Genetic variability among Beauveria brongniartii (Saccardo) Petch isolates fromvarious geographical and host origins based on AFLP analysis

The entomopathogenic hyphomycete Beauveria brongniartii is a promising candidate for biocontrol of economically important agricultural and forest pests. Assessment of genetic relatedness of this species appears to be essential to gain insight into the monitoring of such biocontrol products. Distinction of Beauveria spp. strains with different virulence to target organisms revealed to be a serious constraint in the development of successful biocontrol using these important species. Thus, there is a need to find ways to monitor these strains when applied to natural agents. We have used amplified fragment length polymorphism (AFLPs) markers to estimate genetic variations among fourteen isolates (ten B. brongniartii, two B. bassiana (BALSAMO) VUILLEMIN and two Nomuraea rileyi (FARLOW) SAMSON) obtained from different geographical origins and hosts with differing virulence to scarabs. Seven different AFLP primer combinations yielded a total of 229 AFLP fragments comprised between 30 (EcoRI-ACA/Tru1l-C) to 57 (EcoRI-AAG/Tru1l-CTT) AFLP markers with an average of 54 amplified fragments per primer combination. Fragment size varied between 50-541 base pairs (bp) among the ten B. brongniartii isolates analysed in this study achieving a good resolution between the isolates. The cluster analysis based on genetic distance values clustered all isolates at above 0.40 similarity and demonstrated that some B. brongniartii isolates from distinct geographical origins and various hosts showed a greater genetic variability

Degradation of Chloroaromatics: Purification and Characterization of a Novel Type of Chlorocatechol 2,3-Dioxygenase of Pseudomonas putida GJ31

A purification procedure for a new kind of extradiol dioxygenase, termed chlorocatechol 2,3-dioxygenase, that converts 3-chlorocatechol productively was developed. Structural and kinetic properties of the enzyme, which is part of the degradative pathway used for growth of Pseudomonas putida GJ31 with chlorobenzene, were investigated. The enzyme has a subunit molecular mass of 33.4 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Estimation of the native Mr value under nondenaturating conditions by gel filtration gave a molecular mass of 135 ± 10 kDa, indicating a homotetrameric enzyme structure (4 × 33.4 kDa). The pI of the enzyme was estimated to be 7.1 ± 0.1. The N-terminal amino acid sequence (43 residues) of the enzyme was determined and exhibits 70 to 42% identity with other extradiol dioxygenases. Fe(II) seems to be a cofactor of the enzyme, as it is for other catechol 2,3-dioxygenases. In contrast to other extradiol dioxygenases, the enzyme exhibited great sensitivity to temperatures above 40°C. The reactivity of this enzyme toward various substituted catechols, especially 3-chlorocatechol, was different from that observed for other catechol 2,3-dioxygenases. Stoichiometric displacement of chloride occurred from 3-chlorocatechol, leading to the production of 2-hydroxymuconate.

Aortic arch enlargement and coarctation repair through a left thoracotomy: significance of ductal perfusion

OBJECTIVE To analyse the technique of neonatal aortic arch enlargement without cardiopulmonary bypass through a left posterior thoracotomy, as an adjunct to extended resection for Coarctation and severe arch hypoplasia. METHODS Ten neonates with coarctation, severe arch hypoplasia and a persistent ductus arteriosus (PDA) were subjected to arch repair through a left posterior thoracotomy. Nine of these patients had associated significant intracardiac anomalies; three of them received pulmonary artery (PA) banding. After exclusion from circulation, the roof of the intervening arch between left carotid and left subclavian was enlarged using a patch. After adequate reperfusion, a classic resection and extended end-to-end anastomosis was performed. Median age and weight were 5.5 (1-10) days and 3.3 (2.2-4.1)kg respectively. The median preoperative arch diameter was 1.07 (0.75-1.32)mm/kg body weight. RESULTS All patients could be successfully operated with this approach. The non-ischaemic and ischaemic aortic clamp times were 40 (15-68) and 23 (18-32)min, respectively. The median postoperative arch diameter achieved was 1.43 (1.06-1.46)mm/kg body weight. None of the patients had significant gradient early postoperatively. Two patients with recurrent stenosis were successfully treated with balloon dilatation (1) or surgery with cardiopulmonary bypass (CPB) (1). One patient has a corrected gradient of 16mmHg in the proximal arch which is being observed. The remaining patients are free from stenosis at a median follow-up of 30.1 (13.2-57.8) months. CONCLUSIONS Use of PDA for lower body perfusion allows complex reconstruction of the arch without incurring lower body ischaemia. The extended resection could then be performed without excessive stretch. This modification saves these patients from undergoing a complex arch reconstruction with CPB in the early neonatal perio

