Paulo Ricardo Franco Marcelino

Ethanol production in a simultaneous saccharification and fermentation process with interconnected reactors employing hydrodynamic cavitation-pretreated sugarcane bagasse as raw material

In this study, sugarcane bagasse (SCB) pretreated with alkali assisted hydrodynamic cavitation (HC) was investigated for simultaneous saccharification and fermentation (SSF) process for bioethanol production in interconnected column reactors using immobilized Scheffersomyces stipitis NRRL-Y7124. Initially, HC was employed for the evaluation of the reagent used in alkaline pretreatment. Alkalis (NaOH, KOH, Na2CO3, Ca(OH)2) and NaOH recycled black liquor (successive batches) were used and their pretreatment effectiveness was assessed considering the solid composition and its enzymatic digestibility. In SSF process using NaOH-HC pretreatment SCB, 62.33% of total carbohydrate fractions were hydrolyzed and 17.26g/L of ethanol production (0.48g of ethanol/g of glucose and xylose consumed) was achieved. This proposed scheme of HC-assisted NaOH pretreatment together with our interconnected column reactors showed to be an interesting new approach for biorefineries.

Strategic role of nanotechnology for production of bioethanol and biodiesel

Abstract In spite of the limited sources of fossil fuels, energy demand has been considerably increased since the last century. The problems associated with global warming due to rising atmospheric greenhouse gas levels and scarcity of fossil fuels make it imperative to reduce our heavy dependency on fossil fuels. These reasons forced countries throughout the world to search for new fuel alternatives. Biofuel have gathered considerable attention due to their inherent benefits, like lower greenhouse gas emission, renewability, and sustainability. Commercially, biofuels are produced from vegetable oils, animal fats, and carbohydrates by using transesterification and fermentation. However, biofuel production suffers from high production costs and other technical barriers. Considering the environmental and economic issues, use of nanotechnology seems to be a viable solution. Nanoparticles have a number of interesting properties for the production of second-generation ethanol or transesterification of oils and fats to yield biodiesel. It is advantageous for recovery and reuse of catalysts. The present review discusses the role of nanotechnology in the production of bioethanol and biodiesel. Moreover, applications of nanoparticles for the production of biodiesel and second-generation ethanol with special reference to enzyme immobilization and chemical nano-catalysis have been described.

Maize Inoculation with Azospirillum brasilense Ab-V5 Cells Enriched with Exopolysaccharides and Polyhydroxybutyrate Results in High Productivity under Low N Fertilizer Input

Although Azospirillum strains used in commercial inoculant formulations presents diazotrophic activity, it has been reported that their ability to produce phytohormones plays a pivotal role in plant growth-promotion, leading to a general recommendation of its use in association with regular N-fertilizer doses. In addition, a high variability in the effectiveness of Azospirillum inoculants is still reported under field conditions, contributing to the adoption of the inoculation technology as an additional management practice rather than its use as an alternative practice to the use of chemical inputs in agriculture. To investigate whether the content of stress-resistance biopolymers would improve the viability and performance of Azospirillum inoculants when used as substitute of N-fertilizers, biomass of A. brasilense strain Ab-V5 enriched in exopolysaccharides (EPS) and polyhydroxybutirate (PHB) was produced using a new culture medium developed by factorial mixture design, and the effectiveness of resulting inoculants was evaluated under field conditions. The culture medium formulation extended the log phase of A. brasilense cultures, which presented higher cell counts and increased EPS and PHB contents than observed in the cultures grown in the OAB medium used as control. An inoculation trial with maize conducted under greenhouse conditions and using the biopolymers-enriched Ab-V5 cells demonstrated the importance of EPS and PHB to the long term bacterial viability in soil and to the effectiveness of inoculation. The effectiveness of liquid and peat inoculants prepared with Ab-V5 cells enriched with EPS and PHB was also evaluated under field conditions, using maize as target crop along different seasons, with the inoculants applied directly over seeds or at topdressing under limiting levels of N-fertilization. No additive effect on yield resulted from inoculation under high N fertilizer input, while inoculated plants grown under 80% reduction in N fertilizer showed yields at levels compared to fully fertilized plants, regardless the inoculation method. The presented data highlights the feasibility to partially substitute the N-fertilizer demand in non-legume crops using high-quality inoculant formulations, prepared with diazotrophic bacteria enriched with stress-resistance biopolymers that confer increased viability an effectiveness to the bacterial cells.

