The effect of culture conditions on the morphology of the dimorphic yeast Kluyveromyces marxianus var. marxianus NRRLy2415: a study incorporating image analysis.
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.
O'Shea
D G
DG
Bioprocess Engineering Research Group, School of Biotechnology, Dublin City University, Ireland.
Walsh
P K
PK
D018533:Biomass; D003470:Culture Media; D005285:Fermentation; D007091:Image Processing, Computer-Assisted; D007716:Kluyveromyces / Q000166:cytology* / Q000254:growth & development* / Q000378:metabolism
D003470:Culture Media