ISSN:
1573-5176
Keywords:
light-limited growth
;
carbon fixation
;
growth efficiency
;
N:P ratio
;
luxury storage
;
rice paddy
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Seven unialgal isolates from rice paddies,Ankistrodesmus convolutus, Chlorella sp.,Scenedesmus quadricauda, Frustulia vulgaris, Anabaena sp.,Microcystis aeruginosa andPhormidium mucicola, were investigated for their light-limited growth and photosynthetic characteristics, growth efficiency, and relative requirement for N and P as well as their storage potentials. The maximum growth rate (μmax) ranged from 1.27 to 2.72 d−1 among species. The slope of light-limited growth (αg) showed only small interspecies differences (0.126–0.204 d−1 W−1 m2) except inS. quadricauda (0.092 d−1 W−1 m2). Similarly, the ratio of μmax to αg, Ik(g), varied within a narrow range (8.7–13.9 W m−2) with the exception ofS. quadricauda (19.5 W m−2). The slope of the photosynthetic curve based on chlorophylla (chla), αp(a), was significantly higher in cyanobacteria (0.118–0.189 mg C mg chla −1h−1W−1m2) than in other species (0.070–0.094 mg C mg chla −1h−1W−1m2). The maximum photosynthetic rate based on chla (Pmax(a)) was similar (2.95–3.83 mg C mg chla −1 h−1) with the exception of a high value (6.17 mg C mg chla −1 h−1) inM. aeruginosa. A significant correlation (P〈0.001) existed between αp(a) and Pmax(a). The C-specific maximum photosynthetic rate (Pmax(c)) was inversely correlated to the C/chla ratio. Growth efficiency (μeff), the efficiency to retain photosynthetically-fixed C for growth, showed an interspecies variation ranging from 73–93% and was correlated to the μmax:Pmax(c) ratio. Cyanobacteria exhibited higher efficiency than others. The ratio of Pmax:αp, Ik(p), was higher than Ik(g) by 2.0 to 3.8 times. The optimum N:P ratio, determined as the ratio of minimum cell quotas of N to P (qoN:qoP), showed a wide interspecies variability. It was highest inP. mucicola (54) and lowest inF. vulgaris (10). The maximum storage capacity for excess P and N also varied among species; the maximum capacity for P ranged from 2 to 14 times of its immediate need and the capacity for N varied from 1.2 to 4 times.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00003579
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