Which is not a type of bioremediation

Bioremediation treatments can be in situ or _____

Link the correct descriptions of the bioremediation techniques

Pick the valid disadvantages of bioremediation

The time during which humans have had a substantial impact on our planet

Pick the 5 different types of bioenergy

3 main objectives of ______ are:

1. Reduce organic content (reduction of BOD)

2. Removal/reduction of nutrients i.e., Nitrogen, Phosporus

3. Removal/inactivation of pathogenic microbes

The oxidation of a parent compound to form CO₂ & water, providing energy for growth and reproduction

When partial or incomplete degradation results in synthesis of compounds more complex & stable than parent compounds, that is called...?

_____ is the simultaneous degradation of two compounds where the degradation of the 2nd compound depends on the presence of the 1st compound.

What is the main difference in mineralization of aerobic and anaerobic organisms?

The process of organic compound mineralization is ____ for all substrates e.g. glucose, cellulose, pollutant

______ enzymes degrade macromolecules external to the cell and allow uptake of smaller subunits

Contaminants with similar structures to naturalsubstrates are most easily degraded; opposite is truefor those with unusual chemical structures

Cometabolism occurs when an organism _____ an organic compound, though it cannot use the substrate as an energy source and derives no benefit.

In cometabolism, no energy is available, nor are any of the (C, N, P, S, etc) elements in the compound used as a significant source of material for biosynthetic activity

Co-metabolism is never "accidental" or "fortuitous”

Compounds co-metabolized are _____ normal substrates of the cells, differing sufficiently so that their immediate products cannot be further metabolized

Why organisms perform co-metabolism?

Which is NOT an example of Cometabolism

In ______ initial degradation steps create reactive intermediates which combine with each other or other organic matter to create dimers/polymers.

Substances formed from polymerization are highly stable due to ....

The max level of microbial activity that can be expected under existing environmental conditions.

Hint: Large C inputs may exceed this, causing environmental pollution

Main factors affecting microbial activity and degradation capacity

Previous exposure to contaminant (repeated pesticide applications, frequent spills) causes genes in biodegradation pathway to remain ‘off’

MOs go through a period of _____ when first exposed to a contaminant; time to produce enzymes capable of degradation

When does degradation require genetic changes (mutation, gene transfer) and much longer time frames?

Many organic contaminants have low solubility and form  _____ systems with water (e.g. PCBs, TCE, benzene)

Degradation can occur quickly if the contaminant is not in water-soluble form

Degradation of contaminants that have low water solubility or are strongly sorbed to soil is limited due to

Link the descriptions of contaminant structure factors that affect degradation

As electronegativity increases, biodegradability _____

Accumulation of toxins in cell membrane often result in  ____

Environmental factors affect biodegradation bc they affect MO activity and survival. Pick the correct options

Aerobic degradation is much slower than anaerobic degradation

Oxygen is especially important for the degradation of highly reduced  (E.g. _____ hexadecane C16H34)

Benzene, benzoate, phenol & toluene can be biodegraded under _____ conditions, but reactions are slower and require much longer adaptation periods

Low organic matter = low bacterial numbers = small population of contaminant degraders = slow degradation until population is increased

Link the biodegradation areas with the appropriate results

Microbial utilization of organic contaminants (especially hydrocarbons) creates a demand for _____ and ______

Biodegradation can often be improved by adding fertilizers that contain what? (especially true in oil spill clean-up)

Structure of most contaminants is based on one of the following 3 structures, namely _________. More complex molecules are created by combining &/or adding to these basic structures.

n-alkanes (straight-chain) are structurally similar to fatty acids & plant paraffins and used by many MOs for carbon & energy

____ is the most readily biodegradable type of hydrocarbon

The most common pathway of aerobic degradation involves _______ to one end of the chain by monooxygenase enzyme (1˚ alcohol)

Degradation produces fatty acids as the end product

Arrange according to biodegradability

Why is there much less research done on biodegradation of alicyclics? They are major components of crude oil (20-70%).

Steric effect affects halogenated aliphatics, while the electronic effect is mostly on branched branched aliphatics

Unsubstituted Aromatics contain at least one unsaturated ring system with the general formula ____ (benzene)

Polyaromatics have several shown to be toxic to MOs and carcinogenic in humans; biodegradation extensively studied

Arrange the steps of degradation of unsubstituted aromatics

The toxicity, environmental persistence and lipid solubility of unsubstituted aromatics increase as number of rings _____

The indigenous level of contaminant degradation that occurs without any stimulation or treatment is called ...

Organize the pros and cons of bioremediation

To be capable of bioremediation, microbes (e.g. Alcanivorax borkumensis) must ....

Most abundant components of herbicides (DDT) are ....

A variety of bacteria, algae & fungi can metabolize PAHs. Pick the applicable cyanobacteria

Most developed bioremediation technologies are based on two standard practices which are

Oxygen is commonly a limiting factor in bioremediation because of low solubility in water and ___ rate of diffusion through air and water

Group accordingly

When organic waste sites are rich in carbon, what elements are growth limiting? (The primarily added nutrients)

The optimal ratio of Carbon:Nitrogen:Phosphorus

Modification of the environment to stimulate existing bacteria capable of bioremediation is called ...

_______ is the addition of specific biodegrading MOs at contaminated sites to enhance the existing populations. Genetic engineering can be used to create MOs that degrade pollutants at extremely rapid rates

What causes the failure of genetically engineered bugs for bioaugmentation? Can be overcome with bioreactor use due to controlled conditions

The method of adding specific genes that provide a specific degradation capability to indigenous MO populations depends on what processes for delivery and uptake?