pH-stat: Culture of Synechocystis sp. PCC 6803

Objectives of the culture

General

By introducing a culture of Synechocystis sp cianobaceria. PCC 6803 we intent to ensure that the pH changes resulting from growth and proliferation function as a switch in order to activate the colicins, so that in the artificial system created, as time passes, the colicins produced by Escherichia coli will increase their concentration in their habitat, being inactive until the pH reaches the optimum range of activation, which is when they ´ll get activated and will produce cell lysis and kill the pathogens.

Specific

To develop what we have stated above, we need to know:

• How to establish the culture at the laboratory

• The temporal evolution of the pH in the culture.

Establishing the culture under laboratory conditions.

The material and methods needed are :

• 18 Watts fluorescent tubes of white light, special tubes for aquariums that divide the spectrum mostly between the peaks of the visible red and blue light, which stimulate the photosynthesis.

• Volumetric flasks, 100 ml and 200 ml

• Air Pumps

• Commercial Fertilizer Brand COMPO

• Distilled, tap and analytical water (Type II)

The first experiment consisted of a series of six cultures in which environmental conditions varied so as to know the habitat preferences of the cyanobacterium. We distinguished two different groups:

The first, consisting of C1, C2 and C3, which have tap , distilled and analytical water respectively. It also uses a reflector box, which increases the irradiation of light on the culture, and a magnetic stirrer, which prevents the deposition of cells on the bottom

The second group , which are C4, C5 and C6, without reflector or magnetic stirrer, but we kept the water in the same order as before.

Results and discussion

The other conditions remained constant in both cases, as are detailed in the following table: