Chromobacterium Violaceum Strains Growth Conditions Impacting N- Acyl Homoserine Lactones AHL Production

Mahmoud F Gaballa, Tennessee State University


Chromobacterium violaceum is a Gram-negative bacillus that is a facultative anaerobic, oxidase positive, glucose fermenting, and non-lactose fermenting. C. violaceum is free living which can be found in the soil and water. C. violaceum produces a possible antioxidant called violacein a purple pigment that is considered to be one of the significant characteristics of C.violaceum. Chromobacterium violaceum one of the Gram negative bacteria which use Quorum Sensing (QS) occurs within a single bacterial species, and regulates a lot of different processes ,essentially serving as a simple communication network so that QS is the accumulation of signaling molecule that enable a single cell to sense the communication from other cells .The density and bioluminescence through quorum sensing is manipulated via the signaling molecule N-acyl-homoserine (AHLs) that is produced by C. violaceum. The major objective in this work is to determine the reason why 14N1 cannot produce the pigment on LB media in cultures using heavy cell inoculum and high concentration of AHL on all the C. violaceum strains. C. violaceum 14N23 and 14N1 were isolated from copper basin, Tennessee and (ATCC) 12472 and (ATCC) 31532 obtained from American Type Culture Collection (ATCC), and CV026. 14N1 produces a pigment after 24 hours by using high inoculation 20% which is 10 ml overnight culture of 14N1 to 40 ml LB broth media with different shaker's speed started from (in static culture , 150,175,225). On the AHLs 14N1 did not produce a pigment and that the same with 14N23. However, 12472 did produce a pigment after 24 hours, and the positive control (ATCC) 31532 produced and the negative control CV026 did not.

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Recommended Citation

Mahmoud F Gaballa, "Chromobacterium Violaceum Strains Growth Conditions Impacting N- Acyl Homoserine Lactones AHL Production" (2017). ETD Collection for Tennessee State University. Paper AAI10268834.