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Gao X, Tan Z, Fang Y, Xie Q, Liu W, Tao J, Miao W, Jin P. Effect of mutation of phaC on carbon supply, extracellular polysaccharide production, and pathogenicity of Xanthomonas oryzae pv. oryzae. Sci Rep 2024; 14:18781. [PMID: 39138326 DOI: 10.1038/s41598-024-69621-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Accepted: 08/07/2024] [Indexed: 08/15/2024] Open
Abstract
Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial blight in rice. Polyhydroxyalkanoates (PHAs) consitute a diverse group of biopolyesters synthesized by bacteria under nutrient-limited conditions. The phaC gene is important for PHA polymerization. We investigated the effects of phaC gene mutagensis in Xoo strain PXO99A. The phaC gene knock-out mutant exhibited reduced swarming ability relative to that of the wild-type. Under conditions where glucose was the sole sugar source, extracellular polysaccharide (EPS) production by ΔphaC declined by 44.8%. ΔphaC showed weak hypersensitive response (HR) induction in the leaves of non-host Nicotiana tabacum, concomitant with downregulation of hpa1 gene expression. When inoculated in rice leaves by the leaf-clipping method, ΔphaC displayed reduced virulence in terms of lesion length compared with the wild-type strain. The complemented strain showed no significant difference from the wild-type strain, suggesting that the deletion of phaC in Xoo induces significant alterations in various physiological and biological processes. These include bacterial swarming ability, EPS production, transcription of hrp genes, and glucose metabolism. These changes are intricately linked to the energy utilization and virulence of Xoo during plant infection. These findings revealed involvement of phaC in Xoo is in the maintaining carbon metabolism by functioning in the PHA metabolic pathway.
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Affiliation(s)
- Xue Gao
- College of Plant Protection, Hainan University/Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou, 570228, China
| | - Zheng Tan
- College of Plant Protection, Hainan University/Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou, 570228, China
| | - Yukai Fang
- College of Plant Protection, Hainan University/Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou, 570228, China
| | - Qingbiao Xie
- College of Plant Protection, Hainan University/Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou, 570228, China
| | - Wenbo Liu
- College of Plant Protection, Hainan University/Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou, 570228, China
| | - Jun Tao
- College of Tropical Crops, Hainan University, Haikou, 570228, China
| | - Weiguo Miao
- College of Plant Protection, Hainan University/Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou, 570228, China.
| | - Pengfei Jin
- College of Plant Protection, Hainan University/Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou, 570228, China.
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2
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Corti Monzón G, Bertola G, Herrera Seitz MK, Murialdo SE. Exploring polyhydroxyalkanoates biosynthesis using hydrocarbons as carbon source: a comprehensive review. Biodegradation 2024; 35:519-538. [PMID: 38310580 DOI: 10.1007/s10532-023-10068-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 12/13/2023] [Indexed: 02/06/2024]
Abstract
Environmental pollution caused by petrochemical hydrocarbons (HC) and plastic waste is a pressing global challenge. However, there is a promising solution in the form of bacteria that possess the ability to degrade HC, making them valuable tools for remediating contaminated environments and effluents. Moreover, some of these bacteria offer far-reaching potential beyond bioremediation, as they can also be utilized to produce polyhydroxyalkanoates (PHAs), a common type of bioplastics. The accumulation of PHAs in bacterial cells is facilitated in environments with high C/N or C/P ratio, which are often found in HC-contaminated environments and effluents. Consequently, some HC-degrading bacteria can be employed to simultaneously produce PHAs and conduct biodegradation processes. Although bacterial bioplastic production has been thoroughly studied, production costs are still too high compared to petroleum-derived plastics. This article aims to provide a comprehensive review of recent scientific advancements concerning the capacity of HC-degrading bacteria to produce PHAs. It will delve into the microbial strains involved and the types of bioplastics generated, as well as the primary pathways for HC biodegradation and PHAs production. In essence, we propose the potential utilization of HC-degrading bacteria as a versatile tool to tackle two major environmental challenges: HC pollution and the accumulation of plastic waste. Through a comprehensive analysis of strengths and weaknesses in this aspect, this review aims to pave the way for future research in this area, with the goal of facilitating and promoting investigation in a field where obtaining PHAs from HC remains a costly and challenging process.
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Affiliation(s)
- G Corti Monzón
- Instituto de Ciencia y Tecnología de Alimentos y Ambiente, INCITAA, CONICET, Universidad Nacional de Mar del Plata, Buenos Aires, Argentina.
| | - G Bertola
- Instituto de Ciencia y Tecnología de Alimentos y Ambiente, INCITAA, CONICET, Universidad Nacional de Mar del Plata, Buenos Aires, Argentina
| | - M K Herrera Seitz
- Instituto de Investigaciones Biológicas, IIB, CONICET, Universidad Nacional de Mar del Plata, Buenos Aires, Argentina
| | - S E Murialdo
- Instituto de Ciencia y Tecnología de Alimentos y Ambiente, INCITAA, CIC, Universidad Nacional de Mar del Plata, Buenos Aires, Argentina
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3
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Aslam A, Masood F, Perveen K, Berger MR, Pervaiz A, Zepp M, Klika KD, Yasin T, Hameed A. Preparation, characterization and evaluation of HPβCD-PTX/PHB nanoparticles for pH-responsive, cytotoxic and apoptotic properties. Int J Biol Macromol 2024; 270:132268. [PMID: 38734336 DOI: 10.1016/j.ijbiomac.2024.132268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Revised: 03/13/2024] [Accepted: 05/08/2024] [Indexed: 05/13/2024]
Abstract
Paclitaxel (PTX) is a potent anticancer drug. However, PTX exhibits extremely poor solubility in aqueous solution along with severe side effects. Therefore, in this study, an inclusion complex was prepared between PTX and hydroxypropyl-β-cyclodextrin (HPβCD) by solvent evaporation to enhance the drug's solubility. The HPβCD-PTX inclusion complex was then encapsulated in poly-3-hydroxybutyrate (PHB) to fabricate drug-loaded nanoparticles (HPβCD-PTX/PHB NPs) by nanoprecipitation. The HPβCD-PTX/PHB NPs depicted a higher release of PTX at pH 5.5 thus demonstrating a pH-dependent release profile. The cytotoxic properties of HPβCD-PTX/PHB NPs were tested against MCF-7, MDA-MB-231 and SW-620 cell lines. The cytotoxic potential of HPβCD-PTX/PHB NPs was 2.59-fold improved in MCF-7 cells in comparison to free PTX. Additionally, the HPβCD-PTX/PHB NPs improved the antimitotic (1.68-fold) and apoptotic (8.45-fold) effects of PTX in MCF-7 cells in comparison to PTX alone. In summary, these pH-responsive nanoparticles could be prospective carriers for enhancing the cytotoxic properties of PTX for the treatment of breast cancer.
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Affiliation(s)
- Aqsa Aslam
- SA Centre for Interdisciplinary Research in Basic Sciences, International Islamic University, Islamabad, Pakistan
| | - Farha Masood
- Department of Biosciences, COMSATS University, Islamabad, Pakistan.
| | - Kousar Perveen
- Department of Biosciences, COMSATS University, Islamabad, Pakistan
| | - Martin R Berger
- Toxicology and Chemotherapy Unit, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 581, 69120 Heidelberg, Germany
| | - Asim Pervaiz
- Institute of Biomedical and Allied Health Sciences, University of Health Sciences, Lahore, Pakistan
| | - Michael Zepp
- Toxicology and Chemotherapy Unit, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 581, 69120 Heidelberg, Germany
| | - Karel D Klika
- Molecular Structure Analysis, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
| | - Tariq Yasin
- Department of Chemistry, Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Abdul Hameed
- SA Centre for Interdisciplinary Research in Basic Sciences, International Islamic University, Islamabad, Pakistan
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4
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Mai J, Kockler K, Parisi E, Chan CM, Pratt S, Laycock B. Synthesis and physical properties of polyhydroxyalkanoate (PHA)-based block copolymers: A review. Int J Biol Macromol 2024; 263:130204. [PMID: 38365154 DOI: 10.1016/j.ijbiomac.2024.130204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 01/15/2024] [Accepted: 02/13/2024] [Indexed: 02/18/2024]
Abstract
Polyhydroxyalkanoates (PHAs) are a group of natural polyesters that are synthesised by microorganisms. In general, their thermoplasticity and (in some forms) their elasticity makes them attractive alternatives to petrochemical-derived polymers. However, the high crystallinity of some PHAs - such as poly(3-hydroxybutyrate) (P3HB) - results in brittleness and a narrow processing window for applications such as packaging. The production of copolymeric PHA materials is one approach to improving the mechanical and thermal properties of PHAs. Another solution is the manufacture of PHA-based block copolymers. The incorporation of different polymer and copolymer blocks coupled to PHA, and the resulting tailorable microstructure of these block copolymers, can result in a step-change improvement in PHA-based material properties. A range of production strategies for PHA-based block copolymers has been reported in the literature, including biological production and chemical synthesis. Biological production is typically less controllable, with products of a broad molecular weight and compositional distribution, unless finely controlled using genetically modified organisms. By contrast, chemical synthesis delivers relatively controllable block structures and narrowly defined compositions. This paper reviews current knowledge in the areas of the production and properties of PHA-based block copolymers, and highlights knowledge gaps and future potential areas of research.
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Affiliation(s)
- Jingjing Mai
- Fujian Normal University, College of Environmental and Resource Sciences, College of Carbon Neutral Modern Industry, Fuzhou, Fujian 350000, China
| | - Katrin Kockler
- The University of Queensland, School of Chemical Engineering, St Lucia, Brisbane, Queensland 4072, Australia
| | - Emily Parisi
- Parisi Technologies, LLC Portland, Oregon, United States
| | - Clement Matthew Chan
- The University of Queensland, School of Chemical Engineering, St Lucia, Brisbane, Queensland 4072, Australia
| | - Steven Pratt
- The University of Queensland, School of Chemical Engineering, St Lucia, Brisbane, Queensland 4072, Australia
| | - Bronwyn Laycock
- The University of Queensland, School of Chemical Engineering, St Lucia, Brisbane, Queensland 4072, Australia.
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Aguilar-Carrillo Y, Soto-Urzúa L, Martínez-Martínez MDLÁ, Becerril-Ramírez M, Martínez-Morales LJ. Computational Analysis of the Tripartite Interaction of Phasins (PhaP4 and 5)-Sigma Factor (σ 24)-DNA of Azospirillum brasilense Sp7. Polymers (Basel) 2024; 16:611. [PMID: 38475295 DOI: 10.3390/polym16050611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 02/04/2024] [Accepted: 02/07/2024] [Indexed: 03/14/2024] Open
Abstract
Azospirillum brasilense Sp7 produces PHB, which is covered by granule-associated proteins (GAPs). Phasins are the main GAPs. Previous studies have shown phasins can regulate PHB synthesis. When A. brasilense grows under stress conditions, it uses sigma factors to transcribe genes for survival. One of these factors is the σ24 factor. This study determined the possible interaction between phasins and the σ24 factor or phasin-σ24 factor complex and DNA. Three-dimensional structures of phasins and σ24 factor structures were predicted using the I-TASSER and SWISS-Model servers, respectively. Subsequently, a molecular docking between phasins and the σ24 factor was performed using the ClusPro 2.0 server, followed by molecular docking between protein complexes and DNA using the HDOCK server. Evaluation of the types of ligand-receptor interactions was performed using the BIOVIA Discovery Visualizer for three-dimensional diagrams, as well as the LigPlot server to obtain bi-dimensional diagrams. The results showed the phasins (Pha4Abs7 or Pha5Abs7)-σ24 factor complex was bound near the -35 box of the promoter region of the phaC gene. However, in the individual interaction of PhaP5Abs7 and the σ24 factor, with DNA, both proteins were bound to the -35 box. This did not occur with PhaP4Abs7, which was bound to the -10 box. This change could affect the transcription level of the phaC gene and possibly affect PHB synthesis.
