Hierarchically porous sponge for oily water treatment: Facile fabrication by combination of particulate templates and thermally induced phase separation method

Guowei Wang,Lusha Peng,Bin Yu,Shiguo Chen,Zaochuan Ge,Hiroshi Uyama 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.62 No.-

A polypropylene sponge with hierarchical structure was prepared from a polypropylene solution by combination of micro particle template and the phase separation technique. A simple procedure was proved to be able to fabricate a unique sponge in which both submillimeter-sized holes (≈200 μm) and small macrospores (≈10 μm) are formed. The unique structure was successfully confirmed by scanning electron microscopy measurement. In addition, the sponge showed low density, high hydrophobicity, and superoleophilicity. The sponge exhibited good compressibility, and high performance for the adsorption-release of oils. The adsorbability was proved to be improved in a large scale due to the existence of holes. Furthermore, the sponge demonstrated the ability to remove oil-in-water emulsion. Based on the properties, the present sponge has promising prospects for environmental applications in the treatment of oily water.

Effect of preliminary stresses on the resistance of <i>Escherichia coli</i> and <i>Staphylococcus aureus</i> toward non-thermal plasma (NTP) challenge

Liao, Xinyu,Li, Jiao,Suo, Yuanjie,Ahn, Juhee,Liu, Donghong,Chen, Shiguo,Hu, Yaqin,Ye, Xingqian,Ding, Tian Elsevier 2018 Food Research International Vol.105 No.-

<P>As the development of hurdle technology, cross-protection of various stresses for pathogens posed the potential risk to food safety and public health. This study tried to explore various preliminary stresses including acidity, osmosis, oxidation, heat and cold on the resistance of microbial cells toward the non-thermal plasma (NTP) exposure. The results indicated that short-term (4 h) exposure of Staphylococcus aureus and Escherichia coli to acidity, osmosis, oxidation, heat and cold stresses did not lead to the resistance to the subsequent NTP treatment. On the contrary, acidity, osmosis and heat preadaptation increased the vulnerability of E. coil cells to NTP treatment. After exposing S. aureus to osmosis, oxidation, heat and cold stress for longer period (24 h), the reduction level showed significantly (P < 0.05) higher. Interestingly, long-term (24 h) preliminary exposure of acidic stress exhibited protective effect for S. aureus against the following NTP exposure with less damage in cell membrane integrity, membrane potential and intracellular enzyme activity. It might be due to the protein production for oxidative stress response during preliminary acidic adaptation. In general, the obtained result helped to grasp better understanding of the microbial stress response to NTP treatment and provided insight for the future research in order to accelerate the development of NTP technology in food industry.</P>

Analysis of <i>Staphylococcus aureus</i> cell viability, sublethal injury and death induced by synergistic combination of ultrasound and mild heat

Li, Jiao,Suo, Yuanjie,Liao, Xinyu,Ahn, Juhee,Liu, Donghong,Chen, Shiguo,Ye, Xingqian,Ding, Tian Elsevier 2017 Ultrasonics sonochemistry Vol.39 No.-

<P><B>Abstract</B></P> <P>This study was designed to investigate the combined effects of ultrasound and mild heat on the viability of <I>S. aureus</I> in association with the cell membrane integrity and intracellular enzyme activity. Cells were treated by ultrasound under 55°C for 3, 5, 7, 10, and 15min. The dynamic changes of <I>S. aureus</I> cell viability, sublethal injury and death were evaluated using flow cytometric assay. Microscopies were applied to identify the morphological appearance, ultrastructure and topography of <I>S. aureus</I>. The results showed the membrane damage was synchronous with esterase inhibition during the exposure to sonication, leading to the immediate lethal effect. On the other hand, bacteria under the mild heat at 55°C were inactivated via a sublethal injury process. The different lethal modes were observed between sonication and mild heat treatments, which could synergistically inactivate <I>S. aureus</I>. The antibacterial value of thermo-sonication was greater than the sum of the individual treatments. The thermo-sonication combination synergistically reduced the number of sublethal cells and also resulted in severe cell damage.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The lethal modes induced by ultrasound and mild heat were different. </LI> <LI> Two sterilization techniques were synergistic in cell inactivation. </LI> <LI> Cell viability, sublethal injury and death were distinguished by flow cytometry. </LI> <LI> Thermo-sonication treatment reduced the number of sublethal cells. </LI> <LI> Microscopies revealed <I>S. aureus</I> morphological changes and bactericidal effect. </LI> </UL> </P>

