Optimization of subcritical water hydrolysis of pecan wastes biomasses in a semi-continuous mode

Pecan cultivation has increased in recent years. Consequently, the amount of lignocellulosic residuals from its production has expanded. Thus, there is a necessity to explore and add value to their coproducts. The objective of this work was to obtain reducing sugars from pecan biomasses by the optimization of the subcritical water hydrolysis technology in a semi-continuous mode and the physicochemical and morphological characterization of these materials, such as SEM, TGA and FT-IR analysis. Temperatures of 180, 220 and 260 °C, water/solids mass ratio of 15 and 30 g water/g biomass and total reaction time of 15 min were used. The highest reducing sugar yield was 27.1 g/100 g of biomass, obtained at 220 °C and R-15 for pecan shells. TGA, SEM and FT-IR analysis indicated the modifications of structures and compositions of biomasses in fresh and hydrolyzed samples.

Chemical study, antioxidant activity, and genotoxicity and cytotoxicity evaluation of Ruellia angustiflora

Ruellia angustiflora (Acanthaceae) is known as flower-of-fire, and its leaves are traditionally employed to promote wound healing. This study was aimed at extracting and characterizing the chemical constituents of the extracts of R. angustiflora obtained by ultrasound-assisted and supercritical fluid extractions, and subsequently investigate their antioxidant potential and cyto-genotoxicity. The extract obtained by ultrasound (UAE-EtOH) was characterized by ultraperformance liquid chromatography-mass spectrometer (UPLC-MS), and the extract obtained via supercritical fluid (SFE-CO₂) by gas chromatograph-mass spectrometer (GC-MS). The antioxidant potential was verified by the antiradical activity against the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), and the cyto-genotoxicity evaluation to test cell viability and DNA damage was performed in peripheral blood mononuclear cells (PBMC) cultures. The SFE-CO₂ extract presented some fatty acids, triterpenes, tetraterpenes, tocopherols and phytosterols. The UAE-EtOH extract contained phenolic acids and flavonoids, and showed the highest antioxidant capacity. Neither extract was genotoxic or cytotoxic at the tested concentrations.

One maternal lineage leads the expansion of Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae) in the New and Old Worlds

The bronze bug, Thaumastocoris peregrinus, an Australian native insect, has become a nearly worldwide invasive pest in the last 16 years and has been causing significant damage to eucalypts (Myrtaceae), including Eucalyptus spp. and Corymbia spp. Its rapid expansion leads to new questions about pathways and routes that T. peregrinus used to invade other continents and countries. We used mtDNA to characterize specimens of T. peregrinus collected from 10 countries where this species has become established, including six recently invaded countries: Chile, Israel, Mexico, Paraguay, Portugal, and the United States of America. We then combined our mtDNA data with previous data available from South Africa, Australia, and Europe to construct a world mtDNA network of haplotypes. Haplotype A was the most common present in all specimens of sites sampled in the New World, Europe, and Israel, however from Australia second more frequently. Haplotype D was the most common one from native populations in Australia. Haplotype A differs from the two major haplotypes found in South Africa (D and G), confirming that at least two independent invasions occurred, one from Australia to South Africa, and the other one from Australia to South America (A). In conclusion, Haplotype A has an invasion success over many countries in the World. Additionally, analyzing data from our work and previous reports, it is possible to suggest some invasive routes of T. peregrinus to predict such events and support preventive control measures.

Phylogeography Approach of Diloboderus abderus (Coleoptera: Melolonthidae) in the Southern Cone of America

Diloboderus abderus (Sturm, 1826) (Coleoptera: Melolonthidae) is a serious soil pest of corn, wheat, oat, and natural and cultivated pastures in Argentina, Paraguay, Uruguay, and southern Brazil. Despite its economic importance, the genetic diversity and population structure of D. abderus remain unknown. We sequenced a fragment of the mitochondrial gene cytochrome oxidase I region (COI), of six populations of D. abderus from the Southern Cone of America. The mtDNA marker revealed a high haplotype diversity, high pairwise F_ST values, and significant genetic variations among populations. No correlation was found between genetic and geographical distances, yet the most common haplotype (Dab01) was present in four out of the six populations. Analysis of molecular variance showed that most of the variation was within populations of D. abderus. Tajima's D and Fu's F_S tests indicated no evidence that D. abderus populations are under recent expansion. Our results indicate that genetic-based traits will likely remain localized or spread slowly, and management strategies need to be undertaken on a small scale.

Enzyme-Catalyzed Production of FAME by Hydroesterification of Soybean Oil Using the Novel Soluble Lipase NS 40116

The performance of lipase NS 40116, a novel and promising soluble enzyme obtained from modified Thermomyces lanuginosus microorganism, was investigated in the production of biodiesel (fatty acid methyl esters-FAME) by hydroesterification. In order to investigate the potential of the biocatalyst in its soluble form, this work reports the effect of water content and enzyme load, as well as the recovery and reuse of the biocatalyst. A FAME yield of 94.30% after 12 h was achieved at 35 °C by combining 0.50 wt% of lipase, 15 wt% of water, and a methanol:oil molar ratio of 4.5:1. The analysis of the time course reaction suggests that the triacylglycerides (TAGs) are hydrolyzed by the enzyme in a first step, generating free fatty acids (FFAs), followed by the esterification of these FFAs into FAME. In relation to the reusability assays, the lipase kept approximately 90% of its catalytic activity after five cycles of reuse. In this context, the findings of this study demonstrate that lipase NS 40116 can efficiently catalyze hydroesterification reactions under mild conditions, arising as a competitive alternative for biodiesel synthesis.