Diversity pattern and antibiotic activity of microbial communities inhabiting a karst cave from Costa Rica.

The studies of cave bacterial communities worldwide have revealed their potential to produce antibiotic molecules. In Costa Rica, ~400 caves have been identified; however, their microbial diversity and biotechnological potential remain unexplored. In this work, we studied the chemical composition and microbial diversity of a Costa Rican cave (known as the Amblipigida cave) located in Puntarenas, Costa Rica.

A concept for international societally relevant microbiology education and microbiology knowledge promulgation in society.

Executive Summary: Microbes are all pervasive in their distribution and influence on the functioning and well-being of humans, life in general and the planet. Microbially-based technologies contribute hugely to the supply of important goods and services we depend upon, such as the provision of food, medicines and clean water. They also offer mechanisms and strategies to mitigate and solve a wide range of problems and crises facing humanity at all levels, including those encapsulated in the sustainable development goals (SDGs) formulated by the United Nations.

Venom-microbiomics of eight species of Neotropical spiders from the Theraphosidae family.

Aim: Tarantulas are one of the largest predatory arthropods in tropical regions. Tarantulas though not lethal to humans, their venomous bite kills small animals and insect upon which they prey. To understand the abiotic and biotic components involved in Neotropical tarantula bites, we conducted a venom-microbiomics study in eight species from Costa Rica.

Highly abundant bacteria in the gut of Triatoma dimidiata (Hemiptera: Reduviidae) can inhibit the growth of Trypanosoma cruzi (Kinetoplastea: Trypanosomatidae).

Chagas disease, caused by the protozoan Trypanosoma cruzi, is a zoonosis primarily found in rural areas of Latin America. It is considered a neglected tropical disease, and Triatoma dimidiata is the main vector of the parasite in Central America. Despite efforts, Chagas disease continues to be a public health concern, and vector control remains a primary tool to reduce transmission.

Draft genome sequence of three hydrocarbon-degrading strains isolated from an abandoned century-old oil exploration well.

We present genome sequences of three strains isolated from an abandoned century-old oil exploration well. A sp. genome showed a size of 5,378,420 bp, while genomes sized 3,522,593 and 3,864,311 bp.

Differences in fungal communities in the fur of two- and three-toed sloths revealed by ITS metabarcoding.

Sloths have dense fur on which insects, algae, bacteria and fungi coexist. Previous studies using cultivation-dependent methods and 18S rRNA sequencing revealed that the fungal communities in their furs comprise members of the phyla Ascomycota and Basidiomycota. In this note, we increase the resolution and knowledge of the mycobiome inhabiting the fur of the two- () and three-toed () sloths.

Production of selenium nanoparticles occurs through an interconnected pathway of sulphur metabolism and oxidative stress response in Pseudomonas putida KT2440.

The soil bacterium Pseudomonas putida KT2440 has been shown to produce selenium nanoparticles aerobically from selenite; however, the molecular actors involved in this process are unknown. Here, through a combination of genetic and analytical techniques, we report the first insights into selenite metabolism in this bacterium. Our results suggest that the reduction of selenite occurs through an interconnected metabolic network involving central metabolic reactions, sulphur metabolism, and the response to oxidative stress.

Out of the blue: the independent activity of sulfur-oxidizers and diatoms mediate the sudden color shift of a tropical river.

Background: Río Celeste ("Sky-Blue River") is a river located in the Tenorio National Park (Costa Rica) that has become an important hotspot for eco-tourism due to its striking sky-blue color. A previous study indicated that this color is not caused by dissolved chemical species, but by formation of light-scattering aluminosilicate particles at the mixing point of two colorless streams, the acidic Quebrada Agria and the neutral Río Buenavista.

Results: We now present microbiological information on Río Celeste and its two tributaries, as well as a more detailed characterization of the particles that occur at the mixing point.

Fungi with history: Unveiling the mycobiota of historic documents of Costa Rica.

We studied the physicochemical characteristics and mycobiota associated to five key historic documents from Costa Rica, including the Independence Act of Costa Rica from 1821. We used nondestructive techniques (i.e.

Antibiotic-producing Micrococcales govern the microbiome that inhabits the fur of two- and three-toed sloths.

Sloths have a dense coat on which insects, algae and fungi coexist in a symbiotic relationship. This complex ecosystem requires different levels of controls; however, most of these mechanisms remain unknown. We investigated the bacterial communities inhabiting the hair of two- (Choloepus Hoffmanni) and three-toed (Bradypus variegatus) sloths and evaluated their potential for producing antibiotic molecules capable of exerting control over the hair microbiota.

Biodeterioration and cellulolytic activity by fungi isolated from a nineteenth-century painting at the National Theatre of Costa Rica.

Living organisms can induce deterioration of cultural heritage. Conservation strategies aimed at avoiding damage and aiding restoration, require a comprehensive knowledge of structure, chemical composition, and identity of microorganisms that colonize artworks. The National Theatre of Costa Rica (NTCR), a building with historic architecture, houses several oil paintings from the nineteenth century, some with visible signs of biodeterioration.

Special Issue: Diversity of Extremophiles in Time and Space.

Extreme environments are fascinating ecosystems that have allowed us to increase our knowledge about the evolutionary processes of life [...

The potential of Pseudomonas for bioremediation of oxyanions.

