Lactose and Derivatives

Roelfsema, Willem A.; Kuster, B.F.M.; Heslinga, Michiel C.; Pluim, Hendrik; Verhage, Marinus

doi:10.1002/14356007.a15_107

Cited by 10 publications

(8 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The heterodisaccharide lactose (1,4‐O‐β‐ d ‐galactopyranosyl‐ d ‐glucose) occurs mainly in mammalian milk where it makes up 2–8% of the dry weight, and it is an abundant byproduct of the dairy industry (Roelfsema et al ., ). Technical‐scale hydrolysis of lactose – a challenging process in food and fermentation industry – is catalyzed by microbial (typically fungal) β‐ d ‐galactosidases (bGal).…”

Section: Introductionmentioning

confidence: 97%

Metabolism ofd-galactose is dispensable for the induction of thebeta-galactosidase (bgaD) and lactose permease (lacpA) genes inAspergillus nidulans

Orosz

Fekete

Flipphi

et al. 2014

FEMS Microbiol Lett

View full text Add to dashboard Cite

In this study, we analyze the expression of the Aspergillus nidulans bgaD-lacpA gene couple (encoding an intracellular beta-galactosidase and a lactose permease) in the presence of D-galactose. This monosaccharide can be catabolized via alternative, independent pathways in this model organism. The inductive capabilities of intermediates of the two alternative routes of D-galactose utilization were addressed in loss-of-function mutants defective in a defined step in one of the two pathways. In a galactokinase (galE9) mutant, the cluster is strongly induced by D-galactose, suggesting that formation of Leloir pathway intermediates is not required. The expression profiles of bgaD and lacpA were similar in wild type, L-arabinitol dehydrogenase (araA1), and hexokinase (hxkA1) negative backgrounds, indicating that intermediates of the oxido-reductive pathway downstream of galactitol are not necessary either. Furthermore, bgaD-lacpA transcription was not induced in any of the tested strains when galactitol was provided as the growth substrate. An hxkA1/galE9 double mutant cannot grow on d-galactose at all, but still produced bgaD and lacpA transcripts upon transfer to d-galactose. We therefore concluded that the physiological inducer of the bgaD-lacpA gene cluster upon growth on D-galactose is the nonmetabolized sugar itself.

show abstract

Section: Introductionmentioning

confidence: 97%

Metabolism ofd-galactose is dispensable for the induction of thebeta-galactosidase (bgaD) and lactose permease (lacpA) genes inAspergillus nidulans

Orosz

Fekete

Flipphi

et al. 2014

FEMS Microbiol Lett

View full text Add to dashboard Cite

show abstract

“…Thus, it has been necessary to develop novel lactose derivatives. Lactitol, lactulose, and lactobionic acid are the industrially most important lactose derivatives. − Moreover, the hydrolysis products of lactose, d -galactose and d -glucose, can be oxidized for valuable raw materials ( L -ascorbic acid, D -ascorbic acid, and erythorbic acid), which are used by the pharmaceutical industry . Furthermore, tagatose is manufactured by hydrolyzing lactose to galactose and glucose and isomerizing galactose to tagatose…”

Section: Introductionmentioning

confidence: 99%

Hydrogenation of Lactose over Sponge Nickel CatalystsKinetics and Modeling

Kuusisto

Mikkola

Sparv

et al. 2006

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

Kinetics of lactose hydrogenation to lactitol, an alternative sweetener, over Mo-promoted sponge nickel slurry catalyst in aqueous solutions was studied. Hydrogenation experiments were carried out batchwise in a three-phase laboratory-scale reactor (300 mL, Parr Co.), operating at 20−70 bar and between 110 and 130 °C. The main hydrogenation product was lactitol, while small amounts of lactobionic acid, lactulose, lactulitol, sorbitol, and galactitol were detected as byproducts. The lactitol selectivity within the experimental range varied from 90 to 99%. The selectivity values improved as the hydrogen pressure increased and the reaction temperature decreased. The effect of catalyst loading and catalyst deactivation during consecutive hydrogenation batches was also studied. Fresh and recycled catalysts were characterized by nitrogen adsorption, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), hydrogen temperature-programmed desorption (TPD), and particle-size analysis. Recycled sponge nickel catalyst was able to adsorb less hydrogen compared to fresh one, indicating active site poisoning. Of all byproducts, only lactobionic acid had an inhibiting effect on lactose conversion rate and deactivated the catalyst. By lactobionic acid, deactivated catalyst can be regenerated by controlled alkali wash. The kinetic data were modeled by Langmuir−Hinshelwood−Hougen−Watson (LHHW) kinetics, assuming surface reaction steps are rate determining. Noncompetitive adsorption of molecular hydrogen and lactose was assumed. The fitting of the experimental data to the kinetic model was carried out by a combined Simplex−Levenberg−Marquardt method. The model predicted the experimental concentrations of lactose and lactitol very well. A reasonably good description of the byproducts was obtained.

show abstract

“…Similarly bulk scale accessible are its component sugars d - glucose , produced by hydrolysis of starch, and d - fructose , generated either from glucose by base-induced isomerization or from inulin or sucrose by hydrolysis , lactose and maltose are available in large quantities from whey and starch, and d - xylose , the cheapest pentose, is generated from wood- or straw-derived xylans. l - Sorbose is the cheapest, large-scale accessible l -sugar due to its production from d - sorbitol (= d - glucitol ) in the vitamin C fabrication process .…”

Section: Introductionmentioning

confidence: 99%

Unsaturated O- and N-Heterocycles from Carbohydrate Feedstocks

2002

View full text Add to dashboard Cite

With reference to the impending transition of chemical industry from depleting fossil raw materials to renewable feedstocks--the end of cheap oil is predicted for 2040 at the latest--this account gives an overview on chemically transforming carbohydrates, by far the major part of the annually regrowing biomass, into the following unsaturated O- and N-heterocycles with versatile industrial application profiles: furans, pyrans, dihydropyranones, pyrroles, pyrazoles, imidazoles, pyridinols, pyrazines, and quinoxalines. Although the emphasis was laid on conversions that can be effected in practical one-pot procedures or in a few large-scale-adaptable steps, a broad structural variety of products emerges that have not only diverse chemical functionalities but also hydrophilic "residual sugar" portions that render them water-soluble and readily biodegradable.

show abstract

Lactose and Derivatives

Abstract: The article contains sections titled: 1. Lactose 1.1. Properties … Show more

Cited by 10 publications

References 38 publications

Metabolism ofd-galactose is dispensable for the induction of thebeta-galactosidase (bgaD) and lactose permease (lacpA) genes inAspergillus nidulans

Metabolism ofd-galactose is dispensable for the induction of thebeta-galactosidase (bgaD) and lactose permease (lacpA) genes inAspergillus nidulans

Hydrogenation of Lactose over Sponge Nickel CatalystsKinetics and Modeling

Unsaturated O- and N-Heterocycles from Carbohydrate Feedstocks

Contact Info

Product

Resources

About