Denise Maria Guimarães Freire

Lipase production by Penicillium restrictum in solid-state fermentation using babassu oil cake as substrate

Abstract Growth and enzyme production in SSF by a Brazilian strain of Penicillium restrictum was studied. Solid waste from the babassu oil industry was used as the basic nutrient source and was supplemented with peptone, olive oil or starch at different C/N ratios. The highest lipase activity (30.3 U/g initial dry weight) was achieved after 24 h of cultivation with 2% olive oil enrichment. Lipase activity was very sensitive to the kind and the level of supplementation, and decreased as protease level and pH in the media increased. Maximal levels of glucoamylase and protease were obtained with 4% starch enrichment, indicating that the type of carbon source supplemented to the basal medium determines the major enzymes produced.

Economic analysis of lipase production by Penicillium restrictum in solid-state and submerged fermentations

In the present work an economic analysis of the production of Penicillium restrictum lipase in both submerged (SF) and solid state fermentations (SSF) was performed. For a production scale of 100 m 3 lipase concentrate per year, total capital investment needed for the submerged process was 78% higher than that needed for the solid-state fermentation process. The submerged process proved to be economically unfeasible, as unitary product cost was 68% higher than the product selling price. Contrastingly, the solid-state fermentation process turned out to be very attractive from an economic point of view. Also for a scale of 100 m 3 /year, SSF unitary product cost was 47% lower than the selling price, payback time was 1.5 years, return on investment was 68% and internal return rate was 62% for a 5-year-project life. Furthermore, the profitability of this process remained high even with eventual increases of 40% in product concentration or total capital investment, or decreases of 20% in product price. The great advantage of the SSF process is the extremely cheap raw material it uses as main substrate. ©2000 Elsevier Science S.A. All rights reserved.

Immobilization of lipases on hydrophobic supports involves the open form of the enzyme.

The lipases from Thermomyces lanuginosus and Pseudomonas cepacia have been immobilized on octyl and cyanogen bromide (CNBr) agarose beads. The immobilization on octyl-agarose is slowed with increasing ionic strength, while the immobilization on CNBr is not significantly affected by the ionic strength. The inhibition of the immobilized preparations with diethyl p-nitrophenylphosphate (D-pNPP) was analyzed. The inhibition was more rapid using octyl-lipase preparations than using covalent preparations, and the covalent preparations were much more sensitive to the reaction medium. The addition of detergent increased the inhibition rate of the covalent preparation while an increase on the ionic strength produced a slowdown of the inhibition rate by D-pNPP for both lipases. The effect of the medium on the activity versus fully soluble substrate (methyl mandelate) was in the same direction. The octyl preparations presented a slight decrease in activity when comparing the results using different concentrations of sodium phosphate buffer (between 0.025 and 1M), while the CNBr preparations suffered drastic drops in its activity at high ionic strength. The results confirm that the lipases immobilized on octyl agarose presented their open form stabilized while the covalent preparation maintains a closing/opening equilibrium that may be modulated by altering the medium.

Production of polyhydroxyalkanoates (PHAs) from waste materials and by-products by submerged and solid-state fermentation.

Polyhydroxyalkanoates are biodegradable polymers produced by prokaryotic organisms from renewable resources. The production of PHAs by submerged fermentation processes has been intensively studied over the last 30 years. In recent years, alternative strategies have been proposed, such as the use of solid-state fermentation or the production of PHAs in transgenic plants. This paper gives an overview of submerged and solid-state fermentation processes used to produce PHAs from waste materials and by-products. The use of these low-cost raw materials has the potential to reduce PHA production costs, because the raw material costs contribute a significant part of production costs in traditional PHA production processes.

