Die Autoren danken dem Schweizerischen Nationalfonds Grant No. 31003A-132358/1, 31003A_152972 und No. 151948 und Fundation Pierre Mercier Pour La Science.

1. Herstellung von Chemikalien und Geräte <ol><li> Bilden 500 ml einer 1% Natriumhexametaphosphat (SHMP) (NaPO 3) n-Lösung und durch Autoklavieren sterilisieren. </li><li> Sterilisieren Nitrocellulose (NC) Filter (Porengröße 0,22 um, Durchmesser 47 mm) durch Autoklavieren in geschlossenen Glaspetrischalen. </li><li> Sterilisieren NC-Filter (Porengröße 0,22 um, Durchmesser 25 mm) durch Autoklavieren in geschlossenen Glaspetrischalen. </li><li> Wiegen und beachten Sie das Leergewicht von sterilen 50-ml-Röhrchen (mit Kappe auf) (ein Röhrchen je Probe). </li><li> Vorbereitung Tris-EDTA-Puffer (TE-Puffer) 1x: make Lösung von 10 mM Tris (Tris (hydroxymethyl) aminomethan) und 1 mM EDTA Puffer. PH-Wert auf 8 und durch Autoklavieren sterilisieren. </li><li> Vorbereitung Lysozymlösung (20 mg / ml) durch Auflösen von 0,02 g Lysozym in 1 ml TE-Puffer. Im Idealfall machen frische jeder Zeit. Lagerung bei 4 ° C für nicht mehr als 1 Woche. </li><li> Vorbereitung physiologischen Lösung durch Lösen von 8 g / l Natriumchlorid(NaCl) in destilliertem Wasser. Durch Autoklavieren sterilisieren. </li></ol> 2. Trennung von Biomasse aus Sediment <ol><li> In 3 g Sedimentprobe, um vorher gewogenes steriles 50-ml-Röhrchen unter Verwendung von Ethanol-geflammt Metall Messlöffel. Führen Sie dies in einer sauberen, UV sterilisiert Biosicherheitswerkbank, um Verunreinigungen zu vermeiden. </li><li> 15 ml einer 1% igen sterilen (autoklaviert) SHMP Lösung zu der Probe unter Verwendung eines sterilen Bürette gefüllt. Die SHMP Lösung kann auch gefiltert, um Verunreinigungen zu vermeiden. </li><li> Homogenisieren das Sediment und SHMP-Lösung mit einer Flüssigkeit Dispergierer / Homogenisator (zB Ultra-Turrax-Homogenisator). 70% Ethanol-sterilisiert oder autoklaviert Dispergierlaufrades vor der Verwendung. Führen Sie die Homogenisierung für 1 min bei 17.500 Umdrehungen pro Minute. Ließ die Probe für 2 Minuten ruhen und wiederholen die Homogenisierung für 1 min bei der gleichen Rotordrehzahl. </li><li> Lassen Sie die Probe stehen für 10 min. Bei diesem Schritt werden die schwersten Teilchen (Mineralien) zu begleichen. Die Zellen und alle organischen Bestandteile der Probe jedoch wschlecht in Lösung bleiben. Danach den Überstand (enthaltend Zellbiomasse) in ein sauberes 50-ml-Tube, während kümmert sich nicht um das Sediment Pellet stören. </li><li> Um das Sediment Pellet hinzuzufügen erneut 15 ml einer 1% igen sterilen (autoklaviert) SHMP-Lösung mit einem sterilen Bürette. Dann wiederholen Sie die Schritte 2.3 und 2.4. Diese Wiederholung sorgt für die Trennung von der maximalen Anzahl von Zellen und organische Teilchen aus der Mineralkomponente des Sediments. Der Überstand dieser zweiten Trennung kann mit dem Überstand aus der ersten Trennzusammengeführt werden. Hinweis: Die folgenden Schritte werden alle auf dem Überstand durchgeführt (die Zellbiomasse). Die mineralische Komponente (Sediment Pellet) kann verworfen werden. </li><li> Zentrifugieren Sie die Probe bei 20 g für 1 min. Dieser Schritt erhöht die Beschleunigungskraft genug, um kleine Mineralpartikel absetzen, während die biologischen Zellmaterials noch in Lösung bleibt. Nach dem Zentrifugieren den Überstand (enthaltend Zellbiomasse) in einesauberes 50-ml-Tube. Entsorgen Sie die Mineral Pellet. </li><li> Bestimmen das endgültige Volumen der Lösung, die Biomasse durch Wiegen der Probe. Die Gewichtsbestimmung wird vermieden, daß die Probe in einem Messzylinder übertragen und reduziert die Gefahr einer Kontamination. </li></ol> 3. Sammlung von Biomasse auf Filter Membrane <ol><li> Bereiten Filtrationseinheit (47 mm Durchmesser Membranen) und Vakuumpumpe. Sterilisieren Sie die Filtereinheit entweder durch Autoklavieren oder (wenn Pyrexglas) durch Besprühen mit 70% Ethanol und flamm es mit einem Bunsenbrenner. Abkühlen lassen, bevor Sie mit dem Protokoll. </li><li> In sterilen NC-Membran in die Filtrationseinheit unter Verwendung von Ethanol-geflammt sterilisierten Pinzette. </li><li> Die Hälfte des Überstandsprobe (aus Schritt 2.6) auf der Membranfiltrationseinheit und sammeln Zellen auf der Membran unter Verwendung der Vakuumpumpe. </li><li> Wenn die Flüssigkeit vollständig durch den Filter geleitet, stoppen Sie die Vakuumpumpe und entfernen Sie vorsichtig die Membran unter Verwendung von Ethanol-Flamme sterilisierten Pinzette. Legen Sie die Membran in einer sterilen Petrischale. <ol><li> Schneiden Sie die Membran in die Hälfte unter Verwendung von Ethanol-geflammt sterilisierte Schere. Fügen Sie jede Hälfte der Membran in eine separate 2-ml-Tube. Eine Hälfte der Membran für die DNA-Extraktion und Analyse der gesamten Bakteriengesellschaft verwendet werden. Die andere Hälfte der Filter wird bei -80 ° C gelagert