Using intra-species fungal diversity to get different epigenetic imprints on fungal exometabolite production

J. Frisvada

Author address: 

aCMB, Dept Systems Biol - DTU, Kongens Lyngby, DK

Abstract: 

Fungi that are primarily Competition-selected (C-selected), such as species
of Aspergillus, Penicillium Paecilomyces and Talaromyces, have been reported to produce many different
secondary metabolites (exometabolites). Some of these exometabolites are produced on commonly used
agar or broth media, while others need to be epigenetically induced by exometabolites from other
species. Alternatively histone de-methylation or deacetylation inhibitors may be added to a medium in
order to increase the number and kinds of exometabolites produced by the fungus. Often the use of an
additional medium will increase the number of members of one biosynthetic family of exometabolites. On
the commonly used media Czapek yeast autolysate (CYA) agar and yeast extract sucrose (YES)
agar Aspergillus taichungensis did not produce any prenylated indol alkaloids, while on rice the same
isolate produced 21 different taichunamides. However exometabolites coded by apparently silent gene
clusters can also be discovered by examining isolates of the same species from different geographic
regions. Penicillium antarcticum is a marine-derived fungal species producing a series of bioactive
exometabolites. 47 strains from all over the world were analyzed using HPLC-DAD after growth on CYA
and YES agar. Of these 45 produced asperentins, 40 patulin, 31 antarones, 28 fischerin, 25 atlantinone
A, 23 chrysogines, 22 phthalides, 12 penitrems, 12 deacetoxyfructigenine, 5 a terrestric acid-like
metabolite, 4 atrovenetins, 4 austalides, 3 cytochalasins, 1 an orthosporin-like metabolite and 1
patulodins. Furthermore potentially new extrolites (chromophore families not observed in any
other Penicillium species) were produced by 26, 11, 5, 4, 3, 2, and 6 singleton isolates respectively.
Examining several isolates within a species from different niches and geographic regions is an alternative
way of discovering potentially bioactive exometabolites that could otherwise only be discovered by
genome sequencing and using exometabolite gene cluster search algorithms. These observations
indicate that Aspergilli and Penicillia can be epigenetically imprinted to express their exometabolites in
certain instances.

2017

abstract No: 

18

Full conference title: 

The Fourteenth International Aspergillus Meeting, Asilomar Conference Center, Pacific Grove, CA, USA
    • Asperfest 14 (2017)