LS9 and Gevo are the two latest biofuel start-ups in Silicon Valley backed by venture capital firm Khosla Ventures.

LS9, of San Carlos, was first mentioned by the Mercury News after it launched recently. It is using synthetic biology to produce proprietary biofuels that resemble petroleum — but which are designed to be “renewable, clean, domestically produced, and cost competitive.”

It was founded in 2005 by Khosla Ventures, Flagship Ventures, along with two scientists, Chris Somerville, Director of the Carnegie Institution and Professor of Plant Biology at Stanford University, and George Church, Director of the MIT-Harvard US-Dept. of Energy GTL Center and Professor of Genetics at Harvard. More details on the company’s site.

As for Gevo, of Pasadena, Calif., VentureWire reported on the company today (sub required), citing information from Khosla Ventures’ web site. Chief Scientific Officer Doug Cameron has taken a seat on the company’s board. Cameron is also on the board of LS9 Inc.

Not much is known about the secretive company, other than it has strong ties to the California Institute of Technology:

Among its staff is Marco Landwehr, a member of the Frances H. Arnold Research Group at Caltech, and Andrew Hawkins, a scientist with Caltech ties, who did post-doctoral work with Caltech Associate Professor of Environmental Microbiology Jared Leadbetter.

VB's research team is studying web-personalization... Chime in here, and we’ll share the results.