Biosynthesis and Biodegradability of Copolythioesters from 3,3′‐Thiodipropionic Acid and Plant Oils by Cupriviadus necator

Abstract

To prepare sulfur-containing natural polymers effectively, several plant oils and 3,3'-thiodipropionic acid (TDP) have been used as carbon sources for the biosynthesis of copolymer poly[(3-hydroxybutyrate)-co-(3-mercaptopropionate)] [poly(3HB-co-3MP)] by a wild-type bacterium Cupriviadus necator H16. By using the plant oils, copolymer accumulation and incorporation of 3MP units are greater than those of cases using sugars. The 3MP fraction is controllable over a range of 1-39 mol-% by adjusting the cultivation conditions. Microbial degradability of the copolymers has been examined in an activated sludge supernatant. The biodegradation proceeded by two mechanisms: surface erosion and auto-catalytic hydrolysis, depending on the 3MP unit fraction, and show preferential degradation of 3HB unit sequences.

Enzymatic Synthesis and Chemical Recycling of Polythiocaprolactone

“…Only a few polythioesters with specific molecular structures that were produced via fermentation have been reported to date. [8][9][10][11] It is anticipated, though, that enzymatic methods will be applicable to more versatile polymer structures. Lipase catalyzed synthesis of various polyesters such as PCL by ring-opening polymerization (ROP) of lactones has been extensively studied.…”

Biosynthesis and Properties of Sulfur-Containing Polyhydroxyalkanoates (PHAs) Produced by Wild-Type Strain Cupriavidus necator B-10646

“…In all these works, fructose or gluconate was used as the main carbon source. In [ 39 ], sugars (fructose and glucose) and vegetable oils were used as the main carbon source for C. necator H16. The authors obtained higher concentrations of bacterial biomass (up to 6.3–7.3 g/L) and polymer content (29.0–46.0%) when 3,3′-thiodipropionic acid was added to the main carbon source (vegetable oils) at a concentration of 10.0 g/L.…”

“…It is important to note that the obtained values reflect the actual content of 3MP in the composition of the copolymer, since samples of copolymers isolated from cell biomass and purified were analyzed. An analysis of publications showed ( Table 1 ), that this precursor was studied for the synthesis of sulfur-containing PHA in a series of works [ 22 , 25 , 33 , 35 , 36 , 38 , 39 ]. So, in the culture of bacteria R. eutropha H16 and C. necator H16, depending on the type of carbon source (glucose, fructose, soya oil, safflower oil, castor oil or gluconate), the content of 3MP monomers varied very significantly and was minimally from 4.0 mol.% to 8.0 mol.%; maximally from 34.9 mol.% to 39.0 mol.%.…”

Dynamic polythioesters via ring-opening polymerization of 1,4-thiazine-2,5-diones

“…4 Even so, to the best of our knowledge the potential for constitutional exchange in polythioesters 5 has only been previously explored in the context of short cyclic oligomers (n = 3-4). 6 Polythioesters have recently been designated as biomaterials based on the discovery of poly(3-mercaptoalkanoate) biosynthesis in wild-type and engineered bacteria, 7 providing a new avenue for polythioester preparation and making a better understanding of the properties of such polymers more desirable. In contrast to polythioesters, polyesters and polyamides have already been shown to undergo dynamic interchange, although relatively extreme conditions (250-300 • C, usually with transition metal catalysts) are necessary to observe exchange reactions at useful rates for these polymers.…”