Continuous production processes and an adequate supply of raw materials are necessary to satisfy the growing demand for biodiesel. The use of different feed oils could be necessary to ensure sufficient supply for biodiesel production in certain circumstances; however, changing feed oil during the operation of a continuous reactor causes process disturbances. The present study analyses the effect of feed oil changes on the continuous operation of a industrial continuous stirred-tank reactor (CSTR) using a model which takes the dynamics of oil changes into account. The models previously reported only consider the operation of reactor with only one vegetable oil. The model in this work was developed by mass and energy balances. A methodology to model oil changes is presented. Glycerides and esters were characterized using adequate approaches. Moreover, accurate methods for predicting essential properties in the biodiesel manufacturing were used for the estimation of their thermo-physical properties. The kinetic parameters of the transesterifications were calculated from consistent studies selected from an exhaustive literature revision. The results show that temperature is practically not affected after oil changes; however, the ester concentration varies considerably. The ester mass fraction varying by up to 22.07% after an disturbance.

Pleurotus ostreatus is a saprophytic fungus that grows mainly on living or dead lignocellulose substrates, poor in nutrients and with low levels of minerals and vitamins. The propagation of this organism requires lignocellulose substrates. This fungus is edible with important functional properties. Because the population of trees located in the gardens of the Universidad de Ciencias y Artes de Chiapas generates a considerable amount of organic waste, these can be used as raw material for the cultivation of fungi. Two crops of the mushrooms were carried out in different substrates, the first from leaves of benjamina (Ficus benjamina) and the second was a combination of fig leaves (Ficus carica) and capulín (Prunus serotina). The edible mushrooms obtained from the crops were dehydrated by convection of hot air at 50°C for 24 hours, then ground and stored for disposal in the integration of edible paste formulations. This food has become a staple food because of its variety in processing and consumption, however, its protein content can be low and of poor quality; therefore, it is necessary to incorporate other sources of protein of better quality without altering eating habits or organoleptic characteristics. In this work we studied the nutritional composition and consumer acceptance that results with the addition of mushroom flour in the production of fettuccine pasta. Addition levels were 10% and 20% mushroom meal (hs), the chemical composition (raw protein, carbohydrates, fiber, fat and ash) of both formulations was analyzed based on the aoac (2000). The results indicated a considerable increase in the percentage compositions of fiber and protein when 20% hs was added to the fettuccine pasta formulation with respect to the reported sample without the addition of the mushrooms. In addition, the taste levels perceived by the sensory judges, for the attributes of smell and taste, were also high when 20% hs was incorporated with respect to the fettuccine control paste. This proposal can be considered useful for the preservation of mushrooms, since when dehydrated, despite the low yields, it can become an apt and versatile condiment, because it increases the nutritional components and improves the sensory properties of this type of food, without downplay the sustainable use of waste from plants in university gardens.

Objetivo: Aislar y caracterizar microbiológicamente bacterias extremófilas del manantial “Baños del Carmen” Venustiano Carranza, Chiapas, México. Diseño/metodología/aproximación: Las muestras fueron recolectadas en tres puntos de la fosa principal del sitio. Se realizaron diluciones seriadas y se sembraron en medio LB y agar nutritivo. Se llevaron a cabo resiembras de colonias aisladas con diferente morfología colonial hasta obtener cultivos axénicos. Se llevó a cabo una caracterización morfológica micro y macroscópica de los aislados y una caracterización bioquímica con el kit API 20E Resultados: Tres cepas bacterianas termo alcalófilas fueron encontradas: YEFP-C, YEPF-J, y YEPF-P. Todas las cepas fueron Gram negativas y registraron crecimiento en medios con pH de 8.0 a 10.0 y 50 °C. Además, todas tienen metabolismo fermentativo de carbohidratos y actividad beta galactosidase.  Limitaciones del estudio/implicaciones: La estrategia utilizada se limitó a organismos aerobios heterotróficos; sin embargo, es probable que exista biodiversidad de otro tipo de organismos procariotes y eucariotes en el sitio. Hallazgos/conclusiones: Existe vida bacteriana extremofila en el manantial “Los Baños del Carmen”. Este es el primer reporte con evidencia científica.