Innovative co-production of polyhydroxyalkanoates and methane from broken rice.

Autor: Brojanigo S; Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Università degli Studi di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, PD, Italy. Electronic address: silvia.brojanigo@phd.unipd.it., Alvarado-Morales M; Department of Chemical and Biochemical Engineering, Technical University of Denmark, DK-2800 Kgs Lyngby, Denmark. Electronic address: meal@kt.dtu.dk., Basaglia M; Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Università degli Studi di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, PD, Italy. Electronic address: marina.basaglia@unipd.it., Casella S; Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Università degli Studi di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, PD, Italy. Electronic address: sergio.casella@unipd.it., Favaro L; Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Università degli Studi di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, PD, Italy. Electronic address: lorenzo.favaro@unipd.it., Angelidaki I; Department of Chemical and Biochemical Engineering, Technical University of Denmark, DK-2800 Kgs Lyngby, Denmark. Electronic address: iria@kt.dtu.dk.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2022 Jun 15; Vol. 825, pp. 153931. Date of Electronic Publication: 2022 Feb 17.
DOI: 10.1016/j.scitotenv.2022.153931
Abstrakt: Broken rice, a low-cost starchy residue of the rice industry, can be an interesting substrate to reduce the polyhydroxyalkanoates (PHAs) production cost. However, since the most common PHAs-producing strains lack amylases, this waste must be firstly hydrolysed by additional commercial enzymes. In this work, the acidogenesis phase of the anaerobic digestion was exploited as efficient hydrolysis step to convert broken rice into volatile fatty acids (VFAs) to be used as PHAs carbon source by Cupriavidus necator DSM 545, one of the most promising PHAs-producing microbes. Broken rice, both non-hydrolysed and enzymatically hydrolysed, was processed in two continuous stirred tank reactors, at hydraulic retention times (HRT) of 5, 4 and, 3 days, to produce VFAs. The highest VFAs levels were obtained from non-hydrolysed broken rice which was efficiently exploited for PHAs accumulation by C. necator DSM 545. PHAs contents were higher after 96 h of incubation and, noteworthy, reached the highest value of 0.95 g/L in the case of 4 days HRT without any chemicals supplementation, except vitamins. Moreover, in view of a biorefinery approach, the residual solid fraction was used for methane production resulting in promising CH 4 levels. Methane yields were very promising again for 4 days HRT. As such, this HRT resulted to be the most suitable to obtain effluents with high promise in terms of both PHAs accumulation and CH 4 production. In addition, these results demonstrate that broken rice could be efficiently processed into two valuable products without any costly enzymatic pre-treatment and pave the way for future biorefining approaches where this by-product can be converted in a cluster of added-value compounds. Techno-economical estimations are in progress to assess the feasibility of the entire process, in view of supporting the low-cost conversion of organic waste into valuable products.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal views that have appeared to influence the work described in this manuscript.
(Copyright © 2022 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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