Tree Bark Research Articles

Morphological and molecular characterization of Paractinolaimus uljinensis n. sp. (Nematoda: Actinolaimidae) from Korea, with an updated compendium of the genus.

A new species of the genus Paractinolaimus isolated from the bark of a dead red pine tree was characterized using morphometric data and molecular DNA barcodes. Paractinolaimus uljinensis n. sp. was characterized by its medium sized body 2.50 to 2.98 mm long; lip region truncate, angular and offset by a depression; odontostyle 23.5 to 27.0 μm long; basal shield of pharynx present; vulval opening wide and longitudinal, positioned slightly anteriorly (V = 42.5-47.7); several advulval papillae; female tail long and filiform (324.0-435.0 μm long, c' = 10.1-14.2); a clearly visible copulatory hump; spicules 60.0 to 70.5 μm long; 12 to 15 (mostly 12-14) large contiguous ventromedian supplements, and male tail conoid to broadly rounded. The new species was morphologically compared with P. intermedius, P. sahandi, P. decraemerae, P. acutus, P. macrolaimus, and P. tuberculatus. The phylogenetic relationships among species were reconstructed using 18S- and 28S-rRNA gene sequences. The phylogenies showed well-supported sister relations of Paractinolaimus uljinensis n. sp. with P. sahandi, P. macrolaimus, and P. decraemerae. In addition, the ITS-rRNA gene sequences of Paractinolaimus uljinensis n. sp. were supplied, representing the first characterization of the gene for the genus.

Change of carbon mass after timber harvesting in a natural forest, West Sumatra Indonesia

Forests have an important role in the carbon cycle and in the dynamics of storing and releasing carbon in growth, decay, and disturbance processes. Timber harvesting initially reduces the amount of carbon in the forest. This study aims to analyze the magnitude of changes in carbon mass due to timber harvesting. It was conducted in a forest concessionaire located at Siberut of West Sumatra on a natural forest covering about 48,000 hectares. Selective cutting was implemented for logging where the harvestable trees were over 50 cm in diameter. The amount of carbon mass was obtained based on laboratory tests on tree parts, including trunk, branches, twigs, and bark. The average carbon content in each part of the tree is different. The trunk contains 53.86% of carbon mass, the branches are 51.98%, the twigs are 31.58%, the leaves are 27.91%, and the bark is 32.01%. Timber harvesting was conducted at the forest compartment with an average forest stand density of 71.5 trees ha−1 and a felling intensity of 8.8 trees ha−1, causing damage to 16.17 trees ha−1 stands. Timber harvesting causes a decrease in carbon mass reserves of 43.26% from forest carbon mass of 141.89 tons C ha−1 before harvesting to 80.00 tons C ha−1 after harvesting.

Biomonitoring with Lichens: Evaluating Heavy Metal Concentrations, Environmental Factors, and Lichen Diversity in Bengaluru, Karnataka, India

Lichens are commonly used in biomonitoring due to their unique characteristics that make them a cost-effective option. Unlike chemical analysis, sampling lichen diversity is less expensive, enabling a more extensive sampling coverage while reducing costs. This diverse group of organisms can be used to detect areas that are affected by pollution, land use changes, and ecological imbalances. In recent years, researchers have been working to establish a reliable protocol for lichen sampling in biomonitoring to enhance its utility and minimize any variations caused by extraneous environmental factors. In this article concentrations of heavy metals s (Cd, Cr, Cu, Fe, Ni, Pb and Zn), acidity and electrical conductance of few flowering trees bark (Albizialebbeck, Delonixregia, Pongamiaglabra, Callistemon Lanceolatus, Cassia Fistula, Cassia Javanica) were evaluated to determine the impact the lichen value diversity in six different places based on different environmental factors. It has been stated that the correlation between acidity level and lichen species exists in all investigated tree species. Six lichen species (Chrysothrixcandelaris (L.) Laundon, Graphisscripta (L.) Ach, G. scripta (L.) Ach., leucosorodes Nyl, D. consimilis (Stirton) Awasthi, D. aegialita (Afz. in Ach.) Moore and L.(perplexa Brodo) were registered, among them three were foliose and three were crutose. Lichen leucosorode Nyl was predominant in Albizialebbeck, Delonixregia, Pongamiaglabra trees. It was observed that the lichen diversity was less near heavy traffic location, industrial areas and also rougher bark of trees provided a better habitat of wider variety of lichen species.

