Sodium Alginate Concentration Research Articles

Facile Fabrication of N-Slow Release Fertilizer Hydrogel Beads by Alginate-Based Composites

A novel slow-release N-fertilizer hydrogel beads were developed using sodium alginate (SA) and alginate-talcum (ST) composite as N-absorbent. In this work, the hydrogel composite were fabricated by simple method and low cost. N-fertilizer hydrogel beads were prepared two types, for SA types, which were different sodium alginate (1(SA1), 3(SA3), 5(SA5), 7(SA7), and 10(SA10) wt%). And, for ST types, sodium alginate and talcum were vary ratios to 1:0.5(S1T0.5), 1:1(S1T1), and 1:2 (S1T2). The chemical structure of hydrogel composite beads were characterized via Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The release behavior were investigate by Zero-order kinetic model, First-order kinetic model, Higuchi model and Korsmeyer-Peppas model. We have found that the N-fertilizer release constants in Korsmeyer-Peppas model were decrease with increase SA content for 1-5 wt% in SA hydrogel beads. However, SA contents were more than 5 wt% which rapidly enhanced fertilizer release. In addition, to add talcum in ST hydrogel beads significantly reduced fertilizer release rate. The N-fertilizer hydrogel beads exhibits significantly slow release behavior. These results indicates that the development of slow-release fertilizer hydrogel beads can be improve the effectiveness of N-fertilizer.

Process standardization for alginate encapsulation of potentially probiotic Pediococcus pentosaceus DM101

The main objective of this study was to standardise the procedure for encapsulation of potentially probiotic breast milk isolate Pediococcus pentosaceus DM101 using sodium alginate by extrusion method. The encapsulation parameters were optimized by comparing the encapsulation efficiency obtained with varying concentration of sodium alginate (0.5, 1.0, 1.5 and 2.0%), calcium chloride (0.05, 0.1 and 0.2M) and gelling time (5, 10, 20 and 30 minutes). Encapsulation efficiency was ascertained by finding the survival percentage after exposing the encapsulated cells to acid stress (pH 2.0 for 3h). Encapsulation carried out using two per cent sodium alginate and 0.1M CaCl2 following 20 min gelling time was found to confer maximum protective effect. Encapsulation efficiency of alginate beads prepared under optimized conditions was found to be 81.37±2.44 per cent. The results endorse alginate encapsulation as a means to confer a protective shielding effect thereby facilitating effective probiotic delivery.

The microstructure and physiochemical stability of Pickering emulsions stabilized by chitosan particles coating with sodium alginate: Influence of the ratio between chitosan and sodium alginate

The purpose of this study was to further improve the physiochemical stability of the chitosan (CS) particle-stabilized Pickering emulsion by coating with sodium alginate (SA). The effect of different mass ratios of CS and SA (1:0.5–1:2) on the microstructure, rheology and the stability of the emulsions were comprehensively evaluated by various methods such as optical microscope, scanning electron microscope, rheometer, and low-field nuclear magnetism. The multilayer emulsion with low content of SA (CS:SA = 1:0.5) presented bridging flocculation. If SA concentration was high (CS:SA = 1:1–1:2), the surface of the Pickering emulsion droplets was completely covered by the SA. At this time, multilayer emulsion droplets became stable due to strong electrostatic and/or steric repulsion. Too high SA concentration (CS:GA = 1:2) might also promote the accumulation of moisture. In addition, the CS/SA multilayer emulsion showed higher coalescence stability under different environmental treatments but its creaming stability and flocculation stability were still sensitive to pH (2, 4 and 10), temperature (4 °C and 80 °C) and ionic strength (300–500 mM). In all, the addition of the proper level SA (CS:GA = 1:1–1:2) could increase the stability of CS particle-stabilized Pickering emulsion.

Application of central composite design approach for optimization nitrate removal from aqueous solution by immobilized Pseudomonas putida.

High nitrate concentration is a dangerous pollutant in the environment. Immobilization for the optimum denitrifying bacterial strain isolated from collected wastewater samples was suggested for bioremediation of excessive nitrate concentration from aqueous solutions and its denitrification activity under different pH, nitrate concentration, bacterial beads, temperature and sodium alginate concentration conditions was explored. The active isolate was identified as Pseudomonas putida MT364822.1 by 16S rRNA analysis. Nitrate bioremediation process was optimized by applying response surface methodology based on central composite design approach. Nitrate uptake was significantly affected by variables of study (P-value <0.05). Maximum removal of nitrate (91.1%) was achieved at pH 7, nitrate concentration 400 mg/L, immobilized bacterial beads 3.0 g/L, temperature 35 °C and sodium alginate concentration 2.5% as optimal variable values. For application, immobilized P. putida MT364822.1 removed 82.2% of nitrate from raw fish farm effluent. Storage and reusability experiments showed that the immobilized strain stronger and more stable than the pure strain. The results suggested that immobilized P. putida MT364822.1 is a highly promising and suitable microorganism for use in the bio-removal of nitrate, and the central composite design was more effective in optimizing variables to achieve the best nitrate removal efficiency.

