David Lee Nelson

The text discusses the critical role of enzyme immobilization in enhancing the efficiency, reusability, and stability of biocatalysts in industrial applications. Immobilization techniques include covalent bonding, encapsulation, adsorption, and cross-linking, each with its unique advantages and challenges. Covalent bonding ensures strong, irreversible attachment of enzymes to supports, preventing leaching and maintaining enzyme stability under various conditions. Encapsulation protects enzymes within a semi-permeable matrix, preserving their activity while allowing access to substrates. Adsorption, relying on weak interactions, is simple and reversible but prone to enzyme leaching. Cross-linking involves intermolecular bonding between enzymes and supports, enhancing stability but potentially altering enzyme conformation. Selecting appropriate supports—organic or inorganic—is crucial to minimize enzyme deactivation and maintain activity. Organic supports, like chitosan and alginate, offer biocompatibility and sustainability, while inorganic supports, such as silica and metal oxides, provide robustness and high surface areas. The text highlights the significance of optimizing immobilization techniques for specific enzymes, considering factors like mechanical resistance, substrate diffusion, and compatibility with enzyme structures. Recent advancements include the development of novel supports like hybrid materials and the application of nanotechnology, which offers enhanced stability and catalytic properties. However, challenges like enzyme deactivation, activity loss over time, and high immobilization costs persist. The text emphasizes ongoing research to address these issues, aiming to improve the economic viability and efficiency of immobilized enzymes in industrial processes. The study underscores the importance of tailoring immobilization strategies to specific enzymes and applications, ensuring maximal catalytic performance and reusability.

Oregano (Origanum vulgare L.) is one of the most important aromatic plants in the world, recognized for its applications in food and traditional medicine, as well as for its biological potential and chemical diversity. This study investigated the chemical diversity of 12 accessions of Origanum vulgare subsp. virens from Portugal, grown in the wild and on an experimental field (EF), through a comparative analysis of their essential oils, hydrolate volatiles, and the volatiles obtained by headspace solid-phase microextraction (HS-SPME). The compounds were identified by gas chromatography coupled with mass spectrometry and quantified by gas chromatography with a flame ionization detector. The yields of the essential oil ranged from 1.5 to 3.3% (v/w). A total of 70 compounds were identified in the essential oil, 74 compounds in the hydrolate volatiles, and 48 compounds by HS-SPME. Cluster analysis separated the 36 samples into two main groups, corresponding to the linalool (35–77%) and the terpene-phenolic chemotypes [thymol (24–82%) and carvacrol (18–93%)]. PCA clearly separated the three methodologies of volatiles extraction while keeping similar chemotypes. With few exceptions, the wild and the corresponding EF-grown plants provided comparable volatile profiles. The choice of analytical method can influence the chemical profile, which demonstrates the need for a more comprehensive approach to understanding the chemical descriptors from Portuguese oregano.

The production of second-generation ethanol has been recognized as a promising alternative for reducing greenhouse gas emissions. To achieve this, the hydrolysis of lignocellulosic residues by cellulases and hemicellulases is required, facilitating the release of monosaccharides that are subsequently fermented for ethanol production. In this study, the prospecting and macroscopic characterization of filamentous fungi were conducted, along with the evaluation of potential cellulase producers. Four distinct samples were collected and filamentous fungi were isolated using three different methods. Macromorphological characteristics were assessed in two solid culture media, CMC and oat flour, under incubation at 30 °C. Qualitative cellulase production was analyzed in CMC medium, with enzymatic halos visualized through Congo red staining. To determine the effect of temperature on fungal growth, the growth rates of the isolates were measured at 30 °C, 35 °C, and 40 °C in CMC containing medium. A total of nineteen filamentous fungi were successfully isolated. Limited macromorphological variation was observed in CMC containing medium; however, greater morphological diversity was noted when isolates were cultivated in oat flour medium. The highest growth rates were recorded for B.D.1.3.A at 30 °C, B.D.1.4.B and B.I.3.8.2 at 35 °C, and B.I.3.8.2 at 40 °C. Additionally, the isolates B.D.1.1, B.D.1.4.B, B.I.3.8.2, V.D.7.1, and V.I.2.7.1 exhibited the highest cellulolytic activity. The findings of this study contribute to the identification of potential cellulase producing filamentous fungi, improving the understanding of their biotechnological potential and supporting the development of sustainable technologies.

As amilases possuem aplicação em diversos processos tecnológicos, sendo utilizadas em indústrias alimentícias, têxtil, detergentes, farmacêuticas, entre outras. Sabendo que maioria das enzimas aplicadas é sintetizada por fungos filamentosos, esse trabalho objetivou isolar esses microrganismos, analisar suas características macromorfológicas e verificar potenciais produtores de amilases. Para isso, foram coletadas doze distintas amostras em diferentes regiões de Minas Gerais. O isolamento foi realizado em meio de cultura sólido Ágar-Batata-Dextrose, à 30°C, durante quatro dias em estufa bacteriológica, sendo analisado o crescimento de fungos filamentosos a cada 24h. A partir dos isolados foram analisadas as características macromorfológicas e a produção qualitativa de amilases. No total foram isolados quarenta e quatro fungos filamentosos com distintas características morfológicas, destacando texturas aveludadas, camurças e algodonosas, aspecto seco, topografia lisa, convexa e plana e borda lisa e com poucos filamentos. A produção das amilases foi determinada pelo índice enzimático destacando os microrganismos isolados BD22, CD42, OD42, GD21 e GD41. A partir desse estudo, conclui-se que há uma biodiversidade ainda pouco explorada, a qual possui potencial de aplicação biotecnológico.

