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Abed RMM, Al-Hinai M, Al-Balushi Y, Haider L, Muthukrishnan T, Rinner U. Degradation of starch-based bioplastic bags in the pelagic and benthic zones of the Gulf of Oman. MARINE POLLUTION BULLETIN 2023; 195:115496. [PMID: 37703633 DOI: 10.1016/j.marpolbul.2023.115496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/21/2023] [Accepted: 09/02/2023] [Indexed: 09/15/2023]
Abstract
The Gulf of Oman is becoming increasingly polluted with plastics, hence bioplastics have been considered 'a substitute', although their biodegradability in marine environments has not been well investigated. Most research has been performed on cellulose-based bioplastics, whereas starch-based bioplastics have proven to be a suitable, but less researched, alternative. This study is the first of its kind designed to investigate the degradability of two different types of starch-based bioplastic bags, available in the market and labeled as "biodegradable", in the pelagic and benthic zones of one of the warmest marine environment in the world. Fourier-Transform Infrared Spectroscopy (FTIR) showed a clear reduction in the presence of OH, CH, and CO in the bioplastic bags after 5 weeks of immersion. Thermo-Gravimetric Analysis (TGA) indicated degradation of glycerol, starch, and polyethylene. The biofouling bacterial communities on bioplastic surfaces showed distinct grouping based on the immersion zone. Candidaatus saccharibacteria, Verrucomicrobiae, Acidimicrobiia and Planctomycetia sequences were only detectable on bioplastics in the pelagic zone, whereas Actinomyces, Pseudomonas, Sphingobium and Acinetobacter related sequences were only found on bioplastics in the benthic layer. We conclude that starch-based bioplastics are more readily degradable in the Gulf of Oman than conventional plastics, hence could serve as a better environmentally friendly alternative.
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Affiliation(s)
- Raeid M M Abed
- Biology Department, College of Science, Sultan Qaboos University, P. O. Box: 36, PC 123 Al Khoud, Sultanate of Oman.
| | - Mahmood Al-Hinai
- Biology Department, College of Science, Sultan Qaboos University, P. O. Box: 36, PC 123 Al Khoud, Sultanate of Oman
| | - Yasmin Al-Balushi
- Biology Department, College of Science, Sultan Qaboos University, P. O. Box: 36, PC 123 Al Khoud, Sultanate of Oman
| | - Lorenz Haider
- Institute of Applied Chemistry, IMC University of Applied Sciences Krems, Piaristengasse 1, 3500 Krems, Austria
| | - Thirumahal Muthukrishnan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Ontario M5S 3E5, Canada
| | - Uwe Rinner
- Institute of Applied Chemistry, IMC University of Applied Sciences Krems, Piaristengasse 1, 3500 Krems, Austria
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The application of conventional or magnetic materials to support immobilization of amylolytic enzymes for batch and continuous operation of starch hydrolysis processes. REV CHEM ENG 2022. [DOI: 10.1515/revce-2022-0033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Abstract
In the production of ethanol, starches are converted into reducing sugars by liquefaction and saccharification processes, which mainly use soluble amylases. These processes are considered wasteful operations as operations to recover the enzymes are not practical economically so immobilizations of amylases to perform both processes appear to be a promising way to obtain more stable and reusable enzymes, to lower costs of enzymatic conversions, and to reduce enzymes degradation/contamination. Although many reviews on enzyme immobilizations are found, they only discuss immobilizations of α-amylase immobilizations on nanoparticles, but other amylases and support types are not well informed or poorly stated. As the knowledge of the developed supports for most amylase immobilizations being used in starch hydrolysis is important, a review describing about their preparations, characteristics, and applications is herewith presented. Based on the results, two major groups were discovered in the last 20 years, which include conventional and magnetic-based supports. Furthermore, several strategies for preparation and immobilization processes, which are more advanced than the previous generation, were also revealed. Although most of the starch hydrolysis processes were conducted in batches, opportunities to develop continuous reactors are offered. However, the continuous operations are difficult to be employed by magnetic-based amylases.
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Ahmad A, Rahamtullah, Mishra R. Structural and functional adaptation in extremophilic microbial α-amylases. Biophys Rev 2022; 14:499-515. [PMID: 35528036 PMCID: PMC9043155 DOI: 10.1007/s12551-022-00931-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 01/12/2022] [Indexed: 01/26/2023] Open
Abstract
Maintaining stable native conformation of a protein under a given ecological condition is the prerequisite for survival of organisms. Extremophilic bacteria and archaea have evolved to adapt under extreme conditions of temperature, pH, salt, and pressure. Molecular adaptations of proteins under these conditions are essential for their survival. These organisms have the capability to maintain stable, native conformations of proteins under extreme conditions. The enzymes produced by the extremophiles are also known as extremozyme, which are used in several industries. Stability and functionality of extremozymes under varying temperature, pH, and solvent conditions are the most desirable requirement of industry. α-Amylase is one of the most important enzymes used in food, pharmaceutical, textile, and detergent industries. This enzyme is produced by diverse microorganisms including various extremophiles. Therefore, understanding its stability is important from fundamental as well as an applied point of view. Each class of extremophiles has a distinctive set of dominant non-covalent interactions which are important for their stability. Static information obtained by comparative analysis of amino acid sequence and atomic resolution structure provides information on the prevalence of particular amino acids or a group of non-covalent interactions. Protein folding studies give the information about thermodynamic and kinetic stability in order to understand dynamic aspect of molecular adaptations. In this review, we have summarized information on amino acid sequence, structure, stability, and adaptability of α-amylases from different classes of extremophiles.
