Wax Extracts Research Articles

Natural wax recovery from Musa acuminata biomass using organic solvents

The main aim of this study is to experimentally investigate the yield of extraction and the presence of wax in the extracted yield from Musaacuminata (banana) biomass based on various functional groups that are present in natural wax. Extraction of natural wax from Musaacuminata (banana) biomass has been done by using the Soxhlet apparatus method in the presence of both polar (ethyl acetate and ethanol) and non-polar (toluene and hexane) solvents. The extracted yield has been found as 3.58% from hexane, 5.16% from toluene, 7.03% from ethyl acetate, and 10.26% from ethanol. The wax was also found in the extracted yield only in the case of nonpolar solvents (toluene and hexane). The novelty of this work is that Musaacuminata (banana) waste biomass has been utilized to recover the natural wax using nonpolar solvents and also compared with that of polar solvents to check the scope of wax extraction using polar solvents. Also, statistical analysis has been performed of the extracted yield using both solvents. Thin Layer Chromatography (TLC) and Fourier Transform Infrared Spectroscopy (FTIR) methods have been used to determine the various hydrocarbon chains present in the extracted yield which is similar to that of natural wax.

Water-Repellent Spray for Textiles Using Plant Waste from Conifer Trees.

A superhydrophobic textile coating, applied by using a home drying machine, was developed as an aqueous dispersion of waxes that were extracted from recycled Christmas trees. Because the bulk extraction of waxes yielded a mixture of hydrophobic and hydrophilic compounds, a purification process was tested to determine if removing noncrystallizing wax components would enhance the performance of the coating. The performances of coatings created from the crude and enriched extracts were compared, and no significant difference in hydrophobicity was found. Moreover, although the enriched coating was slightly more breathable, there was not enough of an improvement to justify the additional purification steps, rendering the crude extract more industrially viable. Overall, Christmas tree waxes are readily sourced and are capable of producing superhydrophobic coatings without the need for a costly purification step.

Control of phytopathogen organisms using bioactive compounds contained in orange wax

AbstractOrange wax (OW) is a waxy waste generated in the essential oil purification process (winterization). It has no commercial value. It is discarded or burnt, polluting the environment. The present study demonstrates the possibility of applying it to control phytopathogens. The ethanol‐soluble bioactive compounds of OW were identified and quantified. The effect of orange wax extracts on the growth inhibition of phytopathogenic fungi (Fusarium oxysporum and Colletotrichum gloeosporioides) and Spodoptera frugiperda larvae was evaluated. High‐performance liquid chromatography–mass spectrometry (HPLC‐MS) and gas chromatography–mass spectrometry (GC–MS) quantified 22 bioactive compounds representing 23% (w/w) of OW. Terpineol, limonene, and eremophilene were the most abundant bioactive substances in this material. The distortion of the radial growth of the fungal hyphae was measured in a potato dextrose agar (PDA), and all tested concentrations (6.3, 12.5, 25, 50, and 100 mg/mL) inhibited the radial expansion of C. gloeosporioides. In contrast, only the OW extracts at 50 and 100 mg mL−1 inhibited F. oxysporum. Spray treatments were performed using a Potter spray tower on third‐instar Spodoptera frugiperda larvae. Spraying OW extract at 50 mg mL−1 for 10 s caused the highest larval mortality. However, third‐instar larvae were attracted to consume corn leaves moistened with extract at lower concentrations. Up to 93% of the first‐instar larvae died after eating corn leaves moistened with the extract at 50 mg mL−1. As far as the authors are aware, this is the first scientific report about the use of bioactive compounds of orange wax to control fungi. Spodoptera frugiperda could form the basis for the manufacture of new biopesticides.