werden und dient als eine Sicherung. </li></ol></li><li> Zeigen neuen NC-Membran auf die Filtrationseinheit und sammeln Biomasse aus der zweiten Hälfte des Probenvolumens (aus Schritt 2.6) mit der Vakuumpumpe. </li><li> Wenn die Flüssigkeit vollständig durch den Filter geleitet, stoppen Sie die Vakuumpumpe und entfernen Sie vorsichtig die Membran unter Verwendung von Ethanol-geflammt sterilisierten Pinzette. Legen Sie die gesamte Membran in eine separate 2-ml-Tube. Diese Probe wird für die Behandlung, um Endosporen von vegetativen Zellen getrennt verwendet werden. Die Probe kann bei -20ºC bis zur Verwendung gelagert werden. </li></ol> 4. Lyse von vegetativen Zellen <ol><li> Führen Sie dieBehandlung Endosporen aus vegetativen Zellen auf der zuvor auf einem NC-Membran (Schritt 3.6) gesammelt Biomasse abzutrennen. <ol><li> Wenn die Membran war gefroren, lassen Sie es bei Raumtemperatur für 10 Minuten auftauen. Dann legen Sie die Membran in einer sterilen Petrischale und schneiden Sie es (etwa 4 mal) in kleinere Stücke unter Verwendung von Ethanol-geflammt sterilisierte Schere. Dann legen Sie alle Membranfilterstücke in ein steriles 2 ml-Tube. </li></ol></li><li> Fügen Sie 900 ul 1x TE (Tris-EDTA) Puffer (siehe 1.5) auf das Rohr, das die Probenmembran und mischen durch Wirbel. Bei diesem Schritt wird die Biomasse von der Membran in der TE-Pufferlösung entfernt. </li><li> Das Röhrchen wird in einen Inkubator bei 65 ° C für 10 min und 80 min. Danach entfernen Sie den Schlauch aus dem Inkubator und abkühlen lassen für 15 Minuten. </li><li> 100 ul frisch hergestelltes Lysozym (siehe 1.5), um eine Endkonzentration von 2 mg / ml zu erreichen. Nicht das Lysozym nicht hinzufügen, bevor die Probe auf 37 ° C abgekühlt, da dies könnte degrade des Enzyms. </li><li> Inkubieren der Probe bei 37 ° C für 60 min und 80 min werden die optimalen Bedingungen für die Lysozym vegetative Zellen zu lysieren. </li><li> Nach kompletter Lyse, fügen 250 ul 3 N Natriumhydroxid (NaOH) und 250 &amp; mgr; l 6% Natriumdodecylsulfat (SDS) Lösung zu der Probe. Durch das Hinzufügen dieses, das Probevolumen 1,5 ml erreicht und es besteht eine Endkonzentration von 0,5 N NaOH und einer Endkonzentration von 1% SDS. </li><li> Inkubieren dieser Mischung bei RT für 60 min und 80 min. Zugabe der Base und Reinigungsmittel werden in endgültige Zell-Lyse zu helfen. Die Konzentration dieser Reinigungsmittel hat, um nicht die Endosporen schaden optimiert, während Lysieren vegetativen Zellen. </li><li> Bereiten Sie eine sterile Filtrationseinheit, die Durchmesser von 25 mm Membranen hält durch Autoklavieren, oder (wenn Pyrexglas) Besprühen mit 70% Ethanol und flamm es mit einem Bunsenbrenner. Abkühlen lassen. </li><li> Legen Sie eine 0,2 um NC-Membran (Durchmesser 25 mm) an der Filtrationseinheit unter Verwendung von Ethanol-Flamme sterilisierten Pinzette. &lt;/ li&gt; <li> Hinzufügen der Probe aus Schritt 4.7 auf die Membran und Filtern der Flüssigkeit unter Verwendung der Vakuumpumpe. Wenn Flüssigkeit durchlaufen hat, schalten Sie Vakuumpumpe. Bei diesem Schritt wird die lysierte vegetative Zellmaterial entfernt wird, da es nicht auf die Membran zurückgehalten. Nur Endosporen auf der Membran verbleiben. </li><li> 2 ml steriler physiologischer Lösung zu waschen Rest Wasch- und filtern Sie die Flüssigkeit mit Hilfe der Vakuumpumpe. </li><li> Wenn Flüssigkeit vollständig gefiltert wurde, schalten Sie die Vakuumpumpe. Verlassen die Membran auf der Filtrationseinheit. </li></ol> 5. DNase-Behandlung Hinweis: Führen Sie die DNase-Behandlung direkt auf der Filtermembran. Es ist wichtig, dass die Filtereinheit nicht auslaufen und die Vakuumpumpe wird abgeschaltet. <ol><li> Fügen Sie 450 ul sterilem Wasser, 50 ul DNase-Reaktionspuffer (1x) und 0,5 ul DNase Enzym direkt auf der Filtermembran und lassen Sie es für 15 Minuten stehen gelassen. Wenn möglich, tun dies die Verdauung in einem Raum, der leicht ist Kriegmer als durchschnittliche RT, da das Enzym arbeitet besser bei Temperaturen von 25 ° C und darüber. Anmerkung: Halten des Bunsenbrenners Seite der Filtereinheit erhöht auch die Temperatur und hat den zusätzlichen Vorteil, halten die Umgebung steril daher reduzierten Risiko der Kontamination der Proben. </li><li> Wenn die DNase-Verdau beendet ist, schalten Sie Vakuumpumpe, um das Enzym aus der Probe zu entfernen. </li><li> Abzuwaschen restliche Enzym durch Zusatz und Filtrieren von 1 ml physiologischer Lösung. </li><li> Wenn Flüssigkeit vollständig durchlaufen hat, schalten Sie Vakuumpumpe und entfernen Sie die Filtermembran, Endosporen mit einer sterilen Pinzette und legen Sie sie in eine sterile Petrischale. Hinweis: Die Probe getrennt Endosporen ist nun bereit für Downstream-Analyse. Lagerung bei -20 ° C, wenn für die DNA-Extraktion oder alternativ bei 4 ° C verwendet werden, wenn für die Keimung und Kultivierung verwendet. </li></ol>

