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Urtuvia V, Ponce B, Andler R, Peña C, Diaz-Barrera A. Extended batch cultures for poly(3-hydroxybutyrate- co-3-hydroxyvalerate) (PHBV) production by Azotobacter vinelandii OP growing at different aeration rates. 3 Biotech 2022; 12:304. [PMID: 36276477 PMCID: PMC9525563 DOI: 10.1007/s13205-022-03380-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 09/23/2022] [Indexed: 11/29/2022] Open
Abstract
Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a polymer produced by Azotobacter vinelandii OP. In the bioreactor, PHBV production and its molar composition are affected by aeration rate. PHBV production by A. vinelandii OP was evaluated using extended batch cultures at different aeration rates, which determined different oxygen transfer rates (OTR) in the cultures. Under the conditions evaluated, PHBV with different 3-hydroxyvalerate (3HV) fractions were obtained. In the cultures with a low OTR (6.7 mmol L-1 h-1, at 0.3 vvm), a PHBV content of 38% w w-1 with 9.1 mol % 3HV was achieved. The maximum PHBV production (72% w w-1) was obtained at a high OTR (18.2 mmol L-1 h-1, at 1.0 vvm), both at 48 h. Thus, PHBV production increased in the bioreactor with an increased aeration rate, but not the 3HV fraction in the polymer chain. An OTR of 24.9 mmol L-1 h-1 (at 2.1 vvm) was the most suitable for improving the PHBV content (61% w w-1) and a high 3HV fraction of 20.8 mol % (at 48 h); and volumetric productivity (0.15 g L-1 h-1). The findings indicate that the extended batch culture at 2.1 vvm is the most adequate mode of cultivation to produce higher biomass and PHBV with a high 3HV fraction. Overall, the results have shown that the PHBV production and 3HV fraction could be affected by the aeration rate and the proposed approach could be applied to implement cultivation strategies to optimize PHBV production for different biotechnological applications.
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Affiliation(s)
- Viviana Urtuvia
- Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso, Av. Brasil 2147 Casilla 4059, Valparaíso, Chile
| | - Belén Ponce
- Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso, Av. Brasil 2147 Casilla 4059, Valparaíso, Chile
| | - Rodrigo Andler
- Escuela de Ingeniería en Biotecnología, Centro de Biotecnología de los Recursos Naturales (Cenbio),Universidad Católica del Maule, Talca, Chile
| | - Carlos Peña
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Alvaro Diaz-Barrera
- Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso, Av. Brasil 2147 Casilla 4059, Valparaíso, Chile
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Chin JHC, Samian MR, Normi YM. Characterization of polyhydroxyalkanoate production capacity, composition and weight synthesized by Burkholderia cepacia JC-1 from various carbon sources. Heliyon 2022; 8:e09174. [PMID: 35368536 PMCID: PMC8971576 DOI: 10.1016/j.heliyon.2022.e09174] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 12/27/2021] [Accepted: 03/17/2022] [Indexed: 12/17/2022] Open
Abstract
Polyhydroxyalkanoates (PHA) are microbial polymers that have received widespread attention in recent decades as potential alternatives to some petrochemical-based plastics. However, widespread use of PHA is often impeded by its cost of production. Therefore, the search for and systematic investigation of versatile microbial PHA producers capable of using various carbon sources, even in the form of animal fats, for PHA biosynthesis is desirable. This study highlights the PHA production capacity, monomer composition and molecular weight synthesized by Burkholderia cepacia JC-1, a locally isolated strain from soil, from various carbon sources. In the category of simple sugars and plant oils, the use of glucose and palm oil at C:N ratio of 40 resulted in the highest accumulation of 52 wt% and 36 wt% poly(3-hydroxybutyrate) [P(3HB)] homopolymer and dry cell weight of 2.56 g/L and 3.17 g/L, respectively. Interestingly, B. cepacia JC-1 was able to directly utilize animal-derived lipid in the form of crude and extracted chicken fat, resulting in appreciable dry cell weight and PHA contents of up to 3.19 g/L and 47 wt% respectively, surpassing even that of palm oil in the group of triglycerides as substrates. The presence of antibiotics (streptomycin) in cultivation medium did not significantly affect cell growth and polymer production. The supply of sodium pentanoate as a co-substrate resulted in the incorporation of 3-hydroxyvalerate (3HV) monomer at fractions up to 37 mol%. The molecular weight of polymers produced from glucose, palm oil and chicken fat were in the range of 991–2118 kDa, higher than some reported studies involving native strains. The results from this study form an important basis for possible improvements in using B. cepacia JC-1 and crude chicken fats in solid form for PHA production in the future.