Production of biosurfactants from Pseudomonas aeruginosa PA 1 isolated in oil environments

The potential production of rhamnolipid-type biosurfactants is assessed based on the development of a fermentative process with a strain of Pseudomonas aeruginosa PA1, which was isolated from oil production wastewater in the Northeast of Brazil. These production of molecules using different carbon (n-hexadecane, paraffinic oil, glycerol and babassu oil) and nitrogen sources (NaNO3, (NH4)2SO4 and CH4N2O) was studied. The best results were obtained when using glycerol as substrate. A C/N ratio of 60/1 and use of sodium nitrate as nitrogen source resulted in higher production of the rhamnolipid, expressed by rhamnose (3.16 g/L) and by the yield in relation to biomass (Yp/x = 0.70 g/g). Additionally, physical-chemical characteristics of the spent broth with and without cells were studied, providing a low critical micelle concentration of 19 mg/L and toxicity values of 13 and 13.8 mg/L using two test organisms, the micro crustacean Daphnia similis and the bacterium Vibrio fisheri (Microtox), respectively.

Production of an acidic and thermostable lipase of the mesophilic fungus Penicillium simplicissimum by solid-state fermentation.

The production of a lipase by a wild-type Brazilian strain of Penicillium simplicissimum in solid-state fermentation of babassu cake, an abundant residue of the oil industry, was studied. The enzyme production reached about 90 U/g in 72 h, with a specific activity of 4.5 U/mg of total proteins. The crude lipase showed high activities at 35-60 degrees C and pH 4.0-6.0, with a maximum activity at 50 degrees C and pH 4.0-5.0. Enzyme stability was enhanced at pH 5.0 and 6.0, with a maximum half-life of 5.02 h at 50 degrees C and pH 5.0. Thus, this lipase shows a thermophilic and thermostable behavior, what is not common among lipases from mesophilic filamentous fungi. The crude enzyme catalysed the hydrolysis of triglycerides and p-nitrophenyl esters (C4:0-C18:0), preferably acting on substrates with medium-chain fatty acids. This non-purified lipase in addition to interesting properties showed a reduced production cost making feasible its applicability in many fields.

Enzymatic pre-hydrolysis and anaerobic degradation of wastewaters with high fat contents

Dairy wastewaters containing elevated fat and grease levels (868 mg l−1) were treated in an upflow anaerobic sludge blanket reactor (UASB) and resulted in effluents of high turbidity (757 nephelometric turbidity units), volatile suspended solids up to 944 mg l−1 and COD removal below 50%. When the same dairy wastewater was pre-treated with 0.1% (w/v) of fermented babassu cake containing Penicillium restrictum lipases, turbidity and volatile suspended solids were decreased by 75% and 90%, respectively, and COD removal was as high as 90%.

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.

Evaluation of Different Carbon and Nitrogen Sources in Production of Rhamnolipids by a Strain of Pseudomonas aeruginosa

Culture conditions involving variations in carbon and nitrogen sources and different C:N ratios were examined with the aim of increasing productivity in the process of rhamnolipid synthesis by Pseudomonas aeruginosa. In addition to the differences in productivity, the use of different carbon sources resulted in several proportions related to the types of rhamnolipids synthesized (monorhamnolipids and dirhamnolipids). Furthermore, the variation in nutrients, mainly the nitrogen source, resulted in different amounts of virulence factors, as phenazines and extracellular proteins. The data point out a new concern in the choice of substrate to be used for rhamnolipid production by P. aeruginosa: toxic byproducts.

Nanomaterials for biocatalyst immobilization – state of the art and future trends

Nanotechnology is an area that has been growing over the years, being possible nowadays to find numerous materials constructed at nanoscale. In addition, many applications have been attributed to these “new” materials. In this review is presented a brief overview of nanoparticles used for the immobilization of enzymes. Considering the extensive universe of immobilization in nanoparticles, some were chosen to be exposed here, such as chitosan, graphene, silica, polymers, magnetic, nanoflowers, among others. Advantages, disadvantages and limitations of nanoimmobilization also be discussed. Some applications of nanoimmobilized enzymes are presented, like as biodiesel, flavor synthesis ester and biosensors. The purpose of this paper is to provide an overview of what is being studied in relation to nanoparticles for enzymes immobilization, and some discussions about them, aimed at assisting researchers in future studies and reviews.