title: Permeabilization of Kluyveromyces marxianus with mild detergent for whey lactose hydrolysis and augmentation of mixed culture.
abstract: Cheese whey is a by-product of cheese-manufacturing industries, and the utilization of whey is a challenging problem either to use it or dispose it, because only few microorganisms can metabolize the whey lactose. Enzymatic hydrolysis of whey lactose to glucose and galactose by β-galactosidase is the approach for biotechnological application. Kluyveromyces marxianus cells were permeabilized with non-toxic, biodegradable, anionic detergent N-lauroyl sarcosine (N-LS) for the enzyme activity. The permeabilization process parameters (N-LS concentration, solvent volume, temperature and incubation time) were optimized. The maximum β-galactosidase activity of 1,220 IU/g dry weight was obtained using permeabilized cells under optimized conditions. Moreover, viability of the permeabilized cells was also evaluated, which showed that cells were alive; however, viability was reduced by two log cycles. The permeabilized cells were evaluated for whey lactose hydrolysis. The maximum lactose hydrolysis of 91% was observed with 600 mg (dry cell weight/100 mL) in whey powder (5% w/v) solution at 180-min incubation, pH 6.5 and 30 °C. Further, the hydrolyzed whey was evaluated for amelioration of growth of non-lactose-consuming yeast Saccharomyces cerevisiae. S. cerevisiae was able to grow in hydrolyzed whey simultaneously with K. marxianus. The study confirmed that N-LS could be used to permeabilize K. marxianus cells to make available the enzyme activity.
authors: Institut national de la recherche scientifique, Centre Eau, Terre & Environnement, Université du Québec, 490 de la Couronne, Québec (QC), G1K 9A9, Canada.
authors: Jay Shankar Singh
authors: JS
authors: Yadav
authors: Jyothi
authors: J
authors: Bezawada
authors: Song
authors: S
authors: Yan
authors: R D
authors: RD
authors: Tyagi
authors: R Y
authors: RY
authors: Surampalli
mesh_terms: D002463:Cell Membrane Permeability; D018920:Coculture Techniques; D003611:Dairy Products; D003902:Detergents / Q000494:pharmacology*; D005285:Fermentation; D005656:Fungal Proteins / Q000378:metabolism*; D005690:Galactose / Q000096:biosynthesis; D005947:Glucose / Q000096:biosynthesis; D006868:Hydrolysis; D007716:Kluyveromyces / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D007785:Lactose / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000254:growth & development; D012521:Sarcosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D001616:beta-Galactosidase / Q000378:metabolism*
chemical_list: D003902:Detergents; D005656:Fungal Proteins; C025231:sarkosyl; D001616:beta-Galactosidase; D005947:Glucose; D007785:Lactose; D005690:Galactose; D012521:Sarcosine