Jensen’s medium with 0.2 % (butanol ou éthanol)) for 3 to 5 days or even more. the brown color in the Medium is the sign of the formation of the cysts. 

A remain at your service.

Dear Gangadhar Gaikwad 

 Pls. find the attached files and the references, good luck

Hoping this will be helpful to your project

Regards

Prof. Houda Kawas

http://link.springer.com/article/10.1007%2Fs11104-004-1522-7?LI=true

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC219180/pdf/jbacter00219-0316.pdf

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4340629/

http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2958.2010.07513.x/pdf

http://www.nature.com/ismej/journal/vaop/ncurrent/full/ismej201730a.html

http://pubmedcentralcanada.ca/pmcc/articles/PMC219180/pdf/jbacter00219-0316.pdf

http://www.cell.com/trends/microbiology/fulltext/S0966-842X(14)00086-9

Article Hypercyst Mutants in Rhodospirillum centenum Identify Regula...

Hi Gangadhar

There are some references in attachment 1

https://en.wikipedia.org/wiki/Azotobacter

2

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC211998/

3

https://www.jstor.org/stable/24125109

4

http://www.microbiologyresearch.org/docserver/fulltext/micro/150/2/383.pdf?expires=1492274824&id=id&accname=guest&checksum=0D288B98FBA3CC2E44B473FF5C2C43C5

5

https://www.els.net/WileyCDA/ElsArticle/refId-a0000295.html

6

https://pubmedcentralcanada.ca/pmcc/articles/PMC211998/pdf/jbacter00194-0316.pdf

7

https://books.google.com/books?isbn=0412024217

8

https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-015-1250-9

9

https://books.google.com/books?isbn=8178331152

10

https://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822011000300003

Good Luck

Thank you Mr Laith Al-Ani for your reply, but extremely sorry but the link "https://www.scielo.br/scielo.php?sc...arttext&pid=S1517-83822011000300003" is not opening in my computer..

Can you please help in this matter.

Thanks again

Azotobacter vinelandii is a soil bacterium able to form desiccation-resistant cysts. A cyst consists of a cell containing granules of polyhydroxybutyrate (PHB) and surrounded by a capsule made up of two layers known as the intine and the exine.

Hi Gangadhar Gaikwad,

In order to trigger the formation of the cysts, grow your Azotobacter strains on Jensen`s Medium with 0,2 % of butanol. if not you can add 0,2 % ethanol but the best factor is Butanol. Then incubate for 3 to 5 days. You will notice the growth of colonies with a brownish color: this is the sign of the formation of cysts. To confirm your results, prepare a fresh slide from this culture: the cysts are easily observable under an optical microscope.

Good luck