Identification of Volatile Metabolites from Fungal Endophytes with Biocontrol Potential towards <i>Fusarium oxysporum</i> F. sp. <i>cubense</i> Race 4

Abstract

Problem statement: Fungal endophytes are widely studied for their potential as biocontrol agents towards fungal pathogens. In vitro assessments usually reveal their antibiosis and mycoparasitism nature, but little is understood regarding their production of volatile metabolites as mechanisms of antagonism. Approach: This study explored the potential of fungal endophytes in controlling the pathogen responsible for Fusarium wilt disease. Nine fungal endophytes were tested for their ability to inhibit the growth of the pathogenic Fusarium oxysporum F. sp. cubense race 4 (FocR4) via production of volatile inhibitory metabolites. The type of volatile metabolites produced were subsequently characterized and identified using the Gas-Chromatography Mass-Spectrophotometry (GCMS). Results: Eight of the isolates (BTF05, BTF07, BTF08, BTF15, BTF21, WAA03, WAA02, MIF01) showed positive results with percentages of inhibition varying from 1.43-31.43% while one isolate (ALF01), showed negative result (0% inhibition). Volatile profiles showed that these fungal endophytes produced between 15-47 volatile metabolites per isolate. However, the more volatile metabolites produced by a single endophyte does not indicate better biocontrol potential. Isolate BTF05 produced 47 different volatile metabolites, but has only 8.57% inhibition, compared to isolate BTF21 with 15 metabolites but a percentage of 11.43% inhibition. The potency of the volatile metabolites produced may also influenced the biocontrol potential of the fungal endophytes as some isolates such as BTF08 and MIF01 have only two to three known inhibitory metabolites but have higher PIDG values at 31.43 and 11.43%, respectively. Contrary, isolates WAA02 and WAA03 which has five to six metabolites but PIDG values of less than 3%. Conclusion: Fungal endophytes have the ability to produce several types of volatile metabolites to inhibit the growth of FocR4. These volatile inhibitory metabolites can be further extracted and the amount produced ascertained for future manipulation in biological control of FocR4.

Antifungal Potential of Extracellular Metabolites from Penicillium spp. and Aspergillus spp. Naturally Associated to Potato against Fusarium species Causing Tuber Dry Rot

“…In the same sense, nine fungal endogenous isolated from Musa spp., grass weeds, Mimosa pudica and Allamanda spp., tissues were shown able to suppress Fusarium wilt caused by Fusarium oxysporum f. sp. cubense race 4 (FocR4) as demonstrated based on their ability to produce volatile inhibitory metabolites [43]. This finding is in agreement with previous works recording similar mycelial growth inhibitions using A. niger, A. terreus and A. flavus to control Pythium ultimum.…”

Effects of Metabolite Combinations Produced by <i>Lactobacillus plantarum</i> on Plasma Cholesterol and Fatty Acids in Piglets

“…Effects of Lactobacillus in the gut could slow down the absorption of cholesterol into body as well (Nguyen et al, 2007). Bacteriocin activity with BSH can reduce plasma cholesterol by increasing consequently in the synthesis of bile salts, decreasing the solubility of cholesterol and reducing its uptake in the gut (Sindhu and Khetarpaul, 2003;Liong and Shah, 2005;Ting et al, 2010). This is in agreement with Lee et al (2009), who explained that cholesterol reduction by LAB may involve five mechanisms: (i) LAB inhibit cholesterol synthesis enzymes and thus reduce cholesterol production; (ii) LAB facilitate the elimination of cholesterol in faeces; (iii) LAB inhibit the absorption of cholesterol back into the body by binding with cholesterol; (iv) LAB interfere with the recycling and enhancing the excretion of bile salts; (v) due to the assimilation of lactic acid.…”

Preliminary Study on Immunomodulatory Effect of Sarang-Semut Tubers <i>Myrmecodia tuberosa</i> and <i>Myrmecodia pendens</i>

“…As described by Medina and collaborators (2010), some fungi have capabilities to produce enzyme to degrade tannin into antioxidant phenolics. Furthermore, some fungi endophytes also contributed in plant host defense against pathogenic fungi (Ting et al, 2010). Further investigation is of course needed to assure the involvement of either fungi or ants or even other organisms in Sarang-Semut chemical contents enrichment.…”