Free Cell System Research Articles

Bioremediation of textile wastewater using Bacillus cereus isolated from refinery site: Comparative analysis of free and immobilized cells systems

The textile industries consume a considerable amount of freshwater and discharge untreated or semi-treated pollutants to the environment. Azo dyes, generally employed in textile manufacturing industries, have a hazardous impact on the ecosystem. Incomplete treatment of wastewater containing azo dyes discharges into the aquatic system, which has recalcitrant and toxic properties. Hence, the need for cost-effective and high-performing technologies is essential. In this direction, bacterial degradation is considered an economically viable and efficient technique for the treatment of Active blue (AB) dye. Polyurethane foam (PUF) is a low-cost and hydrophilic material with a microporous structure, which offers an excellent surface-to-volume ratio. Hence, PUF was preferred for the immobilization of isolated bacterial species. For this, a dye-degrading gram-positive bacteria namely Bacillus cereus GS2 IIT (BHU) was isolated from the petroleum sludge. A comparative analysis between free and immobilized cell systems was carried out by varying the process parameters, i.e., batch time, pH, temperature, glucose concentration, and initial AB dye concentration. The corresponding optimum conditions were found to be 6.0 days, 6.5, 30 °C, 1.0 g/L, and 50 mg/L, respectively. The immobilized cell system exceeds the dye removal efficiency (RE) by 10. 7 % compared to the free cell system. The packed bed bioreactor could be able to deliver 98.56 % of dye removal at an inlet loading rate of 30 mg/L d and 50 mg/L of initial dye concentration.

Generation of biosurfactants by P. aeruginosa gi |KP163922| on waste engine oil in a free and immobilized cells system

AbstractThis study investigated biosurfactant production by the bacterial strain of P. aeruginosa gi |KP 163922| for a free and immobilized cells system using waste engine oil (WEO) as a substrate. The polyurethane foam (PUF) cubes (1 cm × 1 cm × 1 cm) were used as carriers for the immobilization. The batch experiments were performed in Erlenmeyer flasks and monitored at every 24‐h interval for both cell systems. The microbial population was counted using the plate count method, and the hydrocarbon degradation percentage was calculated to evaluate the bacterial activity. Surface tension was measured at regular intervals to ensure the presence of biosurfactants. The maximum reduction was 37 and 35 mN/m in a free and immobilized cells system. Immobilization of cells using PUF was found to be efficient in supporting bacterial growth, and after 48 h of incubation, the growth was 2.5 (±0.58) × 1011 CFU/mL. The chemical characterization using Fourier transform infrared (FTIR) spectroscopy confirmed the obtained product as rhamnolipid. Crude biosurfactant yield was found to be maximum in the case of the immobilized system, which was approximately 18 g/L. Scanning electron micrographs (SEM) of the used PUF cubes showed the strong adherence of biofilm to the cube surface and the potential of its reuse in multiple cycles. Gas chromatography–mass spectrometry (GC–MS) analysis confirms that the immobilized strain of P. aeruginosa exhibited superior biodegradation capabilities compared to free cells. Specifically, it was capable of reducing the concentration of polyaromatic hydrocarbons and converting more significant aliphatic compounds into metabolic byproducts such as alkanes, alkenes, cycloalkanes, and carbonyl groups.

Naproxen as environmental pollution, its effect on bacteria metabolism and degradation mechanism in immobilized Planococcus sp. S5

Planococcus sp. S5 belongs to strains that degrade naproxen, one of the most popular non-steroidal anti-inflammatory drugs. In the presented work, the immobilization of the S5 strain was carried out on the Loofah plant sponge, which improved the degradation efficiency, and kinetic studies indicated the abolition of the inhibition by the substrate observed in the free cell system. At the same time, after immobilization, evident changes were observed in the metabolic profile of the strain, which was related to the specific microenvironment of the carrier. The study also presents the naproxen degradation pathway in a system with the immobilized S5 strain for the first time. The analysis of intermediates formed during the decomposition of naproxen indicated that this decomposition occurs through naphthalene and salicylic acid. Furthermore, the degradation of naproxen via 3-hydroxybenzoic acid to gentisic acid is also possible. The high efficiency of naproxen degradation by the immobilised S5 strain enables its use in bioremediation.