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Affiliation(s)
- Yovani Aguilar-Carrillo
- Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Av. San Claudio y Av. 24 Sur, Col. San Manuel Ciudad Universitaria, Puebla 72570, Mexico
| | - Lucía Soto-Urzúa
- Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Av. San Claudio y Av. 24 Sur, Col. San Manuel Ciudad Universitaria, Puebla 72570, Mexico
| | - María De Los Ángeles Martínez-Martínez
- Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Av. San Claudio y Av. 24 Sur, Col. San Manuel Ciudad Universitaria, Puebla 72570, Mexico
| | - Mirian Becerril-Ramírez
- Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Av. San Claudio y Av. 24 Sur, Col. San Manuel Ciudad Universitaria, Puebla 72570, Mexico
| | - Luis Javier Martínez-Morales
- Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Av. San Claudio y Av. 24 Sur, Col. San Manuel Ciudad Universitaria, Puebla 72570, Mexico
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Aghaali Z, Naghavi MR. Biotechnological Approaches for Enhancing Polyhydroxyalkanoates (PHAs) Production: Current and Future Perspectives. Curr Microbiol 2023; 80:345. [PMID: 37731015 DOI: 10.1007/s00284-023-03452-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 08/19/2023] [Indexed: 09/22/2023]
Abstract
The benefits of biotechnology are not limited to genetic engineering, but it also displays its great impact on industrial uses of crops (e.g., biodegradable plastics). Polyhydroxyalkanoates (PHAs) make a diverse class of bio-based and biodegradable polymers naturally synthesized by numerous microorganisms. However, several C3 and C4 plants have also been genetically engineered to produce PHAs. The highest production yield of PHAs was obtained with a well-known C3 plant, Arabidopsis thaliana, upto 40% of the dry weight of the leaf. This review summarizes all biotechnological mechanisms that have been adopted with the goal of increasing PHAs production in bacteria and plant species alike. Moreover, the possibility of using some methods that have not been applied in bioplastic science are discussed with special attention to plants. These include producing PHAs in transgenic hairy roots and cell suspension cultures, making transformed bacteria and plants via transposons, constructing an engineered metabolon, and overexpressing of phaP and the ABC operon concurrently. Taken together, that biotechnology will be highly beneficial for reducing plastic pollution through the implementation of biotechnological strategies is taken for granted.
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Affiliation(s)
- Zahra Aghaali
- Department of Genetic and Plant Breeding, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran.
| | - Mohammad Reza Naghavi
- Division of Biotechnology, Department of Agronomy and Plant Breeding, College of Agricultural and Natural Resources, University of Tehran, Karaj, Iran.
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Martínez MDLÁM, Urzúa LS, Carrillo YA, Ramírez MB, Morales LJM. Polyhydroxybutyrate Metabolism in Azospirillum brasilense and Its Applications, a Review. Polymers (Basel) 2023; 15:3027. [PMID: 37514417 PMCID: PMC10383645 DOI: 10.3390/polym15143027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 06/28/2023] [Accepted: 07/06/2023] [Indexed: 07/30/2023] Open
Abstract
Gram-negative Azospirillum brasilense accumulates approximately 80% of polyhydroxybutyrate (PHB) as dry cell weight. For this reason, this bacterium has been characterized as one of the main microorganisms that produce PHB. PHB is synthesized inside bacteria by the polymerization of 3-hydroxybutyrate monomers. In this review, we are focusing on the analysis of the PHB production by A. brasilense in order to understand the metabolism during PHB accumulation. First, the carbon and nitrogen sources used to improve PHB accumulation are discussed. A. brasilense accumulates more PHB when it is grown on a minimal medium containing a high C/N ratio, mainly from malate and ammonia chloride, respectively. The metabolic pathways to accumulate and mobilize PHB in A. brasilense are mentioned and compared with those of other microorganisms. Next, we summarize the available information to understand the role of the genes involved in the regulation of PHB metabolism as well as the role of PHB in the physiology of Azospirillum. Finally, we made a comparison between the properties of PHB and polypropylene, and we discussed some applications of PHB in biomedical and commercial areas.
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Affiliation(s)
- María de Los Ángeles Martínez Martínez
- Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Av. San Claudio y Av. 24 Sur, Col. San Manuel Ciudad Universitaria, Puebla 72570, Mexico
| | - Lucía Soto Urzúa
- Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Av. San Claudio y Av. 24 Sur, Col. San Manuel Ciudad Universitaria, Puebla 72570, Mexico
| | - Yovani Aguilar Carrillo
- Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Av. San Claudio y Av. 24 Sur, Col. San Manuel Ciudad Universitaria, Puebla 72570, Mexico
| | - Mirian Becerril Ramírez
- Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Av. San Claudio y Av. 24 Sur, Col. San Manuel Ciudad Universitaria, Puebla 72570, Mexico
| | - Luis Javier Martínez Morales
- Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Av. San Claudio y Av. 24 Sur, Col. San Manuel Ciudad Universitaria, Puebla 72570, Mexico
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Dong X, Zhu L, He Y, Li C, Li D. Salinity significantly reduces plastic-degrading bacteria from rivers to oceans. JOURNAL OF HAZARDOUS MATERIALS 2023; 451:131125. [PMID: 36889079 DOI: 10.1016/j.jhazmat.2023.131125] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/28/2023] [Accepted: 03/01/2023] [Indexed: 06/18/2023]
Abstract
Microplastics (MPs) are found in rivers and offshore areas. However, there is a lack of detailed research on the changes of surface microbial species attached to MPs when MPs enter the sea. Moreover, no study has been conducted on changes to plastic-degrading bacteria during this process. In this study, using rivers and offshore in Macau, China as examples, bacterial diversity and bacterial species composition attached to surface water and MPs at four river sampling stations and four offshore sampling stations around Macau were studied. Plastic-degrading bacteria, plastic-related metabolic processes, and plastic-related enzymes were analyzed. The results showed that MPs-attached bacteria in rivers and offshore were different with the planktonic bacteria (PB). The proportion of major families on the surface of MPs continued to increase from rivers to estuaries. MPs could significantly enrich plastic-degrading bacteria both in rivers and offshore. The proportion of plastic-related metabolic pathways on the surface bacteria of MPs in rivers was higher than that in offshore waters. Bacteria on the surface of MPs in rivers may induce higher plastic degradation than offshore. Salinity significantly alters the distribution of plastic-degrading bacteria. MPs may degrade more slowly in the oceans, posing a long-term threat to marine life and human health.
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Affiliation(s)
- Xuri Dong
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China; Plastic Marine Debris Research Center, East China Normal University, Shanghai 200241, China; Region Training and Research Center on Plastic Marine Debris and Microplastics, IOC-UNESCO, 200241, China
| | - Lixin Zhu
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China; Plastic Marine Debris Research Center, East China Normal University, Shanghai 200241, China; Region Training and Research Center on Plastic Marine Debris and Microplastics, IOC-UNESCO, 200241, China
| | - Yanru He
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China
| | - Changjun Li
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China; Plastic Marine Debris Research Center, East China Normal University, Shanghai 200241, China; Region Training and Research Center on Plastic Marine Debris and Microplastics, IOC-UNESCO, 200241, China
| | - Daoji Li
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China; Plastic Marine Debris Research Center, East China Normal University, Shanghai 200241, China; Region Training and Research Center on Plastic Marine Debris and Microplastics, IOC-UNESCO, 200241, China.
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Ferrari F, Striani R, Fico D, Alam MM, Greco A, Esposito Corcione C. An Overview on Wood Waste Valorization as Biopolymers and Biocomposites: Definition, Classification, Production, Properties and Applications. Polymers (Basel) 2022; 14:polym14245519. [PMID: 36559886 PMCID: PMC9787771 DOI: 10.3390/polym14245519] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 12/12/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
Bio-based polymers, obtained from natural biomass, are nowadays considered good candidates for the replacement of traditional fossil-derived plastics. The need for substituting traditional synthetic plastics is mainly driven by many concerns about their detrimental effects on the environment and human health. The most innovative way to produce bioplastics involves the use of raw materials derived from wastes. Raw materials are of vital importance for human and animal health and due to their economic and environmental benefits. Among these, wood waste is gaining popularity as an innovative raw material for biopolymer manufacturing. On the other hand, the use of wastes as a source to produce biopolymers and biocomposites is still under development and the processing methods are currently being studied in order to reach a high reproducibility and thus increase the yield of production. This study therefore aimed to cover the current developments in the classification, manufacturing, performances and fields of application of bio-based polymers, especially focusing on wood waste sources. The work was carried out using both a descriptive and an analytical methodology: first, a description of the state of art as it exists at present was reported, then the available information was analyzed to make a critical evaluation of the results. A second way to employ wood scraps involves their use as bio-reinforcements for composites; therefore, the increase in the mechanical response obtained by the addition of wood waste in different bio-based matrices was explored in this work. Results showed an increase in Young's modulus up to 9 GPa for wood-reinforced PLA and up to 6 GPa for wood-reinforced PHA.
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Using runaway replication to express polyhydroxyalkanoic acid (pha) genes from a novel marine bacterium in enteric bacteria: The influence of temperature and phasins on PHA accumulation. PLoS One 2022; 17:e0275597. [PMID: 36477445 PMCID: PMC9728866 DOI: 10.1371/journal.pone.0275597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 09/20/2022] [Indexed: 12/13/2022] Open
Abstract
While plastics have revolutionized our world, plastic waste has serious environmental and economic impacts. Polyhydroxyalkanoic acid (PHA) is a bacterial carbon and energy reserve shown to be both biodegradable and biocompatible and could potentially replace conventional plastics. However, cost-effective mass production remains elusive. Bacteria often accumulate PHA as cytoplasmic granules. PHA synthase creates the PHA polymer from acetoacyl-CoA monomers, while phasins are small multifunctional proteins that are found in abundance on the granule surface. The PHA synthase gene from a novel marine isolate, Vibrio B-18 (or B-18), was placed in the presence or absence of an upstream phasin gene in a runaway replication plasmid using polymerase chain reaction (PCR) technology. Plasmid gene expression may be induced chemically or thermally. Overexpression of the PHA genes was demonstrated by SDS-PAGE analysis, and microscopy was used to detect PHA accumulation in three different enteric bacteria (Escherichia coli, Klebsiella aerogenes, and Shigella flexneri). While the B-18 genes were clearly overexpressed at 41°C, PHA accumulation occurred more readily at the lower (30°C) non-inducing temperature regardless of chemical induction if the phasin gene was present. A mutational analysis confirmed the identity of the start codon for the PHA synthase gene and provided evidence supporting the requirement for phasins to allow for PHA accumulation in the recombinant hosts. The findings described in this study confirm the conclusions obtained from related studies from other laboratories and lend support to the importance of including a phasin gene in addition to the basic genes needed for PHA synthesis and accumulation in recombinant enteric bacteria, such as Escherichia coli, Klebsiella aerogenes, and Shigella flexneri.
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Coupling Magnetic Field and Salinity Upshock To Improve Polyhydroxyalkanoate Productivity by Haloferax mediterranei Feeding on Molasses Wastewater. Appl Environ Microbiol 2022; 88:e0030522. [PMID: 35695568 PMCID: PMC9275214 DOI: 10.1128/aem.00305-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Low polyhydroxyalkanoate (PHA) volumetric productivity from wastewater limits low-cost PHA production. To resolve this problem, an external magnetic field (MF) coupled with upshock salinity was applied to PHA production by Haloferax mediterranei (family Halobacteriaceae). Elevating the fermentation salinity over the optimal growth salinity (200 g/L) increased the PHA cell content while inhibiting cell proliferation, decreasing volumetric productivity. When a MF of 50 mT in 300 g/L salinity was applied, H. mediterranei proliferation and PHA cell content were promoted, leading to a 7.95% increase in PHA volumetric productivity in synthetic molasses wastewater and a 13.82% increase in glucose feeding compared with those in 200 g/L salinity. Under the MF, osmotic pressure regulation was activated by accumulating K+ and increasing betaine synthesis. The maximum betaine content increased by 74.33% in 300 g/L salinity with a 50-mT MF compared with that in 200 g/L salinity. When a 50-mT MF in 300 g/L salinity was applied, the malondialdehyde (MDA) content decreased by 32.66% and the activity of superoxide dismutase (SOD) increased by 46.89%, which reduced the oxidative damage. This study provides a new solution to enhance PHA volumetric productivity by MF and an insight into the magnetic effects of H. mediterranei. IMPORTANCE The obstacle to replacing petroplastics with PHA is its high production cost. To increase the fermentation economy, a novel strategy of coupling a MF with salinity upshock was applied, which enhanced the PHA volumetric productivity of H. mediterranei in fermenting molasses wastewater. The magnetic effect of H. mediterranei was found at a MF of 50 mT, which improved the salt tolerance of H. mediterranei and reduced the oxidative damage induced by the elevated salinity, thereby promoting proliferation and PHA cell content. This is the first time a technical method for enhancing PHA volumetric productivity by means of a MF has been proposed. Such a strategy can advance the utilization of H. mediterranei for the industrial production of PHA using organic wastewater.
