Microbial degradation of complex aromatic mixtures and analysis of biodegradation products using comprehensive two-dimensional gas chromatography-mass spectrometry

Ugljovodonici nafte i poljoprivredni lignocelulozni otpad neke su od najčešćih zagađujućih supstanci u životnoj sredini, a zajednički im je složen hemijski sastav i prisustvo velikog broja aromatičnih jedinjenja koja ispoljavaju toksične efekte. Cilj ove disertacije bio je proučavanje razgradnje složenih smeša aromatičnih supstanci i to aromatične frakcija dizel goriva D2 (AFD) i komine grožđa koja nastaje u procesu proizvodnje vina. Za ispitivanje biodegradacije korišćena je sveobuhvatna dvodimenzionalna gasna hromatografija sa masenom spektrometrijom (GCxGC-MS). Za razliku od konvencionalne gasne hromatografije, ovom tehnikom se sa većom rezolucijom razdvajaju analiti, pa je pogodnija za analizu složenih smeša...Petroleum hydrocarbons and agricultural lignocellulosic waste are some of the most common environmental pollutants. They have a very complex structure and are composed of a large number of different aromatic compounds that have toxic effects. The aim of this dissertation was to study the degradation of complex aromatic mixtures, namely diesel fuel D2 aromatic fraction (AFD) and grape pomace obtained from the winemaking process. For the biodegradation analysis, comprehensive twodimensional gas chromatography-mass spectrometry was used (GCxGC-MS). Compared with conventional gas chromatography, this technique has a greater separation resolution, thus, it is more successful in the analysis of complex mixtures..

Application of microbial levan as a new component for production of graft copolymer with polystyrene

Polysaccharides based on fructose, also called fructans, are synthetized from sucrose by some plant species and many bacteria, fungi and Archaea. Levan is an exopolysaccharide composed of fructose units and has numerous applications in personal care and cosmetics, medicine and food industry. Polystyrene is the most widespread polymer for plastic production due to its low costing and easy production. Degradation of polystyrene is longterm process, therefore incorporating natural polymers is the desirable approach. In the present study, levan-polystyrene graft copolymer (L-g-PS) was synthetized, characterized and influence of reaction time on grafting reaction at two temperatures was investigated. Levan was isolated after cultivation Bacillus licheniformis NS032. Syntheses of L-g-PS were performed by the free radical reaction using K2S2O8 as initiator. Grafting reactions proceeded in nitrogen atmosphere, at 55ºC and 70ºC and reaction time ranged between 15 and 210 min. FTIR spectra and XRD patterns were recorded using a Thermo Nicolet 6700 Spectrophotometer and Philips PW-1710 automated diffractometer, respectively. The formation of L-d-g-PS was confirmed by FTIR spectra which displayed the presence of all characteristic peaks for both component and X-ray diffractograms which showed amorphous nature of copolymer. Compared to other reaction parameters, the temperature of 70ºC and time of 45 min was more optimal showing higher percentage of grafting

Metabolomic study of the biodegradation pathway of sodium-benzoate in pseudomonas aeruginosa san ai

The goal of this study was to analyze the products of benzoate degradation by polyextremophilic, hydrocarbonoclastic Pseudomonas aeruginosa san ai using targeted metabolomic analysis in order to determine the specificity of the metabolic pathway of sodium-benzoate.Poster: [https://cer.ihtm.bg.ac.rs/handle/123456789/5126

Efficient biodegradation of petroleum n-alkanes and polycyclic aromatic hydrocarbons by polyextremophilic Pseudomonas aeruginosa san ai with multidegradative capacity

