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Anjulal H, Singhvi M, Zinjarde S. Insights into the biodegradation of polyhydroxyalkanoates by the tropical marine isolate, Nocardiopsis dassonvillei NCIM 5124. 3 Biotech 2024; 14:240. [PMID: 39310033 PMCID: PMC11415560 DOI: 10.1007/s13205-024-04079-3] [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: 05/14/2024] [Accepted: 09/01/2024] [Indexed: 09/25/2024] Open
Abstract
In the current study, the ability of an indigenous marine Actinomycete Nocardiopsis dassonvillei (NCIM 5124) to degrade poly(3-hydroxybutyrate)-PHB was examined. From the whole genome sequencing data of the organism, information regarding the PHB depolymerase gene and amino acid sequence (Accession number: MCK9871921.1) was retrieved. In silico studies indicated the presence of a signal peptide characteristic of extracellular enzymes. ProtParam tool predicted that the protein had a molecular mass of 42.46 kDa with an isoelectric point of 4.51. Aliphatic and instability index values suggested that the protein was stable and the observed GARVY value indicated its hydrophilic nature. 3D structure prediction and multiple sequence alignments revealed the presence of Type I catalytic domain [including the oxyanion histidine towards the N terminal, the catalytic triad with serine (as a part of GLSAG pentapeptide), aspartate and histidine], substrate binding and linker domain. The organism was able to grow on PHB in solid and liquid media and effectively degrade it. Maximum enzyme activity (1.8 U/mL/min) was observed after 5 d of incubation in Bushnell Hass Medium containing 0.1% PHB, 1.5% sodium chloride, at 30 °C, pH 7.5 with agitation at 130 rpm. Application of the organism in disintegrating films of PHB and its copolymers was successfully demonstrated on the basis of weight loss and scanning electron microscope analysis. To the best of our knowledge, this is the first report on production of PHB depolymerase with high efficiency by N. dassonvillei, an organism that holds promise in degrading PHB-derived waste material. Supplementary Information The online version contains supplementary material available at 10.1007/s13205-024-04079-3.
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Affiliation(s)
- H. Anjulal
- Department of Biotechnology with Jointly Merged Institute of Bioinformatics and Biotechnology, Savitribai Phule Pune University, Pune, 411007 India
| | - Mamata Singhvi
- Department of Biotechnology with Jointly Merged Institute of Bioinformatics and Biotechnology, Savitribai Phule Pune University, Pune, 411007 India
| | - Smita Zinjarde
- Department of Biotechnology with Jointly Merged Institute of Bioinformatics and Biotechnology, Savitribai Phule Pune University, Pune, 411007 India
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Serrano‐Aguirre L, Prieto MA. Can bioplastics always offer a truly sustainable alternative to fossil-based plastics? Microb Biotechnol 2024; 17:e14458. [PMID: 38568795 PMCID: PMC10990045 DOI: 10.1111/1751-7915.14458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 03/08/2024] [Accepted: 03/14/2024] [Indexed: 04/05/2024] Open
Abstract
Bioplastics, comprised of bio-based and/or biodegradable polymers, have the potential to play a crucial role in the transition towards a sustainable circular economy. The use of biodegradable polymers not only leads to reduced greenhouse gas emissions but also might address the problem of plastic waste persisting in the environment, especially when removal is challenging. Nevertheless, biodegradable plastics should not be considered as substitutes for proper waste management practices, given that their biodegradability strongly depends on environmental conditions. Among the challenges hindering the sustainable implementation of bioplastics in the market, the development of effective downstream recycling routes is imperative, given the increasing production volumes of these materials. Here, we discuss about the most advisable end-of-life scenarios for bioplastics. Various recycling strategies, including mechanical, chemical or biological (both enzymatic and microbial) approaches, should be considered. Employing enzymes as biocatalysts emerges as a more selective and environmentally friendly alternative to chemical recycling, allowing the production of new bioplastics and added value and high-quality products. Other pending concerns for industrial implementation of bioplastics include misinformation among end users, the lack of a standardised bioplastic labelling, unclear life cycle assessment guidelines and the need for higher financial investments. Although further research and development efforts are essential to foster the sustainable and widespread application of bioplastics, significant strides have already been made in this direction.
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Affiliation(s)
- Lara Serrano‐Aguirre
- Polymer Biotechnology Group, Department of Plant and Microbial Biotechnology, Biological Research Centre Margarita SalasSpanish National Research Council (CIB‐CSIC)MadridSpain
- Interdisciplinary Platform for Sustainable Plastics Towards a Circular Economy‐CSIC (SusPlast‐CSIC)MadridSpain
| | - M. Auxiliadora Prieto
- Polymer Biotechnology Group, Department of Plant and Microbial Biotechnology, Biological Research Centre Margarita SalasSpanish National Research Council (CIB‐CSIC)MadridSpain
- Interdisciplinary Platform for Sustainable Plastics Towards a Circular Economy‐CSIC (SusPlast‐CSIC)MadridSpain
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3
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Rodríguez-Alonso G, Toledo-Marcos J, Serrano-Aguirre L, Rumayor C, Pasero B, Flores A, Saborido A, Hoyos P, Hernáiz MJ, de la Mata I, Arroyo M. A Novel Lipase from Streptomyces exfoliatus DSMZ 41693 for Biotechnological Applications. Int J Mol Sci 2023; 24:17071. [PMID: 38069394 PMCID: PMC10707221 DOI: 10.3390/ijms242317071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 11/23/2023] [Accepted: 11/29/2023] [Indexed: 12/18/2023] Open
Abstract
Genome mining of Streptomyces exfoliatus DSMZ 41693 has allowed us to identify four different lipase-encoding sequences, and one of them (SeLipC) has been successfully cloned and extracellularly expressed using Rhodococcus sp. T104 as a host. SeLipC was purified by one-step hydrophobic interaction chromatography. The enzyme is a monomeric protein of 27.6 kDa, which belongs to subfamily I.7 of lipolytic enzymes according to its phylogenetic analysis and biochemical characterization. The purified enzyme shows the highest activity at 60 °C and an optimum pH of 8.5, whereas thermal stability is significantly improved when protein concentration is increased, as confirmed by thermal deactivation kinetics, circular dichroism, and differential scanning calorimetry. Enzyme hydrolytic activity using p-nitrophenyl palmitate (pNPP) as substrate can be modulated by different water-miscible organic cosolvents, detergents, and metal ions. Likewise, kinetic parameters for pNPP are: KM = 49.6 µM, kcat = 57 s-1, and kcat/KM = 1.15 × 106 s-1·M-1. SeLipC is also able to hydrolyze olive oil and degrade several polyester-type polymers such as poly(butylene succinate) (PBS), poly(butylene succinate)-co-(butylene adipate) (PBSA), and poly(ε-caprolactone) (PCL). Moreover, SeLipC can catalyze the synthesis of different sugar fatty acid esters by transesterification using vinyl laurate as an acyl donor, demonstrating its interest in different biotechnological applications.