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Affiliation(s)
- Julian Hock-Chye Chin
- School of Biological Sciences, Universiti Sains Malaysia, 11800, Minden, Penang, Malaysia
| | - Mohd Razip Samian
- School of Biological Sciences, Universiti Sains Malaysia, 11800, Minden, Penang, Malaysia
| | - Yahaya M Normi
- Enzyme and Microbial Technology (EMTech) Research Center, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia.,Department of Cell and Molecular Biology, Faculty of Biotechnology and Bimolecular Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
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3
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Kavitha G, Rengasamy R, Inbakandan D. Polyhydroxybutyrate production from marine source and its application. Int J Biol Macromol 2018; 111:102-108. [DOI: 10.1016/j.ijbiomac.2017.12.155] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 10/18/2017] [Accepted: 12/28/2017] [Indexed: 11/17/2022]
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Noar JD, Bruno-Bárcena JM. Azotobacter vinelandii: the source of 100 years of discoveries and many more to come. MICROBIOLOGY-SGM 2018. [PMID: 29533747 DOI: 10.1099/mic.0.000643] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Azotobacter vinelandii has been studied for over 100 years since its discovery as an aerobic nitrogen-fixing organism. This species has proved useful for the study of many different biological systems, including enzyme kinetics and the genetic code. It has been especially useful in working out the structures and mechanisms of different nitrogenase enzymes, how they can function in oxic environments and the interactions of nitrogen fixation with other aspects of metabolism. Interest in studying A. vinelandii has waned in recent decades, but this bacterium still possesses great potential for new discoveries in many fields and commercial applications. The species is of interest for research because of its genetic pliability and natural competence. Its features of particular interest to industry are its ability to produce multiple valuable polymers - bioplastic and alginate in particular; its nitrogen-fixing prowess, which could reduce the need for synthetic fertilizer in agriculture and industrial fermentations, via coculture; its production of potentially useful enzymes and metabolic pathways; and even its biofuel production abilities. This review summarizes the history and potential for future research using this versatile microbe.
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Affiliation(s)
- Jesse D Noar
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina, USA
| | - Jose M Bruno-Bárcena
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina, USA
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Bonartsev AP, Zharkova II, Yakovlev SG, Myshkina VL, Mahina TK, Voinova VV, Zernov AL, Zhuikov VA, Akoulina EA, Ivanova EV, Kuznetsova ES, Shaitan KV, Bonartseva GA. Biosynthesis of poly(3-hydroxybutyrate) copolymers by Azotobacter chroococcum 7B: A precursor feeding strategy. Prep Biochem Biotechnol 2016; 47:173-184. [PMID: 27215309 DOI: 10.1080/10826068.2016.1188317] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A precursor feeding strategy for effective biopolymer producer strain Azotobacter chroococcum 7B was used to synthesize various poly(3-hydroxybutyrate) (PHB) copolymers. We performed experiments on biosynthesis of PHB copolymers by A. chroococcum 7B using various precursors: sucrose as the primary carbon source, various carboxylic acids and ethylene glycol (EG) derivatives [diethylene glycol (DEG), triethylene glycol (TEG), poly(ethylene glycol) (PEG) 300, PEG 400, PEG 1000] as additional carbon sources. We analyzed strain growth parameters including biomass and polymer yields as well as molecular weight and monomer composition of produced copolymers. We demonstrated that A. chroococcum 7B was able to synthesize copolymers using carboxylic acids with the length less than linear 6C, including poly(3-hydroxybutyrate-co-3-hydroxy-4-methylvalerate) (PHB-4MHV) using Y-shaped 6C 3-methylvaleric acid as precursor as well as EG-containing copolymers: PHB-DEG, PHB-TEG, PHB-PEG, and PHB-HV-PEG copolymers using short-chain PEGs (with n ≤ 9) as precursors. It was shown that use of the additional carbon sources caused inhibition of cell growth, decrease in polymer yields, fall in polymer molecular weight, decrease in 3-hydroxyvalerate content in produced PHB-HV-PEG copolymer, and change in bacterial cells morphology that were depended on the nature of the precursors (carboxylic acids or EG derivatives) and the timing of its addition to the growth medium.
