Role of Ni-tolerant Bacillus spp. and Althea rosea L. in the phytoremediation of Ni-contaminated soils

In our current study, four nickel-tolerant (Ni-tolerant) bacterial species viz, Bacillus thuringiensis 002, Bacillus fortis 162, Bacillus subtilis 174, and Bacillus farraginis 354, were screened using Ni-contaminated media. The screened microbes exhibited positive results for synthesis of indole acetic acid (IAA), siderophore production, and phosphate solubilization. The effects of these screened microbes on Ni mobility in the soil, root elongation, plant biomass, and Ni uptake in Althea rosea plants grown in Ni-contaminated soil (200 mg Ni kg^?1) were evaluated. Significantly higher value for water-extractable Ni (38 mg kg^?1) was observed in case of Ni-amended soils inoculated with B. subtilis 174. Similarly, B. thuringiensis 002, B. fortis 162, and B. subtilis 174 significantly enhanced growth and Ni uptake in A. rosea. The Ni uptake in the shoots and roots of B. subtilis 174-inoculated plants enhanced up to 1.7 and 1.6-fold, respectively, as compared to that in the un-inoculated control. Bacterial inoculation also significantly improved the root and shoot biomass of treated plants. The current study presents a novel approach for bacteria-assisted phytoremediation of Ni-contaminated areas.     

Effect of bacterial inoculation of strains of pseudomonas aeruginosa,alcaligenes feacalis and bacillus subtilis on germination,growth and heavy metal (cd,cr, and ni) uptake of brassica juncea

Bacterial inoculation may influence Brassica juncea growth and heavy metal (Ni, Cr, and Cd) accumulation. Three metal tolerant bacterial isolates (BCr3, BCd33, and BNi11) recovered from mine tailings, identified as Pseudomonas aeruginosa KP717554, Alcaligenes feacalis KP717561, and Bacillus subtilis KP717559 were used. The isolates exhibited multiple plant growth beneficial characteristics including the production of indole-3-acetic acid, hydrogen cyanide, ammonia, insoluble phosphate solubilization together with the potential to protect plants against fungal pathogens. Bacterial inoculation improved seeds germination of B. juncea plant in the presence of 0.1 mM Cr, Cd, and Ni, as compared to the control treatment. Compared with control treatment, soil inoculation with bacterial isolates significantly increased the amount of soluble heavy metals in soil by 51% (Cr), 50% (Cd), and 44% (Ni) respectively. Pot experiment of B. juncea grown in soil spiked with 100 mg kg^?1 of NiCl₂, 100 mg kg^?1 of CdCl₂, and 150 mg kg^?1 of K₂Cr₂O₇, revealed that inoculation with metal tolerant bacteria not only protected plants against the toxic effects of heavy metals, but also increased growth and metal accumulation of plants significantly. These findings suggest that such metal tolerant, plant growth promoting bacteria are valuable tools which could be used to develop bio-inoculants for enhancing the efficiency of phytoextraction.     

Does the lichen mat alleviate the effects of wet deposited nickel on soil microorganisms and Scots pine (Pinus sylvestris L.) seedlings?

A field experiment was conducted in a dry heath forest dominated by Scots pine (Pinus sylvestris L.) and a mat-forming lichen (Cladina stellaris (Opiz) Brodo) to assess the effect of wet-deposited nickel (Ni) on pine seedlings and soil microorganisms, and to explore whether an intact lichen mat could act as a buffer against heavy metal deposits. Pine seedlings were planted in quadrats covered by a natural lichen layer and in quadrats from which the lichen layer had been completely removed. The quadrats were exposed to four levels of Ni deposition: 0 (i.e., distilled water), 10, 100 and 1000 mg m^–2 year^–1 in two growing seasons. Increasing Ni deposition led to an increase in the Ni content of the needles, roots and the soil organic layer. The lichen mat reduced Ni flow to the organic soil layer, but had no significant, reducing effect on needle or root Ni concentration. The most severe Ni treatment had detrimental effects on seedling growth and increased peroxidase activity in the previous years needles. Removal of the lichen layer did not increase susceptibility of seedlings to Ni. Values of maximal carbon use efficiency (Max) and metabolic quotient (qCO₂) of the soil microorganisms indicated protective value of the lichen mat to soil microorganisms at the highest Ni treatment. Skimming per se decreased basal respiration, qCO₂ and concentrations of potassium in the soil and also increased the lag period of the microorganisms as a response to in situ substrate addition.     