The low-affinity calcium channel protein AaFig1 is essential for the growth and development, infection structure differentiation, and pathogenicity of Alternaria alternata

Fig1, as a low-affinity Ca2+ channel, is needed for Ca2+ influx and normal mating found in a few species, but its detailed molecular regulating mechanism in fungi, especially in Alternaria alternata, the causal agent of pear black spot, is still unclear. In this study, Fig1 in A. alternata was cloned, identified and named as AaFig1, and its function was characterized by targeted gene knockout strategy. The results showed that the ΔAaFig1 was severely decreased in vegetative growth, biomass accumulation and sporulation. Fluo-4, AM staining indicated that the Ca2+ content in ΔAaFig1 was decreased. Deletion of AaFig1 reduced the response of A. alternata to exogenous Ca2+ but improved the tolerance to osmotic stresses. Interestingly, the appressorium formation of the ΔAaFig1 strain on hydrophobic and pear wax extract coated surface, and infection hyphae formation on the onion epidermis were significantly reduced, meanwhile, the ΔAaFig1 strain could not penetrate the cellophane. In addition, virulence on wound-inoculated pear fruit and intact pear leaves, melanin production and the activities of cell wall degrading enzymes in AaFig1 strain were reduced. In summary, these results indicate that AaFig1-mediated Ca2+ homeostasis positively regulates the growth and development, infection structure formation and pathogenicity of A. alternata. The findings will provide a basis for developing new strategies to control this pathogen in pear fruit.

Chemical composition and antifungal activity of Capsicum pepper aqueous extracts against plant pathogens and food spoilage fungi.

Capsicum pepper is a rich source of phytochemical compounds such as capsaicinoids, phenols, flavonoids, and so forth. Due to their antimicrobial and antioxidant potential all of these compounds have been assessed and used for both human and plant health benefits. Herein, three fresh varieties of Capsicum annuum (Cacho de Cabra, Bell pepper, and Hungarian Wax varieties) and one fresh and ripe variety of C. baccatum (Cristal) were evaluated. Capsaicin, dihydrocapsaicin, nordihydrocapsaicin and the phenolic content of Capsicum spp. extracts were characterised. The antifungal potential of capsaicinoids and antioxidant activities, and the ecotoxicity of each Capsicum spp. extract, using the model Galleria mellonella, were also evaluated. Phytochemical analyses showed that the Cristal and Hungarian Wax varieties presented the highest amount of capsaicin, dihydrocapsaicin, and nordihydrocapsaicin; while Bell Pepper had the highest phenol content and antioxidant activity. Capsaicinoids' standards and Capsicum spp. extracts showed fungistatic activity against the fungal strains assessed. For the fungal strains assessed, the fungistatic activities of capsaicinoids' standards were higher than those observed in Capsicum spp. extracts. The Hungarian Wax extracts inhibited slightly the growth of Aspergillus niger MUM05.11 and Fusarium oxysporum MUM16.143. Similarly, A. niger, F. oxysporum, Rhizopus arrhizus MUM16.05 and Alternaria sp. UFRO17.178 had their growth retarded by the use of Cacho de Cabra and Cristal extracts. Noticeable changes were observed in the fungal strains' morphologies, such as the presence of fragile fungal structures, pigmentation loss, variation in the reproductive structures size and the conidia number. Capsicum extracts weaken the growth of fungi, indicating their fungistatic potential. Considering the fungistatic potential and non-ecotoxicity of these extracts, it is possible to suggest their use as a tool for pest management in the agri-food sector, controlling the growth and reproduction of fungi without posing a risk to non-target biodiversity.

Efficient catalyst regeneration through solvent-based wax extraction for Co/Al2O3 Fischer-Tropsch catalysts

The regeneration of Fischer-Tropsch (FT) catalysts plays a crucial role in sustaining their catalytic activity and longevity in sustainable production processes. This research investigates the effectiveness of various solvents, including n-hexane, n-heptane, toluene, xylene, and the liquid fraction of FT products (LF-FT), for catalyst regeneration and extracting wax from the 15 wt%Co/Al2O3 catalyst. Toluene, with a unique combination of key parameters such as polarity, solubility, boiling point, aromatic structure, and chemical interactions, exhibited the highest wax removal efficiency of 90.6%. However, due to its 41 °C lower boiling point compared to toluene and very similar wax removal efficiency, n-hexane appears as a more energy-efficient and cost-effective option for this process. The regenerated catalysts showed comparable characteristics, including the textural properties (surface area, pore size, and pore volume), crystallinity, and reducibility, to fresh catalysts. The slightly lower reduction temperature in the regenerated catalyst indicates a higher possibility for the formation of cobalt active sites during the catalyst reduction process with hydrogen, leading to an increased potential for higher catalytic activity. The LF-FT, comprising paraffins, iso-paraffins, olefins, napthenes, and aromatics, provided a unique combination of aliphatic and aromatic moieties, enhancing the solubility of both polar and nonpolar components in FT wax and improving the wax removal efficiency to 91.5%. The higher boiling point and operating temperature of the LF-FT also contributed to its better performance. Efficient separation of hydrocarbons from solvents allowed for solvent reusability in subsequent FT wax removal cycles, making it advantageous for large-scale applications.

