Prospective multicenter study to identify optimal target population for motorized spiral enteroscopy.

Motorized spiral enteroscopy (MSE) enhances small bowel exploration, but the optimal target population for this technique is unknown. We aimed to identify the target population for MSE by evaluating its efficacy and safety, as well as detecting predictors of efficacy. A prospective multicenter observational study was conducted at 9 tertiary hospitals in Spain, enrolling patients between June 2020-2022. Analyzed data included demographics, indications for the procedure, exploration time, depth of maximum insertion (DMI), technical success, diagnostic yield, interventional yield, and adverse events (AE) up to 14 days from enteroscopy. Patients with prior gastrointestinal surgery, unsuccessful balloon enteroscopy and small bowel strictures were analyzed. A total of 326 enteroscopies (66.6% oral route) were performed in 294 patients (55.1% males, 65 years ± 21). Prior abdominal surgery was present in 50% of procedures (13.5% gastrointestinal surgery). Lower DMI (162 vs 275 cm, p = 0.037) and diagnostic yield (47.7 vs 67.5%, p = 0.016) were observed in patients with prior gastrointestinal surgery. MSE showed 92.2% technical success and 56.9% diagnostic yield after unsuccessful balloon enteroscopy (n = 51). In suspected small bowel strictures (n = 49), the finding was confirmed in 23 procedures (46.9%). The total AE rate was 10.7% (1.8% classified as major events) with no differences related to prior gastrointestinal/abdominal surgery, unsuccessful enteroscopy, or suspected small bowel strictures. The study demonstrates that MSE has a lower diagnostic yield and DMI in patients with prior gastrointestinal surgery but is feasible after unsuccessful balloon-enteroscopy and in suspected small bowel strictures without safety concerns.

Microbiological Diversity and Associated Enzymatic Activities in Honey and Pollen from Stingless Bees from Northern Argentina.

Honey and pollen from Tetragonisca fiebrigi and Scaptotrigona jujuyensis, stingless bees from northern Argentina, presented a particular microbiological profile and associated enzymatic activities. The cultured bacteria were mostly Bacillus spp. (44%) and Escherichia spp. (31%). The phylogenetic analysis showed a taxonomic distribution according to the type of bee that was similar in both species. Microbial enzymatic activities were studied using hierarchical clustering. Bacillus spp. was the main bacterium responsible for enzyme production. Isolates with xylanolytic activity mostly presented cellulolytic activity and, in fewer cases, lipolytic activity. Amylolytic activity was associated with proteolytic activity. None of the isolated strains produced multiple hydrolytic enzymes in substantial amounts, and bacteria were classified according to their primary hydrolytic activity. These findings add to the limited knowledge of microbiological diversity in honey and pollen from stingless bees and also provide a physiological perspective of this community to assess its biotechnological potential in the food industry.

Comparative oil extraction from mutt (Myliobatis goodei) liver by enzymatic hydrolysis: free versus immobilized biocatalyst.

BACKGROUND: The development and fine-tuning of biotechnological processes for fish oil extraction constitute a very important focus to contribute to the development of a food industry based on fish consumption. This work lies in a comparative analysis of the oil extraction yield of Myliobatis goodei livers using free and immobilized enzymes. RESULTS: An immobilized biocatalyst was designed from the cell-free extract of a Bacillus sp. Mcn4. A complete factorial design was used to study the components of the bacterial culture medium and select the condition with the highest titers of extracellular enzymatic activities. Wheat bran had a significant effect on the culture medium composition for enzymatic production. The immobilized biocatalyst was designed by covalent binding of the proteins present in the cocktail retaining a percentage of different types of enzymatic activities (Mult.Enz@MgFe2 O4 ). Among the biocatalyst used, Alcalase® 2.4 L and Purazyme® AS 60 L (free commercial proteases) showed extraction yields of 87.39% and 84.25%, respectively, while Mult.Enz@MgFe2 O4 achieved a better one of 89.97%. The oils obtained did not show significant differences in their physical-chemical properties while regarding the fatty acid content, the oil extracted with Purazyme® AS 60 L showed a comparatively lower proportion of polyunsaturated fatty acids. CONCLUSIONS: Our results suggest that the use of by-products of M. goodei is a valid alternative and encourages the use of immobilized multienzyme biocatalysts for the treatment of complex substrates in the fishing industry. © 2023 Society of Chemical Industry.

Interfacial Hyperactivation of Candida rugosa Lipase onto Ca2Fe2O5 Nanoparticles: pH and Ionic Strength Fine-Tuning to Modulate Protein-Support Interactions.

