SURVEY OF THE GUT PATHOGENIC MICROFLORA ASSOCIATED WITH CATERPILLARS OF THE BOX TREE MOTH CYDALIMA PERSPECTALIS WALKER, 1859 (LEPIDOPTERA: CRAMBIDAE)

The invasive box tree moth Cydalima perspectalis is an important and dangerous pest on Buxus spp. In this study, its destructive potential was evaluated in five areas of Bulgaria through the assessment of the defoliation levels caused by the caterpillars on the box trees. The microorganism species composition and diversity in the gut of caterpillars were investigated. In a total of 206 caterpillars, 5 bacterial (Acinetobacter schindleri, Enterococcus casseliflavus,        Klebsiella mobilis, Paenibacillus anaericanus, and Paenibacillus popilliae) and 5 fungal species (Metarhizium sp., Beauveria sp., Verticillium sp., Alternaria sp. and Mucor sp.), were recovered. The most prevalent pathogen (52.4%) was the bacterium P. popilliae. Two entomopathogenic fungi, Metarhizium sp. and Beauveria sp., were observed in high and quite similar prevalences of 29.6% and 28.6%, respectively. The presence of these three pathogens (P. popilliae, Metarhizium sp. and Beauveria sp.) in relatively high levels in the gut of caterpillars indicates the possible role of gut pathogenic microorganisms as agents affecting caterpillar survival in natural populations of the pests. Further research is needed to assess the effect of the identified bacteria and fungi on C. perspectalis life stages

Effect of easily biodegradable amendments on heavy metal solubilization and accumulation in technical crops ‐ a field trial

