The cupA gene cluster of Pseudomonas aeruginosa encodes components and assembly factors of a putative fimbrial structure that enable this opportunistic pathogen to form biofilms on abiotic surfaces. In P. aeruginosa the control of cupA gene expression is complex, with the H-NS-like MvaT protein functioning to repress phase-variable (on/off) expression of the operon. Here we identify four positi...

Attempts to cultivate the virulent Treponema pallidum in the developing hen's egg have yielded no conclusive proof that reproduction has occurred in the embryo, but indicate rather that the spirochetes have merely survived for the periods involved (Calloway and Sharp, 1941). Wile and Snow (1941) and Wile and Johnson (1944) have shown approximately 25 per cent of inoculated embryos to be infecti...

Tuberculosis is a leading global killer that has not been effectively controlled to date. The ability of the causative agent, Mycobacterium tuberculosis, to become dormant is one of the major reasons for extended chemotherapeutic regimens and wide epidemicity. The underlying mechanisms of M. tuberculosis dormancy are not fully understood. In the present work, a LuxR family transcription factor ...

In two strains of fibroblasts originating from fragments of myocardium from a 5 day old rat of the Slonaker-Addis strain, a strain known to develop tumors but rarely, abnormal morphologic alterations took place which eventuated in neoplastic changes. This happened only after repeated exposure of the cultures to an atmosphere of nitrogen (anaerobiosis) and did not occur in the control cultures o...

BRACHET (1934,1950) has proposed that the oxidation source for the anaerobic development of the early amphibian embryo is primarily from a pool of materials such as oxidized glutathione. Inasmuch as an investigation of the defective lactate producing ability of hybrid embryos (Barth, 1946) was contemplated, it seemed desirable to reinvestigate the problem of the source of anaerobic oxidations i...

Five strains of Staphylococcus aureus were examined quantitatively for the production of nuclease under aerobic and anaerobic conditions. Hydrolysis of deoxyribonucleic acid and ribonucleic acid was detected by measuring the release of acidsoluble nucleotides spectrophotometrically. We found that the enzyme was produced anaerobically, as well as aerobically, and that anaerobiosis had no effect ...

The eukaryotic green alga, Chlamydomonas reinhardtii, produces H(2) under anaerobic conditions, in a reaction catalysed by an [FeFe]-hydrogenase. To identify genes that influence H(2) production in C. reinhardtii, a library of 6000 colonies on agar plates was screened with sensitive chemochromic H(2)-sensor films for clones defective in H(2) production. Two mutants of particular interest were f...

Yeast Saccharomyces cerevisiae is auxotrophic for ergosterol in the absence of oxygen. We showed that complex changes in esterification of exogenously supplied sterols were also induced by anaerobiosis. Utilization of oleic acid for sterol esterification was significantly impaired in anaerobic cells. Furthermore, anaerobic cells fed different sterols exhibited striking variation in esterificati...