Singlet oxygen-induced alteration of bacteria associated with phytodetritus: Effect of irradiance.

Contrasting irradiation of senescent cells of the diatom Thalassiosira sp. in association with the bacterium Pseudomonas stutzeri showed the effect of intensity of irradiance on the transfer of singlet oxygen ( O ) to bacteria attached to phytoplanktonic cells. Under low irradiances, O is produced slowly, favors the oxidation of algal unsaturated lipids (photodynamic effect), and limits O transfer to attached bacteria.

Forensic genetic identification of sharks involved in human attacks.

Each year, 75-100 unprovoked shark attacks on humans are recorded, most of them resulting in no or minor injuries, while a few are fatal. Often, shark identification responsible for attacks relies on visual observations or bite wound characteristics, which limits species determination and preclude individual identification. Here, we provide two genetic approaches to reliably identify species and/or individuals involved in shark attacks on humans based on a non-invasive DNA sampling (i.

Bacterial Bioluminescence: Light Emission in Is Not Under Quorum-Sensing Control.

Bacterial-bioluminescence regulation is often associated with quorum sensing. Indeed, many studies have been made on this subject and indicate that the expression of the light-emission-involved genes is density dependent. However, most of these studies have concerned two model species, and .

Hydrogen production by the hyperthermophilic bacterium part I: effects of sulfured nutriments, with thiosulfate as model, on hydrogen production and growth.

Background: and are hyperthermophile bacteria chosen by many research teams to produce bio-hydrogen because of their potential to ferment a wide variety of sugars with the highest theoretical H/glucose yields. However, to develop economically sustainable bio-processes, the culture medium formulation remained to be optimized. The main aim of this study was to quantify accurately and specifically the effect of thiosulfate, used as sulfured nutriment model, on growth, yields and productivities of hydrogen.

Hydrogen production by the hyperthermophilic bacterium Part II: modeling and experimental approaches for hydrogen production.

Background: is a hyperthermophilic bacterium known to produce hydrogen from a large variety of substrates. The aim of the present study is to propose a mathematical model incorporating kinetics of growth, consumption of substrates, product formations, and inhibition by hydrogen in order to predict hydrogen production depending on defined culture conditions.

Results: Our mathematical model, incorporating data concerning growth, substrates, and products, was developed to predict hydrogen production from batch fermentations of the hyperthermophilic bacterium, .