Part 1 - Overview of rumen and ruminants -- 1. Rumen Microbiology: An Overview -- 2. Rumen Microbial Ecosystem of Domesticated Ruminants -- 3. Domesticated Rare Animals (Yak, Mithun and Camel): Rumen Microbial Diversity -- 4. Wild Ruminants -- 5. Structure-and-function of a non-ruminant gut: a porcine model -- Part 2 - Rumen microbial diversity -- 6. Rumen bacteria -- 7. Rumen fungi -- 8. Rumen Protozoa -- 9. Ruminal viruses (Bacteriophages, Archaeaphages) -- 10. Rumen Methanogens -- Part 3 - Rumen manipulation -- 11. Plant SecondaryMetabolites -- 12. Microbial feed additives -- 13. Utilization of organic acids to manipulate ruminal fermentation and improve ruminant productivity -- 14. Selective inhibition of harmful rumen microbes -- 15. Various 'Omics' approaches to understand and manipulate rumen microbial function -- Part 6 - Exploration and exploitation of rumen microbes -- 16. Rumen Metagenomics -- 17. Rumen: an underutilized niche for industrially important enzymes -- 18. Ruminal Fermentations toProduce Liquid and Gaseous Fuels -- 19. Commercial application of rumen microbial enzymes -- 20. Molecular characterization of Euryarcheal community within an anaerobic digester -- Part 5 - Intestinal disorders and rumen microbes -- 21. Acidosis in cattle -- 22. Urea/ ammonia metabolism in the rumen and toxicity in ruminants -- 23. Nitrate/ nitrite toxicity and possibilities of their use in ruminant diet -- Part 6 - Future prospects of rumen microbiology -- 24. The Revolution in Rumen Microbiology.