Carbon utilization patterns in the heterotrophic blue-green alga Chlorogloea fritschii

✍ Scribed by Miller, J. S. ;Allen, M. M.

• Publisher: Springer-Verlag
• Year: 1972
• Weight: 710 KB
• Volume: 86
• Category: Article
• ISSN: 0003-9276
• DOI: 10.1007/bf00412395

✦ Synopsis

1. The metabolic patterns of Chlorogloea ]ritschii, a blue-green alga capable of growing both heterotrophically and autotrophically, were analyzed in cells grown with different carbon and energy sources.

2. The distribution of isotopic carbon incorporated into ceils grown on combinations of CO 2, sucrose and acetate in the light or in the dark was determined after cell fractionation and amino acid isolation. Fractionatiou studies indicated that C./ritschii utilizes organic substrates both in the light and the dark, but that the pattern of incorporation in the light is more similar to that seen in other bluegreen algae grown in the light than to its own pattern in the dark.

3. C02 is also incorporated into both light-and dark-grown cells, but sucrose is the preferred substrate when C02 and sucrose are both present.

4. Label from radioactive sucrose and acetate was distributed into all amino acids separated. Large amounts of label appeared in both the glutamate and aspartare families, suggesting that the Krebs cycle, which appears to be incomplete in other blue-greens, may be fully functional in C./ritschii in the light and in the dark.

Although blue-green algae have been shown to flourish in soils and waters rich in organic nutrients, they have long been considered obhgate autotrophs incapable of assimilating or utilizing, except to a very limited degree, any carbon source other than CO, (Holm-Hansen, 1968; Itoare