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de Oliveira AR, de Toledo Rós B, Jardim R, Kotowski N, de Barros A, Pereira RHG, Almeida NF, Dávila AMR. A comparative genomics study of the microbiome and freshwater resistome in Southern Pantanal. Front Genet 2024; 15:1352801. [PMID: 38699231 PMCID: PMC11063290 DOI: 10.3389/fgene.2024.1352801] [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: 12/08/2023] [Accepted: 04/01/2024] [Indexed: 05/05/2024] Open
Abstract
This study explores the resistome and bacterial diversity of two small lakes in the Southern Pantanal, one in Aquidauana sub-region, close to a farm, and one in Abobral sub-region, an environmentally preserved area. Shotgun metagenomic sequencing data from water column samples collected near and far from the floating macrophyte Eichhornia crassipes were used. The Abobral small lake exhibited the highest diversity and abundance of antibiotic resistance genes (ARGs), antibiotic resistance classes (ARGCs), phylum, and genus. RPOB2 and its resistance class, multidrug resistance, were the most abundant ARG and ARGC, respectively. Pseudomonadota was the dominant phylum across all sites, and Streptomyces was the most abundant genus considering all sites.
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Affiliation(s)
- André R. de Oliveira
- Laboratório de Biologia Computacional e Sistemas, Instituto Oswaldo Cruz, Rio de Janeiro, Brazil
| | | | - Rodrigo Jardim
- Laboratório de Biologia Computacional e Sistemas, Instituto Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Nelson Kotowski
- Laboratório de Biologia Computacional e Sistemas, Instituto Oswaldo Cruz, Rio de Janeiro, Brazil
| | | | | | | | - Alberto M. R. Dávila
- Laboratório de Biologia Computacional e Sistemas, Instituto Oswaldo Cruz, Rio de Janeiro, Brazil
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2
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Das R, Hoysall C, Rao L. Unveiling the origin, fate, and remedial approaches for surfactants in sewage-fed foaming urban (Bellandur) Lake. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 339:122773. [PMID: 37858701 DOI: 10.1016/j.envpol.2023.122773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 10/11/2023] [Accepted: 10/16/2023] [Indexed: 10/21/2023]
Abstract
Foam formation in surface water bodies has become a global phenomenon, but the solutions to this crisis are often insufficient. Foam formation in water bodies is attributed to surfactants and requires a comprehensive assessment of various sources of surfactants to evolve mitigation strategies. The study is focused on thoroughly analyzing surfactants in the water and foam fractions of a large waterbody in Bangalore (India) spanning around 1000 acres (400 ha), which has been foaming for two decades. Results revealed that the key surfactants originate predominantly from anthropogenic sources with a small component emerging from naturogenic sources. Anthropogenic surfactants were found to be predominant (96.5%), with linear alkylbenzene sulphonates (LAS) of various C-chain lengths 12-20 being the most prevalent. Naturogenic surfactants derived from bacterial genera Pseudomonas exhibited significant microbial diversity, accounting for over 19% of total bacterial population in both the water and organic sediments of the lake. Modelling studies and field validation efforts were carried out to understand the fate of LAS in the foaming lake. The results indicated that these surfactants donot degrade under the prevailing conditions and timeframe as wastewater traverses through the lake, and their presence was also observed in the organic sludge sediment. Modeling the underlying processes revealed that a minimum dissolved oxygen (DO) concentration of 3.5 mg/l enables the degradation of over 90% of surfactants within the residence time of 8-10 days in Lake. Additionally, the process of desludging could contribute to an additional increase to the overall efficiency of surfactant removal, simultaneously removing legacy sorbed surfactants to sediments.
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Affiliation(s)
- Reshmi Das
- Centre for Sustainable Technologies, Indian Institute of Science, Bangalore, India.
| | - Chanakya Hoysall
- Centre for Sustainable Technologies, Indian Institute of Science, Bangalore, India
| | - Lakshminarayana Rao
- Centre for Sustainable Technologies, Indian Institute of Science, Bangalore, India
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3
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Bisht B, Verma M, Sharma R, Chauhan P, Pant K, Kim H, Vlaskin MS, Kumar V. Development of yeast and microalgae consortium biofilm growth system for biofuel production. Heliyon 2023; 9:e19353. [PMID: 37662773 PMCID: PMC10472003 DOI: 10.1016/j.heliyon.2023.e19353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 08/09/2023] [Accepted: 08/20/2023] [Indexed: 09/05/2023] Open
Abstract
Background The current study aimed to develop a laboratory-scale biofilm photobioreactor system for biofuel production. Scope & Approach During the investigation, Jute was discovered to be the best, cheap, hairy, open-pored supporting material for biofilm formation. Microalgae & yeast consortium was used in this study for biofilm formation. Conclusion The study identified microalgae and yeast consortium as a promising choice and ideal partners for biofilm formation with the highest biomass yield (47.63 ± 0.93 g/m2), biomass productivity (4.39 ± 0.29 to 7.77 ± 0.05 g/m2/day) and lipid content (36%) over 28 days cultivation period, resulting in a more sustainable and environmentally benign fuel that could become a reality in the near future.