Facile removal of rhodamine B and metronidazole with mesoporous biochar prepared from palm tree biomass: adsorption studies, reusability, and mechanisms

Abstract Biochar was produced by pyrolysing palm tree bark biomass at 500 °C for the removal of rhodamine B (RhB) and metronidazole (MET). Fourier-transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller, X-ray diffraction (XRD), scanning electron microscopy, and energy-dispersive X-ray analyses were used to characterize the biochar. The biochar obtained was crystalline, mesoporous (SBET: 189.157 m2 g−1; pore diameter: 2.207 nm), clustered with prominent O–H and C = O functional groups. The pHpzc of the biochar was 7.98, and it adsorbed RhB and MET maximally at pH 3.4 and 7.2, respectively. The Langmuir and Freundlich isotherms described RhB and MET adsorption, respectively, with maximum adsorption capacities (qmax) of 31.81–224.30 mg/g for RhB and 95.44–26.76 mg/g for MET from 303 to 313 K. Both adsorbates exhibit favourable physisorption processes with pseudo-second-order kinetics, as the most appropriate. The thermodynamic parameter (−ΔG°) demonstrates spontaneous adsorption processes for RhB and MET, with spontaneity increasing with temperature for RhB and decreasing with increasing temperature for MET. The adsorption process was endothermic (+ΔH°) for RhB and exothermic (−ΔH°) for MET. Given its reusability of 96 and 95% for RhB and MET, respectively, mesoporous biochar derived from palm trees is a more promising adsorbent.

The Evaluation of Tree Bark as Filler for Wood-Plastic Composites: Experimental Study and Modelling

Tree bark is one of the waste materials produced during harvesting. In this study, tree bark was evaluated for the production of WPCs. Three tree barks (Oak, Calabrian pine, and Cedar) were added to the matrix as an alternative for wood flour (20-80 mesh). Different tree bark content (10, 20, 40%) were also selected. The tree bark-based WPCs were produced with the flat-pressed method. The effect of tree bark on water absorption (WA) and thickness swelling (TS) were investigated during the 14 days. Tree barks have a significant effect on the WA and TS properties of the composites. As the bark content increased, the WA and TS values decreased. While the WA values increased up to 11.27% for control samples, it is only 3.27% for 40% of tree bark. Similar results were also observed for TS values. Also, the prediction models were developed using multiple linear regression (MLR). Correlation coefficient (R2) values of models were determined as 0.882, 0.853, and 0.850 for oak, Calabrian pine, and cedar WA values and 0.889, 0.839, and 0.879 for oak, Calabrian pine, and cedar TS values, respectively. The results showed that tree bark has the potential as an alternative to wood flour for WPC production.

Phloretin Inhibits the Proliferation of Breast Cancer Cells Through the Down-regulation of Estrogen Receptor α.

Phloretin is a natural flavonoid compound found in some plants, such as apples and pears, as well as in the bark of apple trees. Phloretin has been shown to have inhibitory effects on glucose transporters in cells and can potentially inhibit the growth of cancer cells. However, the mechanism by which phloretin regulates the expression of estrogen receptor alpha (ERα), a key transcription factor in breast cancer, is still unclear. This study investigated how phloretin affects the growth of ERα positive human breast cancer cells. The growth of breast cancer cell lines, including MCF7 and T47D, was examined using cell proliferation and colony formation assays. Western blotting and semi-quantitative RT-PCR were used to examine protein and mRNA levels, respectively. Localization of cellular proteins was analyzed using subcellular fractionation. Transient transfection and reported gene assays were used to elucidate the impact of phloretin on cell proliferation and ERα transactivation. Phloretin decreased ERα expression at the mRNA and protein levels in MCF7 and T47D cells. It also inhibited the binding of ERα to the estrogen response element present in the promoter of target genes. Moreover, treatment with phloretin inhibited the expression of cyclin D1 and breast cancer marker gene pS2, which are known ERα target genes. Consequently, it inhibited the growth of ERα-positive human breast cancer cells. Furthermore, inhibition of breast cancer growth by phloretin was found to be mediated through both the ERα and ERK1/ERK2 pathways. Phloretin, a dihydrochalcone extracted from natural sources, exhibits the ability to regulate ERα function and suppress breast cancer cell proliferation.

