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Costa P, Basaglia M, Casella S, Kennes C, Favaro L, Carmen Veiga M. Autotrophic production of polyhydroxyalkanoates using acidogenic-derived H 2 and CO 2 from fruit waste. BIORESOURCE TECHNOLOGY 2023; 390:129880. [PMID: 37852509 DOI: 10.1016/j.biortech.2023.129880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 10/14/2023] [Accepted: 10/14/2023] [Indexed: 10/20/2023]
Abstract
The environmental concerns regarding fossil plastics call for alternative biopolymers such as polyhydroxyalkanoates (PHAs) whose manufacturing costs are however still too elevated. Autotrophic microbes like Cupriavidus necator, able to convert CO2 and H2 into PHAs, offer an additional strategy. Typically, the preferred source for CO2 and H2 are expensive pure gases or syngas, which has toxic compounds for most PHAs-accumulating strains. In this work, for the first time, H2 and CO2 originating from an acidogenic reactor were converted autotrophically into poly(3-hydroxybutyrate) P(3HB). During the first stage, a mixed microbial community continuously catabolized melon waste into H2 (26.7 %) and CO2 (49.2 %) that were then used in a second bioreactor by C. necator DSM 545 to accumulate 1.7 g/L P(3HB). Additionally, the VFAs (13 gCOD/L) produced during acidogenesis were processed into 2.7 g/L of P(3HB-co-3HV). This is the first proof-of-concept of using acidogenic-derived H2 and CO2 from fruit waste to produce PHAs.
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Affiliation(s)
- Paolo Costa
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Waste to Bioproducts-Lab, Università di Padova, Agripolis, Viale dell'Università 16, Legnaro, Padua 35020, Italy; Chemical Engineering Laboratory, Faculty of Sciences and Centre for Advanced Scientific Research (CICA), University of A Coruña, Rúa da Fraga 10, Coruña 15008 A, Spain
| | - Marina Basaglia
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Waste to Bioproducts-Lab, Università di Padova, Agripolis, Viale dell'Università 16, Legnaro, Padua 35020, Italy
| | - Sergio Casella
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Waste to Bioproducts-Lab, Università di Padova, Agripolis, Viale dell'Università 16, Legnaro, Padua 35020, Italy
| | - Christian Kennes
- Chemical Engineering Laboratory, Faculty of Sciences and Centre for Advanced Scientific Research (CICA), University of A Coruña, Rúa da Fraga 10, Coruña 15008 A, Spain
| | - Lorenzo Favaro
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Waste to Bioproducts-Lab, Università di Padova, Agripolis, Viale dell'Università 16, Legnaro, Padua 35020, Italy.
| | - Maria Carmen Veiga
- Chemical Engineering Laboratory, Faculty of Sciences and Centre for Advanced Scientific Research (CICA), University of A Coruña, Rúa da Fraga 10, Coruña 15008 A, Spain
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2
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Polyhydroxyalkanoate Production from Fruit and Vegetable Waste Processing. Polymers (Basel) 2022; 14:polym14245529. [PMID: 36559896 PMCID: PMC9781074 DOI: 10.3390/polym14245529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/12/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
Traditional plastics represent a tremendous threat to the environment because of increases in polluting manufacturing as well as their very extended degradation time. Polyhydroxyalkanoates (PHAs) are polymers with similar performance to plastic but are compostable and synthesizable from renewable sources and therefore could be a replacement for fossil-based plastics. However, their production costs are still too high, thus demanding the investigation of new and cheap substrates. In this sense, agricultural wastes are attractive because they are inexpensive and largely available. Specifically, fruit and vegetables are rich in sugars that could be fermented into PHAs. In this work two strains, Cupriavidus necator DSM 545 and Hydrogenophaga pseudoflava DSM 1034, well-known PHA-producing microbes, were screened for their ability to grow and accumulate PHAs. Ten different fruit and vegetable processing waste streams, never before reported in combination with these strains, were tested. Residues from red apple and melon were found to be the most suitable feedstocks for PHA production. Under specific selected conditions, C. necator DSM 545 accumulated up to 7.4 and 4.3 g/L of 3-hydroxybutyrate (3HB) from red apple and melon, respectively. Copolymer production was also obtained from melon. These results confirm the attractiveness of food processing waste as a promising candidate for PHA production. Ultimately, these novel substrates draw attention for future studies on process optimization and upscaling with C. necator.
