Tocosh, a traditional Peruvian fermented potato product, is known for its health-promoting properties, including its antioxidant, anti-inflammatory, probiotic, and antibiotic effects, which have popularized its consumption, particularly in rural areas. To gain a better understanding of its antimicrobial properties, this study aimed to perform a comprehensive whole-genome analysis and functional assessment of the Bacillus velezensis TCSH0001 strain isolated from tocosh. The isolate was identified through whole-genome sequencing using the MinION nanopore platform. AntiSMASH analysis revealed nine biosynthetic gene clusters (BGCs) potentially responsible for producing secondary metabolites with antibiotic potential. Notably, seven BGCs showed a 100% similarity to known clusters involved in the biosynthesis of polyketide synthases (PKSs) and non-ribosomal peptides (NRPSs), including difficidin, bacillibactin, bacilysin, macrolactin H, bacillaene, fengycin, and bacillomycin D. In vitro analysis revealed antimicrobial activity against S. aureus strains. In addition, RT-qPCR indicated that the expression of the baeJ (bacillaene), bmyA (bacillomycin D), and pks2A (macrolactin H) occurs predominantly during the exponential growth phase. Our results suggest that this B. velezensis strain has the capacity to produce a diverse array of bioactive compounds, supporting the traditional use of tocosh as a natural antimicrobial agent, and revealing the potential of the strain as a high NRPS producer.

The intensification of shrimp farming contributes to the accumulation of toxic nitrogen compounds, which in turn affect productivity and complicates water quality management, especially under conditions of reduced salinity. This study evaluated the effects of 25% (CO, T2) and 50% (T1) water exchange, in combination with a bioaugmentation treatment using native Bacillus (T2), on nitrogen compound concentrations and bacterial community structure in Litopenaeus vannamei culture under reduced salinity conditions (4ppt). The results demonstrated that treatment with native Bacillus megaterium and Bacillus paralicheniformis (T2) leads to a significant reduction in nitrite and nitrate concentrations, reaching nearly 0 mg/L from day 4. In contrast, T1 and CO treatments showed markedly higher concentration, reaching up to 5 mg/mL and 160 mg/L, respectively. The full-length 16S rRNA gene used for the metataxonomic analysis revealed changes in bacterial composition towards species with nitrifying and probiotic potential, with native Bacillus strains detected exclusively in T2. In addition, a reduction in bacterial diversity was detected, and significant differences were observed between the bacterial communities of T2 and those of T1 and CO (p = 0.001, R ²  =  0,328). The shotgun analysis further revealed a higher abundance of enzymes related to nitrification and dissimilatory nitrate reduction to ammonium in T2 treatment. The results highlighted the active involvement of Gram positive – Bacillus and Gram-negative bacteria such as Shewanella and Psychrobacter , and suggesting heterotrophic nitrification and aerobic denitrification. Overall, native B. megaterium and B. paralicheniformis provided an effective bioaugmentation strategy for the managing nitrate and nitrite in low-salinity shrimp farming, providing an eco-friendly alternative that may enhance productivity and reduce the industry´s water footprint.

Objetivo: Identificación de insectos plaga, predatores y hongos fitopatógenos del cultivo de Loche Cucurbita moschata Duch en Ucupe, Mocupe-Lambayeque. Métodos: el muestreo al azar, se tomaron cinco puntos de muestreo por cultivo. Resultados: Bemisia tabaci ataca al cultivo de loche, se encontró causando raspaduras en el envés de las hojas. Thrips tabaci es una plaga que ubica en los brotes más jóvenes. Diaphania nitidalis, esta es la plaga que ocasiona mayor daño, ya que es un insecto barrenador que ataca al fruto, tallos y flores. Entre los controladores: Chrysoperla externa, Rhinacloa sp., Neides sp., Orius sp. y Cicloneda sanguínea. Entre los hongos fitopatógenos encontrados Cunninghamella spp., Colletotrichium sp., Memnoniella sp., Verticillium sp., Cladosporium sp., Stemphylium sp.

