Showing papers on "Microbial biodegradation published in 2018"
TL;DR: A comprehensive review of the current state of research activities on the application of biodegradation/bioremediation for removing persistent organic pollutants (POPs) such as pesticides, PCBs, PAHs and PPCPs from wastewater is presented.
224 citations
TL;DR: In this paper, a review described fungal PHs degradation, emphasized the relevant physicochemical and biological factors, and discussed the enzymatic systems influencing PHs biodegradation.
164 citations
TL;DR: Results indicate that strain C419 might be a new auxiliary bacterial resource for the biodegradation of fluoroquinolone residue in thermal environments.
112 citations
TL;DR: Investigation of laboratory-scale bioremediation of petroleum-hydrocarbon contaminated soil through development of eight bioreactors found an increase in microbial population was another evidence of TPH biodegradation by microorganism.
101 citations
TL;DR: In this paper, the effects of oil contamination and different remediation strategies (natural attenuation, biostimulation, and bioaugmentation) on physico-chemical and biological parameters of podzolic soil were studied.
94 citations
TL;DR: In this paper, an enhanced electrokinetics technology was developed to decontaminate a hydrocarbon-heavy metal co-contaminated soil by applying biostimulation and selective membranes (cationic and anionic).
79 citations
TL;DR: Bioaugmentation with Geobacillus increased the evolution of CO2 and accelerated the biodegradation phase of PLA and BNCs when tested in compost and inoculated vermiculite with compost mixed culture.
67 citations
TL;DR: Under aerobic seawater conditions (148-195 days at room temperature), poly(3HB- co-3HHx) sheets were statistically similar to cellulose for biodegradation as gaseous carbon loss, although the degradation rate was lower than that for cellulose.
Abstract: Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (poly(3HB-co-3HHx)) thermoplastics are a promising biodegradable alternative to traditional plastics for many consumer applications. Biodegradation measured by gaseous carbon loss of several types of poly(3HB-co-3HHx) plastic was investigated under anaerobic conditions and aerobic seawater environments. Under anaerobic conditions, the biodegradation levels of a manufactured sheet of poly(3HB-co-3HHx) and cellulose powder were not significantly different from one another over 85 days with 77.1 ± 6.1 and 62.9 ± 19.7% of the carbon converted to gas, respectively. However, the sheet of poly(3HB-co-3HHx) had significantly higher methane yield (p ≤ 0.05), 483.8 ± 35.2 mL·g–1 volatile solid (VS), compared to cellulose controls, 290.1 ± 92.7 mL·g–1 VS, which is attributed to a greater total carbon content. Under aerobic seawater conditions (148–195 days at room temperature), poly(3HB-co-3HHx) sheets were statistically similar to cellulose for biodegradation as gaseous...
63 citations
TL;DR: This review is focused on microbial degradation of cyanide and related compounds under anaerobiosis, exploring their potential application in bioremediation of industrial cyanide-containing wastes.
Abstract: Cyanide is one of the most toxic chemicals for living organisms described so far. Its toxicity is mainly based on the high affinity that cyanide presents toward metals, provoking inhibition of essential metalloenzymes. Cyanide and its cyano-derivatives are produced in a large scale by many industrial activities related to recovering of precious metals in mining and jewelry, coke production, steel hardening, synthesis of organic chemicals, and food processing industries. As consequence, cyanide-containing wastes are accumulated in the environment becoming a risk to human health and ecosystems. Cyanide and related compounds, like nitriles and thiocyanate, are degraded aerobically by numerous bacteria, and therefore, biodegradation has been offered as a clean and cheap strategy to deal with these industrial wastes. Anaerobic biological treatments are often preferred options for wastewater biodegradation. However, at present very little is known about anaerobic degradation of these hazardous compounds. This review is focused on microbial degradation of cyanide and related compounds under anaerobiosis, exploring their potential application in bioremediation of industrial cyanide-containing wastes.
62 citations
TL;DR: Marasmiellus sp. as mentioned in this paper showed higher levels of pyrene and benzo[a]pyrene degradation, suggesting that the fungus degraded the compound via the cytochrome P450 system and epoxide hydrolases.
