Amaranthus Biochar-Based Microbial Cell Composites for Alleviation of Drought and Cadmium Stress: A Novel Bioremediation Approach

Metal contamination coupled with aridity is a major challenge for remediation of abiotic stressed soils throughout the world. Both biochar and beneficial bacteria showed significant effect in bioremediation; however, their conjugate study needs more exploration. Two rhizobacteria strains Serratia sp. FV34b Pseudomonas ASe42b isolated from multi-metal drought sites multiple plant-growth-promoting attributes (phosphate solubilization, indole-3-acetic acid, siderophore, ammonia production). were able to tolerate high concentration Cd along being resistant (−0.05 −0.73 MPa). The seldom studied biomass Amaranthus caudatus L. was used preparation by pyrolyzing it at 470 °C 160 min under limited oxygen then using biochar-based microbial cell composites (BMC)s. To check efficiency BMC stress (21 mg kg−1 soil) drought, pot-scale conducted Brassica napus 47 days. BMC5 (Biochar + FV43b) BMC9 ASe42b) improved seed germination, plant biometrical (shoot root biomass, length organs) physiological (photosynthetic pigments, proline, malondialdehyde, relative water content) parameters (exerted until reaches up 50% field capacity) Cd-spiked soil. However, most them, no or few differences observed before after drought. Moreover, maximized accumulation meager transfer shoot, making best bioformulation sustainable bioremediation rapeseed plant.