Detection of antimicrobial traits in fluorescent pseudomonads and molecular characterization of an antibiotic pyoluteorin.
Thirty isolates of fluorescent pseudomonads were obtained from rhizosphere of different crops in Raichur, India. The fluorescent pseudomonad strains were characterized in vitro for biochemical traits, antimicrobial traits, and pyoluteorin antibiotic production. All the isolates that showed fluorescent pigment production under UV light were rod shaped, Gram negative, positive for oxidase, catalase and citrate utilization tests, and negative for indole test. Out of 30 isolates, 07 isolates were positive for HCN production, 15 isolates were positive for H2S production, and all the isolates were positive for siderophore production. Among all the isolates, RFP-22 showed the maximum percent inhibition of mycelium (46.66 %) of Rhizoctonia solani, the pathogen, and the remaining isolates showed the moderate to least inhibition of mycelium growth of R. solani. The 16S rRNA analysis confirmed that the antibiotic positive isolates belonged to genus Pseudomonas. The amplification of 779 bp region in isolates RFP- 4 and RFP-19 corresponded to pyoluteorin antibiotic-coding pltB gene. Further characterization of pyoluteorin antibiotic through TLC and TOF-MS analysis confirmed the presence of pyoluteorin at 274.26 (g/mol) peak and 2.10 min retention time. Biochemical and molecular analyses confirmed the antagonism of Pseudomonas and isolate through pyoluteorin production.
Department of Plant Pathology, University of Agricultural Science, Raichur, India.
J U
JU
Vinay
Department of Plant Pathology, University of Agricultural Science, Raichur, India.
M K
MK
Naik
Department of Microbiology, NBAIR, Bangalore, India.
R
R
Rangeshwaran
Department of Plant Pathology, University of Agricultural Science, Raichur, India.
G
G
Chennappa
Department of Microbiology, PSGVP Mandal's, Shri S I Patil Arts, G B Patel Science and STSKVS Commerce College, Shahada Dist, Nandurbar, MS, 425 409, India.
Sohel S
SS
Shaikh
Department of Microbiology, PSGVP Mandal's, Shri S I Patil Arts, G B Patel Science and STSKVS Commerce College, Shahada Dist, Nandurbar, MS, 425 409, India. sayyedrz@gmail.com.
R Z
RZ
Sayyed
Antibiotic; Fluorescent pseudomonads; Pyoluteorin; TLC; TOF–MS