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Die Autoren haben nichts zu offenbaren.

Der Widerstand der Endosporen externe aggressive physikochemische Faktoren (zB Temperatur oder Waschmittel) wurde verwendet, um ein Verfahren, um bakterielle Endosporen von vegetativen Zellen in Umweltproben getrennt entwickeln. Dies ist die erste umfassende Methode, um Endosporen aus Umweltproben in einem zerstörungsfrei zu isolieren. Früheren Methoden zu quantifizieren ist, nachzuweisen oder zu analysieren Endosporen Proben wurden über die Messung des spezifischen Proxies für Endosporen wie Dipicolinsäur...

Das Ziel dieser Arbeit besteht darin, ein Protokoll für die Abtrennung von bakteriellen Endosporen aus vegetativen Bakterienzellen in Umweltproben bereitzustellen. Die Bildung von bakteriellen Endosporen ist eine Überlebensstrategie, in der Regel durch Verhungern ausgelöst, in einer Anzahl von Bakteriengruppen zum Stamm Firmicutes 1 gehör gefunden. Endosporen-bildende Bakterien sind gut untersucht, vor allem, da eine Reihe von Stämmen sind Krankheitserreger und folglich der medizinischen Bedeutung (zB Bacillus anthracis oder Clostridium difficile). Umwelt Stämme von Endosporen-bildenden Bakterien wurden aus nahezu jedem Umfeld (Boden, Wasser, Sediment, Luft, Eis, menschlichen Darm, Tiere gut, und mehr) 1-3 isoliert. Daher sind Firmicutes das zweithäufigste Stamm in Stammsammlungen 4. Wegen ihrer hardy äußeren Rinde und Schutzkernproteine ​​können Endosporen extremen Umweltbedingungen im Bereich fr überlebenom Austrocknung zu hohe Strahlungs, extreme Temperaturen und schädliche Chemikalien 5. Diese bemerkenswerte Widerstandsfähigkeit macht es eine Herausforderung, DNA von Endosporen 6-8 extrahieren. Dies erklärt wahrscheinlich, warum sie in der Umweltsequenzierungsstudien 9,10 sehen worden. Andere Verfahren, wie die Zielrichtung Endosporen in Umweltproben durch fluoreszierende Antikörper 11, Quantifizierung von Dipicolinsäure (DPA) im Boden 12 und Sediment 13, Durchflusszytometrie 14 oder Pasteurisierung und anschließende Kultivierung 15,16 verwendet worden, um in abzurufen oder zu quantifizieren Endosporen Umweltproben. In den letzten Jahren optimierten DNA-Extraktionsverfahren als auch spezifische molekulare Primer zielen Endosporen spezifischer Gensequenzen wurden entwickelt 10,17-20. Dies hat dazu beigetragen, mehr Biodiversität in dieser Gruppe von Bakterien 21 offenbaren und hat sich auch auf Anwendungen in Industrie und Medizin zum Nachweis von Endosporen geführtZum Beispiel in Milchpulver 19. Das hier vorgestellte Protokoll basiert auf dem Unterschied in der Beständigkeit gegenüber Schad physikochemischen Bedingungen (wie Wärme und Reinigungsmittel) von bakteriellen Endosporen verglichen mit Zellen, vegetativen basiert. Vegetativen Zellen in einer Probe zu zerstören wir nacheinander erhitzen, Lysozym und niedrigen Konzentrationen von Detergentien. Die Zeit und die Kraft dieser Behandlungen sind optimiert worden, um nicht-Sporen zu zerstören, sondern um alle vegetativen Zellen lysieren. Einige Zellen in einer Umweltzellpool sind widerstandsfähiger als andere, so, um die Wahrscheinlichkeit der Zerstörung aller vegetativen Zellen zu erhöhen, verwenden wir drei verschiedene Behandlungen. Der Vorteil und die Neuheit dieses Verfahrens ist, dass die Endosporen nach der Behandlung noch intakt und kann für weitere Downstream-Analysen verwendet werden. Dazu gehören DNA-Extraktion, quantitative PCR (qPCR) und Amplikon oder Metagenom-Sequenzierung (Targeting gezielt die Gruppe der Endosporen und damit Reduzierung diversity, bei gleichzeitiger Erhöhung Deckung). Die Endosporen könnte auch für die nachgeschalteten Anbau oder die Quantifizierung durch Fluoreszenzmikroskopie verwendet werden, Durchflusszytometrie oder Detektion von DPA. Ein wichtiges Merkmal dieses Verfahrens ist, dass durch Vergleichen eines unbehandelten Probe mit einer behandelten Probe, kann man die Menge und Vielfalt von Endosporen in einer Umweltprobe zusätzlich zu der Komponente, die Zellen vegetativen abzuleiten.

