Relative toxicity of native Chilean Bacillus thuringiensis strains against Scrobipalpuloides absoluta (Lepidoptera: Gelechiidae)

The larva of Scrobipalpuloides absoluta , a South American moth, is the most devastating insect pest of tomato production in Chile. The potential for using bacterial insecticides was studied analysing the relative toxicity of native Bacillus thuringiensis (BT) isolates belonging to the Chilean collection. The polymerase chain reaction (PCR) technique was used in order to facilitate the prescreening. Mixtures of homologous specific primers to regions within genes encoding CryI , CryIII and CryIV crystal proteins were employed to generate a PCR product profile of each BT isolate. Four isolates were selected and further characterized by means of SDS-PAGE, Western blot and bioassays on fourth-instar S. absoluta larvae. Relative toxicities were evaluated by LD₅₀ determinations. The entomocidal activity of isolate 121e, an autoagglutinating strain, was threefold higher than toxin synthesized by B. thuringiensis var. kurstaki . This native strain was also active against Culex pipiens larvae, although much less than towards S. absoluta .     

Apoxyria hirtuosa (Wiedemann, 1821) comb. n., lectotype designation, redescription and identification key to species of Apoxyria Schiner, 1866 (Asilidae, Laphriinae)

The type specimens of Neodiogmites hirtuosus (Wiedemann, 1821), two males and one female, deposited at the Museum für Naturkunde der Humboldt-Universität (ZMHB), Berlin were examined. The specimens show the diagnostic characters of Apoxyria Schiner, 1866: face strongly pronounced, swollen and curved hind tibia, and terminalia with epandrium large and hypandrium short and obtuse. A new combination is suggested, Apoxyria hirtuosa (Wiedemann, 1821), and lectotype and paralectotypes are designated. The species is redescribed, the male terminalia is described and illustrated for the first time, and an identification key to Apoxyria is presented.     

TGF-beta1 and IL-6 gene polymorphism in Spanish brucellosis patients

Polymorphisms in the cytokine genes have allowed for the understanding of the genetic determinants in several diseases. We investigated the polymorphism of the transforming growth factor (TGF)-beta1 and IL-6 genes in relation to susceptibility to human brucellosis. We typed 82 Spanish brucellosis patients and 102 healthy controls for TGF-beta1 polymorphisms in codons 10 and 25, and IL-6 promoter polymorphism at position -174 by PCR-SSP methods. The T/T G/G genotype of the TGF-beta1 gene was significantly increased in patients compared to controls (49% vs. 32%) P=0.02; OR=1.99 (1.05-3.80) and the T/C G/G genotype was significantly less common in the patients compared to the controls (32% vs. 49%) P=0.01; OR=0.48 (0.25-0.92). The CC genotype of codon 10 was significantly increased in the patients who had focal forms of the disease as compared with those who did not develop focal forms (19% vs. 4%), P=0.03; OR=0.19 (0.02-1.10). No differences were found in the IL-6 variants between the patients and the controls. These results suggest that polymorphism of the TGF-beta1 gene may be involved in susceptibility to brucellosis and to developing focal forms of the disease in a group of patients from southern Spain.     

Penicillium roqueforti: a multifunctional cell factory of high value‐added molecules

This is a comprehensive review, with 114 references, of the chemical diversity found in the fungus Penicillium roqueforti. Secondary metabolites of an alkaloidal nature are described, for example, ergot alkaloids such as festuclavine, isofumigaclavines A and B, and diketopiperazine alkaloids such as roquefortines A–D, which are derived from imidazole. Other metabolites are marcfortines A–C, PR‐toxin, eremofortines A–E, mycophenolic and penicillic acids, and some γ‐lactones. Also, recent developments related to the structural characteristics of botryodiplodin and andrastin are studied—the latter has anticancer properties. Finally, we discuss the enzymes of P. roqueforti, which can participate in the biotechnological production of high value‐added molecules, as well as the use of secondary metabolite profiles for taxonomic purposes.     

Comparative study of the fermentation of D-glucose/D-xylose mixtures with Pachysolen tannophilus and Candida shehatae

We have performed a comparative analysis of the fermentation of the solutions of the mixtures of D-glucose and D-xylose with the yeasts Pachysolen tannophilus (ATCC 32691) and Candida shehatae (ATCC 34887), with the aim of producing bioethanol. All the experiments were performed in a batch bioreactor, with a constant aeration level, temperature of 30v°C, and a culture medium with an initial pH of 4.5. For both yeasts, the comparison was established on the basis of the following parameters: maximum specific growth rate, biomass productivity, specific rate of substrate consumption (q_s) and of ethanol production (q_E), and overall ethanol and xylitol yields. For the calculation of the specific rates of substrate consumption and ethanol production, differential and integral methods were applied to the kinetic data. From the experimental results, it is deduced that both Candida and Pachysolen sequentially consume the two substrates, first D-glucose and then D-xylose. In both yeasts, the specific substrate-consumption rate diminished over each culture. The values q_s and q_E proved higher in Candida, although the higher ethanol yield was of the same order for both yeasts, close to 0.4 kg kg^у.