Svetlana V. Prudnikova

Degradable Polyhydroxyalkanoates as Herbicide Carriers

The biodegradable polymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) has been used to design experimental sustained-release formulations of the herbicide Zellek Super in the form of films and microgranules. The kinetics of polymer degradation and the dynamics of herbicide release show that the rate and extent of herbicide release from the polymer matrix into the soil depends on the geometry of the carrier and the proportion of the pesticide loaded into it (polymer/pesticide mass ratio). Experiments with the creeping bentgrass (Agrostis stolonifera L.) show that the formulations of the herbicide Zellek Super constructed as microgranules and films can be successfully used to suppress the growth of grasses. This study is the first to demonstrate that biodegradable polyhydroxyalkanoates can be used effectively to construct environmentally friendly sustained-release PHA-herbicide systems that can be placed into the soil together with seeds.

Nanoagroparticles emerging trends and future prospect in modern agriculture system

Increment of technical knowledge has remarkably uplifted logical thinking among scientific communities to shape the theoretical concepts into near product-oriented research. The concept of nanotechnology has overwhelmed almost all forms of lives and has traded its applications in myriad fields. Despite rapid expansion of nanotechnology, sustainable competitions still do exist in the field of agriculture. In current scenario, agriculture is a manifestation demand to provide adequate nutrition for relentless growing global population. It is estimated that nearly one-third of the global crop production is destroyed annually. The loss owes to various stresses such as pest infestation, microbial pathogens, weeds, natural calamities, lack of soil fertility and much more. In order to overcome these limitations, various technological strategies are implemented but a majority of these have their own repercussions. Hence there is a scrawling progress on the evaluation of nanoparticles into agriculture sector which can reform the modern agricultural system. Applications of these nanomaterials can add tremendous value in the current scenario of a global food scarcity. Nanotechnology can address the adverse effects posed by the abundant use of chemical agrochemicals which are reported to cause biomagnification in an ecosystem. Based on these facts and consideration, present review envisages on nanoparticles as nanoherbicides, nanopesticides, onsite detection agro-pathogens and nanoparticles in post harvest management. The review also elucidates on the importance of nanoparticles in soil fertility, irrigation management and its influence on improving crop yield. With scanty reports available on nanotechnology in agriculture system, present review attributes toward developing nanoagroparticles as the future prospect which can give new facelift for existing agriculture system.

Biodegradable poly-3-hydroxybutyrate as a fertiliser carrier.

BACKGROUND Increasing use of mineral fertilisers can lead to accumulation of fertilisers in soil, water and foodstuffs. One of the approaches to preventing these problems is to develop controlled release forms of fertilisers. RESULTS Experimental formulations of the nitrogen fertiliser urea loaded in a degradable matrix of the natural polymer poly-3-hydroxybutyrate (P3HB) in the form of films, pellets and coated granules were constructed and investigated. Nitrogen release into soil occurred as the polymer was degraded, and it was dependent on the geometry of the carrier and the amount of nitrogen loaded in it, showing that nitrogen release can last for 30 days or longer and that release rates can be controlled by varying the fabrication technique employed. P3HB/urea formulations have a favourable effect on the soil microbial community. The use of embedded urea has a beneficial influence on the growth of creeping bentgrass (Agrostis stolonifera) and lettuce (Latuca sativa) and reduces removal of nitrogen with drain water. CONCLUSION The slow-release nitrogen formulations developed in this study can be buried in soil together with seeds preventing nitrogen deficiency. The use of such slow-release formulations can decrease the amounts of chemicals in the environment and prevent their adverse effects on the biosphere.

Efficacy of tebuconazole embedded in biodegradable poly-3-hydroxybutyrate to inhibit the development of Fusarium moniliforme in soil microecosystems.

BACKGROUND An important line of research is the development of a new generation of formulations with targeted and controlled release of the pesticide, using matrices made from biodegradable materials. In this study, slow-release formulations of the fungicide tebuconazole (TEB) have been prepared by embedding it into the matrix of poly-3-hydroxybutyrate (P3HB) in the form of films, microgranules and pellets. RESULTS The average rates of P3HB degradation were determined by the geometry of the formulation, reaching, for 63 days, 0.095-0.116, 0.081-0.083 and 0.030-0.055 mg day-1 for films, microgranules and pellets respectively. The fungicidal activity of P3HB/TEB against the plant pathogen Fusarium moniliforme was compared with that of the commercial formulation Raxil Ultra. A pronounced fungicidal effect of the experimental P3HB/TEB formulations was observed in 2-4 weeks after application, and it was retained for 8 weeks, without affecting significantly the development of soil aboriginal microflora. CONCLUSION TEB release can be regulated by the process employed to fabricate the formulation and the fungicide loading, and the TEB accumulates in the soil gradually, as the polymer is degraded. The experimental forms of TEB embedded in the slowly degraded P3HB can be used as a basis for developing slow-release fungicide formulations.

The New Strain of Acetic Acid Bacteria Komagataeibacter xylinus B-12068 – Producer of Bacterial Cellulose for Biomedical Applications

The strain of acetic acid bacteria Komagataeibacter xylinus B-12068, producing of bacterial cellulose (BC), was isolated and described. The effects of cultivation conditions (carbon sources, temperature, and pH) on BC production and properties were studied in surface and submerged cultures. Glucose was found to be the best substrate for BC production among the sugars tested; ethanol concentration of 3 % (w/v) enhanced the productivity of BC. The highest BC yield (up to 17.0 g/L) was obtained under surface static cultivation conditions, in the modified HS medium supplemented with ethanol, at pH 3.9, after 7 days of cultivation in the thinnest layer of the medium.

