Journal articles: 'Photoautotrophic cyanobacteria'

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Flores, Enrique, and Antonia Herrero. "The cyanobacteria: morphological diversity in a photoautotrophic lifestyle." Perspectives in Phycology 1, no. 2 (November 10, 2014): 63–72. http://dx.doi.org/10.1127/pip/2014/0008.

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McEwen, Jordan T., Iara M. P. Machado, Michael R. Connor, and Shota Atsumi. "Engineering Synechococcus elongatus PCC 7942 for Continuous Growth under Diurnal Conditions." Applied and Environmental Microbiology 79, no. 5 (December 28, 2012): 1668–75. http://dx.doi.org/10.1128/aem.03326-12.

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ABSTRACTSynechococcus elongatusstrain PCC 7942 strictly depends upon the generation of photosynthetically derived energy for growth and is incapable of biomass increase in the absence of light energy. Obligate phototrophs' core metabolism is very similar to that of heterotrophic counterparts exhibiting diverse trophic behavior. Most characterized cyanobacterial species are obligate photoautotrophs under examined conditions. Here we determine that sugar transporter systems are the necessary genetic factors in order for a model cyanobacterium,Synechococcus elongatusPCC 7942, to grow continuously under diurnal (light/dark) conditions using saccharides such as glucose, xylose, and sucrose. While the universal causes of obligate photoautotrophy may be diverse, installing sugar transporters provides new insight into the mode of obligate photoautotrophy for cyanobacteria. Moreover, cyanobacterial chemical production has gained increased attention. However, this obligate phototroph is incapable of product formation in the absence of light. Thus, converting an obligate photoautotroph to a heterotroph is desirable for more efficient, economical, and controllable production systems.

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Iliev, Ivan, Georgi Petkov, Jaromir Lukavsky, Sevdalina Furnadzhieva, and Rayna Andreeva. "Do Cyanobacterial Lipids Contain Fatty Acids Longer Than 18 Carbon Atoms?" Zeitschrift für Naturforschung C 66, no. 5-6 (June 1, 2011): 267–76. http://dx.doi.org/10.1515/znc-2011-5-610.

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Fatty acids of twelve species of cyanobacteria grown under different photoautotrophic conditions were studied and their composition was compared with literature data of many other species. We have come to the conclusion that the lipids of cyanobacteria do not contain fatty acids with a chain longer than 18 carbon atoms. In our opinion, omission of an analytical procedure, i.e. purification of fatty acid methyl esters before gas chromatography, leads to incorrect interpretation of the results. Absence or presence of fatty acids was suggested as a useful taxonomic marker and a proper diagnostic indicator in the commercial application of cyanobacterial biomass.

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Kirkwood, Andrea E., Czesia Nalewajko, and Roberta R. Fulthorpe. "The occurrence of cyanobacteria in pulp and paper waste-treatment systems." Canadian Journal of Microbiology 47, no. 8 (August 1, 2001): 761–66. http://dx.doi.org/10.1139/w01-063.

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Pulp and paper secondary waste-treatment systems in Brazil, Canada, New Zealand, and the U.S.A. contained dynamic cyanobacterial communities, some of which exceeded heterotrophic bacterial biomass. No other viable photoautotrophic populations were detected in the ponds. Regardless of geographical location, Oscillatoriales including Phormidium, Geitlerinema, and Pseudanabaena were the dominant taxa. As well, Chroococcus (Chroococcales) was an important genus in Brazil and New Zealand. The possible impact of cyanobacteria on waste-treatment efficiency deserves further study given their large biomass and diverse metabolic characteristics.Key words: cyanobacteria, blue-green algae, heterotrophic bacteria, community structure, pulp and paper secondary waste treatment.

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Kamravamanesh, Donya, Maximilian Lackner, and Christoph Herwig. "Bioprocess Engineering Aspects of Sustainable Polyhydroxyalkanoate Production in Cyanobacteria." Bioengineering 5, no. 4 (December 18, 2018): 111. http://dx.doi.org/10.3390/bioengineering5040111.

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Polyhydroxyalkanoates (PHAs) are a group of biopolymers produced in various microorganisms as carbon and energy reserve when the main nutrient, necessary for growth, is limited. PHAs are attractive substitutes for conventional petrochemical plastics, as they possess similar material properties, along with biocompatibility and complete biodegradability. The use of PHAs is restricted, mainly due to the high production costs associated with the carbon source used for bacterial fermentation. Cyanobacteria can accumulate PHAs under photoautotrophic growth conditions using CO2 and sunlight. However, the productivity of photoautotrophic PHA production from cyanobacteria is much lower than in the case of heterotrophic bacteria. Great effort has been focused to reduce the cost of PHA production, mainly by the development of optimized strains and more efficient cultivation and recovery processes. Minimization of the PHA production cost can only be achieved by considering the design and a complete analysis of the whole process. With the aim on commercializing PHA, this review will discuss the advances and the challenges associated with the upstream processing of cyanobacterial PHA production, in order to help the design of the most efficient method on the industrial scale.

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Sengupta, Annesha, Prem Pritam, Damini Jaiswal, Anindita Bandyopadhyay, Himadri B. Pakrasi, and Pramod P. Wangikar. "Photosynthetic Co-production of Succinate and Ethylene in a Fast-Growing Cyanobacterium, Synechococcus elongatus PCC 11801." Metabolites 10, no. 6 (June 16, 2020): 250. http://dx.doi.org/10.3390/metabo10060250.

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Cyanobacteria are emerging as hosts for photoautotrophic production of chemicals. Recent studies have attempted to stretch the limits of photosynthetic production, typically focusing on one product at a time, possibly to minimise the additional burden of product separation. Here, we explore the simultaneous production of two products that can be easily separated: ethylene, a gaseous product, and succinate, an organic acid that accumulates in the culture medium. This was achieved by expressing a single copy of the ethylene forming enzyme (efe) under the control of PcpcB, the inducer-free super-strong promoter of phycocyanin β subunit. We chose the recently reported, fast-growing and robust cyanobacterium, Synechococcus elongatus PCC 11801, as the host strain. A stable recombinant strain was constructed using CRISPR-Cpf1 in a first report of markerless genome editing of this cyanobacterium. Under photoautotrophic conditions, the recombinant strain shows specific productivities of 338.26 and 1044.18 μmole/g dry cell weight/h for ethylene and succinate, respectively. These results compare favourably with the reported productivities for individual products in cyanobacteria that are highly engineered. Metabolome profiling and 13C labelling studies indicate carbon flux redistribution and suggest avenues for further improvement. Our results show that S. elongatus PCC 11801 is a promising candidate for metabolic engineering.

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Lau, Nyok-Sean, Minami Matsui, and Amirul Al-Ashraf Abdullah. "Cyanobacteria: Photoautotrophic Microbial Factories for the Sustainable Synthesis of Industrial Products." BioMed Research International 2015 (2015): 1–9. http://dx.doi.org/10.1155/2015/754934.

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Cyanobacteria are widely distributed Gram-negative bacteria with a long evolutionary history and the only prokaryotes that perform plant-like oxygenic photosynthesis. Cyanobacteria possess several advantages as hosts for biotechnological applications, including simple growth requirements, ease of genetic manipulation, and attractive platforms for carbon neutral production process. The use of photosynthetic cyanobacteria to directly convert carbon dioxide to biofuels is an emerging area of interest. Equipped with the ability to degrade environmental pollutants and remove heavy metals, cyanobacteria are promising tools for bioremediation and wastewater treatment. Cyanobacteria are characterized by the ability to produce a spectrum of bioactive compounds with antibacterial, antifungal, antiviral, and antialgal properties that are of pharmaceutical and agricultural significance. Several strains of cyanobacteria are also sources of high-value chemicals, for example, pigments, vitamins, and enzymes. Recent advances in biotechnological approaches have facilitated researches directed towards maximizing the production of desired products in cyanobacteria and realizing the potential of these bacteria for various industrial applications. In this review, the potential of cyanobacteria as sources of energy, bioactive compounds, high-value chemicals, and tools for aquatic bioremediation and recent progress in engineering cyanobacteria for these bioindustrial applications are discussed.

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Veaudor, Théo, Victoire Blanc-Garin, Célia Chenebault, Encarnación Diaz-Santos, Jean-François Sassi, Corinne Cassier-Chauvat, and Franck Chauvat. "Recent Advances in the Photoautotrophic Metabolism of Cyanobacteria: Biotechnological Implications." Life 10, no. 5 (May 19, 2020): 71. http://dx.doi.org/10.3390/life10050071.

