Anaerobic biotransformation of hexachlorocyclohexane isomers by <Emphasis Type="Italic">Dehalococcoides</Emphasis> species and an enrichment culture

The biotransformation of hexachlorocyclohexane isomers (HCH) by two Dehalococcoides mccartyi strains (195 and BTF08) and an enrichment culture was investigated and compared to conversion by the obligate anaerobic strain Clostridium pasteurianum strain DSMZ 525. The D. mccartyi strains preferentially transformed γ-HCH over α-HCH and δ-HCH isomers while β-HCH biotransformation was not significant. In case of the enrichment culture, γ-HCH was preferentially transformed over the δ-HCH, β-HCH and α-HCH isomers. Major observed metabolites in both cases were tetrachlorocyclohexene and as end products monochlorobenzene (MCB) and benzene. Dechlorination of the γ-HCH isomer was linked to an increase in cell numbers for strain 195. γ-HCH transformation was linked to considerable carbon stable isotope fractionation with the enrichment factor ε_c?=???5.5?±?0.8‰ for D. mccartyi strain 195, ε_c?=???3.1?±?0.4‰ for the enrichment culture and ε_c?=???4.1?±?0.6‰ for co-metabolic transformation by C. pasteurianum.     

Redneck, a new mutant of the axolotl (Ambystoma mexicanum) likely affects the development of cranial neural crest.

A novel developmental mutant in the Mexican axolotl is described. Designated redneck (rn), the mutant gene is inherited as a simple Mendelian recessive. In homozygotes, rn causes massive haemorrhage in the posterior head, rostrocaudal compression of the craniovisceral skeleton, abnormal differentiation of vertebral cartilage, micrognathia, aglossia, microphthalmia and abnormal hepatic development. Affected larvae become evident at the onset of feeding, and eventually die of starvation. Based on the tissues affected, we propose that rn affects later developmental events in the differentiation and morphogenesis of a subset of cranial neural crest cells. Thus, rn may prove a valuable model system for examining the role of neural crest cells in the development of cranial and endodermal derivatives.     

Inhibitory effects of bee venom and its components against viruses <Emphasis Type="Italic">in vitro</Emphasis> and <Emphasis Type="Italic">in vivo</Emphasis>

Bee venom (BV) from honey bee (Apis Melifera L.) contains at least 18 pharmacologically active components including melittin (MLT), phospholipase A₂ (PLA₂), and apamin etc. BV is safe for human treatments dose dependently and proven to possess different healing properties including antibacterial and antiparasitidal properties. Nevertheless, antiviral properties of BV have not well investigated. Hence, we identified the potential antiviral properties of BV and its component against a broad panel of viruses. Co-incubation of non-cytotoxic amounts of BV and MLT, the main component of BV, significantly inhibited the replication of enveloped viruses such as Influenza A virus (PR8), Vesicular Stomatitis Virus (VSV), Respiratory Syncytial Virus (RSV), and Herpes Simplex Virus (HSV). Additionally, BV and MLT also inhibited the replication of non-enveloped viruses such as Enterovirus-71 (EV-71) and Coxsackie Virus (H3). Such antiviral properties were mainly explained by virucidal mechanism. Moreover, MLT protected mice which were challenged with lethal doses of pathogenic influenza A H1N1 viruses. Therefore, these results provides the evidence that BV and MLT could be a potential source as a promising antiviral agent, especially to develop as a broad spectrum antiviral agent.     

Microalgae engineering toolbox: Selectable and screenable markers

Engineering microalgae has opened a new era for plant biologists and biotechnologists. Microalgae had been proved as a promising candidate for the production of biopharmaceuticals, nutraceuticals, antioxidants, antimicrobial and antiviral compounds, in dyeing and food industry as well for biofuel production. Genetic transformation of some important microalgae has been successful, but several other potential microalgae species still need scientific attention. The success of the genetic transformation depends mainly on the utilization of the selectable and screenable markers. Like for other higher crop plants, several useful markers have been reported for microalgae transformation. In this follow-up, we compared different marker genes for genetic engineering of approximately all the industrially important microalgae. We have discussed the expression host, the targeted genome, appropriate selection agent, as well as the transformation method. Genetic transformation is an expensive and labor intensive process and this review will aid to shorten the time span by providing a database of appropriate markers for microalgae research which could serve as a guide for those involved in the genetic engineering of microalgae.     

