AUTHOR=Engel Yvonne , Windhorst Carina , Lu Xiaojun , Goodrich-Blair Heidi , Bode Helge B. 

TITLE=The Global Regulators Lrp, LeuO, and HexA Control Secondary Metabolism in Entomopathogenic Bacteria

JOURNAL=Frontiers in Microbiology

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2017.00209

DOI=10.3389/fmicb.2017.00209

ISSN=1664-302X

ABSTRACT=<p><italic>Photorhabdus luminescens</italic> TTO1 and <italic>Xenorhabdus nematophila</italic> HGB081 are insect pathogenic bacteria and producers of various structurally diverse bioactive natural products. In these entomopathogenic bacteria we investigated the role of the global regulators Lrp, LeuO, and HexA in the production of natural products. Lrp is a general activator of natural product biosynthesis in <italic>X. nematophila</italic> and for most compounds in TTO1. Microarray analysis confirmed these results in <italic>X. nematophila</italic> and enabled the identification of additional biosynthesis gene clusters (BGC) regulated by Lrp. Moreover, when promoters of two <italic>X. nematophila</italic> BGC were analyzed, transcriptional activation by Lrp was observed. In contrast, LeuO in <italic>X. nematophila</italic> and <italic>P. luminescens</italic> has both repressing and activating features, depending on the natural product examined. Furthermore, heterologous overexpression of <italic>leuO</italic> from <italic>X. nematophila</italic> in the closely related <italic>Xenorhabdus szentirmaii</italic> resulted in overproduction of several natural products including novel compounds. The presented findings could be of importance for establishing a tool for overproduction of secondary metabolites and subsequent identification of novel compounds.</p>