Wednesday, July 27, 2011

Histroy of Biotechnology

1. Modern Biotechnology



What is biotechnology?


k using scientific methods with organisms to produce new products or new forms of organisms


k any technique that uses living organisms or substances from those organisms to make or modify a product, to improve plants or animals, or to develop micro-organisms for specific uses



Biotechnology is the Multidisciplinary Science


k cell and molecular biology


k microbiology


k genetics


k anatomy and physiology


k biochemistry


k engineering


k computer Science


Computers in Biotechnology


· Computer simulations with virtual reality and other uses help in biotechnology.


· Computer modeling may be done before it is tested with animals


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Application


k virus-resistant crop plants and livestock


k diagnostics for detecting genetic diseases and acquired diseases


k therapies that use genes to cure diseases


k recombinant vaccines to prevent disease


k biotechnology can also aid the environment



Goals of Biotechnology


k To understand more about the processes of inheritance and gene expression


k To provide better understanding & treatment of various diseases, particularly genetic disorders


k To generate economic benefits, including improved plants and animals for agriculture and efficient production of valuable biological molecules


Example: Vitamin A fortified engineered rice



k Ancient biotechnology- early history as related to food and shelter; Includes domestication



k Classical biotechnology- built on ancient biotechnology; Fermentation promoted food production, and medicine



k Modern biotechnology- manipulates genetic information in organism; Genetic engineering



Ancient biotechnology:-History of Domestication and Agriculture



  • Paleolithic peoples began to settle and develop agrarian societies about 10,000 years age



  • Early farmers in the Near East cultivated wheat, barley, and possibly rye



  • 7,000 years ago, pastoralists roamed the Sahara region of Africa with sheep, goats, cattle, and also hunted and used grinding stones in food preparation



  • Early farmers arrived in Egypt 6,000 years ago with cattle, sheep, goats, and crops such as barley, emmer, and chick-pea



  • Archaeologists have found ancient farming sites in the Americas, the Far East, and Europe



  • Not sure why peoples began to settle down and become sedentary

Ø May be in response to population increases and the increasing demand for food


Ø Shifts in climate


Ø The dwindling of the herds of migratory animals


Ø Early Farmers could control their environment when previous peoples could not


Ø People collected the seeds of wild plants for cultivation and domesticated some species of wild animals living around them, performing selective breeding



Ancient Plant germplasm


k The ancient Egyptians saved seeds and tubers, thus saved genetic stocks for future seasons



k Nikolai Vavilov, a plant geneticist, came up with first real plan for crop genetic resource management



k National Seed Storage Laboratory in Fort Collins, Colorado is a center for germplasm storage in the U.S.



k Agricultural expansion and the use of herbicides has put germplasm in danger and led to a global effort to salvage germplasm for gene banks



Classical biotechnology:-Fermented food, 1500 BC


Describes the development that fermentation has taken place from ancient times to the present


k Yeast - fruit juice wine


k Brewing beer - CO2


k Baking bread, alcohol


k Egyptians used yeast in 1500 B.C.


k 1915-1920 Baker’s Yeast


k Fermentation: microbial process in which enzymatically controlled transformations of organic compounds occur


k Fermentation has been practiced for years and has resulted in foods such as bread, wine, and beer


k 9000 B.C. - Drawing of cow being milked Yogurt - 4000 B.C. Chinese Cheese curd from milk - 5000-9000 years ago


k Fermented dough was discovered by accident when dough was not baked immediately



Modern cheese manufacturing involves:


k inoculating milk with lactic acid bacteria


k adding enzymes such as rennet to curdle casein


k heating


k separating curd from whey


k draining the whey


k salting


k pressing the curd


k ripening



k Beer making began as early as 6000-5000 B.C.


k Egypt ~5000 B.C made wine from grapes


k Barley malt – earthenware


Yeast found in ancient beer urns


k Monasteries - major brewers


k 1680 - Leeuwenhoek observed yeast under microscope


k Between 1866 and 1876 - Pasteur established that yeast and other microbes were responsible for fermentation.