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Assefa NG, Hansen H, Altermark B. A unique class I polyhydroxyalkanoate synthase (PhaC) from Brevundimonas sp. KH11J01 exists as a functional trimer: A comparative study with PhaC from Cupriavidus necator H16. N Biotechnol 2022; 70:57-66. [DOI: 10.1016/j.nbt.2022.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 03/25/2022] [Accepted: 05/04/2022] [Indexed: 11/28/2022]
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13
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Behera S, Priyadarshanee M, Das S. Polyhydroxyalkanoates, the bioplastics of microbial origin: Properties, biochemical synthesis, and their applications. CHEMOSPHERE 2022; 294:133723. [PMID: 35085614 DOI: 10.1016/j.chemosphere.2022.133723] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 01/13/2022] [Accepted: 01/20/2022] [Indexed: 06/14/2023]
Abstract
The rising plastic pollution deteriorates the environment significantly as these petroleum-based plastics are not biodegradable, and their production requires natural fuels (energy source) and other resources. Polyhydroxyalkanoates (PHAs) are bioplastic and a sustainable and eco-friendly alternative to synthetic plastics. PHAs can be entirely synthesized using various microorganisms such as bacteria, algae, and fungi. These value-added biopolymers show promising properties such as enhanced biodegradability, biocompatibility, and other chemo-mechanical properties. Further, it has been established that the properties of PHA polymers depend on the substrates and chemical composition (monomer unit) of these polymers. PHAs hold great potential as an alternative to petroleum-based polymers, and further research for economic production and utilization of these biopolymers is required. The review describes the synthesis mechanism and different properties of microbially synthesized PHAs for various applications. The classification of PHAs and the multiple techniques necessary for their detection and evaluation have been discussed. In addition, the synthesis mechanism involving the genetic regulation of these biopolymers in various microbial groups has been described. This review provides information on various commercially available PHAs and their application in multiple sectors. The industrial production of these microbially synthesized polymers and the different extraction methods have been reviewed in detail. Furthermore, the review provides an insight into the potential applications of this biopolymer in environmental, industrial, and biomedical applications.
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Affiliation(s)
- Shivananda Behera
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela, 769 008, Odisha, India
| | - Monika Priyadarshanee
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela, 769 008, Odisha, India
| | - Surajit Das
- Laboratory of Environmental Microbiology and Ecology (LEnME), Department of Life Science, National Institute of Technology, Rourkela, 769 008, Odisha, India.
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14
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Wang Q, Xu Y, Xu P, Yang W, Chen M, Dong W, Ma P. Crystallization of microbial polyhydroxyalkanoates: A review. Int J Biol Macromol 2022; 209:330-343. [PMID: 35398060 DOI: 10.1016/j.ijbiomac.2022.04.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 03/31/2022] [Accepted: 04/03/2022] [Indexed: 12/18/2022]
Abstract
Polyhydroxyalkanoates (PHAs), produced by the microbial fermentation, is a promising green polymer and has attracted much attention due to its excellent biocompatibility, complete biodegradability, and non-cytotoxicity. The physical properties of PHAs are closely related to their chemical and crystalline structure. Therefore, deep understanding and regulating the structure and crystallization of PHAs are the key factors to improve the performance of PHAs. This review first provides a brief overview of the development history, chemical structure, and basic properties of PHAs. Then, the crystal structure, crystal morphology, kinetics theories and crystallization behavior of nucleation-induced PHAs are systematically summarized to provide a theoretical foundation for improving PHAs crystallization rate and physical properties. In the end, the outlook on the crystallization and application prospects of PHAs is also addressed.
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Affiliation(s)
- Qian Wang
- The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Yunsheng Xu
- School of Materials Science and Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Pengwu Xu
- The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.
| | - Weijun Yang
- The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Mingqing Chen
- The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Weifu Dong
- The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Piming Ma
- The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.
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15
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Thulasidharan D, Arumugam A, Uppuluri KB. Research and economic perspectives on an integrated biorefinery approach for the simultaneous production of polyhydroxyalkanoates and biohydrogen. Int J Biol Macromol 2021; 193:1937-1951. [PMID: 34752795 DOI: 10.1016/j.ijbiomac.2021.11.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 11/01/2021] [Accepted: 11/03/2021] [Indexed: 02/07/2023]
Abstract
Alarming environmental impacts have been resulted across the globe due to the recovery and consumption of fossil fuels. The elevated global carbon footprint has paved the way to an alternative to combat the prevalent pollution. On the other hand, the fossil-based plastics produced from the byproducts of petroleum remain intact in the environment leading to pollution. Fossil abated bioproducts are in high demand due to the increase in pollution. This call to utilize feedstock for simultaneous production of biologically useful products through carbon capture utilisation where the leftover carbon-rich substrate is converted into usable chemicals like bioplastics, methanol, urea and various other industrially essential components. The present review extensively focuses on the research and economic perspectives of an integrated biorefinery and addresses technical breaches, bottlenecks, and efficient strategies for the simultaneous production of biohydrogen and polyhydroxyalkanoates.
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Affiliation(s)
- D Thulasidharan
- Centre for Bioenergy, School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur 613 401, India
| | - A Arumugam
- Centre for Bioenergy, School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur 613 401, India.
| | - Kiran Babu Uppuluri
- Centre for Bioenergy, School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur 613 401, India.
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16
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Photoferrotrophy and phototrophic extracellular electron uptake is common in the marine anoxygenic phototroph Rhodovulum sulfidophilum. THE ISME JOURNAL 2021; 15:3384-3398. [PMID: 34054125 PMCID: PMC8528915 DOI: 10.1038/s41396-021-01015-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 05/07/2021] [Accepted: 05/12/2021] [Indexed: 02/03/2023]
Abstract
Photoferrotrophy allows anoxygenic phototrophs to use reduced iron as an electron donor for primary productivity. Recent work shows that freshwater photoferrotrophs can use electrons from solid-phase conductive substances via phototrophic extracellular electron uptake (pEEU), and the two processes share the underlying electron uptake mechanism. However, the ability of marine phototrophs to perform photoferrotrophy and pEEU, and the contribution of these processes to primary productivity is largely unknown. To fill this knowledge gap, we isolated 15 new strains of the marine anoxygenic phototroph Rhodovulum sulfidophilum on electron donors such as acetate and thiosulfate. We observed that all of the R. sulfidophilum strains isolated can perform photoferrotrophy. We chose strain AB26 as a representative strain to study further, and find that it can also perform pEEU from poised electrodes. We show that during pEEU, AB26 transfers electrons to the photosynthetic electron transport chain. Furthermore, systems biology-guided mutant analysis shows that R. sulfidophilum AB26 uses a previously unknown diheme cytochrome c protein, which we call EeuP, for pEEU but not photoferrotrophy. Homologs of EeuP occur in a range of widely distributed marine microbes. Overall, these results suggest that photoferrotrophy and pEEU contribute to the biogeochemical cycling of iron and carbon in marine ecosystems.
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17
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Lee HS, Lee HJ, Kim SH, Cho JY, Suh MJ, Ham S, Bhatia SK, Gurav R, Kim YG, Lee EY, Yang YH. Novel phasins from the Arctic Pseudomonas sp. B14-6 enhance the production of polyhydroxybutyrate and increase inhibitor tolerance. Int J Biol Macromol 2021; 190:722-729. [PMID: 34506862 DOI: 10.1016/j.ijbiomac.2021.08.236] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/18/2021] [Accepted: 08/31/2021] [Indexed: 01/17/2023]
Abstract
Phasin (PhaP), one of the polyhydroxyalkanoate granule-associated protein, enhances cell growth and polyhydroxybutyrate (PHB) biosynthesis by regulating the number and size of PHB granules. However, few studies have applied phasins to various PHB production conditions. In this study, we identified novel phasin genes from the genomic data of Arctic soil bacterium Pseudomonas sp. B14-6 and determined the role of phaP1Ps under different PHB production conditions. Transmission electron microscopy and gel permeation chromatography revealed small PHB granules with high-molecular weight, while differential scanning calorimetry showed that the extracted PHB films had similar thermal properties. The phasin protein derived from Pseudomonas sp. B14-6 revealed higher PHB production and exhibited higher tolerance to several lignocellulosic biosugar-based inhibitors than the phasin protein of Ralstonia eutropha H16 in a recombinant Escherichia coli strain. The increased tolerance to propionate, temperature, and other inhibitors was attributed to the introduction of phaP1Ps, which increased PHB production from lignocellulosic hydrolysate (2.39-fold) in the phaP1Ps strain. However, a combination of phasin proteins isolated from two different sources did not increase PHB production. These findings suggest that phasin could serve as a powerful means to increase robustness and PHB production in heterologous strains.
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Affiliation(s)
- Hye Soo Lee
- Department of Biological Engineering, College of Engineering, Konkuk University, Seoul 05029, Republic of Korea
| | - Hong-Ju Lee
- Department of Biological Engineering, College of Engineering, Konkuk University, Seoul 05029, Republic of Korea
| | - Sang Hyun Kim
- Department of Biological Engineering, College of Engineering, Konkuk University, Seoul 05029, Republic of Korea
| | - Jang Yeon Cho
- Department of Biological Engineering, College of Engineering, Konkuk University, Seoul 05029, Republic of Korea
| | - Min Ju Suh
- Department of Biological Engineering, College of Engineering, Konkuk University, Seoul 05029, Republic of Korea
| | - Sion Ham
- Department of Biological Engineering, College of Engineering, Konkuk University, Seoul 05029, Republic of Korea
| | - Shashi Kant Bhatia
- Department of Biological Engineering, College of Engineering, Konkuk University, Seoul 05029, Republic of Korea; Institute for Ubiquitous Information Technology and Applications, Konkuk University, Seoul 05029, Republic of Korea.
| | - Ranjit Gurav
- Department of Biological Engineering, College of Engineering, Konkuk University, Seoul 05029, Republic of Korea.
| | - Yun-Gon Kim
- Department of Chemical Engineering, Soongsil University, Seoul 06978, Republic of Korea.
| | - Eun Yeol Lee
- Department of Chemical Engineering, Kyung Hee University, Yongin-si, Gyeonggi-do 17104, Republic of Korea.
| | - Yung-Hun Yang
- Department of Biological Engineering, College of Engineering, Konkuk University, Seoul 05029, Republic of Korea; Institute for Ubiquitous Information Technology and Applications, Konkuk University, Seoul 05029, Republic of Korea.
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18
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Sundaria N, Upadhyay A, Prasad A, Prajapati VK, Poluri KM, Mishra A. Neurodegeneration & imperfect ageing: Technological limitations and challenges? Mech Ageing Dev 2021; 200:111574. [PMID: 34562507 DOI: 10.1016/j.mad.2021.111574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 08/29/2021] [Accepted: 09/21/2021] [Indexed: 11/18/2022]
Abstract
Cellular homeostasis is regulated by the protein quality control (PQC) machinery, comprising multiple chaperones and enzymes. Studies suggest that the loss of the PQC mechanisms in neurons may lead to the formation of abnormal inclusions that may lead to neurological disorders and defective aging. The questions could be raised how protein aggregate formation precisely engenders multifactorial molecular pathomechanism in neuronal cells and affects different brain regions? Such questions await thorough investigation that may help us understand how aberrant proteinaceous bodies lead to neurodegeneration and imperfect aging. However, these studies face multiple technological challenges in utilizing available tools for detailed characterizations of the protein aggregates or amyloids and developing new techniques to understand the biology and pathology of proteopathies. The lack of detection and analysis methods has decelerated the pace of the research in amyloid biology. Here, we address the significance of aggregation and inclusion formation, followed by exploring the evolutionary contribution of these structures. We also provide a detailed overview of current state-of-the-art techniques and advances in studying amyloids in the diseased brain. A comprehensive understanding of the structural, pathological, and clinical characteristics of different types of aggregates (inclusions, fibrils, plaques, etc.) will aid in developing future therapies.
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Affiliation(s)
- Naveen Sundaria
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology, Jodhpur, Rajasthan, 342037, India
| | - Arun Upadhyay
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology, Jodhpur, Rajasthan, 342037, India
| | - Amit Prasad
- School of Basic Sciences, Indian Institute of Technology Mandi, Mandi, India
| | - Vijay Kumar Prajapati
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, NH‑8 Bandarsindri, Ajmer, Rajasthan, 305817, India
| | - Krishna Mohan Poluri
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, Uttarakhand, India
| | - Amit Mishra
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology, Jodhpur, Rajasthan, 342037, India.
