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Microbio in food

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microbiology applications in food

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Microbio in food

  1. 1. Submitted by: Aditi Singh B.Tech (BT) V Sem. Roll no.- 7274 Submitted to: Dr.Monika Saxena Deptt. Of Bioscience & Biotechnology
  2. 2. Industrial applications of microbiology In food
  3. 3.  Organism  With ability to grow rapidly  Non-pathogenic  Medium  Available in abundant quantities  Must be cheap  Product  Efficient + Economical recovery methods  purification
  4. 4. Microorganisms used:  Several strains of algae, fungi (yeast & molds), bacteria, protozoa, and viruses.  Genetic Engineering of microorganisms: Genetic engineering, also known as recombinant DNA technology, molecular cloning or gene cloning Recombinant DNA Technology enables isolation of genes from an organism, this gene can be amplified, studied, altered & put into another organism
  5. 5.  Recombinant DNA procedure: 1. Cutting of donor DNA : Restriction endonucleases cut DNA molecule at specific sites and desired fragment is isolated by gel electrophoresis. 2. Cloning of a gene: DNA fragment, which wanted to be cloned, is joined to one of vectors (plasmid, phage, cosmid). For this purpose, vector and donor DNA are first cleaved with the same restriction endonuclease, or with the ones producing the same ends.
  6. 6. Then using DNA ligase, DNA fragment and vector DNA is joined. If fragment has no sticky ends, homopolymer tailing or linker DNA segments can be applied for this step. 3. Transformation : Recombinant vector is put into suitable host organism, like; bacteria, yeast, plant or animal cells, by several physical or chemical methods. Transformed cells are identified by several ways: a. Insertional inactivation (of antibiotic resistant genes on plasmids), b. nucleic acid hybridization c. labeled Ab's for specific proteins (immunological test) are helpful for screening recombinant colonies.
  7. 7.  Factors affecting microbial growth in food  composition  pH  presence and availability of water  oxidation-reduction potential  altered by cooking  physical structure  presence of antimicrobial substances  temperature  lower temperatures retard microbial growth  relative humidity  higher levels promote microbial growth  atmosphere  oxygen promotes growth  modified atmosphere packaging (MAP)  use of shrink wrap and vacuum technologies to package food in controlled atmospheres
  8. 8. Fermented food products Citric acids Amino acids Enzymes Industrial Production In field of foods Vitamins others
  9. 9. 1. L-lysine Production: • Essential amino acids –for human nutrition. • Used as supplement for bread , cereals & other food. • Two steps for commercial production method: I. Formation of DAP(diaminopimedic acid) by E.coli . II. Decarboxylation of DAP by DAP decarboxylase enzyme from Enterobacter aerogenes . DAP Lysine + CO2  E.coli – grown in a medium consisting glycerol of corn steep liquor and (NH4)2HPO4 - under controlled conditions of aeration, temperature & pH for optimum DAP production.  After several days, Enterobacter aerogenes - added to the mixture - produces an enzyme DAP decarboxylase that removes the carboxyl group from DAP to produce lysine
  10. 10. 2. L-Glutamic Acid Production: • Produced by certain species of Micrococcus, Arthrobacter and Brevibacterium . • Medium consists of carbohydrates , peptone, inorganic salts & biotin. • Precursor : -ketoglutaric acid ; enzyme: glutamic dehydrogenase. • Used in food supplement for human and animals, and its sodium salt (monosodium glutamate) is utilized in food preparation. • Used as condiment & flavor-enhancing agent in form of monosodium glutamate. Brevibacterium
  11. 11.  This organic compound used in flavoring extracts in soft drinks, foods & candies; in inks,dyeing, pharmaceuticals (like anticoagulant).  Organism most widely used is the mold: Aspergillus niger  Substrate: Molasses  Sterile medium in dispensed into shallow pans – inoculated with mold pores – under aerobic conditions  Submerged-culture technique: inoculated medium contained in large tanks through wide supply of air is forced; following affects the yield of citric acid:  Strain of mold employed  Composition of medium  Degree of aeration  Temperature of incubation
