109 research outputs found
Microbial Glycosidases for Nondigestible Oligosaccharides Production
There is much interest in the study and production of nondigestible oligosaccharides (NDOs), due to their bioactivities and beneficial effects to the human health. The main approach in the production of NDOs relies on the action of glycosidases performing hydrolysis or transglycosylation of polysaccharides and sugars. In this chapter, a description of the main microbial glycosidases used for NDOs production, their sources, their principal properties, and a description of the production processes with the better results obtained are discussed
Acolhimento temporário institucional
RESUMO
Este trabalho tem como objectivo principal um estudo de campo no Centro de Acolhimento Temporário Gracinda Tito com uma população de 18 crianças e jovens institucionalizados da RAM. Pretende apresentar a temática teórica e legal do acolhimento temporário, caracterizar a instituição-alvo e os participantes no estudo e, finalmente, tentar saber a razão pelo qual as crianças/jovens foram acolhidas, bem como a medida de promoção e protecção aplicada a cada criança e jovem e o seu projecto de vida futuro.ABSTRACT
The main objective of this research work about temporary institutional reception, aims to study the eighteen children and young people received at Gracinda Tito Temporary Reception Center.
This research comes to know the reason why children and young people were received, as well as the promotion and protection measure applied to every child and young, and their future life project
Primjena metode odzivnih površina radi optimiranja proizvodnje mliječne kiseline: obogaćivanje podloge, kontrola temperature i pH-vrijednosti
Two response surface methodologies involving central composite designs have been successfully applied to evaluate the effect of cheese whey, corn steep liquor, ammonium sulphate, temperature and pH control on lactic acid fermentation by Lactobacillus sp. LMI8 isolated from cassava flour wastewater. In the first central composite design, corn steep liquor and ammonium sulphate were investigated as low-cost nitrogen sources in combination with other components to substitute yeast extract for economical production. The best results were obtained with 55 g/L of lactose, 15 g/L of corn steep liquor and 5.625 g/L of ammonium sulphate. At the maximum point, the lactic acid concentration reached 18.68 g/L. After defining the optimal nutritional conditions for lactic acid production, a second central composite design was performed to determine the extent to which temperature and pH influence the lactic acid production with the aim of improving the fermentation process. The second-order polynomial regression model determined that the maximum lactic acid production of 52.37 g/L would be obtained when the optimum temperature and pH were 39.6 °C and 5.9, respectively. Comparing the lactic acid production in shake flask fermentation, there was an increase of 180 % after 30 h of processing, with a conversion efficiency of about 86.12 % of the initial lactose. In addition, lactic acid produced from whey lactose by Lactobacillus sp. LMI8 was optically almost pure D-lactic acid (over 98 % of total lactic acid produced).U radu su uspješno primijenjene dvije metode odzivnih površina, uključujući centralno složeni dizajn, za procjenu učinka koncentracije sirutke, ekstrakta kukuruza, amonijeva sulfata, temperature i pH-vrijednosti na mliječno-kiselu fermentaciju uz pomoć bakterije Lactobacillus sp. LMI8, izolirane iz otpadnih voda nakon proizvodnje brašna kasave. U prvom centralno složenom dizajnu ispitani su ekstrakt kukuruza i amonijev sulfat kao jeftini izvori dušika. Utvrđeno je da se u kombinaciji s ostalim sastojcima mogu upotrijebiti kao ekonomični nadomjestak za kvaščev ekstrakt. Najbolji su rezultati postignuti uporabom 55 g/L laktoze, 15 g/L ekstrakta kukuruza i 5,625 g/L amonijeva sulfata, pri čemu je proizvedeno 18,68 g/L mliječne kiseline. Nakon što je određen optimalni sastav hranjiva, proveden je drugi složeno centralno složeni dizajn kako bi se ispitao utjecaj temperature i pH-vrijednosti na proizvodnju mliječne kiseline i poboljšao proces fermentacije. Polinomskim regresijskim modelom drugoga reda određeno je da se maksimalna proizvodnja mliječne kiseline od 52,37 g/L može postići pri temperaturi od 39,6 °C i pH-vrijednosti od 5,9. U usporedbi s fermentacijom na tresilici, koncentracija mliječne kiseline nakon 30 h bila je 180 % veća, a uspješnost konverzije laktoze iznosila 86,12 %. Također je više od 98 % mliječne kiseline proizvedene iz laktoze sirutke s pomoću Lactobacillus sp. LMI8 bila skoro optički čista D-mliječna kiselina
Environmentally Friendly Production of D(−) Lactic Acid by Sporolactobacillus nakayamae
