Biofiltration of trimethylamine in biotrickling filter inoculated with Aminobacter aminovorans

Background: Trimethylamine (TMA) is the main responsible for the odor associated with rotting fish and other annoying odors generated in many industrial activities. Biofiltration has proved to be efficient for treating odorous gaseous emissions. The main objective of this work was to determine the removal capacity of TMA of a biotrickling filter inoculated with Aminobacter aminovorans and to evaluate the effect of H2S on its performance. Results: The maximumspecific growth rate ofA. aminovorans in a liquid culture was 0.15 h -1 , witha TMAto biomass yield of 0.10 (g g -1) and a specific consumption rate of 0.062 g·g-1·h-1 . The initial specific consumption rate of TMA was highly influenced by the presence of H2S in liquid culture at concentrations of 20 and 69 ppm in heading space oftheflasks.ABTF inoculatedwithA. aminovorans showedremoval efficiencieshigher than98%ina range ofloading rate of 0.2 to 8 g·m-3·h-1 at empty bed residence time (EBRT) of 85 and 180 s. No effect on the elimination capacity and efficiency was detected when H2S was added at 20 and 50 ppm to the inlet gaseous emission, though the fraction of A. aminovorans measured by qPCR in the biofilm decreased. Conclusions:Abiotrickling filter inoculated with A. aminovorans can remove efficiently the TMA in a gaseous stream. The elimination capacity of TMA can be negatively affected by H2S, but its effect is not notorious when it is forming part of a biofilm, due to its high specific consumption rate of TMA.

Characterization and optimization of a heterotrophic bacterium for sulfide degradation / 生物工程学报

The emission of hydrogen sulfide in the waste gas from slaughter plant, fishmeal feed processing and some other food industrial processing could cause serious air pollution to the surrounding environment. The purpose of this study was to screen heterotrophic bacterium strains for the removal of hydrogen sulfide odor. One heterotrophic bacterial mutant ZJNB-B3 was derived from the sulfide degrader Bacillus cereus XJ-2 and its sulfide removal efficiency was 97%. Based on the morphology studies, biochemical tests and 16S rRNA gene analysis, the strain was identified as Bacillus cereus ZJNB-B3. The NCBI GenBank accession number is MF679650. Batch tests showed that the strain tolerated up to 300 mg/L of toxic S²⁻ concentration. Response surface methodology was applied to optimize the conditions of degradation of sulfide. The optimal parameters were as follows: initial sulfide concentration 211.8 mg/L, initial pH 6.72, inoculum volume 5.04%, and incubation temperature 30 ℃. The accumulated sulfate concentration was 63.8 mg/L and the sulfide removal efficiency was 97.3% after 48 h incubation. No sulfuric acid was generated during sulfide oxidation by the strain. Sulfide could be removed effectively by this strain under mild pH conditions. The results suggested that the strain may have great industrial application potential. This study provides the fundamentals for the removal of hydrogen sulfide gas.

Development of a novel compound microbial agent for degradation of kitchen waste

Abstract Large quantities of kitchen waste are produced in modern society and its disposal poses serious environmental and social problems. The aim of this study was to isolate degradative strains from kitchen waste and to develop a novel and effective microbial agent. One hundred and four strains were isolated from kitchen waste and the 84 dominant strains were used to inoculate protein-, starch-, fat- and cellulose-containing media for detecting their degradability. Twelve dominant strains of various species with high degradability (eight bacteria, one actinomycetes and three fungi) were selected to develop a compound microbial agent "YH" and five strains of these species including H7 (Brevibacterium epidermidis), A3 (Paenibacillus polymyxa), E3 (Aspergillus japonicus), F9 (Aspergillus versicolor) and A5 (Penicillium digitatum), were new for kitchen waste degradation. YH was compared with three commercial microbial agents-"Tiangeng" (TG), "Yilezai" (YLZ) and Effective Microorganisms (EM), by their effects on reduction, maturity and deodorization. The results showed that YH exerted the greatest efficacy on mass loss which decreased about 65.87% after 14 days. The agent inhibited NH3 and H2S emissions significantly during composting process. The concentration of NH3 decreased from 7.1 to 3.2 ppm and that of H2S reduced from 0.7 to 0.2 ppm. Moreover, E4/E6 (Extinction value460nm/Extinction value665nm) of YH decreased from 2.51 to 1.31, which meant YH had an obvious maturity effect. These results highlighted the potential application of YH in composting kitchen waste.