54 citations
TL;DR: Rhamnolipid, as a biosurfactant, can be successfully utilized as an additive to improve the microbial biodegradation of PAHs in the environments.
TL;DR: Strain CS-1 significantly reduced the content of pathogenic fungi, including Gibberella, Fusarium, Monographella, Bipolaris, and Volutella, which cause soil-borne diseases in various crops, and may hence be developed into a microbial agent for plant growth improvement.
Abstract: Rhizospheric microorganisms can increase phosphorus availability in the soil. In this regard, the ability of phosphofungi to dissolve insoluble phosphorus compounds is greater than that of phosphate-solubilizing bacteria. The aim of the current study was to identify efficient phosphofungi that could be developed as commercial microbial agents. Among several phosphate-solubilizing fungal isolates screened, strain CS-1 showed the highest phosphorus-solubilization ability. Based on phylogenetic analysis of the internal transcribed spacer region sequence, it was identified as Aspergillus niger. High-performance liquid chromatography analysis revealed that the mechanism of phosphorus solubilization by CS-1 involved the synthesis and secretion of organic acids, mainly oxalic, tartaric, and citric acids. Furthermore, strain CS-1 exhibited other growth-promoting abilities, including efficient potassium release and degradation of crop straw cellulose. These properties help to returning crop residues to the soil, thereby increasing nutrient availability and sustaining organic matter concentration therein. A pot experiment revealed that CS-1 apparently increased the assessed biometric parameters of wheat seedlings, implying the potential of this strain to be developed as a commercial microbial agent. We used Illumina MiSeq sequencing to investigate the microbial community composition in the rhizosphere of uninoculated wheat plants and wheat plants inoculated with the CS-1 strain to obtain insight into the effect of the CS-1 strain inoculation. The data clearly demonstrated that CS-1 significantly reduced the content of pathogenic fungi, including Gibberella, Fusarium, Monographella, Bipolaris, and Volutella, which cause soil-borne diseases in various crops. Strain CS-1 may hence be developed into a microbial agent for plant growth improvement.
TL;DR: Hydrocarbon degradation was linked to current production and to sulfate reduction, at all the tested potentials, and microorganisms belonging to the families Desulfobulbaceae, Desulfuromonadaceae and Geobacteraceae were enriched on the anodes suggesting that both direct electron transfer and sulfur cycling occurred.
TL;DR: Results show that the microbial activity and metabolic richness found in the interstitial water and biofilm of the unsaturated designs were lower than those of the saturated and aerated designs, and canonical correlation analysis indicated that biofilm microbial communities in the three designs played a key role in ibuprofen degradation.
TL;DR: Abundance of the transcripts related to the degradation of aromatic amin compounds, carbazoles, benzoates, naphthalene, ketoadipate pathway, phenols, biphenyls and xenobiotics indicated abundant degradation capabilities in the soils.
Abstract: Agricultural soils are becoming contaminated with synthetic chemicals like polyaromatic compounds, petroleum hydrocarbons, polychlorinated biphenyls (PCBs), phenols, herbicides, insecticides and fungicides due to excessive dependency of crop production systems on the chemical inputs. Microbial degradation of organic pollutants in the agricultural soils is a continuous process due to the metabolic multifunctionalities and enzymatic capabilities of the soil associated communities. The plant rhizosphere with its complex microbial inhabitants and their multiple functions, is amongst the most live and dynamic component of agricultural soils. We analyzed the metatranscriptome data of 20 wheat rhizosphere samples to decipher the taxonomic microbial communities and their multifunctionalities linked with the degradation of organic soil contaminants. The analysis revealed a total of 21 different metabolic pathways for the degradation of aromatic compounds and 06 for the xenobiotics degradation. Taxonomic annotation of wheat rhizosphere revealed bacteria, especially the Proteobacteria, actinobacteria, firmicutes, bacteroidetes, and cyanobacteria, which are shown to be linked with the degradation of aromatic compounds as the dominant communities. Abundance of the transcripts related to the degradation of aromatic amin compounds, carbazoles, benzoates, naphthalene, ketoadipate pathway, phenols, biphenyls and xenobiotics indicated abundant degradation capabilities in the soils. The results highlighted a potentially dominant role of crop rhizosphere associated microbial communities in the remediation of contaminant aromatic compounds.
