Growth, fluorescence, photosynthetic O2 production and pigment content of salt adapted cultures of Arthrospira (Spirulina) platensis

Abstract

The effect of salt concentration (NaCl) on growth, fluorescence, photosynthetic activities and pigment content of the cyanobacterium Arthrospira platensis has been investigated over 15 days. It has been observed that high NaCl concentration induces an increase of the growth, photosynthetic efficiency (α), phycobilin/chlorophyll ratio and a slight decrease of dark respiration and compensation points. Moreover, high NaCl concentration enhances photosystem II (PSII) activity compared to photosystem I (PSI). Results show that the phycobilin-PSII energy transfer compared to the chlorophyll-PSII (F 695,600 /F 695,440 ) increases. However, data obtained about the maximal efficiency of PSII photochemistry are controversial. Indeed, the Fv/Fm ratio decreases in salt adapted cultures, while at the same time the trapping flux per PSII reaction center (TR 0 /RC) and the probability of electron transport beyond Q A (= 0 ) remain unchanged at the level of the donor and the acceptor sites of PSII. This effect can be attributed to the interference of phycobilin fluorescence with Chl a when performing polyphasic transient measurements.

Biotechnology Carbon Capture and Storage by Microalgae to Enhance CO2 Removal Efficiency in Closed-System Photobioreactor

“…Sodium plays a role in cellular osmoregulation. However, excessive levels of sodium may cause a reduction in photosynthetic pigments [75,76]. Micronutrients such as Mg, Ca, Fe, EDTA, Cu, Mn, Mo, B, Co, and Zn are essential nutrients that are required in very small amounts.…”

Study on the mechanism of allelopathic influence on cyanobacteria and chlorophytes by submerged macrophyte (Myriophyllum spicatum) and its secretion

“…In this study, the inhibi-tion of PSII of M. aeruginosa might connect with the damage of D1 protein, which needs energy to be repaired. On the other hand, enhancing of dark respiration could reduce the energy transfer between phycobilisomes and PSII, and PSI could get more energy from the distribution of excitation energy to adapt to salt or light changes (Lu and Vonshak, 1999;Dhiab et al, 2007;Rochaix, 2007). Consequently, the enhancement of dark respiration and PSI activities may be required to repair photosystem and protect PSII from excessive excitation energy, which may be the responses in M. aeruginosa under PA and GA stress.…”

Влияние щелочности, сверхнизкой концентрации диоксида углерода и интенсивности излучения на спектральные свойства, фитобилисомы, фотосинтез, фотосистемы и функциональные группы нативной цианобактерии Calothrix sp. ISC 65

“…In our study a light intensity of 2 μmol photonm -2 s -1 was used, which is lower than the one used by Vonshak (1999, 2002), Poza-Carrion et al (2001), Dhiab et al (2007), Soltani et al (2005), Soltani et al (2007), and many other papers. Strain Nostoc sp.…”

“…Strain Nostoc sp. UAM 205 and 206 have been characterized at extremely limited carbon dioxide concentration but 60 μmol photonm -2 s -1 (Fernandez-Valiente, Leganes, 1989;Zeng, Vonshak, 1998;Poza-Carrion et al, 2001) showed that at a higher light intensity, growing cells had lower photosynthesis activity after photoinhibition under salinity stress, compared with cells growing under lower light intensity condition (Dhiab et al, 2007). However, the carbon dioxide conditions were not considered in this research.…”