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Brojanigo S, Alvarado-Morales M, Basaglia M, Casella S, Favaro L, Angelidaki I. Innovative co-production of polyhydroxyalkanoates and methane from broken rice. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 825:153931. [PMID: 35183640 DOI: 10.1016/j.scitotenv.2022.153931] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/12/2022] [Accepted: 02/12/2022] [Indexed: 06/14/2023]
Abstract
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 CH4 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 CH4 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.
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Affiliation(s)
- Silvia Brojanigo
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Università degli Studi di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, PD, Italy.
| | - Merlin Alvarado-Morales
- Department of Chemical and Biochemical Engineering, Technical University of Denmark, DK-2800 Kgs Lyngby, Denmark.
| | - Marina Basaglia
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Università degli Studi di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, PD, Italy.
| | - Sergio Casella
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Università degli Studi di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, PD, Italy.
| | - Lorenzo Favaro
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Università degli Studi di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, PD, Italy.
| | - Irini Angelidaki
- Department of Chemical and Biochemical Engineering, Technical University of Denmark, DK-2800 Kgs Lyngby, Denmark.
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Palù M, Peprah M, Tsapekos P, Kougias P, Campanaro S, Angelidaki I, Treu L. In-situ biogas upgrading assisted by bioaugmentation with hydrogenotrophic methanogens during mesophilic and thermophilic co-digestion. BIORESOURCE TECHNOLOGY 2022; 348:126754. [PMID: 35077815 DOI: 10.1016/j.biortech.2022.126754] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 06/14/2023]
Abstract
In this study, the effects of bioaugmentation of typically dominant hydrogenotrophic methanogens to CSTR co-digesting cheese whey and manure, under in-situ biomethanation operations were investigated. Reactors working at mesophilic (37 °C) and thermophilic (55 °C) conditions were independently treated and examined in terms of microbial composition and process dynamics. Addition of Methanoculleus bourgensis in the mesophilic reactor led to a stable biomethanation, and an improved microbial metabolism, resulting in 11% increase in CH4 production rate. 16S rRNA and biochemical analyses revealed an enrichment in syntrophic and acidogenic species abundance. Moreover, nearly total volatile fatty acids conversion was observed. Differently, Methanothermobacter thermautotrophicus addition in the thermophilic reactor did not promote biogas upgrading performance due to incomplete H2 conversion and inefficient community adaptation to H2 excess, ultimately favoring acetoclastic methanogenesis. Bioaugmentation constitutes a viable tool to strengthen in-situ upgrading processes and paves the way to the development of more sophisticated and robust microbial inoculants.
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Affiliation(s)
- Matteo Palù
- Department of Biology, University of Padova, Via U. Bassi 58/b, Padova 35121, Italy
| | - Maria Peprah
- Department of Chemical and Biochemical Engineering, Technical University of Denmark, Lyngby DK-2800, Denmark
| | - Panagiotis Tsapekos
- Department of Chemical and Biochemical Engineering, Technical University of Denmark, Lyngby DK-2800, Denmark
| | - Panagiotis Kougias
- Soil and Water Resources Institute, Hellenic Agricultural Organisation DIMITRA, Thermi, Thessaloniki 57001, Greece
| | - Stefano Campanaro
- Department of Biology, University of Padova, Via U. Bassi 58/b, Padova 35121, Italy; CRIBI Biotechnology Center, University of Padova, Padova 35131, Italy.
