Applied Biochemistry

• What is the general background of bioremediation?

  It involves using biological processes to remove pollutants.
• What percentage of soil contaminants are organic?

  65%
• What are the main sources of pollutants in soils?

  Industrial activities, poor waste disposal, accidental spillages
• Why are hydrophobic organic pollutants particularly concerning?

  They are persistent in soils.
• What are the main types of organic pollutants mentioned?

  • Mineral oils (24%)
  • Polycyclic aromatic hydrocarbons (PAHs) (11%)
  • BTEX compounds (10%)
  • Chlorinated hydrocarbons (8%)
  • Others (organic) (12%)
• What are the toxicity concerns associated with mineral oils?

  Toxicity from both oils and additives
• What are the sources of polycyclic aromatic hydrocarbons (PAHs)?

  Combustion of fossil fuels, waste disposal, accidental spills
• What are the health risks associated with BTEX compounds?

  Carcinogenic and neurotoxic effects
• What are chlorinated hydrocarbons commonly used for?

  Solvents, pesticides, preservative agents
• What percentage of pollutants are heavy metals?

  35%
• What are the main remediation strategies mentioned?

  • Excavation and disposal as landfill
  • Soil washing
  • Solvent extraction
  • Advanced oxidation
  • Incineration
  • Bioremediation (microbial and enzymatic)
• What is a disadvantage of microbial bioremediation?

  Pollutants may be toxic to the microbes
• What is a key advantage of enzymatic bioremediation?

  It does not rely on living organisms
• What are the conditions required for enzymatic bioremediation?

  • Temperature
  • pH
  • High affinity to substrate
  • High activity
• What is a disadvantage of in situ enzymatic bioremediation?

  No control on environmental conditions
• What is a benefit of ex situ enzymatic bioremediation?

  More controlled conditions
• What is required for enzymes to be effective in bioremediation?

  High stability and broad operational conditions
• What methods are used for enhancing enzymes for bioremediation?

  • Identification of novel enzymes using functional metagenomics
  • Directed evolution to improve features
  • Nanotechnology for enzyme immobilisation
• What is the purpose of directed evolution in enzyme engineering?

  To improve features or expand substrate range
• What is the main focus of the summary regarding enzymatic bioremediation?

  It is largely unexploited but promising
• What are the critical factors for enzymatic bioremediation applications?

  • Identify enzymes with suitable properties
  • Lower costs of enzyme production
  • Emerging engineering approaches