Melanized-Cationic Cellulose Nanofiber Foams for Bioinspired Removal of Cationic Dyes.

In recent years, water pollution has developed into a severe environmental and public health problem due to rapid urbanization and industrialization, especially in some developing countries. Finding solutions to tackle water pollution is urgently required and is of global importance. Currently, a range of water treatment methods are available; however, a water remediation process that is simple, inexpensive, eco-friendly, and effective for the removal of pollutants down to ppm/ppb concentrations has long been sought after. Herein, we describe a novel approach using fungal melanin for developing melanized-cationic cellulose nanofiber (melanized-C-CNF) foams that can successfully remove pollutants in water systems. The foam can be recycled several times while retaining its adsorption/desorption property, indicating high practicability for adsorbing the cationic dye crystal violet. This work highlights the opportunity to combine both the advanced features of sustainable polymers such as cellulose and the unique properties of fungal melanin to manufacture biohybrid composites for water purification.

Microbial production of melanin and its various applications.

Melanins are natural biopolymers that are known to contribute to different biological processes and to protect organisms from adverse environmental conditions. During the past decade, melanins have attracted increasing attention for their use in organic semiconductors and bioelectronics, drug delivery, photoprotection and environmental bioremediation. Although considerable advances in these fields have been achieved, real-world applications of melanins are still scarce, probably due to the limited and expensive source of natural melanin. Nevertheless, recent biotechnological advances have allowed for relatively large-scale production of microbial melanins, which could replace current commercial melanin. In this review, we first describe different melanin sources and highlight the advantages and disadvantages of each production method. Our focus is on the microbial synthesis of melanins, including the methodology and mechanism of melanin formation. Applications of microbial melanins are also discussed, and an outlook on how to push the field forward is discussed.

Cocultivation of White-Rot Fungi and Microalgae in the Presence of Nanocellulose.

Cocultivation of fungi and algae can result in a mutualistic or antagonistic interaction depending on the species involved and the cultivation conditions. In this study, we investigated the growth behavior and enzymatic activity of two filamentous white-rot fungi (Trametes versicolor and Trametes pubescens) and two freshwater algae (Chlorella vulgaris and Scenedesmus vacuolatus) cocultured in the presence of TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical) oxidized cellulose nanofibrils (CNF) and cellulose nanocrystals (CNC). The growth of fungi and algae was studied in liquid, agar medium, and 3D-printed nanocellulose hydrogels. The results showed that cocultures grew faster under nutrient-rich conditions than in nutrient-depleted conditions. Key cellulose-degrading enzymes, including endoglucanase and laccase activities, were higher in liquid cocultures of T. versicolor and S. vacuolatus in the presence of cellulose compared to single cultures of fungi or algae. Although similar results were observed for cocultures of T. pubescens and C. vulgaris, laccase production diminished over time in these cultures. Fungi and algae were capable of growth in 3D-printed cellulose hydrogels. These results showed that cellulase enzyme production could be enhanced by cocultivating white-rot fungi with freshwater algae under nutrient-rich conditions with TEMPO-CNF and CNC. Additionally, the growth of white-rot fungi and freshwater algae in printed cellulose hydrogels demonstrates the potential use of fungi and algae in hydrogel systems for biotechnological applications, including biofuel production and bio-based fuel cell components. IMPORTANCE Depending on the conditions used to grow fungi and algae in the lab, they can interact in a mutually beneficial or negative way. These interactions could stimulate the organisms to produce enzymes in response to the interaction. We studied how wood decay fungi and freshwater algae grew in the presence and absence of cellulose, one of the basic building blocks of wood. How fungi and algae grew in 3D-printed cellulose hydrogels was also tested. Our results showed that fungi and algae partners produced significantly larger amounts of enzymes that degraded cellulose when grown with cellulose than when grown alone. In addition, fungi and algae were shown to grow in dense nanocellulose hydrogels and could survive the shear conditions during gel structuring while 3D-printing. These cultures could potentially be applied in the biotech industry for applications like energy production from cellulose, biofuel production, and bioremediation of cellulose material.

Infección por virus del papiloma humano: asociación entre infección genital y bucal / Infection with human papillomavirus: association between genital and oral infection

Identificar las características de la infección por VPH en la cavidad bucal asociada a la infección por VPH genital. En el Servicio de Ginecología Maternidad "Concepción Palacios". Caracas. Se estudiaron 60 pacientes con diagnóstico histológico de VPH genital a quienes se les realizó oroscopia, citología bucal y determinación viral por reacción en cadena de polimerasa (PCR) en boca y cérvix. Se aisló el genotipo viral en la cavidad bucal en 48,33 por ciento de las pacientes (29 / 60). Hubo concordancia entre la infección genital y bucal en 44,20 por ciento de los casos. Los genotipos aislados más frecuentes fueron el 6 (71,43 por ciento) y el 11 (22,86 por ciento), solos o en combinación; solo hubo un caso con genotipo 16 (2,86 por ciento). La concordancia entre el genotipo genital y bucal fue de 10,45 por ciento (P=0,1547), sin embargo, cuando el genotipo aislado fue 6 la concordancia fue de 75,86 por ciento. La citología de la cavidad bucal tuvo una sensibilidad de 3,5 por ciento y una especificidad de 93,6 por ciento. La oroscopia tuvo una sensiblidad de 27,6 por ciento y una especificidad de 74,2 por ciento. Es frecuente la asociación entre infección por VPH genital y bucal. Tanto la citología exfoliativa de la boca como la oroscopia, son métodos diagnósticos poco sensibles y específicos.

To describe the characteristics of HPV infection in the oral cavity associated with genital HPV infection. Service of Ginecology of the Maternidad "Concepcion Palacios". Caracas. 60 patients with histological diagnosis of genital HPV were studied with oroscopy, oral cytology and viral determination with polymerase chain reaction (PCR) in the mouth and in the cervix. Viral genotype was isolated in the oral cavity in 48.33 percent of patients (29/60). There was concordance between genital and oral infection in 44.20 percent of cases. Frequently isolated genotypes were 6 (71.43 percent) and 11 (22.86 percent), alone or in combination, there was only one case with genotype 16 (2.86 percent). The concordance between genital and oral genotype was 10.45 percent (p = 0.1547), but when isolated genotype was 6, the agreement was 75.86 percent. The cytology of the oral cavity had a sensitivity of 3.5 percent and a specificity of 93.6 percent. The oroscopy sensitivity was 27.6 percent and the specificity was 74.2 percent. It is often an association between genital and oral HPV infection. Both exfoliative cytology of the mouth and the oroscopy have low sensitivity and specificity as diagnostic methods.