Assessment of enhanced p-cresol biodegradation by encapsulating pre-immobilised Serratia marcescens strain HL 1 on tea waste biochar into polyvinyl alcohol/sodium alginate matrix

In this study, the potential microorganism was isolated from activated sludge to degrade the p-cresol from wastewater. The isolated species (i.e., Serratia marcescens strain ΗL 1) was identified using a 16 S rRNA gene sequencing technique. Microorganism was immobilized into 1% (w/v) tea waste biochar and encapsulated into polyvinyl alcohol (PVA)/sodium alginate (SA) matrix to save the pure species from contaminant and able to sustain under high loading concentration. The maximum biodegradation efficiency was found to be 86.1 ± 2.0% of p-cresol by using PVA/SA (pre-immobilized (PI) (1%) biochar into PVA/SA) matrix which is much higher than the free cell (42.4 ± 0.7%) and immobilized system (73.8 ± 1.0). The % biodegradation of p-cresol was reduced from 86.1 ± 2.0–80.2 ± 1.4% after the fourth cycle. The matrix's surface morphology and the functional group were analysed by SEМ and FTIR, respectively. Monod and Andrew-Haldane model was used to identify biokinetic parameters. This research work revealed that an innovative PI(1%)biochar@PVA/SA matrix would be useful for the bioremediation of p-cresol. The main metabolic by-product obtained were 4-hydroxybenzoylalcohal (m/z = 124), 4-hydroxybenzoic acid (m/z = 138), maleic acid (m/z = 116) and acetaldehyde (m/z = 29)

Investigating the effect of electrosprayed alginate/PVA beads size on the microbial growth kinetics: Phenol biodegradation through immobilized activated sludge

The presence of cyclic organic compounds, including phenol, in the wastewater of many industries has made phenol removal an important issue. Meanwhile, the biological methods of removing phenol have attracted the attention of researchers in recent years. Recently, the use of immobilized microbial cells is proposed as a new approach in industrial wastewater treatment. In this research, the aim is to study the effect of immobilized beads size on the phenol biodegradation efficiency and specific microbial growth rate. For this purpose, electrospray technique was used to immobilize activated sludge in hybrid matrix of alginate and polyvinyl alcohol (PVA). The fabricated alginate/PVA beads were characterized using Fourier transform infrared spectroscopy (FTIR). Evaluation of the results related to the free and immobilized cell systems in the shake flask experiments showed that at low phenol concentrations the immobilized cell system had the same performance as the free cell system, while the immobilized cell system at higher concentrations had a better performance in removing phenol so that at a concentration of 2000 mg/L, removal percentage has increased from 15% to 25–34%. On the other hand, in this survey, the kinetic behavior of activated sludge was in good agreement with Haldane's equation. Moreover, the maximum specific growth rate was measured 0.033 and 0.041 (h−1) beside 544 and 636 mg/L substrate inhibition constant, for free and immobilized cell systems, respectively. This result shows that the phenol biodegradation has been improved by using the cell immobilization technique especially with applying the smaller beads, which is due to improved mass transfer and microbial cell protection from harsh environments.

Entrapment of Mo-reducing Bacterium Increase its Resistance towards Mercury

In ruminants, even trace amounts of molybdenum can be lethal. In areas with high pollution, molybdenum levels in soil and mine tailings can exceed 20,000 ppm. Bioremediation of molybdenum can be challenging when toxic mercury is also present. This research presents a novel approach using dialysis tubing and the molybdenum-reducing activity of Enterobacter sp. strain Dr. Y13 for molybdenum removal from aqueous solutions. Molybdenum blue (Mo-blue), produced during enzymatic reduction, is insoluble in dialysis tubing and this can be a twofold advantage as a method of removal and as a method to protect bacterial cells from heavy metal inhibition, especially mercury. In this experiment, we assess the toxicity-shielding effect of dialysis tubing for molybdenum reduction to Mo-blue by this bacterium in the presence of mercury. As the concentrations of mercury were increased, both free and immobilized cells were strongly inhibited. Modelling using the dissociationone phase exponential decay model gave an IC50 value for the immobilized form of 0.1107 mg/L (95% confidence interval from 0.073 to 0.217 while the IC50 value for the free cell system was 0.023 mg/L (95% C.I. from 0.019 to 0.028). Since the confidence interval for the IC50 values did not overlap, the immobilized system gave better protection from mercury than the free cell system. Toxicity to free cells was higher than toxicity to cells trapped in dialysis tubes, suggesting that trapping Mo-reducing cells may be an effective strategy for bioremediation of water or wastewater contaminated with multiple heavy metals.

