Carbon and Nitrogen and Stuff

3. Gas produced by methanogens.
6. Name for oxygen-depleted environments.
8. a natural fuel such as coal or gas, formed in the geological past from the remains of living organisms.
10. Carbon containing compound found in the atmosphere.
13. A disease causing microbe.
14. Fluid waste from toilets, bathrooms, kitchens and laundries, together with some liquid waste from industry.
17. Digestion that occurs outside the cell.
19. General name for bacteria that convert nitrates into nitrogen gas.
20. Name given to the solid waste from sewage treatment.
21. Made from barley (a grain), hops (a flower) and yeast.

1. The type of bacteria that decomposes organic material in compost heaps.
2. Microbes that break down dead organic matter.
4. Process of adding microbes to a growth medium.
5. General name of bacteria that convert nitrogen gas from the air into nitrogen containing compounds such as nitrates.
7. Name of the process of anaerobic respiration by yeast cells.
9. Process whereby carbon is released back into the atmosphere.
11. Free of microbial contamination.
12. The type of plants that fix nitrogen from the atmosphere into nitrates in the soil.
15. Most of the chemicals that make up living tissue contain this.
16. Sugar found in milk.
18. What you need in a compost bin to stop it getting stinky and rotten.