Effectiveness of carboxylic acids from Pichia membranifaciens against coffee rust

Abstract

Coffee rust is a fungal disease that has affected every coffee-producing region in the world. Given that the effectivity of the protectant and systemic fungicides applied routinely to control the spread of the causative agent of the disease (Hemileia vastatrix) has gradually diminished, besides are harmful to mammals and ecosystems, the objective of this work was to search for a mixture of harmless natural compounds with the potential to be applied in the field. So, a yeast strain producing a battery of long-chain carboxylic acids (CA) with fungicide properties was isolated from soil of coffee crop and identified as Pichia membranifaciens by ITS sequencing. Culture conditions of the yeast were optimized and the CA in the solution were characterized by Gas Chromatography-Mass Spectrometry (GC-MS) as ethyl formate (55.5 g L-1), octadecenoic acid (3.5 g L-1), propionic acid (7.2 g L-1), 3-(octadecanoyl)-propionic acid (7.2 g L-1) and methyl acetate (8.4 g L-1). Randomized field studies were conducted in three different locations in Chiapas, México. Five treatments were tested including three concentrations of the CA solution (389, 584 and 778 ppm) and copper oxychloride (5 000 ppm) as conventional control. The initial coffee rust incidence averages varied between sites: Maravillas (3-9%), Santo Domingo (10-16%) and Búcaro (16-22%). The treatments of CA solution proved to be effective at slowing down the progress of the rust disease even for the sites where initial incidence was high. Likewise, the CA solution reduced the viability of H. vastatrix spores, as assessed by fluorescence microscopy.

Pentahydrated copper sulphate CuSO4.5H2O at different doses for control of Hemileia vastatrix berk & broome

“…Some studies are based on the use of copper fungicides (copper oxychloride and mineral broths) considered the most efficient for the control of coffee rust, since they do not alter the biota of the agroecosystem. 19 Others have the function of penetrating the leaf tissue and have curative effects. 20 Particularly copper sulfate pentahydrate CuSO 4 .5H 2 O, which has been tested at different doses in the present study, has been used in an empirical manner, making approximations as to the doses to be used.…”

Towards an Eco-Friendly Coffee Rust Control: Compilation of Natural Alternatives from a Nutritional and Antifungal Perspective

“…Biological control agents are better than chemical insecticides as they not only have the potential to increase the immune response of coffee crops but also enhance nutrition, preventing significant losses in the production and maturity of the coffee bean ( Figure 3 ) [ 61 , 62 ]. Over the years, plants’ biological and chemical defense functions have been widely researched.…”

The Characterization of a Novel Virus Discovered in the Yeast Pichia membranifaciens

“…Pichia membranifaciens is a pseudofilamentous fungus and a common spoilage organism that contaminates meats, soft cheeses, vegetables, and beverages [ 1 ]. Although P. membranifaciens is frequently associated with spoilage, it can act as a biocontrol agent against plant pathogens and aggressive post-harvest spoilage organisms [ 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. Biological control by Pichia species relies on volatile organic compounds, killer toxins, and glucanases [ 9 , 10 , 11 , 12 ].…”