Production and Characterization of a Bioflocculant from Pichia kudriavzevii MH545928.1 and Its Application in Wastewater Treatment

Abstract

A variety of flocculants have been used to aggregate colloidal substances. However, recently, owing to the adverse effects and high costs of conventional flocculants, natural flocculants such as microbial flocculants are gaining attention. The aim of the study was to produce and characterize a bioflocculant from Pichia kudriavzevii MH545928.1 and apply it in wastewater treatment. A mixture of butanol and chloroform (5:2 v/v) was used to extract the bioflocculant. Phenol–sulphuric acid, Bradford and Carbazole assays were utilized for the identification of carbohydrates, proteins and uronic acid, respectively. Scanning electron microscopy (SEM) and elemental detector were employed to determine the surface morphology and elemental compositions. The removal efficiencies were 73%, 49% and 47% for BOD, COD and P, respectively. The bioflocculant (2.836 g/L) obtained showed the presence of carbohydrates (69%), protein (11%) and uronic acid (16%). The bioflocculant displayed a cumulus-like structure and the elemental composition of C (16.92%), N (1.03%), O (43:76%), Na (0.18%), Mg (0.40%), Al (0.80%), P (14.44%), S (1.48%), Cl (0.31%), K (0.34%) and Ca (20.35). It showed the removal efficiencies of 43% (COD), 64% (BOD), 73% (P) and 50% (N) in coal mine wastewater. This bioflocculant is potentially viable to be used in wastewater treatment.

Isolation and Optimisation of Culture Conditions for a Marine Bioflocculant-Producing Bacterium and Application of Its Bioflocculant in Wastewater Treatment

“…Thereafter, the flocculating activity was evaluated as previously stated. The method of Tsilo et al [ 40 ] was used to determine the influence of cations on flocculation. Metal ions included 1% of NaCl, LiCl, KCl, MnCl 2 , MgCl 2 and FeCl 3 .…”

Microwave‐assisted synthesis, characterization, and application of tragacanth gum grafted copolymer as bioflocculant for the treatment of textile wastewater using coagulation‐flocculation technique: Swelling behavior and biodegradation studies

“…The solutions were subjected to agitation at a speed of 200 rpm for a duration of 3 min, after which they underwent a subsequent period of gentle mixing at a rate of 40 rpm for 5 min. To facilitate the process of sedimentation, the conical flasks were left undisturbed for a duration of 10 min at ambient temperature 44 . Comparative studies have been conducted using synthetic flocculants, such as alum and ferric chloride (120 mg/L).…”

“…A similar methodology was replicated three times for the alum and ferric chloride samples. However, in contrast to the grafted bioflocculant, native gum as bioflocculant, alum, and ferric chloride were used as flocculating agents 44 . The efficacy of the grafted bioflocculant in removing color, TDS, TSS, BOD, COD, sulfate, and nitrate were determined using Equation () as follows: …”

“…To facilitate the process of sedimentation, the conical flasks were left undisturbed for a duration of 10 min at ambient temperature. 44 Comparative studies have been conducted using synthetic flocculants, such as alum and ferric chloride (120 mg/L). A similar methodology was replicated three times for the alum and ferric chloride samples.…”

Screening of bioflocculant and cellulase-producing bacteria strains for biofloc culture systems with fiber-rich carbon source

“…Bioflocculants are composed of biodegradable polymers, such as glycoprotein, polysaccharide, protein, lipids, and nucleic acid that are produced by growing microorganisms ( Lian et al, 2008 ; Liu et al, 2014 ). Bioflocculants were widely used in wastewater treatment through their ability to aggregate suspended solids together and adsorb heavy metals without causing secondary pollution for the environment ( Liu et al, 2020 ; Vimala et al, 2020 ; Tsilo et al, 2022 ). Certain bioflocculant-producing bacteria possessed the antagonistic ability to pathogenic Vibrio species, which could be used to control Vibrio infection and apply as inoculum for bioflocculation simultaneously ( Tuan et al, 2021 ).…”