Loofa (Luffa cylindrica) sponge: Review of development of the biomatrix as a tool for biotechnological applications

Unconventional strategies for liver tissue engineering: plant, paper, silk and nanomaterial-based scaffolds

The paper highlights how significant characteristics of liver can be modeled in tissue-engineered constructs using unconventional scaffolds. Hepatic lobular organization and metabolic zonation can be mimicked with decellularized plant structures with vasculature resembling a native-hepatic lobule vascular arrangement or silk blend scaffolds meticulously designed for guided cellular arrangement as hepatic patches or metabolic activities. The functionality of hepatocytes can be enhanced and maintained for long periods in naturally fibrous structures paving way for bioartificial liver development. The phase I enzymatic activity in hepatic models can be raised exploiting the microfibrillar structure of paper to allow cellular stacking creating hypoxic conditions to induce in vivo-like xenobiotic metabolism. Lastly, the paper introduces amalgamation of carbon-based nanomaterials into existing scaffolds in liver tissue engineering.

In vivo characterization of a luffa-based composite scaffold for subcutaneous implantation in rats

Recent advancements in tissue engineering have witnessed luffa-derived scaffolds, exhibiting their exceptional potential in cellular proliferation, biocompatibility, appropriate interconnectivity, and biomechanical strength. In vivo studies involved implanting fabricated scaffolds subcutaneously in Wistar rats to evaluate their impact on the heart, liver, and kidneys. This approach provided a safe and minimally invasive means to evaluate scaffold compatibility with surrounding tissues. Male Wistar rats were categorized into four distinct groups, Group A, B, C, and D are referred to as 3% LC implanted scaffolds, 5% LC implanted scaffolds, control (without luffa scaffolds), and Sham (without any scaffold implantation), respectively. Histological analysis in all the groups indicated that the animal models did not exhibit any signs of inflammation or toxicity, suggesting favorable tissue response to the implanted scaffolds. Initial observations revealed elevated levels of enzymes and biomarkers in the experimental groups after a 24 h interval, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), bilirubin, creatine kinase-MB (CK-MB), and serum creatinine. However, these parameters normalized 3 weeks post-implantation, with no significant increase compared to the control groups, suggesting that the implanted luffa-based scaffolds did not induce adverse effects on the heart, liver, and kidneys. Furthermore, the scaffold's significant pore size and porosity enable it to release drugs, including antibacterial medications. This study demonstrates promising results, indicating excellent scaffold porosity, sustained drug release, affirming the in vivo biocompatibility, absence of inflammatory responses, and overall tissue compatibility highlighting the immense potential of these luffa-based scaffolds in various tissue engineering and regenerative medicine applications.

3D Spongin Scaffolds as Templates for Electro-Assisted Deposition of Selected Iron Oxides

The skeletons of marine sponges are ancient biocomposite structures in which mineral phases are formed on 3D organic matrices. In addition to calcium- and silicate-containing biominerals, iron ions play an active role in skeleton formation in some species of bath sponges in the marine environment, which is a result of the biocorrosion of the metal structures on which these sponges settle. The interaction between iron ions and biopolymer spongin has motivated the development of selected extreme biomimetics approaches with the aim of creating new functional composites to use in environmental remediation and as adsorbents for heavy metals. In this study, for the first time, microporous 3D spongin scaffolds isolated from the cultivated marine bath sponge Hippospongia communis were used for electro-assisted deposition of iron oxides such as goethite [α-FeO(OH)] and lepidocrocite [γ-FeO(OH)]. The obtained iron oxide phases were characterized with the use of scanning electron microscopy, FTIR, and X-ray diffraction. In addition, mechanisms of electro-assisted deposition of iron oxides on the surface of spongin, as a sustainable biomaterial, are proposed and discussed.

Microalgal-based macro-hollow loofah fiber bio-composite for methylene blue removal: A promising step for a green adsorbent

This study looked into how well the macro-hollow loofah fiber with and without the bio-attaching with green microalga (Chlamydomonas reinhardtii OR242521) was applied methylene blue elimination from water. Based on the results, the biosorption capacity of loofah sponge for methylene blue significantly increased with the increase of contact time, weight of microalgal biofilm, and methylene blue concentration. The maximum biosorption capacity was achieved after 120 min, after 0.042 mgg-1 biofilm weight, and MB concentration of 140 mgL-1. Furthermore, methylene blue's biosorption capacity was strongly affected by pH, reaching its maximum at pH 7. The biosorption capacity of the bio-attached loofah sponge was much higher than that of the loofah sponge, revealing that the microalgae bio-attachment enhanced the biosorption capacity of the loofah sponge. At the end of the MB biosorption process, the used bio-attached loofah sponge can still be utilized once more for the same purpose after the desorption of MB but with a lower biosorption capacity. Furthermore, the loofah sponge could also be applied as a bio-sorbent after domestic use. According to this study, the loofah sponge with or without algal biofilm attachment could be applied as a low-cost efficient bio-sorbent for methylene blue removal from water. However, the loofah sponge's ability for biosorption was dramatically increased by the bio-attachment of microalgae, making it a more potent bio-sorbent. Likewise, this study offers insights into the variables influencing the biosorption capacity of loofah sponges and bio-attached loofah sponges, which could be beneficial for enhancing the biosorption processes.

