RESUMO Biossurfactantes são moléculas multifuncionais produzidas por microrganismos e podem apresentar vantagens em relação aos surfactantes sintéticos, como baixa toxicidade, alta biodegradabilidade, maior redução da tensão superficial e alta diversidade química. No entanto, a produção em escala comercial ainda é escassa devido ao elevado custo dos substratos utilizados. Portanto, no presente trabalho foi avaliada a produção de biossurfactantes utilizando diferentes óleos como fonte de carbono, como óleo de soja, óleo de fritura, óleo diesel, óleo lubrificante novo e usado, a partir de dois gêneros de bactérias isoladas de lodo indústria de cosméticos e solo contaminado com óleo diesel, Lysinibacillus sp. e Bacillus sp. respectivamente. Estas foram identificadas por sequenciamento do fragmento do gene RNAr 16S e mantidas sob refrigeração a 4 ºC em tubos de ensaio, com ágar triptona de soja. Os ensaios de produção foram realizados sob agitação de 200 rpm a 30 °C com duração de 7 dias. A produção de biossurfactante foi analisada pela atividade emulsificante, índice emulsificação e por colapso da gota. As bactérias utilizadas produziram biossurfactante em todos os tipos de óleos testados. O óleo de soja mostrou-se o melhor substrato para produção de biossurfactante a partir do Lysinibacillus sp. e Bacillus sp. com índice de emulsificação de 50 % e 46,63 %, respectivamente.

ABSTRACT Biosurfactants are multifunctional molecules produced by microorganisms and havea some advantages compared to synthetic surfactants, such as low toxicity, high biodegradability ,improved tensoactivity and chemical diversity. However, commercial scale production is not viable due to the high cost of the substrates used. Therefore, in the present work we evaluated the production of biosurfactants using different oils as carbon source, such as soybean oil, frying oil, diesel oil, new and used lubricating oil, from two genera of bacteria isolated from sludge cosmetics industry and soil contaminated with diesel oil, Lysinibacillus sp. and Bacillus sp. respectively. These were identified by sequencing the 16S rRNA gene fragment and kept under refrigeration at 4 ° C in test tubes with tryptone soy agar. The production was carried out under agitation at 200 rpm at 30 °C for 7 days. The biosurfactant production was analyzed by emulsifying activity, emulsification index and drop collapse. The bacteria used produced biosurfactant in all types of oils tested. Soybean oil was the best substrate for the production of biosurfactant from Lysinibacillus sp. and Bacillus sp. with an emulsification index of 50% and 46.63%, respectively.

The objective of this study was to evaluate the degradation of Linear Alkylbenzene Sulfonate (LAS) in anaerobic sequencing batch reactor (ASBR) under denitrifying conditions using swine sludge as inoculum. The reactor was operated for 104 days with synthetic substrate containing nitrate, and LAS was added later (22 mg/L). Considering the added mass of the LAS, the adsorbed mass in the sludge and discarded along with the effluent, degradation of the surfactant at the end of operation was 87%, removal of chemical oxygen demand was 86% and nitrate was 98%. The bacterial community was evaluated by cutting the bands and sequencing of polymerase chain reaction (PCR) fragments and denaturing gradient gel electrophoresis (DGGE). The sequences obtained were related to the phylum Proteobacteria and the alpha-and beta-proteobacteria classes, these bacteria were probably involved in the degradation of LAS. The efficiently degraded LAS in the reactor was operated in batch sequences in denitrifying conditions.

El alquilbenceno sulfonato lineal (LAS) es el tensoactivo sintético más usado en todo el mundo en los produtos de limpeza domestica e industrial y puede llegar a las masas de agua a través de la descarga de aguas residuales sin tratamiento o con un tratamiento ineficaz. El objetivo del estudio consistió en evaluar la capacidad de la microbiota presente en el sedimento del río Tietê en la degradación del tensoactivo anionico - LAS. El experimento se llevó a cabo en un bioreactor de lotes secuenciales en condiciones de desnitrificación con ciclos de 24 horas, agitación de 150rpm, usando 430mL de sedimento y 1 070mL de sustrato sintético constituido por extracto de levadura, almidón soluble, bicarbonato de sodio y sacarosa. El LAS fue añadido a diferentes concentraciones de 15mg/L y 30mg/L. El funcionamiento del bioreactor se dividió en la adaptación de la biomasa con sustrato sintético sin LAS y tres condiciones experimentales: A) adición de 15mg/L de LAS; B) 15mg/L de LAS y reducción del 50% de la concentración del co-sustrato y C) 30mg/L de LAS y la concentración de 100% de co-substrato. Los resultados obtenidos muestran que la eficiencia en la degradación del LAS está directamente relacionada con la población de bacterias desnitrificadoras y que el sedimento del río Tietê se puede utilizar como inóculo en el tratamiento de LAS en condiciones desnitrificadoras. La población de bacterias fue capaz de degradar el LAS independiente de la fuente de carbón adicionada. La remoción de LAS y de nitrato se puede lograr simultáneamente en aguas residuales con una baja carga orgánica. La reducción de la concentración del co-sustrato fue influenciado directamente por la población de bacterias desnitrificantes (2.2x10(13) a 1.0x10(8)MNP/gTVS) y por lo tanto la degradación de LAS (60.1-55.4%). Los microorganismos en el sedimento del río Tietê se pueden usar como inóculo alternativo para el tratamiento de efluentes contaminados con nitrato y LAS.

Linear alkylbenzene sulfonate (LAS) is widely used in the formulation of domestic and industrial cleaning products, the most synthetic surfactants used worldwide. These products can reach water bodies through the discharge of untreated sewage or non-effective treatments. This study evaluates the ability of the microorganisms found in the Tietê river sediment to degrade this synthetic surfactant. The experiment was conducted in a bioreactor, operated in batch sequences under denitrifying conditions, with cycles of 24 hours and stirring at 150rpm, using 430mL of sediments and 1 070mL of a synthetic substrate consisting of yeast extract, soluble starch, sodium bicarbonate and sucrose. LAS was added at different concentrations of 15mg/L and 30mg/L. The reactor operation was divided into the biomass adaptation to the synthetic substrate without LAS and three experimental conditions: a) addition of 15mg/L of LAS; b) 50% reduction the co-substrate concentration and 15mg/L of LAS, and c) addition of 30mg/L of LAS and 100% co-substrate concentration. The results showed that the degradation efficiency of LAS was directly related to the addition of co-substrates and the population of denitrifying bacteria. The removal of LAS and nitrate can be achieved simultaneously in wastewater with low organic loads. The reduction in the co-substrates concentration was directly influenced by the number of denitrifying bacteria (2.2x10(13) to 1.0x10(8)MPN/gTVS), and consequently, LAS degradation (60.1 to 55.4%). The sediment microorganisms in the Tietê river can be used as an alternative inoculum in the treatment of wastewater with nitrate and LAS contamination.