Heavy‐metal soil pollution is a common environmental problem all over the world. In the induced phytoextraction process plants can transport and translocate to their above‐ground tissues significant concentration of contaminants. Since some heavy metals are mostly presented in non‐soluble state, the application of chelating agents is needed. In this study we introduced into the rhizosphere of maize (var. Kneja 530) and sunflower (var. Favorit) plants 1 and 5 mmol l−1 of EDDS and NTA, and 5 g kg−1 of nutrients to enhance the accumulated concentrations of cadmium, lead and zinc. The fraction of CaCl2‐extractable metals increased incrementing the concentration of chelates. This was clearly pronounced for all the metals in the treatments with NTA and for Pb in those with EDDS. Generally, under all the experimental conditions the accumulated heavy‐metal concentrations were found to be significantly higher than in the control. Thus, in the case of higher concentration of NTA and EDDS, the accumulated Cd in the leaves of sunflower was found to be threefold higher. The highest accumulation of Pb in the leaves of maize was observed when nutrients were added (62 mg kg−1). On the other hand, negative effects of the used chelating agents on soil bacteria and fungi at plant harvest were not observed. Moreover, when nutrients were added, the number of studied microorganisms significantly increased. Lengvai biodegradavimą pagerinančių pataisymų priemonių poveikis sunkiųjų metalų tirpumui ir akumuliacijai techniniuose pasėliuose – lauko bandymai Santrauka Dirvožemio užterštumas sunkiaisiais metalais yra dažna aplinkos problema visame pasaulyje. Inicijuotas fitoekstrakcijos procesas augaluose gali perkelti į jų antžeminius audinius dideles teršalų koncentracijas. Kadangi kai kurie sunkieji metalai dažniausiai esti netirpios būsenos, reikia pritaikyti chelatų agentus. Į kukurūzus buvo įterpta rizosfera (var. Kneja 530) ir saulėgrąžos (var. Favorit) EDDS bei NTA 1 ir 5 mmol–1 ir 5 g kg–1 mineralinių medžiagų, padidinant kadmio, švino ir cinko akumuliuotas koncentracijas. Ekstrahuotos CaCl2 metalo frakcijos padidino chelatų koncentracijos didėjimą. Tai pasireiškė visiems metalams, apdorotiems su NTA, ir švinui, paveiktam su EDDS. Visuose eksperimentuose akumuliuoto sunkiojo metalo koncentracijos buvo daug didesnės nei kontroliniame bandinyje. Vadinasi, didesnės NTA ir EDDS koncentracijos atveju akumuliuotas Cd saulėgrąžos lapuose buvo 3 kartus didesnis. Didžiausia Pb akumuliacija miežių lapuose išmatuota, pridėjus mineralinių medžiagų (62 mg kg–1). Kita vertus, neigiamas chelatų agentų naudojimo poveikis dirvožemio bakterijoms ir grybeliams augalų derliuje nebuvo nustatytas. Be to, kai buvo pridėta mineralinių medžiagų, padaugėjo nagrinėjamų mikroorganizmų. Reikšminiai žodžiai: sunkieji metalai, fitoekstrakcija, kviečiai, saulėgrąžos, EDDS, NTA, lauko bandymai, rizosferos mikroorganizmai. Полевые испытания влияния мер, способствующих деградации тяжелых металлов, их разложению и накапливанию в технических посевах Резюме Загрязнение почв тяжелыми металлами – наиболее часто отмечаемая проблема во всем мире. Инициированный процесс фитоэкстракции в растениях может способствовать переносу значительных концентраций загрязнителей в их поверхностные ткани. В связи с тем, что некоторые тяжелые металлы находятся в нерастворенном состоянии, необходимо применение агентов хелатов. В настоящем исследовании в кукурузу была введена ризосфера (вар. Kneja 530) и подсолнечник (вар. favorit) EDDS и NTA 1 и 5 ммоль–1 ir 5 г кг–1 минеральных веществ для увеличения аккумулированных концентраций кадмия, свинца и цинка. Экстрагированные фракции металла CaCl2 способствовали увеличению концентрации хелатов. Это подтверждено исследованием всех металлов, подвергшихся воздействию NTA, и свинца, обработанного с помощью EDDS. Во всех экспериментах концентрации аккумулированного тяжелого металла были значительно больше, чем в контрольном образце. Следовательно, в случае большей концентрации NTA и EDDS содержание аккумулированного в листьях подсолнечника Cd было в три раза больше. Наибольшая аккумуляция Cd в листьях ячменя зафиксирована в случае добавления минеральных веществ (62 мг кг–1). Не было обнаружено и отрицательного воздействия от применения агентов хелатов на бактерии почвы и грибки в урожае растений. Кроме того, в результате добавления минеральных веществ количество исследуемых микроорганизмов увеличилось. Ключевые слова: тяжелые металлы, фитоэкстракция, ячмень, подсолнечник, NTA, EDDS полевые испытания, микроорганизмы ризосферы. First Published Online: 14 Oct 201

Electrospun 5-chloro-8-hydroxyquinoline-Loaded Cellulose Acetate/Polyethylene Glycol Antifungal Membranes Against Esca

Esca is one of the earliest described diseases in grapevines and causes trunk damage and the sudden wilting of the entire plant; it is caused mainly by the species Phaeomoniella chlamydospora (P. chlamydospora) and Phaeoacremonium aleophilum (P. aleophilum). In practice, there are no known curative approaches for fighting esca directly, which is a huge problem for preserving vineyards. Micro- and nanofibrous membranes from cellulose acetate (CA) and cellulose acetate/polyethylene glycol (CA/PEG) containing 5-chloro-8-hydroxyquinolinol (5-Cl8Q) were successfully prepared by electrospinning. The surface morphologies and optical and mechanical properties of the membranes were characterized by using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Vis), water contact angle measurements and mechanical tests. It was found that the bioactive compound release was facilitated by PEG. The antifungal activities of the obtained materials against P. chlamydospora and P. aleophilum were studied. We have demonstrated that 5-Cl8Q is an efficient and sustainable antifungal agent against P. chlamydospora and P. aleophilum. Moreover, for the first time, the present study reveals the possibility of using electrospun polymer membranes containing 5-Cl8Q which impede the penetration and growth of P. chlamydospora and P. aleophilum. Thus, the obtained fibrous materials can be suitable candidates for plant protection against diverse fungi

Oxygenated Analogues of Santacruzamate A

A new approach for the synthesis of Santacruzamate A analogues is demonstrated. The method allows functionalization at position 3 of the gamma-aminobutyric fragment and carbon chain variation