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Affiliation(s)
- Aziz Ahmad
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110,067 India
| | - Rahamtullah
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110,067 India
| | - Rajesh Mishra
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110,067 India
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Kizhakedathil MPJ, C SD. Acid stable α-amylase from Pseudomonas balearica VITPS19-Production, purification and characterization. ACTA ACUST UNITED AC 2021; 30:e00603. [PMID: 33747801 PMCID: PMC7966826 DOI: 10.1016/j.btre.2021.e00603] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 01/05/2021] [Accepted: 02/21/2021] [Indexed: 12/04/2022]
Abstract
α – Amylase was produced from a rhizobacteria Pseudomonas balearica VITPS19. One factor at a time method (OFAT) was employed to optimize the α –amylase production. Three step purification of α – amylase from the fermentation broth. Determining the optimal conditions for enzyme activity. Estimation of the enzymatic kinetic parameters of the α-amylase.
In the present study, α-amylase from Pseudomonas balearica VITPS19 isolated from Kolathur, Tamil Nadu, India was studied. Initially, one factor at a time (OFAT) approach was used to optimize the medium parameters like pH, temperature, carbon and nitrogen sources and the presence of metal ions to enhance the amylase activity. After the optimization, 6.5-fold increase in the enzyme production was observed. Enzyme purification was carried out in three stages. The molecular weight of purified α-amylase was estimated to be 47 kDa.The optimum activity for the purified enzyme was observed at pH 6 in 0.1 M phosphate buffer at 25 ± 2 °C and the activity is enhanced in the presence of ions like Mn2+, Mo6+, Na+, Mg2+and Zn2+ and was inhibited in the presence of Hg2+ ions. Compounds such as Sodium dodecyl sulfate (SDS), Ethylenediaminetetraacetic acid (EDTA), urea and β- mercaptoethanol reduced the amylase activity. The Km and Vmax of the α-amylase was estimated to be 45.23 mM and 20.83 U/mL, respectively.
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Affiliation(s)
- Moni Philip Jacob Kizhakedathil
- Department of Biotechnology, School of Biosciences and Technology, Vellore Institute of Technology University, Vellore - 632014, Tamil Nadu, India
| | - Subathra Devi C
- Department of Biotechnology, School of Biosciences and Technology, Vellore Institute of Technology University, Vellore - 632014, Tamil Nadu, India
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Ademakinwa AN, Agunbiade MO, Ayinla ZA, Agboola FK. Optimization of aqueous two-phase partitioning of Aureobasidium pullulans α-amylase via response surface methodology and investigation of its thermodynamic and kinetic properties. Int J Biol Macromol 2019; 140:833-841. [PMID: 31445154 DOI: 10.1016/j.ijbiomac.2019.08.159] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 08/16/2019] [Accepted: 08/18/2019] [Indexed: 02/04/2023]
Abstract
Industrial enzymes such as α-amylase must be thermostable and also easily purified/concentrated. Hence, aqueous two-phase partitioning systems (ATPS) was exploited for the partitioning of α-amylase from Aureobasidium pullulans due to its numerous advantages over conventional purification strategy. A. pullulans α-amylase was partially purified using ATPS via response surface methodology (RSM). The potentials of the ATPS-purified enzyme for possible industrial application such as resistance to thermal inactivation was investigated in comparison with the crude enzyme. PEG-6000 was the polymer of choice for ATPS as it resulted in higher purification factor (PF), %yield (Y), and partition coefficient (PC). At optimum levels (% w/v) of 20, 12 and 7.5 for PEG-6000, sodium citrate and sodium chloride respectively, maximum PF, Y and PC of 4.2, 88%, and 9.9 respectively were obtained. The response model validation and reliability were established based on the closeness between the experimented and predicted values. The kinetic and thermodynamic parameters such as Q10, t1/2, kd, D - value, Ed, [Formula: see text] [Formula: see text] of the ATPS-purified α-amylase indicated that it was thermostable at 50 to 60 °C compared to the crude α-amylase. A thermodynamically stable and ATPS-purified α-amylase from A. pullulans has properties easily applicable for most industrial processes.
