Metal-resistant Bacteria Research Articles

Heavy metal and antibiotic resistance bacteria in marine sediment of pahang coastal water

The presence of heavy metal and antibiotic resistance bacteria in the marine sediment may indicate heavy metal pollution and antibiotic abuse present in the environment. In this study, a total of 89 bacteria isolated from sediment collected in Teluk Chempedak and Pantai Batu Hitam of Pahang coastal water underwent heavy metal resistance test against Chromium, Cadmium, Nickel, Copper and Cobalt. Previously, these isolates were found to exhibit antibiotic resistance capabilities to at least 5 antibiotics tested. Heavy metal resistance pattern for isolates from Teluk Chempedak was in the form of Cr > Ni >Co >Cd = Cu while for isolates from Pantai Batu Hitam showed a pattern of Cr = Ni >Co >Cu >Cd. Further investigation on the identity of selected isolates that exhibited both antibiotic and heavy metals resistance capabilities using 16S rRNA gene sequences revealed isolates with closest similarities to Staphylococcus saprophyticus and Brevundimonas vesicularis..

Metalotolerance Capacity of Autochthonous Bacteria Isolated From Industrial Waste Effluent

Abstract Microbes play significant roles in remediation of heavy metal polluted industrial effluent using the mechanisms of biosorption and bioaccumulation. In the present study, six heavy metal resistant autochthonous bacteria species namely Bacillus cereus, B. megaterium, B. subtilis, Flavobacterium aquatile, Pseudomonas flourescens and Pseudomonas putida were isolated from effluent samples collected from Paper-mill industry (PMI), Paints and Chemicals Industry (PCI), and Steel-rolling Industry (SRI). The isolates were studied for their heavy metal tolerant capacities at different aqueous salt concentrations. Elemental analysis of the industrial effluent samples collected indicated the presence of heavy metals such as Copper (Cu2+), Manganese (Mn2+), Iron (Fe2+) and Lead (Pb2+) at varying concentrations in μg/ml. Generally, there were variations in the minimum inhibitory concentrations (MIC) of the heavy metal salt to each of the bacteria understudy. The MIC value of each of the bacterial isolates to aqueous solution of Cu2SO4 showed that B. megaterium, B. subtilis, Pseudomonas flourescens and Pseudomonas putida had the same MIC value of 20 ± 1.5 μg/mL while Bacillus cereus and Flavobacterium aquatile had MIC values of 13 ± 1.3 μg/mL and 25 ± 2.1 μg/mL respectively. This variation was also noticeable in aqueous salts of Mn2SO4, Fe2SO4 and Pb2SO4. The bacteria isolates showed sensitivity to heavy metals with increasing zone of inhibition as concentration increased with each isolate showing varying degree of metalotolerance. The effectiveness of the autochthonous bacteria as a means to bio-augment the remediation of heavy metal polluted industrial effluent was further proven and recommended.

Heavy metal tolerance in indigenous bacteria isolated from the industrial sewage in Kemisan River, Tangerang, Banten, Indonesia

Irawati W, Riak S, Sopiah N, Sulistia S. 2017. Heavy metal tolerance in indigenous bacteria isolated from the industrial sewage in Kemisan River, Tangerang, Banten, Indonesia. Biodiversitas 18: 1481-1486. The bacterial study is a part of human calling in preserving the earth. Many indigenous bacteria isolated from heavy metal contaminated sites had resistance to heavy metal toxicity and could be used for heavy metal removal. The aims of this study were to isolate heavy metal-tolerant indigenous bacteria from the industrial sewage of Kemisan River in Tangerang, Banten, Indonesia. The potency of bacterial isolates to remove heavy metals was also determined. The heavy-metal tolerance was determined by measuring the minimum inhibitory concentration. The potency of bacterial isolate for removing heavy metals from the medium was determined by an atomic absorption spectrophotometer. The results showed that there were eight heavy metal-resistant bacteria isolated from Kemisan River with minimum inhibitory concentration ranging from 7 mM to 11 mM. Isolate PbSI1 was the highest lead tolerant bacteria, and also tolerant to copper and zinc. The isolate was able to remove 91.25% lead, 73.38% zinc, and 98.57% copper from medium supplemented with the mixture of these heavy metals. The addition of 9 mM of lead in the medium affected the morphological appearance of isolate colonies i.e PbSI1 and PbSI3 to become darker which might occur due to the survival mechanism of bacteria by absorbing the lead inside the cells. The finding of this study indicated that isolate PbSI1 was a promising bacterium, which could be further developed for heavy metal removal.

