New model substrates for enzymes hydrolysing polyethyleneterephthalate and polyamide fibres

Abstract

Recently the potential of enzymes for surface hydrophilisation and/or functionalisation of polyethyleneterephthalate (PET) and polyamide (PA) has been discovered. However, there was no correlation between enzyme class/activity (e.g. esterase, lipase, cutinase) and surface hydrolysis of these polymers and consequently no simple assay to estimate this capability. Enzymes active on the model substrates bis (benzoyloxyethyl) terephthalate and adipic acid bishexyl-amide, were also capable of increasing the hydrophilicity of PET and PA. When dosed at the identical activity on 4-nitrophenyl butyrate, only enzymes from Thermobifida fusca, Aspergillus sp., Beauveria sp. and commercial enzymes (TEXAZYME PES sp5 and Lipase PS) increased the hydrophilicity of PET fibres while other esterases and lipases did not show any effect. Activity on PET correlated with the activity on the model substrate. Hydrophilicity of fibres was greatly improved based on increases in rising height of up to 4.3 cm and the relative decrease of water absorption time between control and sample of the water was up to 76%. Similarly, enzymes increasing the hydrophilicity of PA fibres such as from Nocardia sp., Beauveria sp. and F. solani hydrolysed the model substrate; however, there was no common enzyme activity (e.g. protease, esterase, amidase) which could be attributed to all these enzymes.

A New Esterase from Thermobifida halotolerans Hydrolyses Polyethylene Terephthalate (PET) and Polylactic Acid (PLA)

“…All other chemicals were of analytical grade from SIGMA (Germany) except the model substrate bis(benzoyloxyethyl)terephthalate (3PET) which was synthesized in two steps as previously described [40].…”

“…Hydrolysis of the model substrate bis(benzoyloxyethyl)terephthalate (3PET) has been proven first to be valuable for the screening of enzymes capable of PET hydrolysis [40] and to provide important mechanistic information [27,32,34,42] about the type of hydrolysis mechanism. In the case of the new esterase Thh_Est, the hydrolysis product found in highest concentration was BA, followed by HEB, both in a comparable concentration higher than 50 mmol per mol of enzyme.…”

Actinomycetes: A Source of Industrially Important Enzymes

“…This can be cost-effective and ecofriendly method in textile industry. Some thermophilic Actinomycetes such as Pseudonocardia thermophila are known producers of nitrile hydratase which is used in the biotransformation of nitriles into different useful compounds, e.g., amides, amines, esters, aldehydes and ketones [38]. Alginate lyases hydrolyze different polysaccharides to produce alinate which has potential to be used as antitumor agent, anticoagulant and anti-inflammatory agent [39].…”

Study on Degradation of Nylon 6 by thermophilic bacteria Anoxybacillus rupiensis Ir3 (JQ912241)

“…(Negoro et al, (1980) pointed that Flavobacterium are able to degrade 6-aminohexanoic cyclic dimer (waste of nylon 6) at 30 °C. It was found that the optimum temperature for 6-aminohexanoate oligomer hydrolase enzyme was between 30°C and 45°C (Heumann et al, 2008). Anoxybacillus is a mild thermophile.…”