Applications of the Third-Generation DNA Sequencing Technology to the Identification of Spoilage Microorganisms in the Brewing Industry.

A new nanopore sequencing-based method has been developed for the detection and identification of a wider range of microorganisms. This method uses universal primers to identify virtually all the bacterial or yeast/fungal species via the amplification and nucleotide sequencing of common ribosomal DNA regions. The simplicity of its protocol makes the method suitable for both small and large breweries.

Identification and characterization of lbpA, an indigoidine biosynthetic gene in the γ-butyrolactone signaling system of Streptomyces lavendulae FRI-5.

Streptomyces lavendulae FRI-5 produces the blue pigment indigoidine and other secondary metabolites (d-cycloserine and nucleoside antibiotics). The production of these useful compounds is controlled by a signaling cascade mediated by the γ-butyrolactone autoregulator IM-2. Previously we revealed that the far regulatory island includes the IM-2 receptor, the IM-2 biosynthetic enzyme, and several transcriptional regulators, and that it contributes to the regulation of indigoidine production in response to the signaling molecule.

Regulation of production of the blue pigment indigoidine by the pseudo γ-butyrolactone receptor FarR2 in Streptomyces lavendulae FRI-5.

The γ-butyrolactone autoregulator signaling cascade is widely distributed among Streptomyces species as an important regulatory system of secondary metabolism. In Streptomyces lavendulae FRI-5, a γ-butyrolactone autoregulator IM-2 and the IM-2 specific receptor FarA control production of the blue pigment indigoidine together with two types of antibiotics: d-cycloserine and the nucleoside antibiotics. Here, we demonstrated by in silico analysis that farR2 (a farA homologue), which is located in a cluster of regulatory genes including farA, belongs to the family of pseudoreceptor regulator genes, and that the expression of farR2 is controlled by the IM-2/FarA regulatory system.

Differential contributions of two SARP family regulatory genes to indigoidine biosynthesis in Streptomyces lavendulae FRI-5.

The Streptomyces antibiotic regulatory protein (SARP) family regulators have been shown to control the production of secondary metabolites in many Streptomyces species as the most downstream regulators in the regulatory cascade. Streptomyces lavendulae FRI-5 produces a blue pigment (indigoidine) together with two types of antibiotics: D-cycloserine and the nucleoside antibiotics. The production of these secondary metabolites is governed by a signaling system consisting of a γ-butyrolactone, IM-2 [(2R,3R,1'R)-2-1'-hydroxybutyl-3-hydroxymethyl-γ-butanolide], and its cognate receptor, FarA.