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A biofilm is formed as a result of adhesion of microorganisms to various surfaces with the production of extracellular polymers (polysaccharides and proteins). Biofilms cause serious problems in the chemical, medical and pharmaceutical industries. Recent findings indicate that some natural phenolic compounds found in plants have an anti-biofouling effect on biofilm formation by Gram-negative bacteria. The anti-biofouling activities of 14 selected phenol and natural phenolic compounds were tested against Pseudomonas aeruginosa, using a microtiter-plate. A modified microtiter-plate assay was used because it enabled indirect measurement of bacterial cells attached to the surface of the wells. This assay involved fixing the bacterial film with methanol, staining with crystal violet dye and then releasing the bound dye with 33% glacial acetic acid. The optical density (OD) of the solution was measured at 570 nm by using an automated ICN Flow Titertek Multiscan Plus reader. Phenol and natural phenolic compounds except ethyl linoleate and tocopherol showed a significant reduction in biofilm formation by P. aeruginosa.

Feedstock for biodiesel production has changed over time and it varies depending on regions. Reports and journal articles on biodiesel feedstock resources over the last decade from 2006 to 2016 were reviewed in this article. The regional trends still maintain as the USA and the EU still predominantly use soybean oil and rapeseed oil, respectively, and palm oil is the major source of biodiesel in Asia. It is expected that the food‐crop based biodiesel will continue to be dominant for the next decade. However, it was found that uses of animal fats and used cooking oil are increasing both in the USA and the EU. Because of the increasing diversity in feedstock inputs to biodiesel, it is necessary to better understand the effects of feedstock characteristics on engine performance and emissions. In this review, we limit the reports on biodiesel emissions to those who used 100% biodiesel combusted in a one‐cylinder, four‐stroke, direct injection engine set up in a laboratory. All the emission results were obtained from the same or similar engine conditions to fairly compare them. CO, CO2, NOx, and PM emissions are compared between the biodiesels derived from soybean oil, rapeseed oil, palm oil, jatropha oil, used cooking oil, animal fats, and algal oil. It was found that more emission studies are needed for algal biodiesel. More in‐depth studies are necessary for PM characteristics including the compositions of trace metals, elemental and organic carbon. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 7–19, 2018

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Reactive oxygen species (ROS) have been found in plants, mammals, and natural environmental processes. The presence of ROS in mammals has been linked to the development of severe diseases, such as diabetes, cancer, tumors, and several neurodegenerative conditions. The most common ROS involved in human health are superoxide (O2•−), hydrogen peroxide (H2O2), and hydroxyl radicals (•OH). Organic and inorganic molecules have been integrated with various methods to detect and monitor ROS for understanding the effect of their presence and concentration on diseases caused by oxidative stress. Among several techniques, fluorescence and electrochemical methods have been recently developed and employed for the detection of ROS. This literature review intends to critically discuss the development of these techniques to date, as well as their application for in vitro and in vivo ROS detection regarding free-radical-related diseases. Moreover, important insights into and further steps for using fluorescence and electrochemical methods in the detection of ROS are presented.

Biofouling is a process of surface colonization by microorganisms through cell adhesion and production of extracellular polymers (polysaccharides and proteins). It often causes serious problems in the chemical, medical and pharmaceutical industries. Recently, it was demonstrated that some natural phenolic compounds found in plants and vegetables have an antibiofouling effect, reducing formation of biofilm by Gram-negative bacteria. In this study, Streptococcus mutans, a Gram-positive bacterium was investigated for the antibiofouling effect of polyphenols. It was hypothesized that the two enzymes, glucosyltransferase and fructosyltransferase, produced by S. mutans, would be inhibited by the natural phenolic compounds. When these two enzymes were inhibited, less (or no) biofilms were formed. Enzymes were separated from a S. mutans culture medium, and their activities were measured with five different polyphenols using microtiter-plates and high-performance liquid chromatography. The results of minimum inhibitory concentration (MIC) were used to determine the enzyme inhibition effect of polyphenols on biofilm formation without killing the cells. Most of the polyphenols used showed considerable reduction of biofilm formation. Gallic acid and tannic acid showed significant enzyme inhibition effects below their MICs.

In this review, we will be discussing existing techniques and recent progress in gasification and pyrolysis techniques for the conversion of cellulosic biomass into a viable source of energy. Topics of discussion will include biomass gasification to produce syngas and process concerns, as well as various ways to address these issues, biomass pyrolysis for production of bio-oil and examples of novel techniques published in recent articles, co-firing of biomass and coal and the use of co-gasification and co-pyrolysis, the combination of pyrolysis and gasification to process pyrolysis products to syngas through gasification and liquifaction of syngas and its conversion to fuels such as ethanol, methanol, and Fisher-Tropsh oil through modified catalysis.

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