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Cyanobacteria constitute the only phylum of oxygen-evolving photosynthetic prokaryotes that shaped the oxygenic atmosphere of our planet. Over time, cyanobacteria have evolved as a widely diverse group of organisms that have colonized most aquatic and soil ecosystems of our planet and constitute a large proportion of the biomass that sustains the biosphere. Cyanobacteria synthesize a vast array of biologically active metabolites that are of great interest for human health and industry, and several model cyanobacteria can be genetically manipulated. Hence, cyanobacteria are regarded as promising microbial factories for the production of chemicals from highly abundant natural resources, e.g., solar energy, CO2, minerals, and waters, eventually coupled to wastewater treatment to save costs. In this review, we summarize new important discoveries on the plasticity of the photoautotrophic metabolism of cyanobacteria, emphasizing the coordinated partitioning of carbon and nitrogen towards growth or compound storage, and the importance of these processes for biotechnological perspectives. We also emphasize the importance of redox regulation (including glutathionylation) on these processes, a subject which has often been overlooked.

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Ohkouchi, N., Y. Kashiyama, J. Kuroda, N. O. Ogawa, and H. Kitazato. "An importance of diazotrophic cyanobacteria as a primary producer during Cretaceous Oceanic Anoxic Event 2." Biogeosciences Discussions 3, no. 3 (June 16, 2006): 575–605. http://dx.doi.org/10.5194/bgd-3-575-2006.

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Abstract. In Livello Bonarelli black shale deposited during Cretaceous Oceanic Anoxic Event 2 (OAE-2, ca. 94 Ma), nitrogen isotopic compositions of bulk sediments are in a narrow range from −2.7 to −0.7. We also determined molecular distribution and nitrogen isotopic compositions of geoporphyrins extracted from the black shale. The nitrogen isotopic compositions of C32 Ni deoxophylloerythroetioporphyrin (DPEP) and total Ni porphyrins are −3.5 and −3.3, respectively, leading us to the estimation that the mean nitrogen isotopic composition of photoautotrophic cell was around +1 during the formation of Bonarelli black shale. This value is suggestive of N2-fixation a dominant process for these photoautotrophs when assimilating nitrogen. Furthermore, Ni-chelated C32 DPEP, derived mainly from chlorophyll a was the highest concentration. Based on these evidence, we conclude that diazotrophic cyanobacteria were major primary producers during that time. The cyanobacteria may be key photoautotrophs during the formation of black shale type sediments intermittently observed throughout the later half of the Earth's history, and hence may have played a crucial role in the evolution of geochemical cycles.

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van der Meer, Marcel T. J., Stefan Schouten, Mary M. Bateson, Ulrich Nübel, Andrea Wieland, Michael Kühl, Jan W. de Leeuw, Jaap S. Sinninghe Damsté, and David M. Ward. "Diel Variations in Carbon Metabolism by Green Nonsulfur-Like Bacteria in Alkaline Siliceous Hot Spring Microbial Mats from Yellowstone National Park." Applied and Environmental Microbiology 71, no. 7 (July 2005): 3978–86. http://dx.doi.org/10.1128/aem.71.7.3978-3986.2005.

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ABSTRACT Green nonsulfur-like bacteria (GNSLB) in hot spring microbial mats are thought to be mainly photoheterotrophic, using cyanobacterial metabolites as carbon sources. However, the stable carbon isotopic composition of typical Chloroflexus and Roseiflexus lipids suggests photoautotrophic metabolism of GNSLB. One possible explanation for this apparent discrepancy might be that GNSLB fix inorganic carbon only during certain times of the day. In order to study temporal variability in carbon metabolism by GNSLB, labeling experiments with [13C]bicarbonate, [14C]bicarbonate, and [13C]acetate were performed during different times of the day. [14C]bicarbonate labeling indicated that during the morning, incorporation of label was light dependent and that both cyanobacteria and GNSLB were involved in bicarbonate uptake. 13C-labeling experiments indicated that during the morning, GNSLB incorporated labeled bicarbonate at least to the same degree as cyanobacteria. The incorporation of [13C]bicarbonate into specific lipids could be stimulated by the addition of sulfide or hydrogen, which both were present in the morning photic zone. The results suggest that GNSLB have the potential for photoautotrophic metabolism during low-light periods. In high-light periods, inorganic carbon was incorporated primarily into Cyanobacteria-specific lipids. The results of a pulse-labeling experiment were consistent with overnight transfer of label to GNSLB, which could be interrupted by the addition of unlabeled acetate and glycolate. In addition, we observed direct incorporation of [13C]acetate into GNSLB lipids in the morning. This suggests that GNSLB also have a potential for photoheterotrophy in situ.

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Noreña-Caro, Daniel, and Michael G. Benton. "Cyanobacteria as photoautotrophic biofactories of high-value chemicals." Journal of CO2 Utilization 28 (December 2018): 335–66. http://dx.doi.org/10.1016/j.jcou.2018.10.008.

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Ohkouchi, N., Y. Kashiyama, J. Kuroda, N. O. Ogawa, and H. Kitazato. "The importance of diazotrophic cyanobacteria as primary producers during Cretaceous Oceanic Anoxic Event 2." Biogeosciences 3, no. 4 (October 26, 2006): 467–78. http://dx.doi.org/10.5194/bg-3-467-2006.

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Abstract. In Livello Bonarelli black shale deposited during Cretaceous Oceanic Anoxic Event 2 (OAE-2, ca. 94 Ma), nitrogen isotopic compositions of bulk sediments are mostly in a narrow range from –2.7 to –0.7‰. We also determined molecular distribution and nitrogen isotopic compositions of geoporphyrins extracted from the black shale. The nitrogen isotopic compositions of C32 Ni deoxophylloerythroetioporphyrin (DPEP) and total Ni porphyrins are –3.5 and –3.3‰, respectively, leading us to the estimation that the mean nitrogen isotopic composition of photoautotrophic cells were around +1‰ during the formation of Bonarelli black shale. This value is suggestive of N2-fixation, a dominant process for these photoautotrophs when assimilating nitrogen. Furthermore, Ni-chelated C32 DPEP, derived mainly from chlorophyll a had the highest concentration. Based on this evidence, we conclude that diazotrophic cyanobacteria were major primary producers during that time. Cyanobacteria may be key photoautotrophs during the formation of black shale type sediments intermittently observed throughout the later half of the Earth's history, and hence may have played a crucial role in the evolution of geochemical cycles even in the later half of the Earth's history.

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Kashiyama, Y., N. O. Ogawa, M. Shiro, R. Tada, H. Kitazato, and N. Ohkouchi. "Reconstruction of the biogeochemistry and ecology of photoautotrophs based on the nitrogen and carbon isotopic compositions of vanadyl porphyrins from Miocene siliceous sediments." Biogeosciences Discussions 5, no. 1 (January 30, 2008): 361–409. http://dx.doi.org/10.5194/bgd-5-361-2008.

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Abstract. We determined both the nitrogen and carbon isotopic compositions of various vanadyl alkylporphyrins isolated from siliceous marine sediments of the Onnagawa Formation (middle Miocene, northeastern Japan) to investigate the biogeochemistry and ecology of photoautotrophs living in the paleo-ocean. The distinctive isotopic signals support the interpretations of previous works that the origin of 17-nor-deoxophylloerythroetioporphyrin (DPEP) is chlorophylls c, whereas 8-nor-DPEP may have originated from chlorophylls a2 or b2 or bacteriochlorophyll a. Although DPEP and cycloheptanoDPEP are presumably derived from common precursory pigments, their isotopic compositions differed in the present study, suggesting that the latter represents a specific population within the photoautotrophic community. Based on the δ 15N values of DPEP (−6.9 to −3.6‰ n=7), the average δ15N value for the entire photoautotrophic community is estimated to be −2 to +1‰, considering the empirical isotopic relationships that the tetrapyrrole nuclei of chloropigments are depleted in 15N by ~4.8‰ and enriched in ;13C by ~1.8‰ relative to the whole cells. This finding suggests that nitrogen utilized in the primary production was supplied mainly through N2-fixation by diazotrophic cyanobacteria. Based on the δ13C values of DPEP (–17.9 to −15.6‰ n=7), we estimated isotopic fractionation associated with photosynthetic carbon fixation to be 8–14‰. This range suggests the importance of β-carboxylation and/or active transport of the carbon substrate, indicating in turn the substantial contribution of diazotrophic cyanobacteria to primary production. Based on the δ15N values of 17-nor-DPEP (−7.4 to −2.4‰ n=7), the δ15N range of chlorophylls c-producing algae was estimated to be −3 to +3‰. This relative depletion in ;15N suggests that these algae mainly utilized nitrogen regenerated from diazotrophic cyanobacteria. Given that diatoms are likely to have constituted the chlorophylls c-producing algae within the biogenic-silica-rich Onnagawa Formation, cyanobacteria-hosting diatoms may have been important contributors to primary production.