<table><tbody><tr><td>Whatman nitrocellulose membrane filters, 0.2 &amp;#956;m pore size, 47 mm diameter</td><td>Sigma-Aldrich</td><td>WHA7182004 Aldrich&amp;nbsp;</td><td></td></tr><tr><td>Tris(hydroxymethyl)aminomethane</td><td>Sigma-Aldrich</td><td>252859 Sigma-Aldrich</td><td>CAS 77-86-1</td></tr><tr><td>EDTA</td><td>Sigma-Aldrich</td><td>E9884 Sigma-Aldrich</td><td>CAS&amp;nbsp; 60-00-4&amp;nbsp;</td></tr><tr><td>Lysozyme from chicken egg white</td><td>Sigma-Aldrich</td><td>62971 Fluka</td><td>powder, CAS&amp;nbsp; 12650-88-3&amp;nbsp;</td></tr><tr><td>Ultra-Turrax homogenizer T18 basic</td><td>IKA</td><td>3720000</td><td></td></tr><tr><td>Glass filter holders for 47&amp;nbsp;mm membranes, Pyrex glass</td><td>EMD Millipore</td><td>XX10 047 00</td><td></td></tr><tr><td>Chemical duty vacuum pump</td><td>Millipore</td><td>WP6122050</td><td>220 V/50 Hz</td></tr><tr><td>Manifold sampling filtration for 25&amp;nbsp;mm membranes</td><td>Millipore</td><td>1225 Sampling Manifold</td><td>polypropylene</td></tr><tr><td>Dnase</td><td>New England Biolabs</td><td>M0303S</td><td>Rnase free</td></tr><tr><td>NaOH</td><td>Sigma-Aldrich</td><td>S5881 Sigma-Aldrich</td><td>CAS&amp;nbsp; 1310-73-2&amp;nbsp;</td></tr><tr><td>Sodium dodecyl sulfphate (SDS)</td><td>Sigma-Aldrich</td><td>L3771 Sigma&amp;nbsp;</td><td></td></tr><tr><td>Whatman nitrocellulose membrane filters, 0.2 &amp;#956;m pore size, 25 mm diameter</td><td>Sigma-Aldrich</td><td>WHA7182002 Aldrich</td><td></td></tr></tbody></table>

physical isolation of endospores from environmental samples by targeted lysis of vegetative cells

Endospore formation is a survival strategy found among some bacteria from the phylum Firmicutes. During endospore formation, these bacteria enter a morpho-physiological resting state that enhances survival under adverse environmental conditions. Even though endospore-forming Firmicutes are one of the most frequently enriched and isolated bacterial groups in culturing studies, they are often absent from diversity studies based on molecular methods. The resistance of the spore core is considered one of the factors limiting the recovery of DNA from endospores. We developed a method that takes advantage of the higher resistance of endospores to separate them from other cells in a complex microbial community using physical, enzymatic and chemical lysis methods. The endospore-only preparation thus obtained can be used for re-culturing or to perform downstream analysis such as tailored DNA extraction optimized for endospores and subsequent DNA sequencing. This method, applied to sediment samples, has allowed the enrichment of endospores and after sequencing, has revealed a large diversity of endospore-formers in freshwater lake sediments. We expect that the application of this method to other samples will yield a similar outcome.