Pseudomonas aeruginosa san ai, an alkaliphilic, metallotolerant bacterium, degraded individual selected petroleum compounds, i.e., n-alkanes (n-hexadecane, n-nonadecane) and polycyclic aromatic hydrocarbons (fluorene, phenanthrene, pyrene) with efficiency of 80%, 98%, 96%, 50% and 41%, respectively, at initial concentrations of 20 mg L 1 and in seven days. P. aeruginosa san ai showed a high biodegradative capacity on complex hydrocarbon mixtures, the aliphatic and aromatic fractions from crude oil. The efficiency of P. aeruginosa san ai degradation of crude oil fractions in seven days reached stage 3–4 of the oil biodegradation scale, which ranges from 0 (no biodegradation) to 10 (maximum biodegradation). Identified metabolites concomitant with genomic and enzymatic data indicated the terminal oxidation pathway for the n-alkane degradation, and the salicylate and phthalate pathways for fluorene biodegradation. Polyextremophilic P. aeruginosa san ai, as a biosurfactant producer with multidegradative capacity for hydrocarbons, can be used in an improved strategy for environmental bioremediation of hydrocarbon-contaminated sites, including extreme habitats characterized by low or elevated temperatures, acidic or alkaline pH or high concentrations of heavy metals

Application of microbial levan as a new component for production of graft copolymer with polystyrene

Polysaccharides based on fructose, also called fructans, are synthetized from sucrose by some plant species and many bacteria, fungi and Archaea. Levan is an exopolysaccharide composed of fructose units and has numerous applications in personal care and cosmetics, medicine and food industry. Polystyrene is the most widespread polymer for plastic production due to its low costing and easy production. Degradation of polystyrene is longterm process, therefore incorporating natural polymers is the desirable approach. In the present study, levan-polystyrene graft copolymer (L-g-PS) was synthetized, characterized and influence of reaction time on grafting reaction at two temperatures was investigated. Levan was isolated after cultivation Bacillus licheniformis NS032. Syntheses of L-g-PS were performed by the free radical reaction using K2S2O8 as initiator. Grafting reactions proceeded in nitrogen atmosphere, at 55ºC and 70ºC and reaction time ranged between 15 and 210 min. FTIR spectra and XRD patterns were recorded using a Thermo Nicolet 6700 Spectrophotometer and Philips PW-1710 automated diffractometer, respectively. The formation of L-d-g-PS was confirmed by FTIR spectra which displayed the presence of all characteristic peaks for both component and X-ray diffractograms which showed amorphous nature of copolymer. Compared to other reaction parameters, the temperature of 70ºC and time of 45 min was more optimal showing higher percentage of grafting

Evolution of humic acids during ex situ bioremediation on a pilot level: The added value of the microbial activity

Environmental pollution is a global problem, while bioremediation technology removes pollutants from the environment using microorganisms. This study was aimed at investigating how a bioremediation process affected soil humification. In soil polluted with petroleum and its derivatives that was submitted to bioremediation, besides the total petroleum hydrocarbons and the number of microorganisms, quantitative and qualitative changes of isolated humic acids were determined during the process. The bioremediation of 150 m3 of polluted soil lasted 150 days. The level of total petroleum hydrocarbons decreased by 86.6 %, while the level of humic acids increased by 26.5 %. The elemental analysis showed the reduction of C and the H/C ratio and the increase of O and the O/C ratio of isolated humic acids during the process. The ratio of absorbencies at 465 and 665 nm also increased. Based on this and the Fourier-transform infrared spectra, it was shown that the humic acids isolated at the end of bioremediation were enriched with oxygen functional groups and aromatic structures. This study provides one of the first insights into the relationship between bioremediation and humification, as well as evidence of how hydrocarbon-degrading microorganisms have a significant influence on changes to humic acid structure during bioremediation

Sensitivity to heavy metals and growth on aromatic compounds of bacterial strains isolated from soil contaminated with petroleum products

Aromatični ugljovodonici dospevaju u životnu sredinu na različite načine, kao što su izlivanje nafte, sagorevanje fosilnih goriva, upotreba pesticida, curenje benzina. Pošto su toksični i potencijalno karcinogeni, razvijaju se različite tehnologije za njihovo uklanjanje, a jedna od najvažnijih je bioremedijacija. Brojna istraživanja pokazala su da teški metali utiču na mikrobne zajednice i njihovu aktivnost, jer izmenjuju esencijalne jone metala, ili modifikuju konformaciju proteina. Dejstvo metala zavisi od njegove koncentracije i dostupnosti u medijumu i vrste mikroorganizma. Teški metali su često prisutni u zemljištu kontaminiranom naftnim derivatima. Osetljivost na teške metale smanjuje biodegradacioni potencijal bakterija koje se koriste u procesu bioremedijacije

