Name: scalable isolation and purification of extracellular vesicles from escherichia coli and other bacteria
Uploaded: 2021-10-13T15:00:00
Description: Watch this Scientific Journal Video about Scalable Isolation and Purification of Extracellular Vesicles from Escherichia coli and Other Bacteria at JoVE.com

The research described above was supported by NIH TL1 TR002549-03 training grant. We thank Drs. John C. Tilton and Zachary Troyer (Case Western Reserve University) for facilitating access to the particle size analyzer instrument; Lew Brown (Spectradyne) for technical assistance with analysis of the particle size distribution data; Dr. David Putnam at Cornell University for providing pClyA-GFP plasmid14; and Dr. Mark Goulian at the University of Pennsylvania for providing us with the E. coli MP113.

NOTE: Ensure that all work involving bacteria and recombinant DNA follows best practices for biosafety containment appropriate for the biosafety hazard level of each strain. Work should be done in accordance with local, national, and international biosafety regulations.
1. Bacterial strains and culturing conditions
NOTE: Bacterial strains used in this study were Escherichia coli MP113, Akkermansia mucinophila,...

<ol>
	<li>Yanez-Mo, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biological+properties+of+extracellular+vesicles+and+their+physiological+functions.">Biological properties of extracellular vesicles and their physiological functions.</a> Journal of Extracellular Vesicles. 4, 27066 (2015).</li><li>Chatterjee, S. N., Das, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electron+microscopic+observations+on+the+excretion+of+cell-wall+material+by+Vibrio+cholerae.">Electron microscopic observations on the excretion of cell-wall material by Vibrio cholerae.</a> Journal of General Microbiology. 49 (1), 1-11 (1967).</li><li>Ciofu, O., Beveridge, T. J., Kadurugamuwa, J., Walther-Rasmussen, J., Hoiby, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chromosomal+beta-lactamase+is+packaged+into+membrane+vesicles+and+secreted+from+Pseudomonas+aeruginosa.">Chromosomal beta-lactamase is packaged into membrane vesicles and secreted from Pseudomonas aeruginosa.</a> Journal of Antimicrobial Chemotherapy. 45 (1), 9-13 (2000).</li><li>Yonezawa, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Outer+membrane+vesicles+of+Helicobacter+pylori+TK1402+are+involved+in+biofilm+formation.">Outer membrane vesicles of Helicobacter pylori TK1402 are involved in biofilm formation.</a> BMC Microbiology. 9, 197 (2009).</li><li>Mashburn, L. M., Whiteley, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Membrane+vesicles+traffic+signals+and+facilitate+group+activities+in+a+prokaryote.">Membrane vesicles traffic signals and facilitate group activities in a prokaryote.</a> Nature. 437 (7057), 422-425 (2005).</li><li>Kato, S., Kowashi, Y., Demuth, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Outer+membrane-like+vesicles+secreted+by+Actinobacillus+actinomycetemcomitans+are+enriched+in+leukotoxin.">Outer membrane-like vesicles secreted by Actinobacillus actinomycetemcomitans are enriched in leukotoxin.</a> Microbial Pathogenesis. 32 (1), 1-13 (2002).</li><li>Petousis-Harris, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effectiveness+of+a+group+B+outer+membrane+vesicle+meningococcal+vaccine+against+gonorrhoea+in+New+Zealand:+a+retrospective+case-control+study.">Effectiveness of a group B outer membrane vesicle meningococcal vaccine against gonorrhoea in New Zealand: a retrospective case-control study.</a> Lancet. 390 (10102), 1603-1610 (2017).</li><li>Kim, O. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bacterial+outer+membrane+vesicles+suppress+tumor+by+interferon-gamma-mediated+antitumor+response.">Bacterial outer membrane vesicles suppress tumor by interferon-gamma-mediated antitumor response.</a> Nature Communications. 8 (1), 626 (2017).</li><li>Thery, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Minimal+information+for+studies+of+extracellular+vesicles+2018+(MISEV2018):+a+position+statement+of+the+International+Society+for+Extracellular+Vesicles+and+update+of+the+MISEV2014+guidelines.">Minimal information for studies of extracellular vesicles 2018 (MISEV2018): a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines.</a> Journal of Extracellular Vesicles. 7 (1), 1535750 (2018).</li><li>Consortium, E. -. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=EV-TRACK:+transparent+reporting+and+centralizing+knowledge+in+extracellular+vesicle+research.">EV-TRACK: transparent reporting and centralizing knowledge in extracellular vesicle research.</a> Nature Methods. 14 (3), 228-232 (2017).</li><li>Watson, D. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+production+and+enhanced+tumor+delivery+of+engineered+extracellular+vesicles.">Efficient production and enhanced tumor delivery of engineered extracellular vesicles.</a> Biomaterials. 105, 195-205 (2016).</li><li>Watson, D. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Scalable,+cGMP-compatible+purification+of+extracellular+vesicles+carrying+bioactive+human+heterodimeric+IL-15/lactadherin+complexes.">Scalable, cGMP-compatible purification of extracellular vesicles carrying bioactive human heterodimeric IL-15/lactadherin complexes.</a> Journal of Extracellular Vesicles. 7 (1), 1442088 (2018).</li><li>Lasaro, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Escherichia+coli+isolate+for+studying+colonization+of+the+mouse+intestine+and+its+application+to+two-component+signaling+knockouts.">Escherichia coli isolate for studying colonization of the mouse intestine and its application to two-component signaling knockouts.</a> Journal of Bacteriology. 196 (9), 1723-1732 (2014).</li><li>Kim, J. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Engineered+bacterial+outer+membrane+vesicles+with+enhanced+functionality.">Engineered bacterial outer membrane vesicles with enhanced functionality.</a> Journal of Molecular Biology. 380 (1), 51-66 (2008).</li><li>Beveridge, T. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structures+of+gram-negative+cell+walls+and+their+derived+membrane+vesicles.">Structures of gram-negative cell walls and their derived membrane vesicles.</a> Journal of Bacteriology. 181 (16), 4725-4733 (1999).</li><li>Reimer, S. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+analysis+of+outer+membrane+vesicle+isolation+methods+with+an+Escherichia+coli+tolA+mutant+reveals+a+hypervesiculating+phenotype+with+outer-inner+membrane+vesicle+content.">Comparative analysis of outer membrane vesicle isolation methods with an Escherichia coli tolA mutant reveals a hypervesiculating phenotype with outer-inner membrane vesicle content.</a> Frontiers in Microbiology. 12, 628801 (2021).</li></ol>

