The objective of this study was to examine the ethanol yield potential of three barley varieties (Xena, Bold, and Fibar) in comparison to two benchmarks, corn and wheat. Very high gravity (VHG; 30% solids) fermentations using both conventional and Stargen 001 enzymes for starch hydrolysis were carried out as simultaneous saccharification and fermentation. The grains and their corresponding dried distiller's grain with solubles (DDGS) were also analyzed for nutritional and value-added characteristics. A VHG traditional fermentation approach utilizing jet-cooking fermentation revealed that both dehulled Bold and Xena barley produced ethanol concentrations higher than that produced by wheat (12.3, 12.2, and 11.9%, respectively) but lower than that produced by corn (13.8%). VHG-modified Stargen-based fermentation of dehulled Bold barley demonstrated comparable performance (14.3% ethanol) relative to that of corn (14.5%) and wheat (13.3%). Several important components were found to survive fermentation and were concentrated in DDGS. The highest yield of phenolics was detected in the DDGS (modified Stargen 001, 20% solids) of Xena (14.6 mg of gallic acid/g) and Bold (15.0 mg of gallic acid/g) when the hull was not removed before fermentation. The highest concentration of sterols in DDGS from barley was found in Xena (3.9 mg/g) when the hull was included. The DDGS recovered from corn had the highest concentration of fatty acids (72.6 and 77.5 mg/g). The DDGS recovered from VHG jet-cooking fermentations of Fibar, dehulled Bold, and corn demonstrated similar levels of tocopherols and tocotrienols. Corn DDGS was highest in crude fat but was lowest in crude protein and in vitro energy digestibility. Wheat DDGS was highest in crude protein content, similar to previous studies. The barley DDGS was the highest in in vitro energy digestibility.

The mechanism of fertility inhibition of conjugation by the F plasmid depends on the presence of both the FinO protein and an antisense RNA, FinP, which together control the expression of the positive regulator of the transfer operon TraJ. FinO both prevents the degradation of FinP, allowing its intracellular concentration to rise, and promotes duplex formation with its target, the traJ mRNA. In this study, deletions in finO were constructed and fused to gst, encoded by the pGEX-2T expression vector, to give GST-FinO fusions of varying lengths. These fusions were then tested for their ability to bind FinP and traJ mRNA, and to promote duplex formation. Our results suggest that the predicted basic N-terminal alpha-helix is involved in RNA binding, while the central domain is involved in duplex formation. The presence of the acidic C-terminal domain protects FinP from ribonucleolase degradation and might enhance binding of the N-terminal alpha-helical domain in a manner reminiscent of the Rom protein of ColE1.

The general stress response mediated by the sigma factor RpoS is important for survival of bacteria in adverse environments. A mutant unable to produce RpoS was constructed using the diazotrophic bacterium Azotobacter vinelandii strain UW. Under nondesiccating, solid-medium growth conditions the wild type was culturable for 16.5 years, while the rpoS mutant remained viable for only 10 months. The rpoS mutant exhibited reduced survival compared to the wild type following hydrogen peroxide stress, and stationary phase cells were killed rapidly by 15 mM H 2 O 2 . Three catalases (Kat1, Kat2, and Kat3) were expressed in the wild type under the conditions used. Kat2 was expressed in exponential phase during shake flask growth and could be induced under highly aerated conditions in all growth phases, suggesting that there was induction by reactive oxygen intermediates. Kat3 was possibly an isoform of Kat2. In contrast, Kat1 was expressed in an RpoS-dependent manner during the mid-exponential to late stationary phases. RpoS expression did not occur exclusively in stationary phase but was influenced by changes in carbon and nitrogen source availability. There was 26-to 28-fold induction of the RpoS protein during acetate-to-glucose and ammonium-to-N 2 diauxic shifts. Following recovery of growth on the alternative carbon or nitrogen source, RpoS protein concentrations declined rapidly to a basal level. However, rpoS mRNA levels did not correlate directly to RpoS levels, suggesting that there was posttranscriptional regulation. Evidence obtained using the RpoS-dependent reporter Kat1 suggested that there is regulation of the RNAP:RpoS holoenzyme at the level of complex formation or activity.The stress and starvation response is primarily regulated by the alternative sigma factor, variably designated 38 , S , or RpoS, in many gram-negative organisms. Expression of this factor during stationary phase has been shown to regulate (positively or negatively) nearly 360 genes or 10% of the annotated genome of Escherichia coli (32), while the homologue in Pseudomonas aeruginosa regulates 772 genes or 14% of the genome (38). RpoS has been shown to regulate the production of secondary metabolites and various pathogenicity determinants in pseudomonads (14,43). In addition to stationaryphase expression, RpoS induction is also observed when E. coli exhausts specific nutrients during growth in minimal medium (35). The magnitude of RpoS induction is the same (ϳ4-fold) whether the stress is a terminal starvation event, such as glucose exhaustion (35), or a transitional starvation event during a diauxic shift from glucose to lactose (10). Following the stress event, the concentration of RpoS decreases to a basal level, whether starvation is alleviated or not (10, 35). Although equivalent studies have been done during nitrogen exhaustion, no RpoS studies have been done during nitrogen diauxie in a diazotroph.Catalase, peroxidase, and superoxide dismutase are used by aerobes in all kingdoms to degrade reactive oxygen intermediates (ROIs), s...

An adult female with severe mental retardation and dysmorphic features is described. A de novo chromosomal aberration involving 8p was found. The karyotype was 46, XX, inv dup (8) (pl2→p23.1). Dosage studies with the DNA probe D8S7, which is located at 8p23→8pter, showed that the patient was monosomic for this marker. Thus the de novo rearrangement generated a duplication‐deficiency chromosome. The possible mechanisms of formation of this abnormal chromosome are discussed.

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