Recent data suggest that the human body is not such a neatly self-sufficient island after all. It is more like a super-complex ecosystem containing trillions of bacteria and other microorganisms that ...inhabit all our surfaces; skin, mouth, sexual organs, and specially intestines. It has recently become evident that such microbiota, specifically within the gut, can greatly influence many physiological parameters, including cognitive functions, such as learning, memory and decision making processes. Human microbiota is a diverse and dynamic ecosystem, which has evolved in a mutualistic relationship with its host. Ontogenetically, it is vertically inoculated from the mother during birth, established during the first year of life and during lifespan, horizontally transferred among relatives, mates or close community members. This micro-ecosystem serves the host by protecting it against pathogens, metabolizing complex lipids and polysaccharides that otherwise would be inaccessible nutrients, neutralizing drugs and carcinogens, modulating intestinal motility, and making visceral perception possible. It is now evident that the bidirectional signaling between the gastrointestinal tract and the brain, mainly through the vagus nerve, the so called "microbiota-gut-vagus-brain axis," is vital for maintaining homeostasis and it may be also involved in the etiology of several metabolic and mental dysfunctions/disorders. Here we review evidence on the ability of the gut microbiota to communicate with the brain and thus modulate behavior, and also elaborate on the ethological and cultural strategies of human and non-human primates to select, transfer and eliminate microorganisms for selecting the commensal profile.
Inulin-type fructans are the most studied prebiotic compounds because of their broad range of health benefits. In particular, plants of the Agave genus are rich in fructans. Agave-derived fructans ...have a branched structure with both β-(2→1) and β-(2→6) linked fructosyl chains attached to the sucrose start unit with a degree of polymerization (DP) of up to 80 fructose units. The objective of this work was to assess the prebiotic potential of three Agave angustifolia Haw fructan fractions (AFF) with different degrees of polymerization. The three fructan fractions were extracted from the agave stem by lixiviation and then purified by ultrafiltration and ion exchange chromatography: AFF1, AFF2 and AFF3 with high (3-60 fructose units), medium (2-40) and low (2-22) DP, respectively. The fructan profile was determined with high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD), which confirmed a branched fructan structure. Structural elucidation was performed by Fourier Transform Infra-Red Spectroscopy. The AFF spectrum shows characteristic fructan bands. The prebiotic effect of these fractions was assessed in vitro through fermentation by Bifidobacterium and Lactobacillus strains. Four growth patterns were observed. Some bacteria did not grow with any of the AFF, while other strains grew with only AFF3. Some bacteria grew according to the molecular weight of the AFF and some grew indistinctly with the three fructan fractions.
Lecanicillium (Verticillium) lecanii produced chitinases using shrimp shell as inducer. Maximum production of beta -N-acetylglucosaminidase was measured at 80h. Enzyme stability was obtained at ...temperatures ranging from 30 to 40 degree C and maximum activity at 50 degree C, pH 6.0. Enzyme activity increased with Ba super(2+), Co super(2+), Fe super(3+) and Zn super(2+). Bioassays against the phyto-pathogenic fungus Oidium spp. showed mycelial and germination inhibition. SDS-PAGE electrophoresis of the partially purified extract revealed four bands of 70, 58, 45 and 31kDa and this extract showed activity of beta -N-acetylglucosaminidase through zymogram analysis. Chitinases produced by L. lecanii are potentially useful against phytopathogenie fungi, insects and chitosan bioconversions.Original Abstract: Lecanicilium (Verticillium) lecanii produjo quitinasas mediante el uso de caparazon de camaron como inductor. La mdxima production de beta -N-acetylglucosaminidasa se obtuvo a las 80h. Se observo estabilidad de la enzima en el intervalo de temperatura entre 30 y 40 degree C y su actividad maxima a los 50 degree C, pH 6,0. La actividad enzimatica se incremento con Ba super(2+), Co super(2+), Fe super(3+) and Zn super(2+). El bioensayo contra el hongo fitopatogeno Oidium spp. mostro inhibicion micelar y de la germinacion. La electroforesis SDS-PAGE del extracto parcialmente purificado mostro cuatro bandas de 70, 58, 45 y 31kDa y este extracto mostro actividad de beta -N-acetylglucosaminidasa a traves de un analisis de zimograma. Las quitinasas producidas por L. lecanii pueden ser potencialmente utilizadas contra hongos fitopatogenos, insectos y en la bioconversion del quitosan.
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