scholarly journals Expanding the toolbox for Synechocystis sp. PCC 6803: validation of replicative vectors and characterization of a novel set of promoters

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Eunice A Ferreira ◽  
Catarina C Pacheco ◽  
Filipe Pinto ◽  
José Pereira ◽  
Pedro Lamosa ◽  
...  
Keyword(s):  
Low Cost ◽  
Carbon Sources ◽  
Proof Of Concept ◽  
Gene Encoding ◽  
Metabolic Plasticity ◽  
Cell Factories ◽  
Wide Range ◽  
Synechocystis Sp ◽  
Pcc 6803

Abstract Cyanobacteria are promising ‘low-cost’ cell factories since they have minimal nutritional requirements, high metabolic plasticity and can use sunlight and CO2 as energy and carbon sources. The unicellular Synechocystis sp. PCC 6803, already considered the ‘green’ Escherichia coli, is the best studied cyanobacterium but to be used as an efficient and robust photoautotrophic chassis it requires a customized and well-characterized toolbox. In this context, we evaluated the possibility of using three self-replicative vectors from the Standard European Vector Architecture (SEVA) repository to transform Synechocystis. Our results demonstrated that the presence of the plasmid does not lead to an evident phenotype or hindered Synechocystis growth, being the vast majority of the cells able to retain the replicative plasmid even in the absence of selective pressure. In addition, a set of heterologous and redesigned promoters were characterized exhibiting a wide range of activities compared to the reference PrnpB, three of which could be efficiently repressed. As a proof-of-concept, from the expanded toolbox, one promoter was selected and assembled with the ggpS gene [encoding one of the proteins involved in the synthesis of the native compatible solute glucosylglycerol (GG)] and the synthetic device was introduced into Synechocystis using one of the SEVA plasmids. The presence of this device restored the production of the GG in a ggpS deficient mutant validating the functionality of the tools/device developed in this study.

scholarly journals Characterization of bioplastics produced by haloarchaeon Haloarcula sp strain NRS20 using cost-effective carbon sources

2021 ◽  
Vol 8 (10) ◽  
pp. 105404
Author(s):  
Nashwa Hagagy ◽  
Amna A N Saddiq ◽  
Hend M Tag ◽  
Hamada Abdelgawad ◽  
Samy Selim
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Carbon Sources ◽  
Cost Effective ◽  
Hypersaline Environment ◽  
Ph Values ◽  
Cell Factories ◽  
Phb Production ◽  
Considerable Concentration

Abstract As good models for developing techniques, Haloarchaea are using as cell factories to produce a considerable concentration of bioplastics, polyhydroxyalkanoate (PHA), polyhydroxybutyrate (PHB), and polyhydroxyvalerate (PHV). In this study, low-cost carbon sources by Sudan Black staining was applied for screening haloarchaea a hypersaline environment (southern coast of Jeddah, Saudi Arabia). The growth of the selected isolate and PHB-production under different carbon sources, temperature, pH values and NaCl concentrations were investigated. The biopolymer was extracted and quantitatively measured. The biopolymer was qualitatively identified by Fourier-transform infra-red analysis (FTIR) and High Performance Liquid Chromatography (HPLC). The potential Haloarcula sp strain NRS20 (MZ520352) could significantly accumulate PHB under nutrient-limiting conditions using different carbon sources including starch, carboxymethyl cellulose (CMC), sucrose, glucose and glycerol with 23.83%, 14%, 11%, 12% and 8% of PHB/CDW respectively under 25% NaCl (w/v), pH 7, at 37 °C. The results of FTIR pattern indicated that the significant peak at 1709.22 cm−1 confirmed the presence of the ester carbonyl-group (C=O) which is typical of PHB. HPLC analysis indicated that produced PHB was detected at 7.5 min with intensity exceeding the standard PHB at 8.0 min. Few potential species of haloarchaea were reported for economical PHB-production, here, Haloarcula sp strain NRS20 showed high content of PHB, exhibited a promising PHB-producer using inexpensive sources of carbon.

scholarly journals Cloning of the psbK gene from Synechocystis sp. PCC 6803 and characterization of photosystem II in mutants lacking PSII-K

1991 ◽  
Vol 266 (17) ◽  
pp. 11111-11115
Author(s):  
M. Ikeuchi ◽  
B. Eggers ◽  
G.Z. Shen ◽  
A. Webber ◽  
J.J. Yu ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Synechocystis Sp ◽  
Pcc 6803

scholarly journals Burkholderia thailandensis E264 as a promising safe rhamnolipids’ producer towards a sustainable valorization of grape marcs and olive mill pomace

