Impact of different by-products from the biodiesel industry and bacterial strains on the production, composition, and properties of novel polyhydroxyalkanoates containing achiral building blocks

Novel extracellular polymeric substances produced by Cupriavidus necator IPT 027 grown on glucose and crude glycerol originated from biodiesel

“…The high levels of crude ash, total lipids, and volatiles at 105°C, in EPS 2 obtained from by-product from biodiesel are likely due to oil seed residues, such as free fatty acids, unhydrolyzed triglycerides, and mineral composition. [9] The variation in the EPS composition and production can to be attributed to many factors, such as carbon sources, microbial cells, process parameter and extraction method. [24] The monosaccharide composition of EPS ( Fig.…”

“…Decomposition profiles of dry samples were obtained with a TGA Waltham PerkinElmer Model Pyris 1 (Massachusetts, USA) using 5 mg of sample in a platinum tray (cross-sectional area of 2.47 × 10 À5 m 2 ) and heated at 10°C/min from 25 to 600°C under a nitrogen flow rate of 20 ml min -1. [9] DSC experiments were performed using samples of 2-4 mg sealed in an aluminum pan with a high-sensitivity SHIMADZU DSC-50 under nitrogen atmosphere. All samples were scanned over a range of À20 to 350°C and equilibrated at 350°C for 3 min to eliminate thermal and stress histories.…”

“…effect of the carbon source. [9] The polydispersity index ranged between 1.36 and 1.87, denoting that extracted polymers presented slightly different polymer chain, in which EPS 1 showed a possibly homogeneous more with respect to EPS 2, justifying different properties between exopolymers as thermal stability and chemical composition. [25] According to EPS of scientific literature, M w of EPS ranging from 10 5 to 2.5 × 10 6 Da.…”

“…[8] The increased demand of natural polymers for various industrial applications in past few years has led to sway interest in EPS production by new sources, among which is included the crude glycerol (CG), an important industrial feedstock, the glycerol-rich phase from biodiesel. [9] CG is produced in large quantities in the world (approximately 4 million tonnes in 2015) during biodiesel production (10 wt% of the total product) and is considered as a waste with associated disposal cost. [1,10] Therefore, their conversion into value-added products is essential for sustainable development.…”

“…[1,10] Therefore, their conversion into value-added products is essential for sustainable development. [9,11] The wide structural, physical, and rheological diversity and other unique properties of EPS produced by bacteria make it industrially and biotechnologically important. The unique biophysicochemical properties of bacterial EPS make it widely useful in the food industry as viscosifying, stabilizing, and emulsifying agents.…”