Heterologous expression of the novel α-helical hybrid peptide PR-FO in Bacillus subtilis

PR-FO is a novel α-helical hybrid antimicrobial peptide (AMP) with strong antimicrobial activities and high stability, and the potential to develop into a new generation of antimicrobial agents. In this study, the encoded gene sequence of SMT3-PR-FO was designed and transformed into B. subtilis WB800N. Fusion proteins with concentrations of 16 mg L⁻¹ (SP_amyQ) and 23 mg L⁻¹ (SP_sacB) were obtained after purification by a Ni–NTA resin column. A total of 3 mg (SP_amyQ) and 4 mg (SP_sacB) of PR-FO with a purity of 90% was obtained from 1 L fermentation cultures. Recombinant PR-FO exhibited high inhibition activities against both gram-negative bacteria and gram-positive bacteria, and low haemolytic activity against human red blood cells. These results indicated that the rSMT3-PR-FO could be expressed under the guidance of SP_amyQ and SP_sacB, and the maltose-induced expression strategy might be a safe and efficient method for the soluble peptides production in B. subtilis.

     

Biobleaching of banana fibre pulp using <Emphasis Type="Italic">Bacillus subtilis</Emphasis> C O1 xylanase produced from wheat bran under solid-state cultivation

A cellulase-free xylanase produced by Bacillus subtilis C 01 from wheat bran under solid-state cultivation was tested for its efficacy in biobleaching of raw banana fibre and banana pulp obtained through a mechanical pulping process. Banana pulp samples treated with crude xylanase (450 nkat g⁻¹ pulp) resulted in a 19.6% increase in the brightness as compared to untreated pulp. The presence of chromophores, hydrophobic compounds and an increased reducing sugar (10.79 mg g⁻¹ pulp) quantity in the bleached solution after enzymatic treatment indicated the removal of materials that were absorbed at 237 nm from the banana pulp.     

Isolation and Identification of Polycyclic Aromatic Hydrocarbon–Degrading Bacteria from Crude Oil Exploration Bore Well Sludge

Two bacterial strains capable of degrading polycyclic aromatic hydrocarbons were isolated from the crude oil exploration bore well sludge and identified by 16s rRNA gene sequencing as Pseudomonas stutzeri and Bacillus subtilis. The bacterial strains Pseudomonas stutzeri and Bacillus subtilis were able to degrade 95.1% and 99.4% of naphthalene (100 mg L^?1) and 99.5% and 94.6% of anthracene (50 mg L^?1), respectively, as a sole carbon and energy source in the liquid phase within a period of 6 days. The specific growth rate was determined for both the species and found to be 0.169 and 0.124 day^?1.     

Contrasting Effects of Farmyard Manure (FYM) and Compost for Remediation of Metal Contaminated Soil

We investigated effect of farm yard manure (FYM) and compost applied to metal contaminated soil at rate of 1% (FYM-1, compost-1), 2% (FYM-2, compost-2), and 3% (FYM-3, compost-3). FYM significantly (P < 0.001) increased dry weights of shoots and roots while compost increased root dry weight compared to control. Amendments significantly increased nickel (Ni) in shoots and roots of maize except compost applied at 1%. FYM-3 and -1 caused maximum Ni in shoots (11.42 mg kg^?1) and roots (80.92 mg kg^?1), respectively while compost-2 caused maximum Ni (14.08 mg kg^?1) and (163.87 mg kg^?1) in shoots and roots, respectively. Plants grown in pots amended with FYM-2 and compost-1 contained minimum Cu (30.12 and 30.11 mg kg^?1) in shoots, respectively. FYM-2 and compost-2 caused minimum zinc (Zn) (59.08 and 66.0 mg kg^?1) in maize shoots, respectively. FYM-2 caused minimum Mn in maize shoots while compost increased Mn in shoots and roots compared to control. FYM and compost increased the ammonium bicarbonate diethylene triamine penta acetic acid (AB-DTPA) extractable Ni and Mn in the soil and decreased Cu and Zn. Lower remediation factors for all metals with compost indicated that compost was effective to stabilize the metals in soil compared to FYM.     

