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Current Opinion in Microbiology Apr 2024Cyanobacteria evolved the oxygenic photosynthesis to generate organic matter from CO and sunlight, and they were responsible for the production of oxygen in the Earth's... (Review)
Review
Cyanobacteria evolved the oxygenic photosynthesis to generate organic matter from CO and sunlight, and they were responsible for the production of oxygen in the Earth's atmosphere. This made them a model for photosynthetic organisms, since they are easier to study than higher plants. Early studies suggested that only a minority among cyanobacteria might assimilate organic compounds, being considered mostly autotrophic for decades. However, compelling evidence from marine and freshwater cyanobacteria, including toxic strains, in the laboratory and in the field, has been obtained in the last decades: by using physiological and omics approaches, mixotrophy has been found to be a more widespread feature than initially believed. Furthermore, dominant clades of marine cyanobacteria can take up organic compounds, and mixotrophy is critical for their survival in deep waters with very low light. Hence, mixotrophy seems to be an essential trait in the metabolism of most cyanobacteria, which can be exploited for biotechnological purposes.
Topics: Cyanobacteria; Photosynthesis; Atmosphere; Oxygen
PubMed: 38325247
DOI: 10.1016/j.mib.2024.102432 -
Environmental Microbiology Jun 2017Huber and collaborators reported in this issue of Environmental Microbiology about freshwater picocyanobacteria that showed phenotypic plasticity in the sense that they...
Huber and collaborators reported in this issue of Environmental Microbiology about freshwater picocyanobacteria that showed phenotypic plasticity in the sense that they appeared as single cells as well as in aggregates. The authors suggested that aggregation might be an inducible defense as a response to the presence of grazers. This has been described for eukaryotic phytoplankton and for the cyanobacterium Microcystis but thus far not for picocyanobacteria. Although inducible defense as an explanation is an attractive possibility, it is also problematic. Aggregation is common among cyanobacteria and it offers many advantages as compared with a free-living lifestyle. Here these advantages are highlighted and the possibility of inducible defense is critically assessed.
Topics: Bacterial Adhesion; Cyanobacteria; Fresh Water; Microbial Consortia; Microcystis; Phytoplankton
PubMed: 28370986
DOI: 10.1111/1462-2920.13739 -
Journal of Industrial Microbiology &... Apr 2022Alkanes are high-energy molecules that are compatible with enduring liquid fuel infrastructures, which make them highly suitable for being next-generation biofuels.... (Review)
Review
Alkanes are high-energy molecules that are compatible with enduring liquid fuel infrastructures, which make them highly suitable for being next-generation biofuels. Though biological production of alkanes has been reported in various microorganisms, the reports citing photosynthetic cyanobacteria as natural producers have been the most consistent for the long-chain alkanes and alkenes (C15-C19). However, the production of alkane in cyanobacteria is low, leading to its extraction being uneconomical for commercial purposes. In order to make alkane production economically feasible from cyanobacteria, the titre and yield need to be increased by several orders of magnitude. In the recent past, efforts have been made to enhance alkane production, although with a little gain in yield, leaving space for much improvement. Genetic manipulation in cyanobacteria is considered challenging, but recent advancements in genetic engineering tools may assist in manipulating the genome in order to enhance alkane production. Further, advancement in a basic understanding of metabolic pathways and gene functioning will guide future research for harvesting the potential of these tiny photosynthetically efficient factories. In this review, our focus would be to highlight the current knowledge available on cyanobacterial alkane production, and the potential aspects of developing cyanobacterium as an economical source of biofuel. Further insights into different metabolic pathways and hosts explored so far, and possible challenges in scaling up the production of alkanes will also be discussed.