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19
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Post-Transcriptional Control in the Regulation of Polyhydroxyalkanoates Synthesis. Life (Basel) 2021; 11:life11080853. [PMID: 34440597 PMCID: PMC8401924 DOI: 10.3390/life11080853] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/15/2021] [Accepted: 08/18/2021] [Indexed: 01/08/2023] Open
Abstract
The large production of non-degradable petrol-based plastics has become a major global issue due to its environmental pollution. Biopolymers produced by microorganisms such as polyhydroxyalkanoates (PHAs) are gaining potential as a sustainable alternative, but the high cost associated with their industrial production has been a limiting factor. Post-transcriptional regulation is a key step to control gene expression in changing environments and has been reported to play a major role in numerous cellular processes. However, limited reports are available concerning the regulation of PHA accumulation in bacteria, and many essential regulatory factors still need to be identified. Here, we review studies where the synthesis of PHA has been reported to be regulated at the post-transcriptional level, and we analyze the RNA-mediated networks involved. Finally, we discuss the forthcoming research on riboregulation, synthetic, and metabolic engineering which could lead to improved strategies for PHAs synthesis in industrial production, thereby reducing the costs currently associated with this procedure.
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20
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Sea-Ice Bacteria Halomonas sp. Strain 363 and Paracoccus sp. Strain 392 Produce Multiple Types of Poly-3-Hydroxyalkaonoic Acid (PHA) Storage Polymers at Low Temperature. Appl Environ Microbiol 2021; 87:e0092921. [PMID: 34160268 PMCID: PMC8357295 DOI: 10.1128/aem.00929-21] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Poly-3-hydroxyalkanoic acids (PHAs) are bacterial storage polymers commonly used in bioplastic production. Halophilic bacteria are industrially interesting organisms, as their salinity tolerance and psychrophilic nature lowers sterility requirements and subsequent production costs. We investigated PHA synthesis in two bacterial strains, Halomonas sp. 363 and Paracoccus sp. 392, isolated from Southern Ocean sea ice and elucidated the related PHA biopolymer accumulation and composition with various approaches, such as transcriptomics, microscopy, and chromatography. We show that both bacterial strains produce PHAs at 4°C when the availability of nitrogen and/or oxygen limited growth. The genome of Halomonas sp. 363 carries three phaC synthase genes and transcribes genes along three PHA pathways (I to III), whereas Paracoccus sp. 392 carries only one phaC gene and transcribes genes along one pathway (I). Thus, Halomonas sp. 363 has a versatile repertoire of phaC genes and pathways enabling production of both short- and medium-chain-length PHA products. IMPORTANCE Plastic pollution is one of the most topical threats to the health of the oceans and seas. One recognized way to alleviate the problem is to use degradable bioplastic materials in high-risk applications. PHA is a promising bioplastic material as it is nontoxic and fully produced and degraded by bacteria. Sea ice is an interesting environment for prospecting novel PHA-producing organisms, since traits advantageous to lower production costs, such as tolerance for high salinities and low temperatures, are common. We show that two sea-ice bacteria, Halomonas sp. 363 and Paracoccus sp. 392, are able to produce various types of PHA from inexpensive carbon sources. Halomonas sp. 363 is an especially interesting PHA-producing organism, since it has three different synthesis pathways to produce both short- and medium-chain-length PHAs.
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21
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Bordel S, van Spanning RJM, Santos-Beneit F. Imaging and modelling of poly(3-hydroxybutyrate) synthesis in Paracoccus denitrificans. AMB Express 2021; 11:113. [PMID: 34370106 PMCID: PMC8353029 DOI: 10.1186/s13568-021-01273-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 07/26/2021] [Indexed: 11/10/2022] Open
Abstract
Poly(3-hydroxybutyrate) (PHB) granule formation in Paracoccus denitrificans Pd1222 was investigated by laser scanning confocal microscopy (LSCM) and gas chromatography analysis. Cells that had been starved for 2 days were free of PHB granules but resynthesized them within 30 min of growth in fresh medium with succinate. In most cases, the granules were distributed randomly, although in some cases they appeared in a more organized pattern. The rates of growth and PHB accumulation were analyzed within the frame of a Genome-Scale Metabolic Model (GSMM) containing 781 metabolic genes, 1403 reactions and 1503 metabolites. The model was used to obtain quantitative predictions of biomass yields and PHB synthesis during aerobic growth on succinate as sole carbon and energy sources. The results revealed an initial fast stage of PHB accumulation, during which all of the acetyl-CoA originating from succinate was diverted to PHB production. The next stage was characterized by a tenfold lower PHB production rate and the simultaneous onset of exponential growth, during which acetyl-CoA was predominantly drained into the TCA cycle. Previous research has shown that PHB accumulation correlates with cytosolic acetyl-CoA concentration. It has also been shown that PHB accumulation is not transcriptionally regulated. Our results are consistent with the mentioned findings and suggest that, in absence of cell growth, most of the cellular acetyl-CoA is channeled to PHB synthesis, while during exponential growth, it is drained to the TCA cycle, causing a reduction of the cytosolic acetyl-CoA pool and a concomitant decrease of the synthesis of acetoacetyl-CoA (the precursor of PHB synthesis).
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22
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Naser AZ, Deiab I, Darras BM. Poly(lactic acid) (PLA) and polyhydroxyalkanoates (PHAs), green alternatives to petroleum-based plastics: a review. RSC Adv 2021; 11:17151-17196. [PMID: 35479695 PMCID: PMC9033233 DOI: 10.1039/d1ra02390j] [Citation(s) in RCA: 132] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 05/02/2021] [Indexed: 11/21/2022] Open
Abstract
In spite of the fact that petroleum-based plastics are convenient in terms of fulfilling the performance requirements of many applications, they contribute significantly to a number of ecological and environmental problems. Recently, the public awareness of the negative effects of petroleum-based plastics on the environment has increased. The present utilization of natural resources cannot be sustained forever. Furthermore, oil is often subjected to price fluctuations and will eventually be depleted. The increase in the level of carbon dioxide due to the combustion of fossil fuel is causing global warming. Concerns about preservation of natural resources and climate change are considered worldwide motivations for academic and industrial researchers to reduce the consumption and dependence on fossil fuel. Therefore, bio-based polymers are moving towards becoming the favorable option to be utilized in polymer manufacturing, food packaging, and medical applications. This paper represents an overview of the feasibility of both Poly Lactic Acid (PLA) and polyhydroxyalkanoates (PHAs) as alternative materials that can replace petroleum-based polymers in a wide range of industrial applications. Physical, thermal, rheological, and mechanical properties of both polymers as well as their permeability and migration properties have been reviewed. Moreover, PLA's recyclability, sustainability, and environmental assessment have been also discussed. Finally, applications in which both polymers can replace petroleum-based plastics have been explored and provided.
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Affiliation(s)
- Ahmed Z Naser
- Advanced Manufacturing Laboratory, University of Guelph Guelph ON Canada
| | - I Deiab
- Advanced Manufacturing Laboratory, University of Guelph Guelph ON Canada
| | - Basil M Darras
- Department of Mechanical Engineering, American University of Sharjah Sharjah UAE
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23
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Shahid S, Razzaq S, Farooq R, Nazli ZIH. Polyhydroxyalkanoates: Next generation natural biomolecules and a solution for the world's future economy. Int J Biol Macromol 2020; 166:297-321. [PMID: 33127548 DOI: 10.1016/j.ijbiomac.2020.10.187] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 10/21/2020] [Accepted: 10/23/2020] [Indexed: 02/08/2023]
Abstract
Petrochemical plastics have become a cause of pollution for decades and finding alternative plastics that are environmental friendly. Polyhydroxyalkanoate (PHA), a biopolyester produced by microbial cells, has characteristics (biocompatible, biodegradable, non-toxic) that make it appropriate as a biodegradable plastic substance. The different forms of PHA make it suitable to a wide choice of products, from packaging materials to biomedical applications. The major challenge in commercialization of PHA is the cost of manufacturing. There are a lot of factors that could affect the efficiency of a development method. The development of new strategic parameters for better synthesis, including consumption of low cost carbon substrates, genetic modification of PHA-producing strains, and fermentational strategies are discussed. Recently, many efforts have been made to develop a method for the cost-effective production of PHAs. The isolation, analysis as well as characterization of PHAs are significant factors for any developmental process. Due to the biodegradable and biocompatible properties of PHAs, they are majorly used in biomedical applications such as vascular grafting, heart tissue engineering, skin tissue repairing, liver tissue engineering, nerve tissue engineering, bone tissue engineering, cartilage tissue engineering and therapeutic carrier. The emerging and interesting area of research is the development of self-healing biopolymer that could significantly broaden the operational life and protection of the polymeric materials for a broad range of uses. Biodegradable and biocompatible polymers are considered as the green materials in place of petroleum-based plastics in the future.
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Affiliation(s)
- Salma Shahid
- Department of Biochemistry, Government College Women University Faisalabad, Pakistan.
| | - Sadia Razzaq
- Department of Chemistry, Government College Women University Faisalabad, Pakistan
| | - Robina Farooq
- Department of Chemistry, Government College Women University Faisalabad, Pakistan
| | - Zill-I-Huma Nazli
- Department of Chemistry, Government College Women University Faisalabad, Pakistan
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24
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Velázquez-Sánchez C, Espín G, Peña C, Segura D. The Modification of Regulatory Circuits Involved in the Control of Polyhydroxyalkanoates Metabolism to Improve Their Production. Front Bioeng Biotechnol 2020; 8:386. [PMID: 32426348 PMCID: PMC7204398 DOI: 10.3389/fbioe.2020.00386] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 04/07/2020] [Indexed: 11/13/2022] Open
Abstract
Poly-(3-hydroxyalkanoates) (PHAs) are bacterial carbon and energy storage compounds. These polymers are synthesized under conditions of nutritional imbalance, where a nutrient is growth-limiting while there is still enough carbon source in the medium. On the other side, the accumulated polymer is mobilized under conditions of nutrient accessibility or by limitation of the carbon source. Thus, it is well known that the accumulation of PHAs is affected by the availability of nutritional resources and this knowledge has been used to establish culture conditions favoring high productivities. In addition to this effect of the metabolic status on PHAs accumulation, several genetic regulatory networks have been shown to drive PHAs metabolism, so the expression of the PHAs genes is under the influence of global or specific regulators. These regulators are thought to coordinate PHAs synthesis and mobilization with the rest of bacterial physiology. While the metabolic and biochemical knowledge related to the biosynthesis of these polymers has led to the development of processes in bioreactors for high-level production and also to the establishment of strategies for metabolic engineering for the synthesis of modified biopolymers, the use of knowledge related to the regulatory circuits controlling PHAs metabolism for strain improvement is scarce. A better understanding of the genetic control systems involved could serve as the foundation for new strategies for strain modification in order to increase PHAs production or to adjust the chemical structure of these biopolymers. In this review, the regulatory systems involved in the control of PHAs metabolism are examined, with emphasis on those acting at the level of expression of the enzymes involved and their potential modification for strain improvement, both for higher titers, or manipulation of polymer properties. The case of the PHAs producer Azotobacter vinelandii is taken as an example of the complexity and variety of systems controlling the accumulation of these interesting polymers in response to diverse situations, many of which could be engineered to improve PHAs production.
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Affiliation(s)
- Claudia Velázquez-Sánchez
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Guadalupe Espín
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Carlos Peña
- Departamento Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Daniel Segura
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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25
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Chek MF, Kim SY, Mori T, Tan HT, Sudesh K, Hakoshima T. Asymmetric Open-Closed Dimer Mechanism of Polyhydroxyalkanoate Synthase PhaC. iScience 2020; 23:101084. [PMID: 32388399 PMCID: PMC7214940 DOI: 10.1016/j.isci.2020.101084] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/01/2020] [Accepted: 04/15/2020] [Indexed: 12/15/2022] Open
Abstract
Biodegradable polyester polyhydroxyalkanoate (PHA) is a promising bioplastic material for industrial use as a replacement for petroleum-based plastics. PHA synthase PhaC forms an active dimer to polymerize acyl moieties from the substrate acyl-coenzyme A (CoA) into PHA polymers. Here we present the crystal structure of the catalytic domain of PhaC from Chromobacterium sp. USM2, bound to CoA. The structure reveals an asymmetric dimer, in which one protomer adopts an open conformation bound to CoA, whereas the other adopts a closed conformation in a CoA-free form. The open conformation is stabilized by the asymmetric dimerization and enables PhaC to accommodate CoA and also to create the product egress path. The bound CoA molecule has its β-mercaptoethanolamine moiety extended into the active site with the terminal SH group close to active center Cys291, enabling formation of the reaction intermediate by acylation of Cys291. Crystal structure of PhaCCs-CAT bound to coenzyme A A unique asymmetric open-closed dimer Restructuring of the CAP subdomain provides a cleft toward the active site The cleft enables the substrate entry and the product egress
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Affiliation(s)
- Min Fey Chek
- Structural Biology Laboratory, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Sun-Yong Kim
- Structural Biology Laboratory, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Tomoyuki Mori
- Structural Biology Laboratory, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Hua Tiang Tan
- School of Biological Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - Kumar Sudesh
- School of Biological Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - Toshio Hakoshima
- Structural Biology Laboratory, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan.
