Applied Microbiology Final Exam

Essential Amino Acids

amino acids that must be obtained from the proteins in their diet

Auxotrophic Mutants

require growth factors because it cannot survive without the amino acid whose biosynthesis is blocked

Polyesters

any of a group of polymers that consist basically of repeated units of an ester

Comentabolism

simultaneous degradation of two compounds

What are the 2 methods of regulation in amino acid synthesis

Repression and Attenuation

How is xanthan gum used?

Emulsifier or thickener

What are the advantages of using microbial produced plastics?

Higher density ensures that objects sink to the bottom sediment layers, where they will degrade. Eliminate reliance an oil and gas to manufacture plastics and are attractive because they are made by a renewable source.

Biomass

collective organic matter produced by living organisms

Bioconversion

converting biomass into alternative energy sources

Hemicellulose

polysaccharides noncovalently associated with cellulose

Biofuels

renewable replacement fuels

Batch Production

product is harvested at completion of the fermentation

Continuous Flow Production

Substrates are fed continuously past immobilized enzymes or into a culture of growing cells, spent medium & desired product are continuously removed

What are the important characteristics of the ideal fermentation microbe?

Ability to ferment a broad range of carbohydrate substrates rapidly

Ethanol tolerance and the ability to produce high concentrations of ethanol

Osmo tolerance

Temperature of tolerance

 High cell viability for repeating recycling

 Appropriate flocculation and sedimentation characteristics to facilitate cell recycling

What happens in the stages of industrial fermentation of alcohol?

Gelatinization of milled grain

Liquifying materials using alpha-amylase

Saccharification of material

Fermentation by yeast

What are the different fuel sources that microbes can make?

Ethanol, Hydrogen, Oil

What are the benefits of using algae to make biofuels?

Does not take up farmland, Main requirement is light, Produces more energy than corn

What conditions need to be monitors in bioreactors?

Temperature, pH, Oxygen Levels

What are industrial products that microbes can produce?

Amino Acids, Industrial Enzymes, Vitamins, and Citric Acid

What types of proteins can be used as therapeutics?

Enzymes and Antibodies

Why are lactic acid bacteria helpful in delivering therapeutic proteins?

Normally associated with human tissues and has previously been shown to be safe

What are the different types of nucleic acids that can be used as therapeutics?

Anti-sense oligonucleotide, small RNA molecules (aptamers), ribozymes and DNAzymes, interfering RNAs, nanozymes, Zinc finger nucleases & CRISPR-Cas nuclease

What are viral vectors?

Virus used to deliver therapeutic genes

Primary Metabolite

substance produced during the growth of new cells.

Secondary Metabolites

substances produced when microbes have entered the stationary phase.

Antibiotics

compounds active against bacteria

Integrons

are resistance genes organized in a single operon.

What are some of the useful secondary metabolites?

Chemotherapeutic Agents, Protease/Peptidase inhibitors, Inhibitors of cholesterol biosynthesis, and Immunosuppressants

What are the different types of antibiotics active against?

Beta-Lactams (Gram positive bacteria), Aminoglycans (Gram positive and gram-negative bacteria), Macrolides (Against gram positive bacteria), Tetracyclines, Gram positive and gram-negative bacteria), Chloramphenicol (Gram positive and gram-negative bacteria), Carbapenems (Gram positive and gram-negative bacteria), and Peptide Antibiotics (Gram positive with some exceptions).

What are the primary goals of antibiotic research?

Improve the yield of an antibiotic during fermentation and subsequent processing steps, Development of new agents, and dealing with antibiotic resistant organisms

Why were semisynthetic penicillins developed?

To get around the penicillin resistance from the penicillinases

How many generations of cephalosporins exist?

5

What signals the production of antibiotics?

Quorum Sensing

Biogeochemical Cycles

recycling of chemical elements by microbes for use by other organisms

Deamination

 

amino groups removed & converted to ammonia (NH₃)

Ammonification

release of ammonia by bacteria & fungi

Nitrification

oxidation of ammonium ions to produce nitrate

Denitrification

nitrate used as an electron acceptor by microbes in the absence of oxygen

Nitrogen Fixation

bacterial process that converts nitrogen gas to ammonia

Lichens

combination of fungus & algae or cyanobacteria in a mutualistic relationship

Dissimilation

protein decomposition releases H₂S into the sulfur cycle

Endoliths

bacteria in rocks & must grow in the near absence of oxygen & with minimal nutrient supplies

What compounds are found in fertilizer?

Nitrogen and Phosphorus

What organisms are involved in carbon fixation? Nitrogen fixation?

Carbon Fixation (Photoautotrophs; algae, lichens, and cyanobacteria) and Nitrogen Fixation (Azotobacter, Beijerinckia, Clostridium pasteurianum, Cyanobacteria, Rhizobium, Bradyrhizobium, Frankia & lichens)

What happens in the different steps of the carbon cycle, include the microbial role in the cycle?

First step in carbon cycle is when photoautotrophs fix carbon dioxide into organic matter using energy from sunlight. The next step is when chemoautotrophs use organic matter for energy; bacteria and fungi decompose organic compounds from dead plants and animals.

Why is it important for microbes to participate in the global nutrient cycles?

