Brewer’s spent grain as a no-cost substrate for polyhydroxyalkanoates production: Assessment of pretreatment strategies and different bacterial strains

• DOI: 10.1016/j.nbt.2021.01.009
• Publication Date: 2021-01-29T06:35:54Z
• Authors: Carlos Corchado-Lopo; Oscar Martínez-Avila; Elisabet Marti; Jordi Llimós; Anna María Busquets; Dan Kucera; Stanislav Obruca; Laia Llenas; Sergio Ponsá
• Keywords: Cupriavidus necator; Bioplastic; Mashing; Bioproducts; Bacillus coagulans; Polyhydroxybutyrate

Polyhydroxyalkanoates (PHAs) are polyesters of significant interest due to their biodegradability and properties similar petroleum-derived plastics, as well the fact that they can be produced from renewable sources such by-product streams. In this study, brewer's spent grain (BSG), main brewing industry, was subjected a set physicochemical pretreatments effect on release reducing sugars (RS) evaluated. The RS obtained were used substrate for further PHA production in Burkholderia cepacia, Bacillus cereus, Cupriavidus necator liquid cultures. Although some proved efficient releasing (acid-thermal pretreatment up 42.1 gRS L−1 0.77 g−1 dried BSG), generation inhibitors scenarios likely affected compared with process run without (direct enzymatic hydrolysis BSG). Thus, maximum accumulation BSG hydrolysates found reference case 0.31 ± 0.02 g per cell weight, corresponding 1.13 0.06 L-1 yield 23 1 mg g-1 BSG. It also C. presented highest tested strains followed closely by B. reaching maxima at 48 h. has been source other bioproducts, these results show potential no-cost raw material producing PHAs waste valorization circular economy scheme.