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1.
Environ Microbiol ; 23(2): 1256-1274, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33393158

RESUMO

Laccases are widely present in bacteria, fungi, plants and invertebrates and involved in a variety of physiological functions. Here, we report that Beauveria bassiana, an economic important entomopathogenic fungus, secretes a laccase 2 (BbLac2) during infection that detoxifies insect immune response-generated reactive oxygen species (ROS) and interferes with host immune phenoloxidase (PO) activation. BbLac2 is expressed in fungal cells during proliferation in the insect haemocoel and can be found to distribute on the surface of haemolymph-derived in vivo fungal hyphal bodies or be secreted. Targeted gene-knockout of BbLac2 increased fungal sensitivity to oxidative stress, decreased virulence to insect, and increased host PO activity. Strains overexpressing BbLac2 showed increased virulence, with reduced host PO activity and lowered ROS levels in infected insects. In vitro assays revealed that BbLac2 could eliminate ROS and oxidize PO substrates (phenols), verifying the enzymatic functioning of the protein in detoxification of cytotoxic ROS and interference with the PO cascade. Moreover, BbLac2 acted as a cell surface protein that masked pathogen associated molecular patterns (PAMPs), enabling the pathogen to evade immune recognition. Our data suggest a multifunctional role for fungal pathogen-secreted laccase 2 in evasion of insect immune defenses.


Assuntos
Beauveria/enzimologia , Beauveria/patogenicidade , Insetos/imunologia , Lacase/imunologia , Proteínas de Membrana/imunologia , Animais , Hemolinfa/metabolismo , Hifas/metabolismo , Evasão da Resposta Imune , Insetos/microbiologia , Lacase/metabolismo , Proteínas de Membrana/metabolismo , Monofenol Mono-Oxigenase/imunologia , Espécies Reativas de Oxigênio/imunologia , Virulência
2.
Gene ; 766: 145130, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32911030

RESUMO

The LytTR family two-component system widely exists in bacterial cells and plays an important role in metabolic regulation. The lytS-L gene that encodes for a LytTR family sensor kinase was knocked out to study its influence on the growth, phenotype, and the biosynthesis of the insecticidal polyketide butenyl-spinosyn in Saccharopolyspora pogona NRRL 30141 (S. pogona). High performance liquid chromatography (HPLC) results showed that the butenyl-spinosyn yield of the lytS-L knockout mutant decreased by 58.9% compared with that of the parental strain. This is manifested by a weak toxicity of the mutant against the insect Helicoverpa assulta (H. armigera). Comparative proteomic analysis revealed the expression characteristics of the proteins in S. pogona and S. pogona-ΔlytS-L: a total of 14 proteins involved in energy metabolism were down-regulated, 9 proteins related to carbon metabolism such as glycolysis, and tricarboxylic acid cycle (TCA) were up-regulated, while 13 proteins involved in the biosynthesis of butenyl-spinosyn were down-regulated (fold change >1.2 or< 0.83). The qRT-PCR (Quantitative Real-time PCR) analysis illustrated that the changes in the expression levels of transcription and translation of the identified genes were consistent. This study explores the function of the two-component system of the LytTR family in S. pogona and shows that the lytS-L gene has an important influence on regulating primary metabolism and butenyl-spinosyn biosynthesis of S. pogona.


Assuntos
Proteínas de Bactérias/genética , Biossíntese de Proteínas/genética , Saccharopolyspora/genética , Animais , Regulação para Baixo/genética , Metabolismo Energético/genética , Insetos/microbiologia , Proteômica/métodos , Regulação para Cima/genética
3.
Trends Parasitol ; 36(10): 816-825, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32811753

RESUMO

Symbiosis with intracellular or gut bacteria is essential for the nutrition of animals with an obligate blood-feeding habit. Divergent bacterial lineages have independently evolved functional interactions with obligate blood feeders, but all converge to an analogous biochemical feature: the provisioning of B vitamins. Although symbionts and blood feeders coevolved interdependently for millions of years we stress that their associations are not necessarily stable. Ancestral symbionts can be replaced by recently acquired bacteria with similar biochemical features, a dynamic that emerges through a combination of phylogenetic and ecological constraints. Specifically, we highlight the lateral transfer of a streamlined biotin (B7 vitamin) operon, and conjecture that its extensive spread across bacterial lineages may drive the emergence of novel nutritional symbioses with blood feeders.