Metalotolerance Capacity of Autochthonous Bacteria Isolated From Industrial Waste Effluent

Abstract Microbes play significant roles in remediation of heavy metal polluted industrial effluent using the mechanisms of biosorption and bioaccumulation. In the present study, six heavy metal resistant autochthonous bacteria species namely Bacillus cereus, B. megaterium, B. subtilis, Flavobacterium aquatile, Pseudomonas flourescens and Pseudomonas putida were isolated from effluent samples collected from Paper-mill industry (PMI), Paints and Chemicals Industry (PCI), and Steel-rolling Industry (SRI). The isolates were studied for their heavy metal tolerant capacities at different aqueous salt concentrations. Elemental analysis of the industrial effluent samples collected indicated the presence of heavy metals such as Copper (Cu2+), Manganese (Mn2+), Iron (Fe2+) and Lead (Pb2+) at varying concentrations in μg/ml. Generally, there were variations in the minimum inhibitory concentrations (MIC) of the heavy metal salt to each of the bacteria understudy. The MIC value of each of the bacterial isolates to aqueous solution of Cu2SO4 showed that B. megaterium, B. subtilis, Pseudomonas flourescens and Pseudomonas putida had the same MIC value of 20 ± 1.5 μg/mL while Bacillus cereus and Flavobacterium aquatile had MIC values of 13 ± 1.3 μg/mL and 25 ± 2.1 μg/mL respectively. This variation was also noticeable in aqueous salts of Mn2SO4, Fe2SO4 and Pb2SO4.The bacteria isolates showed sensitivity to heavy metals with increasing zone of inhibition as concentration increased with each isolate showing varying degree of metalotolerance. The effectiveness of the autochthonous bacteria as a means to bio-augment the remediation of heavy metal polluted industrial effluent was further proven and recommended.

Remediation Performance and Mechanism of Heavy Metals by a Bottom Up Activation and Extraction System Using Multiple Biochemical Materials.

Soil contamination with heavy metals has caused serious environmental problems and increased the risks to humans and biota. Herein, we developed an effective bottom up metals removal system based on the synergy between the activation of immobilization metal-resistant bacteria and the extraction of bioaccumulator material (Stropharia rugosoannulata). In this system, the advantages of biochar produced at 400 °C and sodium alginate were integrated to immobilize bacteria. Optimized by response surface methodology, the biochar and bacterial suspension were mixed at a ratio of 1:20 (w:v) for 12 h when 2.5% sodium alginate was added to the mixture. Results demonstrated that the system significantly increased the proportion of acid soluble Cd and Cu and improved the soil microecology (microbial counts, soil respiration, and enzyme activities). The maximum extractions of Cd and Cu were 8.79 and 77.92 mg kg-1, respectively. Moreover, details of the possible mechanistic insight into the metal removal are discussed, which indicate positive correlation with the acetic acid extractable metals and soil microecology. Meanwhile, the "dilution effect" in S. rugosoannulata probably plays an important role in the metal removal process. Furthermore, the metal-resistant bacteria in this system were successfully colonized, and the soil bacteria community were evaluated to understand the microbial diversity in metal-contaminated soil after remediation.

Role of heavy metals in structuring the microbial community associated with particulate matter in a tropical estuary

Particulate matter (PM), which are chemically and biochemically complicated particles, accommodate a plethora of microorganisms. In the present study, we report the influence of heavy metal pollution on the abundance and community structure of archaea and bacteria associated with PM samples collected from polluted and non-polluted regions of Cochin Estuary (CE), Southwest coast of India. We observed an accumulation of heavy metals in PM collected from CE, and their concentrations were in the order Fe > Zn > Mn > Cr > Pb > Cu > Cd > Co > Ni. Zinc was a major pollutant in the water (4.36–130.50 μgL−1) and in the particulate matter (765.5–8451.28 μgg−1). Heavy metals, Cd, Co, and Pb were recorded in the particulate matter, although they were below detectable limits in the water column. Statistical analysis showed a positive influence of particulate organic carbon, nitrogen, PM-Pb, PM-Zn and PM-Fe on the abundance of PM-archaea and PM-bacteria. The abundance of archaea and bacteria were ten times less in PM compared with planktonic ones. The abundance of PM-archaea ranged between 4.27 and 9.50 × 107and 2.73 to 3.85 × 107 cellsL−1 respectively for the wet and dry season, while that of PM-bacteria was between 1.14 and 6.72 × 108 cellsL−1 for both seasons. Community structure of PM-bacteria varied between polluted and non-polluted stations, while their abundance does not show a drastic difference. This could be attributed to the selective enrichment of bacteria by heavy metals in PM. Such enrichment may only promote the growth of metal resistant archaea and bacteria, which may not participate in the processing of PM. In such cases, the PM may remain without remineralization in the system arresting the food web dynamics and biogeochemical cycles.