The Sociedad Minera Pudahuel bacterial thin-layer leaching process at Lo Aguirre

The thin-layer leaching process originally conceived and developed for leaching oxide ores has been successfully adapted to bacterial leaching of mixed and secondary sulphide ores. The process is currently being applied at the Socicdad Minera Pudahuel Lo Aguirre Plant. About 3000 ton of ore per day are being processed to produce 14000 ton of high-grade copper cathodes per year, in a closed circuit integrated with SX-EW. Changes in the soluble copper grade of the ore from about 1.8C4 to (I.6% have occurred during the last years, which have been compensated by an equivalent increase in the insoluble copper grade. In addition, ore from satellite ore bodies has resulted in acid consumption variations ranging from 611 to 120 kg H₂SO₄ per ton of ore. The main sulphide mineralogical species are chatcocite and bornite, with small amounts of chalcopyrite and covellite. An intensive research program in columns and large-scale heaps has been carried out to define the operating conditions which assure adequate bacterial growth and bacterial activity towards the sulphides. Agglomerated ores with 1.7 2.5% Cur and (I.3-0.6%: Cus, with the insoluble copper mainly present as chalcocite bornite, were leached at a flow rate of 0.2 1 min¹ mu² with a SX-Raffinate solution containing (in g^-1) 5–10 H₂SO₄, 2–4 Fe_T, 1–3 Fe⁺³, 0.5 Cu, as well as impurities resulting from a closed circuit operation. Copper recoveries of 75 85% Cu_T were obtained after 180–250 days of total leaching time, depending on the copper grade, the mineralogical composition, and the acid consumption of the ore. Important bacterial activity was detected. About 10 ³−10⁵ bacteria ml⁻¹ were measured in effluent solutions. Iron oxidation rates of 7–100μg Fe²⁺ h⁻¹ g⁻¹, measured from respirometric tests on agglomerated ore, suggest that an adsorbed biomass of about 10⁷-10⁸ bacteria g⁻¹ must also be present. Further applications of the bacterial thin-layer leaching process to Cerro Colorado and Qucbrada Blanca ores in North Chile are being studied.     

Metal-Dependent Root Iron Plaque Effects on Distribution and Translocation of Chromium and Nickel in Yellow Flag (Iris pseudacorus L.)

Iris pseudacorus L. (yellow flag) is a wide-use wetland plant for constructed wetlands for removing metals from wastewater. This study aims to understand effects of root iron plaque on sequestration and translocation of Cr and Ni in yellow flag seedlings using a hydroponic experiment. Yellow flag seedlings (4-week-old seedlings with 4–6 leaves) with or without iron plaque induction (at 50 mg Fe²⁺ L^?1 for 72 hours) were spiked for 6 days in the Hoagland solution with Cr or Ni at 0.5, 5, and 50 mg L^?1, equivalent to 1, 10, 100 times of thresholds of surface water quality, respectively. Results indicated that root iron plaque significantly reduced translocation of Cr and Ni to root but increased from root to shoot. Root iron plaque formation counteracted Cr toxicity to yellow flag seedlings while the control showed Cr toxicity to root at 5 mg L^?1and to shoot at 50 mg L^?1 with significant biomass loss. Neither Ni exposures caused significant biomass loss nor root iron plaque formation significantly changed Ni distribution among plant parts. Our study suggests that root iron plaque effects on metal sequestration and translocation in yellow flag seedlings were metal-dependent.     

Phytoremediation of Cd,Ni, Pb and Zn by Salvinia minima

Most metals disperse easily in environments and can be bioconcentrated in tissues of many organisms causing risks to the health and stability of aquatic ecosystems even at low concentrations. The use of plants to phytoremediation has been evaluated to mitigate the environmental contamination by metals since they have large capacity to adsorb or accumulate these elements. In this study we evaluate Salvinia minima growth and its ability to accumulate metals. The plants were cultivated for about 60 days in different concentrations of Cd, Ni, Pb and Zn (tested alone) in controlled environmental conditions and availability of nutrients. The results indicated that S. minima was able to grow in low concentrations of selected metals (0.03 mg L^?1 Cd, 0.40 mg L^?1 Ni, 1.00 mg L^?1 Pb and 1.00 mg L^?1 Zn) and still able to adsorb or accumulate metals in their tissues when cultivated in higher concentrations of selected metals without necessarily grow. The maximum values of removal metal rates (mg m² day^?1) for each metal (Cd = 0.0045, Ni = 0.0595, Pb = 0.1423 e Zn = 0.4046) are listed. We concluded that S. minima may be used as an additional tool for metals removal from effluent.     

