ABSTRACT: Host genetics and diet can exert an influence on microbiota and, therefore, on feeding efficiency. This study evaluated the effect of genetic line (fast-growth and high-resistance) in Pacific white shrimp ( Litopenaeus vannamei ) on the hepatopancreatic microbiota and its association with the feeding efficiency in shrimp fed with diets containing different protein sources. Shrimp (2.08 ± 0.06 g) from each genetic line were fed for 36 days with two dietary treatments (animal and vegetable protein). Each of the four groups was sampled, and the hepatopancreatic metagenome was amplified using specific primers for the variable V4 region of the 16S rRNA gene. The PCR product was sequenced on the MiSeq platform. Nineteen bacterial phyla were detected, of which Proteobacteria was the most abundant (51.0 – 72.5 %), Bacteroidetes (3.6 – 23.3 %), Firmicutes (4.2 – 13.7 %), Actinobacteria (1.9 – 12.1 %), and Planctomycetes (1.3 – 9.5 %). Diet was the most influential factor in the taxonomic composition of the microbiota, while genetic line was not a strong influential factor. The results suggest that the taxonomic profile of the bacteria colonizing shrimp hepatopancreas was determined by the diet consumed, similar to what occurs in the intestine. Shrimp in the fast-growth line had greater feeding efficiency regardless of the diet supplied. Finally, the results suggest that Proteobacteria influenced ( p < 0.05) the feeding efficiency of shrimp fed with a vegetable diet. Nevertheless, further studies are required to explore how shrimp genetic line–diet interaction influences microbiota for probiotic development and functional food formulation for farmed shrimp according to the genetic line.

ABSTRACT This short-term study evaluated the effect of non-lethal high CO2 concentration on the transcriptional response of immune-related genes of Pacific white shrimp (Litopenaeus vannamei) cultured in recirculating aquaculture systems (RAS). Two experimental groups were created: high CO2 (47.67±2.04 mg L−1) and low CO2 (2.0±1.93 mg L−1). Shrimp of 8.85±1.20 g were placed randomly at a density equivalent to 100 individuals m−3 and were monitored at 6, 12, 18, and 24 h. The transcriptional response of immune-related genes was analyzed by qPCR. Gene expression of hemocyanin, prophenoloxidase, and heat shock protein 60 was downregulated at 24 h, suggesting affectations on oxygen transportation, melanization, and protein functioning of L. vannamei under high CO2 concentrations. Also, gene up-regulation of lipopolysaccharide- and β-glucan-binding protein and cytosolic manganese superoxide dismutase can impair the bacterial recognition and antioxidant defense of shrimp exposed to high CO2 concentrations. These results suggest that concentration at about 47 mg L−1 of CO2 can significantly influence the transcriptional response modulation of immune-related genes.

Abstract The Chapala Lake is one of the most polluted lakes in Mexico, due to the in flow of effluents from several industrial plants, the lake accumulates pollutants such as chromium(VI) which is considered important for aquatic ecosystem. This study aimed was to evaluate the ability to decrease the concentration of chromium (VI) by Lysinibacillus macroides 2(1B)104A, isolated from sediments of the Chapala Lake. The strain was identified through 16S rRNA sequencing and phylogenetic analysis. Results showed that this strain grows in concentrations of 50, 100, 200 and 300 mgL-1 Cr(VI), in pH ranging 6 to 7, showing 79.508% reduction in concentration 50 mgL-1, determining that the reduction occurs extracellularly. Likewise, it was observed that Lysinibacillus macroides reduced the concentration of Cr(IV) in the broth, it was not observed that the bacteria could sequester Cr(VI) in the membrane or intracellularly. However, it reduced the concentration of Cr(VI) in the broth. Lysinibacillus macroides 2(1B)104A isolate showed having the ability that decrease the concentration of Cr(VI), which makes it a viable options for bioremediation of water polluted with this metal.

