Answer to Question #217491 in Microbiology for Srikanth Kodamasim

Question

Microorganisms can remain dormant for even 200 years without food or O2 and even some can produce calcium carbonate which is the basis for self-healing concrete concept
Dormant state is normally exhibited by Gram +ve bacteria. What are the biomolecules that differentiate these with Gram -ve bacteria? (7 marks)
Give details on the biomolecular content that can be engineered to make a bacterium to be used in the self-healing concept (8 marks)
When you are engineering multiple microorganisms for a similar output, what kind of species relationship you will consider and explain with rationale?

Answer 1

Gram-positive bacteria own a thick cell wall comprising of many layers of peptidoglycan and teichoic acids. In contrast, Gram-negative bacteria have a relatively thin cell wall consisting of a few layers of peptidoglycan surrounded by a second lipid membrane containing lipopolysaccharides and lipoproteins.

Bacteria-based self-healing concrete is a construction material used to repair cracks in concrete, in which bacteria carriers immobilize the bacterial spores.

When engineering multiple microorganisms for a similar output, a self-healing technique using bacteria can fill the cracks in concrete by inducing calcium carbonate precipitation through biomineralization. The basic mechanism of bacteria-based crack healing happens when the concrete crack occurs. The water will then leak via the formed cracks and the capillary pores of concrete [4 ]. With the presence of water and nutrients inside the concrete matrix, the germination of bacteria will take place, and the limestone produced can fill the cracks.