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Kashiyama, Y., N. O. Ogawa, M. Shiro, R. Tada, H. Kitazato, and N. Ohkouchi. "Reconstruction of the biogeochemistry and ecology of photoautotrophs based on the nitrogen and carbon isotopic compositions of vanadyl porphyrins from Miocene siliceous sediments." Biogeosciences 5, no. 3 (May 15, 2008): 797–816. http://dx.doi.org/10.5194/bg-5-797-2008.

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Abstract. We determined both the nitrogen and carbon isotopic compositions of various vanadyl alkylporphyrins isolated from siliceous marine sediments of the Onnagawa Formation (middle Miocene, northeastern Japan) to investigate the biogeochemistry and ecology of photoautotrophs living in the paleo-ocean. The distinctive isotopic signals support the interpretations of previous works that the origin of 17-nor-deoxophylloerythroetioporphyrin (DPEP) is chlorophylls-c1-3, whereas 8-nor-DPEP may have originated from chlorophylls-a2 or b2 or bacteriochlorophyll-a. Although DPEP and cycloheptanoDPEP are presumably derived from common precursory pigments, their isotopic compositions differed in the present study, suggesting that the latter represents a specific population within the photoautotrophic community. The average δ15N value for the entire photoautotrophic community is estimated to be –2 to +1‰ from the δ15N values of DPEP (–6.9 to –3.6‰; n=7), considering that the empirical isotopic relationships that the tetrapyrrole nuclei of chloropigments are depleted in 15N by ~4.8‰ and enriched in 13C by ~1.8‰ relative to the whole cells. This finding suggests that nitrogen utilized in the primary production was supplied mainly through N2-fixation by diazotrophic cyanobacteria. Based on the δ13C values of DPEP (–17.9 to –15.6‰; n=7), we estimated isotopic fractionation associated with photosynthetic carbon fixation to be 8–14‰. This range suggests the importance of β-carboxylation and/or active transport of the carbon substrate, indicating in turn the substantial contribution of diazotrophic cyanobacteria to primary production. Based on the δ15N values of 17-nor-DPEP (–7.4 to –2.4‰ n=7), the δ15N range of chlorophylls-c-producing algae was estimated to be –3 to +3‰. This relative depletion in sup>15N suggests that these algae mainly utilized nitrogen regenerated from diazotrophic cyanobacteria. Given that diatoms are likely to have constituted the chlorophylls-c-producing algae within the biogenic-silica-rich Onnagawa Formation, cyanobacteria-hosting diatoms may have been important contributors to primary production.

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Rajaram, Hema, Akhilesh Kumar Chaurasia, and Shree Kumar Apte. "Cyanobacterial heat-shock response: role and regulation of molecular chaperones." Microbiology 160, no. 4 (April 1, 2014): 647–58. http://dx.doi.org/10.1099/mic.0.073478-0.

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Cyanobacteria constitute a morphologically diverse group of oxygenic photoautotrophic microbes which range from unicellular to multicellular, and non-nitrogen-fixing to nitrogen-fixing types. Sustained long-term exposure to changing environmental conditions, during their three billion years of evolution, has presumably led to their adaptation to diverse ecological niches. The ability to maintain protein conformational homeostasis (folding–misfolding–refolding or aggregation–degradation) by molecular chaperones holds the key to the stress adaptability of cyanobacteria. Although cyanobacteria possess several genes encoding DnaK and DnaJ family proteins, these are not the most abundant heat-shock proteins (Hsps), as is the case in other bacteria. Instead, the Hsp60 family of proteins, comprising two phylogenetically conserved proteins, and small Hsps are more abundant during heat stress. The contribution of the Hsp100 (ClpB) family of proteins and of small Hsps in the unicellular cyanobacteria (Synechocystis and Synechococcus) as well as that of Hsp60 proteins in the filamentous cyanobacteria (Anabaena) to thermotolerance has been elucidated. The regulation of chaperone genes by several cis-elements and trans-acting factors has also been well documented. Recent studies have demonstrated novel transcriptional and translational (mRNA secondary structure) regulatory mechanisms in unicellular cyanobacteria. This article provides an insight into the heat-shock response: its organization, and ecophysiological regulation and role of molecular chaperones, in unicellular and filamentous nitrogen-fixing cyanobacterial strains.

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Ciebiada, Maciej, Katarzyna Kubiak, and Maurycy Daroch. "Modifying the Cyanobacterial Metabolism as a Key to Efficient Biopolymer Production in Photosynthetic Microorganisms." International Journal of Molecular Sciences 21, no. 19 (September 29, 2020): 7204. http://dx.doi.org/10.3390/ijms21197204.

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Cyanobacteria are photoautotrophic bacteria commonly found in the natural environment. Due to the ecological benefits associated with the assimilation of carbon dioxide from the atmosphere and utilization of light energy, they are attractive hosts in a growing number of biotechnological processes. Biopolymer production is arguably one of the most critical areas where the transition from fossil-derived chemistry to renewable chemistry is needed. Cyanobacteria can produce several polymeric compounds with high applicability such as glycogen, polyhydroxyalkanoates, or extracellular polymeric substances. These important biopolymers are synthesized using precursors derived from central carbon metabolism, including the tricarboxylic acid cycle. Due to their unique metabolic properties, i.e., light harvesting and carbon fixation, the molecular and genetic aspects of polymer biosynthesis and their relationship with central carbon metabolism are somehow different from those found in heterotrophic microorganisms. A greater understanding of the processes involved in cyanobacterial metabolism is still required to produce these molecules more efficiently. This review presents the current state of the art in the engineering of cyanobacterial metabolism for the efficient production of these biopolymers.

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Qamar, Hina, Kashif Hussain, Aishwarya Soni, Anish Khan, Touseef Hussain, and Benoît Chénais. "Cyanobacteria as Natural Therapeutics and Pharmaceutical Potential: Role in Antitumor Activity and as Nanovectors." Molecules 26, no. 1 (January 5, 2021): 247. http://dx.doi.org/10.3390/molecules26010247.

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Cyanobacteria (blue-green microalgae) are ubiquitous, Gram-negative photoautotrophic prokaryotes. They are considered as one of the most efficient sources of bioactive secondary metabolites. More than 50% of cyanobacteria are cultivated on commercial platforms to extract bioactive compounds, which have bene shown to possess anticancer activity. The chemically diverse natural compounds or their analogues induce cytotoxicity and potentially kill a variety of cancer cells via the induction of apoptosis, or altering the activation of cell signaling, involving especially the protein kinase-C family members, cell cycle arrest, mitochondrial dysfunctions and oxidative damage. These therapeutic properties enable their use in the pharma and healthcare sectors for the betterment of future generations. This review provides a baseline overview of the anti-cancerous cyanobacterial bioactive compounds, along with recently introduced nanomaterials that could be used for the development of new anticancer drugs to build a healthy future for mankind.

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SOARES, FABIANA, IGOR TIAGO, JOÃO TROVÃO, CATARINA COELHO, NUNO MESQUITA, FRANCISCO GIL, LÍDIA CATARINO, SUSANA M. CARDOSO, and ANTÓNIO PORTUGAL. "Description of Myxacorys almedinensis sp. nov. (Synechococcales, Cyanobacteria) isolated from the limestone walls of the Old Cathedral of Coimbra, Portugal (UNESCO World Heritage Site)." Phytotaxa 419, no. 1 (September 30, 2019): 77–90. http://dx.doi.org/10.11646/phytotaxa.419.1.5.

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Cyanobacteria are photoautotrophic microorganisms able to colonize historic stone monuments, causing severe aesthetic, physical and chemical alterations to the substrate. In a study that aimed to fingerprint the phototrophic community of the biodeteriorated walls of the Old Cathedral of Coimbra (UNESCO World Heritage Site), an unknown Myxacorys-like cyanobacterium was isolated. In this paper, we employed a polyphasic approach based on morphological, ecological and phylogenetic analyses of the partial 16S and the whole 16S-23S ITS rRNA regions. The resulting analyses allowed us to propose the description of a new species, Myxacorys almedinensis sp. nov. within the genus Myxacorys.

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Niemczyk, Emilia, Jerzy Pogrzeba, Agnieszka Adamczyk-Woźniak, and Jacek Lipok. "Boronic Acids of Pharmaceutical Importance Affect the Growth and Photosynthetic Apparatus of Cyanobacteria in a Dose-Dependent Manner." Toxins 12, no. 12 (December 13, 2020): 793. http://dx.doi.org/10.3390/toxins12120793.

