The Multiple DSF-family QS Signals are Synthesized from Carbohydrate and Branched-chain Amino Acids via the FAS Elongation Cycle

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript. Members of the diffusible signal factor (DSF) family are a novel class of quorum sensing (QS) signals in diverse Gram-negative bacteria. Although previous studies have identified RpfF as a key enzyme for the biosynthesis of DSF family signals, many questions in their biosynthesis remain to be addressed. In this study with the phytopathogen Xanthomonas campestris pv. campestris (Xcc), we show that Xcc produces four DSF-family signals (DSF, BDSF, CDSF and IDSF) during cell culture and that IDSF is a new functional signal characterized as cis-10-methyl-2-dodecenoic acid. Using a range of defined media, we further demonstrate that Xcc mainly produces BDSF in the presence of carbohydrates; leucine and valine are the primary precursor for DSF biosynthesis; isoleucine is the primary precursor for IDSF biosynthesis. Furthermore, our biochemical analyses show ...

Formerly known as the “Thermowand,” the Lavatools Javelin thermometer is designed to produce readings within four

Formerly known as the “Thermowand,” the Lavatools Javelin thermometer is designed to produce readings within four seconds with an accuracy of ±0.9 degrees Fahrenheit or better with a range of -40 to 482 degrees. The accuracy improves the closer the item you are measuring is to room temperature. The food-grade tapered probe is 2.75 inches long and made of 18/8 stainless steel. The device is covered with an anti-microbial coating to prevent bacterial growth. The Javelin is available in six colors, including chipotle, butter, sesame, and indigo. It runs on one CR2032 3V battery for at least 4,000 hours of continuous use. Lavatools backs this product with a lifetime warranty. Wired found it takes only 4-6 seconds to return a stable temperature and the reviewers liked that it is inexpensive. However, the testers didn’t like the short probe length and that the range topped out at 482 degrees. Serious Eats compared this thermometer to the ThermoPop from ThermoWorks and found the Lavatools thermometer has the edge when it comes to cooking thinner cuts of meat but can’t reach the center of large roasts like the ThermoPop can. The Lavatools PT12 Javelin Digital In...