Alginate Encapsulation Research Articles

Optimised biopolymer-based capsules for enhancing the mechanical and self-healing properties of asphalt mixtures

The growing need to enhance our road infrastructure has driven the development of several innovative techniques in recent years. Among these advancements, encapsulated rejuvenator solutions for extrinsic self-healing asphalt have emerged as a significant topic of interest. This paper evaluates the effect of optimised capsules containing vegetal oil as a biorejuvenator on the physical, mechanical, and self-healing properties of dense asphalt mixtures. In this study, previously optimised polynuclear alginate-based capsules were synthesised using vibrating jet technology with 5% wt. calcium chloride and a biopolymer-to oil mass ratio 1:7. Optimised capsules were incorporated into the asphalt mixture at concentrations of 0.125% wt., 0.25% wt., and 0.5% wt. Their spatial distribution within the asphalt mixtures was evaluated using an alternative method to CT scans, which utilised machine learning-based image analysis of the core asphalt samples. The main findings of this research are as follows: (1) a uniform distribution of capsules was achieved throughout the asphalt mixture, although clustering was observed at higher concentrations. (2) The capsules successfully survived the asphalt manufacturing process, and mechanical tests highlighted the adhesive properties of the alginate encapsulation material. (3) Asphalt samples with 0.125% wt. capsules exhibited mechanical performance comparable to samples without capsules; however, this content did not significantly enhance their self-healing properties. In contrast, self-healing capabilities were significantly enhanced with a capsule content greater than or equal to 0.25% wt.; however, this enhancement slightly affected some physical–mechanical properties of the dense asphalt mixture.

Removal of Pb(II) and Cd(II) from a Monometallic Contaminated Solution by Modified Biochar-Immobilized Bacterial Microspheres.

Lead (Pb) and cadmium (Cd) are toxic pollutants that are prevalent in wastewater and pose a serious threat to the natural environment. In this study, a new immobilized bacterial microsphere (CYB-SA) was prepared from corn stalk biochar and Klebsiella grimontii by sodium alginate encapsulation and vacuum freeze-drying technology. The removal effect of CYB-SA on Pb(II) and Cd(II) in a monometallic contaminated solution was studied. The results showed that the removal of Pb(II) and Cd(II) by CYB-SA was 99.14% and 83.35% at a dosage of 2.0 g/L and pH = 7, respectively, which was 10.77% and 18.58% higher than that of biochar alone. According to the Langmuir isotherm model, the maximum adsorption capacities of Pb(II) and Cd(II) by CYB-SA at 40 °C were 278.69 mg/g and 71.75 mg/g, respectively. A combination of the kinetic model, the isothermal adsorption model, scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) analyses showed that the main adsorption mechanisms of CYB-SA encompass functional group complexation, ion exchange, electrostatic attraction and physical adsorption. The findings of this study offer practical and theoretical insights into the development of highly efficient adsorbents for heavy metals.

Co-Encapsulation of Coffee and Coffee By-Product Extracts with Probiotic Kluyveromyces lactis.

Coffee and coffee by-products contain several chemical compounds of great relevance, such as chlorogenic acid (CGA), trigonelline, and caffeine. Furthermore, yeasts have been the target of studies for their use as probiotics because of their interesting biochemical characteristics. The combined administration of probiotic microorganisms with components that provide health benefits mediated by alginate encapsulation is an alternative that ensures the stability of cells and chemical compounds. In this context, the aim of this work was to co-encapsulate the probiotic yeast Kluyveromyces lactis B10 and extracts of green coffee beans, coffee silverskin, and PVA (black, green or immature, and sour coffee beans). The bioactive composition, antioxidant and antimicrobial activities of the extracts, microcapsule morphological characteristics and encapsulation efficiency, ability of the encapsulation to protect the yeast cells subjected to gastrointestinal conditions, and antioxidant activity of the microcapsules were evaluated. All the evaluated extracts showed antioxidant activity, of which PVA showed 75.7% and 77.0%, green coffee bean showed 66.4% and 45.7%, and coffee silverskin showed 67.7% and 37.4% inhibition of DPPH and ABTS•+ radicals, respectively, and antimicrobial activity against the pathogenic bacteria E. coli, Salmonella, and S. aureus, with high activity for the PVA extract. The microcapsules presented diameters of between 1451.46 and 1581.12 μm. The encapsulation efficiencies referring to the yeast retention in the microcapsules were 98.05%, 96.51%, and 96.32% for green coffee bean, coffee silverskin, and PVA, respectively. Scanning electron microscopy (SEM) showed that the microcapsules of the three extracts presented small deformations and irregularities on the surface. The K. lactis cells encapsulated in all treatments with the extracts showed viability higher than 8.59 log CFU/mL, as recommended for probiotic food products. The addition of green coffee bean, coffee silverskin, and PVA extracts did not reduce the encapsulation efficiency of the alginate microcapsules, enabling a safe interaction between the extracts and the K. lactis cells.

