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Mexico is among the most important citrus fruit producers in the world. However, during storage, several problems related to fungi can arise. The most common fungal postharvest diseases detected on Citrus limon var Eureka (Italian lime) produced in the Tamaulipas state are green/blue mold (Penicillium spp.), fusarium rot (F. oxysporum, F. solani, F. proliferatum, among others), and anthracnose (Colletotrichum spp.). In this work, we selected yeasts, occurring as the natural epiphytic mycoflora of lemons or from fermented traditional products, to be tested as part of a formulation for protecting stored lemons against fungal diseases. The best-performing yeasts, labeled as LCBG-03 (Meyerozyma guilliermondii), LCBG-30 (Pseudozyma sp.), and LCBG-49 (Saccharomyces cerevisiae), were selected to test their compatibility and biocontrol performance against strains of Penicillium digitatum (AL-38), Fusarium sp. (AL-21), Colletotrichum gloeosporioides (AL-13), and Epicoccum sorghinum (H3A). Based on their in vitro performance regarding the percentage of radial growth inhibition, both applied individually or as two yeasts mixed at equal cellular concentrations, the best combinations (containing M. guilliermondii formulated with either Pseudozyma sp. or S. cerevisiae) were selected with efficacies higher than 95% in both in vitro fungal radial growth rate inhibition and on stored lemon fruits. This work contributes to the search for compatible yeast combinations with the aim to diminish the fungal losses of citrus fruits using biocontrol for citrus postharvest protection. [ABSTRACT FROM AUTHOR]

One hundred new COI sequences of nesting female Kemp's ridley turtles (Lepidochelys kempii) were obtained in the Rancho Nuevo Sanctuary (RNS). The COI sequences were analyzed and contrasted with others retrieved from BOLD and GenBank with the aim of investigating genetic variability, genetic divergence, and haplotypes of the nesting female population at RNS. Four new COI haplotypes for Kemp's ridley were described; two are redundant with (LK-RN01) 97 and (LK-COI-01) 17 specimens belonging to the RNS and other localities, respectively. Nucleotide (0.00052) and haplotype (0.303) diversity showed low and conserved COI values The fixation index (FST) between these main redundant haplotypes showed a high degree of differentiation with ~1. Genetic divergence clearly demonstrated two different Kemp's ridley nesting populations, one from RNS and a second outside Mexico. Phylogenetic COI analysis was useful to differentiate these redundant (LK-COI-01 and RNS LK-RN01) haplotypes and, therefore, these different Kemp's ridley populations. In addition, phylogenetic COI analysis clearly separates Kemp's ridley turtles from other sea turtle species, supporting its use as a barcode marker. [ABSTRACT FROM AUTHOR]

Mezcal fermentation in Guerrero state (Mexico) is very rustic and artisanal and has unique characteristics in each fermented batch, due to its very heterogeneous composition as it contains a high percentage of cooked agave fibers. Two different batches were analyzed, which differed in their fermentation process being spontaneous or driven by a wild inoculum. These batches present low ethanol productivity and different volatile profiles, being acetaldehyde and ethyl acetate the ones that exhibited the highest differences in the spontaneous process. Bacteria community characterized by metagenomics approach showed a high microbial diversity at the beginning of both fermentation processes. Similarly, cultivable approach, conducted to support the metagenomics analysis, showed more species at the beginning of both fermentation processes. In general, Lactobacillaceae family was the most abundant (>50%) in all samples. Reads related to Weissella genus was highly abundant (>40%) at beginning of spontaneous fermentation, whereas genera Lacticaseibacillus and Secundilactobacillus were highly (>40%) abundant at end of the spontaneous and on the wild inoculum fermentations, respectively. Artisanal mezcal musts are characterized by a high bacterial diversity and the use of a wild inoculum reduce this diversity. [Display omitted] • Two fermentation batches were studied in the artisanal mezcal. • Spontaneous or wild inoculum-driven fermentation affects bacterial profile. • Lactobacillaceae and Leuconostocaceae bacteria were the more abundant. • More abundant genera were Acetobacter , Leuconostoc , Weissella and Lactobacillus. [ABSTRACT FROM AUTHOR]

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This study was made to identify the fungi associated with post-harvest decay in avocado fruit from Xalisco city in Nayarit state and to determine their potential biocontrol with Meyerozyma caribbica. The eight isolated fungi were identified as six Colletotrichum gloeosporioides, one Colletotrichum sp., and one Fusarium sp. through morphological characteristics and sequencing the D1/D2 region of the large-subunit rDNA gene. Koch's postulates were fulfilled by pathogenicity tests carried out on avocado fruit; obtaining different severity disease degrees. The yeasts' potential to control avocado diseases has been poorly studied. Therefore, the use of M. caribbica against the isolated fungi was proposed, the inhibition reached was above 78%. Hence, can be considered as a potential biocontrol agent to be applied in avocado fruit in the post-harvest stage. To our knowledge, this is the first report of Fusarium sp. as a causal agent of stem-end root in avocado fruit in Mexico. [ABSTRACT FROM AUTHOR]

