RESUMO
This study aimed to determine the ability of the fungus Trichoderma harzianum strain T22 (Th-T22) to utilize diesel fuel as a carbon source. The potential use of Th-T22 for diesel bioremediation in an artificial soil was tested by inoculating a diesel-sand mixture with a fungal mycelial suspension of Th-T22. Given the ability of ozone to degrade compounds with low biochemical reactivity, the effect of a pre- and post-ozonation was also evaluated. The survival, growth and sporulation of Th-T22 throughout the bioremediation trial were monitored in all the treatments. In the post-ozonation treatments, the biodegradation percentages of diesel removal were 70.16% and 88.35% in Th-T22-inoculated sand treated or untreated with the antibacterial streptomycin, respectively. The results showed that ozonation alone caused good removal efficiencies (41.9%) but it was much more effective if combined with Th-T22 in a post-ozonation regime, whereas pre-ozonation negatively affected the subsequent biodegradation, likely due to its disinfectant and oxidizing effect on Th-T22. The results obtained demonstrated the significant mycoremediation ability of Th-T22 in diesel-contaminated sand and its possible use as a bioremediation agent for diesel spills in polluted sites.
Assuntos
Biodegradação Ambiental , Gasolina , Poluição por Petróleo , Microbiologia do Solo , Poluentes do Solo/toxicidade , Trichoderma/fisiologia , Ozônio , Areia , Solo , Poluentes do Solo/análise , Poluentes do Solo/metabolismo , Trichoderma/metabolismoRESUMO
Adventitious roots (ARs) are post-embryonic roots essential for plant survival and propagation. Indole-3-acetic acid (IAA) is the auxin that controls AR formation; however, its precursor indole-3-butyric acid (IBA) is known to enhance it. Ethylene affects many auxin-dependent processes by affecting IAA synthesis, transport and/or signaling, but its role in AR formation has not been elucidated. This research investigated the role of ethylene in AR formation in dark-grown Arabidopsis thaliana seedlings, and its interaction with IAA/IBA. A number of mutants/transgenic lines were exposed to various treatments, and mRNA in situ hybridizations were carried out and hormones were quantified In the wild-type, the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) at 0.1 µM enhanced AR formation when combined with IBA (10 µM), but reduced it when applied alone; this effect did not occur in the ein3eil1 ethylene-insensitive mutant. ACC inhibited the expression of the IAA-biosynthetic genes WEI2, WEI7, and YUC6, but enhanced IBA-to-IAA conversion, as shown by the response of the ech2ibr10 mutant and an increase in the endogenous levels of IAA. The ethylene effect was independent of auxin-signaling by TIR1-AFB2 and IBA-efflux by ABCG carriers, but it was dependent on IAA-influx by AUX1/LAX3.Taken together, the results demonstrate that a crosstalk involving ethylene signaling, IAA-influx, and IBA-to-IAA conversion exists between ethylene and IAA in the control of AR formation.
Assuntos
Arabidopsis/crescimento & desenvolvimento , Etilenos/metabolismo , Ácidos Indolacéticos/metabolismo , Reguladores de Crescimento de Plantas/fisiologia , Raízes de Plantas/crescimento & desenvolvimento , Arabidopsis/fisiologia , Hibridização In Situ , Indóis/metabolismo , Raízes de Plantas/fisiologiaRESUMO
The abandonment of olive orchards is a phenomenon of great importance triggered mainly by economic and social causes. The aim of this study was to investigate some chemical, biochemical, and microbiological properties in a soil of a southern olive grove abandoned for 25 years. In order to define the effect of the long-term land abandonment on soil properties, an adjacent olive grove managed according to extensive practices was taken as reference (essentially minimum tillage and no fertilization). Soil organic matter, total nitrogen, and pH were significantly higher in the abandoned olive grove due to the absence of tillage and the natural inputs of organic matter at high C/N ratio which, inter alia, increased the number of cellulolytic bacteria and stimulated the activity of ß -glucosidase, an indicator of a more advanced stage of soil evolution. The soil of the abandoned olive orchard showed a lower number of total bacteria and fungi and a lower microbial diversity, measured by means of the Biolog method, as a result of a sort of specialization trend towards low quality organic substrates. From this point of view, the extensive cultivation management seemed to not induce a disturbance to microbiological communities.
Assuntos
Agricultura , Olea , Microbiologia do Solo , Solo/químicaRESUMO
This paper is a review of the patients with multiple myeloma, hospitalized at Clinic of Haematology in Sarajevo during the period from 1993 to 1998. This study encircles 45 patients; 18 males (40%) and 27 females (60%). Clinical and laboratory records, etiology, cytomorphology and radiography were analyzed in detail. The age of patients was 59.4 years (both males and females). The trends of disease showed increasing in 1994, 1997 and 1998, comparing it with other haematological malignancies (in 1993 the percent was 5.41, in 1998 was 15.83, and the average level, during the analyzed period, was 11.34%). The patients usually came in the terminal phase and that is the reason why median survival was 12 months. According to the results, the authors make a conclusion that there are some characteristics of this disease in individuals, comparing them with the results shown in relevant studies. They find the explanation in the exposure of the population to the chronic stress and deficit of energy caused by malnutrition during the aggression against Bosnia and Herzegovina.