Photosynthetic mixed culture polyhydroxyalkanoate (PHA) production from individual and mixed volatile fatty acids (VFAs): Substrate preferences and co-substrate uptake

2014 ◽  
Vol 185 ◽  
pp. 19-27 ◽  
Author(s):  
J.C. Fradinho ◽  
A. Oehmen ◽  
M.A.M. Reis
Keyword(s):  
Fatty Acids ◽  
Mixed Culture ◽  
Volatile Fatty Acids ◽  
Substrate Uptake ◽  
Substrate Preferences ◽  
Pha Production

Production of polyhydroxyalkanoates by glycogen accumulating organisms treating a paper mill wastewater

2008 ◽  
Vol 58 (2) ◽  
pp. 323-330 ◽  
Author(s):  
Simon Bengtsson ◽  
Alan Werker ◽  
Thomas Welander
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Dry Weight ◽  
Paper Mill ◽  
Batch Experiments ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Pha Production ◽  
Paper Mill Wastewater ◽  
Enrichment Strategy

A process for production of polyhydroxyalkanoates (PHA) by activated sludge treating a paper mill wastewater was investigated. The applied strategy was to select for glycogen accumulating organisms (GAOs) by alternating anaerobic/aerobic conditions. Acidogenic fermentation was used as pretreatment to convert various organic compounds to volatile fatty acids which are preferable substrates for PHA production. Enrichment resulted in a culture dominated by GAOs related to Defluviicoccus vanus (56%) and Candidatus Competibacter phosphatis (22%). Optimization of PHA accumulation by the enriched GAO culture was performed through batch experiments. Accumulation of PHA under anaerobic conditions was limited by the intracellular glycogen stored. Under aerobic conditions significant glycogen production (to 25% of sludge dry weight) was observed alongside PHA accumulation (to 22% of sludge dry weight). By applying a subsequent anaerobic period after an initial aerobic, the produced glycogen could be utilized for further PHA accumulation and by this strategy PHA content was increased to 42% of sludge dry weight. The PHA yield over the entire process was 0.10 kg per kg of influent COD treated which is similar to what has been achieved with a process applying feast/famine enrichment strategy with the same wastewater.

scholarly journals Pengaruh sumber karbon terhadap produksi bioplastik polihidroksialkanoat (PHA) dengan ralstonia eutropha

2018 ◽  
Vol 9 (1) ◽  
pp. 28
Author(s):  
Martha Aznury ◽  
Tjandra Setiadi ◽  
Adi Pancoro
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Carbon Source ◽  
Fermentation Process ◽  
Volatile Fatty Acids ◽  
Ralstonia Eutropha ◽  
Operating Conditions ◽  
Batch Bioreactor ◽  
Pha Production ◽  
Fructose Fermentation

Bioplastic Polyhidroxyalknoate (PHA) is a polyester type bioplastic with physicochemical properties resemble to those of polypropilen from petroleum. PHA production was investigated to determine the effect of carbon source on the fermentation process by Ralstonia eutropha. Specifically, Ralstonia eutropha was cultivated in a batch bioreactor to show the dynamics of P(3HB-co-3HV) copolymer production from glucose or fructose as C source. In adition, the effect of volatile fatty acids addition, as stimulator to the copolymer production, was also studied. The operating conditions in a 7 L bioreactor were at temperature 30 oC and pH 7.0. The concentration of carbon source glucose or fructose was 40 g/L, and after 20 hour fermentation, volatile fatty acids were added. With volatile fatty acids addition, the resulting fructose fermentation had PHA content of 32.78%, in which the HV percentage was 11.78%. Meanwhile, the fermentation of glucose, stimulated by volatile fatty acids, gave PHA as much as 20.19% with HV percentage of 8.71%. Therefore,, the Ralstonia eutropha fermentation of fructose as the carbon source gave a higher yield than glucose. Keywords: Volatil Fatty Acid, Fructose, Glucose, PHA, P(3HB-co-3HV), Ralstonia eutropha AbstrakBioplastik polihidroksialkanoat (PHA) adalah bioplastik dari kelompok poliester dengan sifat fisikokimia mirip dengan plastik polipropilen dari minyak bumi. Penelitian ini bertujuan untuk mempelajari pengaruh sumber karbon terhadap poduksi PHA yang dilakukan dengan proses fermentasi menggunakan Ralstonia eutropha. Ralstonia eutropha dikultivasi dalam bioreaktor batch untuk mempelajari dinamika produksi kopolimer P(3HB-co-3HV) dari sumber karbon glukosa atau fruktosa, serta mempelajari pengaruh sumber stimulator asam lemak volatil. Kondisi operasional fermentasi menggunakan bioreaktor 7 L adalah pada temperatur 30 oC dan pH 7. Konsentrasi sumber karbon glukosa atau fruktosa yang digunakan adalah 40 gr/L, dan setelah 20 jam fermentasi ditambahkan asam lemak volatil yang berfungsi sebagai stimulator dalam produksi P(3HB-co-3HV). Panen sel Ralstonia eutropha dilakukan setelah 60 jam. Hasil penelitian menunjukkan fermentasi Ralstonia eutropha dengan substrat fruktosa dan asam lemak volatil sebagai stimulator mempunyai kandungan PHA sebesar 32,78%, dengan kadar HV 11,78%. Pada pemberian substrat glukosa dan asam lemak volatil menunjukkan kandungan PHA sebesar 20,19%, dengan kadar HV 8.71%. Jadi fermentasi Ralstonia eutropha dengan menggunakan substrat fruktosa memberikan yield yang lebih tinggi dibandingkan menggunakan substrat glukosa.Kata Kunci: Asam lemak volatil, fruktosa, glukosa, PHA, P(3HB-co-3HV), Ralstonia eutropha

scholarly journals Economic process to produce biohydrogen and volatile fatty acids by a mixed culture using vinasse from sugarcane ethanol industry as nutrient source