Prevalence of antibiotic and heavy metal resistance in Gram negative bacteria isolated from rivers in northern Pakistan

AbstractAntibiotic and metal resistance is a global occurring phenomenon and a universal threat. The release of antibiotics and metals into the environment like natural water bodies stimulates resistant microbes that could become a reservoir for a resistant gene pool for other pathogenic bacteria. The aim of the study was to determine microbial diversity, distribution of antibiotic and metal resistance bacteria from five rivers. The resistance of 168 Gram negative isolates was tested against 10 antibiotics and five metals. The study revealed a high incidence of bacterial isolates resistant to ampicillin (44.7%), streptomycin (37.3%) and chloramphenicol (33.9%). The highest level of antibiotic resistance was detected in the River Ravi. The multiple antibiotic resistance (MAR) index of the five rivers ranged from <0.2 to 0.6. Isolates displayed tolerance to different concentrations of heavy metals. High antibiotic and metal‐resistances in samples from the Rivers Ravi and Soan suggest co‐resistance amongst the bacterial populations.

Lantana camara—an Ecological Bioindicator Plant for Decontamination of Pb-Impaired Soil Under Organic Waste-Supplemented Scenarios

Heavy metal extraction and processing from ores releases elements into the environment. Soil, being an “unfortunate” sink, has its bionomics impaired and affected by metal pollution. Metals sneak into the food chain and pose risk to humans and other edaphic-dependent organisms. For decontamination, the use of an ecosystem-friendly approach involving plants is known as phytoremediation. In this study, different lead (Pb) concentrations (80, 40, 20, and 10 mg kg−1) were used to contaminate a well-characterized soil, (un)supplemented with organic waste empty fruit bunch (EFB) or spent mushroom compost (SMC), with non-edible plant—Lantana camara. Lead removal by L. camara ranged from 45.51% to 88.03% for supplemented soil, and from 23.7% to 57.8% for unsupplemented soil (P < 0.05). The EFB-supplemented and L. camara-remediated soil showed the highest counts of heavy metal-resistant bacteria (HMRB) (79.67 × 106–56.0 × 106 colony forming units (CFU) g−1 soil), followed by SMC-supplemented and L. camara-remediated soil (63.33 × 106–39.0 × 106 CFU g−1 soil). Aerial metal uptake ranged from 32.08 ± 0.8 to 5.03 ± 0.08 mg kg−1 dry weight, and the bioaccumulation factor ranged from 0.401 to 0.643 (P < 0.05). Half-lives (t1/2) of Pb were 7.24–2.26 d in supplemented soil, 18.39–11.83 d in unsupplemented soil, and 123.75–38.72 d in the soil without plants and organic waste. Freundlich isotherms showed that the intensity of metal absorption (n) ranged from 2.44 to 2.51 for supplemented soil, with regression coefficients of determination (R2) between 0.901 2 and 0.984 0. The computed free-energy change (ΔG) for Pb absorption ranged from −5.01 to 0.49 kJ mol−1 K−1 for EFB-supplemented soil and −3.93 to 0.49 kJ mol−1 K−1 for SMC-supplemented soil.