Non-metal, metal and metalloid oxyanions occur naturally in minerals and rocks of the Earth's crust and are mostly found in low concentrations or confined in specific regions of the planet. However, anthropogenic activities including urban development, mining, agriculture, industrial activities and new technologies have increased the release of oxyanions to the environment, which threatens the sustainability of natural ecosystems, in turn affecting human development. For these reasons, the implementation of new methods that could allow not only the remediation of oxyanion contaminants but also the recovery of valuable elements from oxyanions of the environment is imperative.

Transcriptional control of 2,4-dinitrotoluene degradation in Burkholderia sp. R34 bears a regulatory patch that eases pathway evolution.

The dnt pathway of Burkholderia sp. R34 is in the midst of an evolutionary journey from its ancestral, natural substrate (naphthalene) towards a new xenobiotic one [2,4-dinitrotoluene (DNT)]. The gene cluster encoding the leading multicomponent ring dioxygenase (DntA) has activity on the old and the new substrate, but it is induced by neither.

Streptomyces sp. M54: an actinobacteria associated with a neotropical social wasp with high potential for antibiotic production.

Streptomyces symbionts in insects have shown to be a valuable source of new antibiotics. Here, we report the genome sequence and the potential for antibiotic production of "Streptomyces sp. M54", an Actinobacteria associated with the eusocial wasp, Polybia plebeja.

Low CyaA expression and anti-cooperative binding of cAMP to CRP frames the scope of the cognate regulon of Pseudomonas putida.

Although the soil bacterium Pseudomonas putida KT2440 bears a bona fide adenylate cyclase gene (cyaA), intracellular concentrations of 3',5'-cyclic adenosine monophosphate (cAMP) are barely detectable. By using reporter technology and direct quantification of cAMP under various conditions, we show that such low levels of the molecule stem from the stringent regulation of its synthesis, efflux and degradation. Poor production of cAMP was the result of inefficient translation of cyaA mRNA.

Reconfiguration of metabolic fluxes in Pseudomonas putida as a response to sub-lethal oxidative stress.

As a frequent inhabitant of sites polluted with toxic chemicals, the soil bacterium and plant-root colonizer Pseudomonas putida can tolerate high levels of endogenous and exogenous oxidative stress. Yet, the ultimate reason of such phenotypic property remains largely unknown. To shed light on this question, metabolic network-wide routes for NADPH generation-the metabolic currency that fuels redox-stress quenching mechanisms-were inspected when P.

Temperature and elemental sulfur shape microbial communities in two extremely acidic aquatic volcanic environments.

Aquatic environments of volcanic origin provide an exceptional opportunity to study the adaptations of microorganisms to early planet life conditions. Here, we characterized the prokaryotic communities and physicochemical properties of seepage sites at the bottom of the Poas Volcano crater and the Agrio River, two geologically related extremely acidic environments located in Costa Rica. Both locations hold a low pH (1.

Concomitant prediction of environmental fate and toxicity of chemical compounds.

The environmental fate of many functional molecules that are produced on a large scale as precursors or as additives to specialty goods (plastics, fibers, construction materials, etc.), let alone those synthesized by the pharmaceutical industry, is generally unknown. Assessing their environmental fate is crucial when taking decisions on the manufacturing, handling, usage, and release of these substances, as is the evaluation of their toxicity in humans and other higher organisms.

The putative phosphate transporter PitB (PP1373) is involved in tellurite uptake in KT2440.

Tellurium oxyanions are chemical species of great toxicity and their presence in the environment has increased because of mining industries and photovoltaic and electronic waste. Recovery strategies for this metalloid that are based on micro-organisms are of interest, but further studies of the transport systems and enzymes responsible for implementing tellurium transformations are required because many mechanisms remain unknown. Here, we investigated the involvement in tellurite uptake of the putative phosphate transporter PitB (PP1373) in soil bacterium KT2440.

Microbial Community Structure Along a Horizontal Oxygen Gradient in a Costa Rican Volcanic Influenced Acid Rock Drainage System.

We describe the geochemistry and microbial diversity of a pristine environment that resembles an acid rock drainage (ARD) but it is actually the result of hydrothermal and volcanic influences. We designate this environment, and other comparable sites, as volcanic influenced acid rock drainage (VARD) systems. The metal content and sulfuric acid in this ecosystem stem from the volcanic milieu and not from the product of pyrite oxidation.

Visualizing the invisible: class excursions to ignite children's enthusiasm for microbes.

We have recently argued that, because microbes have pervasive - often vital - influences on our lives, and that therefore their roles must be taken into account in many of the decisions we face, society must become microbiology-literate, through the introduction of relevant microbiology topics in school curricula (Timmis et al. 2019. Environ Microbiol 21: 1513-1528).

ArsH protects Pseudomonas putida from oxidative damage caused by exposure to arsenic.

The two As resistance arsRBC operons of Pseudomonas putida KT2440 are followed by a downstream gene called arsH that encodes an NADPH-dependent flavin mononucleotide reductase. In this work, we show that the arsH1 and (to a lesser extent) arsH2 genes of P. putida KT2440 strengthened its tolerance to both inorganic As(V) and As(III) and relieved the oxidative stress undergone by cells exposed to either oxyanion.

The Bacterial Product Violacein Exerts an Immunostimulatory Effect Via TLR8.

Violacein, an indole-derived, purple-colored natural pigment isolated from Chromobacterium violaceum has shown multiple biological activities. In this work, we studied the effect of violacein in different immune cell lines, namely THP-1, MonoMac 6, ANA-1, Raw 264.7 cells, as well as in human peripheral blood mononuclear cells (PBMCs).