Desulfurization of Dibenzothiophene by Pseudomonas fluorescens (UCP 1514) Leading to the Production of Biphenyl

Dibenzothiophene (DBT) is a typical recalcitrant thiophenic sulfur component of fuels, and its desulphurization has been a model reaction in the treatment of these compounds. Based on this information, the potential of Pseudomonas fluorescens (UCP 1514) on the desulfurization of dibenzothiphene was studied, in order to use it for reducing the sulfur content of diesel oil in compliance with environmental regulations. The result of biodegradation by the bacteria was determined by undertaking high-performance liquid chromatography of the metabolites produced. These can also be identified by gas chromatography with a mass spectrometry detector, and doing so revealed a sulfur-free product, biphenyl, as the final product of the degradation process. The results showed a decrease of 73% in dibenzothiophene content, which means that P. fluorescens removes sulfur from dibenzothiophene with a good selectivity to form biphenyl. These promising results indicate that P. fluorescens has an interesting potential to degrade sulfur-containing compounds in diesel oil and thereby could help in removing sulfur content from diesel oil. The process of microbial desulfurization described herein can be used particularly after carrying out hydrodesulfurization. Consequently, the sulfur content could be reduced even further. Applying P. fluorescens UCP 1514 in dibenzothiophene could help to understand the nature of the biodegradation process and to achieve the regulatory standards for sulfur level in fossil fuels

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

Remoção do Cr(VI) pela biomassa de Cunninghamella elegans UCP/WFCC 542 produzida com substrato de baixo custo

O crescimento das atividades industriais vem acarretando sérios problemas de poluição,devido a geração de grandes quantidades de resíduos potencialmente agressivos causando o desequilíbrio e destruição dos ecossistemas. As águas residuárias da indústria de curtume contêm metais pesados, com destaque para as substãncias contendo cromo, tais como: dicromato de potássio e dicromato de sódio, consideradas perigosas, podendo afetar diretamente os ambientes aquáticos. Desta forma, as contaminações ambientais por cromo são consideradas preocupantes para os recursos naturais, sem qualquer tipo de tratamento, sendo uma ameaça para a flora e fuúna. Em geral, o tratamento de efluente contaminado por metais pesados envolve processos fisicosquímicos complexos e onerosos, além de, ocasionalmente, contribuírem para a formação de novos contaminantes. Sendo assim, estudos foram dirigidos para a busca de alternativas que viabilizem o processo de remoção do cromo, através do processo de tratamento por biossorção, fuzendo uso das propriedades superficiais das biomassas microbianas. Neste estudo foi avaliada a remoção de Cr(VI) pela biomassa liofilizada de Cunninghamella elegans UCP 542, obtida a partir do meio milbocina, asparagina e sacarose. A reoção de diferentes concentrações de Cr(VI) foi realizada em Erlenmeyers de 250 mL contendo I OOmL das soluções de Cr(VI), com pH 6,6. Os frascos foram incubados a temperatura de 28"C, durante dez dias, sob agitação mbital de 150 1pm. Os resultados obtidos pelo método espectrofotométrico com difenilcarbazida indicaram que, as concentrações de 5 e 10 mg/L removeram totalmente o Cr(VI), em 4 dias. No periodo de dez dias, as concentrações de 25, 50 e 75 mg/L de Cr(VI) as biomassa apresentaram habilidade de remoção correspondentes a 65,92, 54,34 e 62,14%, respectivamente. Com a concentração mais elevada de Cr(VI) (100 mg/L) observou-se uma adsorção correspondente a 79,08%. A confirmação do processo de adsorção pela biomassa após remoção do cromo foi observado por microscopia eletrônica de varredura, evidenciando a acumulação do metal pesado pelo micélio do fungo. Os estudos realizados demonstraram o elevado potencial do micélio de C. elegans na remoção do Cr (Vl), sugerindo sua aplicação futura em processos de biorremediação de ambientes poluídos pelo metal pesado

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

Removal of methylene blue dye from aqueous solution using biomass of Cunninghamella echinulata UCP 1297 as superbiosorbent / Remoção do corante azul de metileno de solução aquosa usando biomassa de Cunninghamella echinulata UCP 1297 como superbiossorvente

Nowadays, water pollution caused by dye contaminants has become a severe global issue and aroused tremendous attention, since it is estimated that more than 100 thousand types of commercial organic dyes have been produced. Meanwhile, huge amounts of dyes have been discharged into natural environment during the production process, which causes serious environmental problems. Hence, it is quite urgent to remove the dyestuffs from water, and several methods have been devoted to resolving this issue, including biosorption processes. In this context, this study aimed the decolorization of methylene blue using biomass of Mucoralean fungi Cunninghamella echinulata UCP 1297, as alternative biosorbent. The fungus C. echinulata was initially cultivated in low-cost medium containing 1% corn steep liquor and 5% mature Pacovan banana (Musa sapientum) peel flour, at pH 6, 28ºC and 150 rpm, during 96 h. Fungal biomass obtained after filtration and centrifugation of cultures was subjected to lyophilization. The biosorbent (lyophilized biomass was sieved to obtain particles of size less than 1.0 mm, which were used for decolorization of methylene blue from aqueous solution at concentration of 5 mg/L. Experiments were carried out for 24 and 48h at 28ºC, using a 23 full-factorial design (FFD) to evaluate the influence of agitation, pH and amount of biosorbent. Discoloration was determined by measuring absorbance at 660 nm in UV-Visible spectrophotometer. According to the results, fungal biomass proved to be an excellent biosorbent of methylene blue, showing the highest percentage of removal (95.407%) and (96.427%) were observed in the condition 8 of the FFD, with the maximum levels of the evaluated variables (200 rpm of agitation, pH 9 and 90 mg of biomass). However, in the condition 4 similar variables, except to biomass (200 rpm of agitation, pH 9 and 10 mg of biomass) showed a lower methylene blue removal as 0.413 and 10.249%, respectively to 24 and 48h of incubation. The results indicated that the amount of Cunninghamella echinulata UCP 1297 biomass influenced the decolorization bioprocess of the methylene blue azo dye, proving to be a superbiosorbent. Thus, this study confirmed the suitability of fungal biomass for dye removal process and the cost-effectiveness of it uses due to inexpensive medium for production using agro-industrial residues

Prodigiosin Production by Serratia marcescens UCP 1549 Using Renewable-Resources as a Low Cost Substrate

A new strain of Serratia marcescens UCP1459 isolated from a semi-arid soil produced the natural red pigment prodigiosin, characterized by an uncommon pyrrolylpyrromethane skeleton. Prodigiosin is a promising drug due to its reported antifungal, immunosuppressive and anti-proliferative activities. The objective of this work was to indentify a suitable medium to simultaneously enhance S. marcescens growth and pigment production using renewable resources obtained from industrial wastes. S. marcescens produced the highest level of prodigiosin (49.5 g/L) at 48 h of cultivation using 6% “manipueira” (cassava wastewater) supplemented with mannitol (2%) at pH 7 and 28 °C. Carbohydrates in “manipueira” and mannitol play a role in the enhanced cell growth and prodigiosin production. The purified pigment extracted from the biomass was analyzed by mass spectrophotometry and showed the expected molecular weight of 324 Da corresponding to prodigiosin. In conclusion, we have successfully designed a new, economically feasible medium supporting enhanced S. marcescens growth and a high yield production of prodigiosin