2014 ◽  
Vol 159 ◽  
pp. 380-386 ◽  
Author(s):  
Eduardo Bittencourt Sydney ◽  
Christian Larroche ◽  
Alessandra Cristine Novak ◽  
Regis Nouaille ◽  
Saurabh Jyoti Sarma ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Mixed Culture ◽  
Volatile Fatty Acids ◽  
Nutrient Source ◽  
Economic Process

Production of polyhydroxyalkanoate (PHA) by Ralstonia eutropha JMP 134 with volatile fatty acids from palm oil mill effluent as precursors

2015 ◽  
Vol 72 (11) ◽  
pp. 1889-1895 ◽  
Author(s):  
Tjandra Setiadi ◽  
Martha Aznury ◽  
Azis Trianto ◽  
Adi Pancoro
Keyword(s):  
Fatty Acids ◽  
Palm Oil ◽  
Volatile Fatty Acids ◽  
Ralstonia Eutropha ◽  
Anaerobic Fermentation ◽  
Palm Oil Mill Effluent ◽  
Fed Batch ◽  
Batch Mode ◽  
Pha Production ◽  
Palm Oil Mill

The highest volatile fatty acids (VFAs) concentration from palm oil mill effluent (POME) treated by anaerobic fermentation was achieved for a 1-day process when the main acids used were acetic, propionic and butyric acids. Polyhydroxyalkanoate (PHA) production with VFAs from POME as precursors in the fed-batch mode has advantages over batch mode, both in terms of its productivity and 3HV (3-hydroxyvalerate) composition in the produced polymer. With the fed batch, the productivity increased to 343% and contained more 3HV than those of the batch. The structures of the PHA were identified by different methods and they supported each other; the resulting products consisted of functional groups of 3HB (3-hydroxybutyrate) and 3HV.

scholarly journals Photoheterotrophic Assimilation of Valerate and Associated Polyhydroxyalkanoate Production by Rhodospirillum rubrum

2020 ◽  
Vol 86 (18) ◽  
Author(s):  
Guillaume Bayon-Vicente ◽  
Sarah Zarbo ◽  
Adam Deutschbauer ◽  
Ruddy Wattiez ◽  
Baptiste Leroy
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Rhodospirillum Rubrum ◽  
Carbon Sources ◽  
Industrial Applications ◽  
Purple Nonsulfur Bacteria ◽  
Content Type ◽  
Fermentation Processes ◽  
Bicarbonate Ions ◽  
Pha Production

ABSTRACT Purple nonsulfur bacteria are increasingly recognized for industrial applications in bioplastics, pigment, and biomass production. In order to optimize the yield of future biotechnological processes, the assimilation of different carbon sources by Rhodospirillum rubrum has to be understood. As they are released from several fermentation processes, volatile fatty acids (VFAs) represent a promising carbon source in the development of circular industrial applications. To obtain an exhaustive characterization of the photoheterotrophic metabolism of R. rubrum in the presence of valerate, we combined phenotypic, proteomic, and genomic approaches. We obtained evidence that valerate is cleaved into acetyl coenzyme A (acetyl-CoA) and propionyl-CoA and depends on the presence of bicarbonate ions. Genomic and enzyme inhibition data showed that a functional methylmalonyl-CoA pathway is essential. Our proteomic data showed that the photoheterotrophic assimilation of valerate induces an intracellular redox stress which is accompanied by an increased abundance of phasins (the main proteins present in polyhydroxyalkanoate [PHA] granules). Finally, we observed a significant increase in the production of the copolymer P(HB-co-HV), accounting for a very high (>80%) percentage of HV monomer. Moreover, an increase in the PHA content was obtained when bicarbonate ions were progressively added to the medium. The experimental conditions used in this study suggest that the redox imbalance is responsible for PHA production. These findings also reinforce the idea that purple nonsulfur bacteria are suitable for PHA production through a strategy other than the well-known feast-and-famine process. IMPORTANCE The use and the littering of plastics represent major issues that humanity has to face. Polyhydroxyalkanoates (PHAs) are good candidates for the replacement of oil-based plastics, as they exhibit comparable physicochemical properties but are biobased and biodegradable. However, the current industrial production of PHAs is curbed by the production costs, which are mainly linked to the carbon source. Volatile fatty acids issued from the fermentation processes constitute interesting carbon sources, since they are inexpensive and readily available. Among them, valerate is gaining interest regarding the ability of many bacteria to produce a copolymer of PHAs. Here, we describe the photoheterotrophic assimilation of valerate by Rhodospirillum rubrum, a purple nonsulfur bacterium mainly known for its metabolic versatility. Using a knowledge-based optimization process, we present a new strategy for the improvement of PHA production, paving the way for the use of R. rubrum in industrial processes.

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