What is the Difference Between Nitrifying and Denitrifying Bacteria?

Nitrifying and denitrifying bacteria are essential for the nitrogen cycle, but they have distinct roles and characteristics. The main differences between nitrifying and denitrifying bacteria are:

Function: Nitrifying bacteria are responsible for converting ammonia into nitrites or nitrates, while denitrifying bacteria convert nitrates back to nitrogen gas.
Involved Bacteria: Nitrosomonas and Nitrobacter are the main bacteria involved in nitrification, while Lactobacillus, Spirillum, Pseudomonas, and Thiobacillus are involved in denitrification.
Growth and Development: Nitrifying bacteria have a prolonged growth, while denitrifying bacteria have a faster growth.
Mode of Respiration: Nitrifying bacteria use an aerobic mode of respiration, while denitrifying bacteria use an anaerobic mode of respiration.
Mode of Nutrition: Nitrifying bacteria have an autotrophic mode of nutrition, while denitrifying bacteria have a heterotrophic mode of nutrition.
By-products: The by-product of nitrification is nitrate (NO3–), while the by-product of denitrification is nitrogen gas (N).
Temperature and pH Requirements: Nitrification requires a minimum temperature between 16° and 35°C and an optimum pH between 6 and 8, while denitrification requires a minimum temperature between 26° and 38°C and an optimum pH between 6 and 8.

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Comparative Table: Nitrifying vs Denitrifying Bacteria

Here is a table comparing the differences between nitrifying and denitrifying bacteria:

Feature	Nitrifying Bacteria	Denitrifying Bacteria
Process	Oxidation of ammonia into nitrite, followed by the oxidation of nitrite into nitrate	Reduction of nitrate into nitrite, followed by the reduction of nitrate into nitrogen gas
Products Formed	Nitrite and nitrate	Gaseous forms (diatomic nitrogen and nitrous oxide)
Microorganisms	Common nitrifying microorganisms include Nitrosomonas, Nitrosococcus, Nitrobacter, Nitrospira, Nitrosopumilus maritimus, and Nitrososphaera viennensis	Common denitrifying microorganisms include Paracoccus denitrificans, Thiobacillus denitrificans, and Proteobacteria
Nutrition	Most microbes involved in nitrification are chemoautotrophic	Most microbes involved in nitrification are heterotrophic
pH Range	Nitrification flourishes in the pH range of 6.5 to 8	-

Both nitrifying and denitrifying bacteria are essential for maintaining the nitrogen balance in the environment. Nitrifying bacteria convert ammonia and ammonium into nitrates, while denitrifying bacteria convert nitrates back into atmospheric nitrogen. These processes are crucial for recycling nitrogen and ensuring its availability for living organisms.

Guilherme Mazui

Guilherme Mazui is graduated in journalism from the Federal University of Minas Gerais (UFMG) and a master's degree in Communication from the University of São Paulo (USP). In addition, he has experience in advertising writing and has worked as a content editor in several companies.