Epicoccum is an endophytic fungus famous for its application in the biocontrol of numerous phytopathogenic fungi. Moreover, Epicoccum Sp. are known for their capability
of producing various biologically active compounds with medical applications as antioxidant, antimicrobial, and anticancer agents. In addition to pigments formation and their
industrial application. The aim of this review is to highlight the diversity of compounds
produced by Epicoccum sp. and pointing out their medical, bio-control, and industrial applications.
Discovering new applications for currently known bioactive
metabolites and/ or exploring novel biologically active metabolites
are of critical need nowadays due to the current increasing dilemma
of microbial resistance to available and used antibiotics and
therapeutic agents, beside the emergence of new life threatening
diseases. These problems have encouraged scientists to look for
unconventional sources in order to find novel compounds. Fungi
are promising sources for a wide variety of vital metabolites such as
alkaloids, flavonoids, phenols, steroids and terpenoids [1-3]. Fungi
capacity to synthesize variety of new bioactive metabolites forced
researchers to explore these avenues. Epicoccum is an ascomycotic,
endophytic fungus that is commonly isolated from different
sources in moderate frequencies [4-6]. E. nigrum is famous for its
successful applications in the bio-control of many phyto-pathogens
[7-13], also for its ability to produce diverse classes of chemically,
structurally, and biologically diverse secondary metabolites
[13-17]. The aim of this review is to provide information about
secondary metabolites of Epicoccum and their promising and
current applications. Highlighting the importance of rich sources
of biologically active compounds can contribute in encouraging
searching for novel sources of potent compounds to face current
needs for antimicrobial agents to overcome microbial antibiotic
resistance, and to discover drugs for existing life-threating diseases.
Secondary Metabolites of Epicoccum Species
Epicoccum Sp. produces variety of secondary metabolites such
as polyketides, polyketide hybrids, diketopiperazines, Siderophores,
Carotenoid, and others (Table 1). Majority of these compounds exert
promising biological activities such as antioxidant, antimicrobial,
anticancer, in addition to potential industrial applications of
pigments produced from E. nigrum as a likely safe, nontoxic, and
non-pathogenic fungus. Among the important biologically active
compounds produced by Epicoccum spp., the anticancer drug,
taxol [18]. Also, epicocconone which is known commercially as
fluorophore and is used in cell staining and in gel electrophoresis
for protein detection [19,20], D8646-2-6 which is a telomerase
inhibitor [21,22], in addition to many potential factories for silver
nano-particles production such as Orsellinic acid and Curvularin.
Table 1: some secondary metabolites produced by Epicoccum species and their biotechnological applications.
Epicoccum Spp. As Biocontrol Agents
Epicoccum spp. have proven to be a potent biocontrol agents
against many phytopathgenic fungi, specially Botrytis cinerea
waxflower [23], Claviceps africana in sorghum [24], Pythium spp.
infecting cotton [9], Rhizoctonia solani infecting potato plants
[25], and Sclerotinia sclerotiorum in sunflower [26], Phytophthora
infestans [27], phytoplasma in apple trees [28] and Monilinia spp. in
peaches and nectarines [29-33] and against other plant pathogenic
fungi [10,11,34,35].The action mechanisms exhibited by E. nigrum
as a biocontrol agent varies from reducing host stem disease severity
index, and growing along the fungal pathogen hyphae and inducing
its lysis [36], or through causing degradation of the pathogen
protoplast, malformation in its hyphae, and leakage of cytoplasm
[37]. The polyketide, Flavipin, produced by many Epicoccum Sp is
the reason causing growth inhibition of numerous phytopathogenic
fungi [25,28,38-41]. On the other hand, Epicolactone isolated from
E. nigrum has antifungal activity and can induce root growth [42-
57]. All those studies support using Epicoccum species in different
host plants as a safe biological control agent and encourage deep
investigations for further understanding of the physiological and
molecular aspects of this interaction [57-62].
Emerging of microbial resistance, spread of life-threatening
diseases, and biological control of pathogens destroying
economically important crops, are serious problems that
encourage scientists to search for unconventional sources for novel
compounds with biological activities. Fungi are promising sources
for such compounds due to their ability to produce assortment
of secondary metabolites that could be, if truly investigated, the
solution for currently serious problems. Epicoccum is one of the
pioneer fungi in this field with proven potent ability as promising
biotechnological tool to produce industrially, and biologically
diverse metabolites.