In this study, we determined the presence of class 1 integron-integrase gene in culturable heterotrophic bacteria isolated from river water and sediment sampled upstream and downstream of a wastewater treatment plant effluent discharge. Moreover, we quantified intI1 and sulfonamide resistance genes (sul1 and sul2) in the water and sediment using qPCR. There was no correlation between the results from water and sediment samples, which suggests integron-containing bacteria are differentially retained in these two environmental compartments. The discharge of treated wastewater significantly increased the frequency of intI1 among culturable bacteria and the gene copy number in river water, and increased the number of sul1 genes in the sediment. We also observed seasonal differences in the frequency of the class 1 integron-integrase gene among culturable heterotrophs as well as intI1 copy number in water, but not in sediment. The results suggest that the abundance of class 1 integrons in aquatic habitat depends on anthropogenic pressure and environmental factors.
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http://dx.doi.org/10.1007/s00248-016-0843-4 | DOI Listing |
Sci Rep
January 2025
Department of Biology, Boston University, Boston, MA, USA.
Spatial changes in benthic community structure have been observed across natural gradients in deep-sea ecosystems, but these patterns remain under-sampled on seamounts. Here, we identify the spatial composition and distribution of coral and sponge taxa on four sides of a single central Pacific equatorial "model" seamount within the US EEZ surrounding the Howland and Baker unit of the Pacific Islands Heritage Marine National Monument. This seamount rises from 5,000 + m to mesophotic depths of 196 m, and is influenced by the Equatorial Undercurrent.
View Article and Find Full Text PDFEnviron Pollut
January 2025
School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China. Electronic address:
The soils/sediments organic carbon sorption coefficient (K) of organic substances is one of the indispensable environmental behavioral parameters in chemicals management. Because the test procedure used to measure K is normally expensive and time-consuming, predictive methods are considered vitally important technology to fill the data gap of K. In this study, quantitative structure-property relationship (QSPR) models are developed using a data set with 1477 experimental logK values and seven typical machine learning algorithms.
View Article and Find Full Text PDFEnviron Res
January 2025
Southern California Coastal Water Research Project, Costa Mesa, CA, 92626.
The concentration, character, and distribution of microplastics in coastal marine environments remain poorly understood, with most research focusing on the abundance of microplastics at the sea surface. To address this gap, we conducted one of the first comprehensive assessments of microplastic distribution through the marine water column and in the benthic sediment during the wet and dry season in the coastal waters of the San Pedro Shelf, Southern California, USA. Microplastic concentrations in the water column did not vary significantly across season but were significantly higher in nearshore environments and at the surface of the water column.
View Article and Find Full Text PDFMar Pollut Bull
January 2025
Facultad de Pesquería, Universidad Nacional Agraria La Molina, Av. La Molina S/N, La Molina, Lima 15024, Peru.
Paracas Bay, located in the Humboldt Current system, is a highly variable coastal environment where hypoxia (dissolved oxygen concentrations <2 mg L) has been reported as a persistent feature of bottom conditions. In addition to hypoxia, milky water events have been reported in the bay, most likely associated with the presence of sulfides (i.e.
View Article and Find Full Text PDFMar Pollut Bull
January 2025
State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China.
Investigations of the spatial-temporal variations of nutrients within mangrove coastal zones are essential for assessing the environmental status of an aquatic ecosystems. However, major processes controlling nitrate cycle along the submarine groundwater discharge (SGD) pathway from the mangrove areas to adjacent tidal creek remain underexplored. A time series measurement over a 25 h tidal cycle was conducted in Qinglan Bay tidal creek (Hainan Island, China).
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