The first milk drawn from animals always contains microorganisms.
The bacteria include lactic steptococci, coliform bacteria, psychotropic Gram-negative bacteria. The negative rods are Thermoduric which survive pasterization.
Example: enterocci, and bacilli.
Disease free dairy personal and utilization of sanitary equipment help in reducing the number of bacterial contaminats from external sources.
For the production of different dairy products, it is required to have appropriate culture of microorganisms. The pure culture or mother culture or stock culture are available in lyophilized or freezedried form. Stock culture of desired of desired organisms may be maintained in the dairy cultures of lactic streptoci, Leuconostoc, and Lactobacillus are used.
MICROORGANISMS ASSOCIATED WITH DAIRY PRODUCTS
In the dairy, fermented milk are produced by inculating pasteurised milk with a known culture of microorganisms, sometimes referred to as a starter culture, which can be relied onto produce the desired fermentation, thus assuring a uniformly good product.
1. Principal microbes involved in. Yoghurt
Yoghurt is derived from a turkish word 'Jugurt' which is most famous fermented milk. Made from milk, skimmed milk or flavoured milk.
SNF content is between 11-15%. The flavour in yoghurt is due to acetaldehyde which should be present at 23-41 mg/kg.
Principal microbes involved in Yoghurt:
▪ Streptococcus thermophilus
Also known as Streptococcus salivarius is a gram-positive bacterium, and a fermentive facultative anaerobe. It is non-motile and does not form endospores. It's optimal growth temperature range of 35-42 degree Celsius.
It is classified as a lactic bacterium.
Most widely used in dairy industry.
Significants of Streptococcus thermophilus
a) Adjuvant
Streptococcus thermophilus strain Orla-Jensen 1919 is a constituent in VSL#3. The use of the Streptococcus thermophilus containing VSL#3 may reduce inflammation in mice.
b) Reduced - Fat Cheese
Streptococcus thermophilus helps make reduced fat cheese with similar characteristics to regular. These bacteria are chosen because they produce exopolysaccharide (EPS).
c) Cancer
Chemotherapy often causes mucositis, severe inflammation of primarily the small intestines. The intestinal tissues TH-4 functioned more healthy and less distressed.
d) Antibiotic - Associated Diarrhea
Strains of Streptococcus thermophilus have also reduced risks of AAD (Antibiotic - Associated Diarrhea), an issues that results from taking antibiotics.
▪ Lactobacillus bulgaricus
The function of the starter culture is to ferment lactose (milk sugar) to produce lactic acid. The increase in lactic acid decreases pH and causes milk to clot or form the soft gel that is characteristic of 'yoghurt'.
Significants of Lactobacillus bulgaricus
a) Probiotic Benefits
Have medical qualities because of the normal physiological role they play in preserving gut health. They are currently used to treat a number is conditions, including diarrhea, Crohn's disease and also tooth and gum diseases.
b) Inflammatory Bowel Disease (IBD)
Analysis on prebiotics indicates they may be helpful in treating ulcerative colitis.
c) Constipation
Studies on mice show that L.d bulgaricus may decrease constipation symptoms.
d) Mental Health
Prebiotics might help manage a variety of mental health conditions. This may include ADHD and depression.
2. Principal microbes involved in Kefir
Kefir is fermented milk, produced by a mixed lactic acid bacteria and alcoholic yeast.
Principal microbes involved in Kefir:
▪ Lactobacillus bulgaricus
▪ Lactose - fermenting yeast
3. Principal microbes involved in Cultured Buttermilk
Buttermilk is a liquid substance which is separated from cream during churning process.
Principal microbes involved in Cultured Buttermilk:
▪ Streptococcus lactic
A bacterial species found commonly as a contaminant in milk and dairy products. A common cause of souring and coagulation of milk. Some strains produce nisin, a powerful antibiotic that inhibits growth of many other gram-positive organisms.
▪ Lactococcus lactis
Lactococcus lactis is a Gram-positive bacterium used extensively in the production of buttermilk and cheese.
Significants of Lactococcus lactis
a) In Shuichi Nakamura's, Yusuke V. Marimoto, and Seishi Kudo's study, they seek to prove that some fermentation produced by L.lactis can hinder motility in pathogenic bacteria. Acetate is produced through lactose fermentation by L.lactis to interrupt the rotation of their flagella.
b) Study by Zhang B, created a L.lactis strain that maintains a plasmid containing a tumor metastasis - inhabiting peptide known as KISS1. L.lactis can be used to combat disease.
▪ Leuconostoc
Leuconostoc is a genus of Gram-positive bacteria. All species of this genus are heterofermentative and are able to produce dextron from sucrose. They generally slime-forming.
