Relationship between growth and pH gradients of individual cells of Debaryomyces hansenii as influenced by NaCl and solid substrate

TY - JOUR

T1 - Relationship between growth and pH gradients of individual cells of Debaryomyces hansenii as influenced by NaCl and solid substrate

AU - Mortensen, Henrik Dam

AU - Gori, Klaus

AU - Siegumfeldt, Henrik

AU - Jespersen, Lene

AU - Arneborg, Nils

PY - 2007

Y1 - 2007

N2 - Aims: To examine the relationship between the growth and pH gradients of Debaryomyces hansenii at a single-cell level.Methods and Results: Using bioimaging techniques, the cell areas and early pH gradients (¿pH10), i.e. the pH gradients determined 10 min after initiation of experiments, were determined for single cells of two D. hansenii strains in fluid and on solid (agar) substrate with and without 8% (w/v) NaCl. The combination of NaCl and solid substrate prolonged the growth initiation of both D. hansenii strains additively. In all our experiments, primarily two groups of cells existed; a vital group consisting of growing single cells with intact early pH gradients, and a group of dead cells without early pH gradients.Conclusions: Our results show that growth initiation of the D. hansenii cells is severely affected by NaCl and to a lesser extent by the type of substrate in an additive and strain dependent way. Moreover, the early pH gradient of a vital D. hansenii cell cannot be correlated with the rate of its subsequent growth.Significance and Impact of the Study: Our study reveals new knowledge on the growth and pH gradients of D. hansenii on solid surfaces in the presence of NaCl.

AB - Aims: To examine the relationship between the growth and pH gradients of Debaryomyces hansenii at a single-cell level.Methods and Results: Using bioimaging techniques, the cell areas and early pH gradients (¿pH10), i.e. the pH gradients determined 10 min after initiation of experiments, were determined for single cells of two D. hansenii strains in fluid and on solid (agar) substrate with and without 8% (w/v) NaCl. The combination of NaCl and solid substrate prolonged the growth initiation of both D. hansenii strains additively. In all our experiments, primarily two groups of cells existed; a vital group consisting of growing single cells with intact early pH gradients, and a group of dead cells without early pH gradients.Conclusions: Our results show that growth initiation of the D. hansenii cells is severely affected by NaCl and to a lesser extent by the type of substrate in an additive and strain dependent way. Moreover, the early pH gradient of a vital D. hansenii cell cannot be correlated with the rate of its subsequent growth.Significance and Impact of the Study: Our study reveals new knowledge on the growth and pH gradients of D. hansenii on solid surfaces in the presence of NaCl.

KW - Former LIFE faculty

KW - Debaryomyces hansenii, NaCl stress, pH gradient, single-cell growth, solid-surface growth

U2 - 10.1111/j.1472-765X.2006.02067.x

DO - 10.1111/j.1472-765X.2006.02067.x

M3 - Journal article

C2 - 17309505

SN - 0266-8254

VL - 44

SP - 279

EP - 285

JO - Letters in Applied Microbiology

JF - Letters in Applied Microbiology

IS - 3

ER -