Marco Antônio Záchia Ayub

• PhD
• Full Professorship at Federal University of Rio Grande do Sul

Kombucha, a traditional drink crafted from fermented sweetened black or green tea using a symbiotic association of bacteria and yeasts known as SCOBY, has become a popular product in Western countries. Whey, a nutrient-rich byproduct of dairy production, provides an interesting option as substrate for producing novel beverages. Here, we aimed at ev...

The present work aimed to evaluate the features of yerba mate kombucha during 7 days of fermentation at either 25 ºC or 30 ºC, monitoring physicochemical changes, sensory profile, and sensorial acceptance. The symbiotic microbial culture of active bacteria and yeasts (SCOBY) at the beginning and the end of the bioprocess was also identified. The ye...

The interest for oleaginous yeasts has grown significantly in the last three decades, mainly due to their potential use as a renewable source of microbial oil or single cell oils (SCOs). However, the methodologies for cell disruption to obtain the microbial oil are considered critical and determinant for a large-scale production. Therefore, this wo...

The bioconversion of porungo cheese whey to produce β-galactosidase in batch system was studied. The whey released after curd cutting and precipitation during porungo cheese production was collected in borosilicate flasks. Two strains of Kluyveromyces marxianus, CCT 4086 and CBS 6556, and whey supplementation with different nitrogen sources were ev...

Kombucha is a functional beverage that lacks studies toward standardization of process parameters; thus, the present work aims to evaluate the effect of sucrose content, initial SCOBY mass, and tea composition on several characteristics of the final beverage. For this purpose, a factorial design was performed, and the effect of the three variables...

The production of polyhydroxyalkanoates (PHAs) by Bacillus megaterium using industrial residues, crude glycerol from biodiesel synthesis and rice hull hydrolysate (RHH), as low-cost carbon sources was investigated. The experiments were conducted by shaking flasks at 30 °C and 180 rpm up to 72 h. The extraction of PHA was carried out using sodium hy...

Endophytic fungi (EF) have a notable capacity to produce active molecules of industrial importance, such as hydrolytic enzymes. In this study we investigated the production of lipase by EFs isolated from the Amazonian species Aniba canelilla (Lauraceae), characterized the enzymatic extract obtained from the most promising fungus, and applied the li...

Co-cultivation involving Saccharomyces cerevisiae CAT-1 and native Spathaspora hagerdaliae UFMG-CM Y303 was used to produce ethanol from sugars obtained from steam-exploded sugarcane bagasse (SCB-SE) after enzymatic hydrolysis. The fermentation process was carried out under separate hydrolysis and fermentation (SHF) and simultaneous hydrolysis and...

In recent years, residual glycerol from biodiesel synthesis made this chemical a cheap, readily available carbon source to bioprocess, which is also a form to reduce costs in the fuel industry. We propose and describe a bioprocess using fluidized and packed‐bed continuous bioreactors to convert this residual glycerol into value‐added products such...

The dairy bacteria Propionibacterium sp. and Acidipropionibacterium sp. are versatile and potentially probiotic microorganisms showing outstanding functionalities for the food industry, such as the production of propionic acid and vitamin B12 biosynthesis. They are the only food grade microorganisms able to produce vitamin B12. However, the ferment...

We optimized the production of lactic acid by Lactobacillus plantarum BL011, using acid and enzymatic soybean hull hydrolysates as cultivation media. Selection of cultivation conditions was performed in Erlenmeyer flasks, in orbital shaker at 37 °C and 120 rpm, pH 6.0. Plackett–Burman experimental design was performed as tool to identify the best c...

We investigated the performance of fluidized and packed-bed bioreactors using cells of Spathaspora passalidarum UFMG-CM-469 immobilized on LentiKats® in the fermentation of lignocellulosic biomass hydrolysates. Acid (AH-CYE) and enzymatic (EH-CYE) hydrolyses of a 1:1 mixture of oat and soybean hulls, minimally supplemented with crude yeast extract,...

Ninety-two wild yeasts were isolated from different fruits, for possible use in brewing, using the technological traits of carbohydrate fermentation and hydrogen sulfide production. Twelve yeasts were selected for identification by sequencing (D1/D2 domain or ITS1-5.8S-ITS2 region) and their volatile compounds production analyzed using gas chromato...

