Characterization of cadmium-resistant bacteria for its potential in promoting plant growth and cadmium accumulation in Sesbania bispinosa root

Abstract

The cadmium (Cd) resistant bacteria were isolated from soils of Damanganga river, Vapi, and identified 11 potential Cd resistant bacteria based on 16S rDNA sequences. The Cd resistant bacteria belonged to four different genera: Providencia spp., Morganella sp., Stenotrophomonas sp., and Bacillus spp. The assessment of plant growth-promoting (PGP) parameters revealed that the Cd tolerant bacteria showed one or more PGP properties. Further, a pot experiment was conducted to elucidate the effects of Cd resistant bacteria on the plant growth and the uptake of Cd by Sesbania bispinosa. The bacterized seedlings recorded 36.0-74.8% and 21.2-32.9% higher root and shoot lengths, respectively, in Cd amended soil compared with control. The Cd mobilization in the root of S. bispinosa by microbial inoculants ranged from 0.02 ± 0.01 to 1.11 ± 0.06 ppm. The enhanced concentrations of Cd accumulation in S. bispinosa roots correspond to the effect of the bacterial strains on metal mobilization in soil. The present observations showed that the Cd resistant strains protect the plants against the inhibitory effects of Cd, probably due to the production of PGP properties. The present results provided a new insight into the phytoremediation of Cd contaminated soil.

Cadmium-Tolerant Rhizospheric Bacteria of the C3/CAM Intermediate Semi-Halophytic Common Ice Plant (Mesembryanthemum crystallinum L.) Grown in Contaminated Soils

“…Providencia sp. strains were tested by Kartik et al (2016) and their tolerance to elevated concentrations of Cd together with PGP effect were proven.…”

“…From among numerous strain isolates, the following ones are worth mentioning: Comamonas testosteronii, Flavobacterium sp., Methylobacterium fujisawaense, Alcaligenes piechaudii and Alcaligenes xylosooxidans ( Kanazawa and Mori, 1996 ), Klebsiella planticola ( Sharma et al, 2000 ), Cupriavidus taiwanensis and Pseudomonas aeruginosa ( Siripornaldulsil and Siripornaldulsil, 2013 ), Stenotrophomonas acidaminiphila ( Lin et al, 2016 ), Providencia spp. ( Kartik et al, 2016 ), Bacillus cereus, Alcaligenes faecalis ( El-Meihy et al, 2019 ), Rhizobium pusense ( Li et al, 2019 ), Enterobacter kobei , and Bacillus cereus ( Abdollahi et al, 2020 ), Stenotrophomonas rhizophila, Variovorax boroniumulans , and Sporosarcina pasterurii ( Jalilvand et al, 2020 ). In the context of the above it is emphasized that the bacterial species isolated in the present study have never before been obtained from saline-rich and/or Cd-containing root zones of Mesembryanthemum crystallinum and to the best of our knowledge this is the first contribution to prove the occurrence of rhizospheric salt- and Cd tolerant strains of Rhodococcus erythropolis , Paenibacillus glucanolyticus , and Providencia rettgeri .…”

“…Providencia sp. strains were tested by Kartik et al (2016) and their tolerance to elevated concentrations of Cd together with PGP effect were proven. Abbas et al (2018) stated that microbial populations are typically present in the environments contaminated with heavy metals and showed that they can tolerate toxic levels of these elements.…”

Cadmium Bioremediation Potential of Bacillus sp. and Cupriavidus sp.

“…In another finding Providencia sp., Morganella sp., Stenotrophomonas sp., and Bacillus sp. were studied for their effect on plant growth and uptake of cadmium by roots of Sesbania bispinosa 37 . The bacterial strain Klebsiella pneumoniae MCC 3091 was studied for promoting the growth of rice seedling growth by lessening the phytotoxicity of cadmium 38 .…”

Improvement of Cadmium Detoxification Potential and Plant Growth Promotion by Bacterial Endophytes

“…They also showed great tolerance in combination with plant growth, development and enhancement of biomass on roots and shoots Brassica juncea and B. napus[25][26][27]. Kartik et al[28] also reported bacterial strains such as Stenotrophomonas sp., Providencia spp., Bacillus spp., and Morganella sp. which showed better plant growth promoting activities and greater Cd resistance and detoxification potential in phytoremediation.…”