The current study provides a comprehensive look of the adsorption process of Candida rugosa lipase (CRL) on Ca2Fe2O5 iron oxide nanoparticles (NPs). Protein-support interactions were identified across a broad range of pH and ionic strengths (mM) through a response surface methodology, surface charge determination, and spectroscopic and in silico analyses. The maximum quantity of immobilized protein was achieved at an ionic strength of 50 mM and pH 4. However, this condition did not allow for the greatest hydrolytic activity to be obtained. Indeed, it was recorded at acidic pH, but at 150 mM, where evaluation of the recovered activity revealed hyperactivation of the enzyme. These findings were supported by adsorption isotherms performed under different conditions. Based on zeta potential measurements, electrostatic interactions contributed differently to protein-support binding under the conditions tested, showing a strong correlation with experimentally determined immobilization parameters. Raman spectra revealed an increase in hydrophobicity around tryptophan residues, whereas the enzyme immobilization significantly reduced the phenylalanine signal in CRL. This suggests that this residue was involved in the interaction with Ca2Fe2O2 and molecular docking analysis confirmed these findings. Fluorescence spectroscopy showed distinct behaviors in the CRL emission patterns with the addition of Ca2Fe2O5 at pH 4 and 7. The calculated thermodynamic parameters indicated that the contact would be mediated by hydrophobic interactions at both pHs, as well as by ionic ones at pH 4. In this approach, this work adds to our understanding of the design of biocatalysts immobilized in iron oxide NPs.

Teat-apex colonizer Bacillus from healthy cows antagonizes mastitis-causing Staphylococcus aureus biofilms.

Staphylococcus aureus is the most frequent causal agent of bovine mastitis, which is largely responsible for milk production losses worldwide. The pathogen's ability to form stable biofilms facilitates intramammary colonization and may explain disease persistence. This virulence factor is also highly influential in the development of chronic intramammary infections refractory to antimicrobial therapy, which is why novel therapies that can tackle multiple targets are necessary. Since udder microbiota have important implications in mastitis pathogenesis, they offer opportunities to develop alternative prophylactic and therapeutic strategies. Here, we observed that a Bacillus strain from the teat apex of lactating cows was associated to reduce colonization by S. aureus. The strain, identified as Bacillus sp. H21, was able to antagonize in-formation or mature S. aureus biofilms associated to intramammary infections without affecting cell viability. When exploring the metabolite responsible for this activity, we found that a widespread class of Bacillus exopolysaccharide, levan, eliminated the pathogenic biofilm under evaluated conditions. Moreover, levan had no cytotoxic effects on bovine cellular lines at the biologically active concentration range, which demonstrates its potential for pathogen control. Our results indicate that commensal Bacillus may counteract S. aureus-induced mastitis, and could therefore be used in novel biotechnological strategies to prevent and/or treat this disease.

Tuning surface interactions on MgFe2O4 nanoparticles to induce interfacial hyperactivation in Candida rugosa lipase immobilization.

Lipase adsorption on solid supports can be mediated by a precise balance of electrostatic and hydrophobic interactions. A suitable fine-tuning could allow the immobilized enzyme to display high catalytic activity. The objective of this work was to investigate how pH and ionic strength fluctuations affected protein-support interactions during immobilization via physical adsorption of a Candida rugosa lipase (CRL) on MgFe2O5. The highest amount of immobilized protein (IP) was measured at pH 4, and an ionic strength of 90 mM. However, these immobilization conditions did not register the highest hydrolytic activity (HA) in the biocatalyst (CRLa@MgFe2O4), finding the best values also at acidic pH but with a slight shift towards higher values of ionic strength around 110 mM. These findings were confirmed when the adsorption isotherms were examined under different immobilization conditions so that the maximum measurements of IP did not coincide with that of HA. Furthermore, when the recovered activity was examined, a strong interfacial hyperactivation of the lipase was detected towards acidic pH and highly charged surrounding environments. Spectroscopic studies, as well as in silico molecular docking analyses, revealed a considerable involvement of surface hydrophobic protein-carrier interactions, with aromatic aminoacids, especially phenylalanine residues, playing an important role. In light of these findings, this study significantly contributes to the body of knowledge and a better understanding of the factors that influence the lipase immobilization process on magnetic inorganic oxide nanoparticle surfaces.

Silver nanoparticles synthesized by the heavy metal resistant strain Amycolatopsis tucumanensis and its application in controlling red strip disease in sugarcane.

