Lichens and Humans

Interesting and Useful Organisms

Lichens are interesting organisms. It is an essential part of nature and beneficial for humans. Lichens provide fragrances for perfumes. Several species have historically been used as food after proper preparation. In the future, they can also be used in lichens, antibiotics and sunscreen products.

Lichens come in a wide variety of shapes and body forms. In addition, it has many colors including black, gray, white, green, blue-gray, yellow, orange, red or brown. Despite their appearance, they are not plants. Its body contains both a fungus and an algae. Each organism in one way helps the other.

What Are Lichens?

Lichens are beautiful and somewhat mysterious organisms classified into three main types according to the shape of their bodies.

• Leaf lichen species have a leaf-like appearance.
• In the branchy lichen species, the types have a highly branched form. They can be upright or hanging.
• Types of crustal lichens appear like a crust formed on the surface.

There are also unusual forms of lichen. For example, scaly types appear to be a cross between the crustacean form and the leaf form. Jelly lichens live in moist areas and have a gelatinous appearance when wet.

Habitats, Substrates and Ecology

Lichens are found in many different habitats, including temperate and tropical rainforests, deserts, mountains, tundras, snowy and icy areas, and sea coasts. Also, they grow on many different substrates, including seemingly smooth ones. Possible substrates include:

• Tree and bark
• Rock
• Soil
• Concrete, metal and glass
• Plastic
• Fabric and leather
• Shells of living animals
• Other lichens

Lichens perform useful functions in nature. They provide shelter for other organisms. When lichens grow in rocks, the chemicals they release contribute to slow rock formation and soil formation.

Common Life

Lichen is an example of symbiosis. The algae in the partnership can be an organism called a green-green alga or a blue-green alga, but it is now known as a cyanobacteria.

The fungal component of lichens consists of branching and thread-like structures called hyphae. Algae cells are usually located in the middle of lichens and are surrounded by hyphae. In jelly lichens, fungal hyphae and algae cells are mixed evenly.

Algae cells make food both for themselves and for fungus. They contain chlorophyll that absorbs sunlight. It uses light energy to make carbohydrates from algae, carbohydrates and water. Mushrooms do not contain chlorophyll and cannot produce their own food. The fungus in lichen helps it by protecting the algae.

Wool and Fabric Dyes

Many lichens are gray in color when dry. When a lichen is moistened and absorbs water, the algae cells give the lich a deeper color. The fungal component is usually colorless, but in some cases contains a pigment that gives the lichen its vibrant color.

Making wool and fabric dyes from lichens is an ancient process that is still practiced today. Suitable samples are collected, dissected and added to water. Ammonia is usually added to water.

Paint made from a lichen often has a different color than the intact organism. The colors brown, golden, orange, green, purple, blue, and red depend on the type of lichen used and the type of extraction process.

A Useful Dye and An Interesting Pigment

Litmus paper

Litosol paper is widely used as an acid-base indicator, especially by students who need to know only the approximate pH of a substance. Litmus is a mixture of dyes derived from special lichens, especially Rosella tinctoria. Litmus paper is made from filter paper that has been treated with paint. Neutral litmus paper is purple in color.

Natural Sunscreens

Xanthoria parietina is a leaf lichen containing a yellow pigment called parietin. This pigment absorbs ultraviolet radiation which acts as a sunscreen to protect algae cells in lichen. Some other lichens also contain sunscreens.

Antibiotics, Preservatives and Toxins

Usnea

The Usnea genus has been found in many lichen species, including usnic acid members. In natural medicine, usnea is used as an antibiotic and anti-inflammatory agent. Usnea is also used as a preservative in some products.

Tests in laboratory equipment and laboratory animals show that usnic acid has antimicrobial properties and kills bacteria, fungi, viruses. It also reduces inflammation and prevents the proliferation of some cancer cells. Unfortunately, it can cause severe liver damage in humans. Clinical tests of usnic acid activity in the human body are lacking. Substances may not have the same effect in our body as in isolated cells and laboratory animals.

Wolf Lichen

Wolf lichen has a bright yellow-green color. It grows in Europe and western North America. It contains a yellow chemical called vulpinic acid, which is toxic to mammals.

Wolf lichen has also been used to take the dye extract. It was once used by locals for medicinal purposes. Laboratory research shows that vulpinic acid can kill some types of bacteria.

Perfumes and Deodorants Contents

Oak Moss

Oak moss is used to provide fragrance and durability for perfumes. It grows in Europe and North America, but is more valuable in France.

Essential oils are extracted from oak moss. Essential oils are usually obtained by steam distillation. Oak moss extracts are said to have a beautiful earthy scent that resembles moss aroma and has an undertone of pine wood.

Pseudevernia Furfuracea

Pseudevernia furfuracea is another branch of lichen used in the perfume industry. Lichen was used to fill the body cavity of Ancient Egyptian mummies. Today, lichen components are used in deodorants and also in perfumes due to their pleasant fragrance.

Lichen as Food

It should not be eaten by taking lichen from a rock or tree. Many species are believed to be mildly toxic, and most are not digested in its raw form. Some cultures have learned how to prepare certain lichens to improve their digestibility and even make them a flavor. The long experience of the public has taught which of the native lichens are safe to eat.

The following uses are historical and still occur in some indigenous cultures of North America.

Reindeer moss is a branchy lichen. This is another moss that is actually a lichen. Some Arctic inhabitants have mixed partially digested lichens with raw fish eggs and caribou stomachs. The result was a mixture called “stomach freezing”.

Umbilicaria esculenta is a black leaf lichen that grows on rocks. It has been used in Asian cuisine after fried. Umbilicaria lichens are commonly known as stone tripe.

Some groups have boiled certain types of lichen and mixed them with strawberries, fish, or wild onions before eating them.

With few exceptions, lichens are often preferred as food in times of famine. The vast majority of lichens have not been tested for edibility or safety or a preparation technique that makes them safe to eat. Most people do not eat lichen today due to the possibility of taking the toxic one.

Pollution and Dehydration

Some lichens are very tolerant of contaminants such as nitrogen and sulfur compounds. Others are very sensitive to the presence of one or both of these chemicals. People who can identify lichens can learn about local environmental conditions by observing which species are present. The species act like bioindicators. A bioindicator is a species that demonstrates the health of the environment using its existence, function or behavior.

Lichens have a high resistance to damage by drying and can quickly absorb large amounts of water after drying has ended. This feature has made them usable by humans as dressings and diapers in the past. When organisms dry out, they stop photosynthesis and when they absorb water they start producing food again.

Radiation Exposure

They absorb and store radioactive substances such as lichens, cesarean section and strontium compounds without apparent damage.

Some types of lichen are very resistant to hazardous radiation. In the 2005 experiment, two types of lichens spent sixteen days in space on an orbiting satellite. Here they were exposed to “massive” ultraviolet and cosmic radiation doses. When they returned to Earth, they were almost capable of photosynthesis. In addition, most lichen cells were found to have no visible damage.