Retention of β‐galactosidase activity in crude cellular extracts from <i>Lactobacillus delbrueckii</i> ssp. <i>bulgaricus</i> 11842 upon drying

Vasiljevic, Todor; Jelen, P.

doi:10.1046/j.1471-0307.2003.00090.x

Cited by 16 publications

(10 citation statements)

References 26 publications

(36 reference statements)

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“…Our research, using a high b-galactosidase producer Lactobacillus delbrueckii subsp. bulgaricus strain ATCC 11842, focussed on the economic (Bury & Jelen, 2000) and technical (Kreft, Roth, & Jelen, 2001) feasibility of the process; optimization of the growth media (Vasiljevic & Jelen, 2001) and of the mechanical disruption process (Bury, Jelen, & Kalab, 2001;Geciova, Giesova, & Jelen, 2002); suppression of competing enzymatic reactions (Vasiljevic & Jelen, 2002); stability of the enzyme during the hydrolysis process (Kreft & Jelen, 2000); and sensory aspects of the final products (Vasiljevic, Wismer, & Jelen, 2003). Clearly, before this approach could become successful, additional research would be needed, including a search for a more effective microbial producer of the enzyme and/or involving genetic engineering leading to significant overproduction of the b-galactosidase and suppression of some of the other enzymes catalyzing potentially undesirable reactions.…”

Section: Lactose Hydrolysis By Mechanically Disrupted Bacteriamentioning

confidence: 99%

Lactose: Crystallization, hydrolysis and value-added derivatives

Gänzle

Haase

Jelen

2008

International Dairy Journal

260

176

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Section: Lactose Hydrolysis By Mechanically Disrupted Bacteriamentioning

confidence: 99%

Lactose: Crystallization, hydrolysis and value-added derivatives

Gänzle

Haase

Jelen

2008

International Dairy Journal

260

176

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“…and 5.8 for Streptococcus. After the fermentations, the cell collection and handling were performed as reported previously [34]. Before the production of the CCE, the cell paste samples from each fermentation were randomly selected for the determination of the total solids and the β-gal activity by oven drying and the ONPG (o-nitrophenyl-β-D-galactopyranoside) method, respectively [32].…”

Section: Culture Cultivation and Cell Collectionmentioning

confidence: 99%

“…The crude β-galactosidase preparations were obtained in a similar way to that described before [34]. Prior to cell disruption for the liberation of the intracellular β-gal, the frozen cell paste (14-16% dry matter) was thawed at 37°C in a water bath and reconstituted either in pH 6.8 skim milk salt buffer -SMSB [24] or a 10% (w/v) solution of low heat skim milk powder (Dairyworld foods, Vancouver, BC, Canada) resulting in preparations containing approximately 10% cell paste total solids in both cases.…”

Section: Preparation Of Crude Cellular Extracts and Reaction Mixturesmentioning

confidence: 99%

Oligosaccharide production and proteolysis during lactose hydrolysis using crude cellular extracts from lactic acid bacteria

