AUTHOR=Liu Xiaomeng , Li Zhong , Fan Yongqiang , Lekbach Yassir , Song Yongbo , Xu Dake , Zhang Zhichao , Ding Lei , Wang Fuhui 

TITLE=A Mixture of D-Amino Acids Enhances the Biocidal Efficacy of CMIT/MIT Against Corrosive Vibrio harveyi Biofilm

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.557435

DOI=10.3389/fmicb.2020.557435

ISSN=1664-302X

ABSTRACT=<p>Biocides are widely used for the mitigation of microbial contamination, especially in the field of the aviation fuel industry. However, the long-term use of biocide has raised the concerns regarding the environmental contamination and microbial drug resistance. In this study, the effect of a mixture of <sc>D</sc>-amino acids (<sc>D</sc>-tyrosine and <sc>D</sc>-methionine) on the enhancement of the bactericidal effect of 5-Chloro-2-Methyl-4-isothiazolin-3-one/2-Methyl-2H-isothiazole-3-one (CMIT/MIT) against corrosive <italic>Vibrio harveyi</italic> biofilm was evaluated. The results revealed that <sc>D</sc>-Tyr and <sc>D</sc>-Met alone can enhance the biocidal efficacy of CMIT/MIT, while the treatment of 5 ppm CMIT/MIT, 1 ppm <sc>D</sc>-Tyr and 100 ppm <sc>D</sc>-Met showed the best efficacy comparable to that of 25 ppm CMIT/MIT alone. The triple combination treatment successfully prevented the establishment of the corrosive <italic>V. harveyi</italic> biofilm and effectively removed the mature <italic>V. harveyi</italic> biofilm. These conclusions were confirmed by the results of sessile cell counts, images obtained by scanning electron microscope and confocal laser scanning microscope, and the ATP test kit.</p>