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Affiliation(s)
- A N Ademakinwa
- Department of Physical and Chemical Sciences, Elizade University, Ilara-Mokin, Nigeria; Department of Biochemistry and Molecular Biology, Obafemi Awolowo University, Ile-Ife, Nigeria.
| | - M O Agunbiade
- Biocatalysis and Technical Biology Research Group, Institute of Biomedical and Microbial Biotechnology, Cape Peninsula University of Technology, South Africa
| | - Z A Ayinla
- Department of Biochemistry and Molecular Biology, Obafemi Awolowo University, Ile-Ife, Nigeria; Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic, Troy, NY 12180, USA
| | - F K Agboola
- Department of Biochemistry and Molecular Biology, Obafemi Awolowo University, Ile-Ife, Nigeria
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Sadaf A, Grewal J, Jain I, Kumari A, Khare SK. Stability and structure of Penicillium chrysogenum lipase in the presence of organic solvents. Prep Biochem Biotechnol 2018; 48:977-983. [PMID: 30461349 DOI: 10.1080/10826068.2018.1525566] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The present work describes the enzymatic properties of Penicillium chrysogenum lipase and its behavior in the presence of organic solvents. The temperature and pH optima of the purified lipase was found to be 55 °C and pH 8.0 respectively. The lipase displayed remarkable stability in both polar and non-polar solvents upto 50% (v/v) concentrations for 72 h. A structural perspective of the purified lipase in different organic solvents was gained by using circular dichroism and intrinsic fluorescence spectroscopy. The native lipase consisted of a predominant α-helix structure which was maintained in both polar and non-polar solvents with the exception of ethyl butyrate where the activity was decreased and the structure was disrupted. The quenching of fluorescence intensity in the presence of organic solvents indicated the transformation of the lipase microenviroment P. chrysogenum lipase offers an interesting system for understanding the solvent stability mechanisms which could be used for rationale designing of engineered lipase biocatalysts for application in organic synthesis in non-aqueous media.
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Affiliation(s)
- Ayesha Sadaf
- a Enzyme and Microbial Biochemistry Lab, Department of Chemistry , Indian Institute of Technology Delhi , New Delhi , India
| | - Jasneet Grewal
- a Enzyme and Microbial Biochemistry Lab, Department of Chemistry , Indian Institute of Technology Delhi , New Delhi , India
| | - Isha Jain
- a Enzyme and Microbial Biochemistry Lab, Department of Chemistry , Indian Institute of Technology Delhi , New Delhi , India
| | - Arti Kumari
- a Enzyme and Microbial Biochemistry Lab, Department of Chemistry , Indian Institute of Technology Delhi , New Delhi , India
| | - Sunil K Khare
- a Enzyme and Microbial Biochemistry Lab, Department of Chemistry , Indian Institute of Technology Delhi , New Delhi , India
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Grewal J, Ahmad R, Khare SK. Development of cellulase-nanoconjugates with enhanced ionic liquid and thermal stability for in situ lignocellulose saccharification. BIORESOURCE TECHNOLOGY 2017; 242:236-243. [PMID: 28411048 DOI: 10.1016/j.biortech.2017.04.007] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/30/2017] [Accepted: 04/01/2017] [Indexed: 05/25/2023]
Abstract
The present work aimed to improve catalytic efficiency of Trichoderma reesei cellulase for enhanced saccharification. The cellulase was immobilized on two nanomatrices i.e. magnetic and silica nanoparticles with immobilization efficiency of 85% and 76% respectively. The nanobioconjugates exhibited increase in Vmax, temperature optimum, pH and thermal stability as compared with free enzyme. These could be efficiently reused for five repeated cycles and were stable in 1-ethyl-3-methylimidazoliumacetate [EMIM][Ac], an ionic liquid. Ionic liquids (IL) are used as green solvents to dissolve lignocellulosic biomass and facilitate better saccharification. The cellulase immobilized on magnetic nanoparticles was used for in situ saccharification of [EMIM][Ac] pretreated sugarcane bagasse and wheat straw for two cycles. The structural deconstruction and decrease in biomass crystallinity was confirmed by SEM, XRD and FTIR. The high hydrolysis yields (∼89%) obtained in this one-pot process coupled with IL stability and recycled use of immobilized cellulase, potentiates its usefulness in biorefineries.
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Affiliation(s)
- Jasneet Grewal
- Enzyme and Microbial Biochemistry Laboratory, Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Razi Ahmad
- Enzyme and Microbial Biochemistry Laboratory, Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - S K Khare
- Enzyme and Microbial Biochemistry Laboratory, Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
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Functional characterization and crystal structure of thermostable amylase from Thermotoga petrophila , reveals high thermostability and an unusual form of dimerization. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017. [DOI: 10.1016/j.bbapap.2017.06.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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