The influence of pressure on the growth of methanotrophic bacteria

Wendlandt, K.‐D.; Jechorek, M.; Brühl, E.

doi:10.1002/abio.370130205

Cited by 12 publications

(2 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, in the present work, the air pressure increase stimulated cell growth due to higher oxygen availability in the medium. Several authors have shown that use of increased air or oxygen pressure is an efficient means of oxygenation improvement in various microbial cell cultures (Yang and Wang 1992;Wendlandt et al 1993;Lee et al 1997;Belo and Mota 1998;Pinheiro et al 2003). However, there are limits for the air or oxygen pressure increase depending on the microorganism and strain.…”

Section: Discussionmentioning

confidence: 99%

Effect of hyperbaric stress on yeast morphology: study by automated image analysis

Coelho

Belo

Pinheiro

et al. 2004

Appl Microbiol Biotechnol

View full text Add to dashboard Cite

The effects of hyperbaric stress on the morphology of Saccharomyces cerevisiae were studied in batch cultures under pressures between 0.1 MPa and 0.6 MPa and different gas compositions (air, oxygen, nitrogen or carbon dioxide), covering aerobic and anaerobic conditions. A method using automatic image analysis for classification of S. cerevisiae cells based on their morphology was developed and applied to experimental data. Information on cell size distribution and bud formation throughout the cell cycle is reported. The results show that the effect of pressure on cell activity strongly depends on the nature of the gas used for pressurization. While nitrogen and air to a maximum of 0.6 MPa of pressure were innocuous to yeast, oxygen and carbon dioxide pressure caused cell inactivation, which was confirmed by the reduction of bud cells with time. Moreover, a decrease in the average cell size was found for cells exposed for 7.5 h to 0.6 MPa CO2.

show abstract

Section: Discussionmentioning

confidence: 99%

Effect of hyperbaric stress on yeast morphology: study by automated image analysis

Coelho

Belo

Pinheiro

et al. 2004

Appl Microbiol Biotechnol

View full text Add to dashboard Cite

show abstract

“…The oxygen solubility in the liquid medium can also be raised by the increase of the total air pressure in the cultivation system. Bioreactor headspace pressurization has been proved to be an efficient way of OTR improvement for different microbial cell strains (8)(9)(10)(11). However, there are limits for oxygen partial pressure rise in a cell culture due to the oxidative stress caused by oxygen (12).…”

Section: Introductionmentioning

confidence: 99%

Fed‐Batch Cultivation of Saccharomyces cerevisiae in a Hyperbaric Bioreactor

Belo

Pinheiro

Мота

2003

Biotechnology Progress

View full text Add to dashboard Cite

Fed-batch is the dominating mode of operation in high-cell-density cultures of Saccharomyces cerevisae in processes such as the production of baker's yeast and recombinant proteins, where the high oxygen demand of these cultures makes its supply an important and difficult task. The aim of this work was to study the use of hyperbaric air for oxygen mass transfer improvement on S. cerevisiae fed-batch cultivation. The effects of increased air pressure up to 1.5 MPa on cell behavior were investigated. The effects of oxygen and carbon dioxide were dissociated from the effects of total pressure by the use of pure oxygen and gas mixtures enriched with CO(2). Fed-batch experiments were performed in a stirred tank reactor with a 600 mL stainless steel vessel. An exponential feeding profile at dilution rates up to 0.1 h(-)(1) was used in order to ensure a subcritical flux of substrate and, consequently, to prevent ethanol formation due to glucose excess. The ethanol production observed at atmospheric pressure was reduced by the bioreactor pressurization up to 1.0 MPa. The maximum biomass yield, 0.5 g g(-)(1) (cell mass produced per mass of glucose consumed) was attained whenever pressure was increased gradually through time. This demonstrates the adaptive behavior of the cells to the hyperbaric conditions. This work proved that hyperbaric air up to 1.0 MPa (0.2 MPa of oxygen partial pressure) could be applied to S. cerevisiae cultivation under low glucose flux. Above that critical oxygen partial pressure value, i.e., for oxygen pressures of 0.32 and 0.5 MPa, a drastic cell growth inhibition and viability loss were observed. The increase of carbon dioxide partial pressure in the gas mixture up to 48 kPa slightly decreased the overall cell mass yield but had negligible effects on cell viability.

show abstract