Proteases catalyze the hydrolysis of amide bonds of peptides and proteins, thereby playing crucial roles in the functioning of organisms, as well as having an important role in industrial processes. They are one of the three most widely commercially marketed enzymes. This study aimed to analyze the macromorphological characteristics of seventeen filamentous fungi and identify potential protease producers. The microorganisms were cultivated on a solid culture medium containing skim milk powder at 30 °C for seven days. After the incubation period, macroscopic morphological characteristics of the fungi were observed, and the strain diameters and the enzymatic halos around the colonies were measured. As a result, a wide variety of characteristics among the filamentous fungi was observed, highlighting the diversity of this group. Additionally, Potentials asprotease producers under the conditions presented were observed for eight filamentous fungi. These findings suggest that the these fungal strains might be valuable resources for the production of proteases with high biotechnological potentials.

The prospection of filamentous fungi is essential for understanding fungal biodiversity and exploring its potential in biotechnological processes. Among its applications, cellulase production stands out; it is used for clarifying juice, reducing food viscosity, and producing fermentable sugars from plant residues. This study soughr to isolate filamentous fungi from corn silage samples collected in Gouveia, Minas Gerais, Brazil, using three methods: direct contact, dilution, and pour plate. The isolation was performed on a solid culture medium containing carboxymethylcellulose at 30 °C, with monitoring of the plates for seven days. Eleven filamentous fungi were isolated, all obtained by the pour plate method. Once isolated, spot transfers were performed, and the microorganisms were maintained at 30 °C for macromorphological characterization after eight days. The results showed primarily velvety-textured mycelia with a smooth surface, regular edges, flat topography, white mycelium color, and a dry appearance. Regarding enzymatic activity, halos of up to 27 mm were observed in some samples, indicating potential cellulase production. Given the diversity of the characteristics, it was concluded that there is a plurality of isolated filamentous fungi with potential for cellulolytic enzyme production.

Amylases, crucial in various industries such as food, textile, and biofuels, require optimized production and biochemical characterization. Thus, this study aimed to produce amylases from Rhizopus sp. I 1.2.1, characterize the cultivation conditions and the synthesized enzyme. The fungus was molecularly identified with 99.06% homology in the LSU gene, 98.08% identity in the ITS region, and placed phylogenetically closer to Rhizopus arrhizus CBS 112,07. The LSU gene and ITS region sequences were deposited in GenBank. The CP medium was optimal for amylase production by Rhizopus arrhizus, with peak activity on the 6th day. Supplementation with urea significantly increased amylolytic activity by 110-fold. CP salts outperformed other salts in enzyme production, achieving a maximum amylase activity of 15.5 U/ml. The pH 6.0 was optimal for amylase production, with higher specific activity at pH 5.0. Pumpkin peel and pineapple peel were the best carbon sources for amylase production with an amylolytic activity of 18 and 16 U/mL, respectively. The amylase production showed a significant increase when pineapple peel was used in the presence of glucose 0.5% showing an activity of 22.4 U/mL, representing a 1.5- and 1.6-fold increase over the control. The optimal reaction of the amylase was observed at pH 6.0 and 60 °C. The enzyme remained stable for 240 minutes at 50-55 °C and at pH 4.0-7.0. Amylase was inhibited by glucose concentration and certain salts, but EDTA and K₂SO₄ increased activity by 25%. These results suggest industrial potential based on residual carbon source use, cultivation conditions, and crude enzyme stability.

Macaúba is a fruit found in several regions of the Brazilian territory and stands out for producing an oil with potential characteristics for use as a raw material in industries in different areas such as in the production of biodiesel, biokerosene, organic fertilizers and animal ration. An advanced search was performed in the title and abstract fields of the National Institute of Industrial Property (INPI) database. Patents related to macaúba were grouped by the number of files per decade, number of patents by holder and characteristics of granted patents. With the insertion of this mechanism, the most recent applications were listed through a mapping of patents involving macaúba and the main sectors that invested in the fruit. It was certified that, between 2000 and 2021, thirty patents related to macaúba were registered, and nine were granted. Minas Gerais stood out in technological development, especially after the creation of a public policy for the development of this species and its use, the Pro-macaúba Law (Law No. 19,485/2011). It is the state with the most deposited patents.

Red mud (RM) is composed of a waste alkaline solution (pH = 13.3) obtained from the production of alumina. It contains high concentrations of hematite (Fe₂O₃), goethite (FeOOH), gibbsite [Al(OH)₃], a boehmite (AlOOH), anatase (Tetragonal–TiO₂), rutile (Ditetragonal dipyramidal–TiO₂), hydrogarnets [Ca₃Al₂(SiO₄)_3−x(OH)_4x], quartz (SiO₂), and perovskite (CaTiO₃). It was shown to be an excellent catalytic mixture for biodiesel production. To demonstrate the value of RM, an environmentally friendly process of transesterification in aqueous medium using waste cooking oil (WCO), MeOH, and waste alkaline solution (WAS) obtained from aluminum production was proposed. Triglycerides of WCO reacted with MeOH at 60 °C to yield mixtures of fatty acid methyl esters (FAMEs) in the presence of 0.019% (w/w) WAS/WCO using the WAS (0.204 mol L⁻¹, predetermined by potentiometric titration) from aluminum production by the Bayer process. The use of the new catalyst (WAS) resulted in a high yield of the products (greater than 99% yield).