Fermentation of lactose by yeast cells secreting recombinant fungal lactase

Sundaram Ramakrishnan, B. S. Hartley

Research output: Contribution to journalArticle

42 Citations (Scopus)

Abstract

Strains of Saccharomyces cerevisiae transformed with a yeast multicopy expression vector carrying the cDNA for Aspergillus niger secretory β- galactosidase under the control of ADH1 promoter and terminator were studied for their fermentation properties on lactose (V. Kumar, S. Ramakrishnan, T. T. Teeri, J. K. C. Knowles, and B. S. Hartley, Biotechnology 10:82-85, 1992). Lactose was hydrolyzed extracellularly into glucose and galactose, and both sugars were utilized simultaneously. Diauxic growth patterns were not observed. However, a typical biphasic growth was observed on a mixture of glucose and galactose under aerobic and anaerobic conditions with transformants of a haploid S. cerevisiae strain, GRF167. Polyploid distiller's yeast (Mauri) transformants were selected simply on the basis of the cloned gene expression on X-Gal (5-bromo-4-chloro-3-indolyl-β-D- galactopyranoside) plates. Rapid and complete lactose hydrolysis and higher ethanol (0.31 g/g of sugar) and biomass (0.24 g/g of sugar) production were observed with distiller's yeast grown under aerobic conditions. A constant proportion (10%) of the population retained the plasmid throughout the fermentation period (48 h). Nearly theoretical yields of ethanol were obtained under anaerobic conditions on lactose, glucose, galactose, and whey permeate media. However, the rate and the amount of lactose hydrolysis were lower under anaerobic than aerobic conditions. All lactose-grown cells expressed partial galactokinase activity.

Original languageEnglish (US)
Pages (from-to)4230-4235
Number of pages6
JournalApplied and Environmental Microbiology
Volume59
Issue number12
StatePublished - Jan 1 1993
Externally publishedYes

Fingerprint

Lactase
Lactose
beta-galactosidase
oxic conditions
lactose
Fermentation
fermentation
yeast
sugar
glucose
Yeasts
yeasts
Galactose
anoxic conditions
ethanol
hydrolysis
aerobic conditions
galactose
cells
biotechnology

ASJC Scopus subject areas

  • Biotechnology
  • Food Science
  • Applied Microbiology and Biotechnology
  • Ecology

Cite this

Fermentation of lactose by yeast cells secreting recombinant fungal lactase. / Ramakrishnan, Sundaram; Hartley, B. S.

In: Applied and Environmental Microbiology, Vol. 59, No. 12, 01.01.1993, p. 4230-4235.

Research output: Contribution to journalArticle

@article{c9ccec928fe44187addb3eb923314d62,
title = "Fermentation of lactose by yeast cells secreting recombinant fungal lactase",
abstract = "Strains of Saccharomyces cerevisiae transformed with a yeast multicopy expression vector carrying the cDNA for Aspergillus niger secretory β- galactosidase under the control of ADH1 promoter and terminator were studied for their fermentation properties on lactose (V. Kumar, S. Ramakrishnan, T. T. Teeri, J. K. C. Knowles, and B. S. Hartley, Biotechnology 10:82-85, 1992). Lactose was hydrolyzed extracellularly into glucose and galactose, and both sugars were utilized simultaneously. Diauxic growth patterns were not observed. However, a typical biphasic growth was observed on a mixture of glucose and galactose under aerobic and anaerobic conditions with transformants of a haploid S. cerevisiae strain, GRF167. Polyploid distiller's yeast (Mauri) transformants were selected simply on the basis of the cloned gene expression on X-Gal (5-bromo-4-chloro-3-indolyl-β-D- galactopyranoside) plates. Rapid and complete lactose hydrolysis and higher ethanol (0.31 g/g of sugar) and biomass (0.24 g/g of sugar) production were observed with distiller's yeast grown under aerobic conditions. A constant proportion (10{\%}) of the population retained the plasmid throughout the fermentation period (48 h). Nearly theoretical yields of ethanol were obtained under anaerobic conditions on lactose, glucose, galactose, and whey permeate media. However, the rate and the amount of lactose hydrolysis were lower under anaerobic than aerobic conditions. All lactose-grown cells expressed partial galactokinase activity.",
author = "Sundaram Ramakrishnan and Hartley, {B. S.}",
year = "1993",
month = "1",
day = "1",
language = "English (US)",
volume = "59",
pages = "4230--4235",
journal = "Applied and Environmental Microbiology",
issn = "0099-2240",
publisher = "American Society for Microbiology",
number = "12",

