Rapid, high-titer biosynthesis of melanin using the marine bacterium Vibrio natriegens

Aaron D Smith; Tanya Tschirhart; Jaimee Compton; Tiffany M Hennessa; Eric VanArsdale; Zheng Wang

doi:10.3389/fbioe.2023.1239756

Rapid, high-titer biosynthesis of melanin using the marine bacterium Vibrio natriegens

Front Bioeng Biotechnol. 2023 Sep 13:11:1239756. doi: 10.3389/fbioe.2023.1239756. eCollection 2023.

Authors

Aaron D Smith^{1

2}, Tanya Tschirhart¹, Jaimee Compton¹, Tiffany M Hennessa³, Eric VanArsdale⁴, Zheng Wang¹

Affiliations

¹ United States Naval Research Laboratory, Center for Bio/Molecular Science and Engineering, Washington, DC, United States.
² College of Science, George Mason University, Fairfax, VA, United States.
³ American Society for Engineering Education Postdoctoral Research Associate, United States Naval Research Laboratory, Washington, DC, United States.
⁴ National Research Council Postdoctoral Research Associate, United States Naval Research Laboratory, Washington, DC, United States.

Abstract

Melanin is one of the most abundant natural biomolecules on Earth. These macromolecular biopolymers display several unique physical and chemical properties and have garnered interest as biomaterials for various commercial and industrial applications. To this end, extensive research has gone into refining methods for the synthesis and extraction of melanin from natural and recombinant sources. In this study, we developed and refined a procedure using a recombinant microbial system for the biosynthesis of melanin using the tyrosinase enzyme Tyr1 and tyrosine as a substrate. Using the emergent microbial chassis organisms Vibrio natriegens, we achieved maximal yields of 7.57 g/L, and one of the highest reported volumetric productivities of 473 mg L^-1 h^-1 with 100% conversion rates in an optimized, minimally defined medium. Additionally, we identified and investigated the use of a native copper responsive promoter in V. natriegens for stringent regulation of heterologous protein expression as a cost effective alternative to traditional IPTG-based induction. This research represents a promising advancement towards a green, rapid, and economical alternative for the biomanufacture of melanin.

Keywords: Vibrio natriegens; biomanufacturing; copper induction; melanin; melanin biosynthesis; tyrosinase; tyrosine.

Grants and funding

This work was supported by funds from the Office of Naval Research, Naval Research Laboratory base program (MA-236-018), the Office of the Under Secretary of Defense, Research and Engineering (OUSD (R&E)) Biotech Optimized for Operational Solution and Tactics (BOOST) Program, and Manufacturing Technology (ManTech) Program.