Immobilization of Bacillus sp. Strain Neni-8 in Dialysis Tubing Reduced Copper Toxicity to the Molybdenum Reduction Process

In ruminants, even trace amounts of molybdenum can be lethal. In areas with high pollution, molybdenum levels in soil and mine tailings can exceed 20,000 ppm. Bioremediation of molybdenum can be challenging when toxic copper is also present. This research presents a novel approach using dialysis tubing and the molybdenum-reducing activity of Bacillus sp. strain Neni-8 for molybdenum removal from aqueous solutions. Molybdenum blue (Mo-blue), produced during enzymatic reduction, is insoluble in dialysis tubing and this can be a twofold advantage as a method of removal and as a method to protect bacterial cells from heavy metal inhibition, especially copper. In this experiment, we assess the toxicity-shielding effect of dialysis tubing for molybdenum reduction to Mo-blue by this bacterium in the presence of copper. As the concentrations of copper were increased, both free and immobilized cells were strongly inhibited. Modelling using the dissociationone-phase exponential decay model gave an IC50 value for the immobilized form of 0.1107 mg/L (95% confidence interval from 0.073 to 0.217 while the IC50 value for the free cell system was 0.023 mg/L (95% C.I. from 0.019 to 0.028). Since the confidence interval for the IC50 values did not overlap, the immobilized system gave better protection from copper than the free cell system. Toxicity to free cells was higher than toxicity to cells trapped in dialysis tubes, suggesting that trapping Mo-reducing cells may be an effective strategy for the bioremediation of water or wastewater contaminated with multiple heavy metals.

Comparative study of bioethanol production from bagasse pith by Pichia stipitis in free cell system and immobilized electrosprayed micro-beads: SSF and combined hydrolysates fermentation

Biofuels production from biomass are receiving special attention due to the availability of raw materials, suitable conversion yield and renewability. The primary objective of this study was comparison of bioethanol productivity from bagasse pith by free and immobilized Pichia stipitis. Alginate micro-beads at various sizes fabricated by electrospray technique. At the first stage, bioethanol production using free cells in two processes including fermentation of combined acid and enzymatic hydrolysates and simultaneous saccharification and fermentation (SSF) was optimized. In fermentation of combined hydrolysates, maximum production equal to 9.53 and 12.68 g/L was observed by free and immobilized cells, respectively at cell concentration 6 %, portion of acid hydrolysate 40 % and total sugar concentration 50 %. Besides, maximum production in SSF equal to 9.93 and 10.62 g/L was obtained by free and immobilized cells, respectively at 6 % cell, 4 g solid and enzyme content of 50 FPU/g solid. However, in SSF fermentation, the beads size had no significant effect on ethanol production while in combined hydrolysates fermentation, bioethanol production considerably affected by the beads size and 13.9 g/L ethanol was obtained in minimum beads size. Additionally, long-term stability of beads was examined in repeated-batch cultures, showing effective bioethanol production up to five reuse cycles.

