Metagenome Sequences from Tidal Marsh and Marine Sediment from the Great Bay Estuary of New Hampshire

Tidal marsh and estuarine marine microbial sediment metagenomes from the Great Bay Estuary of New Hampshire were sequenced and found to be dominated by Proteobacteria , Bacteroidetes , Firmicutes , and Actinobacteria. Both types of sediment contained many unclassified bacterial sequences, including the mollusk pathogen Perkinsus marinus , and detectable xenobiotic degradation and nitrogen transformation genes. </jats:p

Assessment of the petroleum hydrocarbon biodegradation potential of the sediment microbial community from an urban fringing tidal marsh of Northern New England

AbstractWe assessed the impact of dodecane,n-hexane and gasoline on the microbial diversity of chronically polluted fringing tidal marsh sediment from the Great Bay Estuary of New Hampshire. Dilution cultures containing saturated alkane concentrations were sampled at zero, one and 10 days, andalkBandcyp153A1alkane hydroxylase gene libraries and 16S rRNA sequences were analyzed. The initial sediment had the most diverse alkane hydroxylase sequences and phylogenetic composition whereas treated sediments became less functionally and phylogenetically diverse with alkane substrates apparently enriching a few dominant taxa. All 1-and 10-day samples were dominated byPseudomonas-type alkane hydroxylase sequences except in dodecane treatments where primarilyRhodococcus--type alkane hydroxylases were detected. 16S rRNA profiling revealed that the Gammaproteobacteria, particularlyPseudomonas, dominated all one day samples, especially then-hexane and gasoline treatments (63.2 and 47.2% respectively) and the 10-dayn-hexane treatment (which contained 60.8%Pseudomonasand 18.6%Marinobacter).In contrast, the 10 days of dodecane treatment enriched for Actinobacteria (26.2%Rhodococcusand 32.4%Mycobacterium)and gasoline treatment enriched for Firmicutes (29.7%; mainlyBacillus, LysinibacillusandRumelibacillus).Our data indicate that fringing tidal marshes contain microbial communities with alkane-degrading abilities similar to larger meadow marshes, and support the hypothesis that alkane exposure reduces the functional and phylogenetic diversity of microbial communities in an alkane-specific manner. Further research to evaluate the ability of such fringing marsh communities to rebound to pre-pollutant diversity levels should be conducted to better assess the threat of petroleum to these habitats.</jats:p

Fungal bioremediation of creosote-contaminated soil: A laboratory scale bioremediation study using indigenous soil fungi

The aim of the study is to determine the efficacy of indigenous soil fungi in removing (PAHs) from creosote-contaminated soil with a view to developing a bioremediation strategy for creosote-contaminated soil. Five fungal isolates, Cladosporium, Fusarium, Penicillium, Aspergillus and Pleurotus, were separately inoculated onto sterile barley grains and incubated in the dark. The colonized barley was inoculated onto creosote-contaminated (250 000 mg kg(-1)) soil in 18 duplicate treatments and incubated at 25 degrees C for seventy days. The soil was amended with nutrient supplements to give a C:N:P ratio of 25:5:1 and tilled weekly. Creosote removal was higher (between 78 and 94%) in nutrient supplemented treatments than in the un-supplemented ones (between 65 and 88%). A mixed population of fungi was more effective (94.1% in the nutrient amended treatment) in creosote removal than single populations wit a maximum of 88%. Barley supported better fungal growth and PAH removal. Pleurotus sp. removed the creosote more than the other isolates. Two and three-ring PAHs were more susceptible to removal than the 4- and 5-ring PAHs, which continued to remain in small amounts to the end of the treatment. Reduction of creosote in the present study was higher than was observed in an earlier experiment using a consortium of microorganisms, mainly bacteria, on the same contaminated soil (Atagana, 2003)