Inactivation mechanisms of non-thermal plasma on microbes: A review

Liao, Xinyu,Liu, Donghong,Xiang, Qisen,Ahn, Juhee,Chen, Shiguo,Ye, Xingqian,Ding, Tian Elsevier 2017 Food Control Vol.75 No.-

<P>The increasing consumption of fresh-like food products requires the development of mild processing technologies without loss of nutritional value and sensory quality of foods. Non-thermal plasma (NTP) is an emerging and promising technology for extending the shelf-life of food products. However, the further development of a novel preservation technology should base on the adequate understandings of the effects on microbial behaviors. Therefore, the aim of this review is to provide an overview of the inactivation mechanisms of NTP technology on microbes. Topics covered are the basic introduction of NTP, the intrinsic and extrinsic factors affecting microbial inactivation effect and the probable mechanisms for microbial inactivation. Many factors, including processing parameters, environmental conditions and microbial properties have been shown to influence the bactericidal effect of NTP. According to previous research, the inhibitory activity of NTP against microbes includes biological and physical scenarios, though the exact mechanisms still remain unknown, requiring more investigations in the future. (C) 2016 Elsevier Ltd. All rights reserved.</P>

Significance of Viable but Nonculturable Escherichia coli: Induction, Detection, and Control

( Tian Ding ),( Yuanjie Suo ),( Qisen Xiang ),( Xihong Zhao ),( Shiguo Chen ),( Xingqian Ye ),( Donghong Liu ) 한국미생물 · 생명공학회 2017 Journal of microbiology and biotechnology Vol.27 No.3

Diseases caused by foodborne or waterborne pathogens are emerging. Many pathogens can enter into the viable but nonculturable (VBNC) state, which is a survival strategy when exposed to harsh environmental stresses. Pathogens in the VBNC state have the ability to evade conventional microbiological detection methods, posing a significant and potential health risk. Therefore, controlling VBNC bacteria in food processing and the environment is of great importance. As the typical one of the gram-negatives, Escherichia coli (E. coli) is a widespread foodborne and waterborne pathogenic bacterium and is able to enter into a VBNC state in extreme conditions (similar to the other gram-negative bacteria), including inducing factors and resuscitation stimulus. VBNC E. coli has the ability to recover both culturability and pathogenicity, which may bring potential health risk. This review describes the concrete factors (nonthermal treatment, chemical agents, and environmental factors) that induce E. coli into the VBNC state, the condition or stimulus required for resuscitation of VBNC E. coli, and the methods for detecting VBNC E. coli. Furthermore, the mechanism of genes and proteins involved in the VBNC E. coli is also discussed in this review.

Preceding treatment of non-thermal plasma (NTP) assisted the bactericidal effect of ultrasound on <i>Staphylococcus aureus</i>

Liao, Xinyu,Li, Jiao,Muhammad, Aliyu Idris,Suo, Yuanjie,Ahn, Juhee,Liu, Donghong,Chen, Shiguo,Hu, Yaqin,Ye, Xingqian,Ding, Tian Elsevier 2018 FOOD CONTROL Vol.90 No.-

<P>Ultrasound is a promising non-thermal inactivation technique. However, ultrasound treatment alone is not very effective. In this study, combined applications of ultrasound and non-thermal plasma (NTP) were assessed for their inactivation efficacy and the physiological change on Staphylococcus aureus cells. The lethal and sublethal injury induced by individual ultrasound, NTP, ultrasound-NTP (UP) and NTP-ultrasound treatments was determined by plate count method. Then, we applied fluorescent technology to demonstrate the physiological variations of S. aureus during various treatments. NTP exposure followed by ultrasound treatment exhibited the highest inactivation rate of S. aureus, Prior NTP helped to provide enough reactive oxygen species (ROS) dissolved in the medium, and the subsequent ultrasound assisted in the injection of ROS into S. aureus cells. This accelerated the reaction between ROS and intracellular biomolecules, which led to the rapid death of the microbes. On the contrary, S. aureus cells treated with ultrasound first were more likely to develop and enhance oxidative response, allowing S. aureus to resist toward the following NTP stressor. Therefore, the findings of this study may be used to the optimization of hurdle technologies of ultrasound and NTP in practice. (C) 2018 Elsevier Ltd. All rights reserved.</P>