Bioprospecting endophytic fungi for bioactive metabolites and use of irradiation to improve their bioactivities

Abstract

The search for new bioactive compounds with innovative modes of action and chemistry are desperately needed to tackle the increased emergence of drug-resistant microbes. With this view, this paper was conducted for the isolation, identification, and biological evaluation of fungal endophytes of eleven different plant species. A total of 69 endophytic strains were isolated and tested for the presence of bioactive metabolites with antifungal, antibacterial, anticancer, and antioxidant properties in their extracts. Upon screening, two promising strains were found to have all the before-mentioned activities. These strains were Aspergillus sydowii isolated from the bark of Ricinus communis and Aspergillus flavus isolated from the twigs of Psidium guajava. Major compounds present in extracts of the two strains were identified by GC-Mass analyses. Several well-known bioactive compounds as well as unreported ones were identified in the fungal extracts of the two strains. Furthermore, gamma irradiation (at 1000 Gy) of the fungal cultures resulted in improved bioactivities of extracts from the two strains. These findings recommend the two fungal strains as sources of antimicrobial, anticancer, and antioxidant compounds which may aid in the development of novel drugs. The presented research also explains the high-value of fungal endophytes as untapped sources of bioactive metabolites.

Harnessing endophytic fungi for biosynthesis of selenium nanoparticles and exploring their bioactivities

“…In this regard, the use of endophytes has emerged as a new research area for green and cost-effective production of several NPs. This novel research area will open a new horizon, on the interface of nanotechnology and microbiology, for novel synthesis of diverse nanomaterials with several applications (Abdelhakim et al 2020 ; El-Sayed et al 2022a ). Today, these endophytes started to find their application in different nanotechnology fields because their metabolic activity is much higher than their free counterparts (Mousa et al 2021 ; El-Sayed et al 2022b ).…”

A new endophyte Monascus ruber SRZ112 as an efficient production platform of natural pigments using agro-industrial wastes

“…In accordance with these results, previous studies reported the same observation on the reducing effect of gamma radiation on the fungal growth 61 , 62 . In the literature, gamma rays as a mutagenic agent was highly recommended several reports 61 , 62 for improvement of several fungal strains over-expressing a wide array of metabolites of industrial significance 63 , 64 . It is worthy here to mention that, several Monascus strains were reported in the literature with divers’ productivities.…”

Bioprospecting endophytic fungi for antifeedants and larvicides and their enhancement by gamma irradiation

“…Endophytic fungal isolates from our previous study (El-Sayed et al 2022a ) were used in this study to test their antifeedant and larvicidal potentials. Among the 69 fungal isolates, Aspergillus sydowii (an endophyte of Ricinus communis ), Aspergillus flavus (an endophyte of Psidium guajava ), and Lasiodiplodia theobromae (an endophyte of Terminalia arjuna ) were selected according to our screening program (mentioned later).…”

“…Furthermore, their high metabolic activity (El-Sayed 2021 ) will ensure their excellence as the ideal biotechnological agent in this regard. For all of these reasons, we have already described the isolation of 69 fungal endophytes and the evaluation of their antimicrobial, anticancer and antioxidant activities (El-Sayed et al 2022a ).…”