Effect of nitrogen limitation on polyhydroxyalkanoates production efficiency, properties and microbial dynamics using a soil-derived mixed continuous culture

Abstract

(2019) Effect of nitrogen limitation on polyhydroxyalkanoates production efficiency, properties and microbial dynamics using a soilderived mixed continuous culture,

Thorough Investigation of the Effects of Cultivation Factors on Polyhydroalkanoates (PHAs) Production by Cupriavidus necator from Food Waste-Derived Volatile Fatty Acids

“…Such a development, furthermore, should be conducted in an economical way as the PHA downstream process also accounts for a significant share in PHA production cost [76]. According to the second heating curves, melting temperatures (T m ) of extracted polymer in this study were in a range of 151.9 to 176.1 • C. Melting enthalpies (∆H), on the other hand, were allocated in a wider range of 15.8 to 66.44 J/g, corresponding to a crystallinity of 10.8 to 45.5%, respectively, and were similar to those in studies by Ntaikou [74], Nygaard et al [77] and Li et al [78]. The low degree of crystallinity of synthesised polymers using real VFAs could be an advantage in facilitating various processing windows as suggested by Rosengart et al [79].…”

“…This result can be attributed to the surplus impurity content in the polymer recovered from the cultivation in the waste-based stream leading to a total weight loss of only around 80%, corresponding to the difference of 15-16% in the total mass loss. The excessive impurity can also be observed from the decomposition curve being gradual in contrast with the steep slope of extracted samples from the synthetic medium, resembling results from studies of Ntaikou et al [74] and Rodrigues [75]. Either downstream processing or food waste-based VFA pre-treatment should therefore be developed to achieve purer recovered PHA.…”

Application of Immersed Membrane Bioreactor for Semi-Continuous Production of Polyhydroxyalkanoates from Organic Waste-Based Volatile Fatty Acids

“…This value was significantly lower than that of synthetic VFAs due to the small fraction of impurities derived from recovered organic residues-based VFAs. The results obtained, however, were found to be the same compared to PHA samples from studies by Nygaard et al [ 48 ] and Ntaikou et al [ 49 ]. According to Rosengart et al [ 50 ], the low degree of crystallinity could be an advantage for widening the processing windows of PHAs.…”

Polyhydroxyalkanoate production by Bacillus thuringiensis: an aspect of biorefining pulp and paper mill sludge.

“…The presence of copolymer like PHBV is denoted by a characteristic absorption peak in the region of 2933-2972 cm -1 . Overall the FTIR spectra of the extracted PHAs show prominent peaks at the wavelengths which are indicative of PHAs and are comparable to the spectra of commercial PHB and PHBV as well as for PHAs recovered from other Bacillus sp (Helm and Naumann 1995;Bhattacharya et al 2016;Ntaikou et al 2019…”