Assuntos
Comportamento Alimentar/fisiologia , Simbiose , Animais , Evolução Biológica , Insetos/classificação , Insetos/genética , Insetos/metabolismo , Insetos/microbiologia , Óperon/genética
5.
Nat Commun ; 11(1): 2694, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32483155

RESUMO

Toxin complex (Tc) toxins are virulence factors of pathogenic bacteria. Tcs are composed of three subunits: TcA, TcB and TcC. TcA facilitates receptor-toxin interaction and membrane permeation, TcB and TcC form a toxin-encapsulating cocoon. While the mechanisms of holotoxin assembly and pore formation have been described, little is known about receptor binding of TcAs. Here, we identify heparins/heparan sulfates and Lewis antigens as receptors for different TcAs from insect and human pathogens. Glycan array screening reveals that all tested TcAs bind negatively charged heparins. Cryo-EM structures of Morganella morganii TcdA4 and Xenorhabdus nematophila XptA1 reveal that heparins/heparan sulfates unexpectedly bind to different regions of the shell domain, including receptor-binding domains. In addition, Photorhabdus luminescens TcdA1 binds to Lewis antigens with micromolar affinity. Here, the glycan interacts with the receptor-binding domain D of the toxin. Our results suggest a glycan dependent association mechanism of Tc toxins on the host cell surface.


Assuntos
Toxinas Bacterianas/toxicidade , Adesão Celular/efeitos dos fármacos , Adesão Celular/fisiologia , Polissacarídeos/metabolismo , Animais , Toxinas Bacterianas/química , Toxinas Bacterianas/farmacocinética , Sítios de Ligação , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Células HEK293 , Heparina/química , Heparina/metabolismo , Humanos , Insetos/microbiologia , Antígenos CD15/química , Antígenos CD15/metabolismo , Modelos Moleculares , Simulação de Acoplamento Molecular , Morganella morganii/patogenicidade , Photorhabdus/patogenicidade , Polissacarídeos/química , Xenorhabdus/patogenicidade
6.
PLoS Pathog ; 16(4): e1008518, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32324832

RESUMO

Competition is one of the fundamental driving forces of natural selection. Beauveria bassiana is a soil and plant phylloplane/root fungus capable of parasitizing insect hosts. Soil and plant environments are often enriched with other fungi against which B. bassiana competes for survival. Here, we report an antifungal peptide (BbAFP1), specifically expressed and localized to the conidial cell wall and is released into the surrounding microenvironment inhibiting growth of competing fungi. B. bassiana strains expressing BbAFP1, including overexpression strains, inhibited growth of Alternaria brassicae in co-cultured experiments, whereas targeted gene deletion of BbAFP1 significantly decreased (25%) this inhibitory effect. Recombinant BbAFP1 showed chitin and glucan binding abilities, and growth inhibition of a wide range of phytopathogenic fungi by disrupting membrane integrity and eliciting reactive oxygen species (ROS) production. A phenylalanine residue (F50) contributes to chitin binding and antifungal activity, but was not required for the latter. Expression of BbAFP1 in tomato resulted in transgenic plants with enhanced resistance to plant fungal pathogens. These results highlight the importance of fungal competition in shaping primitive competition strategies, with antimicrobial compounds that can be embedded in the spore cell wall to be released into the environment during the critical initial phases of germination for successful growth in its environmental niche. Furthermore, these peptides can be exploited to increase plant resistance to fungal pathogens.