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Affiliation(s)
- Bhawna Bisht
- Algal Research and Bioenergy Laboratory, Department of Food Science and Technology, Graphic Era (Deemed to be University), Dehradun, Uttarakhand, 248002, India
| | - Monu Verma
- Algal Research and Bioenergy Laboratory, Department of Food Science and Technology, Graphic Era (Deemed to be University), Dehradun, Uttarakhand, 248002, India
- Water-Energy Nexus Laboratory, Department of Environmental Engineering, University of Seoul, Seoul, 02504, Republic of Korea
| | - Rohit Sharma
- Department of Biotechnology Engineering, University Institute of Engineering, Chandigarh University, Chandigarh, India
| | - P.K. Chauhan
- Faculty of Applied Sciences and Biotechnology, Shoolini University, Solan, 173229, HP, India
| | - Kumud Pant
- Department of Biotechnology, Graphic Era (Deemed to be University), Dehradun, Uttarakhand, 248002, India
| | - Hyunook Kim
- Water-Energy Nexus Laboratory, Department of Environmental Engineering, University of Seoul, Seoul, 02504, Republic of Korea
| | - Mikhail S. Vlaskin
- Joint Institute for High Temperatures of the Russian Academy of Sciences, 13/2 Izhorskaya St, Moscow, 125412, Russian Federation
| | - Vinod Kumar
- Algal Research and Bioenergy Laboratory, Department of Food Science and Technology, Graphic Era (Deemed to be University), Dehradun, Uttarakhand, 248002, India
- Peoples’ Friendship University of Russia (RUDN University), Moscow, 117198, Russian Federation
- Graphic Era Hill University, Dehradun, Uttarakhand 248002, India
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4
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Bochynek M, Lewińska A, Witwicki M, Dębczak A, Łukaszewicz M. Formation and structural features of micelles formed by surfactin homologues. Front Bioeng Biotechnol 2023; 11:1211319. [PMID: 37485321 PMCID: PMC10360134 DOI: 10.3389/fbioe.2023.1211319] [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: 04/24/2023] [Accepted: 06/22/2023] [Indexed: 07/25/2023] Open
Abstract
Surfactin, a group of cyclic lipopeptides produced by Bacillus subtilis, possesses surfactant properties and is a promising natural and biologically active compound. In this study, we present a comprehensive characterization of surfactin, including its production, chromatographic separation into pure homologues (C12, C13, C14, C15), and investigation of their physicochemical properties. We determined adsorption isotherms and interpreted them using the Gibbs adsorption equation, revealing that the C15 homologue exhibited the strongest surface tension reduction (27.5 mN/m), while surface activity decreased with decreasing carbon chain length (32.2 mN/m for C12). Critical micelle concentration (CMC) were also determined, showing a decrease in CMC values from 0.35 mM for C12 to 0.08 mM for C15. We employed dynamic light scattering (DLS), transmission electron microscopy (TEM), and density functional theory (DFT) calculations to estimate the size of micellar aggregates, which increased with longer carbon chains, ranging from 4.7 nm for C12 to 5.7 nm for C15. Furthermore, aggregation numbers were determined, revealing the number of molecules in a micelle. Contact angles and emulsification indexes (E24) were measured to assess the functional properties of the homologues, showing that wettability increased with chain length up to C14, which is intriguing as C14 is the most abundant homologue. Our findings highlight the relationship between the structure and properties of surfactin, providing valuable insights for understanding its biological significance and potential applications in various industries. Moreover, the methodology developed in this study can be readily applied to other cyclic lipopeptides, facilitating a better understanding of their structure-properties relationship.
