Quorum sensing mediated response of Achromobacter denitrificans SP1 towards prodigiosin production under phthalate stress

Abstract

Quorum sensing is a density‐dependent chemical process between bacteria, which may be intergenus or intragenus. N‐acyl homoserine lactones (HSLs) are a type of small signaling molecules associated with Gram‐negative bacteria for monitoring their own population density. The present study unveils the mechanism of HSLs in Achromobacter denitrificans SP1 while transforming di(2‐ethylhexyl) phthalate (DEHP) into prodigiosin in a simple basal salt medium. The primary detection of HSLs was done by the colorimetric method. Fourier‐transform infrared spectroscopy and liquid chromatography–mass spectrometry‐quadrupole time‐of‐flight confirmed and identified the HSLs. The maximum production of HSLs was observed between 24 and 72 h of incubation, which is noted to be a peak time of DEHP degradation. A total of 57.2% of DEHP was degraded within 30 h and complete degradation was observed within 72 h of incubation. Regulation in the synthesis of various acyl‐HSL molecules, viz. 3OC6‐HSL in the initial stage of DEHP stress, 3OC8‐HSL, and C10‐HSL during the time of degradation and 3OC12‐HSL on completion of degradation was noticed. The role of HSLs on the production of prodigiosin was confirmed using vanillin as an HSL inhibitor. Through the selective activation of HSL molecules, A. denitrificans SP1 sustain the changing stressful conditions. Supplementation of acyl‐HSL signal molecules may boost up the efficacy of A. denitrificans SP1 in both DEHP degradation and prodigiosin production which offers great potential towards the management of DEHP containing plastic wastes.

Network And Meta-Omics Reveal The Key Degrader And Cooperation Patterns In An Efficient 1,4-Dioxane-Degrading Microbial Community

“…Six genera were found to be positively correlated with ZM13 in the network, among which the genomic information of Sphingopyxis, Mesorhizobium, Achromobacter and Xanthobacter were acquired and the genes related to 1,4-dioxane degradation in the recovered genomes were revealed. The genus Achromobacter was reported to regulate its own population density through quorum sensing [50], which might explain its high abundance in the community and high degree centrality in the network (Additional le 1: Table S5). The genus Sphingopyxis has been reported to possess degrading capabilities for various environmental contaminants [51].…”

“…After incubation and acclimatization, the culture CH1 was capable of completely degrading 12 mM 1,4-dioxane in three days and could be stably sub-cultured. Degrading experiments with different initial 1,4-dioxane concentrations (20,50,90,110,130,160,190, 210 mM) were performed to assess the tolerance concentration of CH1 and the impacts of initial 1,4-dioxane concentration on the degradation. The methods of kinetic model used to t the degradation data are presented in Additional le 1: Supplementary methods.…”