Understanding ecology of microbiomes in drinking water distribution systems is the most important notion in delivering safe drinking water. Despite cultivation-based methods routinely employed in monitoring drinking water quality, cultivation of speci c indicator organisms alone is not always guarantee for assuring safe drinking water delivery. The presence of complex microbiomes in drinking water distribution systems affects treatment effectiveness leading to poor quality water which as a result affects health of human and animals. Drinking water treatment and distribution systems harbor various microbiota despite efforts made in improving water infrastructures and several waterborne diseases become serious problems in the water industry, specially, in developing Countries. Intermittent water supply, long-time of water storage, low water pressure in distribution systems, storage tankers and pipes as well as contaminated source water are among many of the factors responsible for low drinking water quality which in turn affecting health of people. The aim of this study was to explore microbial diversity and structure in water samples collected from source water, treated water, reservoirs, and several household points of use locations (taps). High throughput Illumina sequencing technology was employed by targeting V4 region of 16S rRNA following Illumina protocol to analyze the community structure of bacteria. The core dominating taxa were Proteobacteria followed by Firmicutes, Bacteroidetes and Actinobacteria. Gamma proteobacteria were dominant among other Proteobacterial classes across all sampling points. Opportunistic bacterial genera such as Pseudomonas, Legionella, Klebsiella, Escherichia, Actinobacteria, as well as eukaryotic microbes like Cryptosporidium, Hartmanella, Acanthamoeba, Aspergillus, and Candida were also the abundant taxa found along the distribution systems. The shift in microbial community structure from source to point of use locations were in uenced by factors such as residual free chlorine, intermittent water supply and long-time storage at the household. The shift in microbial community structure from source to point of use locations were in uenced by factors such as residual free chlorine, intermittent water supply and long-time storage at the household. The complex microbiota which was present in different sample sites receiving treated water from the two treatment plants (Legedadi and Gefersa) starting from source water to household point of consumption across the distribution systems in Addis Ababa brings drinking water quality problem which further causes signi cant health problems to both human and animal health. Treatment ineffectiveness, disinfection ine ciency, poor maintenance actions, leakage of sewage and other domestic wastes are few among many other factors responsible for degraded drinking water quality in this study putting health at high risk which, this, leads to morbidity and mortality. Findings of this research provide important and bassline information to understand th...

In the present day there is no report on characterization and identification of bacterial endophytes isolated from tef (Eragrostis tef) seeds. This study was conducted to screen, identify, and characterize bacterial endophytes isolated from tef seeds germplasm repository and determine if the bacterial provided plant growth promotion. Nine endophytic bacterial species were identified from 83 tef seed accessions using a Biolog microbial identification system, which utilize 95 different carbon sources. Eight of the identified bacterial species could produce amylase, seven of the species could solubilize phosphate and six of the bacteria could degrade cellulose. All the bacteria were shown to enhance growth of wheat (Triticum aestivum) under laboratory condition. Pseudomonas stutzeri, Rhizobium radiobacter, Bacillus butanolivorans, Pseudomonas putida biotype B, Enterobacter cowanii, Pantoea dispersa, Enterobacter cloacae ss dissolvens, Serratia ficaria and Pantoea agglomerans significantly increased mean root dry mass of inoculated Triticum aestivum up to 9.8%, 9.3%, 8.1%, 7.9%, 7.7%, 7.5%, 7%, 6.9% and 5.5% respectively and increase the mean shoot dry mass of Triticum aestivum up to 29%, 25%, 23%, 26%, 23%, 20%, 22% and 19% respectively. In addition, several seed endophytic bacterial species exhibited tolerance to salinity up to 6% and only Bacillus butanolivorans tolerated salinity up to 15% and temperature up to 60°C, this suggested the potential for possible application under stressed environmental conditions and possible utility as bioinoculant for maintaining sustainable agricultural production and productivity without affecting human health.

Hydrocarbon-derived pollutants are becoming one of the most concerning ecological issues. Thus, there is a need to investigate and develop innovative, low-cost, eco-friendly, and fast techniques to reduce and/or eliminate pollutants using biological agents. The study was conducted to isolate, characterize, and identify potential diesel-degrading bacteria. Samples were collected from flower farms, lakeshores, old aged garages, asphalt, and bitumen soils and spread on selective medium (Bushnell Haas mineral salt agar) containing diesel as the growth substrate. The isolates were characterized based on their growth patterns using optical density measurement, biochemical tests, and gravimetric analysis and identified using the Biolog database and 16S rRNA gene sequencing techniques. Subsequently, six diesel degraders were identified and belong to Pseudomonas, Providencia, Roseomonas, Stenotrophomonas, Achromobacter, and Bacillus. Among these, based on gravimetric analysis, the three potent isolates AAUW23, AAUG11, and AAUG36 achieved 84%, 83.4%, and 83% diesel degradation efficiency, respectively, in 15 days. Consequently, the partial 16S rRNA gene sequences revealed that the two most potent bacterial strains (AAUW23 and AAUG11) were Pseudomonas aeruginosa, while AAUG36 was Bacillus subtilis. This study demonstrated that bacterial species isolated from hydrocarbon-contaminated and/or uncontaminated environments could be optimized to be used as potential bioremediation agents for diesel removal.

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The Plant Growth-Promoting Rhizobacteria (PGPR) are the free-living plant roots colonizing bacteria that improve soil fertility, stimulating plant growth, and protecting plants from biotic and abiotic stress factors. The present study was conducted to characterize and identify native PGP bacteria colonizing tef rhizosphere during the flowering stage for a production of bio inoculant. For this concern, 426 samples of different varieties of tef roots and rhizosphere soils were collected. A total of 457 rhizobacteria were isolated and characterized for PGP traits, biocontrol properties, and abiotic stress tolerance ability. 12 rhizobacterial species were identified using the Biolog bacterial identification system. Among these, the majority of the identified bacterial species were utilized different carbon sources that similar to plant root exudates i.e. carbohydrates, carboxylic acids, amide, and amine.Seed germination and seedling growth test were conducted using four identified bacterial species having excellent plant growth-promoting, biotic and abiotic stress tolerance properties, and 100 percent tef seeds germination result occurred on 3 rd and 4 th day after inoculation. shoot and root length of inoculated seeds was measured on last day of the experiment to determine the effect of PGP bacteria on tef crops growth enhancement and increase mean shoots and root length up to 3 and 2.6 cm respectively in comparison to control. PGP bacterial species or strains can be used as bio inoculants to replacing chemical fertilizers for sustaining agricultural productivity and production without affecting soil fertility, living organisms, and their environment.