CYTOMAIA utilizes a closed culture vessel to enclose biological material suspended in a culture medium above which is a gaseous headspace. A sensitive pressure sensor is linked to the culture headspace via a flexible transfer diaphragm to form a non-invasive yet sensitive detection system capable of measuring increases or decreases in pressure. If the biological material respires, dissolved gases in the culture medium exchange with the headspace gases and the pressure sensing mechanism detects the change. Activity of the biological suspension is therefore translated into pressure readings and the sensor converts these to electrical signals which are digitized for further interrogation by a microprocessor. In addition to logging values over time the chip constantly applies an algorithm to assess whether or not significant events are taking place. Culture vessels and microprocessor are housed in an instrument which monitors pressure, maintains optimum growth and gas exchange conditions, and communicates results.
In Speedy Breedy technology:
Speedy Breedy is based on CYTOMAIA in the form of a small, portable, sensitive, precision respirometer which detects and monitors microbial activity and contamination. Liquid, macerated solids or swabbed samples are added to a sterile culture vessel of just 50 ml working volume containing a pre-pelleted medium that is specific for a particular bacterium. The culture vessel is placed into Speedy Breedy which closely controls culture conditions to a pre-determined protocol. Where present, contaminating microorganisms rapidly grow and respiration converts into a significant pressure event which is detected by Speedy Breedy and a “contaminated” message is displayed on the instrument.
As there is a proven correlation between the degree of contamination and time to detection once a significant pressure event has been detected using the time from the start of the test and the time of the significant pressure event Speedy Breedy calculates how many bacteria were in the original sample. Once the test is completed there is an option to automatically pasteurise the sample that has just been grown so the culture vessel can be disposed of as normal garbage. A range of media in pre-populated culture vessels is available from Bactest. Empty, sterile culture vessels are also available. A new culture vessels is required for each test. Culture vessels cannot be reused.
Speedy Breedy is a stand-alone instrument but can also be used attached to a computer for further analysis or visualization of the pressure curves in near real time. Speedy Breedy keeps an audit trail of all tests.
How Does Speedy Breedy Work?
In Shepherd Wastewater technology:
Based on Bactest’s patented CYTOMAIA technology platform, Shepherd comprises a combination of a robust test chamber, sensors and a data logger as well as algorithms and curve stabilizing software which monitors the chamber, processes the information, and converts it into a visual output.
The test chamber is a sealed unit of 2 litre working volume which resides in a buoyancy collar and floats in the activated sludge lane. The sample is drawn directly from the activated sludge lane, analysed and returned on a programmable cycle of approximately one hour. The test chamber houses an air recirculation and exchange system that converts the biomass’ respiratory gas exchange, and hence its activity, into a headspace pressure variable. The absence of pumping for sample loading and unloading prevents fouling of the system. Barrier-protected sensors monitor sensitive pressure changes within the test chamber headspace and data loggers convert them into a near real time BOD5 proxy suitable for managing and optimizing plant processes.
Shepherd also has a three tier software system:
- An operator display panel adjacent to the activated sludge lane
- A cloud-based dashboard that includes a full audit trail and provides a bird’s eye view of plant activity
- An hourly email status system