The production of bioethanol and sugar from sugarcane is an important economic activity in several countries. Sugarcane is susceptible to different phytopathogens. Over the last years, the red stripe disease caused by the bacterium Acidovorax avenae subsp. avenae produced significant losses in sugarcane crops. Bio-nanotechnology emerged as an eco-friendly alternative to the biosynthesis of antimicrobial molecules. The aims of this study were to (a) produce extracellular silver nanoparticles using the heavy metal resistant strain Amycolatopsis tucumanensis, (b) evaluate their antibacterial in vitro effect and (c) determine the potential of silver nanoparticles to protect sugarcane against red stripe disease. Amycolatopsis tucumanensis synthesized spherical silver nanoparticles with an average size of 35 nm. Nanoparticles were able to control the growth of A. avenae subsp. avenae in in vitro assays. In addition, in vivo assays in sugarcane showed a control upon the red stripe disease when silver nanoparticles were applied as preventive treatment. The Disease Severity Index was 28.94% when silver nanoparticles were applied 3 days before inoculation with A. avenae subsp. a venae. To our knowledge, this is the first report of silver nanoparticles extracellularly synthesized by an Amycolatopsis strain that were able to inhibited the growth of A. avenae subsp. avenae and control the red stripe disease in sugarcane.

Genome sequencing and genomic analysis of Amycolatopsis tucumanensis DSM 45259 applicable in gray, red, and nano-biotechnology.

Through the years, the genus Amycolatopsis has demonstrated its biotechnological potential. The need to clean up the environment and produce new antimicrobial molecules led to exploit promising bacterial genera such as Amycolatopsis. In this present work, we analyze the genome of the strain Amycolatopsis tucumanensis AB0 previously isolated from copper-polluted sediments. Phylogenomic and comparative analysis with the closest phylogenetic neighbor was performed. Our analysis showed the genetic potential of the strain to deal with heavy metals such as copper and mitigate oxidative stress. In addition, the ability to produce copper oxide nanoparticles and the presence of genes potentially involved in the synthesis of secondary metabolites suggest that A. tucumanensis may find utility in gray, red, and nano-biotechnology. To our knowledge, this is the first genomic analysis of an Amycolatopsis strain with potential for different biotechnological fields.

Streptomyces: connecting red-nano and grey biotechnology fields.

Anthropogenic activities are often related to the occurrence of simultaneous contaminations with heavy metals and toxic organic compounds. In addition, the increasing demand for food, clothing, and technology has increased the worldwide contamination level. Although it is not fully demonstrated, the high level of contamination in association with the indiscriminate use of antibiotics, led to the appearance of multi-resistant pathogenic microorganisms. Grey and red biotechnologies try to counteract the negative effects of pollution and antimicrobial resistance respectively. Streptomyces is well known in the field of biotechnology. In this review, we discussed the potential of these bacteria to deal with organic and inorganic pollutants and produce nanostructures with antimicrobial activity. To our knowledge, this is the first work in which a biotechnological bacterial genus such as Streptomyces is revised in two different fields of global concern, contamination, and multi-drugs resistant microorganisms.

Effect of the biological functionalization of nanoparticles on magnetic CLEA preparation.

Lipase immobilization using adsorption on magnetic nanoparticles, cross-linked enzyme aggregates (CLEA), and a combination of both techniques was investigated. Experimental designs were used for the optimization of the immobilization observing that the pH and ionic strength play a principal role during the lipase immobilization and its activity. For adsorption on magnetic nanoparticles and CLEA synthesis the optimal condition was pH and 100 mM. Besides, during the CLEA synthesis, glutaraldehyde concentration showed to be a significant effect on the enzyme activity. A comparison between a magnetic CLEA prepared with (Lip@mCLEA) and without (mCLEA) biological functionalized magnetic nanoparticles was made observing that the use of functionalized support showed the best performance activity. All biocatalytic systems developed gives to the enzyme thermal stability between 45 and 70 °C, being Lip@mCLEA the more stable biocatalyst. Similar behavior was observed at different pH, where both Lip@mCLEA and mCLEA showed stability at a range of pH 5 to 8. The immobilized biocatalysts showed the same affinity of the subtract that the free enzyme suggested that the enzyme structure not modified the active site. The combination of both types of immobilization show evidenced the importance of the biological functionalization of the support when magnetic CLEA is produced.

Endo-xylanases from Cohnella sp. AR92 aimed at xylan and arabinoxylan conversion into value-added products.

