*Article* **Identification and Heterologous Expression of the Albucidin Gene Cluster from the Marine Strain** *Streptomyces Albus* **Subsp.** *Chlorinus* **NRRL B-24108**

**Maksym Myronovskyi 1, Birgit Rosenkränzer 1, Marc Stierhof 1, Lutz Petzke 2, Tobias Seiser <sup>2</sup> and Andriy Luzhetskyy 1,3,\***


Received: 14 January 2020; Accepted: 7 February 2020; Published: 10 February 2020

**Abstract:** Herbicides with new modes of action and safer toxicological and environmental profiles are needed to manage the evolution of weeds that are resistant to commercial herbicides. The unparalleled structural diversity of natural products makes these compounds a promising source for new herbicides. In 2009, a novel nucleoside phytotoxin, albucidin, with broad activity against grass and broadleaf weeds was isolated from a strain of *Streptomyces albus* subsp. *chlorinus* NRRL B-24108. Here, we report the identification and heterologous expression of the previously uncharacterized albucidin gene cluster. Through a series of gene inactivation experiments, a minimal set of albucidin biosynthetic genes was determined. Based on gene annotation and sequence homology, a model for albucidin biosynthesis was suggested. The presented results enable the construction of producer strains for a sustainable supply of albucidin for biological activity studies.

**Keywords:** albucidin; herbicide; nucleoside; biosynthetic gene cluster; heterologous expression; *Streptomyces albus* Del14