2021 ◽  
Author(s):  
Alif Chebbi ◽  
Massimiliano Tazzari ◽  
Cristiana Rizzi ◽  
Franco Hernan Gomez Tovar ◽  
Sara Villa ◽  
...  
Keyword(s):  
Energy Source ◽  
Olive Oil ◽  
Low Cost ◽  
Carbon Sources ◽  
Burkholderia Thailandensis ◽  
Rhamnolipid Production ◽  
Key Points ◽  
Wide Range ◽  
Long Chain ◽  
Olive Mill

Abstract Within the circular economy framework, our study aims to assess the rhamnolipid production from winery and olive oil residues as low-cost carbon sources by nonpathogenic strains. After evaluating various agricultural residues from those two sectors, Burkholderia thailandensis E264 was found to use the raw soluble fraction of nonfermented (white) grape marcs (NF), as the sole carbon and energy source, and simultaneously, reducing the surface tension to around 35 mN/m. Interestingly, this strain showed a rhamnolipid production up to 1070 mg/L (13.37 mg/g of NF), with a higher purity, on those grape marcs, predominately Rha-Rha C14-C14, in MSM medium. On olive oil residues, the rhamnolipid yield of using olive mill pomace (OMP) at 2% (w/v) was around 300 mg/L (15 mg/g of OMP) with a similar CMC of 500 mg/L. To the best of our knowledge, our study indicated for the first time that a nonpathogenic bacterium is able to produce long-chain rhamnolipids in MSM medium supplemented with winery residues, as sole carbon and energy source. Key points • Winery and olive oil residues are used for producing long-chain rhamnolipids (RLs). • Both higher RL yields and purity were obtained on nonfermented grape marcs as substrates. • Long-chain RLs revealed stabilities over a wide range of pH, temperatures, and salinities

scholarly journals Recombinant Deg/HtrA proteases from Synechocystis sp. PCC 6803 differ in substrate specificity, biochemical characteristics and mechanism

2011 ◽  
Vol 435 (3) ◽  
pp. 733-742 ◽  
Author(s):  
Pitter F. Huesgen ◽  
Helder Miranda ◽  
XuanTam Lam ◽  
Manuela Perthold ◽  
Holger Schuhmann ◽  
...  
Keyword(s):  
Serine Proteases ◽  
Protein Quality ◽  
Biochemical Characterization ◽  
Pdz Domain ◽  
Control Mechanisms ◽  
Ph Optimum ◽  
Periplasmic Proteins ◽  
Synechocystis Sp ◽  
Pcc 6803

Cyanobacteria require efficient protein-quality-control mechanisms to survive under dynamic, often stressful, environmental conditions. It was reported that three serine proteases, HtrA (high temperature requirement A), HhoA (HtrA homologue A) and HhoB (HtrA homologue B), are important for survival of Synechocystis sp. PCC 6803 under high light and temperature stresses and might have redundant physiological functions. In the present paper, we show that all three proteases can degrade unfolded model substrates, but differ with respect to cleavage sites, temperature and pH optima. For recombinant HhoA, and to a lesser extent for HtrA, we observed an interesting shift in the pH optimum from slightly acidic to alkaline in the presence of Mg2+ and Ca2+ ions. All three proteases formed different homo-oligomeric complexes with and without substrate, implying mechanistic differences in comparison with each other and with the well-studied Escherichia coli orthologues DegP (degradation of periplasmic proteins P) and DegS. Deletion of the PDZ domain decreased, but did not abolish, the proteolytic activity of all three proteases, and prevented substrate-induced formation of complexes higher than trimers by HtrA and HhoA. In summary, biochemical characterization of HtrA, HhoA and HhoB lays the foundation for a better understanding of their overlapping, but not completely redundant, stress-resistance functions in Synechocystis sp. PCC 6803.

Preliminary characterization of a photo-tolerant mutant of Synechocystis sp. PCC 6803 obtained by in vitro random mutagenesis of psbA2

Plant Science ◽  
1996 ◽  
Vol 115 (2) ◽  
pp. 261-266 ◽  
Author(s):  
Yoshihiro Narusaka ◽  
Akio Murakami ◽  
Mari Saeki ◽  
Hirokazu Kobayashi ◽  
Kimiyuki Satoh
Keyword(s):  
Random Mutagenesis ◽  
Preliminary Characterization ◽  
Tolerant Mutant ◽  
Synechocystis Sp ◽  
Pcc 6803
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