In the protocol above, a method is described that is scalable and reliably isolates EVs from various gram-negative/positive and aerobic/anaerobic bacteria. It has several potential stopping points throughout the procedure, although it is better to avoid taking longer than 48 h to isolate EVs from conditioned bacterial culture media.
First, it consists of culturing bacteria to generate conditioned bacterial culture medium. It was found that increasing the culture time to at least 48 h and using...

Extracellular vesicles (EVs) are nanometer-sized, liposome-like structures comprised of lipids, proteins, glycans, and nucleic acids, secreted by both prokaryotic and eukaryotic cells1. Since the early studies visualizing the release of EVs from gram-negative bacteria2, the number of biological functions attributed to bacterial EVs (20-300 nm in diameter) has constantly been growing in the past decades. Their functions include transferring antibiotic resistance3, biofilm formation4, quorum sensing5, and toxin delivery6. There is also growing interest in the use of bacterial EVs as therapeutics, especially in vaccinology7 and cancer therapy8.
Despite the growing interest in EV research, there are still technical challenges regarding methods of isolation. Specifically, there is a need for isolation methods that are reproducible, scalable, and compatible with diverse EV-producing organisms. To create a unified set of principles for planning and reporting EV isolation and research methods, the International Society for Extracellular Vesicles publishes and updates the MISEV position paper9. Moreover, the EV-TRACK consortium provides an open platform for reporting detailed methodologies for EV isolation used in published manuscripts to enhance transparency10.
In this protocol, previous methodologies used for the isolation of EVs from mammalian cell culture were adapted11,12 to enable the isolation of EVs from bacterial cell culture. We sought to employ methods that enable EV isolation from a variety of microbes, which can be scalable, and balance EV purity and yield (as discussed in the MISEV position paper9). After removing bacterial cells and debris by centrifugation and filtration, the culture medium is concentrated either by centrifugal device ultrafiltration (for a volume of up to ~100 mL) or pump-driven TFF (for larger volumes). EVs are then isolated by SEC using columns optimized for the purification of small EVs.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/63155/63155fig01.jpg" /> 
Figure 1: Bacterial EV isolation workflow schematic overview. Abbreviations: EV = extracellular vesicle; TFF = tangential flow filtration; SEC = size exclusion chromatography; MWCO = molecular weight cut-off. <a href="https://www.jove.com/files/ftp_upload/63155/63155fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
A mouse-commensal strain of Escherichia coli (i.e., E. coli MP113) was used as a model organism and modified to express EV-associated nanoluciferase by fusion to cytolysin A, as previously reported14. The methods used here can process at least up to several liters of bacterial cultures and effectively separate EV-associated from non-EV-associated proteins. Finally, this method can also be used for other gram-positive and gram-negative bacterial species. All relevant data of the reported experiments were submitted to the EV-TRACK knowledgebase (EV-TRACK ID: EV210211)10.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>0.5 mL flat cap, thin-walled PCR tubes</td>
			<td>Thermo Scientific</td>
			<td>3430</td>
			<td>it is important to use thin-walled PCR tubes to obtain accurate readings with Qubit</td>
		</tr>
		<tr>
			<td>16% Paraformaldehyde (formaldehyde) aqueous solution</td>
			<td>Electron microscopy sciences</td>
			<td>15700</td>
			<td></td>
		</tr>
		<tr>
			<td>250 mL Fiberlite polypropylene centrifuge bottles</td>
			<td>ThermoFisher</td>
			<td>010-1495</td>
