Microbial dietary preference and interactions affect the export of lipids to the deep ocean

Lipids comprise a significant fraction of sinking organic matter in the ocean and play a crucial role in the carbon cycle. Despite this, our understanding of the processes that control lipid degradation is limited. Here we combined nano-lipidomics and imaging to study the bacterial degradation of diverse algal lipid droplets. Bacteria isolated from marine particles exhibited distinct dietary preferences, ranging from selective to promiscuous degraders. Dietary preference associated with a distinct set of lipid degradation genes rather than with taxonomic origin. Using synthetic communities composed of isolates with distinct dietary preferences, we showed that lipid degradation is modulated by microbial interactions. A particle export model incorporating these dynamics indicates that metabolic specialization and community dynamics may influence lipid transport efficiency in the ocean’s mesopelagic zone., , , # **Microbial dietary preference and interactions affect the export of lipids to the deep ocean**

## Data underlying Figures 1, 2, 3, 4 and 5 have been uploaded to Dryad:

**Figure 1**: Fig1_Data_readable.xls

This figure shows the the lipid content of nitrogen-starved diatoms is dominated by triacylglycerols and free-fatty-acids.

**Figure 2:** Fig2_Data_readable.xlsx

This figure show that marine bacteria exhibit distinct dietary preferences for different groups of phytoplankton lipids.

**Figure 3:** Fig3_Data_readable.xlsx

This figure shows that marine bacteria have widely different lipid degradation kinetics.

**Figure 4:** Fig4_data_readable.xlsx

This figure shows that the lipid degradation kinetics of single bacterial isolates recapitulate their long-term degradation behavior.

**Figure 5:** Fig5_data_readable.xlsx

This figure shows that pairwise interactions among marine bacteria affect the maximum rate and delay time of lipid degradation.

## **Supplementary Figures 1, 2, 3...