Bacterial nanocellulose-clay film as an eco-friendly sorbent for superior pollutants removal from aqueous solutions.

The persistent water treatment and separation challenge necessitates innovative and sustainable advances to tackle conventional and emerging contaminants in the aquatic environment effectively. Therefore, a unique three-dimensional (3D) network composite film (BNC-KC) comprised of bacterial nanocellulose (BNC) incorporated nano-kaolinite clay particles (KC) was successfully synthesized via an in-situ approach. The microscopic characterization of BNC-KC revealed an effective integration of KC within the 3D matrix of BNC. The investigated mechanical properties of BNC-KC demonstrated a better performance compared to BNC. Thereafter, the sorption performance of BNC-KC films towards basic blue 9 dye (Bb9) and norfloxacin (NFX) antibiotic from water was investigated. The maximum sorption capacities of BNC-KC for Bb9 and NFX were 127.64 and 101.68 mg/g, respectively. Mechanistic studies showed that electrostatic interactions, multi-layered sorption, and 3D structure are pivotal in the NFX/Bb9 sorption process. The intricate architecture of BNC-KC effectively traps molecules within the interlayer spaces, significantly increasing sorption efficiency. The distinctive structural configuration of BNC-KC films effectively addressed the challenges of post-water treatment separation while concurrently mitigating waste generation. The environmental evaluation, engineering, and economic feasibility of BNC-KC are also discussed. The cost estimation assessment of BNC-KC revealed the potential to remove NFX and Bb9 from water at an economically viable cost.

In situ shaping of intricated 3D bacterial cellulose constructs using sacrificial agarose and diverted oxygen inflow.

Bacterial cellulose (BC) is gathering increased attention due to its remarkable physico-chemical features. The high biocompatibility, hydrophilicity, and mechanical and thermal stability endorse BC as a suitable candidate for biomedical applications. Nonetheless, exploiting BC for tissue regeneration demands three-dimensional, intricately shaped implants, a highly ambitious endeavor. This challenge is addressed here by growing BC within a sacrificial viscoelastic medium consisting of an agarose gel cast inside polydimethylsiloxane (PDMS) molds imprinted with the features of the desired implant. BC produced with and without agarose has been compared through SEM, TGA, FTIR, and XRD, probing the mild impact of the agarose on the BC properties. As a first proof of concept, a PDMS mold shaped as a doll's ear was used to produce a BC perfect replica, even for the smallest features. The second trial comprised a doll face imprinted on a PDMS mold. In that case, the BC production included consecutive deactivation and activation of the aerial oxygen stream. The resulting BC face clone fitted perfectly and conformally with the template doll face, while its rheological properties were comparable to those of collagen. This streamlining concept conveys to the biosynthesized nanocelluloses broader opportunities for more advanced prosthetics and soft tissue engineering uses.

Photon upconversion crystals doped bacterial cellulose composite films as recyclable photonic bioplastics.

Biopolymers currently utilized as substitutes for synthetic polymers in photonics applications are predominantly confined to linear optical color responses. Herein we expand their applications in non-linear optics by integrating with triplet-triplet annihilation photon upconversion crystals. A photon upconverting biomaterial is prepared by cultivating Pd(II) meso-tetraphenyl tetrabenzoporphine: 9,10-diphenyl anthracene (sensitizer: annihilator) crystals on bacterial cellulose hydrogel that serves both as host and template for the crystallization of photon upconversion chromophores. Coating with gelatin improves the material's optical transparency by adjusting the refractive indices. The prepared material shows an upconversion of 633 nm red light to 443 nm blue light, indicated by quadratic to linear dependence on excitation power density (non-linearly). Notably, components of this material are physically dis-assembled to retrieve 66 ± 1% of annihilator, at the end of life. Whereas, the residual clean biomass is subjected to biodegradation, showcasing the sustainability of the developed photonics material.

A turning point in the bacterial nanocellulose production employing low doses of gamma radiation.

