Active Standard ASTM E2647 | Developed by Subcommittee: E35.15
Book of Standards Volume: 11.05
Historical (view previous versions of standard)
Significance and Use
5.1 Vegetative biofilm bacteria are phenotypically different from suspended cells of the same genotype. Biofilm growth reactors are engineered to produce biofilms with specific characteristics. Altering either the engineered system or operating conditions will modify those characteristics.
5.2 The purpose of this test method is to direct a user in how to grow, sample, and analyze a P. aeruginosa biofilm under low fluid shear and close to the air/liquid interface using the DFR. The P. aeruginosa biofilm that grows has a smooth appearance and is loosely attached. Microscopically, the biofilm is sheet-like with few architectural details. This laboratory biofilm could represent those found on produce sprayers, on food processing conveyor belts, on catheters, in lungs with cystic fibrosis, and oral biofilms, for example. The biofilm generated in the DFR is also suitable for efficacy testing. After the 54 h growth phase is complete, the user may add the treatment in situ or harvest the coupons and treat them individually. Research has shown that P. aeruginosa biofilms grown in the DFR were less tolerant to disinfection than biofilms grown under high shear conditions.5
1.1 This test method specifies the operational parameters required to grow a repeatable2 Pseudomonas aeruginosa biofilm close to the air/liquid interface in a reactor with a continuous flow of nutrients under low fluid shear conditions. The resulting biofilm is representative of generalized situations where biofilm exists at the air/liquid interface under low fluid shear rather than representative of one particular environment.
1.2 This test method uses the drip flow reactor. The drip flow reactor (DFR) is a plug flow reactor with laminar flow resulting in low fluid shear. The reactor is versatile and may also be used for growing and/or characterizing biofilms of different species, although this will require changing the operational parameters to optimize the method based upon the growth requirements of the new organism.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
Other StandardMethod9050 C.1.a Buffered Dilution Water Preparation Eaton, A. D., Clesceri, L. S., and Greenberg, A. E., Eds., Standard Methods for the Examination of Water and Waste Water, 19th Edition, American Public Health Association, American Water Works Association, Water Environment Federation, Washington, DC, 1995.
D5465 Practice for Determining Microbial Colony Counts from Waters Analyzed by Plating Methods
ICS Number Code 13.060.30 (Sewage water)