1
|
Polyhydroxyalkanoate bio-production and its rise as biomaterial of the future. J Biotechnol 2022; 348:10-25. [PMID: 35298952 DOI: 10.1016/j.jbiotec.2022.03.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 02/20/2022] [Accepted: 03/01/2022] [Indexed: 10/18/2022]
Abstract
The first observation of a polyhydroxyalkanoate (PHA) aggregate was in 1888 by Beijenrinck. Despite polyhydroxybutyrate (PHB) being the first type of PHA discovered, it was not extracted and characterized until 1925 by Maurice Lemoigne in France, even before the concept of "macromolecules" was known. After more than 30 years, in 1958, Wilkinson and co-workers rediscovered PHB and its metabolic role in the cells as storage compound. PHB started to be appealing to the industry in the 1980s, when a few companies started to commercialize microbially produced PHAs. During the 1990 s, the focus was on reducing production costs to make PHA production economically feasible, for instance by genetically modified microorganisms and even plants. Since then, many advances have been made: diverse wastes as feedstock, different production processes, and tailored design of biopolymers. This paper summarizes the scientific and technological development of PHAs from their discovery in 1888 until their latest applications and current commercial uses. Future perspectives have been devised too based on the current bottlenecks.
Collapse
|
2
|
Giraldo-Montoya JM, Castaño-Villa GJ, Rivera-Páez FA. Bacteria from industrial waste: potential producers of polyhydroxyalkanoates (PHAs) in Manizales, Colombia. ENVIRONMENTAL MONITORING AND ASSESSMENT 2020; 192:480. [PMID: 32617674 DOI: 10.1007/s10661-020-08461-5] [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: 08/25/2019] [Accepted: 06/25/2020] [Indexed: 06/11/2023]
Abstract
Polymers are currently used in the industry as raw material, yet they are rapidly eliminated and largely contaminate the environment. To address this issue, there is a special interest in biodegradable polymers, namely, polyhydroxyalkanoates (PHAs), produced by microorganisms. This study identifies PHA-producing bacteria from two industrial wastewaters of Manizales, Colombia. The samples were cultured in mineral salt medium with glucose as the carbon source in the presence of Nile red stain. The fluorescent colonies were independently transferred to another medium and assessed through fluorescence microscopy with Nile blue stain. The fluorescent strains under Nile blue staining were purified in Nutrient Agar, and their morphological and microbiological characteristics were determined. The bacteria positive for red-orange fluorescence were purified in Nutrient Agar medium, and molecular analyses were performed by PCR amplification of a 650-bp fragment of the 16S ribosomal DNA gene. The bacteria were also assessed in terms of PHA production. We confirmed the identity of 12 out of 14 PHA-positive strains, which belonged to the following genera: Bacillus, Lactococcus, Citrobacter, Enterobacter, and Acinetobacter. Five of the isolates (Enterobacter cloacae, Enterobacter sp., Enterobacter ludwigii, Bacillus thuringiensis, and Bacillus safensis) are promising strains for PHA production, with production values ranging from 0.360 to 0.9960 g/L. Bacteria that produce more than 0.3 g/L are considered useful for the industrial manufacture of bioplastic. We recommend performing large-scale studies on these strains to assess their use for the industrial production of biopolymers, allowing to generate high-impact bioconversion processes of industrial interest.
Collapse
Affiliation(s)
- Javier M Giraldo-Montoya
- Grupo de Investigación GEBIOME, Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad de Caldas, Calle 65 No. 26-10 Apartado Aéreo 275 Manizales, Caldas, Colombia
- Laboratorio de Biotecnología, Centro de Investigación e Innovación TECNOACADEMIA, Centro Industrial y Desarrollo Empresarial, Servicio Nacional de Aprendizaje - SENA, Autopista Sur Carrera 4a # 53-54, Soacha, Cundinamarca, Colombia
| | - Gabriel J Castaño-Villa
- Grupo de Investigación GEBIOME, Departamento de Desarrollo Rural y Recursos Naturales, Facultad de Ciencias Agropecuarias, Universidad de Caldas, Calle 65 No. 26-10 Apartado Aéreo 275 Manizales, Caldas, Colombia
| | - Fredy A Rivera-Páez
- Grupo de Investigación GEBIOME, Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad de Caldas, Calle 65 No. 26-10 Apartado Aéreo 275 Manizales, Caldas, Colombia.
