RESUMO
Some vegetal species have saponins in their composition with great potential to be used as natural surfactants in organic crops. This work aims to evaluate some surfactants physical properties of Quillaja brasiliensis and Agave angustifolia, based on different methods of preparation and concentration. The vegetal samples were prepared by drying and grinding, frozen and after chopped or used fresh and chopped. The neutral bar soap was used as a positive control. The drying and grinding of samples were the preparation method that resulted in higher foam column height in both species but Q. brasiliensis was superior to A. angustifolia in all comparisons and foam index was 2756 and 1017 respectively. Critical micelle concentration of Q. brasiliensis was 0.39% with the superficial tension of 54.40mNm-1 while neutral bar soap was 0.15% with 34.96mNm-1. Aspects such as genetic characteristics of the species, environmental conditions, and analytical methods make it difficult to compare the results with other studies, but Q. brasiliensis powder has potential to be explored as a natural surfactant in organic farming. Not only the surfactants physical properties of botanical saponins should be taken into account but also its effect on insects and diseases control when decided using them.
RESUMO
O estudo foi realizado em uma propriedade agrícola familiar de base ecológica em Morro Redondo (RS), com intuito de analisar o conhecimento local sobre a fauna edáfica e as práticas de manejo do solo no sistema de produção de hortaliças. A família agricultora ressaltou a função das minhocas no solo, além de compreender que as práticas de manejo influenciam a fauna edáfica. A densidade da fauna edáfica foi maior no inverno, porém com diminuição da diversidade e aumento da dominância. O potencial do uso do conhecimento local como um importante aliado ao conhecimento acadêmico na avaliação da influência das práticas de manejo na fauna edáfica é discutido neste artigo.
The study was conducted on an agroecological family farm in Morro Redondo (RS) in order to verify local knowledge about soil fauna and management practices in ecological horticultural production systems. The family farmer emphasized the role of earthworms in the soil and recognized the influence of management practices on soil fauna. The soil fauna density was higher in winter time, but the diversity was reduced and the dominance was increased. The potential use of local knowledge as a valuable contribution to academic knowledge for assessing the influence of management practices on soil fauna is discussed in this paper.
RESUMO
Introducción: el uso inadecuado de los antimicrobianos es un importante factor de resistencia a estos. En medicina veterinaria, este factor puede influir en el rendimiento de los animales, como en el caso de la mastitis bovina. Objetivo: evaluar la actividad antibacteriana de los aceites esenciales e hidroalcohólicos, de Cymbopogon citratus (DC.) Stapf., Elionurus sp. y Tagetes minuta L. contra bacterias aisladas de leche bovina. Métodos: la actividad antimicrobiana de plantas se evaluó utilizando la técnica de microdilución con la determinación de la concentración inhibitoria mínima. Resultados: los aceites esenciales eran más activos que los hidroalcohólicos, con valores de concentración mínima inhibitoria entre 0,39 y 6,32; 0,10 y 6,32 %; así como de 0,62 a 5 %, para Cymbopogon citratus, Elionurus sp. y Tagetes minuta, respectivamente; mientras que en los extractos hidroalcohólicos, excepto para Tagetes minuta, solo se inhibió Streptococcus uberis con Elionurus sp., pero el extracto hidroalcohólico de Cymbopogon citratus no mostró actividad antibacteriana. Conclusiones: los resultados sugieren el uso de estas plantas como un antimicrobiano natural, que es eficaz sobre bacterias de la mastitis bovina.
Introduction: the inappropriate use of antimicrobials is a major driver of antimicrobial resistance. In veterinary medicine, this factor can influence on animal performance, as in the case of bovine mastitis. Objective: this study is aimed to evaluate the antibacterial activity of essential oils and hydroalcoholic of Cymbopogon citratus (DC.) Stapf., Elionurus sp. and Tagetes minuta L. and the bacteria isolated from bovine milk. Methods: the antimicrobial activity of plants was evaluated using the microdilution technique, determining minimum inhibitory concentration values. Results: the essential oils were more active than the hydroalcoholic, with minimum inhibitory concentration values between 6,32 to 0,39 %; 0,10 and 6,32 %; as well as 0,62 to 5 %, for Cymbopogon citratus, Elionurus and T. minuta, respectively; while EHAs, except for Tagetes minuta, only inhibited Streptococcus uberis to Elionurus sp., being that the hydroalcoholic the Cymbopogon citratus showed no antibacterial activity. Conclusions: these results suggest the use of these plants as natural antimicrobial, being effective against bacteria of bovine mastitis.