			<td></td>
		</tr>
		<tr>
			<td>500 mL Fiberlite polypropylene centrifuge bottles</td>
			<td>ThermoFisher</td>
			<td>010-1493</td>
			<td></td>
		</tr>
		<tr>
			<td>65 mm Polypropylene Round-Bottom/Conical Bottle Adapter</td>
			<td>Beckman Coulter</td>
			<td>392077</td>
			<td>Allows Vivacell to fit in rotor</td>
		</tr>
		<tr>
			<td>Akkermansia mucinophila</td>
			<td>ATCC</td>
			<td>BAA-835</td>
			<td></td>
		</tr>
		<tr>
			<td>Amicon-15 (100 kDa MWCO)</td>
			<td>MilliporeSigma</td>
			<td>UFC910024</td>
			<td></td>
		</tr>
		<tr>
			<td>Avanti J-20 XPI centrifuge</td>
			<td>Beckman Coulter</td>
			<td></td>
			<td>No longer sold by Beckman. Avanti J-26XP is closest contemporary model.</td>
		</tr>
		<tr>
			<td>Bacteroides thetaiotaomicron VPI 5482</td>
			<td>ATCC</td>
			<td>29148</td>
			<td></td>
		</tr>
		<tr>
			<td>Bifidobacterium breve</td>
			<td>NCIMB</td>
			<td>B8807</td>
			<td></td>
		</tr>
		<tr>
			<td>Bifidobacterium dentium</td>
			<td>ATCC</td>
			<td>27678</td>
			<td></td>
		</tr>
		<tr>
			<td>Brain Heart infusion (BHI) broth</td>
			<td>Himedia</td>
			<td>M2101</td>
			<td>After autoclaving, Both BHI broth and agar were introduced into the anaerobic chamber, supplemented with Menadione (1 &#181;g/L), hematin (1.2 &#181;g/L), and L-Cysteine Hydrochloride (0.05%). They were then incubated for at least 24 h under anaerobic conditions before inoculation with the anaerobic bacterial strains.</td>
		</tr>
		<tr>
			<td>C-300 microfluidics cartridge</td>
			<td>Spectradyne</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Chloramphenicol</td>
			<td>MP Biomedicals</td>
			<td>ICN19032105</td>
			<td></td>
		</tr>
		<tr>
			<td>Escherichia coli HST08 (Steller competent cells)</td>
			<td>Takara</td>
			<td>636763</td>
			<td></td>
		</tr>
		<tr>
			<td>Escherichia coli MP1</td>
			<td>Dr. Mark Goulian (gift)</td>
			<td></td>
			<td>commensal bacteria derived from mouse gut</td>
		</tr>
		<tr>
			<td>Fiberlite 500 mL to 250 mL adapter</td>
			<td>ThermoFisher</td>
			<td>010-0151-05</td>
			<td>used with Fiberlite rotor to enable 250 mL bottles to be used for smaller size of starting bacterial culture</td>
		</tr>
		<tr>
			<td>Fiberlite fixed-angle centrifuge rotor</td>
			<td>ThermoFisher</td>
			<td>F12-6x500-LEX</td>
			<td>fits 6 x 500 mL bottles</td>
		</tr>
		<tr>
			<td>Formvar Carbon Film 400 Mesh, Copper</td>
			<td>Electron microscopy sciences</td>
			<td>FCF-400-CU</td>
			<td></td>
		</tr>
		<tr>
			<td>Glutaraldehyde (EM-grade, 10% aqeous solution)</td>
			<td>Electron microscopy sciences</td>
			<td>16100</td>
			<td></td>
		</tr>
		<tr>
			<td>Hematin</td>
			<td>ChemCruz</td>
			<td>207729B</td>
			<td>Stock solution was made in 0.2 M L-histidine solution as&#160; 1.2 mg/mL</td>
		</tr>
		<tr>
			<td>Infinite M Nano+ Microplate reader</td>
			<td>Tecan</td>
			<td></td>
			<td>This equibment was used to measure the mCherry fluorescence</td>
		</tr>
		<tr>
			<td>In-Fusion&#160; HD Cloning Plus</td>
			<td>Takara</td>
			<td>638909</td>
			<td>For cloning of the PCR fragements into the PCR-lineraized vectors</td>
		</tr>
		<tr>
			<td>JS-5.3 AllSpin Swinging-Bucket Rotor</td>
			<td>Beckman Coulter</td>
			<td>368690</td>
			<td></td>
		</tr>
		<tr>
			<td>Lauria Bertani (LB) broth, Miller</td>
			<td>Difco</td>
			<td>244620</td>
			<td></td>
		</tr>
		<tr>
			<td>L-Cysteine Hydrochloride</td>
			<td>J.T. Baker</td>
			<td>2071-05</td>
			<td>It should be weighed and added directly to the autoclaved BHI media inside the anaerobic chamber</td>
		</tr>
		<tr>
			<td>Masterflex Fitting, Polypropylene, Straight, Female Luer to Hose Barb Adapter, 1/8&#34; ID; 25/PK</td>
			<td>cole-parmer - special</td>
			<td>HV-30800-08</td>
			<td>connection adapters for filtration tubing circuit</td>
		</tr>
		<tr>
			<td>Masterflex Fitting, Polypropylene, Straight, Male Luer to Hose Barb Adapter, 1/8&#34; ID; 25/PK</td>
			<td>cole-parmer - special</td>
