PENICILLIUM (BLUE MOLD)

CLASSIFICATION OF PENICILLIUM (BLUE MOLD)​

Kingdom :- Mycota

Division :- Eumycota

Sub-division :- Ascomycotina

Class :- Plectomycetes

Order :- Eurotiales

Family :- Eurotiaceae

Genus :- Penicillium

The Penicillium fungus can easily be found or grown on citrus and other fruits and on foodstuff. It generally grows in association with Aspergillus, but since it is a weak saprophyte it is dominated by Aspergillus.

STUDY OF VEGETATIVE STRUCTURE

• The fungus is a saprophyte and is commonly found on citrus and other fruits, jellies and other foodstuffs.
• The mycelium is freely branched, septate and each cell is uni- or multinucleate.
• The mycelium may grow superficially on the surface of substratum or may penetrate deeply.
• The hyphae are generally coloured due to pigments on the surface of hyphal walls.

STUDY OF CONIDIA​

• The conidia are the asexual spores borne on long, erect and branched conidiophores.
• The branched conidiophore, with its conidia looks like a small ‘Penicillus’ (a brush in Latin).Each conidiophore grows vertically from the mycelium and branches at its upper end. The ultimate branches are known as metulae.
• Each branch of conidiophore ends in bottleshaped sterigmata bearing a group of conidia arranged basipetally.
• The conidia are generally blue, sometimes green or -yellow and give characteristic colour to the colony.
• The conidia are globose to ovoid in shape and appear as glass beads under the microscope.

ASCOCARP, ASCI AND ASCOSPORES​

• The fruiting body or ascocarp is called cleistothecium. It has a wall-peridium made of sterile hyphae which encloses many asci and paraphyses.
• The globose or pear-shaped asci lie scattered inside the cleistothecium.
• Each ascus has eight uninucleate and wheelshaped ascospores.
• The ascospores are ultimately released by the rupture of cleistothecium and after falling on a suitable medium germinate into new mycelia.
• The perfect stage i.e. cleistothecium is known as Eupenicillium, Teleromyces, Carpenteles.

IDENTIFICATION

• Kingdom – Mycota
  1. Chlorophyll absent
  2. Reserve food glycogen
  3. Cell wall of fungal cellulose.
• Division – Eumycota
  1. A definite cell wall present.
• Sub-division:- Ascomycotina
  1. Mycelium septate.
  2. Spores borne endogenously in the ascus.
  3. Spores in definite numbers, in multiples of two, usually eight.
• Class:- Plectomycetes
  1. Ascocarp, a cleistothecium.
• Order– Eurotiales
  1. Cleistothecia sessile
• Family – Eurotiaceae
  1. Asci lie scattered, hymenium not formed.
  2. Peridium made of closely interwoven hyphae.
• Genus – Penicillium
  1. Branched, brush-like conidiophore.

REFERENCES

• https://en.wikipedia.org/wiki/Penicillium
• https://www.shutterstock.com/search/penicillium