Biodegradation and biosorption of Reactive Red 120 dye by immobilized Pseudomonas guariconensis: Kinetic and toxicity study

Abstract

Reactive dyes are pernicious pollutants in textile effluent, which are to be treated passably before discharging into the environment. In the present study, a potential dye degrading bacterial strain Pseudomonas guariconensis was isolated from paddy rhizosphere and was characterized by 16S rRNA gene sequencing. The biodegradation ability of the strain was evaluated by time‐based study with immobilized bacterial cells in calcium alginate biocarrier matrix and also with free cells. The results indicated that the strain exhibited maximum degradation of 91% when immobilized in the biocarrier matrix. The enzymatic study revealed the production of oxidoreductase enzymes. The degraded products were identified as 2‐amino‐3‐phenylpropanoic acid and benzoquinone by gas chromatography–mass spectroscopy (GC‐MS) analysis, and a degradative pathway was derived based on the enzymatic profile. A packed bed column was designed using P. guariconensis VITSAJ5 immobilized in calcium alginate beads as a biosorbent for the removal of Reactive Red 120. The immobilized bacterial cells exhibited 87% uptake of RR120, whereas the nonimmobilized bacterial cells exhibited a maximum uptake of 37%. The phytotoxicity analysis by seed germination assay revealed an enhanced plumule and radicle length, indicating the nontoxic byproducts after the treatment of Reactive Red 120 by VITSAJ5 compared to the untreated Reactive Red 120 solution. Practitioner points Current study is the first report on Pseudomonas guariconensis capable of degrading reactive dyes (Reactive Red 120) It was observed that the degradation potential was maximum when cells were immobilized with Ca‐Ag biocarrier matrix Breakdown metabolism of Reactive Red 120 was derived through pathway prediction Employing immobilized bacteria in a packed bed column found to possess a prominent biosorption ability on the matrix enhancing the degradation process Toxic reactive dye was converted into nontoxic compounds, evidenced by phytotoxicity studies

Biodecolourisation of Reactive Red 120 as a Sole Carbon Source by a Bacterial Consortium—Toxicity Assessment and Statistical Optimisation

“…Even though the observed decolourisation was lower than with the addition of extra carbon sources, the consortium can completely mineralise the dye. Bacillus lentus B1377 [38] was able to achieve complete mineralisation of RR120 when supplemented with NB, on other hand, Pseudomonas gualiconensis [39] was reported to produced toxic metabolite in similar condition. Most of RR120 decolouriser needs glucose/yeast extract more than 3 g/L to achieve significant decolourisation [16,26,30,39,40].…”

“…Bacillus lentus B1377 [38] was able to achieve complete mineralisation of RR120 when supplemented with NB, on other hand, Pseudomonas gualiconensis [39] was reported to produced toxic metabolite in similar condition. Most of RR120 decolouriser needs glucose/yeast extract more than 3 g/L to achieve significant decolourisation [16,26,30,39,40]. Consortium JR3 was able to do so with the least amount of co-substrate.…”

Recent Achievements in Dyes Removal Focused on Advanced Oxidation Processes Integrated with Biological Methods

“…Bacterial treatment Isolation of new strains or consortia from activated sludge, oxidation ditch, palm oil mill effluent or desert soil, alkali-, haloand thermophilic strains implementation, consortium with algae, bacteria immobilization, co-substrate addition, proposal of mechanisms, pathways genome and transcriptome analysis [109][110][111][112][113][114][115][116][117][118][119] Fungal treatment Implementation of microbial consortium (e.g., yeast consortium with ability of lignin valorization dye treatment and biodiesel production), fungi immobilization, isolation of new strains from plant roots or effluent site [120][121][122][123][124][125][126][127][128][129][130] Enzyme treatment Optimization of enzyme production, enzyme immobilization, metabolites and toxicity assessment [131][132][133][134][135][136] Algal treatment…”

Mycoremediation of Textile Effluent: A Toxicological Evaluation and its Possible Correlation with COD

“…The diverse sort of dyes and chemicals used in textile manufacturing makes textile effluents very complex in terms of chemical compositions. According to previous records, in addition to dyes and its auxiliaries over 8000 chemicals are added such as several acids, salts, surfactants, metals, oxidizing and reducing agents (Reddy and Osborne 2020). These recalcitrants in untreated effluents are both harmful to marine and terrestrial organisms and have prolonged effects on health (Hamidi et al, 2014).…”