China
Africa
Explore chapters and articles related to this topic
Carbon Dioxide Sequestration by Microalgae
Published in Gokare A. Ravishankar, Ranga Rao Ambati, Handbook of Algal Technologies and Phytochemicals, 2019
G.V. Swarnalatha, Ajam Shekh, P.V. Sijil, C.K. Madhubalaji, Vikas Singh Chauhan, Ravi Sarada
The supplementation of CO2 and its assimilation in microalgal cells are dependent on the photosynthetic CO2 fixation, known as the Calvin cycle. It has been observed that the CO2 supplementation up-regulated the genes encoding the major enzymes in the Calvin cycle. Phosphoglycerate kinase (PGK) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) are up-regulated. It catalyzes the phosphorylation and reduction of 3-carbon intermediates, respectively, in the presence of ATP and NADPH to generate glyceraldehyde-3-phosphate. This up-regulation of the Calvin cycle by CO2 supplementation shows higher CO2 fixation by microalgae resulting in increased biomass production. Even so, it is reported that the higher CO2 concentration inhibited the photosynthetic efficiency of microalgae. According to Winck et al. (2016), at 10% CO2 supplementation sucrose was reduced, and the xylose was accumulated, which is a clear indication of inhibition of photosynthesis. These results also suggest that photorespiration or an alternative pathway with similar substrates and products may be modulated in cells at a high CO2 concentration. It has been observed that the gene encoding the ferredoxin was up-regulated by CO2 supplementation which is suggested to enhance the Calvin cycle and carbohydrate synthesis (Peng et al. 2016; Zhu et al. 2017).
Biogeneration of Volatile Organic Compounds in Microalgae-Based Systems
Published in Gokare A. Ravishankar, Ranga Rao Ambati, Handbook of Algal Technologies and Phytochemicals, 2019
Pricila Nass Pinheiro, Karem Rodrigues Vieira, Andriéli Borges Santos, Eduardo Jacob-Lopes, Leila Queiroz Zepka
In general, microalgae are commonly grown by converting dissolved, inorganic carbon (CO2) and absorbing solar energy. They have pigments such as chlorophyll and carotenoids, and in some cases phycobiliproteins which are involved in capturing luminous energy to perform photosynthesis. For the CO2 converted into carbohydrates, catalyzed by the enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco), this process is referred to as the Calvin cycle. The Calvin cycle is the metabolic mechanism for fixing CO2 in microalgae. This process comprises three stages; carboxylation, reduction, and regeneration. The end of the cycle forms one molecule of glyceraldehyde-3-phosphate that through the action of enzymes forms phosphoenolpyruvate, and finally pyruvate (Santos et al. 2016a).
Isolation of Chloroplasts for the Study of Oxygen Radical Reactions
Published in Robert A. Greenwald, CRC Handbook of Methods for Oxygen Radical Research, 2018
The grana and stroma thylakoids contain all the chlorophyll; there is none in the envelope. They absorb light energy and use it to produce NADPH and ATP, water being split into oxygen and H+ ions to yield the electrons necessary to reduce NADP+. The stroma of the chloroplast contains enzymes that use NADPH and ATP to drive the conversion of CO2 into sugars by a complicated metabolic pathway (the Calvin cycle).
Still challenging: the ecological function of the cyanobacterial toxin microcystin – What we know so far
Published in Toxin Reviews, 2018
Azam Omidi, Maranda Esterhuizen-Londt, Stephan Pflugmacher
On one hand, in a comparative proteomics study, different isoforms of the same proteins were found in M. aeruginosa toxic and non-toxic strains. Moreover, proteins involved in carbon–nitrogen metabolism and redox balance was expressed in various quantities. Comparisons between toxic and non-toxic strains also showed Calvin cycle enzymes and proteins involved in glycolysis and respiration expressed in higher quantity in M. aeruginosa PCC 7820, a known toxic strain (Tonietto et al., 2012). Under nitrogen depletion, proteins involved in carbon and nitrogen metabolism such as chaperones and proteases were accumulated more in the non-toxic M. aeruginosa strains, PCC 7005 and mcyH− mutant (Alexova et al., 2016).
Insights in nodule-inhabiting plant growth promoting bacteria and their ability to stimulate Vicia faba growth
Published in Egyptian Journal of Basic and Applied Sciences, 2022
Amr M. Mowafy, Mona S. Agha, Samia A. Haroun, Mohamed A. Abbas, Mohamed Elbalkini
The photosynthetic capacity of leaves is related to the nitrogen content primarily because of proteins of the Calvin cycle, and thylakoids represent the majority of leaf nitrogen [44]. Nitrogen availability and internal distribution play a critical role in the regulation of various growth-related and morphogenetic aspects of plant development [45]. One of the important factors indicating the efficiency of nitrogen fertilization is the performance of the photosynthetic apparatus that determines photosynthetic pigment contents in leaves [46].