Systematic screening strategy for fungal laccase activity of endophytes from Otoba gracilipes with bioremediation potential

Fungal laccases are promising for biotechnological applications, including bioremediation and dye biotransformation, due to their high redox potential and broad substrate specificity. However, current bioprospecting methods for identifying laccase-producing fungi can be challenging and time-consuming. For early detection, it was developed a three-step, multi-criteria weighting system that evaluates fungal strains based on: First, the biotransformation capacity of three dyes (i.e., Congo red, brilliant blue G-250, and malachite green), at three different pH values, and with a relative weighting supported for the redox potential of each colorant. The relative decolorization coefficient (RDC), used as th2e first classification criterion, expressed their potential performance. Second, under the same conditions, laccase activity was estimated by observing the different degrees of oxidation of a given substrate. The selection criterion was the relative oxidation coefficient (ROC). Finally, laccase activity was quantified in submerged fermentations using three inducers (i.e., loofah sponge, Tween 80, and veratyl alcohol). This multicriteria screening strategy evaluated sixteen isolated endophytic fungal strains from Otoba gracilipes. The system identified Beltraniopsis sp. ET-17 (at pH values of 5.00 and 5.50) as a promising strain for dye biotransformation, and Phlebia floridensis as the best laccase producer, achieving a high activity of 116 μmol min-1 L-1 with loofah sponge as an inducer. In-vitro testing confirmed the efficacy of P. floridensis, with 53.61 % decolorization of a dye mixture (brilliant blue-Congo red. ratio 1:1) after 15 days of incubation. Thus, with the proposed screening strategy it was possible to highlight two species of interest at an early bioprospecting stage on a Colombian native tree poorly explored.

Fu-Zheng-Tong-Luo formula promotes autophagy and alleviates idiopathic pulmonary fibrosis by controlling the Janus kinase 2/signal transducer and activator of transcription 3 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Fu-Zheng-Tong-Luo (FZTL) formula is a Chinese herbal prescription which is used to treat idiopathic pulmonary fibrosis (IPF). We previously reported that the FZTL formula could improve IPF injury in rats; however, the mechanism remains unelucidated.

AIM OF THE STUDY

To elucidate the effects and mechanisms of the FZTL formula on IPF.

MATERIALS AND METHODS

The bleomycin-induced pulmonary fibrosis rat model and transforming growth factor-β-induced lung fibroblast model were used. Histological changes and fibrosis formation were detected in the rat model after treatment with the FZTL formula. Furthermore, the effects of the FZTL formula on autophagy and lung fibroblast activation were determined. Moreover, the mechanism of FZTL was explored using transcriptomics analysis.

RESULTS

We observed that FZTL alleviated IPF injury in rats and inhibited inflammatory responses and fibrosis formation in rats. Moreover, it promoted autophagy and inhibited lung fibroblast activation in vitro. Transcriptomics analysis revealed that FZTL regulates the Janus kinase 2 (JAK)/signal transducer and activator of the transcription 3 (STAT) signaling pathway. The JAK2/STAT3 signaling activator interleukin 6 inhibited the anti-fibroblast activation effect of the FZTL formula. Combined treatment with the JAK2 inhibitor (AZD1480) and autophagy inhibitor (3-methyladenine) did not enhance the antifibrotic effect of FZTL.

CONCLUSIONS

The FZTL formula can inhibit IPF injury and lung fibroblast activation. Its effects are mediated via the JAK2/STAT3 signaling pathway. The FZTL formula may be a potential complementary therapy for pulmonary fibrosis.

Carbonized loofah sponge-based solid-phase extraction of benzo[a]pyrene from fish followed by liquid chromatography-ultraviolet detection

A simple and sensitive method combining solid-phase extraction (SPE) and high-performance liquid chromatography-ultraviolet detection (HPLC-UV) was developed for the determination of benzo[a]pyrene (BaP) in fish. Loofah sponge (LS) was carbonized and used as an SPE adsorbent. Carbonization decreased the polarity of LS and enhanced its aromaticity. Carbonized loofah sponge (CLS) could capture BaP better through π-π interaction. The carbonization temperature and the SPE conditions were optimized. The linear range of the developed method was within 10-1000 ng g^-1 with a satisfactory correlation coefficient (R²) of 0.9999. The limit of detection (LOD) was 2.0 ng g^-1, which was below the maximum residue limit (5 μg kg^-1) in meat set by the European Union. The method showed good intra-day and inter-day precision with relative standard deviations (RSDs) ranging from 0.4% to 1.7%. Finally, the developed method was applied to the determination of BaP in fish samples. This method is low-cost and environmentally friendly with natural and renewable LS as raw material and it provides an alternative approach for the efficient and simple determination of BaP in aquatic products.

