Ion permeability of the cytoplasmic membrane limits the maximum growth temperature of bacteria and archaea

Abstract

Protons and sodium ions are the most commonly used coupling ions in energy transduction in bacteria and archaea. At their growth temperature, the permeability of the cytoplasmic membrane of thermophilic bacteria to protons is high compared with that of sodium ions. In some thermophiles, sodium is the sole energy-coupling ion. To test whether sodium is the preferred coupling ion at high temperatures, the proton- and sodium permeability was determined in liposomes prepared from lipids isolated from various bacterial and archaeal species that differ in their optimal growth temperature. The proton permeability increased with the temperature and was comparable for most species at their respective growth temperatures. Liposomes of thermophilic bacteria are an exception in the sense that the proton permeability is already high at the growth temperature. In all liposomes, the sodium permeability was lower than the proton permeability and increased with the temperature. The results suggest that the proton permeability of the cytoplasmic membrane is an important parameter in determining the maximum growth temperature.

Lipid membranes from halophilic and alkali-halophilic Archaea have a low H + and Na + permeability at high salt concentration

“…Previous studies on the proton permeability in archaeal and bacterial membranes have demonstrated that most Bacteria and Archaea adjust the permeability of the cytoplasmic membranes to the growth temperature of the organism (Elferink et al 1994; Van de Vossenberg et al 1995). The proton permeability is maintained at a constant level by regulation of the phospholipid composition of the cell membrane as a function of the growth temperature (Van de Vossenberg et al, 1999).…”

“…The proton permeability of the liposomes was measured with the acid-pulse method, monitored with fluorescent probes (Molecular Probes, Leiden, The Netherlands), as described by Nichols and Deamer (1980), Elferink et al (1994), and Van de Vossenberg et al (1995). The probe 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) (pyranine, pK a ϭ 7.3) was used for proton permeability measurements between pH 7.0 and 8.0, and SNAFL (Molecular Probes, Leiden, The Netherlands) (pK a ϭ 7.8) at pH 9.0.…”

Deep subseafloor microbial cells on physiological standby

“…It is interesting that, although bacteria are the predominant prokaryotic domain of life in most environments on the surface of earth, the other prokaryotic domain, the archaea, are very common and even seem to rule the deep subsurface (13,15). The archaea have a selective advantage in that their cell membrane is much less permeable toward passive diffusion of protons or other ions (16). This may enable the archaea to generate an energized membrane with a 100-fold lower energy loss than the bacteria.…”

Viable quantitative PCR for assessing the response of Candida albicans to antifungal treatment

“…The EMA treatment optimization results revealed that increasing the dye concentration, the photoactivation time, and the dye incubation time did not result in a higher signal reduction with heat-killed cells. In addition, EMA apparently cannot penetrate through the viable cell membrane; although, different temperatures generate changes in cell membrane fluidity and permeability (Van de Vossenberg et al 1995). Based on the results of the present study, viable -1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 qPCR can be used to determine the viability of C. albicans when heat treatment is used, and the usefulness of this technique for yeast species was confirmed, as demonstrated previously for some wine yeasts (Andorrà et al 2010) and Zygosaccharomyces bailii cells (Rawstorne and Phister 2009).…”