In the recent years, huge efforts have been conducted to conceive a cost-effective production process of the bacterial nanocellulose (BNC), thanks to its marvelous properties and broadening applications. Herein, we unveiled the impact of gamma irradiation on the BNC yield by a novel bacterial strain Komagataeibacter hansenii KO28 which was exposed to different irradiation doses via a designed scheme, where the productivity and the structural properties of the BNC were inspected. After incubation for 240 h, the highest BNC yield was perceived from the culture treated twice with 0.5 kGy, recording about 475% higher than the control culture. Furthermore, almost 92% of its BNC yield emerged in the first six days. The physicochemical characteristics of the BNCs were investigated adopting scanning electron microscope (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Fourier transform infrared (FTIR). Additionally, the water holding capacity, water release rate, surface area (BET), and mechanical properties were configured for the BNC generated from the control and the irradiated cultures. As a whole, there were no significant variations in the properties of the BNC produced by the irradiated cultures versus the control, proposing the strain irradiation as a valuable, facile, and cheap route to augment the BNC yield.

Assessment of antimicrobial, cytotoxicity, and antiviral impact of a green zinc oxide/activated carbon nanocomposite.

This work deals with the synthesis of zinc oxide nanoparticles/activated carbon (ZnO NPs/AC) nanocomposites with different weight ratios (3:1, 1:1, and 1:3), where the antimicrobial, antiviral, and cytotoxicity impact of the formulated nanocomposites were evaluated versus the crude ZnO and AC samples. The formula (3:1; designated Z3C1) exhibited the utmost bactericidal effect against Gram positive group, unicellular and filamentous fungi. Regarding Gram negative group, the sample (Z3C1) was remarkably effective against Klebsiella pneumonia, unlike the case of Escherichia coli. Moreover, the whole samples showed negligible cytotoxicity against the human WI38 cell line, where the most brutality (4%) was exerted by 1000 µg/mL of the formula (Z1C3). Whilst, the formula (Z3C1) exerted the apical inhibition impact against Herpes simplex (HSV1) virus. Consequently, the synthesized (Z3C1) nanocomposite was sorted out to be fully characterized via different physicochemical techniques including FTIR, XRD, SEM, TEM, Zeta potential, TGA, and BET. XRD indicated a predominance of the crystalline pattern of ZnO NPs over the amorphous AC, while the FTIR chart confirmed an immense combination between the ZnO NPs and AC. SEM, TEM, and size distribution images illustrated that the fabricated ZnO NPs/AC was in the nanoscale size swung from 30 to 70 nm. The distinctive surface area of composite material, recording 66.27 m2/g, clearly disclosed its bioactivity toward different bacterial, fungal, and virus species.

Optimization, purification, and biochemical characterization of thermoalkaliphilic lipase from a novel Geobacillus stearothermophilus FMR12 for detergent formulations.

This study was aimed to produce a high compatible thermoalkaliphilic lipase (TA) with detergents from new thermophilic bacterial strains utilizing fish wastes for industrial application. Among bacterial isolates, a new Geobacillus stearothermophilus FMR12 efficiently utilized fish wastes at a concentration of 20% (w/v), exhibiting highly lipolytic activity at extreme thermal and alkaline pH conditions. Optimized fermentation parameters of TA lipase production were ascertained, promoting the productivity of the TA lipase from 424 to 1038 U/ml. Purification results of TA lipase exposed prominent specific activity of 4788 U/mg, purification fold of 12.44, and 7.8% yield. The purified TA lipase demonstrated outstanding activity and stability in a temperature range of 40-95 °C and pH (4-11), revealing optimal activity at 70 °C and pH 9. The molecular weight of the enzyme was estimated to be 63 kDa. Compared to control, the TA lipase activity was promoted in the presence of calcium chloride. Likewise, Triton X-100 enhanced the activity of the TA lipase, recording 128% of the control enzyme. Interestingly, the TA lipase conserved higher than 90% of its activity after blending with commercial detergents, emphasizing its competence for detergent formulations.

Comprehensive insights into microbial keratinases and their implication in various biotechnological and industrial sectors: A review.

Enormous masses of keratinous wastes are annually accumulated in the environment as byproducts of poultry processing and agricultural wastes. Keratin is a recalcitrant fibrous protein, which represents the major constituent of various keratin-rich wastes, which released into the environment in the form of feathers, hair, wool, bristle, and hooves. Chemical treatment methods of these wastes resulted in developing many hazardous gases and toxins to the public health, in addition to the destruction of several amino acids. Accordingly, microbial keratinases have been drawing much interest as an eco-friendly approach to convert keratinous wastes into valuable products. Numerous keratinolytic microorganisms have been identified, which revealed the competence to hydrolyze keratins into peptides and amino acids. Several types of keratinolytic proteases have been produced that possess diverse biochemical characteristics, conferring them the versatility for implementing in multifarious applications such as detergents, leather and textile industries, animal feeding, and production of bio-fertilizers, in addition to medical and pharmaceutical treatments. This review article emphasizes the significance of keratinases and keratinase based-products via comprehensive insights into the keratin structure, diversity of keratinolytic microorganisms, and mechanisms of keratin hydrolysis. Furthermore, we discuss the biochemical properties of the produced keratinases and their feasible applications in diverse disciplines.

