Effects of adsorption properties and mechanical agitation of two detergent cellulases towards cotton cellulose

Abstract

The impacts of two hybrid cloned commercial cellulases designed for detergency on cotton fibres were compared. HiCel45 has a family 45 catalytic domain and a fungal cellulose binding module (CBM) from the fungus Humicola insolens. BaCel5 has a family 5 catalytic domain and a fungal CBM from Bacillus spp. BaCel5 bound irreversibly to cellulose under the buffer conditions tested while HiCel45 was found to bind reversibly to cellulose because it showed low adsorption. BaCel5 seems to yield more activity towards cotton than HiCel45 under mild stirring conditions, but under strong mechanical agitation both enzymes produce similar amount of sugars. HiCel45 had a more progressive production of residual reducing ends on the fabric than BaCel5. These studies seem to indicate that HiCel45 is a more cooperative enzyme with detergent processes where high mechanical agitation is needed.     

The role of nutrition on epigenetic modifications and their implications on health

Nutrition plays a key role in many aspects of health and dietary imbalances are major determinants of chronic diseases including cardiovascular disease, obesity, diabetes and cancer. Adequate nutrition is particularly essential during critical periods in early life (both pre- and postnatal). In this regard, there is extensive epidemiologic and experimental data showing that early sub-optimal nutrition can have health consequences several decades later.     

Zur Feinstruktur des dorsalen Riesenfasersystems im Bauchmark des Regenwurms

Zusammenfassung Die proximalen Kollateralen der dorsalen Riesenfasern des Regenwurms wurden in Serienschnitten vom Soma bis zum Eintritt in die Riesenfaser verfolgt und im Hinblick auf ihre Feinstruktur und ihre synaptischen Kontakte Untersucht. Es finden sich sowohl chemische als auch elektrische Synapsen. Ihre Feinstruktur wird mit der bekannter Synapsen anderer Wirbellosen und Wirbeltiere verglichen. In beiden Riesenfasersystemen kommen efferente chemische Synapsen mit feinen postsynaptischen Verzweigungen vor, die anscheinend von Bauchmark-Motoneuronen stammen. Das Axon der medianen Riesenfaser weist darüber hinaus nur noch eine elektrische Synapse mit den Rieseninterneuronen auf. Demgegenüber erhalten die Kollateralen der lateralen Riesenfasern zahlreiche Afferenzen, die zum Teil als sensorische Fasern der Epidermis, multisegmentale Fasern der Hauptfaserzüge und Rieseninterneurone identifiziert werden konnten. Weitere Afferenzen stammen vermutlich von unisegmentalen Interneuronen her. Beide lateralen Riesenzellaxone bilden außerdem miteinander eine elektrische Chiasma-Synapse mit besonderen Membraneinfaltungen.

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Ultrastructure of the dorsal giant fibre system in the ventral nerve cord of the earthwormII. Synaptic connections of the proximal collaterals of the giant fibres

Summary The proximal collaterals of the dorsal giant fibres of the earthworm were traced through serial sections from the cell bodies to the giant axons. Their structure and synaptic connections were examined. There are chemical as well as electrical synapses. Their fine structure is compared to that of other known invertebrate and vertebrate synapses. Both giant fibre systems have efferent chemical connections with thin postsynaptic arborizations which probably belong to ventral cord motoneurons. Moreover the median giant axon is connected by an electrical synapse with the giant interneurons. The lateral giant collaterals on the contrary receive many afferences through chemical synapses which were partly identified as sensory fibers from the epidermis, multisegmental axons from the main fibre bundles or giant interneurones. Other afferences probably come from unisegmental interneurones. In addition both lateral giant axons form an electrical chiasma synapse with special membrane folds.

Mit Unterstützung durch die Deutsche Forschungsgemeinschaft Gu 117/1.     

Mercury contamination and stable isotopes reveal variability in foraging ecology of generalist California gulls

Environmental contaminants are a concern for animal health, but contaminant exposure can also be used as a tracer of foraging ecology. In particular, mercury (Hg) concentrations are highly variable among aquatic and terrestrial food webs as a result of habitat- and site-specific biogeochemical processes that produce the bioaccumulative form, methylmercury (MeHg). We used stable isotopes and total Hg (THg) concentrations of a generalist consumer, the California gull (Larus californicus), to examine foraging ecology and illustrate the utility of using Hg contamination as an ecological tracer under certain conditions. We identified four main foraging clusters of gulls during pre-breeding and breeding, using a traditional approach based on light stable isotopes. The foraging cluster with the highest δ¹⁵N and δ³⁴S values in gulls (cluster 4) had mean blood THg concentrations 614% (pre-breeding) and 250% (breeding) higher than gulls with the lowest isotope values (cluster 1). Using a traditional approach of stable-isotope mixing models, we showed that breeding birds with a higher proportion of garbage in their diet (cluster 2: 63–82% garbage) corresponded to lower THg concentrations and lower δ¹⁵N and δ³⁴S values. In contrast, gull clusters with higher THg concentrations, which were more enriched in ¹⁵N and ³⁴S isotopes, consumed a higher proportion of more natural, estuarine prey. δ³⁴S values, which change markedly across the terrestrial to marine habitat gradient, were positively correlated with blood THg concentrations in gulls. The linkage we observed between stable isotopes and THg concentrations suggests that Hg contamination can be used as an additional tool for understanding animal foraging across coastal habitat gradients.     