Controlling wound odor with metronidazole: a systematic review / Control del olor de heridas con metronidazol: revisión sistemática / Controle do odor de feridas com metronidazol: revisão sistemática

AbstractOBJECTIVEVerifying the evidence of therapeutic efficacy in the topical application of metronidazole for controlling wound odor.METHODSA systematic literature review, according to the Cochrane Collaboration recommendations.RESULTS329 articles were identified in the Cochrane, LILACS, SciELO, CINAHL and PubMed databases, with 14 of them being included in the final sample. Two of the studies were double-blind randomized clinical trial studies.CONCLUSIONThe actual effectiveness of metronidazole in controlling wound odor cannot yet be evidenced due to the absence of strong evidence from studies on the subject, despite clinical practice recommending its benefits.

ResumenOBJETIVOVerificar las evidencias de la aplicación tópica de metronidazol en la efectividad terapéutica para el control del olor de heridas.MÉTODORevisión sistemática de literatura, según las recomendaciones de la Cochrane Collaboration.RESULTADOSSe identificaron 329 artículos en las bases de datos Cochrane, LILACS, ScIELO, Cinahl y PubMed, incluyéndose 14 de ellos en la muestra final. De esos, dos estudios son del tipo ensayo clínico, randomizado y doble ciego.CONCLUSIÓNEn virtud de la ausencia de estudios de fuerte evidencia acerca de la efectividad del metronidazol en el control del olor en heridas, aún no se puede evidenciar su real efectividad para dicho fin, pese a que la práctica clínica recomiende sus beneficios.

ResumoOBJETIVOVerificar as evidências da aplicação tópica de metronidazol na eficácia terapêutica para controle de odor de feridas. Método: Revisão sistemática de literatura, segundo as recomendações da Cochrane Collaboration .RESULTADOSIdentificaram-se 329 artigos nas bases de dados Cochrane, LILACS, ScIELO, Cinahl e PubMed, incluindo-se 14 deles na amostra final. Desses, dois estudos são do tipo ensaio clínico, randomizado e duplo-cego.CONCLUSÃODevido à ausência de estudos de forte evidência sobre a eficácia do metronidazol no controle de odor em feridas, ainda não se pode evidenciar a sua real eficácia para tal objetivo, apesar da prática clínica recomendar seus benefícios.

Trans fatty acid-forming processes in foods: a review

There is a mounting concern about the intake of foods containing trans fatty acids (TFA) due to their deleterious effects on human health, mainly on the cardiovascular system. In this way, it is important to consider the processes that form TFA in foods, and the alternatives to minimize them. Among the processes that result in the formation of TFA, the hydrogenation of vegetable oils stands out for its impact on the diet of people living in industrialized countries. Other processes such as edible oil refining, meat irradiation, food frying, and biohydrogenation also contribute to increase the daily intake of TFA.

Existe uma crescente preocupação em relação a ingestão elevada de ácidos graxos trans (AGT), devido aos seus efeitos desfavoráveis à saúde, principalmente sobre o sistema cardiovascular. Assim, é importante considerar os processos queoriginam os AGT nos alimentos, e as alternativas para minimizar a sua formação. Entre os processos que resultam na produção de AGT, a hidrogenação de óleos vegetais tem recebido o maior destaque por seu impacto na dieta de pessoas que vivem em países industrializados. Outros processos, como o refino de óleos vegetais, a irradiação de carnes, o preparo de alimentos fritos e a bio-hidrogenação, também contribuem para aumentar a ingestão diária de AGT.