IGEM:Harvard/2006/Conditions/Cyanobacteria

NOTE: This is all research into what researchers have used for growing the strains. It literally varies from paper to paper.

Temperature

Note: We cannot refrigerate the plates! Below 15C there is no nitrogen fixation and photosynthesis ends there too... see here

• http://www.atcc.org/common/catalog/numSearch/numResults.cfm?atccNum=33912
  • Shows temperature to be ideal at 26C for PCC7942, PCC6803
• Chabot's PhD thesis
  • Keeps at 30C due to temperature-period relationship (period is almost exactly 24 h at 37C)
• Peter Weigele's email
  • Says 20-30C
• PCC 7942 has optimal photosynthetic activity at 35°C
• optimal temperature is 37°C
• another paper saying optimal temperature is 37°C
• 27C is what they used
• 30°C growing temperature from this paper
• another one for 30°C
• We decided to grow our first cultures at 30°C to lean on the side of safety. After we have enough liquid culture to make frozen stocks, we can experiment with higher temperatures.

Light

NOTE: Light is a bit confusing... there are three basic units:

• footcandles
• lux
• microeinsteins (µmol photons m^-2 s^-1)

We have something that measures in lux, but lux is intensity, whereas we want the actual useful "mol photons" that the cyanobacteria can use, which is in microeinsteins. The conversion factor for cool white fluorescent lighting is available at here. Note that the conversion from that, then, is the lux factor times 0.013.

As for our lights, we use Philips Cool White Fluorescent lighting. Most other people use sylvania cool white fluorescent lighting, but there are some groups using our lighting. It shouldn't be a problem then.

Note that the absorption spectrum for chlorophyll can be found here

• http://www.atcc.org/common/catalog/numSearch/numResults.cfm?atccNum=33912
  • Shows light to be ideal at 2000 lux for PCC7942
  • Other page on site shows light to be ideal at 2000-3000lux for PCC6803
• Chabot's PhD thesis
  • Uses 4200 lux (51 microeinsteins), the area is bathed between 4000lux and 6000lux, goes higher for faster growth (PCC7942)
• Peter Weigele's email
  • Says 30uE - 70uE ideal
• Says light at 50uE
• We will use 4000 lux cool white flourescent light.