The genus Cohnella belongs to a group of Gram-positive endospore-forming bacteria within the Paenibacillaceae family. Although most species were described as xylanolytic bacteria, the literature still lacks some key information regarding their repertoire of xylan-degrading enzymes. The whole genome sequence of an isolated xylan-degrading bacterium Cohnella sp. strain AR92 was found to contain five genes encoding putative endo-1,4-ß-xylanases, of which four were cloned, expressed, and characterized to better understand the contribution of the individual endo-xylanases to the overall xylanolytic properties of strain AR92. Three of the enzymes, CoXyn10A, CoXyn10C, and CoXyn11A, were shown to be effective at hydrolyzing xylans-derived from agro-industrial, producing oligosaccharides with substrate conversion values of 32.5%, 24.7%, and 10.6%, respectively, using sugarcane bagasse glucuronoarabinoxylan and of 29.9%, 19.1%, and 8.0%, respectively, using wheat bran-derived arabinoxylan. The main reaction products from GH10 enzymes were xylobiose and xylotriose, whereas CoXyn11A produced mostly xylooligosaccharides (XOS) with 2 to 5 units of xylose, often substituted, resulting in potentially prebiotic arabinoxylooligosaccharides (AXOS). The endo-xylanases assay displayed operational features (temperature optima from 49.9 to 50.4 °C and pH optima from 6.01 to 6.31) fitting simultaneous xylan utilization. Homology modeling confirmed the typical folds of the GH10 and GH11 enzymes, substrate docking studies allowed the prediction of subsites (- 2 to + 1 in GH10 and - 3 to + 1 in GH11) and identification of residues involved in ligand interactions, supporting the experimental data. Overall, the Cohnella sp. AR92 endo-xylanases presented significant potential for enzymatic conversion of agro-industrial by-products into high-value products.Key points• Cohnella sp. AR92 genome encoded five potential endo-xylanases.• Cohnella sp. AR92 enzymes produced xylooligosaccharides from xylan, with high yields.• GH10 enzymes from Cohnella sp. AR92 are responsible for the production of X2 and X3 oligosaccharides.• GH11 from Cohnella sp. AR92 contributes to the overall xylan degradation by producing substituted oligosaccharides.

Whole genome sequence of the multi-resistant plant growth-promoting bacteria Streptomyces sp. Z38 with potential application in agroindustry and bio-nanotechnology.

The genus Streptomyces is widely recognized for its biotechnological potential. Due to a need to improve crops, clean up the environment and produce novel antimicrobial molecules exploiting Streptomyces has become a priority. To further explore the biotechnological potential of these organisms we analyzed the genome of the strain Streptomyces sp. Z38 isolated from contaminated roots tissues. Our analysis not only confirmed the ability of the strain to produce plant growth promoting traits but also a range of mechanisms to cope with the toxic effect of heavy metals through genes involved in metal homeostasis and oxidative stress response. The production of silver nanoparticles indicated that Streptomyces sp. Z38 may find utility in Green, Grey and Red biotechnology.

Control of microbial biofilm formation as an approach for biomaterials synthesis.

The search for new biomaterials with superior mechanical properties is the focus in the area of materials science. A promising pathway is drawing inspiration from nature to design and develop materials with enhanced properties. In this work, a novel strategy to produce functionalized supramolecular bionanomaterials from the microbial biofilm is reported. Tuneable biofilms with specific characteristics were obtained by controlling the culture condition of the microorganism. When the exopolysaccharide (EPS) production was desired the tryptone was the best nutritional component for the EPS production into the biofilm. However, for the expression of a high amount of amyloid protein the combination of peptone and glucose was the best nutritional choice. Each biofilm obtained showed its owner rheology properties. These properties were altered by the addition of extracellular DNA, which increased the viscosity of the biofilm and induced a viscoelastic hydrogel behavior. Besides, as a proof of concept of bionanomaterial, a novel supramolecular polymeric hybrid EPS-Amyloid protein (EPAP) was obtained from the biofilm and it was tested as a new natural functionalized support for enzyme immobilization. The results suggest that this technology could be used as a new concept to obtain biomaterials from biofilms by controlling the nutritional conditions of a microorganism. Understanding environmental factors affecting biofilm formation will help the development of methods for controlling biofilm production and therefore obtaining new biomaterials.

Cadmium-calcium interference in the Rhinella arenarum oviduct.