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Affiliation(s)
- A P Bonartsev
- a A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences , Moscow , Russia.,b Faculty of Biology , Moscow State University , Moscow , Russia.,c Department of Maxillofacial and Oral Surgery , Nizhny Novgorod State Medical Academy , Nizhny Novgorod , Russia
| | - I I Zharkova
- b Faculty of Biology , Moscow State University , Moscow , Russia
| | - S G Yakovlev
- a A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences , Moscow , Russia.,c Department of Maxillofacial and Oral Surgery , Nizhny Novgorod State Medical Academy , Nizhny Novgorod , Russia
| | - V L Myshkina
- a A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences , Moscow , Russia
| | - T K Mahina
- a A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences , Moscow , Russia
| | - V V Voinova
- b Faculty of Biology , Moscow State University , Moscow , Russia.,c Department of Maxillofacial and Oral Surgery , Nizhny Novgorod State Medical Academy , Nizhny Novgorod , Russia
| | - A L Zernov
- a A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences , Moscow , Russia.,c Department of Maxillofacial and Oral Surgery , Nizhny Novgorod State Medical Academy , Nizhny Novgorod , Russia
| | - V A Zhuikov
- a A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences , Moscow , Russia.,c Department of Maxillofacial and Oral Surgery , Nizhny Novgorod State Medical Academy , Nizhny Novgorod , Russia
| | - E A Akoulina
- a A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences , Moscow , Russia
| | - E V Ivanova
- b Faculty of Biology , Moscow State University , Moscow , Russia
| | - E S Kuznetsova
- b Faculty of Biology , Moscow State University , Moscow , Russia
| | - K V Shaitan
- b Faculty of Biology , Moscow State University , Moscow , Russia
| | - G A Bonartseva
- a A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences , Moscow , Russia
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Bonartsev A, Yakovlev S, Boskhomdzhiev A, Zharkova I, Bagrov D, Myshkina V, Mahina T, Kharitonova E, Samsonova O, Zernov A, Zhuikov V, Efremov Y, Voinova V, Bonartseva G, Shaitan K. The terpolymer produced by Azotobacter chroococcum 7B: effect of surface properties on cell attachment. PLoS One 2013; 8:e57200. [PMID: 23468935 PMCID: PMC3582562 DOI: 10.1371/journal.pone.0057200] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Accepted: 01/18/2013] [Indexed: 12/02/2022] Open
Abstract
The copolymerization of poly(3-hydroxybutyrate) (PHB) is a promising trend in bioengineering to improve biomedical properties, e.g. biocompatibility, of this biodegradable polymer. We used strain Azotobacter chroococcum 7B, an effective producer of PHB, for biosynthesis of not only homopolymer and its main copolymer, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB-HV), but also novel terpolymer, poly(3-hydroxybutyrate-co-3-hydroxyvalerate)-poly(ethylene glycol) (PHB-HV-PEG), using sucrose as the primary carbon source and valeric acid and poly(ethylene glycol) 300 (PEG 300) as additional carbon sources. The chemical structure of PHB-HV-PEG was confirmed by (1)H nuclear-magnetic resonance analysis. The physico-chemical properties (molecular weight, crystallinity, hydrophilicity, surface energy) of produced biopolymer, the protein adsorption to the terpolymer, and cell growth on biopolymer films were studied. Despite of low EG-monomers content in bacterial-origin PHB-HV-PEG polymer, the terpolymer demonstrated significant improvement in biocompatibility in vitro in contrast to PHB and PHB-HV polymers, which may be coupled with increased protein adsorption, hydrophilicity and surface roughness of PEG-containing copolymer.
