E 1: Energy Flow (HS), E 3: Designing Energy Transfer (HS), Earth Science, Earth's System, Energy, ES 1: Materials/Energy Flow (MS), ES 4: Carbon Cycling (HS), Interdependent Relationships in Ecosystems, IR 1: Carrying Capacity (HS), Life Science, M&E 1: Photosynthesis (HS), M&E 1: Photosynthesis (MS), Matter & Energy in Organisms/Ecosystems, Physical Science, W 1: Graphing Waves (MS), W 1: Wave Relationships (HS), W 2: Wave Behavior (MS)

Biomass from microalgae

Biomass from microalgae: the potential of domestication towards sustainable biofactories

SUMMARY: Microalgae could potentially be a renewable source of energy for people. Unfortunately, there are many issues right now with growing enough algae and keeping the process affordable (aka: it’s too expensive to grow and use algae commercially). The article is divided up into several sections, each detailing some of the challenges of using algae as a biofuel. First, there are many species of algae, but not all are appropriate or produce enough usable product. Second, how to grow enough algae at a low cost is another problem. Currently, there are three solutions: outdoor ponds, photobioreactors, and surface-attached algal biofilms. Each of these ways has their pros and cons. The third section explains problems with conversion of light to fixed-carbon efficiency. One of the biggest problems with photosynthesis is the inefficiency of RuBisCO. The fourth section talks about ways we can genetically modify algae to become more efficient along the photosynthesis pathway, but again, we run into the problem of RuBisCO. There is some evidence that we can manipulate RuBisCO to make it more effective under certain conditions (excessive light). But, algae also have processes in place to stop photosynthesis under too much light. Using algae as a source of biofuel is promising, but requires a lot more research and changes in the way we grow the algae.

LESSON COMMENTS: The first section of the article can be paired with a pond microscopy lab. Students will be able to see firsthand the various types of algae mentioned in the paper. The second section can be used for an environmental science project or research paper talking about the pros and cons of renewable energy sources, algae as biofuel being one of them. The third and fourth section fits well into a lesson on photosynthesis, reaction rates, and enzymes. RuBisCO and carbon fixing in particular is a good way to connect theory with practice (in class, we talk about enzyme reaction rates, this is a good example of how an inefficient enzyme hinders human technological advancement. Given the importance of this enzyme, it’s not something we can easily work around either).

Benedetti, M., Vecchi, V., Barera, S., & Dall’Osto, L. (2018). Biomass from microalgae: the potential of domestication towards sustainable biofactories. Microbial cell factories, 17(1), 173. doi:10.1186/s12934-018-1019-3