Low-melanin containing pullulan production from sugarcane bagasse hydrolysate by Aureobasidium pullulans in fermentations assisted by light-emitting diode

Pullulan is a polymer produced by Aureobasidium pullulans and the main bottleneck for its industrial production is the presence of melanin pigment. In this study, light-emitting diodes (LEDs) of different wavelengths were used to assist the fermentation process aiming to produce low-melanin containing pullulan by wild strain of A. pullulans LB83 with different carbon sources. Under white light using glucose-based medium, 11.75g.L-1 of pullulan with high melanin content (45.70UA540nm.g-1) was obtained, this production improved in process assisted by blue LED light, that resulted in 15.77g.L-1 of pullulan with reduced content of melanin (4.46UA540nm.g-1). By using sugarcane bagasse (SCB) hydrolysate as carbon source, similar concentration of pullulan (about 20g.L-1) was achieved using white and blue LED lights, with lower melanin contents in last. Use of LED light was found as a promising approach to assist biotechnological process for low-melanin containing pullulan production.

Biosurfactants produced by Scheffersomyces stipitis cultured in sugarcane bagasse hydrolysate as new green larvicides for the control of Aedes aegypti, a vector of neglected tropical diseases.

Biosurfactants are microbial metabolites with possible applications in various industrial sectors that are considered ecofriendly molecules. In recent years, some studies identified these compounds as alternatives for the elimination of vectors of tropical diseases, such as Aedes aegypti. The major bottlenecks of biosurfactant industrial production have been the use of conventional raw materials that increase production costs as well as opportunistic or pathogenic bacteria, which restrict the application of these biomolecules. The present study shows the potential of hemicellulosic sugarcane bagasse hydrolysate as a raw material for the production of a crystalline glycolipidic BS by Scheffersomyces stipitis NRRL Y-7124, which resulted in an emulsifying index (EI24) of 70 ± 3.4% and a superficial tension of 52 ± 2.9 mN.m-1. Additionally, a possible new application of these compounds as biolarvicides, mainly against A. aegypti, was evaluated. At a concentration of 800 mg.L-1, the produced biosurfactant caused destruction to the larval exoskeletons 12 h after application and presented an letal concentration (LC50) of 660 mg.L-1. Thus, a new alternative for biosurfactant production using vegetal biomass as raw material within the concept of biorefineries was proposed, and the potential of the crystalline glycolipidic biosurfactant in larvicidal formulations against neglected tropical disease vectors was demonstrated.

Beyond Ethanol: Contribution of Various Bioproducts to Enhance the Viability of Biorefineries

Environmental pollution by the extensive use of fossil fuels and petroleum-based products is a current worldwide concern. In this context, the development of valuable products from renewable sources is an interesting and environmentally friendly alternative. Lignocellulosic biomass is a renewable low cost feedstock that presents in its composition high quantity of cellulose, carbohydrate extensively studied to produce cellulosic ethanol. However, considering the high cost of 2G ethanol process, the coupled production of other products can help the economic viability in a context of a biorefinery producing bioenergy, biopolymers, biopharmaceutical, nutrients, pigments, surfactants, biochemical, and others, from different fractions of biomass. Products with high economic value such as vitamins B7, B12, C and E, riboflavin, xylitol and lactic acid can be obtained by biotechnological route from sugars released after hydrolysis of cellulose and hemicellulose fraction present in biomass. Thus, an integrated industry that can direct production considering market fluctuation could be thought, taking advantage of biotechnological routes. In this chapter, biorefinery concept is briefly discussed and some bioproducts that can contribute with economic viability of current biorefineries are presented. Some interesting possibilities were discussed, including different compounds with a variety of applications as substitute of traditional products or representing new and innovative ones.

Metal-Based Drugs for Treatment of Malaria

Despite the incessant efforts to decrease exorbitant number of daily deaths, malaria remains a major threat to the public health in many countries. Transmitted by Anopheles mosquitoes, it is caused by infection with Plasmodium parasites that have become resistant to many antimalarial drugs. In this context, series of metal-based compounds have been screened for optimal activity against different Plasmodium species and strains. This chapter briefly reviews current and potential uses of metal complexes (such as iron, cobalt, nickel, gallium, copper, gold, and silver), metal chelators, and organometallic compounds, as interesting medicinal agents that greatly benefits the fight against malaria.

Sugarcane bagasse hydrolysate as a potential feedstock for red pigment production by Monascus ruber

Sugarcane bagasse (SCB) hydrolysate could be an interesting source for red pigment production by Monascus ruber Tieghem IOC 2225. The influence of different wavelength of light-emitting diode (LED) at 250 μmol.m-2.s-1 of photon flux density on red pigment production by M. ruber in glucose-based medium was evaluated. Then, SCB hydrolysate was used as carbon source under the previously selected light incidence conditions. In glucose-based medium, the highest pigment production was achieved in fermentation assisted with orange LED light (8.28 UA490nm), white light (8.26 UA490nm) and under dark condition (7.45 UA490nm). By using SCB hydrolysate-based medium, the highest red pigment production (18.71 AU490nm) was achieved under dark condition and the glucose and cellobiose present in the hydrolysate were metabolized. SCB enzymatic hydrolysate was demonstrated to be a promising carbon source for high thermal stability red pigment production (activation energy of 10.5 kcal.mol-1), turning an interesting alternative for implementation in biorefineries.