Abstract
Fungistatic activity of a Lactic-Acid Bacteria (LAB) was assessed in vitro while isolated from its rumen fluid, against Fusarium oxysporum and Fusarium fujikoroi, basal-rot related species in yellow pitahaya. Fed batch was used to reproduce said LAB. Fungistatic activity kinetic tests were performed on the ferment (S1) and on two of the fractions obtained through centrifugation, supernatant (S2) and biomass (S3). The fungistatic activity was measured in two substrates, agar Man Rogosa Sharpe (MRS) and Potato Dextrose Agar (PDA). On S1 it was also performed lactic acid and acetic acid production kinetic tests as well as substrate consumption and biomass formation. Structural changes were evaluated on the fungi through microscopic electronics. The LAB was molecularly identified as Weissella cibaria. It was found that after eight hours of fermentation, fractions S1 and S3 performed the highest fungistatic activity against F. oxysporum and F. fujikoroi. Porosities were observed in the cell walls of the fungi as an effect of the LAB's fungistatic activity. These results indicate that LABs, when isolated from the animal habitat, may have a biotechnological potential to be used in the development of biocides, useful to control Fusarium in crops; for instance, to control yellow pitahaya basal rot.
Highlights
Lactic-Acid Bacteria (LAB) biopreservative properties are attributable to the capacity they have to inhibit the growth of pathogenic bacteria and some fungus species (Magnusson et al, 2003)
A 695 bp fragment of 16S ribosomal gene of the LAB biochemically identified as W. confusa in studies conducted by Serna et al (2010) was amplified through Polymerase Chain Reaction (PCR) and sequenced
Our results indicate that the metabolite responsible for the highest fungistatic activity was produced during the stationary phase of the microbial growth, being secondary metabolites
Summary
Lactic-Acid Bacteria (LAB) biopreservative properties are attributable to the capacity they have to inhibit the growth of pathogenic bacteria and some fungus species (Magnusson et al, 2003). These bacteria have drawn the attention of researchers as control agents in pathogenic bacteria and fungus causing illnesses in animals and plants. In previous studies conducted by Serna-Cock et al (2010), a species of Weisella able to inhibiting pathogens causing illnesses in humans and animals, Staphylococcus aureus, Streptococcus agalactiae, E. coli and K. neumoinc was reported (Serna-Cock et al, 2012). It has been reported that W. cibaria and Lactobacillus brevis have fungistatic activity against Fusarium species (Mauch et al, 2010).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
