Agriculture depends on fertilizers to provide nutrients for plants. Phosphorus (P) is one of these nutrients and is the second-most necessary for plant growth. Global production of P fertilizer is concentrated in Morocco, China and the United States. A large amounts of P resources are found in organic wastes that can be transformed through phosphate-solubilizing microorganisms during the composting process. In this study, we first determined the enzymatic activity of phosphatases and phytase from Pseudomonas aeruginosa ATC 15442. Second, we evaluated the mineralization of P in mature compost when inoculated with P. aeruginosa ATC 15442, phytases, a cocktail of phosphate-solubilizing enzymes and their combinations. Finally, we evaluated different concentrations of the cocktail trying to release more P in the compost. The results indicated that P. aeruginosa exuded alkaline phosphatases, acid phosphatase, neutral phosphatase and phytase. The enzymatic cocktail increased inorganic P (Pi) when added to the mature compost: this was able to release up to 95% more Pi in the compost compared to the amount of Pi released in the control compost. The current study demonstrated the importance of adding the cocktail to enhance Pi in mature compost; however, further studies are required to confirm the results and practical applications.
Background: Heliopsis longipes root is the widely used organ from the plant due to its culinary and medicinal importance. Nevertheless, during its collection the foliage is discarded. Therefore, it is required to perform studies about the phytochemical content with biological activity present in the different plant organs of the foliage, for a better exploitation of the plant. Hypothesis: The concentration of phenolic compounds with antioxidant activity varies according to the type of plant organ and the geographic location of the plant collection. Study species: Heliopsis longipes Site and years of study: The H. longipes plants were collected in three locations (Conca, San Juan Buenaventura and Beltran) from Sierra Gorda of Mexico, between 2017 and 2018. Methods: In this study, they were analyzed the methanolic extracts from H. longipes leaves and flowers, in order to determine the content of the phenolic compounds and scavenging of radicals activity (DPPH• and ABTS•+). Further characterization of the extracts was carried out by chromatography (UPLC). Results: The total content of polyphenols, flavonoids and condensed tannins varied in depending on the type of plant organ and the origin site of H. longipes , being the leaves of Beltran those that represent the best source of phenolic compounds with scavenging activity of the radicals DPPH• and ABTS•+. In the extracts, phenolic acids and flavonoids were identified. Conclusions: The geographical climatic conditions influence the phenolic content and antioxidant activity of the methanolic extracts from leaves and flowers of H. longipes .