Characterization of an encapsulation device for the production of monodisperse alginate beads for cell immobilization

The consumption of dyes is increasing worldwide in line with the increase of population and demand for clothes and other colored products. However, the efficiency of dyeing processes is still poor and results in large amounts of colored effluents. It is desired to develop a portfolio of enzymes which can be used for the treatment of colored wastewaters. Herein, we used genome sequence information to discover a dye-decolorizing peroxidase (DyP) from Pseudomonas fluorescens Pf-01. Two genes putatively encoding for DyPs were identified in the respective genome and cloned for expression in Escherichia coli, of which one (PfDyP B2) could be overexpressed as a soluble protein. PfDyP B2 shows some typical features known for DyPs which includes the ability to convert dyes at the expense of hydrogen peroxide. Interestingly, t-butyl hydroperoxide could be used as an alternative substrate to hydrogen peroxide. Immobilization of PfDyP B2 in calcium-alginate beads resulted in a significant increase in stability: PfDyP B2 retains 80% of its initial activity after 2 h incubation at 50 °C, while the soluble enzyme is inactivated within minutes. PfDyP B2 was also tested with aniline and ethyl diazoacetate as substrates. Based on GC-MS analyses, 30% conversion of the starting material was achieved after 65 h at 30 °C. Importantly, this is the first report of a DyP-catalyzed insertion of a carbene into an N-H bond.

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Preparation and Characterization of Alginate and Psyllium Beads ContainingLactobacillus acidophilus

The Scientific World JOURNAL ◽

10.1100/2012/680108 ◽

2012 ◽

Vol 2012 ◽

pp. 1-8 ◽

Cited By ~ 23

Author(s):

Farzaneh Lotfipour ◽

Shahla Mirzaeei ◽

Maryam Maghsoodi

Keyword(s):

Lactobacillus Acidophilus ◽

Encapsulation Efficiency ◽

Alginate Beads ◽

Probiotic Bacteria ◽

Partial Substitution ◽

Narrow Size Distribution ◽

Acidic Conditions ◽

Ph Conditions

This paper describes preparation and characterization of beads of alginate and psyllium containing probiotic bacteria ofLactobacillus acidophilusDMSZ20079. Twelve different formulations containing alginate (ALG) and alginate-psyllium (ALG-PSL) were prepared using extrusion technique. The prepared beads were characterized in terms of size, morphology and surface properties, encapsulation efficiency, viabilities in acid (pH 1.8, 2 hours) and bile (0.5% w/v, 2 hours) conditions, and release in simulated colon pH conditions. The results showed that spherical beads with narrow size distribution ranging from1.59±0.04to1.67±0.09 mm for ALG and from1.61±0.06to1.80±0.07mm for ALG-PSL with encapsulation efficiency higher than 98% were achieved. Furthermore, addition of PSL into ALG enhanced the integrity of prepared beads in comparison with ALG formulations. The results indicated that incorporation of PSL into alginate beads improved viability of the bacteria in acidic conditions as well as bile conditions. Also, stimulating effect of PSL on the probiotic bacteria was observed through 20-hour incubation in simulated colonic pH solution. According to ourin vitrostudies, PSL can be a suitable polymer candidate for partial substitution with ALG for probiotic coating.

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Physicochemical Characterization of Alginate Beads Containing Sugars and Biopolymers

Journal of Quality and Reliability Engineering ◽

10.1155/2016/9184039 ◽

2016 ◽

Vol 2016 ◽

pp. 1-7 ◽

Cited By ~ 13

Author(s):

Tatiana Aguirre Calvo ◽

Patricio Santagapita

Keyword(s):

Water Content ◽

Digital Image Analysis ◽

Individual Component ◽

Physicochemical Characterization ◽

Alginate Beads ◽

Complete Characterization ◽

Ft Ir ◽

Different Characteristics ◽

Lower Water Content

Alginate hydrogels are suitable for the encapsulation of a great variety of biomolecules. Several alternatives to the conventional alginate formulation are being studied for a broad range of biotechnological applications; among them the addition of sugars and biopolymers arises as a good and economic strategy. Sugars (trehalose and β-cyclodextrin), a cationic biopolymer (chitosan), an anionic biopolymer (pectin), and neutral gums (Arabic, guar, espina corona, and vinal gums) provided different characteristics to the beads. Here we discuss the influence of beads composition on several physicochemical properties, such as size and shape, analyzed through digital image analysis besides both water content and activity. The results showed that the addition of a second biopolymer, β-CD, or trehalose provoked more compact beads, but the fact that they were compact not necessarily implies a concomitant increase in their circularity. Espina corona beads showed the highest circularity value, being useful for applications which require a controlled and high circularity, assuring quality control. Beads with trehalose showed lower water content than the rest of the system, followed by those containing galactomannans (espina corona, vinal, and guar gums), revealing polymer structure effects. A complete characterization of the beads was performed by FT-IR, assigning the characteristics bands to each individual component.

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