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Affiliation(s)
- Anton Bonartsev
- Faculty of Biology, Moscow State University, Moscow, Russia.
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Ezhov VA, Doronina NV, Trotsenko YA. Biosynthesis of polyhydroxybutyrate/valerate with different molecular weights during the growth of Methylobacterium extorquens G-10 on a methanol-pentanol mixture. APPL BIOCHEM MICRO+ 2013. [DOI: 10.1134/s0003683813020038] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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8
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Salim YS, Sharon A, Vigneswari S, Mohamad Ibrahim MN, Amirul AA. Environmental Degradation of Microbial Polyhydroxyalkanoates and Oil Palm-Based Composites. Appl Biochem Biotechnol 2012; 167:314-26. [DOI: 10.1007/s12010-012-9688-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Accepted: 04/10/2012] [Indexed: 11/29/2022]
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9
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Myshkina VL, Ivanov EA, Nikolaeva DA, Makhina TK, Bonartsev AP, Filatova EV, Ruzhitsky AO, Bonartseva GA. Biosynthesis of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) copolymer by Azotobacter chroococcum strain 7B. APPL BIOCHEM MICRO+ 2010. [DOI: 10.1134/s0003683810030075] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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10
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Wang Y, Ruan L, Chua H, Yu PH. Cloning and expression of the PHA synthase genes phaC1 and phaC1AB into Bacillus subtilis. World J Microbiol Biotechnol 2006. [DOI: 10.1007/s11274-005-9071-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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11
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Third KA, Newland M, Cord-Ruwisch R. The effect of dissolved oxygen on PHB accumulation in activated sludge cultures. Biotechnol Bioeng 2003; 82:238-50. [PMID: 12584766 DOI: 10.1002/bit.10564] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Nitrogen removal from wastewater is often limited by the availability of reducing power to perform denitrification, especially when treating wastewaters with a low carbon:nitrogen ratio. In the increasingly popular sequencing batch reactor (SBR), bacteria have the opportunity to preserve reducing power from incoming chemical oxygen demand (COD) as poly-beta-hydroxybutyrate (PHB). The current study uses laboratory experiments and mathematical modeling in an attempt to generate a better understanding of the effect of oxygen on microbial conversion of COD into PHB. Results from a laboratory SBR with acetate as the organic carbon source showed that the aerobic acetate uptake process was oxygen-dependent, producing higher uptake rates at higher dissolved oxygen (DO) supply rates. However, at the lower DO supply rates (k(L)a 6 to 16 h(-1), 0 mg L(-1) DO), a higher proportion of the substrate was preserved as PHB than at higher DO supply rates (k(L)a 30, 51 h(-1), DO >0.9 mg L(-1)). Up to 77% of the reducing equivalents available from acetate were converted to PHB under oxygen limitation (Y(PHB/Ac) 0.68 Cmol/Cmol), as opposed to only 54% under oxygen-excess conditions (Y(PHB/Ac) 0.48 Cmol/Cmol), where a higher fraction of acetate was used for biomass growth. It was calculated that, by oxygen management during the feast phase, the amount of PHB preserved (1.4 Cmmol L(-1) PHB) accounted for an additional denitrification potential of up to 18 mg L(-1) nitrate-nitrogen. The trends of the effect of oxygen (and hence ATP availability) on PHB accumulation could be reproduced by the simulation model, which was based on biochemical stoichiometry and maximum rates obtained from experiments. Simulated data showed that, at low DO concentrations, the limited availability of adenosine triphosphate (ATP) prevented significant biomass growth and most ATP was used for acetate transport into the cell. In contrast, high DO supply rates provided surplus ATP and hence higher growth rates, resulting in decreased PHB yields. The results suggest that oxygen management is crucial to conserving reducing power during the feast phase of SBR operation, as excessive aeration rates decrease the PHB yield and allow higher biomass growth.
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Affiliation(s)
- Katie A Third
- Division of Science and Engineering, School of Biological Sciences and Biotechnology, Murdoch University, South Street, Murdoch, WA 6150, Australia.