Immobilized microalgal system: An achievable idea for upgrading current microalgal wastewater treatment

Efficient wastewater treatment accompanied by sustainable "nutrients/pollutants waste-wastewater-resources/energy nexus" management is acting as a prominent and urgent global issue since severe pollution has occurred increasingly. Diverting wastes from wastewater into the value-added microalgal-biomass stream is a promising goal using biological wastewater treatment technologies. This review proposed an idea of upgrading the current microalgal wastewater treatment by using immobilized microalgal system. Firstly, a systematic analysis of microalgal immobilization technology is displayed through an in-depth discussion on why using immobilized microalgae for wastewater treatment. Subsequently, the main technical approaches employed for microalgal immobilization and pollutant removal mechanisms by immobilized microalgae are summarized. Furthermore, from high-tech technologies to promote large-scale production and application potentials in diverse wastewater and bioreactors to downstream applications lead upgradation closer, the feasibility of upgrading existing microalgal wastewater treatment into immobilized microalgal systems is thoroughly discussed. Eventually, several research directions are proposed toward the future immobilized microalgal system for microalgal wastewater treatment upgrading. Together, it appears that using immobilization for further upgrading the microalgae-based wastewater treatment can be recognized as an achievable alternative to make microalgal wastewater treatment more realistic. The information and perspectives provided in this review also offer a feasible reference for upgrading conventional microalgae-based wastewater treatment.

Loofah Sandwich Panels: The Effect of Adhesive Content on Mechanical and Physical Properties

In the development of new materials, the focus nowadays is increasingly on their relevance with regard to lightweight construction or environmental compatibility. The idea of a lightweight sandwich panel was inspired by an increasing number of cosmetic accessories that use the fibers of the loofah plant, a rapidly renewable, light, fibrous raw material. The aim of the study was to develop a fiber composite panel based on the fibers of the loofah plant (Luffa cylindrica) as core material and wooden veneer as the skin layer to be used in areas of lead construction. Three different panel variations were produced for the tests, with a fiber-adhesive ratio between 1:1.05, 1:0.8, and 1:0.5. The mechanical strength (flexural strength and internal bond) and the physical properties (density and thickness swelling) were determined as a function of the fiber-adhesive composition. The results show that the flexural strength increased by approx. 400% and the thickness swelling was reduced by 10% with increasing adhesive quantity.

Immobilized Stenotrophomonas maltophilia KB2 in Naproxen Degradation

Immobilization is a commonly used method in response to the need to increase the resistance of microorganisms to the toxic effects of xenobiotics. In this study, a plant sponge from Luffa cylindrica was used as a carrier for the immobilization of the Stenotrophomonas maltophilia KB2 strain since such a carrier meets the criteria for high-quality carriers, i.e., low price and biodegradability. The optimal immobilization conditions were established as a temperature of 30 °C, pH 7.2, incubation time of 72 h, and an optical density of the culture of 1.4. The strain immobilized in such conditions was used for the biodegradation of naproxen, and an average rate of degradation of 3.8 µg/hour was obtained under cometabolic conditions with glucose. The obtained results indicate that a microbiological preparation based on immobilized cells on a luffa sponge can be used in bioremediation processes where it is necessary to remove the introduced carrier.

Production of the Polysaccharide Pullulan by Aureobasidium pullulans Cell Immobilization

This review examines the immobilization of A. pullulans cells for production of the fungal polysaccharide pullulan. Pullulan is a water-soluble gum that exists structurally as a glucan consisting primarily of maltotriose units, which has a variety of food, non-food and biomedical applications. Cells can be immobilized by carrier-binding or entrapment techniques. The number of studies utilizing carrier-binding as a method to immobilize A. pullulans cells appears to outnumber the investigations using cell entrapment. A variety of solid supports, including polyurethane foam, sponge, diatomaceous earth, ion-exchanger, zeolite and plastic composite, have been employed to immobilize pullulan-producing A. pullulans cells. The most effective solid support that was used to adsorb the fungal cells was polyurethane foam which produced polysaccharide after 18 cycles of use. To entrap pullulan-producing fungal cells, agents such as polyurethane foam, polyvinyl alcohol, calcium alginate, agar, agarose, carrageenan and chitosan were investigated. Polysaccharide production by cells entrapped in polyurethane foam, polyvinyl alcohol or calcium alginate was highest and the immobilized cells could be reutilized for several cycles. It was shown that the pullulan content of the polysaccharide synthesized by cells entrapped in calcium alginate beads was low, which limits the method’s usefulness for pullulan production. Further, many of the entrapped fungal cells synthesized polysaccharide with a low pullulan content. It was concluded that carrier-binding techniques may be more effective than entrapment techniques for A. pullulans cell immobilization, since carrier-binding is less likely to affect the pullulan content of the polysaccharide being synthesized.

