A new strain of Serratia marcescens UCP1459 isolated from a semi-arid soil produced the natural red pigment prodigiosin, characterized by an uncommon pyrrolylpyrromethane skeleton. Prodigiosin is a promising drug due to its reported antifungal, immunosuppressive and anti-proliferative activities. The objective of this work was to indentify a suitable medium to simultaneously enhance S. marcescens growth and pigment production using renewable resources obtained from industrial wastes. S. marcescens produced the highest level of prodigiosin (49.5 g/L) at 48 h of cultivation using 6% “manipueira” (cassava wastewater) supplemented with mannitol (2%) at pH 7 and 28 °C. Carbohydrates in “manipueira” and mannitol play a role in the enhanced cell growth and prodigiosin production. The purified pigment extracted from the biomass was analyzed by mass spectrophotometry and showed the expected molecular weight of 324 Da corresponding to prodigiosin. In conclusion, we have successfully designed a new, economically feasible medium supporting enhanced S. marcescens growth and a high yield production of prodigiosin.

BackgroundBiosurfactants are surface-active agents produced by microorganisms that have higher efficiency and stability, lower toxicity and higher biocompatibility and biodegradability than chemical surfactants. Despite its properties and potential application in a wide range of environmental and industrial processes, biosurfactants are still not cost-competitive when compared to their synthetic counterparts. Cost effective technologies and renewable raw substrates as agro-industrial and regional waste from northeast of Brazil as cassava flour wastewater, supplemented with lactose and corn oil are mainly the chemically media for growing microorganism and in turn the production of the biosurfactant of quality. This study aimed to obtained biosurfactant by Serratia marcescens UCP 1549 containing cassava flour wastewater (CWW), by application of a full-factorial design, as sustainable practices in puts the production process in promising formulation medium. The characterization of the biomolecule was carried out, as well as the determination of its stability and toxicity for cabbage seeds. In addition, its ability to stimulate seed germination for agriculture application and oil spill bioremediation were investigated.ResultsSerratia marcescens showed higher reduction of surface tension (25.92 mN/m) in the new medium containing 0.2% lactose, 6% cassava flour wastewater and 5% corn waste oil, after 72 h of fermentation at 28 °C and 150 rpm. The substrate cassava flour wastewater showed a promising source of nutrients for biosurfactant production. The isolate biosurfactant exhibited a CMC of 1.5% (w/v) and showed an anionic and polymeric structure, confirmed by infrared spectra. The biomolecule demonstrated high stability under different temperatures, salinity and pH values and non-toxicity against to cabbage seeds. Thus, exploring biosurfactant their potential role in seeds germinations and the promotion and agricultural applications was investigated. In addition, the effectiveness of biosurfactant for removal burned motor oil adsorbed in sand was verified.ConclusionsThe use of medium containing CWW not only reduces the cost of process of biosurfactant production, but also the environmental pollution due to the inappropriate disposal of this residue. This fact, added to the high stability and non-toxicity of the biosurfactant produced by S. marcescens UCP 1549, confirms its high environmental compatibility, make it a sustainable biocompound that can be replace chemical surfactants in diverse industries. In addition, the effectiveness of biosurfactant for stimulate seed germination and removing burned motor oil from sand, suggests its suitability for agriculture and bioremediation applications.Electronic supplementary materialThe online version of this article (10.1186/s12934-018-1046-0) contains supplementary material, which is available to authorized users.

The world market for biosurfactants has grown gradually. However, the lack of competitiveness with chemical surfactants due to high cost of production remains a concern. Considering the need to reduce the costs of production, the aim of this work was to study the production and structural characterization of a biosurfactant produced by a strain of yeast Candida glabrata UCP 1556. The lowcost medium containing agro-industrial wastes whey 40% (v/v) and 20% (v/v) corn steep liquor were used as substrates in submerged fermentation. Biosurfactant production was detected by surface tension, oil displacement test and Critical Micelle Concentration (CMC). The structural characterization was performed by Fourier transform infrared (FT-IR), gas chromatography-mass spectrometry (GC-MS) and ionic profile. The stability of emulsions and potential in reducing the viscosity also were investigated. The results showed that the biosurfactant reduced the surface tension to 28.8 mN/m with CMC of 2% and showed anionic profile. Additionally, the biosurfactant formed stable emulsions at temperature (0 to 120°C), pH (2 to 12) and NaCl (2 to 12%), reduced the viscosity of soybean oil (

: Research regarding polyphenols has gained prominence over the years because of their potential as pharmacological nutrients. Most polyphenols are flavanols, commonly known as catechins, which are present in high amounts in green tea. Catechins have been found to be promising candidates in the field of biomedicine. The health benefits of catechins, notably their antioxidant effects, are related to their chemical structure and the total number of hydroxyl groups. In addition, catechins possess strong activities against several pathogens, including bacteria, viruses, parasites, and fungi. One major limitation of these compounds is low bioavailability. Catechins are poorly absorbed by intestinal barriers. Some protective mechanisms may be required to maintain or even increase the stability and bioavailability of these molecules within living organisms. Moreover, novel delivery systems, such as scaffolds, fibers, sponges, and capsules, have been proposed. This review focuses on the unique structures and bioactive properties of catechins and their role in inflammatory responses as well as provides a perspective on their use in future human health applications.

