•A thermo-sensitive aqueous biphasic system for recovery of bioactive compounds is explored.•High recovery yield, 96.54 ± 0.09%, of antioxidants was achieved in polymer-rich phase.•Low loss of ...thermo-polymer indicates that ABS is a potential system for antioxidants separation.
Tea is receiving great interests due to potential health benefits associated with long term consumption. Theaflavins, thearubigins and catechins presence in black tea possess high antioxidant capacity and biological activities. Concentration and extraction of these potent antioxidants from Camellia sinensis var. assamica leaves with an aqueous biphasic system (ABS) composed of thermo-sensitive ethylene oxide–propylene oxide (EOPO) random copolymer and salt was demonstrated. The thermo-sensitive EOPO can be recovered upon heating above a lower critical solution temperature (LCST). The partition coefficients of polyphenols based on phenolic content in the EOPO/salt ABS were determined to understand the partition preference of the polyphenols in the extraction system. Effects of different types of salts, tie-line length (TLL), volume ratio (VR), sample loading, pH and equilibration time on the extraction efficiency of polyphenols using ABS were evaluated. The EOPO polymer recovery was performed after the primary aqueous biphasic extraction. The highest recovery of polyphenols in EOPO-rich phase was obtained in EOPO 2500/sulphate ABS at pH of 7.0, TLL of 41.4% (w/w), VR of 1.0, sample loading of 0.3% (w/w) and equilibration time of 12.5 min. A total of 96.54 ± 0.09% of polyphenols was recovered in the EOPO-rich phase of the primary EOPO 2500/sulphate ABS with a partition coefficient of polyphenols (Kpc) of 26.93 ± 0.76. Later, 95.2% of the EOPO 2500 polymer was recovered after the thermo-induction of the polymer-rich phase. This study has successfully demonstrated the feasibility of thermo-sensitive ABS in the extraction and enrichment of antioxidants from plant sources.
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Miracle fruit, Synsepalum dulcificum, contains a glycoprotein known as miraculin. After consuming this glycoprotein, sour foods taste sweet and the effect lasts for up to 4 h. With increasing demand ...for natural and “low-calorie” sweeteners, the use of miraculin as an additive is increasing enormously in the food, medicine and cosmetic industries. In this study, we used reverse micelles formed from a sodium di (2-ethylhexyl) sulfosuccinate (AOT)/isooctane system to purify miraculin from S. dulcificum. We studied factors affecting purification performance, such as surfactant (AOT) concentration and the pH of the crude during forward extraction. During backward extraction, we examined the effects of NaCl concentration, the pH of the aqueous phase and addition of isopropanol. We found that 0.1 mol/L AOT/isooctane solution mixed with crude extract at pH 8 during the forward extraction stage and 0.5 mol/L NaCl solution at pH 11 during the backward stripping stage were optimal purification conditions, from which 22% miraculin was recovered with a purity of 94.8%.
•The best purification for miraculin was obtained when crude pH was adjusted to 8.•Optimum pH of aquous phase in backward extraction was 11.•AOT/isooctane-based system allowed purification of miraculin.
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•The nitrate reductase activity of LAB was screened using an enzymatic assay.•The nitrate reductase activity of LAB was optimized via RSM.•The biosynthesis of AgNPs by LAB was ...enhanced by optimized enzyme activity.•The biosynthesized AgNPs were characterized using various techniques.
Among emerging nanotechnology, silver nanoparticles (AgNPs) get much attention due to their unique physicochemical properties. The present study aimed to optimize the nitrate reductase production in lactic acid bacteria (LAB) for enhanced production of AgNPs and characterize the biosynthesized AgNPs. Lactobacillus plantarum CAM 4 produced higher nitrate reductase activity (121.77 U/mL) under optimized medium containing 0.75 % of glucose, 2 % of KNO3, and pH 5.0 and successfully enhanced the AgNPs biosynthesis. Spectrophotometric analysis revealed that the biosynthesized AgNPs exhibited a peak at 430 nm. DLS analysis indicated the monodispersed characteristic of AgNPs. TEM and FE-SEM analysis shows that the AgNPs were spherical-like shape, while the EDX analysis spectrum revealed the existence of an Ag element in AgNPs. Moreover, biosynthesized AgNPs exhibited antibacterial activity against Gram-positive and Gram-negative pathogens. Results from this study provide notable insights into sustainable and inexpensive methods for the enhanced production of AgNPs using LAB.
