Production of functionally active <Emphasis Type="Italic">Penicillium chrysogenum</Emphasis> isopenicillin N synthase in the yeast <Emphasis Type="Italic">Hansenula polymorpha</Emphasis>

Background  

β-Lactams like penicillin and cephalosporin are among the oldest known antibiotics used against bacterial infections. Industrially, penicillin is produced by the filamentous fungus Penicillium chrysogenum. Our goal is to introduce the entire penicillin biosynthesis pathway into the methylotrophic yeast Hansenula polymorpha. Yeast species have the advantage of being versatile, easy to handle and cultivate, and possess superior fermentation properties relative to filamentous fungi. One of the fundamental challenges is to produce functionally active enzyme in H. polymorpha.     

Vector competence of Coquillettidia linealis (Skuse) (Diptera: Culicidae) for Ross River and Barmah Forest viruses

Abstract Coquillettidia linealis is a severe pest on some of the Moreton Bay islands in Queensland, Australia, but little is known of its breeding habitats and biology. Because of its high abundance and its association with Ross River (RR) and Barmah Forest (BF) viruses by field isolation, its vector competence was evaluated in the laboratory by feeding dilutions of both viruses in blood. For RR, Cq. linealis was of comparable efficiency to Ochlerotatus vigilax (Skuse), recognised as being a major vector. Results were as follows for Cq. linealis and Oc. vigilax , respectively: dose to infect 50%, 10^2.2 and <10^1.7 CCID₅₀/mosquito; 88% and 90% disseminated infection at 4 days postinfection; transmission at 4 days with rates of 68−92% and 25−60%. For BF dose to infect 50%, 10^2.7 and 10^2.0; disseminated infection rates on first transmission day (day 6), 40% and 70%; transmission rates of 8−16% and 0−10%. As a capillary-tube method was used rather than suckling mice to demonstrate transmission, transmission rates may be underestimates. This, the first study of the vector competence of Cq. linealis in Australia, demonstrates that this species deserves control on the southern Moreton Bay islands.     

Size scaling of whole‐body metabolic activity in the noble crayfish (Astacus astacus) estimated from measurements on a single leg

1. Use of electron transport system (ETS) activity in a single leg for estimating whole‐body ETS activity was explored in the noble crayfish Astacus astacus. Oxygen consumption and ETS activity of the whole body and of a walking leg were measured in different‐sized animals at 10 °C to compare the size scaling of oxygen consumption, whole‐body ETS activity and the ratio of whole‐body ETS activity to oxygen consumption (ETS/R). 2. Electron transport system activity of a leg and the ratio of ETS activity of a whole crayfish to that of a leg were correlated with wet mass of animals. Therefore, metabolic potential in whole noble crayfish can be estimated on the basis of the measured ETS activity in a single leg and crayfish mass. This approach provides a valuable tool for determining metabolic characteristics of crayfish without killing them. 3. Mass‐specific oxygen consumption decreased with increasing wet mass, while ETS activity of whole crayfish showed no significant correlation with wet mass. Both oxygen consumption and ETS activity correlated significantly with protein mass. 4. The increase in ETS/R with increasing wet mass of the noble crayfish indicates that small organisms exploit a greater proportion of their metabolic potential for standard metabolism than larger ones. This is the first report on ETS/R in crayfish.     

EARLY STARVATION1 specifically affects the phosphorylation action of starch‐related dikinases

Starch phosphorylation by starch‐related dikinases glucan, water dikinase (GWD) and phosphoglucan, water dikinase (PWD) is a key step in starch degradation. Little information is known about the precise structure of the glucan substrate utilized by the dikinases and about the mechanisms by which these structures may be influenced. A 50‐kDa starch‐binding protein named EARLY STARVATION1 (ESV1) was analyzed regarding its impact on starch phosphorylation. In various in vitro assays, the influences of the recombinant protein ESV1 on the actions of GWD and PWD on the surfaces of native starch granules were analyzed. In addition, we included starches from various sources as well as truncated forms of GWD. ESV1 preferentially binds to highly ordered, α‐glucans, such as starch and crystalline maltodextrins. Furthermore, ESV1 specifically influences the action of GWD and PWD at the starch granule surface. Starch phosphorylation by GWD is decreased in the presence of ESV1, whereas the action of PWD increases in the presence of ESV1. The unique alterations observed in starch phosphorylation by the two dikinases are discussed in regard to altered glucan structures at the starch granule surface.     

A new cardiid bivalve from the Pliocene Baklan Basin (Turkey) and the origin of modern Ponto‐Caspian taxa

Abstract: We present the first record of the cardiid genus Monodacna from the Pliocene of Anatolia, Turkey. Monodacna imrei sp. nov. was found in the Pliocene Killik Formation from the western margin of the Baklan Basin, in very marginal brackish to freshwater lacustrine deposits. The new record extends the stratigraphic range of the modern Ponto‐Caspian genus back into the Pliocene and adds to earlier evidence that modern Ponto‐Caspian taxa originated in the Pliocene of south‐western Turkey.     