Enhanced bioremediation of 2,3′,4,4′,5-pentachlorodiphenyl by consortium GYB1 immobilized on sodium alginate-biochar

2,3′,4,4′,5-pentachlorodiphenyl (PCB 118), a dioxin-like PCB, is often detected in the environment and is difficult to be aerobically biodegraded. In this study, a novel polychlorinated biphenyl degrading consortium GYB1 that can metabolize PCB 118 was successfully obtained by acclimatization process. To enhance the application performance of free bacterial cells, consortium GYB1 was immobilized with sodium alginate and biochar to prepare SC-GYB1 beads. Orthogonal experiments indicated that the optimal composition of the beads (0.2 g) was 2.0% sodium alginate (SA) content, 2.0% wet weight of cells and 1.5% biochar content, which can degrade 50.50% PCB 118 in 5 d. Immobilization shortened the degradation half-life of 1 mg/L PCB 118 by consortium GYB1 from 8.14 d to 3.79 d and made the beads more robust to respond to environmental stress. The SC-GYB1 beads could even keep considerable PCB degradation ability under 200 mg/L Cd2+ stress. According to 16S rRNA gene analysis, Pseudomonas and Stenotrophomonas played the dominant role in consortium GYB1. And embedding obviously altered the community structure and the key bacterial genera during the PCB removal process. Therefore, the immobilization of bacteria consortium by sodium alginate-biochar enhanced the biodegradation of PCB 118, which will provide new insights into functional microorganisms' actual application for PCB restoration.

Formulation, Optimization and Evaluation of Gastroretentive Alginate Beads of Ivacaftor by Using Factorial Design

Aim: The main aim of study is to improve solubility of Ivacaftor by formulating into solid dispersions and to prolong the drug release, the solid dispersion of ivacaftor is formulated into gastroretentive alginate beads by Ionotropic Gelation method by using 24 factorial design. Methods: Ivacaftor solid dispersions were prepared by solvent evaporation method using polyethylene glycol, urea and mannitol as carriers by taking 1:1, 1:2 and 1:3 drug:carrier ratios. The best solid dispersion with better dissolution rate was incorporated into gastroretentive alginate beads by Ionotropic Gelation method using 24 factorial design. The independent variables are Sodium alginate concentration, Calcium chloride concentration, drug:HPMC ratio and drug:chitosan ratio and the dependent variables are percentage entrapment efficiency and percentage in-vitro drug release. The optimization of formulation was carried out using Stat Ease Design Expert Software. Results: The solid dispersion with polyethylene glycol and drug in 1:2 ratio showed better in-vitro dissolution of 98.17% at 120 mins. This solid dispersion was incorporated into gastroretentive alginate beads. The optimized formulation with 2% sodium alginate concentration, 4% calcium chloride concentration, 1:1 ratio of drug:HPMC and 1:1 ratio of drug:chitosan of solid dispersion entrapped alginate beads showed entrapment efficiency of 96.23% and in-vitro drug release of 95.62% at 12 hrs. The FTIR studies shown compatibility between drug and the excipients. The drug release kinetics of optimized formulation followed first order with Fickian diffusion. Conclusion: Ivacaftor entrapped solid dispersion entrapped alginate beads were successfully optimized using 24 full factorial design, which gave maximum entrapment efficiency and high drug release for extended period of 12 hrs. The release of ivacaftor was found to follow first order kinetics by Fickian diffusion. It can be concluded that this method may prove to be a suitable potential option for effective delivery of drug for treatment of cystic fibrosis.

