Polymer by microorganisms

Biocides are used to prevent or retard attack on polymers by microorganisms. 

An important established fact especially regarding the susceptibility of thermoplastic polymers is that while special-purpose additives in these polymers (such as plasticizers, stabilizers, fillers, dyes) can serve as nutrient sources to microorganisms and fungi, the degree of attack also depends on factors such as the lengths of the macromolecule chains, that is, polyethylene, polyvinylchloride, and polystyrene. Biodeterioration of polymers by microorganisms can be considered to be via two processes ... 

Kawai, F. Breakdown of Plastics and polymers by microorganisms. Advances in Biochemical Engineering, 52 (1995), p. 151 -194... 

Preservatives Helps prevent degradation of polymers by microorganisms. Helps prevent fungi and bacteria attack on plastic materials. Makes die plastic material better suited for underground use. 

The PCL and the polyesters from the alkane diols and the alkane dicarboxylic acids were shaped and molded as containers. These containers were in used in horticultural department in seeding the plants. After three months of soil burial, the PCL containers disintegrate and biodegrade. This indicates that extracellular enzymes in the soil may cleave the polymer chain prior to the assimilation of the polymer by microorganisms. 

The biodegradation of synthetic polymers by microorganisms and enzymes is much more common than most earlier anticipations. Several major factors affecting the biodegradation of synthetic polymers are ... 

Kawai F (1995), Breakdown of plastics and polymers by microorganisms , Adv Biochem Eng/biotech, 52, 152-194. 

Biological reactors play a valuable role in tlie conversion of substrates by microorganisms and mammalian cells into a wide range of products such as antibiotics, insulin, and polymers. Figures 11-12, 11-13, and 11-14 illustrate various types of biological reactor, and Figure 11-15 shows the physical characteristics of a typical coimuercial fermentation vessel. 

Byrom, D. 1987. Polymer synthesis by microorganisms technology and economics. 

Most polymers of high molecular weight in their pure state are resistant to attack by microorganisms, for example, although commercial polyethylene is resistant,... 

The polyesters synthesized by microorganisms were first investigated by Lemoigne, who isolated the reserve polymers in Bacillus megaterium in 1925 and identified the polymer to be poly(3-hydroxybutyrate), poly(3HB) [1]. The chemical structure of poly(3HB) is shown in Fig. 1. 

Synthesis of PHAs by microorganisms grown with non-natural carbon sources have been investigated intensively. The major interest has been to understand the relationship between the composition of the carbon source and the composition of the repeating units in the polymer so produced. 

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