SysBioLab, Centre of Marine Sciences (CCMAR), University of Algarve, 8005-139 Faro, Portugal.
Published: October 2021
AI Article Synopsis
Article Abstract
The Ferric uptake regulator (Fur) is crucial to both pathogenic and non-pathogenic bacteria for the maintenance of iron homeostasis as well as the defence against reactive oxygen species. Based on datasets from the genome-wide mapping of transcriptional start sites and transcriptome data, we identified a high confidence regulon controlled by Fur for the model cyanobacterium Synechocystis sp. PCC 6803 and its close relative, strain 6714, based on the conserved strong iron starvation response and Fur-binding site occurrence. This regulon comprises 33 protein-coding genes and the sRNA IsaR1 that are under the control of 16 or 14 individual promoters in strains 6803 and 6714, respectively. The associated gene functions are mostly restricted to transporters and enzymes involved in the uptake and storage of iron ions, with few exceptions or unknown functional relevance. Within the isiABC operon, we identified a previously neglected gene encoding a small cysteine-rich protein, which we suggest calling, IsiE. The regulation of iron uptake, storage, and utilization ultimately results from the interplay between the Fur regulon, several other transcription factors, the FtsH3 protease, and the sRNA IsaR1.
Quantification of cyanobacterial CO fixation rates is vital to determining their potential as industrial strains in a circular bioeconomy. Currently, however, CO fixation rates are most often determined through indirect and/or low-resolution methods, resulting in an incomplete picture of both dynamic behaviors and total carbon fixation potential. To address this, we developed the "Automated Carbon and CO Experimental Sampling System" (ACCESS); a low-cost system for in situ off-gas analysis that supports the automated acquisition of high-resolution volumetric CO uptake rates from multiple cyanobacterial cultures in parallel.
Excitation energy transfer between the photochemically active protein complexes is key for photosynthetic processes. Phototrophic organisms like cyanobacteria experience subtle changes in irradiance under natural conditions. Such changes need adjustments to the excitation energy transfer between the photosystems for sustainable growth.
Background: Cyanobacteria have long been suggested as an industrial chassis for the conversion of carbon dioxide to products as part of a circular bioeconomy. The slow growth, carbon fixation rates, and limits of carbon partitioning between biomass and product in cyanobacteria must be overcome to fully realise this industrial potential. Typically, flux towards heterologous pathways is limited by the availability of core metabolites.
State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, PR China. Electronic address:
Light-controlled motility is advantageous for photosynthetic prokaryotes to better survive in environment with constantly changing light conditions. For cyanobacteria, light is both an energy source for photosynthesis and a stress factor. Consequently, some cyanobacteria evolved the ability to control type-IV pili (T4P)-mediated surface motility using a chemotaxis-like system in response to light signals.
