Halophyte biorefinery for polyhydroxyalkanoates production from Ulva sp. Hydrolysate with Haloferax mediterranei in pneumatically agitated bioreactors and ultrasound harvesting

Supratim Ghosh; Jim Coons; Chris Yeager; Peter Halley; Alexander Chemodanov; Bogdan Belgorodsky; Michael Gozin; Guo-Qiang Chen; Alexander Golberg

doi:10.1016/j.biortech.2021.125964

Halophyte biorefinery for polyhydroxyalkanoates production from Ulva sp. Hydrolysate with Haloferax mediterranei in pneumatically agitated bioreactors and ultrasound harvesting

Bioresour Technol. 2022 Jan;344(Pt B):125964. doi: 10.1016/j.biortech.2021.125964. Epub 2021 Oct 31.

Authors

Supratim Ghosh¹, Jim Coons², Chris Yeager², Peter Halley³, Alexander Chemodanov⁴, Bogdan Belgorodsky⁵, Michael Gozin⁵, Guo-Qiang Chen⁶, Alexander Golberg⁴

Affiliations

¹ Porter School of the Environment and Earth Sciences, Faculty of Exact Science, Tel Aviv University, Tel Aviv 69978, Israel. Electronic address: supratim4737@gmail.com.
² Chemical Diagnostics and Engineering Group, Chemistry Division, Los Alamos National Laboratory, MS J964, Bikini Atoll Rd, Los Alamos, NM 87545 USA.
³ School of Chemical Engineering, University of Queensland, St Lucia QLD 4072 Australia.
⁴ Porter School of the Environment and Earth Sciences, Faculty of Exact Science, Tel Aviv University, Tel Aviv 69978, Israel.
⁵ School of Chemistry, Faculty of Exact Science, Tel Aviv University, Tel Aviv 69978, Israel.
⁶ Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing, PR China.

PMID: 34728090
DOI: 10.1016/j.biortech.2021.125964

Abstract

The present study tested the outdoor cultivation of Haloferax mediterranei for PHA production from green macroalgae Ulva sp. in pneumatically agitated bioreactors and applied ultrasonic separation for enhanced settling of archaeal cells. Scaled-up cultivation (40 L) yielded maximum biomass productivity of 50.1 ± 0.11 mg·L^-1·h^-1 with a PHA productivity of 27 ± 0.01 mg·L^-1·h^-1 and conversion yield of 0.107 g PHA per gram Ulva_DW. The maximum mass fraction of PHA achieved in biomass was calculated to be 56% w/w. Ultrasonic harvesting of Hfx. mediterranei cells approached 30% removal at energy inputs around 7.8 kWh·m^-3, and indicated no significant aggregation enhancement by Ca²⁺ addition. Molecular weight analysis showed an increase in Polydispersity Index (PDI) when the corresponding air velocities were increased suggesting that the polymer was more homogeneous at lower mixing velocities. The current study demonstrated scalable processes for PHA production using Ulva sp. feedstock providing new technologies for halophilic biorefinery.

Keywords: Haloferax mediterranei, pneumatically agitated bioreactors; Halophyte biorefinery; Polyhydroxyalkanoates; Ultrasonic separation.

MeSH terms

Bioreactors
Haloferax mediterranei*
Polyhydroxyalkanoates*
Salt-Tolerant Plants
Ulva*

Substances

Polyhydroxyalkanoates