I am trying to isolate cyanobacteria from soil and freshwater samples, but I have zero experience with them. They grow really slow on plates in colonies ranging from green to brown/black colour. The pictures I attach come from black/brown colonies in three different samples, although the green colours that can be seen in them are not represented in the colony colour. I can only differentiate diatoms in one of the pictures because they are easily distinguishable.
Could anyone with more experience tell me if they look like cyanobacteria? I am trying to obtain pure cultures but they tend to form diffuse colonies which usually overlap.
Any advice in any way will be deeply appreciated. Thank you in advance.
EDIT: Sorry if the quality of the pictures is not enough. I took them with my smartphone directly from an old microscope.
Hello,
Although these photos are not so very clear, but to me, the green filaments (S2) are tolyphothrix sp., at S1 those might be anabena sp., and at O1, those are Chroococcus sp. in green color. If the growth of diatoms are problematic to your cyanobacterial growth, you can add some anti-diatom agent in the growth media before culturing your cyanobacteria.
Best
IMagen O1: las verdes son claramente chroococcales. El tamaño importa por lo que sería interesante si a las fotos añades siempre una escala, en el futuro. Podrían ser Cyanosarcina (hay especies tanto acuáticas como terrrestres).
Si tienes un microscopio de fluorescencia, las cianobacterias presentan autoflorescencia por lo que podrías asegurarte que lo son o no.
Las mejores claves son los 3 volúmenes Cyanoprocariota Süsswasserflora von Mitteleuropa de Komárek.
IMAGEN S2: no soy capaz de discernir si los filamentos tienen o no heterocistes.
así que podrían ser o bien Plectonema (oscillatorial) o algún Tolypothrix como comenta Arnab Majumdar, o Scytonema (ambas nostocales) o algo similar.
IMAGEN S1: Me pasa lo mismo , asi a lo que veo no les veo heterocistes, ( y que fueran alguna Pseudonabaenaceae, pero si son de un cultivo y tienen suficiente nitrógeno, no los necesitan, y no los crean y que fueran una nostocal.
Es verdad que la "pinta" tambien nos podría hacer pensar nostocales, y si que podría ser alguana Anabaena, Dolichospermum...
I agree with Arnab, the filaments in Fig. 02 may also Oscillatoria. For isolation I usually make dilution of soil sample before pouring them into solid medium (BG11 nitrogen free). Then I picked up single colony and put it to liquid medium (better use a well plate). Repeat several times until you have good single culture. Good luck
Thank you all for your answers. Unfortunately, my microscope does not allow to take pictures of better quality, but I appreciate all your effort.
Maria Verdugo Althöfer muchas gracias por la información tan detallada. Estoy usando medio BG-11 comercial de Sigma que ya contiene nitrógeno, por eso puede que no se aprecien heteroquistes en ningún cultivo y eso dificulta la identificación.
No dispongo de muchos medios. Por ejemplo, no tengo la posibilidad de usar microscopio de fluorescencia ni de acceder a los volúmenes de Komárek que me comentas (aunque los he visto referenciar en muchos artículos).
Tendré en cuenta todas tus recomendaciones a nivel de géneros. El problema que tengo con las Chroococcales es que siempre aparecen muy contaminadas con esas otras células (las negras pequeñas, las verdes, las transparentes y las diatomeas). Todas las imágenes están a una ampliación de 1000X, tomadas con el objetivo de 100X de aceite de inmersión. Siento no haber añadido una escala.
Un saludo.
Hola,
http://www.cyanodb.cz/#/Chroococcaceae
En esta página hay una descripción de todos los géneros.
No es una clave, así que sino sabes lo que buscas te tendrías que pasear por todos.
https://fottea.czechphycology.cz/search.php?advanced=1
La revista fottea tiene muchos de sus artículos en abierto, puedes buscar si encuentras algo de algún género concreto que te interese.
Y si surfeas un poco por la red hay PDF libres del tipo "catálogo_ atlas de cianobacterias de ...un lugar.
Yo no cultivo, sólo identifico para el cálculo de Estado ecológico, no te puedo ayudar en aislamiento ni en medios.
Un saludo
MAria
Hola Jesús, my answers may come a little late, I´m sorry. I am very sure that the bluegreen cells in the picture "negra - marrón" are Pleurocapsa minor. However, I don´t know what the smaller purple cells might be. I guess it´s a different species or genus. I don´t know which one. But sure it is not a single-species colony but a mix of different species.
The picture called colonia negra to me seems a clean single-species colony. It might be Nostoc. or maybe some other genus of Nostocales.
The last picture, "S2", is a mix of (at least) two different species. The blue-green filaments might be Phormidium, or Oscillatoria, as suggested before. However I tend to think they might bei Geitlerinema. But that depends on the width of the filaments. Regarding the unicellular forms, I have no idea. Chroococcales for sure, but I couldn´t say which family or species.
You can download some information about freshwater abenthic lgae in streams and rivers in Germany here:
https://www.lanuv.nrw.de/landesamt/veroeffentlichungen/publikationen/arbeitsblaetter?tx_cartproducts_products%5Bproduct%5D=301&cHash=db15bff8ae44071296d50c7fd87d6ffd
The text is in German, but the pictures speak for themselves. : )
best regards, Julia
Hello Julia Foerster , your answers do not come late at all, I still have this same cultures and even more than I need to identify. My lack of experience in culturing and characterising cyanobacteria make me go slower than I would have thought. Thank you for sharing your knowledge, also the text you sent me is being very useful for me.
Kind regards.
In my view, Fig 2 may be Nostoc sp., while Fig 3 may be Oscillatoria sp (filamentous green blue cells) however the culture contained other sp. from microalgae (green cells). In Fig 1 I think the blue connected colony may be Chroococcaceae while the green coccoid cells may be green microalgae.
Hamida R.S. thank you for your answer! I mostly agree with you. If the quality of my microscope was better I could look distinctive features like cell-ends more clearly.
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