New Mexico Consortium: Using Wastewater To Produce a Better Algae for Biofuels


Algae showing more productive mixotrophic growth. Photo Courtesy NMC


Algae showing more productive mixotrophic growth. Photo Courtesy NMC


Joseph Msanne/Photo Courtesy NMC


New Mexico Consortium scientist, Joseph Msanne, along with colleagues Shawn Starkenburg and Juergen Polle, recently published an article titled An Assessment of Heterotrophy and Mixotrophy in Scenedesmus and its Utilization in Wastewater Treatment, in the June 2020 issue of Algal Research.

This review looks at whether growing algae for biofuels using wastewater from different sources can lead to a higher end lipid content in the algae. Using wastewater to grow algae would be a cheaper alternative means of cultivation, and if algae grown in a certain type of wastewater has a higher lipid content, this would lead to a higher biodiesel production.

The researchers looked at wastewater from different sources such as municipal wastewater, urban stormwater-ponds, and food wastewater. All of these types of wastewater contains various macro and micronutrients essential for growth. This paper summarizes previous efforts to grow the microalgae Scenedesmus sp. in different wastewater sources, and gives the results of the effectiveness of nutrient and organic substrate removal, CO2 mitigation, and resulting biomass productivities.

Since biomass productivity is a function of growth, the researchers also investigated the extent of functional genomics resources to study the regulation of central carbon metabolism in Scenedesmus.

Algae showing more productive mixotrophic growth.

What did they find? First, wastewater and high concentrations of CO2 from industrial sources can enhance growth and biomass production in Scenedesmus sp. Second, they found that Scenedesmus sp. can efficiently remove nutrients from a wide variety of different wastewaters. They found that Scenedesmus sp. productivities are generally higher under mixotrophic conditions, meaning they grow best using a mix of different sources of energy and carbon. They also found that the regulatory mechanisms governing carbon partitioning in different Scenedesmus sp. are not well understood. Last, they found that interplay between autotrophic and heterotrophic carbon sources has not been investigated in Scenedesmus. Why is all of this important? This study shows that several microalgae, including Scenedesmus sp., can switch between photoautotrophic and mixotrophic growth by utilizing organic compounds that are often found in wastewater. This means there is great potential for using wastewater in commercial biofuel production. Integrating microalgae biomass production with wastewater treatment would lead to optimizing algal biomass productivity and have great environmental impacts by significantly reducing pollution and eutrophication risks.

The results of this study are promising! This review shows that industrial-scale production of algal biomass using wastewater which is rich with organic matter would provide a cost-effective growth conditions that would greatly benefit biofuel feedstock production.

See the entire article here:

An assessment of heterotrophy and mixotrophy in Scenedesmus and its utilization in wastewater treatment. Joseph Msanne, Juergen Polle, Shawn Starkenburg. Algal Research. June 2020. Volume 8.