Bioflocculant Production Research Articles

Production and characterization of efficient bioflocculant in high-turbidity drinking water treatment: Identification of flocculation-related genes

Bioflocculants are eco-friendly water treatment agents produced by bioflocculant-producing strains that are valuable in drinking water turbidity removal. The major challenges in the application of bioflocculants include low flocculation efficiency, high production costs, and unclear flocculation-related genes. In this study, Pseudomonas sp. ZC-41 a highly efficient bioflocculant-producing strain, was isolated from activated sludge to produce polysaccharide-based bioflocculant MBF-ZC with 94.12% flocculation efficiency under more economical culture conditions, which can solve the problem of low flocculation efficiency. Fourier transform infrared spectra (FTIR) and X-ray photoelectron spectroscopy (XPS) confirmed MBF-ZC contained hydroxyl, carboxyl, and amine groups, crucial for flocculation via adsorption bridging effects as the main flocculation mechanism. The 2393 differentially expressed genes (DEGs) in the transcriptome of strain ZC-41 were classified into five co-expression modules, and the turquoise module was associated with flocculation efficiency and bioflocculant yield. Nineteen flocculation-related genes were identified by combining functional pathways related to sugars. In addition, response surface methodology was optimized to achieve the efficiency of 93.57% for turbidity removal from high-turbidity water by bioflocculant. The results not only provide a solid theoretical foundation to solve the challenges of bioflocculants, but also enrich strategies for high-turbidity drinking water treatment.

Assessment of the bioflocculant production and safety properties of Metabacillus hrfriensis sp. nov. based on phenotypic and whole-genome sequencing analysis

Bioflocculant is considered to have broad application prospect in multi fields for the nontoxic and biodegradation properties. Screening new bioflocculant-producing bacteria with high flocculating activity, stress resistance characteristics, and application security is a significant action in the development of the biofloc technique. A novel bioflocculant-producing species, Metabacillus hrfriensis CT-WN-B3, was isolated from alkali-tolerant strains distributing in Daqing, Heilongjiang Province, China. A strong activity flocculant was detected in the extracellular polymeric substance (EPS) of CT-WN-B3, which could form biofloc more effectively under alkali conditions, with a flocculating rate of more than 70 %. The principal component of the bioflocculant was identified as the polysaccharide of extracellular polymeric substance (EPS) because of its 75.183 ± 2.268 % flocculation contribution, which was very significantly higher than that of the protein and the lipid (p < 0.01). Basing on the whole-genome sequencing analysis of CT-WN-B3, none gene encodes a known virulence factor, but two genes correspond to antibiotic resistance. Antibiotic resistance tests showed CT-WN-B3 was resistant to clindamycin. In the assessment of the antimicrobial spectrum, no antibacterial active substance was detected in the supernatant of CT-WN-B3 culture. Totally, the results of the safety assessment had eliminated the doubts about the application risk of CT-WN-B3. These results indicated that CT-WN-B3 is an alkali-suitable flocculant-producing bacterium for application in multiple fields, under alkali conditions especially.

Isolation and characterization of novel cadmium-resistant Escherichia fergusonii ZSF-15 from industrial effluent for flocculant production and antioxidant enzyme activity.

Cadmium (Cd) is a highly toxic metal that frequently contaminates our environment. In this study, the bioflocculant-producing, cadmium-resistant Escherichia fergusonii ZSF-15 was characterized from Paharang drain, Bawa Chak, Faisalabad, Pakistan. The Cd-resistant E. fergusonii was used to determine the bioflocculant production using yeast-peptone-glycerol medium (pH 6.5) supplemented with 50mg L-1 of Cd. The culture was incubated for 3days at 37°C in a rotary shaker at 120rpm. The fermentation broth was centrifuged at 4000g for 10min after the incubation period. The maximum flocculating activity by isolate ZSF-15 was found to be 71.4% after 48h of incubation. According to the Fourier transform infrared spectroscopy analysis, the bioflocculant produced by strain ZSF-15 was comprised of typical polysaccharide and protein, i.e. hydroxyl, carboxyl, and amino groups. The strain ZSF-15 exhibited bioflocculant activity at range of pH (6-8) and temperature (35-50℃). Maximum flocculation activity (i.e. 71%) was observed at 47℃, whereas 63% flocculation production was observed at pH 8. In the present study, antioxidant enzyme profile of ZSF-15 was also evaluated under cadmium stress. A significant increase in antioxidant enzymes including superoxide dismutase (118%) and ascorbate peroxidase (28%) was observed, whereas contents of catalase (86%), glutathione transferase (13%), and peroxidase (8%) were decreased as compared to control.

