RESUMO
The encapsulation of fisetin into S. cerevisiae cells through sonoporation coupled with drying is reported for the first time in the literature. To establish the best conditions to maximize the amount of internalized fisetin, the cell density (5-10% w/v), fisetin concentration (1-3 mg/mL), acoustic energy density (0-333.3 W/L), and drying method (freeze-drying and spray drying) were analyzed through a Box-Behnken experimental design (BBD) coupled with response surface methodology (RSM). Higher encapsulation efficiency (EE) was achieved with a cell density of 10% w/v, while fisetin concentration of 3 mg/mL favored the encapsulation yield (EY) and antioxidant activity (AA). Higher EE (67.7%), EY (25.7 mg/g), and AA (90%) were registered when an acoustic density of 333.3 W/L was used. Furthermore, both drying protocols promoted fisetin encapsulation, but through spray drying, the EE, EY, and AA were 11.5%, 11.1%, and 26.6% higher than via freeze-drying, respectively. This work proved that fully filled biocapsules were produced through sonoprocessing, and their morphology was influenced by the acoustic energy and drying process. Overall, these results open new perspectives for the application of sonoprocessing-assisted encapsulation, paving the way for developing innovative yeast-based delivery systems for lipophilic compounds such as fisetin. KEY POINTS: ⢠Sonoprocessing improves the encapsulation of fisetin into S. cerevisiae cells ⢠Spray drying promotes fisetin loading into yeasts' intracellular space and cavities ⢠Fisetin binding with yeast extracellular agents are favored by freeze-drying.
Assuntos
Flavonóis , Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Flavonóis/metabolismo , Liofilização , Antioxidantes/metabolismo , Contagem de CélulasRESUMO
A novel baculovirus observed to infect Automeris liberia (Cramer) (bullseye moth) is here described. Caterpillars of A. liberia with symptoms of viral infection were collected from African oil palm plantations in Tailândia, PA, Brazil. Macerated caterpillars were then offered to caterpillars of Automeris cinctistriga (Felder & Rogenhoper), leading to viral symptoms and death before pupation. A transmission electron microscope was used for virus ultrastructural identification. The presence of viral occlusion bodies (OBs) containing multiple nucleocapsids was observed and such features are compatible with Alphabaculovirus (Baculoviridae). Molecular detection by PCR with primers for polyhedrin gene (polh) and for late expression factor-8 gene (lef-8), confirmed that this isolate belonged to Alphabaculovirus genus. To our knowledge, this is the first record of a baculovirus isolated from or associated to Automeris. The name Automeris liberia nucleopolyhedrovirus (AuliNPV) is proposed for the new virus.
Assuntos
Lepidópteros , Mariposas , Nucleopoliedrovírus , Animais , Baculoviridae , Brasil , Libéria , Nucleopoliedrovírus/genética , Nucleopoliedrovírus/ultraestrutura , FilogeniaRESUMO
The cassava hornworm Erinnyis ello ello (Lepidoptera: Sphingidae) is an important pest in Brazil. This insect feeds on host plants of several species, especially Manihot esculenta (cassava) and Hevia brasiliensis (rubber tree). Cassava hornworm outbreaks are quite common in Brazil and can cause great impact over crop production. Granulare and polyhedral-shaped occlusion bodies (OBs) were observed in extracts of dead E. ello larvae from rubber-tree plantations by light and scanning electron microscopy (SEM), suggesting a mixed infection. The polyhedral-shaped OB surface revealed indentations that resemble those found in cypovirus polyhedra. After OB nucleic acid extraction followed by cDNA production and Illumina deep-sequencing analysis, the results confirmed for the presence of a putative novel cypovirus that carries ten segments and also a betabaculovirus (Erinnyis ello granulovirus, ErelGV). Phylogenetic analysis of the predicted segment 1-enconded RdRP showed that the new cypovirus isolate is closely related to a member of species Cypovirus 2, which was isolated from Inachis io (Lepidoptera: Nymphalidae). Therefore, we named this new isolate Erinnyis ello cypovirus 2 (ErelCPV-2). Genome in silico analyses showed that ErelCPV-2 segment 8 (S8) has a predicted amino acid identity of 35.82â% to a hypothetical protein of betabaculoviruses. This putative protein has a cGAMP-specific nuclease domain related to the poxvirus immune nucleases (poxins) from the 2',3'-cGAMP-degrading enzyme family.
