Durvillaea antarctica was extracted with hot water and a sulfate containing polymer was obtained after separation of laminaran and alginic acid with cetrimide and 2% calcium chloride solutions, respectively . Gel electrophoresis showed that the acidic polysaccharide (23 .5% sulfate, 4 .5% uronic acid) was not homogeneous . It was fractionated by anion-exchange chromatography on DEAE Sephadex with increasing concentrations of KCl solutions affording seven fractions . All the fractions showed blood-anticoagulant activity. The fraction eluted with 1 .2 M KCl (34 .85% sulfate, 1 .4% uronic acid) showed the highest thrombin time . The plaque inhibition and the transcription assays of the whole acidic polysaccharide and the partial hydrolysis product against the infectious pancreatic necrosis virus showed a slight antiviral effect .The fucose-containing polymer from D. antarctica is a mixture of sulfated polysaccharides with a different content of sulfate groups and uronic acids . A correlation was observed between the anticoagulant effect and uronic acids content.

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Thiobacillus ferroxidans ATCC 19859 undergoes rapid phenotypic switching between a wild-type state characterized by the ability to oxidize ferrous iron (FeII) and reduced sulfur compounds and a mutant state where it has lost the capacity to oxidize FeII but retains the ability to oxidize sulfur. The mutant has also gained the capacity to swarm. It is proposed that loss of FeII oxidation is due to the reversible transposition of the insertion sequence IST1 into resB encoding a putative cytochrome c-type biogenesis protein. Downstream from resB and co-transcribed with it is resC, encoding another putative cytochrome biogenesis protein. IST1 insertional inactivation of resB could result in the loss of activity of its target c-type cytochrome(s). This putative target cytochrome(s) is proposed to be essential for FeII oxidation but not for sulfur oxidation. Curiously, resB and resC pertain to the proposed system II cytochrome biogenesis pathway whereas gamma Proteobacteria, of which T. ferrooxidans is a member, normally use system I. This could represent an example of lateral gene transfer.

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