Prodigiosin–Iron-Oxide–Carbon Matrix for Efficient Antibiotic-Resistant Bacterial Disinfection of Contaminated Water

Abstract

Cheap and efficient bioactive materials capable of producing potable water are in high demand. We synthesized bioactive prodigiosin-conjugated iron-oxide-activated carbon composite ([Ac] F @Fe 3 O 4 −PG) for the effective removal of microbial contaminants without biofilm formation. The disinfection effect of [Ac] F @Fe 3 O 4 −PG was investigated against antibiotic-resistant Escherichia coli and Bacillus cereus. The reactive oxygen species, glutathione concentration, and intracellular leakages assay, zeta potential, atomic force microscopy, scanning electron microscopy, and fluorescence microscopy were performed to understand the mechanistic route of bacterial disinfection. Results demonstrate the bacterial cell membrane damage due to the surface charge neutralization by cationic [Ac] F @Fe 3 O 4 −PG, thereby affecting the transport system of the cells. The generation of reactive oxygen species further triggered programmed bacterial cell death with apoptosis-like changes in cellular morphology. We demonstrate that the [Ac] F @Fe 3 O 4 −PG matrix is reusable and has long-term antibacterial activity with efficient inhibition of biofilm formation. The study reveals that the [Ac] F @Fe 3 O 4 −PG could be a promising disinfectant for both Gram-negative and Gram-positive pathogens for effective environmental applications.

Ultrasensitive Controlled Release Aptasensor Using Thymine–Hg2+–Thymine Mismatch as a Molecular Switch for Hg2+ Detection

“…W ith the continuous improvement of the industrial level and the continuous utilization of pure water resources, the detection of water pollution by heavy metals has become an increasingly concerning global issue. 1,2 As a kind of a heavy metal pollutant, mercury ions (Hg 2+ ) have a great threat to living things especially to human beings. Even small amounts of Hg 2+ in water can cause irreversible damage to the human body, including headaches, low-grade fevers, adrenaline surges, sleep disorders, etc.…”

The Role of New Inorganic Materials in Composite Membranes for Water Disinfection

“…With the aim of producing drinking water, Arivizhivendhan et al [12] developed a bioactive prodiprodigiosin-conjugated iron-oxide-activated carbon composite ((Ac)F@Fe3O4−PG) for the efficient removal of biological contaminants, especially for the disinfection towards E. coli and Bacillus Jiang et al [51] performed the in-situ photocatalytic synthesis of Ag nanoparticles by crumpled GO membranes for filtration and disinfection. These nanocomposite membranes exhibited around 3 log inactivation for both Escherichia coli and Bacillus subtilis, demonstrating an improved antimicrobial activity that other composite membranes (e.g., GO−TiO 2 nanocomposites).…”

“…With the aim of producing drinking water, Arivizhivendhan et al [12] developed a bioactive prodiprodigiosin-conjugated iron-oxide-activated carbon composite ((Ac)F@Fe 3 O 4 −PG) for the efficient removal of biological contaminants, especially for the disinfection towards E. coli and Bacillus subtilis. Indeed, the composite provoked a cell membrane damage related to the surface charge neutralization by cationic (Ac)F@Fe 3 O 4 −PG, which affected the transport systems of the bacteria.…”

“…Therefore, water treatment and disinfection have been one of the alternatives in satisfying such scarcity of water [10,11]. According to a World Health Organization (WHO) report, it has been documented that around 1.2 billion people in the world depend directly on treated water for consumption [12,13]. When dealing with water treatment and disinfection, the limitations of existing polymeric membranes have promoted the designing of new membrane concepts, e.g., composite membranes.…”

“…It is recommended to evaluate the reusability of new hybrid composites after testing their antibacterial activity and pollutant removal. There are few studies addressing the evaluation of the reuse of such materials [12,88]. In this way, the overall disinfection cost could be reduced.…”