ABSTRACT

CHI-SHUO CHEN, JESSE M. ANAYA , ERIC Y-T CHEN, ERIK FARR, and WEI-CHUN CHIN

8.1 INTRODUCTION

Existing as part of an organic matter continuum, the ability of dissolved organic matter (DOM) polymers to spontaneously assemble into a more bioactive microgels represents a 70 Gt carbon flux [1,2], out of a total DOM budget of 700 Gt carbon. The DOM-particulate organic matter (POM) shunt plays many roles: it redirects organic carbon flow in marine microbial communities [3-5]; reshapes trophic cycling [6-8]; and even serves as cloud condensation nuclei [9]. Conventionally, DOM has been considered a refractory macromolecule, revealing complex chemical compositions and structures [1,10]. However, notwithstanding their broad

significance, it remains unknown whether the macromolecular nature of DOM is susceptible to multiple environmental fluctuations-fluctuations realistic under future climate scenarios [11,12]. Considering the critical nature of the DOM-POM shunt, minute perturbations to DOM assembly, induced by moderate temperature or pH changes, would have effects on the ocean carbon flux and marine ecosystems [13].