An acute toxicity model was constructed on the basis of 901 chemicals tested for toxicity against the luminescent bacteria Vibrio fischeri (formerly Photobacterium phosphoreum, the Microtox test). The model was created using the Multiple Computer-Automated Structure Evaluation (M-CASE) program. The model can correctly predict acute toxicity for 92% of the compounds with an error averaging 0.55 ...

N-acylhomoserine lactone-dependent quorum sensing was first discovered in two luminescent marine bacteria, Vibrio fischeri and Vibrio harveyi. The LuxI/R system of V. fischeri is the paradigm of Gram-negative quorum-sensing systems; however, it is not found in all vibrios. A more complex quorum-sensing regulation is found in V. harveyi. Three parallel systems transmit signals via phosphorelays ...

There are few genera of butterflies that feed on cycads. Among them the genus Eumaeus (Lycaenidae) presents aposematic coloration in all its life stages. In this work we report for the first time the herbivory of young leaflets of Ceratozamia mexicana and Zamia fischeri (Zamiaceae) by caterpillars of E. childrenae in their natural habitat in the Huasteca region, Mexico.

Magnesium-dependent induction of Vibrio fischeri flagellar (Mif) biogenesis depends upon two diguanylate cyclases, suggesting an inhibitory role for cyclic di-GMP. Here, we report that cells defective for the sugar phosphotransferase system (PTS) exhibited a magnesium-independent phenotype similar to that of mutants of the Mif pathway. Unlike Mif mutants, PTS mutants also were hyperbioluminescent.

Recovery of Neosartorya fischeri ascospores subjected to a dry heat treatment (DHT) at 95 degrees C, 50% relative humidity (RH) for 60 minutes increased exponentially as the initial temperature of the recovery buffer increased. Different diluents were evaluated and the same recovery pattern was obtained when water or dilute buffers were used to recover the DHT spores. However, when glycerol was...

Aktif farmasötik bileşenlerin çevresel kalıntıları, riskler ve sağlık sorunları ile ilişkilidir. Bunların çevreye olan etkileri toplumsal bir endişe konusu haline gelmiştir. Bu çalışmada; flurbiprofen, naproksen Na, propranolol HCl, karbamazepin, azitromisin, doksisiklin klindamisin ilaç etken maddelerinin toksisiteleri Aliivibrio fischeri toksisite testi kullanılarak belirlenmiştir. deneyinde,...

Upon infection by pathogenic bacteria, production of reactive oxygen species (ROS) is part of the host organism's first line of defence. ROS damage a number of macromolecules, and in order to withstand such a harsh environment, the bacteria need to have well-functioning ROS scavenging and repair systems. Herein, MutT is an important nucleotide-pool sanitization enzyme, which degrades 8-oxo-dGTP...

The bioluminescence emitted by the marine bacterium Vibrio fischeri is a particularly striking result of individual microbial cells co-ordinating a group behaviour. The genes responsible for light production are principally regulated by the LuxR-LuxI quorum-sensing system. In addition to LuxR-LuxI, numerous other genetic elements and environmental conditions control bioluminescence production. ...

In this study, we demonstrated that the putative Vibrio fischeri rpoN gene, which encodes sigma(54), controls flagellar biogenesis, biofilm development, and bioluminescence. We also show that rpoN plays a requisite role initiating the symbiotic association of V. fischeri with juveniles of the squid Euprymna scolopes.