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Affiliation(s)
- Michał Bochynek
- Department of Biotransformation, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
- InventionBio S.A., Bydgoszcz, Poland
| | - Agnieszka Lewińska
- Faculty of Chemistry, University of Wroclaw, Wroclaw, Poland
- OnlyBio S.A., Bydgoszcz, Poland
| | - Maciej Witwicki
- Faculty of Chemistry, University of Wroclaw, Wroclaw, Poland
| | - Agnieszka Dębczak
- Łukasiewicz Research Network—New Chemical Syntheses Institute, Puławy, Poland
| | - Marcin Łukaszewicz
- Department of Biotransformation, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
- InventionBio S.A., Bydgoszcz, Poland
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Roldán-Carrillo T, Castorena-Cortés G, Álvarez-Ramírez F, Vázquez-Moreno F, Olguín-Lora P. Lipopeptide production by Serratia marcescens SmSA using a Taguchi design and its application in enhanced heavy oil recovery. Prep Biochem Biotechnol 2021; 52:872-884. [PMID: 34865598 DOI: 10.1080/10826068.2021.2004546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Biosurfactant production at reactor level by Serratia marcescens SmSA was optimized and evaluated to enhance the heavy oil recovery on carbonate rocks. Temperature, agitation, and carbon/nitrogen (C/N) ratio were evaluated to optimize biosurfactant production by using a Taguchi (L9) design. The best conditions (C/N ratio: 6, 25 °C, and agitation: 100 rpm) were used to scale up the biosurfactant production with a 3-L bioreactor. The best aeration for biosurfactant production was 0.66 volume of air per volume of liquid per minute (vvm), producing the lowest surface tension (26 mN/m) in 14 h, with a biosurfactant yield of 14.26 g/L as a crude product and 2.85 g/L as a purified product, and a critical micelle concentration of 280 mg/L. The biosurfactant was characterized as a lipopeptide, and it was stable under extreme conditions: pH (2-12), salinity up to 200 g/L, and temperature up to 150 °C confirmed by thermogravimetric analysis. Enhanced oil recovery test was carried out with a carbonate core and heavy oil under reservoir conditions, obtaining an additional recovery of 8%, due to reduced interfacial tension and modified wettability of the rock. These findings highlight the potential application of S. marcescens SmSA biosurfactant in enhanced oil recovery.
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Affiliation(s)
| | | | | | | | - P Olguín-Lora
- Instituto Mexicano del Petróleo, Ciudad de México, México
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Ugya AY, Ajibade FO, Hua X. The efficiency of microalgae biofilm in the phycoremediation of water from River Kaduna. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 295:113109. [PMID: 34216901 DOI: 10.1016/j.jenvman.2021.113109] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 06/09/2021] [Accepted: 06/15/2021] [Indexed: 06/13/2023]
Abstract
This study is aimed at investigating the efficiency of microalgae biofilm in the phycoremediation of water from a polluted river. Freshwater microalgae biofilm inherent in a contaminated petrochemical stream was employed to remediate water from the River Kaduna, which is the largest river in Kaduna town, Kaduna State, Nigeria, and serves as the primary water source in Kaduna town. The results indicate high reduction efficiency of some physicochemical parameters and pollutants (turbidity (71%), conductivity (9.8%), sulfate (37.5%), alkalinity (62.5%), chloride (11.5%), TDS (9.9%), TSS (66.7%), nitrate (42.9%), COD (24%), and BOD (33%), Cd (70.0%), Ni (74.0%) and Pb (71.0%)), indicating the effectiveness of microalgae biofilm in the phycoremediation of water from River Kaduna. According to scanning electron microscope (SEM) observation, the microalgae biofilm has rough surface morphology after the treatment of the river water, which implies that the biofilm was capable of removing the pollutants in water via biosorption. Other characterizations such as XRF, XRD, and FTIR also buttressed that biosorption was the primary removal mechanism of pollutants by microalgae biofilm. Besides, the results also show the production of ROS during the treatment of water from the River Kaduna by the microalgae biofilm. This high concentration of ROS produced during the treatment correlates significantly with pollutant degradation. The GC-MS analysis of the microalgae biofilm shows the involvement of some phytochemicals in the process of pollutant degradation. As a result, microalgae biofilm is a simple and cost-effective method of polluted water phycoremediation with promising applications and future prospects.
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Affiliation(s)
- Adamu Yunusa Ugya
- Key Lab of Groundwater Resources and Environment of Ministry of Education, Key Lab of Water Resources and Aquatic Environment of Jilin Province, College of New Energy and Environment, Jilin University, Changchun, 130012, China; Department of Environmental Management, Kaduna State University, Kaduna, Nigeria
| | - Fidelis Odedishemi Ajibade
- Department of Civil and Environmental Engineering, Federal University of Technology Akure, PMB 704, Nigeria; Key Lab of Environmental Biotechnology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Xiuyi Hua
- Key Lab of Groundwater Resources and Environment of Ministry of Education, Key Lab of Water Resources and Aquatic Environment of Jilin Province, College of New Energy and Environment, Jilin University, Changchun, 130012, China.
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Bhatt P, Verma A, Gangola S, Bhandari G, Chen S. Microbial glycoconjugates in organic pollutant bioremediation: recent advances and applications. Microb Cell Fact 2021; 20:72. [PMID: 33736647 PMCID: PMC7977309 DOI: 10.1186/s12934-021-01556-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Accepted: 02/27/2021] [Indexed: 02/06/2023] Open
Abstract
The large-scale application of organic pollutants (OPs) has contaminated the air, soil, and water. Persistent OPs enter the food supply chain and create several hazardous effects on living systems. Thus, there is a need to manage the environmental levels of these toxicants. Microbial glycoconjugates pave the way for the enhanced degradation of these toxic pollutants from the environment. Microbial glycoconjugates increase the bioavailability of these OPs by reducing surface tension and creating a solvent interface. To date, very little emphasis has been given to the scope of glycoconjugates in the biodegradation of OPs. Glycoconjugates create a bridge between microbes and OPs, which helps to accelerate degradation through microbial metabolism. This review provides an in-depth overview of glycoconjugates, their role in biofilm formation, and their applications in the bioremediation of OP-contaminated environments.