Abstract As an alternative to the excessive use of synthetic fertilizers, farmers use microorganisms that promote growth in plants, to increase roots growth, strengthen natural mechanisms that react to diseases and insects and increase production. The objective of this study was to evaluate the potential of agricultural plaster combined with Bacillus cereus, B. subtilis, Pseudomonas fluorescens and Trichoderma harzianum as plant growth promoter. Its soil application will allow selecting the most productive combination, with higher quality and crop yield. The design was completely random, with three treatments applied to potatoes cultivation (Solanum tuberosum L.) in shaded house conditions and drip irrigation. The treatments were: control (T1), T. harzianum combined with 40 kg ha-1 calcium (T2), B. cereus, B. subtilis, P. fluorescens and T. harzianum combined with 40 kg ha-1 calcium (T3); the source of calcium in T2 and T3 was agricultural gypsum. The evaluated variables were plant height, chlorophyll content, numbers and nutritional composition of leaves, weight and volumetric weight of the tuber. The viability of the microorganisms in the rhizosphere was determined with selective agars for each type of microorganism. There were no statistical differences regard on chlorophyll between treatments; the control significantly exceeded in height compared to the plants from T2 to T4; the number of tubers (51.5 %) and yield (49.4 %) from T3 was significantly higher than T1. At the biocontrol in the tuber for Streptomyces T3 was better (9 %) than T1 (32.14 %). T3 had a higher yield and better standard quality.

Resumen Como alternativa al uso excesivo de fertilizantes sintéticos, los agricultores adoptan el uso de microorganismos promotores de crecimiento en plantas, para potenciar el crecimiento de raíces, fortalecer mecanismos naturales de reacción a enfermedades e insectos y aumentar la producción. El objetivo de este estudio fue evaluar el potencial del yeso agrícola en combinación con Bacillus cereus, B. subtilis, Pseudomonas fluorescens y Trichoderma harzianum como promotor de crecimiento vegetal. Su aplicación al suelo permitirá seleccionar la combinación más productiva, con calidad y rendimiento mayores del cultivo. El diseño fue totalmente al azar, con tres tratamientos aplicados al cultivo de papa (Solanum tuberosum L.) en condiciones de casa sombra y riego por goteo. Los tratamientos fueron: testigo (T1), Trichoderma harzianum combinado con 40 kg ha-1 calcio (T2), B. cereus, B. subtilis, Pseudomonas fluorescens y Trichoderma harzianum combinados con 40 kg ha-1 calcio (T3); la fuente de calcio en T2 y T3 fue yeso agrícola. Las variables evaluadas fueron altura de planta, contenido de clorofila, composición nutrimental de hoja y número, peso y peso volumétrico del tubérculo. La viabilidad de los microorganismos en la rizósfera se determinó con agar selectivo para cada tipo de microorganismo. En el clorofila no hubo diferencias estadísticas entre los tratamientos; el testigo superó significativamente en altura a las plantas de T2 a T4; el número de tubérculos (51.5 %) y rendimiento (49.4 %) de T3 fue significativamente mayor que T1. En el biocontrol en tubérculo contra Streptomyces T3 fue mejor (9%) que T1 (32.14 %). T3 tuvo rendimiento mayor y calidad estándar mejor.

White spot syndrome virus (WSSV) is the viral pathogen with the most negative impact on shrimp farming. In Sonora, Litopenaeus vannamei culture has decreased 50% during 2010-2012 due to WSSV outbreaks. The ORF94 has proven to be most useful for the analysis of WSSV variability. Several studies have suggested a correlation between its Repeat Units (RUs) and WSSV virulence as follows: the fewer RUs (<9) the higher mortality rate. In order to support this, we analyzed shrimps from eight farm periods and identified the WSSV-variety present in each one. In outbreaks, the presence of <8 RUs with a dominance of 3 RUs was notable in the last four years. Although it is still not clear how host-virus interactions and pond's environment affect the transition of the infection just from the presence of the virus in shrimps to an outbreak, these results are a step forward in understanding the pond status and ways of predicting the likelihood of a WSSV infection becoming an outbreak.