We investigated the fermentation of a mixture of oat and soybean hulls (1:1) subjected to acid (AH) or enzymatic (EH) hydrolyses, with both showing high osmotic pressures (> 1200 Osm kg−1) for the production of ethanol. Yeasts of genera Spathaspora, Scheffersomyces, Sugiymaella, and Candida, most of them biodiverse Brazilian isolates and previously...

This study evaluated the lactose hydrolysis by immobilized β-galactosidase, which was produced by Kluyveromyces marxianus using porungo cheese whey as substrate. Initially, the yeast was cultivated in porungo cheese medium at 30 °C and 200 rpm, showing a maximal β-galactosidase production of 14.19 U mL-1. The crude extract obtained was used to eval...

Kombucha is a traditional fermented beverage gaining popularity around the world. So far, few studies have investigated its microbiome using next-generation DNA sequencing, whereas the correlation between the microbial community and metabolites evolution along fermentation is still unclear. In this study, we explore this correlation in a traditiona...

We studied the expression of Bacillus amyloliquefaciens transglutaminase cloned in Escherichia coli BL21(DE3)pLysS harboring the plasmid pBAD/3C/bTGase, a bicistronic expression system, in bioreactor cultivation. Batch and fed-batch controlled as DO-stat strategies were employed for the production of the recombinant enzyme. In 30 h-batch cultivatio...

The bioconversion of porungo cheese whey into galactooligosaccharides (GOS) was investigated using immobilized β-galactosidase in batch system. Two enzymatic immobilization strategies were tested for optima pH and temperature and the best immobilization strategy was used to evaluate the GOS production in two steps. First, different lactose sources...

K. pneumoniae BLh-1 strain was genetically modified aiming at obtaining high ethanol productivity in cultivations using residual glycerol from biodiesel synthesis as substrate. The recombinant strain K. pneumoniae Kp17 was obtained by inserting the multicopy plasmid pTOPOBL17 containing the AdhE gene, and its own promoter, from K. pneumoniae BLh-1....

The industrial application of lipolytic enzymes has been studied mainly due to the ability of these enzymes in catalyze reactions of synthesis and their stability in various organic solvents. One possibility is the use of lipase the organic synthesis, taking advantage as the generation of waste and difficult recovery of sub bioproducts. In this wor...

Nine yeast strains isolated from Latin American biodiversity were screened for ferulic acid (FA) consumption and conversion into aroma compounds such as vanillin, vanillic acid (VA), and 4‐vinylguaiacol (VG). Selected strains (Rhodotorula mucilaginosa UFMG‐CM‐Y3647, UFMG‐CM‐Y2190, UFMG‐CM‐Y665) were evaluated in flask experiments to investigate the...

Production of 2,3-butanediol (2,3-BD) by Pantoea agglomerans strain BL1 was investigated using soybean hull hydrolysate as substrate in batch reactors. The cultivation media consisted of a mixture of xylose, arabinose, and glucose, obtained from the hemicellulosic fraction of the soybean hull biomass. We evaluated the influence of oxygen supply, pH...

Lipases CAL-B, TLL, and RML were used in the synthesis of free fatty acids of grape seed oil as heterogeneous substrate. The best enzyme was used to optimize the reaction variables temperature, enzyme content, and molar ratio of water:oil in batch reactions using experimental planning. The ideal conditions to produce free fatty acids using pure RML...

Vitamin B12 deficiency still persists, mainly caused by low intake of animal food products affecting vegetarians, vegans, and populations of underdeveloped countries. In this study, we investigate the biosynthesis of vitamin B12 by potential probiotic bacterium using an agroindustry residue, the liquid acid protein residue of soybean (LAPRS), as a...

We evaluated the ability of a recently isolated xylose-fermenting strain of Spathaspora hagerdaliae UFMG-CM-Y303 to convert acid AH and enzymatic EH hydrolysates of soybean and oat hulls, or their mixture AEH, into second-generation ethanol and xylitol. All hydrolysates presented high concentrations of glucose and xylose, showing high osmotic press...

