Current knowledge and recent advances in understanding metabolism of the model cyanobacterium Synechocystis sp. PCC 6803

Cyanobacteria are key organisms in the global ecosystem, useful models for studying metabolic and physiological processes conserved in photosynthetic organisms, and potential renewable platforms for production of chemicals. Characterising cyanobacterial metabolism and physiology is key to understanding their role in the environment and unlocking their potential for biotechnology applications. Many aspects of cyanobacterial biology differ from heterotrophic bacteria. For example, most cyanobacteria incorporate a series of internal thylakoid membranes where both oxygenic photosynthesis and respiration occur, while CO2 fixation takes place in specialised compartments termed carboxysomes. In this review, we provide a comprehensive summary of our knowledge on cyanobacterial physiology and the pathways in Synechocystis sp. PCC 6803 (Synechocystis) involved in biosynthesis of sugar-based metabolites, amino acids, nucleotides, lipids, cofactors, vitamins, isoprenoids, pigments and cell wall components, in addition to the proteins involved in metabolite transport. While some pathways are conserved between model cyanobacteria, such as Synechocystis, and model heterotrophic bacteria like Escherichia coli, many enzymes and/or pathways involved in the biosynthesis of key metabolites in cyanobacteria have not been completely characterised. These include pathways required for biosynthesis of chorismate and membrane lipids, nucleotides, several amino acids, vitamins and cofactors, and isoprenoids such as plastoquinone, carotenoids, and tocopherols. Moreover, our understanding of photorespiration, lipopolysaccharide assembly and transport, and degradation of lipids, sucrose, most vitamins and amino acids, and heme, is incomplete. We discuss tools that may aid characterisation of cyanobacterial metabolism, notably CyanoSource, a barcoded library of targeted Synechocystis mutants, which will significantly accelerate characterisation of individual proteins

Literature Alive: Connecting to Story Through the Arts

How can I create \u27living\u27 experiences that will support my students to explore the \u27layers\u27 of meaning in a story? What type of learning activity supports students to build personal \u27connections\u27 with a story? We, along with language arts teachers, face these questions as we collaborate to develop literature studies. Our uncertainty seems to imply confusion as to whether we should emphasize story comprehension, reading skills, or a personal connection as the basis

Using Drama In The Classroom

Drama is a potentially powerful tool for connecting students with learning and content. We know that learning is an active, constructive process of coming to know. And through our classroom involvement with students, we have found that drama can provide a process for learning by living through or experiencing an event. Drama by its very nature involves students in social contexts where they are required to think, talk, manipulate concrete materials, and share viewpoints in order to arrive at decisions (Siks, 1983). Thus, through drama, students explore both factual knowledge and content concepts while trying on social experiences. Heathcote (cited in Johnson and O\u27Neill, 1984) believes that drama confronts students with situations that may change them because of the issues and challenges they must face in the dramatic playing

Cytochrome cM decreases photosynthesis under photomixotrophy in Synechocystis sp. PCC 6803

Photomixotrophy is a metabolic state that enables photosynthetic microorganisms to simultaneously perform photosynthesis and metabolism of imported organic carbon substrates. This process is complicated in cyanobacteria, since many, including Synechocystis sp. PCC 6803, conduct photosynthesis and respiration in an interlinked thylakoid membrane electron transport chain. Under photomixotrophy, the cell must therefore tightly regulate electron fluxes from photosynthetic and respiratory complexes. In this study, we demonstrate, via characterization of photosynthetic apparatus and the proteome, that photomixotrophic growth results in a gradual inhibition of QA- reoxidation in wild-type Synechocystis, which largely decreases photosynthesis over 3 d of growth. This process is circumvented by deleting the gene encoding cytochrome cM (CytM), a cryptic c-type heme protein widespread in cyanobacteria. The ΔCytM strain maintained active photosynthesis over the 3-d period, demonstrated by high photosynthetic O2 and CO2 fluxes and effective yields of PSI and PSII. Overall, this resulted in a higher growth rate compared to that of the wild type, which was maintained by accumulation of proteins involved in phosphate and metal uptake, and cofactor biosynthetic enzymes. While the exact role of CytM has not been determined, a mutant deficient in the thylakoid-localized respiratory terminal oxidases and CytM (ΔCox/Cyd/CytM) displayed a phenotype similar to that of ΔCytM under photomixotrophy. This, in combination with other physiological data, and in contrast to a previous hypothesis, suggests that CytM does not transfer electrons to these complexes. In summary, our data suggest that CytM may have a regulatory role in photomixotrophy by modulating the photosynthetic capacity of cells

Photosynthetic, respiratory and extracellular electron transport pathways in cyanobacteria.

