김영훈

The roles of toxin-antitoxin (TA) systems in bacteria have been debated. Here, the role of five TA systems in regard to biofilm development was investigated (listed as toxin/antitoxin: MazF/MazE, RelE/RelB, ChpB, YoeB/YefM, and YafQ/DinJ). Although these multiple TA systems were reported previously to not impact bacterial fitness, we found that deletion of the five TA systems decreased biofilm formation initially (8 h) on three different surfaces and then increased biofilm formation (24 h) by de

Previously we identified that the Escherichia coli protein MqsR (YgiU) functions as a toxin and that it is involved in the regulation of motility by quorum sensing signal autoinducer-2 (AI-2). Furthermore, MqsR is directly associated with biofilm development and is linked to the development of persister cells. Here we show that MqsR and MqsA (YgiT) are a toxin/antitoxin (TA) pair, which, in significant difference to other TA pairs, regulates additional loci besides its own. We have recently iden

Although the immune response of Caenorhabditis elegans to microbial infections is well established, very little is known about the effects of health-promoting probiotic bacteria on evolutionarily conserved C. elegans host responses. We found that the probiotic Gram-positive bacterium Lactobacillus acidophilus NCFM is not harmful to C. elegans and that L. acidophilus NCFM is unable to colonize the C. elegans intestine. Conditioning with L. acidophilus NCFM significantly decreased the burden of a

The intestinal epithelial cell (IEC) layer of the intestinal tract makes direct contact with a number of microbiota communities, including bacteria known to have deleterious health effects. IECs possess innate protective strategies against pathogenic challenge, which primarily involve the formation of a physicochemical barrier. Intestinal tract mucins are principal components of the mucus layer on epithelial surfaces, and perform a protective function against microbial damage. However, little is

Osteoporosis is a systemic skeletal disease character-ized by low bone mass and micro-architectural dete-rioration of bone tissue, with a consequent increase in bone fragility and fracture susceptibility. In an aged so-ciety with increased life expectancy, the incidence rate of osteoporosis is also rapidly increasing. Inadequate nutrition may negatively influence bone metabolism. Recently, many studies have investigated the function-ality of milk-derived exosomes, which play important roles in c

This study characterizes the factors responsible for the cholesterol reduction by Lactobacillus acidophilus ATCC 43121. In addition, two-dimensional gel electrophoresis (2-DE) and protein profiling was also used to study the response of ATCC 43121 at the proteome level in the presence of cholesterol. The results show that the cell-free supernatant (CFS) produced by ATCC 43121 in the presence of bile salts could also reduce the cholesterol in the broth, whereas all previous reports have suggested

Although bacterial-fungal interactions shape microbial virulence during polymicrobial infections, only a limited number of studies have evaluated this interaction on a genetic level. We report here that one interaction is mediated by sopB, an effector of a type III secretion system (TTSS) of Salmonella enterica serovar Typhimurium. In these studies, we screened 10 TTSS effector-related mutants and determined their role in the killing of C. albicans filaments in vitro during coinfection in plankt

Nature Communications 6: Article number: 7451 (2015); Published: 16 June 2015; Updated: 22 October 2015 The original version of the Supplementary Information attached to this Article contained errors in the sequences of plasmids presented in Supplementary Note 1. The HTML has now been updated to include a corrected version of the Supplementary Information.

In this study, we investigated the relation of probiotic activity of <i>Lacticaseibacillus rhamnosus</i> strain GG (LGG) and expression of microRNA to immune response and longevity in <i>Caenorhabditis elegans</i> host model. First, we evaluated the survival rate of <i>C. elegans</i> due to LGG exposure and bacterial colonization in the intestine. Next, the expression of mRNA and miRNA was analyzed in <i>C. elegans</i> exposure to LGG for 24 h using microarray. After exposure to LGG to <i>C. ele

Dry aging has been widely applied for the aging of meat to produce a unique flavor and tenderness of meat. A number of microorganisms are present, forming a community with interactions that affect the meat aging process. However, their comprehensive compositions are still not well understood. In this study, we analyzed longitudinal changes in microbial and fungal communities in dry-aged beef using a metagenomic platform. 16S rRNA sequencing revealed that dry aging led to an increase in bacterial