Die hier vorgestellten Ergebnisse wurden bereits veröffentlicht 10,21. Bitte für die Umwelt Interpretation und Diskussion der Daten beziehen sich auf diesen Artikel. Das Gesamtverfahren ist in Figur 1 zusammengefaßt und entspricht drei Hauptschritten: Zuerst wird die Trennung von Biomasse aus Sediment oder andere umwelt Matrix; Zweitens ist die Zerstörung von vegetativen Zellen; und drittens die nachgeschaltete Analyse der getrennten Endospore...

Watch this Scientific Journal Video about Physical Isolation of Endospores from Environmental Samples by Targeted Lysis of Vegetative Cells at JoVE.com

Physical Isolation of Endospores from Environmental Samples by Targeted Lysis of Vegetative Cells

A method to single out bacterial endospores from complex microbial communities was developed to perform tailored culture or molecular studies of this group of bacteria.

Physische Isolierung von Endospores aus Umweltproben durch gezielte Lyse von vegetativen Zellen

Endospore formation is a survival strategy found among some bacteria from the phylum Firmicutes. During endospore formation, these bacteria enter a ...

physical-isolation-endospores-from-environmental-samples-targeted

Universidad de Cartagena UDEC

Research

JoVE Journal

Environment

14.1K Aufrufe.  Macquarie University. A method to single out bacterial endospores from complex microbial communities was developed to perform tailored culture or molecular studies of this group of bacteria.

Serie: Physical Isolation of Endospores from Environmental Samples by Targeted Lysis of Vegetative Cells

Culturing and Maintaining Clostridium difficile in an Anaerobic Environment

Clostridium difficile is a Gram-positive, anaerobic, sporogenic bacterium that is primarily responsible for antibiotic associated diarrhea (AAD) and is a significant nosocomial pathogen. C. difficile is notoriously difficult to isolate and cultivate and is extremely sensitive to even low levels of oxygen in the environment. Here, methods for isolating C. difficile from fecal samples and subsequently culturing C. difficile for preparation of glycerol stocks for long-term storage are presented. Techniques for preparing and enumerating spore stocks in the laboratory for a variety of downstream applications including microscopy and animal studies are also described. These techniques necessitate an anaerobic chamber, which maintains a consistent anaerobic environment to ensure proper conditions for optimal C. difficile growth. We provide protocols for transferring materials in and out of the chamber without causing significant oxygen contamination along with suggestions for regular maintenance required to sustain the appropriate anaerobic environment for efficient and consistent C. difficile cultivation.

Culturing and Maintaining Clostridium difficile in an Anaerobic Environment

Clostridium difficile is a pathogenic bacterium that is a strict anaerobe and causes antibiotic associated diarrhea (AAD). Here, methods for isolating, culturing and maintaining C. difficile vegetative cells and spores are described. These techniques necessitate an anaerobic chamber, which requires regular maintenance to ensure proper conditions for optimal C. difficile cultivation.

Kultivierung und Pflege<em&gt; Clostridium difficile</em&gt; In einer anaeroben Umgebung

Clostridium  difficile is a Gram-positive, anaerobic, sporogenic bacterium  that is primarily responsible for antibiotic associated diarrhea (AAD) and is ...

Forschung

Immunologie und Infektion

Isolation, Propagation, and Identification of Bacterial Species with Hydrocarbon Metabolizing Properties from Aquatic Habitats

Hydrocarbon pollutants are recalcitrant to degradation and their accumulation in the environment is toxic to all life forms. Bacteria encode numerous catalytic enzymes and are naturally capable of metabolizing hydrocarbons. Scientists harness biodiversity in aquatic ecosystems to isolate bacteria with biodegradation and bioremediation potential. Such isolates from the environment provide a rich set of metabolic pathways and enzymes, which can be further utilized to scale up the degradation process at an industrial scale. In this article, we outline the general process of isolation, propagation, and identification of bacterial species from aquatic habitats and screen their ability to utilize hydrocarbons as the sole carbon source in vitro using simple techniques. The present protocol describes the isolation of various bacterial species and their subsequent identification using the 16S rRNA analysis. The protocol also presents steps for characterizing the hydrocarbon degrading potential of bacterial isolates. This protocol will be useful for researchers trying to isolate bacterial species from environmental habitats for their biotechnological applications.

We present the process of isolating, propagating, and characterizing hydrocarbon-degrading bacteria from aquatic habitats. The protocol outlines bacterial isolation, identification by the 16S rRNA method, and testing of their hydrocarbon-degrading potential. This article would help researchers in characterizing microbial biodiversity in environmental samples, and specifically screen for microbes with bioremediation potential.

Isolierung, Vermehrung und Identifizierung von Bakterienarten mit kohlenwasserstoffmetabolisierenden Eigenschaften aus aquatischen Lebensräumen

Hydrocarbon pollutants are recalcitrant to degradation and their accumulation in the environment is toxic to all life forms. Bacteria encode numerous ...

