Bacterial community composition in suspended particulate matter of Lake Chala from September 2013- January 2015

Vertical profiles of temperature, dissolved oxygen (DO), conductivity and pH in the water column of Lake Chala, a small (4.2 km2), deep (~90 m), and permanently stratified tropical crater lake at ~880 m above sea level in East Africa (3°19'S, 37°42'E), were measured at 2 m intervals through the upper 50 m of the water column at monthly intervals between September 2013 and January 2015. In the same time interval, suspended particulate matter (SPM) was collected monthly at 13 discrete depths by filtering 5-10L of water over pre-combusted glass fibre filters. A 1/32 section of the same SPM filters as used for brGDGT analysis was used for DNA extraction, after which 16S rRNA gene amplicon sequencing and quantification was performed to generate concentration-depth profiles of the monthly distribution and abundance of bacterial taxa.