Construction and Characterization of a Gradually Inducible Expression Vector for Halobacterium salinarum, Based on the kdp Promoter

Abstract

Gradually inducible expression vectors which are governed by variations of growth conditions are powerful tools for gene expression of conditionally lethal mutants. Furthermore, controlled expression allows monitoring of overproduction of proteins at various stages in their expressing hosts. For Halobacterium salinarum, which is often used as a paradigm for halophilic archaea, such an inducible expression system is not available to date. Here we show that the kdp promoter (Pkdp), which facilitates gene expression upon K ؉ limitation, can be used to establish such a system for molecular applications. Pkdp features a rather high expression rate, with an approximately 50-fold increase that can be easily varied by K ؉ concentrations in the growth medium. Besides the construction of an expression vector, our work describes the characterization of expression patterns and, thus, offers a gradually inducible expression system to the scientific community.

Microbial Regulation of Deterioration and Preservation of Salted Kelp under Different Temperature and Salinity Conditions

“…This study also revealed a large number of halophilic archaea in fresh kelp samples. Studies have shown that these microorganisms can counter the hyperosmotic environment outside the cell by adjusting the osmotic pressure inside and outside the cell such that it has a certain tolerance to a high-salt environment [39], potentially even growing normally in a 30% salt concentration [40]. However, it is very difficult for them to adapt to the osmotic pressure in the normal human body.…”

Novel Enzymes From the Red Sea Brine Pools: Current State and Potential

“…Therefore, suitable haloarchaeon expression systems are often necessary. Successful homologous expression of haloarchaeal proteins has been reported in halophilic archaeal hosts, such as Halobacterium salinarum ( Nomura and Harada, 1998 ; Kixmüller and Greie, 2012 ; Vauclare et al, 2020 ) and Haloferax volcanii ( Hfx. volcanii ) ( Pohlschroder and Schulze, 2019 ; Haque et al, 2020 ).…”

Overview of the genetic tools in the Archaea

“…To mention only several of the most recent studies, in Hb. salinarum , a gradual inducible gene expression system has been developed (Kixmüller and Greie, 2012 ). It relies on the promoter of the potassium uptake system operon (P kdp ), which responds to potassium cation concentrations in the medium.…”