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Affiliation(s)
- Pankaj Bhatt
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Laboratory for Lingnan Modern Agriculture, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, 510642, China
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, 510642, China
| | - Amit Verma
- Department of Biochemistry, College of Basic Science and Humanities, SD Agricultural University, Gujarat, 385506, India
| | - Saurabh Gangola
- School of Agriculture, Graphic Era Hill University, Bhimtal Campus, Dehradun, Uttarakhand, 248002, India
| | - Geeta Bhandari
- Department of Biotechnology, Sardar Bhagwan Singh University, Dehradun, Uttarakhand, 248161, India
| | - Shaohua Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Laboratory for Lingnan Modern Agriculture, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, 510642, China.
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, 510642, China.
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8
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Biosurfactants’ Potential Role in Combating COVID-19 and Similar Future Microbial Threats. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app11010334] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
During 2020, the world has experienced extreme vulnerability in the face of a disease outbreak. The coronavirus disease 2019 (COVID-19) pandemic discovered in China and rapidly spread across the globe, infecting millions, causing hundreds of thousands of deaths, and severe downturns in the economies of countries worldwide. Biosurfactants can play a significant role in the prevention, control and treatment of diseases caused by these pathogenic agents through various therapeutic, pharmaceutical, environmental and hygiene approaches. Biosurfactants have the potential to inhibit microbial species with virulent intrinsic characteristics capable of developing diseases with high morbidity and mortality, as well as interrupting their spread through environmental and hygiene interventions. This is possible due to their antimicrobial activity, ability to interact with cells forming micelles and to interact with the immune system, and compatibility with relevant processes such as nanoparticle synthesis. They, therefore, can be applied in developing innovative and more effective pharmaceutical, therapeutics, sustainable and friendly environmental management approaches, less toxic formulations, and more efficient cleaning agents. These approaches can be easily integrated into relevant product development pipelines and implemented as measures for combating and managing pandemics. This review examines the potential approaches of biosurfactants as useful molecules in fighting microbial pathogens both known and previously unknown, such as COVID-19.
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Adetunji AI, Olaniran AO. Production and potential biotechnological applications of microbial surfactants: An overview. Saudi J Biol Sci 2020; 28:669-679. [PMID: 33424354 PMCID: PMC7783833 DOI: 10.1016/j.sjbs.2020.10.058] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 10/15/2020] [Accepted: 10/26/2020] [Indexed: 12/26/2022] Open
Abstract
Microbial surfactants are amphipathic molecules that consist of hydrophilic and hydrophobic domains, which allow partition of two fluid phases of varying degree of polarity. They are classified into two main groups: bioemulsifier and biosurfactant, depending on their molecular weight. Microbial surfactants occur in various categories according to their chemical nature and producing organisms. These biomolecules are produced by diverse groups of microorganisms including fungi, bacteria, and yeasts. Their production is significantly influenced by substrate type, fermentation technology and microbial strains. Owing to inherent multifunctional properties and assorted synthetic aptitude of the microbes, microbial surfactants are mostly preferred than their chemical counterparts for various industrial and biomedical applications including bioremediation, oil recovery; as supplements in laundry formulations and as emulsion-stabilizers in food and cosmetic industries as well as therapeutic agents in medicine. The present review discusses on production of microbial surfactants as promising and alternative broad-functional biomolecules for various biotechnological applications.