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Olivera ER, Carnicero D, García B, Miñambres B, Moreno MA, Cañedo L, Dirusso CC, Naharro G, Luengo JM. Two different pathways are involved in the beta-oxidation of n-alkanoic and n-phenylalkanoic acids in Pseudomonas putida U: genetic studies and biotechnological applications. Mol Microbiol 2001; 39:863-74. [PMID: 11251808 DOI: 10.1046/j.1365-2958.2001.02296.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In Pseudomonas putida U, the degradation of n-alkanoic and n-phenylalkanoic acids is carried out by two sets of beta-oxidation enzymes (betaI and betaII). Whereas the first one (called betaI) is constitutive and catalyses the degradation of n-alkanoic and n-phenylalkanoic acids very efficiently, the other one (betaII), which is only expressed when some of the genes encoding betaI enzymes are mutated, catabolizes n-phenylalkanoates (n > 4) much more slowly. Genetic studies revealed that disruption or deletion of some of the betaI genes handicaps the growth of P. putida U in media containing n-alkanoic or n-phenylalkanoic acids with an acyl moiety longer than C4. However, all these mutants regained their ability to grow in media containing n-alkanoates as a result of the induction of betaII, but they were still unable to catabolize n-phenylalkanoates completely, as the betaI-FadBA enzymes are essential for the beta-oxidation of certain n-phenylalkanoyl-CoA derivatives when they reach a critical size. Owing to the existence of the betaII system, mutants lacking betaIfadB/A are able to synthesize new poly 3-OH-n-alkanoates (PHAs) and poly 3-OH-n-phenylalkanoates (PHPhAs) efficiently. However, they are unable to degrade these polymers, becoming bioplastic overproducer mutants. The genetic and biochemical importance of these results is reported and discussed.
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Affiliation(s)
- E R Olivera
- Departamento de Bioquímica y Biología Molecular, Facultad de Veterinaria, Universidad de León, 24007 León, Spain
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Abstract
Azotobacter vinelandii is proposed to contain a single beta-ketothiolase activity participating in the formation of acetoacetyl-CoA, a precursor for poly-beta-hydroxybutyrate (PHB) synthesis, and in beta-oxidation (Manchak, J., Page, W.J., 1994. Control of polyhydroxyalkanoate synthesis in Azotobacter vinelandii strain UWD. Microbiology 140, 953-963). We designed a degenerate oligonucleotide from a highly conserved region among bacterial beta-ketothiolases and used it to identify bktA, a gene with a deduced protein product with a high similarity to beta-ketothiolases. Immediately downstream of bktA, we identified a gene called hbdH, which encodes a protein exhibiting similarity to beta-hydroxyacyl-CoA and beta-hydroxybutyryl-CoA dehydrogenases. Two regions with homology to bktA were also observed. One of these was cloned and allowed the identification of the phbA gene, encoding a second beta-ketothiolase. Strains EV132, EV133, and GM1 carrying bktA, hbdH and phbA mutations, respectively, as well as strain EG1 carrying both bktA and phbA mutations, were constructed. The hbdH mutation had no effect on beta-hydroxybutyryl-CoA dehydrogenase activity or on fatty acid assimilation. The bktA mutation had no effect on beta-ketothiolase activity, PHB synthesis or fatty acid assimilation, whereas the phbA mutation significantly reduced beta-ketothiolase activity and PHB accumulation, showing that this is the beta-ketothiolase involved in PHB biosynthesis. Strain EG1 was found to grow under beta-oxidation conditions and to possess beta-ketothiolase activity. Taken together, these results demonstrate the presence of three genes coding for beta-ketothiolases in A. vinelandii.
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Affiliation(s)
- D Segura
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apartado Postal 510-3, Cuernavaca, 62250, Morelos, Mexico
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Yan YB, Wu Q, Zhang RQ. Dynamic accumulation and degradation of poly(3-hydroxyalkanoate)s in living cells of Azotobacter vinelandii UWD characterized by (13)C NMR. FEMS Microbiol Lett 2000; 193:269-73. [PMID: 11111035 DOI: 10.1111/j.1574-6968.2000.tb09435.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The synthesis and degradation of poly(3-hydroxybutyrate) (PHB) and poly(3-hydroxybutyrate-co-hydroxyvalerate) (P(HB-co-HV)) by Azotobacter vinelandii UWD were investigated using natural abundance solution (13)C nuclear magnetic resonance (NMR) in vivo in shake flask culture and in fermenter culture. The synthesis and the degradation of poly(3-hydroxyalkanoate)s (PHA) monomers hydroxybutyrate (HB) and hydroxyvalerate (HV) had different rates. The amount of HB and HV increased dramatically in the initial degradation stage. The results suggest that the intracellular PHA of strain UWD was the subject of dynamic metabolic processing. (13)C NMR in vivo analysis provided a rapid, easy, accurate, non-destructive method to obtain valuable information on the metabolism of PHA.