Assuntos
Coinfecção/genética , Desoxirribonucleases/genética , Granulovirus/genética , Poxviridae/genética , Reoviridae/genética , Animais , Brasil , GMP Cíclico/genética , Genoma Viral/genética , Larva/virologia , Lepidópteros/virologia , Mariposas/virologia , Corpos de Oclusão Virais/genética , FilogeniaRESUMO
Abstract Chrysodeixis includens has become the major Lepidopteran pest of soybean crops, especially in the Brazilian Cerrado (savanna) region. A native isolate of Chrysodeixis includens nucleopolyhedrovirus (ChinNPV) from this region, Buritis, MG, was assessed for its biological and molecular features. In addition, in vitro co-infection with Anticarsia gemmatalis multiple nucleopolyhedrovirus (AgMNPV), another virus of an important soybean pest, was tested. The ChinNPV-Buritis isolate presented an average LC50 of 7,750 occlusion bodies (OBs)/ml of diet in C. includens larvae. Analysis of restriction endonuclease profiles of viral DNA revealed similarities with previously described ChinNPV isolates IE, IF, and IG from Brazil, although the presence of submolar bands indicates genetic heterogeneity. Optical microscopy analysis in conjunction with quantitative PCR (qPCR) demonstrated in vitro infection of this isolate in IPLB-SF-21AE, Sf9, and BTI-Tn-5B1-4 cell lines, but the amount of ChinNPV tends to decrease through serial passages. The qPCR method developed in this study successfully detected both AgMNPV and ChinNPV from cell culture and from infected larvae. The cell line Tn-5B1-4 is indicated for future development of in vitro production and co-infection studies.
Assuntos
Bombyx , Nucleopoliedrovírus , Agentes de Controle Biológico , LarvaRESUMO
BACKGROUND: Cassava (Manihot esculenta) is the basic source for dietary energy of 500 million people in the world. In Brazil, Erinnyis ello ello (Lepidoptera: Sphingidae) is a major pest of cassava crops and a bottleneck for its production. In the 1980s, a naturally occurring baculovirus was isolated from E. ello larva and successfully applied as a bio-pesticide in the field. Here, we described the structure, the complete genome sequence, and the phylogenetic relationships of the first sphingid-infecting betabaculovirus. RESULTS: The baculovirus isolated from the cassava hornworm cadavers is a betabaculovirus designated Erinnyis ello granulovirus (ErelGV). The 102,759 bp long genome has a G + C content of 38.7%. We found 130 putative ORFs coding for polypeptides of at least 50 amino acid residues. Only eight genes were found to be unique. ErelGV is closely related to ChocGV and PiraGV isolates. We did not find typical homologous regions and cathepsin and chitinase homologous genes are lacked. The presence of he65 and p43 homologous genes suggests horizontal gene transfer from Alphabaculovirus. Moreover, we found a nucleotide metabolism-related gene and two genes that could be acquired probably from Densovirus. CONCLUSIONS: The ErelGV represents a new virus species from the genus Betabaculovirus and is the closest relative of ChocGV. It contains a dUTPase-like, a he65-like, p43-like genes, which are also found in several other alpha- and betabaculovirus genomes, and two Densovirus-related genes. Importantly, recombination events between insect viruses from unrelated families and genera might drive baculovirus genomic evolution.
