RESUMO
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.
Assuntos
Bactérias , Biotecnologia/métodos , Aromatizantes/metabolismo , Fungos , Engenharia Metabólica/métodos , Terpenos/metabolismo , Bactérias/genética , Bactérias/metabolismo , Fungos/genética , Fungos/metabolismo , Microbiologia Industrial , Redes e Vias MetabólicasRESUMO
The ultrastructural analysis of the midgut of Cephalotes atratus, C. clypeatus, and C. pusillus reveled that the midgut epithelium lays on a basal lamina and is composed basically of three cell types: digestive cells, regenerative cells, and goblet cells. In these ants, the rough endoplasmic reticulum, in addition to producing digestive enzymes, is involved in the formation of concretions and ion storage in specialized vacuoles present in the midgut. These concretions are spherocrystals and may contribute to stabilize the pH and to maintain symbiotic bacteria found between microvilli. The ultrastructure analysis of these bacteria revealed the presence of a double envelope typical of gram-negative bacteria. For the three species examined, the ultrastructure similarities are conspicuous, suggesting that this may be the pattern for the genus Cephalotes. Details of the relationship between bacteria and microvilli were examined.
Assuntos
Bactérias/ultraestrutura , Trato Gastrointestinal/ultraestrutura , Himenópteros/ultraestrutura , Mucosa Intestinal/microbiologia , Mucosa Intestinal/ultraestrutura , Animais , Citoplasma/ultraestrutura , Complexo de Golgi/ultraestrutura , Corpos de Inclusão/ultraestrutura , Microscopia Eletrônica de Transmissão , Vacúolos/ultraestruturaRESUMO
Light, scanning, and transmission electron microscopy were used to examine the ultramorphology and ultrastructure of the ileum of Cephalotes atratus, Cephalotes clypeatus, and Cephalotes pusillus. Sections along the ileum revealed differences among the three main regions: proximal (or pylorus), medial, and distal. The structural specializations present in the ileum of these three ants have implications especially to the symbiotic bacteria harbored in this region of the digestive tract. The structural similarities are conspicuous for the three species examined, suggesting that this is the pattern adopted by the genus Cephalotes.
Assuntos
Formigas/ultraestrutura , Íleo/ultraestrutura , Animais , Formigas/microbiologia , Bactérias/crescimento & desenvolvimento , Íleo/microbiologia , Microscopia , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , SimbioseRESUMO
The use of optic microscopy and scanning electron microscopy propitiated the comparative examination of the structure of the proventriculus bulb of Cephalotes atratus, Cephalotes clypeatus and Cephalotes pusillus. This portion of the digestive tract possesses highly sclerotized projections which act in the selection of victuals. This structure is of importance to phylogeny studies and thus was compared with others known species of ants in a dendrogram adapted from Eisner (1957). We did not detect differences among the three studied species in the nature of histochemistry and ultra morphology.