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Affiliation(s)
- Y B Yan
- Department of Biological Sciences and Biotechnology, Tsinghua University, 100084, Beijing, PR China
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15
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Savenkova L, Gercberga Z, Bibers I, Kalnin M. Effect of 3-hydroxy valerate content on some physical and mechanical properties of polyhydroxyalkanoates produced by Azotobacter chroococcum. Process Biochem 2000. [DOI: 10.1016/s0032-9592(00)00235-1] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Durner R, Witholt B, Egli T. Accumulation of Poly[(R)-3-hydroxyalkanoates] in Pseudomonas oleovorans during growth with octanoate in continuous culture at different dilution rates. Appl Environ Microbiol 2000; 66:3408-14. [PMID: 10919799 PMCID: PMC92163 DOI: 10.1128/aem.66.8.3408-3414.2000] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas oleovorans ATCC 29347 was grown in chemostat culture at different dilution rates with mineral media varying in their ratios of octanoate to ammonia (C(0)/N(0) ratio). At all dilution rates tested, three distinct growth regimes were observed: (i) carbon limitation with NH(4)(+) in excess at low C(0)/N(0) ratios, (ii) purely nitrogen-limited growth conditions at high C(0)/N(0) ratios with residual octanoate in the culture supernatant, and (iii) an intermediate zone of dual-nutrient-limited growth conditions where both the concentration of octanoate and that of ammonia were very low. The dual-nutrient-limited growth zone shifted to higher C(0)/N(0) ratios with decreasing dilution rates, and the extension of the dual-nutrient-limited growth zone was inversely proportional to the growth rate. The cells accumulated the storage compound medium-chain-length poly[(R)-3-hydroxyalkanoate] (mcl-PHA) during dual (C and N)-nutrient-limited and N-limited growth conditions. Within the dual-nutrient-limited growth zone, the cellular mcl-PHA contents increased when the C(0)/N(0) ratio in the feed was increased, whereas the cellular mcl-PHA level was independent from the feed C(0)/N(0) ratio during N-limited growth. The monomeric composition of the accumulated mcl-PHA was independent of both the dilution rate and the feed C(0)/N(0) ratio and consisted of 12 mol% 3-hydroxyhexanoic acid and 88 mol% 3-hydroxyoctanoic acid. Accumulation of mcl-PHA led to an increase in the cellular C/N ratio and to changes in elemental growth yields for nitrogen and carbon.
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Affiliation(s)
- R Durner
- Department of Microbiology, Swiss Federal Institute for Environmental Science and Technology (EAWAG), Dübendorf, Switzerland
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Sheu DS, Wang YT, Lee CY. Rapid detection of polyhydroxyalkanoate-accumulating bacteria isolated from the environment by colony PCR. MICROBIOLOGY (READING, ENGLAND) 2000; 146 ( Pt 8):2019-2025. [PMID: 10931906 DOI: 10.1099/00221287-146-8-2019] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Colony PCR and semi-nested PCR techniques were employed for screening polyhydroxyalkanoate (PHA) producers isolated from the environment. Three degenerate primers were designed based on multiple sequence alignment results and were used as PCR primers to detect PHA synthase genes. Optimized colony PCR conditions were achieved by adding 3% DMSO combined with 1 M betaine to the reaction mixture. The sensitivity limit of the colony PCR was 1x 10(5) viable cells for Ralstonia eutropha. Nineteen PHA-positive bacteria were used to evaluate this PCR protocol; fifteen of the nineteen could be detected by colony PCR, and the other four could be detected by applying semi-nested PCR detection following colony PCR. In a preliminary screening project, 38 PHA-positive strains were isolated from environmental samples by applying the PCR protocol, and their phenotype was further confirmed by Nile blue A staining assay. By combining the colony PCR and semi-nested PCR techniques, a rapid, reliable and highly accurate detection method has been developed for detecting PHA producers. This protocol is suitable for screening large numbers of environmental isolates. The PHA accumulation ability of well-separated colonies isolated from environmental samples can be directly validated by PCR with no further culturing or chromosomal DNA extraction procedures. In addition to its application to the screening of wild-type isolates, the individual PCR-amplified product is also suitable as a specific probe for PHA operon cloning. The results suggest that the application of this PCR protocol for rapid detection of PHA producers from the environment is plausible.