			<td>HV-30800-24</td>
			<td>connection adapters for filtration tubing circuit</td>
		</tr>
		<tr>
			<td>Masterflex L/S Analog Variable-Speed Console Drive, 20 to 600 rpm</td>
			<td>Masterflex</td>
			<td>HV-07555-00</td>
			<td></td>
		</tr>
		<tr>
			<td>Masterflex L/S Easy-Load Head for Precision Tubing, 4-Roller, PARA Housing, SS Rotor</td>
			<td>Masterflex</td>
			<td>EW-07514-10</td>
			<td></td>
		</tr>
		<tr>
			<td>Masterflex L/S Precision Pump Tubing, PharmaPure, L/S 16; 25 ft</td>
			<td>Cole Palmer</td>
			<td>EW-06435-16</td>
			<td>low-binding/low-leaching tubing</td>
		</tr>
		<tr>
			<td>Menadione (Vitamin K3)</td>
			<td>MP</td>
			<td>102259</td>
			<td>Stock solution was made in ethanol as 1 mg/mL</td>
		</tr>
		<tr>
			<td>MIDIKROS 41.5CM 100K MPES 0.5MM FLL X FLL 1/PK</td>
			<td>Repligen</td>
			<td>D04-E100-05-N</td>
			<td>TFF device we have used to filter up to 2 L of E. coli culture supernatant</td>
		</tr>
		<tr>
			<td>Nano-Glo Luciferase Assay System</td>
			<td>Promega</td>
			<td>N1110</td>
			<td>This assay kit was used to measure the luminescence of the nluc reporter protein</td>
		</tr>
		<tr>
			<td>NanoLuc (Nluc) Luciferase Antibody, clone 965808</td>
			<td>R&#38;D Systems</td>
			<td>MAB10026</td>
			<td></td>
		</tr>
		<tr>
			<td>nCS1 microfluidics resistive pulse sensing instrument</td>
			<td>Spectradyne</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>nCS1 Viewer</td>
			<td>Spectradyne</td>
			<td></td>
			<td>Analysis software for particle size distribution</td>
		</tr>
		<tr>
			<td>OneTaq 2x Master Mix with Standard Buffer</td>
			<td>NEB</td>
			<td>M0482</td>
			<td>DNA polymerase master mix used to perform the routine PCR reactions for colony checking</td>
		</tr>
		<tr>
			<td>Protein LoBind, 2.0 mL, PCR clean tubes</td>
			<td>Eppendorf</td>
			<td>30108450</td>
			<td></td>
		</tr>
		<tr>
			<td>Q5 High-Fidelity 2x Master Mix</td>
			<td>NEB</td>
			<td>M0492</td>
			<td>DNA polymerase master mix used to perform the PCR reactions needed for cloning</td>
		</tr>
		<tr>
			<td>qEV original, 35 nm</td>
			<td>Izon</td>
			<td></td>
			<td>maximal loading volume of 0.5 mL</td>
		</tr>
		<tr>
			<td>qEV rack</td>
			<td>Izon</td>
			<td></td>
			<td>for use with the qEV-original SEC columns</td>
		</tr>
		<tr>
			<td>qEV-2, 35 nm</td>
			<td>Izon</td>
			<td></td>
			<td>maximal loading volume of 2 mL</td>
		</tr>
		<tr>
			<td>Qubit fluorometer</td>
			<td>ThermoFisher</td>
			<td></td>
			<td>Item no longer available. Closest available product is Qubit 4.0 Fluorometer (cat. No. Q33238)</td>
		</tr>
		<tr>
			<td>Qubit protein assay kit</td>
			<td>ThermoFisher</td>
			<td>Q33211</td>
			<td>Store kit at room temperature. Standards are stored at 4 &#176;C.</td>
		</tr>
		<tr>
			<td>Sorvall Lynx 4000 centrifuge</td>
			<td>ThermoFisher</td>
			<td>75006580</td>
			<td></td>
		</tr>
		<tr>
			<td>SpectraMax i3x Microplate reader</td>
			<td>Molecular Devices</td>
			<td></td>
			<td>This equipment was used to measure the nanoluciferase bioluminescence</td>
		</tr>
		<tr>
			<td>Stericup Quick-release-GP Sterile Vacuum Filtration system (150, 250, or 500 mL)</td>
			<td>MilliporeSigma</td>
			<td>S2GPU01RE 
			S2GPU02RE 
			S2GPU05RE</td>
			<td>One or multiple filters can be used to accommodate working volumes. In our experience, you can filter twice the volume listed on the product size.</td>
		</tr>
		<tr>
			<td>Uranyl acetate</td>
			<td>Electron microscopy sciences</td>
			<td>22400</td>
			<td></td>
		</tr>
		<tr>
			<td>Vinyl anaerobic chamber</td>
			<td>Coy Lab</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Vivacell 100, 100,000 MWCO PES</td>
			<td>Sartorius</td>
			<td>VC1042</td>
			<td></td>
		</tr>
		<tr>
			<td>Whatman Anotop 10 Plus syringe filters (0.02 micron)</td>
			<td>MilliporeSigma</td>
			<td>WHA68093002</td>
			<td>to filter MRPS diluent</td>
		</tr>
	</tbody>
</table>