TL;DR: Soil amendment-assisted phytoremediation showed a high efficiency in PAH dissipation and may be a useful remediation technique for mixed contaminated soils.
TL;DR: The MFC-Fenton system provides an effective approach for treating environmental contaminants and indicated that functional bacteria in the genera Chryseobacterium, Stenotrophomonas, Arcobacter, and Comamonas were predominant in the anodic biofilm.
TL;DR: It is demonstrated that dilbit can be effectively degraded by autochthonous microbial consortia from sites with recent exposure to dilbits, and the community structure significantly changed as a response to the diminishing hydrocarbon load.
TL;DR: This study is the first to demonstrate that the newly isolated Stenotrophomonas strain has an efficient BDE 209 degradation ability and would provide new insights for the microbial degradation of PBDEs.
Abstract: Polybrominated diphenyl ethers (PBDEs) have become widespread environmental pollutants all over the world. A newly isolated bacterium from an e-waste recycling area, Stenotrophomonas sp. strain WZN-1, can degrade decabromodiphenyl ether (BDE 209) effectively under aerobic conditions. Orthogonal test results showed that the optimum conditions for BDE 209 biodegradation were pH 5, 25 °C, 0.5% salinity, 150 mL minimal salt medium volume. Under the optimized condition, strain WZN-1 could degrade 55.15% of 65 μg/L BDE 209 under aerobic condition within 30 day incubation. Moreover, BDE 209 degradation kinetics was fitted to a first-order kinetics model. The biodegradation mechanism of BDE 209 by strain WZN-1 were supposed to be three possible metabolic pathways: debromination, hydroxylation, and ring opening processes. Four BDE 209 degradation genes, including one hydrolase, one dioxygenase and two dehalogenases, were identified based on the complete genome sequencing of strain WZN-1. The real-time qPCR demonstrated that the expression level of four identified genes were significantly induced by BDE 209, and they played an important role in the degradation process. This study is the first to demonstrate that the newly isolated Stenotrophomonas strain has an efficient BDE 209 degradation ability and would provide new insights for the microbial degradation of PBDEs.
TL;DR: Kaolinite was more effective than quartz in promoting phenanthrene degradation and bacterial growth and it was revealed that a more intimate association was established between GY2B and kaolinite.
TL;DR: The study suggested that Alcanivorax borkumensis is a potential hydrocarbon-degrading bacterium with higher enzymatic capacities for bioremediation of hydro carbon-polluted environment.
TL;DR: According to the results from the microcosms studies, it can be stated that the substances are eliminated from the aqueous phase with relatively high rates under aerobic conditions due to both sorption and biotransformation processes, and the elimination of the compounds limited in the absence of oxygen as compared to aerobic.
01 Jan 2018
TL;DR: In this article, the effect of polycyclic aromatic hydrocarbons (PAHs) on human health and environment is discussed and the application of microbes to degrade pollutants is getting attention due to its environmental and economic benefits.
Abstract: Nowadays pollution control and abatement are critical issues faced by environmental scientists due to rapid industrialization. Petroleum industry is one of the major industries which release hydrocarbon pollutants in environment. Polycyclic aromatic hydrocarbons (PAHs) are the priority pollutants which are released into the environment by exploration activities of petroleum industries. The indiscriminate accumulation of petroleum hydrocarbon pollutants can be hazardous to the human life and aquatic biota. Due to toxicity of these pollutants, establishing efficient and environment-friendly method to degrade and detoxify these pollutants is an important research challenge. Various physiochemical methods are applied all over the world to remediate of petroleum hydrocarbon pollutants. Bioremediation technique has been developed for treatment of crude oil pollutants using biological agents like bacteria, fungi, algae, and plants. Applications of certain microorganisms have gained importance in the field of applied environmental microbiology. The application of microbes to degrade pollutants is getting attention due to its environmental and economic benefits. They can be used to change bioavailability and toxicity of petroleum hydrocarbons present in polluted soil and aqueous environment. This paper explores hydrocarbons present in petroleum crude. The effect of petroleum hydrocarbon pollutants on human health and environment is also discussed. This chapter also explains microbial degradation of these pollutants.