The transglutaminases form a large family of intracellular and extracellular enzymes that catalyze cross-links between protein molecules. Transglutaminases crosslinking properties are widely applied to various industrial processes, to improve the firmness, viscosity, elasticity, and water-holding capacity of products in the food and pharmaceutical...

Because of their protein cross-linking properties, transglutaminases are widely used in several industrial processes, including the food and pharmaceutical industries. Transglutaminases obtained from animal tissues and organs, the first sources of this enzyme, are being replaced by microbial sources, which are cheaper and easier to produce and puri...

We investigated the production of 2,3‐butanediol by two enterobacteria isolated from an environmental consortium, Klebsiella pneumoniae BLh‐1 and Pantoea agglomerans BL1, in a bioprocess using acid and enzymatic hydrolysates of soybean hull as substrates. Cultivations were carried out in orbital shaker under microaerophilic conditions, at 30°C and...

The present study evaluated 13 strains of yeast for ethanol and xylitol production from xylose. Among them, Spathaspora hagerdaliae UFMG-CM-Y303 produced ethanol yields (YP/S) of 0.25 g g− 1 and 0.39 g g− 1 under aerobic and microaerophilic conditions, respectively, from a mixture of glucose and xylose in flasks. A pH of 5.0 and an inoculum of 3.0...

This work describes the use of an ultrasound system for the enzymatic transesterification of oils using combi-lipases as biocatalyst. The reactions were carried out evaluating the individual use of waste oil and fresh soybean oil, and the immobilized lipases CALB, TLL, and RML were used as biocatalysts. It was performed in a mixture design of three...

We describe a three-steps bioprocess to convert rice husk as source of xylooligosaccharides and then used these prebiotics to grow lactic acid bacteria as a model to produce probiotics from vegetal sources. First, Aspergillus brasiliensis BLf and the recombinant Aspergillus nidulans XynC A773 strains were solid-state cultivated in rice husk to prod...

This work describes the continuous synthesis of ethyl esters via enzymatic catalysis on a packed-bed continuous reactor, using mixtures of immobilized lipases (combi-lipases) of Candida antarctica (CALB), Thermomyces lanuginosus (TLL), and Rhizomucor miehei (RML). The influence of the addition of glass beads to the reactor bed, evaluation of the us...

We investigated the simultaneous production of xylanase and the liberation of xylooligosaccharides in rice husk solid‐state cultivations of Aspergillus brasiliensis BLf1 and by the recombinant Aspergillus nidulans XynC A773 strain. The bioprocess was optimised by experimental fractional design and response surface analysis. Results show that both f...

In this study, we evaluated the capacity of recombinant industrial Saccharomyces cerevisiae YRH 396 and YRH 400 strains to ferment sugars from oat hull and soybean hull hydrolysates into ethanol and xylitol. The strains were genetically modified by chromosomal integration of Pichia stipitis XYLI/XYL2 genes and the overexpression of S. cerevisiae XK...

This work investigated the ability of a recently isolated strain of Candida guilliermondii to convert hexoses and pentoses obtained from acid-enzymatic soybean hull hydrolysates into ethanol and, in smaller amounts, into xylitol. Operational conditions and media formulation were optimized concerning ethanol production using experimental designs (Pl...

An industrial ethanol-producing Saccharomyces cerevisiae strain with genes of fungal oxido-reductive pathway needed for xylose fermentation integrated into its genome (YRH1415) was used to obtain haploids and diploid isogenic strains. The isogenic strains were more effective in metabolizing xylose than YRH1415 strain and able to co-ferment glucose...

We carried out the physico-chemical characterization of Immobead 150, a hydrophobic support for the immobilization of lipases. Thermomyces lanuginosus lipase (TLL) was immobilized on Immobead 150 by multipoint covalent attachment (ImmTLL) and the morphological, textural, structural, thermal, and physico-chemical properties of the support, before an...