Assuntos
Antifúngicos/metabolismo , Beauveria/metabolismo , Esporos Fúngicos/metabolismo , Animais , Antifúngicos/farmacologia , Beauveria/genética , Parede Celular/metabolismo , Quitina/metabolismo , Proteínas Fúngicas/metabolismo , Glucanos/metabolismo , Insetos/microbiologia , Peptídeos , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Espécies Reativas de Oxigênio , Estresse Fisiológico/efeitos dos fármacos , Virulência
7.
Arch Insect Biochem Physiol ; 104(2): e21673, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32212396

RESUMO

Three-domain Cry toxins from the bacterium Bacillus thuringiensis (Bt) are increasingly used in agriculture to replace chemical insecticides in pest control. Most chemical insecticides kill pest insects swiftly, but are also toxic to beneficial insects and other species in the agroecosystem. Cry toxins enjoy the advantages of high selectivity and the possibility of the application by sprays or transgenic plants. However, these benefits are offset by the limited host range and the evolution of resistance to Bt toxins by insect pests. Understanding how Bt toxins kill insects will help to understand the nature of both problems. The recent realization that ABC transporters play a central role in the killing mechanism will play an important role in devising solutions.


Assuntos
Bacillus thuringiensis/química , Toxinas Bacterianas/farmacologia , Agentes de Controle Biológico/farmacologia , Evolução Biológica , Insetos/efeitos dos fármacos , Controle Biológico de Vetores , Animais , Toxinas Bacterianas/toxicidade , Agentes de Controle Biológico/toxicidade , Insetos/microbiologia , Plantas Geneticamente Modificadas/microbiologia
8.
Sci Rep ; 10(1): 4291, 2020 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-32152370

RESUMO

Phytoplasmas are transmitted by insect vectors in a persistent propagative manner; however, detailed movements and multiplication patterns of phytoplasmas within vectors remain elusive. In this study, spatiotemporal dynamics of onion yellows (OY) phytoplasma in its vector Macrosteles striifrons were investigated by immunohistochemistry-based 3D imaging, whole-mount fluorescence staining, and real-time quantitative PCR. The results indicated that OY phytoplasmas entered the anterior midgut epithelium by seven days after acquisition start (daas), then moved to visceral muscles surrounding the midgut and to the hemocoel at 14-21 daas; finally, OY phytoplasmas entered into type III cells of salivary glands at 21-28 daas. The anterior midgut of the alimentary canal and type III cells of salivary glands were identified as the major sites of OY phytoplasma infection. Fluorescence staining further revealed that OY phytoplasmas spread along the actin-based muscle fibers of visceral muscles and accumulated on the surfaces of salivary gland cells. This accumulation would be important for phytoplasma invasion into salivary glands, and thus for successful insect transmission. This study demonstrates the spatiotemporal dynamics of phytoplasmas in insect vectors. The findings from this study will aid in understanding of the underlying mechanism of insect-borne plant pathogen transmission.


Assuntos
Sistema Digestório/microbiologia , Insetos Vetores/microbiologia , Insetos/fisiologia , Cebolas/microbiologia , Phytoplasma/crescimento & desenvolvimento , Doenças das Plantas/microbiologia , Glândulas Salivares/microbiologia , Animais , Interações Hospedeiro-Patógeno , Insetos/microbiologia , Phytoplasma/classificação , Análise Espaço-Temporal
9.
ISME J ; 14(6): 1422-1434, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32111946

RESUMO

Entomopathogenic fungi are one of the key regulators of insect populations in nature. Some species such as Beauveria bassiana with a wide host range have been developed as promising alternatives to chemical insecticides for the biocontrol of insect pests. However, the long-term persistence of the released strains, the effect on non-target hosts and local fungal populations remains elusive, but they are considerable concerns with respect to environmental safety. Here we report the temporal features of the Beauveria population genomics and evolution over 20 years after releasing exotic strains to control pine caterpillar pests. We found that the isolates within the biocontrol site were mostly of clonal origins. The released strains could persist in the environment for a long time but with low recovery rates. Similar to the reoccurrence of host jumping by local isolates, the infection of non-target insects by the released strains was evident to endemically occur in association with host seasonality. No obvious dilution effect on local population structure was evident by the releases. However, the population was largely replaced by genetically divergent isolates once per decade but evolved with a pattern of balancing selection and towards expansion through adaptation, non-random outcrossing and isolate migration. This study not only unveils the real-time features of entomopathogenic fungal population genomics and evolution but also provides added values to alleviate the concerns of environmental safety regarding the biocontrol application of mycoinsecticides.