Topics: Alkanes; Alkenes; Biofuels; Cyanobacteria; Metabolic Engineering
PubMed: 34718648
DOI: 10.1093/jimb/kuab075 -
Marine Drugs Nov 2013Phylogeny is an evolutionary reconstruction of the past relationships of DNA or protein sequences and it can further be used as a tool to assess population structuring,... (Review)
Review
Phylogeny is an evolutionary reconstruction of the past relationships of DNA or protein sequences and it can further be used as a tool to assess population structuring, genetic diversity and biogeographic patterns. In the microbial world, the concept that everything is everywhere is widely accepted. However, it is much debated whether microbes are easily dispersed globally or whether they, like many macro-organisms, have historical biogeographies. Biogeography can be defined as the science that documents the spatial and temporal distribution of a given taxa in the environment at local, regional and continental scales. Speciation, extinction and dispersal are proposed to explain the generation of biogeographic patterns. Cyanobacteria are a diverse group of microorganisms that inhabit a wide range of ecological niches and are well known for their toxic secondary metabolite production. Knowledge of the evolution and dispersal of these microorganisms is still limited, and further research to understand such topics is imperative. Here, we provide a compilation of the most relevant information regarding these issues to better understand the present state of the art as a platform for future studies, and we highlight examples of both phylogenetic and biogeographic studies in non-symbiotic cyanobacteria and cyanotoxins.
Topics: Biodiversity; Biological Evolution; Cyanobacteria; Phylogeny; Toxins, Biological
PubMed: 24189276
DOI: 10.3390/md11114350 -
Journal of Industrial Microbiology &... Jun 2021Cyanobacteria produce a plethora of compounds with unique chemical structures and diverse biological activities. Importantly, the increasing availability of... (Review)
Review
Cyanobacteria produce a plethora of compounds with unique chemical structures and diverse biological activities. Importantly, the increasing availability of cyanobacterial genome sequences and the rapid development of bioinformatics tools have unraveled the tremendous potential of cyanobacteria in producing new natural products. However, the discovery of these compounds based on cyanobacterial genomes has progressed slowly as the majority of their corresponding biosynthetic gene clusters (BGCs) are silent. In addition, cyanobacterial strains are often slow-growing, difficult for genetic engineering, or cannot be cultivated yet, limiting the use of host genetic engineering approaches for discovery. On the other hand, genetically tractable hosts such as Escherichia coli, Actinobacteria, and yeast have been developed for the heterologous expression of cyanobacterial BGCs. More recently, there have been increased interests in developing model cyanobacterial strains as heterologous production platforms. Herein, we present recent advances in the heterologous production of cyanobacterial compounds in both cyanobacterial and noncyanobacterial hosts. Emerging strategies for BGC assembly, host engineering, and optimization of BGC expression are included for fostering the broader applications of synthetic biology tools in the discovery of new cyanobacterial natural products.
Topics: Animals; Biological Products; Cyanobacteria; Genetic Engineering; Humans; Multigene Family
PubMed: 33928376
DOI: 10.1093/jimb/kuab003 -
Current Opinion in Biotechnology Apr 2023Cyanobacteria have promising potential as sustainable cell factories. However, one challenge that is still largely unreported in scaling-up cyanobacteria bioproduction... (Review)
Review
Cyanobacteria have promising potential as sustainable cell factories. However, one challenge that is still largely unreported in scaling-up cyanobacteria bioproduction is phenotypic instability, where the emergence and selection of nonproducing cells leading to loss in production has longer evolutionary timescales to take place in industrial-scale bioreactors. Quantifying phenotypic instability early on in strain development allows researchers to make informed decisions on whether to proceed with scalable designs, or if present, devise countermeasures to reduce instability. One particularly effective strategy to mitigate instability is the use of genome-scale metabolic models to design growth-coupled production strains. In silico studies have predicted that creating certain cofactor imbalances or removing recycling reactions in cyanobacteria can be exploited to stably produce a wide variety of metabolites.
