Molds consist of all kinds of microscopic fungi that develop in the form of multicellular filaments. These multicellular filaments are called hyphae. Molds do not appear in the form of a particular phylogenetic or taxonomic grouping but can be found in the form of Ascomycota, Zygomycota and Deuteromycota. The growth of the mold can be useful in the production of numerous antibiotics, foods,
enzymes and beverages. However, they can also be harmful to some other eatables.

There are several species of molds such as thermophiles, acquatic species,
opportunistic pathogens and saprotrophs. Molds derive the energy to survive from
the organic matter on which they live and not from photosynthesis. Molds produce
hydrolytic enzymes from the dominant hyphal tips. These enzymes breakdown
compound biopolymers like cellulose and starch into simple particles which can
enter the hyphae. Mold in this way causes decomposition of organic matter and
makes reprocessing of nutrients present in the ecosystem possible. The
development of micoorganisms is restricted by hydrolytic enzymes and mycotoxins
which is produced by molds.

Molds produce through tiny spores. The mold spores may be sexual or asexual;
there are some that produce both kinds. They may consist of many or single
nucleus.

Molds breed on a dead organic substance. However, their presence is only
evident to the unaided eye when mold colonies develop. Some molds can breed at
temperature as low as 20°C. Some circumstances do not encourage growth; molds
can survive in a dormant state.

Black bread mold or Rhizopus stolonifer is a commonly circulated Mucoralean mold. Bread mold grows quickly at a temperature between 15 and 30 degree Celsius. This is an asexual mode spore that is produced within sporangia, which break the spores when they grow up. Rhizopus stolonifer or black bread mold is a heterothallic species where sexual production takes place only when opposite mating kinds come in contact.

Black bread mold has an epidemic distribution. As a result it can cause
opportunistic infections to humans, such as zygomycosis. Usually they breed on
soft fruits, such as peaches and strawberries and bread. A moist bread piece
kept in a humid and enclosed container gathers bread mold within a couple of
days. The bread mold breeds on bread and expand from spores, which float in the
air. The mold spore after it drops onto the moist bread grows by distributing
branching threads. A cell wall and cell membrane consists of many nuclei and
cytoplasm that enclose the threads. The threads develop down into the bread and
manufacture digestive enzymes that will modify the bread into a liquid type.
Growing bread mold soaks up the liquid. Ultimately, a new branching thread goes
down into the bread and spreads the bread mold.

Another kind of mold is Phytophora infestans that causes damage to tomatoes and
potatoes. If a mold spore settles on a leaf of a healthy potato plant in moist
and warm conditions, a new hypha breeds out of it and penetrates the leaf
through a stoma. Then small branches will breed out of the hypha and enter the
walls of the leaf cells with the help of enzymes. The hypha then sucks up
nutrients from the cell filling and develops quickly, disperses throughout the
tissues of the plant. This kind of black mold can parasite can destroy the
entire potato plant. The growth of mold can be prevented by preventing water
clogging and keeping the place dust free.