Biotransformação de limoneno e pineno por microrganismos da Amazônia

Abstract

One of the promising ways to use agro-industrial by-products is through the development of biotechnological processes, such as the biotransformation of terpenes, for the production of many metabolites of industrial interest, such as bioaromas. The use of agro-industrial by-products from the citrus industry and paper/cellulose has a high content of substrates, such as limonene and pinene, respectively, and is of great interest for the production of aromas. Also of great interest is the use of microorganisms isolated from different sources as biocatalysts for the production of these compounds. In this context, this doctoral thesis had as its main objective to prospect for new microorganisms from the Amazon with potential for the biotransformation of limonene and pinene, as well as to optimize the process conditions for the production of commercially valued aroma compounds in the pharmaceutical, and cosmetic industries. Chapter 1 presents an updated review article on the biotechnological potential of different microorganisms as potential biocatalysts in limonene and pinene biotransformation processes. In chapter 2, the first stage of the practical work begins with the selection of 31 species of ascomycete fungi of the genera Penicillium, Trichoderma, Pestalotiopsis and 16 basidiomycetes (Agaricomycetes) belonging to the work collection of the Laboratory of Bioassays and Microorganisms of the Amazon of Central Analytical, University Federal do Amazonas. Screening resulted in 9 endophytic fungi, 2 basidiomycetes, and 1 aquatic fungus being considered potential candidates for limonene biotransformation, since they eventually accumulated interesting compounds after 120 h of reaction. However, only Pestalotiopsis mangiferae LabMicrA-505 was the most promising endophytic fungus found in the screening, due to its ability to use all R-(+)-limonene as the only source of carbon and energy in mineral medium, obtaining as main derivatives the limonene-1,2-diol (74.13±0.81%) and limonene-1,2-epoxide (1.88±0.08%) accumulated after 72 h of reaction. In chapter 3, it refers to the results obtained by the experiments that contemplate the selection of 11 actinomycete strains of the genus Streptomyces isolated from rhizosphere soils of inga-cipó (Inga edulis Martius). Of these strains studied, only Streptomyces sp. LabMicra B270 was one of the most promising due to its ability to use all α-pinene as the only source of carbon and energy in mineral medium, obtaining as main products cis-verbenol (57,39±0,07%), verbenone (37,80±2,10%) and myrtenol (4,81±2,02%) accumulated after 72 hours of reaction. Next, Chapter 4 discusses the rotational central composite design (DCCR) used to optimize the main parameters of the limonene-1,2-diol production process from limonene by the fungus Pestalotiopsis mangiferae LabMicrA-505. The optimization of the variables analyzed by the DCCR revealed that the optimal conditions for the biotransformation were 2.0% substrate, 24 °C, 120 rpm and pH 6, resulting in an accumulation of 98.34±1.53% of limonene-1,2-diol after of 96 h of reaction. This research determines the potential of these microorganisms to be used as new biocatalysts. These results set precedents for developing the production of natural flavors and demonstrating the potential of using these Amazonian microorganisms in biotransformation processes.