Evaluation of lactic acid bacterium from chilli waste as a potential antifungal agent for wood products

Abstract

Aims: The aim of this study was to isolate lactic acid bacteria from chilli waste and evaluate metabolites produced for the ability to arrest wood decay. Methods and Results: Using an optical density screening method, one bacterium (isolate C11) was identified as having pronounced antifungal properties against Oligoporus placenta. This isolate was identified as Lactobacillus brevis by 16S rRNA gene sequencing. To determine antifungal activity in wood, Pinus radiata blocks were impregnated with Lact. brevis [C11] cell‐free supernatant and exposed to brown rot fungi O. placenta, Antrodia xantha and Coniophora puteana. The treated timber demonstrated resistance to degradation from all fungi. The antifungal metabolites were heat stable and not affected by proteinase K, but were affected by neutralization with NaOH suggesting the metabolites were of an acidic nature. The presence of lactic and acetic acid was confirmed by HPLC analysis. Conclusions: Lactobacillus brevis [C11] produced acidic metabolites that were able to inhibit the growth of wood decay fungi and subsequent wood decay. Significance and Impact of the Study: Traditional wood treatments are becoming an environmental issue as the public demands more benign options. The use of lactic acid bacteria which are considered safe for general use is a potential alternative to the conventional heavy metal chemicals currently in use.

Waste Degradation and Utilization by Lactic Acid Bacteria: Use of Lactic Acid Bacteria in Production of Food Additives, Bioenergy and Biogas

“…A multitude of studies showed LAB ability to block fungal spoilage of fresh fruits and vegetables, baked and dairy products and silage [54]. Besides, LAB were shown to inhibit the growth of wood-rotting fungi and subsequent wood decay [55].…”

Synergistic Ability of Chitosan and Trichoderma harzianum to Control the Growth and Discolouration of Common Sapstain Fungi of Pinus radiata

“…and Pseudomonas spp., and fungi, such as Ophiostoma spp., Trichoderma spp., and Gliocladium spp. [9][10][11][12][13]. However, the field performance of BCAs has not yet fully been proven as a satisfactory system [14][15][16].…”

Effect of Abiotic Factors on the Antifungal Activity of Lactobacillus Strains Isolated from Commercial Dairy and Fermented Foods from Federal Capital Territory, Nigeria

“…Lactic acid bacteria are of particular interest as effective alternative to chemical preservation because of their food grade status [1,2]. Some LAB have the ability to produce inhibitory growth compound, in the final fermentation products [3], these compounds are known: formic, propionic, butyric, valeric, caproic, phenyllactic and reuterin [4]; acetic and lactic acid [5] and has the ability to retard or eliminate mycelia growth and spore germination, either on their own or synergistically [6].…”