Synergistic effect of ACC deaminase producing Pseudomonas sp. TR15a and siderophore producing Bacillus aerophilus TR15c for enhanced growth and copper accumulation in Helianthus annuus L

• Published in: Chemosphere (Oxford) Vol. 276; p. 130038
• Main Authors: Kumar, Adarsh, Tripti, Maleva, Maria, Bruno, L. Benedict, Rajkumar, Mani
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.08.2021
• Subjects: Consortium of rhizobacteria; Metal tolerance; Plant growth promotion; Resistance; Sunflower; Trifolium repens; Resistance; Consortium of rhizobacteria; Plant growth promotion; Sunflower; Trifolium repens; Metal tolerance
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2021.130038

Copper (Cu) is an essential element, however it’s excess into the environment causes detrimental effect on plant and risks for public health. Four Cu and drought tolerant 1-aminocyclopropane-1-carboxylate (ACC) deaminase producing rhizobacteria were isolated from the roots of Trifolium repens L. growing on Cu smelter contaminated soils, characterized and identified based on 16S rRNA gene sequencing. A consortium of high ACC deaminase (53.74 μM α-ketobutyrate mg−1 protein h−1) producing bacteria Pseudomonas sp. strain TR15a + siderophore producing Bacillus aerophilus strain TR15c significantly (p < 0.05) produced better results for multiple-metal tolerance including Cu (1750 mg kg−1), antibiotic resistance (ampicillin, kanamycin, chloramphenicol, penicillin, tetracycline, and streptomycin) and plant growth promoting attributes (phosphate solubilization: 315 mg L−1, indole-3-acetic acid (IAA) production: 8 mg L−1, ammonia and hydrogen cyanide production) as compared to individual isolates. Pot scale experiment (enriched with 100 mg Cu kg−1) showed inoculation of Helianthus annuus seeds with consortium of TR15a + TR15c had significantly (p < 0.05) improved seed germination by 32%, total dry biomass by 64%, root Cu by 47% and shoot Cu by 75% as compared to uninoculated control whereas 0.2−7 fold higher results were observed for above stated parameters as compared to four individual isolates studied. The result suggests consortium of ACC deaminase producing Pseudomonas sp. TR15a and siderophore producing B. aerophilus TR15c could play a vital role in enhanced Cu uptake and improvement of biomass and may provide a better alternative for decontamination of Cu contaminated natural ecosystem than individual isolates. [Display omitted] •Pseudomonas sp. TR15a and Bacillus aerophilus TR15c produced high ACC deaminase.•Consortium of TR15a + TR15c showed high resistance to multiple metals and antibiotics.•Siderophore production and ACC deaminase activity were improved for consortium.•Growth and Cu concentration in sunflower enhanced after application of consortium.•Consortium act as better phytostabilizer than single inoculant for Cu remediation.