RESUMO
Biosurfactants (BSFs) are molecules produced by microorganisms from various carbon sources, with applications in bioremediation and petroleum recovery. However, the production cost limits large-scale applications. This study optimized BSFs production by Bacillus velezensis (strain MO13) using residual glycerin as a substrate. The spherical quadratic central composite design (CCD) model was used to standardize carbon source concentration (30 g/L), temperature (34 °C), pH (7.2), stirring (239 rpm), and aeration (0.775 vvm) in a 5-L bioreactor. Maximum BSFs production reached 1527.6 mg/L of surfactins and 176.88 mg/L of iturins, a threefold increase through optimization. Microbial development, substrate consumption, concentration of BSFs, and surface tension were also evaluated on the bioprocess dynamics. Mass spectrometry Q-TOF-MS identified five surfactin and two iturin isoforms produced by B. velezensis MO13. This study demonstrates significant progress on BSF production using industrial waste as a microbial substrate, surpassing reported concentrations in the literature.
RESUMO
Soil desertification poses a critical ecological challenge in arid and semiarid climates worldwide, leading to decreased soil productivity due to the disruption of essential microbial community processes. Fungi, as one of the most important soil microbial communities, play a crucial role in enhancing nutrient and water uptake by plants through mycorrhizal associations. However, the impact of overgrazing-induced desertification on fungal community structure, particularly in the Caatinga biome of semiarid regions, remains unclear. In this study, we assessed the changes in both the total fungal community and the arbuscular mycorrhizal fungal community (AMF) across 1. Natural vegetation (native), 2. Grazing exclusion (20 years) (restored), and 3. affected by overgrazing-induced degradation (degraded) scenarios. Our assessment, conducted during both the dry and rainy seasons in Irauçuba, Ceará, utilized Internal Transcribed Spacer (ITS) gene sequencing via Illumina® platform. Our findings highlighted the significant roles of the AMF families Glomeraceae (â¼71% of the total sequences) and Acaulosporaceae (â¼14% of the total sequences) as potential key taxa in mitigating climate change within dryland areas. Moreover, we identified the orders Pleosporales (â¼35% of the total sequences) and Capnodiales (â¼21% of the total sequences) as the most abundant soil fungal communities in the Caatinga biome. The structure of the total fungal community differed when comparing native and restored areas to degraded areas. Total fungal communities from native and restored areas clustered together, suggesting that grazing exclusion has the potential to improve soil properties and recover fungal community structure amid global climate change challenges.
Assuntos
Fungos , Micobioma , Micorrizas , Microbiologia do Solo , Solo , Brasil , Micorrizas/classificação , Micorrizas/genética , Micorrizas/fisiologia , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Solo/química , Mudança Climática , Clima Desértico , Biodiversidade , DNA Fúngico/genética , Estações do Ano , EcossistemaRESUMO
Caesalpinia ferrea Mart. (jucá ou pau-ferro) é uma espécie da família Leguminosae cuja ocorrência estende-se da região Nordeste ao Estado do Rio de Janeiro. Trata-se de uma espécie bastante utilizada na medicina popular pelas suas inúmeras propriedades terapêuticas tais como antiinflamatória, analgésica, antimicrobiana e antitérmica as quais indicam a presença de compostos de interesse farmacológico. Contudo, muitos estudos em plantas também investigam a presença de compostos de interesse industrial. Com base nas propriedades terapêuticas e atividades já descritas para essa espécie, esse trabalho objetivou pesquisar atividades biológicas no extrato de sementes de C. ferrea na busca por compostos de interesse industrial e farmacológico. Os resultados indicaram a presença das atividades celulásica, amilásica, anticoagulante e larvicida contra A. aegypti no extrato aquoso das sementes de C. ferrea, entretanto, não foram observadas as atividades tóxica aguda, hemolítica, heparinásica, antibacteriana e antifúngica.
