Novel Saccharomyces cerevisiae variants slow down the accumulation of staling aldehydes and improve beer shelf-life.

Beer quality generally diminishes over time as staling compounds accumulate through various oxidation reactions. Here, we show that refermentation, a traditional practice where Saccharomyces cerevisiae cells are added to beer prior to bottling, diminishes the accumulation of staling aldehydes. However, commonly used beer yeasts only show a limited lifespan in beer.

DprA is required for natural transformation and affects pilin variation in Neisseria gonorrhoeae.

Natural transformation is the main means of horizontal genetic exchange in the obligate human pathogen Neisseria gonorrhoeae and drives the spread of antibiotic resistance and virulence determinants. Transformation can be divided into four steps: (1) DNA binding, (2) DNA uptake, (3) DNA processing and (4) DNA recombination into the chromosome. The DNA processing enzyme DprA has been shown to shuttle incoming ssDNA to the recombination enzyme RecA during transformation in Bacillus subtilis and Streptococcus pneumoniae.

Genetic transformation of Neisseria gonorrhoeae shows a strand preference.

Natural transformation is the main means of horizontal genetic exchange in the obligate human pathogen Neisseria gonorrhoeae. Neisseria spp. have been shown to preferentially take up and transform their own DNA by recognizing a non-palindromic 10 or 12 nucleotide DNA uptake sequence (DUS10 or DUS12).

DNA uptake sequence-mediated enhancement of transformation in Neisseria gonorrhoeae is strain dependent.

Natural transformation is the main means of horizontal genetic exchange in the obligate human pathogen Neisseria gonorrhoeae. Neisseria spp. have been shown to preferentially take up and transform their own DNA by recognizing the nonpalindromic 10- or 12-nucleotide sequence 5'-ATGCCGTCTGAA-3' (additional semiconserved nucleotides are underlined), termed the DNA uptake sequence (DUS10 or DUS12).

Mismatch correction modulates mutation frequency and pilus phase and antigenic variation in Neisseria gonorrhoeae.

The mismatch correction (MMC) system repairs DNA mismatches and single nucleotide insertions or deletions postreplication. To test the functions of MMC in the obligate human pathogen Neisseria gonorrhoeae, homologues of the core MMC genes mutS and mutL were inactivated in strain FA1090. No mutH homologue was found in the FA1090 genome, suggesting that gonococcal MMC is not methyl directed.

ksgA mutations confer resistance to kasugamycin in Neisseria gonorrhoeae.

The aminoglycoside antibiotic kasugamycin (KSG) inhibits translation initiation and thus the growth of many bacteria. In this study, we tested the susceptibilities to KSG of 22 low-passage clinical isolates and 2 laboratory strains of Neisseria gonorrhoeae. Although the range of KSG minimum inhibitory concentrations (MICs) was narrow (seven-fold), clinical isolates and laboratory strains fell into three distinct classes of KSG sensitivity, susceptible, somewhat sensitive and resistant, with MICs of 30, 60-100 and 200 microg/mL, respectively.