  12. 12. • Food supplements • Microbes can provide inexpensive source of vitames i) Riboflavin (vitamin B2)  Produced by Ashbya gossypii(fungi) by fermentation, a mold that produces 20,000 times the amount it needs for its metabolism. Ashbya gossypii
  13. 13. ii) Cyanocobalamin (Vitamin B12) • Produced by Pseudomonas, Propionibacterium, Streptomyces grown in a cobalt-supplement medium. • This vitamin used in bread, flour, cereal products and animal feeds Propionibacterium iii) Ascorbic Acid (Vitamin C ) • Produced at the rate of 20,000 tonnes per year • by a complicated modification of glucose by Acetobacter sp.
  14. 14. i) Amylase  produced by the mold of Aspergillus oryzae  Used as a spot remover in laundry presoaks, as an adhesive in baking. Aspergillus oryzae Clostridium spp ii) Pectinase  produced by Clostridium sp.  used to ret flex for linen and also used in fruit juice.
  15. 15. iii) Proteases  group of protein digesting enzyme produced by Bacillus subtilis, Aspergillus oryzae  Certain proteases are used in leather manufacturing, liquid glues, laundry presoaks, meat tenderizers, drain openers and spot removers. Yeast iv) Invertase  produced by yeasts  use in making soft centered chocolate Bacillus subtilis
  16. 16. v)Rennin  Produced commercially by fungi; but more recently by genetically modified bacteria  Used to form curds in milk vi) Alginates  Is a typical of the miscellaneous microbial products.  Is a sticky substrate used as a thickener in ice cream, soups or other food.
  17. 17.  Industrial fermentation – Large scale cultivation of microbes/single cells – to produce desired products Used in anaerobic food fermentations: o Vinegar production o Lactic acidproduction o Brewing & wine making industries o Dairy products In biotechnology to obtain useful products from GM plants & animals Vessels called as BIOREACTORS – to control:  Aeration  pH control  temperature
  18. 18. • Derived from French word vinagre, meaning sour wine. • Steps of production: 1. An alcoholic fermentation of carbohydrate – yeast fermentation 2. Oxidation of alcohol to acetic acid – the acetic acid bacteria , species of genus Acetobacter (inoculated onto the shavings) • Medium : milk used in “building-up” the inoculum
  19. 19. • Vinegar, apple vinegar, cider vinegar
  20. 20. Lactic acid • A compound employed to preserve foods, finish fabrics • Lactic acid is commonly produced by bacterial activity on the whey portion of milk. • Microorganism involved in this organic compound: Lactobulgaricus
  21. 21. Beer
  22. 22.  involves growth of Saccharomyces cerevisiae (baker’s yeast) under aerobic conditions  maximizes CO2 production, which leavens bread  other microbes used to make special breads (e.g., sourdough bread)  can be spoiled by Bacillus species that produce ropiness
  23. 23. Yogurt  Milk is feremented by a mixture of Streptococcus salivarius ssp thermophilus and Lactobacillus bulgaricus Often these two are co-cultured with other lactic acid bacteria for taste or health effects (probiotics). These include L. acidophilus, L. casei and Bifidobacterium species.  Acid produced from the fermentation causes the protein in the milk (casein) to coagulate into a semisolid curd
  24. 24. Cheese  Milk is treated with lactic acid bacteria and an enzyme called rennin that partially hydrolyses the protein and causes it to coagulate into “curds.” The liquid portion of the milk at this time is called “whey.”  The whey is separated from the curds, and the curds are aged (“ripened”)  Different microbes in the early and late stages of processing give rise to cheeses with different characteristics
  25. 25. Other fermented foods  sausages  hams  bologna  salami  izushi – fish, rice, and vegetables  katsuobushi – tuna  sauerkraut
  26. 26. for Your Attention...

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