Immobilization of Saccharomyces cerevisiae in Jackfruit (Artocarpus heterophyllus) Seed Fiber for Bioethanol Production

Bioethanol is alternative renewable energy typically obtained from glucose through a fermentation process using Saccharomyces cerevisiae. In the bioethanol fermentation process using yeast, there are several inhibiting factors, such as a high concentration of substrate, ethanol as the product, and nutrients. The present study aimed to investigate the effect of fermentation time (12- 72 hours), immobilized carrier size (sizes of 0.5 cm3 , 1 cm3 , and 1.5 cm3 ), and medium pH (3.0, 4.0, and 5.0) on the ethanol fermentation process using immobilized yeast in jackfruit (Artocarpus heterophyllus) seeds and subsequently to compare its performance with a free cell system. The highest ethanol concentration (89.15 g/L) with a yield of 96.92% was obtained by immobilizing yeast in jackfruit seed at a fermentation time of 72 hours, carrier size of 0.5 cm3 , and medium pH of 5.0. When compared to the free cell system fermentation under identical operating conditions, immobilized yeast in jackfruit seed obtained 1.41 times higher ethanol concentration. Jackfruit seed also led to a higher ethanol concentration compared to other S. cerevisiae carriers. Altogether, our findings imply that jackfruit seed has great potential as a carrier of S. cerevisiae in the process of fermenting glucose into ethanol

Removal of triclocarban from treated wastewater using cell-immobilized biochar as a sustainable water treatment technology

Triclocarban (TCC), an emerging endocrine disruptor, has been commonly found in municipal treated wastewater. Pseudomonas fluorescens MC46 (MC46), an effective TCC-degrading bacterium, could be applied to remove TCC from wastewater. In addition, application of a cell immobilization technique could possibly enhance its removal performance. This study examined microbial cells immobilized on waste biochar (from wood vinegar production) as a highly effective advanced wastewater treatment unit for TCC removal. TCC removal was investigated from real wastewater samples using the following treatments: biochar only, cell-immobilized biochar, and free cell systems in batch (short-term) and semi-batch (long-term) modes. The TCC adsorption capacities of original and potassium hydroxide-modified biochars (no cells) were 8.43 and 9.17 mg/g, respectively. During the batch experiment, the cell-immobilized modified biochar exhibited the highest TCC removal, 79.80%, in the model TCC solution. Five-cycle semi-batch experiments were utilized to investigate the reusability and performance of the treatment systems. After five cycles, the cell-immobilized modified biochar still achieved stable TCC removal (52%) due to the integration of adsorption and biodegradation. Free MC46 cells and biochars (no MC46 cells) only removed 32% and 2% of TCC, respectively, due to cell washout/death and sorbent exhaustion. This important work clearly demonstrates the significant potential for the future utilization of cell-immobilized biochars in a sustainable wastewater treatment system. Furthermore, the use of renewable agro-industrial wastes aid in the development of a strong circular bio-based economy.

Bioethanol Production from Oil Palm Empty Fruit Bunches Using Saccharomyces cerevisiae Immobilized on Sodium Alginate Beads

Bioethanol is an environmentally benign renewable energy commonly obtained from glucose fermentation using Saccharomyces cerevisiae. The purposes of this study are to investigate the effects of time, temperature, pH, immobilized yeast cell loading, beads reuse during ethanol production through batch fermentation of glucose derived from oil palm empty fruit bunches by S. cerevisiae immobilized on Na-alginate beads and to compare the performance of fermentation using immobilized yeast cells and that of using a free cell system. The results revealed that time, temperature, pH, yeast mass and beads reuse significantly affected the ethanol and final glucose concentrations. As expected, a maximum ethanol concentration was obtained from fermentation using immobilized yeast cells at 30 °C, pH 5, and immobilized yeast cell loading of 0.75 g for 48 hours. However, fermentation with a free cell system at the same conditions resulted in lower ethanol yield. The highest ethanol concentration of 88.125 g/L with a productivity of 1.84 g/L·h was achieved from the second cycle fermentation using of immobilized cells beads. The results suggest that an immobilized cell system exhibits great potential applications for improved ethanol production due to its ability to sustain the stability of cell activity, reduce contamination tendency, and protect yeast cells from any possible inhibitions.

