an additional and essential energy source available for photo-synthesis in ultrahigh cell densities, greatly expanding the verylimited photic volume in such cultures and seemingly support-ing photosynthesis in the absence of blue and red light a smalldistance underneath the surface. Since the green range of thespectrum, which represents approximately one-third to one-quarter of the entire photosynthetically active radiation range,corresponds to the maximal flux of solar energy, the intensityof the green light when mutual shading is extreme is sufficientto facilitate photosynthesis at a level corresponding to thatinduced by the red and blue ranges of the spectrum. Furtherinvestigation is required to determine the efficiency of greenlight for photosynthesis in our system.Conclusion. The general conclusions pertaining to determi-nation of the inherent optical properties required for calculat-ing light penetration depth into algal suspension are as follows.(i) A similar absorption coefficient for Chl was found for Spir-ulina cultures grown in widely different reactor types (5). Theabsorption coefficient, however, was quite sensitive to the phys-iological state of algae (not shown), opening the possibility ofmonitoring some aspects of the physiological state of algae inreal time by using nondestructive remote-sensing techniques.(ii) Absorption and scattering coefficients for Chl were quiteclose to those reported for algae in ocean and inland waters.(iii) The vertical attenuation coefficient of downwelling irradi-ance can be used to estimate the depth of light penetration intoa reactor supporting ultrahigh cell densities. (iv) In ultrahigh-cell-density cultures, the photic volume, which is only a smallfraction of the reactor volume, greatly differs for the blue andred light compared with the green light. A photosynthetic rolefor green light under these unique circumstances is suggested.
đang được dịch, vui lòng đợi..