| |
Collapse
|
3
|
Kumar G, Ponnusamy VK, Bhosale RR, Shobana S, Yoon JJ, Bhatia SK, Rajesh Banu J, Kim SH. A review on the conversion of volatile fatty acids to polyhydroxyalkanoates using dark fermentative effluents from hydrogen production. BIORESOURCE TECHNOLOGY 2019; 287:121427. [PMID: 31104939 DOI: 10.1016/j.biortech.2019.121427] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 05/03/2019] [Accepted: 05/04/2019] [Indexed: 06/09/2023]
Abstract
The production of bio/microbial-based polymers, polyhydroxyalkanoates (PHAs) from volatile fatty acids (VFAs) of dark fermentative effluents in the bio-H2 reactor is being paid attention, owing to their commercial demand, applications and as carbon as well as energy storage source. Since, they are the cheap precursors for such valuable renewable biopolymers which all possess the properties; those are analogous to the petro-derived plastics. Several studies were stated, related to the consumption of both individual and mixed VFAs for the potential PHAs production. Their biodegradability nature makes them extremely desirable alternative to fossil-derived synthetic polymers. In this regard, this review summarizes the use of bio-based PHAs production via both microbial and biochemical pathways using dark fermentative bio-H2 production from waste streams as feedstock. Furthermore, this review deals the characteristics, synthesis and production of the bio-based PHAs along with their co-polymers and applications to give an outlook on future research.
Collapse
Affiliation(s)
- Gopalakrishnan Kumar
- Institute of Chemistry, Bioscience and Environmental Engineering, Faculty of Science and Technology, University of Stavanger, Box 8600 Forus, 4036 Stavanger, Norway; School of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Vinoth Kumar Ponnusamy
- Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung City 807, Taiwan; Research Center for Environmental Medicine, Kaohsiung Medical University, Kaohsiung City 807, Taiwan
| | - Rahul R Bhosale
- Department of Chemical Engineering, College of Engineering, Qatar University, P.O Box 2713, Doha, Qatar
| | - Sutha Shobana
- Department of Chemistry and Research Centre, Aditanar College of Arts and Science, Virapandianpatnam, Tiruchendur, Tamil Nadu, India
| | - Jeong-Jun Yoon
- Intelligent Sustainable Materials R&BD Group, Korea Institute of Industrial Technology (KITECH), Cheonan, Chungnam 31056, Republic of Korea
| | - Shashi Kant Bhatia
- Department of Biological Engineering, College of Engineering, Konkuk University, Seoul, Republic of Korea
| | - J Rajesh Banu
- Department of Civil Engineering, Anna University Regional Campus, Tirunelveli, India
| | - Sang-Hyoun Kim
- School of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of Korea.
| |
Collapse
|
4
|
Ntaikou I, Koumelis I, Kamilari M, Iatridi Z, Tsitsilianis C, Lyberatos G. Effect of nitrogen limitation on polyhydroxyalkanoates production efficiency, properties and microbial dynamics using a soil-derived mixed continuous culture. INTERNATIONAL JOURNAL OF BIOBASED PLASTICS 2019. [DOI: 10.1080/24759651.2019.1648016] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Ioanna Ntaikou
- Institute of Chemical Engineering Sciences, Foundation for Research and Technology (ICEHT/FORTH), Patras, Greece
| | - Ioannis Koumelis
- Institute of Chemical Engineering Sciences, Foundation for Research and Technology (ICEHT/FORTH), Patras, Greece
- Department of Chemical Engineering, University of Patras, Patras, Greece
| | - Maria Kamilari
- Department of Biology, University of Patras, Patras, Greece
- Department of Biology, Section of Ecology and Evolution, University of Copenhagen, Copenhagen, Denmark
| | - Zacharoula Iatridi
- Department of Chemical Engineering, University of Patras, Patras, Greece