Glucose oxidase-mediated sodium alginate gelation: Equipment-Free detection of glucose in fruit samples

In this study, a paper-based sensor, combined with a visual distance-readout method, was developed to determine glucose in fruit samples based on the glucose oxidase-mediated sodium alginate gelation. The type of filter paper, the concentration of sodium alginate and the enzymatic reaction conditions were systematically investigated. Under optimal conditions, the increase in diffusion diameter showed a good linear relationship with glucose concentration between 1.4–7.0 mM, and the limit of quantification was 1.4 mM. Finally, the applicability of the proposed strategy was successfully verified by measuring glucose concentrations in fruit samples. The results generated by the developed paper-based sensor were in good agreement with the results obtained from a glucose assay kit. The recoveries were 91.8%–99.1%. In short, the present study developed a simple, low-cost and efficient method for assessing fruit quality and for guiding fruit intake for diabetic patients, especially in remote or resource-limited regions.

Artificial electrochemically active biofilm for improved sensing performance and quickly devising of water quality early warning biosensors

A major challenge for devising an electrochemically active biofilm (EAB)-based biosensor for real-time water quality early-warning is the formation of EAB that requires several days to weeks. Besides the onerous and time-consuming preparation process, the naturally formed EABs are intensively concerned as they can hardly deliver repeatable electrical signals even at identical experimental conditions. To address these concerns, this study employed sodium alginate as immobilization agent to encapsulate Shewanella oneidensis MR-1 and prepared EAB for devising a biosensor in a short period of less than 1 h. The artificial EAB were found capable of delivering highly consistent electrical signals with each other when fed with the same samples. Morphology and bioelectrochemical properties of the artificial EAB were investigated to provide interpretations for these findings. Different concentrations of bacteria and alginate in forming the EAB were investigated for their effects on the biosensor's sensitivity. Results suggested that lower concentration of bacteria would be beneficial until it increased to 0.06 (OD660). Concentration of sodium alginate affected the sensitivity as well and 1% was found an optimum amount to serve in the formation of EAB. A long-term operation of the biosensor with artificial EAB for 110 h was performed. Clear warning signals for incoming toxicants were observed over random signal fluctuations. All results suggested that the artificial EAB electrode would support a rapid devised and highly sensitivity biosensor.

Biochemical pathways and associated microbial process of di-2-ethyl hexyl phthalate (DEHP) enhanced degradation by the immobilization technique in sequencing batch reactor

ABSTRACT A bacterial strain ASLT-13 was successfully isolated from activated sludge and identified as Pseudomonas amygdali. Gas chromatograph-mass spectrometer (GC-MS) analysis indicated that strain ASLT-13 could completely mineralize di 2-ethyl hexyl phthalate (DEHP). DEHP was first metabolized from the longer side chain of the benzene ring into shorter branches (Phatlalic mono-esters) like Dibutyl phthalate (DBP) under the action of degrading genes. DBP was then converted into di-methyl phthalate (DMP), and then hydrolysed to phthalic acid (PA). PA was eventually converted to CO2 and H2O through the TCA cycle. The optimal conditions for immobilization were the sodium alginate (SA) concentration of 6%, CaCl2 concentration of 5%, ratio of bacteria and SA of 1:1, crosslinking time of 6 h. Bacterial quantity and community structure in sequencing batch reactors (SBRs) was investigated by q-PCR and high-throughput sequencing. The results indicated that DEHP removal efficiency was significantly enhanced by immobilization. Arthrobacter, Acinetobacter, Bacillus and Rhodococcus were the predominant genera for DEHP degradation. This study suggested that the cell immobilization technology had a potential application in DEHP wastewater treatment.

Kaolin-Enhanced Superabsorbent Composites: Synthesis, Characterization and Swelling Behaviors

One type of low-cost and eco-friendly organic‒inorganic superabsorbent composite (SAPC) was synthesized by free radical polymerization of acrylic acid (AA), starch (ST), sodium alginate (SA) and kaolin (KL) in aqueous solution. The structure and morphology of the SAPC were characterized by Fourier transform infrared spectrometer (FT-IR), scanning electron microscope (SEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The influence of different reaction conditions on water absorption of SAPC, i.e., SA and KL contents, AA neutralization degree (ND), potassium persulfate (KPS) and N, N′-methylenebisacrylamide (MBA) loading were systematically studied. Under the optimal synthesis conditions, very high water absorption of 1200 g/g was achieved. The swelling kinetic mechanism of SAPC was studied by pseudo-second order swelling kinetics model and Ritger‒Peppas model. The performances of SAPC under different environments were tested and results revealed that this new SAPC had excellent swelling capacity, high water retention, good salt tolerance in monovalent salt solution (NaCl solution) and good pH tolerance between 4 and 10.