Improving the technology of waxes obtaining from oil and fat waste

The object of the research is the extraction of waxes from the waste of the oil and fat industry – spent perlite. As a result of oil winterization, a significant amount of spent filter powders is formed, the disposal of which poses a danger to the environment. At the same time, winterization waste contains a significant amount of oil and wax, which are important components of many types of products. Oil and wax extraction involves the use of volatile, fire-hazardous solvents. An urgent task is to develop new safe and effective technologies for obtaining oils and waxes from winterization waste. The technology of extracting waxes from spent perlite, obtained as a result of winterization of sunflower oil, which involves treatment of perlite with sodium chloride solution, was investigated. Perlite was used according to SOU 15.4-37-210:2004 (CAS Number 93763-70-3) with indicators: mass fraction of fat – 20.1 %, peroxide value – 19.5 ½ O mmol/kg, acid value – 3.5 mg KOH/g. The temperature of mass settling after treatment with sodium chloride is 20 °C, the duration – 10 hours. The following rational conditions for perlite processing using sodium chloride were determined: the concentration of dry sodium chloride (by weight of perlite) – 35.0 %, the duration of mass boiling – 30 minutes. Under these conditions, the experimental value of the saponification value of the obtained wax was 120.5 mg KOH/g. Wax quality indicators: melting point 71.5 °C, acid value 1.6 mg KOH/g, mass fraction of moisture 0.63 %. The obtained results make it possible to obtain high-quality waxes from the waste of the oil and fat industry using a safe and affordable substance (sodium chloride). This will make it possible to avoid the need for waste disposal and increase the profitability of oil and fat enterprises due to obtaining valuable products from production waste

A high epicuticular wax strawberry mutant reveals enhanced resistance to Tetranychus urticae Koch and Botrytis cinerea

Cuticular wax is crucial for plant defense against biotic and abiotic stresses, but its relationship with resistance in strawberries is not well understood. A stable genetic mutant (MT) of ‘Benihoppe’ strawberries with a glossier leaf surface and stronger resistance was identified during cultivation. In this study, we analyzed the anatomical and physiological traits of leaves from ‘Benihoppe’ and its mutant and compared their cuticular wax properties. We also analyzed the differentially expressed genes involved in leaf cuticular wax accumulation and investigated their characteristics against Tetranychus urticae Koch and Botrytis cinerea. Comparisons between morphological and physiological features revealed that the mutant had smaller, darker leaves with a thicker upper epidermis and palisade tissue. GC-MS analysis showed that the total cuticular wax content of the MT leaf (1147.84 μg/dm2) had 1.74 times more total wax content than that of ‘Benihoppe’ (660.66 μg/dm2). The main components of cuticular wax in the MT leaf were primary alcohols (C18, C20, C22, C24, C25 and C26), alkanes (C20 and C31) and fatty acids (C26), whose content increased by 138.37%, 53.69% and 86.80%, respectively, compared with that of ‘Benihoppe’. Based on the comparative transcriptome data, we identified FaKAS2, FaFATA2, FaLACS1, FaKCS12/19, FaPAS2, FaECR, FaCER1 and FAR3/5 as potential key genes involved in wax synthesis of strawberries. Furthermore, MT leaves exhibited lower susceptibility to Tetranychus urticae Koch and its cuticular wax extraction inhibited the growth of Botrytis cinerea more effectively. Therefore, the increase of total cuticular wax and the content of major wax components in MT may be the main contributor to the enhanced resistance. These results not only deepen our understanding of the cuticular wax regulation but also provide potential gene resources for developing more resistant strawberry varieties.

Lenticels are sites of initiation of microcracking and russeting in 'Apple' mango.

