Species identification and mutation breeding of silicon-activating bacteria isolated from electrolytic manganese residue

• Published in: Environmental science and pollution research international 2021, Vol.28 (2), p.1491-1501
• Main Authors: Lv, Ying, Li, Jia, Chen, Zhenxing, Ye, Hengpeng, Du, Dongyun, Shao, Li, Ma, Mengyu
• Format: Article
• Language: English
• Subjects: Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Bacteria; Breeding; DNA, Bacterial; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Fermentation; Growth conditions; Leaching; Manganese; Mutagenesis; Mutation; Ochrobactrum; Particle size; pH effects; Phylogeny; Physical characteristics; Pulp; Research Article; Residues; RNA, Ribosomal, 16S - genetics; rRNA 16S; Shaking; Silicon; Waste Water Technology; Water Management; Water Pollution Control
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-020-10526-4

A strain of silicon-activating bacteria was isolated from electrolytic manganese residue (EMR); identified as a species of Ochrobactrum by integrated microscopic morphological characteristics, biochemical index determination, and clone analysis (i.e., results of 16S rRNA sequence); and temporarily named as Ochrobactrum sp. T-07 (T-07). The optimal growth conditions of the strain T-07 were obtained as follows: temperature of 30 °C, initial pH of 7.0, shaking speed of 180 rev. min −1 , and loading volume of 100 mL. In order to enhance its activation activity of silicon, T-07 went through the ultraviolet (UV) mutagenesis and nitrosoguanidine (NTG) mutagenesis breeding, and the mutant strain T-07-B with higher activity was obtained. Under the optimal fermentation condition (leaching time of 20 days, temperature of 30 °C, initial pH of 7, pulp concentration of 5%, shaking speed of 180 rev. min −1 , and particle diameter of EMR ≤ 180 μm), the available silicon content in the supernatant reached 98.8 mg L −1 , which was 2.4 times of the original strain T-07. Therefore, T-07 can be used as a good backup in developing biological silicon fertilizer for plants.