Single stage bi-substrate transglycosylation reaction for the synthesis of ascorbic acid 2 glucoside using immobilized α-glucosidase

Alpha glucosidases are multifunctional glycoside hydrolases with hydrolysis and transglycosylation ability. It can be utilized for the glycosidic bond synthesis or glycosylation of Ascorbic acid/Vitamin C to its stable analogue, Ascorbic acid 2 glucoside (AA2G), a compound with wide applications in cosmetics and pharma. The application of α-glucosidases for industrial scale transglycosylation is limited due to the low transglycosylation yield of free enzymes. Enzyme immobilization techniques could enable the development of efficient, reusable catalysts. Only a few glycoside hydrolases have been studied in immobilized form for transglycosylation reactions, and α-glucosidases are probably the least explored in this form. Transglycosylation activity of immobilized α-glucosidase from Aspergillus carbonarius BTCF 5 was studied for AA2G synthesis, where different immobilization techniques like calcium alginate encapsulation, adsorption on chitosan beads, covalent cross-linking on magnetic nanoparticles, and cross-linked enzyme aggregates (CLEA) were employed for the immobilization. The immobilization yield of calcium alginate encapsulated enzyme, enzyme immobilized on Fe-MNP support, enzyme immobilized on chitosan beads and as CLEA were 107%, 99%, 46% and 486%, respectively. CLEA was identified as the best immobilization technique for this bi-substrate reaction due to the high immobilization yield and activity retention (30% activity retained after 5 consecutive cycles). Enzyme immobilization increased the transglycosylation activity by 38%, yielding 118 mM AA2G against 72 mM by the free enzyme. This indicates the potential of immobilized α-glucosidase as a catalyst for synthesizing AA2G at an industrial scale.

Ca2+-mediated chitosan/sodium alginate encapsulated Red Monascus Pigment hydrogel beads: Preparation, characterization and release kinetics

Red Monascus Pigment (RMP), a natural pigment, has attracted significant attention due to its suitability for food use and potential health benefits. However, preserving its stability and exploring value-added development opportunities remain crucial challenges. This study outlined the utilization of RMP, by successfully preparing hydrogel beads encapsulating RMP crude extract (RMPCE) through Ca2+-mediated chitosan (CS)/sodium alginate (SA) encapsulation (CO-RMPHB). A systematic investigation into the fabrication and stability parameters, including preparation conditions, temperature, monochromatic light and storage time, was undertaken. Through optimization (SA: 2.50 wt%; CaCl2: 6.00 wt%; CS: 0.50 wt%), maximum encapsulation efficiency of 73.54 ± 2.16 % was achieved. The maximum swelling degree of blank hydrogel beads (BHB) in simulated gastric solution (pH = 1.2, 1.50 ± 0.97 %) was significantly lower than in simulated intestinal solution (pH = 7.0, 28.05 ± 1.43 %), confirming their sensitivity to pH changes. Additionally, the CO-RMPHB (66.08 %, 1000 μL) exhibited superior DPPH radical scavenging capability compared to individual RMPCE or BHB. Furthermore, analysis of the release kinetics based on zero-order, first-order, Higuchi, and Ritger-Peppas models revealed that RMPCE release from CO-RMPHB under in vitro digestion models followed non-Fickian diffusion. This discovery effectively addresses the challenges of the stability and controlled release of RMP, expanding its applications in the food and pharmaceutical industries.