Modulation of Fetal Rat Brain and Liver Phospholipid Content by Intraamniotic Ethyl Docosahexaenoate Administration

Abstract: In an attempt to elucidate the role of docosahexaenoic acid (DHA; 22:6n-3) in the developing brain, a method was devised whereby rapid enrichment of fetal brain and liver lipid with DHA was achieved. Fetal rats at 17 days of gestation were injected intraamniotically with ethyl docosahexaenoate (EtDHA). Control fetuses were administered ethyl oleate (EtOle). Brain lipid DHA content increased by almost 21% (p = 0.02) 3 days after EtDHA administration as compared with EtOle-injected fetuses, whereas liver lipid DHA content increased by almost 60% (p = 0.0002). At this time brain phosphatidylinositol content doubled, whereas phosphatidylserine (PS) content increased by >50% (p = 0.03). Increases in liver PS (+25.8%; p = 0.015) and sphingomyelin (+43.6%; p = 0.01) content were observed. A redistribution of total brain phospholipid (PL) DHA was observed following Et-DHA administration, resulting in a 56.4% increase in PS-DHA abundance (p < 0.05) and an 8.8% decrease in phosphatidylethanolamine-DHA abundance (p = 0.05). These results suggest modulation of fetal brain and liver PL and provide a method for enrichment of DHA content in discrete PLs during intrauterine life.     

Protein disulphide isomerase-assisted functionalization of proteinaceous substrates

Protein disulphide isomerase (PDI) is an enzyme that catalyzes thiol-disulphide exchange reactions among a broad spectrum of substrates, including proteins and low-molecular thiols and disulphides. As the first protein-folding catalyst reported, the study of PDI has mainly involved the correct folding of several cysteine-containing proteins. Its application on the functionalization of protein-based materials has not been extensively reported. Herein, we review the applications of PDI on the modification of proteinaceous substrates and discuss its future potential. The mechanism involved in PDI functionalization of fibrous protein substrates is discussed in detail. These approaches allow innovative applications in textile dyeing and finishing, medical textiles, controlled drug delivery systems and hair or skin care products.     

Ontogenic and nutritional modifications in the intestinal fucosylation process at the weaning period. Influence of dietary fibers

In the rat small intestine, the glycosylation changes which normally take place at the weaning period are characterized by a shift from sialylation of fucosylation. The introduction of dietary fibers at weaning is one of the more striking nutritional modification so that some authors have suggested that the presence of fibers and the development of colonic fermentation might be important for the development of the small intestine, as for the colon. In order to define the respective contribution of ontogenic and nutritional factors to the intestinal glycosylation changes at this period, some aspects of the intestinal glycosylation were studied in five groups of rats (16-day-old suckling rats, prolonged nursing 23-day-old rats, 23-day-old rats weaned at day 19 with either a fiber-free, a cellulose or a pectin diet). Intestinal glycoproteins of suckling rats are characterized by a low fucose content and a high proportion of mannose. The amounts of the neutral sugars (fucose, mannose and galactose), expressed either per gram of intestine or for one intestine, are alwars higher in the fiber-fed groups than in the prolonged-nursing group or the group fed the fiber-free diet. Activities which promote fucosylation process (GDP-fucose production and fucosyltransferase activities) and those which are opposed to fucosylation (endogenous inhibitor of fucosyltransferase and GDP-fucose pyrophosphatase) are strongly modified in opposite ways at day 23 as compared to day 16. These modifications depend on the age of the animal (ontogenic factors) with additional modifications induced by the dietary factors. In particular, similar sugar contents and patterns are obtained with cellulose and pectin diests though the enzymatic activities of the fucosylation pathway are very different. No correlation was found between the caecal content of short chain fatty acids and any of the parameters under study. Thus, dietary fibers induce metabolic changes in the small intestine glycosylation in short-term experiments independently of colonic fermentation. Besides, these results point out that the consideration of fucosyl-transferase activities alone are not sufficient to predict glycoprotein fucose content and that other regulatory sites are involved. Dietary manipulations at the weaning period could represent a good model for the study of glycosylation regulation.     

‘We eat meat every day’: ecology and economy of dietary change among Oaxacan migrants from Mexico to New Jersey

Abstract

In the late twentieth and early twenty-first centuries, the USA has experienced large-scale and continuing immigration from around the world, especially Latin America and, within Latin America, from Mexico. One dimension of these transnational processes is dietary change. In this paper, we qualitatively assess the effects of migration from Oaxaca, Mexico to central New Jersey on the ecology and economy of dietary patterns. We explore multiple factors at the micro and macro levels. Data come from focus groups held among Mexican migrants in New Jersey, and in Oaxaca among people from their sending communities. Economic constraints and lack of culturally appropriate foods are larger barriers to healthy eating than lack of knowledge about appropriate diets. We end with recommendations for nutrition education and interventions.