Characterization of a Mutant in Alga Chlamydomonas reinhardtii that is Tolerant to Low Nitrogen

Jared L. Mayrand, David C. Higgs, Department of Biological Science, University of Wisconsin–Parkside, 900 Wood Rd, Kenosha, WI, 53144

Nitrogen is an element that is incorporated into a variety of biomolecules necessary for all life. Green algae grow at a dramatically reduced rate in a depleted nitrogen environment. They also undergo significant metabolic changes during nitrogen stress, to both scavenge nitrogen from other cellular molecules and induce gametogenesis. We have recently reported a new mutant strain of the model eukaryotic green alga Chlamydomonas reinhardtii, which we termed TLN1, that grows approximately 55% better and with more biomass than a wild-type control in growth media containing 90% less nitrogen. The TLN1 strain is of interest for it might improve growth and save using high amounts of nitrogen fertilizer, at a costs savings, for the production of algal-based renewable biofuels as well as possible pharmaceuticals and natural products. Identifying the causative genetic mutation in TLN1 is critical, and it may lead to applications in other algae and possibly crop plants to significantly reduce use of nitrogen-based fertilizers. To determine the genetic mutation in TLN1, Pacific Bioscience long-read next generation sequencing is being performed on the TLN1 strain and compared to an isogenic wild-type strain. Results from genomic sequencing analysis will be presented. Secondly, we are testing if nitrogen stress induces TLN1 to produce similar or higher amounts of Triacylglyceride (TAG) lipids, which can be used as biodiesel for industrial purposes. Initial tests indicate that TLN1 accumulates TAGs at an increased rate compared to wild type, when grown under nitrogen stress. Future experiments will compare the growth of TLN1 to WT in high and low light intensities as well as other methods to assess changes in nitrogen metabolism that allows TLN1 to grow better in low nitrogen.

Additional Abstract Information

Presenter: Jared Mayrand

Institution: University of Wisconsin - Parkside

Type: Oral

Subject: Biology

Status: Approved

Time and Location

Session: Oral 11
Date/Time: Wed 3:00pm-4:00pm
Session Number: 1107
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