k Top fermentation - developed first, yeast rise to top



k 1833 - Bottom fermentation - yeast remain on bottom



k 1886 – Brewing equipment made by E.C. Hansen and still used today



k World War I – fermentation of organic solvents for explosives (glycerol)



k World War II – bioreactor or fermenter:


k Antibiotics


k Cholesterol – Steroids


k Amino acids


k large quantities of vinegar are produced by Acetobacter on a substrate of wood chips


k fermented fruit juice is introduced at the top of the column and the column is oxygenated from the bottom





Classic Biotechnology Advances


k In the 1950’s, cholesterol was converted to cortisol and sex hormones by reactions such as microbial hydroxylation (addition of -OH group)



k By the mid-1950’s, amino acids and other primary metabolites (needed for cell growth) were produced, as well as enzymes and vitamins



k By the 1960’s, microbes were being used as sources of protein and other molecules called secondary metabolites (not needed for cell growth)


k Today many things are produced:


k Pharmaceutical compounds such as antibiotics


k Amino Acids


k Many chemicals, hormones, and pigments


k Enzymes with a large variety of uses


k Biomass for commercial and animal consumption (such as single-cell protein)



Old Biotechnology meets new


k Fermentation and genetic engineering have been used in food production since the 1980s


k Genetically engineered organisms are cultured in fermenters and are modified to produce large quantities of desirable enzymes, which are extracted and purified


k Enzymes are used in the production of milk, cheese, beer, wine, candy, vitamins, and mineral supplements


k Genetic engineering has been used to increase the amount and purity of enzymes, to improve an enzyme’s function, and to provide a more cost-efficient method to produce enzymes.


k Chymosin, used in cheese production, was one of the first produced



Foundation of Modern Biotechnology


k 1590 - Zacharias Janssen - First two lens microscope (30x)



k 1665 - Robert Hooke - Cork “Cellulae” (Small Chambers)



k Anthony van Leeuwenhoek – (200x) 1676 - animalcules (in pond water) 1684 - protozoa/fungi



k 1838, Matthias Schleiden, determined that all plant tissue was composed of cells and that each plant arose from a single cell


k 1839, Theodor Schwann, came to a similar determination as Schleiden, for animals


k 1858, Rudolf Virchow, concluded that all cells arise from cells and the cell is the basic unit of life


k Before cell theory the main belief was vitalism: whole organism, not individual parts, posses life


k By the early 1880s, microscopes, tissue preservation technology, and stains allowed scientists to better understand cell structure and function



Transforming principle


k 1928 - Fred Griffith performed experiments using Streptococcus pneumonia



k Two strains: Smooth (S) - Virulent (gel coat) Rough (R) - Less Virulent




k Injected R and heat-killed S - mice died and contained S bacteria



k Unsure of what changed R to S, which he called the “Transforming principle”





1952 – Alfred Hershey and Martha Chase



k Used T2 bacteriophage, a virus that infects bacteria


k Radiolabeled the bacteriophage with S35 (Protein) and P32 (DNA)


k Bacterial cells were infected and put in a blender to remove phage particles


k Analysis showed labeled DNA inside the bacteria and was the genetic material





1953 watson and crick


k Determined the structure of DNA


k Rosalind Franklin and Maurice Wilkins provided X-ray diffraction data


k Erwin Chargaff determined the ratios of nitrogen bases in DNA


k DNA replication model - 1953


k DNA bases made up of purine and pyrimidine


k Nobel Prize - 1962



First recombinant DNA experiments


k 1971 scientists manipulated DNA and placed them into bacteria


k 1972 scientists joined two DNA molecules from different sources using the endonuclease EcoRI (to cut) and DNA ligase (to reseal)


k Herbert Boyer later went to Cold Spring Harbor Laboratories and discovered a new technique called gel electrophoresis to separate DNA fragments


k A current is applied so that the negative charged DNA molecules migrate towards the positive electrode and is separated by fragment size




Biotech revolution: cracking the code


k 1961, Nirenberg and Mattei made the first attempt to break the genetic code, using synthetic messenger RNA (mRNA)


k Nirenberg and Leder developed a binding assay that allowed them to determine which triplet codons specified which amino acids by using RNA sequences of specific codons



First DNA cloning


k Boyer, Helling Cohen, and Chang joined DNA fragments in a vector, and transformed an E. coli cell



k Cohen and Chang found they could place bacterial DNA into an unrelated bacterial species



k In 1980 Boyer and Cohen received a patent for the basic methods of DNA cloning and transformation



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