Given that the cadmium (Cd) toxicity could be due to its interference with the calcium (Ca) homeostasis, the aim of this work was to study the effect of Cd over the presence, distribution and volume density (Vv) of Ca and Ca-ATPase in the secretory cells of the pars preconvoluta (PPC) and the pars convoluta (pc) in Rhinella arenarum. The severe effect of the xenobiotic (CdCl2 2.5 mg/kg) in sexually matured females was evaluated. Co-localization, as well as a marked reduction of Ca and Ca-ATPase, was observed in treated animals, in the areas analyzed, compared to control. Low calcium deposits were found in the secreting granules (SG) of the epithelial (ESC) and glandular secretory cells (GSC), while an increase in their cytoplasm and intracellular space was observed. The Ca-ATPase in treated and control animals was detected at the SG and the plasmatic membrane of the ESC and GSC. In relation to the Vv estimates, a substantial reduction of Ca deposits and Ca-ATPase activity was observed in the treated group, with respect to the control. Both amounts of Vv of Ca and Ca-ATPase activity were higher in PPC than in pc, and, higher in ESC than in GSC. These results were associated with the Cd concentration in the oviductal PC, determining that it is a bioaccumulator organ. Thus, this work demonstrated that the Cd interacted with Ca-ATPase, leading to an increase of cytosolic Ca, which is responsible for the possible disruptions in cellular metabolism.

Raw sugarcane bagasse as carbon source for xylanase production by Paenibacillus species: a potential degrader of agricultural wastes.

Paenibacillus species isolated from a variety of natural sources have shown to be important glycoside hydrolases producers. These enzymes play a key role in bio-refining applications, as they are central biocatalysts for the processing of different types of polymers from vegetal biomass. Xylanase production by three native isolates belonging to the genus Paenibacillus was approached by utilizing mineral-based medium and agricultural by-products as a convenient source to produce biocatalysts suitable for their degradation. While varieties of alkali pretreated sugarcane bagasse were useful substrates for the strains from Paenibacillus genus evaluated, raw sugarcane bagasse was the most effective substrate for endoxylanase production by Paenibacillus sp. AR247. This strain was then selected to further improvement of its enzyme production by means of a two-step statistical approach. It was determined that the carbon source, provided as an inexpensive agro-waste, as well as phosphate and magnesium were the culture media components that most influenced the enzyme production, which was improved three times compared to the screening results.

Endoglucanase and xylanase production by Bacillus sp. AR03 in co-culture.

The behavior of three isolates retrieved from different cellulolytic consortia, Bacillus sp. AR03, Paenibacillus sp. AR247 and Achromobacter sp. AR476-2, were examined individually and as co-cultures in order to evaluate their ability to produce extracellular cellulases and xylanases. Utilizing a peptone-based medium supplemented with carboxymethyl cellulose (CMC), an increase estimation of 1.30 and 1.50 times was obtained by the co-culture containing the strains AR03 and AR247, with respect to enzyme titles registered by their individual cultivation. On the contrary, the extracellular enzymatic production decreased during the co-cultivation of strain AR03 with the non-cellulolytic Achromobacter sp. AR476-2. The synergistic behavior observed through the combined cultivation of the strains AR03 and AR247 might be a consequence of the consumption by Paenibacillus sp. AR247 of the products of the CMC hydrolysis (i.e., cellobiose and/or cello-oligosaccharides), which were mostly generated by the cellulase producer Bacillus sp. AR03. The effect observed could be driven by the requirement to fulfill the nutritional supply from both strains on the substrate evaluated. These results would contribute to a better description of the degradation of the cellulose fraction of the plant cell walls in nature, expected to an efficient utilization of renewable sources.

Biofilm inhibition activity of traditional medicinal plants from Northwestern Argentina against native pathogen and environmental microorganisms.

INTRODUCTION:: Plants have been commonly used in popular medicine of most cultures for the treatment of disease. The in vitro antimicrobial activity of certain Argentine plants used in traditional medicine has been reported. The aim of this study was to investigate the antimicrobial, anti-biofilm, and anti-cell adherence activities of native plants (Larrea divaricata, Tagetes minuta, Tessaria absinthioides, Lycium chilense, and Schinus fasciculatus) collected in northwestern Argentina. METHODS:: The activities of the five plant species were evaluated in Bacillus strains and clinical strains of coagulase-negative Staphylococcus isolated from northwestern Argentina and identified by 16S rDNA. RESULT:: Lycium chilense and Schinus fasciculatus were the most effective antimicrobial plant extracts (15.62µg/ml and 62.50µg/ml for Staphylococcus sp. Mcr1 and Bacillus sp. Mcn4, respectively). The highest (66%) anti-biofilm activity against Bacillus sp. Mcn4 was observed with T. absinthioides and L. divaricate extracts. The highest (68%) anti-biofilm activity against Staphylococcus sp. Mcr1 was observed with L. chilense extract. T. minuta, T. absinthioides, and L. divaricata showed percentages of anti-biofilm activity of between 55% and 62%. The anti-adherence effects of T. minuta and L. chilense observed in Bacillus sp. Mcn4 reflected a difference of only 22% and 10%, respectively, between anti-adherence and biofilm inhibition. Thus, the inhibition of biofilm could be related to cell adherence. In Staphylococcus sp. Mcr1, all plant extracts produced low anti-adherence percentages. CONCLUSION:: These five species may represent a source of alternative drugs derived from plant extracts, based on ethnobotanical knowledge from northwest Argentina.

