Biodegradation Of Phenolic Compounds Research Articles

Biodegradation of Phenolic Compounds in Contaminated Water: Efficacy of Immobilized Bacterial Strains and Environmental Factors

Biodegradation of Phenolic Compounds in Contaminated Water: Efficacy of Immobilized Bacterial Strains and Environmental Factors

Uncovering applicability of Navicula permitis algae in removing phenolic compounds: A promising solution for olive mill wastewater treatment

This work identifies Navicula permitis, freshwater diatom algae, by analyzing its 18S DNAr and testing how well it could grow and remove phenolic compounds at varying concentrations from 50 to 250 mg/L. The changes in the culture's chlorophyll fluorescence were measured when being exposed to stress. The biodegradation of phenolic compounds was tested by analyzing the enzyme activities of phenol hydroxlase and catechol dioxygenase in N. permitis. It was found that N. permitis could withstand up to 145.9 mg/L of phenol concentration. The response surface methodology was used to optimize conditions for N. permitis to degrade phenol with 50.08 mg/L of concentration, 106 cells/mL of N. permitis, and 11.38 days of treatment. Phenol removal by the Navicula permitis followed a zero-order kinetic model, and N. permitis used PHase to breakdown the pollutant. The ortho-pathway played a role in phenol metabolism. While degrading phenol, N. permitis produced biomass, which makes it a promising option for environmental remediation.

Synergistic interaction of tween 20 and magnesium@ functionalized graphene oxide nano-composite for dual productivity of biohydrogen and biochar from onion peel waste

This study aimed at developing a novel nano-composite enhancing fermentation/pyrolysis strategy for dual productivity of biohydrogen and biochar from onion peel waste (OPW). Biohydrogen productivity was maximized by adding tween 20 (T20) and magnesium@ functionalized graphene oxide (Mg@FGO) onto the fermentation of OPW. Three semi-continuous stirred tank reactors (CSTR1, CSTR2 and CSTR3) were respectively supplemented with OPW (control), OPW + T20, and OPW + T20+Mg@FGO and operated at constant retention time of 4.0 d. The hydrogen production rate (HPR) of 343.2 ± 36.2 mL/L/d and hydrogen yield (HY) of 30.30 ± 4.6 mL/g CODadded was obtained by CSTR2 which were greater than those achieved in the control (CSTR1) by 2-folds. Further improvement of H2 productivity >200% was achieved in CSTR3 supplemented with T20+Mg@FGO compared with CSTR1. The addition of T20+Mg@FGO in CSTR3 enhanced acetate fermentation pathway, the enzymatic activities and the biodegradation of phenolic compounds. Moreover, microbial diversity analysis of CSTR3 showed the dominance of the H2-producing bacteria related to Firmicutes, Planctomycetes, and Proteobacteria. Further, digestates collected from the CSTR3 were pyrolyzed at temperature of 550 °C, delivering biochar having multiple surface functional groups. Results confirm that adding T20+Mg@FGO onto the fermentation of OPW followed by digestate pyrolysis could be a sustainable strategy for fulfilling the renewable energy requirements.

Genome of the epiphytic bacterium Achromobacter denitrificans strain EPI24, isolated from a macroalga located in the Colombian Caribbean

Marine macroalgae are being recognized as reservoirs of biologically active compounds, as their surfaces are susceptible to the colonization of microorganisms which can produce enzymes with a wide range of molecular architectures. Among these bacteria, Achromobacter is responsible for the biosynthesis of laccases. In this research, we performed a bioinformatic pipeline to annotate the sequenced complete genome of the epiphytic bacterium Achromobacter denitrificans strain EPI24, from the macroalgal surface of the Ulva lactuca species; this strain showed laccase activity which has been previously assessed on plate assays. The genome of A. denitrificans strain EPI24 has a size of ∼6.95 Mb, a GC content of 67.33%, and 6,603 protein-coding genes. The functional annotation of the A. denitrificans strain EPI24 genome confirmed the presence of genes encoding for laccases, which could have functional properties of interest in processes such as the biodegradation of phenolic compounds under versatile and efficient conditions.