The mango cultivar 'Apple' is an important fruitcrop in Kenya, but it is highly susceptible to russeting. The objective was to establish whether lenticels predispose cv. 'Apple' mango to russeting. Fruit mass and surface area increased in a sigmoidal pattern with time. The frequency of lenticels per unit surface area decreased during development. The number of lenticels per fruit was constant. Lenticels were most frequent in the apex region and least common in the cheek and nak (ventral) regions. The cheek region also had lenticels with the largest core areas, whereas the lenticel core areas in the apex region were significantly smaller. Microscopy revealed stomata became covered over with wax deposits at 33 days after full bloom (DAFB). By 78 DAFB, periderm had formed beneath the pore. At 110 and 161 DAFB, cracks had developed and the periderm had extended tangentially and radially. The presence of lenticels increased the strain released upon excision of an epidermal segment, further strain releases occurred subsequently upon isolation of the cuticle and on extraction of the cuticular waxes. The number of lenticels per unit surface area was negatively correlated with the fruit surface area (r2 = 0.62 **), but not affected by fruit size. Mango cv. 'Apple' had fewer, larger lenticels and more russet, compared with 'Ngowe', 'Kitovu' or 'Tommy Atkins' mango. In cv. 'Apple', the lowest lenticel frequency, the largest lenticels and the most russeting occurred at a growing site at the highest altitude, with the highest rainfall and the lowest temperature. Moisture exposure of the fruit surface resulted in enlarged lenticels and more microcracking of the cuticle. Our results establish that russeting in 'Apple' mango is initiated at lenticels and is exacerbated if lenticels are exposed to moisture.

Toward Sustainable Wax Extraction from the Saccharum officinarum L. Filter Cake Byproduct: Process Optimization, Physicochemical Characterization, and Antioxidant Performance.

Saccharum officinarum L. exploitation and processing result in different byproducts, such as filter cake (FC). This study aimed to establish the most suitable experimental conditions to obtain lipophilic bioactive compounds from FC industrial residues, considering their high efficiency, cost-effectiveness, extraction yield, composition, and physicochemical properties. Results indicated that the most appropriate methodology consisted of the pretreatment of the FC sample with H2SO4, followed by ethanolic extraction (B6 method), avoiding energy-consumption FC drying steps and providing ethanol recovery (approx. 90%). The obtained B6 extract yield was 9.59 ± 0.27 g/100 g of FC dry weight, and this methodology proved to be more efficient in obtaining fatty alcohols (20.28 ± 1.48 g/kg extract) and phytosterols (31.56 ± 0.18 g/kg extract) while maintaining lower total monosaccharide concentration (26.19 ± 1.82 mg/g extract). Furthermore, the geographically related multivariate analysis in wax composition and antioxidant activity was evaluated by comparing B6 waxes from Guariba (G) and Univalem (U), both provided by Brazil and collected in June 2020. Overall, the wax composition is affected, but the antioxidant activity is uncompromised, which indicates that the optimized wax extraction method can be applied to FC.

Carnauba Straw as Feedstock for Solid Biofuel Production

Carnauba straw (<em>Copernicia prunifera</em>), residual biomass derived from wax extraction, was evaluated as a potential feedstock for bioenergy production. The characterization was carried out using elemental analysis, proximate analysis, Higher Heating Value (HHV), FTIR spectroscopy, SEM, and FRX. The carbonization, using a Muffle Furnace, was applied as a thermal conversion technique to improve the fixed carbon content, and preliminary densification was done to assess the potential for future production of briquettes. The C, H, N, O, and S percentages were 44.43%, 5.34%, 2.25%, 46.17%, and 1.81%, respectively. The percentage of fixed carbon (14.17%) increased to 31.10% (250°C) and 35.68% (300°C) after carbonization. At 400°C, the HHV presented a decrease of 9.62%, and ash content increased by 177.66%. FTIR spectra showed bands characteristic of hemicellulose, cellulose, and lignin at 3414 - 3393 cm<sup>-1</sup> (O-H) and decrease of absorbance of 74.01% to 81.37% after carbonization; 1738 – 1603 cm<sup>-1</sup> (C=O), with reduction in the order of 73.94% to 78.31%, and 48.97% to 73.76%, when compared to the absorbances of the biomass in nature. The SEM of the carnauba straw in nature presented the main structural components (cellulose, lignin, and hemicellulose). After carbonization, evidence of degradation and coal formation was observed, which corroborates with the decrease in the HHV and increase of ash. The FRX was inserted in the SEM images, and the elements detected were Ca, K, and S. The quantities and order of abundance in biomass natural and carbonized were compatible with other biomasses used as biofuel. The carnauba straw in natural and carbonized was densified to understand the characteristics of the compacted material. The sample carbonized at 300°C presented a solid with the potential for future production of briquettes. All results follow other reported biomasses and could lead to further investigation of the carnauba straw as feedstock for solid fuel production without or in a mixture with other agricultural residues.