Isolation, screening and molecular identification of bioflocculants–producing bacteria

Abstract. Al Khafaji AM, Almansoory AF, Alyousif NA. 2023. Isolation, screening and molecular identification of bioflocculants–producing bacteria. Biodiversitas 24: 4410-4417. Bioflocculants are biological compounds produced by different microorganisms with many applications for wastewater treatment as such become an important product in biotechnology and a consequence to be used in industries. The current study aimed to isolate, identify, and screen bioflocculant-producing bacteria from different sites in Basrah City in Iraq. The production of bioflocculants was enhanced by optimization of various cultural conditions such as (carbon source, nitrogen supply, pH, and inoculum sizes) which were estimated in terms of flocculating activity test. Four wastewater samples and oil- contaminated soil samples were collected. Twenty-one different bacteria were isolated from wastewater and soil. Eleven bacterial isolates showed flocculating activity values of more than 50 %. The results showed that two bacterial isolates were reported as the best bioflocculants-producing isolates with a flocculating activity value of 87.80 % and 81.38 % respectively, these two isolates belonged to Aeromonas simiae and Exiguobacterium profundum which identified by 16S rDNA gene sequencing. Four bacterial isolates were discovered and recorded as new strains in NCBI GenBank with the accession numbers OQ848055 (Escherichia coli strain ANABASR1), OQ848056 (Stutzerimonas balearica strain ANABASR2), OQ848057 (Bacillus jeotgali strain ANABASR3) and OQ848058 (Hydrogenophaga temperata strain ANABASR4). The maximum flocculating activity of 84.49% and 88% was reported for A. simiae and E. profundum respectively under optimum conditions (glucose as carbon source, (NH4)2SO4 as nitrogen source, pH= 7 and 5% inoculum size). The phylogenetic tree was created in the current study based on 16S rDNA gene sequences of bioflocculants –producing bacteria to assess their close relationship and evolution.

Isolation, identification and optimization of exopolysaccharide-based bioflocculant synthesis by soil bacteria Bacillus atrophaeus NR-12

Bioflocculants are polysaccharide-based, biodegradable macromolecules synthesized by soil microorganisms. A bacterium prodicing an extracellular bioflocculant wasisolated from the salty and dry soil and identified as Bacillus atrophaeus. Effects of culture conditions including carbon sources, nitrogen sources, pH, shaker speed on bioflocculant production were studied. Isolate comparative analysis of 16S rRNA sequence identified the isolate to have 99% similarity to Bacillus atrophaeus and it was deposited in the GenBank as Bacillus atrophaeus NR- 2 with accession number OP679007. The strain was characterized by ability to grow and synthesize the bioflocculant in alkaline conditions – pH 11. It was supposed that the strain can overcome adverse effects of environment – alkalinity and salinity by enhanced production of bioflocculant in stress. In the optimized medium (sucrose and tryptone used as C/N sources) the strain produced 4.76 mL bioflocculant.

Isolation, identification and optimization of exopolysaccharide-based bioflocculant synthesis by soil bacteria Bacillus atrophaeus NR-12

Bioflocculants are polysaccharide-based, biodegradable macromolecules synthesized by soil microorganisms. A bacterium prodicing an extracellular bioflocculant wasisolated from the salty and dry soil and identified as Bacillus atrophaeus. Effects of culture conditions including carbon sources, nitrogen sources, pH, shaker speed on bioflocculant production were studied. Isolate comparative analysis of 16S rRNA sequence identified the isolate to have 99% similarity to Bacillus atrophaeus and it was deposited in the GenBank as Bacillus atrophaeus NR- 2 with accession number OP679007. The strain was characterized by ability to grow and synthesize the bioflocculant in alkaline conditions – pH 11. It was supposed that the strain can overcome adverse effects of environment – alkalinity and salinity by enhanced production of bioflocculant in stress. In the optimized medium (sucrose and tryptone used as C/N sources) the strain produced 4.76 mL bioflocculant.