TL;DR: In this article, an aniline-degrading bacterial strain called AN-4a was isolated from textile dyeing sludge and identified as Pigmentiphaga daeguensis.
07 Feb 2018
TL;DR: The genomic attributes of K. pneumoniae AWD5 are revealed for its catabolic characteristics for different aromatic compounds, which makes it suitable for rhizoremediation of PAH-contaminated soil and heavy metal resistance genes indicating adaptation to contaminants.
Abstract: This research employs draft genome sequence data of Klebsiella pneumoniae AWD5 to explore genes that contribute to the degradation of polyaromatic hydrocarbon (PAH) and stimulate plant growth, for rhizosphere-mediated bioremediation Annotation analysis suggests that the strain AWD5 not only possess gene clusters for PAH utilization, but also for utilization of benzoate, fluorobenzoate, phenylacetate (paa), hydroxyphenylacetic acid (hpa), 3-hydroxyphenyl propionate (mhp) A comparative genome analysis revealed that the genome of AWD5 was highly similar with genomes of environmental as well as clinical K pneumoniae isolates The artemis output confirmed that there are 139 different genes present in AWD5 which were absent in genome of clinical strain K pneumoniae ATCC BAA-2146, and 25 genes were identified to be present in AWD5 genome but absent in genome of environmental strain K pneumoniae KP-1 Pathway analyzed using Kyoto Encyclopedia of Genes and Genomes enzyme database revealed the presence of gene clusters that code for enzymes to initiate the opening of aromatic rings The polyaromatic hydrocarbon and benzoate degradation were found to be metabolized through ortho-cleavage pathway, mineralizing the compounds to TCA cycle intermediates Genes for plant growth promoting attributes such as Indole acetic acid (IAA) synthesis, siderophore production, and phosphate solubilization were detected in the genome These attributes were verified in vitro, including IAA (1475 µg/ml), siderophore production (1356%), phosphate solubilization (19828 ng/ml), and ACC deaminase (0118 mM α-ketobutyrate/mg) in the presence of pyrene, and also compared with results obtained in glucose amended medium K pneumoniae AWD5 enhanced the growth of Jatropha curcas in the presence of pyrene-contaminated soil Moreover, AWD5 harbors heavy metal resistance genes indicating adaptation to contaminants The study revealed the genomic attributes of K pneumoniae AWD5 for its catabolic characteristics for different aromatic compounds, which makes it suitable for rhizoremediation of PAH-contaminated soil
TL;DR: This study evaluated mineralization of 14C-pyrene in soils with or without the augmentation of Mycobacterium vanbaalenii PYR-1, and characterized the effect of Brij-35 (synthetic) and rhamnolipid biosurfactant at different amendment rates.
TL;DR: In this article, the microbial mechanisms in nutrient and biosurfactant enhanced soil bioremediation of petroleum hydrocarbons (PHCs) were investigated and a systematic factorial design was conducted and a response surface reduced quadratic model was developed to determine the effects of nutrients and two surfactants (i.e., rhamnolipids and Tween 80) in the 36-day PHC degradation.
TL;DR: This trend demonstrates that the oil fractions initially not bioavailable for microbial degradation, were subsequently released to the sediment via catalytic conversion with laccase and manganese peroxidase, and the oil continues to be biodegraded by microbial populations.
TL;DR: This work shows that, despite their similar chemical structures, biodegradation of the three tested FAs is very distinct and draws attention to the unknown impacts that the accumulation of DFA and TFA may have in the environment as a result of their high recalcitrance.
TL;DR: In this article, a combination of calcium nitrate and denitrifiers was applied to reduce nitrogen and organic pollutants of urban river sediment in order to improve microbial biodegradation.