RESUMO
The role and importance of the true slime moulds (mycetozoans, Mycetozoa, formerly Myxomycetes) for agriculture and food industry are poorly documented, most probably because of a low popularity of these "macroscopic microorganisms" among researchers in the past. Here we report probably for the first time the massive occurrence of true slime moulds in their vegetative, plasmodial form in a product intended for direct consumption, i.e. in a household hydroponic culture of garden cress (Lepidium sativum L.). The plasmodia gradually produced numerous, stalked or sessile sporangia and plasmodiocarps, which made it possible to identify them as Didymium species complex (the stalked sporangia) and Didymium difforme (Pers.) Gray (the sessile sporangia and plasmodiocarps). The mycetozoans were transferred to in vitro culture where they were maintained for several weeks on oat flour. We briefly discuss the importance of this observation from the point of view of biochemical interactions between the plant and the true slime moulds in a general context of slime mould biology. Our observation indicates that the presence of mycetozoan material in food products may be frequent, while its influence on food safety and quality remains unknown.
Assuntos
Contaminação de Alimentos , Microbiologia de Alimentos , Lepidium sativum/microbiologia , Physarida/crescimento & desenvolvimento , Hidroponia , Physarida/isolamento & purificação , Esporângios/crescimento & desenvolvimentoRESUMO
Tests were carried out to determine the effects of commercial preparations of indole-3-acetic acid (IAA), gibberellin (GA) and kinetin, separately and in combination, on Azospirillum lipoferum and A. brasilense. These hormones showed no effect upon morphology, growth rate, or oxygen uptake. Some random effects of GA, kinetin and the combination of hormones--but not of IAA alone--were observed on the number of viable cells. IAA, in the concentrations 0.001-1.0 microgram/ml, inhibited nitrogenase in A. lipoferum but not in A. brasilense. GA and kinetin separately and in combination with IAA had no influence on nitrogenase activity.
Assuntos
Bactérias/efeitos dos fármacos , Giberelinas/farmacologia , Ácidos Indolacéticos/farmacologia , Cinetina/farmacologia , Reguladores de Crescimento de Plantas/farmacologia , Microbiologia do Solo , Bactérias/enzimologia , Bactérias/metabolismo , Nitrogenase/metabolismo , Oxigênio/metabolismoAssuntos
Bactérias/efeitos dos fármacos , Reguladores de Crescimento de Plantas/farmacologia , Plantas/microbiologia , Bactérias/metabolismo , Fenômenos Químicos , Química , Meios de Cultura , Citocininas/farmacologia , Giberelinas/farmacologia , Ácidos Indolacéticos/farmacologia , Fixação de Nitrogênio , Reguladores de Crescimento de Plantas/análise , Solo/análise , Microbiologia do SoloRESUMO
Vinte e quatro amostras de Azospirillum lipoferum e 21 de Azosperilum brasilense foram examinadas em sua capacidade de produzir bacteriocinas. Dezesseis amostras de A. lipoferum exerceram efeito inibidor em outras amostras da mesma especies. Algumas cepas produtoras de A. lipoferum foram simultaneamente sensiveis a bateriocinas produzidas por outras amostras dessa especie. Dez amostras de A. brasilense inibiram apenas A. lipoferum, 2 foram ativas contra tanto A. lipoferum como A. brasilense e uma contra A. brasilense apenas.Nenhum dos produtores foi sensivel a sua propria bacteriocina
