Fatores que influenciam a produção de ácidos carboxílicos a partir de resíduos agroindustriais / Factors that influence the production of carboxylic acids from agroindustrial wastes

RESUMO Os ácidos carboxílicos (ACs) são componentes químicos de base produzidos principalmente a partir da plataforma petroquímica. Entretanto, em razão de impactos ambientais, risco de escassez e elevados preços do petróleo, a produção biológica de AC por meio da digestão anaeróbia de recursos renováveis de baixo custo, como resíduos orgânicos das atividades agroindustriais, vem recebendo atenção crescente. Nesse contexto, o presente artigo objetiva discutir o processo de digestão anaeróbia aliada ao alongamento de cadeia carboxílica, a fim de orientar tomadas de decisão, como, por exemplo, escolha do substrato e definição das condições ambientais e dos parâmetros operacionais. Em geral, as condições que apresentam melhor viabilidade para produção de ácidos carboxílicos de cadeia média (ACCM) são: pH próximo a 6,0; temperatura mesofílica, já que oferece maior estabilidade operacional e os rendimentos obtidos em condições termofílicas não se mostram muito superiores; pressão parcial de hidrogênio (PPH) próxima a 10-5 aliada à limitação de CO2; tempo de residência celular (θc) inferior a 5 dias; e tempo de detenção hidráulica (TDH) baixo para sistemas contínuos. Uma das configurações mais promissoras é o uso de sistemas de dois estágios utilizando baixo pH como inibidor da metanogênese e extração de ACs em linha, para evitar a inibição devido à toxicidade dos produtos.

ABSTRACT Carboxylic acids (CA) are basic chemical components produced mainly through the petrochemical platform. However, due to environmental impacts, risk of scarcity and high petroleum prices, organic production of CA from the anaerobic digestion of low-cost renewable resources, such as organic wastes from agro-industrial activities, has been receiving increasing attention. In this context, the present paper aims to discuss the process of anaerobic digestion allied to the carboxylic chain elongation process, in order to guide decision making such as substrate choice, definition of environmental conditions, and operational parameters. In general, the conditions that present the best viability for MCCA production are: pH close to 6.0; mesophilic temperature since it offers greater operational stability and the yields obtained under thermophilic conditions are not much higher; hydrogen partial pressure (HPP) close to 10-5 combined with CO2 limitation; solids retention time (θc) < 5 days and low hydraulic retention time (HRT) for continuous systems. One of the most promising configurations is the use of two-stage systems using low pH as a methanogenesis inhibitor and inline CA extraction to avoid inhibition due to product toxicity.

Repercussion of microbial additive on the productive, Zoometric and diarrheal incidences of piglets / Repercusión de aditivos microbianos en el comportamiento productivo, zoométrico e incidencia diarreica de lechones

Abstract Objective. To evaluate the impact of two microbial additives on the productive behavior, zoometric, incidence of diarrhea and mortality of post-weaning piglets. Materials and methods. A total of 120 piglets (Duroc / Yorkshire / Landrace) were used, divided into three groups of 40 animals each, control (T1); microbial preparation A (T2) and microbial preparation B (T3). The T2 contained Lactobacillus acidophilus, Lactobacillus bulgariccus y Streptoccus thermophilus. The T3 was composed of microorganisms of T2 plus Saccharomyces cerevisiae and Kluyveromyces fragilis (L-4 UCLV). We used a completely randomized design where we evaluated, live weight, daily mean gain, height: raised at the cross, raised to the rump, body length, for both sexes and diarrheal incidence and mortality. Results. Live weight in the offspring (males and females) consuming microbial additives were higher and of these were higher in T3. Regarding the average daily gain, the largest increases were found in T3 group. Elevated to the cross, raised to the rump and length of body was greater (p<0.05) in T2 and T3 at birth; while at the end of the study in T3 it was superior. The incidence of diarrhea was higher (p<0.05) in the control group. The animals of the groups that consumed microbial preparation had no deaths during the study. Conclusions. The use of the microbial additives evaluated had a positive effect on the productive and zoometric behavior of the piglets. In addition, the reduction of the incidence of diarrhea and mortality of the animals was achieved.