| | - Irini Angelidaki
- Department of Chemical and Biochemical Engineering, Technical University of Denmark, Lyngby DK-2800, Denmark
| | - Laura Treu
- Department of Biology, University of Padova, Via U. Bassi 58/b, Padova 35121, Italy
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Brojanigo S, Gronchi N, Cazzorla T, Wong TS, Basaglia M, Favaro L, Casella S. Engineering Cupriavidus necator DSM 545 for the one-step conversion of starchy waste into polyhydroxyalkanoates. BIORESOURCE TECHNOLOGY 2022; 347:126383. [PMID: 34808314 DOI: 10.1016/j.biortech.2021.126383] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/15/2021] [Accepted: 11/16/2021] [Indexed: 06/13/2023]
Abstract
Starch-rich by-products could be efficiently exploited for polyhydroxyalkanoates (PHAs) production. Unfortunately, Cupriavidus necator DSM 545, one of the most efficient PHAs producers, is not able to grow on starch. In this study, a recombinant amylolytic strain of C. necator DSM 545 was developed for the one-step PHAs production from starchy residues, such as broken rice and purple sweet potato waste. The glucodextranase G1d from Arthrobacter globiformis I42 and the α-amylase amyZ from Zunongwangia profunda SM-A87 were co-expressed into C. necator DSM 545. The recombinant C. necator DSM 545 #11, selected for its promising hydrolytic activity, produced high biomass levels with noteworthy PHAs titers: 5.78 and 3.65 g/L from broken rice and purple sweet potato waste, respectively. This is the first report on the engineering of C. necator DSM 545 for efficient amylase production and paves the way to the one-step conversion of starchy waste into PHAs.
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Affiliation(s)
- Silvia Brojanigo
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Università degli Studi di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, (PD), Italy
| | - Nicoletta Gronchi
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Università degli Studi di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, (PD), Italy
| | - Tiziano Cazzorla
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Università degli Studi di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, (PD), Italy
| | - Tuck Seng Wong
- Department of Chemical & Biological Engineering, The University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD, United Kingdom; National Center for Genetic Engineering and Biotechnology, 113 Thailand Science Park, Phahonyothin Road, Khlong Luang, 12120, Pathum Thani, Thailand
| | - Marina Basaglia
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Università degli Studi di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, (PD), Italy
| | - Lorenzo Favaro
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Università degli Studi di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, (PD), Italy.
| | - Sergio Casella
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Università degli Studi di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, (PD), Italy
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Simonazzi M, Pezzolesi L, Galletti P, Gualandi C, Pistocchi R, De Marco N, Paganelli Z, Samorì C. Production of polyhydroxybutyrate by the cyanobacterium cf. Anabaena sp. Int J Biol Macromol 2021; 191:92-99. [PMID: 34536471 DOI: 10.1016/j.ijbiomac.2021.09.054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 08/30/2021] [Accepted: 09/10/2021] [Indexed: 10/20/2022]
Abstract
Polyhydroxybutyrate (PHB) production by the cyanobacterium cf. Anabaena sp. was here studied by varying the medium composition and the carbon source used to induce mixotrophic growth conditions. The highest PHB productivity (0.06 gPHB gbiomass-1 d-1) was observed when cultivating cf. Anabaena sp. in phosphorus-free medium and in the presence of sodium acetate (5.0 g L-1 concentration), after an incubation period of 7 days. A content of 40% of PHB on biomass, a dry weight of 0.1 g L-1, and a photosynthetic efficiency equal to the control were obtained. The cyanobacterium was then grown on a larger scale (10 L) to evaluate the characteristics of the produced PHB in relation to the main composition of the biomass (the content of proteins, polysaccharides, and lipids): after an incubation period of 7 days, a content of 6% of lipids (52% of which as unsaturated fatty acids with 18 carbon atoms), 12% of polysaccharides, 28% of proteins, and 46% of PHB was reached. The extracted PHB had a molecular weight of 3 MDa and a PDI of 1.7. These promising results demonstrated that cf. Anabaena sp. can be included among the Cyanobacteria species able to produce polyhydroxyalkanoates (PHAs) either in photoautotrophic or mixotrophic conditions, especially when it is grown under phosphorus-free conditions.