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Affiliation(s)
- Guillermo Rodríguez-Alonso
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Universidad Complutense de Madrid (UCM), E-28040 Madrid, Spain; (G.R.-A.); (J.T.-M.); (L.S.-A.); (C.R.); (B.P.); (A.S.)
| | - Juan Toledo-Marcos
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Universidad Complutense de Madrid (UCM), E-28040 Madrid, Spain; (G.R.-A.); (J.T.-M.); (L.S.-A.); (C.R.); (B.P.); (A.S.)
| | - Lara Serrano-Aguirre
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Universidad Complutense de Madrid (UCM), E-28040 Madrid, Spain; (G.R.-A.); (J.T.-M.); (L.S.-A.); (C.R.); (B.P.); (A.S.)
| | - Carlos Rumayor
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Universidad Complutense de Madrid (UCM), E-28040 Madrid, Spain; (G.R.-A.); (J.T.-M.); (L.S.-A.); (C.R.); (B.P.); (A.S.)
| | - Beatriz Pasero
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Universidad Complutense de Madrid (UCM), E-28040 Madrid, Spain; (G.R.-A.); (J.T.-M.); (L.S.-A.); (C.R.); (B.P.); (A.S.)
| | - Aida Flores
- Department of Chemistry in Pharmaceutical Sciences, Faculty of Pharmacy, Universidad Complutense de Madrid (UCM), E-28040 Madrid, Spain; (A.F.); (P.H.); (M.J.H.)
| | - Ana Saborido
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Universidad Complutense de Madrid (UCM), E-28040 Madrid, Spain; (G.R.-A.); (J.T.-M.); (L.S.-A.); (C.R.); (B.P.); (A.S.)
| | - Pilar Hoyos
- Department of Chemistry in Pharmaceutical Sciences, Faculty of Pharmacy, Universidad Complutense de Madrid (UCM), E-28040 Madrid, Spain; (A.F.); (P.H.); (M.J.H.)
| | - María J. Hernáiz
- Department of Chemistry in Pharmaceutical Sciences, Faculty of Pharmacy, Universidad Complutense de Madrid (UCM), E-28040 Madrid, Spain; (A.F.); (P.H.); (M.J.H.)
| | - Isabel de la Mata
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Universidad Complutense de Madrid (UCM), E-28040 Madrid, Spain; (G.R.-A.); (J.T.-M.); (L.S.-A.); (C.R.); (B.P.); (A.S.)
| | - Miguel Arroyo
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Universidad Complutense de Madrid (UCM), E-28040 Madrid, Spain; (G.R.-A.); (J.T.-M.); (L.S.-A.); (C.R.); (B.P.); (A.S.)
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Al-Khairy D, Fu W, Alzahmi AS, Twizere JC, Amin SA, Salehi-Ashtiani K, Mystikou A. Closing the Gap between Bio-Based and Petroleum-Based Plastic through Bioengineering. Microorganisms 2022; 10:microorganisms10122320. [PMID: 36557574 PMCID: PMC9787566 DOI: 10.3390/microorganisms10122320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/17/2022] [Accepted: 11/21/2022] [Indexed: 11/25/2022] Open
Abstract
Bioplastics, which are plastic materials produced from renewable bio-based feedstocks, have been investigated for their potential as an attractive alternative to petroleum-based plastics. Despite the harmful effects of plastic accumulation in the environment, bioplastic production is still underdeveloped. Recent advances in strain development, genome sequencing, and editing technologies have accelerated research efforts toward bioplastic production and helped to advance its goal of replacing conventional plastics. In this review, we highlight bioengineering approaches, new advancements, and related challenges in the bioproduction and biodegradation of plastics. We cover different types of polymers, including polylactic acid (PLA) and polyhydroxyalkanoates (PHAs and PHBs) produced by bacterial, microalgal, and plant species naturally as well as through genetic engineering. Moreover, we provide detailed information on pathways that produce PHAs and PHBs in bacteria. Lastly, we present the prospect of using large-scale genome engineering to enhance strains and develop microalgae as a sustainable production platform.