Facile and green synthesis of reduced graphene oxide/loofah sponge for Streptomyces albulus immobilization and ε-poly-l-lysine production

Facile and green fabrication of reduced graphene oxide on loofah sponge (rGOLS) carrier was applied for cell immobilization of ε-Poly-l-lysine (ε-PL) production. Due to surface properties including large specific surface area, high polarity, and low interaction energy, rGOLS-1 was employed as the optimum rGOLS to enhance immobilization of Streptomyces albulus. Compared with raw LS, batch experiments showed rGOLS-1 facilitated superior cell vitality for ε-PL production due to the presence of reduced graphene oxide. In the sequential fed-batch cultivation of Streptomyces albulus using rGOLS-1 with an aerobic plant fibrous-bed bioreactor (rGOLS-1-AFPB), the maximum ε-PL concentration and productivity reached to 39.2 ± 0.63 g/L and 0.48 g/L/h. The cells immobilized in rGOLS-1 with high vitality and ε-PL production efficiency were reused six times over a period of 624 h. This research afforded an effective approach to enhance the fermentation performance of immobilized cells with the design of an advanced immobilization carrier.

Greenhouse Desalination by Humidification–Dehumidification Using a Novel Green Packing Material

Humidification–dehumidification (HD) is a non-traditional desalination process in which water evaporates from a saline liquid stream and the vapour condenses into purified water. In nature, seawater is heated by solar radiation and evaporates from the air that moistens it. This is known as the rainy cycle. The artificial version of this cycle is called the HD desalination cycle. The latter has received a lot of attention in recent years, and many researchers have studied the complexities of the technology. In the present work, experimental work with a simple configuration was developed and built, consisting of a humidification column followed by a condenser, in which the humidified air is dehumidified to produce fresh water. A novel and unique packaging material was used in the humidifier, consisting of a cellulose plant grown on the banks of the River Nile. In all previous work, the main problem was the type of packaging material that could ensure intimate contact and uniformity between aqueous flow and airflow. Consequently, this new filler material proved extremely suitable in terms of hydrophilicity and interconnectivity. Several variables, including the packing mass of each stage, the number of stages, the flow of air and saltwater, the concentration of saltwater, and the inlet temperature of saltwater and condensation temperature, were examined to determine their influence on the production of fresh water and its salinity. The best results arrived at in this study were wet packing conditions, 0.5 m/s air flowrate, 26 g packing for each of the 6-stage columns, and 500 mL/min water flow rate at 70 °C. It was found that this present setup, which can be coupled with solar heating to make the greenhouse desalination process cost-effective, could produce a high production of fresh water and be competitive compared with other commercial applications.

An in vitro evaluation of luffa cylindrica stem sap in preadipocytes and dermal fibroblasts

BACKGROUND

Luffa cylindrica stem sap (LuCS) has been ethnopharmacologically used as a cosmetic ingredients to improve the facial condition in Asians, but there is no scientific proof about the advantages of LuCS as a supplement for skin elasticity inducer.

PURPOSE

Presently, we have validated the beneficial effect of LuCS in human preadipocyte and fibroblast.

METHODS

In vitro activities of LuCS on expression of cellular elastin and collagen type I were validated using Western blot analysis in human fibroblasts. Effect of LuCS on preadipocyte development was performed using MDI medium containing isobutyl-methylxanthine, dexamethasone, and insulin and then evaluated using oil red O staining.

RESULTS

Treatment of LuCS stimulated the expression of cellular elastin and type I procollagen in human skin fibroblasts. Exposure to LuCS induced lipid accumulation of preadipocytes via activation of CEBP/α signaling pathway in preadipocytes. Expression of collagen I, elastin, or CEBP/α mRNA was decreased by age. 3-bromo-3-methylisoxazol-5-amine enhanced the synthesis of cellular lipid in preadipocytes.

CONCLUSIONS

Collectively, these results suggest the rationale of LuCS treatment in enhancing the skin condition.

Compressible Ionized Natural 3D Interconnected Loofah Membrane for Salinity Gradient Power Generation

Large-scale salinity gradient power energy harvesting has generated broad attention in recent years, in which affordable ion-selective membranes (ISMs) are essential for its practical implementation. In this study, for the first time, ISMs derived from natural loofah sponge are reported, which have features of high hydrophilicity, superior ion conductivity, and 3D interconnected long fibers. The permselectivity and ion conductivity of loofah-based anion-selective membranes (ASMs) and cation-selective membranes (CSMs) are designed by chemical modification of the surface functional groups of loofah fibers and followed with compression and the resin filling. The charged nanochannels inside the ISMs are served as ion conductive and selective channels based on the nanofluidic effects and Donnan exclusion. Meanwhile, the unique isotropic structure endows excellent dimensional stability under the NaCl solution for months. When ISMs are used for salinity gradient power generation from the gradient of artificial seawater and river water, the maximum power density is 18.3 mW m^-2 . When ten units of loofah-based ISMs are stacked in series, a voltage as high as 1.55 V is achieved. The results highlight the great potential of natural fibers for fabricating affordable, durable, and high performance ISMs, paving a sustainable pathway for developing high-performance, durable, and low-cost salinity gradient power generators.

