Search

Isoprene represents a key building block for the production of valuable materials such as latex, synthetic rubber or pharmaceutical precursors and serves as basis for advanced biofuel production. To enhance the production of the volatile natural hydrocarbon isoprene, released by plants, animals and bacteria, the Kudzu isoprene synthase (kIspS) gene has been heterologously expressed in Bacillus subtilis DSM 402 and Bacillus licheniformis DSM 13 using the pHT01 vector. As control, the heterologous expression of KIspS in E. coli BL21 (DE3) with the pET28b vector was used. Isoprene production was analyzed using Gas Chromatography Flame Ionization Detector. The highest isoprene production was observed by recombinant B. subtilis harboring the pHT01-kIspS plasmid which produced 1434.3 μg/L (1275 µg/L/OD) isoprene. This is threefold higher than the wild type which produced 388 μg/L (370 μg/L/OD) isoprene, when both incubated at 30 °C for 48 h and induced with 0.1 mM IPTG. Additionally, recombinant B. subtilis produced fivefold higher than the recombinant B. licheniformis, which produced 437.2 μg/L (249 μg/L/OD) isoprene when incubated at 37 °C for 48 h induced with 0.1 mM IPTG. This is the first report of optimized isoprene production in B. licheniformis. However, recombinant B. licheniformis showed less isoprene production. Therefore, recombinant B. subtilis is considered as a versatile host for heterologous production of isoprene.

Thalassemia is a congenital hemolytic disease caused by defective globin synthesis treated by blood transfusion. Transfusion-transmitted infections still make a great challenge in the management of patients with thalassemia major. The most important worldwide transfusion-transmitted infections are hepatitis B virus (HBV), hepatitis C virus (HCV) and HIV. The objective of this study is to update the prevalence of the three major transfusion-transmitted infections HCV, HBV and HIV among thalassemic patients followed up in the Hematology Department, Children Hospital, Cairo University. The study included 174 multitransfused thalassemic patients (162 major and 12 intermedia), registered at the Pediatric Hematology Clinic, Cairo University. Their age ranged from 2 to 27 years with a mean of 11.26 ± 5.4 years. Patients were subjected to full history taking, stressing on history of blood transfusions (onset, frequency and duration) at a single or multiple centers and abdominal examination. Laboratory investigations including complete blood count, aminotransferases (aspartate aminotransferase and alanine aminotransferase), ferritin and viral markers of HBV surface antigen (HBsAg), HCV antibodies (anti-HCV) and anti-HIV were assayed for all cases by a third-generation ELISA method. HCV PCR was performed for 75 cases. Of the 174 patients, none of them were HBsAg and anti-HIV positive. However, 90 patients were anti-HCV positive (51.7%). HCV PCR was positive in 56 patients (74.3%) of the 75 with positive antibody tested. HCV antibody positivity is statistically significant with age of the patient, serum ferritin and liver transaminases (P < 0.01). HCV-RNA by PCR positivity was significantly related to patients' age and serum ferritin (P < 0.05). Serum ferritin showed statistically significant positive correlation with liver transaminases. Despite the decrease in prevalence of HCV antibody in our patients from 71% in 1995 to 51.7% in our study, yet HCV infection still represents a major health problem for our thalassemic patients, which requires more attention and efforts to challenge. There is a dramatic decrease in the prevalence of HBV infection over the last decade, thanks to mass compulsory vaccination and blood screening. HIV infection does not represent a problem owing to very low population prevalence.