Umwelt

Detecting Cortex Fragments During Bacterial Spore Germination

The process of endospore germination in Clostridium difficile, and other Clostridia, increasingly is being found to differ from the model spore-forming bacterium, Bacillus subtilis. Germination is triggered by small molecule germinants and occurs without the need for macromolecular synthesis. Though differences exist between the mechanisms of spore germination in species of Bacillus and Clostridium, a common requirement is the hydrolysis of the peptidoglycan-like cortex which allows the spore core to swell and rehydrate. After rehydration, metabolism can begin and this, eventually, leads to outgrowth of a vegetative cell. The detection of hydrolyzed cortex fragments during spore germination can be difficult and the modifications to the previously described assays can be confusing or difficult to reproduce. Thus, based on our recent report using this assay, we detail a step-by-step protocol for the colorimetric detection of cortex fragments during bacterial spore germination.

Herein, we describe a colorimetric assay to detect the presence of reducing sugars during bacterial spore germination.

Erkennen Cortex Fragmente während der bakteriellen Sporenauskeimung

The process of endospore germination in Clostridium difficile, and other Clostridia, increasingly is being found to differ from the model spore-forming ...

Visualization of Germinosomes and the Inner Membrane in Bacillus subtilis Spores

The small size of spores and the relatively low abundance of germination proteins, cause difficulties in their microscopic analyses using epifluorescence microscopy. Super-resolution three-dimensional Structured Illumination Microscopy (3D-SIM) is a promising tool to overcome this hurdle and reveal the molecular details of the process of germination of Bacillus subtilis (B. subtilis) spores. Here, we describe the use of a modified SIMcheck (ImageJ)-assistant 3D imaging process and fluorescent reporter proteins for SIM microscopy of B. subtilis spores&#8217; germinosomes, cluster(s) of germination proteins. We also present a (standard)3D-SIM imaging procedure for FM4-64 staining of B. subtilis spore membranes. By using these procedures, we obtained unsurpassed resolution for germinosome localization and show that &#62;80% of B. subtilis KGB80 dormant spores obtained after sporulation on defined minimal MOPS medium have one or two GerD-GFP and GerKB-mCherry foci. Bright foci were also observed in FM4-64 stained spores&#8217; 3D-SIM images suggesting that inner membrane lipid domains of different fluidity likely exist. Further studies that use double labeling procedures with membrane dyes and germinosome reporter proteins to assess co-localization and thus get an optimal overview of the organization of Bacillus germination proteins in the inner spore membrane are possible.

Visualization of Germinosomes and the Inner Membrane in Bacillus subtilis Spores

Germinant receptor proteins cluster in &#8216;germinosomes&#8217; in the inner membrane of Bacillus subtilis spores. We describe a protocol using super resolution microscopy and fluorescent reporter proteins to visualize germinosomes. The protocol also identifies spore inner membrane domains that are preferentially stained with the membrane dye FM4-64.

Visualisierung von Germinosomes und die innere Membran in Bacillus Subtilis Sporen

The small size of spores and the relatively low abundance of germination proteins, cause difficulties in their microscopic analyses using epifluorescence ...

Biotechnik

Investigating the Detrimental Effects of Low Pressure Plasma Sterilization on the Survival of Bacillus subtilis Spores Using Live Cell Microscopy

Plasma sterilization is a promising alternative to conventional sterilization methods for industrial, clinical, and spaceflight purposes. Low pressure plasma (LPP) discharges contain a broad spectrum of active species, which lead to rapid microbial inactivation. To study the efficiency and mechanisms of sterilization by LPP, we use spores of the test organism Bacillus subtilis because of their extraordinary resistance against conventional sterilization procedures. We describe the production of B. subtilis spore monolayers, the sterilization process by low pressure plasma in a double inductively coupled plasma reactor, the characterization of spore morphology using scanning electron microscopy (SEM), and the analysis of germination and outgrowth of spores by live cell microscopy. A major target of plasma species is genomic material (DNA) and repair of plasma-induced DNA lesions upon spore revival is crucial for survival of the organism. Here, we study the germination capacity of spores and the role of DNA repair during spore germination and outgrowth after treatment with LPP by tracking fluorescently-labelled DNA repair proteins (RecA) with time-resolved confocal fluorescence microscopy. Treated and untreated spore monolayers are activated for germination and visualized with an inverted confocal live cell microscope over time to follow the reaction of individual spores. Our observations reveal that the fraction of germinating and outgrowing spores is dependent on the duration of LPP-treatment reaching a minimum after 120 s. RecA-YFP (yellow fluorescence protein) fluorescence was detected only in few spores and developed in all outgrowing cells with a slight elevation in LPP-treated spores. Moreover, some of the vegetative bacteria derived from LPP-treated spores showed an increase in cytoplasm and tended to lyse. The described methods for analysis of individual spores could be exemplary for the study of other aspects of spore germination and outgrowth.

