TY - JOUR TI - Diversity of biodegradative gene populations in aquatic sediments examined by gene-targeted metagenomics DO - https://doi.org/doi:10.7282/T37943P3 PY - 2012 AB - Alkanes are common environmental pollutants in soil and water. The degradation of medium length n-alkanes is initiated under aerobic conditions by alkane monooxygenases which add one atom of molecular oxygen to the terminal carbon resulting in an alkanol product. Alkane monooxygenases fall into two distinct classes: the integral membrane bound AlkB family and the cytoplasmic cytochrome P450 family. Gene-targeted metagenomics was used to examine the microbial diversity and distribution of these two types of alkane monooxygenases in sediments in the United States and Central Asia. The Passaic River in Newark, New Jersey has a long history of industrial pollution making it an ideal site to study monooxygenase diversity. 16S rRNA and alkane monooxgyenase gene populations were analyzed by pyrosequencing to determine if sampling location on the river influenced the microbial community and if triplicate enrichments yield comparable results. Samples were collected at an arbitrary start point (0 meters) and at 10 and 1000 meters down the river. The replicates were similar to each other at two of the three sampling locations and differed slightly at 1000 meters. Sediments from rivers and streams in Central Asia were compared to determine if novel alkane monooxygenase families could be found in a largely unstudied geographic region. The 16S rRNA and monooxygenase gene communities recovered from sediment and enrichments originating from disparate environments with varied anthropogenic influence were compared by pyrosequencing. Novel alkane monooxygenase populations were recovered from sites in Central Asia and comparisons between sites showed that each population was distinct due to their distant geographic origins. The effect of salinity on alkane monooxygenase populations was examined in sediments obtained from Puerto Rico. Samples were collected from the Port of San Juan, an estuary, mangroves, and shore locations. Salinity was not the major determinant of alkane monooxygenase community composition in hexadecane enrichment cultures. The type of environment (mangrove compared to shore or port locations) had the greatest affect on the gene populations recovered. KW - Microbiology and Molecular Genetics KW - Alkanes KW - Microbial ecology KW - Biodegradation KW - Marine sediments LA - eng ER -