scholarly journals Degradation of Penicillin G by Visible Light Irradiation-Assisted Biotransformation by Whole Cell paracoccus sp .

2020 ◽  
Author(s):  
Peng Wang ◽  
Chen Shen ◽  
Qinqin Cong ◽  
Jialin Lu ◽  
Xiaochun Wang
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Genomic Analysis ◽  
Light Irradiation ◽  
Penicillin G ◽  
Key Factors ◽  
Whole Cell ◽  
H Nmr ◽  
Kinetics Of ◽  
Catalytic Effects

Abstract Background: The Paracoccus sp. strain (KDSPL-02) isolated from sludge was identified and evaluated for catalytic activity in the degradation of penicillin G. Results: High degradation efficiency and synergistic catalytic effects of the whole cell and visible light without additional catalysts were observed. The key factors influencing the degradation and kinetics of penicillin G were investigated. The results showed the phenylacetic acid, which was produced during penicillin G biodegradation, exhibited stronger inhibiting effects on KDSPL-02. However, this effect was reduced by visible light irradiation without any additional photocatalyst; furthermore, the rate of penicillin G biodegradation was accelerated, reaching a 100% rate in 12 h at a penicillin G concentration of 1.2 g/L. Four key intermediates produced during penicillin G degradation were isolated and identified by LC–MS, 1H NMR, and 13C NMR. Enzymes involved in the PAA pathway were proposed from a genomic analysis of paracoccus sp. KDSPL-02. Conclusions:These results provide a new method for bio-degrading of penicillin or other antibiotic pollutants using photoaccelerating biocatalysts with greater efficiency and more environmentally friendly conditions.

scholarly journals Degradation of Penicillin G by Visible Light Irradiation-assisted Biotransformation by Whole Cell Paracoccus Sp.

2021 ◽  
Author(s):  
Peng Wang ◽  
Chen Shen ◽  
Qinqin Cong ◽  
Jihua Liu ◽  
Xiaochun Wang
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Genomic Analysis ◽  
Light Irradiation ◽  
Penicillin G ◽  
Key Factors ◽  
Whole Cell ◽  
H Nmr ◽  
Kinetics Of ◽  
Catalytic Effects

Abstract Background: The Paracoccus sp. strain (KDSPL-02) isolated from sludge was identified and evaluated for catalytic activity in the degradation of penicillin G. Results: High degradation efficiency and synergistic catalytic effects of the whole cell and visible light without additional catalysts were observed. The key factors influencing the degradation and kinetics of penicillin G were investigated. The results showed the phenylacetic acid, which was produced during penicillin G biodegradation, exhibited stronger inhibiting effects on KDSPL-02. However, this effect was reduced by visible light irradiation without any additional photocatalyst; furthermore, the rate of penicillin G biodegradation was accelerated, reaching a 100% rate in 12 h at a penicillin G concentration of 1.2 g/L. Four key intermediates produced during penicillin G degradation were isolated and identified by LC–MS, 1H NMR, and 13C NMR. Enzymes involved in the PAA pathway were proposed from a genomic analysis of paracoccus sp. KDSPL-02. Conclusions:These results provide a new method for bio-degrading of penicillin or other antibiotic pollutants using photoaccelerating biocatalysts with greater efficiency and more environmentally friendly conditions.

Study of Thiophene in Phthalocyanine Sensitized SnO2 Photo Catalytic Oxidation’s Oil

2014 ◽  
Vol 608-609 ◽  
pp. 985-990
Author(s):  
Cui Lan Feng
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Oxidation Reaction ◽  
Photocatalytic Oxidation ◽  
Catalytic Performance ◽  
Kinetic Process ◽  
Light Irradiation ◽  
Photo Catalyst ◽  
Kinetics Of ◽  
Catalytic Effects

Based on phthalocyanines --SnO2 as a photo catalyst, this paper uses the degrading difference of thiophene by various catalysts under ultraviolet and visible light irradiation conditions to compare the catalytic effects of the different phthalocyanine compounds --SnO2 photosensitive catalysts, and summarize the reasons and laws to influence the catalysts’ catalytic performance, and analyze the kinetic process of photocatalytic oxidation reaction, and initially discuss kinetics of photocatalytic oxidation reaction and its products.

scholarly journals Adsorption and Photocatalytic Kinetics of Visible-Light Response N-Doped TiO2Nanocatalyst for Indoor Acetaldehyde Removal under Dark and Light Conditions

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Yu-Hao Lin ◽  
Chih-Huang Weng ◽  
Jing-Hua Tzeng ◽  
Yao-Tung Lin
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Light Response ◽  
Reaction Scheme ◽  
Light Irradiation ◽  
Light Conditions ◽  
Volatile Organic ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Kinetics Of

Understanding the removal nature of the indoor volatile organic compounds under realistic environment conditions would give clear guidance for the development of air purification devices. The study investigated the removal of indoor acetaldehyde using visible-light-responsive N-doped TiO2(N-TiO2) photocatalyst under visible-light irradiation (light) and in the absence of light (dark). The adsorption kinetics of acetaldehyde onto N-TiO2followed a pseudo-second-order model. The magnitude of acetaldehyde adsorption is proportional to temperature, and the results were fitted to the Langmuir isotherm model. Moreover, the effect of initial acetaldehyde concentration and visible-light intensity on the photooxidation of acetaldehyde was well described by the Langmuir-Hinshelwood model. Results show that the mesoporous N-TiO2catalyst had a high ability to absorb acetaldehyde in the dark condition, and then acetaldehyde was subsequently photooxidized under visible-light irradiation. The adsorption capacity was found to increase with decreasing temperature. The negative value ofΔG° and the positive value ofΔS° indicate that the adsorption of acetaldehyde onto N-TiO2was a spontaneous process. Finally, a reaction scheme for removal process of indoor acetaldehyde by N-TiO2was proposed.

