title: Proteolytic enzyme mediated antagonistic potential of Pseudomonas aeruginosa against Macrophomina phaseolina.
abstract: A new antagonistic bacterial strain PGPR2 was isolated from the mungbean rhizosphere and documented for the production of hydrolytic enzymes with antifungal activity. Based on the phylogenetic analysis of the 16S rRNA gene sequence and phenotyping, this strain was identified as Pseudomonas aeruginosa. Maximum protease activity (235 U/mL) was obtained at 24 h of fermentation. The protease was purified to homogeneity in three steps: ammonium sulphate precipitation, anion exchange chromatography on DEAE- cellulose resin and gel filtration chromatography using P6 column. The purified enzyme had a molecular weight of -33 kDa. The purified protease exhibited maximum activity at pH 6.0 and retained 80% of activity in a pH range of 5.0 - 9.0. Proteolytic activity was maximum in a temperature range of 40-70 degrees C. However, the enzyme was stable at 40 degrees C for 60 min. Among the metals tested, Mg2+ enhanced the protease activity. Internal amino acid sequence of the protease obtained by MALDI -ToF and subsequent Mascot database search showed maximum similarity to the HtpX protease of P. aeruginosa strain PA7. Thus, by virtue of its early production time, thermostability and effective antifungal ability, the protease purified and characterized from P. aeruginosa PGPR2 has several potential applications as fungicidal agents in agriculture.
authors.affiliation: Department of Genetics, Centre for Excellence in Genomic Sciences, School of Biological Sciences, Madurai Kamaraj University, Madurai 625 021, India.
authors.forename: Devaraj
authors.initials: D
authors.lastname: Illakkiam
authors.affiliation: Department of Genetics, Centre for Excellence in Genomic Sciences, School of Biological Sciences, Madurai Kamaraj University, Madurai 625 021, India.
authors.forename: Nishanth Lipton
authors.initials: NL
authors.lastname: Anuj
authors.affiliation: Department of Genetics, Centre for Excellence in Genomic Sciences, School of Biological Sciences, Madurai Kamaraj University, Madurai 625 021, India.
authors.forename: Paramasivan
authors.initials: P
authors.lastname: Ponraj
authors.affiliation: Department of Genetics, Centre for Excellence in Genomic Sciences, School of Biological Sciences, Madurai Kamaraj University, Madurai 625 021, India.
authors.forename: Manoharan
authors.initials: M
authors.lastname: Shankar
authors.affiliation: Department of Genetics, Centre for Excellence in Genomic Sciences, School of Biological Sciences, Madurai Kamaraj University, Madurai 625 021, India.
authors.forename: Jeyaprakash
authors.initials: J
authors.lastname: Rajendhran
authors.affiliation: Department of Genetics, Centre for Excellence in Genomic Sciences, School of Biological Sciences, Madurai Kamaraj University, Madurai 625 021, India.
authors.forename: Paramasamy
authors.initials: P
authors.lastname: Gunasekaran
mesh_terms: D001203:Ascomycota / Q000187:drug effects*; D002853:Chromatography, Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D010447:Peptide Hydrolases / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D059748:Proteolysis; D011550:Pseudomonas aeruginosa / Q000201:enzymology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D010447:Peptide Hydrolases