Hidrolisado de peixe causa alterações nas características microbiológicas e químicas de substrato.

O hidrolisado de peixe é um fertilizante orgânico obtido da fermentação de resíduos do processamento de pescados marinhos. O presente estudo avaliou os efeitos do hidrolisado de peixe em características microbiológicas e químicas de substrato à base de casca de pinus e solo, em microcosmos. O hidrolisado de peixe estimulou a comunidade de Trichoderma, aumentou a liberação de amônia e aumentou a condutividade elétrica do substrato de forma proporcional à sua concentração no substrato esterilizado e no não esterilizado. O hidrolisado não interferiu nas comunidades de Bacillus, de Pseudomonas e de Fusarium oxysporum f.sp. lycopersici. Também não foram verificadas alterações significativas no pH e na concentração de nitrato do substrato

Eukaryotic communities in drinking water distribution systems around the globe: composition and influencing factor

Eukaryotes are ubiquitous in natural environments where they play an important role in microbial communities. However, information regarding their presence and functional potential in drinking water distribution systems is scarce, as well as the knowledge regarding what factors affect these micro-organisms. In this study we explore the diversity of eukaryotes present in drinking water distribution systems by analyzing DNA sequences retrieved from metagenomic analyses of drinking water samples collected in distribution systems spread in four continents. Starting from this dataset, we identified the eukaryotes present in these systems and provided an evaluation of the factors (e.g., water quality, geographic distance) affecting their compositional and functional potential diversity, highlighting, also, characteristic taxonomic and potential functionality changes caused by design factors, e.g., the type of water source and the disinfection strategy employed. Our analysis identified more than 40 eukaryotic phyla, being Arthropoda, Rotifera and Basidiomycota often the most detected. Eukaryotes linked with putative pathogens growth, as free living amoebas, were detected in most systems, indicating their pervasive presence in drinking water systems. Specific system characteristics affected the identified phyla. For example, even in the presence of exhaustive water treatments, systems fed by surface water presented often a large fraction of phototropic micro-organisms (e.g., Bacillariophyta). In addition, eukaryotic communities are influenced by physico-chemical water quality parameters, with residual disinfectant exhibiting a primary importance. Overall, this study advances our understanding of drinking water distribution systems microbiology, clarifying the microbial ecology of eukaryotes and highlighting the factors affecting their presence and functionality

Phase coexistence in proton glass

Proton glasses are crystals of composition M{sub 1{minus}x}(NW{sub 4}){sub x}W{sub 2}AO{sub 4}, where M = K,Rb, W = H,D, A = P,As. For x = 0 there is a ferroelectric (FE) transition, while for x = 1 there is an antiferroelectric (AFE) transition. In both cases, the transition is from a paraelectric (PE) state of tetragonal structure with dynamically disordered hydrogen bonds to an ordered state of orthorhombic structure. For an intermediate x range there is no transition, but the hydrogen rearrangements slow down, and eventually display nonergodic behavior characteristic of glasses. The authors and other have shown from spontaneous polarization, dielectric permittivity, nuclear magnetic resonance, and neutron diffraction experiments that for smaller x there is coexistence of ferroelectric and paraelectric phases, and for larger x there is coexistence of antiferroelectric and paraelectric phases. The authors present a method for analytically describing this coexistence, and the degree to which this coexistence is spatial or temporal