4. Principal microbes involved in Acidophilus Milk
Acidophilus milk is regular milk enriched with acidophilus, a strain of healthy bacteria, supplementing your diet.
Principal microbes involved in Acidophilus Milk:
▪ Lactobacillus acidophilus
Lactobacillus acidophilus is species of Gram-positive in the genus of Lactobacillus. It is a homofermentive, microaerophilic species, fermenting sugar into lactic acid and grow readily at rather low pH values (below pH 5.0) and has an optimum growth temperature of around 37 degree Celsius (99 degree F).
Occurs naturally in the human and animal gastrointestinal tract and mouth.
Significants of Lactobacillus acidophilus
Lactobacillus acidophilus is a constituent in VSL#3. This proprietary, standardised, formulation of live bacteria may be used in combination with conventional therapies to treat ulcerative colitis.
MICROORGANISMS ASSOCIATED WITH FOOD INDUSTRY
Nature uses microorganisms to carry out fermentation process, and for thousands of years mankind has used yeasts, moulds and bacteria to make food products such as bread, beer, wine, vinegar and cheese, as well as fermented fish, meat and vegetables.
1. Principal microbes involved in Alcohol Production
The modified microorganisms have different nutritional requirements with different culture conditions such as temperature, pH etc.
Principal microbes involved in Alcohol Production:
▪ Saccharomyces cerevisiae
Saccharomyces is a species of yeast. It has been instrumental to winemaking, baking, and brewing since ancient times.
Significance of Saccharomyces cerevisiae
a) Model Organism
Saccharomyces cerevisiae has developed as a model organism because it scores favourly on a number of these criteria:
Small organism with short generation time (1.25 - 2 hours at 30 degree Celsius or 86 degree F) and can be easily cultured.
S.cerevisiae divides with meiosis, allowing it to be a candidate for sexual genetics research.
S.cerevisiae research is a strong economic driver, at least initially, as a result of its established use in industry.
b) In the study of aging
c) Meiosis, Recombination and DNA Repair
S.cerevisiae reproduces by mitosis as diploid cells when nutrients are abundant. However, when starved, these cells undergo meiosis to form haploid spores.
d) Genome Sequencing
S.cerevisiae was the first eukaryotic genome to be completely sequenced. The database is a highly annotated and cross-referenced database for yeast researchers.
e) Gene Function and Interaction
The availability of the S.cerevisiae genome sequence and a set of deletion mutants covering 90% of yeast genome has further enhanced the power of S.cerevisiae as a model for understanding the regulation of eukaryotic cells.
f) Synthetic yeast genome project
g) Astrobiology
h) Brewing
Saccharomyces cerevisiae is used in brewing beer, when it is something called a top - fermenting or top - cropping yeast.
i) Baking
j) Uses in Aquaria
▪ Saccharomyces uvarum
Saccharomyces uvarum is proposed as a proper species within the complex Saccharomyces sensu stricto.
▪ Saccharomyces carlsbergensis
Saccharomyces carlsbergensis, the world's first pure culture Lager yeast.
▪ Candida brassicae
▪ Candida utilis
▪ Kluyveromyces fragilis
Kluyveromyces is a genus of ascomycetous yeasts in the family Saccharomycetacease.
Significance of Kluyveromyces fragilis
Lipid-enhanced production by Kluyveromyces fragilis.
▪ Kluyveromyces lactis
Kluyveromyces is a Kluyveromyces yeast commonly used for genetic studies and industrial applications. It's name comes from the ability to assimilate lactose and convert it into lactic acid.
Significance of Kluyveromyces lactis
Besides E.coli and A.nigar var awamori, K.lactis is one of the main organisms grown in industry in fermenters to produce chymosin on a large scale. Chymosin is used for cheese production.
▪ Zymomonas mobilis
Zymomonas mobilis is a Gram-negative, facultative anaerobe, non-sporulating, polarity-flagellated, rod-shaped bacterium. It has notable bioethanol-producing capabilities, which surpass yeast in some aspects. It is the only species found in the genus Zymomonas.
Significance of Zymomonas mobilis
a) Zymomonas mobilis degrades sugar to pyruvate using the Entner - Doudaroff pathway.
b) Zymomonas mobilis's plasma membrane contains hopanoids, pentocyclic compounds similar to eukaryotic sterols. This allows it to have extraordinary tolerance to ethanol in its environment, around 13%.
c) Z.mobilis does not require controlled addition of oxygen during the fermentation.
d) Low biomass production over S.cerevisiae with respect to producing bioethanol.
