Influence of lignin and cellulose from termite-processed biomass on biochar production and evaluation of chromium VI adsorption.

The increasing water contamination by toxic heavy metals, particularly hexavalent chromium, has become a significant environmental concern. This study explores the pyrolysis of termite-processed biomass, specifically Pinus elliottii particleboard and its termite droppings (TDs), to produce biochar and its application for chromium (VI) adsorption. Termite droppings, rich in lignin, and particleboard, rich in cellulose, were pyrolyzed at various temperatures to assess the effect of biomass composition on biochar properties. The study found that lignin-rich termite droppings produced biochar with higher fixed carbon content and specific surface area than cellulose-rich particleboard biochar. FTIR and Raman spectroscopy revealed significant molecular structure changes during pyrolysis, which influenced the adsorption capabilities of the biochar. Adsorption experiments demonstrated that TD biochar exhibited significantly higher chromium (VI) adsorption capacity, attributed to its distinct chemical composition and enhanced surface properties due to higher lignin content. These findings underscore the crucial role of lignin in producing efficient biochar for heavy metal adsorption, highlighting the practical applicability of termite-processed biomass in water purification technologies.

Chemical composition and chemotaxonomy of Nasutitermes spp. defensive secretion from Brazilian Cerrado for the differentiation of species.

Nasutitermes spp. soldier defensive secretion has a toxic and repellent effect against predators. Chemical profile characterization of this secretion is an interesting tool to differentiate similar termite species. This study aimed to determine defensive secretion composition of Nasutitermes spp. soldier and to apply chemotaxonomy tool for the unambiguous species identification. Fifteen volatile compounds were identified by gas chromatography-mass spectrometry. Multivariate analysis classified populations into three groups. Principal component (PCA), axis 1, was able to separate two groups: group I, colonies 1 and 2 (Nasutitermes corniger) and group II, colony 3 (Nasutitermes ephratae). Therefore, determination of defensive chemical secretion profile proved to be very useful in termite chemotaxonomy, since it was able to differentiate morphologically similar specimens.

Using basic parameters to evaluate adsorption potential of alternative materials: example of amoxicillin adsorption by activated carbon produced from termite bio-waste.

The minimum set of parameters that can be used to assess the adsorption capacity of activated carbon (AC) produced from termite bio-waste was determined. Three types of AC were prepared: AC600 at 600 °C, MAC600 at the same temperature and impregnated with FeCl3, and AC800 at 800 °C. The influence of the solution pH on the adsorption, adsorption kinetics, isotherms and thermodynamic parameters was considered to characterize the amoxicillin (AMX) adsorption process. The AC materials had surface areas (m2 g-1) of approximately 248.8 for AC600, 501.6 for AC800 and 269.5 for MAC600, with point of zero charge (pHPZC) values of 8.3, 7.5 and 1.7, respectively. A time period of 30 min was chosen for the adsorption kinetics, which was best represented by the pseudo-first-order model for AC600, the intraparticle diffusion model for AC800 and the pseudo-second-order model for MAC600. Regarding the isotherms, a maximum adsorption of 23.4 mg g-1 was found for AC800. In general, the thermodynamic parameters demonstrated a non-spontaneous process. It seems that the medium conditions, the adsorbate and adsorbent characteristics, and the Gibbs free energy are the most important parameters to be considered in a preliminary assessment of the adsorption efficiency of specific adsorbent/adsorbate pairs.

The neglected contribution of mound-building termites on CH4 emissions in Brazilian pastures

Based on previous reports, our study aimed to obtain the first estimate on the contribution of termite mounds to CH4 emissions in Brazilian Cerrado pastures. We estimated that termite mounds occupy an area larger than 200,000 ha in degraded pastures, an important loss of grazing area considering the current scenario of land-use change of pastures to other crops in Brazil. Moreover, mound-building termites in degraded pastures may be responsible for CH4 emissions greater than 11 Mt CO2 eq. yr−1, which would notably affect the greenhouse gases (GHG) balance of grass-fed cattle production in Brazil. In this sense, it is urgent to conduct field-scale studies about the CH4 emissions by mound-building termites in pastures and its contribution to the C footprint of Brazilian beef.

Quantitative Structure-Activity Relationship Modeling and Docking of Monoterpenes with Insecticidal Activity Against Reticulitermes chinensis Snyder and Drosophila melanogaster.

