Gustavo Molina

The use of endophytes to obtain bioactive compounds and their application in biotransformation process.

Endophytes are microorganisms that reside asymptomatically in the tissues of higher plants and are a promising source of novel organic natural metabolites exhibiting a variety of biological activities. The laboratory of Bioaromas (Unicamp, Brazil) develops research in biotransformation processes and functional evaluation of natural products. With the intent to provide subsidies for studies on endophytic microbes related to areas cited before, this paper focuses particularly on the role of endophytes on the production of anticancer, antimicrobial, and antioxidant compounds and includes examples that illustrate their potential for human use. It also describes biotransformation as an auspicious method to obtain novel bioactive compounds from microbes. Biotransformation allows the production of regio- and stereoselective compounds under mild conditions that can be labeled as “natural,” as discussed in this paper.

Properties of Cassava Starch-Based Edible Coating Containing Essential Oils

Edible coatings were produced using cassava starch (2% and 3% w/v) containing cinnamon bark (0.05% to 0.30% v/v) or fennel (0.05% to 0.30% v/v) essential oils. Edible cassava starch coating at 2% and 3% (w/v) containing or not containing 0.30% (v/v) of each essential oils conferred increased in water vapor resistance and decreased in the respiration rates of coated apple slices when compared with uncoated fruit. Cassava starch coatings (2% w/v) added 0.10% or 0.30% (v/v) fennel or cinnamon bark essential oils showed antioxidant capacity, and the addition of 0.30% (v/v) of each essential oil demonstrated antimicrobial properties. The coating containing cinnamon bark essential oil showed a significant antioxidant capacity, comparing to fennel essential oil. Antimicrobial tests showed that the addition of 0.30% (v/v) cinnamon bark essential oil to the edible coating inhibited the growth of Staphylococcus aureus and Salmonella choleraesuis, and 0.30% fennel essential oil inhibited just S. aureus. Treatment with 2% (w/v) of cassava starch containing 0.30% (v/v) of the cinnamon bark essential oil showed barrier properties, an antioxidant capacity and microbial inhibition.

Pseudomonas: a promising biocatalyst for the bioconversion of terpenes

The Pseudomonas genus is one of the most diverse and ecologically significant groups of known bacteria, and it includes species that have been isolated worldwide in all types of environments. The bacteria from this genus are characterized by an elevated metabolic versatility, which is due to the presence of a complex enzymatic system. Investigations since the early 1960s have demonstrated their potential as biocatalysts for the production of industrially relevant and value-added flavor compounds from terpenes. Although terpenes are often removed from essential oils as undesirable components, its synthetic oxy-functionalized derivatives have broad applications in flavors/fragrances and pharmaceutical industries. Hence, biotransformation appears to be an effective tool for the structural modification of terpene hydrocarbons and terpenoids to synthesize novel and high-valued compounds. This review highlights the potential of Pseudomonas spp. as biocatalysts for the bioconversion of terpenes and summarizes the presently known bioflavors that are obtained from these processes.

Comparative study of the bioconversion process using R-(+)- and S-(-)-limonene as substrates for Fusarium oxysporum 152B.

This study compared the bioconversion process of S-(-)-limonene into limonene-1,2-diol with the already established biotransformation of R-(+)-limonene into α-terpineol using the same biocatalyst in both processes, Fusarium oxysporum 152B. The bioconversion of the S-(-)-isomer was tested on cell permeabilisation under anaerobic conditions and using a biphasic system. When submitted to permeabilisation trials, this biocatalyst has shown a relatively high resistance; still, no production of limonene-1,2-diol and a loss of activity of the biocatalyst were observed after intense cell treatment, indicating a complete loss of cell viability. Furthermore, the results showed that this process can be characterised as an aerobic system that was catalysed by limonene-1,2-epoxide hydrolase, had an intracellular nature and was cofactor-dependent because the final product was not detected by an anaerobic process. Finally, this is the first report to characterise the bioconversion of R-(+)- and S-(-)-limonene by cellular detoxification using ultra-structural analysis.

Genetic and metabolic engineering of microorganisms for the development of new flavor compounds from terpenic substrates

Abstract Throughout human history, natural products have been the basis for the discovery and development of therapeutics, cosmetic and food compounds used in industry. Many compounds found in natural organisms are rather difficult to chemically synthesize and to extract in large amounts, and in this respect, genetic and metabolic engineering are playing an increasingly important role in the production of these compounds, such as new terpenes and terpenoids, which may potentially be used to create aromas in industry. Terpenes belong to the largest class of natural compounds, are produced by all living organisms and play a fundamental role in human nutrition, cosmetics and medicine. Recent advances in systems biology and synthetic biology are allowing us to perform metabolic engineering at the whole-cell level, thus enabling the optimal design of microorganisms for the efficient production of drugs, cosmetic and food additives. This review describes the recent advances made in the genetic and metabolic engineering of the terpenes pathway with a particular focus on systems biotechnology.