El virus del síndrome de la mancha blanca (VSMB) es un patógeno viral que impacta negativamente la producción de camarón de cultivo. En Sonora, el cultivo de camarón Litopenaeus vannamei disminuyó un 50% durante el período 2010-2012 debido a las mortalidades ocasionadas por la presencia del VSMB. El ORF94 es una región minisatélite muy usada para determinar la variabilidad genómica del virus. Varios estudios han sugerido una correlación entre sus unidades repetidas (UR) y la virulencia de VSMB: a menor UR (<9) mayor frecuencia de mortalidad. Para soportar esta hipótesis, se analizaron camarones de ocho ciclos de cultivo y se identificaron variantes del VSMB presente en cada uno de los ciclos. En ciclos con mortalidades masivas se notó la presencia de UR <8 con una dominancia de 3 UR en los últimos cuatro años. Aunque no está muy claro, la interacción VSMB-hospedero y como afectan los parámetros ambientales de las granjas en la transición de la sola presencia del VSMB a causar mortalidades masivas, estos resultados son solo un avance en el entendimiento de como una infección por el virus puede ocasionar un brote de la enfermedad con mortalidades masivas.

Abstract Residual mushroom waste has the potential to be composted. Sustainable agriculture considers compost and vermicompost as alternatives to be incorporated into organic vegetable production. The aim of this study was to determine the effect of compost (T2), vermicompost tea (T3), compost extract (T4), and their combination plus the addition of an inorganic element (urea) (T5), against a conventional control (T1), on soil properties and yield parameters of tomato plants grown under shade house conditions. Organic matter, moisture, pH, electrical conductivity (EC), cation exchange capacity (CEC), bulk density, leaf nutrient content during flowering (N, P, K, Ca, Mg, Cu, Fe and Zn), chlorophyll content (SPAD units), fruit number and weight, and yield were the variables assessed during this research. A completely randomized experimental design was used. The organic applications showed significant increases in soil moisture (25.4 % T3), EC (0.38 dS·m-1 T5), and CEC (38.6 meq·100 g-1 T4). Crop nutrient requirements were achieved 102 days after transplanting. The chlorophyll content ranged between 46.9 and 51.4 SPAD units. The cv “Grandella” fruits attained optimal weight (152 to 155 g). The number of fruits and yield did not statistically differ between treatments; therefore, it was concluded that the organic substances by themselves or in combination with inorganic fertilizers were able to produce the same effect on yield, and also improve the physicochemical characteristics of the soil.

Resumen Los residuos del cultivo de champiñón presentan potencial para ser compostados. La agricultura sustentable considera el compost y el vermicompost como una alternativa de uso para la producción orgánica de hortalizas. El objetivo del presente estudio fue determinar el efecto del compost (T2), té de vermicompost (T3), extracto de compost (T4) y su combinación más la adición de una fracción inorgánica (urea) (T5), contra un testigo convencional (T1), sobre las propiedades del suelo y parámetros de rendimiento de tomate bajo condiciones de casa sombra. Las variables evaluadas fueron: materia orgánica, humedad, pH, conductividad eléctrica (CE), capacidad de intercambio catiónico (CIC), densidad aparente, contenido nutricional foliar en la etapa de floración (N, P, K, Ca, Mg, Cu, Fe y Zn), clorofila (unidades SPAD), número y peso de frutos y rendimiento. Se utilizó un diseño completamente al azar. Las aplicaciones orgánicas presentaron incrementos significativos en la humedad del suelo (25.4 % T3), CE (0.38 dS·m-1 T5) y CIC (38.6 meq·100 g-1 T4). Después de 102 días del trasplante, se logró cubrir los requerimientos nutricionales del cultivo. La clorofila osciló entre 46.9 y 51.4 unidades SPAD. Los frutos alcanzaron el peso óptimo (152 a 155 g) para cv “Grandella”. El número de frutos y el rendimiento no difirieron estadísticamente entre los tratamientos; por lo que se concluyó que los materiales orgánicos solos o en combinación con fertilizantes inorgánicos fueron capaces de producir el mismo efecto en rendimiento, y además mejorar las características fisicoquímicas del suelo.

