Efeito de um biossurfactante sobre fezes de suínos diluídas em diferentes concentrações: estudo preliminar / The effect of a biosurfactant on pig feces diluted at different concentrations: preliminary study

This is a preliminary study that aimed to evaluate the effect of a biossurfactant on two different concentrations of diluted swine feces. After treatment with the biossurfactant, the concentration of ammonia, chloride, phosphate, dissolved oxygen were analyzed, as well as color, odor, and turbidity. Fecal coliforms were evaluated by means of Escherichia coli counts. It was possible to infer that, under the tested conditions, the biosurfactant had no effect in the treatment of the swine feces.

O presente estudo teve como objetivo avaliar o efeito de um biossurfactante, em estudos preliminares, em duas diferentes concentrações de fezes de suínos diluídas. Após o tratamento com biossurfactante, mediu-se a concentração de nitrogênio amoniacal, cloreto, fosfato, oxigênio dissolvido, bem como a presença de cor, odor e turbidez. Também foram quantificados coliformes totais e fecais através da contagem de Escherichia coli. Como resultado, é possível inferir que, nas condições do presente estudo, o biossurfactante não apresentou efeito no tratamento de fezes de suínos.

Efeito de um biossurfactante sobre fezes de suínos diluídas em diferentes concentrações: estudo preliminar / The effect of a biosurfactant on pig feces diluted at different concentrations: preliminary study

This is a preliminary study that aimed to evaluate the effect of a biossurfactant on two different concentrations of diluted swine feces. After treatment with the biossurfactant, the concentration of ammonia, chloride, phosphate, dissolved oxygen were analyzed, as well as color, odor, and turbidity. Fecal coliforms were evaluated by means of Escherichia coli counts. It was possible to infer that, under the tested conditions, the biosurfactant had no effect in the treatment of the swine feces.(AU)

O presente estudo teve como objetivo avaliar o efeito de um biossurfactante, em estudos preliminares, em duas diferentes concentrações de fezes de suínos diluídas. Após o tratamento com biossurfactante, mediu-se a concentração de nitrogênio amoniacal, cloreto, fosfato, oxigênio dissolvido, bem como a presença de cor, odor e turbidez. Também foram quantificados coliformes totais e fecais através da contagem de Escherichia coli. Como resultado, é possível inferir que, nas condições do presente estudo, o biossurfactante não apresentou efeito no tratamento de fezes de suínos.(AU)

Biosurfactants production by yeasts using soybean oil and glycerol as low cost substrate

Biosurfactants are bioactive agents that can be produced by many different microorganisms. Among those, special attention is given to yeasts, since they can produce many types of biosurfactants in large scale, using several kinds of substrates, justifying its use for industrial production of those products. For this production to be economically viable, the use of residual carbon sources is recommended. The present study isolated yeasts from soil contaminated with petroleum oil hydrocarbons and assessed their capacity for producing biosurfactants in low cost substrates. From a microbial consortium enriched, seven yeasts were isolated, all showing potential for producing biosurfactants in soybean oil. The isolate LBPF 3, characterized as Candida antarctica, obtained the highest levels of production - with a final production of 13.86 g/L. The isolate LBPF 9, using glycerol carbon source, obtained the highest reduction in surface tension in the growth medium: approximately 43% of reduction after 24 hours of incubation. The products obtained by the isolates presented surfactant activity, which reduced water surface tension to values that varied from 34 mN/m, obtained from the product of isolates LBPF 3 and 16 LBPF 7 (respectively characterized as Candida antarctica and Candida albicans) to 43 mN/m from the isolate LPPF 9, using glycerol as substrate. The assessed isolates all showed potential for the production of biosurfactants in conventional sources of carbon as well as in agroindustrial residue, especially in glycerol.

Selection of biosurfactan/bioemulsifier-producing bacteria from hydrocarbon-contaminated soil

Petroleum-derived hydrocarbons are among the most persistent soil contaminants, and some hydrocarbon-degrading microorganisms can produce biosurfactants to increase bioavailability and degradation. The aim of this work was to identify biosurfactant-producing bacterial strains isolated from hydrocarbon-contaminated sites, and to evaluate their biosurfactant properties. The drop-collapse method and minimal agar added with a layer of combustoleo were used for screening, and positive strains were grown in liquid medium, and surface tension and emulsification index were determined in cell-free supernantant and cell suspension. A total of 324 bacterial strains were tested, and 17 were positive for the drop-collapse and hydrocarbon-layer agar methods. Most of the strains were Pseudomonas, except for three strains (Acinetobacter, Bacillus, Rhodococcus). Surface tension was similar in cell-free and cell suspension measurements, with values in the range of 58 to 26 (mN/m), and all formed stable emulsions with motor oil (76-93% E24). Considering the variety of molecular structures among microbial biosurfactants, they have different chemical properties that can be exploited commercially, for applications as diverse as bioremediation or degradable detergents.

