The lipopeptide, surfactin, is produced by Bacillus subtilis. A study has been made on large-scale production of this surfactant. A good yield was obtained from a glucose substrate fermentation by continuously removing the product by foam fractionation. The surfactin could be easily recovered from the collapsed foam by acid precipitation. The yield was also improved by the addition of either iron or manganese salts. Hydrocarbon addition to the medium, which normally increases biosurfactant production, completely inhibited surfactin production by B. subtilis.

No abstract

20 The CanMars Mars Sample Return Analogue Deployment (MSRAD) was a closely 21 simulated end-to-end Mars Sample Return (MSR) mission scenario, with instrumentation, goals, 22 and constraints modeled on the upcoming NASA Mars 2020 rover mission. The exercise utilized 23 the CSA Mars Exploration Science Rover (MESR) rover, deployed to Utah, USA, at a Mars-24 analogue field site. The principal features of the field site located near Green River, Utah, are 25 Late Jurassic inverted, fluvial paleochannels, analogous to features on Mars in sites being 26 considered for the ESA ExoMars rover mission and present within the chosen landing site for the 27 Mars 2020 rover mission. The in-simulation ("in-sim") mission operations team worked 28 remotely from The University of Western Ontario, Canada. A suite of MESR-integrated and 29 hand-held spectrometers was selected to mimic those of the Mars 2020 payload, and a Utah-30 to those of Mars rover landing sites, and in-depth field studies like CanMars as important, pre-48 mission strategic exercises. 49 50 Keywords: Mars, rover, analogue mission, sample return, mission operations 51 52 evidence for past life or its chemical precursors, and place detailed constraints on the past 64 habitability and the potential for preservation of the signs of life". A primary outcome of the 65CanMars analogue mission was the development of specific protocols and analytical approaches 66 geared at achieving the three highest priority MSR science sub-objectives identified by MEPAG; 67 namely: 1) Identify environments that were habitable in the past, and characterize conditions and 68 processes that may have influenced the degree or nature of habitability therein; 2) Assess the 69 potential of conditions and processes to have influenced preservation or degradation of 70 biosignatures and evidence of habitability, from the time of formation to the time of observation. 71