Abstract: In this first study on aeromycota from the state of Sonora, Mexico, the airborne fungal diversity of Ciudad Obregón was determined and quantified with a Hirst-type sampler according to internationally accepted methods (Spanish Aerobiology Network). Spearman statistical correlations between the dominant fungal taxa and several meteorological parameters were established for the dry (January-May) and wet (June-December) seasons for two sampling periods (January-December of 2008 and 2011). The annual fungal indices for 2008 and 2011 were 917 and 1,690 spores, respectively. The dominant spores during both years were Alternaria, Cladosporium and Aspergillus/Penicillium. Statistically significant positive correlations were obtained between the total spore count with precipitation and relative humidity. This study highlights that the dominant genera in arid zones are Alternaria, Aspergillus/Penicillium and Cladosporium, which is similar to other regions. However, in cities with arid climates that are surrounded by crops, Alternaria is dominant, followed by Cladosporium and Aspergillus/Penicillium in smaller proportions. This finding could be related to the systematic use of fungicides in agricultural regions and the selective effect of these agrochemicals. The consequences of fungicide use on human and crop health must be evaluated. Aspergillus/Penicillium does not exhibit a seasonal pattern when studied using the Hirst method.

Resumen: En este primer estudio sobre la aeromicota del estado de Sonora, se determinó y cuantificó la diversidad fúngica de la atmósfera de Ciudad Obregón, de acuerdo a la metodología internacional aceptada (Red Española de Aerobiología), con un captador Hirst. Se estableció la correlación estadística (Spearman) de los principales taxones fúngicos y los parámetros meteorológicos en dos estaciones: seca (enero-mayo) y húmeda (junio-diciembre), en dos periodos de muestreo (enero-diciembre de 2008 y de 2011). El índice anual fúngico para 2008 fue de 917 esporas y en 2011 de 1690. En ambos periodos las principales esporas fueron: Alternaria, Cladosporium y Aspergillus/ Pénicillium. Se obtuvieron correlaciones estadísticas significativas positivas del total de esporas con precipitación y humedad relativa. El estudio resalta que en zonas áridas, los géneros dominantes son Alternaria, Aspergillus/Penicillium y Cladosporium, a semejanza de otras regiones. Sin embargo, se observa que en ciudades de climas áridos rodeadas de cultivos, Alternaria es el taxón dominante, seguido en menor proporción por Cladosporium y Aspergillus/Penicillium. Lo anterior puede relacionarse con el uso sistemático de fungicidas en esas regiones agrícolas y su acción selectiva, cuyas consecuencias deberán evaluarse en la salud humana y sanidad de los cultivos. Aspergillus/Penicillium no tiene un patrón estacional definido cuando se estudia con el método Hirst.

Abstract: Coccidioidomycosis, classified as such as a saprozoonosis disease, which is produced by Coccidioides spp. So far this ailment just had been categorized in two strains C. immitis and C. posadassi. The disease had frequently been associated to dried environments and alkaline soils, where, after rain, fungus spread arthroconidea. The aim of this research was to study the pathological aspects found at necropsy, the serological presence and the spherules existence of the Coccidioides spp. microscopically in naturally infected dogs. From 90 tested animals, serology showed 78.88% positives using Particles agglutination Latex (PAL), and just 21.12% animals were serum-negatives. At necropsy, there were just 25% animals with suggested lesions to the disease in one or more organs, while 75% animals did not show affected organs. Cachexia, cough and limp were significant sources of variation (P < 0.05), in relation with the variable presence of spherules. If animal is skinny or not, it does not represent significant sources of variation (P > 0.05). PAL was poorly correlated with affected organs at necropsy and with spherule presence at histopathology (Kappa= 0.1047, p< 0.05). All 22 affected animals (100%) presented lungs lesions and 77.27% on bones. Macroscopic pulmonary affections were evident at level 4 (lung with more of 70% of affection) while 66 (75%) with out lesions. Kappa correlation between suggestive lesions to coccidioidomycosis and presence of spherules is high (K= 1, p< 0.001). It is necessary to conduct studies of concordance of such positive serology animals using a more sensitive technique such as Polymerase Chain Reaction (PCR).

