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Biocomposites based on collagen and keratin with properties for agriculture and industrie applications

Abstract

In the present research biocomposites based on extracts of collagen and keratin recovered from the leather industry by-products were made and the specific properties for applications in agriculture and industry were studied. To this aim, collagen and keratin have been extracted from bovine leather and sheep wool by-products and have been added and crosslinked with recognized compounds for reduced environmental impact (glycerol, vegetable tanning extract, essential oils with fungicidal properties and insecticides). The biocomposite properties were evaluated on the basis of complex analytical investigations on chemical structure, texture, contact angle, mechanical resistance, water vapor permeability and water absorption, biodegradation, germination and plant biomass growth. The biocomposites have demonstrated pelliculogenic properties and nitrogen controlled release to stimulate germination and nutrition of rape seedlings, which promotes them for agricultural applications, but also other surface properties have been identified, for industrial applications, for example in leather finishing for special destinations. Addition of odorous principles with controlled release recommends this type of biocomposites for environmentally friendly products, maintenance of cleaning, etc.

Open access
Corrosion inhibition of iron surfaces with phosphatidic acid

Abstract

Preventing the corrosion of iron in inaccessible structures requires a coating method that reaches all surface areas and creates a uniform protective layer. An ages old practice to protect iron artefacts is to coat them with animal fat, that is, a mixture of lipids. This “method” is accidentally ingenious: some natural phospholipids found in animal fat have the potential to form a tightly packed self-assembled monolayer on metal oxide surfaces, similar to the surfactant monolayers that have attracted increasing attention lately. Thus, the most primitive corrosion prevention method may point at a way to coat complex iron structures in an industrial environment. Here the ability of phosphatidic acid, a natural lipid, to coat and protect iron surfaces was examined. Iron coated quartz crystal microbalance (QCM) sensors were used for the experiments, to monitor the deposition of the lipid as well as the acidic corrosion (dissolution) of iron in situ, in real time. The sensors were coated by self-assembled monolayers of di-myristoyl phosphatidic acid using the liposome deposition method. In this process, 50-100 nm vesicles formed by the lipid are delivered in an aqueous solution and spontaneously coat the iron surfaces upon contact. QCM and ellipsometry measurements confirmed that continuous bilayer and monolayer surface coatings can be achieved by this method. QCM measurements also confirmed that the layers were corrosion resistant in 0.01M acetic acid solution that would dissolve the thin iron layer in minutes in the absence of the protective coating. XPS results suggested a chemisorption-based mechanism of phosphatidic acid attachment to the iron surface. Hence, liposome deposition of phosphatidic acid offers a suitable solution to coat iron surfaces in inaccessible structures in situ.

Open access
Defense manifestations of enzymatic and non-enzymatic antioxidants in Ricinus communis L. exposed to lead in hydroponics

Abstract

Lead (Pb) is a major inorganic pollutant with no biological significance and has been a global concern. Phytotoxicity of lead induces toxic effects by generating reactive oxygen species (ROS), which inhibits most of the cellular processes in plants. Hydro-ponic experiments were performed with Ricinus communis to investigate the toxicity and antioxidant responses by exposing to different concentrations of lead (0, 200 and 400 µM) for 10 days. Pb stress caused a significant increase in electrolyte leakage, non-enzymatic antioxidants (phenols and flavonoids) and a decrease in the elemental profile of the plant. Histochemical visualization clearly indicates the significant increase of H2O2 production in dose-dependent manner under Pb stress. Likewise, an increase in catalase, guaiacol peroxidase and superoxide dismutase activity was also evident. Ascorbate peroxidase and MDAR, on the other hand, responded biphasically to Pb treatments showing a decrease in concentration. The decline in redox ratio GSH/GSSG was imposed by the indirect oxidative stress of Pb. Hence these findings showed the ameliorative potential of R. communis to sustain Pb toxicity under oxidative stress.

Open access
Evolution of phytochemical and antioxidant activity of Tunisian carob (Ceratonia siliqua L.) pods during maturation

Abstract

The Ceratonia siliqua fruits contain several substances known to have high adaptability to environmental conditions. The aim of this paper is to evaluate the changes in physicochemical properties of different Tunisian provenances of carob pulps harvested at three ripening stages. Furthermore, six provenances were investigated during the ripening process in terms of their moisture, ash, minerals, bioactive compounds, antiradical activity and sugar profile. The results demonstrated that all examined parameters are highly influenced by geographic origin. Concerning ripening impact, our data showed that water and ash content significantly decreased during the development of six provenances, as well as the bioactive and mineral contents. Thus, the total polyphenols (TP), total flavonoids (TF) and condensed tannins (CT) contents exhibited the highest levels in the unripe fruits. The antiradical activity trend was positively correlated to the behavior of the bioactive compounds content. Moreover, the sucrose, glucose and fructose were the main sugar qualified and quantified in carob pods at different ripening stages. At the maturity stage, the monosaccharide contents (glucose and fructose) were slightly reduced, while, the sucrose was rapidly accumulated. In conclusion, the ripening process diversely affected the nutritional composition and generally extended the exploitation of carob fruits. The study could provide valuable information about the suitability of carob pods at different maturity stages as potential biomaterials for nutraceutical applications.