DAMAGE TO PINE PLANTATIONS BY THE APICAL BARK BEETLE AND STEM PESTS IN THE BRANCH «KOROSTYSHIV FORESTRY»

The treetop bark beetle (Ips typographus) is the main pest of Scots pine (Pinus sylvestris L.) in Europe in general and in Ukraine in particular. It affects the phloem (inner bark) of trees, disrupting the supply of nutrients, which can lead to the death of pine plantations, especially young or weakened ones [1].

Understanding the Manufacture of Hetian Administration Banknotes from Xinjiang Using Low- and High-resolution Analytical Methods

ABSTRACT Analytical studies of ancient Chinese handmade papers and paper-based materials have long faced challenges, due to the need for high-quality, scientifically sound data that can lead to suitable diagnostic criteria. This study applies Herzberg staining, micro-computed tomography (micro-CT), Raman spectroscopy, pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), and high-resolution mass spectrometry (HRMS) to five Hetian Administration Banknotes (HABs), a particular type of regional banknotes issued by Ma Hu-shan (1910–1954), a Hui warlord, in southern Xinjiang between 1933 and 1937. The results shed important insights into the use of fiber and dyes on HABs, revealing how locally handmade Sangpi (bark of the mulberry tree, Morus alba L.) papers and imported synthetic dyes (Rhodamine B, Methyl Violet 2B, Direct Black 38, and presumably Sudan II) were combined to serve the needs of the regional economy in southern Xinjiang during the 1930s. We conclude the paper by tentatively proposing guidelines for applying low- and high-resolution analytical methods to understand the manufacture and use of ancient Chinese handmade papers and paper-based materials.

The Interacting Influence of Fire and Tree Characteristics on Douglas-Fir Beetle Host-Tree Selection Five Years Post-Fire

Fire injury stresses Douglas-fir trees (Pseudotsuga menziesii) that survive a wildfire event, allowing subsequent Douglas-fir beetle (Dendroctonus pseudotsugae) infection to kill trees that may have otherwise survived. This study aimed to determine how fire injury, stand, and tree characteristics drive Douglas-fir beetle host tree selection five years post-fire. We paired 28 adjacent beetle-infected and uninfected stands (infected N = 14) and 140 Douglas-fir trees (infected N = 70) within the 416 Fire burn area in Southwest Colorado. We found no statistically significant differences between infected and uninfected stand characteristics. Individual tree height, DBH, and bark char severity index were significantly higher in infected versus uninfected trees. We created a regression decision tree model to determine the influence of fire injury and tree characteristics on the probability of infection. Trees with a height ≥ 27 m, bark char height < 2.3 m, and DBH < 80 cm had the greatest probability of attack (100%). Trees with a height < 27 m, bark char severity index < 5.5, and DBH < 49 cm had the lowest probability of attack (3.7%). Understanding the influence of fire on Douglas-fir beetle host selection allows land managers to model potential epidemic outbreaks and guide proactive management actions that may reduce beetle outbreak severity or preserve high-value trees not killed by fire.

Effect of chemical treatment on physio-mechanical properties of lignocellulose natural fiber extracted from the bark of careya arborea tree

For the first time, the current work has carried out a chemical treatment of a novel ligno-cellulose fiber that is extracted from the bark of an unexplored plant of Careya arborea. Careya arborea (CA), a flowering tree known for its green berries, thrives in the Indian subcontinent and Afghanistan. This research was focused on extracting fibers from the bark of the Cary tree for the first time to corroborate the influence of chemical treatment on its different characteristics. These CA fibers have a high proportion of cellulose, consisting of 71.17 wt percent, together with 27.86 wt percent of hemicellulose, and a reduced density of 1140 kg/m3, making them a suitable candidate for creating lightweight applications in a variety of industries. Chemical treatment has done on the cay fiber with the concentrations of NaOH 5 (wt%), 10 (wt%), and 15 (wt%) solution mixture to improve their characteristics. Estimated the difference between Chemically processed and non-processed Cary fibers and corroborated in results. We performed a number of experiments, including FTIR, XRD, SEM, EDAX, AFM, and TGA, to fully comprehend the changing properties. Chemical testing showed that cellulose changed from its non-crystalline state to cellulose, proving that the treatment was successful in changing the fibre structure. Additionally, the thermo-gravimetric examination showed higher thermal stability 248 °C–325 °C and a rise in the crystallinity index, indicating the treated fibers’ improved potential for high-temperature applications. The treated Cary fibers exhibited excellent surface properties, promising improved adhesion, mechanical performance, offering lightweight and sustainable solutions for diverse applications.

