Coenzyme F420 has been assayed by high-performance liquid chromatography with fluorimetric detection; this permits quantification of individual coenzyme F420 analogs whilst avoiding the inclusion of interfering material. The total intracellular coenzyme F420 content of Methanosarcina barkeri MS cultivated on methanol and on H2-CO2 and of Methanosarcina mazei S-6 cultured on methanol remained re...

Evidence is presented that, in Methanosarcina barkeri oxaloacetate synthesis, an essential and major CO(2) fixation reaction is catalyzed by an apparent alpha(4)beta(4)-type acetyl coenzyme A-independent pyruvate carboxylase (PYC), composed of 64.2-kDa biotinylated and 52.9-kDa ATP-binding subunits. The purified enzyme was most active at 70 degrees C, insensitive to aspartate and glutamate, mil...

Hydrogen (H2) consumption and methane (CH4) production in pure cultures of three different methanogens were investigated during cultivation with 0, 0.2 and 4.21 μM added nickel (Ni). The results showed that the level of dissolved Ni in the anaerobic growth medium did not notably affect CH4 production in the cytochrome-free methanogenic species Methanobacterium bryantii and Methanoculleus bourge...

The adaptive canalization hypothesis predicts that highly fitness-relevant traits are canalized via past selection, resulting in low phenotypic plasticity and high robustness to environmental stress. Accordingly, we hypothesized that the level of phenotypic plasticity of male body size of the predatory mites Phytoseiulus persimilis (low plasticity) and Neoseiulus californicus (high plasticity) ...

BACKGROUND Prenatal or embryonic learning, behavioral change following experience made prior to birth, may have significant consequences for postnatal foraging behavior in a wide variety of animals, including mammals, birds, fish, amphibians, and molluscs. However, prenatal learning has not been previously shown in arthropods such as insects, spiders and mites. METHODOLOGY/PRINCIPAL FINDINGS ...

Introduction: Methanogens are obligate anaerobes that use molecular hydrogen as an energy source and carbon dioxide as a carbon source to produce methane. They are classified as Archaea and are found in many extreme environments, including hydrothermal vents, volcanoes, and also the human microflora. The current Martian atmosphere is low in pressure, very dry (hyper-arid), and high in radiation...

Functional and numerical responses of the predatory mite, Neoseiulus longispinosus (Evans) (Acari: Phytoseiidae) to the red spider mite, Oligonychus coffeae Nietner (Acari: Tetranychidae), infesting tea were determined in a laboratory on leaf discs. Prey consumption increased with increases in temperature and prey density. Handling time decreased and successful attack rate increased with increa...