}

TY - JOUR

T1 - Fermentation of lactose by yeast cells secreting recombinant fungal lactase

AU - Ramakrishnan, Sundaram

AU - Hartley, B. S.

PY - 1993/1/1

Y1 - 1993/1/1

N2 - Strains of Saccharomyces cerevisiae transformed with a yeast multicopy expression vector carrying the cDNA for Aspergillus niger secretory β- galactosidase under the control of ADH1 promoter and terminator were studied for their fermentation properties on lactose (V. Kumar, S. Ramakrishnan, T. T. Teeri, J. K. C. Knowles, and B. S. Hartley, Biotechnology 10:82-85, 1992). Lactose was hydrolyzed extracellularly into glucose and galactose, and both sugars were utilized simultaneously. Diauxic growth patterns were not observed. However, a typical biphasic growth was observed on a mixture of glucose and galactose under aerobic and anaerobic conditions with transformants of a haploid S. cerevisiae strain, GRF167. Polyploid distiller's yeast (Mauri) transformants were selected simply on the basis of the cloned gene expression on X-Gal (5-bromo-4-chloro-3-indolyl-β-D- galactopyranoside) plates. Rapid and complete lactose hydrolysis and higher ethanol (0.31 g/g of sugar) and biomass (0.24 g/g of sugar) production were observed with distiller's yeast grown under aerobic conditions. A constant proportion (10%) of the population retained the plasmid throughout the fermentation period (48 h). Nearly theoretical yields of ethanol were obtained under anaerobic conditions on lactose, glucose, galactose, and whey permeate media. However, the rate and the amount of lactose hydrolysis were lower under anaerobic than aerobic conditions. All lactose-grown cells expressed partial galactokinase activity.

AB - Strains of Saccharomyces cerevisiae transformed with a yeast multicopy expression vector carrying the cDNA for Aspergillus niger secretory β- galactosidase under the control of ADH1 promoter and terminator were studied for their fermentation properties on lactose (V. Kumar, S. Ramakrishnan, T. T. Teeri, J. K. C. Knowles, and B. S. Hartley, Biotechnology 10:82-85, 1992). Lactose was hydrolyzed extracellularly into glucose and galactose, and both sugars were utilized simultaneously. Diauxic growth patterns were not observed. However, a typical biphasic growth was observed on a mixture of glucose and galactose under aerobic and anaerobic conditions with transformants of a haploid S. cerevisiae strain, GRF167. Polyploid distiller's yeast (Mauri) transformants were selected simply on the basis of the cloned gene expression on X-Gal (5-bromo-4-chloro-3-indolyl-β-D- galactopyranoside) plates. Rapid and complete lactose hydrolysis and higher ethanol (0.31 g/g of sugar) and biomass (0.24 g/g of sugar) production were observed with distiller's yeast grown under aerobic conditions. A constant proportion (10%) of the population retained the plasmid throughout the fermentation period (48 h). Nearly theoretical yields of ethanol were obtained under anaerobic conditions on lactose, glucose, galactose, and whey permeate media. However, the rate and the amount of lactose hydrolysis were lower under anaerobic than aerobic conditions. All lactose-grown cells expressed partial galactokinase activity.

UR - http://www.scopus.com/inward/record.url?scp=0027520135&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027520135&partnerID=8YFLogxK

M3 - Article

C2 - 8285714

AN - SCOPUS:0027520135

VL - 59

SP - 4230

EP - 4235

JO - Applied and Environmental Microbiology

JF - Applied and Environmental Microbiology

SN - 0099-2240

IS - 12

ER -