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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 annuus in 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
Real time human micro-organisms biotyping based on Water-Assisted Laser Desorption/Ionization

Abstract

We previously demonstrated that remote infrared Matrix Assisted Laser Desorption Ionization technology (Spidermass) using endogenous water as matrix (or so called water assisted laser desorption/ionization) was enabling real-time in vitro and in vivo analysis of clinical pathological tissues. In the present work, Spidermass was used to biotype human pathogens either from liquid bacteria growth in time course, from petri dish or on smears. Reproducibility experiments as well as bacteria dispersion and lipids identifications with SpiderMass in MS/MS mode were undertaken. The whole of the data establish that SpiderMass instrument allows real time bacteria biotyping and can be useful in clinic for pathogen identification.

Open access
Solid-state fermentation of paper sludge to obtain spores of the fungus Trichoderma asperellum

Abstract

Paper production generates large quantities of a solid waste known as papermaking sludge (PS), which needs to be handled properly for final disposal. The high amount of this byproduct creates expensive economical costs and induces environmental and ecological risks. Therefore, it is necessary to search uses for PS, in order to reduce the negative environmental impact and to generate a more valuable byproduct. Due to the cellulolytic composition of PS, this work evaluated a solid state fermentation process using it as substrate to obtain spores of the fungus Trichoderma asperellum. Optimal conditions to obtain T. asperellum spores were: 60% water content, 3% (w/w) salts (Nutrisol P® and Nutrisol K®), inoculum concentration at 1x105 spores/g, and pasteurized or sterilized PS. Under these conditions it was possible to obtain 2.37x109 spores/g. T. asperellum spores applied directly to pepper (Capsicum anuum) seeds without PS increased significantly seedling dry mass in greenhouse assays. This work suggests an alternative, economic and abundant substrate for production of T. asperellum spores.

Open access
Total nitrogen, water-soluble nitrogen and free amino acids profile during ripening of soft cheese enriched with Nigella sativa seed oil

Abstract

Various antimicrobial solutions have been tested as additives for raw milk traditional cheeses, among which Nigella sativa cold pressed seed oil (NSSO) is recognized for its positive effect on the microbial quality of such products. The overall effect on the quality of enriched cheeses during ripening is still under extensive investigation. Three batches of traditional raw milk brined cheese were included in the current experiment: control cheese without Nigella sativa seed oil (NSSO) and cheese samples enriched with 0.2 and 1% w/w NSSO. Experimental cheese samples were analyzed in duplicates for total nitrogen content (TN), at 0, 14, 28 and 42 days of ripening, while single determinations of total nitrogen (WSN) and free amino acids (FAA) were performed at 14, 28 and 42 ripening days. The TN content revealed similar values for control cheeses and NSSO cheeses, and no significant differences were noticed within the three treatment groups (p >.05) throughout ripening. WSN values followed a significant rising shift in all cheeses during ripening, yet computing data obtained for the three considered treatments, despite an obvious higher WSN content of NSSO enriched cheeses, no statistical significance could be associated to this difference. The FAA composition of the experimental cheeses, varied quantitatively, by increasing with ripening time, but no qualitative variation was noticed during the follow-up period. The FAA composition of the did not vary significantly within treatments.

Open access
Toxic, but beneficial compounds from endophytic fungi of Carica papaya

Abstract

Fungi remain a promising source of novel biologically active compounds with potentials in drug discovery and development. This study was aimed at investigating the secondary metabolites from endophytic Fusarium equiseti and Epicoccum sorghinum associated with leaves of Carica papaya collected from Agulu, Anambra State, Nigeria. Isolation of the endophytic fungi, taxonomic identification, fermentation, extraction and isolation of fungal secondary metabolites were carried out using standard procedures. Chromatographic separation and spectroscopic analyses of the fungal secondary metabolites yielded three toxigenic compounds - equisetin and its epimer 5’- epiequisetin from F. equiseti and tenuazonic acid from E. sorghinum These compounds are known to possess several beneficial biological properties that can be explored for pharmaceutical, agricultural or industrial purposes.

Open access
Indoor air pollution and the contribution of biosensors

Abstract

A vast majority of people today spend more time indoors than outdoors. However, the air quality indoors may be as bad as or even worse than the air quality outside. This is due to the continuous circulation of the same air without proper ventilation and filtration systems, causing a buildup of pollutants. As such, indoor air quality monitoring should be considered more seriously. Indoor air quality (IAQ) is a measure of the air quality within and around buildings and relates to the health and comfort of building occupants. To determine the IAQ, computer modeling is done to simulate the air flow and human exposure to the pollutant. Currently, very few instruments are available to measure the indoor air pollution index. In this paper, we will review the list of techniques available for measuring IAQ, but our emphasis will be on indoor air toxicity monitoring.

Open access