Topics: Cyanobacteria; Bioreactors; Biological Evolution; Metabolic Engineering
PubMed: 36724584
DOI: 10.1016/j.copbio.2023.102899 -
Current Biology : CB Apr 2009
Topics: Aerobiosis; Altruism; Anabaena; Animals; Bacterial Toxins; Cyanobacteria; Light; Organelles; Symbiosis
PubMed: 19368866
DOI: 10.1016/j.cub.2009.01.016 -
Environment International Jan 2013Millions of natural and synthetic organic chemical substances are present in both soil and aquatic environments. Toxicity and/or persistence determine the polluting... (Review)
Review
Millions of natural and synthetic organic chemical substances are present in both soil and aquatic environments. Toxicity and/or persistence determine the polluting principle of these substances. The biological responses to these pollutants include accumulation and degradation. The responses of environments with organic pollutants are perceptible from the dwindling degradative abilities of microorganisms. Among different biological members, cyanobacteria and microalgae are highly adaptive through many eons, and can grow autotrophically, heterotrophically or mixotrophically. Mixotrophy in cyanobacteria and microalgae can provide many competitive advantages over bacteria and fungi in degrading organic pollutants. Laboratory culturing of strict phototrophic algae has limited the realization of their potential as bioremediation agents. In the natural assemblages, mixotrophic algae can contribute to sequestration of carbon, which is otherwise emitted as carbon dioxide to the atmosphere under heterotrophic conditions by other organisms. Molecular methods and metabolic and genomic information will help not only in identification and selection of mixotrophic species of cyanobacteria and microalgae with capabilities to degrade organic pollutants but also in monitoring the efficiency of remediation efforts under the field conditions. These organisms are relatively easier for genetic engineering with desirable traits. This review presents a new premise from the literature that mixotrophic algae and cyanobacteria are distinctive bioremediation agents with capabilities to sequester carbon in the environment.
Topics: Biodegradation, Environmental; Cyanobacteria; Environmental Pollutants; Environmental Pollution; Microalgae; Organic Chemicals
PubMed: 23201778
DOI: 10.1016/j.envint.2012.10.007 -
Microbiology (Reading, England) Nov 2009The presence and deteriorating action of micro-organisms on monuments and stone works of art have received considerable attention in the last few years. Knowledge of the... (Review)
Review
The presence and deteriorating action of micro-organisms on monuments and stone works of art have received considerable attention in the last few years. Knowledge of the microbial populations living on stone materials is the starting point for successful conservation treatment and control. This paper reviews the literature on cyanobacteria and chlorophyta that cause deterioration of stone cultural heritage (outdoor monuments and stone works of art) in European countries of the Mediterranean Basin. Some 45 case studies from 32 scientific papers published between 1976 and 2009 were analysed. Six lithotypes were considered: marble, limestone, travertine, dolomite, sandstone and granite. A wide range of stone monuments in the Mediterranean Basin support considerable colonization of cyanobacteria and chlorophyta, showing notable biodiversity. About 172 taxa have been described by different authors, including 37 genera of cyanobacteria and 48 genera of chlorophyta. The most widespread and commonly reported taxa on the stone cultural heritage in the Mediterranean Basin are, among cyanobacteria, Gloeocapsa, Phormidium and Chroococcus and, among chlorophyta, Chlorella, Stichococcus and Chlorococcum. The results suggest that cyanobacteria and chlorophyta colonize a wide variety of substrata and that this is related primarily to the physical characteristics of the stone surface, microclimate and environmental conditions and secondarily to the lithotype.
Topics: Biodegradation, Environmental; Biodiversity; Calcium Carbonate; Chlorophyta; Construction Materials; Cyanobacteria; Mediterranean Region; Sculpture; Silicon Dioxide
PubMed: 19778965
DOI: 10.1099/mic.0.032508-0 -
The Journal of Biological Chemistry Apr 2018Cyanobacteria are photosynthetic prokaryotes showing great promise as biocatalysts for the direct conversion of CO into fuels, chemicals, and other value-added products.... (Review)
Review
Cyanobacteria are photosynthetic prokaryotes showing great promise as biocatalysts for the direct conversion of CO into fuels, chemicals, and other value-added products. Introduction of just a few heterologous genes can endow cyanobacteria with the ability to transform specific central metabolites into many end products. Recent engineering efforts have centered around harnessing the potential of these microbial biofactories for sustainable production of chemicals conventionally produced from fossil fuels. Here, we present an overview of the unique chemistry that cyanobacteria have been co-opted to perform. We highlight key lessons learned from these engineering efforts and discuss advantages and disadvantages of various approaches.
Topics: Biocatalysis; Biofuels; Biological Products; Cyanobacteria; Industrial Microbiology; Metabolic Engineering; Metabolic Flux Analysis; Photosynthesis
PubMed: 28972147
DOI: 10.1074/jbc.R117.815886