Resumen Objetivo. Evaluar la repercusión de dos aditivos microbianos en el comportamiento productivo, zoométricos, incidencia de diarreas y mortalidad de lechones post-destete. Materiales y métodos. Se emplearon 120 lechones (Duroc/Yorkshire/Landrace), distribuidos en tres grupos de 40 animales cada uno, control (T1); preparado microbiano A (T2) y preparado microbiano B (T3). El T2 contenía Lactobacillus acidophilus, Lactobacillus bulgariccus y Streptoccus thermophilus. El T3 estuvo compuesto por microorganismos del T2 más Saccharomyces cerevisiae y Kluyveromyces fragilis (L-4 UCLV). Se utilizó un diseño completamente aleatorizado donde se evaluó, peso vivo, ganancia media diaria, talla: alzada a la cruz, alzada a la grupa, largo de cuerpo, para ambos sexos e incidencia diarreica y mortalidad. Resultados. Peso vivo en las crías (machos y hembras) que consumieron aditivos microbianos fueron superiores y de estos fueron mayores en el T3. En cuanto a la ganancia media diaria, los mayores incrementos se encontraron en el grupo T3. Alzada a la cruz, alzada a la grupa y largo de cuerpo fue mayor (p<0.05) en el T2 y T3 en el nacimiento; mientras que al final del estudio en el T3 fue superior. La incidencia de diarrea fue mayor (p<0.05) en el grupo control. Los animales de los grupos que consumieron preparado microbiano no presentaron muertes durante el estudio. Conclusiones. El uso de los aditivos microbianos evaluados produjo un efecto positivo en el comportamiento productivo y zoométrico de los lechones. Así mismo, se logró la reducción de la incidencia de diarreas y mortalidad de los animales.

Residuos agroindustriales con potencial para la producción de metano mediante la digestión anaerobia / Agroindustrial wastes methanization and bacterial composition in anaerobic digestion

Las toneladas de residuos orgánicos que se generan anualmente en la agroindustria pueden aprovecharse como materia prima para la producción de metano. Para que los residuos orgánicos se puedan convertir a metano a gran escala, es importante que previamente se realicen sobre ellos pruebas de biodegradabilidad; un parámetro importante que conviene establecer es su potencial bioquímico de metano. En el presente trabajo se estudió la biodegradabilidad, la producción de metano y el comportamiento de poblaciones de eubacterias y arqueobacterias durante la digestión anaerobia de residuos de plátano, mango y papaya provenientes de la agroindustria, adicionando un inóculo microbiano. Los residuos de mango y plátano tenían mayor contenido de materia orgánica (94 y 75 %, respectivamente) que el residuo de papaya con base en su relación sólidos volátiles/sólidos totales. Después de 63 días de tratamiento, la mayor producción de metano se observó en la digestión anaerobia del residuo de plátano: 63,89 ml de metano por g de demanda química de oxígeno del residuo. Los resultados del potencial bioquímico de metano demostraron que el residuo de plátano tiene el mejor potencial para ser usado como materia prima en la producción de metano. A través de un análisis por PCR-DGGE con oligonucleótidos específicos se logró evaluar el tamaño y la composición de las poblaciones de eubacterias y arqueobacterias presentes en la digestión anaerobia de residuos agroindustriales a lo largo del proceso.

The tons of organic waste that are annually generated by agro-industry, can be used as raw material for methane production. For this reason, it is important to previously perform biodegradability tests to organic wastes for their full scale methanization. This paper addresses biodegradability, methane production and the behavior of populations of eubacteria and archaeabacteria during anaerobic digestion of banana, mango and papaya agroindustrial wastes. Mango and banana wastes had higher organic matter content than papaya in terms of their volatile solids and total solid rate (94 and 75 % respectively). After 63 days of treatment, the highest methane production was observed in banana waste anaerobic digestion: 63.89 ml CH4/per gram of chemical oxygen demand of the waste. In the PCR-DGGE molecular analysis, different genomic footprints with oligonucleotides for eubacteria and archeobacteria were found. Biochemical methane potential results proved that banana wastes have the best potential to be used as raw material for methane production. The result of a PCR- DGGE analysis using specific oligonucleotides enabled to identify the behavior of populations of eubacteria and archaeabacteria present during the anaerobic digestion of agroindustrial wastes throughout the process.

