Inducible Antibacterial Activity in the Bacillales by Triphenyl Tetrazolium Chloride

Abstract

de cassia pessotti 4 & Valeska Villegas-escobar 1* the world is in the midst of an antimicrobial resistance crisis, driving a need to discover novel antibiotic substances. Using chemical cues as inducers to unveil a microorganism's full metabolic potential is considered a successful strategy. to this end, we investigated an inducible antagonistic behavior in multiple isolates of the order Bacillales, where large inhibition zones were produced against Ralstonia solanacearum only when grown in the presence of the indicator triphenyl tetrazolium chloride (ttc). this bioactivity was produced in a ttc-dose dependent manner. Escherichia coli and Staphylococcus sp. isolates were also inhibited by Bacillus sp. strains in ttc presence, to a lesser extent. Knockout mutants and transcriptomic analysis of B. subtilis NCIB 3610 cells revealed that genes from the L-histidine biosynthetic pathway, the purine, pyrimidine de novo synthesis and salvage and interconversion routes, were significantly upregulated. Chemical space studied through metabolomic analysis, showed increased presence of nitrogenous compounds in extracts from induced bacteria. the metabolites orotic acid and L-phenylalaninamide were tested against R. solanacearum, E. coli, Staphylococcus sp. and B. subtilis, and exhibited activity against pathogens only in the presence of ttc, suggesting a biotransformation of nitrogenous compounds in Bacillus sp. cells as the plausible cause of the inducible antagonistic behavior.

Towards the sustainable discovery and development of new antibiotics

“…Further, molecular (co-)evolution acting to generate novel metabolites for efficient microbial warfare could be exploited 140 , 141 , for example, by sampling from environments heavily contaminated with antibiotics (like sewage in Southeast Asia or South America), which are known to contain highly resistant microbes 142 , 143 . Complementarily, this can be achieved by laboratory exposure of potent producers to subinhibitory antibiotic concentrations 144 or by co-culturing them together with drug-resistant (pathogenic) strains 145 . Beyond microbial producers, a great variety of plants 146 , 147 , macroscopic filamentous fungi (e.g.…”

Experimental Study on the Inhibition of Bacteria and Algae by Jussiaea stipulacea Ohwi Extract

“…After 24 h of culture, 15 μL of 0.20% 23,5-triphenyltetrazolium chloride (TTC) was added to each well. 15 After being cultured at 37 °C for 4 h with anhydrous ethanol as the control group, color changes were observed. The experiment was repeated three times, and the average value was taken to determine the minimum inhibitory concentration (MIC).…”

A Point Mutation in Cassette Relieves the Repression Regulation of CcpA Resulting in an Increase in the Degradation of 2,3-Butanediol in Lactococcus lactis

“…2.13. Determination of the Metabolism of 2,3-Butanediol at Different Concentrations 2,3,5-triphenyl-2H-tetrazolium chloride (TTC) is a commonly used stain for the detection of plant seeds [34] and microbial viability [35]. TTC is utilized to evaluate the capacity of bacteria to metabolize carbon sources by measuring their metabolic viability.…”