ISSN:
1573-5176
Keywords:
microalgae
;
Chlamydomonas reinhardtii
;
Dunaliellatertiolecta
;
light/dark cycles
;
photobioreactors
;
light utilizationefficiency
;
biomass yield
;
quantum yield
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The green micro-algae Chlamydomonas reinhardtiiand Dunaliella tertiolecta were cultivated undermedium-duration square-wave light/dark cycles with acycle time of 15 s. These cycles were used to simulatethe light regime experienced by micro-algae inexternally-illuminated (sunlight) air-lift loopbioreactors with internal draft tube. Biomass yieldin relation to light energy was determined as gprotein per mol of photons (400–700 nm). Between 600and 1200 μmol m-2 s-1 the yield at a10/5 s light/dark cycle was equal to the yield atcontinuous illumination. Consequently, provided thatthe liquid circulation time is 15 s, a considerabledark zone seems to be allowed in the interior ofair-lift loop photobioreactors (33% v/v) without lossof light utilization efficiency. However, at a 5/10 slight/dark cycle, corresponding to a 67% v/v darkzone, biomass yield decreased. Furthermore, bothalgae, C. reinhardtii and D. tertiolecta,responded similarly to these cycles with respect tobiomass yield. This was interesting because they werereported to exhibit a different photoacclimationstrategy. Finally, it was demonstrated that D.tertiolecta was much more efficient at low (average)photon flux densities (57–370 μmol m-2s-1) than at high PFDs (〉 600 μmol m-2s-1) and it was shown that D. tertiolectawas cultivated at a sub-optimal temperature (20 °C).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1008151526680
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