PRODUÇÃO DE BIOSSURFACTANTES POR BACTÉRIAS ISOLADAS DO SOLO, RIZOSFERA E ÁGUA DO MANGUEZAL DO RIO COCÓ (FORTALEZA CE)

Manguezais são ecossistemas costeiros tropicais e subtropicais, localizados em zonas estuarinas, importantes para a manutenção dos ciclos biogeoquímicos, reprodução de espécies marinhas e para a economia. Apesar disso, sofrem constantemente pressão ambiental, incluindo a contaminação por petróleo e derivados. O uso de biossurfactantes microbianos para descontaminação ambiental tem sido considerado uma alternativa mais sustentável. O objetivo da presente pesquisa foi coletar e caracterizar cepas bacterianas produtoras de biossurfactantes que emulsifiquem derivados de petróleo no Mangue do Rio Cocó, Fortaleza, Ceará. Foi realizada uma coleta no período chuvoso e outra no período seco em dois pontos no Rio Cocó, sendo um deles no Parque Ecológico do Cocó e outro na foz do rio. No total, foram coletadas 4 amostras de solo, 4 de água e 4 de plântulas de Laguncularia racemosa. As amostras coletadas foram homogeneizadas e uma fração foi acrescentada em Erlenmeyers contendo caldo Bushnell-Haas adicionado de querosene e gasolina e incubados em estufa a 30°C por períodos de 48 e 72 h. A partir do crescimento, visualizado pela turvação do meio, foram feitos inóculos sobre a superfície do meio ágar TSA, que foram incubadas em estufa a 35°C por 48 h e posteriormente as colônias crescidas foram selecionadas e isoladas. As cepas foram caracterizadas e a pureza das culturas foi verificada pela técnica de coloração de Gram. A capacidade de produção dos biossurfactantes foi detectada pelo teste do colapso da gota e o emulsificante detectado foi posteriormente avaliado pelos testes de volume e estabilidade de emulsificação e atividade emulsificante. Foram isoladas 58 cepas, sendo 50 delas Gram-negativas e 8 Gram-positivas, assim separadas de acordo com a origem: 21 de água, 21 de sedimento e 16 da rizosfera das plântulas. No total, 55 cepas (95%) tiveram resultados positivos no teste do colapso da gota. Todas as 10 cepas que apresentaram volume de emulsificação acima de 50% em 24 horas também apresentaram estabilidade acima de 50% até 168 horas. Cinco cepas apresentaram atividade emulsificante acima de 2,00 UAE, enquanto 29 cepas mostraram atividade entre 1,00 e 2,00 UAE. Conclui-se que é possível isolar bactérias produtoras de biossurfactantes do Mangue do Rio Cocó e que as cepas mais eficientes nos testes realizados foram isoladas do ponto localizado no Parque Ecológico do Cocó.

Mangroves are tropical and subtropical coastal ecosystems located in estuarine zones, important for the maintenance of biogeochemical cicles, marine fauna reproduction and the economy. However, these environments are under constant pressure, including contamination by oil and its derivatives threatens these environments. The use of microbial biosurfactants for environmental decontamination has been considered an eco-friendly alternative. The aim of this research was to collect and characterize biosurfactant-producing bacterial strains that emulsify oil products in Rio Cocó Mangrove, Fortaleza, Ceará. One collection in rainy season and other one in dry season were made in two points, one of them in Cocó Ecological Park and another one in the river mouth. A total, 4 soil samples, 4 water samples and 4 Laguncularia racemosa seedlings were collected. The samples were homogenized and a fraction was added in Erlemeyers containing Bushnell-Haas broth added with kerosene and gasoline and incubated at 30° C for periods of 48 and 72 h. Inocula were made on the surface of TSA agar medium, incubated at 35°C for 48 h and then colonies were selected and isolated. The strains were characterized and verified the purity of cultures by Gram staining technique. Biosurfactant production capacity was assessed by drop collapse test and the detected emulsion was after assessed by volume and stability emulsification tests and emulsifier activity test. A total, 58 strains were isolated, 50 are Gram-negative and 8 are Gram-positive, separated according the source: 21 from water, 21 from sediment and 16 from the rhizosphere of seedlings. A total of 55 strains (95%) had positive results in the drop collapse test. All 10 strains with emulsification volume above 50% in 24 hours also exhibited stability above 50% up to 168 hours. Five strains showed emulsifying activity above 2 UAE, while 29 strains showed activity between 1 and 2 UAE. We concluded that it is possible to isolate biosurfactant-producing bacteria from Rio Cocó mangrove and that the most efficient strains in the tests were isolated from the point located in the Cocó Ecological Park.