Effect of salinity on scytonemin yield in endolithic cyanobacteria from the Atacama Desert.

Cyanobacteria inhabiting extreme environments constitute a promising source for natural products with biotechnological applications. However, they have not been studied in-depth for this purpose due to the difficulties in their isolation and mass culturing. The Atacama Desert suffers one of the highest solar irradiances that limits the presence of life on its hyperarid core to endolithic microbial communities supported by cyanobacteria as primary producers.

Morphological, molecular, and biochemical study of cyanobacteria from a eutrophic Algerian reservoir (Cheffia).

The cyanobacteria management in water bodies requires a deep knowledge of the community composition. Considering the reliable and thorough information provided by the polyphasic approach in cyanobacteria taxonomy, here we assess the cyanobacterial community structure of the Cheffia reservoir from Algeria. Cyanobacteria were identified on the basis of morphological traits and next-generation sequencing (NGS); toxins-related genes were localized in addition to the identification of toxins; temperature and nutrient level of water samples were also determined.

Microbial colonizers of microplastics in an Arctic freshwater lake.

Microplastics (MPs) have been found everywhere as they are easily transported between environmental compartments. Through their transport, MPs are quickly colonized by microorganisms; this microbial community is known as the plastisphere. Here, we characterized the plastisphere of three MPs, one biodegradable (PHB) and two non-biodegradables (HDPE and LDPE), deployed in an Arctic freshwater lake for eleven days.

Response of Endolithic Strains From the Polyextreme Atacama Desert to Light Radiation.

Cyanobacteria exposed to high solar radiation make use of a series of defense mechanisms, including avoidance, antioxidant systems, and the production of photoprotective compounds such as scytonemin. Two cyanobacterial strains of the genus from the Atacama Desert - which has one of the highest solar radiation levels on Earth- were examined to determine their capacity to protect themselves from direct photosynthetically active (PAR) and ultraviolet radiation (UVR): the UAM813 strain, originally isolated from a cryptoendolithic microhabitat within halite (NaCl), and UAM816 strain originally isolated from a chasmoendolithic microhabitat within calcite (CaCO). The oxidative stress induced by exposure to PAR or UVR + PAR was determined to observe their short-term response, as were the long-term scytonemin production, changes in metabolic activity and ultrastructural damage induced.

Unmasking the identity of toxigenic cyanobacteria driving a multi-toxin bloom by high-throughput sequencing of cyanotoxins genes and 16S rRNA metabarcoding.

Cyanobacterial harmful algal blooms (CyanoHABs) are complex communities that include coexisting toxic and non-toxic strains only distinguishable by genetic methods. This study shows a water-management oriented use of next generation sequencing (NGS) to specifically pinpoint toxigenic cyanobacteria within a bloom simultaneously containing three of the most widespread cyanotoxins (the hepatotoxins microcystins, MCs; and the neurotoxins anatoxin-a, ATX, and saxitoxins, STXs). The 2013 summer bloom in Rosarito reservoir (Spain) comprised 33 cyanobacterial OTUs based on 16S rRNA metabarcoding, 7 of which accounted for as much as 96.

Discovery of carotenoid red-shift in endolithic cyanobacteria from the Atacama Desert.

The biochemical responses of rock-inhabiting cyanobacteria towards native environmental stresses were observed in vivo in one of the Earth's most challenging extreme climatic environments. The cryptoendolithic cyanobacterial colonization, dominated by Chroococcidiopsis sp., was studied in an ignimbrite at a high altitude volcanic area in the Atacama Desert, Chile.

Toxicity at the Edge of Life: A Review on Cyanobacterial Toxins from Extreme Environments.

Cyanotoxins are secondary metabolites produced by cyanobacteria, of varied chemical nature and toxic effects. Although cyanobacteria thrive in all kinds of ecosystems on Earth even under very harsh conditions, current knowledge on cyanotoxin distribution is almost restricted to freshwaters from temperate latitudes. In this review, we bring to the forefront the presence of cyanotoxins in extreme environments.

Phylogeography of cylindrospermopsin and paralytic shellfish toxin-producing nostocales cyanobacteria from mediterranean europe (Spain).

Planktonic Nostocales cyanobacteria represent a challenge for microbiological research because of the wide range of cyanotoxins that they synthesize and their invasive behavior, which is presumably enhanced by global warming. To gain insight into the phylogeography of potentially toxic Nostocales from Mediterranean Europe, 31 strains of Anabaena (Anabaena crassa, A. lemmermannii, A.