Biotransformation of α- and β-pinene into flavor compounds

Products that bear the label “natural” have gained more attention in the marketplace. In this approach, the production of aroma compounds through biotransformation or bioconversion has been receiving more incentives in economic and research fields. Among the substrates used in these processes, terpenes can be highlighted for their versatility and low cost; some examples are limonene, α-pinene, and β-pinene. This work focused on the biotransformation of the two bicyclic monoterpenes, α-pinene and β-pinene; the use of different biocatalysts; the products obtained; and the conditions employed in the process.

Monoterpene bioconversion for the production of aroma compounds by fungi isolated from Brazilian fruits

This work aimed to isolate fungal strains from Brazilian fruits and select potential biocatalysts for the bioconversion of the monoterpenes citronellol, limonene, linalool, and geraniol. Among the 36 fungal strains isolated, 12 were capable to convert citronellol into rose oxide and its isomers, while the biotransformation of limonene led to the formation of 2 derivatives of high market value, carvone and α-terpineol. Furthermore, geraniol was converted into 2 new products and linalool into linalool oxide, ocimenol, geraniol, and also α-terpineol by using several strains. Accordingly, the microorganisms LB-2025, LB-2036, and LB-2038 were selected for further experiments and identified as Penicillium sp., Penicillium sp., and Aspergillus sp., respectively. Induction studies with substrates and products have been evaluated and the production of rose oxide was enhanced from 5- to 8-fold, while the products originated from the biotransformation of limonene have not changed. Thus, this work demonstrates the biotechnological production of new flavor compounds.

Fusarium species-a promising tool box for industrial biotechnology

Global demand for biotechnological products has increased steadily over the years. Thus, need for optimized processes and reduced costs appear as a key factor in the success of this market. A process tool of high importance is the direct or indirect use of enzymes to catalyze the generation of various substances. Also, obtaining aromas and pigments from natural sources has becoming priority in cosmetic and food industries in order to supply the demand from consumers to substitute synthetic compounds, especially when by-products can be used as starting material for this purpose. Species from Fusarium genera are recognized as promising sources of several enzymes for industrial application as well as biocatalysts in the production of aromas, pigments and second generation biofuels, among others. In addition, secondary metabolites from these strains can present important biological activities for medical field. In this approach, this review brings focus on the use of Fusarium sp. strains in biotechnological production of compounds of industrial interest, showing the most recent researches in this area, results obtained and the best process conditions for each case.

Natural flavourings from biotechnology for foods and beverages

Abstract: Natural flavor compounds obtained by biotechnological processes are playing an increasing role in the food, cosmetic, chemical and pharmaceutical industries due to increasing consumer demand for natural food additives. There has been extensive research into the biotechnological production of flavor compounds during the past decade. Biotechnological production is a particularly attractive alternative for flavor production since it occurs under mild conditions, presents high regio- and enantio-selectivity, does not generate toxic wastes and produces products that may be labeled as ‘natural’. The biotechnological production of aroma compounds may be performed in two basic ways: through de novo synthesis or by biotransformation. De novo synthesis refers to the production of complex substances from simple molecules through complex metabolic pathways. Biotransformations are single reactions catalyzed enzymatically to result in a product structurally similar to the substrate molecule. This chapter describes the main groups of flavoring compounds obtained by both methods.

Potential of nanoparticles as drug delivery system for cancer treatment

Abstract Nanotechnology—the construction and use of functional structures designed from atomic or molecular scale—is expected to favor all fields of medicine, with oncology being the most notable beneficiary to date. A new class of modern antitumoral agents has emerged with recent advances in our understanding of molecular genetic and tumor biology. Consequently, new tools have appeared to target molecules in specific signaling pathways with the goal of increasing efficacy and reducing toxicity. NP systems capable of targeting cancer cells, delivering and releasing drugs in a regulated manner, and detecting cancer cells with high specificity and sensitivity are just a few examples of the potential application of nanotechnology to oncological diseases. Within this context, the present chapter provides a comprehensive review about the applications of nanotechnologies tumor treatment, reporting various experiences of preclinical and/or clinical studies in cancer therapy.