The phyllosphere microbiome contributes to plant health and adaptation, yet bacterial communities associated with Eugenia uniflora remain poorly characterized. This study investigated how developmental stage shapes the E. uniflora phyllosphere microbiome and assessed bacterial taxa and associations shared with other Myrtaceae species. The V3–V4 region of the 16S rRNA gene was sequenced from 19 E. uniflora samples representing young and mature trees, as well as 13 samples from mature trees representing three additional Myrtaceae genera (Myrcianthes, Plinia, and Psidium) and other Eugenia species. Community diversity, predicted functional potential, co-occurrence networks, and core taxa were analyzed. In E. uniflora, 1428 bacterial ASVs belonging to 17 phyla and 135 genera were identified, and bacterial community composition differed significantly between developmental stages. Young and mature trees showed distinct taxonomic profiles and predicted functional patterns. Network analysis revealed more connected bacterial communities in young plants and simpler networks in mature plants. Comparison with other Myrtaceae identified 17 core genera, including Methylobacterium–Methylorubrum, Hymenobacter, Sphingomonas, Bdellovibrio, and Terriglobus, which occurred in all 21 mature trees. Overall, developmental stage was associated with changes in the taxonomic, predicted functional potential, and network organization of the E. uniflora phyllosphere microbiome, while shared bacterial taxa and associations across the sampled Myrtaceae genera suggest conserved features of phyllosphere community assembly.

RNA interference (RNAi) technology is an effective tool for silencing specific genes in living organisms, with a wide range of applications. However, its administration through ingestion in insects faces significant challenges, such as degradation by ribonucleases and chemical hydrolysis in natural environments. Functionalizing double-stranded RNA (dsRNA) with nanoparticles (NPs) constitutes an effective strategy to preserve and stabilize these RNAs, allowing their application in controlling populations of Aedes aegypti, a vector of serious diseases such as dengue, malaria, zika, and chikungunya. In this study, a segment of the 3,4-dihydroxyphenylacetaldehyde (DOPAL) synthase gene from wild specimens of A. aegypti originating from the northwest of Peru was amplified and sequenced. Sequencing revealed that the amplified segments contain two single nucleotide polymorphisms (SNPs), both A/G substitutions that do not lead to changes in the amino acid sequence. These segments were used to generate dsRNA through in vitro transcription and cloning in Escherichia coli HT115 (D3). Finally, the obtained dsRNA-DOPAL synthase was functionalized with chitosan NPs from different molecular weight ranges chitosan types (50-190, 190-310, and 310-375 kDa). The interaction between dsRNA-DOPAL synthase and chitosan NPs was confirmed by electrophoretic mobility shift assays (EMSA) and Fourier transformed infrared spectroscopy (FTIR-ATR) analysis. Functionalizing dsRNA-DOPAL synthase with chitosan NPs is a first step to develop an effective strategy for controlling A. aegypti populations. However, further in vivo tests with mosquito larvae in natural habitats (water containers or water bodies for example) are necessary to confirm its effectiveness.

Acute hepatopancreatic necrosis disease (AHPND) is a serious bacterial infection affecting penaeid shrimp, caused primarily by Vibrio species harboring the pirAB toxin genes. While AHPND has been studied extensively in shrimp, its potential impact on other marine invertebrates remains largely unexplored. This study evaluates, for the first time, the susceptibility of juvenile lion's paw scallops (Nodipecten subnodosus) to AHPND-associated Vibrio campbellii (_VCAHPND-VP3) strains isolated from Litopenaeus vannamei shrimp outbreaks. Experimental infection by immersion assays demonstrated a dose-dependent response, with 100 % cumulative mortality at 5 × 10⁶ CFU/mL, while lower concentrations resulted in subclinical infections. The presence of _VCAHPND-VP3 in gill and stomach tissues was confirmed by nested PCR detection of pirAB genes. Comparative pathogenicity assays between _VCAHPND-VP3 and the native Vibrio alginolyticus strain revealed that, despite similar rates of bacterial uptake, only _VCAHPND-VP3 caused high mortality, highlighting the critical role of PirAB toxins in virulence. Whole genome sequencing of the _VCAHPND-VP3 strain confirmed the presence of the pirAB-carrying plasmid, previously reported as pVA1 and revealed additional genes associated with pathogenicity and mobile genetic elements. These results confirm the susceptibility of mollusk species to AHPND-associated Vibrio and highlight potential ecological risks related to the dissemination of pirAB-positive vibrios in coastal environments.