Colletotrichum species are the most important postharvest spoilage fungi of papaya fruit. The objective of this research was to evaluate the effect of temperature and relative humidity on growth rate and time for growth to become visible of five strains of Colletotrichum gloeosporioides isolated from papaya fruit in a complex medium. As a primary model, the radial growth rates were estimated using the Baranyi and Roberts model in papaya agar. The Solver MS Excel function was used to obtain the time to visible mycelium (tv). Secondary models obtained with the Rosso et al. cardinal model of inflection were applied to describe the effect of temperature on the growth rate (μ). The Arrhenius-Davey model was used to model tv. The obtained models seem to be satisfactory for describing both μ and tv. The relative humidity had an effect on μ and tv for all tested C. gloeosporioides isolates, but no model accurately described the behavior of the fungus. External validation of models was performed with papaya fruit. Growth models were developed with the same models used in vitro. The bias and the accuracy factors as indices for performance evaluation of predictive models in food microbiology as a function of temperature and RH were 1.22 and 1.33, respectively, for μ and 1.18 and 1.62, respectively, for tv, indicating accurate predictions. The supply chain of papaya is complex and requires constant conditions, and poor conditions can result in damage to the fruit. Knowledge of the behavior of C. gloeosporioides on papaya fruit and application of the developed models in the supply chain will help to establish transport control strategies to combat these fungi. This research has contributed to development of the first models of growth for C. gloeosporioides in Mexico. Temperature greatly affected fungal rot of papaya at the postharvest stage. Fungal growth occurred when water was available, regardless of the relative humidity. Predictive models may help food processors make decisions for suboptimal supply chains. [ABSTRACT FROM AUTHOR]

Technological and analytical advances to study evolutionary biology, ecology, and conservation of green turtles (Chelonia mydas) are realized through molecular approaches including DNA barcoding. We characterized the usefulness of COI DNA barcodes in green turtles in Mexico to better understand genetic divergence and other genetic parameters of this species. We analyzed 63 sequences, including 25 from green turtle field specimens collected from the Gulf of Mexico and from the Mexican Pacific and 38 already present in the Barcode of Life Data Systems (BOLD). A total of 13 haplotypes were identified with four novel haplotypes from the Pacific Ocean and three novel haplotypes from the Atlantic Ocean. Intraspecific distance values among COI gene sequences by two different models were 0.01, demonstrating that there is not a subdivision for green turtle species. Otherwise, the interspecific distance interval ranged from 0.07 to 0.13, supporting a clear subdivision among all sea turtle species. Haplotype and total nucleotide diversity values of the COI gene reflect a medium genetic diversity average. Green turtles of the Mexican Pacific showed common haplotypes to some Australian and Chinese turtles, but different from the haplotypes of the Mexican Atlantic. COI analysis revealed new haplotypes and confirmed that DNA barcodes were useful for evaluation of the population diversity of green turtles in Mexico. [ABSTRACT FROM AUTHOR]

Background: Urban surface stones in Mexico City are exposed to a temperate climate and a range of atmospheric conditions ranging from mildly impacted to heavily polluted areas. In this study, we focused on the characterization of the cultivable fungal component of selected biological patinas in the surrounding area of Chapultepec castle, a historic monument in Mexico City. Thirty four representative fungal isolates selected based on distinctive differential macroscopic characteristics out of a total of 300 fungi, were characterized using morphological and molecular approaches. Results: This identification strategy based on the combination of phenotypic- and molecular-based methodologies allowed us to discriminate the fungal community in some cases down to the species level. Conclusions: The characterization of this mycoflora revealed the presence of a complex fungal community mainly represented by filamentous fungi belonging to the genera Fusarium, Trichoderma, Aspergillus, Cladosporium, Alternaria, Mucor, Penicillium, Pestalotiopsis, and the dimorphic fungus Aureobasidium, along with the yeast Rhodotorula. A specific distribution of fungi could be observed based on the type of biological patina analyzed. [ABSTRACT FROM AUTHOR]

Technological and analytical advances to study evolutionary biology, ecology, and conservation of green turtles ( Chelonia mydas ) are realized through molecular approaches including DNA barcoding. We characterized the usefulness of COI DNA barcodes in green turtles in Mexico to better understand genetic divergence and other genetic parameters of this species. We analyzed 63 sequences, including 25 from green turtle field specimens collected from the Gulf of Mexico and from the Mexican Pacific and 38 already present in the Barcode of Life Data Systems (BOLD). A total of 13 haplotypes were identified with four novel haplotypes from the Pacific Ocean and three novel haplotypes from the Atlantic Ocean. Intraspecific distance values among COI gene sequences by two different models were 0.01, demonstrating that there is not a subdivision for green turtle species. Otherwise, the interspecific distance interval ranged from 0.07 to 0.13, supporting a clear subdivision among all sea turtle species. Haplotype and total nucleotide diversity values of the COI gene reflect a medium genetic diversity average. Green turtles of the Mexican Pacific showed common haplotypes to some Australian and Chinese turtles, but different from the haplotypes of the Mexican Atlantic. COI analysis revealed new haplotypes and confirmed that DNA barcodes were useful for evaluation of the population diversity of green turtles in Mexico.