Plasma membrane Mg2+, Ca2+ ATPases were isolated from Dunaliella parva by differential centrifugation and subsequent sucrose gradient centrifugation and analyzed for their properties with special emphasis on ecophysiological requirements of this extremely salt-tolerant alga. Most properties (Vmaxand AfM-values, substrate specificity, vanadate and DES sensitivity, resistance against ouabain) ind...

A group IC1 intron occurs in nuclear small-subunit (18S) ribosomal RNA (SSU rRNA) genes of the marine red alga Porphyra spiralis var. amplifolia. This intron occurs at the same position as the self-splicing group IC1 introns in nuclear SSU rDNAs of the fungus Pneumocystis carinii and in the green alga Chlorella ellipsoidea and shares sequence identity with the Pneumocystis carinii intron in dom...

In the unicellularly growing green alga Scenedesmus acutus, the formation of many-celled coenobia may be induced by an infochemical released by the grazer Daphnia magna. We used a standardized bioassay to obtain information about the release of the infochemical by actively feeding D.magna and its chemical nature. The infochemical could not be extracted from the alga or the grazer by aqueous or ...

Carbonic anhydrases (CAs) are metalloenzymes that are omnipresent in nature. CAs catalyze the basic reaction of the reversible hydration of CO₂ to HCO₃- and H⁺ in all living organisms. Photosynthetic organisms contain six evolutionarily different classes of CAs, which are namely: α-CAs, β-CAs, γ-CAs, δ-CAs, ζ-CAs, and θ-CAs. Many of the photosynthetic organisms contain multiple isoforms of each...

The onset of anaerobiosis in darkened, N-limited cells of the green alga Selenastrum minutum (Naeg.) Collins elicited the following metabolic responses. There was a rapid decrease in energy charge from 0.85 to a stable lower value of 0.6 accompanied by rapid increases in pyruvate/phosphoenolpyruvate and fructose-1,6-bisphosphate/fructose-6-phosphate ratios indicating activation of pyruvate kina...

The Trypanosomatidae is closely related to euglenids that harbor plastids acquired from a green alga via secondary endosymbiosis. This discovery led to the idea that trypanosomatid parasites contained a green alga-derived plastid in their evolutionary past, an evolutionary scenario that was criticized based on the rarity of plant/plastid/cyanobacterium-like genes in the completely sequenced gen...

Symbioses between sponges and algae are abundant in the nutrient-poor waters of tropical reefs, yet very little is known of the nutritional interactions that may promote this abundance. We measured nitrogen flux between the sponge Haliclona cymiformis and its symbiotic partner, the rhodophyte Ceratodictyon spongiosum, and assessed the potential importance of this flux to the symbiosis. While th...

Although some alginate lyases have been isolated from marine bacteria, alginate lyases-excreting bacteria from the Arctic alga have not yet been investigated. Here, the diversity of the bacteria associated with the brown alga Laminaria from the Arctic Ocean was investigated for the first time. Sixty five strains belonging to nine genera were recovered from six Laminaria samples, in which Psychr...

In this study, the ability of red alga (Palmaria palmata) and beer draff (brewery waste) for Cu(II) removal was investigated. The influence of factors, such as pH, initial copper concentrations, and contact time, were also studied. Results showed the adsorption process was strongly dependent on the pH value and initial concentration. The optimum pH value was in the range of 5-6. The Langmuir is...

This study investigated the uptake and effects of a common human pharmaceutical, propranolol, on the structure and function of a coastal Baltic Sea model community consisting of macroalga (Ceramium tenuicorne), mussels (Mytilus edulis trossulus), amphipods (Gammarus spp.), water and sediment. The most sensitive species, the mussel, was affected to the same extent as in previous single species s...