Evaluating the effect of Luffa cylindrica stem sap on dermal fibroblasts; An invitro study

Luffa cylindrica stem sap (LuCS) has been traditionally used as a facial cosmetic supplement to enhance the skin condition of Asians. However, LuCS has yet to be described and there is no solid scientific evidence regarding the use of LuCS as an anti-wrinkle agent. In the present study, we have evaluated the functional effect of LuCS and its underlying mechanisms based on scientific evidence. Treatment with LuCS stimulated the growth and migration of human skin fibroblasts. LuCS treatment activated EGFR signaling via the enhanced expression of EGFR and down-regulation of PPARγ in human skin fibroblasts. Exposure to LuCS induced the synthesis of cellular type I procollagen and elastin in consort with the down-regulation of various proteinases including MMP-1, -2 and -9 in human skin fibroblasts. LuCS treatment also reversed the skin damage induced by UV-A irradiation in human skin fibroblasts. 3-bromo-3-methylisoxazol-5-amine was identified as the functional component using UPLC-MS-MS analysis and increased production of cellular type I procollagen. Collectively, these results suggest the efficacy of LuCS supplementation in improving the skin condition via anti-wrinkle effect.

Biotreatment of Cr(VI) and pyrene combined water pollution by loofa-immobilized bacteria

Hexavalent chromium (Cr(VI)) and pyrene are toxic pollutants that are difficult to remediate from soils and wastewater. Serratia sp. strains have been previously demonstrated to remove either Cr(VI) or pyrene and here a new isolate, called the Z6 strain, was demonstrated to remove both simultaneously. The removal occurs primarily by Cr(VI) reduction and pyrene biodegradation, and genome analysis suggests the removal mechanisms are the putative chromate reductase and two assumable pathways of pyrene degradation. The Z6 strain effectively removed most Cr(VI) (up to approximately 86%) and pyrene (up to approximately 57%) in seven different types of wastewater after 7 days of biotreatment. Additionally, the carrier loofa used for bacteria immobilization did not change the kinetics of Cr(VI) reduction or pyrene degradation. The carrier loofa was also effective for multiple uses, with removal capacity not being significantly affected over the first seven cycles with the same carrier loofa. These results provide data for developing practical biotreatment applications of Cr(VI) and pyrene contaminated sites.

A brief review on recent development of multidisciplinary engineering in fermentation of Saccharomyces cerevisiae

Fermentation technology has unprecedented potential to upgrade state-of-art biotechnology and refine the processes used in existing ones, taking into account of complex technical, economic and environmental factors. Given the economic importance and ongoing challenges of biotech sector, multidisciplinary engineering technologies is poised to become an increasingly important tool along with the emergence of modern technology and innovation. This article reviews recent technology advancement in the field of fermentation using Saccharomyces cerevisiae. Interesting research progress has been made by leveraging multiple engineering fields such as electrical engineering, information engineering, electrochemical engineering and new material development, leading to recent development of novel real-time probes (electronic nose technology, analysis of yeast morphology and metabolites, timely control of glucose feed), improved understanding of electro-fermentation (enhanced electronic transfer provision), as well as application of cost-effective and sustainable materials (bioreactor vessel manufactured from textile, and yeast immobilisation support matrix made from abundant natural biomass). To the best of our knowledge, the subject is reviewed for the first time in recent years. Furthermore, this review also constitutes a futuristic S. cerevisiae fermentation process based on the recent advancement discussed.

Non-invasive morphological characterization of cellular loofa sponges using digital microscopy and micro-CT

Loofa sponge is a naturally-grown and decomposable material providing high specific surface area and high porosity for potential application as an environmentally-friendly catalyst carrier. In this work, cellular samples of various loofa types cut from different fiber network regions of the fruits were studied in detail using non-invasive imaging techniques. Digital microscopy was applied to characterize the cellular fiber network, which revealed a honeycomb structure in the core region and a sandwich structure in the wall region. Furthermore, reconstructed three-dimensional (3D) morphological images of the loofa samples obtained via micro-tomography (micro-CT) were utilized to extract the geometrical properties cell size, window diameter and strut thickness as well as porosity and volume-specific surface area. The reconstructed loofa samples revealed porosities of about 92% and specific surface areas up to 2057 m2/m3. In addition, the geometrical properties of manufactured solid foams (ceramic and polyurethane) were also determined via micro-CT and compared with loofa sponge. Finally, the different characteristic cell dimensions were employed to predict the porosity and specific surface area with available geometrical correlations. Deviations between correlation and measurement data (±16%) can be attributed to the peculiarity of the loofa cellular fiber network, which is somewhat different from the tetradecahedral-shaped geometry commonly used as the basis for most of the available correlations.

Facile fabrication of Luffa cylindrica-assisted 3D hydroxyapatite scaffolds

The incidence of bone-related disorders is abruptly increasing worldwide, and the current therapies available are not sufficient to fulfill the growing demands of patients. Porous three-dimensional (3D) structures cast in combination with ceramics and polymers, with an intention to mimic native bone tissues, are gaining importance because of their better physicochemical and biological activities. The purpose of this study is to prepare a porous scaffold using Luffa cylindrica (LC) as a template coated with hydroxyapatite and gelatin. Guar gum (GG) was used as a binder, and hydroxyapatite powder was added to slurry of 10% gelatin and 1% GG in which pieces of LC were dipped followed by sintering at 900°C. The fabricated scaffolds (LC-GG) were analyzed by using different characterization techniques along with evaluation of porosity and water retention ability. The results revealed that the as-formed scaffolds have 70% porosity with more than 90% water retention ability. The degree of spreading of lymphocytes over the scaffold surface was less in comparison with that of the control, which showed the immunocompatibility of the fabricated scaffold. Based on the aforementioned findings, it is assumed that the synthesized porous structures can suitably be used for biomedical applications.