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26
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Godard T, Zühlke D, Richter G, Wall M, Rohde M, Riedel K, Poblete-Castro I, Krull R, Biedendieck R. Metabolic Rearrangements Causing Elevated Proline and Polyhydroxybutyrate Accumulation During the Osmotic Adaptation Response of Bacillus megaterium. Front Bioeng Biotechnol 2020; 8:47. [PMID: 32161752 PMCID: PMC7053513 DOI: 10.3389/fbioe.2020.00047] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Accepted: 01/21/2020] [Indexed: 12/15/2022] Open
Abstract
For many years now, Bacillus megaterium serves as a microbial workhorse for the high-level production of recombinant proteins in the g/L-scale. However, efficient and stable production processes require the knowledge of the molecular adaptation strategies of the host organism to establish optimal environmental conditions. Here, we interrogated the osmotic stress response of B. megaterium using transcriptome, proteome, metabolome, and fluxome analyses. An initial transient adaptation consisted of potassium import and glutamate counterion synthesis. The massive synthesis of the compatible solute proline constituted the second longterm adaptation process. Several stress response enzymes involved in iron scavenging and reactive oxygen species (ROS) fighting proteins showed higher levels under prolonged osmotic stress induced by 1.8 M NaCl. At the same time, the downregulation of the expression of genes of the upper part of glycolysis resulted in the activation of the pentose phosphate pathway (PPP), generating an oversupply of NADPH. The increased production of lactate accompanied by the reduction of acetate secretion partially compensate for the unbalanced (NADH/NAD+) ratio. Besides, the tricarboxylic acid cycle (TCA) mainly supplies the produced NADH, as indicated by the higher mRNA and protein levels of involved enzymes, and further confirmed by 13C flux analyses. As a consequence of the metabolic flux toward acetyl-CoA and the generation of an excess of NADPH, B. megaterium redirected the produced acetyl-CoA toward the polyhydroxybutyrate (PHB) biosynthetic pathway accumulating around 30% of the cell dry weight (CDW) as PHB. This direct relation between osmotic stress and intracellular PHB content has been evidenced for the first time, thus opening new avenues for synthesizing this valuable biopolymer using varying salt concentrations under non-limiting nutrient conditions.
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Affiliation(s)
- Thibault Godard
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Braunschweig, Germany
| | - Daniela Zühlke
- Institute of Microbiology, Universität Greifswald, Greifswald, Germany
| | - Georg Richter
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Braunschweig, Germany
| | - Melanie Wall
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Braunschweig, Germany
| | - Manfred Rohde
- Central Facility for Microscopy, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Katharina Riedel
- Institute of Microbiology, Universität Greifswald, Greifswald, Germany
| | - Ignacio Poblete-Castro
- Biosystems Engineering Laboratory, Center for Bioinformatics and Integrative Biology, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
| | - Rainer Krull
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Braunschweig, Germany.,Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Braunschweig, Germany.,Center of Pharmaceutical Engineering (PVZ), Technische Universität Braunschweig, Braunschweig, Germany
| | - Rebekka Biedendieck
- Braunschweig Integrated Centre of Systems Biology (BRICS), Technische Universität Braunschweig, Braunschweig, Germany.,Institute of Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
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27
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Gabirondo E, Sangroniz A, Etxeberria A, Torres-Giner S, Sardon H. Poly(hydroxy acids) derived from the self-condensation of hydroxy acids: from polymerization to end-of-life options. Polym Chem 2020. [DOI: 10.1039/d0py00088d] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Poly(hydroxy acids) derived from the self-condensation of hydroxy acid are biodegradable and can be fully recycled in a Circular Economy approach.
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Affiliation(s)
- Elena Gabirondo
- Department of Polymer Science and Technology
- Institute for Polymer Materials (POLYMAT)
- Faculty of Chemistry
- University of the Basque Country (UPV/EHU)
- 20018 Donostia
| | - Ainara Sangroniz
- Department of Polymer Science and Technology
- Institute for Polymer Materials (POLYMAT)
- Faculty of Chemistry
- University of the Basque Country (UPV/EHU)
- 20018 Donostia
| | - Agustin Etxeberria
- Department of Polymer Science and Technology
- Institute for Polymer Materials (POLYMAT)
- Faculty of Chemistry
- University of the Basque Country (UPV/EHU)
- 20018 Donostia
| | - Sergio Torres-Giner
- Novel Materials and Nanotechnology Group
- Institute of Agrochemistry and Food Technology (IATA)
- Spanish National Research Council (CSIC)
- 46980 Paterna
- Spain
| | - Haritz Sardon
- Department of Polymer Science and Technology
- Institute for Polymer Materials (POLYMAT)
- Faculty of Chemistry
- University of the Basque Country (UPV/EHU)
- 20018 Donostia
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28
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Soda N, Rehm BHA, Sonar P, Nguyen NT, Shiddiky MJA. Advanced liquid biopsy technologies for circulating biomarker detection. J Mater Chem B 2019; 7:6670-6704. [PMID: 31646316 DOI: 10.1039/c9tb01490j] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Liquid biopsy is a new diagnostic concept that provides important information for monitoring and identifying tumor genomes in body fluid samples. Detection of tumor origin biomolecules like circulating tumor cells (CTCs), circulating tumor specific nucleic acids (circulating tumor DNA (ctDNA), circulating tumor RNA (ctRNA), microRNAs (miRNAs), long non-coding RNAs (lnRNAs)), exosomes, autoantibodies in blood, saliva, stool, urine, etc. enables cancer screening, early stage diagnosis and evaluation of therapy response through minimally invasive means. From reliance on painful and hazardous tissue biopsies or imaging depending on sophisticated equipment, cancer management schemes are witnessing a rapid evolution towards minimally invasive yet highly sensitive liquid biopsy-based tools. Clinical application of liquid biopsy is already paving the way for precision theranostics and personalized medicine. This is achieved especially by enabling repeated sampling, which in turn provides a more comprehensive molecular profile of tumors. On the other hand, integration with novel miniaturized platforms, engineered nanomaterials, as well as electrochemical detection has led to the development of low-cost and simple platforms suited for point-of-care applications. Herein, we provide a comprehensive overview of the biogenesis, significance and potential role of four widely known biomarkers (CTCs, ctDNA, miRNA and exosomes) in cancer diagnostics and therapeutics. Furthermore, we provide a detailed discussion of the inherent biological and technical challenges associated with currently available methods and the possible pathways to overcome these challenges. The recent advances in the application of a wide range of nanomaterials in detecting these biomarkers are also highlighted.
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Affiliation(s)
- Narshone Soda
- School of Environment and Science, Griffith University, Nathan Campus, QLD 4111, Australia. and Queensland Micro- and Nanotechnology Centre (QMNC), Griffith University, Nathan Campus, QLD 4111, Australia
| | - Bernd H A Rehm
- Centre for Cell Factories and Biopolymers (CCFB), Griffith Institute for Drug Discovery (GRIDD), Griffith University, Nathan, QLD 4111, Australia
| | - Prashant Sonar
- School of Chemistry, Physics and Mechanical Engineering, Molecular Design and Synthesis, Queensland University of Technology (QUT), Brisbane, Australia
| | - Nam-Trung Nguyen
- Queensland Micro- and Nanotechnology Centre (QMNC), Griffith University, Nathan Campus, QLD 4111, Australia
| | - Muhammad J A Shiddiky
- School of Environment and Science, Griffith University, Nathan Campus, QLD 4111, Australia. and Queensland Micro- and Nanotechnology Centre (QMNC), Griffith University, Nathan Campus, QLD 4111, Australia
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29
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McIntosh M, Eisenhardt K, Remes B, Konzer A, Klug G. Adaptation of the Alphaproteobacterium Rhodobacter sphaeroides to stationary phase. Environ Microbiol 2019; 21:4425-4445. [PMID: 31579997 DOI: 10.1111/1462-2920.14809] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 08/30/2019] [Accepted: 09/18/2019] [Indexed: 12/20/2022]
Abstract
Exhaustion of nutritional resources stimulates bacterial populations to adapt their growth behaviour. General mechanisms are known to facilitate this adaptation by sensing the environmental change and coordinating gene expression. However, the existence of such mechanisms among the Alphaproteobacteria remains unclear. This study focusses on global changes in transcript levels during growth under carbon-limiting conditions in a model Alphaproteobacterium, Rhodobacter sphaeroides, a metabolically diverse organism capable of multiple modes of growth including aerobic and anaerobic respiration, anaerobic anoxygenic photosynthesis and fermentation. We identified genes that showed changed transcript levels independently of oxygen levels during the adaptation to stationary phase. We selected a subset of these genes and subjected them to mutational analysis, including genes predicted to be involved in manganese uptake, polyhydroxybutyrate production and quorum sensing and an alternative sigma factor. Although these genes have not been previously associated with the adaptation to stationary phase, we found that all were important to varying degrees. We conclude that while R. sphaeroides appears to lack a rpoS-like master regulator of stationary phase adaptation, this adaptation is nonetheless enabled through the impact of multiple genes, each responding to environmental conditions and contributing to the adaptation to stationary phase.
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Affiliation(s)
- Matthew McIntosh
- Institut für Mikrobiologie und Molekularbiologie, IFZ, Justus-Liebig-Universität, 35392, Giessen, Germany
| | - Katrin Eisenhardt
- Institut für Mikrobiologie und Molekularbiologie, IFZ, Justus-Liebig-Universität, 35392, Giessen, Germany
| | - Bernhard Remes
- Institut für Mikrobiologie und Molekularbiologie, IFZ, Justus-Liebig-Universität, 35392, Giessen, Germany
| | - Anne Konzer
- Biomolecular Mass Spectrometry, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Gabriele Klug
- Institut für Mikrobiologie und Molekularbiologie, IFZ, Justus-Liebig-Universität, 35392, Giessen, Germany
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30
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Li R, Yang J, Xiao Y, Long L. In vivo immobilization of an organophosphorus hydrolyzing enzyme on bacterial polyhydroxyalkanoate nano-granules. Microb Cell Fact 2019; 18:166. [PMID: 31601206 PMCID: PMC6785862 DOI: 10.1186/s12934-019-1201-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 08/27/2019] [Indexed: 11/14/2022] Open
Abstract
Background Polyhydroxyalkanoate (PHA) are nano-granules naturally produced by bacteria. Two types of proteins, PHA synthase (PhaC) and phasins (PhaPs), are attached to the PHA surface by covalent and hydrophobic interactions. Utilizing these anchored proteins, functionalized PHA nano-granules displaying proteins of interest can be easily prepared by fermentation. Results In this study, a one-step fabrication method was developed for stable and efficient immobilization of an organophosphorus degrading enzyme on PHA nano-granules. The nano-biocatalysts were produced in recombinant Escherichia coli cells into which the polyhydroxyalkanoate synthesis pathway from Cupriavidus necator had been introduced. Two different strategies, covalent attachment and hydrophobic binding, were investigated by fusing bacterial organophosphorus anhydride hydrolase (OPAA4301) with PhaC and PhaP, respectively. Using both methods, the tetrameric enzyme successfully self-assembled and was displayed on the PHA surface. The display density of the target fused enzyme was enhanced to 6.8% of total protein on decorated PHA by combination of covalent and non-covalent binding modes. Immobilization of the enzyme on PHA granules resulted in higher catalytic efficiency, increased stability and excellent reusability. The kcat values of the immobilized enzymes increased by threefold compared to that of the free enzyme. The pH stability under acidic conditions was significantly enhanced, and the immobilized enzyme was stable at pH 3.0–11.0. Furthermore, more than 80% of the initial enzyme activity retained after recycling ten times. Conclusions This study provides a promising approach for cost-efficient in vivo immobilization of a tetrameric organophosphorus degrading enzyme. The immobilization process expands the utility of the enzyme, and may inspire further commercial developments of PHA nano-biocatalysts. As revealed by our results, combination of covalent and non-covalent binding is recommended for display of enzymes on PHA granules.
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Affiliation(s)
- Ru Li
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, RNAM Center for Marine Microbiology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, People's Republic of China.,University of the Chinese Academy of Sciences, Beijing, 100049, People's Republic of China
| | - Jian Yang
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, RNAM Center for Marine Microbiology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, People's Republic of China
| | - Yunzhu Xiao
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, RNAM Center for Marine Microbiology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, People's Republic of China.,Shenzhen Key Laboratory of Microbial Genetic Engineering, College of Life Sciences and Oceanology, Shenzhen University, Shenzhen, 518055, Guangdong, People's Republic of China
| | - Lijuan Long
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, RNAM Center for Marine Microbiology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, People's Republic of China. .,University of the Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.
