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Experimental studies were carried out to find the difference of preheating characteristics of Datong coal in O2/CO2 and air atmospheres by a circulating fluidized bed. It is found that pulverized coal could be both steadily preheated to above 800°C in the two different atmospheres, but the temperature distribution was more uniform along the riser in O2/CO2 atmosphere. During the preheating, the content of CO in the flue gas can reach 12.32% under the O2/CO2 atmosphere, far higher than that in air (5.94%). Simultaneously, the conversion rate of fixed carbon was higher in O2/CO2 atmosphere compared with that in air. It can be inferred the higher oxygen concentration and higher partial pressure of CO2 have greatly accelerated the gasification reaction. The BET analysis indicated a number of large pores were transformed into micropores during the preheating progress, and the major contributors for overall pore volume of chars and specific surface area are the micro-pores and the mesopores with diameter ranging from 2 nm to 10 nm. The inner pore structure was more developed in O2/CO2 atmosphere. [ABSTRACT FROM AUTHOR]

Toxin-antitoxin (TA) systems are widespread in bacteria and archaea. However, the roles of chromosomally encoded TA systems in bacterial physiology are still open to debate. In this study, a TA module-relBE in Bifidobacterium longum JDM301 (relBE(Bif)) was identified and its function in stress response was evaluated. Bioinformatics analysis of the whole genome sequences of JDM301 revealed a pair of linked genes encoding a RelBE-like TA system (RelBE(Bif)). Our results revealed a bicistronic operon formed by relBE(Bif) in JDM301. Over-expression of RelE(Bif) had a toxic effect on Escherichia coli, which could be neutralized by co-expression of its cognate antitoxin, RelB(Bif) Our data also demonstrated that RelE(Bif) is an mRNA interferase and that the activity of RelE(Bif) can be inhibited by RelB(Bif) These results suggest that RelE(Bif) is a toxic nuclease which arrests cell growth through mRNA degradation, and that the activity of RelE(Bif) can be abolished by co-expression of RelB(Bif) In addition, we also found that the expression of RelBE(Bif) is increased during osmotic stress, suggesting that RelBE(Bif) is activated under this adverse condition. Our results imply that the RelBE(Bif) TA module may represent a cell growth modulator which helps B. longum to deal with osmotic stress., (© The Author 2016. Published by Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)