RESUMO:A atividade antimicrobiana do extrato da casca do caule de Anacardium occidentale L., foi avaliada em três culturas de bactérias isoladas de biofi lme dental. A atividade antimicrobiana foi conduzida em placa de Petri pelo método de difusão para determinação da Concentração Inibitória Mínima (CIM) e Concentração Inibitória Mínima de Aderência (CIMA). Inibição aureolar (CIM) foi observada com concentrações de 12,5 mg/mL em S. mutans e 6,25mg/mL em S. mitis e S. sanguis. Os resultados sugerem que o extrato tem efeito na CIMA em concentrações de 0,31 mg/ mL em S. mutans e S. mitis e de 0,15 mg/mL em S. sanguis e pode ser usado terapeuticamente na odontologia como agente antibacteriano.Unitermos: Anacardium occidentale, atividade antimicrobiana, biofi lme dental.ABSTRACT: "In vitro antimicrobial activity of an extract of Anacardium occidentale L. against Streptococcus species". The antimicrobial activity of the extract of the stem bark of Anacardium occidentale L., was evaluated in three cultures of bacteria of the dental plate. The antimicrobial activity was assayed in Petri dishes using the diffusion method for determination of the minimal inhibitory concentration (MIC) and minimal inhibitory concentration of adherence (MICA). Aureolar inhibition (MIC) was observed with concentrations of 12.5 mg/mL in S. mutans and 6.25 mg/mL in S. mitis and S. sanguis. The results suggest that the extract has effect in the MICA in concentrations of 0.31 mg/mL in S. mutans and S. mitis and of 0.15 mg/mL in S. sanguis and therapeuticly can be used in the dentistry as an antibacterial agent.

The effect of the initial concentration of linear alkylbenzene sulfonate (LAS) on specific methanogenic activity (SMA) was investigated in this work. Six anaerobic flasks reactors with 1 L of total volume were inoculated with anaerobic sludge (2 g VSS L(-1)). The reactors were assayed for 42 days, and fed with volatile fatty acids, nutrients, and LAS. The initial LAS concentrations were 0, 10, 30, 50, 75, and 100 mg L(-1) for the treatment flasks T1 (control), T2, T3, T4, T5, and T6, respectively. When compared with T1, T2 exhibited a 30% reduction in maximum SMA and total methane production (TMP). In treatment T3 through T6, the reductions were 44-97% (T3-T6) for SMA, and 30-90% (T3-T6) for TMP. Total LAS removal increased following the increase in the initial LAS concentration (from 36% at T1 to 76% at T6), primarily due to the high degree of sludge adsorption. LAS biodegradation also occurred (32% in all treatments), although this was most likely associated with the formation of non-methane intermediates. Greater removal by adsorption was observed in long-chain homologues, when compared to short-chain homologues (C13 > C10), whereas the opposite occurred for biodegradation (C10 > C13). The C13 homologue was adsorbed to a great extent (in mass) in T4, T5 and T6, and may also have inhibited methane formation in these treatments.

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