microbiome & contamination

Question 1

what is bioremediation

Answer 1

The clean up of oil or other toxic chemicals by microorganisms

Question 2

microorganisms are used for bioremediation to

Answer 2

Transforming Heavy Metals (mercury)
Petroleum Biodegradation
Biodegradation of synthetic chemicals (xenobiotics)

Question 3

true or false
mercury can be absorbed through the skin and could cause liver and kidney damage

Answer 3

true

Question 4

how is mercury released into the environment

Answer 4

fossil fuel combustion and mining industry

Question 5

atmospheric mercury is found in the form of: Hg⁰ – Vapour. whereas, oxidised mercuric form is Hg²⁺

Microorganisms – metabolize resulting in methylation - yields _________

Answer 5

methyl-mercury (CH3Hg+) which is a 100 X more toxic

Question 6

which bacteria biotransform mercury to its non toxic form?

Answer 6

Pseudomonas aeruginosa

Question 7

how can bioremediation of petroleum be accelerated?

Answer 7

adding nutrients and oxygen

Question 8

what is the benefit of xenobiotics (pesticides)

Answer 8

prevent toxic accumulations and they eventually disappear from the soil

Question 9

what is the role of polychlorinated biphenyls (PCB) xenobiotics in bioremediation

Answer 9

• Used as Industrial coolants or insulators
• Spills or leakage into the environment
• Eventually reaches groundwater
• Toxic, persistent and bio-accumulative

Question 10

what types of biodegradable plastics are there?

Answer 10

1. Photo-biodegradable: structure altered by sunlight (UV) - more amenable to microbial attack

2- 2. Starch-based plastic - starch used to link short fragments of a second biodegradable polymer

Question 11

define antibiotics

Answer 11

Chemicals produced by microorganisms that kill or inhibit growth of other microorganisms

Question 12

true or false

Streptomycetes produce > 2 / 3 of clinically used antibiotics (non-synthetic)

Answer 12

true

Question 13

Polysaccharides produced commercially used as a plasma substitute are known as

Answer 13

dextran

Question 14

which bacteria produce dextran from sucrose?

Answer 14

Lactic acid bacteria (Leuconostoc)

Question 15

what enzymes are often produced by streptococcal strains

Answer 15

streptokinase and streptodornase

Question 16

what does streptokinase and streptodornase do

Answer 16

streptokinase, reduces blood clots

streptodornase, liquefies pus – breaks down deoxyribonucleoprotein and DNA

Question 17

what type of pharmaceuticals do - Brevibacterium flavum - Corynebacterium glutamicum produce

Answer 17

amino acids

Question 18

which microorganisms produce riboflavin (vitamin b2)?

Answer 18

mould: Ashbya gossipii
bacterium: Bacillus subtilis

Question 19

which strains yield high amounts of cobalamin (vitamin b12)

Answer 19

Propionibacterium, Pseudomonas

Question 20

what does Clostridium botulinum produce?

Answer 20

botulinum toxin, which causes severe food poisoning, paralysis, respiratory failure and death

Question 21

which microorganisms produce insecticides

Answer 21

Bacillus thuringiensis and Bacillus sphaericus

Question 22

what is the top fermenting yeast and bottom fermenting yeast

Answer 22

top: Saccharomyces cerevisiae
bottom: Saccharomyces carlsbergensis

Question 23

“live micro-organisms which, when administered in adequate amounts, confer a health benefit on the host” are known as

Answer 23

probiotics

Question 24

how can you reduce microbial count from water samples

Answer 24

• chemical treatment (chlorination/NaCl)
• membrane filtration (filter paper)
• heating (80c)
• uv irradiation (short wavelength (250 nm) - UVC

Question 25

how can the operator reduce microbial count on themselves

Answer 25

* good hygiene * covering when coughing and sneezing * wearing gloves and protective garments

Question 26

how can you reduce microbial count from surfaces

Answer 26

in buildings: proper ventilation, use of disinfectants, proper window fitting in packaging: maintain integrity and shelf-life, delivery and limiting contamination measures equipment: sterilization, disinfection, single use items

Question 27

how can you reduce microbial count in air?

Answer 27

filtration: High-efficiency particulate air (HEPA) filters can remove up to 99.997% of particles greater than 0.3 µm in diameter (high pressure too) chemical disinfection uv irradiation

Question 28

where is the normal flora located in the body

Answer 28

nasopharynx small & large intestine vagina skin urethra stomach

Question 29

what is the metabolic function of the gut microbiota

Answer 29

* Undertake a variety of metabolic functions * Provide vital biochemical pathways for the metabolism of non-digestible carbohydrates (cellulose, hemicellulose, pectins, and gums), some oligosaccharides, unabsorbed sugars, alcohols and host-derived mucins * Synthesis of vitamins - Enteric bacteria secrete Vitamin K and Vitamin B12 * Stimulate the development of certain tissues (Caecum; caecum of germ-free animals is enlarged, thin-walled, and fluid-filled).

Question 30

what is the immune function of the microbiota

Answer 30

Produce antimicrobial compounds - Fatty acids and peroxides to highly specific bacteriocins. * Compete for nutrients and sites of attachment in the gut lining, preventing colonization by pathogens (barrier or competitive-exclusion effect) * Intestinal epithelium is the main interface between the immune system and the external environment. * Exposure to intestinal bacteria is also implicated in the prevention of allergy * The normal flora stimulates the production of cross-reactive antibodies.

Question 31

define The Gut–Brain Axis

Answer 31

Bidirectional communication system that integrates neural, hormonal, and immunological signalling between the gut and the brain.

Question 32

how does stress affect the gut microbiota?

Answer 32

* influences the composition of the gut microbiota * influences the integrity of the gut epithelium and alter peristalsis, secretions, and mucin production

Question 33

what is the function of mucins

Answer 33

* Glycoproteins that are expressed in cells * Signal transduction * Regulation of gene expression * Cell proliferation * Embryogenesis * Cell differentiation * Immunity * Apoptosis * Cancer

Question 34

what is Irritable Bowel Syndrome

Answer 34

Crohn’s disease and ulcerative colitis) • Gut microbiota alteration linked to low-grade intestinal inflammation (inflammatory Bowel Disease)

Question 35

what are the two Systemic Metabolic Diseases

Answer 35

obesity & diabetes type 2

Question 36

true or false Infants (1-12 months) with atopic eczema have a significantly lower bacterial diversity: Bacteroidetes and Proteobacteria

Answer 36

true

Question 37

Proteobacteria cell walls contain lipopolysaccharides. in relation to eczema, what do lipopolysaccharides induce?

Answer 37

immune response

Question 38

what causes pseudomembranous colitis?

Answer 38

antibiotic associated diarrhea, Clostridia difficile