Fungal remediation of Cd(ii) from wastewater using immobilization techniques

The pollution of wastewater by heavy metal ions is hazardous to the environment and human health. Cd(ii) has been recognized as one of the heavy metals that causes severe toxic effects. The present study is aimed at removing Cd(ii) from wastewater using fungal biomass either immobilized on loofa sponges or in Ca-alginate beads. Two fungal species were isolated from pools of Cd(ii)-polluted wastewater obtained from some Egyptian industrial plants, and using internal transcribed spacer (ITS) primers, they were molecularly identified as Penicillium chrysogenum and Cephalotheca foveolata with accession numbers MT664773 and MT664745, respectively. The sorbents used in this study were heat-inactivated mycelia of P. chrysogenum (PEN), heat-inactivated mycelia of C. foveolata (CEP), P. chrysogenum immobilized on loofa sponge (PEN-ILS), C. foveolata immobilized on loofa sponge (CEP-ILS), P. chrysogenum immobilized in Ca-alginate beads (PEN-IA), and C. foveolata immobilized in Ca-alginate beads (CEP-IA). The effects of pH, contact time, initial Cd(ii) concentration, and interfering ions on Cd(ii) removal from aqueous solution were tested. Maximum Cd(ii) sorption capacity was obtained at pH 7.0, with thirty minutes contact time and 0.5 mol l⁻¹ initial Cd(ii) concentration for all sorbents used. However, Ca²⁺ displayed synergistic interference with Cd(ii) that was greater than that from Na⁺ and K⁺, with decreasing sorption capacity for all sorbents. Optimum conditions were applied to real wastewater samples collected from two Egyptian industrial plants. All sorbents had the ability to remove Cd(ii) from wastewater samples, and enhanced removal occurred when fungal cells were immobilized as compared to free cells.

The pollution of wastewater by heavy metal ions is hazardous to the environment and human health.

Adsorption-Degradation of Polycyclic Aromatic Hydrocarbons in Soil by Immobilized Mixed Bacteria and Its Effect on Microbial Communities

The combined action of biosorption and biodegradation can achieve a remarkable reduction of organic pollutants. In this study, Pseudomonas sp. SDR4 and Mortierella alpina JDR7 were selected as the representative microorganisms to investigate adsorption and degradation of polycyclic aromatic hydrocarbons (PAHs) in soil using immobilization technology and the subsequent change of the microbial community structure. The results showed that the adsorption capacity of immobilized carriers was much higher than that of dead microorganisms and that the addition of dead microorganisms did not affect the adsorption characteristics of immobilized carriers. The chemical reaction was the major factor controlling the adsorption rate of PAHs in sterilized soil (CK), nonsterilized soil (CK-1), and soil amended with dead body immobilized JDR7 and SDR4 mixed bacteria (MB-D). The growth and metabolism of Pseudomonas sp. SDR4 and M. alpina JDR7 are the main reason for enhanced PAH degradation in the soil amended with living body immobilized JDR7, SDR4 mixed bacteria (MB).

Sequencing, assembly, annotation, and gene expression: novel insights into browning-resistant Luffa cylindrica

Luffa is a kind of melon crop widely cultivated in temperate regions worldwide. Browning is one of the serious factors affecting the quality of Luffa. Therefore, the molecular mechanism of Luffa browning is of great significance to study. However, the molecular diversity of Luffa cultivars with different browning-resistant abilities has not been well elucidated. In our study, we used high-throughput sequencing to determine the transcriptome of two Luffa cylindrica cultivars '2D-2' and '35D-7'. A total of 115,099 unigenes were clustered, of which 22,607 were differentially expression genes (DEGs). Of these DEGs, 65 encoding polyphenol oxidase, peroxidase, or ascorbate peroxidase were further analyzed. The quantitative real-time PCR (RT-qPCR) data indicated that the expression levels of the LcPPO gene (Accession No.: Cluster-21832.13892) was significantly higher in '35D-7' compared with that in '2D-2'. Several POD genes (Accession No.: Cluster-21832.19847, Cluster-21832.30619 and Cluster-48491.2) were also upregulated. Analysis of the plantTFDB database indicated that some transcription factors such as WRKY gene family may also participate in the regulation of Luffa browning. The results indicated that the divergence of genes expression related to enzymatic reaction may lead to the different browning resistances of Luffa. Our study will provide a theoretical basis for breeding of browning-resistant Luffa.

