Roof Bacteria:
Roof bacteria can take many forms. The most common form is moss or mildew. Roof bacteria is similar to Lichens, as it has a root-like system that attaches to your roof, eats water and expels oxygen. Moss roots are called rhizoids and can anchor the moss to your roof. The moss creates a layer of algae/lichens growth on your roof by collecting windblown soil and spores.
Algae:
This is a non-aquatic, non-flowering plant that does not have leaves or roots. Algae thrives in hot, humid climates and will be more noticeable on the parts of your roof with the least amount of sunlight. Over time, the algae will spread and grow darker on your roof shingles.
Lichens:
Lichens colonies are a fungus that feed on the organic material frequently found in the mineral based granules and limestone fillers that make up roof shingles.