Microbial and enzymatic improvement of anaerobic digestion of waste biomass

Metabolic activities of different microorganisms (Bacillus subtilis, B. licheniformis and Aspergillus niger) and hydrolytic enzymes (concentrations: 1 to 200 mg enzyme solids g^–1 feed) were studied individually and in combinations with respect to H₂ and methane production from damaged wheat grains. Bacillus subtilis, B. licheniformis and pre-existing hydrogen producers (control) produced 45 to 64 l H₂ kg^–1 total solids and subsequently, with the help of added methanogens, 155 to 220 l methane kg^–1 total solids could be produced. H₂ production from damaged wheat grains could be decreased to 28% or enhanced up to 152% with respect to control, by employing various microbial and enzymatic treatments. Similarly, it has been made possible to vary methane production capacities from as low as 17% to as high as 110% with respect to control.     

Inhibitory Activity of Probiotic <Emphasis Type="Italic">Bacillus subtilis</Emphasis> UTM 126 Against <Emphasis Type="Italic">Vibrio</Emphasis> Species Confers Protection Against Vibriosis in Juvenile Shrimp (<Emphasis Type="Italic">Litopenaeus vannamei</Emphasis>)

The bacterial strain Bacillus subtilis UTM 126 produced antimicrobial activity against pathogenic Vibrio species, including V. alginolyticus, V. parahaemolyticus, and V. harveyi. The probiotic effect of B. subtilis was tested by feeding juvenile shrimp (Litopenaeus vannamei) food supplemented with B. subtilis (10⁵ CFU/g) for 28 days before an immersion challenge with V. harveyi at 10⁵ CFU/mL for 24 h. The treatment with B. subtilis UTM 126 decreased final mortality to 18.25%, compared with 51.75% in the control group. Bacillus subtilis UTM 126 has potential applications for controlling pathogenic V. harveyi in shrimp aquaculture.     

Potency of Bacillus thuringiensis and Bacillus subtilis against the cotton leafworm,Spodoptera littoralis (Bosid.) Larvae

The biological activities of two species of bacteria isolated from soil of cotton fields identified as Bacillus subtilis strain NRC313 (BS NRC313) and Bacillus thuringiensis strain NRC335 (BT NRC335) were evaluated against the third larval instar of the cotton leafworm, Spodoptera littoralis (Boisd.). The different entomopathogenic bacteria of BS NRC313and BT NRC335 contained 10 × 10⁸ cell/ml, and caused mortality of 100 and 97.3% for the above mentioned strains, respectively. Concentrations of 2.5 × 10⁸ to 10 × 10⁸ cell/ml of strains BS NRC313 and BT NRC335 were applied to the larvae: LC₅₀ were 3.3 × 10⁸ and 3.9 × 10⁸ cell/ml respectively. The influence of exposure to toxin concentrations manifested in terms of decreasing the adult emergence and prolongation of the generation period. The percentage of larvae that survived and succeeded to pupate increased by decreasing the concentration. The longevity of adult emergence that resulted from larvae treated with Bacillus subtilis were 6.0 ± 0.51 and 9.0 ± 0.63 days at 5 × 10⁸ and 2.5 × 10⁸ cell/ml, respectively compared with 9.8 ± 0.47 in control. The results indicated that Bacillus subtilis was more potent than Bacillus thuringiensis. Field applications of B. thuringiensis, B. subtilis and Reldan achieved 55.6, 67.4 and 89.4% reduction of the cotton leafworm larvae Spodoptera littoralis in clover plants under field conditions.     

Regression model,artificial neural network,and cost estimation for biosorption of Ni(II)-ions from aqueous solutions by Potamogeton pectinatus

This study investigated the application of Potamogeton pectinatus for Ni(II)-ions biosorption from aqueous solutions. FTIR spectra showed that the functional groups of –OH, C–H, –C = O, and –COO– could form an organometallic complex with Ni(II)-ions on the biomaterial surface. SEM/EDX analysis indicated that the voids on the biosorbent surface were blocked due to Ni(II)-ions uptake via an ion exchange mechanism. For Ni(II)-ions of 50 mg/L, the adsorption efficiency recorded 63.4% at pH: 5, biosorbent dosage: 10 g/L, and particle-diameter: 0.125–0.25 mm within 180 minutes. A quadratic model depicted that the plot of removal efficiency against pH or contact time caused quadratic-linear concave up curves, whereas the curve of initial Ni(II)-ions was quadratic-linear convex down. Artificial neural network with a structure of 5 – 6 – 1 was able to predict the adsorption efficiency (R²: 0.967). The relative importance of inputs was: initial Ni(II)-ions > pH > contact time > biosorbent dosage > particle-size. Freundlich isotherm described well the adsorption mechanism (R²: 0.974), which indicated a multilayer adsorption onto energetically heterogeneous surfaces. The net cost of using P. pectinatus for the removal of Ni(II)-ions (4.25 ± 1.26 mg/L) from real industrial effluents within 30 minutes was 3.4 $USD/m³.     

