Improvement of methyl orange dye biotreatment by a novel isolated strain, Aeromonas veronii GRI, by SPB1 biosurfactant addition

Abstract

Aeromonas veronii GRI (KF964486), isolated from acclimated textile effluent after selective enrichment on azo dye, was assessed for methyl orange biodegradation potency. Results suggested the potential of this bacterium for use in effective treatment of azo-dye-contaminated wastewaters under static conditions at neutral and alkaline pH value, characteristic of typical textile effluents. The strain could tolerate higher doses of dyes as it was able to decolorize up to 1000 mg/l. When used as microbial surfactant to enhance methyl orange biodecolorization, Bacillus subtilis SPB1-derived lipopeptide accelerated the decolorization rate and maximized slightly the decolorization efficiency at an optimal concentration of about 0.025%. In order to enhance the process efficiency, a Taguchi design was conducted. Phytotoxicity bioassay using sesame and radish seeds were carried out to assess the biotreatment effectiveness. The bacterium was able to effectively decolorize the azo dye when inoculated with an initial optical density of about 0.5 with 0.25% sucrose, 0.125% yeast extract, 0.01% SPB1 biosurfactant, and when conducting an agitation phase of about 24 h after static incubation. Germination potency showed an increase toward the nonoptimized conditions indicating an improvement of the biotreatment. When comparing with synthetic surfactants, a drastic decrease and an inhibition of orange methyl decolorization were observed in the presence of CTAB and SDS. The nonionic surfactant Tween 80 had a positive effect on methyl orange biodecolorization. Also, studies ensured that methyl orange removal by this strain could be due to endocellular enzymatic activities. To conclude, the addition of SPB1 bioemulsifier reduced energy costs by reducing effective decolorization period, biosurfactant stimulated bacterial decolorization method may provide highly efficient, inexpensive, and time-saving procedure in treatment of textile effluents.

Enhanced Methyl Orange Removal Using a Newly Isolated Bacterial Strain and Potassium‐Iodide‐Doped Hydroxyapatite Nanoparticles

“…The most important observation is the tolerance of the bacterial isolate to high doses (1000 mg L −1 ) of MO for a long period (144 h). This result is in agreement with those of Mnif et al The reported concentration (1000 mg L −1 ) is higher than those reported by others . In contrary, Shah et al observed the inhibitory effect of MO on growth of Pseudomonas spp.…”

Process optimization for effective bio‐decolourization of methyl orange by Pseudomonas aeruginosa 23N1 using chemometric methodology

“…Recently, Mnif et al investigated the MO dye bio‐treatment efficiency of Aeromonas veronii GRI and reported that this strain could tolerate a higher concentration of dye since it could efficiently decolourize up to 1000 mg/L in mineral salt medium (MSM) after 24 h incubation. Ayed et al reported a 92 % degradation of MO (750 mg/L) within 48 h at pH 7 and 30 °C in MSM containing glucose and yeast extract.…”

“…A typical textile industrial wastewater contains methyl orange (MO) dye concentration in the range of 50–150 mg/L . Recently, numerous studies related to bio‐decolourization of MO by bacteria and fungi have been reported . However, the effect of operational parameters (like nutrient composition, pH, and temperature) on the treatment process is yet to be explored elaborately.…”

Textile azo dye decolorization and detoxification using bacteria isolated from textile effluents

“…Finally, on the 3 rd day, decolorization was recorded with 50% efficiency, which then changed to 86% on the 6 th day of experiment for VTK024. The divergence in the decolorization efficiency was caused by the variation in the selectivity of bacterial isolates; the composition and complexity of chemical dyes, specifically relating to the type; and the placement of substituents (para and ortho) in the aromatic rings and the interaction with R!N=N!R bond as mentioned by various researchers (Chaieb et al, 2016;Jha et al, 2016;Mnif et al, 2016). A majority of the bacteriological genera, i.e., Enterococcus, Staphylococcus, Pseudomonas, Proteus, and Bacillus, which were tested in this study, have been published earlier (Chaieb et al, 2016;Neifar et al, 2016).…”

“…such as Proteus vulgaris NCIM 2027 as a dye-decolorizing agent for textile dye degradation has been investigated previously (Saratale et al, 2011). These studies revealed the occurrence of different microbial genera, which were characterized as (Mnif et al, 2016;Ng et al, 2014). However, bacterial isolates, i.e.,…”