The aims of this work were to evaluate the ability of furaldehyde-tolerant yeast strains Saccharomyces cerevisiae P6H9 and Wickerhamomyces anomalus WA-HF5.5 and their cofermentations and to convert soybean and rice hull hydrolysates into ethanol and xylitol. In batch shaker cultures, the strains showed the ability to tolerate high osmotic pressure...

We investigated the environmental performance of white and brown parboiled rice types produced under two alternative cultivation systems, namely minimal tillage and organic farming, using Life Cycle Assessment (LCA). The study was carried out in the most important rice production region of Latin America, the south of Brazil. The functional unit for...

We investigated the enzymatic complex produced by selected fungi strains isolated from the environment using the agro-industrial residues rice husk, soybean hull, and spent malt as substrates. Microbial growth was carried out in solid-state cultivation (SSC) and in submerged cultivations (SC) and the enzymatic activities of xylanase, cellulase, β-x...

Knowledge on the environmental impact caused by rice cultivation, the most consumed cereal in the world, is essential to assess agricultural impact on total global anthropogenic emissions of greenhouse gases. Using Life Cycle Assessment (LCA), we compared the Global Warming Potential (GWP) of white and brown rice from two different cultivation syst...

Probiotic products are dietary supplements containing live microorganisms producing beneficial health effects on the host by improving intestinal balance and nutrient absorption. Among probiotic microorganisms, those classified as lactic acid bacteria are of major importance to the food and feed industries. Probiotic cells can be produced using alt...

In this study, physiological aspects of Lactobacillus plantarum BL011 growing in a new, all-animal free medium in bioreactors were evaluated aiming at the production of this important lactic acid bacterium. Cultivations were performed in submerged batch bioreactors using the Plackett–Burman (PB) methodology to evaluate the influence of temperature,...

Thermomyces lanuginosus lipase (TLL) was covalently immobilized on Immobead 150 (ImmTLL) via epoxy groups of the support and the lysine of the enzyme to be used in the synthesis of butyl butyrate. The optimization of the esterification reaction parameters was carried out by central composite design and response surface methodology, having product y...

Dried powder of microencapsulated Lactobacillus plantarum, a probiotic bacterium, was developed for direct addition into food or food preparations without the need of cold storage, allowing its use at 25 ºC. Cells were microencapsulated in calcium alginate using the electrospray technique. The viability of cells throughout six months of storage, ce...

We studied the dynamics of ethanol production on lactose-hydrolyzed whey (LHW) and lactose-hydrolyzed whey permeate (LHWP) in batch fluidized-bed bioreactors using single and co-cultures of immobilized cells of industrial strains of Saccharomyces cerevisiae and non-industrial strains of Kluyveromyces marxianus. Although the co-culture of S. cerevis...

Optimized hydrolysis of lignocellulosic waste biomass is essential to achieve the liberation of sugars to be used in fermentation process. Ionic liquids, a new class of solvents, have been tested in the pretreatment of cellulosic materials to improve the subsequent enzymatic hydrolysis of the biomass. Optimized application of ionic liquids on bioma...

Grape pomace is an abundant agro-industrial residue that could be used as a source of natural antioxidants, when using appropriate techniques for their extraction. The solid-liquid extraction of bioactive compounds from grape pomace was optimized by experimental design. Temperature, ethanol, and Tween 80 amounts were evaluated by measuring the tota...

In this research, we tried to recover the antioxidant activities of grape pomace by means of using solid-state cultivation (SSC) of Aspergillus niger BLAn1, Phanerochaete chrysosporium BLPc1, and Penicillium sp. BLPen1, three GRAS strains of fungi. We measured the enzymatic activities of β-glucosidase, responsible for liberating the aglycone forms...

We investigated the kinetics of whey bioconversion into ethanol by Kluyveromyces marxianus in continuous bioreactors using the “accelerostat technique” (A-stat). Cultivations using free and Ca-alginate immobilized cells were evaluated using two different acceleration rates (a). The kinetic profiles of these systems were modeled using four different...

In this study, we evaluated the effect of growing Dunaliella tertiolecta microalgae using CO2 from brewing on the production of lipid and carotenoid-rich biomass. An integrated system of microalgae photobioreactors and yeast fermenters was used, thus providing biological CO2 continuously to the microalgae culture. Yeast cultures were first carried...

