Hello! I think that the culture conditions depend on the type and strain. The articles meet the nutritional environment: BG-11, TAP, TP, M-8 (link to article).  In "M

onitoring of Algal Growth Using their Intrinsic Properties "  says that the growing medium TAP better than nutrient medium BG-11.

In the Soviet Union for almost all strains of the culture medium used Tamiya.

I grow microalgae in a glass cylinder (1 or 2 liters), temperature 28-30 C (optimal), bubbling. The light level depends on what shade-requiring strain or Photophilous. I optimized the composition of the culture medium for my strain

http://deepblue.lib.umich.edu/bitstream/handle/2027.42/37944/11_ftp.pdf?sequence=1

http://www.biotek.com/assets/tech_resources/Synergy_H4_Algal_Cell_Growth_App_Note.pdf

http://www.biotek.com/assets/tech_resources/Synergy_H4_Nile_Red_App_Note.pdf

http://www.cellreg.org/Catalog/green.html

BG 11 and Allen and Nelson are the best medium for cyanophycean culture. We are culturing cyanobacteria in 25-28 oC and 14:10 photoperiod.

All my strains are green algae isolated from freshwater samples. They are not from collections, that's why for some of them I do not know the best growing conditions.

Yes, the natural conditions - it is a good starting point for research.

Important geographical location selection algae and a month when you allocate these algae from samples.

You can use a variety of mathematical models in the study helps me a lot the use of mathematical models. (eg, Jorgensen (1985), "Lake managment" chapter 3)

The native conditions are essential to achieve an acceptable growth in the laboratory. In my experience, I think the photoperiod you're applying may be affecting the growth of these microalgae, and according to its native conditions, it could require higher nitrogen and/or phosphorus concentration to handle that kind of light intensity and photoperiod. Also, personally I prefer pneumatically agitation (bubble) instead of mechanical shakeing, since CO2 diffusion is favored in your culture. In my profile you can download two items that can help you with your experiment.

Hi Lorenza,

All strains have their own optimal conditions. You can determine what they are by monitoring growth rates in semi-continuous cultures (nutrient-replete, diluted frequently so that nutrient and light availability don't change - see MacIntyre & Cullen, 2005) in a matrix of irradiance x temperature.

I'd recommend dropping the temperature considerably unless your cultures were isolated from high-temperature waters. Values for temperature optima vary by latitude in marine species (Thomas et al., 2012) and probably do in freshwater species as well. If your isolates are from Sweden, 15-20 °C would probably be a good starting point.

A survey of growth responses of (mostly marine) species, showed that the saturation intensity for most species at 18-20 °C (12:12 L:D) was 50 - 200 µmol photons m^-2 s^-1 (MacIntyre et al., 2002), so 120 should be fine. (The growth rate is 63% of the light-saturated rate at KE, the saturating intensity.)

Plastic cell culture flasks should be fine if they are aged to leach out volatile plasticizers before use. Soak them in a detergent such as Micro90 and/or dilute HCl for several days before rinsing and sterilizing them. However, the medium may need to be amended with Se (Price et al., 1987). It used to be a constituent of Pyrex glass and enough leached out during autoclaving to satisfy the cells'  need when most media recipes were being developed. Se is required for spindle formation during division, so Se-starved cells will often arrest pre-division.

Some taxa are sensitive to high shear stress, so you can probably provide CO2 more effectively by bubbling. If biomass is low, so demand is low, the enhanced diffusion with gently shaking may be enough. If you bubble with air, it's probably a good idea to run it through an activated charcoal filter to remove organics before introducing it to the culture.

Good luck.

MacIntyre, H. L. & Cullen, J. J. 2005. Using cultures to investigate the physiological ecology of microalgae. In: Andersen, R. A. [Ed.] Algal Culture Techniques. Academic Press, New York, pp. 287-326.

MacIntyre, H. L., Kana, T. M., Anning, T. & Geider, R. J. 2002. Photoacclimation of photosynthesis irradiance response curves and photosynthetic pigments in microalgae and cyanobacteria. J. Phycol. 38:17-38.

Price, N. M., Thompson, P. A. & Harrison, P. J. 1987. Selenium: an essential element for growth of the coastal marine diatom Thalassiosira pseudonana (Bacillariophyceae). J. Phycol. 23:1-9.

Thomas, M. K., Kremer, C. T., Klausmeier, C. A. & Litchman, E. 2012. A global pattern of thermal adaptation in marine phytoplankton. Science 338:1085-88.

my first doubt: why that light cycle which does not dd up to 24 hours? would this be 18:6? In any case, some dark hours might be a good idea to build up some CO2.  The suggstion on temperature and light (Hugh's answer) sounds good. However, I would use air bubbling rather than shaking, It mighthelp with CO2, at least inpart, but it would certainly help in getting rid of all that pesky  oxygen which builds up in algal cultures, poisoning Rubisco and thus upsetting the CO2 uptake mechanism. You don't say, but after a fewhours you probably have high pH values and high O2, ideal situation for your caboxylase to act as oxydase (in other words, ideal situation for photorespiration, which would justify the apperance of your culltures).

Try air bubblig, and if you want to boost growth, try adding some CO2.

By the way, Plastic, as long as pretreated (again, Hugh's answer) is fine. is it clear plastic or ooured. if so, which colour? did you check light transmission?) I have ha fairly good reults with several colours, but one never knows: We shall be here for any additional doubt or question

Good luck  

For our cyanobacterial cultures we use WC or BG-11 medium, and conditions: 12:12 h (light:dark) cycle, temperature around 22°C.

I'm conducting research, where I check the influence of temperature variants on the growth rate. I invite you to see my profile.

The daily shaking at 150 -160 rpm might also be the source of your problem, as not all species can withstand mixing at this speed! Instead, try bubbling normal air, use a range of light intensity (e.g. 65 to 80 μE m−2 s−1 ) to determine the most suitable condition, ensure a good pH is maintained (usually 8-9), and try to avoid contamination from other foreign sources. Above all, try different combinations of the above stated parameters, and try as much as you could to mimic its natural environment. Good luck Lorenza Ferro .