The final products of the ethanol industry are alcoholic beverages, industrial ethanol and biofuels. They are produced by the same production process, which includes fermentation and distillation of raw materials which come from plant biomass. At the end of the distillation process a waste effluent is obtained called vinasse or stillage. The direct disposal of stillages on land or in groundwater (rivers, streams or lakes), or even for the direct irrigation of crops, pollutes the environment due to their high organic contents, dissolved solids and many other compounds which are toxic or could be contaminants under certain environmental conditions. This work reviews the characterization of vinasses from different feedstock sources and the main treatments for conditioning the soluble solids of vinasses before their disposal.
BackgroundA modified laboratory-scale upflow anaerobic sludge blanket (UASB) reactor was used to obtain methane by treating hydrous ethanol vinasse. Vinasses or stillage are waste materials with high organic loads, and a complex composition resulting from the process of alcohol distillation. They must initially be treated with anaerobic processes due to their high organic loads. Vinasses can be considered multipurpose waste for energy recovery and once treated they can be used in agriculture without the risk of polluting soil, underground water or crops. In this sense, treatment of vinasse combines the elimination of organic waste with the formation of methane. Biogas is considered as a promising renewable energy source. The aim of this study was to determine the optimum organic loading rate for operating a modified UASB reactor to treat vinasse generated in the production of hydrous ethanol from sugar cane molasses.ResultsThe study showed that chemical oxygen demand (COD) removal efficiency was 69% at an optimum organic loading rate (OLR) of 17.05 kg COD/m3-day, achieving a methane yield of 0.263 m3/kg CODadded and a biogas methane content of 84%. During this stage, effluent characterization presented lower values than the vinasse, except for potassium, sulfide and ammonia nitrogen. On the other hand, primers used to amplify the 16S-rDNA genes for the domains Archaea and Bacteria showed the presence of microorganisms which favor methane production at the optimum organic loading rate.ConclusionsThe modified UASB reactor proposed in this study provided a successful treatment of the vinasse obtained from hydrous ethanol production.Methanogen groups (Methanobacteriales and Methanosarcinales) detected by PCR during operational optimum OLR of the modified UASB reactor, favored methane production.
xico IntroductionA limiting factor for sustainable development of aquaculture is the presence of bacterial diseases induced principally by associated opportunistic bacterial flora, which become pathogenic when farmed organisms are exposed to stress caused by: poor quality environmental conditions, high stocking densities and inadequate feeding or management techniques . This may lead to physiological and ecological imbalance in the hosted animal, causing massive mortalities (Ruangpan and Kitao 1991;Lightner 1993;Jeney and Jeney 1995). Recently, interest has arisen in preventing bacterial diseases by controlling or eliminating opportunistic pathogens through the use of probiotic bacteria (Moriarty 1997;Gó mez-Gil et al. 2000;Devaraja et al. 2002). The manipulation of bacterial composition in the hosted animals and/or the environment could control the proliferation of bacterial pathogens, through the addition of selected probiotic bacterial species and by the control of AbstractAims: To carry out a rapid and reliable identification of bacterial diversity in the oyster Crassostrea gigas from Todos Santos Bay, México, in the current study we applied the molecular techniques of fluorescent in situ hybridization (FISH) and polymerase chain reaction (PCR). In order to reach this goal, genus and group-specific oligonucleotides targeted to 16S rDNA/rRNA were used. Methods and Results: Oysters were collected and different tissues were analysed by means of culture-independent methodologies. In the digestive glands and gonads c-Proteobacteria and Gram-positive bacteria with a low G+C content, were identified as metabolically active by FISH. In the oyster gills a higher active diversity was observed, including Gram-positive bacteria with a low and high G+C content, members of the Cytophaga/Flavobacterium cluster and cProteobacteria. Consistent with FISH analysis, the amplification of 16S rDNA genes fragments with genus and group-specific oligonucleotides confirmed the presence of the same groups, as well as members of the a-and b-Proteobacterias, Pseudomonas spp. and Bacillus spp. Conclusions: The combination of accurate and very easy-to-apply molecular methods allowed us to carry out a rapid screening of high bacterial diversity in oysters. Significance and Impact of the Study: This work is the first report about bacterial diversity in oyster tissues analysed by FISH and PCR, without using culture-dependent methods and allowed us to determine the phylogenetic diversity of the bacterial communities present in oyster cultures, including bacteria with and without metabolic activity, as well as uncultivable cells, which are generally underestimated by traditional identification. Journal of Applied Microbiology
