Bioconversion of bread waste into high-quality proteins and biopolymers by fermentation of archaea Haloferax mediterranei

Razan Unis, Rima Gnaim, Mrinal Kashyap, Olga Shamis, Nabeel Gnayem, Michael Gozin, Alexander Liberzon, Jallal Gnaim, Alexander Golberg

Research output: Contribution to journalArticlepeer-review

Abstract

The valorization of bread waste into high-quality protein and biopolymers using the halophilic microorganism Haloferax mediterranei presents a sustainable approach to food waste management and resource optimization. This study successfully coproduced protein and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) biopolymer with a biomass content of 8.0 ± 0.1 g L−1 and a productivity of 11.1 mg L−1 h−1. The fermentation process employed 3.0% w/v of enzymatically hydrolyzed bread waste. The amino acid profile of the cell biomass revealed a total content of 358 g kg−1 of biomass dry weight (DW), including 147 g kg−1 DW of essential amino acids. The protein quality, assessed through in-vitro enzyme digestion, indicated a high-quality protein with a digestibility value of 0.91 and a protein digestibility-corrected amino acid score (PDCAAS) of 0.78. The PHBV biopolymer component (36.0 ± 6.3% w/w) consisted of a copolymer of 3-hydroxybutyrate and 3-hydroxyvalerate in a 91:9 mol% ratio. This bioconversion process not only mitigates food waste but also generates valuable biomaterials.

Original languageEnglish
Article number1491333
JournalFrontiers in Microbiology
Volume15
DOIs
StatePublished - 2024

Keywords

  • Haloferax mediterranei
  • biopolymer
  • bread waste
  • microbial fermentation
  • poly(3-hydroxybutyrate-co-3-hydroxyvalerate)

All Science Journal Classification (ASJC) codes

  • Microbiology (medical)
  • Microbiology

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