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Penicillium

a common genus with more than 250 species two ascomycetous teleomorphs (Talaromyces and Eupenicillium) has preference for moderate and colder climates spoilage agents, industrial application, mycotoxins Only a few species are pathogenic

Identification of Penicillium

Overview of presentation

· Macro-morphology: Colony color (obverse/reverse) Colony size Exudate Soluble pigment · Micro-morphology: Branching pattern Shape phialide · Ehrlich test

Colony colors and diameters in various Penicillium species - obverse

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Various colony diameters in Penicillium

Reverse in various Penicillium species

Soluble pigment production in Penicillium

Exudate production in Penicillium

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Summery of presentation I

· Macro-morphology: Colony color (obverse/reverse) Colony size Exudate Soluble pigment · Micro-morphology: Branching pattern Shape phialide · Ehrlich test

Flask-shaped

Paecilomyces

Lanceolate = acerose

conidia

phialides

conidia Stipe

Penicillium conidiophore = Penicillus

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Branching patterns Penicillium

Penicillium glabrum Monoverticillate OR simple

Penicillium citrinum Biverticillate OR One-stage branched

Penicillium brevicompactum

Terverticillate or Two-staged branched

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Penicillium aurantiogriseum

Terverticillate or Two-staged branched

Flask-shaped

Paecilomyces

Lanceolate = acerose

Paecilomyces

· Phialides with broad base and long narrow neck · Conidiophore branching irregularly · Cultures mostly not green · Thermophilic

Paecilomyces variotii

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Penicillium Biverticillium

· Penicillus biverticillate = one-staged branched · Phialides acerose = lanceolate

Flask-shaped phialides

CREA: Creatine Sucrose agar

Cultivation for identification

· Czapek (Yeast) agar (CZ/CYA): macro-morphology · Malt Extract Agar (MEA): macro- and micromorphology · Creatine agar (CREA), used for identification of terverticillate Penicillia · Yeast Extract Agar (YES), used only in the synoptic key, only macro-morphology · Incubation 7 days at 25°C

Creatine(1 H2O) Sucrose KCl MgSO4.7H2O FeSO4.7H2O K2HPO4.3H2O Bromocresol purple Agar Distilled water 3g 30 g 0.5 g 0.5 g 0.01 g 1.3 g 0.05 g 15 g 1000 ml

Final pH 8.0 ± 0.2 (adjust after medium is auto-claved). NOTE: a modification of CREA (=CRE) with 1.6 g K3PO4.7H2O can also be used.

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Examples growth on CREA

Acid / Base production on CREA

7 days

12 days

12 days

12 days

12 days

12 days

Ehrlich reaction

· Filter paper test; detection of presence of indole metabolites · Plug for 7 days old CYA culture · Place filterpaper with Ehrlich reagens on the mycelium side of the plug (propeller) · Read after 5 and 10 minutes · No reaction / violet (/yellow / brown)

Ehrlich reaction patterns

Violet reactions

No reaction

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Summary of presentation II

· Macro-morphology: Colony color (obverse/reverse) Colony size Exudate Soluble pigment · Micro-morphology: Branching pattern Shape phialide · Ehrlich test

Microscopic preparation of Aspergillus and Penicillium

Lactic acid with analine blue Drop of alcohol Preparations from Malt Extract Agar

Developments ­ (polyphasic) identification

· Identification based on macro- and micromorphological criteria, but also by use of nutritional and ecophysiological test media · Molecular identification (sequencing) · Extrolite (secondary metabolite) profiling · OR a combination from the methods mentioned above...

SIM 49: Penicillium subgenus Penicillium: new taxonomic schemes, mycotoxins and other extrolites (www.studiesinmycology.org) On-line database about Penicillium subg. Penicillium: http://www.cbs.knaw.nl/databases/index.htm (select Penicillium database)

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On-line database Penicillium subgenus Penicillium

· Experimental phase; feedback always welcome! · Use well defined and well prepared media, accurate incubators · Use mean values (also for colors!) rather than extremes · The more data is used, the higher the accuracy of the result · Check your result with the description mentioned in SIM49 (data might slightly differ since it is converted for this electronic key)

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Information

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