| | | | - Gerasimos Lyberatos
- Institute of Chemical Engineering Sciences, Foundation for Research and Technology (ICEHT/FORTH), Patras, Greece
- School of Chemical Engineering, National Technical University of Athens, Athens, Greece
| |
Collapse
|
5
|
Ciesielski S, Górniak D, Możejko J, Świątecki A, Grzesiak J, Zdanowski M. The diversity of bacteria isolated from antarctic freshwater reservoirs possessing the ability to produce polyhydroxyalkanoates. Curr Microbiol 2014; 69:594-603. [PMID: 24939384 PMCID: PMC4201758 DOI: 10.1007/s00284-014-0629-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 04/30/2014] [Indexed: 11/30/2022]
Abstract
The diversity of polyhydroxyalkanoates-producing bacteria in freshwater reservoirs in the Ecology Glacier foreland, Antarctica, was examined by a cultivation-dependent method. Isolated strains were analyzed phylogenetically by 16S rRNA gene sequencing, and classified as members of Alpha-, Beta-, or Gammaproteobacteria classes. Polymerase chain reaction was used to detect PHA synthase genes. Potential polyhydroxyalkanoates (PHAs) producers belonging mainly to Pseudomonas sp., and Janthinobacterium sp. were isolated from all five sampling sites, suggesting that PHA synthesis is a common bacterial feature at pioneer sites. All Pseudomonas strains had the genetic potential to synthesize medium-chain-length PHAs, whereas some isolated Janthinobacterium strains might produce short-chain-length PHAs or medium-chain-length PHAs. It is the first report revealing that Janthinobacterium species could have the potential to produce medium-chain-length PHAs.
Collapse
Affiliation(s)
- Slawomir Ciesielski
- Department of Environmental Biotechnology, University of Warmia and Mazury in Olsztyn, ul. Sloneczna 45G, 10-718, Olsztyn, Poland,
| | | | | | | | | | | |
Collapse
|
6
|
Studies on the Microbial Synthesis and Characterization of Polyhydroxyalkanoates Containing 4-Hydroxyvalerate Using γ-Valerolactone. Appl Biochem Biotechnol 2013; 170:1194-215. [DOI: 10.1007/s12010-013-0247-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 04/15/2013] [Indexed: 10/26/2022]
|
7
|
Chansatein O, Urairong H, Rodtong S. Development of Cultivation Media for Polyhydroxyalkanoates Accumulation in Bacterial Cells Isolated from Cassava Pulp. ACTA ACUST UNITED AC 2012. [DOI: 10.3923/rjbsci.2012.31.37] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
8
|
Lee SH, Kim JH, Mishra D, Ni YY, Rhee YH. Production of medium-chain-length polyhydroxyalkanoates by activated sludge enriched under periodic feeding with nonanoic acid. BIORESOURCE TECHNOLOGY 2011; 102:6159-66. [PMID: 21463934 DOI: 10.1016/j.biortech.2011.03.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2011] [Revised: 03/08/2011] [Accepted: 03/08/2011] [Indexed: 05/20/2023]
Abstract
The potential use of activated sludge for the production of medium-chain-length polyhydroxyalkanoates (MCL-PHAs) was investigated. The enrichment of bacterial populations capable of producing MCL-PHAs was achieved by periodic feeding with nonanoic acid in a sequencing batch reactor (SBR). Denaturing gradient gel electrophoresis analysis revealed Pseudomonas aeruginosa strains to be predominant in the bacterial community during the SBR process. The composition of PHA synthesized by the enriched biomass from nonanoic acid consisted of a large concentration (>89 mol%) of MCL monomer units and a small amount of short-chain-length monomer units. Under fed-batch fermentation with continuous feeding of nonanoic acid at a flow rate of 0.225 g/L/h and a C/N ratio of 40, a maximum PHA content of 48.6% dry cell weight and a conversion yield (Y(p/s)) of 0.94 g/g were achieved. These results indicate that MCL-PHA production by activated sludge is a promising alternative to typical pure culture approaches.
