Cadmium biosorption and mechanism investigation using a novel Bacillus subtilis KC6 isolated from pyrite mine

Influence of biochar and microorganism co-application on stabilization of cadmium (Cd) and improved maize growth in Cd-contaminated soil

“…Dried farm soil (5 kg per pot) was added to each pot (27 cm × 20 cm × 24 cm). The experimental soil was spiked artificially with 0, 10 ppm (49.25 mg Cd(NO 3 ) 2 kg −1 soil), and 30 ppm (147.75 mg Cd(NO 3 ) 2 kg −1 soil) as per treatment using cadmium nitrate as a Cd source before adding into the pots Inoculation culture of microorganisms i.e., Trichoderma harzianum (fungus) strain Y1 (MI 1 ) (Liaquat et al, 2020 ), and Bacillus subtilis (bacteria) strain KC6 (MI 2 ) (Xie et al, 2021 ), and combined microbial inoculation strains (MI 3 ) were made in the lab of College of Resources and Environmental Sciences, Gansu Agricultural University, Lanzhou, China, in an Erlenmeyer flask, and then mixed with the artificially contaminated Cd soil by pouring the soil in pots on the plastic sheet, and allowed the microbes to get mixed properly and then again refilled the plastic pots with soils. The maize-straw biochar (BC 1 ), cow-manure biochar (BC 2 ), and poultry-manure biochar (BC 3 ) were incorporated at 5% (w/w) in Cd contaminated soil and were properly mixed with microbes.…”

Corncob biochar combined with Bacillus subtilis to reduce Cd availability in low Cd-contaminated soil

“…46 The sorption peak near 1240 cm −1 was attributed to a P-O bond of the phosphodiester group of nucleic acids and phospholipids. 28 The number of functional groups decreased with increasing temperature. According to Zama, the loss of functional groups such as hydroxyl (O-H) and asymmetric C-H on methyl 23 can be attributed to the thermal decomposition of most functional groups at higher pyrolysis temperatures.…”

“…54 Several secretions were observed between cells under Cd stress, which may bond Cd into the cellular organs and cytoplasm through chelation. 28 Moreover, CB may provide a habitat for colonization and protect B. subtilis from direct competition with other bacteria, 55 which would enhance the activity and functionality of the microbial community. 34,56 The mechanism for B. subtilis adsorption can be divided into two steps: (1) adsorption by active transport followed by sequestration of Cd inside the bacterial cells, 2,36,37,57 and (2) adsorption and chelation by the extracellular polymer substances and bacterial secretion outside the bacterial cells.…”

“…10 Bacillus subtilis (B. subtilis) can resist the stress from Cd adsorption, and the intracellular adsorption is relatively stable; consequently, Cd is generally not released back into the environment. 27,28 Moreover, B. subtilis produces bacteriocins that have broad spectrum antibacterial properties with signicant acid, alkali, and high temperature resistances 29 while being harmless to humans. 30,31 In addition, combining biochar and microorganisms allows the former to provide essential nutrients and attachment points for the latter, which facilitates the survival and growth of exogenous bacteria when introduced to new soil 32,33 and reduces the nutritional deciency of the soil.…”

Thinking for the future: Phytoextraction of cadmium using primed plants for sustainable soil clean‐up

“…in the contaminated soil can enhance the accumulation rate of cadmium in Catharanthus roseus (Mushtaq et al, 2020) and Chlorophytum laxum (Prapagdee & Wankumpha, 2017), respectively. Pseudomonas aeruginosa and Bacillus subtilis are strains used to enhance the effects of Cd phytoextraction in rice (Xie et al, 2021). For Lycopersicon esculentum , supplementing Pseudomonas aeruginosa in the soil resulted in less Cd uptake due to the complexation of Cd and its immobilization (Khanna et al, 2019).…”