Haematococcus lacustris (formerly called Haematococcus pluvialis) is regarded as the most promising microalgae for the production of natural astaxanthin, which is secondary metabolism used as a ...dietary supplement, also for cosmetic applications, due to its high anti-oxidant activity. Astaxanthin has a wide range of biological activities and high economic potential, and currently dominates the market in its synthetic form. Furthermore, because of the difficulty of bioprocess and the high cost of cultivation, astaxanthin extracted from this microalga is still expensive due to its low biomass and pigment productivities. Large-scale biomass production in biotechnological production necessitates the processing of a large number of cultures as well as the use of both indoor and outdoor systems, such as open pond raceway systems and photo-bioreactors (PBR). The photo-bioreactors systems are suitable for mass production because growth conditions can be controlled, and the risk of contamination can be reduced to a certain extent and under specific culture parameters. This review discusses current technologies being developed to improve cultivation and operation efficiency and profitability, as well as the effect of parameter factors associated with H. lacustris cultivation on biomass and astaxanthin bioproduction, and even strategies for increasing bioproduction and market potential for H. lacustris astaxanthin.
► We examine expanded bed adsorption (EBA) system packed with resin to remove acetate in fermentation broth. ► Integrated EBA to stirred tank bioreactor (STR) enhanced the growth of E. coli. ► ...Optimized STR/EBA system enhanced the production of periplasmic interferon alpha2b.
A stirred tank bioreactor (STB) integrated with an expanded bed adsorption (EBA) system containing anion-exchange resin (Diaion WA30) was developed for in situ removal of acetate to increase the production of α-interferon-2b (α-PrIFN-2b) by Escherichia coli (E. coli). Although the total acetate (9.79g/L) secreted by E. coli in the integrated STB/EBA system was higher than that in a bioreactor with dispersed resin or a conventional batch bioreactor, cell growth (14.97g/L) and α-PrIFN-2b production (867.4μg/L) were significantly improved owing to the high efficiency of acetate removal from the culture. The production of α-PrIFN-2b in the integrated STB/EBA system was improved by 3-fold and 1.4-fold over that obtained in a conventional batch bioreactor and a bioreactor containing dispersed resins, respectively.
Current advances in biotechnology have been looked at as alternative approaches towards the limited product recovery due to time- and cost-consuming drawbacks on the conventional purification ...methods. This study aimed to purify bovine serum albumin (BSA) as an exemplary target product using an aqueous impregnated resin system (AIRS). This method implies the concept of hydrophobicity of polymer that impregnated into the resins and driven by electrostatic attractions and hydrophilicity of aqueous salt solution to extract the target product.
The extraction behaviors of impregnation in terms of stability and adsorption kinetics via protein-aqueous polymer impregnated resin were studied. Impregnation stability was determined by the leaching factor of polyethylene glycol (PEG). The major factors such as PEG molecular weights and concentration, pH of aqueous salt solution, extraction methods (sonication and agitation) and types of adsorbent material and concentration of aqueous salt phase influencing on partitioning of biomolecule were also investigated.
For impregnation stability, the leaching factor for Amberlite XAD4 did not exceed 1%. The scanning electron microscopy (SEM) image analysis of Amberlite XAD4 attributes the structural changes with impregnation of resins. For adsorption kinetics, Freundlich adsorption isotherm with the highest R
value (0.95) gives an indication of favorable adsorption process. Performance of AIRS impregnated with 40% (w/w) of PEG 2000 was found better than aqueous-two phase system (ATPS) by yielding the highest recovery of BSA (53.72%). The outcomes of this study propound the scope for the application of AIRS in purification of biomolecules.
