The effect of culture conditions on the morphology of the dimorphic yeast Kluyveromyces marxianus var. marxianus NRRLy2415 : a study incorporating image analysis

• Published in: Applied microbiology and biotechnology Vol. 53; no. 3; pp. 316 - 322
• Main Authors: O'SHEA, D. G, WALSH, P. K
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01-03-2000; Springer Nature B.V
• Subjects: Biological and medical sciences; Biomass; Biotechnology; Culture Media; Environmental changes; Environmental conditions; Fermentation; Fundamental and applied biological sciences. Psychology; Genetics; image analysis; Image Processing, Computer-Assisted; Kluyveromyces - cytology; Kluyveromyces - growth & development; Kluyveromyces - metabolism; Kluyveromyces marxianus; Methods. Procedures. Technologies; Microbial engineering. Fermentation and microbial culture technology; Morphology; Studies; Yeast; Yeasts; Microorganism growth; Yeast; Environmental factor; Fungi; Continuous process; Image analysis; Batchwise; Morphology; Microorganism culture; Ascomycetes; Thallophyta; Computer aided analysis; Kluyveromyces marxianus var. marxianus
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s002530050027

The effect of changing environmental conditions on the morphology of the yeast Kluyveromyces marxianus var. marxianus NRRLy2415 was investigated in batch and continuous culture, using a previously developed computer-aided image analysis protocol [O'Shea and Walsh (1996) Biotechnol Bioeng 51: 679 690]. The morphology of the organism is primarily controlled by the specific growth rate, mu. This finding was contrary to a previous investigation [Walker and O'Neill (1990) J Chem Tech Biotechnol 49: 75-89]. When the organism is cultured in batch with excess oxygen, mu can approach the maximum specific growth rate, microm, and the primary morphology of the culture is yeast-like. However, if the organism is cultured in a chemostat, thereby controlling the growth rate, the morphology reverts to a pseudohyphal form. This response is thought to be an adaptation by the organism to its environment, whereby it assumes a foraging form under adverse environmental conditions. The use of computer-aided image analysis made possible the discrimination of subtle morphological differences between samples and the determination of the relationship between morphology and growth rate.