Spectroscopic Techniques for Estimation of Physiological State of Blue-Green Algae after Weak External Action

Abstract

Nowadays cyanobacterial blooms in open reservoirs and estuaries became one of the most important ecological problem. The optimal way to solve this problem is to develop innovative methods for controlling the number of bloom-forming cyanobacteria based on weak external actions, which have no serious consequences for the entire ecological system. A novel efficient technique for in vivo estimation of cyanobacterial viability for online ecological monitoring of the results of weak external actions was elaborated by using a combination of different spectroscopic methods. It has been shown that the results obtained by means of conventional spectrophotometry and fluorimetry for cyanobacterial culture as a whole and the data obtained by fluorescent microscopic spectroscopy applied to a single cell are strictly related.

Studying Cyanobacteria by Means of Fluorescence Methods: A Review

“…Historically, since the 1960s, researches had noted that changes in physiological state of cyanobacterial cell, occurring when it is grew old or is treated with different external actions, manifest themselves as corresponding changes in the intrinsic selffluorescence spectrum [43]. Several studies have shown that changes in the pigment fluorescence are associated with the changes in the enzymatic activity of the cell and an increase in the permeability of the cell membrane, which can be used as an indicator of aging for cyanobacterial species [41,44]. Today, there is no doubt that the in vivo analysis of fluorescence characteristics of photosynthetic apparatus is a powerful tool for studying the impact of a wide variety of environmental factors on cyanobacteria [24,45].…”

“…The former gives underestimated results, and the latter, overestimated results. Thus, the analysis of the viability of living cyanobacterial cells should be carried out considering a set of fluorescence spectra with different excitation wavelength, to elucidate the impact of each photosynthetic pigment [41,44,49]. The examples of one-excitation-wavelength studies are also present in the literature [59,60].…”

“…The changes in spectral characteristics of living photosynthetic cells indicate changes in their physiological state and can be applied for the studies of the results of stress states and external actions. Light-, heat-, ultrasound-, and toxin-induced changes can be distinguished by means of confocal microscopic spectroscopy since all these external actions are stress factors affecting photosynthetic process [44].…”

“…However, while working with living cells, the caution must be taken. The studies of the photosynthetic cells require some additional specific skills and techniques to perform measurements and to carry out data processing [35,41,42,44]. The efficiency of photosynthesis and photosynthetic rate are highly dependent on irradiance.…”

Prospects of fluorescence methods application for monitoring of cyanobacterial cultures in biotechnology

“…Fluorescence methods for monitoring physiological state and biological diversity of cyanobacterial cultures are well-known and widely used [13][14][15]. In this work we try to emphasize methods of fluorescence spectroscopy most perspective for industrial and biotechnological applications.…”