Assessment of Biological Contamination from Wooden Artifacts of Golesti Museum

Wood, a traditional common material with multiple applications in civil and religious [...

<i>Cladosporium</i> sp. Isolate as Fungal Plant Growth Promoting Agent

Cladosporium species are active in protecting plants against different biotic and abiotic stresses. Since these species produced a wide range of secondary metabolites responsible for the adaptation to new habitats, plant health and performance, they are of great interest, especially for biostimulants in agriculture. Cladosporium sp. produces protein hydrolysates (PHs), a class of biostimulants, by cultivation on medium with keratin wastes (feathers) as carbon and energy sources. The aim of this study was to select a Cladosporium isolate with potential to be used as plant growth promoting agent. The characteristics of Cladosporium isolates as plants biostimulants were evaluated through several tests, such as: antagonism versus plants pathogens, effect on plant growth of secreted volatiles produced by isolates, secretion of hydrolytic enzymes, production of 3-indole acetic acid, zinc and phosphorous solubilization, capacity to promote tomato seedlings growth (pot experiments). Cladosporium isolate T2 presented positive results to all tests. Encouraging results were obtained treating tomato seedlings with PHs from isolate Cladosporium T2 cultured on medium supplemented with 1% (w/w) chicken feathers, for which growth parameters, such as stem weight, stem height, and root weight were significantly higher by 65%, 32%, and 55%, respectively, compared to those treated with water

Qualitative Assessment of Beneficial Microorganisms

Modern agriculture needs various plant growth stimulant products

A Biotechnological Process for Valorizing Poultry Feathers through Keratinolytic Cladosporium Isolates

Protein hydrolysates, as plant biostimulants, have beneficial effects on the growth, yield and [...

Nanocomposites Based Electrosensitive Platforms for Nitrite and Biogenic Amines Determination

Highly electrosensitive platforms have been developed using different nanocomposite materials based on carbon allotropes and different metallic nanoparticles for determination of nitrite and biogenic amines (BAs). The nitrification process occurred in soil represents an important source of pollution. The nitrification consists in biological oxidation of the relatively immobile ammonium (NH4+) to highly mobile nitrate, via nitrite. This process is carried out mainly by the ammonia–oxidizing bacteria (Nitrosomonas sp. and Nitrobacter sp.) present in the soil microbial population [1,2]. The nitrite contamination of ground and surface waters represents the major concern associated with the nitrification process. Additionally, the growing needs for food and environmental safety has led to an increase in research for the detection of biogenic amines (BAs) in recent years. Despite the fact that BAs are increasingly present in food and beverages, causing toxic effects in the body, legislation that limits their presence in food chains needs to be updated, thus requiring sensitive tools for their detection [3,4]. Miniaturized analytical tools have been developed based on nanocomposite materials obtained through combination of different carbon allotrope materials (nanoribbons, nanotubes—single and multiwalled—and nanofibers) with metallic nanoparticles (Ag, Au-Ag, Pt, Cu). Thus, carbon based screen-printed electrodes (SPE) were chemically modified with the obtained nanocomposite materials and further characterized using different electrochemical techniques. In order to allow a selective and sensitive determination of analytes, an electropolymerized film was deposed on the modified sensors. For BAs determination were realized with two configurations of biosensors, a bienzymatic one consisting in immobilization of diamine oxidase (DAO) and horseradish peroxidase (HRP) onto the modified sensors, and, respectively, a mono-enzymatic system based on immobilization of DAO onto the modified sensors. It was taken into account that the charge of carbon-based nanomaterials on the surface of the sensors should not exceed 5%, in order to ensure a low based current. Morpho-structural and electrochemical characterization studies of the modified SPEs have been performed in order to achieve a high sensitivity and selectivity of detection, applying a low overvoltage. The co-polymeric film ensured a better stability of the nanocomposite material layers at the electrode surface and an optimal matrix for enzymes immobilization. Optimization of the nanocomposite-based sensors were performed, and finally detection of biogenic amines was carried out using biosensors based on single-walled carbon nanotubes and Pt nanoparticles, while nitrite determination was performed using multi-walled carbon nanotubes and AgNP modified sensors at applied potentials between −0.45 and +0.6 V vs. Ag/AgCL. The developed sensors and biosensors showed good sensitivities of nitrite and BAs detection. Although the enzyme DAO has a low enough activity to catalyze the oxidation of amine of interest, the detection limits were lowered due to the electrocatalytic activity of nanocomposite materials and the HRP enzyme used

Ag⁰–Ginger Nanocomposites Integrated into Natural Hydrogelated Matrices Used as Antimicrobial Delivery Systems Deposited on Cellulose Fabrics

In the textile, medical, and food industries, many of the applications have targeted the use of textile fabrics with antimicrobial properties. Obtaining eco-friendly coatings is of wide interest, especially for applications related to wound dressing or to food packaging. In order to obtain coatings with antimicrobial properties through environmentally friendly methods, a series of experiments were carried out on the use of natural polymers loaded with silver nanoparticles. In this study, coatings with antimicrobial properties were obtained by depositing natural composites based on rice flour, carob flour, or alginate on cotton fabrics. These antimicrobial coatings were multicomponent systems, in which the host matrix was generated via hydration of natural polymers. The nanocomposite obtained from the phytosynthesis of silver particles in ginger extract was embedded in hydrogel matrices. The multicomponent gels obtained by embedding silver nanoparticles in natural polymer matrices were deposited on cotton fabric and were studied in relation to nanoparticles and the type of host matrix, and the antimicrobial activity was evaluated. Fabrics coated with such systems provide a hydrophilic surface with antimicrobial properties and can therefore be used in various areas where textiles provide antibacterial protection

Degradation of keratin substrates by keratinolytic fungi

Background: The hydrolysis of keratin wastes by microorganisms is considered a biotechnological alternative for recycling and valorization through keratinolytic microorganisms. Despite their resistant structure, keratin wastes can be efficiently degraded by various microorganisms through the secretion of keratinases, which are promising enzymes for several applications, including detergents, fertilizers, and leather and textile industry. In an attempt to isolate keratinolytic microorganisms that can reach commercial exploitation as keratinase producers, the current work assesses the dynamics of keratin biodegradation by several keratinolytic fungal strains isolated from soil. The activity of fungal strains to degrade keratin substrates was evaluated by SEM, FTRIR-ATR spectra and TGA analysis. Results: SEM observations offered relevant information on interactions between microorganism and structural elements of hair strands. FTIR spectra of the bands at 1035–1075 cm-1 assigned to sulfoxide bond appeared because of S–S bond breaking, which demonstrated the initiation of keratin biodegradation. According to TGA, in the second zone of thermal denaturation, where keratin degradation occurs, the highest weight loss of 71.10% was obtained for sample incubated with Fusarium sp. 1A. Conclusions: Among the tested strains, Fusarium sp. 1A was the most active organism in the degradation process with the strongest denaturation of polypeptide chains. Because keratinolytic microorganisms and their enzymes keratinases represent a subject of scientific and economic interest because of their capability to hydrolyze keratin, Fusarium sp. 1A was selected for further studies

Modeling the Properties of Curcumin Derivatives in Relation to the Architecture of the Siloxane Host Matrices

