Immobilization of the β-galactosidase fromAspergillus niger on chitosan

Leuba, Jean-Louis; Widmer, François

doi:10.1007/bf02996747

Cited by 10 publications

(5 citation statements)

References 20 publications

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“…After centrifugation, chitosan was extensively washed, lyophilized, and powdered in a mortar. The processing of rigid chitosan particles has already been described (Leuba and Widmer, 1977). Epichlorhydrin-cross linked chitosan was prepared as follows : commercial chitosan (100 g) was swollen for 90 rain in 75 mM sodium acetate buffer (pH 4.0).…”

Section: Methodsmentioning

confidence: 99%

“…The amount of chitosan-bound protein was estimated from a mass balance (difference between the amount of protein in solution before and after immobilization, and in the combined washings), using the Folin reagent (Lowry et al, 1951). The active preparations were reduced with sodium borohydride for stabilization (Leuba and Widmer, 1977), and stored at 4°C in 50 mM Tris-HCI buffer (pH 7.5), containing 0.02% sodium azide. The various theories developed to explain the reactions of glutaraldehyde with proteins have recently been reviewed (Branner-J~rgensen, 1978).…”

Section: Methodsmentioning

confidence: 99%

“…Extensive work has also been carried out in our laboratory on the immobilization of Aspergillus niger /3-galactosidase on chitosan (Leuba and Widmer, 1977;Leuba et al, 1978;Widmer, 1979).…”

Section: Introductionmentioning

confidence: 99%

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Immobilization of proteinases on Chitosan

Leuba

Widmer

1979

Biotechnol Lett

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SUMMARYTrypsin, pronase and subtilisin were immobilized on chitosan by glutaraldehyde coupling. Significant retention of activity was observed when synthetic substrates as well as casein were used. The specific activities of the bound proteinases ranged from 38% to 79% of their initial specific activities. The pH-activity profile of trypsin was slightly shifted toward alkaline values, and its thermal stability was increased. Immobilized trypsin was found to be less sensitive to its natural inhibitors than the soluble enzyme.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Immobilization of proteinases on Chitosan

Leuba

Widmer

1979

Biotechnol Lett

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“…Healing activity Muzzarelli [28,29] , Balassa 30] , Leuba and Widmer 31,32] , Kasumi et al [33 , Bissett and Sternberg [34] 1980-89 Treatment of industrial residues; Heavy metals biosorption Muzzarelli et al [35,36] , Muzzarelli [37]…”

Section: Period Application Potential References 1970-79mentioning

confidence: 99%

Review of fungal chitosan: past, present and perspectives in Brazil

2018

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Fungal chitosan is a polymer that has been discussed and studied since 1859 in the world with great advances occurring over the years. Due to its global importance, this review aims to expose the history of the production and application of fungal chitosan in Brazil. Data collection was done at the Scielo, Sciencedirect and Pubmed databases, considering the period of the last 50 years. The inclusion criteria were articles on pure or associated chitosan and, in particular, fungal chitosan produced or applied by Brazilian research groups. At the end of the review, it was noticed a fungal chitosan very studied in different continents, and in Brazil is still used in specific and small groups. With the present work, it is expected that the diffusion of the studies will be accelerated and that potential research groups for fungal chitosan may grow through interaction with the existing ones.

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“…Immobilization of lactase on chitosan might be useful in processing milk by-products into valuable sweeteners, or into nutritional media for fermentation processes. Its possible application to solving many problems related to the use of lactose should also be considered (Leuba and Widmer, 1977;Greenberg and Mahoney, 1981).…”

Section: Immobilization Of Lactasementioning

confidence: 99%

Xanthan production from whey treated with immobilized lactase

El-Sawah¹,

Microbiology²

1999

Pakistan J. of Biological Sciences

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Lactase was produced by Streptococcus salivarius subsp. thermophilus grown on deproteinized whey. Maximum lactase production in 6.85 percent whey supplemented with certain nutrients was 54.5 U/ml. Lactase was purified by ammonium sulfate and acetone fractionation and gel filtration. It was immobilized on chitin and chitosan by covalent binding. Lactase immobilized on chitosan had the highest activity for hydrolysis of whey lactose. The maximum amount of glucose produced by the immobilized lactase was 20 percent of lactose during conversion of 71 percent lactose in 6 h. Xanthomonas campestris was able to convert glucose, galactose, mixture of them, lactose, or whey to xanthan, where the yield was 86, 67, 83, 2, and 1.8 percent respectively, after 72 h in batch fermentation. When deproteinized whey, which was hydrolyzed by immobilized lactase, was used for xanthan production. The synthesis of icanthan was generally as good as with comparable conventional media, the yield reached to 65 percent.

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Immobilization of the β-galactosidase fromAspergillus niger on chitosan

Cited by 10 publications

References 20 publications

Immobilization of proteinases on Chitosan

Immobilization of proteinases on Chitosan

Review of fungal chitosan: past, present and perspectives in Brazil

Xanthan production from whey treated with immobilized lactase

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