Spectra of the formaldehyde-induced ultraweak luminescence from yeast cells

Relationship between delayed luminescence emission and mitochondrial status in Saccharomyces cerevisiae

Delayed luminescence (DL) is gradually used in various detection of biological systems as a rapid detection technique, however, its biological mechanism was still not clear. In this study, a new model of DL detection system for liquid biological samples is established to investigate the DL emission of Saccharomyces cerevisiae cells cultured in different glucose concentrations. We analyzed the relationship between the DL emission and cell growth, cell vitality, mitochondrial morphology, mitochondrial DNA (mtDNA) copy number, adenosine triphosphate (ATP), oxygen consumption rate (OCR), as well as mitochondria membrane potential (MMP) in S. cerevisiae cells cultured with 0.01, 0.05, 0.15, 3, 10 and 20 g/L glucose respectively. It was found that the DL emission had strong correlation with mitochondrial morphology, OCR, and MMP. The results suggested that DL is an indicator of mitochondria status under different glucose supply conditions, and may be an effective method to detect mitochondrial metabolism related disorders.

When microbial conversations get physical

It is widely accepted that microorganisms are social beings. Whereas communication via chemical signals (e.g. quorum sensing) has been the focus of most investigations, the use of physical signals for microbial cell-cell communication has received only limited attention. In this Opinion article, I postulate that physical modes of microbial communication could be widespread in nature. This is based on experimental evidence on the microbial emission and response to three physical signals: sound waves, electromagnetic radiation and electric currents. These signals propagate rapidly, and even at very low intensities, they provide useful mechanisms when a rapid response is required. I also make some suggestions for promising future research avenues that could provide novel and unsuspected insights into the physical nature of microbial signaling networks.

Photon Emission from Perturbed and Dying Organisms: Biomedical Perspectives

Living systems spontaneously emit ultraweak light (ultraweak photon emission, UPE) during the process of metabolic reactions associated with the normal physiological state. Stress factors and pathological states change parameters of that emission, such as intensity, yield, temporal, statistical and spectral characteristics. Thus, properties of UPE are inherently associated with and derived from biochemical and biophysical excitation processes. UPE can be considered as a holistic expression of the perturbation of the physiological state of the bio-system and may carry information on the bioenergetics, kinetics and character of biochemical and physiological processes, functioning of the regulatory feedback systems and the degree of perturbation by internal and external factors. This article presents an overview of the fundamentals of UPE and its relation to physiological processes.

Activity-dependent neural tissue oxidation emits intrinsic ultraweak photons

Living organisms have been known to spontaneously emit ultraweak photons in vivo and in vitro. Origin of the photon emission remains unclear, especially in the nervous system. The spontaneous ultraweak photon emission was detected here from cultured rat cerebellar granule neurons using a photomultiplier tube which was highly sensitive to visible light. The photon emission was facilitated by the membrane depolarization of neurons by a high concentration of K+ and was attenuated by application of tetrodotoxin or removal of extracellular Ca2+, indicating the photon emission depending on the neuronal activity and likely on the cellular metabolism. Furthermore, almost all the photon emission was arrested by 2,4-dinitrophenylhydrazine, indicating that the photon emission would be derived from oxidized molecules. Detection of the spontaneous ultraweak photon emission will realize noninvasive and real-time monitoring of the redox state of neural tissue corresponding to the neuronal activity and metabolism.