Biotesting of polymeric waste excluded from solid waste waste

Introduction. Annually, the volume of accumulated polymers in landfills in Ukraine is growing by more than 1 million tons, but the volume of recycled polymer packaging over the past ten years has not exceeded 3%. The goal is to establish the degree of toxicological impact on biosphere objects of polymers extracted from solid waste, to assess the safety of using household polymer waste as a secondary raw material for further processing. The task is to establish the degree of biological and toxicological safety of polymer wastes extracted from solid waste. Methods and techniques: toxicological - determination of water toxicity on acute Daphnia magna according to DSTU 4173: 2003 (ISO 6341: 1996, MOD) and chronic according to DSTU 4166: 2003 (ISO 10706: 2000, MOD), and Paramecium caudatum ciliates, soil microflora reactions (saprotrophic soil bacteria CFU / g) according to MR 2609-82, the assessment of phytotoxic effects on higher plants was carried out by vegetation methods according to ISO 17402-2008, ISO 17126-2005a, ISO 22030: 2005b, ISO 11269 -1:2012a. Results. The research results show that aqueous extracts from waste polymers extracted from solid waste and their mixture do not have a pronounced toxic effect on aquatic organisms. There is no significant effect on soil bacteria. The study of the effect of polymer waste on seed germination did not reveal phytotoxic effects for any crop. A slight phytotoxic effect was observed during the study of PVC and PS waste. Wheat and mustard were the most sensitive. The level of phytotoxic effect was within acceptable limits and did not exceed 5.67%. Evaluation of phytotoxic effects on stem length showed the presence of effects from all processed products except PVC. The impact, characterized as weak, ranged from - 2.06% (PP) to - 13.27% (PS). The effect on root length was found for samples with PS waste (-7.23%), which was characterized as weak and PVC (-43.52%) - medium. Watercress and mustard were the most sensitive plants to the effects of polymer waste. Conclusions. The studied samples of polymer waste do not show hygienically significant toxic effects on water and soil test objects, even in concentrations of 1: 1, so the impact on the above test organisms polymer waste removed from solid waste is classified as hazard class 4. According to the assessment of phytotoxic effect, polymer waste removed from solid waste is classified as hazard class 4, except for PVC - hazard class 3.

Synthesis, Fungitoxic Activity against Botrytis cinerea and Phytotoxicity of Alkoxyclovanols and Alkoxyisocaryolanols

Clovane and isocaryolane derivatives have been proven to show several levels of activity against the phytopathogenic fungus Botrytis cinerea. Both classes of sesquiterpenes are reminiscent of biosynthetic intermediates of botrydial, a virulence factor of B. cinerea. Further development of both classes of antifungal agent requires exploration of the structure–activity relationships for the antifungal effects on B. cinerea and phytotoxic effects on a model crop. In this paper, we report on the preparation of a series of alkoxy-clovane and -isocaryolane derivatives, some of them described here for the first time (2b, 2d, 2f–2h, and 4c–4e); the evaluation of their antifungal properties against B. cinerea, and their phytotoxic activites on the germination of seeds and the growth of radicles and shoots of Lactuca sativa (lettuce). Both classes of compound show a correlation of antifungal activity with the nature of side chains, with the best activity against B. cinerea for 2d, 2h, 4c and 4d. In general terms, while 2-alkoxyclovan-9-ols (2a–2e) exert a general phytotoxic effect, this is not the case for 2-arylalkoxyclovan-9-ols (2f–2i) and 8-alkoxyisocaryolan-9-ols (4a–4d), where stimulating effects would make them suitable candidates for application to plants.

Valorization of Biomass Residues by Biosorption of Microelements in a Closed-Loop Cycle

The concept of the research data presented assumes the valorization of goldenrod residues from supercritical CO2 extraction following the circular economy principles. The biomass was enriched with microelements (Cr, Zn, Cu) by biosorption from single and multielemental solutions in batch and packed bed reactors. Modeling of biosorption equilibrium supported by instrumental analysis (SEM and FTIR) of material properties was employed to explain the metal ions binding mechanism. The preferential biosorption of Cr(III) over the divalent ions, allows the possibility of valorization of goldenrod residue in a garden-scale biosorption tank acting as a fixed-bed reactor working in an open circulation run and fed with microelements diluted in rainwater. The use of fertigation solution in optimal doses of micronutrients did not show any phytotoxic effect. Using the post-sorptive solution as a source of micronutrients for plants showed significant effects on growth parameters (increased chlorophyll content by 54%) compared to groups fertilized with commercial formulation (13% higher sprout mass). Additionally, fertigation with the post-sorption solution leads to the biofortification of cucumber sprouts. The recycling process results in two products: enriched biomass as a potential feed additive (with Cr(III), Cu(II), and Zn(II)) and a post-sorption solution (with Zn(II) and Cu(II) only) used in the fertigation of plants. Graphical Abstract

