Dataset: Synechococcus growth rate: varying light levels
Deployment: Krause_DISL_2013-2015

Culturing of Synechococcus clones:

Monocultures of four Synechococcus clones (1333, 1334, 2370, 2515) were used to examine variation and controls on Si quotas and rates of Si accumulation.  Cultures were procured from the National Center for Marine Algae and Microbiota (NCMA) at the Bigelow Laboratory for Ocean Sciences in Boothbay Harbor, Maine.  Many of these clones are also available in other culture collections and have various strain names; here we will refer to each by their NCMA strain number (a.k.a. CCMP number).  

All clones were maintained in aged surface Sargasso Sea water with f/2 media constituents with 10 – 100 uM Si depending on the experiment as detailed below.  The temperature was 21C with low light 65 microeinsteins per second per square meter (uE/m2/s) on a 12 h light : 12 h dark photocycle.  pH was regulated in all cultures by bubbling with humidified ambient air which was sterilized by passage through a bacterial filter prior to entering each culture vessel.  Unless otherwise specified, all experiments were conducted under these temperature and light conditions.  The pH was monitored daily and remained below 8.5 in all experiments.  

Influence of light limitation:

Light limitation was used to determine the effect of growth rate on cellular silicon content.  Cultures were exposed to a 12 h light : 12 h dark photocycle and were shaded using neutral density film to reduce irradiance. 

Treatments included light levels (percentages relative to incubator irradiance 65 uE/m2/s):
A. High, 100 % (no shade)
B. Medium, 50 %
C. low, 25 % .