Examinando por Materia "16S rRNA"

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First metabarcoding characterization of seabird guano microbiomes along the Peruvian coast: environmental filtering shapes taxonomically simplified but functionally stable communities
(Research Square, 2026-05-05) Cosme de la Cruz, Roberto Carlos; Cántaro Segura, Héctor Baroni; Meseth Macchiavello, Enrique; Calixto García, Anderson Rafael; López Pinto, María del Pilar; Ruiz Escobar, Vicente; Palomino Paccua, Luz Angélica; Calderón, Arturo; Salvatierra, Licia; Valdez, Renzo; Medina, Susan
Seabird guano from the islands off the Peruvian coast constitutes an organic fertilizer resource of recognized strategic importance; however, the microbial communities associated with this substrate had remained entirely uncharacterized. The present study provides the first comprehensive, cultureindependent characterization of bacterial and fungal communities in guano collected from 13 guanoproducing zones along the Peruvian coastline, encompassing deposits from the Guanay cormorant (Leucocarbo bougainvillii) and the Peruvian booby (Sula variegata), the two dominant and representative guano-producing bird species. Using 16S rRNA and ITS amplicon metabarcoding, combined with physicochemical analysis and functional prediction through FAPROTAX, and FUNGuild, we found that bacterial communities were consistently dominated by Bacillota (> 90%), particularly the order Bacillales, with halotolerant and endospore-forming genera, among which Saccharomonospora was notably abundant; this genus exhibited the strongest positive correlation with potassium content (+ 0.80, p 95%), with Aspergillus as the only genus showing a significant positive differential-abundance signal in Guanay cormorant guano relative to Peruvian booby guano. Within this exploratory framework, although the overall composition of bacterial and fungal communities did not differ significantly between the two bird species, differential abundance analysis identified specific bacterial taxa, including Pseudomonas, Atopostipes, and Lentibacillus, as significantly enriched in Guanay cormorant guano, revealing microbial differences that, while subtle, are ecologically relevant across host species. The predicted functional profile suggested a broadly stable metabolic repertoire oriented towards organic matter mineralization and nitrogen transformation across samples. These findings provide a first microbiological baseline for the evidence-based management of Peruvian island guano as a sustainable biofertilization resource.
Symbiotic and agronomic characterization of Bradyrhizobial strains nodulating cowpea in Northern Peru
(Springer International Publishing, 2016-06-03) Valdez, Renzo; Soriano, Bertha; Prado, Gardenia; Zavaleta, David; Matsubara, Minoru; Zúñiga Dávila, Doris Elizabeth; Dion, Patricie; Valladolid, Ángel; Ruesta Campoverde, Nelson Asdrúbal; Castellano Hinojosa, Antonio; Correa Galeote, David; Bedmar, Eulogio J.
Eighty bacterial strains were isolated from root nodules of cowpea (Vigna unguiculata) plants agriculturally grown in Northern Peru. After isolation, fifty of them reinfected cowpea and eight showed better symbiotic performance than control plants treated with nitrate both under greenhouse and field. Repetitive extragenic palindromic polymerase chain reaction (REP-PCR) clustered the strains into 3 REP-PCR groups. The partial sequence of the 16S rRNA gene from a representative strain of each REP-PCR pattern showed that the strains were closely related to members of genus Bradyrhizobium of the Alphaproteobacteria, but affiliation at the species level was not clear. Pairwise alignments among globally aligned sequences of the 16S rRNA genes, the sequencing of the housekeeping genes atpD, glnII, and recA, and their concatenated phylogenetic analysis showed that strains Rc-391-01 and Rc-458-01 grouped with B. yuanmingense B071T and that strain Rc-352-01 clustered with Bradyrhizobium liaoningense 2281T. Examination of the three representative strains to behave as plant growth-promoting rhizobacteria (PGPRs) showed that none of them solubilized calcium triphosphate and that they all three produced siderophores and IAA-related compounds and had ACC-deaminase activity.