Mixture design as a potential tool in modeling the effect of light wavelength on Dunaliella salina cultivation: an alternative solution to increase microalgae lipid productivity for biodiesel production.

For a feasible microalgae biodiesel, increasing lipid productivity is a key parameter. An important cultivation parameter is light wavelength (λ). It can affect microalgal growth, lipid yield, and fatty acid composition. In the current study, the mixture design was used as an alternative to model the influence of the λ on the Dunaliella salina lipid productivity. The illumination was considered to be the mixture of different λ (the light colors blue, red, and green). All experiments were performed with and without sodium acetate (4 g/L), as carbon source, allowing the identification of the impact of the cultivation regimen (autotrophic or mixotrophic). Without sodium acetate, the highest lipid productivity was obtained using blue and red light. The use of mixotrophic cultivations significantly enhanced the results. The optimum obtained result was mixotrophic cultivation under 65% blue and 35% green light, resulting in biomass productivity of 105.06 mgL-1day-1, a lipid productivity of 53.47 mgL-1day-1, and lipid content of 50.89%. The main fatty acids of the oil obtained in this cultivation were oleic acid (36.52%) and palmitic acid (18.31%).

Fuzzy Soft Skills Assessment through Active Learning Sessions.

This research aims to present a Fuzzy Expert System with psychologist expertise that seeks to assist professors, researchers and educational institutions in assessing the level of incorporation of students' Soft Skills while attending Active Learning sessions. The difficulties encountered by higher education institutions, researchers and professors in evaluating subjective and behavioral components, such as Soft Skills, was one of the problems that motivated the undertaking of this research. The theoretical framework on which this work is based includes the development and evaluation of Soft Skills in students, some concepts and characteristics about Active Learning and the main attributes and properties of Fuzzy Logic. This research is of an exploratory applied nature, a qualitative and quantitative approach is proposed, in which the methodological triangulation between the bibliographic analysis, the case study and the modeling and implementation of the expert system called Fuzzy Soft Skills Assessment was used to achieve the objective proposed.

The realm of cellulases in biorefinery development.

Geopolitical concerns (unstable supply of gasoline, environmental pollution, and regular price hikes), economic, and employment concerns have been prompting researchers, entrepreneurs, and policy makers to focus on harnessing the potential of lignocellulosic feedstock for fuel ethanol production and its commercialization. The carbohydrate skeleton of plant cell walls needs to be depolymerised into simpler sugars for their application in fermentation reactions as a chief carbon source of suitable ethnologic strains for ethanol production. The role of cellulolytic enzymes in the degradation of structural carbohydrates of the plant cell wall into ready-to-fermentable sugar stream is inevitable. Cellulase synergistically acts upon plant cell wall polysaccharides to release glucose into the liquid media. Cellulase predominantly dominates all the plant cell wall degrading enzymes due to their vast and diverse range of applications. Apart from the major applications of cellulases such as in detergent formulations, textile desizing, and development of monogastric feed for ruminants, their role in biorefinery is truly remarkable. This is a major area where new research tools based upon fermentation based formulations, biochemistry, and system biology to expedite the structure-function relationships of cellulases including cellulosomes and new designer enzymatic cocktails are required. In the last two decades, a considerable amount of research work has been performed on cellulases and their application in biomass saccharification. However, there are still technical and economic impediments to the development of an inexpensive commercial cellulase production process. Advancements in biotechnology such as screening of microorganisms, manipulation of novel cellulase encoding traits, site-specific mutagenesis, and modifications to the fermentation process could enhance the production of cellulases. Commercially, cheaper sources of carbohydrates and modified fermentation conditions could lead to more cost-effective production of cellulases with the goal to reduce the cost of ethanol production from lignocellulosics. Implementation of integrated steps like cellulase production and cellulase mediated saccharification of biomass in conjunction with the fermentation of released sugars in ethanol in a single step so called consolidated bio-processing (CBP) is very important to reduce the cost of bioethanol. This paper aims to explore and review the important findings in cellulase biotechnology and the forward path for new cutting edge opportunities in the success of biorefineries.

Molecular assay optimized by Taguchi experimental design method for venous thromboembolism investigation.

Two mutations - Factor V Leiden (1691G > A) and the 20210G > A on the Prothrombin gene - are key risk factors for a frequent and potentially fatal disorder called Venous Thromboembolism. These molecular alterations can be investigated using real-time Polymerase Chain Reaction (PCR) with Fluorescence Resonance Energy Transfer (FRET) probes and distinct DNA pools for both factors. The objective of this paper is to present an application of Taguchi Experimental Design Method to determine the best parameters adjustment of a Molecular Assays Process in order to obtain the best diagnostic result for Venous Thromboembolism investigation. The complete process contains six three-level factors which usually demands 729 experiments to obtain the final result, if using a Full Factorial Array. In this research, a Taguchi L27 Orthogonal Array is chosen to optimize the analysis and reduce the number of experiments to 27 without degrading the final result accuracy. The application of this method can lessen the time and cost necessary to achieve the best operation condition for a required performance. The results is proven in practice and confirmed that the Taguchi method can really offer a good approach for clinical assay efficiency and effectiveness improvement even though the clinical diagnostics can be based on the use of qualitative techniques.

Adjustment of the Operational Parameters of an Unconventional Integrated and Illuminated Internally Photobioreactor (ILI-PBR) for the Batch Autotrophic Cultivation of the Chlorella minutissima, Using the Taguchi Method.

Microalgae crops targeting biotechnological applications are conducted in photobioreactors, which allow the adjustment and control of parameters of luminosity, agitation and mixing in the cultivation medium to promote better cell growth and accumulation of metabolites. In this sense, the present work used the Taguchi method to find the best adjustment of the operational parameters of an unconventional photobioreactor denominated internally illuminated integrated photobioreactor (ILI-PBR) with LED light aiming at elevating the biomass concentration, volumetric biomass productivity, and volumetric lipid productivity of Chlorella minutissima microalgae cultivated under autotrophic regime. The effects of the factors were evaluated: illumination (blue, white and red); photoperiod (12 h light:12 h dark, 1 h light:1 h dark, and 24 h clear:0 h dark); aeration (0, 3 vvm, 0.4 vvm, and 0.5 vvm); and recirculation flow rate of cultivation medium (5 L min-1, 6.5 L min-1, and 9 L min-1) on the variable responses: biomass concentration, biomass volumetric productivity, lipid content, and volumetric lipid productivity. The use of the Taguchi method allowed the increase of biomass concentration, volumetric biomass productivity, and volumetric lipid productivity in the biomass of Chlorella minutissimain 8.6%, 42%, and 143%, respectively, with the adjustment of the operational parameters of the photobioreactor used.

Avaliação das condições reacionais para a síntese enzimática do butirato de butila empregando lipase de Candida rugosa / Evaluation of the reaction conditions for the enzymatic synthesis of the butyl butyrate using lipase from Candida rugosa

Lipase de Candida rugosa na forma livre foi usada na síntese de butirato de butila pela esterificação direta de n-butanol com ácido butírico. Um planejamento fatorial completo 24 foi empregado para determinar a influência da razão molar do álcool para ácido (1:0,5­2,5), concentração de agente dessecante (0­20 por cento), concentração de enzima (40­80 mg) e temperatura de incubação (30­60 C) no rendimento de esterificação. A concentração de agente dessecante foi o fator mais significativo na esterificação, sendo sua influência negativa. O progresso da esterificação foi favorecido para substratos contendo ácido em excesso, mesmo em baixa concentrações de enzima (40 mg), sendo a conversão de 50 por cento...