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Key Words
- %, Percent
- Akt, Threonine protein kinase
- Bioemulsifiers
- Biosurfactants
- Biotechnological applications
- CMC, Critical micelle concentration
- CTAB, Cethyltrimethylammonium bromide
- Da, Dalton
- E24, Emulsification index
- IC50, Half-maximal inhibitory concentration
- KDa, Kilodalton
- MBC, Minimum bactericidal concentration
- MIC, Minimum inhibitory concentration
- Microbial surfactants
- SACs, Surface active compounds
- ST, Surface tension
- Surface-active compounds
- g/L, Gram per litre
- h, Hour
- mL, Millilitre
- mN/M, Millinewton per metre
- mg/L, Milligram per liter
- mg/mL, Milligram per milliliter
- nm, Nanometre
- sec, Second
- v/v, volume per volume
- µL, Microlitre
- µg/mL, Microgram per milliliter
- µm, Micrometre
- ˚C, Degree Celsius
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Affiliation(s)
- Adegoke Isiaka Adetunji
- Discipline of Microbiology, School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal (Westville campus), Private Bag X54001, Durban 4000, South Africa
| | - Ademola Olufolahan Olaniran
- Discipline of Microbiology, School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal (Westville campus), Private Bag X54001, Durban 4000, South Africa
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Havenga B, Ndlovu T, Clements T, Reyneke B, Waso M, Khan W. Exploring the antimicrobial resistance profiles of WHO critical priority list bacterial strains. BMC Microbiol 2019; 19:303. [PMID: 31870288 PMCID: PMC6929480 DOI: 10.1186/s12866-019-1687-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 12/17/2019] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND The antimicrobial resistance of clinical, environmental and control strains of the WHO "Priority 1: Critical group" organisms, Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa to various classes of antibiotics, colistin and surfactin (biosurfactant) was determined. METHODS Acinetobacter baumannii was isolated from environmental samples and antibiotic resistance profiling was performed to classify the test organisms [A. baumannii (n = 6), P. aeruginosa (n = 5), E. coli (n = 7) and K. pneumoniae (n = 7)] as multidrug resistant (MDR) or extreme drug resistant (XDR). All the bacterial isolates (n = 25) were screened for colistin resistance and the mobilised colistin resistance (mcr) genes. Biosurfactants produced by Bacillus amyloliquefaciens ST34 were solvent extracted and characterised using ultra-performance liquid chromatography (UPLC) coupled to electrospray ionisation mass spectrometry (ESI-MS). The susceptibility of strains, exhibiting antibiotic and colistin resistance, to the crude surfactin extract (cell-free supernatant) was then determined. RESULTS Antibiotic resistance profiling classified four A. baumannii (67%), one K. pneumoniae (15%) and one P. aeruginosa (20%) isolate as XDR, with one E. coli (15%) and three K. pneumoniae (43%) strains classified as MDR. Many of the isolates [A. baumannii (25%), E. coli (80%), K. pneumoniae (100%) and P. aeruginosa (100%)] exhibited colistin resistance [minimum inhibitory concentrations (MICs) ≥ 4 mg/L]; however, only one E. coli strain isolated from a clinical environment harboured the mcr-1 gene. UPLC-MS analysis then indicated that the B. amyloliquefaciens ST34 produced C13-16 surfactin analogues, which were identified as Srf1 to Srf5. The crude surfactin extract (10.00 mg/mL) retained antimicrobial activity (100%) against the MDR, XDR and colistin resistant A. baumannii, P. aeruginosa, E. coli and K. pneumoniae strains. CONCLUSION Clinical, environmental and control strains of A. baumannii, P. aeruginosa, E. coli and K. pneumoniae exhibiting MDR and XDR profiles and colistin resistance, were susceptible to surfactin analogues, confirming that this lipopeptide shows promise for application in clinical settings.
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Affiliation(s)
- Benjamin Havenga
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602 South Africa
| | - Thando Ndlovu
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602 South Africa
| | - Tanya Clements
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602 South Africa
| | - Brandon Reyneke
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602 South Africa
| | - Monique Waso
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602 South Africa
| | - Wesaal Khan
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602 South Africa
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11
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Clements T, Ndlovu T, Khan W. Broad-spectrum antimicrobial activity of secondary metabolites produced by Serratia marcescens strains. Microbiol Res 2019; 229:126329. [PMID: 31518853 DOI: 10.1016/j.micres.2019.126329] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 08/01/2019] [Accepted: 09/03/2019] [Indexed: 12/17/2022]
Abstract
The genus Serratia is a predominantly unexplored source of antimicrobial secondary metabolites. The aim of the current study was thus to isolate and evaluate the antimicrobial properties of biosurfactants produced by Serratia species. Forty-nine (n = 34 pigmented; n = 15 non-pigmented) biosurfactant producing Serratia strains were isolated from environmental sources and selected isolates (n = 11 pigmented; n = 11 non-pigmented) were identified as Serratia marcescens using molecular typing. The swrW gene (serrawettin W1 synthetase) was detected in all the screened pigmented strains and one non-pigmented strain and primers were designed for the detection of the swrA gene (non-ribosomal serrawettin W2 synthetase), which was detected in nine non-pigmented strains. Crude extracts obtained from S. marcescens P1, NP1 and NP2 were chemically characterised using ultra-performance liquid chromatography coupled to electrospray ionisation mass spectrometry (UPLC-ESI-MS), which revealed that P1 produced serrawettin W1 homologues and prodigiosin, while NP1 produced serrawettin W1 homologues and glucosamine derivative A. In contrast, serrawettin W2 analogues were predominantly identified in the crude extract obtained from S. marcescens NP2. Both P1 and NP1 crude extracts displayed broad-spectrum antimicrobial activity against clinical, food and environmental pathogens, such as multidrug-resistant Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus and Cryptococcus neoformans. In contrast, the NP2 crude extract displayed antibacterial activity against a limited range of pathogenic and opportunistic pathogens. The serrawettin W1 homologues, in combination with prodigiosin and glucosamine derivatives, produced by pigmented and non-pigmented S. marcescens strains, could thus potentially be employed as broad-spectrum therapeutic agents against multidrug-resistant bacterial and fungal pathogens.
