Effects of Calcium Chloride Concentration on Chlamydomonas Reinhardtii Algae Growth

Effects of Calcium Chloride Concentration on Chlamydomonas reinhardtii Algae Growth

Group 304: Dalton Brookshire, Mikayla Flemming,

 Amy Eckart, Gabrielle Silva

Southern Illinois University Edwardsville

25 April 2016

What affect does CaCl2 have on Algae Growth?

Introduction        

The vast consumption of fossil fuels exploded in the 18th century at the beginning of the industrial revolution. Energy demands have drastically increased as society grew and prospered. As the world depletes more and more fossil fuels, not only does the pollution increase, fossil fuels are becoming more scarce and expensive.  The question most people are asking is how to find a renewable energy source that not only burns cleaner but, is also inexpensive to produce. The answer to this question is biofuels. Rudolf Diesel, the inventor of the diesel engine, originally designed the diesel engine to run on peanut oil. It was later replaced with crude oil because at the time it was cheaper and more efficient than producing biofuel.  With all of today's advances in technology biofuels are now much easier to produce.

Why use algae as a biofuel? As stated in the Journal of Industrial and Engineering Chemistry, “microalgae are important as feedstock in production of liquid biofuels such as biodiesel, bioethanol and bio-oil. Biodiesel and bioethanol can be produced from lipids and carbohydrates of microalgae biomass, respectively,”(Lee, 2015). Compared to other feedstocks, algae is easily manipulated, grown, and harvested. The availability of biofuels is very promising. Because they are able to be produced easily from numerous sources, it makes it less likely that we would run out of biofuel. The abundance of available biofuels also has the potential of making biofuel less expensive compared to oil fuel. In addition to its availability and price, biofuel is a much healthier option. The biofuels would be less damaging to the air, resulting in less air pollution from fuels. It is also a healthier option for the car itself (longer life span, efficiency, etc.). In an experiment conducted by Lapinskiene and coworkers found that diesel fuel is toxic to soil microorganisms, while biodiesel is nontoxic at soil saturation (Lapinskiene et al., 2006).

The purpose of this experiment is to determine if growth of green microalgae is related to the nutrient concentration of calcium chloride. This experiment's prediction states that an increased amount of calcium relative to the control group will result in a higher growth rate of the algae. Other experiments have shown that certain species of algae requires a reasonable amount of calcium to grow (Allen, 1995). In this experiment the algae species, Chlamydomonas reinhardtii, will be used to test the hypothesis.  

Methods

In this experiment the concentrations of calcium chloride will be altered in the TAP media to determine its effect on algae growth. The control group kept the calcium chloride the same at 2.0 grams per 200 milliliters. Experimental group 1 has one-half times the amount in the control group, Experimental group 2 has one and a half times the amount in the control group, and Experimental group 3 has two times the amount of CaCl₂ in the control group. Each group has three flasks making a total of twelve flasks containing the various amounts of CaCl₂ in them. The flasks were autoclaved and 5 ml of algae was placed in each flask, using a sterile technique to limit the amount of possible contamination. Before the procedure, hands and the flasks were sprayed each time they exited and entered the laminar flow hood. The twelve flasks are also under a constant light source throughout the day and night. On Mondays, Wednesdays, and Fridays, OD 750 nm readings are done to measure algae growth. The OD readings are done in sterile conditions: spraying hands, flasks, and cuvettes with 95% ethanol before entering the area that the procedure is being performed. 500 micro liters are then  placed into each cuvette, which then are directly placed into the OD reader. The OD reader gave how much algae was in that small sample, which was then recorded for observation.