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31
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Martínez-Martínez MDLA, González-Pedrajo B, Dreyfus G, Soto-Urzúa L, Martínez-Morales LJ. Phasin PhaP1 is involved in polyhydroxybutyrate granules morphology and in controlling early biopolymer accumulation in Azospirillum brasilense Sp7. AMB Express 2019; 9:155. [PMID: 31555910 PMCID: PMC6761214 DOI: 10.1186/s13568-019-0876-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 09/09/2019] [Indexed: 11/10/2022] Open
Abstract
Phasins are amphiphilic proteins involved in the regulation of the number and size of polyhydroxybutyrate (PHB) granules. The plant growth promoting bacterium Azospirillum brasilense Sp7 accumulates high quantities of bioplastic PHB as carbon and energy source. By analyzing the genome, we identified six genes that code for proteins with a Phasin_2 domain. To understand the role of A. brasilense Sp7 PhaP1 (PhaP1Abs) on PHB synthesis, the phaP1 gene (AMK58_RS17065) was deleted. The morphology of the PHB granules was analyzed by transmission electron microscopy (TEM) and the PHB produced was quantified under three different C:N ratios in cultures subjected to null or low-oxygen transfer. The results showed that PhaP1Abs is involved in PHB granules morphology and in controlling early biopolymer accumulation. Using RT-PCR it was found that phasin genes, except phaP4, are transcribed in accordance with the C:N ratio used for the growth of A. brasilense. phaP1, phaP2 and phaP3 genes were able to respond to the growth conditions tested. This study reports the first analysis of a phasin protein in A. brasilense Sp7.
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32
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Liu C, Baffoe DK, Zhan Y, Zhang M, Li Y, Zhang G. Halophile, an essential platform for bioproduction. J Microbiol Methods 2019; 166:105704. [PMID: 31494180 DOI: 10.1016/j.mimet.2019.105704] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 07/25/2019] [Accepted: 08/27/2019] [Indexed: 11/24/2022]
Abstract
Industrial biotechnology aims to compete as a stronger alternative ensuring environmental friendly microbial-based production that seeks to curb the predicament of pollution. However, the high cost of bioprocessing is a severe drawback, and therefore, new approaches must be developed to overcome this challenge. Halophiles have shown potentials of overcoming this challenge and are of much preference for unsterile and continuous contamination-free bioprocess due to their unique ability to grow under harsh environmental conditions. Recent advances in genetic manipulations have been established to better the performance of halophiles for industrial applications. Many researchers produced various products such as polyhydroxyalkanoates (PHA), ectoines, biosurfactants, and antioxidants using halophiles, and further efforts have been established to develop halophiles as the foundation for low-cost bioprocess. This paper provides a useful reference for researchers on the merits, drawbacks, achievements, and application of halophiles for bioproduction.
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Affiliation(s)
- Changli Liu
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin 150040, China.
| | - Dennis Kingsley Baffoe
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin 150040, China.
| | - Yuanlong Zhan
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin 150040, China.
| | - Mengying Zhang
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin 150040, China.
| | - Yahui Li
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin 150040, China.
| | - Guocai Zhang
- School of Forestry, Northeast Forestry University, No. 26 Hexing Road, Harbin 150040, China.
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33
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Costa SS, Miranda AL, de Morais MG, Costa JAV, Druzian JI. Microalgae as source of polyhydroxyalkanoates (PHAs) - A review. Int J Biol Macromol 2019; 131:536-547. [PMID: 30885732 DOI: 10.1016/j.ijbiomac.2019.03.099] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 03/10/2019] [Accepted: 03/15/2019] [Indexed: 01/09/2023]
Abstract
Polyhydroxyalkanoates (PHA) are biopolymers synthesized by different microorganisms and considered substitute powers for petroleum-based plastics because they have similar mechanical properties as synthetic polymers, can be processed in a similar way and are fully biodegradable. Currently commercial PHAs are produced in fermenters using bacteria and large amounts of organic carbon sources and salts in the culture media, accounting for approximately 50% of the total production costs. A greater commercial application of the PHA is limited to a decrease in the cost of production. Several studies suggest that microalgae are a type of microorganisms that can be used to obtain PHAs at a lower cost because they have minimum nutrient requirements for growth and are photoautotrophic in nature, i.e. they use light and CO2 as their main sources of energy. Thus, this work aims to provide a review on the production of PHAs of different microalgae, focusing on the properties and composition of biopolymers, verifying the potential of using these bioplastics instead of petroleum based plastics. Studies of stimulation PHA synthesis by microalgae are still considered incipient. Still, it is clear that microalgae have the potential to produce biopolymers with lower cost and can play a vital role in the environment.
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Affiliation(s)
- Samantha Serra Costa
- Institute of Health Sciences, RENORBIO, Federal University of Bahia, Salvador, Bahia, Brazil; Federal University of the Recôncavo of Bahia, Feira de Santana, Bahia, Brazil.
| | - Andréa Lobo Miranda
- Institute of Health Sciences, RENORBIO, Federal University of Bahia, Salvador, Bahia, Brazil; Federal Institute of Baiano, Santa Inês, Bahia, Brazil
| | - Michele Greque de Morais
- Laboratory of Biochemical Engineering, College of Chemistry and Food Engineering, Federal University of Rio Grande, Rio Grande, Brazil
| | - Jorge Alberto Vieira Costa
- Laboratory of Biochemical Engineering, College of Chemistry and Food Engineering, Federal University of Rio Grande, Rio Grande, Brazil
| | - Janice Izabel Druzian
- Department of Bromatological Analysis, College of Pharmacy, Federal University of Bahia, Salvador, Bahia, Brazil
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34
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Designing Novel Interfaces via Surface Functionalization of Short-Chain-Length Polyhydroxyalkanoates. ADVANCES IN POLYMER TECHNOLOGY 2019. [DOI: 10.1155/2019/3831251] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Polyhydroxyalkanoates (PHA), a microbial plastic has emerged as promising biomaterial owing to the broad range of mechanical properties. However, some studies revealed that PHA is hydrophobic and has no recognition site for cell attachment and this is often a limitation in tissue engineering aspects. Owing to this, the polymer is tailored accordingly in order to enhance the biocompatibilityin vivoas well as to suit the intended application. Thus far, these surface modifications have led to PHA being widely used in various biomedical and pharmaceutical applications such as cardiac patches, wound management, nerve, bone, and cartilage repair. This review addresses the surface modification on biomedical applications focusing on short-chain-length PHA such as poly(3-hydroxybutyrate) [P(3HB)], poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)].
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35
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Green RT, East AK, Karunakaran R, Downie JA, Poole PS. Transcriptomic analysis of Rhizobium leguminosarum bacteroids in determinate and indeterminate nodules. Microb Genom 2019; 5:e000254. [PMID: 30777812 PMCID: PMC6421345 DOI: 10.1099/mgen.0.000254] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 01/15/2019] [Indexed: 01/25/2023] Open
Abstract
Two common classes of nitrogen-fixing legume root nodules are those that have determinate or indeterminate meristems, as in Phaseolus bean and pea, respectively. In indeterminate nodules, rhizobia terminally differentiate into bacteroids with endoreduplicated genomes, whereas bacteroids from determinate nodules are less differentiated and can regrow. We used RNA sequencing to compare bacteroid gene expression in determinate and indeterminate nodules using two Rhizobium leguminosarum strains whose genomes differ due to replacement of the symbiosis (Sym) plasmid pRP2 (strain Rlp4292) with pRL1 (strain RlvA34), thereby switching symbiosis hosts from Phaseolus bean (determinate nodules) to pea (indeterminate nodules). Both bacteroid types have gene expression patterns typical of a stringent response, a stressful environment and catabolism of dicarboxylates, formate, amino acids and quaternary amines. Gene expression patterns were indicative that bean bacteroids were more limited for phosphate, sulphate and iron than pea bacteroids. Bean bacteroids had higher levels of expression of genes whose products are predicted to be associated with metabolite detoxification or export. Pea bacteroids had increased expression of genes associated with DNA replication, membrane synthesis and the TCA (tricarboxylic acid) cycle. Analysis of bacteroid-specific transporter genes was indicative of distinct differences in sugars and other compounds in the two nodule environments. Cell division genes were down-regulated in pea but not bean bacteroids, while DNA synthesis was increased in pea bacteroids. This is consistent with endoreduplication of pea bacteroids and their failure to regrow once nodules senesce.
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Affiliation(s)
- R. T. Green
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - A. K. East
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK
| | - R. Karunakaran
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - J. A. Downie
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
| | - P. S. Poole
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK
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36
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Mato A, Tarazona NA, Hidalgo A, Cruz A, Jiménez M, Pérez-Gil J, Prieto MA. Interfacial Activity of Phasin PhaF from Pseudomonas putida KT2440 at Hydrophobic-Hydrophilic Biointerfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:678-686. [PMID: 30580527 DOI: 10.1021/acs.langmuir.8b03036] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Phasins, the major proteins coating polyhydroxyalkanoate (PHA) granules, have been proposed as suitable biosurfactants for multiple applications because of their amphiphilic nature. In this work, we analyzed the interfacial activity of the amphiphilic α-helical phasin PhaF from Pseudomonas putida KT2440 at different hydrophobic-hydrophilic interfacial environments. The binding of PhaF to surfaces containing PHA or phospholipids, postulated as structural components of PHA granules, was confirmed in vitro using supported lipid bilayers and confocal microscopy, with polyhydroxyoctanoate- co-hexanoate P(HO- co-HHx) and Escherichia coli lipid extract as model systems. The surfactant-like capabilities of PhaF were determined by measuring changes in surface pressure in Langmuir devices. PhaF spontaneously adsorbed at the air-water interface, reducing the surface tension from 72 mN/m (water surface tension at 25 °C) to 50 mN/m. The differences in the adsorption of the protein in the presence of different phospholipid films showed a marked preference for phosphatidylglycerol species, such as 1-palmitoyl-2-oleoyl- sn-glycero-3-phosphoglycerol. The PHA-binding domain of PhaF (BioF) conserved a similar surface activity to PhaF, suggesting that it is responsible for the surfactant properties of the whole protein. These new findings not only increase our knowledge about the role of phasins in the PHA machinery but also open new outlooks for the application of these proteins as biosurfactants.
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Affiliation(s)
| | | | - Alberto Hidalgo
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas , Universidad Complutense de Madrid , 28040 Madrid , Spain
| | - Antonio Cruz
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas , Universidad Complutense de Madrid , 28040 Madrid , Spain
| | | | - Jesús Pérez-Gil
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas , Universidad Complutense de Madrid , 28040 Madrid , Spain
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37
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Long JY, Song KL, He X, Zhang B, Cui XF, Song CF. Mutagenesis of PhaR, a Regulator Gene of Polyhydroxyalkanoate Biosynthesis of Xanthomonas oryzae pv. oryzae Caused Pleiotropic Phenotype Changes. Front Microbiol 2018; 9:3046. [PMID: 30619137 PMCID: PMC6304360 DOI: 10.3389/fmicb.2018.03046] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 11/27/2018] [Indexed: 01/04/2023] Open
Abstract
Polyhydroxyalkanoates (PHAs) are intracellular carbon and energy storage materials produced in various microorganisms under nutrient-limited conditions. PhaR is a regulatory protein involved in PHA synthesis. Xanthomonas oryzae pv. oryzae (Xoo) is one of the most important bacterial pathogens in rice and has PHA biosynthesis genes in its genome, but the biological function of phaR in Xoo is unknown. In this study, we investigated the effects of the mutagenesis of phaR gene in Xoo strain PXO99A. Compared to the wildtype, the PhaR gene knock-out mutant PXO99ΔphaR was hypermotile and showed decreased growth rates in both rich and limited nutrient media. PXO99ΔphaR also showed almost 75% decrease in extracellular polysaccharide (EPS) production. When inoculated in rice leaves by leaf-clipping method, PXO99ΔphaR displayed reduced virulence in terms of lesion length and bacterial multiplication compared with the wildtype strain. PXO99ΔphaR also showed enhanced hypersensitive response (HR) induction in the leaves of non-host Nicotiana benthamiana with elevated hpa1 gene expression. Introduction of a cosmid containing the phaR coding sequence restored the phenotypes of the mutant to those of the wildtype strain. These results suggest that PhaR gene is an important gene that affects multiple bacterial characteristics, including EPS production, growth rate, defense response induced harpin production and motility, related to its virulence in plant.
