A técnica de cultura de células e tecidos vegetais in vitro tem sido estudada para a produção de plantas e biomassa vegetal com alto padrão de qualidade fitossanitária e genética. Esta técnica se baseia na capacidade da célula vegetal de praticamente qualquer tecido, de regredir ao seu estado indiferenciado e se multiplicar e/ou redefinir nova via metabólica para tornar-se outro tipo celular, podendo gerar novos tecidos e até mesmo uma nova planta completa. O desenvolvimento vegetal in vitro depende da disponibilidade de condições ideais, como a composição do meio de cultura, balanço de reguladores de crescimento, estimulação com elicitores, entre outras. As indústrias farmacêuticas e de produtos naturais tem se beneficiado da biotecnologia vegetal através da possibilidade de produzir metabólitos secundários in vitro, produção esta que seria mais vantajosa devido à redução de tempo, qualidade e quantidade de material vegetal a ser extraído pela indústria, quando comparado à produção in natura. Segundo diversos estudos mostrados na literatura consultada, a produção destes metabólitos pode ser maior in vitro do que nos extratos de plantas de campo.

Percussive air hammer tools have been used for many years to increase drilling ROP (rate of penentration) in air drilling applications. Similar developments for mud hammer tools have not been as successful. The incompressible nature of drilling mud makes the percussive action much slower to actuate using the same design methodology, rendering the tool ineffective. Other developments have suffered from reliability issues which have limited their drilling hours, therefore making them economically unfeasible. A novel percussive mechanically-actuated Hammer Motor, suitable for either mud or air drilling applications, has changed the landscape. This unique hammer assembly is assembled into a standard mud motor, without affecting the bit to bend distance. The percussive action of the tool is designed such that the bit remains in contact with the formation, while the hammering takes place against the top of the drive mandrel, driving the bit into the formation. The percussive impacts serve to greatly increase the effectiveness of the roller cone bit in crushing the rock, thus significantly increasing ROP. This paper illustrates a case study from Brazil, where the Operator has been using turbine motors or conventional motors to drill vertical wells through hard rock formations. The Hammer Motor displayed significantly higher ROP than the benchmark established by the other motors, while also reducing bit costs. These improvements in drilling performance improve the economics of drilling these hard rock formations, and are also applicable to other drilling applications.

Plants that produce secondary metabolites with allelopathic activity or phytotoxicity can be biotechnologically important, serving as sources of allelochemicals, and thus contributing to the agroindustrial sector. Vismia japurensis (Hypericaceae) is an Amazonian species that grows in clumps called vismiais, from which most other plants are absent. Accordingly, the objective of this study was to identify possible phytotoxicity effects of hexane and methanol extracts of Vismia japurensis leaves and branches in vivo and from seedlings grown in vitro on Lactuca sativa. In addition, fresh and dry leaves were assayed by the sandwich method in order to determine their ability to release allelochemicals. The hexanic extract from in vitro seedlings reduced germination by 10%, while the methanol extract produced a 16% reduction in germination speed. Root growth of Lactuca sativa was inhibited by 64.7% when subjected to hexane leaf extract, by 39.3% under the influence of hexane branch extract, and by 96.09% for in vitro seedling hexanic extract. When analysed by thin layer chromatography and 1H nuclear magnetic resonance, extracts showed evidence of terpenes, anthraquinones and flavonoids, with greater intensity of signals in the aromatic region of in vitro seedling hexanic extract. Clearly, Vismia japurensis has a high biotechnological potential in terms of the production of substances of low polarity with capacity to interfere in plant development.

Duroia saccifera (Rubiaceae) occurs in the Amazon rainforest and their extracts showed antibacterial properties. To obtain greater quantities of active substances, leaf segments from in vitro D. saccifera seedlings were used as explants for calli induction; calli were multiplied via multiple subcultures, dried and extracted with hexane followed by ethyl acetate (EtOAc) and methanol (MeOH). As D. macrophylla had been reported to produce antimycobacterial substances, we assayed calli extracts against Mycobacterium tuberculosis (H37Rv strain). Calli EtOAc extract was active, with a minimal inhibitory concentration (MIC) of ≤ 25 mg mL-1, IC90of 19.5 mg mL-1 and minimal bactericidal concentration (MBC) of 200 mg mL-1. EtOAc extract was analyzed by Thin Layer Chromatography (TLC) and Nuclear Magnetic Resonance (NMR) to determine its chemical profile, and was found to be rich in terpenes. Chromatographic fractionation of the EtOAc extract yielded a mixture of two sterols, β-sitosterol and stigmasterol (in proportion of 2:1), which were identified by 1H and 13C NMR analysis. As far as we know, this is the first report of Duroia saccifera in vitro cell culture, antituberculosis activity of calli extract and β-sitosterol and stigmasterol isolation from in vitro plant cell culture.