Assuntos
Beauveria/genética , Insetos/microbiologia , Pinus/parasitologia , Doenças das Plantas/parasitologia , Animais , Beauveria/fisiologia , Genoma Fúngico , Especificidade de Hospedeiro , Insetos/fisiologia , Metagenômica , Controle Biológico de Vetores
10.
Adv Exp Med Biol ; 1204: 129-140, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32152945

RESUMO

C-type lectins (CTLs) are a family of carbohydrate-recognition domain (CRD)-containing proteins that bind to ligands in a calcium-dependent manner. CTLs act as important components of insect innate immune responses, such as pattern recognition, agglutination, encapsulation, melanization, phagocytosis and prophenoloxidase activation, as well as gut microbiome homeostasis maintenance, to defend against pathogens. Besides, some insect CTLs can facilitate pathogen infection and colonization. In this review, we describe the properties of insect CTLs and focus on explaining their role in viral, bacterial, parasitic and fungal infections.


Assuntos
Imunidade Inata/imunologia , Insetos/imunologia , Insetos/microbiologia , Lectinas Tipo C/imunologia , Aglutinação/imunologia , Animais , Insetos/química
11.
Arch Microbiol ; 202(6): 1275-1284, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32185410

RESUMO

Insect and mite pests are damaging stressors that are threatening the cultivation of tea plants, which result in enormous crop loss. Over the years, the effectiveness of synthetic pesticides has allowed for its prominent application as a control strategy. However, the adverse effects of synthetic pesticides in terms of pesticide residue, environmental contamination and insect pest resistance have necessitated the need for alternative strategies. Meanwhile, microbial pesticides have been applied to tackle the damaging activities of the insect and mite pests of tea plants, and their performances were scientifically adjudged appreciable and environmental friendly. Herein, entomopathogenic microbes that were effective against tea geometrid (Ectropis obliqua Prout), tea green leafhopper (Empoasca onukii Matsuda), paraguay tea ampul (Gyropsylla spegazziniana), tea mosquito bug (Helopeltis theivora Waterhouse) and red spider mite (Oligonychus coffea Nietner) have been reviewed. The current findings revealed that microbial pesticides were effective and showed promising performances against these pests. Overall, this review has provided the basic and integrative information on the integrated pest management (IPM) tool(s) that can be utilized towards successful control of the aforementioned insect and mite pests.


Assuntos
Camellia sinensis/parasitologia , Insetos , Ácaros , Controle Biológico de Vetores/normas , Animais , Insetos/microbiologia , Insetos/virologia , Praguicidas/normas
12.
PLoS One ; 15(3): e0223629, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32196505

RESUMO

Bats are well known reservoir hosts for RNA and DNA viruses. The use of captive bats in research has intensified over the past decade as researchers aim to examine the virus-reservoir host interface. In this study, we investigated the effects of captivity on the fecal bacterial microbiome of an insectivorous microbat, Mops condylurus, a species that roosts in close proximity to humans and has likely transmitted viral infections to humans. Using amplicon 16S rRNA gene sequencing, we characterized changes in fecal bacterial community composition for individual bats directly at the time of capture and again after six weeks in captivity. We found that microbial community richness by measure of the number of observed operational taxonomic units (OTUs) in bat feces increases in captivity. Importantly, we found the similarity of microbial community structures of fecal microbiomes between different bats to converge during captivity. We propose a six week-acclimatization period prior to carrying out infection studies or other research influenced by the microbiome composition, which may be advantageous to reduce variation in microbiome composition and minimize biological variation inherent to in vivo experimental studies.


