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Primary sludge, from different pulp and paper mills, was used as feedstock in simultaneous saccharification and fermentation (SSF) processes to produce ethanol. SSF was carried out with Saccharomyces cerevisiae ATCC 26602 yeast and NS 22192 enzymatic extract using 150gL(-1) of carbohydrates (CH) from primary sludge. The effect of sterilization, reduction of enzyme dosage and fed-batch vs. batch conditions were studied. The removal of sterilization can be considered since no contamination or atypical by-products were observed, although SSF efficiency slightly decreased. The reduction of the enzyme dosage from 35 to 15FPUgCH(-1) was successful. Despite of initial mixing difficulties, batch SSF enabled higher ethanol concentration (41.7gL(-1)), conversion yield (48.9%) and productivity (0.78gL(-1)h(-1)), compared to the fed-batch process at the same conditions of low enzyme dosage of 5FPUgCH(-1) and high solids content of 21.7%, rarely found in literature., (Published by Elsevier Ltd.)

Soybean rust caused by Phakopsora pachyrhizi Syd. & P. Syd is a destructive foliar disease of soybean (Glycine max L), which was first confirmed in North America in Louisiana during 2004 (4). Soybean rust (SBR) has also been reported late in the growing season as far north as Illinois, Indiana, and Iowa. SBR was first confirmed in Mexico in 2005 in the state of San Luis Potosi on soybean (3) and subsequently reported in the states of Tamaulipas, Veracruz, and the southwestern coast of Chiapas. Symptoms of SBR were observed on leaves of multiple, nearly mature soybean plants near the city of Campeche (19.72796°N, 90.0771°W) on the Gulf Coast of the Yucatan Peninsula during November 2008. Angular and irregular chlorotic lesions on leaves contained necrotic spots and pale brown, erumpent, cone-like uredinia with a central opening. Ellipsoid to obovoid, echinulate, light tan urediniospores (10 to 13 × 16 to 18 μm) were observed microscopically. DNA was extracted from leaf tissue containing uredinia and from asymptomatic tissue with the DNeasy Plant Mini Kit (Qiagen, Valencia, CA). P. pachyrhizi was confirmed in the symptomatic leaves by a PCR assay with Ppm1/Ppa2 primers, but not from the asymptomatic leaves (1). Subsequently, the DNA extracted from symptomatic and asymptomatic leaf tissues was tested again in another laboratory by a specific quantitative PCR assay (1), and positive results for the presence of soybean rust were obtained only from the symptomatic tissue. As a final confirmatory step, amplified DNA from the PCR assay was sequenced, and the results matched P. pachyrhizi sequences in the GenBank database. To our knowledge, these observations confirm for the first time the presence of P. pachyrhizi in the state of Campeche of southern Mexico. Although it was confirmed on soybean during 2008, it is not known how long the pathogen has been present or which other hosts may be infected there. The presence of SBR on the Yucatan Peninsula is significant because of its potential effects on local plant hosts. In addition, the climate allows possible year-round survival of the pathogen and long-distance transport of urediniospores to the United States. Potential transport of SBR spores from this part of Mexico to the United States has been reported through the application of NOAA's HYSPLIT (Hybrid Single Particle Lagrangian Integrated Transport) model and atmospheric back-trajectory analysis (2). References: (1) R. D. Frederick et al. Phytopathology 92:217, 2002. (2) S. V. Krupa et al. Plant Dis. 90:1254, 2006. (3) A. C. Rodriguez et al. Plant Dis. 90:1260, 2006. (4) R. W. Schneider et al. Plant Dis. 89:774, 2005.