SUMMARY: Singh was cultivated under axenic conditions at 25–30° in a buffered physiological salt solution containing 1% (w/v) proteose peptone and a suitable additional carbon source. Optimal growth and maximum cyst formation were obtained aerobieally under constant agitation in vessels coated with silicone. The addition of a thickening agent did not improve growth. No cysts were formed at low oxygen tensions. This may reflect a fundamental metabolic block in cyst formation. Growth curves were obtained with a variety of carbon sources: glucose, maltose and mannose supported optimal growth; lactose supported unusual growth which resembled diauxie. By testing for reducing sugars, no utilization of glucose was detected. A specific chemical test for glucose revealed that glucose was utilized during growth and by resting suspensions. Through the use of uniformly labelled C glucose, it was possible to demonstrate that glucose was assimilated and also used as an energy source during growth. The osmotic concentration required for optimal growth was in itself not optimal when the total osmotic pressure was kept constant and the concentration of utilizable carbon sources was decreased.


Article metrics loading...

Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error