Elevated carbon dioxide levels lead to proteome-wide alterations for optimal growth of a fast-growing cyanobacterium, Synechococcus elongatus PCC 11801

Abstract

The environmental considerations attributing to the escalation of carbon dioxide emissions have raised alarmingly. Consequently, the concept of sequestration and biological conversion of CO 2 by photosynthetic microorganisms is gaining enormous recognition. In this study, in an attempt to discern the synergistic CO 2 tolerance mechanisms, metabolic responses to increasing CO 2 concentrations were determined for Synechococcus elongatus PCC 11801, a fast-growing, novel freshwater strain, using quantitative proteomics. The protein expression data revealed that the organism responded to elevated CO 2 by not only regulating the cellular transporters involved in carbon-nitrogen uptake and assimilation but also by inducing photosynthesis, carbon fixation and glycolysis. Several components of photosynthetic machinery like photosystem reaction centers, phycobilisomes, cytochromes, etc. showed a marked up-regulation with a concomitant downshift in proteins involved in photoprotection and redox maintenance. Additionally, enzymes belonging to the TCA cycle and oxidative pentose phosphate pathway exhibited a decline in their expression, further highlighting that the demand for reduced cofactors was fulfilled primarily through photosynthesis. The present study brings the first-ever comprehensive assessment of intricate molecular changes in this novel strain while shifting from carbon-limited to carbon-sufficient conditions and may pave the path for future host and pathway engineering for production of sustainable fuels through efficient CO 2 capture.

Glucosidase Inhibitors Screening in Microalgae and Cyanobacteria Isolated from the Amazon and Proteomic Analysis of Inhibitor Producing Synechococcus sp. GFB01

“…Another protein that showed greater expression in nutritional limitation, with under expression in the control, is a glyceraldehyde-3-phosphate dehydrogenase, and in this group there is also a glyceraldehyde-3-phosphate dehydrogenase with similar expression in both conditions; this protein is associated with carbon fixation [ 96 ] and is essential to the Calvin cycle in the catabolic degradation of glucose [ 97 , 98 ]. It is an important biotechnological hub for the production of Isopentenyl pyrophosphate (IPP) and 4-Dimethylaminopyridine (DMAP) for terpenes biosynthesis, 3-hydroxypropionic acid [ 99 ] and lipids [ 100 ] including PHB [ 42 ].…”

WITHDRAWN: Effect of Elevated CO2 on Photosynthetic Accumulation and Sucrose Metabolism-related Enzyme Activity and Gene Expression Patterns in Goji Berry (Lycium Barbarum L.)

“…Further, a previous study found no difference in photosynthetic rate between Triodia pungens plants grown in ambient or eCO 2 concentration; in which case, eCO 2 resulted in lower g s and Tr, improved WUE, and higher dry biomass [32]. However, studies have also shown that plants often show photosynthetic down-regulation under long-term eCO 2 exposure, while biomass production may change and even decrease due to species-speci c responses to different durations of treatment exposure [33,34]. A high CO 2 concentration resulted in reduced RubisCo concentration, and both photosynthesis and photorespiration decreased to maintain substrate concentrations [35].…”

Integrating Transcriptomics and Metabolomics to Characterize Metabolic Regulation to Elevated CO2 in Chlamydomonas Reinhardtii

“…In the LT cells, genes encoding the transcript of nitrate/nitrite transporter (NRT), which transports extracellular nitrate/ nitrite into cells, were notably downregulated. Subsequently, nitrate is taken up into algal cells, where it is first reduced to nitrite by NADH-dependent nitrate reductase (NR) and further reduced to ammonium by ferredoxin nitrite reductase (Fd-NiR) (Allen et al 2005;Bowler et al 2010;Mehta et al 2019). There are two ways for ammonium assimilation, one is to form carbon skeletons via the GS-GOGAT pathway and the other is to generate carbamoyl-phosphate by carbamoyl-phosphate synthase (CPS) (Fig.…”

“…Genes involved in nitrogen metabolism significantly change in cells under LT but no significant change was found in cells under ST (Table 3). In Synechococcus elongates, the elevated expression of NrtA, NrtC (a nitrate transport ATP-binding protein), glutamate synthase (ferredoxin), glutamine synthetase III, glutamine synthetase, and ferredoxin-nitrite reductase was observed in a possible effort to maintain the homeostasis of C:N ratio at high CO 2 (Mehta et al 2019). Furthermore, metabolic analysis showed that L-glutamate and L-proline were significantly downregulated in LT vs CK (Table 2).…”