Structure of hydrocarbonoclastic nitrate-reducing bacterial communities in bioturbated coastal marine sediments

Abstract

The organisation of denitrifying microorganisms in oil-polluted bioturbated sediments was investigated in mesocosms under conditions as closer as possible to that observed in the environment. Molecular and culture-dependent approaches revealed that denitrifying Gammaproteobacteria were abundant in oil-polluted and bioturbated sediments suggesting that they may play a key role in hydrocarbon degradation in the environment. T-RFLP and gene libraries analyses targeting nirS gene showed that denitrifying microbial communities structure was slightly affected by either the addition of Hediste diversicolor or crude oil revealing the metabolic versatility of denitrifying microorganisms. From oil-polluted sediments, distinct denitrifying hydrocarbonoclastic bacterial consortia were obtained by enrichment cultures on high molecular weight polyaromatic hydrocarbons (PAHs) (dibenzothiophene, fluoranthene, pyrene and chrysene) under nitrate-reducing conditions. Interestingly, molecular characterisation of the consortia showed that the denitrifying communities obtained from oiled microcosms with addition of H. diversicolor were different to that observed without H. diversicolor addition, especially with fluoranthene and chrysene revealing the bacterial diversity involved in the degradation of these PAHs.

nirS-Encoding denitrifier community composition, distribution, and abundance along the coastal wetlands of China

“…Phylogenetic analysis showed that a large proportion of the unique OTUs matched with uncultured environmental nirS assemblages. The majority of the closely matched sequences in the GenBank were retrieved from sediment e n v i r o n m e n t s , i n c l u d i n g H a i h e R i v e r e s t u a r y (KC106788), Yangtze estuary (KF363218; EU236006; KM892169; EU235754) (Zhang et al 2014;Zheng et al 2015), Bahia del Tobari estuary (KC614247), San Francisco Bay estuary (GQ453730) (Mosier and Francis 2010), Bohai Gulf (JN257854), East Pacific sea (GU348415), coastal sea in France (KJ640012) (Stauffert et al 2014), as well as coastal regions in Baltic sea (DQ072204) (Hannig et al 2006) and the South Pacific (AJ811468) (Castro-Gonzalez et al 2005). The nirS gene sequences of cluster IX were closely related to the cultivated denitrifiers of Proteobacteria Pseudomonadales (CP000304) (90 % identity) (Yan et al 2008).…”

Substrates specialization in lipid compounds and hydrocarbons of Marinobacter genus

“…Ribosomal or denitrifying genes affiliated to the genus Marinobacter have been identified in oil spill simulation mesocosms with marine coastal sediment (Stauffert et al 2014), estuarine sediment (Gray et al 2011), or m a n g r o v e s e d i m e n t ( d o s S a n t o s e t a l . 2 0 11 ) .…”

Effect of Aloe Vera wastes on physico-chemical properties and microbiological activity in soils

“…Among toxic substances contained in aloin, polycyclic aromatic hydrocarbons (PAHs) are known by their harmful effect once in the ecosystem; they are one of the most common groups with known or potential toxic properties [8]. PAHs are a substantial threat to ecological function and soil biodiversity [9].The response of microbial communities to chronic inputs of PAHs [10,11,12] has received little attention compared to the effect of acute contaminations [13,14,15]. Indeed, previous studies demonstrated that PAH change bacterial communities structure and diversity [16,17,18].…”