The goal of this study was to perform in silico identification of bioinsecticidal potential of 42 monoterpenes against Drosophila melanogaster and Reticulitermes chinensis Snyder. Quantitative structure-activity relationship (QSAR) modeling was performed for both organisms, while docking and molecular dynamics were used only for Drosophila melanogaster. Neryl acetate has the lowest interaction energy (-87 kcal/mol) against active site of acetylcholinesterase, which is comparable to the ones of methiocarb and pirimicarb (-90 kcal/mol) and reported PDB binder 9-(3-iodobenzylamino)-1,2,3,4-tetrahydroacridine (-112.67 kcal/mol). Interaction stability was verified by molecular dynamics simulations and showed that the stability of ACHE active site complexes with three selected terpenes is comparable to the one of the pirimicarb and methiocarb. Overall, our results suggest that pulegone, citronellal, carvacrol, linalyl acetate, neryl acetate, citronellyl acetate, and geranyl acetate may be considered as a potential pesticide candidates.

Does Distance Among Colonies and Resource Availability Explain the Intercolonial Aggressiveness in Nasutitermes aff. coxipoensis?

Aggressive behaviour can ensure animal access to local resources. To reduce constant costs in the defence of territories, species could save energy with conflicts avoiding aggression with neighbour or in situations with abundance of resources. In the present study, we analysed the effect of distance among colonies and resource availability on the aggression level and responses to chemical cues of Nasutitermes aff. coxipoensis (Holmgren) (Termitidae: Nasutitermitinae). Manipulation of resource offer was conducted in the field, where nests with different distances were kept without addition of baits (control), with addition of three or 16 sugarcane baits/nest. After 3 months, aggressiveness, linear and Y-shaped trail-following bioassays were carried out with all pairwise combinations of colonies in each treatment. Our results showed that aggressive index of N. aff. coxipoensis was affected by the resource availability. However, individuals from colonies with 0 and 3 baits/nest showed a higher number of fighting with neighbours than those from non-neighbours colonies. Termite workers from colonies without baits (control) followed shorter distance in the linear trails compared to those from colonies with addition of baits. In all treatments, there was no preference of workers in relation to the choice of chemical cues from own or other colonies. The response of intercolonial aggressiveness in N. aff. coxipoensis seems to be resource-dependent. These results may contribute to the comprehension of the use of space by N. aff. coxipoensis and could be useful to explain patterns of termite co-occurrence at different spatial scales, from local (inside the nest-e.g. cohabitation of nests by inquilines) to regional (e.g. around the nest).

Forrageamento e sobrevivência de colônias do cupim Nasutitermes sp em laboratório / Foraging and maintenance of Nasutitermes sp colonies (Isoptera: Termitidae) in laboratory

Os cupins são insetos sociais da ordem Isoptera, com cerca de 2.900 espécies catalogadas no mundo. No Brasil, são várias as espécies de importância agrícola e florestal. Caracterizam-se por colônias complexas do ponto de vista social e estrutural, muitas vezes subterrâneas, o que dificulta o seu completo conhecimento. Diante deste fato, este trabalho teve como objetivo a criação de colônias de cupins com importância agrícola em laboratório, para determinar as condições necessárias ao seu desenvolvimento, incluindo preferências de forrageamento. Colônias jovens foram coletadas em campo e mantidas em laboratório, num sistema artificial com condições estruturais (abrigo) e ambientais (luz, temperatura, umidade relativa do ar) que buscaram ser as mais similares possíveis àquelas naturais. Diferentes substratos foram oferecidos como opção alimentar. Após estabelecimento da criação laboratorial e observação do forrageamento de colônias do cupim Nasutitermes sp, verificou-se a preferência de forrageamento por raiz, seguida de matéria orgânica, folhas secas e frescas, equivalentemente. Verificou-se também sua adaptação à um sistema estrutural artificial composto por caixa central e caixa de alimentação, permitindo a manutenção das colônias por tempo indeterminado.

Termites are social insects of Isoptera order, with about 2,900 species cataloged in the world. In Brazil, there are several species of agricultural and forestry importance. They are characterized by complex colonies from the social and structural point of view, often subterranean, which hinders their complete knowledge. In view of this fact, this work had as objective the breeding of termite colonies with agricultural importance in the laboratory, of the genus Nasutitermes, to determine the necessary conditions for its development, including foraging preferencesfor different parts of Paspalum notatum. Young colonies were collected in field and kept in laboratory, in an artificial system with structural conditions (shelter) and environmental conditions (light, temperature, relative humidity) that sought to be the most similar to those natural ones. Different parts of P. notatum were offered as food option, in a test with a chance of choice. After establishing of laboratory rearingand observing the foraging of Nasutitermesspp. colonies, it was verified the preference of foraging by root, followed by decaying fragments, dry and fresh leaves, equivalently. It was also verified its adaptation to an artificial structural system composed of central box and feeding box, allowing the maintenance of the colonies for a minimum period of 5 months.

