1. Ecological Interplays in microbial enzymology - an introduction.- 2. Diversity of Microbial Enzymes in the Soil Ecosystem.- 3. Microbial Enzymes of Wastewater and Sludge.- 4. Occurrence And Distribution Of Microbial Enzymes Of Fresh Water.- 5. Marine Microbial Enzymes - An Overview.- 6. Hydrolytic enzymes producing bacteria from Algerian hot springs: attractive industrial molecules.- 7. Enzymology of Microbial Biofilms.- 8. An Oxisoil "Arenito Cauia" Attributes Changed After Crop-Livestock Integration System.- 9. Microbial Enzymes - Role in the Soil Fertility.- 10. Microbial Enzymes In The Recycling Of Wastes.- 11. Soil Microbial Enzymes And Mitigation Of Heavy Metals Uptake By Plants.- 12. Communities Of Microbial Enzymes And Biodegradation Of Persistent Environmental Pollutants.- 13. Implication of enzymes in the adaptation of extremophilic microbes.- 14. Application Of Microbial Enzymes In Industries And Medicine.- 15. Microbial Enzymes in the Biosynthesis of Metal Nano Particles.- 16. Effect Of Agrochemicals On Soil Microbial Enzymes.- 17. Effects Of Aquatic (Freshwater And Marine) Pollution On Microbial Enzyme Activities.- 18. In silico analysis of biochemical pathways in bacterial enzyme synthesis.- 19. Microbial enzymes for sustainable development - future guidelines.