Removal of 3-methylindole by lactic acid bacteria in vitro

Abstract

3-Methylindole (3MI) is a substance with an unpleasant odor that is found in intact male pigs and is known to negatively affect consumers of pork. The growth of four strains of lactic acid bacteria [Lactobacillus brevis 1.12 (L. brevis 1.12), L. plantarum 102, L. casei 6103 and L. plantarum ATCC8014] in incubation medium with 3MI was studied. The four strains were tested for their ability to remove 3MI from the medium. The growth of L. brevis 1.12 remained steady as the levels of 3MI increased 3MI from 0.2 to 1.0 μg/ml. The 3MI removal ability of L. brevis 1.12 was the strongest among the four strains, and the highest removal rate was 65.35±0.3% in 1 ml incubation medium containing 1.0 μg/ml 3MI for 120 h. Furthermore, the supernatant fluid of the fermentation broth of L. brevis 1.12 had a stronger ability to remove 3MI than cell pellets and cell extracts and the removal rate was 14.4±0.3% in 24 h. Further results indicate that the mode of removal of 3MI was not through the physical binding of cells by L. brevis 1.12.

Isolation and characterization of two Acinetobacter species able to degrade 3-methylindole

“…is coordinated by a dioxygenase enzyme [17], and methyl oxidation of 3MI by cytochrome P450 enzymes [44]. It was reported that enzyme extract or supernatant fluid from the culture media of 3MI-degrading isolates showed degradation following incubation with 3MI [3, 14]. In our study, the successful degradation of 3MI by the supernatant of the fluid media from the two strains was observed after incubation for 48 h (Fig 9).…”

“…plantarum ATCC8014) in which the 3MI removal ability of L . brevis 1.12 was the strongest among the four strains, and the highest removal rate was 65.35% in 1 mL incubation medium containing 1.0 mg/L 3MI for 120 h [14]. Sharma et al .…”

“…Similar results was reported using lactic acid bacterium L . brevis 1.12 [14]. Strains NTA1-2A and TAT1-6A were also tested in vivo during fermentation of chicken manure.…”

“…The degradation of 3MI was also reported in a methanogenic consortium isolated from an enrichment of wetland soil [13]. Lactobacillus brevis 1.12 was reported best out of four lactic acid bacteria in its tolerance and ability of removing 3-methylindole [14]. Biotransformation of 3MI was also recorded in methanogenic consortia with complete mineralization by sulfate reducing bacteria derived from marine sediment of Victoria Harbor [15].…”

Microbial Degradation of Indole and Its Derivatives

“…Gu and Berry [32] reported the degradation of 3-methylindole via 3-methyloxindole using a methanogenic consortium derived from enrichment of wetland soil. The removal of 3-methylindole was monitored by the four strains of lactic acid bacteria (Lactobacillus brevis 1.12 (L. brevis 1.12), L. plantarum 102, L. casei 6103, and L. plantarum ATCC8014); L. brevis 1.12 was the best at removing 3-methylindole [88]. Gu et al [45] reported that a methanogenic bacterial consortia derived from marine sediment from Victoria Harbour transformed 3-methylindole to 3methyloxindole, whereas a sulfate-reducing consortium mineralized 3-methylindole completely via 3-methyloxindole and -methyl-2-aminobenzeneacetic acid (Figure 7(c)).…”