Production of Bioflocculant through Fermentation of Spoilt Orange Juice with Bacillus spp Isolated from Sediment of Local Clay Pot

The biodegradable and non-toxic Bioflocculants have attracted considerable interest as alternative to non-biodegradable chemical flocculants. However, the cost of fermentation media for bioflocculant production and low flocculation efficiency is a major challenge. In this study, we grow Bacillus spp isolated from sediment of local clay pot on spoilt orange juice to produce bioflocculant. The culture supernatant of the bacilli grown on spoilt orange juice were screen for bioflocculant production using Jar test method and Kaolin clay suspension as model wastewater. The effect of pH and temperature on the bioflocculant production were also studied. The effect of cations on bioflocculation rate of the bioflocculant produced were tested via hybridization of the bioflocculant with the cations. The bioflocculation efficiency of the bioflocculant on sample wastewaters were also determined. The bacilli isolated initially had flocculation rate between 31.1±1.6 % to 76.4±1.2% when cultured on screening media. Bioflocculation rate peaked to 77.9% at 40 oC while the lowest flocculation rate (55.41%) was obtained at 25 oC. The optimum bioflocculant production (about 78%) was recorded at pH 6 – 7 while the highest bioflocculant production (84.2%) was achieved at 96th hour of incubation. Na+ and Fe3+ had serious inhibitory effect on the bioflocculant while K+, Ca2+, Mg2+ and Al3+ had less or no effect on the bioflocculant. The bioflocculant had up to 77.7% and 64.5 % on Kitchen wastewater and aquaculture wastewater. This study reveals the potential for utilization of spoilt orange juice as fermentable substrate for bioflocculant production especially if the fermentation conditions and flocculation parameters are well optimized.

Production and characterization of bioflocculant produced by Bacillus subtilis OL818309 and its flocculating effect on harmful algae

Bioflocculation is said to be a biological process where solid particles are separated from liquid suspension with the help of microorganisms. They are preferred to be an alternative to synthetic flocculants as they are non-toxic, eco-friendly and biodegradable compounds. The lower yield and efficacy limit industrial application of microbial flocculants. Hence, it is mandatory to determine a microbial source which had ability to produce bioflocculant at larger quantity with high efficiency. Therefore, it was intended in this study to isolate and identify a potential bioflocculant producing bacterium from Kurichi Lake and characterize the produced bioflocculant. The strain was identified as Bacillus subtilis through 16S rRNA sequencing deposited in the GenBank with accession number OL818309. Optimization of growth parameters for maximal bioflocculation was analyzed. It was found that pH of 7, growth temperature of 35 to 40°C at 48 hours of incubation with inoculum density of 3%, shaking speed of 165 rpm with guar gum as carbon source and yeast extract as nitrogen source aid in highest bioflocculant production. Moreover, batch fermentation was considered as suitable method for industrial scalability of bioflocculant production with a yield of 2.651 g/L. The bioflocculants are characterized by using FTIR, SEM, GC-MS and TGA. The purified bioflocculant was applied on algal polluted water. BOD, COD, TSS and TDS were evaluated. It was observed that 98.20% of flocculation occurred and clear supernatant was obtained. Overall results suggested that this strain has an ability to produce bioflocculants for industrial uses and also for environmental remediation.

Microbial flocculants as an excellent alternative to synthetic flocculants for industrial application: A comprehensive review

Flocculation is used to effectively separate suspended colloids in domestic and industrial wastewater. Flocculants are classified into three categories as organic, inorganic and natural flocculants. Its flocculating properties, ease of use and commercial use have led to the widespread use of organic and inorganic flocculants. However, it can cause serious health problems due to its carcinogenicity and neurotoxicity. Therefore, natural bioflocculants are used to treat wastewater without harming humans and the environment. Natural flocculants are non-toxic, environmentally friendly and capable of flotation even at low concentrations. This article also discusses the classification, functions, mechanisms and applications of flocculants. Applications of natural flocculants and flocculation efficiency in the treatment of industrial wastes such as food, heavy metal and dyeing are discussed. Future studies will use methods to understand how agricultural and food wastes are used for cost-effective bioflocculant production. Bacterial consortia and new novel marine bacteria are indicated for large-scale industrial production.

The last 25 years of research on bioflocculants for kaolin flocculation with recent trends and technical challenges for the future.

