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The cumulative effects of anthropogenic stress on freshwater ecosystems are becoming increasingly evident and worrisome. In lake sediments contaminated by heavy metals, the composition and structure of microbial communities can change and affect nutrient transformation and biogeochemical cycling of sediments. In this study, bacterial and archaeal communities of lake sediments under fish pressure contaminated with heavy metals were investigated by the Illumina MiSeq platform. Despite the similar content of most of the heavy metals in the lagoon sediments, we found that their microbial communities were different in diversity and composition. This difference would be determined by the resilience or tolerance of the microbial communities to the heavy metal enrichment gradient. Thirty-two different phyla and 66 different microbial classes were identified in sediment from the three lagoons studied. The highest percentages of contribution in the differentiation of microbial communities were presented by the classes Alphaproteobacteria (19.08%), Cyanophyceae (14.96%), Betaproteobacteria (9.01%) y Actinobacteria (7.55%). The bacteria that predominated in sediments with high levels of Cd and As were Deltaproteobacteria, Actinobacteria, Coriobacteriia, Nitrososphaeria and Acidobacteria (Pomacocha), Alphaproteobacteria, Chitinophagia, Nitrospira and Clostridia (Tipicocha) and Betaproteobacteria (Tranca Grande). Finally, the results allow us to expand the current knowledge of microbial diversity in lake sediments contaminated with heavy metals and to identify bioindicators taxa of environmental quality that can be used in the monitoring and control of heavy metal contamination.

This article contains data on the bacterial communities of lagoon sediments with fish potential in the Central Andes of Peru. The surface sediment samples were collected from four lagoons destined for continental water fish farming. DNA extraction was performed from 0.5 g of sample through the Presto™ Soil DNA Extraction Kit. Bacterial sequencing of the 16S rRNA amplicon was performed on the DNA extracted from the sediment. At least 36 Phyla bacteria were detected, the bacterial communities being dominated by Proteobacteria, Cyanobacteria, Actinobacteria, Firmicutes, Chloroflexi. These data can be used for predictive analysis to gain a better understanding of the dynamics of bacterial communities in environments under pressure from fish farming.

La presente investigación tuvo como objetivo detectar una proteína asociada a la necrosis hepatopancreática aguda (AHPND), en cultivos semi-intensivos en Ecuador. Se recolectaron camarones enfermos de tres camaroneras en la zona de Bellavista, provincia El Oro. Los hepatopáncreas fueron macerados y cultivados en medio TCBS y subcultivos en TSA y caldo LB. De las cepas bacterianas obtenidas, se extrajo las proteínas usando un kit comercial y se separaron mediante migración en gel SDS-PAGE. Estas fueron analizadas con un espectrómetro de masas MALDI TOF/TOF. La confirmación de las cepas se realizó mediante PCR utilizando cebadores TUMSAT-Vp3, que son específicos para detectar AHPND. Una de las cepas tuvo secuencias peptídicas similares a la de la proteína PirvpB, causante de AHPND, y fue identificada como perteneciente a Vibrio parahaemolyticus y portadora del gen que codifica PirvpB, por tanto, positiva para AHPND. Los resultados mostraron que es posible usar la espectrometría de masas MALDI TOF/TOF en la detección de proteínas asociadas a AHPND en el cultivo de camarón.