Collapse
Affiliation(s)
- Sun Hee Lee
- Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon 305-764, Republic of Korea
| | | | | | | | | |
Collapse
|
9
|
The influence of nitrogen limitation on mcl-PHA synthesis by two newly isolated strains of Pseudomonas sp. J Ind Microbiol Biotechnol 2010; 37:511-20. [DOI: 10.1007/s10295-010-0698-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2009] [Accepted: 02/10/2010] [Indexed: 11/30/2022]
|
10
|
Sujatha K, Mahalakshmi A, Solaiman DKY, Shenbagarathai R. Sequence Analysis, Structure Prediction, and Functional Validation ofphaC1/phaC2Genes ofPseudomonassp. LDC-25 and Its Importance in Polyhydroxyalkanoate Accumulation. J Biomol Struct Dyn 2009; 26:771-9. [DOI: 10.1080/07391102.2009.10507289] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
11
|
Zhang X, Luo R, Wang Z, Deng Y, Chen GQ. Application of (R)-3-Hydroxyalkanoate Methyl Esters Derived from Microbial Polyhydroxyalkanoates as Novel Biofuels. Biomacromolecules 2009; 10:707-11. [DOI: 10.1021/bm801424e] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Xiaojun Zhang
- Multidisciplinary Research Center, Shantou University, Shantou, Guangdong 515063, China, and Department of Biological Science and Biotechnology, Tsinghua University, Beijing 100084, China
| | - Rongcong Luo
- Multidisciplinary Research Center, Shantou University, Shantou, Guangdong 515063, China, and Department of Biological Science and Biotechnology, Tsinghua University, Beijing 100084, China
| | - Zhen Wang
- Multidisciplinary Research Center, Shantou University, Shantou, Guangdong 515063, China, and Department of Biological Science and Biotechnology, Tsinghua University, Beijing 100084, China
| | - Yuan Deng
- Multidisciplinary Research Center, Shantou University, Shantou, Guangdong 515063, China, and Department of Biological Science and Biotechnology, Tsinghua University, Beijing 100084, China
| | - Guo-Qiang Chen
- Multidisciplinary Research Center, Shantou University, Shantou, Guangdong 515063, China, and Department of Biological Science and Biotechnology, Tsinghua University, Beijing 100084, China
| |
Collapse
|
12
|
Poirier I, Jean N, Guary JC, Bertrand M. Responses of the marine bacterium Pseudomonas fluorescens to an excess of heavy metals: physiological and biochemical aspects. THE SCIENCE OF THE TOTAL ENVIRONMENT 2008; 406:76-87. [PMID: 18793794 DOI: 10.1016/j.scitotenv.2008.07.038] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2008] [Revised: 06/24/2008] [Accepted: 07/10/2008] [Indexed: 05/26/2023]
Abstract
A Pseudomonas fluorescens strain was isolated from oxic marine sediments obtained from the strand zone of the St Anne Bay (a moderately metal-contaminated site to the west of Cherbourg harbour). The strain, which exhibited a high tolerance to metal contamination when cultivated (minimal inhibitory concentration=950 microM [62 mg L(-1)] for Zn, 660 microM [42 mg L(-1)] for Cu, and 505 microM [57 mg L(-1)] for Cd), was further characterized by its physiological and biochemical responses to metal additions to the culture medium. Bacterial growth was significantly disturbed by 380 microM Zn (25 mg L(-1)), 315 microM Cu (20 mg L(-1)) and 90 microM Cd (10 mg L(-1)). The Zn-containing alkaline phosphatase was studied as an intoxication biomarker. Its activity was stimulated (+9%) by an excess of Zn, but inhibited by Cd (-55%) and Cu (-10%), these two elements could displace the native Zn or/and disturb the enzyme 3D-structure. Bacterial O(2) consumption was recorded as a global physiological response to metal stress. This parameter dropped with increasing Cd and Cu contamination (-49% and -45%, respectively, at 20 mg L(-1)). By contrast, Zn increased O2 consumption (approximately +40% for the different tested concentrations). The proteomes of bacteria grown in the presence or absence of 20 mg metal L(-1) were characterized by 2D-gel electrophoresis. The number of spots exhibiting a difference in intensity between the contaminated sample and the control was 65, 68, and 103, for Zn, Cu and Cd, respectively. Among them, 45, 61 and 82 spots respectively appeared de novo or increased in intensity, indicative of metal-stimulated synthesis, particularly for Cu and Cd. In summary, whereas Cd and Cu treatments both stressed cells and slowed down primary metabolism to differing extents, Zn has a stimulating action on several physiological and biochemical parameters.
