Transfer of manganese and ferro ions by manganese bacteria

The experimental results of the redox of manganese and ferro ions by manganese bacteria are described. Under the aerobic conditions, the manganese bacteria can oxidate Mn2+ into Mn4+. In the course of the manganese bacteria multiplication, the continual increaes of environmental pH is advantageous to the oxidation of manganese and the rise of environmental temperature helps the bacteria to speed the oxidation of manganese ions. The manganese bacteria can fastly oxidate Fe2+ in the culture containing low vaient ferro into Fe3+, its oxidation speed being faster than that of manganese oxide. Under the anaerobic conditions,the manganese bacteria can reduce high valent ferro in solutioninto low valent ferro and distinctly lower the environmental pH.

Abundance of total bacteria, ATP and manganese-oxidating bacteria in the sediments and manganese nodules of the Northwestern Pacific Ocean

In the seawater and sediments of the ocean, there exist huge quantities of bacteria whose living activities cause various chemical reaction processes. It is demonstrated that microorganisms play a fundamental role on chemical changes of the sediments and diageneses. Over the last twenty years, great interest has been increased about the role of deep-sea bacteria in the ferromanganese sedimentary process. Much work has been done on this aspect in the Atlantic Ocean, the Baltic Sea and the Pacific O-

Antibiotic contamination control mediated by manganese oxidizing bacteria in a lab-scale biofilter

Antibiotic micro-pollution is usually found at the ng/L–level in drinking water sources or discharge water of wastewater treatment plants. In this study, a novel approach mediated by manganese oxidizing bacteria(Mn OB) in a biofilter was developed to control the pollution. The results indicated that the biogenic manganese oxide(Mn O x) produced during the oxidation of the feeding manganese ions could coat the surface of the filtering sand effecting the simultaneous removal of antibiotics. It was found that the removal of antibiotics is insured as long as the feeding manganese was well removed and was not influenced by the hydraulic loading. The growth rate of the Mn OB group revealed that the antibiotic concentration at 50 and 100 ng/L promoted their activity, but it was inhibited at 500 and 1000 ng/L. The structure of the bacterial community was stable in the presence of antibiotics(50 ng/L), but their extracellular processes changed. The removal performance of the feeding manganese seemed to relate to the extracellular processes of the dominant bacterial genus. Moreover, the freshly formed Mn O x was a buserite-like material that was rich in Mn(III) and Mn(IV)(94.1%), favoring the degradation. The biofilter did not generate additional antibiotic resistant genes in the presence of antibiotics.

Prevalence of Bacillus sp.among the biofilm forming community on Ti surface in marine environment

Prevalence of bacterial species involved in biomineralization of manganese on titanium （Ti） surfaces in marine environment was revealed in this research work. This study involves one year sea water exposure of Ti and their periodical biofilm characterization was carried out to quantify the manganese oxidizing bacterial （MOB） presence in the biofilm formed on titanium surfaces. The total viable count study of Ti coupons exposed to sea water for one year resulted in 60% of the MOB in overall biofilm population. The biochemical characterization of MOB isolates were performed for the genus level identifcation of the seven bacterial isolates. Further, the seven strains were subjected to 16S rRNA gene sequencing. Evolutionary analysis was performed using MEGA 7 to obtain closely related strains within the groups. The manganese oxidizing ability of the bacterial isolates were determined with Leucoberbelin Blue Assay （LBB） and Atomic Absorption Spectroscopy studies （hAS）. The results show that among the isolated marine MOB species, Bacillus sp. and Leptothrix sp. have the maximum Mn oxidizing property. The microtitre plate assay was performed to determine the biofilm forming ability of the isolated marine MOB species. All the results have confirmed the prevalence of Bacillus sp. among the biofilm colonizers on Ti surfaces when exposed in sea water.