Structural characteristics of polysaccharide microcapsules from Nostoc commune, and their applications in skin wound healing and pathological repair

In this study, the extraction conditions of Nostoc commune Vauch polysaccharide (NCVP) were optimized by single factor and orthogonal experiments. Then, the NCVP microcapsules (NCVPM) were prepared. After analyzing the microcapsule structural and thermal characteristics, the skin wound healing ability was studied by establishing back trauma rat models. Results showed that the NCVP yield was 10.37% under the following optimum conditions: 210 min extraction time, solid–liquid ratio of 1:50 and extraction temperature of 90 °C. The overall performance of the microcapsule was the best when the concentration of sodium alginate, calcium chloride and chitosan was 2%, 3% and 0.3%, respectively. NCVPM had spherical morphology, typical microcapsule structural characteristics and good thermal stability, and NCVP was dispersed in the microcapsules. NCVPM showed good biocompatibility and biodegradability, which met the requirements for slow-release polymer materials. After 14 days of treatment, the wound healing rate was 92.4%, the cells were arranged neatly and regularly, the cell nucleus became large and elliptical, the cell had a tendency to divide, and the fibers and microvessel were significantly more. By evaluating the mechanism, NCVPM could increase the content of hydroxyproline and glutathione to protect cells from oxidative damage, leading in turn to accelerated wound healing and shorter wound healing times. It could also accelerate cell division, collagen and microvascular production by increasing transcription levels of vascular endothelial growth factor mRNA and miRNA-21.

Optimization of Immobilization Condition of Protease Extracted from Silver Catfish (Pangasius Sutchi) Viscera in Calcium Alginate by using Response Surface Methodology (RSM)

The term of immobilized enzymes refers to enzymes that physically entrapped within pores of synthetic or natural polymeric network with no alteration in the enzyme catalytic activities. In this study, protease from silver catfish viscera have been extracted, partially purified by acetone precipitation method and immobilised in the calcium alginate beads. Various range of sodium alginate (1–5% w/v) and calcium chloride (0.1–0.5 M) concentrations were used for the optimization purpose. Proteolytic activity of the protease in the alginate beads was measured as a response to the independent variables by using casein as a substrate. The highest actual and predicted proteolytic activities were at run 12 with 674.77 CDU/mg and 639.26 CDU/mg, respectively, under predetermined factors, in which the sodium alginate and calcium chloride solution concentrations were at 3.00% (w/v) and 0.30 M, respectively. The lowest actual and predicted proteolytic activities were at run 2 with the values of 77.35 CDU/mg and 71.53 CDU/mg, respectively, whereby factors include were a sodium alginate of 4.00% (w/v) and 0.20 M of calcium chloride solution. For the experimental feasibilities, the optimum conditions that was feasible to be carried out was with a sodium alginate of 2.99% (w/v) and 0.30 M calcium chloride solution. Verification for the optimum condition was performed and there was no significant difference (p &gt; 0.05) between the predicted (638.19 CDU/mg) and verified (699.82 CDU/mg) values. Thus, indicating that the model was significant and can be used to produce the immobilize protease under the optimum condition.

Rheological and thermal characterization of pinto saltillo bean (Phaseolus vulgaris L.) protein isolates/sodium alginate gels

The aim of the present study was to investigate the gelling properties of Pinto Saltillo bean isolate protein (PSBIP) enriched with sodium alginate (SA). In solution, phase diagrams indicated cosolubility at different concentrations of the PSBIP-SA system that is homogeneous at low concentrations of PSBPI (<150 g/L) and SA (<20 g/L). All studied systems behave as a shear-thinning fluid in all tested concentrations; the values of η0 obtained using the Carreau model suggest stronger interactions between PSBPI (100 g/L) and SA (20 g/L) indicating the presence of a molecular network that cannot be significantly altered at low shear rates. In frequency studies, mixed gels formed through internal ionic gelation and temperature gradient denaturation, indicates that SA concentrations higher than 20 g/L increase the G′ and G″ values, improving the mechanical spectra in some cases of the binary gels; the K′, K″, n’, and n’’ values suggest that the modifications of the dynamic rheological properties of PSBPI-SA gels are synergistic. Viscoelastic analyses indicate that SA reduces the random associations of proteins in the mixed gels due to a more ordered network structure.

