The microbial biology of West Marin waste (Point Reyes Light, 04.16.2009)


craptrap-1vacuumCow waste from Straus Family Creamery and human sewage from a Marshall manhole could help scientists develop better tests for the presence of harmful pathogens. Last month, Lawrence Berkeley National Laboratory postdocs Eric Dubinsky and Cindy Wu, assisted by Shariff Osman, conducted a census of poo microbes. Cattle and septic wastes were separately loaded into diffusion chambers—with semi-permeable membranes keeping bacteria in while allowing water and minerals in and out. The chambers were hung inside crab traps  (left top) and submerged into Walker Creek at Gale Ranch (below) and Tomales Bay by Nick’s Cove (above). At various time intervals, large syringes extracted the diluted wastes, which were then filtered under vacuum (left bottom) to concentrate bacteria onto disks and frozen on dry ice. Their DNA will be placed onto the PhyloChip—a new gadget developed by Gary Andersen that differentiates between 32,000 bacteria types. Current water quality tests don’t discriminate between contamination sources, leading to unnecessary beach closures and ranch restrictions. The team will determine which bacteria are unique to humans and which are unique to agriculture, and how those bacteria react in fresh versus salt water over time. Using that information, they hope to formulate a suite of indicator microbes that can accurately assess water safety.



~ by Janet Fang on April 16, 2009.

One Response to “The microbial biology of West Marin waste (Point Reyes Light, 04.16.2009)”

  1. What a crappy job

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