Metabolic Profile and Mycoherbicidal Activity of Three Alternaria alternata Isolates for the Control of Convolvulus arvensis, Sonchus oleraceus, and Xanthium strumarium

Alternaria alternata isolates C1, S1, and X3 were isolated respectively from the weeds Convolvulus arvensis, Sonchus oleraceus, and Xanthium strumarium in Algiers during 2016 and identified by morphological and molecular analyses. The aim of this investigation was to chemically characterize the exometabolome of these fungi and to evaluate the myco-herbicidal potential of their culture filtrates, crude extracts, or fractions towards target weeds. Results revealed a great heterogeneity in the biochemical profiles of the exometabolome with the remarkable presence of two compounds: tenuazonic acid (TeA) and triprenyl phenol-7 (SMTP-7). To the best of our knowledge, SMTP-7—found in all the isolates—as well as 12-methoxycitromycin detected in the culture filtrate of isolate C1, have never been reported to be produced by A. alternata. Some fractions of isolates C1 and S1 showed symptoms (necrosis and chlorosis) on the detached leaves of C. arvensis and S. oleraceus, respectively with up to 100% phytotoxic effect at low concentration. In conclusion, biochemical characterization revealed great difference of C1, S1, and X3 exometabolomethat is likely to explain the difference in their phytotoxic activity. Some fractions (d1, e1, h1, i1, a2, and f2) of isolates C1 and S1 of A. alternata caused severe necrosis and chlorosis on the injured detached leaves of C. arvensis and S. oleraceus, respectively.

Characterization and Antimicrobial Studies of Iturin-Like and Bogorol-Like Lipopeptides From Brevibacillus spp. Strains GI9 and SKDU10

Accession numbers for whole-genome sequence of Brevibacillus sp. strain GI9 and SKDU10 are CAGD01000001 to CAGD01000061 and LSSO00000000, respectively. Members of the genus Brevibacillus have been demonstrated to produce a variety of bioactive compounds including polyketides, lipopeptides and bacteriocins. Lipopeptides are non-ribosomally synthesized surface-active compounds with antimicrobial, antitumor, and immune-stimulatory activities. They usually exhibit strong antifungal and antibacterial activities and are considered as promising compounds in controlling fungal diseases. In this study, we have characterized two lipopeptides from Brevibacillus sp. strains GI9 and SKDU10. The corresponding lipopeptides were purified by reverse-phase high-performance liquid chromatography. Mass analysis and characterization by MALDI-TOF-MS (Matrix-assisted laser desorption ionization time-of-flight mass spectrometry) analysis revealed production of an iturin-like lipopeptide by strain GI9 and bogorol-like lipopeptide by strain SKDU10. Both lipopeptides exhibited broad spectrum antibacterial activity and inhibited the growth of various fungi. They showed minimum inhibitory concentration (MIC) values between 90 and 300 μg/ml against indicator strains of bacteria and drug-resistant Candida indicator strains. The lipopeptides did not show phytotoxic effect in seed germination experiments but caused hemolysis. Further, both lipopeptides inhibited the growth of fungi on fruits and vegetables in in vitro experiments, thereby exhibited potential use in biotechnological industry as effective biocontrol agents.

