I have isolated an actinomycetes from the soil , molecular identification (16S DNA) of this strain confirmed that it belongs to the species of Nocardiopsis rose (whit 99% of similarity), but my strain doesn't form spore chain that characterized most strain of Nocardiopsis, attached microscopic morphology of my strain
Is this a possible case?
Slm,
Je pense que elle est en fonction de son biotope Wa Alahou A3lam ...Bon courage
Si tu as respecté le temps d'incubation nécessaire pour pouvoir observer les hyphes et les spores...si, aussi, la souche n'a pas été stressée...Eh ben je ne peux te répondre.
Hi Dr. Messaoudi Omar
I read your query. May I suggest you that can you repeat the morphology experiment in triplicate in two different media.
1. Study the colony morphology meticulously.
2. Try to get well isolated colonies of your isolate.
3. Ensure that your isolate is pure.
4. From that you do light microscopy to get good resolved picture at 1000x magnification. (as the picture which are pasted here are challenging to understand due to lack of good resolution.)
5. Please refer:
A). http://ac.els-cdn.com/S0944501315000518/1-s2.0-S0944501315000518-main.pdf?_tid=9fe606da-a56f-11e6-817c-00000aab0f6b&acdnat=1478581132_7d8cff41cc52e24e75e7636a342c7fdc
B). http://www.microbiologyresearch.org/docserver/fulltext/ijsem/26/4/ijs-26-4-487.pdf?expires=1478581537&id=id&accname=guest&checksum=D200829DA2B1BE392F811D8FD8AB52C1
Hope this would help to correlate the 16s Phylogeny data and microscopic outcomes.
Good luck
Best Regards
Girish
Hello,
How do you culture it? Actinomycetes may not produce spores in a liquid culture (especially spore chains), therefore they should be cultured on an agar medium. I do not exactly know for Nocardiopsis, but for streptomycetes 16S rDNA may not be enough to define species, because actinomycetes are highly similar considering this sequence.
Kind regards,
Adrian
Adrian is absolutely correct. You should go for culturing it in agar medium rather than a broth if you have done so. Otherwise you can follow the feedback of Dr. Mahajan for better results.
The correct protocol for actinobacteria is to use ISP (International Streptomyces project) media together with the type strain so that you can make a valid comparison.
Shirling, E. B. & Gottlieb, D. (1966). Methods for characterization of Streptomyces species. Int J Syst Bacteriol 16, 313- 340.
Hi:
I agree with "Christopher M M Franco" . The standard and the most essential reference for Isolation, cultivation, and identification of Streptomyces spp. is that of Shirling, E. B. & Gottlieb (below):
Shirling, E. B. & Gottlieb, D. (1966). Methods for characterization of Streptomyces species. Int J Syst Bacteriol 16, 313- 340.
Thank you very much for your answer:
1. The incubation period is 14 days on the GYM agar medium as well on the ISP2 medium, I confirm that the culture is pure.
2. The slides for microscopic observation were prepared by the slide culture method described in the protocol of Shirling, E. B. & Gottlieb, D. (1966), after 14 days of incubation.
3. For Nocardiopsis, it is the same principle as Streptomyces as well as other actinomycetes, when you have 99.00% is not the same as 99.99%.
4. thank you Dr Girish B. Mahajan for the articles
Kind regards,
Omar MESSAOUDI
Dear Omar,
You may need to re-culture the strain in specific media recommended for the strain and proceed for careful examination if the morphology is in accordance with the established characteristics. I am in agreement with Christopher M M Franco, for actinomycetes characterisation.
salam,
I am in agreement with other colleagues for actinobacteria characterization. You can also use other media recommended for the morphologic study and especially those used for the identification of Nocardiopsis rose so that you can make a valid comparison as you suggested Dr. Christopher M M Franco.
In addition, try with “chitin–vitamin agar medium”. Sporulation of actinobacteria is very well on this poor medium.
In any case, it is not because your strain doesn’t form spores chain, it is not a Nocardiopsis! I work on the genus Streptosporangium. All Streptosporangium species form sporangia on aerial mycelia which is a taxonomic characteristic for this genus (as its name indicates) but the recently described species Streptosporangium algriensis (Boubetra et al., 2015) and S. jomthongense (Intra et al., 2014) produce no sporangia on aerial hyphae, they produce single spores.
In addition, based on the relatively low percentage (99%) noted between your strain and other type strains of Nocardiopsis, it’s quite possible that your strain represents a novel species of the genus Nocardiopsis. Previous studies have shown that many Nocardiopsis species have high 16S rRNA gene sequence similarities (100%), but have low DNA–DNA relatedness values (below the 70 % cut-off point).
Good luck.
Dear Fawzia
Thanks for your comment,
This is what i mean, sometimes we have exceptions, like the example of Streptosporangium algriensis and S. jomthongense which does not produce sporangia , like the other membre of Streptosporangium, as well as the example of Streptomyces polyantibioticus which produce sporangia , and do not form chains of spores like the other species of Streptomyces. And many other examples
Thanks
Omar
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