I am studying antimicrobial substances of lactic acid bacteria. Recently, I freeze-dried conditioned MRS media using disposable LDPE plastic bag. Surprisingly, all the tested samples (reconstituted in 0.1x vol) exhibiting various activities against indicator bacteria including non-conditioned MRS (negative control 1) and bacteria with no activity (negative control 2). The prior experiment (10 mL) was conducted in 50-mL PP tube rather than in LDPE bag (100 mL). Is it possible any interference leached/extracted from the PD bag?
I think yes, it is possible, but you can try to test the antimicrobial activity of a known quantity of your LDPE bag.
Thank you all. I will try a mock using water to extract any possible additives or leaching materials to examine the antimicrobial activity. Meanwhile, I had changed the containers to glass Petri dishes and T-flasks made with PS.
It is possible, especially if the bags were also "anti-static" (these are normally pink) - these contain surfactant additives such as Ethyloxylated amides/amines. Common surfactant residues from such agents used during product cleaning as part of the manufacturing process can also be an issue. See this paper:
ANTIBACTERIAL ACTIVITY OF CHEMICAL COMPOUNDS USED AS SURFACTANTS Nikola Kosmowska, Weronika Łuczak, Daniela Gwiazdowska*1, Katarzyna Michocka2, Daria Wieczorek2
- Badges
- Science topic
- Similar topics
- Biological Science
- Microbiology
- Microorganisms
- Bacteria