8 Dissimilatory metal reducing bacteria (DMRB) are capable of reducing contaminants such as 9 Cr(VI), Se(VI) and U(VI) during respiration, a process that has a pronounced impact on the 10 mobility of these contaminants in surface and subsurface environments. DMRB can also 11 reduce Fe(III), most commonly associated with solid phase (hydr)oxide minerals such as 12 ferrihydrite, goethite, or hema...

The carbohydrate metabolism of the autotrophically grown blue-green alga, Tolypothrix tenuis, was studied. The alga respires glucose, fructose, galactose, and ribose. About 60% of the glucose consumed is converted by starved cells into a glucose polysaccharide. Glucose uptake and O(2) consumption are not inhibited by 0.01 m arsenite or by 0.005 m iodoacetamide. The distribution of (14)C in the ...

Plocamium cartilagineum is a common red alga on the benthos of Antarctica and can be a dominant understory species along the western Antarctic Peninsula. Algae from this region have been studied chemically, and like "P. cartilagineum" from other worldwide locations where it is common, it is rich in halogenated monoterpenes, some of which have been implicated as feeding deterrents toward sympatr...

The present paper was dealt with the qualitative and quantitative screening of some phytoconstituents of a blue green alga Aphanothece pallida (Kütz.) Rabengh. and in vitro antibacterial activity study of four various organic solvent extracts with different polarities (benzene, chloroform, acetone and methanol) of the same alga, collected from a pond of Diara of Hooghly district, West Bengal. T...

Cryptomonad algae acquired their plastids by the secondary endosymbiotic uptake of a eukaryotic red alga. Several other algal lineages acquired plastids through such an event [1], but cryptomonads are distinguished by the retention of a relic red algal nucleus, the nucleomorph [2]. The nucleomorph (and its absence in other lineages) can reveal a great deal about the process and history of endos...

Somatic cells of the multicellular alga Volvox carteri contain a visual rhodopsin that controls the organism's phototactic behavior via two independent photoreceptor currents. Here, we report the identification of an opsinlike gene, designated as volvoxopsin (vop). The encoded protein exhibits homologies to the opsin of the unicellular alga Chlamydomonas reinhardtii (chlamyopsin) and to the ent...

The unicellular green alga Haematococcus pluvialis is used as a biological production system for astaxanthin. It accumulates large amounts of this commercially interesting ketocarotenoid under a variety of environmental stresses. Here we report the identification and expression of three different beta-carotene ketolase genes (bkt) that are involved in the biosynthesis of astaxanthin in a single...

Algae include a diverse array of photosynthetic eukaryotes excluding land plants. Explaining the origin of algal plastids continues to be a major challenge in evolutionary biology. Current knowledge suggests that plastid primary endosymbiosis, in which a single-celled protist engulfs and "enslaves" a cyanobacterium, likely occurred once and resulted in the primordial alga. This eukaryote then g...

Extreme desiccation and irradiation increase the formation of reactive oxygen species in organisms. Lichens are highly resistant to potential damage, but it is not known whether biochemical interaction between their fungal and algal partners is involved in conferring stress tolerance. Here, we show that antioxidant and photoprotective mechanisms in the lichen Cladonia vulcani are more effective...