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Affiliation(s)
- Der-Shyan Sheu
- Graduate Institute of Agricultural Chemistry, National Taiwan University, 1, Sec. 4, Roosevelt Rd, Taipei 106, Taiwan1
| | - Yun-Ting Wang
- Graduate Institute of Agricultural Chemistry, National Taiwan University, 1, Sec. 4, Roosevelt Rd, Taipei 106, Taiwan1
| | - Chia-Yin Lee
- Graduate Institute of Agricultural Chemistry, National Taiwan University, 1, Sec. 4, Roosevelt Rd, Taipei 106, Taiwan1
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García B, Olivera ER, Miñambres B, Fernández-Valverde M, Cañedo LM, Prieto MA, García JL, Martínez M, Luengo JM. Novel biodegradable aromatic plastics from a bacterial source. Genetic and biochemical studies on a route of the phenylacetyl-coa catabolon. J Biol Chem 1999; 274:29228-41. [PMID: 10506180 DOI: 10.1074/jbc.274.41.29228] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Novel biodegradable bacterial plastics, made up of units of 3-hydroxy-n-phenylalkanoic acids, are accumulated intracellularly by Pseudomonas putida U due to the existence in this bacterium of (i) an acyl-CoA synthetase (encoded by the fadD gene) that activates the aryl-precursors; (ii) a beta-oxidation pathway that affords 3-OH-aryl-CoAs, and (iii) a polymerization-depolymerization system (encoded in the pha locus) integrated by two polymerases (PhaC1 and PhaC2) and a depolymerase (PhaZ). The complete assimilation of these compounds requires two additional routes that specifically catabolize the phenylacetyl-CoA or the benzoyl-CoA generated from these polyesters through beta-oxidation. Genetic studies have allowed the cloning, sequencing, and disruption of the genes included in the pha locus (phaC1, phaC2, and phaZ) as well as those related to the biosynthesis of precursors (fadD) or to the catabolism of their derivatives (acuA, fadA, and paa genes). Additional experiments showed that the blockade of either fadD or phaC1 hindered the synthesis and accumulation of plastic polymers. Disruption of phaC2 reduced the quantity of stored polymers by two-thirds. The blockade of phaZ hampered the mobilization of the polymer and decreased its production. Mutations in the paa genes, encoding the phenylacetic acid catabolic enzymes, did not affect the synthesis or catabolism of polymers containing either 3-hydroxyaliphatic acids or 3-hydroxy-n-phenylalkanoic acids with an odd number of carbon atoms as monomers, whereas the production of polyesters containing units of 3-hydroxy-n-phenylalkanoic acids with an even number of carbon atoms was greatly reduced in these bacteria. Yield-improving studies revealed that mutants defective in the glyoxylic acid cycle (isocitrate lyase(-)) or in the beta-oxidation pathway (fadA), stored a higher amount of plastic polymers (1.4- and 2-fold, respectively), suggesting that genetic manipulation of these pathways could be useful for isolating overproducer strains. The analysis of the organization and function of the pha locus and its relationship with the core of the phenylacetyl-CoA catabolon is reported and discussed.
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Affiliation(s)
- B García
- Departamento de Bioquímica y Biología Molecular, Facultades de Biología y Veterinaria, Campus de Vegazana s/n, Universidad de León, 24007 León, España
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Affiliation(s)
- C Sasikala
- Department of Botany, Osmania University, Hyderabad, India
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