New types of antimicrobial compounds produced by Lactobacillus plantarum

Abstract

. New types of antimicrobial compounds were identified in the culture filtrate of Lactobacillus plantarum VTT E-78076. Activity was detected in the low molecular mass fraction separated by gel chromatography. This fraction totally inhibited the growth of the Gram-negative test organism, Pantoea agglomerans (Enterobacter agglomerans) VTT E-90396. Characteristic compounds from this fraction were identified by GC/MS-analysis and the identification was confirmed using pure commercial reference compounds in identical chromatographs and in antimicrobial tests. The active fraction included benzoic acid (CAS 65-85-0), 5-methyl-2,4-imidazolidinedione (CAS 616-03-5, methylhydantoin), tetrahydro-4-hydroxy-4-methyl-2H-pyran-2-one (CAS 674-26-0, mevalonolactone) and 3-(2-methylpropyl)-2,5-piperazinedione (CAS 5845-67-0, cyclo(glycyl-L-leucyl)). These compounds in concentrations of 10 ppm inhibited growth of the test organism by 10-15% when acting separately, but 100% when all were applied together with 1% lactic acid. The inhibition was 40% by 1% lactic acid alone. The compounds were also active against Fusarium avenaceum (Gibberella avenacea) VTT D-80147. The inhibition was 10-15% by separate compounds in concentrations of 10 ppm and maximally 20% in combinations. Fungal growth was not inhibited by lactic acid. Inhibition by unfractionated Lact. plantarum culture filtrate was 37% and by the low molecular mass fraction, 27%.

Lactobacillus reuteri -produced cyclic dipeptides quench agr -mediated expression of toxic shock syndrome toxin-1 in staphylococci

“…Similarly, it was found that Gram-positive Lactobacillus plantarum species also produced cyclic dipeptides, including cyclo(L-Phe-L-Pro), cyclo(L-Phe-trans-4-OH-L-Pro), and cyclo(Gly-L-Leu), which exhibited antifungal activity (28,46). Although the fungal inhibitory properties of cyclo (L-Tyr-L-Pro) and cyclo(L-Phe-L-Pro) produced by L. reuteri RC-14 have yet to be tested, neither of the two compounds displayed toxicity against S. aureus (Fig.…”

Control of the Growth of Coliforms and Moulds in Sorghum Malting by Bacterial and Yeast Cultures

“…listed in Table I were determined against the eight moulds by the disc diffusion method 19,23 . Moulds were incubated for 5 days at 25°C.…”

“…Gram-negative bacteria has been reported 19 . It is possible that the P. pentosaceus strain used in this study produced such antimicrobial compounds.…”

A Simple Method for the Efficient Isolation of Genomic DNA from Lactobacilli Isolated from Traditional Indian Fermented Milk (dahi)

“…According to the classification advanced by Orla-Jensen, the genus Lactobacillus was further divided into three subgeneraThermobacterium, Streptobacterium and Betabacterium in accordance with the observed optimal growth temperature characteristics and hexose fermentation pathways [1]. Lactobacilli are gram positive, rod shaped, catalase negative bacteria and could safely be considered the most important of all lactic acid bacteria owing to their role in various food and feed fermentations, production of many important metabolites, and owing to their role in the prevention of food spoilage, intoxication and infection by acting as antagonists against other pathogens by the production of antimicrobials [2][3][4]. With the growing population, and the demand exerted on the quality fermented dairy products, Lactobacilli have increasingly been under the research scanner for the last two decades.…”