The stalk of Bacillus lunaticus can act as an antenna to expand the ability to absorb organic phosphoric acid from the environment.The introduced nutrients diffuse to the main body of the cell, where they are rapidly absorbed through the metabolic process.Researchers usefluorescence microscopeTo observe the position of organic phosphoric acid entering into the cells of Bacillus lunaticus.And othersGram negative bacteriaSimilarly, Bacillus crescentii also has two layers of membrane, in which there is peripheral cytoplasm.Experiments prove that organic phosphoric acid cancell surface(including handle) access.Once passing through the outer membrane, the organic phosphoric acid is converted into inorganic phosphoric acid and diffuses from the stalk to the peripheral cytoplasm.When phosphoric acid reaches the periplasm of the cell body, it passes through the intima and enters the cytoplasm.
This stalk can significantly increase the contact between cells and the environment without increasing the cell volume and surface area.Using mathematical models, the researchers confirmed that the nutrient absorption method using this antenna is far more effective than other forms.The model also speculates that bacteria absorb nutrients from their mitigation through diffusion.
Genome sequencing
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American scientists complete genome sequencing of Bacillus lunaticus
William C., Rockville Genome Research Institute (TIGR), MarylandThe international research team led by Nierman completed the sequencing of Bacillus lunaticus.The paper was published in the Journal of the National Academy of Sciences (PNAS).
Bacillus lunaticus is a non-toxic single cell organism. It lives in water and has many genes in common with pathogens.This bacterium lives in a nutrient poor environment and has a ring chromosome containing 3700 genes.A single bacilli cell can divide into two different types of cells, motile cells and petiolate cells.Therefore, its genome sequence is important for researchEvolutionary biologySome aspects of asymmetric cell division, such as the mechanism, are useful.Bacillus lunaticus is a simple and highly operable single cell model system for studyingcell differentiationAsymmetric division and their coordination with the process of cell cycle.There are less than 4000 genes in the bacteria of Staphylococcus. "
The researchers combined Bacillus lunaticus with other sequencing organisms such asEscherichia coliandXylella fastidiosa A comparison was made.Comparative analysis may reveal infectious pathogens such asTyphusSymptoms of typhus and other pathogens, some clues about the pathogenicity.Typhus and other pathogens have adapted toHuman cellsBut many genes needed for independent survival have been lost.
The researchers wrote that the total comparison between the genome of Stenobacter lunata and the genome of typhus and other pathogens "may eventually help us to identify the 'core' cell cycle genes required for correct cell cycle progression in Stenobacter lunata and the 'peripheral' genes that play a role in regulating cell cycle but are not necessary for the overall viability." Pathogens such as typhusRickettsia proctorThe genome was sequenced by a team from Uppsala University in Sweden in 1998.
The known genes that are critical to cell cycle in the genome of Bacillus crescentii, such as ctrA, parAB and recA, are found inTyphusThe genome of the pathogen Rickettsia proboschii has their similarities.However, the researchers determined that other Steptococcus genes, such as those encoding flagella, have no similarity in the genome of typhus and other pathogens.
An analysis of the genome of Stenococcus revealed its striking similarity to soil microorganisms.Even more surprising to researchers is the existence of genes encoding enzymes for decomposing plant polysaccharides, such as cellulose, lignin and gum, as well as transportation systems for transporting the generated sugar. Plants are actually the source of heat for Staphylococcus bacteria.
