Production and Use of Lipases in Bioenergy: A Review from the Feedstocks to Biodiesel Production

Lipases represent one of the most reported groups of enzymes for the production of biofuels. They are used for the processing of glycerides and fatty acids for biodiesel (fatty acid alkyl esters) production. This paper presents the main topics of the enzyme-based production of biodiesel, from the feedstocks to the production of enzymes and their application in esterification and transesterification reactions. Growing technologies, such as the use of whole cells as catalysts, are addressed, and as concluding remarks, the advantages, concerns, and future prospects of enzymatic biodiesel are presented

Factorial Design to Optimize Biosurfactant Production by Yarrowia lipolytica

In order to improve biosurfactant production by Yarrowia lipolytica IMUFRJ 50682, a factorial design was carried out. A 24 full factorial design was used to investigate the effects of nitrogen sources (urea, ammonium sulfate, yeast extract, and peptone) on maximum variation of surface tension (ΔST) and emulsification index (EI). The best results (67.7% of EI and 20.9 mN m−1 of ΔST) were obtained in a medium composed of 10 g 1−1 of ammonium sulfate and 0.5 g 1−1 of yeast extract. Then, the effects of carbon sources (glycerol, hexadecane, olive oil, and glucose) were evaluated. The most favorable medium for biosurfactant production was composed of both glucose (4% w/v) and glycerol (2% w/v), which provided an EI of 81.3% and a ΔST of 19.5 mN m−1. The experimental design optimization enhanced ΔEI by 110.7% and ΔST by 108.1% in relation to the standard process

Produção de biossurfactante por levedura

Biosurfactants are molecules extracellularly produced by bacteria, yeast and fungi that have significant interfacial activity properties. This review focuses on relevant parameters that influence biosurfactant production by yeasts. Many works have investigated the optimization of yeast biosurfactant production, mainly within the last decade, revealing that the potential of such microorganisms is not well explored in the industrial field. The main points to increase the process viability lays on the reduction of the production costs and enhancement of biosynthesis efficiency through optimization the culture conditions (carbon and nitrogen source, pH, aeration, speed agitation) and the selection of inexpensive medium components

APROVEITAMENTO DE RESÍDUOS AGROINDUSTRIAIS: PRODUÇÃO DE ENZIMAS A PARTIR DA CASCA DE COCO VERDE

Investigou-se o aproveitamento da casca do coco verde, mediante fermentação semisólida, para produção de enzimas. A casca de coco foi previamente desidratada, moída e classificada em três diferentes granulometrias, ou seja, 14, 28 e 32 mesh Tyler. Todas as enzimas obtidas tiveram sua produção máxima na faixa de 24 e 96 horas, o que corresponde ao tempo de produção industrial corrente. Cada granulometria produziu complexos enzimáticos ricos em diferentes atividades. O estudo realizado validou a hipótese do aproveitamento do resíduo da casca do coco verde na produção de enzimas por Aspergillus niger. Abstract The utilization of immature coconut peel as substrate for enzyme production by solid state fermentation was investigated. The coconut peel was previously dehydrated, milled and classified in three distinct granulometries: 14, 28 and 32 mesh Tyler. All the enzymes obtained had its maximum production in 24 to 96 hour interval, which correspond to the current industrial production time. Each granulometry produced rich enzymatic complexes with different activities. This study validates the hypothesis of benefit immature coconut peel as raw material for enzyme production by Aspergillus niger

Obtenção de extratos de guaraná ricos em cafeína por processo enzimático e adsorção de taninos Production of caffeine-rich guarana extracts using an enzymatic process and tannin adsorption

As bebidas sabor guaraná são muito populares no Brasil e têm apresentado um excelente potencial de vendas no mercado externo. De acordo com as leis brasileiras, bebidas sabor guaraná devem conter entre 0,02 g a 0,2 g de semente de guaraná ou equivalente, para cada 100 mL de produto. Tais teores são usualmente obtidos pela adição de um extrato concentrado hidroalcoólico ou xarope de açúcar contendo extrato de guaraná diretamente à bebida. A utilização desses extratos em concentrações mais elevadas, entretanto, é limitada pela presença dos taninos, que conferem adstringência e coloração escura ao produto final. Neste trabalho, foi estudado o desenvolvimento de um processo enzimático para obtenção de extratos não alcoólicos de guaraná, de forma a produzir um extrato contendo baixas concentrações de taninos e teores elevados de cafeína, utilizando-se planejamento experimental e processos de adsorção. Por meio de um planejamento fatorial fracionário, foram determinadas as quantidades de 0,25% (v/v) de pectinase e 0,1% (v/v) de glucoamilase, sendo mantidas no planejamento composto central, que obteve como condições ótimas: 0,23% (v/v) de celulase, 0,86% (v/v) de hemicelulase e 1% (v/v) de alfa-amilase durante 5,5 h de extração a 200 rpm e 50 °C, obtendo-se uma relação cafeína/tanino de 1,65. Com o processo de adsorção com óxido de magnésio a 10% (p/v), foi alcançada uma relação de cafeína-tanino de 7,3.<br>Guarana-flavoured beverages are very popular in Brazil and have shown an excellent sales potential on foreign markets. According to Brazilian law, each 100 mL of guarana-flavoured beverages must contain between 0.02 g and 0.2 g of guarana seed or its equivalent. These levels are normally obtained by adding a concentrated hydroalcoholic extract or sugar syrup containing guarana extract, directly to the beverage. However, the use of more concentrated extracts is limited by the presence of tannins, which imparts astringency and a dark colour to the final product. In this work the development of an enzymatic process to obtain non-alcoholic guarana extracts with low tannin concentrations and high caffeine contents was studied using an experimental design and adsorption processes. By way of a fractional factorial design the quantities of 0.25% (v/v) pectinase and 0.1% (v/v) glucoamylase were determined, which were maintained in the central composite design, obtaining as the optimal conditions: 0.23% (v/v) cellulase, 0.86% (v/v) hemicellulase, 1% (v/v) alpha-amylase, 5.5 h extraction time, 200 rpm and 50 °C, producing a caffeine/tannin ratio of 1.65. Using a magnesium oxide adsorption process at 10% (w/v), a caffeine/tannin ratio of 7.3 was obtained