Abstract
Euglena is capable of growth under various variety of nutritional and environmental conditions. Euglena is possible to grow under diverse culture conditions with and without light illumination, namely under both heterotrophic and photoautotrophic conditions. Euglena can synthesize most of vitamins and biofactors except for the exception, such as vitamin B1 and B12. In the present study, the effects of nicotinamide and its analogues on the flagellar detachment of Euglena were investigated using nicotinamide and the 12 kinds of structural analogues (nicotinic acid, pyrazine, pyrazine-2-carboxylic acid, 2-picolinamide, methylnicotinate, N-methylnicotinamide, 3-methylpyridine, pyridine-3-sulfate, pyridoxine, pyridoxal, pyridoxamine, isonicotinic acid hydrazide), NAD+, and NADP+. Among these compounds, nicotinamide, nicotinic acid, pyrazine-2-carboxylic acid, methylnicotinate, 2-picolinamide, and N-methylnicotinamide caused the flagellar detachment and then cell division stopped. It was also found that when the nicotinamide added to Euglena cells was diluted with water or culture medium, cell division occurred and then flagella were regenerated after 24 h, resulting in the onset of euglenoid exercise. The electrophoresis of the detached flagellar proteins revealed that the proteins resembled tublin (55 kDa) and paraflagella rod 2 (69 kDa)