Occurrence of plasmids in multi metal and drug resistant gram negative bacteria isolated From hospital wastewater

Occurrence of plasmids in multi metal and drug resistant gram negative bacteria isolated From hospital wastewater

Cu-resistant Kocuria sp. CRB15: a potential PGPR isolated from the dry tailing of Rakha copper mine

Rhizobacteria may enhance biomass production and heavy metal tolerance of plants under stress conditions. The present study was carried out for isolation of metal-resistant bacteria that can be further utilized for phytoremediation process. A potential metal-resistant strain CRB15 was isolated from rhizospheric region of Saccharum spontaneum that was found to be resistant against Cu (6.29 mM), Zn (3.25 mM), Pb (1.5 mM), Ni (1.25 mM), and Cd (0.25 mM). SEM analysis was performed for evaluation of morphological changes on bacterial isolate. FTIR analysis observed the change in wavenumbers after the addition of Cu. 16S rDNA sequence analysis showed that CRB15 isolate matched best with genus of Kocuria and was named as Kocuria sp. CRB15. The isolate Kocuria sp. CRB15 was a potential plant growth-promoting rhizobacterium as it had a high IAA (46 µg ml−1), P solubilisation (39.37 µg ml−1), ammonia production (30.46 µmol ml−1), and hydrogen cyanide production capacity. Root–shoot elongation assay conducted on Brassica nigra under lab conditions with strain CRB15 demonstrated positive effects of strain CRB15 in root and shoot elongation of Cu-treated seedlings. This study proved the Kocuria sp. CRB15 a potential PGPR for bacterial-assisted phytoremediation.

Isolation and characterization of a biosurfactant-producing heavy metal resistant Rahnella sp. RM isolated from chromium-contaminated soil

Objective of the study was to isolate heavy metal resistant bacteria from chromium-contaminated subsurface soil and investigate biosurfactant production and heavy metal bioremediation. Based on 16S rRNA gene sequence and phylogenetic analysis, the isolate was identified as Rahnella sp. RM. The biosurfactant production by heavy metal resistant Rahnella sp. RM was optimized using Box- Behnken design (BBD). The maximum emulsification activity was obtained 66% at 6% soybean meal in pH 7.0 and 33.5°C. The biosurfactant was characterized using Field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR) and matrix assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF). The highest metal removal rates using the biosurfactant were found 74.3, 72.5, and 70.1%, respectively, at the 100 mg/L amended flasks at 48 h. This study indicated the biosurfactant from heavy metal resistant Rahnella sp. RM could be used as a potential tool to remediate the metals in contaminated environments.

Acid and Heavy Metal Tolerant Bacillus sp. from Rat-Hole Coal Mines of Meghalaya, India

Coal is a major natural resource of Northeast India and the indigenous process of coal mining known as rat-hole mining results in the pumped mine water being released to the nearby land and water bodies contaminating the area and destroying life forms due to acid mine drainage. The present study aimed at isolating acid and metal resistant bacteria from the rat-hole coal mines to assess their acid and metal tolerance isolated two Bacillus sp. with good tolerance to iron, cadmium and chromium which grew well at pH 5 and could remain viable up to pH 2 without any apparent growth. Growth experiments at pH 2–4 indicated the failure of the isolates to grow and produce colony though they survived metabolically viable. However the inoculum obtained from broth culture incubated for 72 h at pH 2–4 produced distinct colonies when plated in medium at pH 5. Bacillus subtilis subsp. inaquosorum SK22 showed comparatively higher maximum tolerable concentration (MTC) for iron in comparison to Bacillus cereus SK44. Both had the same MTC for both cadmium and chromium. The minimum inhibitory concentration (MIC) and maximum bactericidal concentration (MBC) was similar for cadmium and chromium for both the Bacillus sp. MIC and MBC for iron was higher in case of Bacillus subtilis subsp. inaquosorum SK22 than that of Bacillus cereus SK44. This higher resistance to acidic pH and high metal concentration indicated their potential to be good candidates for bioremediation of contaminated soil and water bodies affected by rat-hole mining and acid mine drainage.

Characterization of Nickel Tolerant Bacteria Isolated from Heavy Metal Polluted Glass Industry for its Potential Role in Bioremediation

