Heterocyst and akinete differentiation in cyanobacteria: a view toward cyanobacterial symbiosis

Singh, Pratika; Khan, Azmi; Srivastava, Amrita

doi:10.1016/b978-0-12-819311-2.00016-4

Cited by 11 publications

(9 citation statements)

References 151 publications

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“…According to data in the literature, in the absence of a nitrogen source in the culture medium, 5–10% of the cells of the filaments of nitrogen-fixing cyanobacteria differentiate into heterocysts within about 24 h [ 50 ]. Heterocysts supply the vegetative cells with fixed nitrogen and receive carbohydrates from them in return [ 51 , 52 ]. This mutual exchange of balanced nutrients is regulated at the gene level to ensure their optimal growth and adaptation for long-term survival.…”

Section: Discussionmentioning

confidence: 99%

Influence of Mo and Fe on Photosynthetic and Nitrogenase Activities of Nitrogen-Fixing Cyanobacteria under Nitrogen Starvation

Sadvakasova

Kossalbayev

Token

et al. 2022

Cells

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The potential of cyanobacteria to perform a variety of distinct roles vital for the biosphere, including nutrient cycling and environmental detoxification, drives interest in studying their biodiversity. Increasing soil erosion and the overuse of chemical fertilizers are global problems in developed countries. The option might be to switch to organic farming, which entails largely the use of biofertilisers. Cyanobacteria are prokaryotic, photosynthetic organisms with considerable potential, within agrobiotechnology, to produce biofertilisers. They contribute significantly to plant drought resistance and nitrogen enrichment in the soil. This study sought, isolated, and investigated nitrogen-fixing cyanobacterial strains in rice fields, and evaluated the effect of Mo and Fe on photosynthetic and nitrogenase activities under nitrogen starvation. Cyanobacterial isolates, isolated from rice paddies in Kazakhstan, were identified as Trichormus variabilis K-31 (MZ079356), Cylindrospermum badium J-8 (MZ079357), Nostoc sp. J-14 (MZ079360), Oscillatoria brevis SH-12 (MZ090011), and Tolypothrix tenuis J-1 (MZ079361). The study of the influence of various concentrations of Mo and Fe on photosynthetic and nitrogenase activities under conditions of nitrogen starvation revealed the optimal concentrations of metals that have a stimulating effect on the studied parameters.

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Section: Discussionmentioning

confidence: 99%

Influence of Mo and Fe on Photosynthetic and Nitrogenase Activities of Nitrogen-Fixing Cyanobacteria under Nitrogen Starvation

Sadvakasova

Kossalbayev

Token

et al. 2022

Cells

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“…When comparing the vegetative cells and spores produced by these organisms, the only shared characteristic that could be identified was the enlargement of the cell envelope in spores. Although the reduction in cell size is characteristic of endospores, exospores, myxospores and cysts, this was not the case for akinetes, in which enlargement is a recognized feature [28, 60]. While the CEMOVIS images revealed significant structural changes in the cell envelope, common structural components in all spore types were absent.…”

Section: Discussionmentioning

confidence: 99%

Multiple roads lead to Rome: unique morphology and chemistry of endospores, exospores, myxospores, cysts and akinetes in bacteria

et al. 2023

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The production of specialized resting cells is a remarkable survival strategy developed by many organisms to withstand unfavourable environmental factors such as nutrient depletion or other changes in abiotic and/or biotic conditions. Five bacterial taxa are recognized to form specialized resting cells: Firmicutes, forming endospores; Actinobacteria, forming exospores; Cyanobacteria, forming akinetes; the δ-Proteobacterial order Myxococcales, forming myxospores; and Azotobacteraceae, forming cysts. All these specialized resting cells are characterized by low-to-absent metabolic activity and higher resistance to environmental stress (desiccation, heat, starvation, etc.) when compared to vegetative cells. Given their similarity in function, we tested the potential existence of a universal morpho-chemical marker for identifying these specialized resting cells. After the production of endospores, exospores, akinetes and cysts in model organisms, we performed the first cross-species morphological and chemical comparison of bacterial sporulation. Cryo-electron microscopy of vitreous sections (CEMOVIS) was used to describe near-native morphology of the resting cells in comparison to the morphology of their respective vegetative cells. Resting cells shared a thicker cell envelope as their only common morphological feature. The chemical composition of the different specialized resting cells at the single-cell level was investigated using confocal Raman microspectroscopy. Our results show that the different specialized cells do not share a common chemical signature, but rather each group has a unique signature with a variable conservation of the signature of the vegetative cells. Additionally, we present the validation of Raman signatures associated with calcium dipicolinic acid (CaDPA) and their variation across individual cells to develop specific sorting thresholds for the isolation of endospores. This provides a proof of concept of the feasibility of isolating bacterial spores using a Raman-activated cell-sorting platform. This cross-species comparison and the current knowledge of genetic pathways inducing the formation of the resting cells highlights the complexity of this convergent evolutionary strategy promoting bacterial survival.

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“…Indeed, publications continue to refer to it erroneously as “unique to cyanobacteria”. 74 Füser and Steinbüchel 75 had already reported cyanophycin-metabolising genes from non-cyanobacteria strains in 2007, and of the non-redundant protein sequences currently available in databases, only ∼16% are cyanobacterial (Fig. 3).…”

Section: Cyanophycin and The Bacteria That Produce Itmentioning

confidence: 99%

Cyanophycin and its biosynthesis: not hot but very cool

2023

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Heterocyst and akinete differentiation in cyanobacteria: a view toward cyanobacterial symbiosis

Cited by 11 publications

References 151 publications

Influence of Mo and Fe on Photosynthetic and Nitrogenase Activities of Nitrogen-Fixing Cyanobacteria under Nitrogen Starvation

Influence of Mo and Fe on Photosynthetic and Nitrogenase Activities of Nitrogen-Fixing Cyanobacteria under Nitrogen Starvation

Multiple roads lead to Rome: unique morphology and chemistry of endospores, exospores, myxospores, cysts and akinetes in bacteria

Cyanophycin and its biosynthesis: not hot but very cool

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