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Affiliation(s)
- Dina Al-Khairy
- Division of Science and Math, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
| | - Weiqi Fu
- Division of Science and Math, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
- Department of Marine Science, Ocean College, Zhejiang University & Donghai Laboratory, Zhoushan 316021, China
| | - Amnah Salem Alzahmi
- Division of Science and Math, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
- Center for Genomics and Systems Biology (CGSB), Institute Abu Dhabi, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
| | - Jean-Claude Twizere
- Division of Science and Math, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
- Laboratory of Viral Interactomes Networks, Unit of Molecular Biology of Diseases, Interdisciplinary Cluster for Applied Genoproteomics (GIGA Institute), University of Liège, 4000 Liège, Belgium
| | - Shady A. Amin
- Division of Science and Math, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
- Center for Genomics and Systems Biology (CGSB), Institute Abu Dhabi, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
| | - Kourosh Salehi-Ashtiani
- Division of Science and Math, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
- Center for Genomics and Systems Biology (CGSB), Institute Abu Dhabi, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
- Correspondence: (K.S.-A.); (A.M.)
| | - Alexandra Mystikou
- Division of Science and Math, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
- Center for Genomics and Systems Biology (CGSB), Institute Abu Dhabi, New York University Abu Dhabi, Abu Dhabi 129188, United Arab Emirates
- Correspondence: (K.S.-A.); (A.M.)
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Characterization of Streptomyces nymphaeiformis sp. nov., and its taxonomic relatedness to other polyhydroxybutyrate-degrading streptomycetes. Int J Syst Evol Microbiol 2022; 72. [DOI: 10.1099/ijsem.0.005266] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A polyhydroxybutyrate (PHB)-degrading actinomycete, strain SFB5AT, was identified as a species of
Streptomyces
based on its membrane fatty acid profile and the presence of ll-diaminopimelic acid in the cell wall. It formed sporulating mycelia on most agar media, but flat or wrinkled, moist colonies on trypticase soy agar. Spores were smooth, cylindrical, and borne on long, straight to flexuous chains. It produced a light brown diffusible pigment, but not melanin. Comparison of genomic digital DNA–DNA hybridization (dDDH) and average nucleotide identity (ANI) values indicated that strain SFB5AT was related to
Streptomyces litmocidini
JCM 4394T,
Streptomyces vietnamensis
GIMV4.0001T,
Streptomyces nashvillensis
JCM 4498T and
Streptomyces tanashiensis
JCM 4086T, plus 11 other species. However, the dDDH and ANI values were well below the species differentiation thresholds of <70 and <95 %, respectively; also, multilocus sequence analysis distances exceeded the species threshold of 0.007. Moreover, strain SFB5AT differed from the other species in pigmentation and its ability to catabolize arabinose. Strain SFB5AT and 11 of its 15 closest relatives degraded PHB and have genes for extracellular, short-chain-length denatured polyhydroxyalkanoate depolymerases. These enzymes from strain SFB5AT and its closest relatives had a type 1 catalytic domain structure, while those from other relatives had a type 2 structure, which differs from type one in the position of a consensus histidine in the active site. Thus, phenotypic and genotypic differences suggest that strain SFB5AT represents a new species of Streptomyces, for which we propose the name Streptomyces nymphaeiformis sp. nov. The type strain is SFB5AT (=NRRL B-65520T=DSM 112030T).
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6
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Miri S, Saini R, Davoodi SM, Pulicharla R, Brar SK, Magdouli S. Biodegradation of microplastics: Better late than never. CHEMOSPHERE 2022; 286:131670. [PMID: 34351281 DOI: 10.1016/j.chemosphere.2021.131670] [Citation(s) in RCA: 81] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 07/13/2021] [Accepted: 07/23/2021] [Indexed: 06/13/2023]
Abstract
Plastics use is growing due to its applications in the economy, human health and aesthetics. The major plastic particles in the form of microplastics (MPs) released into the environment are made up of polyethylene (PE), polypropylene (PP), polyvinylchloride (PVC), and polyethylene terephthalate (PET). Tremendous usage and continuous accumulation of MPs in the environment pose a global threat to ecosystems and human health. The current knowledge of biotechnological, aerobic and aerobic biodegradation approaches emphasizes the microbial culture's potential towards MPs removal. This review selectively provides recent biotechnological advances such as biostimulation, bioaugmentation and enzymatic biodegradation that can be applied for MPs removal by biodegradation and bioaccumulation. This review summarizes the knowledge and the research exploration on the biodegradation of synthetic organic MPs with different biodegradability. However, further research is still needed to understand the underlying mechanism of MPs biodegradation in soil and water systems, leading to the development of an effective method for MPs removal.
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Affiliation(s)
- Saba Miri
- Department of Civil Engineering, Lassonde School of Engineering, York University, North York, Toronto, Ontario, M3J 1P3, Canada; Institut National de La Recherche Scientifique, Centre-Eau, Terre et Environnement, 490, Rue de La Couronne, Québec, G1K 9A9, Canada
| | - Rahul Saini
- Department of Civil Engineering, Lassonde School of Engineering, York University, North York, Toronto, Ontario, M3J 1P3, Canada
| | - Seyyed Mohammadreza Davoodi
- Department of Civil Engineering, Lassonde School of Engineering, York University, North York, Toronto, Ontario, M3J 1P3, Canada; Institut National de La Recherche Scientifique, Centre-Eau, Terre et Environnement, 490, Rue de La Couronne, Québec, G1K 9A9, Canada
| | - Rama Pulicharla
- Department of Civil Engineering, Lassonde School of Engineering, York University, North York, Toronto, Ontario, M3J 1P3, Canada
| | - Satinder Kaur Brar
- Department of Civil Engineering, Lassonde School of Engineering, York University, North York, Toronto, Ontario, M3J 1P3, Canada; Institut National de La Recherche Scientifique, Centre-Eau, Terre et Environnement, 490, Rue de La Couronne, Québec, G1K 9A9, Canada.
