Utilization of naproxen by Amycolatopsis sp. Poz 14 and detection of the enzymes involved in the degradation metabolic pathway.

The pollution of aquatic environments by drugs is a problem for which scarce research has been conducted in regards of their removal. Amycolatopsis sp. Poz 14 presents the ability to biotransformation naphthalene at high efficiency, therefore, in this work this bacterium was proposed as an assimilator of naproxen and carbamazepine. Growth curves at different concentrations of naproxen and carbamazepine showed that Amycolatopsis sp. Poz 14 is able to utilize these drugs at a concentration of 50 mg L-1 as a source of carbon and energy. At higher concentrations, the bacterial growth was inhibited. The transformation kinetics of naproxen showed the total elimination of the compound in 18 days, but carbamazepine was only eliminated in 19.9%. The supplementation with cometabolites such as yeast extract and naphthalene (structure similar to naproxen) at 50 mg L-1, showed that the yeast extract shortened the naproxen elimination to 6 days and reached a higher global consumption rate compared to the naphthalene cometabolite. The biotransformation of carbamazepine was not improved by the addition of cometabolites. The partial sequencing of the genome of Amycolatopsis sp. Poz 14 detected genes encoding putative enzymes for the degradation of cyclic aromatic compounds and the activities of aromatic monooxygenase, catechol 1,2-dioxygenase and gentisate 1,2-dioxygenase exhibited their involving in the naproxen biodegradation. The HPLC-MS analysis detected the 5-methoxysalicylic acid at the end of the biotransformation kinetics. This work demonstrates that Amycolatopsis sp. Poz 14 utilizes naproxen and transforms it to 5-methoxysalicylic acid which is the initial compound for the catechol and gentisic acid metabolic pathway.

Ecological longevity of Polaskia chende (Cactaceae) seeds in the soil seed bank, seedling emergence and survival.

Soil seed banks are essential elements of plant population dynamics, enabling species to maintain genetic variability, withstand periods of adversity and persist over time, including for cactus species. However knowledge of the soil seed bank in cacti is scanty. In this study, over a 5-year period we studied the seed bank dynamics, seedling emergence and nurse plant facilitation of Polaskia chende, an endemic columnar cactus of central Mexico. P. chende seeds were collected for a wild population in Puebla, Mexico. Freshly collected seeds were sown at 25 °C and 12-h photoperiod under white light, far-red light and darkness. The collected seeds were divided in two lots, the first was stored in the laboratory and the second was use to bury seeds in open areas and beneath a shrub canopy. Seeds were exhumed periodically over 5 years. At the same time seeds were sown in open areas and beneath shrub canopies; seedling emergence and survival were recorded over different periods of time for 5 years. The species forms long-term persistent soil seed banks. The timing of seedling emergence via germination in the field was regulated by interaction between light, temperature and soil moisture. Seeds entered secondary dormancy at specific times according to the expression of environmental factors, demonstrating irregular dormancy cycling. Seedling survival of P. chende was improved under Acacia constricta nurse plants. Finally, plant facilitation affected the soil seed bank dynamics as it promoted the formation of a soil seed bank, but not its persistence.

BIOLOGICAL PROPERTIES AND CHEMICAL COMPOSITION OF JATROPHA NEOPAUCIFLORA PAX.

BACKGROUND: Ethnopharmacological relevance. Jatropha neopauciflora (Pax) is an endemic species of the Tehuacan- Cuicatlan Valley, Mexico. This species has long been used as a remedy to alleviate illnesses of bacterial, fungal and viral origin. Aim of the study. Experimentally test the traditional use of Jatropha neopauciflora in Mexican traditional medicine. MATERIALS AND METHODS: The methanol extract (MeOH1), of Jatropha neopauciflora (Euphorbiaceae) was obtained by maceration. Next, the methanol (MeOH2) and hexane (H) fractions were obtained. The essential oil was obtained by hydro- distillation. The extract, fractions and essential oil were analyzed by GC-MS. The antimicrobial activity was measured by the disc diffusion agar and radial inhibition growth methods. RESULTS: The extract and fractions showed antibacterial activity against eleven strains (five Gram-positive and six Gram- negative) and a bacteriostatic effect in the survival curves for Staphylococcus aureus and Vibrio cholerae. The extract and fractions were also shown to have antifungal activity, particularly against Trichophyton mentagrophytes (CF50 = MeOH1: 1.07 mg/mL, MeOH2: 1.32 mg/mL and H: 1.08 mg/mL). The antioxidant activity of MeOH1 (68.6 µg/mL) was higher than for MeOH2 (108.1 µg/mL). The main compounds of the essential oil were ß-pinene, 1,3,8-p-menthatriene, ledene, m- menthane, linalyl acetate and 3-carene. The main compounds of MeOH1 were ß-sitosterol, lupeol and pyrogallol; the main compounds of MeOH2 were ß-sitosterol, spathulenol, coniferyl alcohol and lupeol; and the main compounds of H were ß-sitostenone, γ-sitosterol and stigmasterol. CONCLUSIONS: This study indicates that Jatropha neopauciflora is a potential antibacterial and antifungal agent.

Aflatoxins, hydroxylated metabolites, and aflatoxicol from breast muscle of laying hens.

Aflatoxins (AF) are toxic fungal secondary metabolites that are pathological to animals and humans. This study identified and quantified AF (AFB(1), AFB(2), AFG(1), AFG(2)) and their hydroxylated metabolites (AFM(1), AFM(2), AFP(1)) and aflatoxicol (AFL) from laying hen breast muscles. Aflatoxins pass from cereal feed to the laying hen tissues, causing economic losses, and from there to humans. To detect the passage of AF from feed to hen breast muscle tissues, an experiment that included 25 Hy-Line W36 121-wk-old hens was performed for 8 d. Hens in individual cages were distributed into 3 groups: a control group, with feed free of AFB(1), and 2 experimental groups, with feed spiked with 2 AFB(1) dosages: 30 µg·kg(-1) (low) or 500 µg·kg(-1) (high). The daily feed consumption per hen was recorded and afterward hens were euthanized and breast muscles were collected, weighed, and dried individually. Aflatoxins were extracted by 2 chemical methods and quantified by HPLC. Both methods were validated by lineality (calibration curves), recovery percentage (>80%), limit of detection, and limit of quantification. The AF (µg·kg(-1)) averages recovered in control breast muscles were as follows: AFB(1) (18); AFG(1), AFM(2), and AFL (0); AFG(2) (1.3); AFM(1) (52), and AFP1 (79). Hens fed with feed spiked with 30 µg·kg(-1) of AFB(1) had AFG(1) (16); AFG(2) (72); AFM(1) (0); AFM(2) (18); AFP(1) (145); and AFL (5 µg·kg(-1)). Hens with feed spiked with 500 µg·kg(-1) of AFB(1) had AFG(1) (512); AFG(2) (7); AFM(1) (4,775); AFM(2) (0); AFP(1) (661); and AFL (21 µg·kg(-1)). The best AF extraction method was Qian and Yang's method, modified by adding additional AF from both Supelclean LC18 SPE columns; its limit of detection (0.5 ng·mL(-1)) was lower compared with that of Koeltzow and Tanner, which was 1 ng·mL(-1).