Research Paper
Isolation of Pseudomonas fluorescence species from fish waste, assessment of siderophore production and their antibiotic activity by dual culture plate techniques
Siderophores are organic compounds with low molecular masses that are produced by microorganisms. Under the iron-restricted condition, many bacteria produce iron chealating siderophores. Siderophore chealate iron and supply to bacterial cell by outer membrane receptors. A great variation is seen in siderophore structure produced by many bacteria. Bacterial strains also produce fluorescence as the one like Pseudomonas fluorescence. They are prevalent in compost soil environment. They have received much attention in recent years because of their potential roles and application in various areas of environmental research. Their significance is because of their ability to kill bacterial and fungal pathogens. They act as an antibiotic and they have a wide range of chemical structures and specific properties. Even though siderophores have been reported from a variety of organisms inhabiting diverse environments. The study of marine siderophores is in its infancy as compared to their terrestrial counterparts. Therefore, the present investigation was carried out to detect and characterize siderophores of unique Pseudomonas spp. isolated from sediments collected from the marine environment. Fish waste is one of major source of marine bacteria like Pseudomonas, Vibrio and Streptococcus Sp. The isolated strains were confirmed by biochemical characterization. The biosynthesis of a yellow-green, fluorescent, water-soluble pigment by p.fluorescens occurred only when the bacteria were iron-deficient and was not directly influenced by the nature of the organic carbon source. The pigment formed a very stable Fe3+ complex and was purified in this form. P.fluorescens produced only one molecular type of fluorescent pigment; however, its lability under mild alkaline conditions led to the formation of several pigmented decomposition products. Both its biosynthesis and its chemical properties (formation of a stable Fe3+ complex) suggest that the fluorescent pigment is a desferrisiderophore. The strain was grown in King`s B liquid for fluorescent pigment production and after that, it was extracted with acetone. Siderophore and their derivatives have a large application in agriculture as it increases soil fertility and is a biocontrol agent for fungal and bacterial pathogen. The present study deals with the isolation of the fluorescent isolates of P.fluorescens possessing a variety of promising properties which make them as better microbes. Twelve P.fluorescens isolates were isolated on King’s B and Pseudomonas isolation agar medium and their production of fluorescence under an UV transilluminator was assessed. The aim of the present study is to outline and discuss the important roles and form of siderophores in fish waste compost soil and to emphasize their significant roles that these small organic molecules could play an important role in biocontrol processes. A simple confrontation assay for identifying potential antagonists was developed. Fluorescent Pseudomonas isolates PS6, PS7, PS8, and PS10 were found to be antagonistic against both Bacterial and Fungal Pathogens.
Published by: K. Srimathi, Dr. H. Ann Suji
Author: K. Srimathi
Paper ID: V4I4-1500
Paper Status: published
Published: August 22, 2018
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