| | - Sara Magdouli
- Department of Civil Engineering, Lassonde School of Engineering, York University, North York, Toronto, Ontario, M3J 1P3, Canada
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Serrano-Aguirre L, Velasco-Bucheli R, García-Álvarez B, Saborido A, Arroyo M, de la Mata I. Novel Bifunctional Acylase from Actinoplanes utahensis: A Versatile Enzyme to Synthesize Antimicrobial Compounds and Use in Quorum Quenching Processes. Antibiotics (Basel) 2021; 10:antibiotics10080922. [PMID: 34438972 PMCID: PMC8388760 DOI: 10.3390/antibiotics10080922] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 07/25/2021] [Accepted: 07/27/2021] [Indexed: 12/02/2022] Open
Abstract
Many intercellular communication processes, known as quorum sensing (QS), are regulated by the autoinducers N-acyl-l-homoserine lactones (AHLs) in Gram-negative bacteria. The inactivation of these QS processes using different quorum quenching (QQ) strategies, such as enzymatic degradation of the autoinducers or the receptor blocking with non-active analogs, could be the basis for the development of new antimicrobials. This study details the heterologous expression, purification, and characterization of a novel N-acylhomoserine lactone acylase from Actinoplanes utahensis NRRL 12052 (AuAHLA), which can hydrolyze different natural penicillins and N-acyl-homoserine lactones (with or without 3-oxo substitution), as well as synthesize them. Kinetic parameters for the hydrolysis of a broad range of substrates have shown that AuAHLA prefers penicillin V, followed by C12-HSL. In addition, AuAHLA inhibits the production of violacein by Chromobacterium violaceum CV026, confirming its potential use as a QQ agent. Noteworthy, AuAHLA is also able to efficiently synthesize penicillin V, besides natural AHLs and phenoxyacetyl-homoserine lactone (POHL), a non-natural analog of AHLs that could be used to block QS receptors and inhibit signal of autoinducers, being the first reported AHL acylase capable of synthesizing AHLs.
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8
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Krishnan S, Chinnadurai GS, Ravishankar K, Raghavachari D, Perumal P. Statistical augmentation of polyhydroxybutyrate production by Isoptericola variabilis: Characterization, moulding, in vitro cytocompatibility and biodegradability evaluation. Int J Biol Macromol 2020; 166:80-97. [PMID: 33096176 DOI: 10.1016/j.ijbiomac.2020.10.089] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 10/02/2020] [Accepted: 10/12/2020] [Indexed: 02/08/2023]
Abstract
This study aimed to explore the production of polyhydroxybutyrate (PHB), a polyhydroxyalkanoate (PHA), which has been widely considered as a potential substitute for the synthetic polymers. Among 53 actinomycete isolates, 11 of them were found to be PHB positive and the quantity of PHB from the positive isolates varied from 10.5 to 29.82 wt% on a dry cell weight basis. A strain designated as PPLAT 012, accumulated relatively higher PHB and has been identified as Isoptericola variabilis by 16S rRNA gene sequence analysis. An effort has also been made to optimize the PHB production by the hyper-producing strain using the conventional, one-factor-at-a-time, and statistical response surface methodologies and the maximum PHB production (46.18%) in DSMZ medium, amended with 12% glucose and 9% potassium nitrate with a pH of 7.0. Further, the characteristic properties such as processability, cytocompatibility and biodegradability of the extracted PHB was also demonstrated. The physical properties of the recovered PHB was further improved by blending with PLA and the resultant blends were characterized. The present investigation has demonstrated that the isolate, Isoptericola variabilis, could be utilized as a potential source for the production of PHB with desirable characteristics, suitable for biomedical applications.
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Affiliation(s)
- Sivakumar Krishnan
- Centre for Advanced Studies in Botany, University of Madras, Guindy Campus, Chennai 600 025, India
| | - Gandhi Shree Chinnadurai
- Centre for Advanced Studies in Botany, University of Madras, Guindy Campus, Chennai 600 025, India
| | - Kartik Ravishankar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
| | | | - Palani Perumal
- Centre for Advanced Studies in Botany, University of Madras, Guindy Campus, Chennai 600 025, India.
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Camacho-Ruiz MA, Müller-Santos M, Hernández-Mancillas XD, Armenta-Perez VP, Zamora-Gonzalez E, Rodríguez JA. A sensitive pH indicator-based spectrophotometric assay for PHB depolymerase activity on microtiter plates. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2020; 12:4048-4057. [PMID: 32756615 DOI: 10.1039/d0ay00840k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
A continuous spectrophotometric assay for the screening of PHB depolymerase activity in microtiter plates was developed. We evaluated crystalline PHB in the suspension and coated it with the addition of a pH indicator to detect the breakage of the ester bond by proton titration. The reaction rate and the concentration of the recombinant PhaZ1 from Paucimonas lemoignei PHB depolymerase presented a linear correlation. A comparison of the proposed method with the turbidimetric method adapted to the microtiter plates revealed that the use of indicators increases the response signal by at least 5-fold, resulting in increased sensitivity and better signal-to-noise ratio. Furthermore, the proposed method offers a wide range of pH from 5.0 to 9.2 by using different buffer-indicator pairs and was employed for the screening of PHB-depolymerase activity on 140 bacterial strains isolated from Lake Chapala. Eleven strains were positive for PHB-depolymerase activity, which were ACSLRF-27, ACPLRF-6, and ACPLRF-5 (16S rRNA sequence alignment revealed 99-100% similarity with Actinomadura geliboluensis strain A8036, Streptomyces cavourensis strain NRRL 2740, and Streptomyces coelicolor strain DSM 40233, respectively); these that showed the highest activities. In conclusion, the method was successfully applied for finding new strains and for quantifying the PHB depolymerases activity with crystalline PHB.
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Affiliation(s)
- Maria Angeles Camacho-Ruiz
- Biotecnología Industrial, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco (CIATEJ), Zapopan, Jalisco 45019, Mexico.