Cyanobacteria have evolved elaborate electron transport pathways to carry out photosynthesis and respiration, and to dissipate excess energy in order to limit cellular damage. Our understanding of the complexity of these systems and their role in allowing cyanobacteria to cope with varying environmental conditions is rapidly improving, but many questions remain. We summarize current knowledge of cyanobacterial electron transport pathways, including the possible roles of alternative pathways in photoprotection. We describe extracellular electron transport, which is as yet poorly understood. Biological photovoltaic devices, which measure electron output from cells, and which have been proposed as possible means of renewable energy generation, may be valuable tools in understanding cyanobacterial electron transfer pathways, and enhanced understanding of electron transfer may allow improvements in the efficiency of power output. This article is part of a Special Issue entitled Organization and dynamics of bioenergetic systems in bacteria, edited by Conrad Mullineaux.We are grateful to the Environmental Services Association Education Trust, EnAlgae (European Regional Development Fund: INTERREG IVB NEW programme), and the Department of Biotechnology, India, for financial support.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.bbabio.2015.10.00

Retreating to nature : rethinking 'therapeutic landscapes'

There is a long history of removing oneself from ‘society’ in order to recuperate or repair. This paper considers a yoga and massage retreat in Southern Spain, and what opportunities this retreat experience might offer for recuperation and the creation of healthy bodies. The paper positions ‘nature’ as an active participant, and as ‘enrolled’ in the experiences of the retreat as a ‘therapeutic landscape’, and questions how and what particular aspects of yoga practice (in intimate relation with place) give rise to therapeutic experiences

Effectively Reaching the Equine Community in Kentucky

Since 2009, Extension Specialists and County Extension Agents from the University of Kentucky in the Southeast United States have conducted an annual educational event; the Kentucky Equine Farm and Facilities Expo field-day. These annual field-days have provided practical, hands-on demonstrations and seminars for 135-250 members of the equine community per event. Participants have been a mix of horse owners in relation to farm size, number of horses and business vs. recreation. Many participants have not been previous consumers of Extension educational programming. One of the major draws of the Farm and Facility Expo field days has been the host sites, which have included various well-known Thoroughbred, Sport-Horse and Quarter Horse farms, with an increased number of participants observed when the event was held at well-known farms. Partnerships have been established with many equine related businesses, with over 30 companies displaying their products and services at the event. The educational programs at these events have been conducted by Extension Specialists, industry experts and Extension Agents and have included timely topics such as weed identification and control, vaccination protocols, farm safety, pasture management and renovation, rotational grazing, feeding and nutrition, fencing options, barn design, on-farm solar energy and many others. Post-event evaluations have been conducted and, of the more than 2,400 persons who attended these events, 84.25% of the respondents have found the information presented useful in the management of their horse operation, 78.5% planned to make at least one change in their horse operation and 90% were very satisfied with the event

Emerging Species and Genome Editing Tools: Future Prospects in Cyanobacterial Synthetic Biology

Recent advances in synthetic biology and an emerging algal biotechnology market have spurred a prolific increase in the availability of molecular tools for cyanobacterial research. Nevertheless, work to date has focused primarily on only a small subset of model species, which arguably limits fundamental discovery and applied research towards wider commercialisation. Here, we review the requirements for uptake of new strains, including several recently characterised fast-growing species and promising non-model species. Furthermore, we discuss the potential applications of new techniques available for transformation, genetic engineering and regulation, including an up-to-date appraisal of current Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR associated protein (CRISPR/Cas) and CRISPR interference (CRISPRi) research in cyanobacteria. We also provide an overview of several exciting molecular tools that could be ported to cyanobacteria for more advanced metabolic engineering approaches (e.g., genetic circuit design). Lastly, we introduce a forthcoming mutant library for the model species Synechocystis sp. PCC 6803 that promises to provide a further powerful resource for the cyanobacterial research community