Bruno Perlatti

Polymeric Nanoparticle-Based Insecticides: A Controlled Release Purpose for Agrochemicals

Insects are one of the biggest animal populations with a very successful evolutive history, once they can be found chiefly in all possible environments all over the world, and the num‐ ber of species and individuals. Their success can be attributed to several important evolu‐ tionary aspects like wings, malleable exoskeleton, high reproductive potential, habits diversification, desiccation-resistant eggs and metamorphosis, just to name a few. Some spe‐ cies are especially valuable for humans due to their ability in providing several important goods, such as honey, dyes, lac and silk. On the other hand, many insects are vectors of many diseases, and many others damages crop plantations or wood structures, causing seri‐ ous health and economic issues.

Validation and application of HPLC-ESI-MS/MS method for the quantification of RBBR decolorization, a model for highly toxic molecules, using several fungi strains.

A novel analytical method using HPLC-MS/MS operating in selected reaction monitoring (SRM) for evaluation of fungi efficacy to decolorize Remazol Brilliant Blue R (RBBR) dye solution was developed, validated and applied. The method shows high sensibility allowing the detection of 4.6 pM of RBBR. Four fungal strains were tested in liquid medium, three strains of Aspergillus (Aspergillus aculeatus, Aspergillus flavus and Aspergillus fumigatus) and Phanerochaete chrysosporium. All fungi were able to degrade the dye, with efficiencies ranging from 40% for P. chrysosporium up to 99% for A. flavus during a 30-day incubation period. During the experiment, increased accumulation of degradation products was observed in A. flavus cultures containing RBBR. Through the use of full scan HPLC-MS technique it was possible to propose the biogenesis of the microbial metabolic degradation pathway. Screening using microorganisms and RBBR may be hereafter used to investigate microbial biodegradation of high toxicity molecules such as dioxins.

Green chemistry, sustainable agriculture and processing systems: a Brazilian overview

There is a pressing need for renewable and optimal use of resources towards sustainable primary production and processing systems worldwide. Current technologies for food and feedstock production are held accountable for several environmental problems, such as for instance soil and water contamination due to the use of hazardous substances, generation of toxic products and even excess of biomass that is considered waste. To minimize or solve these questions in order to produce an adequate quantity of reliable and healthy food, fibers and other products and energy, new paradigms focusing on sustainable agriculture, bio-based industries or biorefineries have emerged over the last decades. Biorefineries integrate sustainable and environmentally friendly concepts of Green Chemistry with intelligent and integrated farming processes, optimizing the agricultural production. Thermochemical and biochemical processes are excellent alternatives for the production of new classes of renewable biofuels and feedstock, showing relatively small impact on greenhouse gas emissions and important pathways to obtain platform chemicals. This review discusses the current and incipient technological developments for using biomass to generate bio-based chemicals over the last decade, focusing on Green Chemistry concepts towards sustainable agriculture and processing models in Brazil.

Use of Lignins from Sugarcane Bagasse for Assembling Microparticles Loaded with Azadirachta indica Extracts for Use as Neem-Based Organic Insecticides

Microcapsules of sugarcane bagasse lignin loaded with organic extracts of neem (Azadirachta indica) were prepared and evaluated as potential bioinsecticides. Lignins were extracted and modified by oxidation and acetylation reactions providing different biopolymers. Afterwards, they were characterized through several analytical techniques. The formulations were initially prepared as colloidal suspension of lignin nanoparticles, which were then spray-dried. The products were submitted to quality control protocols using high performance liquid chromatography (HPLC), thermal and photochemical degradation studies, followed by biological assays against Spodoptera frugiperda and Diatraea saccharalis. The formulations showed increases in both thermal and photo stability of approximately 40% compared with control samples. All the formulated microparticles were efficient against the insects evaluated and required a shorter time to achieve 100% mortality than the controls. The use of sugarcane bagasse lignins to prepare microparticles improved the resistance of neem extracts against abiotic factors, retaining the biological activity of this biopesticide.