Lipases are being extensively researched for the production of biodiesel as a "silver bullet" in order to avoid the drawbacks of the traditional alkaline transesterification. In this review, we analyzed the main factors involved in the enzymatic synthesis of biodiesel, focusing in the choice of the immobilization protocol, and the parameters involv...

The bioconversion of residual glycerol obtained from biodiesel synthesis into 1,3-propanediol (1,3-PD) was carried out using Ca-alginate immobilized-cells cultures of Klebsiella pneumoniae BLh-1. The immobilization parameters bead size and cell concentration were determined for the best possible productivity and were found to be 3.4 mm and 100 mg m...

In this work, β-fructofuranosidase and β-fructosyltransferase were covalently immobilized on chitosan spheres, using glutaraldehyde as a coupling agent, in order to produce invert sugar and fructooligosaccharides (FOS). Maxinvert L was used to make β-fructofuranosidase biocatalyst yielding 7000 HU/g. A partial purified β-fructosyltransferase from V...

Although reactions of transesterification are generally catalyzed by one specific lipase preparation, the concept of “combi-lipase” could be better explored for the production of biodiesel, since oils are heterogeneous substrates. In this research, we tested this concept by evaluating the enzymatic transesterification of olive and palm oils, two di...

We investigated the bioconversion of whey and whey permeate into ethanol by Kluyveromyces marxianus immobilized in Ca-alginate, in both batch and continuous cultivations. Different strains of K. marxianus and cultivation media were tested in batch mode and the effects of dilution rate (D) and substrate concentration were investigated in continuous...

The aim of this research was to characterize the γ-PGA produced by Bacillus subtilis BL53, comparing the influence of cultivation time on the rheological and thermal biopolymer characteristics in order to identify its potential applications. Bacterial cultivations were carried out in bioreactors under previously optimized conditions (medium E, 37 °...

The aims of this study were to evaluate the effects of the addition of metabolic precursors and polydimethylsiloxane (PDMS) as an oxygen carrier to cultures of Bacillus subtilis BL53 during the production of γ-PGA. Kinetics analyses of cultivations of different media showed that B. subtilis BL53 is an exogenous glutamic acid-dependent strain. When...

It is well established that the performance of lipase B from Candida antarctica (CALB) as catalyst for esterification reactions may be improved by the use of ultrasound technology or by its immobilization on styrene-divinylbenzene beads (MCI-CALB). The present research evaluated the synthesis of butyl acetate using MCI-CALB under ultrasonic energy,...

In this work, the combined use of ultrasound energy and molecular sieves was investigated for the synthesis of ethyl butyrate, ester with mango and banana notes, catalyzed by the immobilized lipase from Thermomyces lanuginosus (Lipozyme TL-IM). Initially, the best concentrations of biocatalysts (35%) and butyric acid (0.7M) were tested using ultras...

Lipase from Staphylococcus warneri EX17 (SWL) was purified and immobilized via interfacial adsorption using the hydrophobic supports Octyl-sepharose, Immobead 150, and MCI GEL CHP20P. The purity of the obtained immobilized biocatalysts, Octyl-SWL, Immobead-SWL, and MCI-SWL, was evaluated by SDS-PAGE and their thermal and solvent stability were test...

The concept of the combi-lipase biocatalyst has been proposed. It is based on the combination of different lipases as biocatalysts in reactions using heterogeneous substrates. The hydrolysis of soybean oil was evaluated as a model substrate, and Novozym 435 (CALB), Lipozyme TL-IM (TLL), and Lipozyme RM-IM (RML) were used as biocatalysts. Results sh...

Thermomyces lanuginosus lipase (TLL) was immobilized on native and modified Immobead 150, with epoxy groups removed by hydrolysis and oxidized to add aldehyde on its surface. Immobilizations on both supports were performed by adsorption, adsorption and cross-linking, covalent attachment, multipoint covalent attachment, and, for the modified support...

In this research, the effects of ultrasound stirring and the addition of molecular sieves on esterification reactions between butyric acid and several alcohols catalyzed by immobilized lipase from Rhizomucor miehei (Lipozyme RM-IM) were studied. Among the tested alcohols, 1-propanol and isobutanol allowed the highest activities, whereas Lipozyme RM...

