Identification of differentially expressed genes in sorghum (Sorghum bicolor) brown midrib mutants

Sorghum, a species able to produce a high yield of biomass and tolerate both drought and poor soil fertility, is considered to be a potential bioenergy crop candidate. The reduced lignin content characteristic of brown midrib (bmr) mutants improves the efficiency of bioethanol conversion from biomass. Suppression subtractive hybridization combined with cDNA microarray profiling was performed to characterize differential gene expression in a set of 13 bmr mutants, which accumulate significantly less lignin than the wildtype plant BTx623. Among the 153 differentially expressed genes identified, 43 were upregulated and 110 down regulated in the mutants. A semiquantitative RT–PCR analysis applied to 12 of these genes largely validated the microarray analysis data. The transcript abundance of genes encoding L-phenylalanine ammonia lyase and cinnamyl alcohol dehydrogenase was less in the mutants than in the wild type, consistent with the expectation that both enzymes are associated with lignin synthesis. However, the gene responsible for the lignin synthesis enzyme cinnamic acid 4-hydroxylase was upregulated in the mutants, indicating that the production of monolignol from L-phenylalanine may involve more than one pathway. The identity of the differentially expressed genes could be useful for breeding sorghum with improved efficiency of bioethanol conversion from lignocellulosic biomass

HCl Removal Using Calcined Ca–Mg–Al Layered Double Hydroxide in the Presence of CO2 at Medium–High Temperature

This present work aimed to investigate the influence of CO2 on HCl removal using calcined Ca–Mg–Al layered double hydroxides (CaMgAl-LDHs) at medium–high temperature (400–800 °C) in a fixed-bed reactor. It was revealed that a moderate CO2 concentration (~6%) in the flue gas of the municipal solid-waste incinerators could reduce the HCl capacity of the CaMgAl-layered double oxides (CaMgAl-LDOs). The highest capacity for HCl removal was observed over the CaMgAl-LDOs at 600 °C. However, sintering was also detected when the reaction temperature was below the calcination temperature (600 °C). Moreover, the decreasing HCl adsorption capacity of CaMgAl-LDOs was attributed to the existence of CO2 in the flue gas, which could efficiently inhibit the decomposition of carbonates as well as the conversion into metal chloride during the HCl removal process

Intermediate-Temperature Creep Deformation and Microstructural Evolution of an Equiatomic FCC-Structured CoCrFeNiMn High-Entropy Alloy

The tensile creep behavior of an equiatomic CoCrFeNiMn high-entropy alloy was systematically investigated over an intermediate temperature range (500⁻600 °C) and applied stress (140⁻400 MPa). The alloy exhibited a stress-dependent transition from a low-stress region (LSR-region I) to a high-stress region (HSR-region II). The LSR was characterized by a stress exponent of 5 to 6 and an average activation energy of 268 kJ mol−1, whereas the HSR showed much higher corresponding values of 8.9⁻14 and 380 kJ mol−1. Microstructural examinations on the deformed samples revealed remarkable dynamic recrystallization at higher stress levels. Dislocation jogging and tangling configurations were frequently observed in LSR and HSR at 550 and 600 °C, respectively. Moreover, dynamic precipitates identified as M23C6 or a Cr-rich σ phase were formed along grain boundaries in HSR. The diffusion-compensated strain rate versus modulus-compensated stress data analysis implied that the creep deformation in both stress regions was dominated by stress-assisted dislocation climb controlled by lattice diffusion. Nevertheless, the abnormally high stress exponents in HSR were ascribed to the coordinative contributions of dynamic recrystallization and dynamic precipitation. Simultaneously, the barriers imposed by these precipitates and severe initial deformation were referred to so as to increase the activation energy for creep deformation

Screening for and Identification of an Anti-clam Vibrio Marine Bacterium from an Aquaculture Pond in the Yellow Sea

The identification and use of probiotic bacterial stains is a practical approach to protect clams grown in aquaculture farms from disease. The inhibition of the pathogenic bacterium Vibrio alginolyticus was used as a trait to select a candidate probiotic bacterial strain in this study. An ideal bacterial strain, SW-1, was isolated from seawater from a clam farm. The selected isolate SW-1 was identified based on its physiological, morphological, and biochemical characteristics and its 16S rDNA sequence. The experiments showed that strain SW-1 had a high similarity to Pseudoalteromonas piscicida and could inhibit the growth of V. alginolyticus (V.-MP-1). SW-1 also improved the survival of clams following challenge with the pathogenic V.-MP-1. The mortality of clams was 100% after infection with 10(8) CFU/mL of V. alginolyticus, whereas mortality was only 11% when clams were infected with 10(8) CFU/mL of V.-MP1 while simultaneously exposed to the same concentration of Pseudoalteromonas SW-1, indicating that Pseudoalteromonas SW-1 could be used as a probiotic to protect farmed clams, and thus reduce the effects of antibiotics on aquatic environment