Caesalpinia ferrea Mart. is a species belonging to Leguminosae family commonly known in Brazil as "jucá" or "pau-ferro". It occurs in Brazil from the Northeast Region to the State of Rio de Janeiro and it is widely utilized in folk medicine due to its several therapeutic properties such as anti-inflammatory, analgesic, antimicrobial and antithermic, which indicate the presence of compounds of pharmacological interest. Besides, many studies with plants look for the presence of compounds with industrial applications. Based upon the therapeutic and bioactive properties described for this species so far, this work aimed to investigate several biological activities in the water extract of C. ferrea seeds. The results indicated the presence of the following activities: cellulase, amylase, anticoagulant and larvicide against A. aegypti in the water extract of C. ferrea seeds. Nevertheless, the extract did not show the other activities assayed: acute toxic activity, hemolytic, heparinasic, antibacterial and antifungal activities.
RESUMO
In this work, biological effects of the water extract of Moringa oleifera seeds (WEMOS) were assessed on eggs and 3rd instar larvae of Aedes aegypti and on its toxicity upon laboratory animals (Daphnia magna, mice and rats). Crude WEMOS showed a LC50 value of 1260µg/mL, causing 99.2 ± 2.9 percent larvae mortality within 24 h at 5200µg/mL, though this larvicidal activity has been lost completely at 80ºC/10 min. WEMOS did not demonstrate capacity to prevent egg hatching. After extensive dialyses of the crude WEMOS into watersoluble dialyzable (DF) and nondyalizable (NDF) fractions, only DF maintained its efficacy to kill larvae. Acute toxicity evaluations on daphnids (EC50 of 188.7µg/mL) and mice (LD50 of 446.5 mg/kg body weight) pointed out to low toxicity. Despite the thymus hypertrophy, WEMOS revealed to be harmless in orally and subacutelytreated rats. In conclusion, WEMOS has thermostable bioactive compounds against Ae. aegypti larvae with apparent molecular mass lower than 12 kDa and moderately toxic potential.
Neste trabalho, o extrato aquoso das sementes de Moringaoleifera (EASMO) foi avaliado quanto aos seus efeitos biológicos sobre ovos e larvas de Aedes aegypti no 3ºestágio de desenvolvimento e sua toxicidade sobre animais de laboratório(Daphnia magna, camundongos e ratos). O EASMO bruto revelou uma CL50 de 1.260 µg/mL, causando 99, 2 ± 2, 9 por cento de mortalidade em 24 h na concentração de 5.200 µg/mL, embora o mesmo não tenha sido capaz de impedir a eclosão dos ovos. A atividade larvicida extinguiu-se após aquecimento do extrato a 80ºC/10 min. Diálises sucessivas do EASMO bruto resultaram em duas frações solúveis em água (Fração dializável, FD; Fração nãodializável, FND), dentre as quais apenas a FD mostrou ação larvicida. Testes de toxicidade aguda realizadosem dáfnias (CE50 de 188, 7 µg/mL) e camundongos (DL50 de446,5 mg/kg de peso corpóreo) evidenciaram baixa toxicidade. Apesar da hipertrofia tímica, o EASMO mostrou ser atóxicoapós tratamento subagudo via oral em ratos. Conclui-se, portanto, que o EASMO apresenta substâncias com capacida de larvicida contra Ae. aegypti, as quais possuem massa molecular aparente menor que 12 kDa e potencial tóxico moderado.
Assuntos
Animais , Camundongos , Ratos , Aedes/efeitos dos fármacos , Daphnia/efeitos dos fármacos , Moringa oleifera/química , Extratos Vegetais/farmacologia , Larva/efeitos dos fármacos , Óvulo/efeitos dos fármacos , Extratos Vegetais/toxicidade , Ratos Wistar , Sementes/química , Fatores de TempoRESUMO
Hexane, chloroform and ethanol extracts of six marine macroalgae (Rhodophyta and Chlorophyta) from North Ceará coast (Northeast Brazil) were evaluated for antibacterial activity by the single disk method. Best results were shown by the hexane extracts of Amansia multifida against enteric Gram-negative strains such as Enterobacter aerogenes, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, S. Choleraesuis, Serratia marcescens, Vibrio cholerae and the Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus.