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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
Low-frequency ultrasound can drive the transport of nanoparticles and molecules in polymer gels for biotechnology applications

Abstract

This paper reports the use of low-frequency ultrasound to influence transport in porous hydrogels with a transducer attached in direct contact with the hydrogel. This is a different configuration than for ultrasound-generating devices utilized previously for enhancing transport of molecules. The advantages of the system reported in this manuscript are that (i) much less acoustic power is required to influence the transport in the hydrogel that is in direct contact with the ultrasonic transducer, and (ii) no cavitation is induced in the hydrogel to influence the transport. This system was first tested in bench-top in vitro experiments by quantifying the transport of gold nanoparticles stimulated by low-frequency ultrasound. Then, to provide an in vivo example for potential biotechology applications, the system was demonstrated to be capable of transporting drugs across the tunics of a rabbit eye into the ocular circulation so as to target the transported drug to the outer retina.

Open access
Optical properties of translucent zirconia: A review of the literature

Abstract

Translucent monolithic zirconia is the newest option of zirconia-based ceramics, which aimed to substitute the opaque classic yttria-stabilized tetragonal zirconia polycrystal (Y-TZPs) in more demanding esthetic cases.

The aim of this review was to assess the available literature regarding the optical, chemical and mechanical properties of translucent zirconia ceramics.

This systematic review was developed according to the PRISMA (Preferred Reporting Items for Systematic Review and Meta-analysis) guidelines. An electronic literature search was undertaken through Medline (National Library of Medicine) via PubMed to identify relevant articles, published in the interval 2010-2018. The search was limited to the English language publications, in vitro studies of color and microstructure of translucent zirconia material.

Yttria-stabilized tetragonal zirconia polycrystals (Y-TZPs) has excellent mechanical properties, but its intense white color and high opacity represent an esthetic limit. Cubic zirconia represents a new generation of dental ceramics with molecular structure and physical properties different from the conventional zirconia. Dental manufacturers created new formulations of this restorative material, introducing new cubic varieties of zirconia with improved optical properties. Translucent monolithic zirconia provides a new restorative option that combines strength with improved esthetics, due to its increased translucency. Translucent zirconia is indicated for anterior and posterior restorations but should be used carefully for discolored teeth, because the background color can affect the final esthetic appearance of the restoration.

Open access
Screening of metabolites from endophytic fungi of some Nigerian medicinal plants for antimicrobial activities

Abstract

Endophytic fungi associated with Nigerian plants have recently generated significant interest in drug discovery programmes due to their immense potential to contribute to the discovery of new bioactive compounds. This study was carried out to investigate the secondary metabolites of endophytic fungi isolated from leaves of Newbouldia laevis, Ocimum gratissimum, and Carica papaya. The plants were collected from Agulu, Anambra State, South-East Nigeria. Endophytic fungal isolation, fungal fermentation; and extraction of secondary metabolites were carried out using standard methods. The crude extracts were screened for antimicrobial activities using the agar well diffusion method, and were also subjected to high performance liquid chromatography (HPLC) analysis to identify their constituents. A total of five endophytic fungi was isolated, two from N. laevis (NL-L1 and NL-L2), one from O. gratissimum (SL-L1), and two from C. papaya (PPL-LAC and PPL-LE2). In the antimicrobial assay, the extracts of NL-L2, SL-L1, and PPL-LE2 displayed mild antibacterial activity against both Gram negative and Gram positive test bacteria. PPL-LAC extract showed mild activity only against S. aureus, while no antimicrobial activity was recorded for NL-L1 extract. All the endophytic fungal extracts showed no activity against the test fungi C. albicans and A. fumigatus. HPLC analysis of the fungal extracts revealed the presence of ethyl 4-hydroxyphenyl acetate and ferulic acid in NL-L1; ruspolinone in NL-L2; protocatechuic acid, scytalone, and cladosporin in SL-L1; indole-3-acetic acid and indole-3-carbaldehyde in PPL-LE2; and indole-3-acetic acid in PPL-LAC. The findings of this study revealed the potentials possessed by these plants as source of endophytes that express biological active compounds. These endophytes hold key of possibilities to the discovery of novel molecules for pharmaceutical, agricultural and industrial applications.

Open access
Switching from petro-plastics to microbial polyhydroxyalkanoates (PHA): the biotechnological escape route of choice out of the plastic predicament?

Abstract

The benefit of biodegradable “green plastics” over established synthetic plastics from petro-chemistry, namely their complete degradation and safe disposal, makes them attractive for use in various fields, including agriculture, food packaging, and the biomedical and pharmaceutical sector. In this context, microbial polyhydroxyalkanoates (PHA) are auspicious biodegradable plastic-like polyesters that are considered to exert less environmental burden if compared to polymers derived from fossil resources.

The question of environmental and economic superiority of bio-plastics has inspired innumerable scientists during the last decades. As a matter of fact, bio-plastics like PHA have inherent economic drawbacks compared to plastics from fossil resources; they typically have higher raw material costs, and the processes are of lower productivity and are often still in the infancy of their technical development. This explains that it is no trivial task to get down the advantage of fossil-based competitors on the plastic market. Therefore, the market success of biopolymers like PHA requires R&D progress at all stages of the production chain in order to compensate for this disadvantage, especially as long as fossil resources are still available at an ecologically unjustifiable price as it does today.

Ecological performance is, although a logical argument for biopolymers in general, not sufficient to make industry and the society switch from established plastics to bio-alternatives. On the one hand, the review highlights that there’s indeed an urgent necessity to switch to such alternatives; on the other hand, it demonstrates the individual stages of the production chain, which need to be addressed to make PHA competitive in economic, environmental, ethical, and performance-related terms. In addition, it is demonstrated how new, smart PHA-based materials can be designed, which meet the customer’s expectations when applied, e.g., in the biomedical or food packaging sector.

Open access
3D polyelectrolyte scaffolds to mimic exocrine glands: a step towards a prostate-on-chip platform

Abstract

We report our approach to creating a microfluidic chip (namely UroLOC) that mimics the acinar/tubular structure and the luminal microenvironment of exocrine glands. The chip utilises a nanostructured membrane that is designed to provide a 3-dimensional supporting scaffold for the growth of exocrine acinus epithelial cells. The nanostructured membrane was produced using layer-by-layer assembly of polyelectrolytes, and formed into 3-dimensional hemispherical cavities and “finger-like” structures in order to mimic the natural architecture of acini found in exocrine glands. We utilised normal (PNT2) and cancerous (PC3, LNCaP) prostate epithelial cells to demonstrate the proof-of-concept of using MALDI (Matrix Assisted Laser Desorption Ionisation) profiling of secretions collected after 48 hours of cell growth, with no concentration or purification steps and without any a priori on the knowledge of targeted proteins. This MALDI profiling analysis of the crude supernatants from 3 different cell lines (PNT2, PC3 and LNCaP) demonstrated the capacity of the MALDI profiling approach to discriminate between the different secretome signatures. The UroLOC concept and secretome profiling that we describe opens new opportunities in terms of liquid-biopsy based diagnosis, particularly for the early stages of carcinogenesis.

Open access