RESUMEN
The soil is a dynamic environment, influenced by abiotic and biotic factors, which can result in changes in plant development. This study aimed to assess the impact on vegetative growth of chia (Salvia hispanica L) inoculated with Trichoderma harzianum and on the rhizosphere microbiome. The experimentation was conducted in a greenhouse under controlled conditions growing chia plants in pots containing soil with a clayey texture. Different concentrations of T. harzianum (0; 2.5; 5.0; 10.0; 20.0 µL. g-1 of seed) were applied to the chia seeds before planting. Morphological parameters, including plant height (cm), number of branches, stem diameter (mm), number of days to flowering and shoot and root dry masses (g) were quantitatively assessed. After the cultivation period, soil samples from the rhizosphere region were collected for subsequent chemical and metagenomic analyses. These samples were also compared with the control soil, collected before installing the experiment. The results showed that increasing doses of T. harzianum promoted a significant increase in the diameter of the stem, number of branches, dry biomass of the root system and the number of days to flowering, without modifying the overall height of the plants. Soil metagenomics indicated that T. harzianum inoculation modified the microbial diversity of the rhizosphere environment, with more pronounced effects observed in samples treated with higher concentrations of the inoculant. Furthermore, there were changes in the chemical composition and enzymes related to soil quality in correlation with the concentrations of the applied inoculant. This study demonstrated that inoculating chia seeds with T. harzianum not only promotes specific morphogenetic characteristics of the plant, but it also has a significant impact on the microbial diversity and biochemical functionality of the soil, including an observed increase in the populations of T. harzianum and T. asperellum.
Asunto(s)
Metagenómica , Salvia , Microbiología del Suelo , Salvia/microbiología , Rizosfera , Biomasa , Hypocreales/fisiología , Raíces de Plantas/microbiologíaRESUMEN
Chia, is a gluten-free, rich in proteins, oilseed that is "on trend" as an alternative ingredient in food production, adding nutritional value. As a reservoir of natural biodiversity, lactic acid bacteria development, during spontaneous chia flour fermentation (sourdough) for 10â¯days, were investigated by culturing and high throughput sequencing (HTS). Culture-dependent analysis showed a rapid increase in total LAB numbers from the second day of sourdough refreshment. Taxonomical identification of LAB isolates by rep-PCR and further 16S rRNA sequencing was performed. Besides Among identified LAB by culture-dependent approach, species from genus Enterococcus were the most abundant; Lactococcus (Lc. lactis), Lactobacillus (L. rhamnosus) and Weissella (W. cibaria) species were also isolated. By HTS, twelve OTUs belonging to LAB genera were identified during chia sourdough fermentation with an increased Lactobacillus diversity. Enterococcus (E.) faecium, E. mundtii, W. cibaria and L. rhamnosus were detected as dominant species in the final propagation stages while Bacillus and Clostridium were mostly present during first fermentation stages. The investigation of biotechnological and safety traits (acidification ability, protein hydrolysis, exopolysaccharides production, antimicrobial activity and antibiotic resistance) of 15 representative LAB strains was performed. Strains characterization led to the selection of Lc. lactis CH179, L. rhamnosus CH34 and W. cibaria CH28 as candidates to be used as novel functional starter culture for gluten-free chia fermented products. As far as we know, this is the first study providing information on the molecular inventory of LAB population during spontaneous fermentation of chia sourdough.