Reuse by compounds by living organism and in generating energy, without microbes, life would not exist.

Where does phosphate accumulate and where does it come from?

Accumulate in the sea and Deposited by bird droppings

Which biogeochemical cycles have an atmospheric cycle, and which does not?

Phosphorus (no), Carbon (Yes), Nitrogen (Yes), and Sulfur (Yes)

How can bacteria increase the Earth’s temperature?

Generation of Methane

Biomining

 

microbes are used to leach metals from low-grade ores

Biosportion

microbes are used to leach metals from low-grade ores

What are common properties of microbes involved in biomining?

Chemolithoautotrophs and Acidophiles

 

Which microbes are used in biomining?

Acidithiobacillus ferrooxidans and Leptospirillium ferrooxidans

How does dump leaching work?

Broken rock is piled 100 or more feet high on a relievedly impermeable surface and watered. Water is repeatedly circulated and recirculated through the piles of rock. Pyrite oxidizes, causing solution to become strongly acidic and rich in ferric sulfate. Continued recirculation causes other metal sulfides to be solubilized and effluent is pumped into a basic called a launder and iron scraps are added to precipitate the copper. Remaining Fe²⁺-rich solution is transferred to shallow oxidation ponds where A. ferroxidans, from ore, rapidly oxidizes Fe²⁺—> Fe³⁺and forms some additional sulfuric acid through oxidation of sulfur compounds. Much of Fe³⁺ precipitates as ferric hydroxide Fe(OH)₃. Supernatant acidic ferric sulfate solution is then pumped back to the top of the dump.

What substances can microbes help to mine?

Copper, uranium, Gold, and Coal

What are the benefits of biomining?

Bioleaching causes minimal damage to the environment, could drastically reduce the amount of greenhouse gasses in our atmosphere, simple process that does not require a lot of expertise to operate or complicated machinery, energy consumption is less than traditional mining.

What are the disadvantages of biomining?

Bacteria dissolve metal at a significantly lower rate than the mining and smelting process, and heat created from the dissolving process can kill the bacteria if too much happens at once.

What do microbes remove from coal?

Sulfur

What can bioleaching remove from the environment?

Arsenic and other harmful things

What are the different pathways of biomining?

Thiosulfate Pathway, Polysulfide Pathway, and Acid Solubility

Aquatic Microbiology

study of microbes & activities in natural waters

Bioluminescence

light emission by living organisms

Eutrophication

overabundance of nutrients in lakes & streams

Indicator Organisms

used to detect fecal contamination of water

Flocculation

removal of colloidal materials (clay), bacteria, & viruses by adding alum

Filtration

passing water through fine sand or charcoal; microbes adsorb to sand particles

Drinking water is tested for what microbes?

Coliforms, Giardia, and Cryptosporidium

What are the methods for determining the presence of coliforms in water?

Most Probable Number (MPN), Membrane Filtration Method, ONPG, and MUG

Where are a majority of the photosynthetic organism found in freshwater?

Limnetic Zone

What are the steps in water treatment?

Coagulation and Filtration (Particulates in raw water settle out, Flocculation, Filtration) and Disinfection by chlorination, ozone treatment, and or UV light

How is water disinfected in water treatment?

Disinfection by chlorination, Ozone treatment, UV light

What happens if too much phosphate is released onto water?

Overgrowth of algae

Sewage (wastewater)

all the water from a household that is used for washing & toilet wastes

Biochemical oxygen demand

measure of the biodegradable organic matter in water

Bulking

floating sludge

What happens in the different steps in sewage treatment?

Primary Sewage treatment, Secondary sewage treatment, Disinfection and release, sludge digestion, oxidation ponds, and tertiary sewage treatment

Why is the presence of estrogen in water a concern?

Interfere with the hormonal system of human and animals

Where is methane produced during sewage treatment?

Sludge digestor

Bioremediation

of microbes to detoxify or degrade pollutants

Biodegradable Organic Compound

undergoes a biological transformation

Mineralization

complete degradation to end products of CO₂, water & other inorganic compounds

Persistent Organic Compound:

does not undergo biodegradation in certain environments

Recalcitrant Compound

resists biodegradation in a wide variety of environments

Xenobiotics

chemicals that do not naturally occur in nature

Commensalism

interactive association between two populations of different species where one population benefits while the other is not affected

Mutualism

interaction of two organisms of different species in which both benefit

What conditions are needed for bioremediation?

Aerobic and Anaerobic

What agency regulated pollutants?

U.S. Environmental Protection Agency

How is a microbial community better at dealing with a toxic substance compared to a single species of microbe?

Likely to be more resistant to toxic product of biodegradation, because one of its members be able to detoxify it. Microbial community is dynamic

What is required for composting?

Mixture of soil, partially decayed plants and sometimes manure of commercial fertilizer. Periodic turning or raking of the compost pile

What are the different types of bioremediations?

Composting, Land Farming, in-situ, and above ground bioreactors

How are microbes modified to increase their degradation pathways?

Get different plasmids (genes)

Why is fertilizer used in bioremediation?

Adds nitrate and phosphate

Are microbes able to effectively work in municipal landfills?

No, because its anaerobic

What type of microbes do you need for the effective breakdown of organic compounds in the environment?

Many different types of microbes