Mangroves are considered biodiversity hotspots threatened by various anthropogenic tensors such as pollution, which affect the taxonomic and functional diversity of microorganisms and therefore the stability of the ecosystem. Despite metagenomic work, knowledge of gene expression in contaminated mangroves is limited. Our general objective was to characterize the metatranscriptome at the taxonomic and functional level of bacteria associated with nutrient cycling and xenobiotic degradation of a mangrove contaminated by wastewater from the Colombian Caribbean. Total RNA was extracted from three soil samples from a mangrove affected by sewage for the construction of the cDNA library, and sequencing by the Illumina HiSeq 4000 platform. We found a domain of the phylum Firmicutes and Proteobacteria, represented mainly by Bacillus and Desulfuromonas respectively. Functional annotation showed high gene expression in metabolic pathways related to carbohydrate metabolism and processing of genetic information. Regarding biogeochemical cycles, the highest transcriptional activity was found in the assimilation of formaldehyde (methane metabolism), dissimilatory nitrate reduction (nitrogen metabolism), and reduction of sulfate (sulfur metabolism), which indicates a predominance of anaerobic processes and, decomposition of organic matter. Benzoate degradation was the pathway with the highest transcriptional activity in the degradation of xenobiotics. The predominance of few taxonomics could indicate selection of taxonomic groups by wastewater, advanced ecosystem degradation and loss of ecosystem resilience future.

红树林被认为是受到各种人为张量（如污染）威胁的生物多样性热点，这会影响微生物的分类和功能多样性，进而影响生态系统的稳定性。尽管进行了宏基因组学研究，但是在受污染的红树林中基因表达的知识仍然有限。我们的总体目标是在细菌的分类和功能水平上表征与转录活性有关的转录组，该细菌与哥伦比亚加勒比海废水污染的红树林的养分循环和异源生物降解有关。从受污水影响的红树林的三个土壤样品中提取总RNA，以构建cDNA文库，并通过Illumina HiSeq 4000平台进行测序。我们发现了主要以芽孢杆菌为代表的菌纲和变形杆菌门域和Desulfuromonas。功能注释显示与碳水化合物代谢和遗传信息处理有关的代谢途径中的高基因表达。关于生物地球化学循环，在同化甲醛（甲烷代谢），异化硝酸盐还原（氮代谢）和硫酸盐还原（硫代谢）方面发现了最高的转录活性，这表明厌氧过程和有机物的分解占主导地位。 。苯甲酸酯降解是异源生物降解中具有最高转录活性的途径。少数生物分类学的优势可能表明，废水分类生物分类的选择，先进的生态系统退化和未来生态系统复原力的丧失。