scalable isolation and purification of extracellular vesicles from escherichia coli and other bacteria

Diverse bacterial species secrete ~20-300 nm extracellular vesicles (EVs), comprised of lipids, proteins, nucleic acids, glycans, and other molecules derived from the parental cells. EVs function as intra- and inter-species communication vectors while also contributing to the interaction between bacteria and host organisms in the context of infection and colonization. Given the multitude of functions attributed to EVs in health and disease, there is a growing interest in isolating EVs for in vitro and in vivo studies. It was hypothesized that the separation of EVs based on physical properties, namely size, would facilitate the isolation of vesicles from diverse bacterial cultures. 
The isolation workflow consists of centrifugation, filtration, ultrafiltration, and size-exclusion chromatography (SEC) for the isolation of EVs from bacterial cultures. A pump-driven tangential flow filtration (TFF) step was incorporated to enhance scalability, enabling the isolation of material from liters of starting cell culture. Escherichia coli was used as a model system expressing EV-associated nanoluciferase and non-EV-associated mCherry as reporter proteins. The nanoluciferase was targeted to the EVs by fusing its N-terminus with cytolysin A. Early chromatography fractions containing 20-100 nm EVs with associated cytolysin A - nanoLuc were distinct from the later fractions containing the free proteins. The presence of EV-associated nanoluciferase was confirmed by immunogold labeling and transmission electron microscopy. This EV isolation workflow is applicable to other human gut-associated gram-negative and gram-positive bacterial species. In conclusion, combining centrifugation, filtration, ultrafiltration/TFF, and SEC enables scalable isolation of EVs from diverse bacterial species. Employing a standardized isolation workflow will facilitate comparative studies of microbial EVs across species.