RESUMEN. La industria de la acuariofilia es un mercado que se encuentra en expansión. Aun cuando no existe información exacta respecto a cifras y valores del comercio internacional, se calcula que esta industria genera ganancias sobre US$ 300 millones con una tasa de crecimiento anual del 14%. De esta cifra, aproximadamente US$ 28 a 44 millones corresponden a peces ornamentales de origen marino. No obstante, una de las controversias que ha generado el comercio de especies marinas es que casi la totalidad de los organismos son capturados del medio natural, y en muchos casos de manera ilegal. En este trabajo se realiza una revisión que incluye: historia de la acuariofilia, principales especies ornamentales de importancia comercial, comercio internacional, riesgos del comercio de especies marinas, estrategias de conservación y situación actual en México. En este último tema, se abordan aspectos que describen el desarrollo y perspectivas del mercado de la acuariofilia marina y algunas iniciativas de instituciones académicas y privadas dirigidas al desarrollo de la acuicultura sostenible de especies marinas de ornato de importancia comercial en el país. Palabras clave: recursos marinos ornamentales, comercio internacional, acuariofilia marina, acuicultura sustentable, México. Ornamental marine fishkeeping: a trade of challenges and opportunitiesABSTRACT. The aquariums industry is a trade that is expanding. Although there is no accurate information regarding the figures of the aquarium industry in the international scenario, it is estimated to generate revenues over US$ 300 million with an annual growth rate of 14%. Approximately US$ 28 to 44 million of this amount is generated by the ornamental marine fish trade. However, the trade in marine species has aroused controversy regarding the extraction of almost all traded marine organisms from wild populations and, in many cases, illegally. This paper presents a review that includes: the ornamental marine fishkeeping history, the species of commercial importance, the international trade scenario, risks of the aquarium industry, conservation strategies, and the current situation of this trade in Mexico. The last section focuses on describing the development and market prospects of the marine aquarium trade. Additionally, some initiatives from academic and private institutions aimed at developing sustainable aquaculture on ornamental marine fish species of commercial importance in Mexico are provided. Keywords: ornamental marine resources, international trade, marine fishkeeping, sustainable aquaculture, Mexico. ___________________Corresponding author: Galdy Hernández Zárate (galdyhz@gmail.com) INTRODUCCIÓNLa acuariofilia marina se ha convertido en un pasatiempo popular y de gran expansión a nivel mundial. Los avances en la crianza de organismos marinos (vertebrados e invertebrados) en cautiverio bajo condiciones controladas, así como el desarrollo de tecnologías para acuarios han facilitado la afición
Wood-plastic composites (WPCs) are considered to be highly durable materials and immune to any type of biological attack. However, when one of these composites is exposed to accelerated weathering, its surface is affected by the appearance of cracks, which constitute an ideal access route for biotic agents. Although the destruction of wood caused by termites is recognized worldwide, information on their effects on WPC-based products is scarce. Thus, in this study, we aimed to examine the effects of termite attacks on weathered and nonweathered pinewood residue/recycled high-density polyethylene composites. In this study, WPCs with 40 wt % wood were prepared. Test samples obtained by compression molding and profile extrusion were subjected to weathering cycles for 1000 and 2000 h with a UV-type accelerated tester equipped with UVA-340 fluorescent lamps. Afterward, specimens were exposed to the attack of higher termites (Nasutitermes nigriceps) native to the Yucatan Peninsula. Subsequently, flexural mechanical essays, Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) analyses were performed. FTIR spectroscopy and DSC showed that the surfaces of the compression-molded specimens were degraded to a higher extent because of the accelerated weathering. The microscopy results revealed that severe damage was caused by the termites on the surface of the compression-molded samples. Statistical analysis of the mechanical test results showed that biotic attack produced significant changes in the samples previously exposed to accelerated weathering. The results show that the processing method directly affected the sample performance because of differences in the surface composition. The profile-extruded composites seemed to better resist termite attack.
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