Efficacy of Gamma-Irradiated Macroporous Microbial Biomat for Lead Removal: A Proposed Application to Aquacultures

Lead mobilization in aquaculture and its generated health hazards prompted the use of a cheap and reusable method for its removal within a short duration. A 3D macroporous microbial biomat formed of Trichoderma viride immobilized on luffah was used for Pb removal. The biomat was used to remove 79% of initial 400 mg/kg Pb in 24 h that increased to 87% under optimized conditions of pH, temperature, and contact time. In order to reduce the time needed for Pb bioremoval to 1 h, pretreated biomats were used, resulting in an increase in removal from 58% to 96% upon exposure to gamma radiation (0.01 kilogray [kGy]). The irradiated biomat was studied in terms of morphology, elemental analysis of surface biosorbed Pb and surface functional groups using scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and Fourier transform infrared (FTIR) spectroscopy. The results show a difference in the adsorption pattern. The biomat was reused efficiently for 3 consecutive cycles and was also used in fixed bed column showing 89% removal for downward flow and in real aquaculture samples. Pretreated microbial biomats are very suitable for use in fixed bed reactors or as a biofilter and can be tested in recirculating aquaculture systems (RASs), thereby contributing to water conservation and aquaculture sustainability. Integr Environ Assess Manag 2020;16:508-516. © 2020 SETAC.

Modification of Luffa Sponge for Enrichment of Phosphopeptides

The enrichment technique is crucial to the comprehensive analysis of protein phosphorylation. In this work, a facile, green and efficient synthetic method was set up for quaternization of luffa sponge. The resultant luffa sponge showed strong anion-exchange characteristics and a high adsorption ability for phosphate ions. Along with the unique physical properties, e.g., tenacity and porous texture, quaternized luffa sponge was demonstrated to be a well-suited solid-phase extraction (SPE) material. The quaternized luffa sponge-based SPE method was simple, cost-effective and convenient in operation, and was successfully applied to the capture of phosphopeptides from protein digests. The enrichment approach exhibited exceptionally high selectivity, sensitivity and strong anti-interference ability. Four phosphopeptides were still detected by using the digest mixture of β-casein and bovine serum albumin with a molar ratio of 1:100. 21 phosphopeptides were identified from the tryptic digest of non-fat milk.

Properties of Luffa Fiber Reinforced PHBV Biodegradable Composites

In this study, composites of poly (hydroxybutyrate-co-valerate) (PHBV) with untreated luffa fibers (ULF) and NaOH-H₂O₂ treated luffa fibers (TLF) were prepared by hot press forming. The properties of luffa fibers (LFs) and composites were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and other analysis methods. Results showed that pre-treatment effectively removed pectin, hemicellulose, and lignin, thus reducing the moisture absorptivity of LFs. The flexural strength of TLF/PHBV was higher than that of ULF/PHBV. With 60% LF content, the flexural strengths of ULF/PHBV and TLF/PHBV reached 75.23 MPa and 90.73 MPa, respectively, 219.7% and 285.6% more than that of pure PHBV. Water absorptivities of composites increased with increase in LF content. Water absorptivity of TLF/PHBV was lower than that of ULF/PHBV. The flexural strengths of composites decreased after immersion in water at room temperature. Meanwhile, flexural strength of TLF/PHBV was lower than that of ULF/PHBV. Pretreatment of LFs effectively improved the bonding between fibers and PHBV, resulting in enhanced and thus improved the moisture resistance of composites.

Facile synthesis of porous Mo2C/C composites by using luffa sponge-derived carbon template in molten salt media

Herein, we report the synthesis of a new type of porous Mo2C/C composite by using luffa sponge-derived carbon template and ammonium molybdate ((NH4)6Mo7O24•4H2O) in molten NaCl-KCl salt media. The product exhibits a higher specific surface area and three-dimensional porous structure, including macrochannels, micropores and mesopores. The desirable porous structure results from the carbon template structure and Mo2C coating formed.

Study on new artificial floating island removing pollutants

In this study, two types of artificial floating islands (AFIs), group A (consists of 1# and 2# traditional AFIs with plant and soil) and group B (consists of 4# and 5# new-type AFIs with plant, substrate, and with luffa sponge and corncob hanging at the bottom), were constructed, respectively. The removal effects and degradation mechanisms of luffa sponge and corncob in group B were compared and investigated. Plant height, root growth, and packing degradation of the two types of AFIs were studied. Temperature, dissolved oxygen (DO), and pH on the decontamination effects of AFI were discussed. The results showed that group A and group B AFIs showed great significant differences in removal of COD_Cr, TN, NO₃^--N, NH₄⁺-N, and TP (p < 0.05). The TP removal of group B was 92.8 ± 0.6%, and the TN removal and NO₃^--N removal were significantly higher than that of group A, which was 90.3 ± 0.8% and 96.0 ± 2.2%, respectively; The addition of luffa sponge and corncob could enhance the biodegradability of sewage and the nitrogen and phosphorus removal efficiency of group B. The plant growth height of group B planted with Lythrum salicaria was 2.36 times higher than that of group A. The effect of temperature on TP was significantly greater than that of TN, and both groups of AFIs presented continuous improvement capacities of TN and TP removal when the temperature was above 15 °C. Group B was observed with a lower pH range of 6.69~7.12, which was more suitable for denitrification than group A. The release of carbon source of 5#-corncob AFI was 2.51 times higher than 4#-luffa sponge AFI at the end of the experiment.

