Quorum Sensing as a Trigger That Improves Characteristics of Microbial Biocatalysts

Abstract

Quorum sensing (QS) of various microorganisms (bacteria, fungi, microalgae) today attracts the attention of researchers mainly from the point of view of clarifying the biochemical basics of this general biological phenomenon, establishing chemical compounds that regulate it, and studying the mechanisms of its realization. Such information is primarily aimed at its use in solving environmental problems and the development of effective antimicrobial agents. This review is oriented on other aspects of the application of such knowledge; in particular, it discusses the role of QS in the elaboration of various prospective biocatalytic systems for different biotechnological processes carried out under aerobic and anaerobic conditions (synthesis of enzymes, polysaccharides, organic acids, etc.). Particular attention is paid to the biotechnological aspects of QS application and the use of biocatalysts, which have a heterogeneous microbial composition. The priorities of how to trigger a quorum response in immobilized cells to maintain their long-term productive and stable metabolic functioning are also discussed. There are several approaches that can be realized: increase in cell concentration, introduction of inductors for synthesis of QS-molecules, addition of QS-molecules, and provoking competition between the participants of heterogeneous biocatalysts, etc.).

Using Fungi in Artificial Microbial Consortia to Solve Bioremediation Problems

“…In case of competition for a substrate, consortium members can release metabolites into the environment that negatively affect other consortium members (organic acids, mycotoxins, antibiotics, antimicrobial peptides, enzymes) [ 122 , 123 , 124 , 125 , 126 ]. As a rule, these processes are regulated by cell Quorum Sensing (QS) [ 16 ]. QS molecules and the conditions of their formation can be used to control or regulate the expression of certain genes, control the composition of consortia, and ensure intercellular connections between certain consortium members [ 34 , 120 , 127 ].…”

“…At the same time, the extremely interesting properties possessed by those variants of consortia are created by cells of these prokaryotic microorganisms (i.e., bacteria and archaea) and eukaryotic microorganisms (in particular, filamentous fungi and yeast), which are able to coexist and catalyze biodegradation and bioremediation processes [ 12 ]. Such an artificial consortia, involving cells of microorganisms from different kingdoms [ 13 , 14 , 15 , 16 , 17 ], are especially attractive from a scientific and practical point of view, due to the possibility of expanding its total metabolic potential. At the same time, all the advantages that the artificial consortia of microorganisms themselves have over natural analogues, which have mainly been described in the literature on bacterial cells, are preserved: easy-to-use reproducibility of the compositions of the consortia; the possibility of introducing maximum targeted metabolic activity into the consortia cells, which are improved, including through the genetic modification of cells; targeted variation of the ratios of cell concentrations in the consortium, to regulate the rates of associated biochemical processes catalyzed by cells; sustainable functioning of the created consortia, which are accompanied by increased degrees of conversion of the original substrates, including toxic compounds [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ].…”

“…Thus, the information that has been accumulated today indicates that the bioremediation of various environments, with the participation of fungal cultures as part of the used consortia, is implemented using biosorption, complexing and other physical and chemical processes, in addition to extracellular catalytic and intracellular metabolic reactions. Moreover, compared with the design of bacterial artificial consortia, in order to solve similar issues of bioremediation in synthetically formed biosystems containing fungal and yeast cultures, it is necessary to not only take into account the compatibility and antagonism of different microorganisms, but to also consider the features of cross-kingdom reactions [ 16 , 20 ]. In particular, chemically similar quorum-sensing signaling molecules such as lactone-containing molecules can appear in the microenvironment of the cells of different microorganisms (bacteria and fungi) which can, in turn, contribute to the formation of a synergistic effect from their participation in consortia.…”

“…At the same time, the extremely interesting properties possessed by those variants of consortia are created by cells of these prokaryotic microorganisms (i.e., bacteria and archaea) and eukaryotic microorganisms (in particular, filamentous fungi and yeast), which are able to coexist and catalyze biodegradation and bioremediation processes [12]. Such an artificial consortia, involving cells of microorganisms from different kingdoms [13][14][15][16][17], are especially attractive from a scientific and practical point of view, due to the possibility of expanding its total metabolic potential. At the same time, all the advantages that the artificial consortia of microorganisms themselves have over natural analogues, which have mainly been described in the literature on bacterial cells, are preserved:…”

Metal Nanomaterials and Hydrolytic Enzyme-Based Formulations for Improved Antifungal Activity

“…To date, a significant amount of information has been accumulated about QS in the cells of various fungi and molecules that are produced by the fungi themselves in response to an increase in their concentration per unit volume. These QSMs are produced in order to trigger the processes of fungal cell transition to a state of stable intercellular communication, synchronization of the functions of multicellular populations, and biochemical changes in the cells themselves [133][134][135][136][137]. The ability of individual enzymes to catalyze the hydrolysis of fungal QSMs allows them to be attributed to the so-called Quorum Quenching enzymes (QQE).…”