Synthesis of silver nanoparticles using bacterial exopolysaccharide and its application for degradation of azo-dyes

Saravanan, Chinnashanmugam; Rajesh, Rajendiran; Kaviarasan, Thanamegam; Muthukumar, Kaliappan; Kavitake, Digambar; Shetty, Prathapkumar Halady

doi:10.1016/j.btre.2017.02.006

Cited by 154 publications

(52 citation statements)

References 36 publications

(46 reference statements)

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“…Also, EPS play an important role in mass transfer via biofilm, in adsorption of different metals and organic/inorganic compounds by the biofilm, and, most importantly, in providing structural support to the biofilm (i.e., resistance to shear) [9][10][11]. They are used in a wide variety of industrial applications, including food, textile dye removal from water, pharmaceutical, emulsifiers, stabilizers, bio-nanotechnology, metal removal and recovery, removal of toxic organic compounds and soil remediation [12][13][14][15][16][17]. It is very important to understand the structure of EPS in order to use them in these areas.…”

Section: Introductionmentioning

confidence: 99%

Characterization and Production of Extracellular Polysaccharides (EPS) by Bacillus Pseudomycoides U10

et al. 2018

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We aimed to determine the effect of Luria-Bertani (LB) medium, nutrient broth (NB) and tryptic soy broth (TSB), pH, temperature, and incubation time on the production of extracellular polysaccharides (EPS). The effect of glucose, whey and glycerol on bacterial EPS production by Bacillus pseudomycoides U10 was also tested. LB was better than NB and TSB for EPS production. Maximum EPS production was obtained when 1 g/L whey was added to the growth medium. The influence of incubation times (24-96 h), different pH values (6.5, 7.0, 7.5, 8.0 and 9.0) and temperature (25, 30, 37 and 45 • C) were also tested. The optimum pH level was 7.0 and the highest EPS production was observed at 37 • C after 60 h of incubation. Glycerol was not a good carbon source for cell growth and EPS production. The difference in carbohydrate and protein amount was related to the different types of EPS (dissolved and particulate). In general, the uronic acid content in particulate EPS was lower than in dissolved EPS. The maximum uronic acid was obtained from dissolved EPS (16 mg uronic acid/g EPS). According to X-ray diffraction (XRD), thermogravimetric EPS have a poorly crystalline nature and exhibit two-step degradations, corresponding to the weight loss of moisture and/or carboxyl group and the pyrolysis of EPS, without distinctive changes in different media conditions. Small-angle X-ray scattering (SAXS) data indicate the layer thickness of the bacterial EPS is from 12.04 to 14.07 Å for whey and dissolved LB conditions, respectively. It was found that EPS structures changed with whey addition, such as higher d-values, lower weight losses and more filamentous structures which seemed to be related to increasing durability and/or stability.

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Section: Introductionmentioning

confidence: 99%

Characterization and Production of Extracellular Polysaccharides (EPS) by Bacillus Pseudomycoides U10

et al. 2018

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“…By far, the most investigated variable influencing the biosynthesis of AgNP is reaction duration, typically in the range of minutes (51,57) to days (38,58,59). As expected, the longer the duration, the more and potentially larger particles are produced.…”

Section: Incubation Timementioning

confidence: 78%

“…The occurrence of these changes is not understood. (23,38,42,50,51,55,(57)(58)(59)(60)(61) The shape and relative size of the nanoparticles produced are shown. If more than one report exists for a given organism, the average has been used.…”

Section: Incubation Timementioning

confidence: 99%

“…(110,128,136) While 1 mM AgNO3 is typical, (58,67,80,90,111,130) concentrations of 9 mM or higher have been used. (23,59,68) However, as the reduction of Ag + is thought to be a method of detoxifying Ag, it is logical to presume that once the reduction system is saturated any excess Ag + will have toxic effects on the cell, that is, there must be an upper limit that the systems can handle. Such toxicity would be detrimental to the enzymatic activity of the mechanism leading to a decrease in reduction activity, and will likely be species dependent.…”

Section: Silver Substratementioning

confidence: 99%

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Bacteria and nanosilver: the quest for optimal production

