Functional potential and assembly of microbes from sediments in a lake bay and adjoining river ecosystem for polycyclic aromatic hydrocarbon biodegradation

Abstract

Summary Lake and adjoining river ecosystems are ecologically and economically valuable and are heavily threatened by anthropogenic activities. Determining the inherent capacity of ecosystems for polycyclic aromatic hydrocarbon (PAH) biodegradation can help quantify environmental impacts on the functioning of ecosystems, especially on that of the microbial community. Here, PAH biodegradation potential was compared between sediments collected from a lake bay (LS) and an adjoining river (RS) ecosystem. Microbial community composition, function, and their co‐occurrence patterns were also explored. In the RS, the biodegradation rates (KD) of pyrene or PAH were almost two orders of magnitude higher than those in the LS. Sediment functional community structure and network interactions were dramatically different between the LS and RS. Although PAH degradation genes (p450aro, quinoline, and qorl) were detected in the LS, the community activity of these genes needed to be biostimulated for accelerated bioremediation. In contrast, functional communities in the RS were capable of spontaneous natural attenuation of PAH. The degradation of PAH in the RS also required coordinated response of the complex functional community. Taken together, elucidating functions and network interactions in sediment microbial communities and their responses to environmental changes are very important for the bioremediation of anthropogenic toxic contaminants.

Polycyclic Aromatic Hydrocarbons in Sediments from Typical Algae, Macrophyte Lake Bay and Adjoining River of Taihu Lake, China: Distribution, Sources, and Risk Assessment

“…This may be due to the denser population on both sides of the adjoining river of Taihu Lake in Dongshan Town, which was more affected by residential activities (fossil fuel, wood, and coal combustion) and industrial emissions (diesel and gasoline combustion). In addition, the average concentration of PAHs in sediments from the adjoining river was nearly three times (P = 0.026 < 0.05) than those of the macrophyte, algae lake bay, which was due to river ecosystems supporting numerous human activities, such as human infrastructure around a river that exert considerable anthropogenic pressure [1,2]. Pollution entered the river at many different locations (point source of PAHs) along the length of the river.…”

“…Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants that are prevalent in the environment, which could be transported to the lakes and rivers through surface runoff, sewage discharge, atmospheric deposition, and some other means, such as oil leaks [1][2][3][4]. PAHs entering the water body are easily adsorbed on the particles and tend to accumulate in the sediments [5].…”

Functional redundancy in response to runoff input upholds microbial community in hydrocarbon-contaminated land-sea continuum

“…von Netzer et al, 2016), but information in the context of coalescence is lacking. However, the microbial communities inhabiting the land-sea continuum play a pivotal role in determining the fate of pollutants (Bauer et al, 2013;Duran and Cravo-Laureau, 2016), involving microbial network interactions, which are probably affected by terrigenous inputs (Yan et al, 2021). It has been shown that different metabolic groups, ensuring not only degradation functions but also involved in biogeochemical cycles (Roling and van Bodegom, 2014), compose HC degrading microbial communities.…”

“…DNA-array provides the opportunity to follow easily the microbial community functional dynamics that could be useful to monitor the effect of coalescence event. This approach, used in environmental continuum, has provided contrasted results showing either the stability (Avila-Jimenez et al, 2020) or the vulnerability (Yan et al, 2021) of the functional microbial network. To the best of our knowledge, such studies on the functional diversity and the functional networks are still missing within the land-sea continuum.…”

Anthropogenic activities change the relationship between microbial community taxonomic composition and functional attributes

“…Planktonic microbial communities are one of the most important components in aquatic ecosystems (Wang et al ., 2015; Ortiz‐Álvarez et al ., 2020). To date, many previous studies suggest that anthropogenic activities associate with chemical pollutants and excessive nutrients have profound effects on planktonic microbial community composition and functional attributes (Liu et al ., 2019; Pan et al ., 2019; Yan et al ., 2021). However, few studies have considered multiple functional attributes of microbial communities after anthropogenic activity disturbance using a metagenomic approach.…”