Antibiotics and Deep Tank Fermenters Alexander Flemming had mold (Penicillium notatum) grow on a petri dish of bacteria He noticed that mold inhibited the growth of the bacteria Today, we need large scale production of antibiotics (fermentation) Fermenters (large tank) have The right size, way to mix the microorganisms with substrates, probes to monitor optimum conditions, and ways to prevent contamination Penicillium chrysogenum is put into the tank without glucose When the mold is missing glucose (its energy source) it produces Penicillin as a secondary metabolite When stressed, it produced penicillin to protect itself from other bacteria that may harm it

Antibiotics and Deep Tank Fermenters

Citric Acid Citric Acid is a metabolite also produced by mold (Aspergillus niger) Used as a food preservative and flavor enhancer Continuous-batch fermentation is used (substrate added and product removed continuously)

Biogas Production One option for renewable energy Uses prokaryotes and archaea (extremophiles discovered by Carl Woese) Biogas is made of: methane, carbon dioxide, nitrogen, hydrogen sulfide, water 4 stages of production- each stage requires specific microorganisms The last stage, production of methane, requires an archaea species No oxygen can be in the tank (bacteria used are anaerobic)

Biogas Production

Zone of Inhibition

Bioremediation Bioremediation is the field that uses biological agents (mostly microbes) to clean up environmental problems Bacteria can be used to break down pollutants that can harm the environmental or living organisms Polluted water, oil spills, mercury pollution, benzene pollution

Example 1: Marinobacter and Benzene Benzene can be released into the water during oil exploration Benzene is a carcinogen and is very stable Marinobacter is used because it can live in high salt environments Salty water (brine) is also produced during oil exploration Marinobacter breaks benzene down in carbon dioxide

Example 2: Pseudomonas and Oil Physical and chemical clean ups of oil spills are not that effective Oil can harm marine and terrestrial ecosystems Pseudomonas can degrade oil is rhamnolipid is present Works even better if glycerol is present Glycerol is thought to give the Pseudomonas extra nutrients 58% of crude oil was degraded in one experiment done in 2005

Example 3: Pseudomonas and Mercury Pollution Mercury is discarded from paint and light bulbs Mercury can get into the soil and water and be dangerous to animals and humans Mercury gets converted into methyl-mercury by Desulfovibrio desulfuricans Methyl-mercury can attach to smaller fish, which are eaten by bigger fish Humans then eat the bigger fish and digest the methyl-mercury Pseudomonas converts methyl-mercury into elemental mercury which is harmless

Example 4: Bacteriophage and Water Treatment Bacteriophages are viruses that infect and can kill bacteria Bacteriophages are present in human waste products They are easy to detect They can be used as an indicator organism to determine if water in contaminated