Application of a Quantitative HPLC-ESI-MS/MS Method for Flavonoids in Different Vegetables Matrices

Plant flavonoids have been increasingly studied for its importance in plant metabolism, inter-species interactions and human health-promoting effects. Each botanical species has a distinct flavonoid profile, and as such, this work aimed to develop and apply a high-performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) method to quantify specific flavonoids in different plants and parts. Six flavonoids (isoquercitrin, quercetin, naringin, naringenin, hesperidin and rutin), two isoflavonoids (daidzin and daidzein) and one coumarin (umbelliferone) were targeted. Calibration curves showed good correlations (R2 > 0.994) and limits of quantification (≤ 500 ng mL-1). The method was applied for detection of analytes in common bean seeds (Phaseolus vulgaris), soybean leaves (Glycine max), and sour orange (Citrus aurantium), sweet orange (Citrus sinensis), and Tahiti lime (Citrus latifolia) flavedo after ultrasound assisted acidic hydroalcoholic extraction. The method was tuned for quick and efficient extraction. Principal component analysis was helpful for the discrimination of matrices based on their flavonoid profiles.

Efficacy of botanical extracts from Brazilian savannah against Diabrotica speciosa and associated bacteria

Botanical extracts are a plentiful resource of molecules with different biological activities, such as insecticides and antimicrobial pesticides. In this context, the aim of this work was to evaluate the efficacy of botanical extracts from the Brazilian savannah against Diabrotica speciosa and bacterial strains isolated from the gut of this insect under aseptic conditions. The bacterial isolates were identified by genomic and proteomic approaches, and bioassayed against eighteen botanical extracts in vitro. The best results of bacterial inhibitions were obtained for the extracts of Casearia sylvestris and Psidium laruotteanum. Fractions of C. sylvestris and P. laruotteanum, quantitatively evaluated by chromatographic analyses, showed a relationship between the bactericidal activity and phytochemical profile. In vivo assays showed that P. laruotteanum was also effective for the control of D. speciosa. Those results show that selected natural products can have both antimicrobial and insecticidal activities.

MALDI-TOF MS identification of microbiota associated with pest insect Diabrotica speciosa

Resistance development in pest insects has guided the advance of cleaner and more effective strategies for pest control. An interesting and promising strategy is the manipulation of insects via their gut microbiota. To evaluate the feasibility of this strategy, Diabrotica speciosa, a highly polyphagous pest insect from South America that causes substantial damage to several important crops, was reared under controlled conditions. Aerobic culturable bacteria were isolated from the gut of D. speciosa and identified using proteomic fingerprints obtained by matrix‐assisted laser desorption ionization coupled to time‐of‐flight mass spectrometry (MALDI‐TOF MS), as well as by genomic methods via partial sequencing of the 16S rRNA gene. Seventy‐three strains belonging to 17 genera and up to 29 different species were isolated. γ‐Proteobacteria of the orders Pseudomonadales and Enterobacteriales were the predominant. A core gut microbiome for the genus Diabrotica could be inferred when microbiotas from different species from the genus were compared. Molecular and spectrometric techniques indicated complete agreement of genera classification, although cluster analysis revealed distinct taxonomic grouping patterns. MALDI‐TOF MS provided reliable identification of culturable gut bacteria, demonstrating similar efficacy, with cheaper and faster results relative to partial 16S rRNA gene sequencing, and also showed an interesting and unexpected phyloproteomic correlation.

Biodegradation of 1,2,3,4-tetrachlorodibenzo-p-dioxin in liquid broth by brown-rot fungi.

Dioxins are a class of extremely hazardous molecules that might pose a threat to the environment. This work evaluated the microbial degradation of 1,2,3,4-tetrachlorodibenzo-p-dioxin (1,2,3,4-TCDD), in liquid broth using three brown-rot fungi and one white-rot fungi as control. A fast and reliable extraction method with recoveries of over 98% together with a validated GC-MS method was developed, and applied to quantify 1,2,3,4-TCDD in liquid broth, mycelia and reaction flask, with detection limits of 10 ppb. Among the four strains tested, brown-rot fungus Aspergillus aculeatus showed best results, removing up to 21% of dioxin after 30-day incubation. The results open both a path for biotechnological interest in bioremediation purposes and environmental behavior studies by using brown-rot fungus.