Micro organisms in Food By Swastika S 232BT008 1st M Sc Biotechnology Micro organisms are living entities of microscopic size which cannot be seen by naked eye and include bacteria viruses yeasts and molds together designated as fungi algae and protozoa Food Microbiology is the branch of microbiology that studies the role of Micro organisms in food spoilage food production and food borne diseases Good food organisms typically refers to beneficial microorganisms that are intentionally added to food for various purposes such as fermentation preservation or enhancing flavor Examples 1 Lactic Acid Bacteria Lactobacillus Used in yogurt and cheese production They convert lactose into lactic acid which gives these products their characteristic tangy flavor and helps preserve them Leuconostoc Used in sauerkraut fermentation where they convert sugars into lactic acid and contribute to the product s sour taste 2 Probiotics These are live beneficial microorganisms found in foods like yogurt kefir and some fermented foods Probiotics are believed to promote gut health and may offer various health benefits 3 Brewer s and Baker s Yeast Different strains of Saccharomyces cerevisiae are used in brewing beer and making bread respectively They contribute to the flavor and texture of these products 4 Acetobacter acetic acid giving vinegar its sour taste Used to ferment alcoholic beverages like wine and cider into vinegar These bacteria convert ethanol into Bad food organisms typically refers to harmful microorganisms that can cause foodborne illnesses when they contaminate food These microorganisms can lead to food poisoning and other health issues if consumed Examples 1 Salmonella It is a type of bacteria commonly associated with raw poultry eggs and unpasteurized dairy products Consuming food contaminated with Salmonella can lead to symptoms such as diarrhea abdominal cramps fever and vomiting 2 Escherichia coli E coli Some strains of E coli can cause food poisoning Contaminated ground beef raw produce and unpasteurized milk are common sources E coli infections can result in symptoms like severe diarrhea and kidney damage 3 Listeria monocytogenes Listeria is a bacterium found in soil and water It can grow at refrigeration temperatures making it a concern for ready to eat foods Listeria infections can lead to flu like symptoms and they are particularly dangerous for pregnant women newborns and individuals with weakened immune systems 4 Vibrio cramps Vibrio species are found in raw or undercooked seafood particularly oysters and shellfish These infections can result in symptoms such as diarrhea vomiting and abdominal pain 5 Clostridium perfringens This bacterium can multiply rapidly in large batches of cooked food left at room temperature for too long Consuming food contaminated with Clostridium perfringens can lead to diarrhea and abdominal Overgrown microorganisms in fruits which typically lead to spoilage or fermentation are generally not desirable for consumption in their overgrown state However there are specific scenarios in which overgrown microorganisms can still be used or repurposed 1 Fermentation wine or fruit vinegar 2 Composting organic matter and nutrients to the compost enriching the soil for future plant 3 Insect Traps as bait in traps to attract and capture certain insects such as fruit flies 5 Natural Fertilizer as they decompose they release nutrients into the soil enriching it for plant growth growth 4 Animal Feeds Yeast Genera 1 Saccharomyces 2 Candida 3 Kluyveromyces Saccharomyces cerevisiae This yeast species is crucial in breadmaking brewing beer and wine production and the production of certain distilled spirits like whiskey It is also used in the fermentation of various foods including some types of pickles soy sauce and certain dairy products Candida milleri Used in the production of Roquefort and other blue cheeses where it contributes to the characteristic blue mold growth and flavor development Kluyveromyces lactis Used in the dairy industry for the production of cheese and other dairy products Kluyveromyces marxianus Used in the fermentation of kefir and various dairy products as well as in ethanol production 4 Debaryomyces 5 Pichia applications 6 Cryptococcus 7 Hanseniaspora development 8 Zygosaccharomyces Debaryomyces hansenii Used in the production of certain types of cheese such as Emmental and Gouda Pichia pastoris Used in biotechnology and recombinant protein production including some food related Cryptococcus laurentii Used in the fermentation of olives to produce Spanish style green olives Hanseniaspora uvarum Commonly found in wine fermentations and contributes to wine aroma and flavor Zygosaccharomyces rouxii Used in the fermentation of soy sauce and contributes to its flavor and aroma Important Mold Genera 1 Aspergillus Aspergillus flavus and Aspergillus parasiticus these molds are known for producing aflatoxins which are potent mycotoxins that can contaminate peanuts corn rice and other crops Aflatoxins are carcinogenic and can cause liver damage 2 Penicillium Penicillium roqueforti and Penicillium camemberti Used intentionally in cheese making these molds contribute to the blue veins in blue cheeses e g Roquefort and the white rind on soft cheeses e g Camembert 3 Alternaria Commonly found on fruits and vegetables these molds can produce mycotoxins like alternariol which may be a health concern in certain situations 4 Fusarium These molds can produce mycotoxins called trichothecenes and fumonisins They are often associated with grains particularly corn and wheat and can have adverse health effects if ingested 5 Rhizopus These molds are involved in the fermentation process for certain foods like tempeh a traditional Indonesian soybean product 6 Cladosporium Commonly found on various fruits and vegetables Cladosporium molds are generally not known to produce significant mycotoxins 7 Botrytis Botrytis cinerea also known as noble rot is used in wine making Under controlled conditions it can enhance the flavor and sweetness of grapes for dessert wines 8 Mucor Mucor molds can be involved in the fermentation process for some food products such as certain 9 Aureobasidium Often found on fresh produce particularly tomatoes these molds can lead to spoilage but are varieties of soft cheese and fermented soybean products generally not known to produce significant mycotoxins 10 Eurotium These molds are involved in the fermentation process for foods like soy sauce and