Bio-composite of Fe-sludge biochar immobilized with Bacillus Sp. in packed column for bio-adsorption of Methylene blue in a hybrid treatment system: Isotherm and kinetic evaluation

The present study highlights the potential of bio-composite of Fe-sludge biochar and Bacillus sp for decolorization of Methylene blue (MB) dye. The Packed Bed Continuous Reactor (PBCR) hybrid system was containing bio-composite of Fe-sludge biochar with an ultraviolet system containing 600 mg ⋅L−1 MB dye. PBCR treated effluent was passed through the immobilized Bacillus sp. cells for biodegradation. The adsorption capacity of Fe-sludge biochar was 29.13 mg/g after 5 treatment cycles in PBCR. The kinetics parameters for pseudo-first-order, K1 and R2 were found to be 0.007 min −1 and 0.95; pseudo-second-order K2 and R2 were 1.69 g/mg/min and 1.0, respectively for bio-composite of Fe-sludge biochar Adsorption isotherm parameters values for Langmuir (KL), Freundlich (KF), and R2 were found to be 0.0366 L mg −1, 0.685 mg g-1 and 0.37 and 0.79, respectively. The Monod growth kinetic parameters Ks, μmax/Ks and μmax were found 41.3 mg day −1, 0.0103 mg day −1, and 0.426 day −1 respectively. Fe-sludge biochar immobilized with bacteria cell shows higher removal efficiency of MB dye in comparison to free bacterial cells system. Adsorption using the hybrid process (engineered biochar + bacteria) could be more effective and low-cost green approach for the organic pollutants removal from the industrial effluent.

Synergistic adsorption and biodegradation of heavy crude oil by a novel hybrid matrix containing immobilized Bacillus licheniformis: Aqueous phase and soil bioremediation

Recently, slurry phase bioremediation as a simple and economical method is shown to be a successful technique for remediation of clayey soils. Besides, the use of microbial cell immobilization as a promising technique has drawn the attention of some researchers. The primary objective of this survey is to examine the synergistic adsorption and biodegradation performance of heavy crude oil by an isolated Bacillus licheniformis immobilized in a novel hybrid matrix (PUF/alginate/microbial cell) in aqueous phase. Isotherm studies and adsorption kinetics of crude oil on PUF matrix were carried out and their results revealed a good correlation between experimental data and Langmuir’s isotherm and maximum monolayer coverage was found out to be 1.25 g/g PUF. The other objective of this research is examination of hybrid matrix in slurry phase bioremediation of heavy crude oil polluted clayey soil as a reluctant model soil. In order to model, optimize, and investigate the factors affecting the total organic carbon (TOC) reduction, response surface methodology (RSM) was applied. For this purpose, the effect of three variables including crude oil concentration (5000–25,000 mg/kg dry soil), soil salinity (0–10%), and water to soil ratio (WSR: 2–10) have been studied. In this study, TOC reduction was achieved in ranging from 39% to 80% in crude oil polluted soil after 21 days. Additionally, experiments by polyurethane foam (PUF)-immobilized cell, alginate-immobilized cell, and freely cell suspended systems were conducted to compare the performance of hybrid-immobilized cell with other systems. Our results showed the superiority of immobilized cells in hybrid matrix of PUF/alginate compared to other immobilized cell (IC) and free cell (FC) systems. Overall, the results indicated that the hybrid matrix with simultaneous adsorption-biodegradation capacity is potentially suitable for further development for oil spill treatment and it can be used as an efficient cleaning method in TOC removal from actual polluted soils.

Enhanced biodegradation of light crude oil by immobilized Bacillus licheniformis in fabricated alginate beads through electrospray technique.

Petroleum contamination of marine environments due to exploitation and accidental spills causes serious harm to ecosystems. Bioremediation with immobilized microorganisms is an environmentally friendly and cost-effective emerging technology for treating oil-polluted environments. In this study, Bacillus licheniformis was entrapped in Ca alginate beads using the electrospray technique for light crude oil biodegradation. Three important process variables, including inoculum size (5-15% v/v), initial oil concentration (1500-3500ppm), and NaCl concentration (0-30g/L), were optimized to obtain the best response of crude oil removal using response surface methodology (RSM) and Box-Behnken design (BBD). The highest crude oil removal of 79.58% was obtained for 1500ppm of crude oil after 14days using immobilized cells, and it was lower for freely suspended cells (64.77%). Our result showed similar trends in the effect of variables on the oil biodegradation rate in both free cell (FC) and immobilized cell (IC) systems. However, according to the analysis of variance (ANOVA) results, the extent of the variables' effectiveness was different in FC and IC systems. In the immobilized cell system, all variables had a greater effect on the rate of light crude oil degradation. Moreover, to evaluate the effectiveness of free and immobilized B. licheniformis in bioremediation of an actual polluted site, the crude oil spill in natural seawater was investigated. The results suggested the stability of beads in the seawater, as well as high degradation of petroleum hydrocarbons by free and immobilized cells in the presence of indigenous microorganisms.