Forrageamento e sobrevivência de colônias do cupim Nasutitermes sp em laboratório / Foraging and maintenance of Nasutitermes sp colonies (Isoptera: Termitidae) in laboratory

Os cupins são insetos sociais da ordem Isoptera, com cerca de 2.900 espécies catalogadas no mundo. No Brasil, são várias as espécies de importância agrícola e florestal. Caracterizam-se por colônias complexas do ponto de vista social e estrutural, muitas vezes subterrâneas, o que dificulta o seu completo conhecimento. Diante deste fato, este trabalho teve como objetivo a criação de colônias de cupins com importância agrícola em laboratório, para determinar as condições necessárias ao seu desenvolvimento, incluindo preferências de forrageamento. Colônias jovens foram coletadas em campo e mantidas em laboratório, num sistema artificial com condições estruturais (abrigo) e ambientais (luz, temperatura, umidade relativa do ar) que buscaram ser as mais similares possíveis àquelas naturais. Diferentes substratos foram oferecidos como opção alimentar. Após estabelecimento da criação laboratorial e observação do forrageamento de colônias do cupim Nasutitermes sp, verificou-se a preferência de forrageamento por raiz, seguida de matéria orgânica, folhas secas e frescas, equivalentemente. Verificou-se também sua adaptação à um sistema estrutural artificial composto por caixa central e caixa de alimentação, permitindo a manutenção das colônias por tempo indeterminado.(AU)

Termites are social insects of Isoptera order, with about 2,900 species cataloged in the world. In Brazil, there are several species of agricultural and forestry importance. They are characterized by complex colonies from the social and structural point of view, often subterranean, which hinders their complete knowledge. In view of this fact, this work had as objective the breeding of termite colonies with agricultural importance in the laboratory, of the genus Nasutitermes, to determine the necessary conditions for its development, including foraging preferencesfor different parts of Paspalum notatum. Young colonies were collected in field and kept in laboratory, in an artificial system with structural conditions (shelter) and environmental conditions (light, temperature, relative humidity) that sought to be the most similar to those natural ones. Different parts of P. notatum were offered as food option, in a test with a chance of choice. After establishing of laboratory rearingand observing the foraging of Nasutitermesspp. colonies, it was verified the preference of foraging by root, followed by decaying fragments, dry and fresh leaves, equivalently. It was also verified its adaptation to an artificial structural system composed of central box and feeding box, allowing the maintenance of the colonies for a minimum period of 5 months.(AU)

Delineating species boundaries using an iterative taxonomic approach: the case of soldierless termites (Isoptera, Termitidae, Apicotermitinae).

Species boundaries are traditionally inferred using morphological characters, although morphology sometimes fails to correctly delineate species. To overcome this limitation, researchers have widely taken advantage of alternative methods such as DNA barcoding or analysis of cuticular hydrocarbons (CHs) profiles, but rarely use them simultaneously in an iterative taxonomic approach. Here, we follow such an approach using morphology, DNA barcoding and CHs profiles to precisely discriminate species of soldierless termites, a diversified clade constituting about one-third of the Neotropical termite species richness, but poorly resolved taxonomically due to the paucity of useful characters. We sampled soldierless termites in various forest types of the Nouragues Nature Reserve, French Guiana. Our results show that morphological species determination generally matches DNA barcoding, which only suggests the existence of three cryptic species in the 31 morphological species. Among them, Longustitermes manni is the only species whose splitting is corroborated by ecological data, other widely distributed species being supported by DNA barcoding. On the contrary, although CHs profiles provide a certain taxonomic signal, they often suggest inconsistent groupings which are not supported by other methods. Overall, our data support DNA barcoding and morphology as two efficient methods to distinguish soldierless termite species.

Chemical composition and biological activities of soldiers of the Brazilian termite species, Nasutitermes macrocephalus (Isoptera: Natutitermitinae).

