Separation of hyaluronic acid from fermentation broth by tangential flow microfiltration and ultrafiltration

Zhou, Haidong; Ni, Jinren; Huang, Wenxiu; Zhang, Jiandong

doi:10.1016/j.seppur.2006.03.011

Cited by 40 publications

(26 citation statements)

References 23 publications

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“…The quality of an active fermented bioproduct is highly dependent on the downstream process conditions [1]. During production of lactic acid starters, centrifugation is F. Streit the method usually employed to concentrate the cells before their stabilization.…”

Section: Introductionmentioning

confidence: 99%

“…Cross-flow microfiltration is commonly applied as the first step for harvesting bioproducts such as enzymes, antibiotics and organic acids produced by microorganisms. The bioproduct is recovered in the permeate and further extracted using other selective separation processes [1,3,6]. Another application of microfiltration concerns the clarification of beer, wine, cider and fruit juices [3,7].…”

Section: Introductionmentioning

confidence: 99%

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Microfiltration conditions modify Lactobacillus bulgaricus cryotolerance in response to physiological changes

Streit¹,

Athès²,

Bchir³

et al. 2010

Bioprocess Biosyst Eng

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This work aimed at analyzing the effect of microfiltration conditions (cross-flow velocity and transmembrane pressure) on the quality of frozen Lactobacillus bulgaricus CFL1 starters produced on pilot scale. Microfiltered cells were less resistant during the concentration process than centrifuged cells. In contrast, bacterial cryotolerance during freezing was improved after microfiltration, in a range of 28-88%, depending on the microfiltration conditions. During frozen storage, cell resistance was also affected by microfiltration conditions, either positively or negatively, compared to centrifugation. The best cryotolerance was obtained for cells microfiltered at a cross-flow velocity of 2 m/s and a transmembrane pressure of 0.15 MPa. This improvement was explained by considering membrane fatty acid composition of Lb. bulgaricus CFL1. This condition increased unsaturated to saturated and cyclic to saturated fatty acid ratios, which enhanced membrane fluidity, thus helping the cells to better resist freezing and frozen storage.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Microfiltration conditions modify Lactobacillus bulgaricus cryotolerance in response to physiological changes

Streit¹,

Athès²,

Bchir³

et al. 2010

Bioprocess Biosyst Eng

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“…The phenol precipitation, for desproteinization, and the ultracentrifugation, for removal of LPS, were replaced by enzymatic treatment and by ultraWltration in the presence of chelating agent and detergent [26,27,33]. The new methods have the advantages of not using a toxic and corrosive solvent as phenol and reducing the volume and number of ethanol precipitation, an explosion prone reagent.…”

Section: Resultsmentioning

confidence: 99%

Purification of capsular polysaccharide produced by Haemophilus influenzae type b through a simple, efficient and suitable method for scale-up

Takagi¹,

Lima²,

Albani³

et al. 2008

J Ind Microbiol Biotechnol

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Haemophilus influenzae type b, an encapsulated bacterium, causes meningitis in infants worldwide. The capsular polysaccharide conjugated to a carrier protein is effective in the prevention of such infections. The traditional purification process of polysaccharide from bacterial cultures for vaccine production is based on several selective precipitations with solvents such as: ethanol, phenol, and cationic detergents. The separations of solid and liquid phases are based on continuous centrifugation in explosion proof installations. The lipopolysaccharides are separated by ultracentrifugation. A simple and efficient method that can easily be scaled-up was developed for purification of polysaccharides. The ethanol precipitation was reduced to only two steps. The phenol treatment was substituted by ultrafiltration and enzymatic digestion. Lipopolysaccharide was removed by ultrafiltration together with addition of detergent and chelating agent.

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“…22,23 The EGDE solution was prepared by diluting the crosslinker in 0.025M disodium tetraborate solution (pH 9.0). 38 Gelatin films were equilibrated in a 2-propanol solution for 30 minutes and then immersed in a HMDC solution in 2-propanol. 39 Crosslinking films (Method A) Samples were crosslinked by immersing the already prepared uncrosslinked extracted gelatin films in the different crosslinking reagent solutions.…”

Section: Crosslinking Reagent Solutionsmentioning

confidence: 99%

Influence of crosslinkers and crosslinking method on the properties of gelatin films extracted from leather solid waste

Catalina

Attenburrow

Cot

et al. 2010

J of Applied Polymer Sci

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Gelatin was extracted from chrome tanned leather waste with the aim to produce a durable coating or film. Crosslinking has shown to improve the physical performance of a film/coating. The effect of the method of crosslinking and the use of different crosslinking agents were studied. The extracted gelatin was crosslinked either by immersion of preformed films into a crosslinker solution (Method A) or by the addition of the crosslinking reagent to the gelatin solution prior to film formation (Method B). The different results obtained between both methods may be due to: the relative concentration of crosslinking reagent, the introduction of crosslinks within different regions of gelatin (triple helical regions and random coil regions), and the reaction rate. Method A of crosslinking is more likely to form crosslinks outside but close to the triple helical regions, disrupting the order and stability of the helical structure. Crosslinks may form preferentially within the random coil regions when Method B of crosslinking is used. Both methods led to the formation of chemical crosslinks in the extracted gelatin films, as demonstrated by the reduction of the degree of aqueous swelling and the proportion of low molecular weight fractions.

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Separation of hyaluronic acid from fermentation broth by tangential flow microfiltration and ultrafiltration

Cited by 40 publications

References 23 publications

Microfiltration conditions modify Lactobacillus bulgaricus cryotolerance in response to physiological changes

Microfiltration conditions modify Lactobacillus bulgaricus cryotolerance in response to physiological changes

Purification of capsular polysaccharide produced by Haemophilus influenzae type b through a simple, efficient and suitable method for scale-up

Influence of crosslinkers and crosslinking method on the properties of gelatin films extracted from leather solid waste

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