SYNTHESIS AND SPECTRAL CHARACTERIZATION OF NEW SALVADORICINE ANALOGUES

Salvadoricine is an indole alkaloid isolated from the leaves of Salvadora persica Linn. This natural product has interesting and diverse biological profile. An effective one-pot synthesis of Salvadoricine analogues via multicomponent reaction of α-amidoalkylation is proposed. The conditions for the reaction of benzothiazole, alkyl chloroformates and 3-acetylindole were found. The structure of the obtained in good yields analogues of natural alkaloid - Salvadoricine was proved by spectral methods

Tobacco Plant Growth-Promoting and Antifungal Activities of Three Endophytic Yeast Strains

In this research, the biosynthetic and biocontrol potential of endophytic yeast to improve the growth and development of tobacco has been elucidated. Three yeast strains were enriched and isolated from different plant tissues. Partial sequence analysis of ITS5-5.8-ITS4 region of the nuclear ribosomal DNA with universal primers identified YD5, YE1, and YSW1 as Saccharomyces cerevisiae (S. cerevisiae), Zygosaccharomyces bailii (Z. bailii), and Saccharomyces kudriavzevii (S. kudriavzevii), respectively. When cultivated in a medium supplemented with 0.1% L-tryptophan, isolated yeast strains produced indole-3-acetic acid (IAA). The capacities of those strains to improve the mobility of phosphorus and synthesize siderophores has been proven. Their antimicrobial activities against several Solanaceae plant pathogenic fungi (Alternaria solani pathovar. tobacco, Rhizoctonia solani, and Fusarium solani pathovar. phaseoli) were determined. S. cerevisiae YD5, Z. bailii YE1, and S. kudriavzevii YSW1 inhibited the growth of all tested pathogens. Yeast strains were tested for endophytic colonization of tobacco by two different inoculation methods: soil drench (SD) and leaf spraying (LS). To establish colonization in the various tissues of tested tobacco (Nicotiana tabaccum L.) plants, samples were taken on the seventh, fourteenth, and twenty-first days after treatment (DAT), and explants were inoculated on yeast malt agar (YMA). Both techniques of inoculation showed a high frequency of colonization from 83.33% to 100%. To determine the effectiveness of the microbial endophytes, their effect on some physiological processes in the plant were analyzed, such as photosynthesis, stomatal conductivity, and transpiration intensity. The effect of single and double treatment with yeast inoculum on the development and biochemical parameters of tobacco was reported. Plants have the ability of structural and functional adaptation to stress effects of different natures. All treated plants had a higher content of photosynthetic pigments compared to the control. Photosynthesis is probably more intense, and growth stimulation has been observed. The chlorophyll a/b ratio remained similar, and the total chlorophyll/carotenoid ratio slightly increased as a result of elevated chlorophyll levels. The most significant stimulating effect was recorded in tobacco plants treated by foliar spraying with Z. bailii YE1 and S. cerevisiae YD5. In contrast, S. kudriavzevii YSW1 had a better effect when applied as a soil drench. Thus, S. cerevisiae YD5, Z. bailii YE1, and S. kudriavzevii YSW1 have a high potential to be used as a biocontrol agents in organic agriculture

Electrospun Eco-Friendly Materials Based on Poly(3-hydroxybutyrate) (PHB) and TiO2 with Antifungal Activity Prospective for Esca Treatment