Survivability of probiotic under simulated gastrointestinal conditions as affected by synbiotic (alginate-arabinoxylan) encapsulation

ABSTRACT The food industry is faced with a significant challenge in maintaining the viability and stability of probiotics during processing and in model food. Encapsulation technology offers a promising solution to this issue. This study was aimed to investigate the effect of Sodium Alginate (SA) and arabinoxylan (AX) composite encapsulation on the viability & stability of Lactobacillus rhamnosus GG. The AX was extracted from maize and characterized, and then the SA-AX composite was used to encapsulate the probiotics. The resulting microbeads were analyzed for their morphological, molecular, and physicochemical properties. The MAX-SA microbeads demonstrated the highest efficiency at 97.9 ± 0.6%, followed by MAX at 95 ± 1.5% and SA at 92 ± 1.4%. The FTIR spectra revealed specific functional groups in the samples. The MAX-SA and MSA matrices had a dispersed structure, while the MAX matrix had a smooth microstructure. The microcapsules had an average size ranging from 718 ± 2 mm to 734 ± 2 mm. The viability of the encapsulated probiotics was assessed under storage conditions, simulated gastrointestinal conditions, and model food. Encapsulated probiotics showed higher viability than free probiotics in simulated gastrointestinal conditions, and pineapple juice fortified with encapsulated probiotics showed a higher probiotic count. Overall, the study found that MAX-SA was the most effective in maintaining probiotic viability under stressed conditions.

Harnessing plant-beneficial bacterial encapsulation: A sustainable strategy for facilitating cadmium bioaccumulation in Medicago sativa

Plant-beneficial bacteria (PBB) have emerged as a promising approach for assisting phytoremediation of heavy metal (HM)-contaminated soils. However, their colonization efficiency is often challenged by complex soil environments. In this study, we screened one rhizobacterium (Klebsiella variicola Y38) and one endophytic bacterium (Serratia surfactantfaciens Y15) isolated from HM-contaminated soils and plants for their high resistance to Cd and strong growth-promoting abilities. These strains were encapsulated individually or in combination with alginate and applied with Medicago sativa in Cd-contaminated soil pot experiments. The effectiveness of different bacterial formulations in promoting plant growth and enhancing Cd bioconcentration in M. sativa was evaluated. Results showed that PBB application enhanced plant growth and antioxidant capacity while reducing oxidative damage. Encapsulated formulations outperformed unencapsulated ones, with combined formulations yielding superior results to individual applications. Quantitative PCR indicated enhanced PBB colonization in Cd-contaminated soils with alginate encapsulation, potentially explaining the higher efficacy of alginate-encapsulated PBB. Additionally, the bacterial agents modified Cd speciation in soils, resulting in increased Cd bioaccumulation in M. sativa by 217–337 %. The alginate-encapsulated mixed bacterial agent demonstrated optimal effectiveness, increasing the Cd transfer coefficient by 3.2-fold. Structural equation modeling and correlation analysis elucidated that K. variicola Y38 promoted Cd bioaccumulation in M. sativa roots by reducing oxidative damage and enhancing root growth, while S. surfactantfaciens Y15 facilitated Cd translocation to shoots, promoting shoot growth. The combined application of these bacteria leveraged the benefits of both strains. These findings contribute to diversifying strategies for effectively and sustainably remediating Cd-contaminated soils, while laying a foundation for future investigations into bacteria-assisted phytoremediation.

Short-range molecular order is the driving factor for starch digestibility and texture of alginate-encapsulated rice beads.