Evaluación del crecimiento y producción de Pleurotus ostreatus sobre diferentes residuos agroindustriales del departamento de Cundinamarca / Evaluation of growth and production of pleurotus ostreatus on different agroindustrials wastes of Cundinamarca

Se llevó a cabo la evaluación del cultivo de Pleurotus ostreatus, para determinar el residuo sobre el cual este hongo genera mejor crecimiento y producción. Los sustratos evaluados fueron residuos agroindustriales del departamento de Cundinamarca (capacho de uchuva, cáscara de arveja y tusa de maíz); teniendo como sustrato control el aserrín de roble. Las mezclas a evaluar fueron empacadas en bolsas de 1Kg de volumen de mezcla de sustrato, del cual el 78 por ciento fue el residuo agroindustrial. Se esterilizaron e inocularon con 30g de semillas de Pleurotus ostreatus, adquiridas comercialmente. Se evaluó el tiempo de corrida del micelio, el diámetro de los carpóforos, el número de hongos producidos por bolsa, el peso fresco, la eficiencia biológica y el rendimiento de cada uno de los sustratos trabajados. Finalmente, el mejor sustrato para el crecimiento y producción de Pleurotus ostreatus fue el capacho de uchuva ya que alcanzó una eficiencia biológica de 76.1 por ciento en un período total de producción de 41 días y una rentabilidad de 39.03 Kg/m2 con excelentes características organolépticas, considerándose así un sustrato adecuado y eficiente para el cultivo de este hongo.

The culture of Pleurotus ostreatus was evaluated to determine the best waste on which this mushroom can show the highest growth and production rates.. The substrates evaluated were agroindustrial wastes of theDepartment of Cundinamarca (dry skin of goldenberries (Physalis), skin of pea pods and maize cobs). The control substrate was sawdust of oak. The mixtures evaluated were packed in bags of 1 kg containing 78 % ofagroindustrial waste of the volume of substrate mixture . Mixtures were sterilized and inoculated with 30 g ofseeds of Pleurotus ostreatus obtained commercially. Running time of the mycelium, diameter of fruit bodies,number of fruit bodies produced per bag, fresh weight, biological efficiency, and yield were evaluated on eachof the substrates. Finally, the best substrate for the growth and production of Pleurotus ostreatus was the dryskin of goldenberries (Physalis) with a biological efficiency of 76.1% after a total production period of 41 days and a yield of 39.03 Kg/m2 with excellent organoleptic characteristics, therefore being an adequate and efficient substrate for cultivating this mushroom.

Selection of microorganisms for biosurfactant production using agroindustrial wastes

Biosurfactant production by some bacterial isolates using molasses, milk whey and cassava flour wastewater (manipueira) as substrates was evaluated and compared with the production in conventional medium. Isolates growing in manipueira medium decreased the surface tension around 42%, the highest reduction among all the substrates tested. From the eleven isolates tested, eight were able to decrease the surface tension to levels below 30 mN/m using manipueira as substrate. The isolates LB5a, LB2a, LB262, LBB and LB1a that gave surface tension about 26 mN/m were identified as Bacillus sp. Natural manipueira (high solids content) and decanted manipueira (no solids) were investigated as culture media for biosurfactant production by selected microorganisms. Natural manipueira medium showed minimum surface tension of 28 mN/m (LB5a isolate) whereas for decanted manipueira the lowest value was 26 mN/m (isolate LB2a). Average diameter of growth on manipueira agar was 7.2 cm for isolate LB5a suggesting a high growth capacity on this substrate. Manipueira comprises a potential alternative culture medium for biosurfactant production by the selected isolates.

Alguns isolados bacterianos foram avaliados quanto à capacidade de produção de biossurfatantes a partir de melaço, soro de leite e manipueira como substratos. A produção nestes meios alternativos foi comparada com a produção em meio de cultura convencional. Dentre os meios testados, a manipueira demonstrou a maior percentagem de redução na tensão superficial atingindo valores ao redor de 42%. Dos onze isolados testados, oito foram capazes de diminuir a tensão superficial para níveis inferiores à 30mN/m utilizando manipueira como substrato. Os isolados LB 5a, LB2a, LB262, LBB e LB1a apresentaram tensão superficial em torno de 26 mN/m sendo selecionados e posteriormente identificados como pertencentes ao gênero Bacillus sp. A manipueira natural (alto teor de sólidos) e a manipueira decantada (ausência de sólidos) foram investigadas como meios de cultivo para produção de biossurfatantes pelos microrganismos selecionados. O meio de manipueira natural apresentou tensão superficial minima de 28 mN/m (isolado LB5a) enquanto que o meio de manipueira decantada apresentou tensão superficial mínima de 26 mN/m (isolado LB2a). O diâmetro de crescimento médio do isolado LB5a em ágar manipueira foi de 7.2 cm sugerindo maior capacidade de crescimento neste substrato. A manipueira demonstrou potencial como meio de cultura alternativo para a produção de biossurfatantes pelos isolados selecionados.