Bacterial cellulose/hyaluronic acid nanocomposites production through co-culturing Gluconacetobacter hansenii and Lactococcus lactis under different initial pH values of fermentation media

This research investigated the effectiveness of electrocoagulation using iron and aluminium electrodes for treating cooling tower blowdown (CTB) waters containing dissolved silica (Si(OH)4), Ca2 + and Mg2 + . The removal of each target species was measured as a function of the coagulant dose in simulated CTB waters with initial pH values of 5, 7, and 9. Experiments were also performed to investigate the effect of antiscaling compounds and coagulation aids on hardness ion removal. Both iron and aluminum electrodes were effective at removing dissolved silica. For coagulant doses ≤3 mM, silica removal was a linear function of the coagulant dose, with 0.4 to 0.5 moles of silica removed per mole of iron or aluminium. Iron electrodes were only 30% as effective at removing Ca2 + and Mg2 + as compared to silica. There was no measurable removal of hardness ions by aluminium electrodes in the absence of organic additives. Phosphonate based antiscaling compounds were uniformly effective at increasing the removal of Ca2 + and Mg2 + by both iron and aluminium electrodes. Cationic and amphoteric polymers used as coagulation aids were also effective at increasing hardness ion removal.

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Characterization of Melanoidins and Color Development in Dulce de Leche, a Confectionary Dairy Product With High Sucrose Content: Evaluation of pH Effect, an Essential Manufacturing Process Parameter

Frontiers in Nutrition ◽

10.3389/fnut.2021.753476 ◽

2021 ◽

Vol 8 ◽

Author(s):

Analía Rodríguez ◽

Patricia Lema ◽

María Inés Bessio ◽

Guillermo Moyna ◽

Cristina Olivaro ◽

...

Keyword(s):

Enzymatic Hydrolysis ◽

Ph Effect ◽

Dairy Product ◽

Gel Filtration ◽

Significant Degree ◽

Product Analysis ◽

Molecular Weights ◽

Ph Values ◽

Initial Ph

The effect on color of the initial pH employed in dulce de leche (DL) production was evaluated through physicochemical and spectroscopical characterization of the melanoidins formed in the process. Melanoidins originated at pH values of 6.5, 7.0, and 7.5, and they were released by the enzymatic hydrolysis of the protein backbone and purified by gel filtration. They showed a significant degree of polydispersity, in general, with molecular weights (MWs) below 1,800 Da. DL produced at a higher pH released melanoidins with higher average MW after the enzymatic hydrolysis. They also presented darker colors (dE*ab, C*), more closely resembling those typical of the commercial product. Analysis of the fractions isolated by gel filtration using HPLC-DAD and multinuclear NMR showed an heterogeneous and complex composition. Even though structurally related, the 1H NMR spectra of melanoidins showed a higher degree of aromaticity at higher pH values. In conclusion, the pH employed in DL production affects the amount and structure of the colored products originated by MR reactions, and thus the color of the final product.

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Production of nisin-containing bacterial cellulose nanomaterials with antimicrobial properties through co-culturing Enterobacter sp. FY-07 and Lactococcus lactis N8

Carbohydrate Polymers ◽

10.1016/j.carbpol.2020.117131 ◽

2021 ◽

Vol 251 ◽

pp. 117131

Author(s):

Ge Gao ◽

Huiqiang Fan ◽

Yibo Zhang ◽

Yiyan Cao ◽

Te Li ◽

...

Keyword(s):

Bacterial Cellulose ◽

Lactococcus Lactis ◽

Antimicrobial Properties ◽

Cellulose Nanomaterials

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Enhanced mechanical properties of bacterial cellulose nanocomposites produced by co-culturing Gluconacetobacter hansenii and Escherichia coli under static conditions

Carbohydrate Polymers ◽

10.1016/j.carbpol.2019.04.071 ◽

2019 ◽

Vol 219 ◽

pp. 12-20 ◽

Cited By ~ 9

Author(s):

Ke Liu ◽

Jeffrey M. Catchmark

Keyword(s):

Escherichia Coli ◽

Mechanical Properties ◽

Bacterial Cellulose ◽

Gluconacetobacter Hansenii ◽

Cellulose Nanocomposites ◽

Static Conditions

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Evaluation of Different Methods for Cultivating Gluconacetobacter hansenii for Bacterial Cellulose and Montmorillonite Biocomposite Production: Wound-Dressing Applications

Polymers ◽

10.3390/polym12020267 ◽

2020 ◽

Vol 12 (2) ◽

pp. 267 ◽

Cited By ~ 2

Author(s):

Katharine Valéria Saraiva Hodel ◽

Larissa Moraes dos Santos Fonseca ◽

Isa Moreira da Silva Santos ◽

Jamile Costa Cerqueira ◽

Raimundo Evangelista dos Santos-Júnior ◽

...

Keyword(s):

Bacterial Cellulose ◽

Wound Dressing ◽

Industrial Applications ◽

Medical Product ◽

Water Holding Capacity ◽

Mechanical And Thermal Properties ◽

Water Release ◽

Thermal Stabilities ◽

Gluconacetobacter Hansenii ◽

Water Holding

Bacterial cellulose (BC) has received considerable attention due to its unique properties, including an ultrafine network structure with high purity, mechanical strength, inherent biodegradability, biocompatibility, high water-holding capacity and high crystallinity. These properties allow BC to be used in biomedical and industrial applications, such as medical product. This research investigated the production of BC by Gluconacetobacter hansenii ATCC 23769 using different carbon sources (glucose, mannitol, sucrose and xylose) at two different concentrations (25 and 50 g∙L−1). The BC produced was used to develop a biocomposite with montmorillonite (MMT), a clay mineral that possesses interesting characteristics for enhancing BC physical-chemical properties, at 0.5, 1, 2 and 3% concentrations. The resulting biocomposites were characterized in terms of their physical and barrier properties, morphologies, water-uptake capacities, and thermal stabilities. Our results show that bacteria presented higher BC yields in media with higher glucose concentrations (50 g∙L−1) after a 14-day incubation period. Additionally, the incorporation of MMT significantly improved the mechanical and thermal properties of the BC membranes. The degradation temperature of the composites was extended, and a decrease in the water holding capacity (WHC) and an improvement in the water release rate (WRR) were noted. Determining a cost-effective medium for the production of BC and the characterization of the produced composites are extremely important for the biomedical applications of BC, such as in wound dressing materials.

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Spin-Gitter-Relaxationszeit-T1-Untersuchungen an Hyaluronsäure. / Spin-Lattice-Relaxationtime-T1 Measurements of Hyaluronic Acid

Zeitschrift für Naturforschung C ◽

10.1515/znc-1979-7-804 ◽

1979 ◽

Vol 34 (7-8) ◽

pp. 508-511 ◽

Cited By ~ 6

Author(s):

H. Hofmann ◽

O. Schmut ◽

H. Sterk ◽

H. Kopp

Keyword(s):

Hyaluronic Acid ◽

Acid Solutions ◽

Spin Lattice ◽

Ph Values

Reductions with [3H]NaBH4 proof that the decrease in viscosity of hyaluronic acid solutions caused by lowering the pH does not depend on a depolymerisation of hyaluronic acid. At the same time investigations at different pH-values, show a sigmoide increase of the Spin-Lattice-Relaxationtime T1. This increase depends on a progressive aggregation of the hyaluronic acid molecule. The effect seems to be induced by the decrease of ionization of the carboxylgroups, by acidification of the solution.

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