Rice grain analogues with slow starch digestibility are commonly associated with an unsatisfactory texture, often leading to consumer dissatisfaction. Alginate encapsulation has been applied to reduce the digestibility of corn and potato starch. The fine molecular structures of rice starch can greatly determine its digestibility and texture. However, it remains unclear whether a combination of alginate encapsulation and varied starch molecular structures can be employed to create rice grain analogues that offer both slow starch digestibility and an appealing texture. For the first time, the present study constructed alginate-encapsulated rice beads (as a rice grain analogue). A wide range of starch digestion rates were found among alginate-encapsulated rice beads prepared with different rice varieties, and only certain rice varieties (e.g. Subei and Nanjing) were able to result in rice beads with slower starch digestibility than their parental rice kernels. More importantly, all rice beads showed a relatively softer texture compared to their parental rice kernels. Correlation analysis showed that starch digestion rate, hardness and stickiness were all positively correlated with the ratio of short-range amorphous regions in rice bead samples, as obtained from Fourier transform-infrared spectroscopy, but not with the relative crystallinity. Collectively, these results suggest that rice beads with slower starch digestion rate and softer texture could be obtained by choosing rice varieties that develop more short-range ordered structure after cooking. © 2024 Society of Chemical Industry.

Encapsulation in Alginates Hydrogels and Controlled Release: An Overview.

This review aims to gather the current state of the art on the encapsulation methods using alginate as the main polymeric material in order to produce hydrogels ranging from the microscopic to macroscopic sizes. The use of alginates as an encapsulation material is of growing interest, as it is fully bio-based, bio-compatible and bio-degradable. The field of application of alginate encapsulation is also extremely broad, and there is no doubt it will become even broader in the near future considering the societal demand for sustainable materials in technological applications. In this review, alginate's main properties and gelification mechanisms, as well as some factors influencing this mechanism, such as the nature of the reticulation cations, are first investigated. Then, the capacity of alginate gels to release matter in a controlled way, from small molecules to micrometric compounds, is reported and discussed. The existing techniques used to produce alginates beads, from the laboratory scale to the industrial one, are further described, with a consideration of the pros and cons with each techniques. Finally, two examples of applications of alginate materials are highlighted as representative case studies.

Advancing bacterial endophyte encapsulation in alginate for sustainable agriculture: Method comparisons, morphology and viability assessment

This study focused on encapsulating Kosakonia radicincitans in alginate beads and capsules using the Ionic External Gelation (IEG) and Reverse Gelation (RG) methods. The results showed that both IEG and RG methods provided high encapsulation efficiencies (84.61% and 85.22%, respectively) without additives. The beads and capsules displayed distinct morphological characteristics, with beads exhibiting smooth and homogeneous surfaces, while capsules appeared rougher and more irregular. The biodegradability study revealed that the encapsulated materials exhibited higher mass loss at elevated temperatures, indicating the potential rapid release of bacterial cells into the soil-plant system. However, the viability of bacteria persisted around the particles even after 60 days in the soil, suggesting that drying temperature and ambient temperature play crucial roles in determining the biofertilizer's persistence in the soil. This research highlights the complexities associated with the long-term effects of encapsulated biofertilizers, which are critical for advancing toward sustainable environmental and agricultural solutions.

Molecular identification of bacteria (Klebsiella aerogenes, PP335235) isolated from street food (Fried Rice); study of its antibiotic sensitivity pattern and probiotic fortification of fruit juice (Fragaria ananassa, Passiflora ligularis and Phyllanthus e

Street food is an integral part of India's culinary culture, offering patrons a wide range of affordable options. However, concerns about the public's health risks associated with street food consumption persist due to inadequate infrastructure and the transient nature of street vendors. Contaminated street food can lead to foodborne illnesses such as gastroenteritis, typhoid fever, pneumonia, food poisoning, and hepatitis A. Probiotics, which are beneficial bacteria, are potentially effective by targeting specific infections. Probiotic-enriched fruit drinks present an innovative approach to improving population nutrition and probiotic provision. Lactobacillus gasseri is a gram-positive bacterium that has been demonstrated to be a promising strain of probiotic due to its resistance to acidity and beneficial effects on gut health. Alginate encapsulation improves the stability and release of probiotic strain. Probiotic fruit juices can be made from fruits that are rich in antioxidants and nutrients, such as Passiflora ligularis, Fragaria ananassa, and Phyllanthus emblica. The aim of this study was to use molecular methods to discover Klebsiella aerogenes (PP335235) isolated from street foods. The study also sought to determine the isolate's pattern of antibiotic sensitivity and explore the potential of fortifying fruit juice with Lactobacillus gasseri as a probiotic nutraceutical therapeutic strategy.