Climate‐driven changes to the spatio‐temporal distribution of the parasitic nematode,Haemonchus contortus,in sheep in Europe

Recent climate change has resulted in changes to the phenology and distribution of invertebrates worldwide. Where invertebrates are associated with disease, climate variability and changes in climate may also affect the spatio‐temporal dynamics of disease. Due to its significant impact on sheep production and welfare, the recent increase in diagnoses of ovine haemonchosis caused by the nematode Haemonchus contortus in some temperate regions is particularly concerning. This study is the first to evaluate the impact of climate change on H. contortus at a continental scale. A model of the basic reproductive quotient of macroparasites, Q₀, adapted to H. contortus and extended to incorporate environmental stochasticity and parasite behaviour, was used to simulate Pan‐European spatio‐temporal changes in H. contortus infection pressure under scenarios of climate change. Baseline Q₀ simulations, using historic climate observations, reflected the current distribution of H. contortus in Europe. In northern Europe, the distribution of H. contortus is currently limited by temperatures falling below the development threshold during the winter months and within‐host arrested development is necessary for population persistence over winter. In southern Europe, H. contortus infection pressure is limited during the summer months by increased temperature and decreased moisture. Compared with this baseline, Q₀ simulations driven by a climate model ensemble predicted an increase in H. contortus infection pressure by the 2080s. In northern Europe, a temporal range expansion was predicted as the mean period of transmission increased by 2–3 months. A bimodal seasonal pattern of infection pressure, similar to that currently observed in southern Europe, emerges in northern Europe due to increasing summer temperatures and decreasing moisture. The predicted patterns of change could alter the epidemiology of H. contortus in Europe, affect the future sustainability of contemporary control strategies, and potentially drive local adaptation to climate change in parasite populations.     

Deciphering role of technical bioprocess parameters for bioethanol production using microalgae

Microalgae biomass is considered an important feedstock for biofuels and other bioactive compounds due to its faster growth rate, high biomass production and high biomolecules accumulation over first and second-generation feedstock. This research aimed to maximize the specific growth rate of fresh water green microalgae Closteriopsis acicularis, a member of family Chlorellaceae under the effect of pH and phosphate concentration to attain enhanced biomass productivity. This study investigates the individual and cumulative effect of phosphate concentration and pH on specific growth characteristics of Closteriopsis acicularis in autotrophic mode of cultivation for bioethanol production. Central-Composite Design (CCD) strategy and Response Surface Methodology (RSM) was used for the optimization of microalga growth and ethanol production under laboratory conditions. The results showed that high specific growth rate and biomass productivity of 0.342 day⁻¹ and 0.497 g L⁻¹ day⁻¹ respectively, were achieved at high concentration of phosphate (0.115 g L⁻¹) and pH (9) at 21st day of cultivation. The elemental composition of optimized biomass has shown enhanced elemental accumulation of certain macro (C, O, P) and micronutrients (Na, Mg, Al, K, Ca and Fe) except for nitrogen and sulfur. The Fourier transform infrared spectroscopic analysis has revealed spectral peaks and high absorbance in spectral range of carbohydrates, lipids and proteins, in optimized biomass. The carbohydrates content of optimized biomass was observed as 58%, with 29.3 g L⁻¹ of fermentable sugars after acid catalyzed saccharification. The bioethanol yield was estimated as 51 % g ethanol/g glucose with maximum of 14.9 g/L of bioethanol production. In conclusion, it can be inferred that high specific growth rate and biomass productivity can be achieved by varying levels of phosphate concentration and pH during cultivation of Closteriopsis acicularis for improved yield of microbial growth, biomass and bioethanol production.     

Isolation and identification of cuticular compounds from the mediterranean flour moth,Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), their antibacterial activities and biological functions

Cuticular analysis of Ephestia kuehniella females by gas chromatography-mass spectrometry revealed the presence of four groups of chemical compounds including alkane, alcohol, aldehyde and fatty acid. The cuticular n-alkanes ranged from 12 to 18, 20, 23, 24 and 29 carbon atoms in the chain. The most abundant n-alkanes detected in the cuticular extracts were C₁₄ (14.98%) and C₁₈ (8.15%). Cuticular fatty acids included hexadecenoic acid, 9-octadecenoic acid and 9,12-octadecenoic acid. Two types of alcohol including, 2-methyl-Z,Z-3,13-octadecadienol and 9-methyl-Z-10-tetradecen-1-ol acetate, were found in the cuticular lipids of the females. Two aldehyde components, (E)-11-hexadecenal and 9,17-octadecadienal, were identified in the cuticular extract of E. kuehniella. Antibacterial activity of the cuticular compounds was tested against Bacillus subtilis, Bacillus thuringiensis and Escherichia coli. These compounds from the moths inhibited the growth of Gram-positive bacteria. The functional characteristics of the cuticular compounds operating as pheromones, species-associated compounds and host-resistant compounds to bacterial infection are discussed.     

Delipidated retroviruses as potential autologous therapeutic vaccines--a pilot experiment

This pilot experiment in a simian immunodeficiency virus (SIV) chronic infection model aimed at extending our previous findings that vaccination with delipidated SIV resulted in more potent and diversified antiviral responses (1). Macaques chronically infected with SIVmac239 treated with antiretroviral therapy (ART) were vaccinated with autologous delipidated virus via consecutive lymph node targeted immunizations-1, 1 and 10 mug of virus spaced monthly. Results showed all animals had lasting viral load reduction approaching 1 log compared to set-point, and disease delay. Delipidation may enhance processing/ presentation of viral antigen eliciting potent antiviral control even at such late infection stage.