Food Biotechnology

Food Biotechnology

1. Techniques

   • Manipulating genes in food production
     • Restriction enzyme (cuts DNA only at specific sequences) and DNA ligase (join together 2 DNA strands) are used
     • Using messenger RNA (mRNA): more precise way
       • makes DNA from mRNA using reverse transcriptase, then DNA polymerase
   • Inserting DNA into plasmids
     • Plasmids responsible for carrying genes that grant resistance to the organism to antibiotics
   • Inserting DNA into cells
     • Ballistic bombardment: shot into plant tissue
     • Electroporation: electric field applied to bacteria cells, allowing pores to appear momentarily => DNA inserted
     • Microinjection: used for animal cells
   • Screening cells for gene insertion
     • Verifies whether it was successful insertion by using marker genes (that code for easily recognizable product)
       • Followed by Polymerase Chain Reaction (PCR) that generates copies of DNA in short period of time
   • Gene expression through genetic switches: confirms whether the cell receiving the desired gene has the ability to express it and to synthesize the resulting product
   • Propagating growth of genetically engineered cells
     • Bacteria: bioreactors or fermentors
     • Plant tissue: grown in cell culture under controlled lab conditions
     • Animal production: inserted into surrogate mothers and allowed to mature

2. Substantial equivalence: food should be substantially equivalent to an existing food => considered as safe as the conventional food

   • Substantially equivalent: genetically engineered organism needs to be characterized; food product resulting from the genetic manipulation must be characterized
   • Substantially equivalent foods, except for defined differences: require safety assessment for the defined difference
   • Not substantially equivalent to existing foods: no conventional counterpart

3. Improving food processing aids

   • Amino acids: glutamic acid; phenylalanine
   • Gums: overproduction; xanthan gum; gellan
   • Enzymes: pectinase; proteases; chymosin
   • Microorganisms: insert S. diastaticus gene that codes for amylase into S. cerevisiae to break down starch without affecting taste

4. Improving Animal products

   • Bovine somatotropin hormone (BST): increase milk production
   • Probiotics
   • Lactoferrin: produce healthier animals => minimize need for antibiotic therapy

5. Improving Plant products

   • Insect-resistant: insert CRY protein that is toxic to insects into E. coli
   • Herbicide-resistant: degrade active ingredient in herbicides
   • Microbial disease-resistant: vaccine inserted
   • Drought-resistant: trehalose
   • Pevent spoilage: antisensing => prevent gene expression of polygalacturonase (PG) that causes softening
   • Enhancing quality attributes: genes of natural sweeteners like Thaumatin inserted
   • Increase nutritional content
   • Prevent production of harmful compounds: cassava with low levels of cyanogenic compounds

6. Benefits & Concerns

   • Benefits
     • Alleviating food shortages
     • Minimizing impact on the environment
     • Improving nutritional health
   • Concerns
     • Harmful?
     • Harm ecosystem balance?
     • Dictation of food biotech practices by big companies?
     • Creation of unnatural consequences?