Molecular Approaches to Screen Bioactive Compounds from Endophytic Fungi

Abstract

Endophytic fungi are capable of producing plant associated metabolites and their analogs with therapeutic value. In order to identify the potential endophytic isolates producing bioactive compounds, one need to screen all isolated endophytes, which may run into hundreds. Isolation of endophytic fungi is relatively a simple process; but screening of the isolated fungi for required metabolite production is a cumbersome process. Endophytic fungi producing plant associated metabolites may contain genes involved in the entire biosynthetic pathway(s). Therefore, ascertaining the presence of key enzymes of a particular biosynthetic pathway could serve as a molecular marker for screening of these endophytes to produce that metabolite. In absence of entire biosynthetic pathways in endophytic fungi, plant genes associated with that metabolic pathway could serve as markers. This review focuses on the impact of molecular approaches to screen the endophytic fungi for the production of bioactive compounds. An attempt has been made on screening of anticancer compounds like taxol (paclitaxel), podophyllotoxin, and camptothecin using molecular markers. The advantages of molecular approaches over conventional methods to screen endophytic fungi and also identification of endophytic fungi are discussed.

Diversity and bioactive potential of culturable fungal endophytes of Dysosma versipellis; a rare medicinal plant endemic to China

“…Therefore, to protect these valuable medicinal plants and maintain the supply of PTOX for anticancer drugs, alternative sources are eagerly sought. Among these, endophytic fungi have the potential to produce PTOX 21 for the production of podophyllotoxin 21 . However, to date, only a few PTOX-producing fungi associated with Berberidaceae plants have been reported 22 , 23 .…”

Lead Compounds from Mangrove-Associated Microorganisms

“…Even though these microorganisms still hold enormous biosynthetic potential, as demonstrated by recent genome sequence studies, a vast amount of novel fungal and/or bacterial taxonomic groups still lies unexplored [ 79 ]. To a large extent, this is due to limitations in traditional isolation procedures, as well as the non-culturable feature of many of these latter microorganisms [ 87 ]. To overcome this problem, molecular approaches, such as high-throughput sequencing and metagenomics, have become promising tools for unraveling the biosynthetic potential of hitherto uncultured microorganisms, evading the need for isolation of individual species [ 87 , 88 ], and thus providing an inexhaustible source of new microbial taxa.…”

“…To a large extent, this is due to limitations in traditional isolation procedures, as well as the non-culturable feature of many of these latter microorganisms [ 87 ]. To overcome this problem, molecular approaches, such as high-throughput sequencing and metagenomics, have become promising tools for unraveling the biosynthetic potential of hitherto uncultured microorganisms, evading the need for isolation of individual species [ 87 , 88 ], and thus providing an inexhaustible source of new microbial taxa. Genome mining and bioinformatics approaches also serve as powerful strategies towards the prediction of key biosynthetic clusters from genome sequence analysis data, providing a wealth of information that can be linked to cryptic secondary metabolites, as exemplified in the case of neothioviridamide ( 144 ) from Streptomyces sp.…”

Antimicrobial Activity of Cultivable Endophytic Fungi Associated with Hancornia Speciosa Gomes Bark

“…It is well-known that the production of bioactive metabolites depends greatly on the culture medium on which the fungus is grown [ 8 , 43 , 44 ]. In the present study, the best antimicrobial activity was observed when rice was used as a substrate.…”