Study of structural and mechanical properties of sodium alginate gels

Rheological parameters are an important characteristic of semisolid dosage forms. Structural and mechanical characteristics have a noticeable effect on the processes of release and absorption of drugs from ointments, as well as on their consumer properties: spreadability, adhesion, the ability to squeeze out of the tubes.&#x0D; The aim: to study the rheological parameters of aqueous solutions of sodium alginate in various concentrations to create medicinal hydrogel compositions.&#x0D; Materials and methods: sodium alginate (Shandong Topsea Seaweed Industrial Co., Ltd., China) was used as a gelling agent. The physicochemical properties of the samples were studied according to generally accepted methods of the State Pharmacopoeia of Ukraine. Rheological studies of experimental samples were carried out using a rotational viscometer «Rheolab QC», by Anton Paar (Austria) with coaxial cylinders C-CC27/SS at a temperature 20–25 °С.&#x0D; Results and discussion: the rheological profiles of sodium alginate gels have a non-Newtonian type of flow, which makes it possible to characterize them as systems with plastic-viscous properties. Gels with a sodium alginate concentration of 1.5–2 % have the best indicators of yield stress, hysteresis loop area, mechanical stability and dynamic flow coefficients. This indicates a low degree of destruction of the structural grid in the process of mechanical action and the presence of thixotropic bonds.&#x0D; Conclusions: sodium alginate gel base at 0.5 % and 1 % concentration is less stable under stress compared to sodium alginate bases at 1.5 % and 2 % concentration. The gel base of sodium alginate at a concentration of 2 % has the optimal mechanical stability value.

FORMULATION OPTIMIZATION AND EVALUATION OF TINIDAZOLE IN-SITU

The study deals with formulation optimization and evaluation of tinidazole gel by using sodium alginate as gelling agent calcium chloride, sodium citrate were used as cross linking agent. The polymeric solution of drug is in solution form before it administered to the body. But after administration when it comes in contact with acidic pH it’s converted into gel form and the drug tinidazole released from the dosage form constantly and slowly. The formulation is effective for the treatment of gastric ulcer because of Helicobacter pylori. 32 full factorial design were used for the optimization of the formulation 12 trial batches were prepared and 9 factorial design batches in which 2 factor 3 level factorial design were used for the optimization. The concentration of sodium alginate, were taken in 3 level low, medium, high and the prepared formulation were evaluated.

Sodium alginate and pectin estimation in raft forming pharmaceuticals by high performance liquid chromatography method

AbstractThe high performance liquid chromatographic (HPLC) method was developed for the combined estimation of sodium alginate and pectin in raft forming pharmaceuticals on C18 column ZORBAX ODS (1.5 cm × 4.6 mm, 5 μm) with UV detection at 378 nm. The assay condition comprised of phosphate buffer pH 7.4 and methanol 60:40% v/v at a flow rate of 1.25 mL/min. The separation of sodium alginate and pectin with good resolution and a retention time less than 8 min was attained. The method was linear over a range of 200–800 μg/mL of sodium alginate and pectin. The regression values obtained from linearity curve of sodium alginate and pectin were 0.9993 and 0.9991, respectively. The retention time of sodium alginate and pectin was 3.931 and 7.470 min, respectively. The percent recovery of sodium alginate and pectin ranged from 94.2–98.5% and 92.1–98.4% respectively. The limit of detection (LOD) and limit of quantification (LOQ) of sodium alginate were found to be 2.443 and 3.129 μg/mL and the LOD and LOQ of pectin were 3.126 and 3.785 μg/mL, respectively. The resolution of sodium alginate and pectin was found in the range of 1.03–1.89 and 1.10–1.91, respectively. This method has been successfully applied to analyze the concentrations of sodium alginate and pectin in raft forming drug delivery systems.

Microencapsulation with the usage of sodium alginate: A promising method for preserving stonewort (Characeae, Charophyta) oospores to support laboratory and field experiments

This work proposes the use of a biomaterial sodium alginate for microencapsulating stonewort oospores. The microencapsulation method has been adopted and optimized to improve research work carried out on the oospores. A detailed protocol for the production of microcapsules with stonewort oospores has been presented, with particular attention paid to the critical stages and factors interfering with the efficient production process. The advantages and disadvantages of this method have also been indicated. Microcapsules with oospores can be successfully used in various laboratory (observation of the germination phases) and field experiments (reintroduction of rare species of stonewort). Alginate microcapsule may consist of water taken directly from the habitat of the stonewort, a medium, as well as specific additives (antibiotics or fungicides). The hardness of the encasement is regulated by the concentration of the sodium alginate. The optimum alginate concentration for oospores is between 2 and 3%. Encasements produced with less than 2% sodium alginate concentration do not form circular microcapsules during gelation. On the other hand, concentration >3% may limit the oospores' ability to germinate (higher density of the microcapsule). In such a dense environment, the germinating primary cells may encounter difficulties in outgrowing the microcapsule. It has been shown that alginate encasement creates an effective protective layer for the oospores inside it. The oospore is protected from mechanical damage as well as from direct exposure to the external environment; especially from pathogens and other microorganisms that can inhibit its germination and limit the growth of the protonemal and primary rhizoidal cell. The main application of oospore microencapsulation using sodium alginate is facilitating further mechanical manipulations of oospores, which by nature are very small structures (max. length 1 mm), while a microcapsule with an oospore embedded inside it can have a diameter from 3 to 5 mm (as required).