Biofilm inhibition activity of traditional medicinal plants from Northwestern Argentina against native pathogen and environmental microorganisms

Abstract: INTRODUCTION: Plants have been commonly used in popular medicine of most cultures for the treatment of disease. The in vitro antimicrobial activity of certain Argentine plants used in traditional medicine has been reported. The aim of this study was to investigate the antimicrobial, anti-biofilm, and anti-cell adherence activities of native plants (Larrea divaricata, Tagetes minuta, Tessaria absinthioides, Lycium chilense, and Schinus fasciculatus) collected in northwestern Argentina. METHODS: The activities of the five plant species were evaluated in Bacillus strains and clinical strains of coagulase-negative Staphylococcus isolated from northwestern Argentina and identified by 16S rDNA. RESULT: Lycium chilense and Schinus fasciculatus were the most effective antimicrobial plant extracts (15.62µg/ml and 62.50µg/ml for Staphylococcus sp. Mcr1 and Bacillus sp. Mcn4, respectively). The highest (66%) anti-biofilm activity against Bacillus sp. Mcn4 was observed with T. absinthioides and L. divaricate extracts. The highest (68%) anti-biofilm activity against Staphylococcus sp. Mcr1 was observed with L. chilense extract. T. minuta, T. absinthioides, and L. divaricata showed percentages of anti-biofilm activity of between 55% and 62%. The anti-adherence effects of T. minuta and L. chilense observed in Bacillus sp. Mcn4 reflected a difference of only 22% and 10%, respectively, between anti-adherence and biofilm inhibition. Thus, the inhibition of biofilm could be related to cell adherence. In Staphylococcus sp. Mcr1, all plant extracts produced low anti-adherence percentages. CONCLUSION: These five species may represent a source of alternative drugs derived from plant extracts, based on ethnobotanical knowledge from northwest Argentina.

Draft Genome Sequence of Achromobacter sp. Strain AR476-2, Isolated from a Cellulolytic Consortium.

Achromobacter sp. AR476-2 is a noncellulolytic strain previously isolated from a cellulolytic consortium selected from samples of insect gut. Its genome sequence could contribute to the unraveling of the complex interaction of microorganisms and enzymes involved in the biodegradation of lignocellulosic biomass in nature.

Mucor circinelloides whole-cells as a biocatalyst for the production of ethyl esters based on babassu oil.

The intracellular lipase production by Mucor circinelloides URM 4182 was investigated through a step-by-step strategy to attain immobilized whole-cells with high lipase activity. Physicochemical parameters, such as carbon and nitrogen sources, inoculum size and aeration, were studied to determine the optimum conditions for both lipase production and immobilization in polyurethane support. Olive oil and soybean peptone were found to be the best carbon and nitrogen sources, respectively, to enhance the intracellular lipase activity. Low inoculum level and poor aeration rate also provided suitable conditions to attain high lipase activity (64.8 ± 0.8 U g(-1)). The transesterification activity of the immobilized whole- cells was assayed and optimal reaction conditions for the ethanolysis of babassu oil were determined by experimental design. Statistical analysis showed that M. circinelloides whole-cells were able to produce ethyl esters at all tested conditions, with the highest yield attained (98.1 %) at 35 °C using an 1:6 oil-to-ethanol molar ratio. The biocatalyst operational stability was also assayed in a continuous packed bed reactor (PBR) charged with glutaraldehyde (GA) and Aliquat-treated cells revealing half-life of 43.0 ± 0.5 and 20.0 ± 0.8 days, respectively. These results indicate the potential of immobilized M. circinelloides URM 4182 whole-cells as a low-cost alternative to conventional biocatalysts in the production of ethyl esters from babassu oil.