The role of arsenic resistant Bacillus aryabhattai MCC3374 in promotion of rice seedlings growth and alleviation of arsenic phytotoxicity. (November 2018)

• Record Type: Journal Article
• Authors: Ghosh, Pallab Kumar; Maiti, Tushar Kanti; Pramanik, Krishnendu; Ghosh, Sudip Kumar; Mitra, Soumik; De, Tarun Kumar
• Is Part Of: Chemosphere. Volume 211(2018)
• Page Start: 407
• Page End: 419
• Publication Date: 2018-11
• Subjects: Bioremediation -- Arsenate reduction -- Heavy metal -- 1-Aminocyclopropane-1-carboxylate deaminase -- Plant growth promotion -- Ethylene production; MALDI-TOFMS Matrix assisted laser desorption ionization-time of flight mass spectrometry -- FAME Fatty acid methyl ester -- SEM Scanning electron microscopy -- TEM Transmission electron microscopy -- EDAX Energy dispersive X-ray spectroscopy -- FTIR Fourier transform infrared spectroscopy -- XRF X-ray fluorescence; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2018.07.148
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: The biological agents have been utilized as an affordable alternative to conventional costly metal remediation technologies for last few years. The present investigation introduces arsenic (As) resistant plant growth promoting rhizobacteria (PGPR) isolated from the As-contaminated agricultural field of West Bengal, India that alleviates arsenic-induced toxicity and exhibited many plant growth promoting traits (PGP). The isolated strain designated as AS6 has identified as Bacillus aryabhattai based on phenotypic characteristics, physio-biochemical tests, MALDI-TOFMS bio-typing, FAME analysis and 16S rDNA sequence homology. The strain found to exhibit five times more resistance to arsenate than arsenite with minimum inhibitory concentrations (MIC) being 100 mM and 20 mM respectively. The result showed that accumulation of As was evidenced by SEM- EDAX, TEM-EDAX studies. The intracellular accumulation of arsenic was also confirmed as in bacterial biomass by AAS, FTIR, XRD and XRF analyses. The increased rate of As (V) reduction by this strain found to be exploited for the remediation of arsenic in the contaminated agricultural field. The strain also found to exhibit important PGP traits viz., ACC deaminase activity (2022 nmol α-ketobutyrate/mg protein/h), IAA production (166 μg/ml), N2 fixation (0.32 μgN fixed/h/mg proteins) and siderophore production (72%) etc. Positive influenced of AS6 strain on rice seedlings growth promotion under As stress was observed considering the several morphological, biochemical parameters including antioxidants activities as compared with an uninoculated set. Thus this strain might be exploited for stress amelioration and plant growth enhancement of rice cultivar under arsenic spiked agricultural soil. Highlights: As resistant Bacillus aryabhattai AS6 strain isolated from contaminated rhizosphere. AS6 strain could tolerate As (∨) and As (ΙΙΙ) upto 100 mM and 20 mM respectively. It exhibited IAA and siderophore production, P-solubilization and ACCD activity. High As removal and bioaccumulation of AS6 confirmed from various in vitro studies. It improved rice seedling growth under As(V)-spiked soil by reducing phytotoxicity.