BackgroundThe desulphurization of dibenzothiophene (DBT), a recalcitrant thiophenic fossil fuel component by Serratia marcescens (UCP 1549) in order for reducing the Sulphur content was investigated. The Study was carried out establishing the growth profile using Luria Bertani medium to different concentrations of DBT during 120 hours at 28°C, and orbital Shaker at 150 rpm.ResultsThe results indicated that concentrations of DBT 0.5, 1.0 and 2.0 mM do not affected the growth of the bacterium. The DBT showed similar Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MCB) (3.68 mM). The desulphurization of DBT by S. marcescens was used with 96 hours of growth on 2 mM of DBT, and was determined by gas chromatography (GC) and GC-mass spectrometry. In order to study the desulphurization process by S. marcescens was observed the presence of a sulfur-free product at 16 hours of cultivation.ConclusionsThe data suggests the use of metabolic pathway “4S” by S. marcescens (UCP 1549) and formed biphenyl. The microbial desulphurization process by Serratia can be suggest significant reducing sulphur content in DBT, and showed promising potential for reduction of the sulfur content in diesel oil.

A novel bacterium pigmented isolate from Caatinga soil was characterized by biochemical and molecular assays, as well as, by rep-polymerase chain reaction (PCR) and 16S rDNA sequencing, and was identified as Serratia marcescens based on 99% of similarity. The identity of the sequences were compared by pairs of critical species of S. marcescens found in National Center for Biotechnology Information (NCBI) with a 96% homology of the isolated species to species database. The wild strain was able to produce biosurfactant (BS) using cassava (Manihot esculenta Crantz) wastewater, with addition of lactose, and corn oil, according to full factorial design 2 3 , at 28°C, and static condition. The net liquid metabolic reduced the surface tension of the water from 70 to 30.60 mN/m during the stationary phase (assay eight constituted by 6.0% cassava wastewater, 1.0% lactose and 7.5% corn oil), and produced emulsifier agent (4.012 UEA) at the same condition. This study identified the pigmented bacterium as new strain of S. marcescens, and showed it has potential to promote both emulsions formation and surface tension reduction in cassava wastewater (6.0%), lactose (1.0%) and corn oil (7.5%) proved as an alternative economical medium for commercial biosurfactant processes.

Os surfactantes químicos ou biológicos são compostos anfifílicos que apresentam propriedades de redução das tensões superficial e interfacial pela acumulação na interface de fluidos imiscíveis, aumento da solubilidade e da biodegradabilidade de compostos hidrofóbicos. Nesse sentido, o potencial de produção de biossurfactante por Pseudomonas fluorescens foi investigado utilizando o meio de cultura Luria Bertani, contendo petróleo como substrato nas concentrações de 4 e 8%, sob agitação orbital de 150 rpm, à temperatura de 37ºC, por 60 horas. Os resultados obtidos indicaram que P. fluorescens produziu um biossurfactante que reduziu a tensão superficial de 70 para 30,04 mN/m. Esses dados demonstraram também sua habilidade para remover e degradar petróleo, por meio da produção de agente surfactante, sugerindo uma possibilidade futura de aplicação nos processos de contaminantes hidrofóbicos como o petróleo.

O interesse em surfactantes de origem microbiana tem aumentado consideravelmente nos últimos anos. A preocupação ambiental entre os consumidores, combinada às novas legislações de controle do meio ambiente, aumentou a procura por surfactantes naturais em substituição aos derivados petroquímicos. Os surfactantes microbianos têm sido testados em muitas aplicações ambientais e industriais, como na biorremediação, na dispersão de manchas oleosas e na recuperação de petróleo, substituindo os surfactantes químicos. Além disso, também podem ser utilizados nas indústrias de alimentos, cosméticos, detergentes e na agricultura. Neste trabalho foi produzido biossurfactante por Chromobacterium violaceum ATCC 12472, utilizando nutrientes de baixo valor agregado. A tensão superficial do biossurfactante produzido por C. violaceum ATCC 12472 teve valores entre 29 e 40 mN/m. O melhor resultado foi observado no ensaio 8 (milhocina 8,0%, lactose 1,0% e óleo de milho pós-fritura 7,5%) do planejamento fatorial, com 72 horas de fermentação, reduzindo a tensão superficial da água de 71 para 29 mN/m. Os melhores resultados do índice (E24) e da atividade de emulsificação (UEA) foram observados no ponto central, sendo utilizados para ambos os métodos o óleo de milho, que resultou no E24 de 2% e atividade com valores acima de 6 UAE. Os resultados obtidos demonstram o elevado potencial de C. violaceum na produção de um promissor biossurfactante.