The defensive secretion of the frontal gland from termite soldiers is a mixture of monoterpenes, sesquiterpenes and diterpenes, the latter being the most representative. Analyses of the dichloromethane extract from soldiers of the Brazilian termite, Nasutitermes macrocephalus (Silvestri, 1903) (Isoptera, Nasutitermitinae), described for the first time, allowed to identify the presence of two monoterpenes (alpha-pinene and limonene) and two sesquiterpenes (beta-trans-caryophyllene and gamma-selinene) [corrected] by GC-EIMS, and the isolation of one rippertane and six trinervitane diterpenes by RP-HPLC. The chemical structures of the purified compounds were elucidated by interpretation of their spectroscopic data (1D and 2D NMR, EIMS, HRESIMS, and specific optical rotation) and the complete unequivocal assignment of the 3a-hydroxy-trinervita-1(15),8(19)-dien-2-one (6) was included in this paper, to complement the lack of information in the literature. Antibacterial, antifungal and cytotoxicity against cancer cell lines activities were evaluated. In particular, the compounds 2alpha,3beta-dihydroxytrinervita-l(15),8(19)-diene (2) and 3alpha-hydroxy-15-rippertene (7) exhibited the better activities against the clinically isolated Gram-positive bacterium methicillin-resistant Staphylococcus aureus BMB 9393, both with a MIC value of 31.2 microg mL(-1). This is the first description of a rippertane diterpene (7) as an antibacterial agent.

Ingested and biomineralized magnetic material in the prey Neocapritermes opacus termite: FMR characterization.

The temperature dependence of Ferromagnetic Resonance spectra, from 5K to 280K, was used to study the magnetic material present in Neocapritermes opacus termite, the only prey of the Pachycondyla marginata ant. The analysis of the resonant field and peak-to-peak linewidth allowed estimating the particle diameters and the effective anisotropy energy density, K(EFF), as a sum of the bulk and surface contributions. It allowed to magnetically distinguish the particles of termites as collected in field from those of termites after 3 days under a cellulose diet, introduced to eliminate ingested/digested material. The data also, suggest the presence of oriented magnetite nanoparticles with diameters of 11.6+/-0.3nm in termites as collected in field and (14.0+/-0.4nm) in that under a cellulose diet. Differences between their K(EFF) and its components are also observed. Two transitions are revealed in the resonant field temperature dependence, one at about 50K that was associated to surface effects and the other at about 100K attributed to the Verwey transition.

Trinervitene diterpenes from soldiers of two Nasutitermes species from French Guyana.

Methanolic extracts of soldiers of Nasutitermes guayanae and N. surinamensis have been shown to contain complex mixtures of diterpenes and monoterpenes. Eighteen diterpenes have been isolated and identified; twelve of them are previously known nasute termite diterpenes, while six are new trinervitene diterpenes. 2alpha,9beta-Dihydroxy-3beta,8beta-oxido-1(15)-trinervitene has been isolated from N. guayanae, while 3alpha,14alpha-diacetoxy-2beta-hydroxy-1(15),8(19),9-trinervitatriene, 14alpha-acetoxy-2beta,3alpha-dihydroxy-1(15),8(19),9-trinervitatriene, 2beta,3alpha-diacetoxy-11beta,14alpha-dihydroxy-1(15),8(19)-trinervitadiene, 9alpha,14alpha-diacetoxy-2beta,3alpha-dihydroxy-1(15),8(19)-trinervitadiene, and 2beta,9alpha,14alpha-triacetoxy-3alpha-hydroxy-1(15),8(19)-trinervitadiene have been isolated from N. surinamensis. Their structures were determined on the basis of their spectroscopic properties.

Magnetic material arrangement in oriented termites: a magnetic resonance study.

Temperature dependence of the magnetic resonance is used to study the magnetic material in oriented Neocapritermes opacus (N.o.) termite, the only prey of the migratory ant Pachycondyla marginata (P.m.). A broad line in the g = 2 region, associated to isolated nanoparticles shows that at least 97% of the magnetic material is in the termite's body (abdomen + thorax). From the temperature dependence of the resonant field and from the spectral linewidths, we estimate the existence of magnetic nanoparticles 18.5+/-0.3 nm in diameter and an effective magnetic anisotropy constant, K(eff) between 2.1 and 3.2 x 10(4)erg/cm(3). A sudden change in the double integrated spectra at about 100K for N.o. with the long body axis oriented perpendicular to the magnetic field can be attributed to the Verwey transition, and suggests an organized film-like particle system.