Tree–litter–soil system C:N:P stoichiometry and tree organ homeostasis in mixed and pure Chinese fir stands in south subtropical China

IntroductionCultivation of Chinese fir (Cunninghamia lanceolata) have alleviated timber shortages and mixed stands with Chinese fir and indigenous species represent a sustainable forestry model. Studying system nutrient balance and tree nutrient homeostasis can provide insights into the ecological advantages of Chinese fir mixed stands and guide the management of plantations.MethodsMixed Chinese fir plantations with two native broadleaf species (Michelia macclurei and Mytilaria laosensis) and pure Chinese fir stands were examined for our study. The responses in carbon (C), nitrogen (N), and phosphorus (P) distribution and their stoichiometric characterization in the tree–litter–soil system to stand changes were evaluated. In addition, the ecological stoichiometric homeostasis of leaves, branches, trunks, bark and roots was used to measure the trees’ adaptive capacity to stand changes.ResultsThe results showed that the mixed stands of Michelia macclurei and Chinese fir significantly increased soil OC, TN, and TP, and improved the carbon sequestration and nutrient storage functions of the plantations. The mixed stands improved the litter mass and C:N and C:P to different degrees. The soil N and P imbalance reduced the leaf N:P, resulting in N limitation of different trees, while the principal component analysis showed that the improvement of soil TN in the mixed plantation alleviated the N limitation. In addition, mixed stands reduced N, P, and N:P homeostasis in branch, trunk, and bark of some Chinese fir trees, whereas mixed species showed flexibility in leaf N:P homeostasis.DiscussionTherefore, the selection of mixed species for mixed forests is a critical factor to consider when creating mixed plantations. These results contribute to our understanding of the ecological stoichiometry of fir plantations and are of considerable importance for the sustainable development of plantations as well as for the response to global climate change.

Is a Forest Fire a Natural Disaster? Investigating the Fire Tolerance of Various Tree Species-An Educational Module.

Wildfires are unplanned conflagrations perceived as a threat by humans. However, fires are essential for the survival of fire-adapted plants. On the one hand, wildfires cause major damage worldwide, burning large areas of forests and landscapes, threatening towns and villages, and generating high levels of air pollution. On the other hand, fire-adapted plants (pyrophytes) in the fire landscapes of the Earth are able to survive exposure to heat (e.g., because of their thick bark, which protects their living tissue) and benefit from fire directly (e.g., fire initiates cone opening and seed release) or indirectly (e.g., fewer competing plants of fire-sensitive species remain, seeds germinate in the ash-fertilized soil). We present the experimental set-up and results of a fire experiment on bark samples used as a basis to assess the fire tolerance of various trees. Fire tolerance is defined as the ability of a tree to survive a surface fire (up to 200 °C and 5 min duration). The measure of the fire tolerance for a tree species is the time taken for the vascular cambium under the insulating bark to reach the critical temperature of 60 °C. Within an educational module, we provide worksheets for teachers and students enabling them to analyze the fire tolerance of various tree barks.

Therapeutic Uses of Mee Tree (Madhuca longifolia)

