There have been a lot of reports finding that the production of DAPG, PCA, pyrrolnitrin (Prn), pyoluteorin (Plt), and hydrogen cyanide (HCN) by P.
The presence of genes for the biosynthesis of 2,4-diacetylphloroglucinol (DAPG), phenazine-1-carboxylic acid (PCA), pyrrolnitrin (Prn), pyoluteorin (Plt), and hydrogen cyanide (HCN) was determined by the polymerase chain reaction (PCR) using the primer sets described in Supplementary Table 1.
As previously mentioned, the antimicrobial compound DAPG is a major determinant in the biological control activity of a range of plant pathogens by many fluorescent Pseudomonas spp.
Molecular detection of phl (DAPG) gene from fluorescent Pseudomonas isolates
PCR amplification for phl (DAPG) and plt (pyoluteorin) was performed according to Naik et al (2008) and for the pvdA (siderophore) gene and it was performed according to Takase et al (2000).
Further, to assess their ability to produce DAPG, genomic DNA of 38 fluorescent Pseudomonas spp.
DAPG is an antibiotic known to be active against a broad spectrum of microorganisms and is involved in the suppression of many plant diseases (Defago 1993; Keel et al., 1990; Keel et al., 1992; Weller and Thomashow 1993).
Quantity of DAPG produced by Pseudomonas aeruginosa An-F.
Extraction of 2, 4 diacetylphloroglucinol (2, 4 DAPG)
For the detection of an antibiotic, 2, 4- DAPG, a volume of 5 il of sample was spotted on to the aluminium coated sheets with silica gel.
The presence of DAPG was detected by spraying dinitro salicylic acid (DNS) on the TLC plate with [R.sub.f] value of 0.88, phenazine with the [R.sub.f] value of 0.57 in the isolates viz., Pf1, FP7, TPF17, TPF53 and TPF54 respectively.
The polyketide antibiotic DAPG is a phenolic molecule synthesized by the condensation of three molecules of acetyl coenzymeA with one molecule of malonyl coenzymeA to produce the precursor monoacetylphloroglucinol, which is subsequently transacetylated to generate PHL utilizing a CHS-type enzyme (21).