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Affiliation(s)
- Mara Simonazzi
- Dipartimento di Scienze Biologiche, Geologiche ed Ambientali (BiGeA), Università di Bologna, via S. Alberto 163, Ravenna, Italy
| | - Laura Pezzolesi
- Dipartimento di Scienze Biologiche, Geologiche ed Ambientali (BiGeA), Università di Bologna, via S. Alberto 163, Ravenna, Italy; Centro Interdipartimentale di Ricerca Industriale Fonti Rinnovabili, Ambiente, Mare ed Energia (CIRI-FRAME), Università di Bologna, via S. Alberto 163, Ravenna, Italy
| | - Paola Galletti
- Centro Interdipartimentale di Ricerca Industriale Fonti Rinnovabili, Ambiente, Mare ed Energia (CIRI-FRAME), Università di Bologna, via S. Alberto 163, Ravenna, Italy; Dipartimento di Chimica "Giacomo Ciamician", Università di Bologna, via S. Alberto 163, Ravenna, Italy
| | - Chiara Gualandi
- Centro Interdipartimentale di Ricerca Industriale Fonti Rinnovabili, Ambiente, Mare ed Energia (CIRI-FRAME), Università di Bologna, via S. Alberto 163, Ravenna, Italy; Centro Interdipartimentale di Ricerca Industriale (CIRI) Meccanica Avanzata e Materiali (CIRI-MAM) Università di Bologna, Viale Risorgimento 2, Bologna, Italy
| | - Rossella Pistocchi
- Dipartimento di Scienze Biologiche, Geologiche ed Ambientali (BiGeA), Università di Bologna, via S. Alberto 163, Ravenna, Italy; Centro Interdipartimentale di Ricerca Industriale Fonti Rinnovabili, Ambiente, Mare ed Energia (CIRI-FRAME), Università di Bologna, via S. Alberto 163, Ravenna, Italy
| | - Nicole De Marco
- Dipartimento di Scienze Biologiche, Geologiche ed Ambientali (BiGeA), Università di Bologna, via S. Alberto 163, Ravenna, Italy
| | - Zoe Paganelli
- Dipartimento di Scienze Biologiche, Geologiche ed Ambientali (BiGeA), Università di Bologna, via S. Alberto 163, Ravenna, Italy
| | - Chiara Samorì
- Centro Interdipartimentale di Ricerca Industriale Fonti Rinnovabili, Ambiente, Mare ed Energia (CIRI-FRAME), Università di Bologna, via S. Alberto 163, Ravenna, Italy; Dipartimento di Chimica "Giacomo Ciamician", Università di Bologna, via S. Alberto 163, Ravenna, Italy.
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Pagliano G, Galletti P, Samorì C, Zaghini A, Torri C. Recovery of Polyhydroxyalkanoates From Single and Mixed Microbial Cultures: A Review. Front Bioeng Biotechnol 2021; 9:624021. [PMID: 33644018 PMCID: PMC7902716 DOI: 10.3389/fbioe.2021.624021] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 01/18/2021] [Indexed: 01/08/2023] Open
Abstract
An overview of the main polyhydroxyalkanoates (PHA) recovery methods is here reported, by considering the kind of PHA-producing bacteria (single bacterial strains or mixed microbial cultures) and the chemico-physical characteristics of the extracted polymer (molecular weight and polydispersity index). Several recovery approaches are presented and categorized in two main strategies: PHA recovery with solvents (halogenated solvents, alkanes, alcohols, esters, carbonates and ketones) and PHA recovery by cellular lysis (with oxidants, acid and alkaline compounds, surfactants and enzymes). Comparative evaluations based on the recovery, purity and molecular weight of the recovered polymers as well as on the potential sustainability of the different approaches are here presented.