Collapse
Affiliation(s)
- I Poirier
- Equipe Microorganismes-Métaux-Toxicité, Laboratoire d'Etudes et de Recherches Marines, Institut National des Sciences et Techniques de la Mer, Conservatoire National des Arts et Métiers, BP 324, F-50103 Cherbourg Cedex, France.
| | | | | | | |
Collapse
|
13
|
Serafim LS, Lemos PC, Albuquerque MGE, Reis MAM. Strategies for PHA production by mixed cultures and renewable waste materials. Appl Microbiol Biotechnol 2008; 81:615-28. [PMID: 19002455 DOI: 10.1007/s00253-008-1757-y] [Citation(s) in RCA: 163] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2008] [Revised: 10/09/2008] [Accepted: 10/18/2008] [Indexed: 11/26/2022]
Abstract
Production of polyhydroxyalkanoates (PHA) by mixed cultures has been widely studied in the last decade. Storage of PHA by mixed microbial cultures occurs under transient conditions of carbon or oxygen availability, known respectively as aerobic dynamic feeding and anaerobic/aerobic process. In these processes, PHA-accumulating organisms, which are quite diverse in terms of phenotype, are selected by the dynamic operating conditions imposed to the reactor. The stability of these processes during long-time operation and the similarity of the polymer physical/chemical properties to the one produced by pure cultures were demonstrated. This process could be implemented at industrial scale, providing that some technological aspects are solved. This review summarizes the relevant research carried out with mixed cultures for PHA production, with main focus on the use of wastes or industrial surplus as feedstocks. Basic concepts, regarding the metabolism and microbiology, and technological approaches, with emphasis on the kind of feedstock and reactor operating conditions for culture selection and PHA accumulation, are described. Challenges for the process optimization are also discussed.
Collapse
Affiliation(s)
- Luisa S Serafim
- REQUIMTE/CQFB, Chemistry Department, FCT/UNL, 2829 516, Caparica, Portugal
| | | | | | | |
Collapse
|
14
|
Vishnuvardhan Reddy S, Thirumala M, Kishore Reddy TV, Mahmood SK. Isolation of bacteria producing polyhydroxyalkanoates (PHA) from municipal sewage sludge. World J Microbiol Biotechnol 2008. [DOI: 10.1007/s11274-008-9839-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
15
|
Roh C, Villatte F. Isolation of a low-temperature adapted lipolytic enzyme from uncultivated micro-organism. J Appl Microbiol 2008; 105:116-23. [DOI: 10.1111/j.1365-2672.2007.03717.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
16
|
Ciesielski S, Pokoj T, Klimiuk E. Molecular insight into activated sludge producing polyhydroxyalkanoates under aerobic–anaerobic conditions. J Ind Microbiol Biotechnol 2008; 35:805-14. [DOI: 10.1007/s10295-008-0352-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2007] [Accepted: 04/01/2008] [Indexed: 10/22/2022]
|
17
|
Ayub ND, Pettinari MJ, Méndez BS, López NI. The polyhydroxyalkanoate genes of a stress resistant Antarctic Pseudomonas are situated within a genomic island. Plasmid 2007; 58:240-8. [PMID: 17629557 DOI: 10.1016/j.plasmid.2007.05.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2007] [Revised: 05/02/2007] [Accepted: 05/30/2007] [Indexed: 01/04/2023]
Abstract
Pseudomonas sp. 14-3 is an Antarctic bacterium that shows high stress resistance in association with high polyhydroxybutyrate (PHB) production. In this paper genes involved in PHB biosynthesis (phaRBAC) were found within a genomic island named pha-GI. Numerous mobile elements or proteins associated with them, such as an integrase, insertion sequences, a bacterial group II intron, a complete Type I protein secretion system and IncP plasmid-related proteins were detected among the 28 ORFs identified in this large genetic element (32.3kb). The G+C distribution was not homogeneous, likely reflecting a mosaic structure that contains regions from diverse origins. pha-GI has strong similarities with genomic islands found in diverse Proteobacteria, including Burkholderiales species and Azotobacter vinelandii. The G+C content, phylogeny inference and codon usage analysis showed that the phaBAC cluster itself has a complex mosaic structure and indicated that the phaB and phaC genes were acquired by horizontal transfer, probably derived from Burkholderiales. These results describe for the first time a pha cluster located within a genomic island, and suggest that horizontal transfer of pha genes is a mechanism of adaptability to stress conditions such as those found in the extreme Antarctic environment.
