Microbes deterioration processes

Materials of Construction MIC processes are those processes by which manufactured materials deteriorate through the presence and activities of microbes. These processes can be either direct or indirect. Microbial biodeterioration of a great many materials (including concretes, glasses, metals and their alloys, and plastics) occurs by diverse mechanisms and usually involves a complex community consisting of many different species of microbes. 

The marine environment presents a hostile and seemingly unlikely situation for the survival of archaeological wood, yet it does survive. Normally, wood does not survive long enough in marine environments to enter the archaeological record because of the activities of wood-boring animals and aerobic microbes. However, studies have shown that rapid burial in the anoxic sediments of the seabed will protect ships timbers and wooden artefacts from the physical, chemical and biological processes that influence the deterioration of exposed wood. 

The deterioration of plastic by microorganisms is due to an extracellular process of enzymatic activity. The enzymes secreted by organisms as part of their life cycle are reactive chemicals that are able to break down large molecules such as plastic and plasticizers into smaller ones since large molecules cannot pass through the organism cell wall. These smaller molecules can be absorbed into the microbes through their cell walls. The cell receives the nutrients it needs via various chemical pathways thus survival and reproduction. 

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