Natural Transformation of Gram-Positive Streptococcus Pneumoniae

Natural transformation is the growth curve of Gram-positive pathogen Streptococcus pneumoniae and its avirulent derivatives. This bacterium grows in three phases: pre-competent, competent and post-competent but uptake of exogenous DNA seems to be unimportant. In 1944 Avery et al of Rockefeller Institute (NY) delayed the progress of Gram-positive bacterial genetics by his ignorance about DNA bio-macromolecule, their TCA insoluble precipitate were just few nucleotides before the discovery of the double helix DNA of Watson and Crick (1953).