title: LaDuke Spring
design: Samples were collected from Cyanobacterial mats using a #4 cork borer (38.5 mm^2) and immediately frozen on dry ice and stored at -80C until further processing. Nucleic acids were extracted and purified with the fastDNA spin kit (Molecular Biosciences) using the manufacturer's instructions. Cells were suspended in the manufacturer's lysis solution and lysed by bead beating in a Fastprep cell disrupter (Bio101 Savant Instruments, New York, NY) for 45 s at a speed setting of 6.5 m/s. A segment of the Synechococcus psaA gene was PCR amplified (primers psaAcenterforward: 5-TTCCACTACCACAAGCGGGCTCC-3, psaAreverse: 5-CAGGCCACCCTTGAAGGTG-3) and sequenced by J. Craig Venter Institute according to the GS FLX Titanium Series Rapid Library Preparation Method Manual.