Immobilized Cells of Bacillus circulans ATCC 21783 on Palm Curtain for Fermentation in 5 L Fermentation Tanks

Palm curtain was selected as carrier to immobilize Bacillus circulans ATCC 21783 to produce β-cyclodextrin (β-CD). The influence for immobilization to CGTase activity was analyzed to determine the operation stability. 83.5% cyclodextrin glycosyltransferases (CGTase) of the 1st cycle could be produced in the 7th cycle for immobilized cells, while only 28.90% CGTase was produced with free cells. When palm curtain immobilized cells were reused at the 2th cycle, enzyme activities were increased from 5003 to 5132 U/mL, which was mainly due to physical adsorption of cells on palm curtain with special concave surface structure. Furthermore, conditions for expanded culture of immobilized cells in a 5 L fermentation tank were optimized through specific rotation speed procedure (from 350 r/min to 450 r/min with step size of 50 r/min) and fixed ventilation capacity (4.5 L/min), relations between biomass, enzyme activity, pH, and oxygen dissolution was investigated, and the fermentation periods under the two conditions were both 4 h shorter. Compared with free cell, immobilized cell was more stable, effective, and had better application potential in industries.

Properties of Two-Variety Natural Luffa Sponge Columns as Potential Mattress Filling Materials

Luffa sponge (LS) is a resourceful material with fibro-vascular reticulated structure and extremely high porosity, which make it a potential candidate for manufacturing light mattress. In this study, two types of LS columns, namely high-density (HD) and low-density (LD) columns, were investigated as materials for filling the mattress. The results showed that the compressive strength of HD LS columns was significantly greater than that of LD LS columns. However, the densification strains of the two types of LS column were both in the range of 0.6 to 0.7. Besides, HD LS columns separately pressed to the smooth plateau region and the initial densification region exhibited a partial recovery of instant height when they were unloaded, and then both of them showed no more than 4.2% of height recovery after being allowed to rest at a constant temperature and humidity for 24 h. In contrast, when LD LS columns were compressed to the smooth plateau region, the height recovery was less than 1.62% compared to when they were pressed to the initial densification region, and that was more than 15.62%. Similar to other plant fibers used as mattress fillers, the two types of LS columns also showed good water absorption capacity—both of them could absorb water from as much as 2.07 to 3.45 times their own weight. At the same time, the two types of LS columns also showed good water desorption. The water desorption ratio of HD and LD LS columns separately reached 76.86 and 91.44%, respectively, after being let rest at a constant temperature and humidity for 13 h.

Production of a halotolerant biofilm from green coffee beans immobilized on loofah fiber (Luffa cylindrica) and its effect on phenanthrene degradation in seawater

A biofilm developed from low quality green coffee beans was tested for its capacity to degrade the polynuclear aromatic hydrocarbon (PAH), phenanthrene (Phe), in seawater. Microorganisms were immobilized on two types of Luffa cylindrica (with three and four placental cavities), and the effects of moisture content (20, 30 and 40% of water holding capacity) and particle size (<0.42 mm, 0.42-0.86 mm and 0.86-2.0 mm) of green coffee beans on microbial activity were considered. Biofilm growth determined by respirometry showed a highest microbial activity at a moisture content of 40% and particle size of 0.42-0.86 mm. The loofah fiber with three placental cavities showed the highest adherence of microorganisms. The kinetics of microbial growth in both seawater and distilled water and the scanning electron microscopies indicated that the microorganisms associated with green coffee beans are halotolerant. In fact, I-GCB-SW-G biofilm degraded 67.56% of Phe (50 mg L^-1) in seawater, at a significantly higher rate than in distilled water (I-GCB-DW-W).

In-Depth Analysis of the Structure and Properties of Two Varieties of Natural Luffa Sponge Fibers

The advancement in science and technology has led to luffa sponge (LS) being widely used as a natural material in industrial application because of its polyporous structure and light texture. To enhance the utility of LS fibers as the reinforcement of lightweight composite materials, the current study investigates their water absorption, mechanical properties, anatomical characteristics and thermal performance. Hence, moisture regain and tensile properties of LS fiber bundles were measured in accordance with American Society for Testing and Materials (ASTM) standards while their structural characteristics were investigated via microscopic observation. Scanning electron microscopy (SEM) was used to observe the surface morphology and fractured surface of fiber bundles. The test results show that the special structure where the phloem tissues degenerate to cavities had a significant influence on the mechanical properties of LS fiber bundles. Additionally, the transverse sectional area occupied by fibers in a fiber bundle (S_F), wall thickness, ratio of wall to lumen of fiber cell, and crystallinity of cellulose had substantial impact on the mechanical properties of LS fiber bundles. Furthermore, the density of fiber bundles of LS ranged within 385.46–468.70 kg/m³, significantly less than that of jute (1360.40 kg/m³) and Arenga engleri (950.20 kg/m³). However, LS fiber bundles demonstrated superior specific modulus than Arenga engleri.