Determination of bioremediation properties of soil-borne Bacillus sp. 5O5Y11 and its effect on the development of Zea mays in the presence of copper

Today, industrial activities lead to the accumulation of heavy metals in the soil, water, and air due to mine deposits and operations, fertilizers, and drugs used in agriculture, and urban wastes. Using microorganism bioremediation of metals is an important technique in solving these problems. Herein, a rhizoid bacterium isolated from orchids that grow in Ovit plateau was defined as Bacillus sp. 5O5Y11 by conventional and molecular methods and the bioremediation properties of strain were investigated. It was capable of growth at high salt (10-15%) concentration, wide temperature (10-45 °C) and pH range (pH 4.5-8.0), and was observed to have strong lecithinase, gelatinase activity, and nitrate reduction. When the plant growth-promoting properties of this strain were examined, strong siderophore and ammonium production were observed in in vitro conditions. Bacillus sp. 5O5Y11 was found to have high tolerance to a group of heavy metals [iron (Fe), copper (Cu), lead (Pb), silver (Ag), zinc (Zn)]. Minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) values of copper metal on Bacillus sp. 5O5Y11 were determined as 12.5 mM and 50 mM, respectively. The effectiveness of this bacterium on the germination and growth of maize plant in the presence and absence of copper were investigated. These results suggest that Bacillus sp. 5O5Y11 is a microorganism, which has potential in metal bioremediation and plant growth promotion.

A heavy metal tolerant novel bacterium, Bacillus malikii sp. nov., isolated from tannery effluent wastewater

The taxonomic position of a Gram-stain positive and heavy metal tolerant bacterium, designated strain NCCP-662(T), was investigated by polyphasic characterisation. Cells of strain NCCP-662(T) were observed to be rod to filamentous shaped, motile and strictly aerobic, and to grow at 10-50 °C (optimum 30-37 °C) and at pH range of 6-10 (optimum pH 7-8). The strain was found to be able to tolerate 0-12 % NaCl (w/v) and heavy metals (Cr 1200 ppm, Pb 1800 ppm and Cu 1200 ppm) in tryptic soya agar medium. The phylogenetic analysis based on the 16S rRNA gene sequence of strain NCCP-662(T) showed that it belongs to the genus Bacillus and showed high sequence similarity (98.2 and 98.0 %, respectively) with the type strains of Bacillus niabensis 4T19(T) and Bacillus halosaccharovorans E33(T). The chemotaxonomic data showed that the major quinone is MK-7; the predominant cellular fatty acids are anteiso-C15 :0, iso-C14:0, iso-C16:0 and C16:0 and iso-C15:0; the major polar lipids are diphosphatidylglycerol, phosphatidylglycerol along with several unidentified glycolipids, phospholipids and polar lipids. The DNA G+C content was determined to be 36.9 mol%. These data also support the affiliation of strain NCCP-662(T) with the genus Bacillus. The level of DNA-DNA relatedness between strain NCCP-662(T) and B. niabensis JCM 16399(T) was 20.5 ± 0.5 %. On the basis of physiological and biochemical characteristics, phylogenetic analyses and DNA-DNA hybridization data, strain NCCP-662(T) can be clearly differentiated from the validly named Bacillus species and thus represents a new species, for which the name Bacillus malikii sp. nov. is proposed with the type strain NCCP-662(T) (= LMG 28369(T) = DSM 29005(T) = JCM 30192(T)).