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Purpose: To isolate and characterise the oxidative stress-responsible disulfide bond proteins (DSBP) from Pseudomonas aeruginosa, under hydrogen peroxide (H2O2) and gamma ray-induced stress conditions. Materials and methods: Oxidative stress in P. aeruginosa was induced by H2O2 or 60Co γ-rays. DSBP of P. aeruginosa were isolated by using a thiol affinity purification method and liquid chromatography-mass spectrometry (LC-MS/MS). Induction of DSBP and their transcriptional levels were analysed by Western blot and quantitative-polymerase chain reaction (q-PCR), respectively. Results: We isolated and identified 40 DSBP in P. aeruginosa. A comparison of DSBP patterns under different stress conditions, including exposure to 0.5 mM H2O2 and 30 Gy of gamma rays, was carried out. We selected 13 DSBP based on their increased intensity under oxidative stress and investigated their expression levels using q-PCR. Of these 13 proteins, P. aeruginosa ( PA) 0126 and PA0277 transcriptional levels were strongly induced (4- to 9-fold) by gamma ray. A corresponding induction in the translational levels of PA0126 was confirmed by Western blot analysis. PA0126 was identified is a hypothetical protein with 206 amino acids and contained three cysteine residues. A shift in molecular weight of PA0126 under oxidised/reduced state indicated its homo-oligomeric structure under non-reducing condition. Conclusion: PA0126, a hypothetical protein with disulfide bonds was identified as a key responder to oxidative stress along with other known DSBP of P. aeruginosa. We determined that all DSBP underwent a redox cycling. Furthermore, our results give deeper insight into the relationship between oxidative stress and DSBP in P. aeruginosa. [ABSTRACT FROM AUTHOR]

Ionizing irradiation is a useful technique for disinfestation under plant quarantine as well as post-harvest management. Effects of gamma irradiation treatment were tested on different developmental events of Carposina sasakii , which is a serious pest of various orchard crops. Apple fruits infested by C. sasakii were irradiated by gamma rays ranging from 0 to 300 Gy. Inhibition rates were determined on behavioral events related to development, including larval exit from apples, cocoon formation, adult eclosion, and oviposition. Failure rates of all these developmental events increased with increasing doses of irradiation. Rates of larval exit from apples and cocoon formation decreased to 13.2% and 1.7%, respectively, at 300 Gy. However, the adult eclosion rate decreased to 5.4% at 100 Gy and was completely inhibited at doses greater than 150 Gy. LD99 values for the inhibition of cocoon formation and adult emergence was estimated into 313.4 and 191.0 Gy. Furthermore, adults developed from irradiated larvae completely failed to lay eggs. Thus, irradiation of infested apples at doses of 200 Gy and higher completely inhibited the next generation of C. sasakii . Our results suggest that gamma irradiation treatment would be a promising technique for the control of C. sasakii . [ABSTRACT FROM AUTHOR]

Abstract: Aloe has been widely used in food products, pharmaceuticals, and cosmetics because of its aromatic and therapeutic properties. In the present study, the ethanolic extracts of aloe gel were gamma-irradiated from 10 to 100kGy. After gamma irradiation, the color of the ethanolic extracts of aloe gel changed to red; this color persisted up to 40kGy but disappeared above 50kGy. Liquid chromatography/mass spectrometry analysis demonstrated the production of a new, unknown compound (m/z=132) after gamma irradiation of the ethanolic extracts of aloe gel. The amount of this unknown compound increased with increasing irradiation up to 80kGy, and it was degraded at 100kGy. Interestingly, it was found that gamma irradiation significantly increased the antioxidant activity, as measured by the 1,1-diphenyl-2-picrylhydrazyl-radical scavenging capacity. The antioxidant activity of aloe extract was dramatically increased from 53.9% in the non-irradiated sample to 92.8% in the sample irradiated at 40kGy. This strong antioxidant activity was retained even at 100kGy. These results indicate that gamma irradiation of aloe extract can enhance its antioxidant activity through the formation of a new compound. Based on these results, increased antioxidant activity of aloe extracts by gamma rays can be applied to various industries, especially cosmetics, foodstuffs, and pharmaceuticals. [Copyright &y& Elsevier]

Abstract: Pretreating wheat straw with a combination of dilute acid and gamma irradiation was performed in an attempt to enhance the enzymatic hydrolysis for bioethanol production. The glucose yield was significantly affected by combined pretreatment (3% sulfuric acid-gamma irradiation), compared with untreated wheat straw and individual pretreatment. The increasing enzymatic hydrolysis after combined pretreatment is resulting from decrease in crystallinity of cellulose, loss of hemicelluloses, and removal or modification of lignin. Therefore, combined pretreatment is one of the most effective methods for enhancing the enzymatic hydrolysis of wheat straw biomass. [Copyright &y& Elsevier]