Research in the field of natural dyes has constantly focused on methods of conditioning curcumin and diversifying their fields of use. In this study, hybrid materials were obtained from modified silica structures, as host matrices, in which curcumin dyes were embedded. The influence of the silica network structure on the optical properties and the antimicrobial activity of the hybrid materials was monitored. By modifying the ratio between phenyltriethoxysilane:diphenyldimethoxysilane (PTES:DPDMES), it was possible to evaluate the influence the organosilane network modifiers had on the morphostructural characteristics of nanocomposites. The nanosols were obtained by the sol–gel method, in acid catalysis. The nanocomposites obtained were deposited as films on a glass support and showed a transmittance value (T measured at 550 nm) of around 90% and reflectance of about 11%, comparable to the properties of the uncovered support. For the coatings deposited on PET (polyethylene terephthalate) films, these properties remained at average values of T550 = 85% and R550 = 11% without significantly modifying the optical properties of the support. The sequestration of the dye in silica networks reduced the antimicrobial activity of the nanocomposites obtained, by comparison to native dyes. Tests performed on Candida albicans fungi showed good results for the two curcumin derivatives embedded in silica networks (11–18 mm) by using the spot inoculation method; in comparison, the alcoholic dye solution has a spot diameter of 20–23 mm. In addition, hybrids with the CA derivative were the most effective (halo diameter of 17–18 mm) in inhibiting the growth of Gram-positive bacteria, compared to the curcumin derivative in alcoholic solution (halo diameter of 21 mm). The results of the study showed that the presence of 20–40% by weight DPDMES in the composition of nanosols is the optimal range for obtaining hybrid films that host curcumin derivatives, with potential uses in the field of optical films or bioactive coatings

Influence of Foliar Treatment with Suspensions Rich in <i>Trichoderma</i> Chlamydospores on <i>Momordica charantia</i> Physiology, Yield, and Quality

Several strategies promote phyllosphere colonization by soil-born Trichoderma plant-beneficial strains. One of these strategies is foliar spraying with suspensions containing large amounts of chlamydospores—spores with thick cell wall structures that make them highly resistant to harsh environmental conditions. Trichoderma biomass was produced by cultivation on a cornmeal medium and compared with the biomass produced on potato dextrose broth by microscopic and thermogravimetric analyses. The analyses revealed increased chlamydospore content and thermostability in the fungal biomass produced on the corn meal medium. The Trichoderma suspension rich in chlamydospores was sprayed on bitter gourd (Momordica charantia) leaves at two inoculant concentrations, 106 and 108 ufc/mL. The effect of these treatments on the plant physiological parameters, leaf photosynthetic pigments, polyphenol and flavonoid contents, antioxidant activities of the leaves and fruits, and yield was compared to the control (plants sprayed with water) and to the experimental treatment involving spraying with 108 ufc/mL of propagules produced in potato dextrose broth. The effect of chlamydospore-rich suspensions on plant physiological parameters was more pronounced and long-lasting compared with the other treatments. The treatment with chlamydospore-rich suspension enhanced the accumulation of polyphenols and flavonoids in the leaves (by 17% and 50%, respectively) and fruits (by 18% and 31%, respectively) and increased the antioxidant activity. The Trichoderma treatment increased the yield by +25.33–53.07%. The application of the foliar treatment with Trichoderma suspensions did not modify the cytocompatibility of the extracts from the fruits determined on the L929 cells

<i>Ganoderma lucidum</i>-Mediated Green Synthesis of Silver Nanoparticles with Antimicrobial Activity

“Green chemistry” is a simple and easily reproductible method that provides nanoparticles characterized by better stability and good dispersion in an aqueous solution. Nanoparticles can be synthesized by algae, bacteria, fungi, and plant extracts. Ganoderma lucidum is a commonly used medicinal mushroom with distinctive biological properties, such as antibacterial, antifungal, antioxidant, anti-inflammatory, anticancer, etc. In this study, aqueous mycelial extracts of Ganoderma lucidum were used to reduce AgNO3 to form silver nanoparticles (AgNPs). The biosynthesized nanoparticles were characterized by UV-visible spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) analysis. The maximum UV absorption was obtained at 420 nm, which represents the specific surface plasmon resonance band for biosynthesized silver nanoparticles. SEM images showed particles as predominantly spherical, while FTIR spectroscopic studies illustrated the presence of functional groups that can support the reducing of ion Ag+ to Ag(0). XRD peaks ratified the presence of AgNPs. The antimicrobial effectiveness of synthesized nanoparticles was tested against Gram-positive and Gram-negative bacterial and yeasts strains. The silver nanoparticles were effective against pathogens, inhibiting their proliferation, and thus reducing the risk to the environment and to public health