Isolation, identification, and characterization of an Aspergillus niger bioflocculant-producing strain using potato starch wastewater as nutrilite and its application

Abstract

A bioflocculant (MBFA18) was produced by Aspergillus niger (A18) using potato starch wastewater (PSW) as nutrients. The cultivation processes and flocculating treatment for PSW purification were systematically studied. The flocculating rate of the MBFA 18 achieved 90.06% (kaolin clay) under the optimal cultivation condition (PSW with 5950 mg/L COD, 20 g/L glucose, 0.2 g/L urea and without phosphorus source addition and pH adjustment). Furthermore, effects of flocculant dosage, initial pH, coagulant aid (CaCl2) addition and sedimentation time on the PSW treatment were discussed and studied in detail. The optimum flocculation treatment conditions were determined according to the treatment efficiency, cost and flocculation conditions. During the PSW treatment, 2 mL/L bioflocculant (1.89 g/L) dosage and 0.5 mol/L coagulant aid addition were applied without pH adjustment and 91.15% COD and 60.22% turbidity removal rate could be achieved within 20 min. The comparative study between the bioflocculant and conventional chemical flocculants showed excellent flocculating efficiency of MBFA 18 with lower cost (4.7 yuan/t), which indicated that the bioflocculant MBFA 18 produced in PSW substrate has a great potential to be an alternative flocculant in PSW treatment.

Isolation, Identification and Characterization of Bioflocculant-Producing Bacteria from Activated Sludge of Vulindlela Wastewater Treatment Plant

“…In the laboratory, 10-fold serial dilutions of the water sample were conducted with 0.85% of saline solution [16]. About 1 mL of sludge water sample was transferred into 9 mL of sterile saline solution and agitated for 30 s. From these, serial dilutions (1 × 10 −1 and 10 −2 ) were made; 100 µL of the serially diluted and undiluted samples was aseptically plated on Nutrient agar plates [19]. Nutrient agar plates were incubated at 37 • C for 3 days.…”

“…Each flask with the mixture was placed in a shaking incubator (LAB-Consumables, Durban, South Africa) at a speed of 160 rpm and temperature of 30 • C. After 72 h of incubation, 2 mL of broth culture was centrifuged at 8000 rpm for 30 min at 4 • C to remove bacterial cells. The cell-free supernatant was used to evaluate bioflocculant activity [19,21].…”

Isolation and characterization of Aspergillus niger NBC001 underlying suppression against Heterodera glycines

“…The culture filtrate of NBC001 was prepared by centrifuging at 2,000 rpm for 20 min 50 . Ten ml of the supernatant was filtered through a sterile 0.22 μm polyethersulfone filter (Whatman, Clifton, NJ, USA) for the in vitro experiments 51 .…”

Challenges and Opportunities of Biocoagulant/Bioflocculant Application for Drinking Water and Wastewater Treatment and Its Potential for Sludge Recovery

“…Additional study on another phylum might be interesting to provide alternative technologies. Extensive studies on fungus- and alga-based biocoagulants/bioflocculants will contribute to this topic, considering that research from these sources is currently still scarce [ 28 , 150 , 151 , 152 ].…”