Production of a novel bioflocculant MNXY1 by Klebsiella pneumoniae strain NY1 and application in precipitation of cyanobacteria and municipal wastewater treatment

Abstract

Aims To isolate and characterize the novel bioflocculant-producing bacteria, to optimize the bioflocculant production and evaluate its potential applications. Methods and Results Klebsiella pneumoniae strain NY1, a bacterium that produces a novel bioflocculant (MNXY1), was selected on the chemically defined media. It was classified according to the 16S rRNA gene sequence, morphological and microscopic characteristics. MNXY1 was characterized to contain 26% protein and 66% total sugar. The constituent sugar monomers of MNXY1, revealed by NMR analysis, are glucose, galactose and quinovose. Favorable culture conditions for MNXY1 production were determined. Strain NY1 produces a high level (14.9 g l−1) of MNXY1. MNXY1 is thermostable and tolerant to the extreme pH. It precipitated 54% of cyanobacteria from laboratory culture and 72% of the total suspended solids from raw wastewater. Conclusions Strain NY1 was identified to produce a novel bioflocculant MNXY1. The outstanding performance of MNXY1 in practical applications and its availability in copious amounts make it attractive for further investigation and development for industrial scale applications.

Assessment of Bacillus pumilus Isolated from Fresh Water Milieu for Bioflocculant Production

“…Bioflocculants are natural product metabolites of microorganisms that have capacity to flocculate various suspended solids including colloidal solids and cells [1,2]. Chemical flocculants have been extensively applied in various industries owing to their cost-effectiveness and high flocculating efficiency [3]; however, many researchers are investigating the use of bioflocculants as a result of health problems implicated in the use of chemical flocculants.…”

“…Consequently, the use of these chemical flocculants is now a restricted cause of concern. These inevitable disadvantages of chemical flocculants have shifted the focus on investigating a variety of microorganisms for their flocculant-producing potentials [1,6].…”

Biodesalination: A Case Study for Applications of Photosynthetic Bacteria in Water Treatment

“…strain PCC 6803 (Jittawuttipoka et al, 2013). Moreover, bioflocculant activity is not limited to released cyanobacterial EPSs (Taniguchi et al, 2005;Kim et al, 2011a;Nie et al, 2011). Interestingly, the bound EPSs of cyanobacterial and heterotrophic cells have also been indicated to aid flocculation.…”

Production of a value added compound from the H-acid waste water—Bioflocculants by Klebsiella pneumoniae

“…Over the pH range 6-8, the highest MBF-7 yield was 8.9 g/L. The optimal pH for bioflocculant production was 7.0 because initial pH of culture medium could affect electrification state of microorganism cell, redox potential, microorganism nutriment assimilation and enzyme reaction [19,20]. …”