Production of dyestuffs from indole derivatives by naphthalene dioxygenase and toluene dioxygenase

AIMS: To isolate and characterize the phorate [O,O-diethyl-S-(ethylthio)methyl phosphoradiothioate] degrading bacteria from agricultural soil, and their assessment for multifarious biological activities of environmental and agronomic significance. METHODS AND RESULTS: Based on their morphological and biochemical characteristics, the selected isolates PS-1, PS-2 and PS-3 were presumptively identified as Rhizobium, Pseudomonas and Proteus species, respectively. The HPLC analysis of phorate in bioaugmented soil revealed its complete disappearance within 40 days. The degradation isotherms of the isolates PS-1, PS-2 and PS-3 suggested time-dependent disappearance of phorate following the first-order rate kinetics at the corresponding rate constants of 0.04, 0.05 and 0.04 d-1. Besides, the isolates concurrently exhibited substantial phosphate solubilization, indole acetic acid (IAA) and siderophore production, as well as limited biocontrol activity against fungal phytopathogens. CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY: The data revealed the potential of isolates for collateral plant growth promotion, biocontrol and bioremediation. The selected strains may serve as an important bioresource for development of effective super-bioinoculants.