Description of Paratetrahymena parawassi n. sp. using Morphological and Molecular Evidence and a Phylogenetic Analysis of Paratetrahymena and Other Taxonomically Ambiguous Genera in the Order Loxocephalida (Ciliophora,Oligohymenophorea)

ABSTRACT. The marine scuticociliate Paratetrahymena parawassi n. sp. is described on the basis of morphology, especially infraciliature, and the sequence of its small subunit (SSU) rRNA gene to become the second known member of its genus. Paratetrahymena and other ciliates in the order Loxocephalida possess a mixture of morphological and morphogenetic features characteristic of the subclasses Hymenostomatia and Scuticociliatia. Accordingly, we used SSU rRNA sequences to analyze the phylogeny of Paratetrahymena and three other loxocephalid genera. Paratetrahymena and Cardiostomatella vermiformis formed a moderately well‐supported clade that diverged at a deep level from all other scuticociliates, supporting separation of loxocephalids from other scuticociliates as a suprafamilial taxon. Sathrophilus holtae was a sister taxon to Paratetrahymena and Cardiostomatella in a poorly supported, unresolved relationship; nevertheless, association of all three genera into a single clade was supported by an approximately unbiased (AU) test. Any association of these genera singly or as a group with the Hymenostomatia was rejected decisively by AU tests and by a complete absence in the loxocephalids of the unique nucleotide identities that distinguish hymenostomes. Therefore, the morphological and morphogenetic similarities of loxocephalids to hymenostomes may be plesiomorphies, and the conflicting mix of scuticociliate and hymenostome characteristics seen in loxocephalids may result from differing rates of character evolution. Dexiotrichides pangi and Urocentrum, which is currently classified as a peniculid, formed a small clade that associated with hymenostomes and peritrichs. Monophyly of the Loxocephalida with Dexiotrichides and/or Urocentrum included was not rejected by AU; however, inclusion of Urocentrum in the Peniculia was rejected by AU tests. A hypothesis is offered to explain the lack of resolution of loxocephalid ciliates and Urocentrum in phylogenetic trees, namely that their phylogenetic positions are influenced by a combination of heterogeneous data and long‐branch attraction caused by poor representation of taxa in analyses. The well‐known genus Cyclidium, a member of the order Pleuronematida, was revealed to be polyphyletic as a byproduct of our analyses of loxocephalids. In particular, Cyclidium porcatum appears to fall outside the clade containing typical members of the subclass Scuticociliatia and thus invites investigation as a possible member of the order Loxocephalida.     

Prevalence of non-strongyle gastrointestinal parasites of horses in Riyadh region of Saudi Arabia

This study aimed to provide recent data on the occurrence of non-strongyle intestinal parasite infestation in horses in the Riyadh region of Saudi Arabia as a basis for developing parasite control strategies. We conducted necropsy for 45 horses from September 2006 to November 2007 in the Riyadh region, Saudi Arabia. 39 out of 45 horses were infected with intestinal parasites with an infestation rate of 86.6%. Infestations with seven nematode species and two species of Gasterophilus larva were found. The most prevalent parasites were Strongyloides westeri (64.4%) and Parascaris equorum (28.8%) followed by Habronema muscae (22.2%). Trichostrongylus axei and Oxyuris equi were less common at (11.1%) and (8.8%), respectively. Habronema megastoma and Setaria equine were found in two horses only (4.4%). Gasterophilus intestinalis larvae were recovered from 39 horses (86.6%) and Gasterophilus nasalis larvae were found in 17 horses (37.7%). Season had a significant effect on the prevalence of P. equorum and G. nasalis, while age of horses had a significant effect only on the prevalence of P. equorum. The husbandry in Saudi Arabia appears to be conductive to parasites transmitted in stables or by insects rather than in pasture.     

Eimeria saudiensis N. Sp. (Apicomplexa: Eimeriidae) from the Arabian Oryx (Oryx leucoryx) in Saudi Arabia

Oocysts of Eimeria saudiensis n. sp. (Apicomplexa: Eimeriidae) are described from the feces of the Arabian oryx, Oryx leucoryx , from the Riyadh Zoo, Saudi Arabia. The oocysts were ellipsoidal or slightly ovoid, 31.2 times 24.5 (24.3–36.5 times 20.0–27.6) μm with a bilayered wall about 1.7 μm thick. The micropyle was covered by a dome-shaped cap. The oocyst residuum was absent, but tiny polar granules were present. The sporocysts were elongate ovoid, 14.3 times 7.2 (11.5–18.5 times 6.0–9.0) μm, had a Stieda body, but lacked a substiedal body. The sporocyst residuum was present, composed of numerous small granules. The sporozoites were elongate club-shaped, and contained two prominent refractile bodies.