EBR预处理对盐胁迫下葡萄幼苗叶片抗氧化物质及酶活性的影响

以2年生葡萄(Vitis vinifera L.)酿酒品种赤霞珠扦插苗为材料,在水培条件下,分别用0、0.05、0.10和0.20mg/L 24-表油菜素内酯(EBR)预处理幼苗,然后进行50mmol/L NaCl胁迫,分别在胁迫6d和12d测定幼苗叶片中超氧阴离子(O_2~)、丙二醛(MDA)、抗氧化物质含量以及相关酶活性,探讨EBR预处理对葡萄幼苗耐盐性的影响。结果表明:与单独盐胁迫处理相比,不同浓度的EBR预处理使盐胁迫葡萄幼苗叶片O_2~和MDA含量显著降低,同时使其抗氧化物质抗坏血酸(AsA)、脱氢抗坏血酸(DHA)、还原型谷胱甘肽(GSH)和氧化型谷胱甘肽(GSSG)含量以及抗坏血酸过氧化物酶(APX)、谷胱甘肽还原酶(GR)、超氧化物歧化酶(SOD)活性显著升高;其中,0.10mg/L EBR预处理的表现最佳,在盐胁迫12d时,其葡萄叶O_2~和MDA含量比单独盐胁迫处理分别显著降低30.5%和22.0%,其叶片相应AsA和GSH的含量较单独盐胁迫处理分别显著提高82.8%和27.9%,且GR、APX和SOD活性分别显著提高7.2%、8.5%和24.0%。研究发现,在盐胁迫条件下,适宜浓度的外源BRs预处理能够显著降低葡萄叶片中活性氧含量,提高抗氧化物质含量和抗氧化酶活性,以促进AsA-GSH循环的快速有效运转,有效减轻植株的过氧化伤害,缓解盐胁迫对葡萄幼苗的伤害,提高葡萄的耐盐性。     

Biogenic production of cyanide and its application to gold recovery

Chromobacterium violaceum is a cyanogenic (cyanide-producing) microorganism. Cyanide is used on an industrial scale to complex and recover gold from ores or concentrates of ores bearing the precious metal. A potentially useful approach in gold mining operations could be to produce cyanide biologically in relatively small quantities at the ore surface. In this study, C. violaceum grown in nutrient broth formed a biofilm and could complex and solubilize 100% of the gold on glass test slides within 4–7 days. Approximately 50% of the cyanide-recoverable gold could be mobilized from a biooxidized sulfidic-ore concentrate. Complexation of cyanide in solution by gold appeared to have a beneficial effect on cell growth — viable cell counts were nearly two orders of magnitude greater in the presence of gold-coated slides or biooxidized ore substrates than in their absence. C. violaceum was cyanogenic when grown in alternative feedstocks. When grown in a mineral salt solution supplemented with 13.3% v/v swine fecal material (SFM), cells exhibited pigmentation and suspended cell concentrations comparable to cultures grown in nutrient broth. Glycine supplements stimulated production of cyanide in 13.3% v/v SFM. In contrast, glycine was inhibitory when added at the time of inoculation in the more concentrated SFM, decreasing cell numbers and reducing ultimate bulk-solution cyanide concentrations. However, aeration and addition of glycine to stationary phase cells grown on 13.3% v/v SFM anaerobically resulted in rapid production and high concentrations (up to 38 mg l⁻¹) of cyanide. This indicates that biogenesis of cyanide may be supported in remote areas using locally produced and inexpensive agricultural feedstocks in place of commercial media. Journal of Industrial Microbiology & Biotechnology (2001) 26, 134–139. Received 06 June 2000/ Accepted in revised form 30 September 2000     

Evaluation of the antimutagenic potential of chitosan oligosaccharide: Rec, Ames and Umu tests

Two types of chitosan oligosaccharides (COS), COS I (1-kDa < MW < 3-kDa) and COS II (3-kDa < MW < 5-kDa), were tested for antimutagenic activities against chemical mutagens using Umu gene expression, Ames, and Bacillus subtilis Rec mutagenicity tests. At the highest chitosan oligosaccharide dose (1 mg) tested, mutagenic activity of indirect-acting mutagen was inhibited by 50% in the Umu gene expression system and in the Ames test. Chitosan oligosaccharide (0.01, 0.1 and 1 mg) also suppressed 4-nitroquinoline-N-oxide (NQO)-induced mutagenicity in the B. subtilis Rec^– assay.     