Assuntos
Quirópteros/microbiologia , Microbioma Gastrointestinal/genética , Insetívoros/microbiologia , Animais , DNA Bacteriano/genética , Fezes/microbiologia , Firmicutes/genética , Insetos/microbiologia , Filogenia , Proteobactérias/genética , RNA Ribossômico 16S/genética , Análise de Sequência de RNA
13.
Subcell Biochem ; 94: 81-121, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32189297

RESUMO

The composition of insect hemolymph can change depending on many factors, e.g. access to nutrients, stress conditions, and current needs of the insect. In this chapter, insect immune-related polypeptides, which can be permanently or occasionally present in the hemolymph, are described. Their division into peptides or low-molecular weight proteins is not always determined by the length or secondary structure of a given molecule but also depends on the mode of action in insect immunity and, therefore, it is rather arbitrary. Antimicrobial peptides (AMPs) with their role in immunity, modes of action, and classification are presented in the chapter, followed by a short description of some examples: cecropins, moricins, defensins, proline- and glycine-rich peptides. Further, we will describe selected immune-related proteins that may participate in immune recognition, may possess direct antimicrobial properties, or can be involved in the modulation of insect immunity by both abiotic and biotic factors. We briefly cover Fibrinogen-Related Proteins (FREPs), Down Syndrome Cell Adhesion Molecules (Dscam), Hemolin, Lipophorins, Lysozyme, Insect Metalloproteinase Inhibitor (IMPI), and Heat Shock Proteins. The reader will obtain a partial picture presenting molecules participating in one of the most efficient immune strategies found in the animal world, which allow insects to inhabit all ecological land niches in the world.


Assuntos
Antibacterianos/imunologia , Antibacterianos/metabolismo , Proteínas de Insetos/imunologia , Proteínas de Insetos/metabolismo , Insetos/imunologia , Peptídeos/imunologia , Peptídeos/metabolismo , Animais , Hemolinfa/imunologia , Hemolinfa/metabolismo , Insetos/microbiologia
14.
Sci Rep ; 10(1): 2974, 2020 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-32076084

RESUMO

The Chinese cordyceps, a complex of the fungus Ophiocordyceps sinensis and its species-specific host insects, is also called "DongChongXiaCao" in Chinese. Habitat degradation in recent decades and excessive harvesting by humans has intensified its scarcity and increased the prices of natural populations. Some counterfeits are traded as natural Chinese cordyceps for profit, causing confusion in the marketplace. To promote the safe use of Chinese cordyceps and related products, a duplex PCR method for specifically identifying raw Chinese cordyceps and its primary products was successfully established. Chinese cordyceps could be precisely identified by detecting an internal transcribed spacer amplicon from O. sinensis and a cytochrome oxidase c subunit 1 amplicon from the host species, at a limit of detection as low as 32 pg. Eleven commercial samples were purchased and successfully tested to further verify that the developed duplex PCR method could be reliably used to identify Chinese cordyceps. It provides a new simple way to discern true commercial Chinese cordyceps from counterfeits in the marketplace. This is an important step toward achieving an authentication method for this Chinese medicine. The methodology and the developmental strategy can be used to authenticate other traditional Chinese medicinal materials.


Assuntos
Cordyceps/genética , Medicamentos Falsificados/análise , Medicamentos de Ervas Chinesas/análise , Fraude/prevenção & controle , Reação em Cadeia da Polimerase , Animais , Cordyceps/química , Medicamentos Falsificados/química , Medicamentos Falsificados/economia , DNA Fúngico/isolamento & purificação , Medicamentos de Ervas Chinesas/economia , Medicamentos de Ervas Chinesas/normas , Complexo IV da Cadeia de Transporte de Elétrons/genética , Fraude/economia , Genes Fúngicos/genética , Genes de Insetos/genética , Proteínas de Insetos/genética , Insetos/genética , Insetos/microbiologia
15.
J Appl Microbiol ; 129(2): 411-421, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32086853

