7 wonders of the microbe world - life on #mars (7/7)

in summary

- looking at microbes in extreme environments on earth helps us understand how life may have been on life (or indeed is)

- by looking for signs of microbes on earth can help us understand how to look for such on mars

7 wonders of the microbe world - #geneticengineering (6/7)

in summary

- genetically modifying microbes can produce, medicines, food and maybe even fuel

- 1st done in 1973

- genetic engineering is about adding things to microbes

- e.g. insulin used to be taken from slaughtered pigs but in the 1980's scientists discovered how to produce it for humans using modifications to e-coli

7 wonders of the microbe world - antibiotics (5/7)

in summary

- bacteria that harm us reproduce in the body creating toxins that harm us by damaging tissues and organs

- they can also produce antibiotics to protect themselves from other microbes

- they work by disrupting a critical function in the bacterial cell (eg renewing cell wall during growth so eventually bursts)

- but microbes can become resistant to antibiotics

7 wonders of the microbe world - nitrogen fixation (4/7)

in summary

- microbes generate at least 1/2 of the oxygen we breath

- they fix nitrogen - a key building block for life

- the only way humans can get nitrogen is via the food we eat - which microbes fix the nitrogen into

- fix - take and combine with oxygen or hydrogen into compounds that plants can make use of

- crop rotation uses this relationship to make soil more fertile

7 wonders of the microbe world - food preservation (3/7)

in summary .....

microbes are responsible for producing cheese, bread, yoghurt, beer

other microbes can do us a lot of harm - by contaminating food

so how to preserve food?

- salting, drying, icing, pickling,smoking, fermentation

- or often use extremes of temperature

7 wonders of the microbe world - black death (2/7)

1683 invention of microscope allowed discovery of microbes by a dutchman

in 14th century black death microbe became deadly

thrives at a person's healthy temperature

the microbe invades fleas, rats, cats, dogs, farm animals and humans

fleas spread it (microbe blocks flea's stomach so the flea needs to feed) so when it does feed on a hosts blood it regurgitates the microbes into the hosts bloodstream

immune systems launches white blood cells to defend the host but the microbe multiplies within them and kills the white blood cells

microbe then floods out stronger than before so it can overcome white blood cells

symptoms start as a sneeze or like flu

but then painful black lesions on skin in joints - exude pus - and the host dies a slow excruciating death over several days

14th century outbreak started in mongolia 1330 and spread along trade routes

in 4 years - 1347 to 1351 microbe killed around 75m people worldwide (including 1/3rd of the entire population of europe)

reached england summer 1348 - between then and 1350 around 40% of the english population died from the black death

some say english reformation was caused by black death because at the time of the plague the religious leaders couldn't explain how or why the disease spread

and of course the nursery song "ring oh ring of roses" has its background in the symptoms of black death and the practice of carrying pouches of sweet smelling  herbs to ward it off

7 wonders of the microbe world - beer (1/7)

1st evidence of beer - 6000AD (egyptians called their beer names like joy bringer or heavenly) - 10% alcohol content

did a piece of bread fall into soaking grain by mistake - and so the 1st beer started?

without microbes there would be no beer

different yeasts produce different types of beers