Evaluation of eliciting activity of peptidil prolyl cys/trans isomerase from <em>Pseudonomas fluorescens</em> encapsulated in sodium alginate regarding plant resistance to viral and fungal pahogens

Use of chemical pesticides poses a threat for environment and human health, so green technologies of crop protection are of high demand. Some microbial proteins able to activate plant defense mechanisms and prevent the development of resistance in plant pathogens, may be good alternative to chemicals, but practical use of such elicitors is limited due to need to protect them against adverse environment prior their delivery to target receptors of plant cells. In this study we examined a possibility to encapsulate heat resistant FKBP-type peptidyl prolyl cis-trans isomerase (PPIase) from Pseudomonas fluorescens, which possesses a significant eliciting activity in relation to a range of plant pathogens, in sodium alginate microparticles and evaluated the stability of resulted complex under long-term UV irradiation and in the presence of proteinase K, as well as its eliciting activity in three different “plant-pathogen” models comparing to that of free PPIase. The obtained PPIase-containing microparticles consisted of 70% of sodium alginate, 20% of bovine serum albumin, and 10% of PPIase. In contrast to free PPIase, which lost its eliciting properties after 8-h UV treatment, encapsulated PPIase kept its eliciting ability unchanged; after being exposed to proteinase K, its eliciting ability twice exceeded that of free PPIase. Using “tobacco-TMV”, “tobacco-Alternaria longipes”, and “wheat-Stagonospora nodorum” model systems, we showed that encapsulation process did not influence on the eliciting activity of PPIase. In the case of the “wheat-S. nodorum” model system, we also observed a significant eliciting activity of alginate-albumin complex and almost doubled activity of encapsulated PPIase as compared to the free PPIase. As far as we know, this is the first observation of a synergistic interaction between alginate and other compound possessing any bioactive properties. The results of the study show some prospects for a PPIase use in agriculture

Формирование микроструктурированных пленок поли-3-оксибутирата с регулируемой топографией поверхности

The possibility of fabrication of microstructured poly-3-hydroxybutyrate films by self-assembly water microdroplets technique, using artificial templates and polymer inverse emulsions has been studied. It has been established that self-assembly water microdroplets technique allows forming ordered microstructures of poly-3-hydroxybutyrate with a hexagonal arrangement of cells with an adjustable diameter from 1 to 4 цт. It has been shown that application of inverse emulsions of poly-3-hydroxybutyrate allows us to fabricate porous films with a pore size in the range from 0.4 to 3 ^m, while the structure of the films and the pore size can be controlled by changing the polymer concentration in the dispersion medium and the volume ratio of the phases. Using spin-coating technique and artificial templates, it is possible to obtain poly-3-hydroxybutyrate microstructured replicas, which are characterized by a high degree of uniformity and the absence of defective areas. It has been shown that the formed microstructured poly-3-hydroxybutyrate films with controlled surface topography are promising for use as scaffolds for stem cells.Исследована возможность формирования микроструктурированных пленок поли-3-оксибутирата методом «самоорганизации» микрокапель воды с помощью искусственных шаблонов и обратных эмульсий полимера. Установлено, что методом «самоорганизации» можно сформировать упорядоченные микроструктуры поли-3-оксибутирата с гексагональным расположением ячеек регулируемого диаметра от 1 до 4 мкм. Показано, что путем применения обратных эмульсий поли-3-оксибутирата можно получить пористые пленки с заданным размером пор от 0,4 до 3 мкм, при этом структуру пленок и размер пор в них можно регулировать путем изменения концентрации полимера в дисперсионной среде и объемного соотношения фаз. С помощью метода центрифугирования и применения искусственных шаблонов можно создавать точные реплики поли-3-оксибутирата, которые характеризуются высокой степенью однородности по всей площади и отсутствием дефектных областей. Показано, что сформированные микроструктурированные пленки поли-3-оксибутирата с регулируемой топографией поверхности перспективны для использования в качестве скаффолдов для культивирования стволовых клеток