Einsatz molekularer Marker zur Analyse der genetischen Diversität unterschiedlicher Populationen der Blutlauszehrwespe, Aphelinus mali (Haldeman) (Hymenoptera: Aphelinidae)

Die Blutlaus Eriosoma lanigerum (Hausmann) wurde Ende des 18. Jahrhunderts nach Europa eingeschleppt. E. lanigerum ist ein Schädling des Apfels, wobei es durch die Saugtätigkeit der Aphiden zu Wuchshemmungen (Blutlauskrebs, Blutlausgallen) infolge von Stoffwechselstörungen, zu irreversiblen Trieb- und Knospenschäden bis hin zum Absterben des Baumes kommen kann. Durch ihre versteckte Lebensweise unter den Rindenschuppen des Baumes sowie auf Grund von flüssigkeitsabweisenden Wachsausscheidungen sind die Tiere sehr gut gegen chemische Bekämpfungsmaßnahmen geschützt. Alternativ kann eine biologische Bekämpfung über den natürlichen Gegenspieler der Blutlaus, die Blutlauszehrwespe Aphelinus mali (HALDEN), erfolgen. Zwar kann sich diese Zehrwespe in wärmeren Gebieten sehr gut vermehren, bei niedrigen Frühjahrstemperaturen kann die Populationsdichte aber stark minimiert werden oder ganz einbrechen. Auch feuchte Witterung wird von A. mali nicht gut vertragen und schmälert die Parasitierungsraten. Die Blutlauszehrwespe hat einen Entwicklungsnullpunkt bei 8,3 bis 9,0°C, während die Blutlaus erst bei ca. 5°C ihre Entwicklung einstellt. Damit ergibt sich die Frage, ob es Biotypen dieser Schlupfwespe gibt, die möglicherweise besser an die vor Ort herrschenden Klimabedingungen angepasst sind. Ziel der vorliegenden Untersuchungen war es daher, das Ausmaß der genetischen Diversität zwischen einzelnen Populationen zu erfassen und somit Aussagen über eventuell auftretende Biotypen der Wespe treffen zu können.The endoparasitoid Aphelinus mali (HALDEMAN) (Hymenoptera: Aphelinidae) has been introduced from its native home North America to Europe in 1920 as a biological control agent for the woolly apple aphid Eriosoma lanigerum (HAUSMANN). When A. mali appears early in spring with the temperatures being relatively low at this time, the rate of parasitism and consequently the effectivity of the parasite is quite low. Thus, an identification and a subsequent release of A. mali biotypes which might be better adapted to the prevailing environmental conditions could result in higher parasitisation rates by this parasitoid. As a first step towards the identification of A. mali biotypes we examined the extent of genetic diversity in A. mali field populations and in individuals from a laboratory rearing A. mali was collected from different regions such as Germany (BBA Dossenheim, Lake Constance, Altes Land, Stuttgart-Mühlhausen, Ahrweiler), Canada, France, Italy and the Netherlands and genomic DNA was analysed using the AFLP-Technique (Amplified Fragment Length Polymorphism) as well as amplification and sequence analysis of the ITS-2 (Internally Transcribed Spacer) region