Biodegradation of a Complex Phenolic Industrial Stream by Bacterial Strains Isolated from Industrial Wastewaters

Molecular and metabolomic tools were used to design and understand the biodegradation of phenolic compounds in real industrial streams. Bacterial species were isolated from an industrial wastewater treatment plant of a phenol production factory and identified using molecular techniques. Next, the biodegradation potential of the most promising strains was analyzed in the presence of a phenolic industrial by-product containing phenol, alfa-methylstyrene, acetophenone, 2-cumylphenol, and 4-cumylphenol. A bacterial consortium comprising Pseudomonas and Alcaligenes species was assessed for its ability to degrade phenolic compounds from the phenolic industrial stream (PS). The consortium adapted itself to the increasing levels of phenolic compounds, roughly up to 1750 ppm of PS; thus, becoming resistant to them. In addition, the consortium exhibited the ability to grow in the presence of PS in repeated batch mode processes. Results from untargeted metabolomic analysis of the culture medium in the presence of PS suggested that bacteria transformed the toxic phenolic compounds into less harmful molecules as a survival mechanism. Overall, the study demonstrates the usefulness of massive sequencing and metabolomic tools in constructing bacterial consortia that can efficiently biodegrade complex PS. Furthermore, it improves our understanding of their biodegradation capabilities.

Reversible immobilization of laccase onto glycopolymer microspheres via protein-carbohydrate interaction for biodegradation of phenolic compounds

It is challenging to regenerate enzyme carriers when covalently immobilized enzymes suffered from inactivation during continuous operations. Hence, it is urgent to develop a facile strategy to immobilize enzymes reversibly. Herein, the non-covalent interaction between protein and carbohydrate was used to adsorb and desorb enzymes reversibly. Laccase was immobilized onto glycopolymer microspheres via protein-carbohydrate interaction using lectins as the intermediates. The enzyme loading and immobilization yield were up to 49 mg/g and 77.1% with highly expressed activity of 107.9 U/mg. The immobilized laccase exhibited enhanced pH stability and high activity in catalyzing the biodegradation of paracetamol. During ten successive recoveries, the immobilized laccases could be recycled while maintaining relatively high enzyme activity. The glycopolymer microspheres could be efficiently regenerated by elution with an aqueous solution of mannose or acid for further enzyme immobilization. This glycopolymer microspheres has excellent potential to act as reusable carriers for the non-covalent immobilization of different enzymes.

Biodegradation of phenolic compounds in waste foundry sand: Physical and chemical characterization of foundry sand and bacterial degradation kinetics

The foundry sand agglomerated with the phenolic resin becomes a hazardous waste after its use in the metallurgical industry. Thus, the present work aimed to study the biodegradation of phenolic compounds present in the waste phenolic foundry sand, such as phenol, o-cresol and m-cresol which were used as the only carbon source to Burkholderia genus. The foundry sand showed an initial concentration of phenol, m-cresol and o-cresol as 953, 360 and 110 mg L−1, respectively. After the bioprocess, a degradation efficiency of 97% for phenol and 100% for m-cresol and o-cresol, at temperature 28 °C and agitation 180 rpm and also no bacterial toxicity were observed. Thus, the bioremediation of waste foundry sand with reducing environmental and economic impacts through an ecologically correct and also low-cost process becomes potential to be applied on an industrial scale.

Efficient phenol degradation by laccase immobilized on functional magnetic nanoparticles in fixed bed reactor under high-gradient magnetic field.

Enzymatic degradation of emerging contaminants has gained great interest for the past few years. However, free enzyme often incurs high costs in practice. The immobilized laccase on the polyethylenimine (PEI)‐functionalized magnetic nanoparticles (Fe3O4–NH2–PEI–laccase) was fabricated to efficiently degrade phenolic compounds continuously in a newly fixed bed reactor under a high‐gradient magnetic field. The degradation rate of continuous treatment in the bed after 18 h was 2.38 times as high as that of batch treatment after six successive operations with the same treatment duration. Under the optimal conditions of volume fraction of nickel wires mesh, flow rate of phenol solution, phenol concentration, and Fe3O4–NH2–PEI–laccase amount, the degradation rate of phenol kept over 70.30% in 48 h continuous treatment. The fixed bed reactor filled with Fe3O4–NH2–PEI–laccase provided a promising avenue for the continuous biodegradation of phenolic compounds for industrial wastewater in practice.

Biodegradation of phenolic compounds using immobilized Pseudomonas aeruginosa on granular activated carbon: Effect of immobilization, kinetic study and microbial regeneration

Phenol and its derivatives are one of the major pollutants present in industrial effluents. In this work, Pseudomonas aeruginosa (ATCC 9027) has been effectively used to carry out biodegradation of phenol, 3-aminophenol, and catechol. In order to develop an industrially viable technology, P. aeruginosa has been immobilized on granular activated carbon (GAC). The biofilm thickness was found in the range 14 to 34 μm. The adsorbed P. aeruginosa on the GAC is found to be efficient for bio-degradation of the phenolic compounds and in addition they also helped in regeneration of the activated carbon systems which in turn reduce the operability cost. The extent of bio-regeneration varied between 33-66%. Haldane’s growth kinetic equation is found to be suitable to fit the specific growth rate data of P. aeruginosa.

