• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.1
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• pp.96-101
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• 2019

This study was conducted to investigate the effects of the light quality of a Light Emitting Diode (LED) on the phosphate uptake of Prasinophytes Tetraselmis suecica and Tetraselmis tetrathele. These species were exposed to a blue LED (max = 450 nm), a yellow LED (max = 590 nm), a red LED (max = 630 nm) and a fluorescent lamp (control) at $100{\mu}mol\;m^{-2}\;s^{-1}$. The maximum uptake rates (${\rho}_{max}$) of T. suecica and T. tetrathele under the red LED were $6.35pmol\;cell^{-1}\;hr^{-1}$ and $9.85pmol\;cell^{-1}\;hr^{-1}$, respectively. The half saturation constants (Ks) of two species were $9.43{\mu}M$ and $21.2{\mu}M$, respectively. The phosphate affinity of the two species under the red LED was higher than that of other wavelengths. Thus, the optimum light source to ensure economically effective and productive growth in a Tetraselmis culture system (Photo-Bioreactor) would be red LEDs because of the high growth rate shown, regardless of relatively low nutrient conditions.

• Korean Journal of Ecology and Environment
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• v.36 no.2 s.103
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• pp.139-149
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• 2003

This study was conducted to determine limiting nutrients and the physiological characteristics of phytoplankton in response of nutrients in Lake Paldang from March 2002 to October 2002. A field research was conducted along with laboratory batch culture experiment to find the limiting nutrients and the growth kinetics. According the results of Chl. a TP relationship, TN/TP ratio, and nutrient addition bioassay, phosphorus appeared to be a major limiting nutrient in Lake Paldang and thus the lake productivity was greatly influenced by it. P limitation for the phytoplankton of Lake Paldang varied with season, and the possibility of limitation by nitrogen and silica also occurred. The degree of P limitation was greatest during spring when the concentration of dissolved phosphorus is relatively much lower than summer and autumn. The maximum growth rate (${\mu}_{max}$) and half saturation concentration ($K_u$) of Lake Paldang phytoplankton ranged from 0.8${\sim}$1.1$day^1$ and from 0.1${\sim}$O.8${\mu}M$, respectively. $K_u$ was highest during May ($0.8{\mu}M$) and the lowest during September ($0.1{\mu}M$). Such result may be induced by the phytoplankton cell quota that showed the lowest concentration ($0.13{\mu}gP/{\mu}gChl.$ a) during May. The growth kinetics showed that phytoplankton growth in Lake Paldang was faster during summer and autumn than spring, suggesting that the Potential of algal bloom is high after the summer monsoon season.