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Yeasts and bacteria were isolated and identified in the fermentation of artisanal mezcal made with Agave convallis from Oaxaca. A representative sample of must was seeded in ADS medium for yeasts, MRS for lactic bacteria and GYC for acetic bacteria; the selected strains were determined by conventional methods. 27 strains were obtained, and from their macroscopic and microscopic morphology and biochemical tests, it was possible to identify the yeasts Candida lusitanae (8 strains), Candida tropicalis (1 strain), Candida sp. (1 strain), Kluyveromyces sp. (1 strain) and Kluyveromyces marxianus (1 strain). Regarding acetic acid bacteria, Acidomonas sp. (2 strains) and Acetobacter sp (5 strains). Of the lactic acid bacteria, Lactobacillus sp. (1 strain), Streptococcus sp. (2 strains), Lactobacillus plantarum (1 strain), Lactobacillus sp. (3 strains) and Spirochaete sp. (1 strain). [ABSTRACT FROM AUTHOR]

In the municipality of Arriaga, Chiapas, the death of physic nut (Jatropha curcas L.) 1 and 2-year old plantations has been observed since 2009, with symptoms of wilting and basal stem rot. The registered incidence has been up to 85%; the virulence of the pathogen is very high because it causes the death of the plant in a period of 20 to 30 days. The objective of this study was to determine the causal agent of the physic nut death. Laboratory isolates were conducted from field samples of diseased plant material of stem and root tissue, in Petri dishes with B King (BK) and triphenyl tetrazolium chloride (TTC) medium, incubated at 28 °C for 48 h. The isolates obtained were purified and subjected to biochemical and hypersensitivity tests on tobacco (Nicotiana tabacum) cv. Xanthi. The identification was positive for three isolates of Ralstonia solanacearum. However, it was not possible to complete Koch's postulates; therefore, R. solanacearum is only consigned at association level. [ABSTRACT FROM AUTHOR]