Question

Which bacteria on organic matter bring about the decomposition and release ammonia?
A. Lactobacillus bacteria
B. Putrefying bacteria
C. Ammonifying bacteria
D. None of the above

Answer 1

Hint: A living organism carries out biochemical processes to maintain life. However, after its death the body tissues break down due to lack of maintenance by hydrolysis. This process of decomposition is brought about by bacteria that live in the body of animals including humans. These bacteria are strictly anaerobic in nature.

Complete answer:
Option (a) is incorrect. Lactobacillus is a Gram-positive bacterium. They are present in the digestive system, urinary system and genital system of human beings. The relationship between these bacteria and human beings can be termed as mutualism – because the human host provides it with nutrients and in return, the bacteria protect the human beings from pathogens and help to treat diarrhoea and certain skin diseases like eczema.
Option (b) is correct. Putrefying bacteria function to decompose organic matter through the process of putrefaction. The process involves liquefaction of the organs of the body, decomposition of proteins and tissues. It is brought about by the action of anaerobic bacteria that lives in the digestive tract. The putrefying bacteria convert the amino acids to ammonium ions which can be further converted to ammonia. It is one of the stages of decomposition.
Option (c) is incorrect. Ammonifying bacteria are known to convert organic nitrogen to ammonia. It occurs through both aerobic and anaerobic pathways. Ammonifying bacteria work on dead plant and animal matters as well as their waste products. These bacteria release ammonium ions or organic ammonia which further undergoes conversion into nitrates.

Hence, the correct answer is option (B).

Note: Putrefying bacteria act exclusively on dead and decaying organisms and decompose the tissues of the body and release ammonia. It is one of the stages of decomposition after death. The putrefying bacteria carry out the process of decomposition by anaerobic means. The ammonia obtained from the process then undergoes the process of nitrification and is ultimately returned to the atmosphere as nitrogen.