Enhanced polyhydroxybutyrate (PHB) accumulation in heterotrophically grown Arthrospira platensis under nitrogen deprivat
- PDF / 927,595 Bytes
- 10 Pages / 595.276 x 790.866 pts Page_size
- 91 Downloads / 199 Views
Enhanced polyhydroxybutyrate (PHB) accumulation in heterotrophically grown Arthrospira platensis under nitrogen deprivation Chanchanok Duangsri 1 & Nat-Anong Mudtham 1 & Aran Incharoensakdi 2,3 & Wuttinun Raksajit 1 Received: 15 April 2020 / Revised and accepted: 22 September 2020 # Springer Nature B.V. 2020
Abstract The non-heterocystous cyanobacterium Arthrospira platensis was investigated for the conditions under which high accumulation of polyhydroxybutyrate (PHB) occurred. Cells grown photoautotrophically under nitrogen-deprived conditions had high accumulation of PHB whose granules were clearly visualized using Nile-Red staining. A further increase of PHB was observed in cells grown photoheterotrophically for 3 days under nitrogen-deprived condition with 0.50%(w/v) acetate supplementation (−N +Act) showing the maximum PHB contents of 19.2 ± 0.5%(w/w DW). This was significantly higher than that in cells grown under the same condition but with either 0.1%(w/v) butyrate, or 0.75%(w/v) glucose, or 0.1%(w/v) propionate supplementation (P < 0.05). RT-PCR analysis revealed that photoheterotrophically grown cells under −N+ Act condition had a significant increase of phaB and phaC transcript levels (P < 0.05) compared with those supplemented with other organic carbons. The representative FTIR spectra of the extracted polymer from A. platensis showed prominent peaks at 1721 cm−1 and 1279 cm−1 for the carbonyl (C=O) stretching of the ester group and asymmetric C–O–C stretching vibration, respectively. This spectral pattern is comparable with that of the standard PHB spectra, thus confirming the chemical nature of the extract. The overall results demonstrated that the enhanced PHB accumulation in A. platensis was attributed to the increased expression of phaB and phaC responsible for increased PHB biosynthesis when cells were grown photoheterotrophically in nitrogen-deprived medium containing organic carbon compounds. Keywords Acetate . Arthrospira platensis . phaBC genes . PHB . Photoheterotrophy
Introduction Bio-based plastics are very promising as an alternative to petroleum-based plastics as they are biocompatible, biodegradable, and environmentally friendly (Keshavarz and Roy 2010; Drosg et al. 2015; Raza et al. 2018). The production of bioplastics from biorenewable sources has the potential to reduce environmental pollution and contribute to a more
* Wuttinun Raksajit [email protected] 1
Program of Animal Health Technology, Faculty of Veterinary Technology, Kasetsart University, Bangkok 10900, Thailand
2
Laboratory of Cyanobacterial Biotechnology, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
3
Royal Society of Thailand, Academy of Science, Bangkok 10300, Thailand
sustainable society (Getachew and Woldesenbet 2016). Volatile fatty acids (VFAs) as a renewable carbon source for bioplastic production have received great attention (Fradinho et al. 2014). Therefore, the use of VFAs such as acetic, butyric, and propionic acids as a substrate for polyhydroxybutyra
Data Loading...