Toxic effects of the fungicide tebuconazole on the root system of fusarium-infected wheat plants

The study investigates toxic effects of the fungicide tebuconazole (TEB) on Fusarium-infected wheat (Triticum aestivum) plants based on the morphological characteristics of root apices and changes in the integrated parameters of redox homeostasis, including the contents of free proline and products of peroxidation of proteins (carbonylated proteins, CP) and lipids (malondialdehyde, MDA) in roots. In two-day-old wheat sprouts infected by Fusarium graminearum, the levels of proline, CP, and border cells of root apices are higher than in roots of uninfected sprouts by a factor of 1.4, 8.0, and 3, respectively. The triazole fungicide tebuconazole (TEB) at the concentrations of 0.01, 0.10, and 1.00 μg ml-1 of medium causes a dose-dependent decrease in the number of border cells. The study of the effects of TEB and fusarium infection on wheat plants in a 30-day experiment shows that the effect of the fungicide TEB on redox homeostasis in wheat roots varies depending on the plant growth stage and is significantly different in ecosystems with soil and plants infected by Fusarium phytopathogens. The study of the morphology of root apices shows that the toxic effects of TEB and fusarium infection are manifested in the destructive changes in root apices and the degradation of the root tip mantle.

Siberian plants: untapped repertoire of bioactive endosymbionts

BackgroundEndosymbionts are microorganisms present in all plant species, and constitute the subject of interest among the scientific community. These symbionts have gained considerable attention in recent years, owing to their emerging biological roles. Global challenges, such as antimicrobial resistance, treatment of infectious diseases such as HIV and tuberculosis, cancer, and many genetic disorders, exist. Endosymbionts can help address these challenges by secreting valueadded bioactive compounds with various activities.ObjectiveHerein, we describe the importance of plants inhabiting Siberian niches. These plants are considered to be among the least studied organisms in the plant kingdom worldwide. Barcoding these plants can be of interest for exploring bioactive endosymbionts possessing myriad biological properties.MethodsA systematic survey of relevant scientific reports was conducted using the PubMed search engine. The reports were analyzed, and compiled to draft this review.ResultsThe literature survey on Siberian plants regarding endosymbionts included a few reports, since extremely few exploratory studies have been conducted on the plants in these regions. Studies on the endosymbionts of these plants are highly valuable, as they report potent endosymbionts possessing numerous biological properties. Based on these considerations, this review aims to create awareness among the global scientific community working on related areas.ConclusionThis review could provide the basis for barcoding novel endosymbionts of Siberian plants and their ecological importance, which can be exploited in various sectors. The main purpose of this review is to create awareness of Siberian plants, which are among the least studied organisms in the plant kingdom, with respect to endosymbionts, among the scientific community.

Fungicidal activity of slow-release P(3HB)/TEB formulations in wheat plant communities infected by Fusarium moniliforme

Fungicidal activity of experimental tebuconazole (TEB) formulations was investigated in laboratory soil ecosystems in wheat plant communities infected by Fusarium moniliforme. TEB was embedded in the matrix of poly-3-hydroxybutyrate, shaped as films and microgranules. These formulations were buried in the soil with wheat plants, and their efficacy was compared with that of commercial formulation Raxil and with the effect of pre-sowing treatment of seeds. In the experiment with the initially infected seeds and a relatively low level of natural soil infection caused by Fusarium fungi, the effects of the experimental P(3HB)/TEB formulations and Raxil were comparable. However, when the level of soil infection was increased by adding F. moniliforme spores, P(3HB)/TEB granules and films reduced the total counts of fungi and the abundance of F. moniliforme more effectively than Raxil. Seed treatment or soil treatment with Raxil solution showed an increase in the percentage of rot-damaged roots in the later stages of the experiment. In the early stage (between days 10 and 20), the percentage of rot-damaged roots in the soil with TEB embedded in the slowly degraded P(3HB) matrix was similar to that in the soil with Raxil. However, the efficacy of P(3HB)/TEB formulations lasted longer, and in later stages (between days 20 and 30), the percentage of rot-damaged roots in that group did not grow. In experiments with different TEB formulations and, hence, different fungicidal activities, the increase in plant biomass was 15–17 to 40–60% higher than in the groups where TEB was applied by using conventional techniques.

Development and characterization of ceftriaxone-loaded P3HB-based microparticles for drug delivery

Abstract In this study, polymer-based microparticles are used to improve the therapeutic properties of ceftriaxone (CEF) and render them safer. Poly-3-hydroxybutyrate (P3HB) and poly-3-hydroxybutyrate/polyethylene glycol (P3HB-PEG)-based microparticles were prepared by two methods: a double emulsification technique and spray-drying. The microparticles were characterized in terms of size and zeta potential, morphology, total drug loading and drug release. The microparticles had spherical shapes with diameters of a size range from 0.74 to 1.55 µm (emulsification technique) and from 3.84 to 6.51 µm (spray-drying); CEF encapsulation efficiency was around 63% and 49% for these methods respectively. The CEF release from microparticles obtained by spray-drying reached 100% after 150 h, while for microparticles obtained by emulsification technique the total release of CEF did not exceed 34% after 312 h. The release profiles could be best explained by Zero order kinetics model, Higuchi and Korsmeyer-Peppas models, as the plots showed high linearity. Antibacterial activity of the microparticles was evaluated against gram-positive and gram-negative bacterial strains. In general, CEF encapsulation in polymeric microparticles preserves the therapeutic efficacy of the CEF and provides its prolonged effect.