Covalent immobilization of laccase on Fe3O4–graphene oxide nanocomposite for biodegradation of phenolic compounds

Covalent immobilization of laccase on Fe3O4–graphene oxide nanocomposite for biodegradation of phenolic compounds

Influence of photodegradation on the removal of color and phenolic compounds from palm oil mill effluent by Arthrospira platensis

Palm oil mill effluent (POME) released from conventional treatment systems poses severe environmental problems due to its dark color, its high chemical oxygen demand (COD), and high content of phenolic compounds. However, the possible biodegradation of phenolic compounds and color by microalgae was not well explored. This research aimed to reveal optimal conditions for pollutant removal through biodegradation by the cyanobacterium Arthrospira platensis. This species was grown under a range of POME fractions and environmental conditions (irradiance, salinity, nutrients) during which growth, final biomass, color, COD, and phenolic compound levels were followed. POME fractions influenced A. platensis growth rate, final biomass, COD, and color removal. The optimization of phenolic compound removal by using central composite design (CCD) response surface methodology (RSM) showed that low light and high initial phenolic compounds promoted the activity of A. platensis to degrade phenolic compounds. The combination of high initial phenolic compounds and high light intensity increased the growth rate up to 0.45 days−1 and final biomass up to 400 mg L−1, while total phenolic compounds were almost completely (94%) removed. Finally, this study showed that phenolic compounds and color degradation from POME were dominated by the activity of photodegradation at high irradiance, while the activity of A. platensis dominated at low light intensity.

FeOx@GAC catalyzed microbubble ozonation coupled with biological process for industrial phenolic wastewater treatment: Catalytic performance, biological process screening and microbial characteristics

Phenolic compounds are common ccontaminants in industrial effluents. In this study, a combined catalytic microbubble ozonation and biological process was developed and applied for efficient industrial phenolic wastewater (PWW) treatment. Catalytic activity of an iron-oxides (FeOx) doped granular activated carbon (GAC) catalyst (FeOx@GAC) in microbubble ozonation for PWW treatment was investigated. The results demonstrated that the FeOx@GAC catalyzed microbubble ozonation (O3/FeOx@GAC) obtained significantly higher reaction rate constant (k1 = 0.023 min−1) in TOC removal compared to the bare GAC catalyzed microbubble ozonation (O3/GAC, k1 = 0.013 min−1) and ordinary microbubble ozonation (k1 = 0.008 min−1). Destruction rate constant of phenolic compounds (k2) was improved from 0.014 min−1 (ordinary microbubble ozonation) to 0.025 min−1 (O3/FeOx@GAC). The 60-min pretreatment of PWW by O3/FeOx@GAC process enhanced BOD5/COD ratio from 0.31 to 0.76 and reduced the acute bio-toxicity by 79.2%. Screening and characterization of biological post-treatment processes were conducted among activated sludge process (ASP), up-flow anaerobic sludge blanket (UASB) and membrane bioreactor (MBR). UASB and ASP showed limited phenolic compounds removal of 35.4% and 57.0% with lower bio-toxicity resistance than MBR (94.9% phenolic compounds removal). The combined process O3/FeOx@GAC-MBR was thus developed and achieved high COD removal (98.0%) and phenolic compounds degradation (99.4%). PWW pretreatment by O3/FeOx@GAC process decreased membrane fouling rate of MBR by 88.2% by reducing proteins/polysaccharides accumulation in both extracellular polymeric substances and soluble microbial products. 16S rRNA high-throughput sequencing revealed the predominance of phylum Proteobacteria, class Alphaproteobacteria and genera Mycobacterium, Gordonia, Pedomicrobium & Defluviimonas in biological PWW treatment bio-systems. Pearson correlation coefficient and ANOVA analysis verified that Mycobacterium possessed high bio-toxicity resistance and was the main contributor to the biodegradation of phenolic compounds.

