Glutathione synthesis is a characteristic capability of several bacterial strains along with other microorganisms, and is mainly regarded as an additional method in which protection from cellular damage due to various environmental and cellular factors are furthered. In this sense, the presence of glutathione may be considered to be of direct importance if not considerably vital in the survival of microorganisms which are capable of producing it, such as Escherichia coli (Chesney, Eaton, and Mahoney, 1996).
Hence, in the context of bacteriology, it is important to understand the prevalence, synthesis, and specific roles of glutathione. The presence and synthesis of glutathione is generally accepted as a form of protection of bacteria against cellular damage derived from reactive oxygen species and other considerably toxic substances (Copley and Dhillon, 2002). Although such a purpose is evidently advantageous, it is understandable that not all microorganisms are capable of producing glutathione.
In fact, glutathione synthesis is more often observed in gram negative bacteria than gram positive variants; in this sense, it is generally accepted that being capable of glutathione biosynthesis is rarely a characteristic of gram positive bacteria, as expected though there are exceptions as exemplified in Enterococcus and Streptococcus strains (Copley and Dhillon, 2002).
Giving focus to the process of glutathione biosynthesis, it is important to point out that even though the capability to synthesize glutathione is widely distributed not only among microorganisms but also in other forms of life, a general schematic or process is followed regarding its production. The main requirements for the formation of glutathione are glutamic acid and cysteine, which are then processed in the presence of glutamylcysteine synthetase; afterwards, the resulting combination is fused with glycine as directed by the glutathione synthetase enzyme (Copley and Dhillon, 2002).
Through this process, intracellular levels of glutathione are either maintained or increased. Which of course is a determinant factor not only for increased resistance towards harmful elements, but also as mentioned, the occurrence and continuous presence of glutathione in bacterial cells are necessary for survival upon the introduction of lethal compounds or free radicals. Due to its nature, the occurrence and effects of glutathione has gained interest in the field of bacteriology, hence its protective effects has been assessed through various methods in several studies.
In one study, the protective effects of glutathione was exhibited by increasing the survival of bacterial strains upon the introduction of chlorine oxidants, wherein E. coli strains which did not have glutathione were considerably lower in total population as compared to strains that were capable of producing it (Chesney, Eaton, and Mahoney, 1996). From another study, instead of assessing the protective capabilities of glutathione in bacteria that naturally produce glutathione, the protective effects was instead assessed through Staphylococcus aureus populations in the presence of glutamine.
The same trend in terms of the protective properties of glutathione as the inhibitory effects of glutamine was significantly decreased upon the introduction of glutathione (Grossowicz, 1947). From the studies discussed, it is evident that observing the beneficial effects and properties of glutathione was an area of interest for decades. However, even with the presence of numerous studies for such aim, it is a given fact that the the complete understanding of glutathione and its effects are still unachieved.
In essence, the process or mechanism of how glutathione blocks the effects of toxins and oxidative elements is still barely understood (Chesney, Eaton, and Mahoney, 1996). Therefore, in addition to testing other properties of glutathione, it is only but proper to assume that a possible direction for future studies regarding glutathione is towards completely mapping out the process in which it nullifies toxins and free radicals.