Resumen: La Coccidioidomicosis, clasificada como una saprozoonosis, es causada por el hongo Coccidoides spp., del cual, a la fecha, solo se han clasificado dos especies: C. immitis y C. posadassi. La enfermedad ha sido frecuentemente reportada en áreas con climas secos y con suelos alcalinos en los cuales el hongo puede liberar un gran número de artroconideos después de la lluvia. Este estudio tuvo como finalidad investigar aquellos aspectos patológicos encontrados a la necropsia y la presencia serológica de la enfermedad, así como la presencia del hongo a nivel microscópico en perros infectados naturalmente. De los 90 animales seleccionados, el 60% estaban delgados; la Prueba de Aglutinación en Látex (PAL), clasificó al 78.8% y 21.12% fueron seronegativos. A la necropsia el 25% presentaron lesiones sugestivas a la enfermedad en uno o más órganos, y el 75% no presentaron evidencias. La presencia de caquexia, tos y claudicación resultaron ser fuentes significativas de variación (P < 0.05) con respecto a la variable respuesta que es la presencia de esférulas. Respecto a que si el animal está o no delgado no representó una fuente significativa de variación (P > 0.05). PAL está pobremente correlacionada con la aparición de lesiones en órganos durante la necropsia y a la presencia de esférula en la histopatología (Kappa= 0.1079, p>0.05). De los 22 animales afectados, el 100% presentó lesiones pulmonares y el 77.27 % en hueso. La histopatología reveló el 25% (22 casos) presentaron la esférula de Coccidioides spp., y el 75% (66 casos) sin lesión. La correlación entre las lesiones sugestivas a Coccidioidomicosis y la presencia de esférulas de Coccidioides spp. es alta (Kappa= 1, p>0.001). Es recomendable realizar estudios de concordancia de estos animales positivos a serología con el uso de una técnica más sensible como la reacción en cadena de la polimerasa (PCR).

By means of molecular techniques more than 47 species of the genus Naegleria have been identified, but in Mexico, only 4 of these species have been so identified. The objective of this study was to identify a higher number of Naegleria spp. in recreational areas in Hornos, Sonora. Nine sites were selected and sampling was performed from June to September of 2004. Fifteen isolated species were identified genetically by means of sequencing ribosomal DNA, 9 specimens as N. lovaniensis, 5 as N. tihangensis and 1 as N. americana. It is the first time that N. americana and N. tihangensis are reported in this region. The latter species is closely related to another pathogenic amoeba, N. australiensis. One of the isolated strains of N. lovaniensis is unique because it differs by 1 bp from the other strains of this species.

Por medio de técnicas moleculares se han identificado más de 47 especies del género Naegleria, pero en los estudios hechos en México sólo 4 han sido identificadas. El objetivo de este estudio fue identificar el mayor número de Naegleria spp. en sitios recreativos en Hornos, Sonora. Para ésto, se seleccionaron 9 sitios que se muestrearon durante los meses de junio a septiembre de 2004. Se identificaron genéticamente 15 especies aisladas mediante secuenciación de DNA ribosomal, 9 ejemplares como N. lovaniensis, 5 como N. tihangensis y 1 como N. americana. Es la primera vez que se registra la presencia de N. americana y N. tihangensis en la región; esta última especie está muy relacionada con otra amiba patógena, N. australiensis. Una de las cepas aisladas de N. lovaniensis resultó ser única porque difiere en 1 par de bases de las otras cepas de esta especie.