Manganese Removal by Biofiltration Using Activated Carbon-barium Alginate-entrapped Cells: Morphology, Durability, Settling Velocity, and Treatment Efficiency

Occurrence of manganese in water supplies causes colored water and pipe rusting in water treatment and distribution systems. Moreover, consumption of manganese-contaminated water may lead to neurotoxicity in humans. Biofilters have the potential to alleviate the manganese issue through bio-oxidation, particle separation, and adsorption processes. Biofiltration performance can be enhanced by augmentation of the manganese-oxidizing bacterium entrapped in polymeric materials. This study aimed to investigate the potential of barium alginate-entrapped cells supplemented with powdered activated carbon (PAC) for manganese removal. Streptomyces violarus strain SBP1, an effective manganese-oxidizing bacterium, was selected. The experiments were divided into 2 parts, including 1) characterization of barium alginate bead and 2) manganese removal testing. Effect of PAC content (1, 5, and 10% w/v) in the entrapment material on bead morphology, bead durability, and settling velocity (relative to a filtration medium) was investigated. Micro-structural observation using a scanning electron microscope showed that the PAC was distributed through intra-porous structure of the beads. The PAC-supplemented barium alginate beads improved durability (up to three-time higher Young’s modulus values). The PAC-supplemented barium alginate beads gave similar settling velocity compared to a filtration medium. The manganese removal efficiencies by the PAC-supplemented beads (no cells) ranged from 48 to 53%. Based on barium alginate bead characterization and manganese removal performance, the bead with 5% PAC content was selected for cell entrapment. The investigation revealed that the entrapped cells achieved faster manganese removal rate than free cell system. The findings from this study indicated high potential of the entrapped cells for use in future biofilter applications.

Emergence of nanomaterials as potential immobilization supports for whole cell biocatalysts and cell toxicity effects.

The traditional approach of fermentation by a free cell system has limitations of low productivity and product separation that need to be addressed for production enhancement and cost effectiveness. One of potential methods to solve the problems is cell immobilization. Microbial cell immobilization allows more efficient up-scaling by reducing the nonproductive growth phase, improving product yield and simplifying product separation. Furthermore, the emergence of nanomaterials such as carbon nanotubes, graphene, and metal-based nanomaterials with excellent functional properties provides novel supports for cell immobilization. Nanomaterials have catalytic properties that can provide specific binding site with targeted cells. However, the toxicity of nanomaterials towards cells has hampered its application as it affects the biological system of the cells, which cannot be neglected in any way. This gray area in immobilization is an important concern that needs to be addressed and understood by researchers. This review paper discusses an overview of nanomaterials used for cell immobilization with special focus on its toxicological challenges and how by understanding physicochemical properties of nanomaterials could influence the toxicity and biocompatibility of the cells.

Continuous Ethanol Production from Molasses via Immobilized Saccharomyces cerevisiae on Different Carriers on Pilot Scale

IMMOBILIZATION of yeast cells for continuous ethanol production has been extensively studied worldwide during the past few years because it showed significant advantages compared to the production by free cell system. Using renewable substrates such as Egyptian cane and beet molasses becomes necessary to reduce food crops for bioethanol production. This study investigates the immobilization of commercial strain of Saccharomyces cerevisiae on different carriers (sugarcane bagasse, rice straw, wheat straw, and Na-alginate) for continuous ethanol production on a pilot scale. The results demonstrated that sugarcane bagasse was the best carrier for yeast cell immobilization. This substrate produced 66.30g/ L ethanol, 2.76g/ L/ hr as ethanol productivity, and 81% fermentation efficiency from the theoretical value, using a mixture of Egyptian cane and beet molasses with 16% initial sugar at 30°C and pH 4.5. Also, the production process is retained until 18 days continuously. From this study, it was clear that lignocellulosic materials provide suitable, cheap, and renewable carriers for immobilization of yeast cells used in the continuous ethanol production process.