Statistical prediction and sensitivity analysis of kinetic rate constants for efficient thermal valorization of plastic waste into combustible oil and gases

Sensitivity analyses of rate constants for chemical kinetics of the pyrolysis reaction are essential for the efficient valorization of plastic waste into combustible liquids and gases. Finding the role of individual rate constants can provide important information on the process conditions, quality, and quantity of the pyrolysis products. The reaction temperature and time can also be reduced through these analyses. For sensitivity analysis, one possible approach is to estimate the kinetic parameters using MLRM (multiple linear regression model) in SPSS. To date, no research reports on this research gap are documented in the published literature. In this study, MLRM is applied to kinetic rate constants, which slightly differ from experimental data. The experimental and statistically predicted rate constants varied up to 200% from their original values to perform sensitivity analysis using MATLAB software. The product yield was examined after 60 min of thermal pyrolysis at a fixed temperature of 420 °C. The predicted rate constant “k(8)” with a slight difference of 0.02 and 0.04 from the experiment revealed 85% oil yield and 40% light wax after 60 min of operation. The heavy wax was missing from the products under these conditions. This rate constant can be utilized to maximize the commercial-scale extraction of liquids and light waxes from thermal pyrolysis of plastics.

Extraction and Clarification of Orange Wax Obtained from Waste of the Citrus Industry

AbstractThe processing of the orange leads to a large generation of waste, which is underutilized or discarded. Thus, this study proposes a route to treat oily waste from the orange juice industry, transforming it into a by‐product of higher added value to the chemical industry. The orange wax is obtained by hydrodistillation and solvent extraction, and the clarification of the wax is carried out with the oxidative treatment using H2O2. A 32 Experimental Design confirmed that the factors, temperature, and concentration of the reactant, influence both response variables, the colorimetric changes and yield. The obtained waxes are characterized by chromatographic (CG‐MS), thermal, and rheological analysis. The results of the CG‐MS indicate that the clarification method is effective as the components responsible for the pigmentation and odor of the wax cannot be identified after the clarification process. Thermogravimetry analysis and differential exploratory calorimetryindicate a slight increase in thermal stability and a decrease in crystallinity after the clarification process. Rheological analyses show that the obtained waxes present similar flow behavior as commercial beeswax. Therefore, it can be affirmed that this work obtains a green wax from a residue for potential replacement of commercial waxes according to its properties analyzed.Practical applications: This work shows the extraction of orange wax from oily industrial wastes for possible applications in the food and cosmetics industries. The orange wax can be a sustainable substitute for nonrenewable products and supply the wax market due to the high demand. In addition, methods for processing and characterization of the waxes are presented in this work.

Fractionation and Characterization of Triterpenoids from Vaccinium vitis-idaea L. Cuticular Waxes and Their Potential as Anticancer Agents.

Fruit and leaf cuticular waxes are valuable source materials for the isolation of triterpenoids that can be applied as natural antioxidants and anticancer agents. The present study aimed at the semi-preparative fractionation of triterpenoids from cuticular wax extracts of Vaccinium vitis-idaea L. (lingonberry) leaves and fruits and the evaluation of their cytotoxic potential. Qualitative and quantitative characterization of obtained extracts and triterpenoid fractions was performed using HPLC-PDA method, followed by complementary analysis by GC-MS. For each fraction, cytotoxic activities towards the human colon adenocarcinoma cell line (HT-29), malignant melanoma cell line (IGR39), clear renal carcinoma cell line (CaKi-1), and normal endothelial cells (EC) were determined using MTT assay. Furthermore, the effect of the most promising samples on cancer spheroid growth and viability was examined. This study allowed us to confirm that particular triterpenoid mixtures from lingonberry waxes may possess stronger cytotoxic activities than crude unpurified extracts. Fractions containing triterpenoid acids plus fernenol, complexes of oleanolic:ursolic acids, and erythrodiol:uvaol were found to be the most potent therapeutic candidates in the management of cancer diseases. The specificity of cuticular wax extracts of lingonberry leaves and fruits, leading to different purity and anticancer potential of obtained counterpart fractions, was also enclosed. These findings contribute to the profitable utilization of lingonberry cuticular waxes and provide considerable insights into the anticancer effects of particular triterpenoids and pharmacological interactions.