This paper reports the prebiotic efficacy of soluble crude polysaccharides (SCP) from palm kernel cake on the growth rates and acidifying property of probiotic lactic acid bacteria (LAB), ...Lactobacillus plantarum ATCC 8014 and Lactobacillus rhamnosus ATCC 53103, to investigate into the potential SCP of an agriculture by-product as a novel prebiotic. The highest extraction yield of SCP (2.90%) was obtained using NaOH. The extracted polysaccharides were highly soluble (>97%). The highest percentage of protein (0.63 ± 0.09%) and the total carbohydrate content (55.36 ± 0.33%) were observed in NaOH-extracted SCP (SCP
N
) and citric acid-extracted SCP (SCP
CA
). Water-extracted SCP (SCP
W
) contained the highest percentage of glucose, whereas SCP
CA
demonstrated the presence of two major monosaccharides, galactose and mannose. Structural analysis of SCP showed peaks in the range of 1000-1077 cm
−1
, an indication of the presence of polysaccharides and alpha (α)- or beta (β)-glycosidic linkages. The degree of hydrolysis increased with the increase of pH from 5 to 8 following 4 h incubation. SCP
W
and SCP
CA
were more resistant (95%) to α-amylase as compared to fructooligosaccharides (FOS). As in the case of FOS (∼98%), SCP
W
(∼99%) and SCP
CA
(∼98%) were resistant to artificial human gastric juice and their degree of hydrolysis had negative correlation with the pH. The product was found to markedly stimulate the proliferation of the tested probiotics and acid production. All the above findings are supportive of the fact that polysaccharides extracted from CKC have a vast potential to be exploited as novel prebiotic.
This work aimed to optimize the parameters affecting partitioning of a bacteriocin-like inhibitory substances (BLIS) from Lactococcus lactis Gh1 in extractive fermentation using polyethylene glycol ...(PEG)/dextran aqueous two-phase system (ATPS). This system was developed for the simultaneous cell cultivation and downstream processing of BLIS. Results showed that the molecular weight of PEG, PEG concentration, and dextran T500 affect the partition coefficient (K), purification factor (PF), and yield of BLIS partitioning. ATPS composed of 10% (w/w) PEG2000 and 8% (w/w) dextran T500, provided the greatest conditions for the extractive BLIS production. The K (1.00 ± 0.16), PF (2.92 ± 0.37) and yield (77.24 ± 2.81%) were increased at selected orbital speed (200 rpm) and pH (pH 7). Sustainable growth of the cells in the bioreactor and repeated fermentation up to the eighth extractive batch were observed during the scale up process, ensuring a continuous production and purification of BLIS. Hence, the simplicity and effectiveness of ATPS in the purification of BLIS were proven in this study.
Demand for high-throughput bioprocessing has dramatically increased especially in the biopharmaceutical industry because the technologies are of vital importance to process optimization and media ...development. This can be efficiently boosted by using microtiter plate (MTP) cultivation setup embedded into an automated liquid-handling system. The objective of this study was to establish an automated microscale method for upstream and downstream bioprocessing of α-IFN2b production by recombinant Escherichia coli. The extraction performance of α-IFN2b by osmotic shock using two different systems, automated microscale platform and manual extraction in MTP was compared.
The amount of α-IFN2b extracted using automated microscale platform (49.2 μg/L) was comparable to manual osmotic shock method (48.8 μg/L), but the standard deviation was 2 times lower as compared to manual osmotic shock method. Fermentation parameters in MTP involving inoculum size, agitation speed, working volume and induction profiling revealed that the fermentation conditions for the highest production of α-IFN2b (85.5 μg/L) was attained at inoculum size of 8%, working volume of 40% and agitation speed of 1000 rpm with induction at 4 h after the inoculation.
Although the findings at MTP scale did not show perfect scalable results as compared to shake flask culture, but microscale technique development would serve as a convenient and low-cost solution in process optimization for recombinant protein.
Mixotrophic metabolism was evaluated as an option to augment the growth and lipid production of marine microalga Tetraselmis sp. FTC 209. In this study, a five-level three-factor central composite ...design (CCD) was implemented in order to enrich the W-30 algal growth medium. Response surface methodology (RSM) was employed to model the effect of three medium variables, that is, glucose (organic C source), NaNO3 (primary N source), and yeast extract (supplementary N, amino acids, and vitamins) on biomass concentration, Xmax, and lipid yield, Pmax/Xmax. RSM capability was also weighed against an artificial neural network (ANN) approach for predicting a composition that would result in maximum lipid productivity, Prlipid. A quadratic regression from RSM and a Levenberg-Marquardt trained ANN network composed of 10 hidden neurons eventually produced comparable results, albeit ANN formulation was observed to yield higher values of response outputs. Finalized glucose (24.05 g/L), NaNO3 (4.70 g/L), and yeast extract (0.93 g/L) concentration, affected an increase of Xmax to 12.38 g/L and lipid a accumulation of 195.77 mg/g dcw. This contributed to a lipid productivity of 173.11 mg/L per day in the course of two-week cultivation.
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