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The dynamic increase in the commercial application of antimicrobial derivatives of boronic acids, and potential impact of their presence in aquatic systems, supports the necessity to study the toxicity of these substances towards microorganisms of crucial meaning in the environment. One example of the mentioned derivatives is tavaborole (5-fluoro-substituted benzoxaborole), a pharmaceutical agent with antifungal activity. Cyanobacteria were used as model organisms, which are photoautotrophic prokaryotes, as representative aquatic bacteria and photoautotrophs associated with the plant kingdom. To the best of our knowledge, we investigated this issue for the first time. In order to recognize the under-stress response of those microorganisms, the concentration of photopigments—a key factor in the activity of photosynthetic apparatus—was measured spectrophotometrically. We found that the 3-piperazine bis(benzoxaborole) significantly suppressed the growth of halophilic and freshwater cyanobacteria, at a concentration 3.0 mM and 0.3 mM, respectively. Our results also showed that the tested substances at micromolar concentrations stimulated the growth of cyanobacteria, particularly in the freshwater strain Chroococcidiopsis thermalis. The tested substances acted with various strengths, depending on their structure and concentration; nevertheless, they had a greater influence on the synthesis of phycobiliproteins (e.g., lowered their concentration) than on the formation of chlorophyll and carotenoids.

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Mikkat, Stefan, Sabine Fulda, and Martin Hagemann. "A 2D gel electrophoresis-based snapshot of the phosphoproteome in the cyanobacterium Synechocystis sp. strain PCC 6803." Microbiology 160, no. 2 (February 1, 2014): 296–306. http://dx.doi.org/10.1099/mic.0.074443-0.

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Cyanobacteria are photoautotrophic prokaryotes that occur in highly variable environments. Protein phosphorylation is one of the most widespread means to adjust cell metabolism and gene expression to the demands of changing growth conditions. Using a 2D gel electrophoresis-based approach and a phosphoprotein-specific dye, we investigated the protein phosphorylation pattern in cells of the model cyanobacterium Synechocystis sp. strain PCC 6803. The comparison of gels stained for total and phosphorylated proteins revealed that approximately 5 % of the protein spots seemed to be phosphoproteins, from which 32 were identified using MALDI-TOF MS. For eight of them the phosphorylated amino acid residues were mapped by subsequent mass spectrometric investigations of isolated phosphopeptides. Among the phosphoproteins, we found regulatory proteins, mostly putative anti-sigma factor antagonists, and proteins involved in translation. Moreover, a number of enzymes catalysing steps in glycolysis or the Calvin–Benson cycle were found to be phosphorylated, implying that protein phosphorylation might represent an important mechanism for the regulation of the primary carbon metabolism in cyanobacterial cells.

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Wada, K., R. Masui, H. Matsubara, and L. J. Rogers. "Properties and structure of the soluble ferredoxin from Synechococcus 6301 (Anacystis nidulans). Relationship to gene sequences." Biochemical Journal 252, no. 2 (June 1, 1988): 571–75. http://dx.doi.org/10.1042/bj2520571.

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Photoautotrophic cultures of the unicellular cyanobacterium Synechococcus 6301 (Anacystis nidulans) possessed a single [2Fe-2S] ferredoxin with a midpoint redox potential of -385 mV. Determination of the amino acid sequence of the ferredoxin showed that it consisted of 98 residues, with methionine and tryptophan both absent, and with only the four cysteine residues that are required to co-ordinate the iron-sulphur cluster. Comparisons with other ferredoxin sequences showed that most resemblance was to those from filamentous cyanobacteria, with up to 87% homology. There was less resemblance to the ferredoxins of unicellular cyanobacteria, with 25 differences when compared with that from another Synechococcus sp. However, the sequence of Synechococcus 6301 ferredoxin was identical with that derived for a gene sequence for a putative ferredoxin from the genotypically closely related Synechococcus 7942 (Anacystis nidulans R2). In contrast, the sequence showed substantial differences from that corresponding to a putative ferredoxin gene from Synechococcus 6301 reported by Cozens & Walker [(1988) Biochem. J. 252, 563-569].

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Ng, Andrew H., Bertram M. Berla, and Himadri B. Pakrasi. "Fine-Tuning of Photoautotrophic Protein Production by Combining Promoters and Neutral Sites in the Cyanobacterium Synechocystis sp. Strain PCC 6803." Applied and Environmental Microbiology 81, no. 19 (July 24, 2015): 6857–63. http://dx.doi.org/10.1128/aem.01349-15.

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ABSTRACTCyanobacteria are photosynthetic cell factories that use solar energy to convert CO2into useful products. Despite this attractive feature, the development of tools for engineering cyanobacterial chassis has lagged behind that for heterotrophs such asEscherichia coliorSaccharomyces cerevisiae. Heterologous genes in cyanobacteria are often integrated at presumptively “neutral” chromosomal sites, with unknown effects. We used transcriptome sequencing (RNA-seq) data for the model cyanobacteriumSynechocystissp. strain PCC 6803 to identify neutral sites from which no transcripts are expressed. We characterized the two largest such sites on the chromosome, a site on an endogenous plasmid, and a shuttle vector by integrating an enhanced yellow fluorescent protein (EYFP) expression cassette expressed from either the Pcpc560or the Ptrc1Opromoter into each locus. Expression from the endogenous plasmid was as much as 14-fold higher than that from the chromosome, with intermediate expression from the shuttle vector. The expression characteristics of each locus correlated predictably with the promoters used. These findings provide novel, characterized tools for synthetic biology and metabolic engineering in cyanobacteria.

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Koksharova, Olga A., Ivan O. Butenko, Olga V. Pobeguts, Nina A. Safronova, and Vadim M. Govorun. "The First Proteomic Study of Nostoc sp. PCC 7120 Exposed to Cyanotoxin BMAA under Nitrogen Starvation." Toxins 12, no. 5 (May 9, 2020): 310. http://dx.doi.org/10.3390/toxins12050310.

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The oldest prokaryotic photoautotrophic organisms, cyanobacteria, produce many different metabolites. Among them is the water-soluble neurotoxic non-protein amino acid beta-N-methylamino-L-alanine (BMAA), whose biological functions in cyanobacterial metabolism are of fundamental scientific and practical interest. An early BMAA inhibitory effect on nitrogen fixation and heterocyst differentiation was shown in strains of diazotrophic cyanobacteria Nostoc sp. PCC 7120, Nostoc punctiforme PCC 73102 (ATCC 29133), and Nostoc sp. strain 8963 under conditions of nitrogen starvation. Herein, we present a comprehensive proteomic study of Nostoc (also called Anabaena) sp. PCC 7120 in the heterocyst formation stage affecting by BMAA treatment under nitrogen starvation conditions. BMAA disturbs proteins involved in nitrogen and carbon metabolic pathways, which are tightly co-regulated in cyanobacteria cells. The presented evidence shows that exogenous BMAA affects a key nitrogen regulatory protein, PII (GlnB), and some of its protein partners, as well as glutamyl-tRNA synthetase gltX and other proteins that are involved in protein synthesis, heterocyst differentiation, and nitrogen metabolism. By taking into account the important regulatory role of PII, it becomes clear that BMAA has a severe negative impact on the carbon and nitrogen metabolism of starving Nostoc sp. PCC 7120 cells. BMAA disturbs carbon fixation and the carbon dioxide concentrating mechanism, photosynthesis, and amino acid metabolism. Stress response proteins and DNA repair enzymes are upregulated in the presence of BMAA, clearly indicating severe intracellular stress. This is the first proteomic study of the effects of BMAA on diazotrophic starving cyanobacteria cells, allowing a deeper insight into the regulation of the intracellular metabolism of cyanobacteria by this non-protein amino acid.

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Kumazawa, Shuzo, Shin-ichi Yumura, and Hidekazu Yoshisuji. "PHOTOAUTOTROPHIC GROWTH OF A RECENTLY ISOLATED N2-FIXING MARINE NON-HETEROCYSTOUS FILAMENTOUS CYANOBACTERIUM, SYMPLOCA SP. (CYANOBACTERIA)." Journal of Phycology 37, no. 4 (August 28, 2001): 482–87. http://dx.doi.org/10.1046/j.1529-8817.2001.037004482.x.

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Pernil, Rafael, and Enrico Schleiff. "Metalloproteins in the Biology of Heterocysts." Life 9, no. 2 (April 3, 2019): 32. http://dx.doi.org/10.3390/life9020032.