RESUMO

AIMS: Mitochondrial fission is an essential dynamics that maintains mitochondrial morphology and function. This study seeks to determine the roles of mitochondrial fission in the filamentous entomopathogenic fungus Beauveria bassiana. MATERIAL AND METHODS: Three fission-related genes (BbFis1, BbMdv1 and BbDnm1) were functionally characterized via protein intracellular localization and construction of gene disruption mutants. RESULTS: Mitochondrial localization was only observed for BbFis1 which interacts with BbMdv1, but BbMdv1 did not have interaction with BbDnm1. Single disruption mutant of three genes generated the elongated and enlarged mitochondria which could not be eliminated via the mitophagy. Three mutant strains displayed the reduced ATP synthesis and vegetative growth compared with the wild type. Three genes were involved in the early stage of conidiation and unnecessary for the late stage. However, all three genes significantly contribute to blastospore development under submerged condition, and the loss of BbMdv1 had the greatest effects compared with the losses of BbFis1 or BbDnm1. Finally, disruption of three genes significantly attenuated fungal virulence, but their mutations had different influences. CONCLUSIONS: In addition to their consistent roles in mitochondrial division and mitophagy, three fission-related genes perform divergent roles in the development and virulence of the entomopathogenic fungus B. bassiana. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows that mitochondrial fission is associated with lifecycle of B. bassiana. These findings provide information for the manipulation of fungal physiology and facilitate the application of entomopathogenic fungi.


Assuntos
Beauveria/crescimento & desenvolvimento , Beauveria/patogenicidade , Insetos/microbiologia , Dinâmica Mitocondrial/fisiologia , Mitofagia , Animais , Beauveria/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Dinâmica Mitocondrial/genética , Mitofagia/genética , Esporos Fúngicos/crescimento & desenvolvimento , Virulência/genética
16.
Molecules ; 25(3)2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32046140

RESUMO

Essential oils (EOs) have been known for a long time, and they are used in several fields such as medicine and aromatherapy, as well as in the food and pharmaceutical industries. In the last decade, EOs have also been applied to contrast the biodeterioration of cultural heritage, representing a powerful resource in green conservation strategies. In this study, an integrated approach based on microscopic observation, in vitro culture, and molecular investigation was preliminarily employed to identify biological systems colonizing wooden artworks. In order to contrast the biodeterioration processes induced by fungal colonization (Aspergillus flavus) or insect infestation (Anobium punctatum), wooden artworks were exposed to the volatile compound of Origanum vulgare or Thymus vulgaris essential oils (EOs), the chemical composition of which was determined by GC-MS using both polar and apolar columns. Artwork exposure was performed in ad-hoc-assembled "clean chambers." Evaluating the effects on biological systems, the compatibility with artwork constitutive materials, and the lack of negative effects on human health and environmental pollution, the use of EOs as a valid alternative to traditional biocides must be considered.


Assuntos
Desinfetantes/farmacologia , Óleos Voláteis/farmacologia , Animais , Antifúngicos/farmacologia , Aspergillus flavus/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Insetos/microbiologia , Testes de Sensibilidade Microbiana/métodos , Origanum/química , Thymus (Planta)/microbiologia
17.
Yeast ; 37(4): 313-320, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32061177

RESUMO

The Wickerhamiella and Starmerella genera form a clade (W/S clade) that branches close to Yarrowia lipolytica in the Saccharomycotina species tree. It comprises approximately 90 recognized species and 50 putative new species not formally described yet. The large majority of the members of the W/S clade are ecologically associated with flowers and floricolous insects. Many species exhibit unusual metabolic traits, like fructophily and the production of sophorolipids, which are glycolipids that can be used as environmentally friendly biosurfactants. Genomic data have not only firmly established the W/S clade but have also revealed a tumultuous evolution of metabolism marked by losses and gains of important metabolic pathways, among which alcoholic fermentation. Possibly the most surprising finding brought to light by comparative genomics concerned the large number of genes acquired by some species of the W/S clade from bacteria through horizontal gene transfer, many of which were shown to be functional in their new setting. This was facilitated by the genetic tractability of one species in the clade, Starmerella bombicola, which is used for the industrial production of sophorolipids. We suggest that high-density coverage of genome sequencing in this clade, combined with the possibility to conduct molecular genetics experiments in at least one species, has the potential to set the stage for yet more exciting discoveries concerning the evolution of yeast metabolism.


