Microbial fiber carbon materials

Observations of the affected materials under the light microscope has shown that it is a microbial contamination, and the black spots are located on calcium carbonate particles (fillers) and rice hulls fibers. In some cases, the black substance covered calcium carbonate or rice hulls particles completely. 

Completely biodegradable Here the polymer matrix is derived from natural sources (such as starch or microbially grown polymers), and the fiber reinforcements are produced from common crops such as flax or hemp. Microorganisms are able to consume these materials in their entirety, eventually leaving carbon dioxide and water as by-products (Katarzyna et al., 2010). 

Of course, natural fibers like wool and cotton are broken down through biotic processes. Microorganisms have evolved enzymes that attack key bonds in these natural polymers, thereby releasing monomers that can be used as carbon and energy sources for microbial growth. In contrast, microorganisms lack enzymes to break down many synthetic fibers, thus these materials persist and accumulate in the environment. 

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