BIOMASS PRODUCTION AND SINGLE-CELL PROTEIN (SCP) ENCAPSULATION OF BACTERIA Bacillus cereus SN7

Bacillus cereus SN7 is a bacterium with potential applications in producing Single-Cell Protein (SCP). SCP can be an alternative to protein derived from traditional sources like agriculture, fisheries, and animal husbandry. Encapsulation is a process used to stabilize cells, aiming to potentially enhance probiotics' viability and stability throughout production, storage, and handling. This study aims to make capsules from B. cereus SN7 single-cell protein to protect them from contaminants. This study used a survey method, which carried out in-situ processing of bacteria, as well as conducting experiments on the formation of bacterial encapsulation, testing the effectiveness of encapsulation, and observing the viability of B. cereus SN7 bacteria by counting the number of colonies. B. cereus produced biomass with a total dry weight of 1.3708 g/mL. The alginate encapsulation experiments can be formed into capsule beads that protect bacteria. The best encapsulation process is an alginate-based coating, which is indicated by the ability of the alginate to withstand temperature, pH, and salinity

65 Testing the effects of rigid encapsulations on bovine primordial follicle quiescence versus growth

OBJECTIVES/GOALS: There is an interest in developing a bioprosthetic ovary for ovarian tissue transplantation. The properties of the ovarian extracellular matrix need to be better understood in order to replicate the human ovary. We tested the effects of an encapsulating hydrogel at different rigidities on bovine primordial follicle activation, growth, and survival. METHODS/STUDY POPULATION: Bovine primordial follicles were isolated from ovarian cortex. A mean of 9.9 follicles (range 3-24) were encapsulated per bead in either 1% or 5 % alginate across 4 experiments. The encapsulated follicles were subsequently crosslinked in a calcium sulfate solution. Follicles were then cultured for 8 days with light microscopy imaging taken every other day along with media exchanges. Follicles were then examined using immunofluorescence. Growth and survival curves were constructed and all statistical analyses were performed using Graph Pad Prism 9. RESULTS/ANTICIPATED RESULTS: A total of 372 follicles were encapsulated across 32 beads (16 in 1% alginate and 16 in 5% alginate). There were no differences in initial follicle size between the two conditions (33.53 µm vs. 32.45 µm, p=0.47). At the end of 8 days, there was no difference between follicle size (59.55 vs. 56.06, p=0.48). Additionally, there was no difference in survival between 1% and 5% alginate encapsulation (57.75% vs. 52.43%. p=0.40). Immunofluorescence is being performed on encapsulated follicles to confirm the presence of DDX4, a molecular marker of oocytes, after 8 days in culture. Additional encapsulated follicles have also been submitted for histologic sectioning and hematoxylin and eosin staining to better characterize the viability and health of these follicles after 8 days in culture. DISCUSSION/SIGNIFICANCE: There was no significant difference in growth or survival between primordial follicles cultured in 1% or 5% alginate gels. Immunofluorescent analysis confirmed the presence of viable follicles at the end of 8 days of culture. Future work needs to further explore how factors in the ovarian extracellular matrix impact follicle maintenance and growth.

Ovotestis Isolation and Cryopreservation of Nesiohelix samarangae (Oriental Snail) as a Snail Model for Conserving Other Endangered Snail Species.

This study aimed to develop a cryopreservation system for the reproductive organs of Nesiohelix samarangae (oriental snail) to support the conservation of their species. The reproductive glands of N. samarangae are divided into numerous acini by acinar boundaries. Within each acinus, the presence of spermatogonia, spermatocytes, spermatids, and sperm were observed, indicating various stages of sperm development. The spermatocytes were irregular in shape and possessed large nuclei. Spermatids, on the other hand, were predominantly located within the lumen of the tissue and exhibited densely packed nuclei. Furthermore, sperm with tails attached were observed within the tissue. In order to preserve the oriental snail species, we utilized the vitrification method to freeze the reproductive organs. Comparing the two methods, it was observed that cryopreservation of ovotestis using 2% alginate encapsulation exhibited superior viability following thawing, surpassing the viability achieved with the non-encapsulated approach. In this study, the establishment of a cryopreservation system for the reproductive organs of the oriental snail not only contributes to the genetic conservation of the endangered snail species but also plays a role in maintaining genetic resources and diversity.