Butyl butyrate is an ester present in pineapple flavor that is very important for the food and beverages industries. In this work, we performed the optimization of the reaction of butyl butyrate synthesis catalyzed by the immobilized lipase Lipozyme TL-IM. n-Hexane was selected as the most appropriate solvent. Other reaction parameters such as temp...

In this work two immobilized preparations of lipase (EC 3.1.1.3) B from Candida antarctica (CALB) were compared for the synthesis of fatty acid methyl esters (FAME) using soybean oil. Commercial Novozym 435 (CALB-435) and CALB immobilized on styrene-divinylbenzene beads (CALB-MCI) were tested for the transesterification reactions. Central composite...

This work describes a process of multipoint covalent immobilization of the lipases from Rhizomucor miehei (RML) and type B from Candida antarctica (CALB) in modified Immobead 150 support. Acid hydrolysis, followed by oxidation with sodium periodate, was applied to modify Immobead 150 by exchanging its epoxy groups to aldehyde in its surface. Immobi...

The sourdough fermentation in bread making is strongly motivated due to its beneficial aspects on flavor, texture, shelf life, and the nutritional properties of the obtained products. In this research, the yeasts Kluyveromyces marxianus and Dekkera bruxellensis, and the bacterium Lactobacillus plantarum were used as alternative starter cultures in...

The aims of this research were to screen and characterize a new microbial source of γ-PGA, to optimize aspects of culture conditions and medium composition using central composite design and response surface methodologies. The influence of bioreactor stirring rates on the production of γ-PGA was also investigated and the oxygen volumetric mass tran...

A stepwise strategy was devised to optimize the bioconversion of residual glycerol from biodiesel synthesis into 1,3-propanediol (1,3-PD) by a new strain Klebsiella pneumoniae. This strain is unique in its ability to convert glycerol simultaneously into 1,3-PD. The influence of glycerol concentration, pH, temperature, nitrogen and mineral sources w...

β-d-Galactosidase from Kluyveromyces lactis was immobilized on glutaraldehyde-activated chitosan and used in a packed-bed reactor for the continuous hydrolysis of lactose and the synthesis of galactooligosaccharides (GOS). The biocatalyst was tested for its optima pH and temperature, thermal stability in the presence of substrate and products, and...

Co-fermentation and simultaneous saccharification of rice hull hydrolysate (RHH) were investigated for the production of ethanol and xylitol by Saccharomyces cerevisiae, Spathaspora arborariae, or the combination of both. In bioreactor cultures under oxygen limitation, S. cerevisiae was capable of metabolizing glucose from RHH, which contained smal...

Background In this work two immobilized preparations of lipase (EC 3.1.1.3) B from Candida antarctica (CALB) were compared as biocatalysts in the synthesis of ethyl butyrate, a short-chain esters with fruity notes. Commercial Novozym 435 and CALB immobilized on styrene-divinylbenzene beads (MCI-CALB) were tested for esterification reactions. Centra...

The yeast Brettanomyces/Dekkera can cause important spoilage in wines, with the production of ethylphenols and other off-flavor compounds. This study aimed at determining the presence of this yeast and the ethylphenols produced by them in Brazilian red wines, establishing their relationship with other chemical characteristics. Isolates of Brettanom...

Poly(3-hydroxybutyrate)—P(3HB)—is a natural biodegradable polyester synthesized by several bacteria, produced from renewable resources. The effects of oxygen transfer rate on the intracellular accumulation of P(3HB) was evaluated, aiming at increasing P(3HB) synthesized by Bacillus megaterium DSM 32T in bioreactor batch cultures. Bench-scale biorea...

Two immobilized preparations from Thermomyces lanuginosus lipase (TLL) were compared in the synthesis of butyl butyrate. The commercial Lipozyme TL-IM, and TLL immobilized on styrene-divinylbenzene beads (MCI-TLL) were tested in the esterification reaction using n-hexane as solvent. The variables temperature (30-60°C), substrate molar ratio (1:1 to...