ABSTRACTHeavy metal contamination of the environment is a serious concern because of their deleterious effects on biological systems. To the best of our knowledge, this is the first investigation on isolation of heavy metal resistant bacteria from contaminated sites of glass industrial area.The study focused on isolation and characterization of Ni2+ resistant bacteria from these sites and analysis of their Ni2+ accumulation potential. Out of 38 different bacterial isolates 3 bacteria were able to tolerate up to 24 mM Ni2+ concentration. These bacterial strains were identified as E. coli (AS17b), Escherichia coli (AS21) and Microbacterium sp. (AS33) by 16S rRNA (16S ribosomal RNA) sequencing and their basic local alignment search tool search analysis. Growing cell of E. coli and Microbacterium sp. revealed accumulation of 0.12, 0.08 and 0.06 µg, of Ni2+/mg dry weight of cells, respectively, by 72 hr. Similarly resting cell of these strains showed accumulation of 0.27, 0.11 and 0.08 µg of Ni2+/mg dry weight of cells by 150 min, respectively. These results reveal that strain E. coli (AS21) shows maximum accumulation efficiency for Ni2+ among different isolates studied under shaking as well as starving conditions. Hence, E. coli (AS21) could serve as an efficient and promising bacterium for bioremediation of nickel-contaminated sites.

Cadmium and lead tolerant bacteria isolated from industrial waste water

An in vitro study was conducted to isolate, identify and characterize heavy metal resistant bacteria from industrial waste water and to determine their tolerance capacity to cadmium and lead. Different morphological, physiological and biochemical tests were carried out to identify the bacterial isolates in the waste water. A total of eight bacterial isolates viz., Staphyllococcus intermedius, Pseudomonas aeruginosa, Bacillus cereus, Bacillus subtilis, Escherichia coli, Acinetobacter baumanii, Pseudomonas flavescens and Acinetobacter lwofii were identified from metal polluted tannery and steel industrial areas. Bacterial response to cadmium tolerance was determined by treating them with CdCl2 solution at a rate of 1, 2, 2.5 and 5 μg/ml. In case of lead tolerant bacteria, PbCl2 solution was applied at a rate of 0.05, 0.125, 0.2 and 0.5 μg/ml. Pseudomonas aeruginosa isolated from waste water of steel industries and Bacillus cereus from tannery area was found to be the most tolerant species to the different doses of cadmium and lead. The study indicated that Pseudomonas aeruginosa and Bacillus cereus could be good candidates for the treatment and elimination of heavy metals from industrial waste water. The present study may be helpful to the bioremediation of heavy metals in the contaminated environment.&#x0D; Dhaka Univ. J. Biol. Sci. 26(1): 29-38, 2017 (January)

The occurrence of heavy metals and metal-resistant bacteria in water and bottom sediments of the Straszyn reservoir (Poland)

The aim of this study is to investigate the distribution of selected heavy metals and metal–resistant bacteria in water and bottom sediments of the surface drinking water reservoir for Gdansk. The following sequence of metals in regard to metal concentration in sediments can be written down: Zn > Pb > Cu > Cd. The evaluation of metals accumulation was performed using the Muller index, to indicate the bottom sediment's contamination and geochemical classification of sediment quality according to Polish standards. The Muller geochemical index was changing in a wide range: < 1–4.1. Although the maximum value of Muller's geochemical index determined for copper indicates that the sediment is ‘strongly contaminated’, in general the analysed bottom sediments were classified as the I and II category according to Polish geochemical standards. From the microbiological side a significant part of heterotrophic bacteria isolated from the bottom sediment and surface water (raw and treated water) showed a resistance to 0.2 mM and 2 mM concentrations of zinc, copper and lead. The highest percentages of metal–resistant bacteria were recorded in the sediments of the reservoir (60%–88%). The share of metal–resistant strains in the raw water was significantly lower (34%–61%). The results indicate also that water treatment processes may contribute to the selection of resistant strains.

Evaluation of Heavy Metals Resistant Micrococcus sp. Isolated from Rivers in Basra, Iraq

The present study aims to isolation, identification and characterization of heavy metal resistant bacteria from six rivers in Basra Southern Iraq. Two species of Micrococcus (M. halobius and M. kristinae) were isolated on the basis of morphological and biochemical profiles and selected based on high levels of heavy metals (cadmium, lead, copper and nickel) resistance. The concentrations of dissolved heavy metals (Cd, Pb, Cu and Ni) in rivers were determined. The maximum tolerance concentration (MTC) of isolates against Pb, Cu, Cd and Ni was determined in solid media after 72 h incubation. All isolates were resistant to Pb (2200-2600) μg mL-1, Cu (400) μg mL-1, Cd (300-400) μg mL-1 and Ni (200-300) μg ml-1. Living biomass of M. halobius and M. kristinae were used for the removal of heavy metal ions at different concentrations (25, 50 and 100) μg mL-1 from aqueous metal solutions. The best concentration of removal was 25 μg mL-1 after 72 h incubation at 120 rpm. Percent removal efficiency of M. kristinae was 47.22, 26.26 for Cu and Pb respectively, and for M. halobius was 31.52, 27.87 for Cd and Ni respectively.