In the past, our ancestors maintained a close relationship with the environment. They knew the value of many plants. One tree that our ancestors preserved is the Mee tree. Madhuca longifolia belonging to the family Sapotaceae, is one of those multipurpose forest tree species that provide an answer for the food, fodder and fuel. It is widely distributed in the South Asian countries, Especially in Sri Lanka. Mee tree is a large deciduous tree growing widely under dry tropical and sub-tropical climatic conditions. The tree has religious and aesthetic value in the tribal culture. The trees with best girth in forest are often Mee trees as it is protected and cared by forest dwellers. Aim of the study is to identify the therapeutic uses of this plant in Sri Lanka. Ancient classical texts were used to collect data on Mee tree especially, Medicinal plants (Indigenous and Exotic) used in Ceylon. Articles were filtered through journals, magazines and newspapers. Databases such as Google scholar, Springer and Agroforestry were used to search journal articles. The journal articles from 2010-2022 were considered as eligible for this review. Search terms such as Madhuca longifolia, Mee tree, Medicinal uses were used to search journal articles. The final summary was formulated after a thorough reading of all above materials. As the results, the plant contains Vitamins, Ethylcinnamate, Amyrin acetates, Hexacosanol, Linoleic acid, Palmitic acid and many more chemical constituents. The Mee tree has analgesic, diuretic, tonic, aphrodisiac, astringent and demulcent properties with various parts of the plant. The parts are used in certain treatments in Ayurvedic medicine. The flowers, leaves, bark, roots, and seeds of the Mee tree are used to prepare medicines for rheumatism, bronchitis, headache, skin diseases, and worm infestations. The study was concluded as, this tree was so close and familiar to the lives of the people. This tree has many benefits for mankind, and many people have been interested in preserving it. However, due to the deforestation that has taken place in the country in the last few decades, the existence of Mee trees has been severely threatened. Today, Mee tree is a scarce resource in Sri Lanka. People should aware about protecting the plant for future generation. 
 Keywords: Madhuca longifolia, Mee tree, Medicinal uses, Deforestation

The MOVECLIM - AZORES project: Bryophytes from Pico Island along an elevation gradient.

In September 2012, a comprehensive survey of Pico Island was conducted along an elevational transect, starting at Manhenha (10 m a.s.l.) and culminating at the Pico Mountain caldera (2200 m a.s.l.). The primary objective was to systematically inventory the bryophytes inhabiting the best-preserved areas of native vegetation environments. Twelve sites were selected, each spaced at 200 m elevation intervals. Within each site, two 10 m x 10 m plots were established in close proximity (10-15 m apart). Within these plots, three 2 m x 2 m quadrats were randomly selected and sampled for bryophytes using microplots measuring 10 cm x 5 cm, which were then collected into paper bags. Six substrates were surveyed in each quadrat: rock, soil, humus, organic matter, tree bark and leaves/fronds. Three replicates were obtained from all substrates available and colonised by bryophytes, resulting in a maximum of 18 microplots per quadrat, 54 microplots per plot, 108 microplots per site, and a total of 1296 microplots across the 12 sites on Pico Island. Two-thirds of the maximum expected number of microplots (n = 878; 67.75%) were successfully collected, yielding a total of 4896 specimens. The vast majority (n = 4869) were identified at the species/subspecies level. The study identified a total of 70 moss and 71 liverwort species or subspecies. Elevation levels between 600-1000 m a.s.l., particularly in the native forest plots, exhibited both a higher number of microplots and greater species richness. This research significantly enhanced our understanding of Azorean bryophyte diversity and distribution, contributing valuable insights at both local and regional scales. Notably, two new taxa for the Azores were documented during the MOVECLIM study, namely the pleurocarpous mosses Antitrichiacurtipendula and Isotheciuminterludens.

Conspicuous, green flowers are an honest signal of nectar rewards in a bird-pollinated tree (Fuchsia excorticata, Onagraceae)

Bird-pollinated flowers typically appear ‘red’. Fuchsia excorticata (Onagraceae), a gynodioecious tree species endemic to New Zealand, is a notable exception. It produces ‘green’, cauliflorous flowers at early stages in flower ontogeny, when pistils are receptive. Flowers later turn ‘red’ as they lose their receptivity. We conducted field observations and spectrographic analyses to test whether: (1) receptive, green-phase flowers are actually more conspicuous to avian pollinators against their natural backgrounds than unreceptive, red-phase flowers, (2) green-phase flowers produce more nectar, and (3) relationships between flower conspicuousness and nectar production are similar in females and hermaphrodites. Results showed that the reflectance properties of green-phase flowers sharply contrast ‘orange’ tree bark, their natural visual background, rendering them more conspicuous to the avian eye than red-phase flowers. Green-phase flowers also produced more nectar than red-phase flowers as an honest signal of rewards. Similar results were observed in both female and hermaphrodite plants. Overall results provide an unusual example of reversed flower-background colour contrasts, with ‘reddish’ hues being incorporated into the visual backgrounds of floral displays rather than being associated with the flowers themselves. They also illustrate that flower conspicuousness can serve as an honest signal of nectar rewards to pollinators.

