Metabolite diversification by cultivation of the endophytic fungus Dothideomycete sp. in halogen containing media: Cultivation of terrestrial fungus in seawater

The endophytic fungus, Dothideomycete sp. CRI7, isolated from the terrestrial plant, Tiliacora triandra, was salt tolerant, capable of growing in the culture medium prepared from seawater; salts in seawater did not have any effects on the fungal growth. Metabolite productions of the fungus CRI7 cultivated in media prepared from seawater (MSW), prepared from deionized water supplemented with potassium bromide (MKBr) or potassium iodide (MKI), and prepared from deionized water (MDW) were investigated. It was found that the cultivation of the fungus CRI7 in MKBr and MSW enabled the fungus to produce nine new metabolites (1–9). The production of an azaphilone, austdiol (10), of the fungus CRI7 grown in MDW was 0.04 g/L, which was much lower than that grown in MSW, MKBr, and MKI media which provided the yields of 0.5, 0.9, and 1.2 g/L, respectively, indicating that halogen salts significantly enhanced the production of the polyketide 10. The cultivation of terrestrial fungi in media containing halogen salts could therefore be useful for the metabolite diversification by one strain-many compounds (OSMAC) approach. Moreover, the isolated polyketides had significant biosynthetic relationship, suggesting that the cultivation of fungi in halogen containing media could provide the insights into certain polyketide biosynthesis. One of the isolated compounds exhibited antibacterial activity with the MIC value of 100 μg/mL.     

Low Message Sensation Health Promotion Videos Are Better Remembered and Activate Areas of the Brain Associated with Memory Encoding

Greater sensory stimulation in advertising has been postulated to facilitate attention and persuasion. For this reason, video ads promoting health behaviors are often designed to be high in “message sensation value” (MSV), a standardized measure of sensory intensity of the audiovisual and content features of an ad. However, our previous functional Magnetic Resonance Imaging (fMRI) study showed that low MSV ads were better remembered and produced more prefrontal and temporal and less occipital cortex activation, suggesting that high MSV may divert cognitive resources from processing ad content. The present study aimed to determine whether these findings from anti-smoking ads generalize to other public health topics, such as safe sex. Thirty-nine healthy adults viewed high- and low MSV ads promoting safer sex through condom use, during an fMRI session. Recognition memory of the ads was tested immediately and 3 weeks after the session. We found that low MSV condom ads were better remembered than the high MSV ads at both time points and replicated the fMRI patterns previously reported for the anti-smoking ads. Occipital and superior temporal activation was negatively related to the attitudes favoring condom use (see Condom Attitudes Scale, Methods and Materials section). Psychophysiological interaction (PPI) analysis of the relation between occipital and fronto-temporal (middle temporal and inferior frontal gyri) cortices revealed weaker negative interactions between occipital and fronto-temporal cortices during viewing of the low MSV that high MSV ads. These findings confirm that the low MSV video health messages are better remembered than the high MSV messages and that this effect generalizes across public health domains. The greater engagement of the prefrontal and fronto-temporal cortices by low MSV ads and the greater occipital activation by high MSV ads suggest that that the “attention-grabbing” high MSV format could impede the learning and retention of public health messages.     

Biotechnological production of the European corn borer sex pheromone in the yeast Yarrowia lipolytica

The European corn borer (ECB) Ostrinia nubilalis is a widespread pest of cereals, particularly maize. Mating disruption with the sex pheromone is a potentially attractive method for managing this pest; however, chemical synthesis of pheromones requires expensive starting materials and catalysts and generates hazardous waste. The goal of this study was to develop a biotechnological method for the production of ECB sex pheromone. Our approach was to engineer the oleaginous yeast Yarrowia lipolytica to produce (Z)-11-tetradecenol (Z11-14:OH), which can then be chemically acetylated to (Z)-11-tetradecenyl acetate (Z11-14:OAc), the main pheromone component of the Z-race of O. nubilalis. First, a C14 platform strain with increased biosynthesis of myristoyl-CoA was obtained by introducing a point mutation into the α-subunit of fatty acid synthase, replacing isoleucine 1220 with phenylalanine (Fas2p^I1220F). The intracellular accumulation of myristic acid increased 8.4-fold. Next, fatty acyl-CoA desaturases (FAD) and fatty acyl-CoA reductases (FAR) from nine different species of Lepidoptera were screened in the C14 platform strain, individually and in combinations. A titer of 29.2 ± 1.6 mg L^-1 Z11-14:OH was reached in small-scale cultivation with an optimal combination of a FAD (Lbo_PPTQ) from Lobesia botrana and FAR (HarFAR) from Helicoverpa armigera. When the second copies of FAD and FAR genes were introduced, the titer improved 2.1-fold. The native FAS1 gene's overexpression led to a further 1.5-fold titer increase, reaching 93.9 ± 11.7 mg L^-1 in small-scale cultivation. When the same engineered strain was cultivated in controlled 1 L bioreactors in fed-batch mode, 188.1 ± 13.4 mg L^-1 of Z11-14:OH was obtained. Fatty alcohols were extracted from the biomass and chemically acetylated to obtain Z11-14:OAc. Electroantennogram experiments showed that males of the Z-race of O. nubilalis were responsive to biologically-derived pheromone blend. Behavioral bioassays in a wind tunnel revealed attraction of male O. nubilalis, although full precopulatory behavior was observed less often than for the chemically synthesized pheromone blend. The study paves the way for the production of ECB pheromone by fermentation.     

