Microbial enrichment and gene functional categories revealed on the walls of a spent fuel pool of a nuclear power plant

Microorganisms developing in the liner of the spent fuel pool (SFP) and the fuel transfer channel (FTC) of a Nuclear Power Plant (NPP) can form high radiation resistant biofilms and cause corrosion. Due to difficulties and limitations to obtain large samples from SFP and FTC, cotton swabs were used to collect the biofilm from the wall of these installations. Molecular characterization was performed using massively parallel sequencing to obtain a taxonomic and functional gene classification. Also, samples from the drainage system were evaluated because microorganisms may travel over the 12-meter column of the pool water of the Brazilian Nuclear Power Plant (Angra1), which has been functioning since 1985. Regardless of the treatment of the pool water, our data reveal the unexpected presence of Fungi (Basidiomycota and Ascomycota) as the main contaminators of the SFP and FTC. Ustilaginomycetes (Basidiomycota) was the major class contributor (70%) in the SFP and FTC reflecting the little diversity in these sites; nevertheless, Proteobacteria, Actinobacteria, Firmicutes (Bacilli) were present in small proportions. Mapping total reads against six fungal reference genomes indicate that there is, in fact, a high abundance of fungal sequences in samples collected from SFP and FTC. Analysis of the ribosomal internal transcribed spacer (ITS) 1 and 2 regions and the protein found in the mitochondria of eukaryotic cells, cytochrome b (cytb) grouped our sample fungi in the clade 7 as Ustilago and Pseudozyma. In contrast, in the drainage system, Alphaproteobacteria were present in high abundances (55%). The presence of Sphingopyxis, Mesorhizobium, Erythrobacter, Sphingomonas, Novosphingobium, Sphingobium, Chelativorans, Oceanicaulis, Acidovorax, and Cyanobacteria was observed. Based on genomic annotation data, the assessment of the biological function found a higher proportion of protein-coding sequences related to respiration and protein metabolism in SFP and FTC samples. The knowledge of this biological inventory present in the system may contribute to further studies of potential microorganisms that might be useful for bioremediation of nuclear waste.

Analysis of the Appendicularia class (subphylum Urochordata) as a possible tool for biomonitoring four estuaries of the tropical region

This study aims to characterize the differences between physical and chemical parameters of water quality indicators and eutrophication in four estuaries of the state of Rio de Janeiro and relate them to full density of the species that belong to the Appendicularia class with the purpose of seeking bioindicators for estuarine areas. The estuaries studied were from the rivers Macaé, São João, Bracuí, and Perequê-Açu. The physicochemical parameters monitored for evaluation of the water bodies and used for the correlation with the appendicularians were pH, temperature, nitrite, nitrate, N-ammonia, total nitrogen, phosphate, total phosphorus, dissolved oxygen (DO), suspended particulate matter (SPM), chlorophyll a, heterotrophic bacteria, and fecal coliform. The estuaries Bracuí and São João showed enhanced qualities of water and lower degrees of eutrophication than Macae and Perequê-Açu estuaries. The species of the Appendicularia class found in this study were Oikopleura longicauda (Vogt, 1854), Oikopleura dioica Fol, 1872, Oikopleura fusiformis Fol, 1872, and Fritillaria haplostoma Fol, 1872. The density of appendicularians and O. longicauda was inversely related to the nutrient values and SPM; nonetheless, no species of appendicularians could be used as a bioindicator of any estuary in the current study. Studies on the quality of estuary waters and the search for other bioindicators belonging to other zooplankton groups are recommended to confirm the obtained results and to expand the knowledge of these coastal environments.

Global environmental changes: setting priorities for Latin American coastal habitats

As the effects of the Global Climate Changes on the costal regions of Central and South Americas advance, there is proportionally little research being made to understand such impacts. This commentary puts forward a series of propositions of strategies to improve performance of Central and South American science and policy making in order to cope with the future impacts of the Global Climate Changes in their coastal habitats.