Toxicity of β-(1→3,1→6)-ᴅ-glucans produced by Diaporthe sp. endophytes on Metarhizium anisopliae (Metschnikoff) Sorokin assessed by conidia germination speed parameter

Previously, our study reported that β-(1→3,1→6)-ᴅ-glucans produced by endophytes Diaporthe sp. G27-60 and G65-65 (GenBank accession codes JF766998 and JF767007, respectively) are promising antiproliferative agents against human breast carcinoma (MCF-7) and hepatocellular carcinoma (HepG2-C3A) cells. However, effects of Diaporthe exopolysaccharides on eukaryotic healthy cells are not described in current literature. The fungus Metarhizium anisopliae has been employed as teste-system to evaluate the toxicity of pharmaceutical and agricultural-interest substances, considering, among other parameters, conidia germination speed. The current study aimed to verify the effect of different concentrations of Diaporthe β-glucans on the germination speed of M. anisopliae. Conidia were incubated with β-glucans treatments (50, 200 and 400 μg/mL) at 28 ºC, sampled throughout 24 h and analyzed by light microscopy. At the end of 24 h of incubation, the amount of germinated conidia was ≈99% for controls and ranged from 97.7 to 98.6% for treatments. Bayesian analysis indicated that Diaporthe glucans had no toxicity on M. anisopliae and the curve of germination occurred as expected for this fungal strain. Considering the validity of filamentous fungi as model systems, these results are important data about the toxicity of these endophytic EPS on healthy cells and may be associated with previous results obtained for these polymers against tumor cells. Keywords: bayesian analysis, conidia germination, endophytic fungi, exopolysaccharide, fungal model-system

Campomanesia adamantium (Cambess.) O. Berg e Campomanesia sessiliflora (o.berg) mattos: estudo fitoquímico e toxicidade frente à Artemia salina l. (Crustacea) como indicadores preliminares na elaboração de produtos biotecnológicos: Campomanesia adamantium (Cambess.) O. Berg and Campomanesia sessiliflora (o.berg) mattos: phytochemical study and toxicity against Artemia salina l. (Crustacea) as preliminary indicators in the preparation of biotechnological products

A Campomanesia adamantium (Cambess.) O. Berg e a Campomanesia sessiliflora (O.Berg) Mattos (guaviras) são utilizadas para atividades terapêuticas na medicina popular, porém é necessária a extração dos metabólitos da planta com vistas ao desenvolvimento de produtos terapêuticos e o uso de bioindicadores para avaliar a sua  toxicidade. Foram realizadas as etapas de coleta e preparação do extrato botânico, obtidas soluções etanólicas a 20% e submetidas à análise. Os extratos etanólicos das folhas de C. adamantium e C. sessiliflora demonstraram perfis químicos semelhantes para flavonoides e taninos, negativos para esteroides, terpenos e saponinas, e pouco conclusivo para alcalóides, porém com presença de precipitado indicativo de compostos azotados. Os testes foram realizados em diversas concentrações. Ao revisitar os resultados prévios de citotoxicidade sobre Artemia salina Leach., foi verificado que os espécimes apresentaram resultados estabelecidos dentro da faixa de toxicidade elevada, onde o extrato da C. sessiliflora apresentou valor para CL50 de 65,78 μg mL-1  e com perfil de toxicidade variando entre 11,20 e 120,38 μg mL-1, compatível faixa de elevada toxicidade para todas as correlações dos testes, definidas para mortalidade de 10% e 90% da população exposta, respectivamente. Igualmente a C. adamantium também mostrou valores médios da CL50  em 52,03 μg mL-1 dentro da faixa de toxicidade elevada e suas concentrações atribuídas para as dosagens mínimas e máximas entre 8,45 e 95,44 μg mL-1, recaíram na faixa de elevado risco de toxicidade, revelando a necessidade de cuidado no uso do extrato. Desta forma fica evidente o potencial de toxicidade dos extratos de C. adamantium  e C. sessiliflora sobre Artemia salina L. mostrando que este pode ser promissor na inibição do crescimento in vitro de tumores sólidos humano em estudos. O bioensaio serve como uma ferramenta de pré-triagem para estudo de drogas antitumorais e para o desenvolvimento de novos medicamentos

Bioremediation potential of endophytic fungi Mucor sp. isolated from Eichhornia crassipes (Mart.)