Immobilization of laccase by 3D bioprinting and its application in the biodegradation of phenolic compounds

Due to the increasing quantities of phenolic compounds present in wastewater, the use of enzymatic degradation with the laccase has attracted much attention as a green option for their removal. In this work, we developed a novel immobilization technology using 3D bioprinting for laccase immobilization. The hydrogel mechanism properties were optimized by experimenting with different component ratios of sodium alginate (SA), acrylamide (AM), and hydroxyapatite (HA). The improved mechanism properties were validated by morphology pictures and rheology characteristics. The optimal AM:HA:SA ratio was determined to be 4:1.2:1. We then employed an extrusion-based bioprinting technique to prepare the immobilized laccase. The substrate conversion was increased with the addition of HA, which improved the permeability of the matrix, and proved to be suitable for immobilization. The resulting immobilized laccase was used for the biodegradation of p-chlorophenol. The effects of the initial substrate concentration, pH, and temperature were evaluated. The immobilized laccase exhibited good storage stability and reusability, retaining over 80% of its initial activity after 72 h of storage, and was able to be reused for seven batches. These results highlight that the immobilized laccase prepared by 3D bioprinting has great potential for use in the biodegradation of phenolic compounds.

Biodegradation of phenolic compounds in high saline wastewater by biofilms adhering on aerated membranes

High saline phenolic wastewater is a typical toxic and refractory industrial wastewater. A single membrane–aerated biofilm reactor (MABR) was used to treat wastewater containing phenol, p–nitrophenol and hydroquinone under increasing phenolic loading and salinity conditions. More than 95 % of phenolic compounds were removed, and a removal efficiency of 8.9 g/m2 d for total phenolic (TP) contents was achieved under conditions with 32 g/L of salt and 763 mg/L of influent TP contents. The microbial diversity, structure and function of a biofilm exposed to different conditions were investigated by high–throughput 16S rRNA gene sequencing and metagenomics. Salinity and specific TP loading substantially affected the bacterial community. Gammaproteobacteria, Actinobacteria and Betaproteobacteria contributed more to initial phenolic compound degradation than other classes, with Pseudomonas and Rhodococcus as the main contributing genera. The key phenolic–degrading genes of different metabolic pathways were explored, and their relative abundance was strengthened with increasing phenolic loading and salinity. The diverse cooperation and competition patterns of these microorganisms further promoted the high removal efficiency of multiple phenolic contaminants in the biofilms. These results demonstrate the feasibility of MABR for degrading multiple phenolic compounds in high saline wastewater.

Characterization of a newly isolated strain Comamonas sp. ZF-3 involved in typical organics degradation in coking wastewater

The aim of this study was to investigate the characteristic of a newly isolated strain Comamonas sp. ZF-3 involved in typical organics degradation in coking wastewater (CWW). The results showed that the isolated strain had efficient biodegradability of phenolic compounds and heterocyclic compounds in CWW, meanwhile, phenol and indole could be respectively used as sole carbon source for its growth, which demonstrated the bioaugmentation potential of the isolated strain in CWW treatment. During phenol and indole degradation processes, part of metabolites (e.g., 2,3-hexanedione, 2-ethyl-1-hexanol, nonanal, 2-propyl-1-heptanol, butanoic acid, butyl ester and butanoic acid, anhydride) remained in effluents, with NH4+-N concentration having no obvious reduction, which implied the biological treatment of CWW should be accomplished by complex microbial communities in many steps.

Nanocapsulation of horseradish peroxidase (HRP) enhances enzymatic performance in removing phenolic compounds

As ubiquitous environmental pollutants, phenolic compounds are requested to be efficiently removed from wastewater. Enzymes, such as Horseradish peroxidase (HRP), have been demonstrated with great potential in removing phenolic compounds. Different from the general immobilization technology, the encapsulation of individual enzymes within nanogel has been employed in this work. Here we show that, the encapsulated HRP could remarkably enhance enzymatic performance, including thermostability, catalytic efficiency, environmental tolerance and, most importantly, the biodegradation of phenolic compounds. For instance, the removal efficiencies of phenol and BPA increased by 7-fold and 3.5-fold, respectively. On the other hand, the diverted removal efficiencies were obtained for a series of phenolic compounds. Based on molecular modelling, the biodegradabilities of phenolic compounds were rationalized according to their redox potentials and binding affinities with enzymes. In summary, our work indicates that the nanocapsulation of enzyme should be a promising strategy in removing different types of phenolic compounds from wastewater.

