Response of an atrazine-degrading bacterium strain Acinetobacter sp. DNS32 to inorganic nitrogen source

Abstract:

[Objective] The diversity of fungi in soils and sediments of Erdos paleo salt lake in Inner Mongolia and the strains containing functional enzymes were identified. [Methods] Three isolation media containing designed concentrations of NaCl were used to separate and cultivate fungi. Based on analysis of morphology and ITS sequences, the phylogenetic of tested bacterial strains was performed. The enzyme activity in the salt lake fungi was qualitatively determined using 6 kinds of screened media. [Results] Total 2 121 strains of fungi were separated from the salt lake. These strains were divided into 45 morphospecies and 27 generas based on the analysis of morphology and ITS sequences. The dominant genus was Aspergillus. Twenty-two of 45 morphospecies produced enzyme, six produced protease(s), six produced cellulase(s), two produced compound enzyme, one produced amylase enzymes and one produced lipase. Meanwhile, four morphospecies could simultaneously produce three. [Conclusion] The fungi from the Erdos salt lake in Inner Mongolia are rich in diversity and can produce various enzymes. This study provides a basis for the further characterization and utilization of halophilic microbes.

Key words:Atrazine, Acinetobacter sp. DNS32, Inorganic nitrogen source, Degradation ability, Gene expression