Do you know about algae and their potential in today’s world? Do you know how to get started with algae?
Algae are photosynthetic organisms that are distributed worldwide. They can be grown in any type of water ranging from wastewater to seawater with sizes ranging from microscopic (diatoms) to tens of meters in length (giant kelps).
But more notably, algae are becoming increasingly important in the research world.
Why work with algae?
Algae are one of the potential renewable feedstocks for a number of industries including:
- waste water treatment
- health supplements and
- animal feed
Currently, the hot topic regarding algae is algae biofuels in which researchers are studying metabolic pathways and physiochemical parameters and using genetic engineering of algae to create a replacement for fossil fuels. Algae have tremendous power to fight energy shortages around the world because of their effective energy balance and carbon sequestration potential.
Microalgae feedstock is better than other feedstocks (e.g., plants), as it does not require agricultural land and can reproduce more rapidly than any other plant. Algae can be cultivated in open (raceway ponds) as well closed systems (photo bioreactors). Also, there are ten of thousand of algae species, many of which are yet to be discovered.
Below are the basic points to think about before starting to culture algae.
Basic fundamentals of algae culture
Algae are water-borne, photosynthetic organisms that require light, carbon dioxide and micronutrients, mainly nitrogen and phosphorus, depending on the species. You will have to take this into consideration when starting your cultures.
To optimize conditions, grow algae in conical flasks containing 100 mL of media. Media conditions should be optimized based on the type of algae and the eventual product (e.g., algae used to produce fertilizer may have different growth requirements than algae used to produce recombinant proteins).
Selection of water source
Algae can be cultured in distilled water, tap water or Milli-Q water depending on the requirements. For domestic requirements, such as bio-fertilizers and bio-remediating agents, tap water is one of the best water sources, as it already contains essential extra nutrients required for algae to grow. For molecular experiments, it is best to use Milli-Q water or distilled water to avoid any unwanted salt or trace element contamination that might affect your results.
You should also choose the water source considering your regional environment, which will be important for large-scale production.
To optimize, grow algae in triplicate in distilled water, tap water or Milli-Q water with a standard media requirement for particular species. For ex: Fogg’s medium is used for Chlorella sp.
Chemical and physical parameters
Different chemical and physical parameters are used to optimize growth of algae based on the product requirement.
Optimize chemical parameters, such as pH, metal ions, and salinity, for each new experiment. You will also need to optimize physical conditions of your cultures such as: temperature, color, aeration time, and exposure to light. You can find some excellent sources such as GrowingAlgae or oilgae on the internet for starting ranges.
When optimizing initial conditions, remember that these conditions will eventually need to be scaled up considerably.
To make it easy for you, I have categorized the media types required by some common algae species used for biodiesel production.
|MLA, BG-11||Cyanobacteria cultures, for ex: Anabaena|
|Black Sea medium||Brackish Water organisms|
|Bold Basal medium, ASP2||Fresh Water organisms|
Analyze the growth dynamics
Once you have identified the growth conditions you will use, you need to determine the growth dynamics and calculate the dry biomass before the death phase starts.
The growth curve varies from species to species but is generally from 10 to 35 days.
For example, the Chlorella Pyrendoisa growth curve under control conditions is as follows:
Lag Phase: Till 4th Day
Log Phase: Starts at early 5th day till 8th day
Stationary Phase: 8th day till late 10th or early 11th day
Death Phase: Start by early 11th day
How to plot Algae Growth curve?
There are different parameters that can be selected to plot the growth curve algae. One can select optical density, dry weight, chlorophyll content, etc. I have done my experiments using optical density and dry weight and it has given me replicable results every time. The observations of optical density are calculated by checking the absorption at a particular wavelength, which varies from species to species.
Remember, the growth curve depends on various factors such as light/dark cycle, carbon source, nitrogen and phosphorus, trace elements, light, pH, temperature and will need to be determined again if any of these factors are changed.
So, come, gather, and let’s explore the massive potential of algae.