The generation of kaolin-containing wastewater is an inevitable consequence in a number of industries including mining, wastewater treatment, and bitumen processing. In some cases, the production of kaolin tailings waste during the production of bitumen or phosphate is as high as 3 times greater than the actual produced product. The existing inventory of nearly five billion barrels of oil sands tailings alone represents a massive storage and reclamation challenge, as well as a significant economic and environmental liability. Current reclamation options like inorganic coagulants and organic synthetic polymers may settle kaolin effectively, but may themselves pose an additional environmental hazard. Bioflocculants are an emerging alternative, given the inherent safety and biodegradability of their bio-based compositions. This review summarizes the different research attempts towards a better bioflocculant of kaolin, with a focus on the bioflocculant source, composition, and effective flocculating conditions. Bacillus bacteria were the most prevalent single species for bioflocculant production, with wastewater also hosting a large number of bioflocculant-producing microorganisms while serving as an inexpensive nutrient. Effective kaolin flocculation could be obtained over a broad range of pH values (1-12) and temperatures (5-95°C). Uronic acid and glutamic acid were predominant sugars and amino acids, respectively, in a number of effective bioflocculants, potentially due to their structural and charge similarities to effective synthetic polymers like polyacrylamide. Overall, these results demonstrate that bioflocculants can be produced from a wide range of microorganisms, can be composed of polysaccharides, protein or glycoproteins and can serve as effective treatment options for kaolin. In some cases, the next obstacle to their wide-spread application is scaling to industrially relevant volumes and their deployment strategies.

A Novel Bioflocculant Produced by Cobetia marina MCCC1113: Optimization of Fermentation Conditions by Response Surface Methodology and Evaluation of Flocculation Performance when Harvesting Microalgae.

A preliminary study was carried out to optimize the culture medium conditions for producing a novel microbial flocculant from the marine bacterial species Cobetia marina. The optimal glucose, yeast extract, and glutamate contents were 30, 10, and 2 g/l, respectively, while the optimal initial pH of the culture medium was determined to be 8. Following response surface optimization, the maximum bioflocculant production level of 1.36 g/l was achieved, which was 43.40% higher than the original culture medium. Within 5 min, a 20.0% (v/v) dosage of the yielded bioflocculant applied to algal cultures resulted in the highest flocculating efficiency of 93.9% with Spirulina platensis. The bioflocculant from C. marina MCCC1113 may have promising application potential for highly productive microalgae collection, according to the findings of this study.

Isolation of a Marine Bacterium and Application of Its Bioflocculant in Wastewater Treatment

Bioflocculation has become the method of choice in wastewater treatment because of its effectiveness, environmental friendliness and innocuousness to humans. In this study, the bioflocculant-producing bacterium was isolated and its bioflocculant was used in wastewater treatment. The isolate was identified by 16S rRNA gene sequencing analysis. Its culture conditions (inoculum size, carbon and nitrogen sources, pH, temperature and time) were optimised using the one-factor-at-a-time assay. The cytotoxicity of the bioflocculant was assessed on human colorectal adenocarcinoma cells (Caco2) by tetrazolium-based colorimetric method. The ability of the bioflocculant to reduce biochemical oxygen demand (BOD) and chemical oxygen demand (COD) in wastewater was evaluated using Jar test. The bacterium was identified as Bacillus subtilis CSM5 and the maximum flocculating activity of 92% was observed when fructose and urea were used as nutrients and the culture conditions were adjusted to 30 °C, pH 9, 160 rpm and 72 h of incubation. Caco2 exhibited 90% viability when the highest bioflocculant concentration of 200 µg/µL was used. The reduction of BOD and COD was achieved at 59 ± 3.1 and 75 ± 0.4%, respectively. In conclusion, B. subtilis CSM5 is a good candidate for bioflocculant production and its bioflocculant has good potential for use in wastewater treatment.

Assessing the effect of multiple variables on the production of bioflocculant by Serratia marcescens: Flocculating activity, kinetics, toxicity, and flocculation mechanism.

