Project description:The purpose of this study was to characterize carbon metabolism and gene regulation in Alicyclobacillus acidocaldarius during growth on wheat arabinoxylan and the effect of pentose and hexose sugars on gene expression Chemostat studies and global transcriptome analysis were used to accomplish this goal.
Project description:The purpose of this study was to characterize carbon metabolism and gene regulation in Alicyclobacillus acidocaldarius during growth on monosaccharides in an effort to determine whether carbon catabolite repression was active. Chemostat studies and global transcriptome analysis were used to accomplish this goal.
Project description:Sulfolobus acidocaldarius has been previously reported to grow on a broad range of sugars, but there is limited information on the ability of the organism to metabolize multiple sugars simultaneously. We report here the ability of S. acidocaldarius to utilize glucose and xylose simultaneously without di-auxie effect. The organism utilized a mixture of 1 g/L glucose and 1 g/L xylose with a growth rate of 0.079 h-1 compared to 0.074 h-1 and 0.22 h-1 when the organism was grown on xylose 2 g/L and 2 g/L glucose respectively as sole carbon sources. An increase in xylose concentration to 2 and 4 g/L in a medium containing 1 g/L glucose resulted in a growth rate of 0.082 and 0.085 h-1. However, increasing glucose concentration by 2 and 4 g/L when xylose concentration was maintained at 1 g/L decreased the growth rate to 0.062 and 0.052 h-1 respectively. S. acidocaldarius appeared to be utilizing the sugars at a rate roughly proportional to their concentration in the medium, resulting in complete utilization of these sugars at same time. The organism did not show preference for either glucose or xylose when it was grown on both sugars. Similar results were obtained with a combination of glucose, arabinose and galactose. These observations strongly suggest that S. acidocaldarius does not regulate utilization of the sugars tested herein using carbon catabolite repression (CCR) commonly found in most bacteria. The mechanism by which the organism utilized a mixture of sugar is yet to be elucidated. However, we were able to identify genes encoding for the putative glucose ABC transporters; but the putative xylose transporter was not identified. A study of S. acidocaldarius grown in glucose, xylose, or the two carbon sources combined in mid-log. Analyzed on Nimblegen 4-plex S. acidocaldarius DSM 639 array weblink: http://microbesonline.org/cgi-bin/microarray/viewExp.cgi?expId=1723
Project description:Sulfolobus acidocaldarius has been previously reported to grow on a broad range of sugars, but there is limited information on the ability of the organism to metabolize multiple sugars simultaneously. We report here the ability of S. acidocaldarius to utilize glucose and xylose simultaneously without di-auxie effect. The organism utilized a mixture of 1 g/L glucose and 1 g/L xylose with a growth rate of 0.079 h-1 compared to 0.074 h-1 and 0.22 h-1 when the organism was grown on xylose 2 g/L and 2 g/L glucose respectively as sole carbon sources. An increase in xylose concentration to 2 and 4 g/L in a medium containing 1 g/L glucose resulted in a growth rate of 0.082 and 0.085 h-1. However, increasing glucose concentration by 2 and 4 g/L when xylose concentration was maintained at 1 g/L decreased the growth rate to 0.062 and 0.052 h-1 respectively. S. acidocaldarius appeared to be utilizing the sugars at a rate roughly proportional to their concentration in the medium, resulting in complete utilization of these sugars at same time. The organism did not show preference for either glucose or xylose when it was grown on both sugars. Similar results were obtained with a combination of glucose, arabinose and galactose. These observations strongly suggest that S. acidocaldarius does not regulate utilization of the sugars tested herein using carbon catabolite repression (CCR) commonly found in most bacteria. The mechanism by which the organism utilized a mixture of sugar is yet to be elucidated. However, we were able to identify genes encoding for the putative glucose ABC transporters; but the putative xylose transporter was not identified.
