Chromium (VI) ion adsorption features of chitosan film and its chitosan/zeolite conjugate 13X film

This research evaluated the importance of the adsorption properties of chitosan a chitosan/zeolite conjugate film for the removal of Cr(VI) ions from solutions in the 5–260 mg/L concentration range, when the pH was adjusted to 4.0 and 6.0. The uptake capacities of the films formed by chitosan and by the chitosan/zeolite conjugate were calculated by mass balance. The equilibrium isotherms were fitted to the Langmuir, Freundlich and Redlich-Peterson models. The chitosan film seems to be a good sorbent for Cr(VI) at pH 4, but its physical instability suggests the need for a more resilient support. Due to this fact zeolite was added to the chitosan matrix in solution and a chitosan/zeolite (CS/Zeo) film was thus formed. The solubility of the film and the characterization of the different matrices by FTIR, TGA and X-Ray showed that a cross-linked structure was formed between the chitosan and zeolite and the solubility of the film increased. In this study, the low manufacturing cost of the CS/Zeo matrix, the good uptake of Cr(VI) at acidic pH (17.28 mg/g) and the non desorption of Cr(VI) from the film in water suggests this combination should be tested in industrial environment.The authors are grateful for the Coordination of Improvement of Higher Education Personnel (CAPES - Brazil) for PhD fellowship and the financial support received from Financier of Studies and Projects (FINEP - Brazil), National Council for Scientific and Technological Development (CNPq - Brazil), Catholic University of Pernambuco (UNICAP - Brazil), University of Minho (UMINHO - Portugal). They also acknowledge Antonio Soares Vicente (UMINHO - Portugal) who kindly supplied the chitosan

Evaluation antimicrobial and antiadhesive properties of the biosurfactant lunasan produced by Candida sphaerica UCP 0995

Abstract Different groups of biosurfactants exhibit diverse properties and display a variety of physiological functions in producer microorganisms; these include enhancing the solubility of hydrophobic/water-insoluble compound, heave metal binding, bacterial pathogenesis, cell adhesion and aggregation, quorum sensing and biofilm formation. Candida sphaerica was grown in a low cost medium, consisting of distilled water supplemented with 9% refinery residue of soybean oil and 9% corn steep liquor, for 144 h at 28°C and 150 rpm. The cell-free supernatant obtained at the end of the experiments was submitted to extraction, and afterward the biosurfactant was isolated using methanol with a yield of 9 g l -1 . The critical micelle concentration of the biosurfactant was found to be 0.25 mg ml -1 with a surface tension of 25 mN m -1 . Several concentrations of the biosurfactant (0.625-10 mg ml -1 ) were used to evaluate its antimicrobial and antiadhesive activities against a variety of microorganisms. The biosurfactant showed antimicrobial activity against Streptococcus oralis (68%), Candida albicans (57%), and Staphylococcus epidermidis(57.6%) for the highest concentration tested. Furthermore, the biosurfactant at a concentration of 10 mg ml -1 inhibited the adhesion between 80 and 92% of Pseudomonas aeruginosa, Streptococcus agalactiae, Streptococcus sanguis12. Inhibition of adhesion with percentages near 100% occurred for the higher concentrations of biosurfactant used. Results gathered in this study point to a potential use of the biosurfactant in biomedical applications

Rhizopus arrhizus ucp1295 como fonte econômica para produção de biopolímeros funcionais quitina e quitosana utilizando substratos renováveis / Rhizopus arrhizus ucp1295 as economic source for production of functional biopolymers chitin and chitosan using renewable substrates

Neste trabalho foi investigada a produção de quitina e quitosana por Rhizopus arrhizus UCP 1295 isolado do solo da Caatinga do Estado de Pernambuco, Brasil, utilizando o efluente industrial de doces e milhocina como substratos de baixo custo, considerando a versatilidade de aplicação das biomoléculas. O micro-organismo foi cultivado em diferentes concentrações dos substratos efluente da indústria de doces e milhocina (CSL) em diferentes valores de pH, de acordo com um planejamento fatorial completo 23. Após 96 h de fermentação, a biomassa produzida foi liofilizada e submetida ao tratamento com álcali- ácido-. Os polissacarídeos extraídos foram caracterizados por espectroscopia por transformada de Fourier (FTIR) na região do infravermelho. A maior produção de biomassa (14,11 g/L) foi obtida na condição 6 (8% de efluente industrial de doces, 5% de milhocina e pH 5), enquanto os maiores rendimentos de quitina (169,3 mg/g) e quitosana (239,1 mg/g) foram obtidos em meio contendo 4% de efluente da indústria de doces, sem milhocina, nas condições 3 (pH 7) e 1 (pH 5), respectivamente. A quitina apresentou grau de acetilação de 71,4% e a quitosana de 86,0%, de desacetilação, respectivamente. Além disso, foi demonstrado que o efluente industrial de balas e milhocina são substratos renováveis e alternativos na formulação de novos meios de produção de quitina e quitosana. A versatilidade das biomoléculas deve-se as suas propriedades bioquímicas únicas, como biocompatibilidade, biodegradabilidade, não toxicidade, capacidade de formar filmes e aplicações industriais promissoras