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Affiliation(s)
- Tanya Clements
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa
| | - Thando Ndlovu
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa
| | - Wesaal Khan
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa.
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12
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Wu X, Huang J, Lu Z, Chen G, Wang J, Liu G. Thiothrix eikelboomii interferes oxygen transfer in activated sludge. WATER RESEARCH 2019; 151:134-143. [PMID: 30594082 DOI: 10.1016/j.watres.2018.12.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 12/13/2018] [Accepted: 12/14/2018] [Indexed: 06/09/2023]
Abstract
This study revealed that, Thiothrix eikelboomii, a well-known filamentous bacterium that causes sludge bulking, could also interfere oxygen transfer during wastewater treatment. The volumetric oxygen transfer coefficient (KLa) in filamentous-bulking sludge (FBS) was found to be 43% lower than that in floc-forming sludge (FFS) at similar biomass concentrations, partially because the filamentous bacteria had increased the sludge apparent viscosity. The KLa value for FBS, however, was still significantly lower than that for FFS even if both sludges had similar apparent viscosity. Numerous tiny and free-swimming filaments were observed to attach on the air bubble surface, presumably reducing the liquid film renewal and increasing the liquid film thickness. Moreover, the filaments were co-coated with extracellular polymeric substances of protein and polysaccharide, which could make them performing like "amphiphilic molecules" of surfactants to hinder oxygen transfer. Therefore, the particular surface property of filaments and their interaction with air bubbles could also impact oxygen transfer. Thiothrix eikelboomii was identified to be the responsible filamentous bacterium that lowered the KLa value, while other filamentous bacteria with short filaments did not interfere oxygen transfer. This study implies that controlling sludge bulking benefits not only sludge settling but also oxygen transfer.
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Affiliation(s)
- Xianwei Wu
- School of Environment, Guangdong Engineering Research Center of Water Treatment Processes and Materials, And Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, 510632, China
| | - Ju Huang
- School of Environment, Guangdong Engineering Research Center of Water Treatment Processes and Materials, And Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, 510632, China
| | - Zichuan Lu
- School of Environment, Guangdong Engineering Research Center of Water Treatment Processes and Materials, And Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, 510632, China
| | - Gaofeng Chen
- School of Environment, Guangdong Engineering Research Center of Water Treatment Processes and Materials, And Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, 510632, China
| | - Jianmin Wang
- Department of Civil, Architectural and Environmental Engineering, Missouri University of Science and Technology, Rolla, MO, 65409, USA
| | - Guoqiang Liu
- School of Environment, Guangdong Engineering Research Center of Water Treatment Processes and Materials, And Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, 510632, China.
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Clements T, Ndlovu T, Khan S, Khan W. Biosurfactants produced by Serratia species: Classification, biosynthesis, production and application. Appl Microbiol Biotechnol 2018; 103:589-602. [DOI: 10.1007/s00253-018-9520-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 11/08/2018] [Accepted: 11/12/2018] [Indexed: 10/27/2022]
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Tan YN, Li Q. Microbial production of rhamnolipids using sugars as carbon sources. Microb Cell Fact 2018; 17:89. [PMID: 29884194 PMCID: PMC5994124 DOI: 10.1186/s12934-018-0938-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 05/31/2018] [Indexed: 12/27/2022] Open
Abstract
Rhamnolipids are a class of biosurfactants with effective surface-active properties. The high cost of microbial production of rhamnolipids largely affects their commercial applications. To reduce the production post, research has been carried out in screening more powerful strains, engineering microbes with higher biosurfactant yields and exploring cheaper substrates to reduce the production cost. Extensive refining is required for biosurfactant production using oils and oil-containing wastes, necessitating the use of complex and expensive biosurfactant recovery methods such as extraction with solvents or acid precipitation. As raw materials normally can account for 10-30% of the overall production cost, sugars have been proven to be an alternative carbon source for microbial production of rhamnolipids due to its lower costs and straightforward processing techniques. Studies have thus been focused on using tropical agroindustrial crop residues as renewable substrates. Herein, we reviewed studies that are using sugar-containing substrates as carbon sources for producing rhamnolipids. We speculate that sugars derived from agricultural wastes rich in cellulose and sugar-containing wastes are potential carbon sources in fermentation while challenges still remain in large scales.
