The potential role of marine fungi in organic matter degradation and transformations

Marine fungi (mycoplankton) are ubiquitous in all marine habitats but often understudied compared to their terrestrial counterparts. As organoheterotrophs, mycoplankton consume organic matter for energy and carbon and are capable of degrading both labile organic matter and recalcitrant organic matter such as lignocellulose. Although enzymatic and genomic analyses reveal mycoplankton’s ability to catabolize organic matter in the marine water column, evidence regarding their preference for dissolved organic matter (DOM) vs. particulate organic matter (POM) at an environmental-relevant concentration is scarce. Using Ascomycota strains isolated from the Sargasso Sea, we inoculated mycoplankton cultures in filtered seawater medium amended with different organic matter substrates, including glucose, lignin, cellulose, and chitin (the latter three not totally dissolved in water), at 10 mM C and incubated under dark for 1-4 weeks. Responding mycoplankton biovolumes were higher in the lignin, cellulose, and chitin treatments than in the glucose treatment, suggesting their preference for POM, possibly due to hyphal penetration into solids. After ~4 weeks, dimorphism from hyphae to yeast occurred in the lignin treatment, suggesting a potential switch of mechanism in growth and organic matter utilization. With further analysis of POM and DOM in the incubations, it is possible to link mycoplankton ecology to organic matter degradation and transformation.

Presentation Preference: Poster

Primary Presenter: Shuting Liu, Kean University (liushut@kean.edu)

Authors:

Shuting Liu, Kean University  (liushut@kean.edu)

Jessica Godfrey, Bermuda Institute of Ocean Sciences, Global Futures Laboratory, Arizona State University  (jgodfr10@bios.asu.edu)

Rachel Parsons, Bermuda Institute of Ocean Sciences, Global Futures Laboratory, Arizona State University  (rparso11@bios.asu.edu)

Chelsea Oti, Kean University  (otic@kean.edu)

Derek Melendez, Kean University  (meledere@kean.edu)

Keri Opalk, University of California Santa Barbara  (keri.opalk@ucsb.edu)

Elisa Halewood, University of California Santa Barbara  (wallner@ucsb.edu)

Craig Carlson, University of California Santa Barbara  (craig_carlson@ucsb.edu)

Leocadio Blanco-Bercial, Bermuda Institute of Ocean Sciences, Global Futures Laboratory, Arizona State University  (leocadio@asu.edu)