Exploring links between bacteria, enzymes, and organic compounds in seawater and sea spray aerosol

Matthew Pendergraft1, Francesca Malfatti2, Daniel Petras3, Jeremiah Minich4, Pedro Belda-Ferre5, Sierra DeAngelo6, Clare Morris7, Ke'La Kimble8, Mitchell Santander9, Pieter Dorrestein10, Lihini Aluwihare11, Rob Knight12, Farooq Azam1 and Kimberly A Prather1, (1)Scripps Institution of Oceanography, La Jolla, CA, United States, (2)University of Trieste, Life Sciences Department, Trieste, Italy, (3)University of California San Diego, Scripps Institution of Oceanography, La Jolla, United States, (4)Scripps Institution of Oceanography, Marine Biology Research Division, La Jolla, CA, United States, (5)University of California San Diego, Department of Pediatrics, La Jolla, CA, United States, (6)Colgate University, Hamilton, United States, (7)University of California San Diego, Scripps Institution of Oceanography, La Jolla, CA, United States, (8)University of California San Diego, La Jolla, United States, (9)University of California San Diego, Chemistry and Biochemistry, La Jolla, CA, United States, (10)University of California San Diego, Collaborative Mass Spectrometry Innovation Center, La Jolla, CA, United States, (11)Scripps Institution of Oceanography, La Jolla, United States, (12)University of California San Diego, Departments of Pediatrics and Computer Science & Engineering, La Jolla, CA, United States
Abstract:
Aerosols play vital roles in the Earth’s atmosphere, such as cloud seeding and ice nucleation. Sea spray aerosol (SSA) is the most abundant atmospheric aerosol by mass. SSA composition can determine the particles’ atmospheric roles, and SSA composition is determined by seawater organic matter composition. At ~1e6 cells/ml, heterotrophic bacteria disproportionately influence organic matter composition in numerous ways including through the release of ectoenzymes that hydrolyze various dissolved substrates. Previous research has indicated that bacterial-enzymatic activity in the water can influence SSA composition. Here we present the data integration from enzyme activity measurements determined with fluorogenic substrates, 16S amplicon sequencing, and liquid chromatography tandem mass spectrometry investigations of seawater and SSA from phytoplankton bloom mesocosm experiments. Individually, these datasets inform us of the enzymatic, microbial, and chemical diversity and activity of these model ocean-atmosphere systems. But to gain a more comprehensive understanding of the drivers of SSA composition, we explore connections between the bacterial, enzymatic, and organic compound diversity of the seawater and SSA. We extend the results from these mesocosm experiments to their implications for the global ocean and atmosphere.