Strategies to enhance biohydrogen production from microalgae: A comprehensive review

Microalgae represent a promising renewable feedstock for the sustainable production of biohydrogen. Their high growth rates and ability to fix carbon utilizing just sunlight, water, and nutrients make them well-suited for this application. Recent advancements have focused on improving microalgal hydrogen yields and cultivation methods. This review aims to summarize recent developments in microalgal cultivation techniques and genetic engineering strategies for enhanced biohydrogen production. Specific areas of focus include novel microalgal species selection, immobilization methods, integrated hybrid systems, and metabolic engineering. Studies related to microalgal strain selection, cultivation methods, metabolic engineering, and genetic manipulations were compiled and analyzed. Promising microalgal species with high hydrogen production capabilities such as Synechocystis sp., Anabaena variabilis, and Chlamydomonas reinhardtii have been identified. Immobilization techniques like encapsulation in alginate and integration with dark fermentation have led to improved hydrogen yields. Metabolic engineering through modulation of hydrogenase activity and photosynthetic pathways shows potential for enhanced biohydrogen productivity. Considerable progress has been made in developing microalgal systems for biohydrogen. However, challenges around process optimization and scale-up remain. Future work involving metabolic modeling, photobioreactor design, and genetic engineering of electron transfer pathways could help realize the full potential of this renewable technology.

Alginate-Based Encapsulation Fabrication Technique for Drug Delivery: An Updated Review of Particle Type, Formulation Technique, Pharmaceutical Ingredient, and Targeted Delivery System.

Alginate is a natural biopolymer widely studied for pharmaceutical applications due to its biocompatibility, low toxicity, and mild gelation abilities. This review summarizes recent advances in alginate-based encapsulation systems for targeted drug delivery. Alginate formulations like microparticles, nanoparticles, microgels, and composites fabricated by methods including ionic gelation, emulsification, spray drying, and freeze drying enable tailored drug loading, enhanced stability, and sustained release kinetics. Alginate microspheres prepared by spray drying or ionic gelation provide gastric protection and colon-targeted release of orally delivered drugs. Alginate nanoparticles exhibit enhanced cellular uptake and tumor-targeting capabilities through the enhanced permeation and retention effect. Crosslinked alginate microgels allow high drug loading and controlled release profiles. Composite alginate gels with cellulose, chitosan, or inorganic nanomaterials display improved mechanical properties, mucoadhesion, and tunable release kinetics. Alginate-based wound dressings containing antimicrobial nanoparticles promote healing of burns and chronic wounds through sustained topical delivery. Although alginate is well-established as a pharmaceutical excipient, more extensive in vivo testing is needed to assess clinical safety and efficacy of emerging formulations prior to human trials. Future opportunities include engineered systems combining stimuli-responsiveness, active targeting, and diagnostic capabilities. In summary, this review discusses recent advances in alginate encapsulation techniques for oral, transdermal, and intravenous delivery, with an emphasis on approaches enabling targeted and sustained drug release for enhanced therapeutic outcomes.

The Efficacy of Nile Tilapia Vaccination by Formalin killed Streptococcus agalactiae Encapsulated in Alginate Microcapsules

