Polyhydroxyalkanoates production from short and medium chain carboxylic acids by Paracoccus homiensis

Abstract

The aim of this study was to evaluate an effect of short and medium chain carboxylic acids (CAs) rich stream derived from acidogenic mixed culture fermentation of acid whey on polyhydroxyalkanoates (PHAs) synthesis by Paracoccus homiensis and compare it with the impact of individual synthetic CAs. The obtained results confirmed that the analyzed bacterium is able to metabolize synthetic CAs as the only carbon sources in the growth medium with maximum PHAs production yields of 26% of cell dry mass (CDM). The replacement of the individual CAs by a CAs-rich residual stream was found to be beneficial for the Paracoccus homiensis growth. The highest biomass concentration reached about 2.5 g/L with PHAs content of 17% of CDM. The purified PHAs were identified as poly(3-hydroxybutyrate-co-3-hydroxyvalerate) by applying gas chromatography coupled with mass spectrometry, Fourier transform infrared spectroscopic spectra and UV–Vis spectra. Furthermore, a differential scanning calorimetric, thermogravimetric and water contact angle analysis proved that the extracted copolymers have useful properties. The obtained data are promising in the perspective of developing a microbial PHAs production as a part of an integrated valorization process of high CAs content waste-derived streams.

Physicochemical characterization of polyhydroxybutyrate (PHB) produced by the rare halophile Brachybacterium paraconglomeratum MTCC 13074

“…The T d for PHB produced by B. paraconglomeratum ranged from 248.6 to 258.3 °C and the T m ranged between 138 and 166 °C which was considerably higher than that of commercially synthesized biopolymers [ 34 ]. The same was observed with the PHBs of Paracoccus homiensis [ 35 ].…”

Effect of short- and medium-chain fatty acid mixture on polyhydroxyalkanoate production by Pseudomonas strains grown under different culture conditions

“…Thus, our data suggested that neither lactic acid nor ethanol affected the PHA productivity negatively. Furthermore, quite low PHA productivity was reported in the cultivation of P. homiensis grown on the same (as in our study) SMCFA extracted -rich stream, suggesting that the presence of butyric acid as the dominant component had more inhibitory effect due to the fact that a single short-chain-fatty acid in the medium resulted in the lowest PHA production efficiency compared with others (Szacherska et al, 2021).…”

“…Comparable biomass data (1.03 g/L) were reported in P. oleovorans culture supplemented with volatile fatty acid streams from chicken manure where acetate was the predominant acid ( Aremu et al, 2021 ). Higher biomass concentration was determined by our research group by supplementation of the culture medium with the same SMCFA extracted -rich stream in the cultivation of Paracoccus homiensis ( Szacherska et al, 2021 ). Moreover, our results confirmed that PHA productivity increased under nitrogen limitation, reaching a maximum value of 4.5 mg/L h at 24 h of the fermentation after ammonium exhaustion in the growth medium was reached.…”

“…They are synthesized mainly by bacteria of the Pseudomonas genus. Due to their useful properties, PHAs have great potential in biomedical, agricultural, and industrial applications (Tan et al, 2021). Nevertheless, the commercialization of PHAs in the world market is currently limited, mainly due to the high production costs compared to synthetic polymers.…”

Paracoccus kondratievae produces poly(3‐hydroxybutyrate) under elevated temperature conditions

“…A large phylogenetic diversity of bacterial and archaeal species have a native PHA‐producing capability (Kim & Rhee, 1999 ; Kourilova et al, 2020 ; Mohandas et al, 2018 ; Tu et al, 2022 ; Yamane et al, 1996 ). Within the gram‐negative genus Paracoccus , several species were characterized as PHA producers, including Paracoccus pantotrophus (Ucisik‐Akkaya et al, 2009 ), Paracoccus homeinsis (Szacherska et al, 2022 ) and Paracoccus denitrificans (Yamane et al, 1996 ). The latter species has been extensively studied for its PHA‐producing capability.…”