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Affiliation(s)
- Giorgia Pagliano
- Department of Chemistry “Giacomo Ciamician”, University of Bologna, Ravenna, Italy
| | - Paola Galletti
- Department of Chemistry “Giacomo Ciamician”, University of Bologna, Ravenna, Italy
- CIRI-Fonti Rinnovabili, Ambiente, Mare ed Energia, Ravenna, Italy
| | - Chiara Samorì
- Department of Chemistry “Giacomo Ciamician”, University of Bologna, Ravenna, Italy
- CIRI-Fonti Rinnovabili, Ambiente, Mare ed Energia, Ravenna, Italy
| | - Agnese Zaghini
- Department of Chemistry “Giacomo Ciamician”, University of Bologna, Ravenna, Italy
| | - Cristian Torri
- Department of Chemistry “Giacomo Ciamician”, University of Bologna, Ravenna, Italy
- CIRI-Fonti Rinnovabili, Ambiente, Mare ed Energia, Ravenna, Italy
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Fojt J, David J, Přikryl R, Řezáčová V, Kučerík J. A critical review of the overlooked challenge of determining micro-bioplastics in soil. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 745:140975. [PMID: 32712500 DOI: 10.1016/j.scitotenv.2020.140975] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 07/12/2020] [Accepted: 07/12/2020] [Indexed: 06/11/2023]
Abstract
Currently, non-biodegradable oil-based plastics are gradually being replaced by bio-based biodegradable plastics to prevent the formation of microplastics. For biodegradable materials to decompose completely, however, they require specific conditions that are rarely met in ecosystems. Paradoxically, this may lead to the fast production of microplastics from biodegradable materials, i.e. micro-bioplastics. Until recently, the scientific focus has been solely on the estimation of conventional microplastics. As a result, there is a lack of analytical methods for determining the amount of micro-bioplastics in soil. In this review, we address this problem by summarising sample pre-treatments and analytical techniques suitable for the determination of conventional microplastics, which serve as inspiration for the determination of micro-bioplastics from polyhydroxybutyrates, polylactic acid and polybutylene adipate terephthalate in soil. The analytical techniques include both pyrolysis-based techniques, i.e. thermoanalytical and non-thermoanalytical approaches including sample pre-separation and respective detection limits. We conclude that due to the incomplete knowledge of the production rate of micro-bioplastics, fate, sorption properties and toxicity, it is necessary to develop and validate a rapid and suitable method for their determination. Indeed, the use of thermoanalytical approaches seems to be the most promising strategy. Furthermore, we suggest how the development and analysis of micro-bioplastics should be addressed in future research.
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Affiliation(s)
- Jakub Fojt
- Institute of Chemistry and Technology of Environmental Protection, Faculty of Chemistry, Brno University of Technology, Purkyňova 118, 612 00 Brno, Czech Republic
| | - Jan David
- iES Landau, Institute for Environmental Sciences, Group of Environmental and Soil Chemistry, University of Koblenz-Landau, Fortstraße 7, 76829 Landau, Germany
| | - Radek Přikryl
- Institute of Material Science, Faculty of Chemistry, Brno University of Technology, Purkyňova 118, 612 00 Brno, Czech Republic
| | - Veronika Řezáčová
- Institute of Chemistry and Technology of Environmental Protection, Faculty of Chemistry, Brno University of Technology, Purkyňova 118, 612 00 Brno, Czech Republic
| | - Jiří Kučerík
- Institute of Chemistry and Technology of Environmental Protection, Faculty of Chemistry, Brno University of Technology, Purkyňova 118, 612 00 Brno, Czech Republic.
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Brojanigo S, Parro E, Cazzorla T, Favaro L, Basaglia M, Casella S. Conversion of Starchy Waste Streams into Polyhydroxyalkanoates Using Cupriavidus necator DSM 545. Polymers (Basel) 2020; 12:polym12071496. [PMID: 32635554 PMCID: PMC7407217 DOI: 10.3390/polym12071496] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 06/26/2020] [Accepted: 06/30/2020] [Indexed: 01/23/2023] Open
Abstract
Due to oil shortage and environmental problems, synthetic plastics have to be replaced by different biodegradable materials. A promising alternative could be polyhydroxyalkanoates (PHAs), and the low-cost abundant agricultural starchy by-products could be usefully converted into PHAs by properly selected and/or developed microbes. Among the widely available starchy waste streams, a variety of residues have been explored as substrates, such as broken, discolored, unripe rice and white or purple sweet potato waste. Cupriavidus necator DSM 545, a well-known producer of PHAs, was adopted in a simultaneous saccharification and fermentation (SSF) process through an optimized dosage of the commercial amylases cocktail STARGEN™ 002. Broken rice was found to be the most promising carbon source with PHAs levels of up to 5.18 g/L. This research demonstrates that rice and sweet potato waste are low-cost feedstocks for PHAs production, paving the way for the processing of other starchy materials into bioplastics.
