WEEK 5 INCLASS WEDNESDAY FERMENTATION AND PHOTOSYNTHESIS FERMENTATION

WEEK 5 IN-CLASS WEDNESDAY FERMENTATION AND PHOTOSYNTHESIS

FERMENTATION ERRATUM: b-galactosidase converts galactose to glucose b-galactosidase converts lactose into glucose and galactose Lactase is part of the b-galactosidase family of enzymes

FERMENTATION E. coli is a Gram negative chemoheterotroph that switches between different processes to utilize sugars. In an experiment, scientists were growing E. coli in some enriched medium. When the bacilli was growing well, they removed all the medium and resuspended the live bacterial pellet in a fresh medium with lactose as the sole carbon source. These experiments were set up in multiple conditions to test different aspects of the cells metabolism as outlined below. Start from transcription of genes and end with bioenergetics to explain what would be the outcome of these experiments Tubes with X-gal Tubes with a p. H indicator Cells grown aerobically Experiment 1 Experiment 3 Cells grown in oxygen limited Experiment 2 Experiment 4

BACTERIAL FERMENTATION : SUGARS AND INDICATOR S. aureus ferments mannitol Acid turns p. H and medium yellow Acid and gas in liquid media E. coli ferments lactose in Eosin Methylene Blue Agar p. H change in indicator Low acid causes colonies to be pink High acid precipitates Eosin

FERMENTATION: MANNITOL • Presence of FA, ↑ mannitol fermentation • Mutating mannitol fermentation operon • Complementing with plasmids

FERMENTATION: LACTOSE (HOMO LACTIC – LACTOBACILLUS ) C 12 H 22 O 11+ H 2 O C 6 H 12 O 6 + C 6 H 12 O 6 CH 3 CH(OH) COOH cheesescience. net

FERMENTATION : LACTOSE (MIXED ACID – E. COLI ) Glucose Pyruvate 2 lactate Glucose Pyruvate Acetic acid + CO 2 Glucose Pyruvate Ethanol + CO 2 Glucose Pyruvate Acetoin + CO 2 Glucose Malate/Succinate/Fumarate DOI: 10. 3389/fmicb. 2015. 00150

FERMENTING LACTOSE: THOUGHT EXPERIMENT E. coli is a lactose fermenter and so is Lactobacillus acidophillus. Why is yougurt made with Lactobacillus spp instead of E. coli ? What would happen if E. coli was used instead? Provide evidence.

FERMENTATION TESTS A: Deamination of trypophan B: Acid production on glucose C: Butanediol production on Glucose D: Citrate as sole carbon source Acetoin Butanediol Citrate Pyruvate Kreb’s cycle

ANAEROBIC RESPIRATION: NITRATES uwyo. edu

AEROBIC RESPIRATION: OXIDASE vetsci. org TMPD + a-napthol Cyt c oxidase microbiology notes Indophenol blue • Obligate aerobes are always positive. Eg: Pseudomonas aeruginosa • Facultative aerobes may be positive is they express the complex. Other oxidases • Anaerobes are always negative

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PHOTOSYNTHESIS

VARIATION = FLEXIBILITY = DIVERSITY = ADAPTABILITY = SURVIVAL Cell membrane Chlorosomes Phycobilisomes