Comparative and Functional Analyses Reveal Conserved and Variable Regulatory Systems That Control Lasalocid Biosynthesis in Different Streptomyces Species

Abstract

Compared to its elaborated biosynthetic pathway, the regulation of lasalocid biosynthesis remains obscure. Here, we characterize the roles of regulatory genes in lasalocid biosynthetic gene clusters of two distinct Streptomyces species and identify a conserved repressor-activator system, LodR2–LodE, which could sense changes in the concentration of lasalocid and coordinate its biosynthesis with self-resistance.

A novel PGPR strain, Streptomyces lasalocidi JCM 3373T, alleviates salt stress and shapes root architecture in soybean by secreting indole‐3‐carboxaldehyde

“…We generated a‐ S. lasalocidi JCM 3373 T mutant constitutively expressing green fluorescent protein (GFP). The gene encoding GFP was cloned into the plasmid pSET152 under the drive of constitutive promoter PkasO* and then integrated into the chromosome of S. lasalocidi JCM 3373 T (Liu et al, 2023). The roots inoculated with S. lasalocidi JCM 3373 T ‐GFP at different times were manually sectioned and then stained with 20 μg/mL propidium iodide (PI) (Redkar et al, 2018).…”

Discovery and Biosynthesis of Streptolateritic Acids A–D: Acyclic Pentacarboxylic Acids from Streptomyces sp. FXJ1.172 with Promising Activity against Potato Common Scab

“…FXJ1.172 or its mutants was produced as previously described . Next, 2 mL of the seed culture was transferred into 200 mL of a liquid SSC medium supplemented with 1 μg/mL CCCP. The cultures were incubated for 10 days at 28 °C and then extracted according to the previous procedure .…”

“…FXJ1.172 was obtained from GenBank (CP119133.2). The Streptomyces mutant strains were constructed from wild-type strains by gene replacement via homologous recombination as previously described or CRISPR-BEST-mediated base editing . Positive mutants were identified by PCR screening and were further confirmed by sequencing.…”

“…A seed culture of Streptomyces sp. FXJ1.172 or its mutants was produced as previously described . Next, 2 mL of the seed culture was transferred into 200 mL of a liquid SSC medium supplemented with 1 μg/mL CCCP.…”

“…The cultures were incubated for 10 days at 28 °C and then extracted according to the previous procedure. 27 HPLC analysis of the extracts was performed on a Shimadzu Prominence HPLC system with a Waters Xbridge octyl decyl silane column (4.6 × 150 mm, 5 μm). A gradient elution with a binary solvent system at 1 mL/min was employed using water as mobile phase A and methanol as mobile phase B.…”