Bioflocculants gain attention as alternatives to chemical flocculants because they are more environmentally friendly and highly biodegradable. This study aims to improve the bioflocculant production by Serratia marcescens using one-variable-at-a-time (OVAT) analysis and analyze its flocculating activity performance, toxicity, and the flocculation mechanism. The effect of multiple variables including initial inoculum size, pH, mixing speed, temperature, growth medium, and incubation period was assessed through OVAT. Flocculating activity was then determined via jar test analysis, and toxicity test was performed using Daphnia magna and Daphnia pulex. The flocculation mechanism was determined via particle size distribution and zeta potential analysis. The optimum conditions for the improved bioflocculant production were as follows: 10% v/v initial inoculum size, pH 7, mixing speed of 150 rpm, room temperature, nutrient broth medium, and 72 h of incubation period. Scanning electron microscopy showed flake-like intact structure with coarse surface. The produced bioflocculant showed flocculating activity of 48% in 5227 ± 580 NTU initial kaolin turbidity with 1 mg/L concentration and 5% v/v dosage of bioflocculant, following the second-order kinetics. Toxicity test to D. magna and D. pulex showed the 48 h LC50 values of 8.06 and 6.42 g/L, respectively; these values are greatly higher than the fabricated chemical flocculants. The flocculation process using bioflocculant produced by S. marcescens was suggested to occur via bridging mechanism because it greatly affected the particle size distribution. Results indicated that bioflocculant produced by S. marcescens is much environmentally friendly and has great potential for turbidity removal in water/wastewater.

Production of bioflocculants from spent brewer's yeast and its application in the treatment of effluents with textile dyes

Advances in chemical synthesis have increased the complexity and degradation resistance of dyes used in textile processes. This fact interferes drastically with conventional biological wastewater treatment and demands further methods to avoid environmental damage. In this sense, this work presents a bioflocculant produced by the alkaline hydrolysis of spent brewer's yeast, a residue from the brewing industry, as well as the evaluation of its performance in the precipitation of recalcitrant dyes. The optimum hydrolysis system was accessed by a full 23 factorial design in terms of NaOH concentration, yeast mass, and temperature, followed by a kinetic study. The solid fraction composition of the produced flocculant agent is 46 % of proteins and 29 % of polysaccharides. The performance of the bioflocculant was evaluated in two different systems, real textile wastewater containing rhodamine and a synthetic solution with flavine. The effects of the flocculation variables pH, temperature, agitation, and flocculant agent dosage were taken into consideration. Color removal outcomes above 80 and 90 % were attained for rhodamine and flavine systems, respectively. Further analysis of real textile wastewater for treated and untreated samples in terms of BOD, COD, TOC, and light metals was performed. A biodegradability test showed the employed treatment could increase microbial assimilation of the sample and reduce its persistent compounds. This work shows, for the first time, the feasibility of the bioflocculant from spent brewer's yeast and features its potential applicability to recalcitrant compounds precipitation in textile wastewaters.

ISOLATION AND IDENTIFICATION OF EXOPOLYSACCHARIDE-BASED BIOFLOCCULANT OF SOIL BACTERIA BACILLUS SIMPLEX PBB-17

Bioflocculation is a dynamic process resulting from the synthesis of extracellular polymer by living cells. In this study it was researched production, characterization and practical application of exopolysaccharide-based bioflocculant by a novel bacterial strain Bacillus simplex PBB-17 isolated from saline soil. Comparative analysis of 16S rRNA sequence identified the isolate to have 99% similarity to Bacillus simplex and it was deposited in the GenBank as Bacillus simplex PBB-17 with accession number MH165385. In addition, FTIR spectrum was obtained for partial characterization of the exopolysaccharides synthesized by Bacillus simplex PBB-17.

Production of bioflocculant from Klebsiella pneumoniae: Evaluation of fish waste extract as substrate and flocculation performance

The bioflocculant producing bacterial strain – UKD24 was isolated from the domestic sewage treatment plant. The isolated strain was identified as Klebsiella pneumoniae by using 16S rRNA gene sequencing. The K. pneumoniae UKD24 showed remarkable flocculation rates when grown with the carbon sources namely glucose, sucrose and lactose, and many commercial nitrogen sources. Furthermore, the fish waste extract (FE) was used to enhance the productivity of the bioflocculant as a nitrogen supplement and it showed significant level of flocculation rate similar to the commercial nitrogen sources. The Box-Behnken experiments were designed to predict the optimal conditions for bioflocculant production and it suggested that glucose - 3.247 g L-1, FE - 0.5 g L-1 and inoculum size - 1% are the suitable levels for bioflocculant production. The FTIR analysis of the bioflocculant showed the functional groups related to the polysaccharides and the EEM analysis showed the fluorescence components related to the proteins and humic acids. The biochemical composition of the bioflocculant was identified as polysaccharides (24.36 ± 1.5%) and protein (12.15 ± 0.2%). The tested optimum conditions of the bioflocculant to induce flocculation were tested in the kaolin wastewater and it showed the optimum dosage of flocculant was 5 mg L-1 and the pH range was broad as 5 to 10. The cation dependency tests revealed that the monovalent and divalent cations are highly suitable for flocculation while the trivalent cations showed a moderate flocculation. The Cr(VI) removal efficiency of the bioflocculant showed that ∼35% of heavy metal is trapped into flocks during the flocculation.

