Factors Influencing the Bioavailability of Organic Molecules to Bacterial Cells-A Mini-Review

Abstract

The bioavailability of organic compounds to bacterial cells is crucial for their vital activities. This includes both compounds that are desirable to the cells (e.g., sources of energy, carbon, nitrogen, and other nutrients) and undesirable compounds that are toxic to the cells. For this reason, bioavailability is an issue of great importance in many areas of human activity that are related to bacteria, e.g., biotechnological production, bioremediation of organic pollutants, and the use of antibiotics. This article proposes a classification of factors determining bioavailability, dividing them into factors at the physicochemical level (i.e., those related to the solubility of a chemical compound and its transport in aqueous solution) and factors at the microbiological level (i.e., those related to adsorption on the cell surface and those related to transport into the cell). Awareness of the importance of and the mechanisms governing each of the factors described allows their use to change bioavailability in the desired direction.

Keywords: availability; bacteria; membranes; organic chemicals; solubility.

Figure 1

Bioavailability of organic chemicals according to Ortega-Calvo et al. [13]. Adapted with permission from Ref. [13]. Copyright 2013, American Chemical Society.

Figure 2

Main areas of importance of organic chemicals’ bioavailability to bacteria cells.

Figure 3

Main strategies of increasing of bioavailability of organic compounds (grey circles) at the physicochemical level: (A) solubilisation; (B) transport in micelles; (C) transport on carriers.

Figure 4

Main strategies of increasing bioavailability of organic compounds (grey circles) at the microbiological level: (A) cell membrane modification, e.g., with surfactant; (B) organic compound adsorption on the cell surface; (C) chemotaxis towards chemicals.