Ecotoxicity of degradation product from dye Reactive Black 5 by electrochemical degradation products using MFC as a source of electricity

Poster presented at: 58th Meeting of the Serbian Chemical Society, Belgrade, Serbia, June 9-10, 2022Abstract: [https://cer.ihtm.bg.ac.rs/handle/123456789/5269

Supplementary data for the article: Medić, A.; Lješević, M.; Inui, H.; Beškoski, V.; Kojić, I.; Stojanović, K.; Karadžić, I. Efficient Biodegradation of Petroleum N-Alkanes and Polycyclic Aromatic Hydrocarbons by Polyextremophilic Pseudomonas Aeruginosa San Ai with Multidegradative Capacity. RSC Adv. 2020, 10 (24), 14060–14070. https://doi.org/10.1039/C9RA10371F

Supplementary material for: [https://doi.org/10.1039/c9ra10371f]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/3995

Evaluation of assays for screening polycyclic aromatic hydrocarbon-degrading potential of bacteria

Within a 30-day incubation laboratory study, the polycyclic aromatic hydrocarbon (PAH) degradation profile of two bacteria, Planomicrobium sp. RNP01 and Rhodococcus sp. RNP05 were studied by three microtiter plate assays to reveal the combination of certain biological and biochemical characteristics which are reliable indicators in evaluation of bacterial biodegradation abilities. The three assays, which are hydrocarbon growth assay, 2,6-DCPIP assay and dehydrogenase activity assay revealed that Rhodococcus sp. RNP05 exhibited better potential for PAH degradation than Planomicrobium sp. RNP01. Differences between initial and final optical density and specific growth rate constants were significantly higher (r = 0.995, P < 0.05) in case of Rhodococcus sp. RNP05 on all tested substrates, as compared to Planomicrobium sp. RNP01. This was confirmed by GC-FID analyses. Dehydrogenase activity of Rhodococcus sp. RNP05 was higher (r = 0.9995, P < 0.05) than Planomicrobium sp. RNP01 and correlated positively with the hydrocarbon growth assay (r = 0.999, P < 0.05, for Rhodococcus sp. RNP05, r = 0.986, P < 0.05 for Planomicrobium sp. RNP01). This study has shown that the combination of these assays could be used for determining the bioremediation potential of PAHs in petroleum contaminated soil with the ability of screening a large number of bacterial strains.Degradacija policikličnih aromatičnih ugljovodonika (polycyclic aromatic hydrocarbons - PAH) ispitivana je testovima u mikrotitar pločama pomoću dva bakterijska soja Planomicrobium sp. RNP01 i Rhodococcus sp. RNP05, u periodu od 30 dana. Rezultati ispitivanja su ukazali da se kombinacijom određenih bioloških i biohemijskih karakteristika mogu kreirati dobri indikatori u proceni bakterijskog degradacionog potencijala. Tri testa, 2,6-DCPIP test, test dehidrogenazne aktivnosti i test rasta na ugljovodonicima pokazali su da Rhodococcus sp. RNP05 ima veći potencijal za degradaciju PAH jednjenja u odnosu na Planomicrobium sp. RNP01. Razlike u početnoj i krajnjoj optičkoj gustini i specifične konstante rasta bile su značajno više (r = 0,995, P < 0,05) u testu sa Rhodococcus sp. RNP05 na svim testiranim supstratima, u poređenju sa Planomicrobium sp. RNP01, a dobijeni rezultati su potvrđeni gasno-hromatogafskom-FID analizom. Dehidrogenazna aktivnost soja Rhodococcus sp. RNP05 bila je viša u odnosu na Planomicrobium sp. RNP01 (r = 0,9995, P < 0,05) i u pozitivnoj korelaciji sa testom rasta na ugljovodonicima (r = 0,999, P < 0,05, za Rhodococcus sp. RNP05, r = 0,986, P < 0,05 za Planomicrobium sp. RNP01). Rezultati prikazanog istraživanja ukazuju na to da se kombinacija ovih testova može koristiti za određivanje bioremedijacionog potencijala za razgradnju PAH jedinjenja u zemljištu zagađenim naftom, pri čemu se dobija i mogućnost testiranja velikog broja bakterijskih sojeva