Pseudomonas aeruginosa is a pathogen that causes healthcare-associated infections (HAIs) worldwide. It is unclear whether P. aeruginosa isolated from the natural environment has the same pathogenicity and antimicrobial resistance potential as clinical strains. In this study, virulence- and resistance-associated genes were compared in 14 genomic sequences of clinical and environmental isolates of P. aeruginosa using the VFDB, PATRIC, and CARD databases. All isolates were found to share 62% of virulence genes related to adhesion, motility, secretion systems, and quorum sensing and 72.9% of resistance genes related to efflux pumps and membrane permeability. Our results indicate that both types of isolates possess conserved genetic information associated with virulence and resistance mechanisms regardless of the source. However, none of the environmental isolates were associated with high-risk clones (HRCs). These clones (ST235 and ST111) were found only in clinical isolates, which have an impact on human medical epidemiology due to their ability to spread and persist, indicating a correlation between the clinical environment and increased virulence. The genomic variation and antibiotic susceptibility of environmental isolates of P. aeruginosa suggest potential biotechnological applications if obtained from sources that are under surveillance and investigation to limit the emergence and spread of antibiotic resistant strains

The effect of chromium removal by Algae-bacteria Bostrychia calliptera (Rhodomelaceae) consortia under laboratory conditions. Water pollution is one of the most important environmental problems worldwide. Recently, biotechnology studies have oriented efforts to study algae-bacterium consortia with the aim to understand the mechanisms to find a possible solution in environmental sciences. This study determined the percentage of chromium removal by the alga-bacterium association exposed to a set of different chromium concentrations under controlled in vitro conditions. Wild plants of Bostrychia calliptera associated with bacterial populations were collected from Dagua River, Pacific coast of Colombia, and were monitored in the laboratory. The trial was conducted with synthetic seawater in bioreactors at two chromium levels: 5 and 10mg/L, and four different experimental treatments: i) algae-bacteria (AB), ii) algae with antibiotic (AA), iii) algal surface sediment, Natural Bacterial Consortium (CBN), and iv) the control without algae or bacteria. The experimental design followed a model of two factors (chromium concentration x combination types) with repeated measures using one factor. The microbial population behavior and the chromium concentration percentage were monitored by using atomic absorption spectroscopy (AAS). According to the data, Algae-bacteria (AB) treatment was the most efficient combination at 10mg/L (87%), whereas the bacterial consortia (CBN) was the most efficient at 5mg/L (62.85%). The results showed significant differences of chromium uptake between algae-bacteria (AB) and natural bacterial consortia (CBN), meaning the importance of those treatments in the chromium removal from coastal waters.

In this study Bacillus cereus was used to evaluate the Cr6+ reducing capacity in electroplating effluents. TheCr6+ bioreduction assays were carried out using real waste water (RWW) from an electroplating plant and artificial wastewater (AWW), with and without added glucose. The AWW was prepared using Ni ,Zn ,Cu, Pb, and Cr salts, simulating RWW concentrations. The Cr6+ concentration and bacterial growth were monitored three times a day for the duration of five days. Also, were evaluated the effects of wastewater on B. cereus B1 morphology using scanning electron microscopy. Cr6+ reduction percentage of 100 % was reached for AWW containing glucose, of 71 % for AWW without glucose, of 75.6 % for RWW with glucose, and of 31.7 % for RWW without glucose. Despite the low reduction percentage obtained for RWW without glucose, concentrations of 0.14 mg/L of Cr6+ were reached, which were within allowed limits (0.5mg/L of Cr6+). Electron Microscopy showed alterations in the bacterial cell wall and a decrease in size, mainly in the bacteria exposed to RWW. The results allow us to propose B. cereus B1 as a promising microorganism for use in the bioremediation of effluents containing Cr6+.

• Bioinoculants enhanced S. lycopersicum yield, which was reflected in its growth. • All bacterial isolates exhibited nitrogen-fixing capacity, confirmed by nifH gene amplification. • First report of IAA production in N. resinovorum, A. insuavis and Curtobacterium sp. • Potassium solubilization was observed in 72 % of strains; 90.9 % solubilized phosphate.

The oil spills and their derivatives produce strong impacts on the balance of ecosystems, as they not only destroy their biodiversity, but also leave serious consequences that hinder their resilience. In the last decades, microbiology studies have shown evidences that in polluted areas microorganisms develop abilities to break pollutants. In order to determine the ability of native microorganisms from petroleum contaminated soil to degrade kerosene, two strains of microorganisms previously isolated from a soil exposed to petroleum derivatives, which showed contaminant tolerance, were selected by means of minimum inhibitory concentration (MIC). Removal assays of saturated aliphatic hydrocarbons (C-10 to C-16 n-alkanes) whit strain selected strains were performed and they were analyzed by gas chromatography and masses (GC-MS). The microorganisms were identified as Candida metapsilosis SH1 and Burkholderia cepacia SH3, with tolerance to concentrations greater than 10% of kerosene and with selective biodegradation capacity of long chain hydrocarbons, causing fragmentation correlated with the increase of hydrocarbons of short chains (C10 to C12). These results show promising applications of the microorganisms analyzed to mitigate the contamination of sites affected by hydrocarbons. Los derrames de petróleo y sus derivados producen fuertes impactos en el equilibrio de los ecosistemas, ya que no sólo arrasan con su biodiversidad, sino que dejan graves consecuencias que dificultan su capacidad de resiliencia. Se ha reportado que microorganismos de zonas contaminadas con hidrocarburos desarrollan habilidades para la degradación de estos contaminantes. Con el propósito de determinar la capacidad de microorganismos nativos de suelo contaminado con petróleo para degradar el queroseno, se seleccionaron dos cepas de microorganismos previamente aisladas de un suelo expuesto a derivados del petróleo, que mostraron tolerancia al contaminante, mediante pruebas de concentración mínima inhibitoria (CMI). Las cepas seleccionadas se evaluaron mediante bioensayos de remoción de hidrocarburos alifáticos saturados (n-alcanos de C-10 a C-16) que fueron analizados por comparación de abundancias relativas usando un cromatógrafo de gases-masas (GC-MS). Los microorganismos se identificaron como Candida metapsilosis SH1 y Burkholderia cepacia SH3, con tolerancia a concentraciones mayores del 10% de queroseno y capacidad de biodegradación selectiva de hidrocarburos de cadenas largas, causando fraccionamiento correlacionado con el aumento de hidrocarburos de cadenas cortas (C10 a C12). Estos resultados evidencian aplicaciones promisorias de los microorganismos analizados para mitigar la contaminación de sitios afectados por hidrocarburos.