Novel fluoropeptidomimetics: synthesis, stability studies and protease inhibition

Designer fluoropeptidomimetics as protease inhibitors are revealed. The key peptidomimetic region in the inhibitors contains a '-CHF-S-' moiety and is designed to mimic the tetrahedral oxyanion species during the hydrolysis of a peptide bond. Designed fluoropeptidomimetics in aqueous methanol slowly (in several hours to days) yielded the corresponding methyl ether and/or the oxazole derivatives after cyclization. Alkyl substitutions at the C-2 position exhibited enhanced aqueous stability. Nature of '-CHF-S-' moiety and the stabilities of various fluoropeptidomimetics in aqueous solution are disclosed in detail. Fluoropeptidomimetics containing bulky substitutions at P1 such as compounds 15 and 16 exhibited time-dependent loss of activities against chymotrypsin, upto [corrected] 67% and 79% with a Ki of 63 and 120 microM, respectively. Fluoropeptidomimetics are a novel class of protease inhibitors and the next generation of fluoropeptidomimetics should incorporate enhanced stability.     

Anti-cancer Properties of Protein Hydrolysate from the Posterior Salivary Gland of Amphioctopus membranaceus (Quoy & Gaimard, 1832)

International Journal of Peptide Research and Therapeutics - The present study was carried out to evaluate the anti-cancer properties of protein hydrolysate from posterior salivary gland (PSG) of...     

Polymorphism in hcnAB Gene in Pseudomonas Species Reveals Ecologically Distinct Hydrogen Cyanide-Producing Populations

Bacterial HCN production is catalyzed by the membrane-bound enzyme HCN synthase. HCN synthase is encoded by a cluster of three genes, hcnABC, which form an operon. Polymorphism in the three genes may affect the catalytic efficiency of the enzyme and influence HCN production. In this study, we selected a ～570 bp portion of hcnAB gene consisting of a cysteine cluster at the 3′ end of hcnA that matches the iron-sulfur binding signature of 2[Fe–S] ferredoxins and the ADP binding-fold in the 5′ end of hcnB from 50 strains of HCN producing bacteria to analyze polymorphism in the gene. Both motifs have been credited to have a role in bacterial HCN synthesis. Analysis of the partial hcnAB gene showed that the bacteria grouped into four groups. Pairwise comparison of the distinctness ratios revealed that the HCN groups identified in this study were ecologically distinct populations and distinctness between the groups was reflected in HCN production by the bacteria. Supplementary materials are available for this article. Go to the publisher's online edition of Geomicrobiology Journal to view the supplemental file.     

Maintenance of mosquito vectors: effects of blood source on feeding,survival, fecundity,and egg hatching rates

Artificial membrane‐feeding techniques have replaced direct feeding on animals for the maintenance of malaria and arbovirus vectors in many laboratories. Membrane feeding facilitates controlled experimentation of pathogen transmission during mosquito feeding. Sheep blood is commonly used due to its availability and low cost. We evaluated the impact of blood source (human, guinea pig, sheep, and hamster via direct feeding) on feeding rates, adult survival, fecundity, hatching rates, and developmental times for five species of laboratory‐colonized mosquitoes (Anopheles dirus, An. cracens, An. minimus, An. sawadwongporni, and Ae. aegypti). We found that feeding rates differ among blood sources within mosquito species. Survival, fecundity, and hatching rates were lower in all Anopheles species and Ae. aegypti after membrane feeding on sheep blood. Survival rates seven days post‐feeding on sheep blood were significantly lower (P<0.05) for An. dirus (84.2%), An. minimus (67.2%), An. sawadwongporni (51.5%), and An. cracens (35.5%) relative to other blood sources. An. minimus and An. sawadwongporni laid no eggs by seven days post‐feeding with sheep blood, while An. dirus and An. cracens produced significantly fewer numbers of eggs and demonstrated significantly lower hatching rates relative to what was observed with the other blood sources. These findings support the conclusion that sheep blood is not a suitable blood source for laboratory rearing of Anopheles spp.