Potentially Massive and Global Non-Pyrogenic Production of Condensed "Black" Carbon through Biomass Oxidation.

With the increased occurrences of wildfires worldwide, there has been an increase in scientific interest surrounding the chemistry of fire-derived "black" carbon (BC). Traditionally, wildfire research has assumed that condensed aromatic carbon (ConAC) is exclusively produced via combustion, and thus, ConAC is equated to BC. However, the lack of correlations between ConAC in soils or rivers and wildfire history suggests that ConAC may be produced non-pyrogenically. Here, we show quantitative evidence that this occurs during the oxidation of biomass with environmentally ubiquitous hydroxyl radicals. Pine wood boards exposed to iron nails and natural weather conditions for 12 years yielded a charcoal-like ConAC-rich material. ConAC was also produced during laboratory oxidations of pine, maple, and brown-rotted oak woods, as well as algae, corn root, and tree bark. Back-of-the-envelope calculations suggest that biomass oxidation could be producing massive non-pyrogenic ConAC fluxes to terrestrial and aquatic environments. These estimates (e.g., 163-182 Tg-ConAC/year to soils) are much higher than the estimated pyrogenic "BC" fluxes (e.g., 128 Tg-ConAC/year to soils) implying that environmental ConAC is primarily non-pyrogenic. This novel perspective suggests that wildfire research trajectories should shift to assessing non-pyrogenic ConAC sources and fluxes, developing new methods for quantifying true BC, and establishing a new view of ConAC as an intermediate species in the biogeochemical processing of biomass during soil humification, aquatic photochemistry, microbial degradation, or mineral-organic matter interactions. We also advise against using BC or pyrogenic carbon (pyC) terminologies for ConAC measured in environmental matrices, unless a pyrogenic source can be confidently assigned.

Computational Approaches to Evaluate the Acetylcholinesterase Binding Interaction with Taxifolin for the Management of Alzheimer's Disease.

Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are enzymes that break down and reduce the level of the neurotransmitter acetylcholine (ACh). This can cause a variety of cognitive and neurological problems, including Alzheimer's disease. Taxifolin is a natural phytochemical generally found in yew tree bark and has significant pharmacological properties, such as being anti-cancer, anti-inflammatory, and antioxidant. The binding affinity and inhibitory potency of taxifolin to these enzymes were evaluated through molecular docking and molecular dynamics simulations followed by the MMPBSA approach, and the results were significant. Taxifolin's affinity for binding to the AChE-taxifolin complex was -8.85 kcal/mol, with an inhibition constant of 326.70 nM. It was observed to interact through hydrogen bonds. In contrast, the BChE-taxifolin complex binding energy was observed to be -7.42 kcal/mol, and it was significantly nearly equal to the standard inhibitor donepezil. The molecular dynamics and simulation signified the observed interactions of taxifolin with the studied enzymes. The MMPBSA total free energy of binding for AChE-taxifolin was -24.34 kcal/mol, while BChE-taxifolin was -16.14 kcal/mol. The present research suggests that taxifolin has a strong ability to bind and inhibit AChE and BChE and could be used to manage neuron-associated problems; however, further research is required to explore taxifolin's neurological therapeutic potential using animal models of Alzheimer's disease.

Evaluation of the antimicrobial activity of some bacteria-derived bio-active pigments