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Cyanobacteria are photoautotrophic microorganisms present in almost all ecologically niches on Earth. They exist as single-cell or filamentous forms and the latter often contain specialized cells for N2 fixation known as heterocysts. Heterocysts arise from photosynthetic active vegetative cells by multiple morphological and physiological rearrangements including the absence of O2 evolution and CO2 fixation. The key function of this cell type is carried out by the metalloprotein complex known as nitrogenase. Additionally, many other important processes in heterocysts also depend on metalloproteins. This leads to a high metal demand exceeding the one of other bacteria in content and concentration during heterocyst development and in mature heterocysts. This review provides an overview on the current knowledge of the transition metals and metalloproteins required by heterocysts in heterocyst-forming cyanobacteria. It discusses the molecular, physiological, and physicochemical properties of metalloproteins involved in N2 fixation, H2 metabolism, electron transport chains, oxidative stress management, storage, energy metabolism, and metabolic networks in the diazotrophic filament. This provides a detailed and comprehensive picture on the heterocyst demands for Fe, Cu, Mo, Ni, Mn, V, and Zn as cofactors for metalloproteins and highlights the importance of such metalloproteins for the biology of cyanobacterial heterocysts.

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Koksharova, Olga A., and Nina A. Safronova. "Non-Proteinogenic Amino Acid β-N-Methylamino-L-Alanine (BMAA): Bioactivity and Ecological Significance." Toxins 14, no. 8 (August 7, 2022): 539. http://dx.doi.org/10.3390/toxins14080539.

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Research interest in a non-protein amino acid β-N-methylamino-L-alanine (BMAA) arose due to the discovery of a connection between exposure to BMAA and the occurrence of neurodegenerative diseases. Previous reviews on this topic either considered BMAA as a risk factor for neurodegenerative diseases or focused on the problems of detecting BMAA in various environmental samples. Our review is devoted to a wide range of fundamental biological problems related to BMAA, including the molecular mechanisms of biological activity of BMAA and the complex relationships between producers of BMAA and the environment in various natural ecosystems. At the beginning, we briefly recall the most important facts about the producers of BMAA (cyanobacteria, microalgae, and bacteria), the pathways of BMAA biosynthesis, and reliable methods of identification of BMAA. The main distinctive feature of our review is a detailed examination of the molecular mechanisms underlying the toxicity of BMAA to living cells. A brand new aspect, not previously discussed in any reviews, is the effect of BMAA on cyanobacterial cells. These recent studies, conducted using transcriptomics and proteomics, revealed potent regulatory effects of BMAA on the basic metabolism and cell development of these ancient photoautotrophic prokaryotes. Exogenous BMAA strongly influences cell differentiation and primary metabolic processes in cyanobacteria, such as nitrogen fixation, photosynthesis, carbon fixation, and various biosynthetic processes involving 2-oxoglutarate and glutamate. Cyanobacteria were found to be more sensitive to exogenous BMAA under nitrogen-limited growth conditions. We suggest a hypothesis that this toxic diaminoacid can be used by phytoplankton organisms as a possible allelopathic tool for controlling the population of cyanobacterial cells during a period of intense competition for nitrogen and other resources in various ecosystems.

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Ngoennet, Siripat, Yasuhiro Nishikawa, Takashi Hibino, Rungaroon Waditee-Sirisattha, and Hakuto Kageyama. "A Method for the Isolation and Characterization of Mycosporine-Like Amino Acids from Cyanobacteria." Methods and Protocols 1, no. 4 (December 3, 2018): 46. http://dx.doi.org/10.3390/mps1040046.

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This report provides a broadly applicable and cost-effective method for the purification of mycosporine-like amino acids (MAAs) from cyanobacteria. As MAAs are known to have multiple bioactivities for health and beauty, a universal isolation method of MAAs from biomass is attractive. In particular, the biomass of photosynthetic microorganisms such as cyanobacteria is of interest as a natural source of useful compound production, because of their photoautotrophic property. The method presented here is applicable for the isolation of mycosporine-2-glycine (M2G), which is a rare MAA produced in a halotolerant cyanobacterium. This method also allowed for the isolation of two of the most common MAAs, shinorine (SHI) and porphyra-334 (P334). A three-step separation process using low pressure liquid chromatography yielded purified MAAs, which were characterized by nuclear magnetic resonance (NMR) and liquid chromatography-mass spectrometry (LC/MS) analyses. The purified MAAs exhibited free radical scavenging activity in the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay. The experimental parameters obtained in this report may allow for a scale-up of the MAA purification process for future industrial applications.

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Gundolf, Richard, Sandra Oberleitner, and Juliane Richter. "Evaluation of New Genetic Toolkits and Their Role for Ethanol Production in Cyanobacteria." Energies 12, no. 18 (September 12, 2019): 3515. http://dx.doi.org/10.3390/en12183515.

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Since the public awareness for climate change has risen, increasing scientific effort has been made to find and develop alternative resources and production processes to reduce the dependency on petrol-based fuels and chemicals of our society. Among others, the biotechnological fuel production, as for example fermenting sugar-rich crops to ethanol, is one of the main strategies. For this purpose, various classical production systems like Escherichia coli or Saccharomyces cerevisiae are used and have been optimized via genetic modifications. Despite the progress made, this strategy competes for nutritional resources and agricultural land. To overcome this problem, various attempts were made for direct photosynthetic driven ethanol synthesis with different microalgal species including cyanobacteria. However, compared to existing platforms, the development of cyanobacteria as photoautotrophic cell factories has just started, and accordingly, the ethanol yield of established production systems is still unreached. This is mainly attributed to low ethanol tolerance levels of cyanobacteria and there is still potential for optimizing the cyanobacteria towards alternative gene expression systems. Meanwhile, several improvements were made by establishing new toolboxes for synthetic biology offering new possibilities for advanced genetic modifications of cyanobacteria. Here, current achievements and innovations of those new molecular tools are discussed.

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Bland, Erik, and Largus T. Angenent. "Pigment-targeted light wavelength and intensity promotes efficient photoautotrophic growth of Cyanobacteria." Bioresource Technology 216 (September 2016): 579–86. http://dx.doi.org/10.1016/j.biortech.2016.05.116.

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Tsuzuki, Mikio, Katsuhiko Okada, Haruna Isoda, Masayuki Hirano, Tetsuo Odaka, Hirotaka Saijo, Risa Aruga, Hiroki Miyauchi, and Shoko Fujiwara. "Physiological Properties of Photoautotrophic Microalgae and Cyanobacteria Relevant to Industrial Biomass Production." Marine Biotechnology 21, no. 3 (March 29, 2019): 406–15. http://dx.doi.org/10.1007/s10126-019-09890-1.

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Leister, Dario. "Experimental evolution in photoautotrophic microorganisms as a means of enhancing chloroplast functions." Essays in Biochemistry 62, no. 1 (September 8, 2017): 77–84. http://dx.doi.org/10.1042/ebc20170010.

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The term ‘experimental evolution’ refers to short-term evolutionary experiments with microorganisms under controlled conditions in which selection is expected to occur. In combination with whole-genome sequencing and genetic engineering, the method has become a powerful tool to study evolutionary mechanisms and engineer new microbial variants. It has been most extensively used in the model species Escherichia coli and Saccharomyces cerevisiae, but more recently photosynthetic microorganisms have been subjected to experimental evolution. In such assays, strains were generated that had become more tolerant to certain abiotic environmental factors or evolved new traits during co-propagation with other organisms. These strains were viable under conditions that were lethal to the non-adapted progenitor and in a few cases, the causative mutations were identified. Because cyanobacteria like Synechocystis or green algae like Chlamydomonas reinhardtii share many features with crop plants – which are not amenable to such experiments – experimental evolution with photosynthetic microorganisms has the potential to identify novel targets for improving the capacity of plants to acclimate to environmental change. Here, I provide a survey of the experiments performed so far in cyanobacteria and green algae, focusing on Synechocystis and C. reinhardtii, and discuss the promise and the challenges of such approaches.

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Carpine, Roberta, Giuseppe Olivieri, Klaas J. Hellingwerf, Antonino Pollio, and Antonio Marzocchella. "Industrial Production of Poly-β-hydroxybutyrate from CO2: Can Cyanobacteria Meet this Challenge?" Processes 8, no. 3 (March 10, 2020): 323. http://dx.doi.org/10.3390/pr8030323.