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Affiliation(s)
- Yun Nian Tan
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459 Singapore
- Institute of Chemical and Engineering Sciences, Agency for Science, Technology and Research, 1 Pesek Road, Singapore, Jurong Island 627833 Singapore
| | - Qingxin Li
- Institute of Chemical and Engineering Sciences, Agency for Science, Technology and Research, 1 Pesek Road, Singapore, Jurong Island 627833 Singapore
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Novel Method Reveals a Narrow Phylogenetic Distribution of Bacterial Dispersers in Environmental Communities Exposed to Low-Hydration Conditions. Appl Environ Microbiol 2018; 84:AEM.02857-17. [PMID: 29374034 DOI: 10.1128/aem.02857-17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 01/14/2018] [Indexed: 12/20/2022] Open
Abstract
In this study, we developed a method that provides profiles of community-level surface dispersal from environmental samples under controlled hydration conditions and enables us to isolate and uncover the diversity of the fastest bacterial dispersers. The method expands on the porous surface model (PSM), previously used to monitor the dispersal of individual bacterial strains in liquid films at the surface of a porous ceramic disc. The novel procedure targets complex communities and captures the dispersed bacteria on a solid medium for growth and detection. The method was first validated by distinguishing motile Pseudomonas putida and Flavobacterium johnsoniae strains from their nonmotile mutants. Applying the method to soil and lake water bacterial communities showed that community-scale dispersal declined as conditions became drier. However, for both communities, dispersal was detected even under low-hydration conditions (matric potential, -3.1 kPa) previously proven too dry for P. putida strain KT2440 motility. We were then able to specifically recover and characterize the fastest dispersers from the inoculated communities. For both soil and lake samples, 16S rRNA gene amplicon sequencing revealed that the fastest dispersers were substantially less diverse than the total communities. The dispersing fraction of the soil microbial community was dominated by Pseudomonas species cells, which increased in abundance under low-hydration conditions, while the dispersing fraction of the lake community was dominated by Aeromonas species cells and, under wet conditions (-0.5 kPa), also by Exiguobacterium species cells. The results gained in this study bring us a step closer to assessing the dispersal ability within complex communities under environmentally relevant conditions.IMPORTANCE Dispersal is a key process of bacterial community assembly, and yet, very few attempts have been made to assess bacterial dispersal at the community level, as the focus has previously been on pure-culture studies. A crucial factor for dispersal in habitats where hydration conditions vary, such as soils, is the thickness of the liquid films surrounding solid surfaces, but little is known about how the ability to disperse in such films varies within bacterial communities. Therefore, we developed a method to profile community dispersal and identify fast dispersers on a rough surface resembling soil surfaces. Our results suggest that within the motile fraction of a bacterial community, only a minority of the bacterial types are able to disperse in the thinnest liquid films. During dry periods, these efficient dispersers can gain a significant fitness advantage through their ability to colonize new habitats ahead of the rest of the community.
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Ndlovu T, Rautenbach M, Khan S, Khan W. Variants of lipopeptides and glycolipids produced by Bacillus amyloliquefaciens and Pseudomonas aeruginosa cultured in different carbon substrates. AMB Express 2017; 7:109. [PMID: 28571307 PMCID: PMC5451376 DOI: 10.1186/s13568-017-0367-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 03/06/2017] [Indexed: 11/30/2022] Open
Abstract
The quantitative and qualitative effect of water immiscible and miscible carbon-rich substrates on the production of biosurfactants, surfactin and rhamnolipids, by Bacillus amyloliquefaciens ST34 and Pseudomonas aeruginosa ST5, respectively, was analysed. A small-scale high throughput 96 deep-well micro-culture method was utilised to cultivate the two strains in mineral salt medium (MSM) supplemented with the water miscible (glucose, glycerol, fructose and sucrose) and water immiscible carbon sources (diesel, kerosene and sunflower oil) under the same growth conditions. The biosurfactants produced by the two strains were isolated by acid precipitation followed by an organic solvent extraction. Ultra-performance liquid chromatography coupled to electrospray ionisation mass spectrometry was utilised to analyse yields and characterise the biosurfactant variants. For B. amyloliquefaciens ST34, maximum surfactin production was observed in the MSM supplemented with fructose (28 mg L−1). In addition, four surfactin analogues were produced by ST34 using the different substrates, however, the C13–C15 surfactins were dominant in all extracts. For P. aeruginosa ST5, maximum rhamnolipid production was observed in the MSM supplemented with glucose (307 mg L−1). In addition, six rhamnolipid congeners were produced by ST5 using different substrates, however, Rha–Rha–C10–C10 and Rha–C10–C10 were the most abundant in all extracts. This study highlights that the carbon sources utilised influences the yield and analogues/congeners of surfactin and rhamnolipids produced by B. amyloliquefaciens and P. aeruginosa, respectively. Additionally, glucose and fructose were suitable substrates for rhamnolipid and surfactin, produced by P. aeruginosa ST5 and B. amyloliquefaciens ST34, which can be exploited for bioremediation or as antimicrobial agents.