Mabey

Cristaldi

Oyston

et al. 2019

Critical Reviews in Biotechnology

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Silver nanoparticles (AgNPs) have potential uses in many applications, but current chemical production methods are challenged by scalability, limited particle stability, and the use of hazardous chemicals. The biological processes present in bacteria to mitigate metallic contaminants in their environment present a potential solution to these challenges. Before commercial exploitation of this technology can be achieved, the quality of bacteriogenic AgNPs needs to be improved for certain applications. While the colloidal and morphological stabilities of biogenic AgNPs are widely regarded as superior to chemogenic particles, little control over the synthesis of particle morphologies has been achieved in biological systems. This article reviews a range of biosynthetic reaction conditions and how they affect AgNP formation in bacteria to understand which are most influential. While there remains uncertainty, some general trends are emerging: higher Ag + concentrations result in higher AgNP production, up to a point at which the toxic effects begin to dominate; the optimal temperature appears to be heavily species-dependent and linked to the optimal growth temperature of the organism. However, hotter conditions generally favour higher production rates, while colder environments typically give greater shape diversity. Little attention has been paid to other potentially important growth conditions including halide concentrations, oxygen exposure, and irradiation with light. To fully exploit biosynthetic production routes as alternatives to chemical methods, hurdles remain with controlling particle morphologies and require further work to elucidate and harness. By better understanding the factors influencing AgNP production a foundation can be laid from which shape-controlled production can be achieved.

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“…Nanoremediation has recently gained popularity, which deals with wastewater treatment applications, and it is considered very efficient, eco-friendly, and cost-effective due to the unique functionalities of the nanomaterials to treat industrial effluents [24]. During the remediation process, nanomaterials are used as adsorbent, which potentially remove pollutants from wastewater, and enhance the chemical and adsorption activities due to their small size and high surface area with better porosity characteristics [25][26][27]. Nanomaterials and commercial activated carbon have the same characteristics of large surface area, however, nanomaterials are synthesized easily at a lower cost, and they are required in a smaller amount for the effective pollutants' removal.…”

Section: Introductionmentioning

confidence: 99%

Utilization of nano-olive stones in environmental remediation of methylene blue from water

Al-Ghouti

Dib

2020

J Environ Health Sci Engineer

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Background The use of agricultural waste as a low-cost adsorbent for the removal of hazardous methylene blue (MB) from aqueous solution was investigated. In this research, the potentiality of using black nano olive stones (black NOS) and green nano olive stones (green NOS) for MB adsorption was conducted. Methods Various remediation parameters such as initial MB concentration, pH, and temperature were investigated. Thermodynamic study was carried out to determine the homogeneity of the adsorbent and spontaneity of the adsorption process. Different physical and chemical characterizations were studied using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), Brunauer-Emmett-Teller (BET) surface area, pore radius and pore volume. Results It was found that NOS exhibits an acidic nature, however the highest MB removal efficiency was recorded at pH 10; reaching up to 71%. The negative value of the heat of the adsorption process (ΔH°) indicated the reaction followed an exothermic pathway while the negative value of Gibbs adsorption (ΔG°) further suggested its spontaneous nature. The results indicated that the Freundlich model described well the adsorption process with 99.5% correlation coefficient for green NOS. FTIR was used to analyze functional groups on the adsorbents' surfaces that could play vital roles in the remediation process. SEM analysis revealed that the adsorbents comprised of abundant spherical deep cavities and porous nature. Conclusion The result obtained successfully demonstrated the potential of using black and green NOS as suitable adsorbents for the removal of MB from water.

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Synthesis of silver nanoparticles using bacterial exopolysaccharide and its application for degradation of azo-dyes

Cited by 154 publications

References 36 publications

Characterization and Production of Extracellular Polysaccharides (EPS) by Bacillus Pseudomycoides U10

Characterization and Production of Extracellular Polysaccharides (EPS) by Bacillus Pseudomycoides U10

Bacteria and nanosilver: the quest for optimal production

Utilization of nano-olive stones in environmental remediation of methylene blue from water

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