Assuntos
DNA Fúngico/isolamento & purificação , Saccharomycetales/classificação , Saccharomycetales/genética , Animais , DNA Fúngico/genética , Evolução Molecular , Flores/microbiologia , Transferência Genética Horizontal , Glicolipídeos/biossíntese , Glicolipídeos/genética , Insetos/microbiologia , Redes e Vias Metabólicas , Filogenia , Saccharomycetales/isolamento & purificação
18.
Can J Microbiol ; 66(4): 274-287, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31961710

RESUMO

Fungal chitinases play essential roles in chitin degradation, cell wall remodeling, chitin recycling, nutrition acquisition, autolysis, and virulence. In this study, 18 genes of the glycoside hydrolase 18 (GH18) family were identified in the Isaria cicadae genome. Seventeen of the genes belonged to chitinases and one was an endo-ß-N-acetylglucosaminidase (ENGase). According to phylogenetic analysis, the 17 chitinases were designated as subgroups A (7 chitinases), B (7), and C (3). The exon-intron organizations of these genes were analyzed. The conserved regions DxxDxDxE and S/AxGG and the domains CBM1, CBM18, and CBM50 were detected in I. cicadae chitinases and ENGase. The results of analysis of expression patterns showed that genes ICchiA1, ICchiA6, ICchiB1, and ICchiB4 had high transcript levels in the different growth conditions or developmental stages. Subgroup A chitinase genes had higher transcript levels than the genes of all other chitinases. Subgroup B chitinase genes (except ICchiB7) presented higher transcript levels in chitin medium compared with other conditions. ICchiC2 and ICchiC3 were mainly transcribed in autolysis medium and in blastospores, respectively. Moreover, ICchiB1 presented higher transcript levels than genes of other chitinases. This work provides an overview of the GH18 chitinases and ENGase in I. cicadae and provides a context for the chitinolytic potential, functions, and biological controls of these enzymes of entomopathogenic fungi.


Assuntos
Quitinases/genética , Proteínas Fúngicas/genética , Fungos/enzimologia , Genoma Fúngico , Animais , Quitina/metabolismo , Quitinases/metabolismo , Proteínas Fúngicas/metabolismo , Fungos/genética , Insetos/microbiologia , Família Multigênica , Filogenia
19.
Appl Microbiol Biotechnol ; 104(2): 489-508, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31797006

RESUMO

The aim of this review is to give a summary of natural lignocellulose-degrading systems focusing mainly on animal digestive tracts of wood-feeding insects and ruminants in order to find effective strategies that can be applied to improve anaerobic digestion processes in engineered systems. Wood-feeding animals co-evolved with symbiotic microorganisms to digest lignocellulose-rich biomass in a very successful way. Considering the similarities between these animal gut systems and the lignocellulose-based biotechnological processes, the gut with its microbial consortium can be a perfect model for an advanced lignocellulose-degrading biorefinery. The physicochemical properties and structure of the gut may provide a scheme for the process design, and the microbial consortium may be applied as genetic resource for the up-scaled bioreactor communities. Manipulation of the gut microbiota is also discussed in relation to the management of the reactor communities.


Assuntos
Biotecnologia/métodos , Microbioma Gastrointestinal , Insetos/microbiologia , Lignina/metabolismo , Ruminantes/microbiologia , Anaerobiose , Animais , Reatores Biológicos/microbiologia , Biotransformação , Lignina/química
20.
Annu Rev Entomol ; 65: 431-455, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31610133

RESUMO

The evolution of a mutualism requires reciprocal interactions whereby one species provides a service that the other species cannot perform or performs less efficiently. Services exchanged in insect-fungus mutualisms include nutrition, protection, and dispersal. In ectosymbioses, which are the focus of this review, fungi can be consumed by insects or can degrade plant polymers or defensive compounds, thereby making a substrate available to insects. They can also protect against environmental factors and produce compounds antagonistic to microbial competitors. Insects disperse fungi and can also provide fungal growth substrates and protection. Insect-fungus mutualisms can transition from facultative to obligate, whereby each partner is no longer viable on its own. Obligate dependency has (a) resulted in the evolution of morphological adaptations in insects and fungi, (b) driven the evolution of social behaviors in some groups of insects, and (c) led to the loss of sexuality in some fungal mutualists.


Assuntos
Fungos/fisiologia , Insetos/microbiologia , Simbiose , Animais , Evolução Biológica
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