UCA_8B,7B_1:Day 1

Rio San Pedro sediment + 0.3 g paper + 0.1 g CaSO4

Group B8 (Laura Lucena Del Amo and Noelia Moares Fernández) 
Group B7(Pablo Lucas Ezequiel Garín Ortega and Alba Mejías Gallardo)

Objective:

Our main goal in this experiment is to realize the variety of different microorganisms that we can find in a generic sample with the proper envrioment (such as light diponibility, oxygen difusion...). We are also looking forward to understand the complex variety of metabolic capacities of microrganisms and how the waste products from their metabolism  can be the metabolic requirement of other group of microorganism.
Through this experiment we can verify our main hypothesis.


Labware

• Transparent bottle
• Test tube
• Sediment/soil
• Water in situ
• Funnels
• Enrichment materials: paper (celulose) and CaSO4
• Electronic balance
• Parafilm
• Wash-bottle with water in situ
• Tupper
• Agitator
• Spatulas
• Tube and syringe
• Shovel

Experimental protocol

1. We add 20 g of mud (from Rio San Pedro) in a tupper, until we fill a third part of it.
2. We mix the mud with a moderate amount of water, until it has the appearance of a milkshake. 
3. Mix the enrichment substratum with the hydrated mud. (We added 0,3g of paper/celulosa and 0,1g of CaSO4).
4. Transfer the sediment that we have mixed to the test tube little by little with the aid of a funnel. We must tap it while transfering until it doesn't have any bubble).
5. Clean the material used.
6. Prepare another mix of sediment, this time with 100g of sand and 20g of mud (from Rio San Pedro).
7. Repeat step 4, adding a little bit of water until everything is hydrated (not in excess) and tranfered.
8. Clean the top of the test tube with paper.
9. Let the sediment rest for some minutes.
10. Add 2cm of water above the sediment. (We must let an air layer on the top of the tube, at least of 2-3cm).
11. Cover with parafilm.
12. Label the test tube, being careful not to cover the light source.

Initial hypotesis

We prepared two different test tubes to observe the proliferation of microorganisms in the winogradsky column, one was prepared by us (group B8) and the second one was prepared by  group B7. 

In the first one we added celulose and CaSO4, this tube is going to receive a natural light source,

meanwhile the second tube is going to be kept in darkness and has a glucose supply.

Our hypotesis is that in the first tube will grow up photosynthetic (autotroph) microorganisms on the top, there will also be heterotrophic microorganisms (chemoorganotroph) at the bottom. This is due to the fact that the organisms on the top receive a bigger amount of light and the organisms at the bottom get the nutrients from the photosynthetic organisms. These organisms are probably going to be mostly aerobic since they have an oxygen supply from the air. The only microorganisms that will not be aerobic are the ones that we find at the bottom, because they don't get enough oxygen.

In the second tube we suppose that will proliferate chemorganotroph microorganisms as well as chemoinorganotroph microorganisms (autotroph), there will be aerobic organisms on the top and anaerobic organisms at the bottom.

a)

b)    

Some pictures of our test tubes once that are filled with sediment and ready to let microorganisms proliferate inside of it. We hope we get good results that verify our hypothesis.

a) tube exposed to light, with Rio San Pedro sediment + 0.3 g paper + 0.1 g CaSO4

b) tube not exposed to light, with Rio San Pedro sediment + 0.3 g paper + 0.1 g CaSO4 and a supply glucose