Asunto(s)
Biodiversidad , Pan/microbiología , Lactobacillales/aislamiento & purificación , Lactobacillales/fisiología , Salvia/microbiología , Bacterias/clasificación , Bacterias/crecimiento & desarrollo , Bacterias/aislamiento & purificación , Bacterias/metabolismo , Fermentación , Harina/microbiología , Microbiología de Alimentos , Lactobacillales/clasificación , Lactobacillales/metabolismo , ARN Ribosómico 16S/genéticaRESUMEN
Chia seeds provide a suitable environment for microorganisms. However, it is difficult to disinfect these seeds with water and/or chemical disinfectant solutions because the mucilage in the seeds can absorb water and consequently form gels. High-intensity light pulses (HILP) is one of the most promising emerging technologies for inactivating microorganisms on surfaces, in clear liquids and beverages, and on solid foods. The aim of this work was to evaluate the effect of HILP on Salmonella Typhimurium in culture medium (in vitro tests) and inoculated onto chia seeds (in vivo tests). HILP was effective against Salmonella Typhimurium under both conditions: 8 s of treatment (10.32 J/cm2) resulted in a 9-log reduction during in vitro tests, and 15 s of treatment (19.35 J/cm2) resulted in a 4-log reduction on the inoculated chia seeds. Salmonella Typhimurium inactivation kinetics were accurately described using the Weibull model (R2 > 0.939). These results indicate that the use of HILP for microbial inactivation on seeds could generate products suitable for human consumption.
Asunto(s)
Manipulación de Alimentos , Microbiología de Alimentos , Viabilidad Microbiana , Salmonella typhimurium , Salvia , Semillas , Manipulación de Alimentos/métodos , Microbiología de Alimentos/métodos , Salmonella typhimurium/efectos de la radiación , Salvia/microbiología , Semillas/microbiología , AguaRESUMEN
Abstract One bioactive compound, identified as alternariol 9-methyl ether, was isolated from the crude extract of the endophytic fungus Alternaria sp. Samif01 residing in the roots of Salvia miltiorrhiza Bunge. Alternariol 9-methyl ether was active against bacteria with minimum inhibitory concentration values ranging from 25 to 75 µg/mL and median inhibitory concentration (IC50) values ranging from 16.00 to 38.27 µg/mL. The IC50 value of alternariol 9-methyl ether against spore germination of Magnaporthe oryzae was 87.18 µg/mL. Alternariol 9-methyl ether also showed antinematodal activity against Bursaphelenchus xylophilus and Caenorhabditis elegans with IC50 values of 98.17 µg/mL and 74.62 µg/mL, respectively. This work is the first report on alternariol 9-methyl ether and its biological activities from the endophytic fungus Alternaria sp. Samif01 derived from S. miltiorrhiza Bunge. The results indicate the potential of Alternaria sp. Samif01 as a source of alternariol 9-methyl ether and also support that alternariol 9-methyl ether is a natural compound with high potential bioactivity against microorganisms.
Asunto(s)
Animales , Alternaria/química , Antiinfecciosos/aislamiento & purificación , Endófitos/química , Lactonas/aislamiento & purificación , Alternaria/aislamiento & purificación , Antiinfecciosos/metabolismo , Bacterias/efectos de los fármacos , Endófitos/aislamiento & purificación , Lactonas/metabolismo , Pruebas de Sensibilidad Microbiana , Magnaporthe/efectos de los fármacos , Nematodos/efectos de los fármacos , Raíces de Plantas/microbiología , Salvia/microbiologíaRESUMEN
One bioactive compound, identified as alternariol 9-methyl ether, was isolated from the crude extract of the endophytic fungus Alternaria sp. Samif01 residing in the roots of Salvia miltiorrhiza Bunge. Alternariol 9-methyl ether was active against bacteria with minimum inhibitory concentration values ranging from 25 to 75µg/mL and median inhibitory concentration (IC50) values ranging from 16.00 to 38.27µg/mL. The IC50 value of alternariol 9-methyl ether against spore germination of Magnaporthe oryzae was 87.18µg/mL. Alternariol 9-methyl ether also showed antinematodal activity against Bursaphelenchus xylophilus and Caenorhabditis elegans with IC50 values of 98.17µg/mL and 74.62µg/mL, respectively. This work is the first report on alternariol 9-methyl ether and its biological activities from the endophytic fungus Alternaria sp. Samif01 derived from S. miltiorrhiza Bunge. The results indicate the potential of Alternaria sp. Samif01 as a source of alternariol 9-methyl ether and also support that alternariol 9-methyl ether is a natural compound with high potential bioactivity against microorganisms.