Total microbial activity and microbial composition of a mangrove sediment are reduced by oil pollution at a site in the Arabian Gulf

Abstract

In a study carried out to determine the effect of oil pollution on the microbiota of sediment associated with mangroves in the United Arab Emirates, sediment samples were collected from oil-polluted and nonpolluted mangrove sites. The levels of the total recoverable hydrocarbons and the polycyclic aromatic hydrocarbons assayed were noticeably higher in the polluted sediment. Microbial activity as measured by the hydrolysis of fluorescein diacetate and by the total populations of the culturable aerobic and anaerobic bacteria, streptomycete and non-streptomycete actinomycetes, and filamentous fungi and yeasts was significantly (P < 0.05) lower in the polluted than in the nonpolluted sediment. The estimated total aerobic and anaerobic hydrocarbon-utilizing bacteria were significantly (P < 0.05) higher in the polluted than in the nonpolluted sediments. Four days after the addition of the water-soluble fractions of the light Arabian crude oil to the nonpolluted sediment, at 10 different concentrations, there was a significant (P < 0.05) reduction (65%) in the microbial activity of the sediment compared with that of nonamended sediment. Concentrations of water-soluble fractions at 0.1% and above significantly and progressively reduced microbial activity, with total cessation of activity recorded at levels >50%. This study is the first to evaluate the effect of oil pollution on aerobic and anaerobic microbial flora of sediment of mangrove communities.

Marine coastal sediments microbial hydrocarbon degradation processes: contribution of experimental ecology in the omics’era

“…Over the past few years, field studies have been performed in marine sediments addressing the impact of oil on microbial communities, by following their organization and/or by characterizing their composition. In most cases this has been approached by spatial comparisons of contrasting contaminated and uncontaminated sites (El-Tarabily, 2002; Miralles et al, 2007, 2010); or sites with different oil contents (LaMontagne et al, 2004; Dias et al, 2011; Iannelli et al, 2012; Kimes et al, 2013). In this way, following the bacterial diversity of oil-polluted retention basin sediments from the Berre lagoon (France) through nine stations, we have demonstrated that bacterial community structure was associated with the gradient of oil contamination (Païssé et al, 2008).…”

18S rDNA Sequences from Microeukaryotes Reveal Oil Indicators in Mangrove Sediment

“…Changes in the weather, regional geomorphic shifts and anthropogenic impacts on coastal areas establish the taxonomic characteristics and spatial-temporal dynamics of their communities [12], strengthening the great potential of these organisms as bioindicators of environmental changes, which was already described by conventional tools for filamentous fungi [13], yeast [10], [13], [14], nematodes [15], [16] and ciliates [17] in estuaries. Despite these findings, no studies have evaluated the impact of oil on microeukaryotes in mangrove sediments using molecular techniques.…”

Different bacterial groups for biodegradation of three- and four-ring PAHs isolated from a Hong Kong mangrove sediment

“…strains were isolated to anthropogenic pollution. The sediments were rich in organic matter, iron and sulfide, and were sinks for many pollutants such as PAHs [16,17]. Ke et al [18] reported that mangrove sediments had extensive potential to degrade three-and four-ring PAHs.…”