In November 2015, Microepics showcased our activities in Madri+d Science Week. These free-to-attend events are aimed at the public of all education levels, and are sponsored by the Dirección General de Universidades e Investigación de la Consejería de Educación, Juventud y Deporte de la Comunidad de Madrid (Fundación madri+d para el Conocimiento).
Our objective was to open the door on the world of Protists to the participants in a workshop, “Invisible Nature: Meet the Protozoa of the soil and rivers of the Madrid Sierra”. This activity fits perfectly both with the diffusion of Microepics, and the fact that 2015 was the FAO International Year of Soils. The presence of protists is important in terrestrial ecosystems like soils and mosses. It is suggested that a decrease in microbial biodiversity in soils reduces their ability to withstand stress conditions. Several studies on terrestrial trophic chains estimate that protists may be responsible for up to 70% of soil respiration and play a significant role in the worm nutrition, in turn vital for promoting soil porosity, decomposition of organic matter and recycling of nutrients. Changes in the structure and dynamics of protist communities are also considered to affect the rate of soil formation and fertility.
The 42 participants in our workshop were diverse in background and education level, with at least a forty year age spread. They included pupils from primary and secondary school (aged 10 and 14, respectively), sixth-formers, as well as secondary school teachers, professional chemists and informatics specialists. In the three hours the workshop lasted, we showed participants how to collect protists from natural environments, how to observe them under the microscope, what are the common ways for isolation, identification, quantification, and classification into trophic groups. We used a variety of sample types (from soil, peat-bogs, natural granite basin sediments, river sediment and water), collected from distinct areas of the Sierra (de Madrid). Some of the samples were screened on an overhead projector, using a microscope-computer link, to explain, in vivo, the movement and structures of protists and other essential microfauna (water fleas, annelid and nematode worms, tardigrades).
To help participants classify protists observed under the microscope, we presented them with a key to easy identification with relevant bibliographic references and links to information on the web pages, which we include at the end of this blog.
Some participants enjoyed adding vital dyes (methylen blue, neutral red) to observe microscopic bacteria within the cytoplasm of heterotrophic protists and in the surrounding media. Others expressed their interest in fixed permanent slides of pathogenic protists and ciliates impregnated with silver. Most were surprised to discover the simplicity of the media for enrichment and initial cultivation of many protists (media based on toasted lettuce, wheat grains, rice, skimmed milk, earth, etc.; all conveniently filtered and sterilized to eliminate unwanted contamination).
But perhaps the most enjoyable moment was at the end of the workshop when participants were given their going away presents: magnets and stickers printed micrographs showing protists from natural environments.
For Microepics it was a challenge and a pleasure to teach this scientific workshop. We hope that we awakened a spark of interest for the microscopic world, in our uninitiated participants. If you are interested in this type of activity, watch this space for this year’s calls and registration deadlines.
Bibliography and Weblinks
|Streble, H., Krauter, D. (1987). Atlas de los microorganismos de agua dulce. La vida en una gota de agua. Editorial Omega. ISBN: 978-84-282-0800-0|
|Jahn, T.L.,Bovee, E.C., Jahn, F.F. (1949). How to know the protozoa. WCB McGraw-Hill.|
|Patterson, D.J., Hedley, S. (1996). Free living Freshwater Protozoa: A Colour Guide. CRC Press|
|Encyclopedia of Life.|
|Protist Information Server.|
|Protist Video Library.|
|Microworld. World of Ameboid Organisms.|