Definition of Biotechnology in Canadian Legislation Biotechnology is the application of science and engineering in the direct or indirect use of living organisms in their natural or modified forms Commonly accepted definition Biotechnology is the application of scientific and engineering principles to the processing of materials by biological agents to provide goods and services Biotech products are ubiquitous New and improved foods Industrial chemicals Pharmaceuticals Livestock Agriculture Diagnostics Bioremediation

Organisms and cells used in Biotechnology Every biotech process is dependent directly or indirectly on cells cells used include both eukaryotes and prokaryotes bacteria e.g. E.coli, B. subtilis Yeast Cultured insect cells Cultured mammalian cells Plant cells Fungi

Micro-organisms used classified into wild type strains and recombinant strains Wild type -naturally occurring m/o e.g. Aspergillus oryzae soy sauce Saccharomyces cerevisiae ethanol Aspergillus niger citric acid Penicillin chrysogenum penicillin Recombinant strains- m/o that have had their genetic material altered using recombinant DNA technology also known as GMOs (genetically manipulated organisms

Bacteria Adv:  simple physiology  short generation times  large yield (up to 10% of mass)  can get some products secreted into the medium  certain specific bacteria are useful because we know a lot about their physiology and how to optimize growth  certain specific bacteria are useful because we know a lot about genetics Disadv:  Proteins cloned and expressed in them often do not fold properly so are biologically inactive  Synthesized protein may be toxic to bacteria  Bacteria lack enzymes for certain post translational modifications e.g. glycosylation Average bacterial cell is 1 – 4 um

Yeast- simple eukaryotes Adv easy to grow can perform many of post translational modifications required for human proteins can be induced to secrete certain proteins into growth medium for harvesting Disadv presence of active proteases that degrade foreign proteins Yeast are around 5-8um in diameter.

Immortal cell lines Animal cells, often derived from cancerous 20um diameter mammalian tumours and so cells grow and reproduce at a faster rate than normal cells Adv: grow indefinitely produce mammalian products with ease potentially hazardous Disadv: relatively slow to grow (comp to microbes) problematic for manipulation contamination Expensive Plant cells useful for manipulating plants beginning to be used in bioreactors too often the plant can be used as the bioreactor in the field e.g. golden rice some problems if need to isolate product Need no C source

Below are Epithelial cells in culture, stained for keratin (red) and DNA (green)Epithelial cellsstainedkeratinDNA One of the earliest human cell lines, the cultured HeLa cells shown here have been stained with Hoechst turning their nuclei blue.HeLaHoechstnuclei

Insect cells Another kind of eukaryotic cell Adv: Grow at room temperature Special features that allow over expression Disadv Difficult to work with Expensive Slow gen. Time Not suitable for proteins with repetitive sequences Insect cell line 15um diameter

Fungi  been used historically  difficult to manipulate  a lot known about culture conditions  just beginning to learn about  genetics and manipulation A Fungal hypha has a diameter of around 8 um

Electron Micrograph of Aspergillus showing Conidiospores

Viruses used as vectors in gene therapy e.g Herpes simplex Bacteriophage have potential as antibacterial agents