Abstract: Introduction: Halophiles can be found in hypersaline environments and they can synthesize products of industrial interest. Method: In this work, 37 bacterial strains were isolated from the sediment of a dried-out maar of the “Hoya Rincón de Parangueo” (Mexico) on different culture media with 20% NaCl and pH 9, while potential industrial extracellular enzymes were determined. Results: Eight genera Salsuginibacillus, Alkalibacillus, Bacillus, Staphylococcus, Oceanobacillus, Halomonas and Nesterenkonia besides 15 distinct species belonging to Actinobacteria, Firmicutes and Proteobacteria were identified. The L371, LTA7 and SU3 isolates produced proteases, M20, L5, L7, L8, Y1, Y2, M3, M9 and RA lipases, LTA4 and SU3 amylases, while LTA7, Y2, M5, M9 and RA caseinases with enzymatic activity at pH 9. Production of siderophore was found in 17 isolates. Discussion or Conclusion: It is reported for the first experimental evidence of siderophores production by N. alba, Alkalibacillus and Oceanobacillus at 6% NaCl (w/v). Isolates RE, RG1, RG2, RH1, RA and I11 showed 2.8% to 4.1% genetic distance with Nesterenkonia species and might represent new species.

Resumen: Introducción: Los microorganismos halófilos los podemos encontrar en ambientes hipersalinos y pueden sintetizar productos de interés industrial. Método: En el presente trabajo, 37 aislados se obtuvieron del sedimento del maar desecado de la “Hoya Rincón de Parangueo” (México) en diferentes medios de cultivo que contenían 20% de NaCl y pH de 9, se determinó el potencial de producción de enzimas extracelulares de interés industrial por estos aislados. Resultados: Se identificaron ocho géneros bacterianos Salsuginibacillus, Alkalibacillus, Bacillus, Staphylococcus, Oceanobacillus, Halomonas y Nesterenkonia además de 15 especies diferentes de Actinobacteria, Firmicutes y Proteobacteria. Los aislados L371, LTA7 y SU3 produjeron proteasas, M20, L5, L7, L8, Y1, Y2, M3, M9 y RA lipasas, LTA4 y SU3 amilasas y LTA7, Y2, M5, M9 y RA cacesinasas a pH de 9. La producción de sideróforos se encontró en 17 aislados. Discusión o Conclusión: Se reporta la primera evidencia experimental de la producción de sideróforos por N. alba, Alkalibacillus and Oceanobacillu a una concentración de NaCl al 6% (p/v). Los aislados RE, RG1, RH1, RA e I11 tuvieron una distancia genética de 2.8% a 4.1% con especies de Nesterenkonia por lo que pueden representar nuevas especies.

Background: The application of polycyclic aromatic hydrocarbons (PAHs) will affect the bacterial community structure as some groups will be favoured and others not. An alkaline saline soil with electrolytic conductivity (EC) 56 dS m-1 was spiked with anthracene and acetone while their effect on bacterial community structure was investigated. Results: The percentages of Acidobacteria and Actinobacteria decreased over time, while the percentage of Proteobacteria, mostly Xanthomonadales, increased. The percentage of the phylotypes belonging to the Nocardioides, Rhodococcus and Streptomyces, known degraders of PAHs, was larger in the anthracene-amended soil than in the acetone-amended and unamended soil at day 14. The phylotypes belonging to the genera Sphingomonas, also a known degrader of PAHs, however, was lower. Weighted and unweighted PCoA with UniFrac indicated that phylotypes were similar in the different treatments at day 0, but changed at day 1. After 14 days, phylotypes in the unamended and acetone-amended soil were similar, but different from those in the anthracene-spiked soil. Conclusions: It was found that incubating the soil and contaminating it with anthracene changed the bacterial community structure, but spiking the soil with acetone had little or no effect on the bacterial community structure compared to the unamended soil.

Conventional microbiological culture techniques are frequently insufficient to confirm endophthalmitis clinical cases which could require urgent medical attention because it could lead to permanent vision loss. We are proposing PCR-DGGE and 16S rRNA gene libraries as an alternative to improve the detection and identification rate of bacterial species from endophthalmitis cases.