What were the van Leeuwenhoek’s ‘green streaks’?
An article in the online magazine ‘Micscape’ alludes to a potential re-writing of the history books… van In 1674 , van Leeuwenhoek described ‘green streaks’ when he looked at some lake water under the microscope. Previously, it was thought that these microorganisms were Spirogyra, a green alga with beautifully spiralled chloroplasts. However, reanalysis of the original Dutch text suggests that van Leeuwenhoek may in fact have been looking at filament-forming cyanobacteria, perhaps from the coiled Dolichospermum genus.
If correct, this represents not only the first record of living aquatic microorganisms, but also the first observation of bacteria, preceding van Leeuwenhoek’s next account by two years. The authors rightly acknowledge that they cannot be sure about the identification of the ‘green streaks’, but it may prove to be a point of contention for historians!