Human activities impact microbial communities of Amazon Mangroves

Abstract

Mangroves provide a unique ecological environment for complex microbial communities. They are particularly important in controlling the chemical environment of the ecosystem. Microbial diversity analyses of these ecosystems help us understand the environmental dynamics and the changes due to impacts. Amazonian mangroves are distributed across Amapa, Para and Maranhao states occupying an area of 9,000 km2 and correspond to 70% of the mangroves in Brazil, in which studies on microbial biodiversity are extremely rare. The present study aimed to determine changes in microbial community structure along the PA-458 highway that divided the mangrove. Mangrove samples were collected from three zones, (i) under anthropogenic actions, (ii) in the process of recovery and (ii) preserved. Total DNA was extracted, submitted for 16S rDNA amplification and sequenced on the Illumina MiSeq platform. Reads were analyzed using USEARCH tools and packages available in R Platform. The most abundant phyla were Proteobacteria, followed by Firmicutes and Bacteroidetes in all three mangrove locations. Genera such as Desulfuromonas, Desulfatiglans, Collinsella, Dorea, Dialister were not found in the impacted mangrove. The impacted mangrove proved to be ecologically different from other mangroves. Our results show that human impact in the mangrove areas has resulted in loss of biodiversity, caused by the construction of the PA-458 highway, reducing the support and maintenance of habitat life and the ecosystems resilience to disturbance.