Extremophillic Microbes and

Shadow BiosphereAdhityo Wicaksono

Adaptations in extreme environments

How extremophiles live

Thermophiles Resists 45-120ºC heat

Membrane adaptations

Enzyme adaptations

Examples: Thermococcus sp, Sulfolobus sp

Cryophiles Resists down to -20ºC

Enzymatic adaptations

Anti-freeze protein

Examples: Arthrobacter sp and Psychrobacter sp

Barophiles Resists pressure up to 38-117 Mpa

Waxy cell membranes, relatively impermeable to nutrients

Sensitive to UV, lack DNA repair

Example: Halomonas sp

Acidophiles and Alkaliphiles

Resists below pH 2.0 (acidophiles) or beyond 8.5 (alkaliphiles)

Acidophiles: Develop very efficient proton pump mechanism in the membrane, acid-tolerant protein

Alkaliphiles: Cell wall contains acidic polymeres, proton accumulators

Examples: Acetorbacter, Thiobacillus (acidophiles), Natronomonas, Halorhodospira (alkaliphiles)

Radio resistant Resists radiation higher than 1000 Gy

Has efficient DNA repair mechanisms

Example: Deinoccoccus radiodurans, Thermococcus gammatolerans

Metal tolerant Resists high concentration of heavy metal

Adaptation by saving energy by less excretion

Examples: Ferroplasma sp, Cupriavidus metallidurans

Extremophiles and strange life

Extremophiles are important for: Understanding the adaptation of life in

extreme environment helpful in astrobiology and SETI program

Genetic accession for synthetic biology Understanding the possibility of life unlike

the common life on Earth which relies in different amount of nutrient

Shadow Biosphere and Second Genesis

Life on Earth, unlike the common one. Is there another genesis of life after our own?

Shadow biosphere There is possibility of life with biochemistry

process totally different from the common one on Earth exists hidden (Cleland and Copley, 2005)

Possibly microbial

GFA-J was once a candidate, but it refuted

Second Genesis Possibility of there was other origin of life

on Earth than the one in 4.5 billion years ago (Davies and Lineweaver, 2005)

It possible if the results are lives with completely different mechanism or processes from the common one

Is there alien among us?

Extensive study in extremophile microbiology is required, especially to search through the extreme and hidden place on Earth

The existance of strange life may broaden the concept of life, that can be use also to search in space

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