Aerobic nitrite oxidation in marine environments plays a key role the nitrification process. Marine bacteria involved this nitrate-producing process have however been seldom studied compared with ammonia-oxidizing community. Here, we report for first time community structure of aerobic nitrite-oxidizing (NOB) seasonal upwelling and oxygen-deficient area off Central Chile. Analysis 16S rRNA by tag pyrosequencing was combined specific quantitative polymerase chain reaction (qPCR) reverse...

Flavobacterium psychrophilum is the etiological agent of bacterial coldwater disease and rainbow trout fry syndrome in salmonid aquaculture worldwide. However, there have been few studies into capacity F. to form biofilms how these cellular accretions differ from planktonic cells or they affect potential virulence. We evaluated biofilm formation by three Chilean isolates (LM-02-Fp, LM-06-Fp LM-13-Fp) two non-Chilean strains (JIP02/86 NCMB1947T), compared states obtain insights expression...

Abstract Piscirickettsia salmonis is the causative agent of piscirickettsiosis, a disease with high socio-economic impacts for Chilean salmonid aquaculture. The identification major environmental reservoirs P . has long been ignored. Most microbial life occurs in biofilms, possible implications outbreaks as pathogen seed banks. Herein, we report on an vitro analysis biofilm formation by Psal-103 (LF-89-like genotype) and Psal-104 (EM-90-like genotype), aim which was to gain new insights into...

The strong seasonal variability in physical-chemical conditions of the Eastern South Pacific Ocean creates an ideal setting to study spatiotemporal distribution key marine microbial communities.. We herein report a nearly 4-year-long time series amoA gene counts ammonia oxidizing archaea (AOA) and bacteria (betaproteobacteria, bAOB) by quantitative PCR, GI.1a Thaumarchaeota MG-II Euryarchaeota CARD-FISH, picoplanktonic community flow cytometry for this area. During spring-summer,...

ABSTRACT Microbial life forms are among the most ubiquitous on Earth, yet many remain understudied in Caribbean estuaries. We report prokaryote community composition of Urabá Estuary Colombian using 16S rRNA gene-transcript sequencing. also assessed potential functional diversity through 38 metabolic traits inferred from gene data. Water samples were collected six sampling stations at two depths with contrasting light-penetration conditions along an approximately 100 km transect Gulf...

The authors declare that the research was conducted in absence of any commercial or financial relationships could be construed as a potential conflict interest.

We report the seasonal and single-diurnal variability of potentially active members prokaryote community in coastal surface waters off central Chile relationship between nitrifiers solar radiation by combining 16S cDNA-based pyrosequencing, RT-qPCR specific gene markers for (amoA, general AOA, AOA-A, AOA-B, Nitrosopumilus maritimus beta-AOB; rRNA Nitrospina-like NOB), irradiance measurements. also evaluated effects artificial UVA-PAR PAR spectra on RT-qPCR. All (except AOA-B ecotype) were...

The growing biogeochemical and economic importance of biogenic methane contained in gas hydrates necessitates a better understanding the microorganisms involved last phase organic matter degradation. Here, distribution relative abundance methylotrophic methane-producing Archaea (mMPA) were studied an upwelling area off central Chile by rRNA dot blot hybridization. mMPA detected mostly during active periods, more abundant deeper layer water column (>50 m), where they represented ~10%...

Flavobacterium psychrophilum is the causative agent of bacterial cold-water disease and rainbow trout fry syndrome, hence this bacterium placed among most important salmonid pathogens in freshwater aquaculture industry. Since bacteria biofilms differ substantially from free-living counterparts, study sought to find main differences gene expression between sessile planktonic states F. LM-02-Fp NCMB1947T, with focus on stress-related changes occurring during biofilm formation. To end, samples...

Piscirickettsia salmonis is a bacterial pathogen that severely impact the aquaculture in several countries as Canada, Scotland, Ireland, Norway, and Chile. It provokes Piscirickettsiosis outbreaks marine phase of salmonid farming, resulting economic losses. The monophyletic genogroup LF-89 divergent EM-90 are responsible for most severe Therefore, development methods quick genotyping P. genogroups field samples vital veterinary diagnoses understanding population structure this pathogen....

Abstract Piscirickettsiosis is a fish disease caused by the facultative intracellular bacterium, Piscirickettsia salmonis . Even though entry routes of P in are not fully clear yet, skin seems to be main portal some salmonid species. Despite importance mucous barrier fighting waterborne pathogens, interaction between mucus and bacterium unknown. This study seeks determine vitro changes growth two Chilean P. strains (LF‐89‐like EM‐90‐like genotypes) type strain LF‐89 T under exposures from...

Piscirickettsiosis is a fish disease caused by the Gram-negative bacterium Piscirickettsia salmonis. This has high socio-economic impact on Chilean salmonid aquaculture industry. The cryptic character in environment and their main reservoirs are yet unknown. Bacterial biofilms represent ubiquitous mechanism of cell persistence diverse natural environments risk factor for pathogenesis several infectious diseases, but microbiological significance waterborne veterinary including...

Archaeal and bacterial assemblages in the Oxygen Minimum Zone of

La respiracion es la variable clave para comprender el flujo de energia y materia en cualquier ecosistema. De hecho, del ecosistema un componente critico ciclo carbono podria ser importante regulacion respuesta biosfera al cambio climatico. proceso basico usado por biota obtencion degradacion organica satisfacer sus necesidades supervivencia; su medicion entrega estimado cantidad minima que necesita organismo. acuerdo con esto, total comunidad acuatica puede igualada a mantener estructura...

Abstract We herein report the diversity and relative abundance of chemolithotrophic nitrifying bacteria in a continuous‐flow bioreactor using 16S‐ribosomal RNA quantitative dot‐blot hybridizations. About 14.9% total bacterial population, determined by epifluorescence microscopy suspended phase, was represented bacteria. Of this fraction, ammonia‐ nitrite‐oxidizing accounted for 10% 90%, respectively, latter group being mostly N/frospira‐like. On other hand, nitrifiers adhesion/colonization...

The data that support the findings of this study are available on request from corresponding authors. not publicly due to privacy or ethical restrictions.

Abstract Nitrospina bacteria are among the most important nitrite oxidizers in coastal and open‐ocean environments, but relevance of genus contrasts with scarceness information on their ecophysiology habitat range. Thus far, have been only detected at high abundance Chilean waters. These levels often higher than other latitudes. In this study, 16S‐ rRNA gene transcripts (hereafter just transcripts) was measured by reverse transcription quantitative PCR a rocky intertidal gradient compared...