Evaluation of the nutritional composition and antioxidant activity of Bjerkandera adusta

Abstract Bjerkandera adusta, a globally distributed fungus, is commonly used in the nutritional practices of the East Asian population. In this study, we evaluated the nutritional composition of the lyophilized mycelium of B. adusta as well as the phenolic composition and antioxidant activity of its extracts. The mycelium exhibited moisture (7.97 %), ash (3.27 %), and fiber (5.31 %) content values similar to the established values reported in the available literature. In addition, a high protein (9.32 %) and carbohydrate (63.45 %) content was shown, with a low lipid (1.36 %) content. The energy value per 100 g sample of mycelium was 1445.85 kJ. The results obtained indicated a statistically significant variation (p < 0.05) in the phenolic composition (81.84-110.96 mg gallic acid equivalents (GAE) per g of extract), free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity (IC50 29.05-340.46 µg·mL-1), phosphomolybdenum antioxidant content (34.89-55.64 %), reduction of ferricyanide ion (66.55-69.4 %), and thiobarbituric acid reactive substance (TBARS) values (44.66-133.03 %). These results are unprecedented for this species and emphasize its nutraceutical potential.

Morphophysiological characterization of Ceratocystis fimbriata isolates from yerba mate / Caracterização morfofisiológica de isolados de Ceratocystis fimbriata de erva-mate

ABSTRACT: This study aimed to morphologically characterize the isolates of Ceratocystis fimbriata from yerba mate and to evaluate the effect of culture medium and temperature on mycelial growth and sporulation of C. fimbriata. For the morphological characterization of the 11 monosporic isolates of the fungus, slides were prepared to determine the dimensions of the sexual and asexual structures of the fungus. Four experiments were conducted to evaluate the mycelial growth and to evaluate the sporulation of C. fimbriata in different culture mediums and temperatures. The isolates of C. fimbriata from yerba mate showed perithecia with brown to black necks, divergent ostiolar hyphae, hatshaped hyaline ascospores, single-celled, cylindrical endoconidia, and globular to ovoid aleurioconidia. PDA and V8-agar media showed the highest mycelial growth. The average optimum temperature for mycelial growth and sporulation of isolates of C. fimbriata of yerba mate were 22.5 and 22.4 ºC, respectively.

RESUMO: Este estudo teve como objetivo caracterizar morfologicamente os isolados de Ceratocystis fimbriata e avaliar o efeito do meio de cultura e da temperatura no crescimento micelial e na esporulação de C. fimbriata. Para a caracterização morfológica dos 11 isolados monospóricos do fungo foram preparadas lâminas para determinar as dimensões das estruturas sexuadas e assexuadas do fungo. Quatro experimentos foram conduzidos para avaliar o crescimento micelial e esporulação of C. fimbriata em diferentes meios de culturae temperaturas. Os isolados de C. fimbriata de erva-mate apresentaram peritécios com pescoço de marrom a preto, hifa ostiolar divergente, ascósporos hialinos em formato de chapéu, endoconídios unicelulares, cilíndricos, e aleuroconídios com formato globoso a ovoide. Os meios de cultura PDA e V8-ágar apresentaram os maiores crescimentos miceliais. A temperatura ótima média para crescimento micelial e esporulação dos isolados de C. fimbriata de erva-mate foram de 22,5 e 22,4 ºC, respectivamente.

Bioautography to assess antibacterial activity of Ottonia martiana Miq. (Piperaceae) on the human oral microbiota

Ottonia martiana Miq. (Piperaceae), planta conhecida popularmente por "anestésia" e empregada no tratamento de odontalgias devido à sua ação anestésica sobre a mucosa oral, foi investigada por meio de ensaios antibacterianos de difusão em disco de papel e de bioautografia frente a microorganismos presentes na microbiota oral humana [Streptococcus mutans (ATCC 25175), Streptococcus mitis (ATCC 49456), Streptococcus pyogenes (ATCC 19615), Streptococcus salivarius (ATCC 25975), Escherichia coli (ATCC 11229 e 25922), Pseudomonas aeruginosa (ATCC 27853), Enterobacter aerogenes (ATCC 27853). Os resultados dos bioensaios mostraram que o extrato bruto de O. martiana (32.9 mg mL-1) apresenta potencial antibacteriano frente às bactérias Gram-positivas testadas. Dentre as substâncias bioativas detectadas foram identificadas a piperovatina (Rf 0.35), piperlonguminina (Rf 0.52) e a isopiperlonguminina (Rf 0.52). A piperovatina e isopiperlonguminina foram isoladadas do extrato das raízes de O. martiana, guiadas pelo teste de bioautografia.

Ottonia martiana Miq. (Piperaceae), a plant known popularly in southern Brazil as "anestésia" and used in the treatment of odontalgia for its anesthetic action on the oral mucosa, was investigated for antibacterial activity by paper disc agar diffusion and bioautographic methods, against microorganisms present in the human oral cavity [Streptococcus mutans (ATCC 25175), Streptococcus mitis (ATCC 49456), Streptococcus pyogenes (ATCC 19615), Streptococcus salivarius (ATCC 25975), Escherichia coli (ATCC 11229 and 25922), Pseudomonas aeruginosa (ATCC 27853) and Enterobacter aerogenes (ATCC 27853).The crude extract of O. martiana (32.9 mg mL-1) had antibacterial potential against all Gram-positive bacteria tested. Analysis of the bioautograms led to the detection of bioactive substances, among which it was possible to identify piperovatine (Rf 0.35), piperlonguminine (Rf 0.52) and isopiperlonguminine (Rf 0.52). The piperovatine and isopiperlonguminine were isolated from the roots of O. martiana, guided by a bioautographic antibacterial bioassay.