The interest in the production of lactic acid has increased due to its wide range of applications. In the present study, the variables that affect fermentative D(−) lactic acid production were investigated: neutralizing agents, pH, temperature, inoculum percentage, agitation, and concentration of the medium components. An experimental design was applied to determine the optimal concentrations of the medium components and fermentation was studied using different feeding strategies. High production (122.41 g/L) and productivity (3.65 g/L·h) were efficiently achieved by Sporolactobacillus nakayamae in 54 h using a multipulse fed-batch technique with an initial medium containing 35 g/L of yeast extract (byproduct of alcohol production), 60 g/L of crystallized sugar, and 7.5 mL/L of salts. The fermentation process was conducted at 35°C and pH 6.0 controlled by NaOH with a 20% volume of inoculum and agitation at 125 rpm. The production of a high optically pure concentration of D(−) lactic acid combined with an environmentally friendly NaOH-based process demonstrates that S. nakayamae is a promising strain for D(−) lactic acid production
Prospective Biodegradable Plastics from Biomass Conversion Processes
The biomass energy source has been a promising renewable alternative for fossil fuels and their inevitable environmental impacts on Earth’s life, from which the greenhouse gas (GHG) emissions and the environment pollution followed by consequent ecosystem imbalance are major concerns. Biofuels and bioplastics are well-known examples of renewable products obtained from biomass that has shown increasing potential to succeed the conventional fuels and plastics. However, biofuels and especially bioplastics have faced their main hindrance in their uncompetitive costs. Furthermore, the “drop-in” plastics are the market leaders, which reduce the carbon footprint but continue to state the biodegradability concern attributed to most of plastic products, the packaging sector. This chapter outlines the common features and feedstocks of biofuels and bioplastics aiming to support their associated production set toward the bio-based and biodegradable poly(lactic acid) (PLA) and polyhydroxyalkanoates (PHAs) as promising models with fast-growing production capacity forecasted for the next years and biodegradable solution for short-lived and disposable plastic materials
<b>Agave syrup as a substrate for inulinase production by <i>Kluyveromyces marxianus</i> NRRL Y-7571
Biochars from Spirulina as an alternative material in the purification of lactic acid from a fermentation broth
In this study, Spirulina biochar obtained from fast pyrolysis was evaluated as an alternative to commercial activated carbon for lactic acid (LA) purification from a fermentation broth. Thermally (350 and 400 C treatment of the biochar in N2 atmosphere for 4 h) and chemically (KOH solution impregnation of the algal material and fast pyrolysis to obtain the biochar) activated Spirulina biochars were also tested. The biochars were previously characterized using SEM and FT-IR. Two purification methodologies were evaluated: filtration and stirring. The stirring method prove to be simpler, faster and chipper, with excellent purification results. All the evaluated biochars presented a performance comparable to that of activated carbon in the stirring methodology. Spirulina biochar and the KOH activated biochar were the once with the best results, with 92 and 82% LA recovery and 82 and 90% protein removal efficiencies, respectively.Fil: Piloni, Roxana Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Coelho, Luciana Fontes. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Sass, Daiane Cristina. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Lanteri, Mario Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones y Transferencia de Villa María. Universidad Nacional de Villa María. Centro de Investigaciones y Transferencia de Villa María; ArgentinaFil: Bertochi, Maria Aparecida Zaghete. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Moyano, Elizabeth Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Contiero, Jonas. Universidade Estadual Paulista Julio de Mesquita Filho; Brasi
Aerobic biodegradation of butanol and diesel oil blends
This work aimed to evaluate the aerobic biodegradation of butanol/diesel oil blends (5, 10, 15, 20%, v/v) in comparison to the biodiesel/diesel oil blend (20%, v/v). Respirometric experiments simulating the contamination of natural environments (soil and water from a river) were carried out in biometer flasks (250 mL) used to measure microbial carbon dioxide (CO2) production. The automated turbidimeter Bioscreen C was used to follow the growth of Pseudomonas aeruginosa LBI on butanol/diesel oil blends. A redox indicator (2,6-dichlorophenol indophenol - DCPIP) test was used to evaluate the capability of four inocula to biodegrade the blends with 20% (v/v). The experiment which simulated the soil contamination demonstrated that butanol is less biodegradable than diesel oil, and for this reason the increase in the portion of butanol in the butanol/diesel blend from 5 to 20% had negative effects on biodegradation. While in soil the biodiesel/diesel blend was more easily biodegraded than the butanol/diesel blend, in water this order was the inverse. The insoluble fuels (diesel and biodiesel) were poorly biodegraded in water and the biodegradation of the butanol/diesel blend was favored by the water solubilization of the butanol, which enhances the bioavailability of this compound. On the other hand, initial concentrations of butanol in the water higher than 10 mL L-1 inhibited the cell growth of the tested microorganisms. Thus, butanol toxicity presumably had a significant effect on the degree of biodegradation of the fuel blends.Key words: Butanol, biodiesel, diesel, biodegradation, blends, soil, water
- …