Assessment of heavy metal concentrations and associated resistant bacterial communities in bulk and rhizosphere soil of Avicennia marina of Pichavaram mangrove, India

Heavy metals are known to pose a potential threat to terrestrial and aquatic flora and fauna. Due to increasing human influence, heavy metal concentrations are rising in many mangrove ecosystems. Therefore, an assessment of heavy metal (Cd, Cr, Cu, Ni, Pb, Fe, Mn, and Zn) concentrations was conducted within the bulk soil and rhizosphere soil of Avicennia marina at the Pichavaram Mangrove Forest in India. The rhizosphere soil showed higher concentrations of metals than the bulk soil. Compared to the bulk soil, the metals Cd, Fe, Mn, and Zn were 6.0–16.7% higher, whereas Cr, Cu, Ni, and Pb were 1.7–2.8% higher concentration. Among the three selected sampling sites (dense mangrove forest, estuarine region, and sea region), the sea region had the highest concentration of all heavy metals except Zn. The trend of the mean metal concentration was Fe > Mn > Cr > Ni > Cu > Pb > Zn > Cd. Heavy metals concentrations elevated by the 2004 tsunami were persistent even after 4 years, due to sedimentary soil processes, the rhizosphere effect of mangroves, and anthropogenic deposition. Analysis of the heavy metal-resistant bacteria showed highest bacterial count for Cr-resistant bacteria and rhizosphere soil. The maximum level of heavy metal-resistant bacteria was observed at the site with the highest heavy metal contamination. The heavy metal-resistant bacteria can be used as indicator of heavy metal pollution and furthermore in bioremediation.

Uranium Removal from Wastewater Using Immobilized Multiple Heavy-Metal and Antibiotic Resistance E. coli Isolated from Aborshid Egypt

In this study 6 bacterial isolate, isolated Uranium Ore samples from Aborshid Egypt, were characterized for their response to 15 antibiotics and 10 heavy metals Beside Uranium. The results revealed a varying response of the Ore bacteria to the tested heavy metals. All isolates showed multiple metal resistance towards two to six heavy metals, with MIC ranging from 50 to 1000 ppm. The most potent of the strains in both groups were resistant to Pb, Ni, Cu and Zn. highly metal-resistant bacteria could be used with potential application for treatment of wastewaters, using Immobilized Bacterial cells isolated from Egypt uranium Ore, Uranium removal from uranium refining wastewater, the most potent isolate was identified the Egyptian strains belong to E. coli, based on 16S rRNA gene sequencing the nucleotide sequences reported here were deposited to the NCBI Nucleotide Sequence Database under accession numbers (MF496270) by the name of Mostafa gomaa fadl.

English

English

Cd immobilization and reduced tissue Cd accumulation of rice (Oryza sativa wuyun-23) in the presence of heavy metal-resistant bacteria

Two metal-resistant Bacillus megaterium H3 and Neorhizobium huautlense T1-17 were investigated for their immobilization of Cd in solution and tissue Cd accumulation of rice (Oryza sativa wuyun-23) in the Cd-contaminated soil. Strains H3 and T1-17 decreased 79–96% of water-soluble Cd in solution and increased grain biomass in the high Cd-contaminated soil. Inoculation with H3 and T1-17 significantly decreased the root (ranging from 25% to 58%), above-ground tissue (ranging from 13% to 34%), and polished rice (ranging from 45% to 72%) Cd contents as well as Cd bioconcentration factor of the rice compared to the controls. Furthermore, H3 and T1-17 significantly reduced the exchangeable Cd content of the rhizosphere soils compared with the controls. Notably, strain T1-17 had significantly higher ability to reduce Cd bioconcentration factor and polished rice Cd uptake than strain H3. The results demonstrated that H3 and T1-17 decreased the tissue (especially polished rice) Cd uptake by decreasing Cd availability in soil and Cd bioconcentration factor and the effect on the reduced polished rice Cd uptake was dependent on the strains. The results may provide an effective synergistic bioremediation of Cd-contaminated soils in the bacteria and rice plants and bacterial-assisted safe production of rice in Cd-contaminated soils.