Microbiology Resource of the Month: The Genome of Filamentous Fungus Phialemoniopsis curvata

July 30, 2019

Announcement: Draft Genome Sequence of Filamentous Fungus Phialemoniopsis curvata, Isolated from Diesel Fuel
Resource: Genome sequence of a fungus that can contaminate diesel fuel.
The hydrocarbons that compose various fuels are not often thought of as accessible nutrients, but a recent Microbial Resource Announcement reports a fungus that uses diesel as its primary carbon source.
Drs. Vanessa Varaljay and Wendy Goodson, along with a team of scientists, first identified biofouling, or accumulated growth of microorganisms, on a diesel tank. This led the scientific team to identify the source of contamination as Phialemoniopsis curvata. We asked them about their scientific discovery.

Where is Phialemoniopsis curvata normally found? 

Varaljay: Phialemoniopsis curvata (formerly Phialemonium curvatum) can be found in soil and clinical environments.  The genus overall appears to be ubiquitously distributed in the environment, including soil and water.     
P. curvata strain D216 under 200x light microscopy
P. curvata strain D216 under 200x light microscopy
Source: Lloyd Nadeau

What was the source for this fungal isolate? Why is this important?

Goodson: The fungal isolate was isolated from a biofouled diesel tank from the southeastern US. This finding suggests that this fungal isolate is able to adapt to, and even grow in, a fuel environment, which not all environmental organisms can do!  We also demonstrated in the laboratory that P. curvata can grow as a biofilm in B20 biodiesel (as its sole carbon source) and aqueous minimal medium. 
P. curvata strain D216 grown (left) as a biofilm in B20 biodiesel and aqueous minimal medium in laboratory culture and grown (right) as filaments on a potato dextrose agar (PDA) plate.
P. curvata strain D216 grown (left) as a biofilm in B20 biodiesel and aqueous minimal medium in laboratory culture and grown (right) as filaments on a potato dextrose agar (PDA) plate.
Source: Vanessa Varaljay

What does the genome sequence suggest about the ability of P. curvata to grow using biofuel as a nutrient source? 

Varaljay: P. curvata D216 harbors enzymes such as lipases and cutinases which may help it to hydrolyze the fatty acid methyl esters in the fuel.  The genome also harbors putative fatty acid transporters and the beta oxidation pathway which further suggests that P. curvata can uptake fuel metabolites (fatty acids) and then use them as a nutrient source.

How will you use the P. curvata genome sequence in your future research? 

Goodson: We will continue to mine the genome for enzymes and pathways relevant to fuel biofouling and biocorrosion.  We plan to use the genome information from this organism as part of larger study to rapidly detect biofouling in fuel tanks. 

How will other scientists in the research community use this resource?

Varaljay: Considering this is the first draft genome sequence for this organism, other researchers can now leverage the genome information for understanding how P. curvata strains survive and grow in other environments.  The genome sequence can now also serve as a reference genome for eukaryotic gene-targeted and metagenomics studies and be used as a resource for mining industrially-relevant enzymes. 

Why Microbiology Resource Announcements

“Scientific research has benefited from the resources developed and shared between scientists — from software published on Github to plasmids made available on Addgene. These resources facilitate our work and allow researchers to build on and extend the work of others. Indeed, some of the most impactful papers have been those describing resources — the Ecoli Keio Knockout Collection manuscript, for example, has been cited nearly 5,000 times. Many resources are worth sharing. We hope your next submission will spur someone else’s work or, potentially, inspire collaboration in our community.” – Microbiology Resource Announcements Editor-in-Chief Irene Newton.

Author: Julie Wolf, Ph.D.

Julie Wolf, Ph.D.
Dr. Julie Wolf is in science communications at Indie Bio, and is a former ASM employee.