Bioassay Approach to Prescribe Safe-limits of Exposure to Non Ionizing Radiation in Ecosystems

A biological assay that quantifies hazardous response in living matter to an electromagnetic stimulus, is evolved. Considering the various susceptible aspects of physio-anatomical systems constituting a living subject, a dominance criterion to determine an optimum all-or-none response limit of exposure to electromagnetic pollutions is established. Based on the statistics of proneness and susceptibility of discrete physio-anatomical parts of living systems (biotic components) to polluting radiations (abiotic environment), the stochastic nature of damage involved is considered to formulate a quantal index which specifies a “safe” intensity-level of electromagnetic radiation to which living systems can be exposed without encountering any deleterious effects. The locations of vulnerable parts which are affected by radiation are identified through random mosaic modeling of a test subject. Using this model, a susceptance priority sequence of biotic components is constructed. This sequence is then terminated at a point of weightage proportional to the diversity of victim population. The biotic species falling within this limit of truncation are subsequently studied to assay the tolerance (optimum lethal dose) of the test subject to the radiation in question. The possibility of simulating the entire ecological system under consideration by means of a microprocessor is suggested.     

A colicin-tolerant Escherichia coli mutant that confers hfl phenotype carries two mutations in the region coding for the C-terminal domain of FtsH (HflB)

An Escherichia coli mutant, ER437, which was originally isolated for colicin tolerance, was found to carry two amino acid changes in the C-terminal portion of FtsH (HflB). These mutations were demonstrated to reduce the ability of FtsH to degrade the phage lambda CII protein in vivo and in vitro, providing a rationalization for the mutant Hfl phenotype.