Criticsal analysis of claims of radiosynthesis by fungi

Abstract

'Radiosynthesis' had been described as the capture and metabolic use of energy from ionizing radiation. Past literature (Dadachova, E., Bryan, R. A., Huang, X., Moadel, T., Schweitzer, A. D., Aisen, P., Nosanchuk, J. D., Casadevall, A. (2007). PloS one, 2(5): e457, and papers and patent following) has purportedly demonstrated this in fungi, wherein increased fungal growth was seen upon treatment with low-dose ionizing radiation. Melanin was proposed as the agent of energy capture and transduction. Examination of the previous work reveals a number of issues that call into question both radiosynthesis and a mechanism involving melanin. Notably, the energy deposited in their irradiated systems was too low to show the amount of growth seen, and the carbon sources provided in the media were sufficient to support the observed growth and proliferation. Further, the results often fail to show what they are claimed to show, or are misinterpreted. Finally, indirect evidence provided does not support either radiosynthesis or that the mechanism for the observed growth requires melanin. This thesis re-evaluates past work, and concludes that radiosynthesis has not been demonstrated. This thesis also proposes an alternate hypothesis: misinterpretation of the effects of radiation as though from a different stimulus, resulting in an expressional shift appropriate for that stimulus or a more generalized response. Finally, this thesis proposes that a micro-scale stochastic view may be useful for future research in examining the responses of fungi and singlecelled organisms in low-dose ionizing radiation.