Christine Campbell

On the origin of 24-norcholestanes and their use as age-diagnostic biomarkers

24-norcholestanes have been shown to be useful biomarkers to assess the age of sediments and petroleum, but until now, the biological sources of their precursors, i.e., 24-norsterols, were unclear. We have unambiguously identified relatively high concentrations of 24- norcholesta-5,22-dien-3β-ol in the diatom Thalassiosira aff. antarctica (6%–10% of total sterols) and, in much lower concentrations, in the dinoflagellate Gymnodinium simplex (0.2% of total sterols). These identifications and other reports of 24-norsterols in dinoflagellates suggest that both diatom and dinoflagellate species are major sources for 24-norcholestanes in sediments and petroleum. The evolutionary history of these organisms suggests that observed increases of 24-norcholestane concentration in the Jurassic and the Cretaceous are related to dinoflagellate expansion, whereas an increase in the Oligocene-Miocene is likely caused by diatom expansion. Our results also explain the biogeographical distribution of 24-norcholestanes, i.e., high concentrations at high (paleo)latitudes are likely caused by diatoms, while low concentrations at lower (paleo)latitudes are likely caused by dinoflagellates.

Unlocking nature’s treasure-chest: screening for oleaginous algae

Micro-algae synthesize high levels of lipids, carbohydrates and proteins photoautotrophically, thus attracting considerable interest for the biotechnological production of fuels, environmental remediation, functional foods and nutraceuticals. Currently, only a few micro-algae species are grown commercially at large-scale, primarily for “health-foods” and pigments. For a range of potential products (fuel to pharma), high lipid productivity strains are required to mitigate the economic costs of mass culture. Here we present a screen concentrating on marine micro-algal strains, which if suitable for scale-up would minimise competition with agriculture for water. Mass-Spectrophotometric analysis (MS) of nitrogen (N) and carbon (C) was subsequently validated by measurement of total fatty acids (TFA) by Gas-Chromatography (GC). This identified a rapid and accurate screening strategy based on elemental analysis. The screen identified Nannochloropsis oceanica CCAP 849/10 and a marine isolate of Chlorella vulgaris CCAP 211/21A as the best lipid producers. Analysis of C, N, protein, carbohydrate and Fatty Acid (FA) composition identified a suite of strains for further biotechnological applications e.g. Dunaliella polymorpha CCAP 19/14, significantly the most productive for carbohydrates, and Cyclotella cryptica CCAP 1070/2, with utility for EPA production and N-assimilation.

Pringsheim's living legacy: CCALA, CCAP, SAG and UTEX culture collections of algae

The major service culture collections of algae form the backbone of the curatorial and service roles for the phycological community as a whole. Four of the largest culture collections, Culture Collection of Algae at the Laboratory of Algology (CCALA) in the Czech Republic, Culture Collection of Algae and Protozoa (CCAP) in the UK, Culture Collection of Algae at Gottingen University (SAG) in Germany, and Culture Collection of Algae at the University of Texas at Austin (UTEX) in the USA can all trace their origins back to the pioneering work of Prof. E.G. Pringsheim. His work and the inspiration he provided to others have ensured that these collections continue to develop to fulfill the requirements of current and future generations of phycologists. This article discusses the historical developments, synergies, and ongoing contributions of these four algal collections.

The CCAP KnowledgeBase: linking protistan and cyanobacterial biological resources with taxonomic and molecular data

The roles of Biological Resource Centres (BRCs), such as the Culture Collection of Algae and Protozoa (CCAP), have extended beyond their traditional maintenance and provision of curated microorganisms to the user community. A major driver for change has been the exponential increase in metagenomics and environmental sequencing data over the last few years. This has underlined a critical requirement for molecular information on reference biological materials, which would allow better taxonomic interpretation, greater biological understanding and additional exploitation of these data. This is especially relevant for the relatively poorly studied protists (algal/autotrophic as well as heterotrophic) and prokaryotic cyanobacteria, which despite their huge biodiversity, reflected in the genomic data that has been generated, are under-represented in BRCs worldwide. Here we describe the functionalities of the Culture Collection of Algae and Protozoa (CCAP) KnowledgeBase (http://www.ccap.ac.uk), developed as a one-stop shop for quality-controlled biological material, hyperlinked to manually curated molecular, bibliographic and taxonomic information. This has been built around the CCAP live collection, which constitutes one of the most genotypically diverse collections in the world with representatives of all the major eukaryotic lineages and the cyanobacteria.

Morphology and phylogenetic affinities of Thecadinium foveolatum sp. nov. (Dinophyceae: Thecadiniaceae), a new marine benthic dinoflagellate from the West of Scotland

A new chloroplast-containing species of the sand-dwelling benthic dinoflagellate Thecadinium was isolated and cultured from a single cell collected from shallow waters of the marine Loch Ewe in North West Scotland. The cultured cells are described by light and scanning electron microscopy and the genetic affinities examined by comparison of ribosomal RNA gene sequences. Thecadinium foveolatum Bolch sp. nov. is heavily armoured with thecal plates that are ornamented with evenly distributed pores and contains numerous globular, dark golden-brown chloroplasts. Cells are broadly ovoid and slightly laterally compressed, with a descending cingulum displaced approximately half of the cell width. The thick thecal plates, numerous pores and the strongly displaced cingulum clearly differentiate this species from the only other chloroplast-containing species, T. kofoidii, and the remaining non-photosynthetic Thecadinium species described. Analysis of large-subunit rDNA sequences of Thecadinium foveolatum and other members of the Peridiniphycidae indicate that this new species is allied to the gonyaulacalean lineage rather than the peridinialean taxa included in the analyses.

Nomenclatural note on a Thecadinium species (Dinophyceae, Gonyaulacales), which was described as new independently three times within two months

Three Thecadinium species, independently described as new in three separate publications, are actually regarded as conspecific. The combined plate formula is Po 3′ 1a 6″ 5‐7/8c 5s 6″′ 2″″. The size range of the species is 38–65 l m in length and 23–42 lm in depth. It has one or two strongly lobed chloroplasts. The correct name of the species is Thecadinium yashimaense Yoshimatsu, Toriumi et Dodge 2004. Thecadinium mucosum Hoppenrath et Taylor 2004 and Thecadinium foveolatum Bolch 2004 are taxonomical synonyms. This note clarifies the plate tabulation and other features of the species.