Cladosporium herbarum

Spores produced by C. herbarum can be lemon-shaped or cone-shaped, often composed of 2-4 cells (3-23 mm). One-celled conidia (5.5-13 x 3.8-6 μm) also exist. In culture, newly-formed spores appear mostly 1-celled, later forming tree-like colonies with multiple branches. The stalks which produce C. herbarum spores are 250 μm long and 3-6 μm wide. They appear swollen at the tip and in between cells, and have irregularly bent branches. Under microscopy, these stalks appear pale or dark brown in color and have smooth or rough walls. When submerged in fluid, they become brittle and break up completely into spores and rod-like fragments. Colonies grown on Czapek yeast extract agar (CYA) and malt extract agar (MEA) appear velvety or fluffy, with smooth or slightly wrinkled walls, and are green or brown in color. The reverse side of the colony appears a darker green or grey/black. Colonies can appear both sparse or densely grown. At 5 °C (41 °F), colonies are 1-2 mm in diameter.

This species is distributed worldwide, inhabiting polar, temperate, mediterranean, subtropical, tropical, forest, grassland, and arable soil regions. It is found frequently in wood exposed to soil, deep soil depths, and the highly nutritious soil directly surrounding the roots of plants (rhizosphere). It is one of the early colonizers on dying and dead plants (saprobe), especially the leaves and stems of both aquatic and desert plant species (for example ferns and mosses). It is the most common fungal species found on living leaves (given suitable conditions) and dead plant material in very moist environments. It also has an adaptation to high salt concentrations (has been found in high salinity sediments) and extremely dry areas (xerophilic). Cladosporium herbarum causes spoilage of fresh fruits and vegetables including yams, peaches, nectarines, apricots, plums, cherries, tomatoes, and melons. Its common occurrence on fresh apples can lead to contamination of apple juice and fruit based products. It has also been found in eggs, hazelnuts, cereals, chickpeas, soybeans, and frozen fruit pastries. Cladosporium herbarum can also spoil cheese and pasteurized soft cheese, causing problems during its manufacturing. Being able to survive at temperatures below freezing, C. herbarum can cause "black spot" spoilage of meat in cold storage (between −6 °C (21 °F) and 0 °C (32 °F)). …