EDIBLE MICROORGANISMS

Supervised By/ prof. Hasham RadhwanPrepared by / Ali Alshahrani

Microorganisms can be consumed as food known as edible microorganism.Micro-organisms used are fungi , yeast, algae & bacteria.

The following table shows average different compositions of main groups of micro– organisms (% dry wt.)

COMPARISION OF MICRO-ORGANISMS

ADVANTAGES DIS ADVANTAGESFUNGI Easy to grow & harvest Lower growth rates &

lower protein content

ALGAE Easy to grow & harvest & high quality protein

Non –digestible cellulosic cell wall, concentrate heavy metals

YEAST Larger in size, lower NA content , familiarity & acceptability

Poor digestibility, low protein content, slow growth rate

BACTERIA High protein content, digestible cell wall

High NA content, small in size, low density

Blue green Algae (genus Spirulina) harvested and eaten for centuries by the Aztecs in Mexico and Africa

Mushrooms , the fruiting bodies of microorganisms that live on decaying lignocellulosic soil one of the highly prized food items.

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enrichment of the human diet.

Preservation of food.

enrichment of food substrates biologically.

Protein quality is increased by the synthesis of essential amino acids such as lysine, first limiting amino acid in rice. In the Malaysian tape fermentation the content of lysine is raised, improving its protein quality.

Microbial protein can be extracted from the cells and converted to meat substitutes. Mold Rhizopus oligosporus cheap source of protein and enriches food with vitamin B12

and increasing the niacin and riboflavin content. The grasses are the most efficient fixers and utilizers of carbon dioxide, producing

sugars, starches, and cellulose. Grasses can double their cell-mass in two to three weeks. A 1000 kg harvest of grass

can be repeated every two to three weeks. yeasts are much more efficient in this regard. A yeast (1000 kg) grown in tanks on

limited land space can produce 168,000 kg of cells containing 84,000 kg of protein every two weeks

There is much hunger, starvation, and malnutrition in parts of the world today, and the world population is predicted to reach eight to twelve billion by the year 2050.

As world population increases, the supply of meat and other animal products available per person is likely to decrease.

Only about twenty-five species of more than two thousand edible fungi are widely

accepted as human food

The four most important mushrooms :■ white mushroom or button mushroom (Agaricus campestris)■ black forest mushroom shiitake (Lentinus edodes)■ straw mushroom (Volvariella volvacea)■ oyster mushroom (Pleurotus ostreatus).

white mushroomblack forest mushroom

straw mushroom oyster mushroom

Mushrooms can be grown on inexpensive, non enable substrates like cereal straws, banana leaves, sawdust, animal manure.

Mushrooms high in essential amino acids and have great nutritional value.

Mushrooms, a microbial product, are thus likely to play an important role in feeding the world in the future

Single cell oil

■ Lipids obtained from microbes or single celled entity.■ Obtained from yeast , bacteria and microalgae.■ Lipid accumulation by microorganisms depends on : genetic constituents different culture conditions ( pH , temp , culture time )

Single cell oil might be defined as the edible oils obtainable from microorganisms being similar In type and composition to those oils and fats from plants or animals

Some Application Of Microorganisms

Food products ■ Alcoholic drinks

■ Dairy products

■ Bread Vinegar

■ Pickled foods

■ Mushrooms

■ Single-cell protein

Products from microorganisms ■ Enzymes

■ Amino acids

■ Antibiotics

■ Citric acid

Some Industrial Application Of Microbial Produced Enzymes

Probiotics as ‘Live microorganisms’ which when administered in adequate amounts confer a health benefit on the host.

There are large numbers of probiotics currently used and available in dairy fermented food, especially in yogurts.

The most beneficial organisms include those of:Lactobacillus.Bifidobacterium.Streptococcus.Lactococcus. Saccharomyces.

The physiological effects related to probiotic bacteria include:

Reduction of gut pH, Production of some digestive enzymes and vitamins Production of antibacterial substances, e.g., organic acids. Antibiotic therapy. Reduction of cholesterol level in the blood Stimulation of immune functions. Suppression of bacterial infections. Removal of carcinogens. Improvement of calcium absorption.