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10
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Characterization of an intracellular poly(3-hydroxyalkanoate) depolymerase from the soil bacterium, Pseudomonas putida LS46. Polym Degrad Stab 2020. [DOI: 10.1016/j.polymdegradstab.2020.109127] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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11
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Satti SM, Shah AA. Polyester-based biodegradable plastics: an approach towards sustainable development. Lett Appl Microbiol 2020; 70:413-430. [PMID: 32086820 DOI: 10.1111/lam.13287] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 02/17/2020] [Accepted: 02/18/2020] [Indexed: 11/29/2022]
Abstract
Non-degradability of conventional plastics, filling of landfill sites, raising water and land pollution and rapid depletion of fossil resources have raised the environmental issues and global concerns. The current demand and production of plastics is putting immense pressure on fossil resources, consuming about 6% of the global oil and is expected to grow up to 20%. The polyester-based biodegradable plastics (BPs) are considered as a remedy to the issue of plastics waste in the environment. BPs appear to manage the overflow of plastics by providing new means of waste management system and help in securing the non-renewable resources of nature. This review comprehensively presents the environmental burdens due to conventional plastics as well as production of polyester-based BPs as an alternative to conventional commodity plastics. The diversity of micro-organisms and their enzymes that degrade various polyester-based BPs (PLA, PCL, PHB/PHBV and PET) has also been described in detail. Moreover, the impact of plastics degradation products on soil ecology and ecosystem functions has critically been discussed. The report ends with special focus on future recommendations for the development of sustainable waste management strategies to control pollution due to plastics waste. SIGNIFICANCE AND IMPACT OF THE STUDY: Polyester-based BPs considered as a solution to current plastic waste problem as well as leading polymers in terms of biodegradability and sustainability has been critically discussed. The role of microorganisms and their enzymes involved in the biodegradation of these polymers and ecotoxicological impact of degradation products of BPs on soil microbial community and biogeochemical cycles has also been described. This report will provide an insight on the key research areas to bridge the gap for development of simulated systems as an effective and emerging strategy to divert the overflow of plastic in the environment as well as for the greener solution to the plastic waste management problems.
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Affiliation(s)
- S M Satti
- Department of Microbiology, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan.,University Institute of Biochemistry and Biotechnology, PMAS Arid Agriculture University, Rawalpindi, Pakistan
| | - A A Shah
- Department of Microbiology, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
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12
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Zadjelovic V, Chhun A, Quareshy M, Silvano E, Hernandez-Fernaud JR, Aguilo-Ferretjans MM, Bosch R, Dorador C, Gibson MI, Christie-Oleza JA. Beyond oil degradation: enzymatic potential of Alcanivorax to degrade natural and synthetic polyesters. Environ Microbiol 2020; 22:1356-1369. [PMID: 32079039 PMCID: PMC7187450 DOI: 10.1111/1462-2920.14947] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 02/18/2020] [Indexed: 12/31/2022]
Abstract
Pristine marine environments are highly oligotrophic ecosystems populated by well‐established specialized microbial communities. Nevertheless, during oil spills, low‐abundant hydrocarbonoclastic bacteria bloom and rapidly prevail over the marine microbiota. The genus Alcanivorax is one of the most abundant and well‐studied organisms for oil degradation. While highly successful under polluted conditions due to its specialized oil‐degrading metabolism, it is unknown how they persist in these environments during pristine conditions. Here, we show that part of the Alcanivorax genus, as well as oils, has an enormous potential for biodegrading aliphatic polyesters thanks to a unique and abundantly secreted alpha/beta hydrolase. The heterologous overexpression of this esterase proved a remarkable ability to hydrolyse both natural and synthetic polyesters. Our findings contribute to (i) better understand the ecology of Alcanivorax in its natural environment, where natural polyesters such as polyhydroxyalkanoates (PHA) are produced by a large fraction of the community and, hence, an accessible source of carbon and energy used by the organism in order to persist, (ii) highlight the potential of Alcanivorax to clear marine environments from polyester materials of anthropogenic origin as well as oils, and (iii) the discovery of a new versatile esterase with a high biotechnological potential.
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Affiliation(s)
| | - Audam Chhun
- School of Life Sciences, University of Warwick, Warwick, UK
| | - Mussa Quareshy
- School of Life Sciences, University of Warwick, Warwick, UK
| | | | - Juan R Hernandez-Fernaud
- School of Life Sciences, University of Warwick, Warwick, UK.,Unidad de investigación-HUC, La Laguna-Tenerife, Spain
| | - María M Aguilo-Ferretjans
- School of Life Sciences, University of Warwick, Warwick, UK.,Department of Biology, University of the Balearic Islands, Spain
| | - Rafael Bosch
- Department of Biology, University of the Balearic Islands, Spain.,IMEDEA (CSIC-UIB), Esporles, Spain
| | - Cristina Dorador
- Laboratorio de Complejidad Microbiana y Ecología Funcional, Universidad de Antofagasta, Antofagasta, Chile.,Departamento de Biotecnología, Universidad de Antofagasta, Antofagasta, Chile.,Centre for Biotechnology & Bioengineering (CeBiB), Santiago, Chile
| | - Matthew I Gibson
- Department of Chemistry, University of Warwick, Warwick, UK.,Warwick Medical School, University of Warwick, Warwick, UK
| | - Joseph A Christie-Oleza
- School of Life Sciences, University of Warwick, Warwick, UK.,Department of Biology, University of the Balearic Islands, Spain.,IMEDEA (CSIC-UIB), Esporles, Spain
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13
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Biochemical properties and biotechnological applications of microbial enzymes involved in the degradation of polyester-type plastics. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2020; 1868:140315. [DOI: 10.1016/j.bbapap.2019.140315] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 10/07/2019] [Accepted: 10/22/2019] [Indexed: 01/03/2023]
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14
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Biodegradation of polyhydroxybutyrate by Pseudomonas sp. DSDY0501 and purification and characterization of polyhydroxybutyrate depolymerase. 3 Biotech 2019; 9:359. [PMID: 31544013 DOI: 10.1007/s13205-019-1871-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Accepted: 08/12/2019] [Indexed: 02/05/2023] Open
Abstract
Strain DSDY0501 with polyhydroxybutyrate (PHB)-degrading ability was isolated from activated sludge. The morphological, physiological, and biochemical properties of the strain and phylogenetic analysis indicated that the strain belongs to Pseudomonas sp. The strain used PHB as the sole carbon source and degraded PHB films completely in 21 h in liquid culture. An extracellular PHB depolymerase was purified from the supernatant of the culture by ultrafiltration and Sephacryl S-200 gel filtration. The specific activity of the purified enzyme increased 24.2-fold, and the recovery yield was 16.61%. Extracellular PHB depolymerase, a monomeric enzyme with a molecular weight of approximately 57.9 kDa, showed optimum activity at 60 °C and pH 9.0, and was stable in the temperature range of 10-60 °C and a pH range of 6.0-10.0. The secondary structure of the enzyme contained approximately 60% α-helix and 40% β-pleated sheet according to the circular dichroism spectrum. Mass spectrum analysis showed that the main degradation product of the enzyme was PHB monomer, indicating the exo-type action of this PHB depolymerase.