Assuntos
Genoma Viral , Granulovirus/genética , Lepidópteros/virologia , Animais , Bases de Dados Genéticas , Granulovirus/classificação , Granulovirus/isolamento & purificação , Larva/virologia , Lepidópteros/crescimento & desenvolvimento , Manihot/parasitologia , Fases de Leitura Aberta/genética , Filogenia , Pirofosfatases/genética , Análise de Sequência de DNA , Proteínas Virais/classificação , Proteínas Virais/genéticaRESUMO
The method of single-strand conformational polymorphism (SSCP) was modified in our laboratories for the characterization of baculoviruses, insect viruses with great potential for use as bioinsecticides in biological protection programs. A series of primers were synthesized after the comparison of the polyhedrin gene sequences of over 20 baculoviruses. Polyhedrin is a highly conserved protein which is responsible for the persistence of the virus in the environment. Universal primers were designed which could be used in polymerase chain reactions (PCR) containing genomic DNA from an array of nucleopolyhedrosis viruses (NPVs) including these which are used as biopesticides against important pests of forests and crops, such as Anticarsia gemmatalis, Spodoptera frugiperda, Lymantria dispar, Lymantria monacha and many others. PCR products were denatured and subjected to single-strand DNA electrophoresis at variable temperatures (MSSCP) where, after silver staining, they gave ssDNA band patterns characteristic for each baculovirus species. This technique can be potentially applied to detect baculoviruses in insects collected in the field, as well as to plant tissues and the excrements or bodies of predators without need for sequencing the PCR products. Sometimes MSSCP can be used not only for species determination but also as an indication of genomic variability which can be related to infectivity.
Assuntos
Baculoviridae/classificação , Baculoviridae/genética , Controle Biológico de Vetores , Polimorfismo Conformacional de Fita Simples/genética , Animais , Variação Genética , Insetos/virologia , Reação em Cadeia da Polimerase , Especificidade da Espécie , Proteínas Estruturais Virais/genéticaRESUMO
The genome of Anticarsia gemmatalis multiple nucleopolyhedrovirus isolate 2D (AgMNPV-2D), which is the most extensively used virus pesticide in the world, was completely sequenced and shown to have 132 239 bp (G+C content 44.5 mol%) and to be capable of encoding 152 non-overlapping open reading frames (ORFs). Three ORFs were unique to AgMNPV-2D, one of which (ag31) had similarity to eukaryotic poly(ADP-ribose) polymerases. The lack of chiA and v-cath may explain some of the success and growth of the AgMNPV biological control programme, as it may explain the high recovery of polyhedra sequestered inside dead larvae in the field, which are collected and used for further application as biological pesticides in soybean fields. The genome organization was similar to that of the Choristoneura fumiferana defective MNPV (CfDefNPV). Most of the variation between the two genomes took place near highly repetitive regions, which were also closely associated with bro-coding regions. The separation of the NPVs into groups I and II was supported by: (i) a phenogram of the complete genomes of 28 baculovirus and Heliothis zea virus 1, (ii) the most parsimonious reconstruction of gene content along the phenograms and (iii) comparisons of genomic features. Moreover, these data also reinforced the notion that group I of the NPVs can be split further into the AgMNPV lineage (AgMNPV, CfDefNPV, Epiphyas postvittana NPV, Orgyia pseudotsugata MNPV and C. fumiferana MNPV), sharing eight defining genes, and the Autographa californica MNPV (AcMNPV) lineage (AcMNPV, Rachiplusia ou NPV and Bombyx mori NPV), sharing nine defining genes.
Assuntos
Genoma Viral , Controle de Insetos/métodos , Lepidópteros/virologia , Nucleopoliedrovírus/genética , Animais , Composição de Bases , Sequência de Bases , Genes Virais/genética , Larva/virologia , Dados de Sequência Molecular , Nucleopoliedrovírus/isolamento & purificação , Fases de Leitura Aberta/genética , Alinhamento de Sequência , Análise de Sequência , Proteínas Virais/genéticaRESUMO
Anticarsia gemmatalis multicapsid nucleopolyhedrovirus (AgMNPV) is one of the most successful biological insecticides. In this study, we cloned and sequenced a 12.5 kbp BamHI-D restriction endonuclease fragment of the AgMNPV isolate 2D genome that includes the gp64 gene. We compared this highly conserved region with that of other baculoviruses. AgMNPV contained two genes, p22.2 and v-trex, in common with Choristoneura fumiferana MNPV (CfMNPV) that were not present in other baculoviruses. The v-trex gene has homology to a eukaryotic 3' repair exonuclease and appears to have been acquired from an invertebrate host. The v-trex gene product has the potential to be involved in virus recombination or UV-light tolerance. Multigene phylogenetic analysis suggested that AgMNPV is most closely related to Orgyia pseudotsugata MNPV (OpMNPV). AgMNPV differed from other group I NPVs in that ChiA and v-cath gene homologues were missing from the region downstream of the gp64 gene. Proteinase assays and genetic probes suggest the v-cath gene is absent from AgMNPV.