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Affiliation(s)
| | | | | | | | | | - Cong-Feng Song
- Department of Plant Pathology, College of Plant Protection, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing, China
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Chek MF, Hiroe A, Hakoshima T, Sudesh K, Taguchi S. PHA synthase (PhaC): interpreting the functions of bioplastic-producing enzyme from a structural perspective. Appl Microbiol Biotechnol 2018; 103:1131-1141. [DOI: 10.1007/s00253-018-9538-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 11/20/2018] [Accepted: 11/22/2018] [Indexed: 02/07/2023]
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Fan F, Wu X, Zhao J, Ran G, Shang S, Li M, Lu X. A Specific Drug Delivery System for Targeted Accumulation and Tissue Penetration in Prostate Tumors Based on Microbially Synthesized PHBHHx Biopolyester and iRGD Peptide Fused PhaP. ACS APPLIED BIO MATERIALS 2018; 1:2041-2053. [DOI: 10.1021/acsabm.8b00524] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Fan Fan
- Department of Biological Science and Bioengineering, Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an 710049, Shaanxi, P. R. China
| | - Xingjuan Wu
- Department of Biological Science and Bioengineering, Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an 710049, Shaanxi, P. R. China
| | - Jiping Zhao
- Department of Biological Science and Bioengineering, Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an 710049, Shaanxi, P. R. China
| | - Ganqiao Ran
- Department of Biological Science and Bioengineering, Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an 710049, Shaanxi, P. R. China
| | - Sen Shang
- Department of Biological Science and Bioengineering, Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an 710049, Shaanxi, P. R. China
| | - Mingchuan Li
- Molecular Biotechnology Center, Universita di Torino, 10126 Torino, Italy
| | - Xiaoyun Lu
- Department of Biological Science and Bioengineering, Key Laboratory of Biomedical Information Engineering of the Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an 710049, Shaanxi, P. R. China
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Tarazona NA, Maestro B, Revelles O, Sanz JM, Prieto MA. Role of leucine zipper-like motifs in the oligomerization of Pseudomonas putida phasins. Biochim Biophys Acta Gen Subj 2018; 1863:362-370. [PMID: 30419286 DOI: 10.1016/j.bbagen.2018.11.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 11/05/2018] [Accepted: 11/07/2018] [Indexed: 12/31/2022]
Abstract
BACKGROUND Phasins are low molecular mass proteins that accumulate strongly in bacterial cells in response to the intracellular storage of polyhydroxyalkanoates (PHA). Although lacking catalytic activity, phasins are the major components of the surface of the PHA granules and could be potentially involved in the formation of a network-like protein layer surrounding the polyester inclusions. Structural models revealed phasins to possess coiled-coil regions that might be important in the establishment of protein-protein interactions. However, there is not experimental evidence of a coiled-coil mediated oligomerization in these proteins. METHODS Structure prediction analyses were used to characterize the coiled-coil motifs of phasins PhaF and PhaI -produced by the model bacterium Pseudomonas putida KT2440-. Their oligomerization was evaluated by biolayer interferometry and the in vivo two-hybrid (BACTH) system. The interaction ability of a series of coiled-coil mutated derivatives was also measured. RESULTS The formation of PhaF and PhaI complexes was detected. A predicted short leucine zipper-like coiled-coil (ZIP), containing "ideal" residues located within the hydrophobic core, was shown responsible for the oligomers stability. The substitution of key residues (leucines or valines) in PhaI ZIP (ZIPI) for alanine reduced by four fold the oligomerization efficiency. CONCLUSIONS These results indicate that coiled-coil motifs are essential for phasin interactions. Correct oligomerization requires the formation of a stable hydrophobic interface between both phasins. GENERAL SIGNIFICANCE Our findings elucidate the oligomerization motif of PhaF and PhaI. This motif is present in most phasins from PHA-accumulating bacteria and offers a potentially important target for modulating the PHA granules stability.
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Affiliation(s)
- Natalia A Tarazona
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas, CSIC, Madrid 28040, Spain
| | - Beatriz Maestro
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Elche 03202, Spain
| | - Olga Revelles
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas, CSIC, Madrid 28040, Spain
| | - Jesús M Sanz
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas, CSIC, Madrid 28040, Spain; Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Elche 03202, Spain
| | - M Auxiliadora Prieto
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas, CSIC, Madrid 28040, Spain.
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Balakrishna Pillai A, Jaya Kumar A, Kumarapillai H. Enhanced production of poly(3-hydroxybutyrate) in recombinant Escherichia coli and EDTA-microwave-assisted cell lysis for polymer recovery. AMB Express 2018; 8:142. [PMID: 30182189 PMCID: PMC6123327 DOI: 10.1186/s13568-018-0672-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Accepted: 08/31/2018] [Indexed: 11/12/2022] Open
Abstract
Poly(3-hydroxybutyrate) (PHB) is a bacterial polymer of great commercial importance due to its properties similar to polypropylene. With an aim to develop a recombinant system for economical polymer production, PHB biosynthesis genes from Bacillus aryabhattai PHB10 were cloned in E. coli. The recombinant cells accumulated a maximum level of 6.22 g/L biopolymer utilizing glycerol in shake flasks. The extracted polymer was confirmed as PHB by GC-MS and NMR analyses. The polymer showed melting point at 171 °C, thermal stability in a temperature range of 0-140 °C and no weight loss up to 200 °C. PHB extracted from sodium hypochlorite lysed cells had average molecular weight of 143.108 kDa, polydispersity index (PDI) 1.81, tensile strength of 14.2 MPa and an elongation at break of 7.65%. This is the first report on high level polymer accumulation in recombinant E. coli solely expressing PHB biosynthesis genes from a Bacillus sp. As an alternative to sodium hypochlorite cell lysis mediated polymer extraction, the effect of combined treatment with ethylenediaminetetraacetic acid and microwave was studied which attained 93.75% yield. The polymer recovered through this method was 97.21% pure, showed 2.9-fold improvement in molecular weight and better PDI. The procedure is simple, with minimum polymer damage and more eco-friendly than the sodium hypochlorite lysis method.
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Affiliation(s)
- Aneesh Balakrishna Pillai
- Environmental Biology Laboratory, Rajiv Gandhi Centre for Biotechnology (RGCB) Poojappura, Thycaud P. O., Thiruvananthapuram, Kerala 695014 India
| | - Arjun Jaya Kumar
- Environmental Biology Laboratory, Rajiv Gandhi Centre for Biotechnology (RGCB) Poojappura, Thycaud P. O., Thiruvananthapuram, Kerala 695014 India
| | - Harikrishnan Kumarapillai
- Environmental Biology Laboratory, Rajiv Gandhi Centre for Biotechnology (RGCB) Poojappura, Thycaud P. O., Thiruvananthapuram, Kerala 695014 India
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Anis SNS, Mohd Annuar MS, Simarani K. Microbial biosynthesis and in vivo depolymerization of intracellular medium-chain-length poly-3-hydroxyalkanoates as potential route to platform chemicals. Biotechnol Appl Biochem 2018; 65:784-796. [PMID: 29806235 DOI: 10.1002/bab.1666] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 05/23/2018] [Indexed: 01/15/2023]
Abstract
Biosynthesis and in vivo depolymerization of intracellular medium-chain-length poly-3-hydroxyalkanoates (mcl-PHA) in Pseudomonas putida Bet001 grown on lauric acid were studied. Highest mcl-PHA fraction (>50 % of total biomass) and cell concentration (8 g L-1 ) were obtained at carbon-to-nitrogen (C/N) ratio 20, starting cell concentration 1 g L-1 , and 48 H fermentation. The mcl-PHA comprised of 3-hydroxyhexanoate (C6 ), 3-hydroxyoctanote (C8 ), 3-hydroxydecanoate (C10 ), and 3-hydroxydodecanoate (C12 ) monomers. In vivo action was studied in a mineral liquid medium without carbon source, and in different buffer solutions with varied pH, molarity, ionic strength, and temperature. The monomer liberation rate reflected the mol percentage distribution of the initial polymer subunit composition. Rate and percentage of in vivo depolymerization were highest in 0.2 M Tris-HCl buffer (pH 9, strength = 0.2 M, 30 °C) at 0.21 g L-1 H-1 and 98.6 ± 1.3 wt%, respectively. There is a congruity vis-à-vis to specific buffer type, molarity, pH, ionic strength, and temperature values for superior in vivo depolymerization activities. Direct products from in vivo depolymerization matched the individual monomeric composition of native mcl-PHA. It points to exo-type reaction for the in vivo process, and potential biological route to chiral molecules.
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Affiliation(s)
- Siti Nor Syairah Anis
- Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| | - Mohd Suffian Mohd Annuar
- Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| | - Khanom Simarani
- Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
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Burkholderia xenovorans LB400 possesses a functional polyhydroxyalkanoate anabolic pathway encoded by the pha genes and synthesizes poly(3-hydroxybutyrate) under nitrogen-limiting conditions. Int Microbiol 2018; 21:47-57. [DOI: 10.1007/s10123-018-0004-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Revised: 03/27/2018] [Accepted: 03/27/2018] [Indexed: 10/16/2022]
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44
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Leong YH, Isa ASM, Mohamed Mahmood M, Moey CEJ, Utar Z, Soon YI, Majid MIA. Acute and repeated dose 28-day oral toxicity of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) nanoparticles in Sprague-Dawley rats. Regul Toxicol Pharmacol 2018; 95:280-288. [PMID: 29567329 DOI: 10.1016/j.yrtph.2018.03.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 03/14/2018] [Accepted: 03/18/2018] [Indexed: 10/17/2022]
Abstract
This study aimed to investigate the oral acute and subacute toxicity of Poly [3-hydroxybutyrate-co-4-hydroxybutyrate], P(3HB-co-4HB) in the form of nanoparticles in Sprague-Dawley rats. Acute oral administration of P(3HB-co-4HB) nanoparticles was performed as a single dose up to 2000 mg/kg in six female rats for 14 days. Subacute toxicity study via oral administration for 28 days at doses of 0 (control), 500, 1000 and 2000 mg/kg in rats (10 rats in each group, female:male = 1:1) was conducted. The estimated lethal dose (LD50) of P(3HB-co-4HB) nanoparticles was >2000 mg/kg. No mortality, unusual changes in behaviour, adverse clinical signs, abnormal changes in body weights or food consumption were observed on all animals treated with P(3HB-co-4HB) nanoparticles during 14 days of the acute toxicity study. In the subacute test, there was no mortality and toxicologically significant changes in clinical signs, body weights, food consumption, hematology, clinical biochemistry, urinalysis, macroscopic findings, organ weights as well as histopathological examination were observed.
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Affiliation(s)
- Yin-Hui Leong
- National Poison Centre, Universiti Sains Malaysia, 11800, USM, Penang, Malaysia.