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The increasing impact of plastic materials on the environment is a growing global concern. In regards to this circumstance, it is a major challenge to find new sources for the production of bioplastics. Poly-β-hydroxybutyrate (PHB) is characterized by interesting features that draw attention for research and commercial ventures. Indeed, PHB is eco-friendly, biodegradable, and biocompatible. Bacterial fermentation processes are a known route to produce PHB. However, the production of PHB through the chemoheterotrophic bacterial system is very expensive due to the high costs of the carbon source for the growth of the organism. On the contrary, the production of PHB through the photoautotrophic cyanobacterium system is considered an attractive alternative for a low-cost PHB production because of the inexpensive feedstock (CO2 and light). This paper regards the evaluation of four independent strategies to improve the PHB production by cyanobacteria: (i) the design of the medium; (ii) the genetic engineering to improve the PHB accumulation; (iii) the development of robust models as a tool to identify the bottleneck(s) of the PHB production to maximize the production; and (iv) the continuous operation mode in a photobioreactor for PHB production. The synergic effect of these strategies could address the design of the optimal PHB production process by cyanobacteria. A further limitation for the commercial production of PHB via the biotechnological route are the high costs related to the recovery of PHB granules. Therefore, a further challenge is to select a low-cost and environmentally friendly process to recover PHB from cyanobacteria.

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Jung, Patrick, Laura Briegel-Williams, Anika Simon, Anne Thyssen, and Burkhard Büdel. "Uncovering biological soil crusts: carbon content and structure of intact Arctic, Antarctic and alpine biological soil crusts." Biogeosciences 15, no. 4 (February 23, 2018): 1149–60. http://dx.doi.org/10.5194/bg-15-1149-2018.

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Abstract. Arctic, Antarctic and alpine biological soil crusts (BSCs) are formed by adhesion of soil particles to exopolysaccharides (EPSs) excreted by cyanobacterial and green algal communities, the pioneers and main primary producers in these habitats. These BSCs provide and influence many ecosystem services such as soil erodibility, soil formation and nitrogen (N) and carbon (C) cycles. In cold environments degradation rates are low and BSCs continuously increase soil organic C; therefore, these soils are considered to be CO2 sinks. This work provides a novel, non-destructive and highly comparable method to investigate intact BSCs with a focus on cyanobacteria and green algae and their contribution to soil organic C. A new terminology arose, based on confocal laser scanning microscopy (CLSM) 2-D biomaps, dividing BSCs into a photosynthetic active layer (PAL) made of active photoautotrophic organisms and a photosynthetic inactive layer (PIL) harbouring remnants of cyanobacteria and green algae glued together by their remaining EPSs. By the application of CLSM image analysis (CLSM–IA) to 3-D biomaps, C coming from photosynthetic active organisms could be visualized as depth profiles with C peaks at 0.5 to 2 mm depth. Additionally, the CO2 sink character of these cold soil habitats dominated by BSCs could be highlighted, demonstrating that the first cubic centimetre of soil consists of between 7 and 17 % total organic carbon, identified by loss on ignition.

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Salvador, Nemésio Neves Batista, Baptista Bina, and Fernando Frigo. "Cyanobacteria Occurrence in Photosynthetic Stabilization Ponds." International Journal for Innovation Education and Research 6, no. 2 (February 28, 2018): 208–20. http://dx.doi.org/10.31686/ijier.vol6.iss2.973.

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Photoautotrophic organisms, particularly cyanobacteria, have great ecological importance due to their photosynthetic capacity, and biosynthetic versatility in diverse and extreme environments. However, photosynthetic ponds, they may be serious and dangerous producers of potentially toxic toxins. Their release and bloom in treated effluent receiving bodies are a major concern because of the negative consequences on aquatic biota and the risks to public health. The aim of this study is to analyze the occurrence, composition, density and spatio-temporal distribution of cyanobacteria in sewage treatment plants by photosynthetic ponds in ten cities located in the central region of the São Paulo State, Brazil. The results recorded high densities of Microcystis sp. with a maximum average of 9.4x105 cells per millilitre (cells/mL); Synechococcus sp., with an average of 7.8x105; Synechocystis aquatilis with 7.2x105; Merismopedia tenuissima with 4.8x105; and Phormidium sp. with 1.9x105. Among these species found, the highest occurrence was M. tenuissima. The high densities show that these ponds are an aquatic environment conducive to the development of cyanobacteria and, potentially, an important source of cyanotoxin production. Therefore, studies and monitoring of the effects on the receiving water bodies are recommended by determining their cyanobacteria densities and investigating the possible presence of cyanotoxins.

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Langford, H. J., T. D. L. Irvine-Fynn, A. Edwards, S. A. Banwart, and A. J. Hodson. "A spatial investigation of the environmental controls over cryoconite aggregation on Longyearbreen glacier, Svalbard." Biogeosciences 11, no. 19 (October 7, 2014): 5365–80. http://dx.doi.org/10.5194/bg-11-5365-2014.

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Abstract. A cryoconite granule is a near-spherical aggregation of biota and abiotic particles found upon glacier surfaces. Recently, microstructural studies have revealed that photosynthetic microorganisms and extracellular polymeric substances (EPS) are omnipresent within cryoconite granules and have suggested their importance as biological "forming factors". To assess these forming factors, and their biological control over aggregate size and stability, across a typical Arctic valley glacier surface, a suite of rapid, spectrophotometric, microplate methods were utilised. Subsequent spatial mapping of these data revealed distinct patterns. Labile carbohydrates were found to increase up-glacier, suggestive of EPS production for cryoprotection and nutrient assimilation. Conversely, pigment concentrations were found to increase towards the glacier terminus and valley sides, suggestive of allochthonous input, a general reduction in physical disturbance and of the build-up of photosynthetic pigments and less labile cyanobacterial sheath material. Aggregate size was found to increase towards the glacier edges, linked to the input of particulate matter from the valley sides, and to broadly increase down-glacier, in the same way as pigment concentrations. Statistical analyses of transect data revealed that the photoautotrophic count and carbohydrate–chlorophyll ratio of the cryoconite sampled could explain 83% of the measured variation in aggregate size and stability. Considering solely aggregate size, the number and length of photoautotrophic filaments could explain 92% of the variation in this parameter. These findings demonstrate the two-dimensional distribution of key biological controls upon cryoconite aggregation for the first time, and highlight the importance of filamentous cyanobacteria and EPS production to the development of stable cryoconite granules.

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Dexter, Jason, Dariusz Dziga, Jing Lv, Junqi Zhu, Wojciech Strzalka, Anna Maksylewicz, Magdalena Maroszek, Sylwia Marek, and Pengcheng Fu. "Heterologous expression of mlrA in a photoautotrophic host – Engineering cyanobacteria to degrade microcystins." Environmental Pollution 237 (June 2018): 926–35. http://dx.doi.org/10.1016/j.envpol.2018.01.071.

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Xiong, Wenxuan, Yue Tao, Panpan Wang, Kaiting Wu, and Lanzhou Chen. "Impact of Environmental Factors on the Formation and Development of Biological Soil Crusts in Lime Concrete Materials of Building Facades." Applied Sciences 12, no. 6 (March 15, 2022): 2974. http://dx.doi.org/10.3390/app12062974.

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Microbial colonization leads to the formation of biological soil crusts (BSCs) on the surface of architecture, which causes the deterioration of construction materials. However, little information is available on the formation of BSCs on lime concrete materials of early architecture. In this study, the variances of microbial communities, physicochemical properties, and surrounding environmental factors of the lime concrete facades from the early architecture of Wuhan University were investigated. It was found that the surface of lime concrete materials was internally porous and permeable, embedded with biofilms of cyanobacteria, mosses, bacteria, and fungi. Redundancy analysis (RDA) analysis showed that the abundances of photoautotrophic microorganisms depended on light intensity and moisture content of construction materials, while that of heterotrophic microorganisms depended on total nitrogen (TN) and NO3−-N content. The deposition of total carbon (TC), NH4+-N, and total organic carbon (TOC) was mainly generated by photoautotrophic microorganisms. The lime concrete surface of early architecture allowed internal growth of microorganisms and excretion of metabolites, which promoted the biodeterioration of lime concrete materials.

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Marzocchella, Antonio, Roberta Carpine, Giuseppe Olivieri, Klaas J. Hellingwerf, Antonino Pollio, and Gabriele Pinto. "PHOTOAUTOTROPHIC PRODUCTION OF POLY-.-HYDROXYBUTYRATE (PHB) FROM CYANOBACTERIA: NITRATE EFFECTS AND SCREENING OF STRAINS." Environmental Engineering and Management Journal 18, no. 6 (2019): 1337–46. http://dx.doi.org/10.30638/eemj.2019.127.

