PHYSIOLOGICAL FLUCTUATIONS UNDERLYING THE METABOLIC INTERACTIONS OF A CRYPTIC SULFUR CYCLING BACTERIAL CONSORTIUM

Cryptic sulfur cycling consists of tightly coupled sulfur exchange between bacteria that are often missed by bulk geochemical measurements, enabling important “hidden” carbon transformations. To investigate this cryptic cycling, we studied the “pink berries”, a consortium of sulfide oxidizing phototrophs and sulfate reducing bacteria. To probe this syntrophic metabolism and elucidate links between the carbon and sulfur cycles, we used a multipronged approach consisting of PacBio HiFi metagenomes, paired to metaproteomic and metabolomic sampling. Pink berries were incubated in sterile marsh water over 48 hours and sampled during peak light and peak dark conditions. Proteins were then extracted, run on an LC-MS/MS and compared to a peptide database assembled from contemporaneous metagenomes of complete genomes in megabase-size contigs. Parallel aggregates were sampled for both exo/endometabolites. Our high quality metaproteomes identified ~2000 proteins per sample, with a good ratio of spectra matching to our database(~half).  From the endometabolomic data, we detected 184 putative distinct metabolites spanning central carbon pathways to secondary metabolites.  Integrating these data, we find fluctuations in and metabolic connections between carbon and sulfur pathways. This work sheds light on the intimate metabolic interactions in cryptic biogeochemical interactions and offers new insights about the chemical basis of bacterial symbiosis.

Presentation Preference: Poster

Primary Presenter: Braulio Castillo Villaseñor, University of California, Santa Barbara (bscvillasenor@gmail.com)

Authors:

Braulio Castillo Villaseñor, UCSB  (bsb402@ucsb.edu)

Olivia Mathieson, NCSU  (olmathie@ncsu.edu)

Anna Warsaw, UCSB  (awarsaw@ucsb.edu)

Emily Junkins, UCSB  (ejunkins@ucsb.edu)

Michael Ochsenkühn, NYU Abu Dhabi  (mao13@nyu.edu)

Shady Amin, NYU Abu Dhabi  (samin@nyu.edu)

Manuel Kleiner, NCSU  (mkleine@ncsu.edu)

Elizabeth Wilbanks, UCSB  (ewilbanks@ucsb.edu)