A bioflocculant from Corynebacterium glutamicum and its application in acid mine wastewater treatment

Abstract

Although many microorganisms have been found to produce bioflocculants, and bioflocculants have been considered as attractive alternatives to chemical flocculants in wastewater treatment, there are few reports on bioflocculants from the safe strain C. glutamicum, and the application of bioflocculants in acid wastewater treatment is also rare attributed to the high content of metal ions and high acidity of the water. In this study, a novel bioflocculant produced by Corynebacterium glutamicum Cg1-P30 was investigated. An optimal production of this bioflocculant with a yield of 0.52 g/L was achieved by Box–Behnken design, using 12.20 g/L glucose, 4.00 g/L corn steep liquor and 3.60 g/L urea as carbon and nitrogen source. The structural characterization revealed that the bioflocculant was mainly composed of 37.50% neutral sugar, 10.03% uronic acid, 6.32% aminosugar and 16.51% protein. Carboxyl, amine and hydroxyl groups were the functional groups in flocculation. The biofocculant was thermally stable and dependent on metal ions and acidic pH, showing a good flocculating activity of 91.92% at the dosage of 25 mg/L by aid of 1.0 mM Fe3+ at pH 2.0. Due to these unique properties, the bioflocculant could efficiently remove metal ions such as Fe, Al, Zn, and Pb from the real acid mine wastewater sample without pH adjustment, and meanwhile made the acid mine wastewater solution become clear with an increased neutral pH. These findings suggested the great potential application of the non-toxic bioflocculant from C. glutamicum Cg1-P30 in acid mine wastewater treatment.

Isolation, screening and molecular identification of bioflocculants–producing bacteria

“…Where, as producers of bioflocculants, the bacterial isolates with the highest positive screening test results were chosen. Metal ions are also believed to affect the flocculating activity of bioflocculants, this is because the addition of cations decreases the negative ions in kaolin particles and biopolymer flocculants (Liu et al 2023).…”

Bioflocculant Producing Bacillus megaterium from Poultry Slaughterhouse Wastewater: Elucidation of Flocculation Efficacy and Mechanism

“…According to [12] (2023), the manufacturing cost has been identified as a significant obstacle to the widespread implementation of bioflocculants in industrial settings.…”

“…According to [12] (2023), the manufacturing cost has been identified as a significant obstacle to the widespread implementation of bioflocculants in industrial settings. Consequently, there is a pressing need to explore strategies to mitigate these costs.…”

“…According to the green chemistry analogy, chemical flocculants are unfavorable because they are environmentally hazardous; therefore, the need for safer eco-friendly alternatives does not need to be emphasized but is a necessity; consequently, bioflocculants are gaining popularity. Despite this, bioflocculants are deemed not ideal for use on an industrial scale because of their high production costs, low yields, and poor flocculation efficiency [12]. Therefore, it is of the utmost importance to screen for novel bioflocculantproducing microorganisms that produce bioflocculants with high flocculating capabilities and higher yields and understand how they function, including their optimal conditions, so that they can be applied on an industrial scale.…”

Bioinspired Flexible Hydrogelation with Programmable Properties for Tactile Sensing

“…The emergence of bio-machine interface and biomedical engineering technologies, such as epidermal electrodes, multimodal physiological signals monitoring, biosensing, neuronal electrical recording and stimulation, repair of sensorimotor functions, virtual reality, augmented reality, etc., demands tactile sensing platforms with high-efficiency haptic sensing capabilities along with biocompatibility, to detect the physiological functions of human skin and empower industrial robotic and prosthetic technologies to sense tactile information. [1][2][3][4][5][6] In this regard, hydrogels show significant advantages due to their capability of combining solid-like viscoelasticity, liquid-like permeability, and swelling properties, as well as the ability to provide an in vivo mimicking microenvironment, [7][8][9] thus comprising promising substrate alternatives for tactile sensing applications. [10,11] Nevertheless, the state-of-the-art polymeric hydrogel-based tactile sensors and E-skin technologies suffer from irreversible covalent conjugation, unregulated physicochemical properties, and limited biocompatibility, thus Scheme 1.…”