Production and Optimization of Bioflocculant isolated from bacteria

Production and Optimization of Bioflocculant isolated from bacteria

Production of polysaccharide bioflocculants and gene co-expression network analysis in a biomass-degrading bacterium, Pseudomonas sp. GO2

Several bacteria exhibit reveal excellent production ability of bioflocculants through directly utilizing untreated biomass. However, mechanisms of bioflocculant synthesis in these bacteria remain to be fully clarified. In this study, a biomass-degrading bacterium Pseudomonas sp. GO2 produced a polysaccharide bioflocculant with the maximal flocculating efficiency of 91.5% when corn stover was used as the sole carbon source. To investigate the molecular mechanism of bioflocculant production, the transcriptome of GO2 strain was measured. Using pairwise comparisons and WGCNA analysis, a total of 1032 differentially expressed genes (DEGs) were successfully divided into four co-expression modules. Among them, one specific module (turquoise) was closely associated with CMCase and xylanase activities, and two modules (brown and yellow) were significantly related to the flocculating efficiency. Finally, DEGs related to seven CAZymes and eight secretory proteins were identified as key candidate genes, and seven potential gene clusters associated with these genes may play important roles in biomass degradation and bioflocculant synthesis in GO2 strain. The results not only enrich genomic resource but also provides a solid theory foundation for the rational synthesis of high efficient and low cost bioflocculants.

The potency of microbial flocculant produced by B. licheniformis using molasses as the carbon source and its application in food industry wastewater treatment

Flocculants play an important role in removing colloids, suspended particles, and dyes from industrial wastewater. Presently, synthetic flocculants have been widely applied in the industrial sector as colloidal aggregates. The use of these flocculants is known to harm human health and the environment for them being neurotoxic, strong carcinogens, and cannot be degraded by microbes. Therefore, bio-flocculants are an alternative to reduce the usage of synthetic flocculants. Moreover, studies on the application of food industry wastewater as food ingredients are increasingly being developed. It is estimated that the need for safe and biodegradable flocculants will also increase. This study was conducted to examine the production of bio-flocculants from Bacillus licheniformis using molasses as a carbon source under different molasses concentrations (15 g/l and 30 g/l) and incubation times (24, 48 and 72 h). The bio-flocculant from B. licheniformis was then applied to treat tofu industry wastewater for turbidity removal, reduction of Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD). The highest flocculation rate of bio-flocculant was achieved at 46,62% to kaolin suspension by 15 g/l molasses within 24 h culture time. On the purification of tofu industry wastewater, the efficiency of turbidity removal of 15 g/l and 30 g/l molasses concentration variations were 70.03% and 43.04% respectively. Bio-flocculant produced also performed great BOD and COD removal by 75.9% and 80.2% which proceed by variation of 15 g/l molasses within 24 h incubation time. These high rate of turbidity, COD, and BOD removal by bio-flocculant indicates its effectiveness on industrial application in wastewater treatment.

Optimal production of bioflocculant from Pseudomonas sp. GO2 and its removal characteristics of heavy metals

Bioflocculant may be a promising bioactivator for heavy metal removal duo to its eco-friendly properties and remarkable ability to adsorb heavy metals. In this study, bioflocculant production from a bacterium, Pseudomonas sp. GO2, was optimized and its removal efficiency for two heavy metal ions was evaluated. Results demonstrated that the maximal flocculation efficiency was achieved with concentration levels of 5 g/L glucose, 3 g/L casein, and 5 g/L NaCl, with an initial pH of 9.0, and a fermentation time of 48 h. Bioflocculant produced by GO2 had a stronger removal efficiency for Cd2+ than that of Pb2+, with highest removal efficiencies of 85.38% and 80.87%, respectively. The adsorption process was mainly dependent on the monolayer and chemisorption based on the adsorption isotherm and kinetic models. This study demonstrated that bioflocculant produced by the GO2 strain has the potential to be used in heavy metal treatment from industrial wastewater.