Separation of Escherichia coli from natural samples for identification of sources and microcosm inoculation.
Marcos Tavares CarneiroDaniel Vidal PerezRenato Castiglia FeitosaJulio Cesar WassermanPublished in: Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology] (2020)
Obtaining uncultured Escherichia coli from natural waters is an important step in the study of microbes in the environment, which are critical for bacterial decay and microbial source tracking. The quality of the samples used can influence the assays, because high contaminant concentrations, differing cell ages, and physiologic states can impair results. The proposed separation is based on a three-step filtration method applied to replicates of seven samples from a sewage plant affluent, collected in different periods. Aliquots of the leachate were inoculated into microcosms, aiming to observe the cultivability of the cells. The assay resulted in colimetry values ranging between 104 and 105 cells. In the leachate, averages of 1.05% of total coliforms and 1.10% of Escherichia coli were recovered from original samples. Although enduring unfavorable temperatures, salinities, and nutritional conditions, the inoculated microcosm populations grew approximately 310 times after 24 h. The final leachate contained cultivable cells in appropriate physiological states and quantities for inoculum in microcosm sets. The bacteria obtained from the leachate were also appropriate for surveys of microbial source tracking, because, in the developed procedure, organisms were separated from contaminants, while cell concentrations were sufficient for inocula.
Keyphrases
- escherichia coli
- induced apoptosis
- cell cycle arrest
- single cell
- endoplasmic reticulum stress
- microbial community
- high throughput
- cell therapy
- signaling pathway
- stem cells
- cell death
- klebsiella pneumoniae
- cross sectional
- staphylococcus aureus
- mass spectrometry
- biofilm formation
- pseudomonas aeruginosa
- heavy metals
- bone marrow
- candida albicans
- gram negative
- multidrug resistant
- anaerobic digestion