Exploring the Nonconserved Sequence Space of Synthetic Expression Modules in Bacillus subtilis.

Increasing protein expression levels is a key step in the commercial production of enzymes. Predicting promoter activity and translation initiation efficiency based solely on consensus sequences have so far met with mixed results. Here, we addressed this challenge using a "brute-force" approach by designing and synthesizing a large combinatorial library comprising ∼12 000 unique synthetic expression modules (SEMs) for Bacillus subtilis.

Improved Xylose Metabolism by a Mutant of Saccharomyces cerevisiae.

Engineering for the utilization of pentose sugars is an important goal for the production of second-generation bioethanol and biochemicals. However, lacks specific pentose transporters, and in the presence of glucose, pentoses enter the cell inefficiently via endogenous hexose transporters (HXTs). By means of engineering, we have developed a quadruple hexokinase deletion mutant of that evolved into a strain that efficiently utilizes d-xylose in the presence of high d-glucose concentrations.

Cellular responses of Saccharomyces cerevisiae at near-zero growth rates: transcriptome analysis of anaerobic retentostat cultures.

Extremely low specific growth rates (below 0.01 h(-1) ) represent a largely unexplored area of microbial physiology. In this study, anaerobic, glucose-limited retentostats were used to analyse physiological and genome-wide transcriptional responses of Saccharomyces cerevisiae to cultivation at near-zero specific growth rates.

Extreme calorie restriction and energy source starvation in Saccharomyces cerevisiae represent distinct physiological states.

Cultivation methods used to investigate microbial calorie restriction often result in carbon and energy starvation. This study aims to dissect cellular responses to calorie restriction and starvation in Saccharomyces cerevisiae by using retentostat cultivation. In retentostats, cells are continuously supplied with a small, constant carbon and energy supply, sufficient for maintenance of cellular viability and integrity but insufficient for growth.

Quantitative physiology of Saccharomyces cerevisiae at near-zero specific growth rates.

Growth at near-zero specific growth rates is a largely unexplored area of yeast physiology. To investigate the physiology of Saccharomyces cerevisiae under these conditions, the effluent removal pipe of anaerobic, glucose-limited chemostat culture (dilution rate, 0.025 h(-1)) was fitted with a 0.