RESUMO
2,4-Dichlorophenoxyacetic acid (2,4-D) is the third most applied pesticide in Brazil to control broadleaf weeds in crop cultivation and pastures. Due to 2,4-D's high mobility and long half-life under anoxic conditions, this herbicide has high probability for groundwater contamination. Bioremediation is an attractive solution for 2,4-D contaminated anoxic environments, but there is limited understanding of anaerobic 2,4-D biodegradation. In this study, methanogenic enrichment cultures were obtained from Amazonian top soil (0-40 cm) and deep soil (50 -80 cm below ground) that biotransform 2,4-D (5 µM) to 4-chlorophenol and phenol. When these cultures were transferred (10% v/v) to fresh medium containing 40 µM or 160 µM 2,4-D, the rate of 2,4-D degradation decreased, and biotransformation did not proceed beyond 4-chlorophenol and 2,4-dichlorophenol in the top and deep soil cultures, respectively. 16S rRNA gene sequencing and qPCR of a selection of microbes revealed no significant enrichment of known organohalide-respiring bacteria. Furthermore, a member of the genus Cryptanaerobacter was identified as possibly responsible for phenol conversion to benzoate in the top soil inoculated culture. Overall, these results demonstrate the effect of 2,4-D concentration on biodegradation and microbial community composition, which are both important factors when developing pesticide bioremediation technologies.
Assuntos
Herbicidas , Poluentes do Solo , Ácido 2,4-Diclorofenoxiacético , Biodegradação Ambiental , Brasil , RNA Ribossômico 16S/genética , Solo , Microbiologia do SoloRESUMO
The present study was to investigate the effects of visfatin on the morphological structure and function of the rat uterus during inflammation. The expression and distribution of visfatin, morphological structure, eosinophils (EOS), myeloperoxidase (MPO) and cytokines in the uterus of the LPS-induced rat were studied using hematoxylin-eosin staining (HE), immunohistochemical methods, western blots and enzyme-linked immunosorbent assay (ELISA). The present study showed that visfatin positive cells dispersed widely in the uterus, and strong positive staining was observed mainly in the cell cytoplasm. Compared with saline group, in visfatin group, more uterine glands were found, EOS increased, and the difference was significant (P<0.05), MPO reduced, and the difference was significant (P<0.01). In addition, visfatin was able to increase the secretion of IL-1b, IL-6, and TNF-a (P<0.01). Compared with LPS group, in vifatin+LPS group, the uterine glands of the lamina propria increased, the myometrium became thinner, the number of EOS and MPO reduced obviously, but the difference was not significant (P>0.05), and after LPS stimulated body, visfatin decrease the level of IL-1b, IL-6, TNF-a (P<0.01). The above results suggest that visfatin could affect the morphological structure of rat uterus; Visfatin could modulate the inflammatory response in rats' uterus by regulating the quantity of inflammatory cells, such as EOS and MPO, and the level of inflammatory cytokines, such as IL-1b, IL-6, TNF-a.
El objetivo del presente estudio fue investigar los efectos de la visfatina sobre la estructura morfológica y la función del útero de la rata durante la inflamación. Se estudiaron la expresión y distribución de la visfatina, la estructura morfológica, eosinófilos, mieloperoxidasa y citoquinas en el útero de rata mediante la tinción de H&E, métodos inmunohistoquímicos, Western blots y ELISA. El estudio mostró que las células visfatina positivas se dispersan ampliamente en el útero, junto a una fuerte tinción positiva, principalmente en el citoplasma de la célula. En comparación con el grupo control, en el grupo visfatina, se encontraron más glándulas uterinas, se observó un aumento de EOS y la diferencia fue significativa (p<0,05), MPO reducida siendo esta diferencia también significativa (p<0,01). Además, la visfatina fue capaz de aumentar la secreción de IL-1b, IL-6 y TNF-a (P<0,01). En comparación con el grupo LPS, visfatina+grupo LPS, las glándulas uterinas de la lámina propia aumentaron, se observó un miometrio más delgado, y número reducido de EOS y MPO, sin embargo, la diferencia no fue significativa (P>0,05). Después de estímulo LPS en el cuerpo, se registró un nivel menor de visfatina en IL-1b, IL-6, TNF-a (P<0,01). Los resultados anteriores sugieren que visfatina podría afectar a la estructura morfológica del útero de rata. Además, podría modular la respuesta inflamatoria en el útero mediante la regulación de la cantidad de células inflamatorias, tales como EOS y MPO.