Open access
Optimization of in vitro asymbiotic seed germination protocol for Serapias vomeracea

Abstract

Serapias vomeracea is an economically important orchid species which is over-collected from nature, because of its glucomannan-rich tubers. Thus, optimization of in vitro culture methodology in this species is required to meet industrial needs and to secure its populations in nature. This study aimed to optimize the surface sterilization protocol for S. vomeracea seeds and to select the optimal seed germination medium by comparing the commonly used media in in vitro orchid culture. During seed surface sterilization, ethyl alcohol (EtOH) pre-treatment prior to sodium hypochlorite (NaOCl) treatment increased the disinfection success and viable seed yield when examined using the triphenyl tetrazolium chloride (TTC) seed viability test. Also, low-g force centrifugation as an additional step in the surface sterilization method separated the seeds without embryo from the viable seeds and thereby decreased potential counting errors after incubation. Comparison of media showed that solid Knudson C (KN) medium induced the highest number of germinated seeds. However, seed germination success of Lindemann (LN) and Vacin & Went (VW) media was found to be higher when the media was used in liquid form. Half-strength liquid VW was the only medium that induced higher germination success than the other full-strength media. The highest number of ungerminated seeds was found when using KN medium whereas liquid VW medium gave the lowest number. In general, protocorm formation was triggered when the media were used in liquid form. However, rhizoid elongation was suppressed in liquid media. These findings suggest that this optimized seed surface sterilization method offers a simple and effective alternative to classical methods. Additionally, solid KN medium may be considered as a cost-effective and reliable alternative to other commonly-used complex media in S. vomeracea cultures.

Open access
Proteases with caspase 3-like activity participate in cell death during stress-induced microspore embryogenesis of Brassica napus

Abstract

Microspore embryogenesis is a model system of plant cell reprogramming, totipotency acquisition, stress response and embryogenesis initiation. This in vitro system constitutes an important biotechnological tool for haploid and doubled-haploid plant production, very useful for crop breeding. In this process, microspores (cells that produce pollen grains in planta) are reprogrammed toward embryogenesis by specific stress treatment, but many microspores die after the stress. The occurrence of cell death is a serious limiting problem that greatly reduces microspore embryogenesis yield. In animals, increasing evidence has revealed caspase proteolytic activities as essential executioners of programmed cell death (PCD) processes, however, less is known in plants. Although plant genomes do not contain caspase homologues, caspase-like proteolytic activities have been detected in many plant PCD processes. In the present study, we have analysed caspase 3-like activity and its involvement in stress-induced cell death during initial stages of microspore embryogenesis of Brassica napus. After stress treatment to induce embryogenesis, isolated microspore cultures showed high levels of cell death and caspase 3-like proteolytic activity was induced. Treatments with specific inhibitor of caspase 3-like activity reduced cell death and increased embryogenesis induction efficiency. Our findings indicate the involvement of proteases with caspase 3-like activity in the initiation and/or execution of cell death at early microspore embryogenesis in B. napus, giving new insights into the pathways of stress-induced cell death in plants and opening a new way to improve in vitro embryogenesis efficiency by using chemical modulators of cell death proteases.

Open access
Anti-inflammatory and analgesic activities of methanol extract of Helianthus annuus Linn. (Asteraceae) leaf

