV 9 possess lower MIC concentration about 0.56 mg/ml and 0.13 mg/ml against tested strains. The checkerboard method revealed synergistic interaction between EF4 extract and Penicillin combination, and antagonistic with Tetracycline combination. The lowest concentration of EF4 and KOV 9 extracts which inactivates the β-lactamase activity were calculated to be 17.57 µg/ml and 47 µg/ml. The TLC Bioautography of EF 4 revealed prominent zone of inhibition at Rf value of 0.8. This investigation suggests the extracellular extracts of EF 4 to be a potential broad-spectrum antimicrobial compound. Therefore, further study is needed to isolate the pure compounds from these crude extracts. Keywords: Endophytic fungi, minimum inhibitory concentration, β-lactamase inactivation study Cite this ArticleB. Iswarya, K. Vijaya Ramesh, Promising Antimicrobial Compounds from an Endophytic Fungus Penicillium daleae EF 4 Isolated from the Seaweed Enteromorpha flexuosa Linn. Research & Reviews: A Journal of Microbiology and Virology. 2019; 9(1): 25–37p.