Giant Viruses of Amoeba Called Melting Pots of Microbial Evolution

The recently isolated Marseille virus, a giant virus from amoeba, contains a 368-kb genome, a minimum of 49 proteins, and its own messenger RNAs, according to Didier Raoult from the Universite de la Mediterranee in Marseille, France, and his collaborators there and at several U.S. institutions. Phylogenetic analysis indicates that this new virus is the prototype of a family of large DNA viruses of eukaryotes. The genome of the virus consists of amix of typical viral core genes and genes apparently from assorted eukaryotic hosts and their parasites or symbionts, both bacterial and viral. The results suggest that amoebae are "melting pots" of microbial evolution where diverse forms emerge, including giant viruses with complex gene repertoires, according to Raoult and his collaborators.


Small Genome of M. pneumoniae Belies Complex Functions

Despite having a highly compact genome and being considered a "simple" organism, the bacterial pathogen Mycoplasma pneumoniae lives a complex and independent life, getting by on a minimal medium containing a mere "19 essential nutrients," according to Peer Bork of the European Molecular Biology Laboratory in Heidelberg, Germany, Luis Serrano at Centre for Genomic Regulation Universitat Pompeu Fabra in Barcelona, Spain, and their collaborators. Thus, for example, this bacterial species contains noncoding RNAs and exon- and intronlike structures within transcriptional operons, allowing for gene regulation that rivals that of eukaryotes in terms of its complexity, the researchers point out. Moreover, its metabolic responses and adaptation strategies are "similar to more complex bacteria," suggesting that it may harbor "other, unknown regulatory mechanisms." Details appear in the 27 November 2009 Science.


HHS Reviewing Countermeasures; IOM Report Updates National Vaccine Plan

In December, Health and Human Services (HHS) Secretary Kathleen Sebelius announced a sweeping review of federal countermeasures approaches to public health threats, including bioterrorism. The ultimate goal is to develop a "modernized countermeasure production process where we have more promising discoveries, more advanced development, more robust manufacturing, better stockpiling, and more advanced distribution practices," she says. In a separate but related development in December, a panel of the Institute of Medicine (IOM) in Washington, D.C., issued a report identifying 18 priority areas for updating the National Vaccine Plan. They include devising a strategy to accelerate development of high-priority vaccines, expanding funding for safety research and monitoring, and implementing a national communications strategy to clarify the importance of vaccines and to bolster public confidence in them, according to Claire Broome of the Rollins School of Public Health at Emory University in Atlanta, Ga., who chaired the IOM committee. The IOM report, "Priorities for the National Vaccine Plan," is available online (http://www.nap.edu).


Steps toward Harnessing Photosynthetic Bacteria for Liquid Fuel

A genetically modified strain of the photosynthetic cyanobacterium Synechoccus elongatus efficiently uses carbon dioxide to produce isobutyraldehyde gas, which can be collected and readily converted into isobutanol, a liquid fuel that is a plausible substitute for gasoline, according to James Liao from the Henry Samueli School of Engineering and Applied Science at the University of California, Los Angeles (UCLA), and his collaborators. "This new approach avoids the need for biomass deconstruction, either in the case of cellulosic biomass or algal biomass, which is a major economic barrier for biofuel production," he says. Although such cells could produce isobutanol directly, the UCLA researchers call it "easier to use an existing and relatively inexpensive chemical catalysis process" for the gas-to-liquid final step. Details appear in the December 2009 Nature Biotechnology. Separately, trace amounts of nickel can be used to induce a genetically engineered version of cyanobacteria cells to "self-destruct" and thus release their contents on demand, according to Xinyao Liu and Roy Curtiss of the Biodesign Institute at Arizona State University in Tempe and their collaborators. "This system that we have developed is a means to a ‘green' recovery of materials not requiring energy-dependent physical or chemical processes," Curtiss says.