UC Santa Cruz
Engineering photosynthetic bacteria as factories for the sustainable manufacturing of vitamins and medications
- Author(s): Hicks, McKenna
- Advisor(s): Bernick, David
- et al.
Much of the world struggles with inadequate access to essential medicines and proper nutrition due to high pharmaceutical prices and unreliable distribution. Moreover, the industrial chemical synthesis of such products has a detrimental environmental impact due to the sheer volume of hazardous byproducts generated in the manufacturing process and the exorbitant energy overhead. My solution is to decentralize the production of these critical resources by engineering cyanobacteria to produce essential medicines and supplements sustainably, photosynthetically, and on-site at local healthcare facilities. Biosynthesis of products in cyanobacteria is eco-friendly because they use sunlight as their energy, water as an electron donor, and air as their carbon source. I have undertaken two separate engineering endeavors in Synechococcus elongatus PCC 7942 to produce acetaminophen and human-usable vitamin B12. The genes for acetaminophen, 4ABH and nhoA, were transformed into PCC 7942, which was then analyzed via HPLC and a colorimetric assay, and confirmed as acetaminophen-producing. Vitamin B12 assembly was tested in PCC 7942, which was confirmed to remodel its native, inactive pseudo-B12 into human-active vitamin B12. The aim of this B12 work is to show that, since the addition of the genes ssuE and bluB enable vitamin B12 assembly in PCC 7942, they may also enable its production in the closely-related, edible, and robust cyanobacterium, Arthrospira platensis, which contains nearly all essential vitamins, but lacks human-usable vitamin B12. The addition of vitamin B12 to the metabolic spectrum of this organism would improve its nutritional profile and create an easy-to-cultivate multivitamin. To facilitate the first steps of this work, I developed a novel axenicity protocol for A. platensis, and sequenced the genome of strain UTEX 2340. This sequencing identified a novel cyanophage present within the A. platensis genome. This work helps pave the way for solar-powered chemical synthesis and furthers research into A. platensis and its biotechnological applications.