Undine E.M. Achilles-Day

Barcoding Tetrahymena: Discriminating Species and Identifying Unknowns Using the Cytochrome c Oxidase Subunit I (cox-1) Barcode

DNA barcoding using the mitochondrial cytochromecoxidase subunit I (cox-1) gene has recently gained popularity as a tool for species identification of a variety of taxa. The primary objective of our research was to explore the efficacy of using cox-1 barcoding for species identification within the genusTetrahymena. We first increased intraspecific sampling forTetrahymena canadensis, Tetrahymena hegewischi, Tetrahymena pyriformis, Tetrahymena rostrata, Tetrahymena thermophila, and Tetrahymena tropicalis. Increased sampling efforts show that intraspecific sequence divergence is typically less than 1%, though it may be more in some species. The barcoding also showed that some strains might be misidentified or mislabeled. We also used cox-1 barcodes to provide species identifications for 51 unidentified environmental isolates, with a success rate of 98%. Thus, cox-1 barcoding is an invaluable tool for protistologists, especially when used in conjunction with morphological studies.

Beyond the “Code”: A Guide to the Description and Documentation of Biodiversity in Ciliated Protists (Alveolata, Ciliophora)

Recent advances in molecular technology have revolutionized research on all aspects of the biology of organisms, including ciliates, and created unprecedented opportunities for pursuing a more integrative approach to investigations of biodiversity. However, this goal is complicated by large gaps and inconsistencies that still exist in the foundation of basic information about biodiversity of ciliates. The present paper reviews issues relating to the taxonomy of ciliates and presents specific recommendations for best practice in the observation and documentation of their biodiversity. This effort stems from a workshop that explored ways to implement six Grand Challenges proposed by the International Research Coordination Network for Biodiversity of Ciliates (IRCN‐BC). As part of its commitment to strengthening the knowledge base that supports research on biodiversity of ciliates, the IRCN‐BC proposes to populate The Ciliate Guide, an online database, with biodiversity‐related data and metadata to create a resource that will facilitate accurate taxonomic identifications and promote sharing of data.

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.

Tolerance of the resting cysts of Colpoda inflata (Ciliophora, Colpodea) and Meseres corlissi (Ciliophora, Spirotrichea) to desiccation and freezing

The survival of ciliate resting cysts, in the presence and absence of soil, was studied under two environmental stresses: desiccation and freezing. Laboratory strains of the common species Colpoda inflata and the rare species Meseres corlissi were used in these experiments, which yielded the following results: 1) Freezing of cysts in soil with a residual moisture level exceeding approximately 30% was destructive for both species. 2) Survival of Meseres corlissi cysts depended largely on the presence of soil. 3) In the absence of soil, Colpoda inflata cysts had greater tolerance to desiccation and freezing than Meseres corlissi cysts. Possible consequences for the distribution of natural populations are discussed.

Isolation of clonal cultures of endosymbiotic green algae from their ciliate hosts.

Using Paramecium bursaria as a model organism improved protocols have been developed to isolate clonal endosymbiotic algae. This involved micromanipulation of individual protists, rupturing to release endosymbionts followed by enrichment on complex media and a series of plating steps, under low light (PAR ~10μmol photons m(-2)s(-1)).

Developing an ecologically relevant heterogeneous biofilm model for dental-unit waterlines

Abstract This study monitored the biodiversity of microbes cultured from a heterogeneous biofilm which had formed on the lumen of a section of dental waterline tubing over a period of 910 days. By day 2 bacterial counts on the outlet-water showed that contamination of the system had occurred. After 14 days, a biofilm comparable to that of clinical waterlines, consisting of bacteria, fungi and amoebae had formed. This showed that the proprietary silver coating applied to the luminal surface of the commercial waterline tubing failed to prevent biofilm formation. Molecular barcoding of isolated culturable microorganisms showed some degree of the diversity of taxa in the biofilm, including the opportunistic pathogen Legionella pneumophila. Whilst the system used for isolation and identification of contaminating microorganisms may underestimate the diversity of organisms in the biofilm, their similarity to those found in the clinical environment makes this a promising test-bed for future biocide testing.

Future algal biofuels: implications of environmental temperature on production strain selection

Current and future economic mass production of microalgae or cyanobacteria will require suitable, preferably relatively high, levels of photosynthetically active radiation (PAR). Most large-scale productions sites, as well as those under development or under consideration, have been located between 40N and 40S raising the possible issue of the algae being periodically, or routinely, subjected to elevated temperatures (>30°C). The effects of environmental temperatures in the range 8–35°C on the marine, oleaginous model alga Nannochloropsis oculata were assessed. Active growth was observed at all temperatures except 35°C, where cells bleached and died. The implications of elevated temperature regimes were assessed for a variety of potential biofuel producing, biotechnologically relevant freshwater, marine and hyper-saline algae and the implications for their biotechnological exploitability discussed.