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15
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Sayyed RZ, Wani SJ, Alyousef AA, Alqasim A, Syed A, El-Enshasy HA. Purification and kinetics of the PHB depolymerase of Microbacterium paraoxydans RZS6 isolated from a dumping yard. PLoS One 2019; 14:e0212324. [PMID: 31211775 PMCID: PMC6581247 DOI: 10.1371/journal.pone.0212324] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 06/01/2019] [Indexed: 11/18/2022] Open
Abstract
Poly-β-hydroxybutyrate (PHB) depolymerase is known to decompose PHB, biodegradable polymers and therefore has great commercial significance in the bioplastic sector. However, reports on PHB depolymerases from isolates obtained from plastic-contaminated sites that reflect the potential of the source organism is scarce. In this study, we evaluated the production of extracellular PHB depolymerase from Microbacterium paraoxydans RZS6 isolated from the plastic-contaminated site in the municipal area of Shahada, Maharashtra, India, for the first time. The isolate was identified using 16S rRNA gene sequencing, gas chromatographic analysis of fatty acid methyl esters (GC-FAME), and BIOLOG method. Ithydrolyzed PHB on minimal salt medium (MSM) containing PHB as the only source of carbon. The isolate produced PHB depolymerase at 45°C during 48 h of incubation. The enzyme was purified most efficiently using octyl-sepharose CL-4B column, with the highest purification yield of 6.675 Umg-1mL-1. The activity of the enzyme was enhanced in the presence of Ca2+ and Mg2+ ions but inhibited by Fe2+ (1 mM) ions and mercaptoethanol (1000 rpm). the nzyme kinetic analysis revealed that the enzyme was a metalloenzyme; requiring Mg2+ ions, that showed optimum enzyme activity at 30°C (mesophilic) and under neutrophilic (pH 7) conditions. Scale-up from the shake-flask level to a laboratory-scale bioreactor further enhanced the enzyme yield by 0.809 UmL-1. The molecular weight of the enzyme (40 kDa), as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, closely resembled the PHB depolymerase of Aureobacterium saperdae. Our findings highlighted the applicability of M. paraoxydans as a producer of extracellular PHB depolymerase having potential of degrading PHB under diverse conditions.
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Affiliation(s)
- R. Z. Sayyed
- Department of Microbiology, PSGVP Mandal’s, Arts, Science, and Commerce College, Shahada Maharashtra, India
- * E-mail:
| | - S. J. Wani
- Department of Microbiology, PSGVP Mandal’s, Arts, Science, and Commerce College, Shahada Maharashtra, India
| | - Abdullah A. Alyousef
- Microbiology Research Group, Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Abdulaziz Alqasim
- Microbiology Research Group, Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Asad Syed
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Hesham Ali El-Enshasy
- School of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia (UTM), Skudai, Johor Bahru, Malaysia
- City of Scientific Research and Technology Applications, New Burg Al Arab, Alexandria, Egypt
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16
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Sharma PK, Mohanan N, Sidhu R, Levin DB. Colonization and degradation of polyhydroxyalkanoates by lipase-producing bacteria. Can J Microbiol 2019; 65:461-475. [PMID: 30897336 DOI: 10.1139/cjm-2019-0042] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Biodegradation of short-chain-length polyhydroxyalkanoates (scl-PHAs) and medium-chain-length polyhydroxyalkanoates (mcl-PHAs) was studied using 2 bacteria, Pseudomonas chlororaphis and Acinetobacter lwoffii, which secrete an enzyme, or enzymes, with lipase activity. These bacteria produced clear zones of depolymerization on Petri plates containing colloidal solutions of PHA polymers with different monomer compositions. Lipase activity in these bacteria was measured using p-nitrophenyl octanoate as a substrate. In liquid medium, scl-PHA (e.g., PHBV) and mcl-PHA (e.g., PHO) films were used as the sole carbon source for growth, and after 7 days, 5%-18% loss in mass of PHA films was observed. Scanning electron microscopy of these films revealed bacterial colonization of the polymers, with cracks and pitting in the film surfaces. Degradation of polymers released 3-hydroxyhexanoate, 3-hydroxyoctanoate, and 3-hydroxydecanoate monomers into the liquid medium, depending on the starting polymer. Genes encoding secretory lipases, with amino acid consensus sequences for lipase boxes and oxyanion holes, were identified in the genomes of P. chlororaphis and A. lwoffii. Although amino acid consensus sequences for lipase boxes and oxyanion holes are also present in PHA depolymerases identified in the genomes of other PHA-degrading bacteria, the P. chlororaphis and A. lwoffii lipases had low homology with these depolymerases.