Optimization of the process conditions for biodegradation of phenolic compounds in olive mill wastewater using Bacillus subtilis in bioreactor cultures

Optimization of the process conditions for biodegradation of phenolic compounds in olive mill wastewater using Bacillus subtilis in bioreactor cultures

Laccase immobilized on magnetic nanoparticles modified by amino-functionalized ionic liquid via dialdehyde starch for phenolic compounds biodegradation

Abstract In this work, an efficient biocatalyst immobilized on magnetic nanoparticles modified by amino-functionalized ionic liquid using dialdehyde starch as cross-linker (Fe3O4-NIL-DAS) was fabricated. It was found that activity retention (73.7%), immobilization efficiency (85.8%) and storage stability (>80% of initial activity retained after 30 days) of laccase immobilized on Fe3O4-NIL-DAS (Fe3O4-NIL-DAS@lac) were improved significantly. Moreover, the immobilized laccase could effectively remove phenolic compounds (phenol, 4-chlorophenol and 2,4-dichlorophenol) in a wider temperature and pH range, exhibiting maximum removal efficiencies with 86.1%, 93.6% and 100% for phenol, 4-chlorophenol and 2,4-dichlorophenol, respectively, and high stability was confirmed by retention of 83.5% of the initial activity after six cycles. Fe3O4-NIL-DAS and Fe3O4-NIL-DAS@lac were characterized by transmission electron microscopy, energy dispersive spectrometer, zeta potential analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction analysis, magnetic hysteresis loops, circular dichroism and etc. Research results indicated that a novel and efficient strategy for enzyme immobilization to biodegrade phenolic compounds was developed.

Biodegradation of high concentration phenol using sugarcane bagasse immobilized Candida tropicalis PHB5 in a packed-bed column reactor

Biodegradation of phenolic compounds in wastewater can be effectively carried out in packed bed reactors (PBRs) employing immobilized microorganisms. A low-cost, reusable immobilization matrix in PBR can provide economic advantages in large scale removal of high concentration phenol. In this study, we evaluated the efficiency and reusability of sugarcane bagasse (SCB) as a low-cost immobilization support for high strength phenol removal in recirculating upflow PBR. An isolated yeast Candida tropicalis PHB5 was immobilized onto the SCB support and packed into the reactor to assess phenol biodegradation at various influent flow rates. Scanning electron microscopy exhibited substantial cell attachment within the pith and onto the fibrous strand surface of the SCB support. The PBR showed 97% removal efficiency at the initial phenol concentration of 2400 mg L−1 and 4 mL min−1 flow rate within 54 h. Biodegradation kinetic studies revealed that the phenol biodegradation rate and biodegradation rate constant were dependent on the influent flow rate. A relatively higher rate of biodegradation (64.20 mg g−1 h−1) was found at a flow rate of 8 mL min−1, indicating rapid phenol removal in the PBR. Up to six successive batches (phenol removal >94%) were successfully applied in the PBR using an initial phenol concentration of 400–2400 mg L−1 at a flow rate of 4 mL min−1 indicating the reusability of the PBR system. The SCB-immobilized C. tropicalis could be employed as a cost-effective packing material for removal of high strength phenolic compounds in real scale PBR.

Cyclodextrin-Based Polymer-Supported Bacterium for the Adsorption and in-situ Biodegradation of Phenolic Compounds.

Dual function polymer materials with immobilized Sphingobium Chorophenolicum (SpC) bacterium cells are reported herein that undergo tandem adsorption and biodegradation of phenolic compounds. The cross-linked polymer materials contain β-cyclodextrin (β-CD) with incremental hexamethylene diisocyanate (HDI) cross-linker at variable mole ratios (X = 1, 3, or 6), denoted as HDI-X systems. The adsorptive uptake properties of the insoluble HDI-X polymers (X = 3 and 6) with various phenolic compounds [pentachlorophenol (PCP), 2,4,6-trichlorophenol (TCP), and 2,4,6-trimethylphenol (TMP)] were studied using batch adsorption isotherms. The molecular selective phenol removal (SR) capacity of the HDI-3 and HDI-6 materials was evaluated by electrospray ionization mass spectrometry (ESI-MS). The results were compared against granular activated carbon (GAC) and native β-CD, where 1D/2D 1H NMR spectral characterization of the complexes formed between phenolic guests and a soluble polymer (HDI-1) in aqueous solution provide insight on the intermolecular interactions and the role of cross-linking effects. Immobilization of SpC onto HDI-3 was shown to form a composite polymer/bacterium material. The composite system displays synergistic removal effects due to tandem PCP adsorption and SpC biodegradation to yield by-products such as 2,6-dichloro-1,4-hydroquinone (DCHQ). Apoptosis and cytotoxicity of DCHQ were evaluated using three breast cancer cell lines.