Nile tilapia is one of the major farmed fish that is often infected with Streptococcus. Oral vaccination is the most preferable technique, but the antigen is usually degraded by gastric juice. Encapsulation by alginate could be effective in protecting the antigen. The aim of this study was to assess the effectiveness of vaccinating Nile tilapia using formalin-killed Streptococcus agalactiae encapsulated in alginate. The average diameter of fabricated microcapsules was 500±20 μm, with 86% encapsulation efficacy. Fish were then divided into four groups (30 fish per group): group A: fish vaccinated by alginate microcapsules covered by formalin-killed cells (FKC), group B: fish vaccinated by non-covered FKC, group C: fish fed with empty alginate microcapsules and group D: fish feed with commercial pellets as control group. All groups were treated for 14 days and then fed with commercial pellets. Blood samples were collected on days 7, 14, 21, and 28 days post-vaccination. Bactericidal activity, lysozyme activity and serum antibody titer were significantly elevated in group A (p<0.001) compared to other treated groups. Then, gene expression analysis was performed at 29 days post-vaccination to evaluate the expression of main immune contributors such IgM, IgT, TCR β, CD4, CD8α, IL 1β, IL 8, IFN 1, and TNFα. The analysis showed significant upregulation of all tested genes in group A compared to other treated groups (p<0.001). Lastly, a challenge test was done on day 30 post-vaccination by injecting 4.6×106 CFU mL−1 of virulent S. agalactiae. The relative percent of survival (RPS) were 92± 2%, 48± 5% and 4± 3% for groups A, B and C respectively. The obtained result indicated that alginate encapsulation provided antigen protection due to its higher immunogenicity compared to non-covered vaccine. Hence, the fabricated vaccine could be incorporated with food and orally administered to Nile tilapia to prevent S. agalactiae infection.

Viability test of yeast encapsulation (Candida tropicalis) using sodium alginate polymer in bread production

This study explores sodium alginate encapsulation’s impact on Candida tropicalis yeast cell viability and its influence on bread making. Encapsulation protects yeast cells from damage during drying and storage. The research used 10% and 15% sodium alginate for two isolates and one control. Statistical analysis, including Kruskal Wallis and Mann-Whitney tests in Microsoft Excel SPSS, showed significant effects. Sodium alginate encapsulation notably improved Candida tropicalis yeast cell viability and final bread swelling, especially at 15% concentration. Mann-Whitney tests on organoleptic parameters revealed panelist preferences: Candida tropicalis 2 with 15% sodium alginate for color, taste, and texture, while Candida tropicalis 1 with 15% sodium alginate for aroma. This study suggests sodium alginate’s potential to enhance yeast viability and improve bread quality, offering insights for food processing and preservation applications. The research findings may contribute to developing effective encapsulation techniques for yeast-based products.

Alginate encapsulation technology of bacteria for promising self-healing concrete

Concrete is a material that is often used in construction in Indonesia. Concrete has the disadvantage that it tends to form cracks. The cracks that form start from small cracks and then enlarge, causing a decrease in quality. Self-healing concrete is a type of concrete that could repair itself with the help of healing agents in the form of bacteria. There are several methods of mixing bacteria into concrete, one of which is by mixing bacteria directly or using a shell which is often called encapsulation. The purpose of this study was to analyze the behavior of the addition of Bacillus Megaterium bacterial encapsulation in terms of compressive strength of concrete with encapsulation proportions of 0%, 2% and 4% by volume weight and using alginate-based shells. The samples used were 15 x 30 cm cylindrical specimens. These specimens were then tested after 7 days and 28 days. Based on test result, it was found that the highest compressive strength was obtained when 2% alginate capsules were added on day 7 and day 28, namely 25.6 MPa and 32.2 MPa. Concrete begun to heal after 2 weeks of curing based on visual observation.

Encapsulated human islets in alginate fiber maintain long-term functionality.

Maintenance of islet function after in vitro culture is crucial for both transplantation and research. Here we evaluated the effects of encapsulation in alginate fiber on the function of human islets which were distributed by the Alberta Islet Distribution Program. Encapsulated human islets from 15 deceased donors were cultured under 5.5 or 25 mM glucose conditions in vitro. The amounts of C-peptide and glucagon secreted from encapsulated islets into the culture media were measured periodically, and immunohistochemical studies were performed. Encapsulated islets maintained C-peptide and glucagon secretion for more than 75 days in 5 cases; in two cases, their secretion was also successfully detected even on day 180. α- and β-cell composition and β-cell survival in islets were unaltered in the fiber after 75 or 180 days of culture. The encapsulated islets cultured with 5.5 mM glucose, but not those with 25 mM glucose, exhibited glucose responsiveness of C-peptide secretion until day 180. We demonstrate that alginate encapsulation enabled human islets to maintain their viability and glucose responsiveness of C-peptide secretion after long-term in vitro culture, potentially for more than for 180 days.