Biological Activity of Lasiodiplodia pseudotheobromae IBRL OS- 64 Extracts, an Endophytic Fungus Isolated from Medicinal Herb, Ocimum sanctum Against Foodborne Diarrhea-Caused Bacteria

Abstract

Introduction: Foodborne disease is a serious public health problem worldwide and most of the disease is related to food spoilage by bacteria. Thus, there is a need for the discovery of a natural antibiotic to inhibit these foodborne bacteria. Materials and Methods: Disk diffusion and broth microdilution assays were performed to access the antibacterial activity of the fungal extracts against test bacteria. Meanwhile, the scanning electron microscope (SEM) was employed to study the structural degeneration of bacterial cells exposed to the extracts. Results: The ethyl acetate extract of Lasiodiplodia pseudotheobromae IBRL OS-64 demonstrated favorable antibacterial activity towards all test bacteria with inhibition zone ranged from 15.0 mm to 26.0 mm. All test bacteria were resistant to hexane and butanolic extracts. Minimum inhibition concentration (MIC) values of the ethyl acetate extract between 62.5 µg/mL to 500 µg/mL whereas minimum bactericidal concentration (MBC) was in the range of 125 µg/mL to 2000 µg/mL. The SEM micrographs exhibited major abnormalities that occurred on the bacterial cells after exposure to the extract with alteration in their morphology and cell death beyond repair. Conclusion: The extracts of L. pseudotheobromae IBRL OS-64 may be an effective antibacterial agent to treat foodborne bacteria.

Antifungal Activity of Endophytic Fungi Associated With Ocimum Sanctum

“…Since dichloromethane is a mid-polar solvent and has the ability to extract molecules with antifungal activity, it was the subject of the current study. The polarity of the organic solvent affects the antimicrobial activity of the fungal extract, and midpolar solvents are optimum for isolating compounds with antimicrobial activity from fungi, claim Taufiq and Darah [33]. The majority of antibacterial substances in nature, according to Tong [35], exist as mid-polar molecules and can therefore be extracted using either dichloromethane or ethyl acetate.…”

“…present in natural goods, and any alterations to those functionalities may have an impact on the polarity of those molecules. The presence of bioactive compounds in natural products and their activity may therefore be impacted by the choice of organic solvent used in the extraction process [33].…”

Volatile Bioactive Compounds from Lasiodiplodia pseudotheobromae IBRL OS-64, an Endophytic Fungus Residing in the Leaf of Ocimum sanctum

“…The endophytic fungus, Lasiodiplodia pseudotheobromae IBRL OS-64 and test bacteria were provided by the Industrial Biotechnology Research Laboratory (IBRL), School of Biological Sciences, Universiti Sains Malaysia, Penang, Malaysia. The culture was grown and maintained as described by Taufiq and Darah (2020).…”

Antibacterial and Antibiofilm Activities of Crude Extract of Lasiodiplodia pseudotheobromae IBRL OS-64 against Foodborne Bacterium, Yersinia enterocolitica

“…Cultivation and extraction of the fungal secondary metabolite were performed according to Taufiq and Darah [17]. Two mycelial agar plugs were then inoculated into 250 mL Erlenmeyer flasks containing 100 mL of YES (yeast extract sucrose) broth and were cultivated in dark-static conditions at 30°C for 16 days.…”