Isolation of ammonium- and nitrite-oxidizing bacterial strains from soil, and their potential use in the reduction of nitrogen in household waste water

Abstract

Abstract:Currently, nitrogen has become the main element of water pollution, causing riverine, lacustrine and coastal eutrophication. The continuous contamination of aquifers and the absence of planned water resource utilization, boost its scarcity, and has been the only way in which our societies become aware of the urgent need to process the generated wastewater. The objective of this research was to evaluate the nitrifying capacity of different autochthonous bacterial isolates from soils from nearby sources of domestic wastewater drainage. For this, bacteria were isolated from Pirro River, contaminated with nitrogen of domestic sewage. Nitrifying bacteria were counted by serial dilution and agar plates, and were isolated until obtaining axenic colonies. These were identified by biochemical batteries or genetic sequencing, and the quantification of their nitrifying capacity was obtained by the methods 4500-NH4 + -F and 4500-NO-2-B, all between September 26, 2011 and March 16, 2014. A total of seven strains of nitrifying microorganisms were isolated and purified, including four Streptomyces sp., one Pseudomonas putida, one Sphingomonas sp. and one Aeromonas sp. We found that there were 2.23 x 10 5 UFC/g of soil of ammonium oxidizing bacteria and 2.2 x 10 4 CFU/g of soil of nitrite oxidizing bacteria in the samples. The quantification of the nitrifying capacity of the strains by colorimetric methods, determined that the maximum ammonium removal capacity was 0.050 mg N/L/day and 0.903 mg N/L/day of nitrite. The collection of few strains of nitrifying organisms and a low CFU count, can be attributed to the technique used, since this only recovers 1 % of the microorganisms present in a sample, which, however, is acceptable for studies which main purpose is to obtain cultivable microorganisms. Future research should consider removal tests with higher ammonium and nitrite levels, to find the maximum capacity of the isolated microorganisms, and evaluate their potential use in wastewater treatment systems. Rev. Biol. Trop. 65 (4): 1527-1539. Epub 2017 December 01.

Biological Nitrogen Transformation Efficiency in Removing Nitrogen and Improving Water Quality from Zakho Municipal Wastewater in Kurdistan Region/Iraq

“…In the second step of nitrification of converting nitrite to nitrate. Nitrobacter is considered main identified genus responsible of second step, other genera, like Nitrospina, Nitrococcus, and Nitrospira found to be active in oxidizing nitrite to nitrate [21]. Nitrate ions is the most environmentally concerned as it associates with many health and environmental issues as it carries the same negative charge of soil colloids and easily leached by water from the soil to aquifers and water bodies.…”

DNA Barcoding and Water Quality Analysis of Nitrifying Bacteria in Lebak Lebung Swamp, South Sumatera

“…The nitrification process is played by the bacteria Nitrosomonas sp. which converts ammonia into nitrites [6] and the bacteria Nitrobacter sp. which will oxidize nitrites to nitrates [7,8].…”