Cyanobacteria are oxygenic phototrophic prokaryotes that have evolved to produce ultraviolet-screening mycosporine-like amino acids (MAAs) to lessen harmful effects from obligatory exposure to solar UV radiation. The cyanobacterial MAA biosynthetic cluster is formed by a gene encoding 2-epi-5-epi-valiolone synthase (EVS) located immediately upstream from an O-methyltransferase (OMT) encoding gene, which together biosynthesize the expected MAA precursor 4-deoxygadusol. Accordingly, these genes are typically absent in non-producers. In this study, the relationship between gene cluster architecture and constitutive production of MAAs was evaluated in cyanobacteria isolated from various Brazilian biomes. Constitutive production of MAAs was only detected in strains where genes formed a co-linear cluster. Expectedly, this production was enhanced upon exposure of the strains to UV irradiance and by using distinct culture media. Constitutive production of MAAs was not detected in all other strains and, unexpectedly, production could not be induced by exposure to UV irradiation or changing growth media. Other photoprotection strategies which might be employed by these MAA non-producing strains are discussed. The evolutionary and ecological significance of gene order conservation warrants closer experimentation, which may provide a first insight into regulatory interactions of genes encoding enzymes for MAA biosynthesis.

Free access databases of DNA sequences containing microbial genetic information have changed the way scientists look at the microbial world. Currently, the NCBI database includes about 516 distinct search results for Cyanobacterial genomes distributed in a taxonomy based on a polyphasic approach. While their classification and taxonomic relationships are widely used as is, recent proposals to alter their grouping include further exploring the relationship between Cyanobacteria and Melainabacteria. Nowadays, most cyanobacteria still are named under the Botanical Code; however, there is a proposal made by the Genome Taxonomy Database (GTDB) to harmonize cyanobacteria nomenclature with the other bacteria, an initiative to standardize microbial taxonomy based on genome phylogeny, in order to contribute to an overall better phylogenetic resolution of microbiota. Furthermore, the assembly level of the genomes and their geographical origin demonstrates some trends of cyanobacteria genomics on the scientific community, such as low availability of complete genomes and underexplored sampling locations. By describing how available cyanobacterial genomes from free‐access databases fit within different taxonomic classifications, this mini‐review provides a holistic view of the current knowledge of cyanobacteria and indicates some steps towards improving our efforts to create a more cohesive and inclusive classifying system, which can be greatly improved by using large‐scale sequencing and metagenomic techniques.

The effects of the absence of nitrogen and phosphorus on AA media and three different light intensities (100% Light, 60.0± 2.7 μmol m-2 s-1, 50% Light, 30.0± 2.7 μmol m-2 s-1, and 13.5% Light, 8.1± 2.7 μmol m-2 s-1) on cell production and synthesis of heterocytes and akinetes were determined in a strain of Nostoc paludosum. In the experiment concerning the absence of nutrients, significant variations were observed between the control group and the groups with absence of nutrients, especially in cell numbers and in synthesis of heterocytes and akinetes. The absence of nitrogen boosted the formation of heterocytes and the absence of phosphorus produced the most akinetes. As for the different light conditions, the growth curves determined for each treatment showed that cell synthesis is slightly affected by the reduction of illuminance. The different light intensities are capable of reducing the maximum growth rates of Nostoc paludosum, with 13.5% light restriction being the most effective on limiting the cell growth rate and inducing the formation of akinetes. The synthesis of heterocyte does not seem directly correlated to light intensity, being better explained by nutritional factors. The data found contributes to the understanding of some of the factors involving growth and synthesis of special structures in Nostoc paludosum.

Mycosporine-like amino acids (MAAs) are natural UV-absorbing sunscreens that evolved in cyanobacteria and algae to palliate harmful effects from obligatory exposure to solar radiation. Multiple lines of evidence prove that in cyanobacteria all MAAs are derived from mycosporine-glycine, which is typically modified by an ATP-dependent ligase encoded by the gene mysD. The function of the mysD ligase has been experimentally described but haphazardly named based solely upon sequence similarity to the d-alanine-d-alanine ligase of bacterial peptidoglycan biosynthesis. Combining phylogeny and alpha-fold tertiary protein structure prediction unambiguously distinguished mysD from d-alanine-d-alanine ligase. The renaming of mysD to mycosporine-glycine-amine ligase (MG-amine ligase) using recognised enzymology rules of nomenclature is, therefore, proposed, and considers relaxed specificity for several different amino acid substrates. The evolutionary and ecological context of MG-amine ligase catalysis merits wider appreciation especially when considering exploiting cyanobacteria for biotechnology, for example, producing mixtures of MAAs with enhanced optical or antioxidant properties.

A gestão de pessoas é uma área essencial nas organizações, pois o desempenho humano, que se baseia na capacitação e qualidade da condição de trabalho dos colaboradores, reflete a performance organizacional. Algumas condições especiais de trabalho, como o modelo remoto ou à distância mediado por Tecnologias de Informação e Comunicação (TIC), precisam de atenção especial por parte da gestão de pessoas para seu funcionamento. Nesse contexto, o objetivo deste estudo foi identificar o panorama geral sobre a modalidade de trabalho remoto, baseado na literatura e em estudo de caso único, para análise comparativa junto à uma empresa do setor de TIC e automação comercial, e entender como a gestão de pessoas atua diante do “home office”. A metodologia empregada possui abordagem qualitativa e método comparativo. Esta pesquisa apresentou alguns resultados principais, sendo: qualidades como foco e disciplina são essenciais para direcionar o colaborador para o trabalho remoto; as percepções de vantagens e desvantagens de trabalhadores no “home office” variam consideravelmente e dependem de fatores individuais como personalidade e experiência; somente por meio de comunicação ativa e “feedback” construtivo é possível evitar o isolamento pessoal e profissional sentido por uma parcela dos trabalhadores em regime remoto. Contudo, a principal e real contribuição deste estudo é a proposição de “framework” para guiar iniciativas de estabelecimento de trabalho remoto, evitando parte dos problemas mais comuns desse tipo de regime de trabalho.