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Affiliation(s)
- Parveen K Sharma
- a Department of Biosystems Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada
| | - Nisha Mohanan
- a Department of Biosystems Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada
| | - Ravinder Sidhu
- b Manitoba Institute for Materials & Faculty of Science, University of Manitoba, Winnipeg, MB R3T 5V6, Canada
| | - David B Levin
- a Department of Biosystems Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada
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17
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Debbarma P, Raghuwanshi S, Singh J, Suyal DC, Zaidi MGH, Goel R. Comparative in situ biodegradation studies of polyhydroxybutyrate film composites. 3 Biotech 2017; 7:178. [PMID: 28664365 DOI: 10.1007/s13205-017-0789-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 06/09/2017] [Indexed: 11/28/2022] Open
Abstract
Application of polyhydroxybutyrate (PHB) to plastic industry has expanded over the last decades due to its attracting features over petro-based plastic, and therefore, its waste accumulation in nature is inevitable. In the present study, a total of four bacterial strains, viz., MK3, PN12, PW1, and Lna3, were formulated into a consortium and subsequently used as biological tool for degradation of biopolymers. The consortium was tested through λ max shifts under in vitro conditions for utilization of PHB as sole carbon source. Talc-based bioformulations of consortium were used for the degradation of PHB film composites under in situ conditions. After 9 months of incubation, the recovered samples were monitored through Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM), respectively. Analytical data, viz., changes in λ max shifts (212-219 nm), FT-IR spectra, and SEM micrographs, revealed the biodegradation potential of developed consortium against PHB film composites, i.e., higher degradation of copolymer films was found over blend films. The used consortium had enhanced the rate of natural degradation and can be further used as a natural tool to maintain and restore global environmental safety.
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Affiliation(s)
- Prasenjit Debbarma
- Department of Microbiology, College of Basic Sciences and Humanities, G. B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, 263145, India
| | - Shikha Raghuwanshi
- Department of Microbiology, College of Basic Sciences and Humanities, G. B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, 263145, India
| | - Jyoti Singh
- Department of Microbiology, College of Basic Sciences and Humanities, G. B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, 263145, India
| | - Deep Chandra Suyal
- Department of Microbiology, College of Basic Sciences and Humanities, G. B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, 263145, India
| | - M G H Zaidi
- Department of Chemistry, College of Basic Sciences and Humanities, G. B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, 263145, India
| | - Reeta Goel
- Department of Microbiology, College of Basic Sciences and Humanities, G. B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, 263145, India.
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18
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García-Hidalgo J, Acebal C, de la Mata I, Arroyo M. Developing an efficient strategy for immobilization of PHB depolymerase on magnetite-based nanoparticles for degrading polyhydroxybutyrate in acidic conditions. BIOCATAL BIOTRANSFOR 2017. [DOI: 10.1080/10242422.2017.1315942] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Javier García-Hidalgo
- Departamento de Bioquímica y Biología Molecular I, Facultad de Biología, Universidad Complutense de Madrid, Madrid, Spain
| | - Carmen Acebal
- Departamento de Bioquímica y Biología Molecular I, Facultad de Biología, Universidad Complutense de Madrid, Madrid, Spain
| | - Isabel de la Mata
- Departamento de Bioquímica y Biología Molecular I, Facultad de Biología, Universidad Complutense de Madrid, Madrid, Spain
| | - Miguel Arroyo
- Departamento de Bioquímica y Biología Molecular I, Facultad de Biología, Universidad Complutense de Madrid, Madrid, Spain
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19
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Hanafy RA, Couger MB, Baker K, Murphy C, O'Kane SD, Budd C, French DP, Hoff WD, Youssef N. Draft genome sequence of Micrococcus luteus strain O'Kane implicates metabolic versatility and the potential to degrade polyhydroxybutyrates. GENOMICS DATA 2016; 9:148-53. [PMID: 27583205 PMCID: PMC4993860 DOI: 10.1016/j.gdata.2016.08.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 08/08/2016] [Indexed: 01/03/2023]
Abstract
Micrococcus luteus is a predominant member of skin microbiome. We here report on the genomic analysis of Micrococcus luteus strain O'Kane that was isolated from an elevator. The partial genome assembly of Micrococcus luteus strain O'Kane is 2.5 Mb with 2256 protein-coding genes and 62 RNA genes. Genomic analysis revealed metabolic versatility with genes involved in the metabolism and transport of glucose, galactose, fructose, mannose, alanine, aspartate, asparagine, glutamate, glutamine, glycine, serine, cysteine, methionine, arginine, proline, histidine, phenylalanine, and fatty acids. Genomic comparison to other M. luteus representatives identified the potential to degrade polyhydroxybutyrates, as well as several antibiotic resistance genes absent from other genomes.
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Affiliation(s)
- Radwa A Hanafy
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, United States
| | - M B Couger
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, United States
| | - Kristina Baker
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, United States
| | - Chelsea Murphy
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, United States
| | - Shannon D O'Kane
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, United States
| | - Connie Budd
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, United States
| | - Donald P French
- Department of Integrative Biology, Oklahoma State University, Stillwater, OK, United States
| | - Wouter D Hoff
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, United States
| | - Noha Youssef
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, United States
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20
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Gowda U S V, Shivakumar S. Poly(-β-hydroxybutyrate) (PHB) depolymerase PHAZ Pen from Penicillium expansum: purification, characterization and kinetic studies. 3 Biotech 2015; 5:901-909. [PMID: 28324398 PMCID: PMC4624153 DOI: 10.1007/s13205-015-0287-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 02/21/2015] [Indexed: 11/24/2022] Open
Abstract
Very few studies have been dedicated to R-hydroxyacids (R-HA) production using extracellular polyhydroxyalkanoate depolymerases (ePhaZs).
