Role of extracellular polymeric substances (EPS) from <i>Pseudomonas putida</i> strain MnB1 in dissolution of natural rhodochrosite

Abstract

<p><strong>Abstract.</strong> Microbially mediated oxidation of Mn(II) to Mn oxides have been demonstrated in previous studies, however, the mechanisms of bacteria how to dissolve and oxidize using a solid Mn(II) origin are poorly understood. In this study, we examined the role of extracellular polymeric substances (EPS) from <i>P. putida</i> strain MnB1 in enhancing dissolution of natural rhodochrosite. The results showed that <i>P. putida</i> strain MnB1 cell can effectively dissolve and oxidize natural rhodochrosite to generate Mn oxides, and EPS were found to play an important role in increasing dissolution of natural rhodochrosite. Compared with EPS-free treatment, dissolution rate of natural rhodochrosite in the presence of bacterial EPS was significantly increased with decreasing initial pH and increasing EPS concentration, ionic strength and rhodochrosite dosage (<i>p</i> < 0.05). The fourier-transform infrared spectroscopy (FTIR) analysis implies that the functional groups like N-H, C=O and C-H in EPS contributed to the dissolution of natural rhodochrosite. This study is helpful for understanding the mechanisms of the formation of biogenic Mn oxides using a solid Mn(II) origin.</p>

Biologically-induced synthetic manganese carbonate precipitate (BISMCP) for potential applications in heavy metal removal

“…Therefore, these FT-IR results in MCP-4 to MCP-9 suggest that the functional groups of N–H in amine (protein), C O in amide I, and C–O in urethane (carbamic acid) could be due to the formation of BISMCP; it is comparable with the previous results of Enyedi et al [ 26 ]. Since all samples (MCP-4 to MCP-9) contained the CO 3 2− band and FT-IR bands matched to the previous study [ 3 , 26 , 87 , 79 ]; the functional groups in this study can be likewise identified as rhodochrosite mineral or MnCO 3 material [ 3 , 26 , 79 , 86 ].…”

“…The absorption bands at 1641.79 cm −1 in all samples MCP-4 to MCP-9 indeed confirm the existence of C O binding and strong stretching of CO 3 2− in Amide I [ [3] , [80] ]. Moreover, the weak adsorption band at 1081.34 cm −1 is related to symmetric C–O stretching in the urethane group [ 3 , 37 , 61 , 79 , 83 ]. In addition, the bands at 805.22 cm −1 are occupied by the phosphate group of the P–CH 3 binding and the strong stretching silicon group of the Si–O binding.…”

EFFECT OF pH, MINING TAILINGS CONCENTRATION AND CULTURE MEDIUM ON THE PERFORMANCE OF POLYMETALLIC BIOLEACHING AT FLASK LEVEL

“…Pseudomonas putida strain MnB1 EPS can enhance the dissolution of rhodochrosite in mediums with pH ranging from 5.0 to 8.0. This effect can be attributed to N-H, C=O and C-H groups found in EPS (Wang and Pan 2014).…”