January 2020 – World of Science

Idea behind: A new living substance can transform from wet sand mixture into soild bricks & even help to reproduce copies of itself

Now, let us have basic knowledge about PHOTOSYNTHETIC BACTERIA

Photosynthetic bacteria are unique species of microorganisms which contian compound called bacteriochlorophyll,which allows them to photosynthesize . Photosynthetic bacteria are anoxygenic phototrops(are gammaproteobacteria & alphaproteobacteria that capture energy from light and stored as ATP) distributed widely in nature in the fields,lakes,ponds,rivers &oceans. These bacteria have capability to utilize sulfate, thiosulphate & hydrogen donors as well as various organic compounds.These are also able to fix carbon dioxide & molecular nitrogen under anaerobic conditions .These have also developed an extraordinary metabolic versatility.

Background : Researchers from university of Colorado, boulder, used a type of photosynthetic bacteria that absorbs carbon dioxide, sunlight , nutrients & produces calcium carbonate -rigid compound found in rocks , pearls & seashells .

Let’s have view on the formation of calcium carbonate minerals by photosynthetic bacteria

Biomineralization is naturally occuring process in living organisms. In this review, we will discuss microbially induced calcium carbonate precipitation. This biomineralization is chemical alteration of environment by microbial activity that results in precipitation of minerals. In nature, this widespread phenomenon leads to formation of more than 60 biological minerals that exists as extra-cellularly inorganic crystals or extracellular mineralization syntheses (eg carbbonate precipitation) which is a rigid compound found in rocks, pearls & seashells

How Living Solidbricks Created ?

Researchers grew these bacteria in a warm mixture of salt water & combined it with sand & gelatin. The mixture was poured into mould & as it cooled the gelatin set forming ‘Scaffold’ able to support further bacterial growth. The bacteria deposited as calcium carbonate throughout the scaffold, turning soft sludge into harder substance after about a day. The mixture looks green initially but color fades as it dries.

Benefits Of Ecofriendly Living Solidbricks

Material is potentially strong enough for use as bricks in construction.
Major benefit is that the whole process revolves around bacteria, they help build bricks & are kept alive so they are able to produce more bricks later on.
Material could be useful for construction in inhospitable environments like desert or even in space
It is also a low-carbon alternative to concrete that could be used to make buildings that absorbs greenhouse gases rather than releasing them, for the same reason living bricks are more ecofriendly

Ref: Research at MIT

What is Gene Editing?

Genome editing, or genome engineering, or gene editing, is a type of genetic engineering in which DNA is inserted, deleted, modified or replaced in the genome of a living organism.

Hand of scientist replacing DNA – genetic engineering and gene manipulation concept

Rather than directions going one way from DNA to RNA to proteins,latest study shows that RNA itself modulates how DNA is transcribed using Gene Editing

Genome editing is technology that give the ability to change organisms DNA or can be altered at particular locations in genome.CRISPR-CAS9 is a recent genome editing which has been developed.It is short clustered regularly interspaced short palindromic repeats & is associated with protein 9.

CRISPR -CAS9 System consist of two components

DNA cutting protein called CAS9.
RNA molecule known as GUIDE RNA (sg RNA) bound together,they form a complex,that can identify & cut specific sections of DNA

IDEA BEHIND THE CRISPR-CAS9

CRISPR-CAS9 was adapted from naturally genome editing system in bacteria.The bacteria capture snippets of DNA from invading viruses & use them to create DNA segments known as CRISPR arrays.The CRISPR arrays allow the bacteria to ”remember” the viruses.If viruses attack again,bacteria produces RNA segments from CRISPR arrays to traget the viruses DNA.The bacteria then uses CAS9 enzyme to cut particular part of DNA.

How Does CRISPR -CAS9 Works?

CRISPR -CAS9 work similarly,A small piece of RNA with short ‘Guide’sequence that attaches to target sequence of DNA in genome.RNA also binds to CAS9 enzyme .As in bacteria,the modified RNA is used to recognize the DNA sequence,CAS9 enzyme cuts the DNA at targeted location .Instead CAS9 other enzymes like(cpf 1) can also be used.Once DNA is cut,uses the cells own DNA repair machinery to add or delete pieces of genetic material or to alter DNA by replacing an existing segment with customized DNA sequence.

Now let us have a clear idea by having a view on this below video.

Month: January 2020

Making up of living solidbricks using photosynthetic bacteria