| | - Anis Syaffini Mat Isa
- Malaysian Institute of Pharmaceuticals and Nutraceuticals (IPharm), National Institutes of Biotechnology Malaysia, Ministry of Science, Technology and Innovation, Block 5-D, Halaman Bukit Gambir, 11700 Penang, Malaysia
| | - Mazlianum Mohamed Mahmood
- Malaysian Institute of Pharmaceuticals and Nutraceuticals (IPharm), National Institutes of Biotechnology Malaysia, Ministry of Science, Technology and Innovation, Block 5-D, Halaman Bukit Gambir, 11700 Penang, Malaysia
| | - Chiew Erh Jacqueline Moey
- Malaysian Institute of Pharmaceuticals and Nutraceuticals (IPharm), National Institutes of Biotechnology Malaysia, Ministry of Science, Technology and Innovation, Block 5-D, Halaman Bukit Gambir, 11700 Penang, Malaysia
| | - Zulkhurnain Utar
- Malaysian Institute of Pharmaceuticals and Nutraceuticals (IPharm), National Institutes of Biotechnology Malaysia, Ministry of Science, Technology and Innovation, Block 5-D, Halaman Bukit Gambir, 11700 Penang, Malaysia
| | - Yong-Ing Soon
- Malaysian Institute of Pharmaceuticals and Nutraceuticals (IPharm), National Institutes of Biotechnology Malaysia, Ministry of Science, Technology and Innovation, Block 5-D, Halaman Bukit Gambir, 11700 Penang, Malaysia
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Fan F, Wang L, Ouyang Z, Wen Y, Lu X. Development and optimization of a tumor targeting system based on microbial synthesized PHA biopolymers and PhaP mediated functional modification. Appl Microbiol Biotechnol 2018; 102:3229-3241. [PMID: 29497797 DOI: 10.1007/s00253-018-8790-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Revised: 01/14/2018] [Accepted: 01/15/2018] [Indexed: 01/08/2023]
Abstract
Polyhydroxyalkanoate (PHA) is a class of microbial synthesized biodegradable and biocompatible aliphatic polymer which has been developed into nanoparticles (NPs) for sustained release of hydrophobic compounds. Taking advantage of the natural PHA binding protein PhaP which could be steadily adsorbed onto PHA NPs through hydrophobic interaction, a tumor targeting system was developed in this study by presenting an epidermal growth factor receptor (EGFR)-targeting peptide (ETP) on the surface of PHA NPs, via PhaP mediated adsorption. To reveal the effects of residual emulsifiers on PhaP mediated ETP modification and optimize the tumor targeting capacity of the system, a novel emulsifier-free PHA NPs (EF-NPs) was fabricated together with other two kinds of conventional emulsifier-required PHA NPs (PVA-NPs and P68-NPs, which were prepared with poly(vinyl alcohol) (PVA) and Pluronic F68 as emulsifiers, respectively). By analyzing the surface hydrophobicity, the amount of adsorbed fusion protein, and the cellular uptake of all kinds of PHA NPs, our results demonstrated that EF-NPs with stronger surface hydrophobicity were the most proper formulation for further PhaP mediated ETP functionalization. The residual PVA and Pluronic F68 affected the modification efficiency and secondary structure of ETP-PhaP fusion protein, and finally obstructed the targeting effect of ETP-PhaP modified PVA-NPs and P68-NPs to EGFR over-expressed tumor cells. The animal experiment further confirmed the effectiveness and feasibility of in vivo application of ETP-PhaP functionalized EF-NPs, indicating that it could be served as a promising tumor targeting system with satisfactory EGFR targeting ability. This PhaP mediated bio-modification process also opens a wide way for developing various PHA-based targeting systems by presenting different tumor or other tissue-specific targeting peptides.
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Affiliation(s)
- Fan Fan
- Department of Biological Science and Bioengineering, Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, Shaanxi, People's Republic of China
| | - Leilei Wang
- Department of Biological Science and Bioengineering, Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, Shaanxi, People's Republic of China
| | - Zhenlin Ouyang
- Department of Biological Science and Bioengineering, Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, Shaanxi, People's Republic of China
| | - Yurong Wen
- Department of Biological Science and Bioengineering, Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, Shaanxi, People's Republic of China
| | - Xiaoyun Lu
- Department of Biological Science and Bioengineering, Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, Shaanxi, People's Republic of China.
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46
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Bello-Gil D, Maestro B, Fonseca J, Dinjaski N, Prieto MA, Sanz JM. Poly-3-Hydroxybutyrate Functionalization with BioF-Tagged Recombinant Proteins. Appl Environ Microbiol 2018; 84:e02595-17. [PMID: 29196289 PMCID: PMC5795070 DOI: 10.1128/aem.02595-17] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 11/27/2017] [Indexed: 11/20/2022] Open
Abstract
Polyhydroxyalkanoates (PHAs) are biodegradable polyesters that accumulate in the cytoplasm of certain bacteria. One promising biotechnological application utilizes these biopolymers as supports for protein immobilization. Here, the PHA-binding domain of the Pseudomonas putida KT2440 PhaF phasin (BioF polypeptide) was investigated as an affinity tag for the in vitro functionalization of poly-3-hydroxybutyrate (PHB) particles with recombinant proteins, namely, full-length PhaF and two fusion proteins tagged to BioF (BioF-C-LytA and BioF-β-galactosidase, containing the choline-binding module C-LytA and the β-galactosidase enzyme, respectively). The protein-biopolyester interaction was strong and stable at a wide range of pHs and temperatures, and the bound protein was highly protected from self-degradation, while the binding strength could be modulated by coating with amphiphilic compounds. Finally, BioF-β-galactosidase displayed very stable enzymatic activity after several continuous activity-plus-washing cycles when immobilized in a minibioreactor. Our results demonstrate the potentialities of PHA and the BioF tag for the construction of novel bioactive materials.IMPORTANCE Our results confirm the biotechnological potential of the BioF affinity tag as a versatile tool for functionalizing PHA supports with recombinant proteins, leading to novel bioactive materials. The wide substrate range of the BioF tag presumably enables protein immobilization in vitro of virtually all natural PHAs as well as blends, copolymers, or artificial chemically modified derivatives with novel physicochemical properties. Moreover, the strength of protein adsorption may be easily modulated by varying the coating of the support, providing new perspectives for the engineering of bioactive materials that require a tight control of protein loading.
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Affiliation(s)
- Daniel Bello-Gil
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Elche, Spain
| | - Beatriz Maestro
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Elche, Spain
| | - Jennifer Fonseca
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Elche, Spain
| | - Nina Dinjaski
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CIB-CSIC), Madrid, Spain
| | - M Auxiliadora Prieto
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CIB-CSIC), Madrid, Spain
| | - Jesús M Sanz
- Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Elche, Spain
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Olaya-Abril A, Luque-Almagro VM, Manso I, Gates AJ, Moreno-Vivián C, Richardson DJ, Roldán MD. Poly(3-hydroxybutyrate) hyperproduction by a global nitrogen regulator NtrB mutant strain of Paracoccus denitrificans PD1222. FEMS Microbiol Lett 2018; 365:4705890. [PMID: 29228177 PMCID: PMC5812496 DOI: 10.1093/femsle/fnx251] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 11/29/2017] [Indexed: 12/27/2022] Open
Abstract
Paracoccus denitrificans PD1222 accumulates short-length polyhydroxyalkanoates, poly(3-hydroxybutyrate), under nitrogen-deficient conditions. Polyhydroxybutyrate metabolism requires the 3-ketoacyl-CoA thiolase PhaA, the acetoacetyl-CoA dehydrogenase/reductase PhaB and the synthase PhaC for polymerization. Additionally, P. denitrificans PD1222 grows aerobically with nitrate as sole nitrogen source. Nitrate assimilation is controlled negatively by ammonium through the two-component NtrBC system. NtrB is a sensor kinase that autophosphorylates a histidine residue under low-nitrogen concentrations and, in turn, transfers a phosphoryl group to an aspartate residue of the response regulator NtrC protein, which acts as a transcriptional activator of the P. denitrificans PD1222 nasABGHC genes. The P. denitrificans PD1222 NtrB mutant was unable to use nitrate efficiently as nitrogen source when compared to the wild-type strain, and it also overproduced poly(3-hydroxybutyrate). Acetyl-CoA concentration in the P. denitrificans PD1222 NtrB mutant strain was higher than in the wild-type strain. The expression of the phaC gene was also increased in the NtrB mutant when compared to the wild-type strain. These results suggest that accumulation of poly(3-hydroxybutyrate) in the NtrB mutant strain of PD1222 responds to the high levels of acetyl-CoA that accumulate in the cytoplasm as consequence of its inability to efficiently use nitrate as nitrogen source.
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Affiliation(s)
- Alfonso Olaya-Abril
- Departamento de Bioquímica y Biología Molecular, Universidad de Córdoba, Edificio Severo Ochoa, 1a planta, Campus de Rabanales, Córdoba, 14071, Spain
| | - Víctor M Luque-Almagro
- Departamento de Bioquímica y Biología Molecular, Universidad de Córdoba, Edificio Severo Ochoa, 1a planta, Campus de Rabanales, Córdoba, 14071, Spain
| | - Isabel Manso
- Departamento de Bioquímica y Biología Molecular, Universidad de Córdoba, Edificio Severo Ochoa, 1a planta, Campus de Rabanales, Córdoba, 14071, Spain
| | - Andrew J Gates
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Conrado Moreno-Vivián
- Departamento de Bioquímica y Biología Molecular, Universidad de Córdoba, Edificio Severo Ochoa, 1a planta, Campus de Rabanales, Córdoba, 14071, Spain
| | - David J Richardson
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - María Dolores Roldán
- Departamento de Bioquímica y Biología Molecular, Universidad de Córdoba, Edificio Severo Ochoa, 1a planta, Campus de Rabanales, Córdoba, 14071, Spain
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Maestro B, Sanz JM. Polyhydroxyalkanoate-associated phasins as phylogenetically heterogeneous, multipurpose proteins. Microb Biotechnol 2017; 10:1323-1337. [PMID: 28425176 PMCID: PMC5658603 DOI: 10.1111/1751-7915.12718] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 03/19/2017] [Accepted: 03/22/2017] [Indexed: 01/01/2023] Open
Abstract
Polyhydroxyalkanoates (PHAs) are natural polyesters of increasing biotechnological importance that are synthesized by many prokaryotic organisms as carbon and energy storage compounds in limiting growth conditions. PHAs accumulate intracellularly in form of inclusion bodies that are covered with a proteinaceous surface layer (granule-associated proteins or GAPs) conforming a network-like surface of structural, metabolic and regulatory polypeptides, and configuring the PHA granules as complex and well-organized subcellular structures that have been designated as 'carbonosomes'. GAPs include several enzymes related to PHA metabolism (synthases, depolymerases and hydroxylases) together with the so-called phasins, an heterogeneous group of small-size proteins that cover most of the PHA granule and that are devoid of catalytic functions but nevertheless play an essential role in granule structure and PHA metabolism. Structurally, phasins are amphiphilic proteins that shield the hydrophobic polymer from the cytoplasm. Here, we summarize the characteristics of the different phasins identified so far from PHA producer organisms and highlight the diverse opportunities that they offer in the Biotechnology field.
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Affiliation(s)
- Beatriz Maestro
- Instituto de Biología Molecular y CelularUniversidad Miguel HernándezAv. Universidad s/nElche03202Spain
| | - Jesús M. Sanz
- Instituto de Biología Molecular y CelularUniversidad Miguel HernándezAv. Universidad s/nElche03202Spain
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Chen GQ, Zhang J. Microbial polyhydroxyalkanoates as medical implant biomaterials. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2017; 46:1-18. [DOI: 10.1080/21691401.2017.1371185] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Guo-Qiang Chen
- School of Life Sciences, Tsinghua University, Beijing, China
- Center for Synthetic and Systems Biology, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China
- Center for Nano and Micro Mechanics, Tsinghua University, Beijing, China
- Department of Chemical Engineering, MOE Key Lab of Industrial Biocatalysis, Tsinghua University, Beijing, China
| | - Junyu Zhang
- Laboratory of Fear and Anxiety Disorders, Institute of Life Science, Nanchang University, Nanchang, China
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Zhao H, Yao Z, Chen X, Wang X, Chen GQ. Modelling of microbial polyhydroxyalkanoate surface binding protein PhaP for rational mutagenesis. Microb Biotechnol 2017; 10:1400-1411. [PMID: 28840964 PMCID: PMC5658623 DOI: 10.1111/1751-7915.12820] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 07/07/2017] [Accepted: 07/13/2017] [Indexed: 02/05/2023] Open
Abstract
Phasins are unusual amphiphilic proteins that bind to microbial polyhydroxyalkanoate (PHA) granules in nature and show great potential for various applications in biotechnology and medicine. Despite their remarkable diversity, only the crystal structure of PhaPAh from Aeromonas hydrophila has been solved to date. Based on the structure of PhaPAh, homology models of PhaPAz from Azotobacter sp. FA‐8 and PhaPTD from Halomonas bluephagenesis TD were successfully established, allowing rational mutagenesis to be conducted to enhance the stability and surfactant properties of these proteins. PhaPAz mutants, including PhaPAzQ38L and PhaPAzQ78L, as well as PhaPTD mutants, including PhaPTDQ38M and PhaPTDQ72M, showed better emulsification properties and improved thermostability (6‐10°C higher melting temperatures) compared with their wild‐type homologues under the same conditions. Importantly, the established PhaP homology‐modelling approach, based on the high‐resolution structure of PhaPAh, can be generalized to facilitate the study of other PhaP members.
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Affiliation(s)
- Hongyu Zhao
- Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China
| | - Zhenyu Yao
- Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China
| | - Xiangbin Chen
- Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China
| | - Xinquan Wang
- MOE Laboratory of Protein Science, Beijing Advanced Innovation Center for Structural Biology, Collaborative Innovation Center for Biotherapy, School of Life Sciences, Tsinghua University, Beijing, 100084, China.,Collaborative Innovation Center for Biotherapy, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu, China
| | - Guo-Qiang Chen
- Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China.,Manchester Institute of Biotechnology, University of Manchester, Manchester, UK.,Center for Nano and Micro-Mechanics, Tsinghua University, Beijing, 100084, China.,MOE Key Lab for Industrial Biocatalysis, Tsinghua University, Beijing, 100084, China
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