• Uncategorized

Growthof Diatoms in Varying Nutrient and Light Conditions

Thisexperiment studies how diatoms grow in different light and nutrientconditions. Diatoms are eukaryotic phytoplankton which play animportant role in the ocean ecosystems, carbon cycle and also formthe primary food sources in upwelling and coastal systems (Armbrust29).Diatoms depend on phosphorus and nitrogen for their growth and usesilica to develop their glass shells. The understanding of theconditions required for the growth of algae is important because itfacilitates the accurate prediction of the future of climate andcarbon cycle (Smoland Eugene 7).


  • Sixteen 70ml canted neck flasks

  • Pipette

  • Media containing nitrogen, phosphorous and silica

  • Media containing nitrogen

  • Media containing phosphorus

  • Media containing silica

  • Diatom culture

  • Slides

  • 8 lamps


Day1: Pouring of media, inoculation of cultures and taking firstmeasurements

  • Labeling of flasks from 1 – 16

  • The four different media were poured into two flasks each up to the amount of 40 ml

  • Inoculation of culture was done by pipetting 1.5ml of the cock in each of the flasks

  • Eight of the flasks for each of the media was placed under the light

  • the remaining eight flasks for each media were placed ten inches away from the light (ISB 1)

Countingcells using hemocytometer

  • About 10 μL of the culture was loaded onto the slide.

  • The slide was placed under the microscope and the number of cells inside the squares of the grid are counted.


Countingcells using flow cytometry

Thecells were counted using an influx sorter. They were fixed dailythrough by being pipetted into the culture and inverting them into amixture of all the three media.


Collectionof all measurements outlined in the procedure was done and recorded.





Hemocytometer&nbspprovidedthe most reasonable results of the two cell counting methods. Diatomswere found to grow better in high light than in low light. Thediatoms also grew well in full nutrient conditions than in limitednutrient conditions.


Armbrust,E. Virginia. &quotThe life of diatoms in the world`soceans.&quot&nbspNature459.7244(2009): 185-192.

ISB.DiatomLab Experiments.Institute for Systems Biology Press, 2015.

Smol,John P., and Eugene F. Stoermer, eds.&nbspThediatoms: applications for the environmental and earth sciences.Cambridge University Press, 2010.

Close Menu