Chemical characterization of n-alkane compounds in the leaves of Holoptelea integrifolia and its repellence against Japanese encephalitis vector

Epicuticular wax extract bearing n-alkane compounds were isolated from leaves of Holoptelea integrifolia and its chemical characterization was done by GC-MS analysis. Seven n-alkane compounds were isolated from epicuticular wax of H. integrifolia, which are Undecane [C11H24], Decane 5-methyl- [C11H24], Dodecane [C12H26], Undecane, 3,6-dimethyl- [C12H26], Hexadecane, 2,6,10,14-tetramethyl- [C20H42], Tridecane [C13H28], and Tetradecane [C14H30]. Different concentrations of crude extract as well as epicuticular wax extract bearing n-alkane each @ 2, 4 and 5 ppm cm-2 applied on human hand surface for repellence against Culex vishnui (vectors of JE) and at different time of exposure, gave a maximum protection of 73.33 per cent in the case of crude extract, and 94.33 per cent with epicuticular wax extract, both at 5 ppm cm-2, up to five hours of exposure.

Isolation of high-purity friedelin and 3-hydroxyfriedel-3-en-2-one from cork smoker wash solids

Cork smoker wash solids (black wax) that is obtained in the process of making corkboard by treating the ground cork with superheated steam is useless waste, generating environmental problems. On the other hand, black wax is a rich source of friedelin (1) and 3-hydroxyfriedel-3-en-2-one (3), pentacyclic triterpenoids belonging to the friedelane family. In the present work, a simple, fast, and efficient procedure for the extraction of highly purified friedelin and 3-hydroxyfriedel-3-en-2-one from black wax is presented. Extraction of black wax with hexane or acetone afforded a mixture of friedelin and 3-hydroxyfriedel-3-en-2-one. However, chromatographic separation of 1 and 3, due to their very similar Rf coefficients, is difficult, especially on a multigram scale. Therefore, the conversion of 3-hydroxyfriedel-3-en-2-one to an acetyl derivative 4 was proposed by acetylation of the above mixture. Appropriate selection of the eluent sequence allows for rapid and efficient separation of the resulting mixture of 1 and 4.

Wax-extraction effect on water permeances of three isolated plant cuticles.

The cuticle is a heterogeneous, extracellular biopolymer, which is synthesized by epidermal cells. It plays many physiological and ecological roles but its main function is the reduction of water loss from plants when the stomata are closed. Cuticular waxes are essential part of the cuticle structure and their presence is limitation factor in controlling water permeability. Therefore, knowledge about amounts and chemical composition of cuticular waxes is necessary in order to understand their functions. This study was conducted to find out the effect of wax extraction on water permeability of three isolated plant species cuticles. The cuticles were enzymatically isolated and waxes were extracted from the cuticles using chloroform. The results showed that the water permeance was affected by removing waxes from cuticle structure and it was increased by high factor for all treated plants. This study showed no correlation between wax coverage of each single species and its water permeability

Comparing anatomy, chemical composition, and water permeability of suberized organs in five plant species: wax makes the difference