Vasiljevic

Jelen

2003

Lait

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-The extent of the lactose hydrolysis and oligosaccharide formation through transgalactosyl reactions by crude cellular extracts (CCE) containing intracellular β-galactosidase from disrupted Lactobacillus delbrueckii subsp. bulgaricus 11842, Lactobacillus delbrueckii subsp. lactis DMF 3078 or Streptococcus thermophilus 143 was investigated in lactose-containing buffered solutions or skim milk. Lactose hydrolysis was performed with lactose concentration ranging from 5 to 30% (w/w) at 30, 40, 50 or 60°C and terminated after 120 min. The proteolytic activities of the CCEs in skim milk systems were also assessed. All CCEs produced di-, tri-and tetrasaccharides in addition to monosaccharides as major products of the lactose hydrolysis in buffered lactose solutions. However, only Lb. lactis produced tetrasaccharides at detectable levels in skim milk preparations. The amount and the rate of oligosaccharide formation were significantly (P < 0.05) affected by the origin of the enzyme, lactose concentration and temperature. The maximum oligosaccharide production by all CCEs was reached at 50°C in 30% (w/w) lactose solution. St. thermophilus CCE produced significantly higher (P < 0.05) amounts of oligosaccharides than the other two CCE preparations at all lactose concentrations studied. However, Lb. bulgaricus CCE showed better lactose-hydrolyzing ability and higher proteolytic activity than the other two CCEs. The lactose hydrolysis generally proceeded faster at 50-60°C than at 30-40°C as opposed to the proteolytic maxima reached at 40°C.Crude cellular extract / β-galactosidase / thermophilic dairy culture / lactose hydrolysis / transferase reaction / proteolytic activity Résumé -Production d'oligosaccharides et protéolyse lors de l'hydrolyse de lactose par extraits cellulaires bruts de bactéries lactiques. Le degré d'hydrolyse du lactose et la formation d'oligosaccharides par réaction de transgalactosylation sous l'action d'extraits cellulaires bruts (ECB) contenant de la β-galactosidase obtenue par rupture de Lactobacillus delbruekii subsp. bulgaricus 11842, Lactobacillus delbruekii subsp. lactis DMF 3078 et Steptococcus thermophilus 143 ont été étudiés sur des solutions tamponnées de lactose ou sur le lait écrémé. L'hydrolyse du lactose a été effectuée sur des concentrations de 5 à 30 % (masse) à des températures de 30, 40, 50 et 60°C pour une durée totale de 120 min. L'activité protéolytique des ECBs sur les systèmes à base de lait écrémé a également été évaluée. Tous les ECBs ont produit des di-, tri-et tetrasaccharides en plus des monosaccharides comme composants majeurs de l'hydrolyse du lactose contenu dans les solutions tamponnées. Toutefois, seul Lb. lactis a produit des tetrasaccharides à un niveau * Corresponding author: paul.jelen@ualberta.ca 454 T. Vasiljevic, P. Jelen

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“…Sales opportunities of lactose-free products are high all over the world, especially in countries with a high percentage of lactoseintolerant people (Harju et al 2012;Jelen and Tossavainen 2003). More than 70% of the world population suffers from lactose intolerance (Vasiljevic and Jelen 2003), but its occurrence largely depends on the population group: only approx. 10% of Northern Europeans but more than 90% of South-East Asians suffer from this intolerance (Jelen and Tossavainen 2003).…”

Section: Introductionmentioning

confidence: 99%

Fermented milk products: effects of lactose hydrolysis and fermentation conditions on the rheological properties

Schmidt

Mende

Jaros

et al. 2015

Dairy Sci. & Technol.

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Lactose-free dairy products become increasingly important for lactoseintolerant consumers, but there are only few studies concerning the rheological properties of fermented dairy products from lactose-hydrolysed milk. Hydrolysation was performed with commercial β-galactosidase either before or during fermentation (cohydrolysis). In each trial, fermentation of the base milk was carried out simultaneously using the same starter cultures for (a) untreated milk (reference) (b) hydrolysed milk as substrate and (c) by performing lactose hydrolysis and fermentation simultaneously (co-hydrolysis). In total, five thermophilic starter cultures and two products (yoghurt and Greek-style yoghurt) were investigated. Results show that the influence of hydrolysis of lactose on the properties of the fermented dairy products strongly depends on starter culture and substrate. For starters C and D, apparent viscosity (extracted from flow curves at a shear rate of 75 s −1 ) of fermented milks was only marginally affected by lactose hydrolysis, ranging between approx. 0.34-0.31 and 0.37-0.31 Pa.s, respectively. Hydrolysed products from starters A and E exhibited significant lower apparent viscosity (0.16 and 0.24 Pa.s) compared with their respective references (0.29 and 0.35 Pa.s). Fermentation of both substrates (regular yoghurt, Greek-style yoghurt) with starter B resulted in a decrease of yield stress and apparent viscosity because of lactose hydrolysis only for Greek-style yoghurt. Furthermore, a trend towards higher EPS synthesis was found when using hydrolysed milk. The results clearly show that products made from lactose-hydrolysed milk with similar rheological properties as the reference product can be obtained but that there is a lack of information concerning the complex interactions between starter culture and milk substrate.

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Retention of β‐galactosidase activity in crude cellular extracts from Lactobacillus delbrueckii ssp. bulgaricus 11842 upon drying

Cited by 16 publications

References 26 publications

Lactose: Crystallization, hydrolysis and value-added derivatives

Lactose: Crystallization, hydrolysis and value-added derivatives

Oligosaccharide production and proteolysis during lactose hydrolysis using crude cellular extracts from lactic acid bacteria

Fermented milk products: effects of lactose hydrolysis and fermentation conditions on the rheological properties

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