Os fungos endofíticos são microrganismos que vivem no interior de tecidos ou órgãos dos vegetais, sem causar danos aos seus hospedeiros. Dentre as inúmeras características desses microrganismos está o seu potencial biorremediador Este trabalho teve como objetivo a avaliação do potencial biorremediador do endófito Mucor sp. isolado de Eichhornia crassipes (Mart.) (Pontederiaceae), verificando a tolerância e capacidade de absorção do metal pesado cádmio (Cd), os efeitos desse metal na morfologia celular e no sistema de defesa antioxidante do fungo, e também o comportamento da planta modelo Solanum lycopersicum cultivar Calabash Rouge, inoculada com o endófito na presença do metal cádmio. Os resultados apresentados indicaram que um fungo endofítico do gênero Mucor, isolado da macrófita aquática E. crassipes, oriunda de uma lagoa contaminada com metais pesados, apresentou resistência a altas concentrações do metal cádmio. Este fungo apresentou uma modificação na sua morfologia em altas concentrações do metal, além de possuir a capacidade de reter este metal, tanto no interior do seu citoplasma, quanto em sua parede celular, o que pode estar ligada a mecanismos de desintoxicação e sequestro de metais relacionados à formação de complexos Cd-GSH. O mesmo fungo também apresentou um aumento na relação GSH/GSSG nos tratamentos com o metal. Os resultados ainda demonstraram que o estresse causado pelo metal induziu a ativação de enzimas antioxidantes SOD, CAT e GR no isolado endofitico. Além disso, este endófito, quando inoculado em plantas de tomate (Solanum lycopersicum), aumentou a capacidade de absorção do metal na parte aérea desta planta, além de promover crescimento da mesma, nos tratamentos sem o metal, Desta forma o isolado endofítico (CM3) Mucor sp. mostrou um potencial biorremediador, podendo ser utilizado como ferramenta para diminuir os danos causados a saúde humana e ao meio ambiente pelos metais pesados, principalmente o metal cadmio, e também na promoção de crescimento de plantasEndophytic fungi live in the interior of plant tissues or organs, without causing harm to their hosts. Among several interesting characteristics of these microorganisms, some of them present a good potential for bioremediation. This study aimed at assessing the bioremediation potential of endophytic fungus Mucor sp. isolated from a Eichhornia crassipes (Mart.) (Pontederiaceae), analyzing chemical absorption ability and fungal tolerance to the heavy metal cadmium (Cd), besides testing the effects of cadmium on the cell morphology, the antioxidant defense system of the fungus, and the behavior of model plant (Solanum lycopersicum) variety Calabash Rouge inoculated with a spore suspension of Mucor sp. in the presence of cadmium. The results indicated that the endophytic fungus isolated from a Eichhornia crassipes (Mart.) plant located in a lagoon contaminated with heavy metals showed resistance to high concentrations of cadmium. The isolated fungus was identified as Mucor sp. The morphology studies demonstrated the occurrence of modifications on the fungus when in high concentrations of the metal. Furthermore, it was possible to verify that the fungus has a capacity to retain metal, both in the cytoplasm and cell wall. This aspect can be linked to detoxification and sequestration mechanisms of metals related to formation of Cd-GSH complexes, since this fungus also presented increase of GSH/GSSG ratio in the treatments with metal. The results also demonstrated that the stress caused by cadmium induces the activation of antioxidant enzymes SOD, CAT and GR in Mucor sp.. Moreover, the inoculation of this fungus in tomato plants increased the biosorption capacity of the cadmium in aerial parts of the plant, besides promoting its growth in the treatments without the metal. Thus the endophytic isolate (CM3) Mucor sp. presented a promising potential as a bioremediator, which can be used as a tool for reducing the damage caused by heavy metals, especially cadmium, to human health and environmen

<b>Isolation, identification, and metabolic characterization of endophytic fungi from </b><b><i>Attalea geraensis</i></b><b> Barb. Rodr.</b>

This study aimed to characterize the endophytic fungi found on the leaves of Attalea geraensis, analyzing their synthesized chemical compounds.Our findings showed that a total of 225 leaf fragments were sampled, with fungal growth observed in 80 of them, representing a colonization frequency of 35.5%. Forty-three isolates were randomly selected and grouped into 29 morphogroups based on morphological characteristics. Sequences obtained from amplifying the 18S region of rDNA led to the identification of 17 endophytic isolates through BLAST analysis in the GenBank database. Phylogenetic analyses provided precise identification of various species and genera, including Diaporthe macintoshii, Diaphorte sp., Phomopsis sp., among others.Chemical analyses revealed the predominant presence of coumarins in all fungal extracts, albeit with variations in intensity. Tannins were detected in 14 out of 17 extracts, ranging from moderate to low intensity. Variations in metabolite classes were observed among different genera, indicating distinct adaptations for biotic interactions. PCA indicated that the first two Principal Components explained 82.84% of the total variance in metabolite class data. The factor distribution highlighted three accession groups, showing a high correlation between coumarin and tannin contents.These results suggest significant diversity of cultivable endophytic fungi in Attalea geraensis leaves, with important implications for understanding the ecology of these organisms and their metabolic potential.Chemical screening of the isolated fungi showed the presence of coumarins in all extracts, varying in intensity. Tannins were detected in 14 out of 17 extracts, with moderate to low intensity. Different genera exhibited distinct chemical profiles, suggesting adaptations for environmental interactions.Principal Component Analysis (PCA) demonstrated that the first two principal components accounted for 82.84% of the total variance in metabolite classes. The distribution of factors highlighted three accession groups, with high correlation between coumarin and tannin contents.Overall, the findings underscored the diversity of cultivable endophytic fungi associated with Attalea geraensis leaves and provided insights into their metabolic potential and ecological roles.</p