Abstract

This study evaluate the anti-inflammatory and analgesic properties of Helianthus annuus Linn. in rats. Methanol extract of Helianthus annuus (HAE) leaf was used in this study. Formalin- and egg-albumin induced-paw edema were used to investigate the anti-inflammatory activities while acetic acid-induced writhing reflex and tail flick models were used to evaluate the analgesic properties. The doses of HAE used were 150, 300 and 600 mg/kg. Acetylsalicylic acid (ASA) was used as reference drug in the anti-inflammatory and writhing reflex models while pentazocine (reference drug) was used in tail flick model. The negative control was dosed 5% tween-20 (10 ml/kg). The HAE exhibited significant (P < 0.05) dose-dependent anti-inflammatory and analgesic activities. At 3 hour (h) post treatment, the HAE (300 mg/kg) produced 33.33% and 32.94% while ASA produced 36.36% and 35.29% reduction in paw volume in the formalin and egg-albumin induced paw edema models respectively when compared with negative control. In the acetic acid-induced writhing reflex, ASA and HAE (600 mg/kg) produced 67.89% and 35.78% reduction in the number of writhing, respectively when compared with the negative control. Pentazocine and HAE (300 mg/kg) caused 67.62% and 35.24% increase in pain reaction time when compared with the negative control. The study affirms the folkloric uses of Helianthus annuusin the management of pain and inflammation.

Open access
Application of whey retentate as complex nitrogen source for growth of the polyhydroxyalkanoate producer Hydrogenophaga pseudoflava strain DSM1023

Abstract

Polyhydroxyalkanoates, microbial polyesters produced in vivo starting from renewable resources, are considered the future materials of choice to compete recalcitrant petro-chemical plastic on the polymer market. In order to make polyhydroxyalkanoates market-fit, (techno)economics of their production need to be improved. Among the multifarious factors affecting costs of polyhydroxyalkanoate production, increased volumetric productivity is of utmost importance. Improving microbial growth kinetics and increasing cell density are strategies leading to a high concentration of catalytically active biomass within a short time; after changing cultivation conditions, these cells can accumulate polyhydroxyalkanoates as intracellular products. The resulting increase of volumetric productivity for polyhydroxyalkanoates can be realized by supplying complex nitrogen sources to growing microbial cultures. In the present study, the impact of different expensive and inexpensive complex nitrogen sources, in particular whey retentate, on the growth and specific growth rates of Hydrogenophaga pseudoflava was tested.

Based on a detailed kinetic process analysis, the study demonstrates that especially whole (not hydrolyzed) whey retentate, an amply available surplus material from dairy industry, displays positive effects on cultivations of H. pseudoflava in defined media (increase of concentration of catalytically active biomass after 26.25 h of cultivation by about 50%, increase of specific growth rate μ from 0.28 to 0.41 1/h during exponential growth), while inhibiting effects (inhibition constant K i = 6.1 g/L) of acidically hydrolyzed whey retentate need to be overcome. Considering the huge amounts of surplus whey accruing especially in Europe, the combined utilization of whey permeate (carbon source) and whey retentate (complex nitrogen source) for biopolyester production can be considered a viable bioeconomic strategy for the next future.

Open access
Future Biotechnology

Abstract

The field of biotechnology is large and could be considered tritely as simply the development of technology that is based on biology. It is clear that the concepts of biotechnology can spread to cover many different fields of application and so the future developments in biotechnology will be similarly wide-ranging across many fields of applications. Here we focus onto medical biotechnology and further refine our discussion onto considering aspects of genetics and nanotechnologies that could impact on the development of future biotechnologies in the medical field. These areas that we consider in this brief article provide the basis for a panel discussion on Future Biotechnology at the European Biotechnology Congress held in Valencia, Spain in April 2019.

Open access
Physiological role of Prion Protein in Copper homeostasis and angiogenic mechanisms of endothelial cells

Abstract

The Prion Protein (PrP) is mostly known for its role in prion diseases, where its misfolding and aggregation can cause fatal neurodegenerative conditions such as the bovine spongiform encephalopathy and human Creutzfeldt–Jakob disease. Physiologically, PrP is involved in several processes including adhesion, proliferation, differentiation and angiogenesis, but the molecular mechanisms behind its role remain unclear. PrP, due to its well-described structure, is known to be able to regulate copper homeostasis; however, copper dyshomeostasis can lead to developmental defects. We investigated PrP-dependent regulation of copper homeostasis in human endothelial cells (HUVEC) using an RNA-interference protocol. PrP knockdown did not influence cell viability in silenced HUVEC (PrPKD) compared to control cells, but significantly increased PrPKD HUVEC cells sensitivity to cytotoxic copper concentrations. A reduction of PrPKD cells reductase activity and copper ions transport capacity was observed. Furthermore, PrPKD-derived spheroids exhibited altered morphogenesis and their derived cells showed a decreased vitality 24 and 48 hours after seeding. PrPKD spheroid-derived cells also showed disrupted tubulogenesis in terms of decreased coverage area, tubule length and total nodes number on matrigel, preserving unaltered VEGF receptors expression levels. Our results highlight PrP physiological role in cellular copper homeostasis and in the angiogenesis of endothelial cells.

Open access