Abstract
From engineering point of view, the effect of light intensity distribution on the stability of growth rate can play an important role in designing of effective photobioreactors and sustaining of stable growth rates. In these series of experiments, in order to keep the operational parameters at almost constant level, a semi-continuous culture method was developed. In this cultivation method, a part of culture broth containing grown cells was repeatedly replaced with the fresh medium at a predetermined time interval to keep the cell concentration and the volume of the broth constant at initial values. Thus it was possible to cultivate photosynthetic cells under defined light intensity distributions.
Under one side and both side illumination and also reflection by mirror photosynthetic cells were cultivated in flat plate photobioreactors with various light path lengths. The obtained results showed that stability of the growth rate strongly depended on the distribution of light intensity and ratio of light intensity at light zone to that at dark zone inside photobioreactors. These parameters should be taken into consideration for stable cultivation of photosynthetic cells.
