BIOCHEMISTRY OF GEO MICROBES BIOMINERALIZATION Submitted to: Submitted by:Dr. S.K. Srivastva Suman 15MSCBC003 MSc Biochemistry 3rd semester

CONTENT Introduction Role of geomicrobes as geoactive agents Biomineralization Types of biomineralization Biologically induced mineralization Microbes involves in BIM Biologically controlled mineralization Method of BCM Microbes involves in BCM Process of magnetite in Magnetotactic bacteria Significance of Biomineralization

INTRODUCTION Microbes play geo active role in biosphere . All kind of microbes include prokaryotes and Eukaryotes

, their symbiotic association etc. contribute geological phenomena and many geological processes like metal and mineral transformation.

The ubiquity and importance of microbes in biosphere processes.

ROLE OF GEOMICROBES AS GEOACTIVE AGENTS

Key topics within the geomicrobiology frame work includes biogeochemical cycles of the elements, mineral formation, mineral deterioration(which can include such as subjects as bioweathering and processes leading to soil & sediment formation) and chemical transformation of metals, metalloids and radionuclides.

BIOMINERALIZATION Definition: A process by which living forms influences

the precipitation of mineral materials. The process creates heterogeneous accumulation

composites composed of biogenic and inorganic compounds.

Living forms produces carbonates phosphate oxalates silica iron or sulfur containing minerals.

Biomineralization occurs extracellular involves often crystalline, materials forming on the outer wall of the cell.

Intracellular biomineralization is mineral formation within the cell such as calcite formation for the group of the algae the Coccolithophorides.

TYPES OF BIOMINERALIZATION

Mineral synthesis can be categorized into two categories: Biologically Induced Mineralization Biologically Controlled Mineralization

BIOLOGICALLY INDUCED MINERALIZATION

Mineral forms by this process, generally nucleate & grow extracellulary as a result of metabolic activity.

Subsequent chemical reaction involving metabolic by products such as O2, HCO-3, etc.

In some the organisms secrete one or more metabolic products that react with ions or compounds in the environment resulting on the subsequent deposition of mineral particles.

MICROBES INVOLVES IN BIM No of microbes involves in biologically

Induced mineralization process . Some of microbes are: Mycorrhiza, Lichen,

Cynobacteria like Synechococcus spp., Bacteria like Leptospirillum spp. , Thiobacillus

ferroxidans, sulfur reducing bacteria etc. Archea like sulfolobus spp., Acidimicrobium

ferroxidans spp., acidianus spp., Metallosphaera spp., sulfurococcus yellowstonesis. etc.

EXAMPLES OF MINERAL BY BIM Calcium Carbonate: Carbonate are long lived locally abundant

sediments, promotes calcite/ Aragonite and Dolomite precipitates.o These precipitates occurs in, on or around the organic matter of the

cells that they produce.o These carbonate minerals presents on lake, sea floors etc. Chemical Reaction: Ca2+ + 2HCO3- ↔ CaCO3 + CO2 + H2O Microbial populations involved in this mineral formation are :

Cynobacteria, Algae such as green, brown, red algae and Chrysophytes such as Coccolithophores & few protozoa like Forminifera.

OTHER EXAMPLES OF MINERALS FORMED BY BIM

BIOLOGICALLY CONTROLLED MINERALIZATION

Microbes exerts considerable active control over all aspects of the nucleation and mineral growth stages.

A specific site within the cytoplasm or the cell wall is sealed off from the external environment creating geochemical condition independently.

2 common methods of space delineation can occur.1. Involve the development of intercellular space between

cells.2. Formation of intracellular deposition vesicles.

METHOD

Once the cellular compartment is formed

the cells sequestering specific ions of choice

transferring them to mineralization site , where conc. Increased until saturation achieved

Super saturation are then regulated by managing the rate at which mineral constituents are brought into the cell via specific transport enzymes.

CONTINUE

nucleation controlled by exposing organic ligands with distinct sterochemical and electrochemical properties

tailored to interact with the mineralizing ions.

MICROBES INVOLVE IN BCM

Many microbes involves in biologically controlled mineralization process

These are: Magnetotactic bacteria Diatoms Emiliania huxleyi etc.

EXAMPLE OF MINERAL BY BCM

Magnetite: Magnetite formation done by Magnetotactic

Bacteria, which is microaerophilic, posses bidirectional motility and contain membrane bounded a no of intracellular, linear arranged magnetosomes , house mineral grains.

The actual crystallization of magnetite then involves the reaction of the ferric hydroxide with more Fe2+:

Fe2+ + 2OH− + 2Fe(OH)3→Fe3O4 + 4H2O

IMAGE OF MAGNETOTACTIC BACTERIA

PROCESS OF MAGNETITE IN MAGNETOTACTIC BACTERIA

CONTINUE

This is accomplished by cell synthesis of specific receptor proteins.

Firstly they recognized to Fe(III)- siderophores then to with the aid of other transport proteins.

These proteins guide the coordinated Fe(III) to plasma. Specific magnetosome associated proteins play a role in

vesicle formation prior to biomineralization.

SIGNIFICANCES OF BIOMINERALIZATION

Great significance in scientific and commercial application

Metal sorption, precipitate can be important and useful in metal and radionuclide removal during bioremediation metal radionuclide contaminate water .

Efficiently removal of Fe and Mn ions from water in waste water treatment plants.

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