Eco-Friendly Chitosan Production by Syncephalastrum racemosum and Application to the Removal of Acid Orange 7 (AO7) from Wastewaters

Due to the existence of new methodologies that have reduced the production costs of microbiological chitosan, this paper puts forward the use of agro-industrial residues in order to produce microbiological chitosan and to apply chitosan as an innovative resource for removing acid orange 7 (AO7) from wastewaters. The best culture conditions were selected by a full 24 factorial design, and the removal of the dye was optimized by a 23 central composite rotational design. The results showed that corn steep liquor (CSL) is an agro-industrial residue that can be advantageously used to produce microbiological chitosan with yields up to 7.8 g/kg of substrate. FT-IR spectra of the product showed typical peak distributions like those of standard chitosan which confirmed the extracted product was chitosan-like. The efficiency of removing low concentrations of AO7 by using microbiological chitosan in distilled water (up to 89.96%) and tap water (up to 80.60%) was significantly higher than the efficiency of the control (chitosan obtained from crustaceans), suggesting that this biopolymer is a better economic alternative for discoloring wastewater where a low concentration of the dye is considered toxic. The high percentage recovery of AO7 from the microbiological chitosan particles used favors this biopolymer as a possible bleaching agent which may be reusable

Microbial Enhance of Chitosan Production by Rhizopus arrhizus Using Agroindustrial Substrates

molecule

Produção e purificação parcial de PPD-maleína para diagnóstico do mormo em equídeos

Objetivou-se com este estudo produzir e purificar parcialmente a PPD-maleína a partir de amostras de Burkholderia mallei isoladas de equídeos no Brasil com potencial para uso no diagnóstico do mormo. As linhagens de B. mallei fenotipicamente caracterizadas e de virulência comprovada foram inoculadas em caldo Dorset-Henley para crescer e metabolizar. Em seguida, as proteínas foram separadas por precipitação com ácido tricloroacético e precipitadas com sulfato de amônia. As PPDs-maleínas foram concentradas em 1,0mg/mL e na avaliação realizada em cobaios foi eficaz no desenvolvimento da hipersensibilidade do tipo tardia e consequentemente na identificação de animais verdadeiro positivos e exclusão dos verdadeiro negativos, sendo uma possibilidade em potencial para utilização no diagnóstico do mormo

Sustainable biosurfactant produced by Serratia marcescens UCP 1549 and its suitability for agricultural and marine bioremediation applications

Abstract Background Biosurfactants are surface-active agents produced by microorganisms that have higher efficiency and stability, lower toxicity and higher biocompatibility and biodegradability than chemical surfactants. Despite its properties and potential application in a wide range of environmental and industrial processes, biosurfactants are still not cost-competitive when compared to their synthetic counterparts. Cost effective technologies and renewable raw substrates as agro-industrial and regional waste from northeast of Brazil as cassava flour wastewater, supplemented with lactose and corn oil are mainly the chemically media for growing microorganism and in turn the production of the biosurfactant of quality. This study aimed to obtained biosurfactant by Serratia marcescens UCP 1549 containing cassava flour wastewater (CWW), by application of a full-factorial design, as sustainable practices in puts the production process in promising formulation medium. The characterization of the biomolecule was carried out, as well as the determination of its stability and toxicity for cabbage seeds. In addition, its ability to stimulate seed germination for agriculture application and oil spill bioremediation were investigated. Results Serratia marcescens showed higher reduction of surface tension (25.92 mN/m) in the new medium containing 0.2% lactose, 6% cassava flour wastewater and 5% corn waste oil, after 72 h of fermentation at 28 °C and 150 rpm. The substrate cassava flour wastewater showed a promising source of nutrients for biosurfactant production. The isolate biosurfactant exhibited a CMC of 1.5% (w/v) and showed an anionic and polymeric structure, confirmed by infrared spectra. The biomolecule demonstrated high stability under different temperatures, salinity and pH values and non-toxicity against to cabbage seeds. Thus, exploring biosurfactant their potential role in seeds germinations and the promotion and agricultural applications was investigated. In addition, the effectiveness of biosurfactant for removal burned motor oil adsorbed in sand was verified. Conclusions The use of medium containing CWW not only reduces the cost of process of biosurfactant production, but also the environmental pollution due to the inappropriate disposal of this residue. This fact, added to the high stability and non-toxicity of the biosurfactant produced by S. marcescens UCP 1549, confirms its high environmental compatibility, make it a sustainable biocompound that can be replace chemical surfactants in diverse industries. In addition, the effectiveness of biosurfactant for stimulate seed germination and removing burned motor oil from sand, suggests its suitability for agriculture and bioremediation applications