### Effects of microorganism on food

Bacteria and fungi are mainly responsible for the spoilage of food. Which may take place at any time, the spoiling microorganism changes the color, odor, and culture of the food.

#### 1: Bacterial effect on food:

Bacteria spoil and poison that food.

a: Spoilage of food: Many of the saprophytic bacteria decay the food stuff like rotting of vegetables, fruits, meat, fish, bread, the souring of milk, cheese, butter, pickles. Saprophytic bacteria like Pseudomonas, Clostridium bacillus.

b: Purification: Spoilage of microorganism like proteolytic microorganism forming amino acids, amines, ammonia, hydrogen sulfide etc.

c: Fermentation:; Contamination of carbohydrates by carbohydrate fermenting microorganism forming acids like RDH.

d: Facility: Spoilage of fats by lipolytic microorganisms by forming fatty acids and glycerols.

e: Spoilage of milk: The protein is decomposed by the proteolytic microorganism to give slimy milk with pigmented and odor.

f: Botulism: It is the most dangerous and fatal type of food poisoning caused by the Clostridium boutulina, which is obligate anaerobic, endospore-forming gram-negative bacteria. It produces exotoxin in canned food. So the consumption of such food caused paralysis of pharynx and diaphragm through its effects on nerves.

g: Bacillus poisoning: This is due to cereus it occurs in preserved food. It causes colic pain, diarrhea, and vomiting. Bacillus aerothermophelus and Bacillus term difference are responsible for the diseases.

h: Staphylococcus poisoning: Due to the staphylococcus aureus cause diarrhea, vomiting, nausea, which occurred in preserved vegetable food.

i: Salmonellosis:It is caused by Salmonella enteridis and Salmonella typhimurium which contaminate the food like meat which leads to salmonellosis characterized by chills, nausea ,diarrhea, vomiting.

#### 2: Fungal spoilage

The spoilage of food by fungi and mucor or molds which produce the secondary metabolites called as mycotoxins. These toxins make the food inedible.

Example: Sumac in caused by Fusarium moniliform

Patulin caused by Fusarium penicillium

Trichothecenes by Fusarium tricot herma

Mycotoxins are carcinogenic i.e they are cancer-causing, mutagenic, teratogenic i.e embryotoxic, hepatotoxin i.e liver toxin, neurotoxin i.e nerve toxin, sarcotoxin.e death of tissue, haemotoxins i.e blood toxin, also toxin produced by Aspergillum flavor, Aspergillumparasitic.

### Role of microorganism as food

#### 1: Bacteria as a source of food:

a: Single-called proteins are produced from waste material by using some species of pseudomonas.

b: Dairy products: butter cheese curds are produced by lactobacillus, lacidipine.

c: Industrial food products: Vinegar is produced by Acetobacter, Mycoderma, and Citrovorum.

d: Fermented food; Yeast and molds help in preparation of alcohol, various food like a pickle. These are produced by the activity of streptococcus.

#### 2: Cyanobacteria as a source of food:

Blue-green algae nostoc commune are consumed as vegetables in china japan. It is also used as animal food.

#### 3: Fungi as a source of food:

Different kinds of mushrooms like Agaricus campestris are used as nutritious food.

#### 4: Ripening of milk products:

In dairy industries, different kinds of mycotic species are involved converting lactogen to lactic acid. Examples: Mucor ruinous.

#### 5: Algae as a source of food:

Algae are rich in carbohydrates, many organic and inorganic substances and vitamins so they are important to form of food consumed in a wide range in the world.

### Soil microorganism

Soil microbes and nutrient recycling soil microorganism exist in large number in the soil as long as there is a carbon source for energy. A large number of bacteria in the soil exists, but because of their small size, they have a smaller biomass. Actinomycetes are a factor of 10 times smaller in number but larger in size. So they are similar in biomass to bacteria. Fungus population numbers are smaller but they dominate the oil biomass when the soil is not disturbed. Bacteria, actinomycetes, and protozoa are hardy and can tolerate more soil disturbance than fungal populations so they dominate in tilled soils while fungal and nematode populations tend to dominate in untilled or no-till soils. There are more microbes in a teaspoon of soil than there are people on the earth. Soil contains about 8 to 15 tons of bacteria, fungi, protozoa, nematodes, earthworms and arthropods.

Microbial soil organic matter decomposition organic matter decomposition serves two functions for the microorganism, providing energy for growth and supplying carbon for the formation of new cells. Soil organic matter is composed of the living i.e microorganism, the dead i.e fresh residues, the very idea i.e humus fraction. The very dead or humus is the ling term soil microorganism fraction that is thousands of years old and-and is resistant to decomposition. Soil organic matter has two components called the active (35%) and the passive.

65% soil microorganism, active soil microorganism is composed of the living and dead fresh plant or animal material which is food for microbes and is composed of easily digested sugars and proteins. The passive soil microorganism is resistant to decomposition by microbes and is higher in lignin. Microbes need regular supplies for active soil microorganism in the soil to survive in the soil. Long-time no-tilled soils have significantly greater levels of microbes, more active carbon, more SOM, and more stored carbon than conventionally tilled soils. A majority of the microbes in the soil exist under starvation conditions and thus they tend to be in a dormant state, especially in tilled soils. dead plant residues and plant nutrients become food for the microbes in the soil. Soil organic matter is basically all the organic substances in the soil both living and dead. Soil organic matter includes plants, blue-green algae, microorganism, fungi, bacteria, nematodes, beetles, springtails etc and the fresh and decomposing organic matter from plants, animals, and microorganism.

Soil organic matter can be broken down into its component parts. One hundred grams or 100 Pounds of dead plant material yields about 60 to 80 gram of carbon dioxide, which is released into the atmosphere. The remaining 20-40 gram of nutrients is decomposed and turned into about 3-8 gram of microorganism, 3-8 gram of non-humic compounds and 10-30 gram of humus. The molecular structure of soil organic matter is mainly carbon and oxygen with some hydrogen and nitrogen and a small amount of phosphorus and sulfur. Soil organic matter is the bi-product of carbon and nitrogen cycle.

Soil organic matter nutrients in the soil have a current value of $680 for each 1% soil organic matter or$68 per ton of soil organic matter based on economic values for commercial fertilizer. Some are composed of the mostly compound of carbon but associated with carbon is a high amount of nitrogen and sulfur from proteins, phosphorus, and potassium. Soil organic matter should be considered like an investment in a certificate of deposit (CD). Soils that are biologically active and have higher amounts than soils that are biologically inactive and contain less active organic matter. Under no-till conditions, small amounts of nutrients are released annually to provide nutrients slowly and effectively to plant roots. However, with tillage large amount of nutrients can be released since the soil organic matter is consumed and destroyed by microbes.

References:

Miller, Jr. G.T. Living in the Environment. Wadsworth Publication, 2003.

S.C., Santee. Environmental Science. India, New Center: New Center Book Agency (P) Ltd, 2004.

T., Richard. Environmental Science Towards a Sustainable Future. India: PHI (P) Ltd., 2008.

• Spoilage of microorganism like proteolytic microorganism forming amino acids, amines, ammonia, hydrogen sulfide etc.
• Contamination of carbohydrates by carbohydrate fermenting microorganism forming acids like RDH.
• Spoilage of fats by lipolytic microorganisms by forming fatty acids and glycerols.
• The spoilage of food by fungi and mucor or molds which produce the secondary metabolites called as mycotoxins. These toxins make the food inedible.
• Algae are rich in carbohydrates, many organic and inorganic substances and vitamins so they are important to form of food consumed in a wide range in the world.
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