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10
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Treu L, Tsapekos P, Peprah M, Campanaro S, Giacomini A, Corich V, Kougias PG, Angelidaki I. Microbial profiling during anaerobic digestion of cheese whey in reactors operated at different conditions. BIORESOURCE TECHNOLOGY 2019; 275:375-385. [PMID: 30599281 DOI: 10.1016/j.biortech.2018.12.084] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 12/20/2018] [Accepted: 12/23/2018] [Indexed: 06/09/2023]
Abstract
This study investigates the efficiency in methane production of lab-scale mesophilic (37 °C) and thermophilic (54 °C) continuous stirred tank reactors fed with cheese whey at different operational conditions. Results showed that whey mono-digestion was feasible at mesophilic conditions, while at thermophilic conditions frequent acidification incidents were recorded. The limited buffer capacity of the influent feedstock was responsible for the unstable anaerobic digestion process. The co-digestion of cheese whey with cattle manure maintained the pH levels higher than 7.0, and therefore, stable methane production rates were achieved without any significant accumulation of volatile fatty acids. An additional enhancement of the methane productivity was achieved by in-situ H2 dispersion. Microbial community composition was investigated using high-throughput 16S rRNA gene amplicon sequencing and results were correlated with process parameters. Hydrogenotrophic methanogens were the dominant archaea during the whole experiment at mesophilic and thermophilic conditions.
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Affiliation(s)
- Laura Treu
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark; Department of Biology, University of Padua, 35131 Padua, Italy; Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padua, 35020 Legnaro, PD, Italy
| | - Panagiotis Tsapekos
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark.
| | - Maria Peprah
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark
| | | | - Alessio Giacomini
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padua, 35020 Legnaro, PD, Italy
| | - Viviana Corich
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padua, 35020 Legnaro, PD, Italy
| | - Panagiotis G Kougias
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark; Institute of Animal Science, Hellenic Agricultural Organisation Demeter, Paralimni 58100, Greece
| | - Irini Angelidaki
- Department of Environmental Engineering, Technical University of Denmark, Kgs. Lyngby, DK-2800, Denmark
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Rodríguez Gamero JE, Favaro L, Pizzocchero V, Lomolino G, Basaglia M, Casella S. Nuclease expression in efficient polyhydroxyalkanoates-producing bacteria could yield cost reduction during downstream processing. BIORESOURCE TECHNOLOGY 2018; 261:176-181. [PMID: 29660658 DOI: 10.1016/j.biortech.2018.04.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 04/04/2018] [Accepted: 04/05/2018] [Indexed: 06/08/2023]
Abstract
Industrial manufacturing of polyhydroxyalkanoates (PHAs) requires purification of PHAs granules from high-cell-density cultures. Cells are broken by homogenization and PHAs granules are cleansed and treated to obtain PHAs latexes. However, cell lysis releases large amounts of DNA which results in an increasing viscosity of the medium, hampering the following downstream steps. Drop in viscosity is generally achieved by costly procedures such as heat treatment or the supplementation of hypochlorite and commercially available nucleases. Searching for a cost-effective solution to this issue, a nuclease gene from Staphylococcus aureus has been integrated into two efficient PHAs-producing bacteria: Cupriavidus necator DSM 545 and Delftia acidovorans DSM 39. Staphylococcal nuclease has been proficiently expressed in both microbial hosts without affecting PHAs production. Moreover, the viscosity of the lysates of recombinant C. necator cells was greatly reduced, indicating that the engineered strain is expected to yield large reduction cost in PHAs downstream processing.
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Affiliation(s)
- Jesús E Rodríguez Gamero
- Department of Agronomy Food natural Resources Animals and Environment (DAFNAE), Università di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, PD, Italy
| | - Lorenzo Favaro
- Department of Agronomy Food natural Resources Animals and Environment (DAFNAE), Università di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, PD, Italy
| | - Valentino Pizzocchero
- Department of Agronomy Food natural Resources Animals and Environment (DAFNAE), Università di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, PD, Italy
| | - Giovanna Lomolino
- Department of Agronomy Food natural Resources Animals and Environment (DAFNAE), Università di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, PD, Italy
| | - Marina Basaglia
- Department of Agronomy Food natural Resources Animals and Environment (DAFNAE), Università di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, PD, Italy.
| | - Sergio Casella
- Department of Agronomy Food natural Resources Animals and Environment (DAFNAE), Università di Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, PD, Italy
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