Ultra-tiny bacteria (Introduction)

by David Turell , Tuesday, March 03, 2015, 19:29 (3552 days ago)

By using tiny filtration pores, ultra-tiny bacteria have been found. Their incomplete genomes suggest they depend on other bacteria to complete their metabolism:-http://www.pnas.org/content/early/2015/02/18/1420955112.long-"To concentrate these cells in a sample, they filtered groundwater collected at Rifle, Colorado through successively smaller filters, down to 0.2 microns, which is the size used to sterilize water. The resulting samples were anything but sterile. They were enriched with incredibly tiny microbes, which were flash frozen to -272 degrees Celsius in a first-of-its-kind portable version of a device called a cryo plunger. This ensured the microbes weren't damaged in their journey from the field to the lab.-"The frozen samples were transported to Berkeley Lab, where Luef, with the help of Luis Comolli of Berkeley Lab's Life Sciences Division, characterized the cells' size and internal structure using 2-D and 3-D cryogenic transmission electron microscopy. The images also revealed dividing cells, indicating the bacteria were healthy and not starved to an abnormally small size.-"The bacteria's genomes were sequenced at the Joint Genome Institute, a DOE Office of Science User Facility located in Walnut Creek, California, under the guidance of Susannah Tringe. The genomes were about one million base pairs in length. In addition, metagenomic and other DNA-based analyses of the samples were conducted at UC Berkeley, which found a diverse range of bacteria from WWE3, OP11, and OD1 phyla.-"This combination of innovative fieldwork and state-of-the-art microscopy and genomic analysis yielded the most complete description of ultra-small bacteria to date.-"Among their findings: Some of the bacteria have thread-like appendages, called pili, which could serve as "life support" connections to other microbes. The genomic data indicates the bacteria lack many basic functions, so they likely rely on a community of microbes for critical resources.-"The scientists also discovered just how much there is yet to learn about ultra-small life.-"'We don't know the function of half the genes we found in the organisms from these three phyla," says Banfield."