Penicillium expansum produced maximum extracellular polyhydroxybutyrate depolymerase (~6 U/mL) by 72 h when grown in mineral salt medium containing 0.2 % w/v PHB, pH 5.0, at 30 °C and 200 rpm shaking conditions. Partial purification of the extracellular poly(-β-hydroxybutyrate) depolymerase PHAZPen from P. expansum by two steps using ammonium sulphate (80 % saturation) and affinity chromatography using concanavalin A yielded 22.76-fold purity and 43.15 % recovery of protein. The enzyme composed of a single polypeptide chain of apparent molecular mass of 20 kDa, as determined by SDS-PAGE, stained positive for glycoprotein by periodic–schiff base (PAS) staining. Optimum enzyme activity was detected between pH 4.0 and 6.0 at 45–50 °C with pH 5.0 and 50 °C supporting maximum activity. The enzyme was stable between pH 4.0 and 6.0 at 55 °C for 1 h with a residual activity of almost 70–80 %. The enzyme was completely inhibited by 1 mM DTT/1 mM HgCl2 and N-ethylmaleimide (10 mM) indicating the importance of essential disulphide bonds (cystine residues) and tyrosine for enzyme activity or probably for maintaining the native enzyme structure. Among the various divalent and trivalent metal ions, mercuric chloride, ferric citrate and ferrous sulphate inhibited enzyme activity. The enzyme showed substrate specificity towards only PHB and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and no other lipid or other p-nitrophenyl fatty acids or with polycaprolactone, showing that it was a true depolymerase and not any lipase or cutinase. Preliminary investigation revealed β-hydroxybutyrate as the end product of PHB hydrolysis by P. expansum, suggesting that the enzyme acted principally as an exo-type hydrolase. The above properties when compared with other fungal PHB depolymerases reported till date suggest the distinct nature of the PHB depolymerase of P. expansum.
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Affiliation(s)
- Vaishnavi Gowda U S
- Department of Microbiology, Centre for Post Graduate Studies, Jain University, 18/3, 9th Main, Jayanagar 3rd Block, Bangalore, 560011, India
| | - Srividya Shivakumar
- Department of Microbiology, Centre for Post Graduate Studies, Jain University, 18/3, 9th Main, Jayanagar 3rd Block, Bangalore, 560011, India.
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21
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Martínez V, de Santos PG, García-Hidalgo J, Hormigo D, Prieto MA, Arroyo M, de la Mata I. Novel extracellular medium-chain-length polyhydroxyalkanoate depolymerase from Streptomyces exfoliatus K10 DSMZ 41693: a promising biocatalyst for the efficient degradation of natural and functionalized mcl-PHAs. Appl Microbiol Biotechnol 2015; 99:9605-15. [PMID: 26156240 DOI: 10.1007/s00253-015-6780-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 06/15/2015] [Accepted: 06/17/2015] [Indexed: 11/30/2022]
Abstract
Cloning and biochemical characterization of a novel extracellular medium-chain-length polyhydroxyalkanoate (mcl-PHA) depolymerase from Streptomyces exfoliatus K10 DSMZ 41693 are described. The primary structure of the depolymerase (PhaZSex2) includes the lipase consensus sequence (serine-histidine-aspartic acid) which is known for serine hydrolases. Secondary structure analysis shows 7.9 % α-helix, 43.9 % β-sheet, 19.4 % β-turns, and 31.2 % random coil, suggesting that this enzyme belongs to the α/β hydrolase fold family, in agreement with other PHA depolymerases and lipases. The enzyme was efficiently produced as an extracellular active form in Rhodococcus and purified by two consecutive hydrophobic chromatographic steps. Matrix-assisted laser desorption-time-of-flight (MALDI-TOF) analysis of the purified enzyme revealed a monomer of 27.6 kDa with a midpoint transition temperature of 44.2 °C. Remarkably, the activity is significantly enhanced by low concentrations of nonionic and anionic detergents and thermal stability is improved by the presence of 10 % glycerol. PhaZSex2 is an endo-exohydrolase that cleaves both large and small PHA molecules, producing (R)-3-hydroxyoctanoic acid monomers as the main reaction product. Markedly, PhaZSex2 is able to degrade functionalized polymers containing thioester groups in the side chain (PHACOS), releasing functional thioester-based monomers and oligomers demonstrating the potentiality of this novel biocatalyst for the industrial production of enantiopure (R)-3-hydroxyalkanoic acids.
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Affiliation(s)
- Virginia Martínez
- Department of Biochemistry and Molecular Biology, Facultad de Biología, Universidad Complutense de Madrid, Madrid, Spain.,Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Hørsholm, Denmark
| | - Patricia Gómez de Santos
- Department of Biochemistry and Molecular Biology, Facultad de Biología, Universidad Complutense de Madrid, Madrid, Spain.,Department of Biocatalysis, Institute of Catalysis, CSIC, Madrid, Spain
| | - Javier García-Hidalgo
- Department of Biochemistry and Molecular Biology, Facultad de Biología, Universidad Complutense de Madrid, Madrid, Spain
| | - Daniel Hormigo
- Department of Biochemistry and Molecular Biology, Facultad de Biología, Universidad Complutense de Madrid, Madrid, Spain.,Department of Pharmacy and Biotechnology, Biomedical Sciences Faculty, European University of Madrid, Madrid, Spain
| | - M Auxiliadora Prieto
- Department of Environmental Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Miguel Arroyo
- Department of Biochemistry and Molecular Biology, Facultad de Biología, Universidad Complutense de Madrid, Madrid, Spain
| | - Isabel de la Mata
- Department of Biochemistry and Molecular Biology, Facultad de Biología, Universidad Complutense de Madrid, Madrid, Spain.
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