Nanobubbles activate anaerobic growth and metabolism of Pseudomonas aeruginosa

Abstract

The effect of nanobubbles on anaerobic growth and metabolism of Pseudomonas aeruginosa was investigated. P. aeruginosa grew earlier in the culture medium containing nanobubbles and the bacterial cell concentration in that culture medium was increased a few times higher compared to the medium without nanobubbles under anaerobic condition. Both gas and protein, which are the metabolites of P. aeruginosa, were remarkably produced in the culture medium containing nanobubbles whereas those metabolites were little detected in the medium without nanobubbles, indicating nanobubbles activated anaerobic growth and metabolism of P. aeruginosa. The carbon dioxide nanobubbles came to be positively charged by adsorbing cations and delivered ferrous ions, one of the trace essential elements for bacterial growth, to the microbial cells, which activated the growth and metabolism of P. aeruginosa. The oxygen nanobubbles activated the activities of P. aeruginosa as an oxygen source.

Review on the Significant Interactions between Ultrafine Gas Bubbles and Biological Systems

“…On the other hand, the oxygen UBs increase the dissolved oxygen concentration in the medium and promote the development of P. aeruginosa cultures. 12 Likewise, Sobieszuk and colleagues discovered that oxygen UBs maximize a specific growth rate of Saccharomyces cerevisiae in both batch and semibatch cultures by providing the oxygen source for the yeast. 54 On the side of inhibition effects, Nghia et al hypothesized that UBs can improve water quality for aquaculture.…”

“…9−11 There has been evidence showing that the exposure of some microorganisms, specifically bacteria and fungi, to the UBcontaining environment, can significantly affect their growth, either inhibiting or enhancing, depending on the species as well as ultrafine bubbles' composition. 12,13 Ultimately, a better understanding of these microbes' nurturing environment could benefit not only microbiological and biotechnological studies but also give value to their roles in food and pharmaceutical industries along with bioremediation and waste decomposition. 14−19 Based on these growing number of applications of ultrafine bubbles in biological regimes, the goal of this paper is to provide a brief introduction of UBs and then summarize the recently reported studies on the interaction between UBs and biological cells of various types.…”

“…Besides plant cells, UBs also have a close relationship with bacterial cells. Since bacterial biofilms are highly problematic in technical and medical aspects (i.e., infrastructure fouling or water contamination), UBs can be used to generate the collision across the surfaces to detach these microorganism residues from those substrates back into the bulk solution. − There has been evidence showing that the exposure of some microorganisms, specifically bacteria and fungi, to the UB-containing environment, can significantly affect their growth, either inhibiting or enhancing, depending on the species as well as ultrafine bubbles’ composition. , Ultimately, a better understanding of these microbes’ nurturing environment could benefit not only microbiological and biotechnological studies but also give value to their roles in food and pharmaceutical industries along with bioremediation and waste decomposition. − …”

Preventing Static Biofilm Formation of Staphylococcus aureus on Different Types of Surfaces Using Microbubbles

“…Microbubbles (MBs) have been formerly shown to have some influences on the growth of both microbes and mammalian cells, − and thus are used widely in biofilm treatment and prevention, namely, by utilizing MBsin fluid shear to remove bacterial adhesion to glass surfaces, or employing MBs as antibiotic delivery systems as well as activating ultrasonic resonance in MBs to produce cavitation or form spore-forming jets . However, the aim of this study is to modify glass surfaces to be hydrophobic and then introduce MB as a temporary shielding layer to test antiadhesion against bacterial cells and antibiofilm formation.…”

Use of Nanobubbles to Improve Mass Transfer in Bioprocesses

“…These findings collectively underscore the potential of nanobubbles to improve mass transfer and enhance biogas production in anaerobic digestion, proving them to be a valuable addition to bioprocesses aimed at higher efficiency and sustainability in methane production and organic waste treatment. Nanobubbles also activate the anaerobic growth and metabolism of Pseudomonas aeruginosa by delivering essential elements and serving as a source of oxygen, thereby enhancing bacterial activity under anaerobic conditions [96]. For gas bioconversion, such as in eutrophic waters where algal blooms can cause methane emissions owing to a lack of or low oxygen concentration (anoxia/hypoxia) in the medium, the use of oxygen nanobubbles in lake sediments serves as a good supply, increasing the presence of methanotrophs and decreasing methane emissions, and serving as a substrate for subsequent biotransformation into CO 2 [97], demonstrating a possible mitigation strategy for poorly soluble gases in water.…”