Beauveria bassiana: as a potential microbial biocontrol agent for tea mosquito bug, Helopeltis theivora Waterhouse (Hemiptera: Miridae) in Dooars and Darjeeling, India

Background In the present study, the efficacy of two isolates of Beauveria bassiana namely, BKN20 and BKN1/14 was evaluated against the tea mosquito bug (TMB), Helopeltis theivora, Waterhouse (Hemiptera: Miridae) damaging harvestable shoots of tea plants in the Dooars and Darjeeling regions of West Bengal, India. Results Laboratory study revealed that, in both isolates, BKN20 was more pathogenic than BKN1/14, exhibiting 76% mortality of the test insect. The BKN20 isolate was formulated as an aqueous suspension (5%AS), and evaluated against TMB through micro-plot trials in tea plantations. The Micro-plot field study revealed a maximum of 72.19% reduction in the shoot damage due to TMB in plots sprayed with a 1000 ml/ha concentration of BKN20 5%AS containing 2 × 107 conidia/ml, as compared to the synthetic insecticide (Thiamethoxam 25%WG), where a 63.12% reduction in the shoots was recorded. Furthermore, different concentrations of the formulated BKN20 5%AS were evaluated against the test insect at 2 locations of tea gardens in the Dooars and Darjeeling regions. The results from both locations revealed that 1000 and 1200 ml/ha concentrations of BKN20 5%AS (each concentration containing 2 × 107 conidia/ml) significantly (p < 0.05) reduced the TMB population and they were more effective than Thiamethoxam 25%WG (120 g/ha). However, non-significant differences in crop yields were recorded. The formulation BKN20 5%AS was found to be non-pathogenic to non-target insects, i.e. natural enemies present in the tea ecosystem. BKN20 5%AS had no phytotoxic effect on the tea leaves, with acceptable organoleptic attributes. Conclusion The BKN20 isolate could be commercialized as an alternative microbial insecticide to reduce the load of chemical insecticides in the tea ecosystem.

Potential of the entomopathogenic fungus, Metarhizium anisopliae s.l. in controlling live-wood eating termite, Microtermes obesi (Holmgren) (Blattodea: Termitidae) infesting tea crop

Background In recent years, Microtermes obesi (Holmgren) (Blattodea: Termitidae) has been recorded as a major pest of tea crop, causes significant losses in production. Managing termite pests in tea crops through an integrated approach has been suggested, and the use of microbial biocontrol agent is one of the economical methods. The present study evaluated the pathogenic efficacy of an entomopathogenic fungus Metarhizium anisopliae s.l. (= M. anisopliae) against M. obesi damaging tea plants under field conditions. Results Metarhizium anisopliae s.l. was formulated as 5% aqueous suspension (AS). Large-scale field trials with formulated entomopathogen revealed that 1000 and 1200 ml concentrations of M. anisopliae s.l. 5%AS (each concentration containing 2 × 107 conidia/ml) each in 400 l of water/ha significantly (P < 0.05) reduced the population of M. obesi in tea gardens at Dooars and Darjeeling regions, India. In the field study, M. anisopliae s.l. was more effective than the standard insecticide and was non-pathogenic on the beneficial insects present in the tea gardens. In addition, M. anisopliae s.l. 5%AS had no phytotoxic effect on the tea leaves, with acceptable organoleptic attributes. Conclusion Metarhizium anisopliae s.l. isolate can be commercialized as an alternative natural termiticide to reduce the load of synthetic insecticides in the tea crop.

Effect of Cutting Size on the Performance of Exogenous Auxin IBA in Vegetative Propagation of Rubus erythroclados Mart. ex Hook. f.

Aim: The climbing shrub Rubus erythroclados Mart. ex Hook. f. (amora-verde) has great food (fruits) and medicinal (leaves) potential. However, this species remains understudied. The objective of this study was to evaluate the interaction between cutting size and IBA concentration in the vegetative propagation of R. erythroclados by stem cuttings. Study Design: The experimental design used was completely randomized in a 3x5 factorial combination. The cutting size factor was represented by three levels (10, 15 and 20 cm) and IBA concentration factor by five levels (0, 1,000, 2,000, 3,000 and 4,000 mg L-1). Results: There was an interaction between the factors in 13 of the 19 variables analyzed, being: live cuttings at 30 and 60 days, live cuttings with callus formation, sprouted cuttings at 30, 60 and 90 days, rooted cuttings, shoot number, shoot diameter, root number, root length, length of the largest root and root diameter. Size increase of the R. erythroclados cuttings caused a decrease in the phytotoxic effect of IBA in the development of the aerial part. The effect of IBA in response to rooting induction, in the larger size of R. erythroclados cuttings, required an increase in IBA concentration compared to the cuttings of shorter size. Conclusion: Cuttings of 10 and 15 cm treated with 1,000 mg L-1 of IBA showed greater rooting (20.0%) compared to the other treatments, being, therefore, indicated for the vegetative propagation of R. erythroclados by stem cuttings.