2. Principal microbes involved in Meat - Curing
The important contamination comes from external sources during bleeding, handling, and processing. Molds of many genera may reach the surface of meats and grow there. Sometimes, human Pathogens can also act on meat contamination.
Principal microbes involved in Meat - Curing :
▪ Achromobacter
Achromobacter is a genus of bacteria, included in the family Alcaligenaceae in the order Burkholderiales. The cells are Gram-negative straight rods and are motile by using one to 20 peritrichous flagella.
MICROORGANISMS ASSOCIATED WITH FOOD INDUSTRY
Nature uses microorganisms to carry out fermentation process, and for thousands of years mankind has used yeasts, moulds and bacteria to make food products such as bread, beer, wine, vinegar and cheese, as well as fermented fish, meat and vegetables.
1. Principal microbes involved in Alcohol Production
The modified microorganisms have different nutritional requirements with different culture conditions such as temperature, pH etc.
Principal microbes involved in Alcohol Production:
▪ Saccharomyces cerevisiae
Saccharomyces is a species of yeast. It has been instrumental to winemaking, baking, and brewing since ancient times.
Significance of Saccharomyces cerevisiae
a) Model Organism
Saccharomyces cerevisiae has developed as a model organism because it scores favourly on a number of these criteria:
Small organism with short generation time (1.25 - 2 hours at 30 degree Celsius or 86 degree F) and can be easily cultured.
S.cerevisiae divides with meiosis, allowing it to be a candidate for sexual genetics research.
S.cerevisiae research is a strong economic driver, at least initially, as a result of its established use in industry.
b) In the study of aging
c) Meiosis, Recombination and DNA Repair
S.cerevisiae reproduces by mitosis as diploid cells when nutrients are abundant. However, when starved, these cells undergo meiosis to form haploid spores.
d) Genome Sequencing
S.cerevisiae was the first eukaryotic genome to be completely sequenced. The database is a highly annotated and cross-referenced database for yeast researchers.
e) Gene Function and Interaction
The availability of the S.cerevisiae genome sequence and a set of deletion mutants covering 90% of yeast genome has further enhanced the power of S.cerevisiae as a model for understanding the regulation of eukaryotic cells.
f) Synthetic yeast genome project
g) Astrobiology
h) Brewing
Saccharomyces cerevisiae is used in brewing beer, when it is something called a top - fermenting or top - cropping yeast.
i) Baking
j) Uses in Aquaria
▪ Saccharomyces uvarum
Saccharomyces uvarum is proposed as a proper species within the complex Saccharomyces sensu stricto.
▪ Saccharomyces carlsbergensis
Saccharomyces carlsbergensis, the world's first pure culture Lager yeast.
▪ Candida brassicae
▪ Candida utilis
▪ Kluyveromyces fragilis
Kluyveromyces is a genus of ascomycetous yeasts in the family Saccharomycetacease.
Significance of Kluyveromyces fragilis
Lipid-enhanced production by Kluyveromyces fragilis.
▪ Kluyveromyces lactis
Kluyveromyces is a Kluyveromyces yeast commonly used for genetic studies and industrial applications. It's name comes from the ability to assimilate lactose and convert it into lactic acid.
Significance of Kluyveromyces lactis
Besides E.coli and A.nigar var awamori, K.lactis is one of the main organisms grown in industry in fermenters to produce chymosin on a large scale. Chymosin is used for cheese production.
▪ Zymomonas mobilis
Zymomonas mobilis is a Gram-negative, facultative anaerobe, non-sporulating, polarity-flagellated, rod-shaped bacterium. It has notable bioethanol-producing capabilities, which surpass yeast in some aspects. It is the only species found in the genus Zymomonas.
Significance of Zymomonas mobilis
a) Zymomonas mobilis degrades sugar to pyruvate using the Entner - Doudaroff pathway.
b) Zymomonas mobilis's plasma membrane contains hopanoids, pentocyclic compounds similar to eukaryotic sterols. This allows it to have extraordinary tolerance to ethanol in its environment, around 13%.
c) Z.mobilis does not require controlled addition of oxygen during the fermentation.
d) Low biomass production over S.cerevisiae with respect to producing bioethanol.
2. Principal microbes involved in Meat - Curing
The important contamination comes from external sources during bleeding, handling, and processing. Molds of many genera may reach the surface of meats and grow there. Sometimes, human Pathogens can also act on meat contamination.
Principal microbes involved in Meat - Curing :
▪ Achromobacter
Achromobacter is a genus of bacteria, included in the family Alcaligenaceae in the order Burkholderiales. The cells are Gram-negative straight rods and are motile by using one to 20 peritrichous flagella.
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