Microbial community study of the iron ore concentrate of the Sishen Iron Ore Mine, South Africa

As a result of the advancing global technologies and civilisation, there has been a progressive depletion of high-grade mineral deposits. Consequently, it has become increasingly important to process lower-grade ores. Phosphorous (P) and particular potassium (K) contained in the iron ore concentrates of the Sishen Iron Ore Mine have a detrimental effect on the steel making process, whereby these alkali’s cause cracks to form in the refractory lining of blast furnaces. It is initially essential to determine which microbes are indigenously present at the Sishen Iron Ore Mine before strategising how best to employ them to industrial advantage. Therefore, the objective of this study was to determine which microorganisms are indigenous to the iron ore and soil of the Sishen Iron Ore Mine. The bacterial 16S PCR and fungal ITS PCR revealed several bacterial and fungal species present in the mine environment. The bacterial isolates were found to be closely related to Herbaspirillum species, as well as Acidithiobacillus ferrooxidans, while the fungal isolates were closely related to Aureobasidium pullulans, Phaeosphaeria nodorum, Aspergillus fumigatus, and Candida parapsilosis. Isolating A. fumigatus from the iron ore/soil of the mine may indicate that A. niger, the most common fungi used for the production of citric acid, can adapt to the stringent mine environment. This would allow the application of A. niger for the production of citric acid, which may be used for the chemical leaching of the P and K from the iron ore concentrate of the Sishen Iron Ore Mine.     

Combined effect of chemical fertilisers and rhizosphere-competent Bacillus subtilis BSK17 on yield of Cicer arietinum

A chemical fertiliser-adaptive variant, Bacillus subtilis BSK17, showed induction in growth at 0.32?M of Urea, 0.05?M of DAP, 0.04?M of MoP and 0.08 of gypsum. In addition, B. subtilis BSK17 produced various plant growth-promoting substances and showed higher colony growth inhibition of Fusarium oxysporum that increased with increase in incubation time and reached the maximum by 78% at 120?h. In field, antibiotic-resistant marker strains of B. subtilis BSK17^ery+ and B. subtilis BSK17^tet+ showed more improvement in seed yield (90% than the control and 24% than full dose of chemical fertilisers) of Cicer arietinum when applied with half dose of chemical fertilisers (N₅₊₅P₁₅₊₁₅K₁₅S_10+10+10). Root length, shoot length, fresh and dry weight of root and shoot of plants were enhanced after 120?days in comparison to control; all values were significant at 1% CD. The strain significantly colonised the rhizosphere of C. arietinum by 6.64 log cfu after 120?days.     

Biosorption of nickel (II) from effluent of electroplating industry by immobilized cells of Bacillus species

In this study, Ni (II) biosorption capacity of immobilized cells of Bacillus sp. was investigated. Biosorption of Ni (II) was carried out in batch experiments and the important environmental conditions were optimized. The uptake of metal was rapid, and equilibrium was attained within 270 min. Bacillus strains (ten cultures) were isolated from nickel electroplating effluent by heat shock method. These isolates were grown up in nutrient broth supplemented with Ni (II)(50 mg/L). The culture, exhibiting maximum biosorption capacity (q^max: 118 mg/g), was selected and labeled Bacillus Bio‐4. In order to develop an economical biosorption process cell mass of Bacillus, Bio‐4 was immobilized in Na‐alginate. It was concluded from the results that biosorption of nickel is highly dependent on the type of sorbent and experimental conditions employed. Our results demonstrate that 6.0 mg immobilized cells (18 mg cell biomass in 3.0 mL of 1% Na alginate) had a maximum biosorption capacity of 113 mg Ni(II) per liter of suspension at pH 8.0, 100 rpm and 25°C. The Ni (II) removal was estimated to be 97.4%.