Sewer Simulator Incubator

Our SRBioQuencher project aims to construct an engineered bacterium capable of inhibiting biofilm formation in sewers. After successfully constructing the engineered bacteria, a sewer environment needs to be simulated in the laboratory to verify the feasibility of the topic. In order to simulate the urban sewer environment in our laboratory, we constructed a sewer simulator incubator.

The Sewer Simulator Incubator is an experimental device for studying the growth characteristics and biofilm formation mechanism of sulfate-reducing bacteria (SRB) under a sewer environment. It can simulate the conditions of low oxygen, high pollution and flow in the sewer to provide a suitable environment for SRB. The main components of the sewer simulator incubator are as follows:

1. PVC plastic pipe: PVC plastic pipe is the main body of the incubator, its surface roughness can increase the adhesion of biofilm, as well as provide a certain mechanical strength and corrosion resistance. The length, diameter and number of PVC plastic pipe can be adjusted according to the experimental needs to simulate different sizes and shapes of sewers.
2. Water pump: The water pump is the power source of the incubator, which controls the flow rate and direction of the culture solution inside the PVC plastic pipe to simulate the flow state of sewage in a sewer. The power and flow rate of the water pump can be adjusted according to the experimental needs to simulate the effects of different degrees of shear and turbulence on the biofilm.
3. Conical flask: Conical flask is the auxiliary part of the incubator, which can be used to store and change the culture solution, as well as to monitor the temperature, pH, sulfate concentration and other parameters of the culture solution. The conical flask is connected to the PVC plastic pipe through glass tubing to ensure circulation of the nutrient solution throughout the system.

Sewer simulator incubator work as follows:

First, the nutrient culture solution containing appropriate amounts of sulfate and other nutrients is injected into the conical flask and oxygen is replaced throughout the system with nitrogen or other inert gas to create anaerobic or low oxygen conditions.

Glass tubes containing SRB inoculum or biofilm fragments were then inserted into conical flasks and sealed at both ends with rubber stoppers to prevent air entry.

Next, the water pump was turned on to circulate the nutrient solution from the conical flask through the glass tube into the PVC plastic tube. Meanwhile, the flow rate and direction of the pump were adjusted to simulate different flow conditions.

Finally, the biofilm inside the PVC plastic tube was regularly observed and sampled, and the temperature and PH of the nutrient solution, as well as parameters related to SRB metabolism, such as hydrogen sulfide and methane, were detected through the conical flask.

The Sewer Simulator Incubator is a simple but effective experimental device that can provide additional information and understanding of the physiological and biochemical characteristics and ecological functions of SRBs in the sewer environment.