Investigating the Detrimental Effects of Low Pressure Plasma Sterilization on the Survival of Bacillus subtilis Spores Using Live Cell Microscopy

This protocol illustrates the important consecutive steps required to assess the relevance of monitoring vitality parameter and DNA repair processes in reviving Bacillus subtilis spores after treatment with low pressure plasma by tracking fluorescence-labelled DNA repair proteins via time-resolved confocal microscopy and scanning electron microscopy.

Untersucht die nachteiligen Effekte der Low Druck Plasmasterilisation auf das Überleben von Bacillus Subtilis Sporen mittels Live Cell Mikroskopie

Plasma sterilization is a promising alternative to conventional sterilization methods for industrial, clinical, and spaceflight purposes. Low pressure ...

Biologie

Investigating Teliospore Germination Using Microrespiration Analysis and Microdissection

Smut fungi are the etiological agents of several devastating agricultural diseases. They are characterized by the production of teliospores, which are thick-walled dispersal agents. Teliospores can remain dormant for decades. The dormancy is characterized by low metabolic rates, paused macromolecular biosynthesis and greatly reduced levels of respiration. Upon receiving required environmental signals, teliospores germinate to produce haploid cells, which can initiate new rounds of infection. Teliospore germination is characterized by the resumption of macromolecular biosynthesis, increased respiration and dramatic morphological changes. In order to precisely measure changes in cellular respiration during the early stages of germination, we have developed a simple protocol employing a Clark-type respirometer. The later stages of germination are distinguished by specific morphological changes, but germination is asynchronous. We developed a microdissection technique that enables us to collect teliospores at distinct germination stages.

Smut fungi cause many devastating agricultural diseases. They are dispersed as dormant teliospores that germinate in response to environmental cues. We outline two methods to investigate molecular changes during germination: measuring respiration increase to detect metabolic activation and assessing changing molecular events by isolating teliospores at distinct morphological stages.

Untersuchung von Teliospore Keimen mit Microrespiration Analyse und Mikrodissektion

Smut fungi are the etiological agents of several devastating agricultural diseases. They are characterized by the production of teliospores, which are ...

Isolation and Selection of Entomopathogenic Fungi from Soil Samples and Evaluation of Fungal Virulence against Insect Pests

Entomopathogenic fungi (EPF) are one of the microbial control agents for integrated pest management. To control local or invasive pests, it is important to isolate and select indigenous EPF. Therefore, the soil bait method combined with the insect bait (mealworm, Tenebrio molitor) system was used in this study with some modifications. The isolated EPF were then subjected to the virulence test against the agricultural pest Spodoptera litura. Furthermore, the potential EPF strains were subjected to morphological and molecular identifications. In addition, the conidia production and thermotolerance assay were performed for the promising EPF strains and compared; these data were further substituted into the formula of effective conidia number (ECN) for laboratory ranking. The soil bait-mealworm system and the ECN formula can be improved by replacing insect species and integrating more stress factors for the evaluation of commercialization and field application. This protocol provides a quick and efficient approach for EPF selection and will improve the research on biological control agents.

Here we present a protocol based on the&#160;mealworm (Tenebrio molitor)-bait system that was used for isolating and selecting entomopathogenic fungi (EPF) from soil samples. An effective conidia number (ECN) formula is used to select high stress tolerant EPF based on physiological characteristics for pest microbial control in the field.

Isolierung und Selektion entomopathogener Pilze aus Bodenproben und Bewertung der Pilzvirulenz gegen Schadinsekten

Entomopathogenic fungi (EPF) are one of the microbial control agents for integrated pest management. To control local or invasive pests, it is important ...

Comparison of Methods for Isolating Entomopathogenic Fungi from Soil Samples

The goal of the present study is to compare the effectiveness of using insect baits versus artificial selective medium for isolating entomopathogenic fungi (EPF) from soil samples. The soil is a rich habitat for microorganisms, including EPF particularly belonging to the genera Metarhizium and Beauveria, which can regulate arthropod pests. Biological products based on fungi are available in the market mainly for agricultural arthropod pest control. Nevertheless, despite the high endemic biodiversity, only a few strains are used in commercial bioproducts worldwide. In the present study, 524 soil samples were cultured on potato dextrose agar enriched with yeast extract supplemented with chloramphenicol, thiabendazole, and cycloheximide (CTC medium). The growth of fungal colonies was observed for 3 weeks. All Metarhizium and Beauveria EPF were morphologically identified at the genus level. Additionally, some isolates were molecularly identified at the species level. Twenty-four out of these 524 soil samples were also surveyed for EPF occurrence using the insect bait method (Galleria mellonella and Tenebrio molitor). A total of 51 EPF strains were isolated (41 Metarhizium spp. and 10 Beauveria spp.) from the 524 soil samples. All fungal strains were isolated either from croplands or grasslands. Of the 24 samples selected for comparison, 91.7% were positive for EPF using Galleria bait, 62.5% using Tenebrio bait, and 41.7% using CTC. Our results suggested that using insect baits to isolate the EPF from the soil is more efficient than using the CTC medium. The comparison of isolation methods in addition to the identification and conservation of EPF has a positive impact on the knowledge about biodiversity. The improvement of EPF collection supports scientific development and technological innovation.

Entomopathogenic fungal colonies are isolated from tropical soil samples using Tenebrio bait, Galleria bait, as well as selective artificial medium, i.e., potato dextrose agar enriched with yeast extract supplemented with chloramphenicol, thiabendazole, and cycloheximide (CTC medium).

Vergleich von Methoden zur Isolierung entomopathogener Pilze aus Bodenproben

The goal of the present study is to compare the effectiveness of using insect baits versus artificial selective medium for isolating entomopathogenic ...

Isolation of Culturable Yeasts and Molds from Soils to Investigate Fungal Population Structure

Soil is host to an incredible amount of microbial life, with each gram containing up to billions of bacterial, archaeal, and fungal cells. Multicellular fungi such as molds and unicellular fungi, broadly defined as yeasts, fulfill essential roles in soil ecosystems as decomposers of organic material and as food sources for other soil dwellers. Fungal species diversity in soil is dependent on a multitude of climatic factors such as rainfall and temperature, as well as soil properties including organic matter, pH, and moisture. Lack of adequate environmental sampling, especially in regions of Asia, Africa, South America, and Central America, hinders the characterization of soil fungal communities and the discovery of novel species. 
We characterized soil fungal communities in nine countries across six continents using ~4,000 soil samples and a protocol developed in the laboratory for the isolation of yeasts and molds. This protocol begins with separate selective enrichment for yeasts and the medically relevant mold Aspergillus fumigatus, in liquid media while inhibiting bacterial growth. Resulting colonies are then transferred to solid media and further processed to obtain pure cultures, followed by downstream genetic characterization. Yeast species identity is established via sequencing of their internal transcribed spacer (ITS) region of the nuclear ribosomal RNA gene cluster, while global population structure of A. fumigatus is explored via microsatellite marker analysis. 
The protocol was successfully applied to isolate and characterize soil yeast and A. fumigatus populations in Cameroon, Canada, China, Costa Rica, Iceland, Peru, New Zealand, and Saudi Arabia. These findings revealed much-needed insights on global patterns in soil yeast diversity, as well as global population structure and antifungal resistance profiles of A. fumigatus. This paper presents the method of isolating both yeasts and A. fumigatus from international soil samples.

This protocol is an effective, speedy method of culturing yeasts and the mold Aspergillus fumigatus from large sets of soil samples in as little as 7 days. The methods can be easily modified to accommodate a range of incubation media and temperatures as needed for experiments.

Isolierung von kultivierbaren Hefen und Schimmelpilzen aus Böden zur Untersuchung der Pilzpopulationsstruktur

Soil is host to an incredible amount of microbial life, with each gram containing up to billions of bacterial, archaeal, and fungal cells. Multicellular ...

Isolation, Characterization, and Total DNA Extraction to Identify Endophytic Fungi in Mycoheterotrophic Plants

Mycoheterotrophic plants present one of the most extreme forms of mycorrhizal dependency, having totally lost their autotrophic capacity. As essential as any other vital resource, the fungi with which these plants intimately associate are essential for them. Hence, some of the most relevant techniques in studying mycoheterotrophic species are the ones that enable the investigation of associated fungi, especially those inhabiting roots and subterranean organs. In this context, techniques for identifying culture-dependent and culture-independent endophytic fungi are commonly applied. Isolating fungal endophytes provides a means for morphologically identifying them, analyzing their diversity, and maintaining inocula for applications in the symbiotic germination of orchid seeds. However, it is known that there is a large variety of non-culturable fungi inhabiting plant tissues. Thus, culture-independent molecular identification techniques offer a broader cover of species diversity and abundance. This article aims to provide the methodological support necessary for starting two investigation procedures: a culture-dependent and an independent one. Regarding the culture-dependent protocol, the processes of collecting and maintaining plant samples from collection sites to laboratory facilities are detailed, along with isolating filamentous fungi from subterranean and aerial organs of mycoheterotrophic plants, keeping a collection of isolates, morphologically characterizing hyphae by slide culture methodology, and molecular identification of fungi by total DNA extraction. Encompassing culture-independent methodologies, the detailed procedures include collecting plant samples for metagenomic analyses and total DNA extraction from achlorophyllous plant organs using a commercial kit. Finally, continuity protocols (e.g., polymerase chain reaction [PCR], sequencing) are also suggested for analyses, and techniques are presented here.

The current article aims to provide detailed and adequate protocols for the isolation of plant-associated endophytic fungi, long-term preservation of isolates, morphological characterization, and total DNA extraction for subsequent molecular identification and metagenomic analyses.

Isolierung, Charakterisierung und Gesamt-DNA-Extraktion zur Identifizierung endophytischer Pilze in mykoheterotrophen Pflanzen

Mycoheterotrophic plants present one of the most extreme forms of mycorrhizal dependency, having totally lost their autotrophic capacity. As essential as ...