Main conclusionThe efficiency of suberized plant/environment interfaces as transpiration barriers is not established by the suberin polymer but by the wax molecules sorbed to the suberin polymer.Suberized cell walls formed as barriers at the plant/soil or plant/atmosphere interface in various plant organs (soil-grown roots, aerial roots, tubers, and bark) were enzymatically isolated from five different plant species (Clivia miniata, Monstera deliciosa, Solanum tuberosum, Manihot esculenta, and Malus domestica). Anatomy, chemical composition and efficiency as transpiration barriers (water loss in m s−1) of the different suberized cell wall samples were quantified. Results clearly indicated that there was no correlation between barrier properties of the suberized interfaces and the number of suberized cell layers, the amount of soluble wax and the amounts of suberin. Suberized interfaces of C. miniata roots, M. esculenta roots, and M. domestica bark periderms formed poor or hardly any transpiration barrier. Permeances varying between 1.1 and 5.1 × 10−8 m s−1 were very close to the permeance of water (7.4 × 10−8 m s−1) evaporating from a water/atmosphere interface. Suberized interfaces of aerial roots of M. deliciosa and tubers of S. tuberosum formed reasonable transpiration barriers with permeances varying between 7.4 × 10−10 and 4.2 × 10−9 m s−1, which were similar to the upper range of permeances measured with isolated cuticles (about 10−9 m s−1). Upon wax extraction, permeances of M. deliciosa and S. tuberosum increased nearly tenfold, which proves the importance of wax establishing a transpiration barrier. Finally, highly opposite results obtained with M. esculenta and S. tuberosum periderms are discussed in relation to their agronomical importance for postharvest losses and tuber storage.

The calcineurin-responsive transcription factor Crz1 is required for regulation of infection structure differentiation, calcium homeostasis and cell wall integrity in Alternaria alternata

Ca2+/calcineurin signaling pathway is crucial in regulating growth, stress response and pathogenicity of phytopathogenic fungi. However, there is little information about the downstream calcineurin-responsive zinc finger transcription factor Crz1 in Alternaria alternata, the pathogenic factors of pear black spot. Here, AaCrz1 was identified in A. alternata and its function was characterized by generating target gene knockout strains. The results showed that ΔAaCrz1 was impaired in vegetative growth and spore morphology. The infection structures in the ΔAaCrz1 inhibited on hydrophobic and pear wax extract coated surface. Deletion of AaCrz1 increased sensitivity to different stresses, especially the hypersensitivity to Ca2+. In addition, AaPMC1 and AaPMR1 genes were regulated by AaCrz1 in response to Ca2+ level. CFW staining indicated that the cell wall of ΔAaCrz1 was damaged, and the ΔAaCrz1 displayed a reduction in the expression of genes related to cell wall biosynthesis, such as chitin synthases (CHS) and β-1,3-glucan synthase (FKS). Furthermore, AaCrz1 was involved in the full virulence of A. alternata on pear fruit. Collectively, this study suggests that identified AaCrz1 is essential for the development, infection structure formation, calcium homeostasis, cell wall integrity and virulence of A. alternata.

Nelumbo nucifera leaves as source of water-repellent wax: Extraction through polar and non-polar organic solvents

Nelumbo nucifera leaves are rich source of natural wax possessing super-hydrophobic properties. It provides protection to them from ecological turbulences and climatic wear and tear. In this study, various experiments have been conducted to observe the yield of extraction and the determination of various functional groups, which are present in natural wax, derived from Nelumbo nucifera leaves. The natural wax has been extracted from lotus leaves through non-polar (hexane) and polar (ethanol) solvent via different extraction methods. The superhydrophobic wax has been successfully extracted with hexane. Whereas, ethanol did not extract the water-repellent wax of lotus leaf. Considering the cumulative amount, i.e. (desired + undesired), the maceration shows the extraction of 2.9% (%w/w, through hexane) and 10.2% (%w/w, through ethanol), while it was found 2.5% (%w/w, cycle period 15 min) and 9.0% (%w/w, cycle period 26 min) respectively, in case of Soxhlet extraction technique. For this specific case of natural wax recovery from biomass (lotus leaf), the maceration (traditional method) resulted a little bit superior extraction yield in comparison to the Soxhlet extraction method for extraction of crude wax. In the case of non-polar solvent (hexane), an extraction yield of 1.97% (%w/w) through maceration method was observed while in the case of non-polar solvent (ethanol), an extraction yield of 1.62% (%w/w) through Soxhlet extraction was observed. The TLC analysis on both types of extracts was performed. For the detection of various hydrocarbon chains in the crude wax extracts, FTIR was also performed. Topography of wax surface and wax-coated waterproof fabric was compared through SEM.