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Sarnaik, Aditya, Mary H. Abernathy, Xiaorui Han, Yilan Ouyang, Ke Xia, Yin Chen, Brady Cress, et al. "Metabolic engineering of cyanobacteria for photoautotrophic production of heparosan, a pharmaceutical precursor of heparin." Algal Research 37 (January 2019): 57–63. http://dx.doi.org/10.1016/j.algal.2018.11.010.

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Schmidt, Olaf, Jens Dyckmans, and Stefan Schrader. "Photoautotrophic microorganisms as a carbon source for temperate soil invertebrates." Biology Letters 12, no. 1 (January 2016): 20150646. http://dx.doi.org/10.1098/rsbl.2015.0646.

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We tested experimentally if photoautotrophic microorganisms are a carbon source for invertebrates in temperate soils. We exposed forest or arable soils to a 13 CO 2 -enriched atmosphere and quantified 13 C assimilation by three common animal groups: earthworms (Oligochaeta), springtails (Hexapoda) and slugs (Gastropoda). Endogeic earthworms ( Allolobophora chlorotica ) and hemiedaphic springtails ( Ceratophysella denticulata ) were highly 13 C enriched when incubated under light, deriving up to 3.0 and 17.0%, respectively, of their body carbon from the microbial source in 7 days. Earthworms assimilated more 13 C in undisturbed soil than when the microbial material was mixed into the soil, presumably reflecting selective surface grazing. By contrast, neither adult nor newly hatched terrestrial slugs ( Deroceras reticulatum ) grazed on algal mats. Non-photosynthetic 13 CO 2 fixation in the dark was negligible. We conclude from these preliminary laboratory experiments that, in addition to litter and root-derived carbon from vascular plants, photoautotrophic soil surface microorganisms (cyanobacteria, algae) may be an ecologically important carbon input route for temperate soil animals that are traditionally assigned to the decomposer channel in soil food web models and carbon cycling studies.

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Toyoshima, Masakazu, Yuma Tokumaru, Fumio Matsuda, and Hiroshi Shimizu. "Assessment of Protein Content and Phosphorylation Level in Synechocystis sp. PCC 6803 under Various Growth Conditions Using Quantitative Phosphoproteomic Analysis." Molecules 25, no. 16 (August 6, 2020): 3582. http://dx.doi.org/10.3390/molecules25163582.

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The photosynthetic apparatus and metabolic enzymes of cyanobacteria are subject to various controls, such as transcriptional regulation and post-translational modifications, to ensure that the entire cellular system functions optimally. In particular, phosphorylation plays key roles in many cellular controls such as enzyme activity, signal transduction, and photosynthetic apparatus restructuring. Therefore, elucidating the governing functions of phosphorylation is crucial to understanding the regulatory mechanisms underlying metabolism and photosynthesis. In this study, we determined protein content and phosphorylation levels to reveal the regulation of intracellular metabolism and photosynthesis in Synechocystis sp. PCC 6803; for this, we obtained quantitative data of proteins and their phosphorylated forms involved in photosynthesis and metabolism under various growth conditions (photoautotrophic, mixotrophic, heterotrophic, dark, and nitrogen-deprived conditions) using targeted proteomic and phosphoproteomic analyses with nano-liquid chromatography-triple quadrupole mass spectrometry. The results indicated that in addition to the regulation of protein expression, the regulation of phosphorylation levels of cyanobacterial photosynthetic apparatus and metabolic enzymes was pivotal for adapting to changing environmental conditions. Furthermore, reduced protein levels of CpcC and altered phosphorylation levels of CpcB, ApcA, OCP, and PsbV contributed to the cellular response of the photosynthesis apparatus to nitrogen deficiency.

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Kallio, Pauli, Amit Kugler, Samuli Pyytövaara, Karin Stensjö, Yagut Allahverdiyeva, Xiang Gao, Peter Lindblad, and Pia Lindberg. "Photoautotrophic production of renewable ethylene by engineered cyanobacteria: Steering the cell metabolism towards biotechnological use." Physiologia Plantarum 173, no. 2 (May 6, 2021): 579–90. http://dx.doi.org/10.1111/ppl.13430.

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Asato, Y. "Toward an understanding of cell growth and the cell division cycle of unicellular photoautotrophic cyanobacteria." Cellular and Molecular Life Sciences (CMLS) 60, no. 4 (April 1, 2003): 663–87. http://dx.doi.org/10.1007/s00018-003-2079-y.

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Marcus, Yehouda, Hagit Altman-Gueta, Aliza Finkler, and Michael Gurevitz. "Mutagenesis at Two Distinct Phosphate-Binding Sites Unravels Their Differential Roles in Regulation of Rubisco Activation and Catalysis." Journal of Bacteriology 187, no. 12 (June 15, 2005): 4222–28. http://dx.doi.org/10.1128/jb.187.12.4222-4228.2005.

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ABSTRACT Orthophosphate (Pi) has two antagonistic effects on ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), stimulation of activation and inhibition of catalysis by competition with the substrate RuBP. The enzyme binds Pi at three distinct sites, two within the catalytic site (where 1P and 5P of ribulose 1,5-bisphosphate [RuBP] bind), and the third at the latch site (a positively charged pocket involved in active-site closure during catalysis). We examined the role of the latch and 5P sites in regulation of Rubisco activation and catalysis by introducing specific mutations in the enzyme of the cyanobacterium Synechocystis sp. strain PCC 6803. Whereas mutations at both sites abolished the Pi-stimulated Rubisco activation, substitution of residues at the 5P site, but not at the latch site, affected the Pi inhibition of Rubisco catalysis. Although some of these mutations substantially reduced the catalytic turnover of Rubisco and increased the Km (RuBP), they had little to moderate effect on the rate of photosynthesis and no effect on photoautotrophic growth. These findings suggest that in cyanobacteria, Rubisco does not limit photosynthesis to the extent previously estimated. These results indicate that both the latch and 5P sites participate in regulation of Rubisco activation, whereas Pi binding only at the 5P site inhibits catalysis in a competitive manner.

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Koch, Moritz, Sofía Doello, Kirstin Gutekunst, and Karl Forchhammer. "PHB is Produced from Glycogen Turn-over during Nitrogen Starvation in Synechocystis sp. PCC 6803." International Journal of Molecular Sciences 20, no. 8 (April 20, 2019): 1942. http://dx.doi.org/10.3390/ijms20081942.

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Polyhydroxybutyrate (PHB) is a polymer of great interest as a substitute for conventional plastics, which are becoming an enormous environmental problem. PHB can be produced directly from CO2 in photoautotrophic cyanobacteria. The model cyanobacterium Synechocystis sp. PCC 6803 produces PHB under conditions of nitrogen starvation. However, it is so far unclear which metabolic pathways provide the precursor molecules for PHB synthesis during nitrogen starvation. In this study, we investigated if PHB could be derived from the main intracellular carbon pool, glycogen. A mutant of the major glycogen phosphorylase, GlgP2 (slr1367 product), was almost completely impaired in PHB synthesis. Conversely, in the absence of glycogen synthase GlgA1 (sll0945 product), cells not only produced less PHB, but were also impaired in acclimation to nitrogen depletion. To analyze the role of the various carbon catabolic pathways (EMP, ED and OPP pathways) for PHB production, mutants of key enzymes of these pathways were analyzed, showing different impact on PHB synthesis. Together, this study clearly indicates that PHB in glycogen-producing Synechocystis sp. PCC 6803 cells is produced from this carbon-pool during nitrogen starvation periods. This knowledge can be used for metabolic engineering to get closer to the overall goal of a sustainable, carbon-neutral bioplastic production.

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Steinman, Alan D., Karl E. Havens, J. William Louda, Nancy M. Winfree, and Earl W. Baker. "Characterization of the photoautotrophic algal and bacterial communities in a large, shallow, subtropical lake using HPLC-PDA based pigment analysis." Canadian Journal of Fisheries and Aquatic Sciences 55, no. 1 (January 1, 1998): 206–19. http://dx.doi.org/10.1139/f97-239.

