Effect of hyperbaric stress on yeast morphology: study by automated image analysis
- 253 Downloads
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.
KeywordsGlucose Consumption Rate Average Cell Size Carbon Dioxide Partial Pressure Carbon Dioxide Pressure Cell Size Distribution
M.A.Z. Coelho is grateful for the scholarship and financial support given by CAPES and CNPq (Brazil) for this work development in Portugal. A.L. Amaral was supported by PRAXIS XXI/BD/20325/99 grant and R. Pinheiro was also supported by PRAXIS XXI/BD/11498/97 grant of Fundação para a Ciência e Tecnologia (Portugal).
- Lee J, Lee SY, Park S (1997) Fed-batch culture of Escherichia coli W by exponential feeding of sucrose as a carbon source. Biotechnol Tech 11:59–62Google Scholar
- Miller GE (1959) Use of dinitrosalicylic acid reagent for determination of reducing sugar. Anal Chem 31:426–428Google Scholar
- Nakamura K, Enomoto A, Fukushima H, Nagai K, Hakoda M (1994) Disruption of microbial cells by the flash discharge of high-pressure carbon dioxide. Biosci Biotechnol Biochem 58:1297–1301Google Scholar
- Onken U, Liefke E (1989) Effect of total and partial pressure (oxygen and carbon dioxide) on aerobic microbial processes. In: Fiechter A (ed) Advances in biochemical engineering/biotechnology. Springer, Berlin Heidelberg New York, pp 137–169Google Scholar
- Pons MN, Vivier H (1998) Morphometry of yeast. In: Wilkinson MHF, Schut F (eds) Digital image analysis of microbes: imaging, morphometry, fluorometry and motility techniques and applications. Wiley, New York, pp 199–224Google Scholar
- Russ CR (2002) The image processing handbook, 4th edn. CRC, Boca RatonGoogle Scholar
- Shimada S, Andou M, Naito N, Yamada N, Osumi M, Hayashi R (1993) Effects of hydrostatic pressure on the ultrastructure and leakage of internal substances in the yeast Saccharomyces cerevisiae. Appl Microbiol Biotechnol 40:123–131Google Scholar
- Thibault J, LeDuy A, Côté F (1987) Production of ethanol by Saccharomyces cerevisiae under high-pressure conditions. Biotechnol Bioeng 30:74–80Google Scholar
- Vicente A, Meinders JM, Teixeira JA (1996) Sizing and counting of Saccharomyces cerevisiae floc populations by image analysis, using an automatically calculated threshold. Biotechnol Bioeng 51:673–678Google Scholar
- Wendlandt KD, Jechorek M, Brühl E (1993) The influence of pressure on the growth of methanotrophic bacteria. Acta Biotechnol 13:11–115Google Scholar