There is a growing interest and concern for both the safety of the human population and the protection of the environment which has spurred renewed interest in the search for alternative chemicals from microbial origins which are biodegradable and environmentally friendly. Production of stable bio-products has been reported to be strain-dependent. The aim of this study was to evaluate the antimicrobial activity of pigments extracted from some pigmented native bacteria on some tomato spoilage pathogenic bacteria and fungi. In total, four pigment-producing bacteria spp. were isolated from samples including underneath tomato roots, soils from vegetation sites, wastewater from potato processing sites, tree liters, and tree bark using the enrichment culture and pour plating technique. The isolates were morphologically and biochemically identified as Serratia sp., Salinococcus sp., Exiguobacterium sp., and Xanthomonas sp. The crude bacteria pigments were tested for bio-activity (antimicrobial activity) against some tomato-derived spoilage bacteria (Xanthomonas sp. and Clavibacter sp.) and fungi pathogens (Alternaria alternata and Phytophthora infections) respectively. Among the isolates, pigments of Serratia sp had inhibition zones of 34.5mm and 32.1mm against Xanthomonas sp. and Clavibacter sp. bacteria and 27.8mm and 29.7mm against Alternaria alternata and Phytophthora infectans respectively. While Salinococcus sp. had 30.5mm and 34.2mm against the bacteria species and 27.9mm and 29.3mm against the fungi respectively. These are promising results. Therefore, further purification of the pigment should lead to discovering potent antimicrobial bio-active ingredients for drug development in the pharmaceutical industry.

Alteration of biomass toxicity in torrefaction – A XDS-CALUX bioassay study

Torrefaction constitutes one of the promising technologies for the management of waste biomass and the production of high-carbon products for combustion, gasification, adsorption of pollutants or soil treatment. Unfortunately, waste biomass may be contaminated with toxic persistent organic pollutants, such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDF) and dioxin-like biphenyls (dl-PCB). Literature does not provide consistent measurements on how the low-temperature thermochemical processing, such as torrefaction, affects the toxicity of biomass. This contribution assesses how a torrefaction treatment, conducted at 200 °C, modifies the toxicity due to PCDD/PCDF/dl-PCB in biomass. We deploy the XDS-CALUX biotest on five types of waste biomass (sewage sludge, tree bark, cattle manure, spent coffee ground, common reed), before and after treatment. The content of total dioxin- & biphenyl fraction compounds in the raw biomass, investigated in this study, varies from 0.14 to 3.67 pg BEQ·g−1d.m., and in the torrefied biomass between 0.17 and 6.00 pg BEQ·g−1d.m.; BEQ stands for bioanalytical equivalent. This increase is statistically insignificant at p = 0.05, taking into account all types of examined biomass. This proves that low-temperature torrefaction cannot detoxify biomass, i.e., chars, produced from biomass characterized by elevated concentration of PCDD/PCDF/dl-PCB, will reflect the contamination of the feedstocks. With respect to heavy metals, we conclude that only the content of Cd in biomass, and, to a lesser extent, the abundance of Cu and Fe, modify the toxicity of this material during its thermochemical treatment at low temperature.

Tree barks for retrospective measurement and source appointment of airborne perfluoroalkyl and polyfluoroalkyl substances

Tree bark is a useful bioindicator of atmospheric pollution. It is specially suitable for airborne perfluoroalkyl and polyfluoroalkyl substances (PFASs) investigation due to persistence of ionic PFASs. The present work firstly systematically studied tree barks as a bioindicator of airborne PFASs. Comparison with the regular active and passive samplers found barks could produce long-term measurement of airborne PFASs, and could record the historical emission of PFASs with retrospective time frame as long as decades. Factors, e.g. tree type, trunk diameter, and sampling depth, can affect PFAS accumulation in barks, and these factors should be kept consistent during sampling. In a study area spatial distribution of airborne PFASs can be obtained by interpolation of bark results, and the concerned region can be located. Properties of the emission sources can be characterized, and the potential sources can be tracked based on the bark results. Their contributions can be further estimated by the source appointment strategies. In the economically and industrially developed study area of the present study, eight cities of southern Jiangsu Province of China, total ionic PFAS concentration of camphor bark samples collected in 34 sites was 0.44–359 ng/g dw (dry weight), dominated by perfluoroalkyl carboxylic acids (PFCAs). Two types of possible sources were characterized as with long-chained PFCAs and PFOA (perfluorooctanoic acid) as the main components respectively. The sources were appointed as fluoropolymer manufacturing and textile industries, the important PFAS application fields, and their relative contribution was estimated as 32.5% and 67.5% respectively. The present study can provide useful advice to the method framework of using barks for long-term occurrence investigation, concerned region location, and emission source appointment of airborne PFASs in a study area. Based on the bark results, effective strategies can be further made for PFAS pollution elimination and risk control.