The synergetic effect of biochar (BC) and plant growth promoting bacteria (PGPB) on phytoremediation potential of plants in heavy metal (HM) contaminated soils was not well understood. A pot experiment was carried out to evaluate the effects of banana pith derived BC (0, 2.5 and 5%, w/w) as soil amendment together with inoculation of PGPB Bacillus thuringiensis SE1C2 on the growth, physiological response and phytoremediation potential of Sorghum bicolor (L.) Moench in Cd and Zn contaminated soils. Combined treatment of BC 5% and SE1C2 increased plant shoot length, root length, fresh weight and dry weight but decreased Cd and Zn accumulation as compared to other treatments. The BC 5% treatment also increased SE1C2 colonization in rhizosphere soils and tissue interior of S. bicolor even under HM stress. In addition, the plants treated with BC 5% and SE1C2 also had increased chlorophyll, carotenoid and antioxidant enzymes while lower leaf malondialdehyde and proline contents which suggest their potential in improving HM stress tolerance in plants. Similarly, the combined BC 5% and SE1C2 treatment considerably improved enzymatic activities (acid phosphatases, alkaline phosphatases, β-glucosidase and urease) in HM contaminated soils. Thus, this study concludes that the combined treatment of Bacillus thuringiensis SE1C2 and banana pith BC could be exploited as an effective strategy for improving the plant growth and phytostabilization potential in HM contaminated soils.

生物炭（BC）和植物生长促进细菌（PGPB）对重金属（HM）污染土壤中植物的植物修复潜力的协同作用尚不清楚。通过盆栽试验评价香蕉髓BC（0%、2.5%和5%，w/w）作为土壤改良剂与接种PGPB苏云金芽孢杆菌SE1C2对高粱生长、生理反应和植物修复潜力的影响。 (L.) 镉和锌污染土壤中的 Moench。与其他处理相比，BC 5%和SE1C2联合处理增加了植物地上部长度、根长度、鲜重和干重，但降低了Cd和Zn积累。即使在 HM 胁迫下，BC 5% 处理也增加了 SE1C2 在S. bicolor根际土壤和组织内部的定殖。此外，用BC 5%和SE1C2处理的植物还增加了叶绿素、类胡萝卜素和抗氧化酶，同时降低了叶片丙二醛和脯氨酸含量，这表明它们在提高植物的HM胁迫耐受性方面具有潜力。同样，BC 5% 和 SE1C2 联合处理显着提高了 HM 污染土壤中的酶活性（酸性磷酸酶、碱性磷酸酶、β-葡萄糖苷酶和脲酶）。因此，本研究得出结论，苏云金芽孢杆菌SE1C2 和香蕉髓 BC的联合处理可以作为改善 HM 污染土壤中植物生长和植物稳定潜力的有效策略。