Ex vivo generated human T-lymphoid progenitors as a tool to accelerate immune reconstitution after partially HLA compatible hematopoietic stem cell transplantation or after gene therapy.

Prolonged T-cell immunodeficiency following HLA- incompatible hematopoietic stem cell transplantation (HSCT) represents a major obstacle hampering the more widespread use of this approach. Strategies to fasten T-cell reconstitution in this setting are highly warranted as opportunistic infections and an increased risk of relapse account for high rates of morbidity and mortality especially during early month following this type of HSCT. We have implemented a feeder free cell system based on the use of the notch ligand DL4 and cytokines allowing for the in vitro differentiation of human T-Lymphoid Progenitor cells (HTLPs) from various sources of CD34+ hematopoietic stem and precursor cells (HSPCs). Co- transplantion of human T-lymphoid progenitors (HTLPs) and non- manipulated HSPCs into immunodeficient mice successfully accelerated the reconstitution of a polyclonal T-cell repertoire. This review summarizes preclinical data on the use of T-cell progenitors for treatment of post- transplantation immunodeficiency and gives insights into the development of GMP based protocols for potential clinical applications including gene therapy approaches. Future clinical trials implementing this protocol will aim at the acceleration of immune reconstitution in different clinical settings such as SCID and leukemia patients undergoing allogeneic transplantation. Apart from pure cell-therapy approaches, the combination of DL-4 culture with gene transduction protocols will open new perspectives in terms of gene therapy applications for primary immunodeficiencies.

Fermentative ethanol production from Madhuca indica flowers using immobilized yeast cells coupled with solar driven direct contact membrane distillation with commercial hydrophobic membranes

The objective of the present investigation is to develop and evaluate economic production of biofuels (ethanol) using immobilized yeast cells (Saccharomyces cerevisiae NCIM 3095) from renewable carbon source Madhuca indica (Mahua flowers). The entrapment of yeast cells in calcium alginate-polyvinyl alcohol (CA-PVA) film were found most suitable immobilizing matrix as a protective carrier to increase the stability and tolerance limit during continuous fermentation. Under similar fermentation conditions, immobilized yeast cells produced higher ethanol yield (∼0.48 g/g) and productivity (∼28 g/L/h) as compared to traditional suspended free cells system in continuous fermentation with dilution rate of 0.4/h. Further, the fermenter was coupled with solar driven membrane distillation (SDMD) process for separation and concentration of ethanol after fermentation. The new system does not require centrifugation/microfiltration for separation and/or recycle of biomass as the cells were immobilized and could be easily separated by simple filtration. The SDMD with cross flow module in rectangular shape and counter-current flow of streams (hot and cold) ensured higher ethanol flux (23 kg EtOH/m2/24 h) in comparison to existing literature. The new process design is compact yet flexible, eco-friendly, energy intensive and sustainable process for the development of economic biofuel production.

Performance and kinetics of triclocarban removal by entrapped Pseudomonas fluorescens strain MC46

This study investigated removal of triclocarban (TCC) from contaminated wastewater by Pseudomonas fluorescens strain MC46 entrapped in barium alginate. Appropriate entrapped cell preparation conditions (cell-to-entrapment material ratio and cell loading) for removing TCC were examined. The highest TCC removal by the entrapped and free cell systems at the initial TCC concentration of 10 mg/L was 72 and 45%, respectively. TCC was degraded to less toxic compounds. Self-substrate inhibition was found at TCC concentration of 30 mg/L. The kinetics of TCC removal by entrapped and free cells fitted well with Edwards model. Scanning and transmission electron microscopic observations revealed that entrapment matrices reduced TCC-microbe contact, which lessened TCC inhibition. A live/dead cell assay also confirmed reduced microbial cell damage in the entrapped cell system compared to the free cell system. This study reveals the potential of entrapment technology to improve antibiotic removal from the environment.