Collapse
Affiliation(s)
- Nicolás D Ayub
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina
| | | | | | | |
Collapse
|
18
|
Raynal M, Pruden A. Aerobic MTBE biodegradation in the presence of BTEX by two consortia under batch and semi-batch conditions. Biodegradation 2007; 19:269-82. [PMID: 17562189 DOI: 10.1007/s10532-007-9133-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2006] [Accepted: 05/11/2007] [Indexed: 10/23/2022]
Abstract
This study explores the effect of microbial consortium composition and reactor configuration on methyl tert-butyl ether (MTBE) biodegradation in the presence of benzene, toluene, ethylbenzene and p-xylenes(BTEX). MTBE biodegradation was monitored in the presence and absence of BTEX in duplicate batch reactors inoculated with distinct enrichment cultures: MTBE only (MO-originally enriched on MTBE) and/or MTBE BTEX (MB-originally enriched on MTBE and BTEX). The MO culture was also applied in a semi-batch reactor which received both MTBE and BTEX periodically in fresh medium after allowing cells to settle. The composition of the microbial consortia was explored using a combination of 16S rRNA gene cloning and quantitative polymerase chain reaction targeting the known MTBE-degrading strain PM1T. MTBE biodegradation was completely inhibited by BTEX in the batch reactors inoculated with the MB culture, and severely retarded in those inoculated with the MO culture (0.18+/-0.04 mg/L-day). In the semi-batch reactor, however, the MTBE biodegradation rate in the presence of BTEX was almost three times as high as in the batch reactors (0.48+/-0.2 mg/L-day), but still slower than MTBE biodegradation in the absence of BTEX in the MO-inoculated batch reactors (1.47+/-0.47 mg/L-day). A long lag phase in MTBE biodegradation was observed in batch reactors inoculated with the MB culture (20 days), but the ultimate rate was comparable to the MO culture (0.95+/-0.44 mg/L-day). Analysis of the cultures revealed that strain PM1T concentrations were lower in cultures that successfully biodegraded MTBE in the presence of BTEX. Also, other MTBE degraders, such as Leptothrix sp. and Hydrogenophaga sp. were found in these cultures. These results demonstrate that MTBE bioremediation in the presence of BTEX is feasible, and that culture composition and reactor configuration are key factors.
Collapse
Affiliation(s)
- M Raynal
- Department of Civil and Environmental Engineering, Colorado State University, Fort Collins, CO 80523, USA.
| | | |
Collapse
|
19
|
Suriyamongkol P, Weselake R, Narine S, Moloney M, Shah S. Biotechnological approaches for the production of polyhydroxyalkanoates in microorganisms and plants - a review. Biotechnol Adv 2006; 25:148-75. [PMID: 17222526 DOI: 10.1016/j.biotechadv.2006.11.007] [Citation(s) in RCA: 192] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2006] [Revised: 11/23/2006] [Accepted: 11/23/2006] [Indexed: 11/18/2022]
Abstract
The increasing effect of non-degradable plastic wastes is a growing concern. Polyhydroxyalkanoates (PHAs), macromolecule-polyesters naturally produced by many species of microorganisms, are being considered as a replacement for conventional plastics. Unlike petroleum-derived plastics that take several decades to degrade, PHAs can be completely bio-degraded within a year by a variety of microorganisms. This biodegradation results in carbon dioxide and water, which return to the environment. Attempts based on various methods have been undertaken for mass production of PHAs. Promising strategies involve genetic engineering of microorganisms and plants to introduce production pathways. This challenge requires the expression of several genes along with optimization of PHA synthesis in the host. Although excellent progress has been made in recombinant hosts, the barriers to obtaining high quantities of PHA at low cost still remain to be solved. The commercially viable production of PHA in crops, however, appears to be a realistic goal for the future.
Collapse
Affiliation(s)
- Pornpa Suriyamongkol
- Plant Biotechnology Unit, Alberta Research Council, Vegreville, Alberta, Canada T9C 1T4
| | | | | | | | | |
Collapse
|