Preliminary Study On The Mechanism Of Interaction Between Marine Microorganisms And Ferromanganese Nodules(Crusts)

In order to understand the role of marine microorganisms in the formation of ferromanganese nodules(crusts),deepen the understanding of the relationship between microorganisms and ferromanganese nodules(crusts),further enrich the study of microbial-mineral interaction and biomineralization process of ferromanganese nodules(crusts),and restore the formation process of oceanic ferromanganese nodules(crusts).The interaction between marine microorganisms and oceanic ferromanganese nodules(crusts)has been studied,and the interaction mechanism has been discussed by studying the effects of microbial action on elements migration and minerals composition of ferromanganese nodules(crusts).Marine microorganisms and oceanic ferromanganese nodules(crusts)are material for the interaction experiments.The marine microorganisms are Marinibacillus campisalis,Sulfitobacter and Sporosarcina.The effects of microorganisms on elements migration of ferromanganese nodules(crusts)were analyzed by X-ray fluorescence(XRF),inductively coupled plasma optical emission spectrometry(ICP-OES)and inductively coupled plasma mass spectrometry(ICP-MS).The effects of microorganisms on minerals composition of ferromanganese nodules(crusts)were analyzed by transmission electron microscopy(TEM),scanning electron microscopy(SEM),energy dispersive spectrometer(EDS)and X-ray diffraction(XRD).The results show that the main minerals of ferromanganese nodules(crusts)are kaolinite and plagioclase,which mainly distribute in the core,and a small amount of quartz,cristobalite,siderite,hematite and other iron minerals.The minerals content in crust is low,mainly containing ferromanganese minerals,enriching a large number of Fe,Mn,Ti,Co,Ni,Cu and other metal elements.Microorganisms can promote the dissolution and release of major metal elements in ferromanganese nodules(crusts),and also have adsorption and fixation effects on these elements.Marinibacillus campisalishas has strong dissolution and release effects on Fe,Mn,Co,Ni and Cu,and has strong adsorption effects on Fe,Mn,Co and Ni;Sulfitobacter has strong dissolution and release effects on Mn and Co,and has strong adsorption effects on Ni.Sporosarcina has strong dissolution and release of Fe,Mn,Co and Cu,and strong adsorption of Fe,Mn,Co and Ni.Through the adsorption of microorganisms,new minerals can be formed on the surface of bacteria.Under the interaction of microorganisms,the contents of plagioclase,siderite,hematite and goethite in ferromanganese nodules(crusts)increased in varying degrees.The mechanism of interaction between marine microorganisms and oceanic ferromanganese nodules(crusts)is mainly as follows: microorganisms can destroy and dissolve ferromanganese nodules(crusts)through the action of enzymes,metabolites or various secretions,and then release the main structural elements of the crust,such as Fe,Mn,Co,Ni and Cu,to produce various metal ions;at the same time,due to the unique characteristics of microorganisms,these metal ions in the solution can be adsorbed to the surface of the bacteria efficiently.As time goes on,new minerals,such as various ferromanganese minerals,can be formed.It is inferred that marine microorganisms can promote the enrichment of metal elements in seawater,thus promote the formation of ferromanganese nodules(crusts).