Bacterial nanocellulose from agro-industrial wastes: low-cost and enhanced production by Komagataeibacter saccharivorans MD1.

Bacterial nanocellulose (BNC) has been drawing enormous attention because of its versatile properties. Herein, we shed light on the BNC production by a novel bacterial isolate (MD1) utilizing various agro-industrial wastes. Using 16S rRNA nucleotide sequences, the isolate was identified as Komagataeibacter saccharivorans MD1. For the first time, BNC synthesis by K. saccharivorans MD1 was investigated utilizing wastes of palm date, fig, and sugarcane molasses along with glucose on the Hestrin-Schramm (HS) medium as a control. After incubation for 168 h, the highest BNC yield was perceived on the molasses medium recording 3.9 g/L with an initial concentration of (v/v) 10%. The physicochemical characteristics of the BNC sheets were inspected adopting field-emission scanning electron microscope (FESEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) analysis. The FESEM characterization revealed no impact of the wastes on either fiber diameter or the branching scheme, whereas the AFM depicted a BNC film with minimal roughness was generated using date wastes. Furthermore, a high crystallinity index was estimated by XRD up to 94% for the date wastes-derived BNC, while the FTIR analyses exhibited very similar profiles for all BNC films. Additionally, mechanical characteristics and water holding capacity of the produced BNCs were studied. Our findings substantiated that expensive substrates could be exchanged by agro-industrial wastes for BNC production conserving its remarkable physical and microstructural properties.

Farming thermoelectric paper.

Waste heat to electricity conversion using thermoelectric generators is emerging as a key technology in the forthcoming energy scenario. Carbon-based composites could unleash the as yet untapped potential of thermoelectricity by combining the low cost, easy processability, and low thermal conductivity of biopolymers with the mechanical strength and good electrical properties of carbon nanotubes (CNTs). Here we use bacteria in environmentally friendly aqueous media to grow large area bacterial nanocellulose (BC) films with an embedded highly dispersed CNT network. The thick films (≈10 µm) exhibit tuneable transparency and colour, as well as low thermal and high electrical conductivity. Moreover, they are fully bendable, can conformally wrap around heat sources and are stable above 500 K, which expands the range of potential uses compared to typical conducting polymers and composites. The high porosity of the material facilitates effective n-type doping, enabling the fabrication of a thermoelectric module from farmed thermoelectric paper. Because of vertical phase separation of the CNTs in the BC composite, the grown films at the same time serve as both the active layer and separating layer, insulating each thermoelectric leg from the adjacent ones. Last but not least, the BC can be enzymatically decomposed, completely reclaiming the embedded CNTs.

Production of Thermoalkaliphilic Lipase from Geobacillus thermoleovorans DA2 and Application in Leather Industry.

Thermophilic and alkaliphilic lipases are meeting a growing global attention as their increased importance in several industrial fields. Over 23 bacterial strains, novel strain with high lipolytic activity was isolated from Southern Sinai, Egypt, and it was identified as Geobacillus thermoleovorans DA2 using 16S rRNA as well as morphological and biochemical features. The lipase was produced in presence of fatty restaurant wastes as an inducing substrate. The optimized conditions for lipase production were recorded to be temperature 60°C, pH 10, and incubation time for 48 hrs. Enzymatic production increased when the organism was grown in a medium containing galactose as carbon source and ammonium phosphate as nitrogen source at concentrations of 1 and 0.5% (w/v), respectively. Moreover, the optimum conditions for lipase production such as substrate concentration, inoculum size, and agitation rate were found to be 10% (w/v), 4% (v/v), and 120 rpm, respectively. The TA lipase with Triton X-100 had the best degreasing agent by lowering the total lipid content to 2.6% as compared to kerosene (7.5%) or the sole crude enzyme (8.9%). It can be concluded that the chemical leather process can be substituted with TA lipase for boosting the quality of leather and reducing the environmental hazards.