ISSN:
1432-1793
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract A study of phosphate assimilation by coastal marine plankton revealed that both phytoplankton and microheterotrophs incorporated radioactive phosphorus (33P). Size fractionation of the particulate matter (using 1 μm pore diameter Nucleopore® membrane filters), antibiotic treatment (using garamycin), and independent estimaties of photoautotrophic (14CO2 uptake) and heterotrophic (3H-glucose uptake) activities were employed to separate phyto- and bacterioplankton phosphate uptake. Results indicated that phytoplankton 33P-uptake was best estimated by the fraction of particulate matter retained on the 1 μm membrane filters. Usually, less than 10% of the phytoplankton (based on chlorophyll a measurements) passed the 1 μm pore-diameter filters, whereas about 90% of the heterotrophic activity passed. At least 50% of the 33P-uptake was associated with the 〈1 μm fraction. It may be possible to resolve the phytoplankton and bacterial contributions to 33P-uptake by comparing the percent of total 33P-uptake with the percent of total 3H-glucose uptake associated with the 〉1 μm fraction.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00390622