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Pigment abundances of the oxygenic and anoxygenic photoautotrophic communities from sediments and the water column in Lake Okeechobee, Florida, were estimated using reverse-phase high-performance liquid chromatographic (RP-HPLC) and photodiode array (PDA) UV/VIS (350-800 nm) spectrophotometric analyses. Thirty lipophilic pigments were identified and measured in the samples, with the most abundant overall (sediment and open-water samples combined) being chlorophyll a (38.1%), fucoxanthin (12.6%), pheophytin a (7.6%), zeaxanthin (6.6%), and pyropheophytin a (3.6%). Relative abundance of chlorophyll a was greater in the water column than in the sediments (58.3 versus 24.3% of all pigments) whereas pheophytin a comprised 9.1% of the total pigments in the sediments but only 3.7% of the total pigments in the water column. Principal component analysis (PCA) separated the sediment samples from those collected in the water column; this discrimination appears to be a function of pigment integrity in that sediment assemblages had much greater relative abundances of degraded pigments. Different regions of the lake were weakly separated by PCA based on pigments. The relatively weak degree of separation may reflect the overwhelming abundance of chlorophyll a at all sites. Overall, the pigment assemblage in Lake Okeechobee suggests cyanobacteria-diatom dominance. Out of 65 sampling events, pigments from anoxygenic photoautotrophs (e.g., bacteriochlorophylls) were detected 17 times but accounted for >20% of total chlorophyll only five times. Bacteriochlorophylls were observed only in the sediments and were most abundant during June and September, when winds were calm and temperatures warm, and at relatively shallow sites.

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Summerfield, Tina C., and Louis A. Sherman. "Global Transcriptional Response of the Alkali-Tolerant Cyanobacterium Synechocystis sp. Strain PCC 6803 to a pH 10 Environment." Applied and Environmental Microbiology 74, no. 17 (July 7, 2008): 5276–84. http://dx.doi.org/10.1128/aem.00883-08.

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ABSTRACT Many cyanobacterial strains are able to grow at a pH range from neutral to pH 10 or 11. Such alkaline conditions favor cyanobacterial growth (e.g., bloom formation), and cyanobacteria must have developed strategies to adjust to changes in CO2 concentration and ion availability. Synechocystis sp. strain PCC 6803 exhibits similar photoautotrophic growth characteristics at pH 10 and pH 7.5, and we examined global gene expression following transfer from pH 7.5 to pH 10 to determine cellular adaptations at an elevated pH. The strategies used to develop homeostasis at alkaline pH had elements similar to those of many bacteria, as well as components unique to phototrophic microbes. Some of the response mechanisms previously identified in other bacteria included upregulation of Na+/H+ antiporters, deaminases, and ATP synthase. In addition, upregulated genes encoded transporters with the potential to contribute to osmotic, pH, and ion homeostasis (e.g., a water channel protein, a large-conductance mechanosensitive channel, a putative anion efflux transporter, a hexose/proton symporter, and ABC transporters of unidentified substrates). Transcriptional changes specific to photosynthetic microbes involved NADH dehydrogenases and CO2 fixation. The pH transition altered the CO2/HCO3 − ratio within the cell, and the upregulation of three inducible bicarbonate transporters (BCT1, SbtA, and NDH-1S) likely reflected a response to this perturbed ratio. Consistent with this was increased transcript abundance of genes encoding carboxysome structural proteins and carbonic anhydrase. Interestingly, the transition to pH 10 resulted in increased abundance of transcripts of photosystem II genes encoding extrinsic and low-molecular-weight polypeptides, although there was little change in photosystem I gene transcripts.

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Heal, Katherine R., Wei Qin, Francois Ribalet, Anthony D. Bertagnolli, Willow Coyote-Maestas, Laura R. Hmelo, James W. Moffett, et al. "Two distinct pools of B12analogs reveal community interdependencies in the ocean." Proceedings of the National Academy of Sciences 114, no. 2 (December 27, 2016): 364–69. http://dx.doi.org/10.1073/pnas.1608462114.

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Organisms within all domains of life require the cofactor cobalamin (vitamin B12), which is produced only by a subset of bacteria and archaea. On the basis of genomic analyses, cobalamin biosynthesis in marine systems has been inferred in three main groups: select heterotrophic Proteobacteria, chemoautotrophic Thaumarchaeota, and photoautotrophic Cyanobacteria. Culture work demonstrates that many Cyanobacteria do not synthesize cobalamin but rather produce pseudocobalamin, challenging the connection between the occurrence of cobalamin biosynthesis genes and production of the compound in marine ecosystems. Here we show that cobalamin and pseudocobalamin coexist in the surface ocean, have distinct microbial sources, and support different enzymatic demands. Even in the presence of cobalamin, Cyanobacteria synthesize pseudocobalamin—likely reflecting their retention of an oxygen-independent pathway to produce pseudocobalamin, which is used as a cofactor in their specialized methionine synthase (MetH). This contrasts a model diatom,Thalassiosira pseudonana, which transported pseudocobalamin into the cell but was unable to use pseudocobalamin in its homolog of MetH. Our genomic and culture analyses showed that marine Thaumarchaeota and select heterotrophic bacteria produce cobalamin. This indicates that cobalamin in the surface ocean is a result of de novo synthesis by heterotrophic bacteria or via modification of closely related compounds like cyanobacterially produced pseudocobalamin. Deeper in the water column, our study implicates Thaumarchaeota as major producers of cobalamin based on genomic potential, cobalamin cell quotas, and abundance. Together, these findings establish the distinctive roles played by abundant prokaryotes in cobalamin-based microbial interdependencies that sustain community structure and function in the ocean.

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SQUIER, ANGELA H., DOMINIC A. HODGSON, and BRENDAN J. KEELY. "Evidence of late Quaternary environmental change in a continental east Antarctic lake from lacustrine sedimentary pigment distributions." Antarctic Science 17, no. 3 (August 17, 2005): 361–76. http://dx.doi.org/10.1017/s0954102005002804.

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A sediment core from Progress Lake, one of the oldest lacustrine sequences in East Antarctica, contains distinct zones dating from a previous interglacial (most likely Marine Isotope Stage 5e, c. 125–115 kyr BP) and the present interglacial (Marine Isotope Stage 1), separated by a transition zone representing when the lake became sub-glacial. Profiles of fossil pigments, determined using high performance liquid chromatography and liquid chromatography-tandem mass spectrometry, show distinct differences in the photoautotrophic community during these two interglacial periods. The first was dominated by algae and purple phototrophic bacteria, with periods of photic zone euxinia indicated by pigments from anoxygenic phototrophic bacteria. Specific chlorophyll a derivatives reveal periods when grazing pressure impacted significantly on the phytoplankton community. The virtual absence of pigments in the transition zone reflects severe restriction of photoautotrophic activity, consistent with the lake having become sub-glacial. Retreat of snow and ice in the late Holocene (3345 14C yr BP) allowed establishment of a less diverse primary producer community, restricted to algae and cyanobacteria. Grazers were severely restricted and oxidative transformation was more important than during the previous interglacial. The pigment data provide a unique and detailed insight in to the evolution of the lake ecology over an interglacial-glacial-interglacial transition and strong evidence that the Marine Isotope Stage 5e interglacial in this region of coastal East Antarctica was several degrees warmer than at present.

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Ungerer, Justin, Kristen E. Wendt, John I. Hendry, Costas D. Maranas, and Himadri B. Pakrasi. "Comparative genomics reveals the molecular determinants of rapid growth of the cyanobacteriumSynechococcus elongatusUTEX 2973." Proceedings of the National Academy of Sciences 115, no. 50 (November 8, 2018): E11761—E11770. http://dx.doi.org/10.1073/pnas.1814912115.

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Cyanobacteria are emerging as attractive organisms for sustainable bioproduction. We previously describedSynechococcus elongatusUTEX 2973 as the fastest growing cyanobacterium known.Synechococcus2973 exhibits high light tolerance and an increased photosynthetic rate and produces biomass at three times the rate of its close relative, the model strainSynechococcus elongatus7942. The two strains differ at 55 genetic loci, andsome of these loci must contain the genetic determinants of rapid photoautotrophic growth and improved photosynthetic rate. Using CRISPR/Cpf1, we performed a comprehensive mutational analysis ofSynechococcus2973 and identified three specific genes,atpA,ppnK, andrpaA, with SNPs that confer rapid growth. The fast-growth–associated allele of each gene was then used to replace the wild-type alleles inSynechococcus7942. Upon incorporation, each allele successively increased the growth rate ofSynechococcus7942; remarkably, inclusion of all three alleles drastically reduced the doubling time from 6.8 to 2.3 hours. Further analysis revealed that our engineering effort doubled the photosynthetic productivity ofSynechococcus7942. We also determined that the fast-growth–associated allele ofatpAyielded an ATP synthase with higher specific activity, while that ofppnKencoded a NAD+kinase with significantly improved kinetics. TherpaASNPs cause broad changes in the transcriptional profile, as this gene is the master output regulator of the circadian clock. This pioneering study has revealed the molecular basis for rapid growth, demonstrating that limited genetic changes can dramatically improve the growth rate of a microbe by as much as threefold.

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Journal articles on the topic 'Photoautotrophic cyanobacteria'

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