To assess which SEC chromatography fractions were enriched for EVs, the SEC column was loaded with 2 mL of E. coli MP1-conditioned culture medium that had been concentrated 1,000-fold by TFF, and sequential fractions were collected. Using MRPS, it was found that Fractions 1-6 contained the most EVs (Figure 2A). Subsequent fractions contained very few EVs, comprising instead of EV-free proteins (Figure 2B). EVs were primarily &#60;100 nm in diameter (<st...

Watch this Scientific Journal Video about Scalable Isolation and Purification of Extracellular Vesicles from Escherichia coli and Other Bacteria at JoVE.com

Scalable Isolation and Purification of Extracellular Vesicles from Escherichia coli and Other Bacteria

Bacteria secrete nanometer-sized extracellular vesicles (EVs) carrying bioactive biological molecules. EV research focuses on understanding their biogenesis, role in microbe-microbe and host-microbe interactions and disease, as well as their potential therapeutic applications. A workflow for scalable isolation of EVs from various bacteria is presented to facilitate standardization of EV research.

Scalable Isolation and Purification of Extracellular Vesicles from Escherichia coli and Other Bacteria

Diverse bacterial species secrete ~20-300 nm extracellular vesicles (EVs), comprised of lipids, proteins, nucleic acids, glycans, and other molecules ...

Research

JoVE Journal

Biology

High Throughput Screening of Fungal Endoglucanase Activity in Escherichia coli

High Throughput Screening of Fungal Endoglucanase Activity in Escherichia coli

Cellulase enzymes (endoglucanases, cellobiohydrolases, and &beta;-glucosidases) hydrolyze cellulose into component sugars, which in turn can be converted ...

Isolation and Purification of Kinesin from Drosophila Embryos

Isolation and Purification of Kinesin from Drosophila Embryos

Motor proteins move cargos along microtubules, and transport them to specific sub-cellular locations. Because altered transport is suggested to underlie a ...

Identification of Protein Complexes in Escherichia coli using Sequential Peptide Affinity Purification in Combination with Tandem Mass Spectrometry

Identification of Protein Complexes in Escherichia coli using Sequential Peptide Affinity Purification in Combination with Tandem Mass Spectrometry

Since most cellular processes are mediated by macromolecular assemblies, the systematic identification of protein-protein interactions (PPI) and the ...

Rapid Protocol for Preparation of Electrocompetent Escherichia coli and Vibrio cholerae

Rapid Protocol for Preparation of Electrocompetent Escherichia coli and Vibrio cholerae

Electroporation has become a widely used method for rapidly and efficiently introducing foreign DNA into a wide range of cells. Electrotransformation has ...

Non-chromatographic Purification of Recombinant Elastin-like Polypeptides and their Fusions with Peptides and Proteins from Escherichia coli

Non-chromatographic Purification of Recombinant Elastin-like Polypeptides and their Fusions with Peptides and Proteins from Escherichia coli

Elastin-like polypeptides are repetitive biopolymers that exhibit a lower critical solution temperature phase transition behavior, existing as soluble ...

A Rapid, Scalable Method for the Isolation, Functional Study, and Analysis of Cell-derived Extracellular Matrix

The extracellular matrix (ECM) is recognized as a diverse, dynamic, and complex environment that is involved in multiple cell-physiological and ...

Flow Cytometric Analysis of Extracellular Vesicles from Cell-conditioned Media

Flow cytometry (FC) is the method of choice for semi-quantitative measurement of cell-surface antigen markers. Recently, this technique has been used for ...

Purification and Analysis of Caenorhabditis elegans Extracellular Vesicles

Purification and Analysis of Caenorhabditis elegans Extracellular Vesicles

The secretion of small membrane-bound vesicles into the external environment is a fundamental physiological process of all cells. These extracellular ...

Isolation and Characterization of Cyanobacterial Extracellular Vesicles

Cyanobacteria are a diverse group of photosynthetic, Gram-negative bacteria that play critical roles in global ecosystems and serve as essential ...

Isolation of microRNAs from Tick Ex Vivo Salivary Gland Cultures and Extracellular Vesicles

Isolation of microRNAs from Tick Ex Vivo Salivary Gland Cultures and Extracellular Vesicles

Ticks are important ectoparasites that can vector multiple pathogens. The salivary glands of ticks are essential for feeding as their saliva contains many ...