For a long time I was using the first one, it was the best for me, combining both natural and artificial (technological) systems.

However, for the actualization I recommend you

Kirchman, David L. (2012): Processes in Microbial Ecology. Oxford University Press. ISBN-10:0199586934

It is up-to-date (2012), very well documented and excellent from the didactical point of view.

Cheers

Mirek Macek

1) Microbial Ecology by atlas and Bartha

2) Biology of Microorganism by Brocks

Which topic do you want to focus?

To Sohel, 

I would like to focus more on diversity of microbes in environments, microbial nutrient cycling  and their interactions.

Cheers,

Sean

For microbial ecology in rhizosphere (Its nutrient and interaction) my publication may be helpful to you. 

Please go through

https://www.researchgate.net/publication/296701342_Plant_Growth_Promoting_Rhizobacteria_A_Sustainable_Approach_to_Agro-ecosytstem?_iepl%5BviewId%5D=yd6OnoXiIQm6fg2zK0tzGcYN&_iepl%5BprofilePublicationItemVariant%5D=default&_iepl%5Bcontexts%5D%5B0%5D=prfpi&_iepl%5BinteractionType%5D=publicationTitle

Chapter Plant Growth Promoting Rhizobacteria: A Sustainable Approach...

https://www.researchgate.net/publication/269098466_Role_of_Plant_Growth-Promoting_Rhizobacteria_and_Their_Formulation_in_Biocontrol_of_Plant_Diseases?_iepl%5BviewId%5D=A47ZP9zzHqivKqoqa5IiAdtD&_iepl%5BprofilePublicationItemVariant%5D=default&_iepl%5Bcontexts%5D%5B0%5D=prfpi&_iepl%5BinteractionType%5D=publicationTitle

Chapter Role of Plant Growth-Promoting Rhizobacteria and Their Formu...

192

Hi Sean

These are some Textbook 1

https://www.amazon.com/Microbial-Ecology-Larry-L-Barton/dp/0470048174

2

https://utah.instructure.com/courses/313117/assignments/2066490

3

https://books.google.iq/books/about/Microbial_Ecology.html?id=51Rt3X9UMfIC&redir_esc=y

4

https://books.google.iq/books?id=EcxkOMDHgzwC&source=gbs_similarbooks

Chapter23: PGPR: A Good Step to Control Several of Plant Pathogens

Chapter PGPR: A Good Step to Control Several of Plant Pathogens

6

https://books.google.iq/books?id=fmmJGHKh2qIC&source=gbs_similarbooks

7

https://books.google.iq/books?id=CsMa0MkwZqsC&source=gbs_similarbooks

8

https://books.google.iq/books?id=Qy_vBwAAQBAJ&source=gbs_similarbooks

9

https://books.google.iq/books?id=wpZ5AgAAQBAJ&source=gbs_similarbooks

9

https://books.google.iq/books?id=sfD1teRZUIQC&source=gbs_similarbooks

Good Luck