Extrusion bioprinting of hydroxyethylcellulose-based bioink for cervical tumor model

The present study demonstrates the extrusion printing of highly viscous and thixotropic hydroxyethylcellulose-based bioinks blended with various concentrations of sodium alginate (SA) and embedded with HeLa cells. The cell viability is shown to be inversely proportional to the relative SA content and can be as high as 81.5 % following one day of incubation. Furthermore, the biocompatibility of the hydrogel matrix supports cell proliferation resulting in an order of magnitude larger number of cells after a 7-day incubation. The cell viability is negatively affected mostly by the extrusion printing itself with some cell death occurring during their embedding in the hydrogels. After embedding the HeLa cells in the blends containing 1 and 2.5 % SA, the cell viability is not significantly affected by the residence time of up to 90 min before the bioink extrusion. The printed constructs can be utilized as a cervical tumor model.

Preparation of Nano‐Emulsion‐Based Hydrogels Conjugated Curcumin as Model Functional Lipid Bioactive Compound

AbstractThe preparation of nanoemulsion‐based alginate hydrogels, containing curcumin was the aim of current study. The nanoemulsions of coconut oil were prepared using solvent‐displacement technique and then the obtained nanoemulsions were converted to hydrogels using the ion‐gelling process. The effects of formulation parameters, namely, sodium alginate concentration (1–2 g L−1), the weight ratio of calcium chloride to sodium alginate (2–4), and curcumin to sodium alginate (1–3), were also evaluated on swelling percentage, gel fraction, curcumin load, curcumin release, and antibacterial inhibitory zone of hydrogels. All studied characteristics were successfully correlated to the selected independent variables by second‐order polynomial equations as models, with relatively high coefficients of determinations (R2 &gt; 86). According to multiple numerical optimization analysis, the most desired hydrogels can be obtained using 1.9 g L−1 sodium alginate, curcumin/sodium alginate of 2.5 g g−1, and calcium chloride/sodium alginate of 2.2 g g−1, with the maximum swelling ratio (216%), gel fraction (29.9%), curcumin load (59.12%), antibacterial activity (clear‐zone diameter of 5.27 cm), and the least curcumin release after 12 hours (87.75%). It was also resulted that the curcumin release from prepared optimum hydrogel obeys the first order kinetics. No significant differences between the measured and predicted data confirmed the suitability of suggested models.

BACTERIAL DESULFURIZATION OF DIBENZOTHIOPHENE BY PSEUDOMONAS SP. STRAIN KWN5 IMMOBILIZED IN ALGINATE BEADS

Biodelfurization of petroleum has emerged as a potential alternative to the hydrodesulfurization and oxidative desulfurization processes. However, the main obstacle in its commercial application is the efficiency and practicality of using bacterial cells. Pseudomonas sp. strain KWN5 was tested for the ability to use dibenzothiophene (DBT) in n-tetradecane as the sole sulfur source with two phase oil-water system. The biodesulfurization ability of strain KWN5 was evaluated by immobilized cells with dibenzothiophene as substrates. The cells immobilized by entrapping them with sodium alginate (SA) had high DBT biodesulfurization activity and could degrade 100 mg DBT/L in n-tetradecane of 46.76–100%, depended on concentrations of sodium alginate and cells within 24 h at 37oC with shaking at 160 rpm. The combination of SA concentration of 3% (w/v) with bacterial cells OD660 40 (25.52 mg DCW/mL) has an optimal biodesulfurization activity on 100 mg DBT/L in n-tetradecane, which is equal to 71.85% biodesulfurization. The immobilized cells of Pseudomonas sp. strain KWN5 in alginate beads were more efficient for the degradation of DBT and can be reused for five cycles (220 h) without any loss in their activity. The results of this study clearly show the role of the effects of cell immobilization in increasing the process of biodesulfurization.