scholarly journals Effect of photoinitiator on chain degradation of hyaluronic acid

2019 ◽  
Vol 23 (1) ◽  
Author(s):  
Bo Min Hong ◽  
Su A Park ◽  
Won Ho Park
Keyword(s):  
Hyaluronic Acid ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Light Irradiation ◽  
Proton Nuclear Magnetic Resonance ◽  
Attenuated Total Reflectance ◽  
Oxygen Species ◽  
Photochemical Process ◽  
Phenol Group ◽  
H Nmr

Abstract Objectives Photocrosslinking systems of polymers have been widely studied using UV or visible light irradiation. However, the photodegradation behavior derived from light irradiation was rarely reported, comparing with the photocrosslinking. In this study, the tyramine-modified hyaluronic acid (HA/Tyr) hydrogel was prepared using riboflavin (RF) as a photoinitiator, and the degradation behavior of HA by the reactive oxygen species (ROS) generated in photochemical process was investigated. Materials and methods The HA/Tyr conjugate was synthesized by EDC/NHS chemistry to introduce phenol group. Degree of substitution (DS, %) of phenol group to HA molecule was about 25%. The structural change of HA/Tyr was measured by proton nuclear magnetic resonance (1H-NMR) and attenuated total reflectance infrared spectroscopy (ATR-FTIR), and the rheological properties of photocrosslinked HA/Tyr hydrogel were investigated by rheometer. Results The HA/Tyr solution with 25% substitution formed a stable hydrogel via visible light irradiation in the presence of RF photoinitiator. Rheological data of HA/Tyr solution showed that the storage modulus (G’) was increased with increasing HA concentration. Additionally, it was found that RF initiated by visible light irradiation induced the degradation of HA molecular chain, and consequently reduced the viscosity of HA/Tyr solutions. Conclusion The results indicate that RF-based photoinitiator system caused the degradation of HA molecule by ROS generated in photochemical process as well as the crosslinking of HA/Tyr.

Kinetics of Humic Acids Photodegradation in Aqueous Solution Using TiO2/ ZnO/Co Composite Photocatalyst

2019 ◽  
Vol 962 ◽  
pp. 117-121
Author(s):  
Muhammad Ali Zulfikar ◽  
Dira Irnameria ◽  
Muhamad Nasir
Keyword(s):  
Aqueous Solution ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Degradation Rate ◽  
Light Irradiation ◽  
Organic Substances ◽  
Composite Photocatalyst ◽  
Taste And Odor ◽  
Uv Visible ◽  
Kinetics Of

Humic acid (HA) is a major component of natural organic substances and affects water quality, such as color, taste and odor. Therefore, removal of HA from surface water or wastewater is very important. In this paper, the photodegradation kinetics of these compounds using TiO2/ZnO/Co composite photocatalyst under visible light irradiation was investigated. The progress of photocatalytic degradation of the HA has been observed by measuring the absorbance in UV-Visible spectrophotometer. The results reveal that the TiO2/ZnO/Co composite photocatalyst exhibits much better photocatalytic activity than those of pure TiO2 and TiO2/ZnO on photodegradation of HA under visible light irradiation, with degradation rate constants were found 0.0163, 0.0079 and 0.0032 (min-1), respectively.

Cu Doped TiO2: Visible Light Assisted Photocatalytic Antimicrobial Activity and High Temperature Anatase Stability

2018 ◽  
Author(s):  
Snehamol Mathew ◽  
Priyanka Ganguly ◽  
Stephen Rhatigan ◽  
Vignesh Kumaravel ◽  
Ciara Byrne ◽  
...  
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Density Functional ◽  
Anatase Phase ◽  
Sol Gel ◽  
Chemical Properties ◽  
Light Irradiation ◽  
Health Concern ◽  
Bacterial Inactivation ◽  
X Ray

Indoor surface contamination by microbes is a major public health concern. A damp environment is one potential sources for microbe proliferation. Smart photocatalytic coatings on building surfaces using semiconductors like titania (TiO<sub>2</sub>) can effectively curb this growing threat.<b> </b>Metal-doped titania in anatase phase has been proved as a promising candidate for energy and environmental applications. In this present work, the antimicrobial efficacy of copper (Cu) doped TiO<sub>2 </sub>(Cu-TiO<sub>2</sub>) was evaluated against <i>Escherichia coli</i> (Gram-negative) and <i>Staphylococcus aureus</i> (Gram-positive) under visible light irradiation. Doping of a minute fraction of Cu (0.5 mol %) in TiO<sub>2 </sub>was carried out <i>via</i> sol-gel technique. Cu-TiO<sub>2</sub> further calcined at various temperatures (in the range of 500 °C – 700 °C) to evaluate the thermal stability of TiO<sub>2</sub> anatase phase. The physico-chemical properties of the samples were characterised through X-ray diffraction (XRD), Raman spectroscopy, X-ray photo-electron spectroscopy (XPS) and UV-visible spectroscopy techniques. XRD results revealed that the anatase phase of TiO<sub>2</sub> was maintained well, up to 650 °C, by the Cu dopant. UV-DRS results suggested that the visible light absorption property of Cu-TiO<sub>2 </sub>was enhanced and the band gap is reduced to 2.8 eV. Density functional theory (DFT) studies emphasises the introduction of Cu<sup>+</sup> and Cu<sup>2+</sup> ions by replacing Ti<sup>4+</sup> ions in the TiO<sub>2</sub> lattice, creating oxygen vacancies. These further promoted the photocatalytic efficiency. A significantly high bacterial inactivation (99.9%) was attained in 30 mins of visible light irradiation by Cu-TiO<sub>2</sub>.

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