Esca is a type of grapevine trunk disease that severely affects vine yield and longevity. Phaeomoniella chlamydospora (P. chlamydospora) is one of the main fungi associated with esca. The aim of the present study was to obtain eco-friendly materials with potential antifungal activity against P. chlamydospora based on biodegradable and biocompatible poly(3-hydroxybutyrate) (PHB), nanosized TiO2-anatase (nanoTiO2), and chitosan oligomers (COS) by conjunction of electrospinning and electrospraying. One-pot electrospinning of a suspension of nanosized TiO2 nanoparticles in PHB solution resulted in materials in which TiO2 was incorporated within the fibers (design type “in”). Simultaneous electrospinning of PHB solution and electrospraying of the dispersion of nanosized TiO2 in COS solution enabled the preparation of materials consisting of PHB fibers on which TiO2 was deposited on the fibers’ surface (design type “on”). Several methods including scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction analysis (XRD), thermogravimetric analyses (TGA) and water contact angle were utilized to characterize the obtained materials. The incorporation of nanoTiO2 in the PHB fibers, as well as nanoTiO2 deposition onto the surface of the PHB fibers resulted in increased roughness and hydrophobicity of the obtained composite fibrous materials. Moreover, TiO2-on-PHB fibrous material exhibited complete inhibition of fungal growth of P. chlamydospora. Therefore, the obtained eco-friendly fibrous materials based on PHB and nanoTiO2 are promising candidates for protection against esca in agriculture

Electrospun Polymer Materials with Fungicidal Activity: A Review

In recent years, there has been special interest in innovative technologies such as polymer melt or solution electrospinning, electrospraying, centrifugal electrospinning, coaxial electrospinning, and others. Applying these electrokinetic methods, micro- or nanofibrous materials with high specific surface area, high porosity, and various designs for diverse applications could be created. By using these techniques it is possible to obtain fibrous materials from both synthetic and natural biocompatible and biodegradable polymers, harmless to the environment. Incorporation of low-molecular substances with biological activity (e.g., antimicrobial, antifungal) is easily feasible. Moreover, biocontrol agents, able to suppress the development and growth of plant pathogens, have been embedded in the fibrous materials as well. The application of such nanotechnologies for the creation of plant protection products is an extremely promising new direction. This review emphasizes the recent progress in the development of electrospun fungicidal dressings and their potential to be applied in modern agriculture

Poprawa właściwości hydrofobowych i przeciwgrzybicznych materiałów z elektroprzędzonego octanu celulozy poprzez zastosowanie nanocząsteczek ZnO

Suitable conditions for the preparation of nano- and microstructured materials from cellulose acetate and cellulose acetate/ZnO from solutions/suspensions in aceton/water by electrospinning/electrospraying were found. The materials obtained were characterised by scanning electron microscopy (SEM), X-ray diffraction analysis (XRD) and contact angle measurements. The antifungal activity of the materials obtained against Phaeomoniella chlamydospora, which is one of the main species causing diseases in grapevines, was studied as well. It was found that electrospinning of CA solutions with a concentration of 10 wt% reproducibly resulted in the preparation of defect-free fibres with a mean fibre diameter of ~780 nm. The incorporation of ZnO nanoparticles resulted in the fabrication of hybrid materials with superhydrophobic properties (contact angle 152°). The materials decorated with ZnO possessed antifungal activity against P. chlamydospora. Thus, the fibrous materials of cellulose acetate decorated with ZnO particles obtained can be suitable candidates to find potential application in agriculture for plant protection.W pracy wskazano odpowiednie warunki do otrzymywania materiałów nano- i mikrostrukturalnych z octanu celulozy i octanu celulozy/ZnO z roztworów/zawiesin w acetonie/wodzie metodą elektroprzędzenia/elektrorozpylania. Uzyskane materiały scharakteryzowano za pomocą skaningowej mikroskopii elektronowej (SEM), dokonano analizy dyfrakcji rentgenowskiej (XRD) oraz pomiarów kąta zwilżania. Zbadano również działanie przeciwgrzybiczne uzyskanych materiałów przeciwko Phaeomoniella chlamydospora, który jest jednym z głównych gatunków wywołujących choroby winorośli. Stwierdzono, że podczas elektroprzędzenia z roztworów CA o stężeniu 10% wag. w sposób powtarzalny otrzymywano włókna wolne od defektów o średniej średnicy ~ 780 nm. Wprowadzenie nanocząstek ZnO zaowocowało wytworzeniem materiałów hybrydowych o właściwościach superhydrofobowych (kąt zwilżania 152°). Materiały z dodatkiem ZnO wykazywały działanie przeciwgrzybiczne przeciwko P. chlamydospora. Stwierdzono, że otrzymane materiały mogą być stosowane w rolnictwie do ochrony roślin