Isolation of Pantoea ananatis from sugarcane and characterization of its potential for plant growth promotion.

Each year, approximately 170 million metric tons of chemical fertilizer are consumed by global agriculture. Furthermore, some chemical fertilizers contain toxic by-products and their long-term use may contaminate groundwater, lakes, and rivers. The use of plant growth-promoting bacteria may be a cost-effective strategy for partially replacing conventional chemical fertilizers, and may become an integrated plant nutrient solution for sustainable crop production. The main direct bacteria-activated mechanisms of plant growth promotion are based on improvement of nutrient acquisition, siderophore biosynthesis, nitrogen fixation, and hormonal stimulation. The aim of this study was to isolate and identify bacteria with growth-promoting activities from sugarcane. We extracted the bacterial isolate SCB4789F-1 from sugarcane leaves and characterized it with regard to its profile of growth-promoting activities, including its ability to colonize Arabidopsis thaliana. Based on its biochemical characteristics and 16S rDNA sequence analysis, this isolate was identified as Pantoea ananatis. The bacteria were efficient at phosphate and zinc solubilization, and production of siderophores and indole-3-acetic acid in vitro. The isolate was characterized by Gram staining, resistance to antibiotics, and use of carbon sources. This is the first report on zinc solubilization in vitro by this bacterium, and on plant growth promotion following its inoculation into A. thaliana. The beneficial effects to plants of this bacterium justify future analysis of inoculation of economically relevant crops.

Diagnóstico microbiológico e histopatológico de mortalidade em avestruzes (Struthio camelus) / Microbiological and histological diagnosis in mortality of ostrich (Struthio camelus)

Several young ostrich, including nestlings, with lassitude and inappetence followed by death or victim of sudden death were immediately brought to diagnosis at an Animal Health Laboratory. At necropsy, animals presented hemorrhage and altered content of the vitelline sac, and necrotic foci in the small intestine; one animal showed necrotic pleuropneumonia with psammomatosus bodies in the lung parenchyma. The cultures from different samples revealed Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Serratia marcescens, Enterobacter aglomerans, and Pseudomonas mendocina. It was suggested one case of septicemia in an animal with exclusive growth of K. pneumoniae isolated from samples of small intestine, lung, and liver.