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Ndlovu T, Rautenbach M, Vosloo JA, Khan S, Khan W. Characterisation and antimicrobial activity of biosurfactant extracts produced by Bacillus amyloliquefaciens and Pseudomonas aeruginosa isolated from a wastewater treatment plant. AMB Express 2017; 7:108. [PMID: 28571306 PMCID: PMC5451374 DOI: 10.1186/s13568-017-0363-8] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 03/06/2017] [Indexed: 11/17/2022] Open
Abstract
Biosurfactants are unique secondary metabolites, synthesised non-ribosomally by certain bacteria, fungi and yeast, with their most promising applications as antimicrobial agents and surfactants in the medical and food industries. Naturally produced glycolipids and lipopeptides are found as a mixture of congeners, which increases their antimicrobial potency. Sensitive analysis techniques, such as liquid chromatography coupled to mass spectrometry, enable the fingerprinting of different biosurfactant congeners within a naturally produced crude extract. Bacillus amyloliquefaciens ST34 and Pseudomonas aeruginosa ST5, isolated from wastewater, were screened for biosurfactant production. Biosurfactant compounds were solvent extracted and characterised using ultra-performance liquid chromatography (UPLC) coupled to electrospray ionisation mass spectrometry (ESI-MS). Results indicated that B. amyloliquefaciens ST34 produced C13-16 surfactin analogues and their identity were confirmed by high resolution ESI-MS and UPLC-MS. In the crude extract obtained from P. aeruginosa ST5, high resolution ESI-MS linked to UPLC-MS confirmed the presence of di- and monorhamnolipid congeners, specifically Rha-Rha-C10-C10 and Rha-C10-C10, Rha-Rha-C8-C10/Rha-Rha-C10-C8 and Rha-C8-C10/Rha-C10-C8, as well as Rha-Rha-C12-C10/Rha-Rha-C10-C12 and Rha-C12-C10/Rha-C10-C12. The crude surfactin and rhamnolipid extracts also retained pronounced antimicrobial activity against a broad spectrum of opportunistic and pathogenic microorganisms, including antibiotic resistant Staphylococcus aureus and Escherichia coli strains and the pathogenic yeast Candida albicans. In addition, the rapid solvent extraction combined with UPLC-MS of the crude samples is a simple and powerful technique to provide fast, sensitive and highly specific data on the characterisation of biosurfactant compounds.
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Affiliation(s)
- Thando Ndlovu
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602 South Africa
| | - Marina Rautenbach
- BIOPEP Peptide Group, Department of Biochemistry, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602 South Africa
| | - Johann Arnold Vosloo
- BIOPEP Peptide Group, Department of Biochemistry, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602 South Africa
| | - Sehaam Khan
- Faculty of Health and Applied Sciences, Namibia University of Science and Technology, 13 Storch Street, Private Bag 13388, Windhoek, Namibia
| | - Wesaal Khan
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602 South Africa
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Hanano A, Shaban M, Almousally I. Biochemical, Molecular, and Transcriptional Highlights of the Biosynthesis of an Effective Biosurfactant Produced by Bacillus safensis PHA3, a Petroleum-Dwelling Bacteria. Front Microbiol 2017; 8:77. [PMID: 28179901 PMCID: PMC5263155 DOI: 10.3389/fmicb.2017.00077] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 01/11/2017] [Indexed: 11/13/2022] Open
Abstract
Petroleum crude oil (PCO)-dwelling microorganisms have exceptional biological capabilities to tolerate the toxicity of petroleum contaminants and are therefore promising emulsifier and/or degraders of PCO. This study describes a set of PCO-inhabiting bacterial species, one of which, identified as Bacillus safensis PHA3, produces an efficient biosurfactant which was characterized as a glycolipid. Fourier transform infrared spectrometer, nuclear magnetic resonance, Thin layer chromatography, HPLC, and GC-MS analysis of the purified biosurfactant revealed that the extracted molecule under investigation is likely a mannolipid molecule with a hydrophilic part as mannose and a hydrophobic part as hexadecanoic acid (C16:0). The data reveal that: (i) PHA3 is a potential producer of biosurfactant (9.8 ± 0.5 mg mL-1); (ii) pre-adding 0.15% of the purified glycolipid enhanced the degradation of PCO by approximately 2.5-fold; (iii) the highest emulsifying activity of biosurfactant was found against the PCO and the lowest was against the naphthalene; (iv) the optimal PCO-emulsifying activity was found at 30-60°C, pH 8 and a high salinity. An orthologous gene encodes a putative β-diglucosyldiacylglycerol synthase (β-DGS) was identified in PHA3 and its transcripts were significantly up-regulated by exogenous PAHs, i.e., pyrene and benzo(e)pyrene but much less by mid-chain n-alkanes (ALKs) and fatty acids. Subsequently, the accumulation of β-DGS transcripts coincided with an optimal growth of bacteria and a maximal accumulation of the biosurfactant. Of particular interest, we found that PHA3 actively catalyzed the degradation of PAHs notably the pyrene and benzo(e)pyrene but was much less effective in the mono-terminal oxidation of ALKs. Such characteristics make Bacillus safensis PHA3 a promising model for enhanced microbial oil recovery and environmental remediation.
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Affiliation(s)
- Abdulsamie Hanano
- Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria Damascus, Syria
| | - Mouhnad Shaban
- Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria Damascus, Syria
| | - Ibrahem Almousally
- Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria Damascus, Syria
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