RESUMO
We studied the production and the potential use of a purple-pigment produced by an Antarctic bacterial isolate. This pigment was identified as violacein, a metabolite produced by many bacterial strains and reported that it has antiproliferative activity in many cell lines. We analyzed the effect of temperature and the composition of the growth medium on pigment production, achieving the highest yield at 20 °C in Tryptic Soy Broth medium supplemented with 3.6 g/L glucose. We doubled the yield of the pigment production when the process was scaled up in a 5 L bioreactor (77 mg/L of crude pigment). The pigment was purified and identified by mass spectrometry (DI-EI-MS) and Nuclear Magnetic Resonance (NMR) spectroscopy as violacein. We performed survival assays that showed that the pure pigment has antiproliferative activity and sensitize HeLa cells (cervix cell carcinoma) to cisplatin. Besides, the pigment did not show genotoxic activity in HeLa cells as found performing micronucleus assays. These results suggest that this pigment may be used as anticancer or sensitizer to cisplatin drug in cervix cancer.
Assuntos
Bactérias/metabolismo , Indóis/metabolismo , Indóis/farmacologia , Pigmentos Biológicos/metabolismo , Pigmentos Biológicos/farmacologia , Regiões Antárticas , Bactérias/isolamento & purificação , Reatores Biológicos , Sobrevivência Celular , Células HeLa , Humanos , Indóis/química , Pigmentos Biológicos/química , Pigmentos Biológicos/isolamento & purificaçãoRESUMO
Statistical experimental designs were used to formulate a culture medium for zeaxanthin production by an Antarctic Flavobacterium sp. P8 strain. Eleven nutritional factors were assayed in shaken flasks. The effect of temperature on zeaxanthin and carotenoid production was also studied. Peptone, yeast extract, and sodium chloride were the nutrients that caused the principal impact on the biomass growth. These components were further studied to enhance zeaxanthin and total carotenoid concentrations. Although a high production rate of zeaxanthin and carotenoids was achieved, the aerobic characteristics of the bacterial strain and the oxygen requirements for zeaxanthin biosynthesis incorporate a factor that requires additional consideration. Scaling up the process to a 5â¯L-bioreactor that increased dissolved oxygen availability resulted in a 4.5-fold increase in the total carotenoid content and an almost 9-fold increase in zeaxanthin, which represented 98% of the total carotenoids produced. The results reveal that Flavobacterium sp. P8 is a promising strain for zeaxanthin production.
Assuntos
Reatores Biológicos/microbiologia , Flavobacterium/metabolismo , Zeaxantinas , Carotenoides/análise , Carotenoides/metabolismo , Meios de Cultura/química , Meios de Cultura/metabolismo , Temperatura , Zeaxantinas/análise , Zeaxantinas/metabolismoRESUMO
Carotenoids are isoprenoid pigments used by pharmaceutical, cosmetic, food and feed industry as antioxidants and colorants. Although traditional sources of carotenoids are fruits, vegetables and chemical synthesis, prospecting for alternative sinks of common and/or unusual carotenoids is important for the development of natural carotenoid industry. In this work, 30 pigmented bacterial strains from Fildes Peninsula in King George Island, Antarctica, were isolated and identified by 16S rRNA gene sequencing and classified in three phyla, Bacteroidetes, Firmicutes and Actinobacteria. After cells extraction, ten different carotenoids were identified based on the chromatographic and spectroscopic characteristic obtained by HPLC-PDA and HPLC-PDA-APCI-MS analyses. Strains assigned to Bacteroidetes affiliated to Flavobacterium, Chryseobacterium and Zobellia genera, presented a pigment profile composed of zeaxanthin, ß-cryptoxanthin and ß-carotene. Firmicutes strains of Planococcus genus produced a C50 carotenoid, identified as C.p. 450 glucoside. Actinobacteria isolates were mainly assigned to Arthrobacter genus, and few to Salinibacterium and Cryobacterium genera. Arthrobacter strains produced C50 carotenoids such as decaprenoxanthin and its glucosylated derivatives, as well as some C40 carotenoids such as lycopene which is used as synthesis precursors of the C50 carotenoids. Salinibacterium and Cryobacterium genera produced C.p. 450 free form and its glucosylated derivatives. Although most isolates produce carotenoids similar in diversity and quantity than those already reported in the literature, novel sources for C50 carotenoids results from this work. According to their carotenoid content, all isolates could be promising candidates for carotenoids production.
RESUMO
The effectiveness of a commercial inoculum for degrading a dairy wastewater with high fat content was evaluated, and compared with an activated sludge inoculum from a dairy wastewater treatment pond. Both inocula reached similar chemical oxygen demand removal in batch experiments. The population dynamics was also studied by determining heterotrophic counts. Predominant microorganisms were differentiated by colony morphology and genomic fingerprinting (BOX-PCR) analysis. The higher population diversity and the wider range of CO2 production rate observed in batch reactors inoculated with activated-sludge, indicated that microorganisms from this inoculum were well adapted and may have had synergic activity for the degradation of the dairy effluent. When the bioreactor was operated with the commercial inoculum in continuous mode, according to its microbial growth kinetics, other microorganisms became predominant. These results showed that inoculated microorganisms did not persist in the open system and periodic addition of microorganisms may be needed to achieve a high performance treatment.
Assuntos
Bactérias Aeróbias/metabolismo , Gorduras/metabolismo , Eliminação de Resíduos Líquidos/métodos , Poluentes da Água/metabolismo , Animais , Bactérias Aeróbias/citologia , Biodegradação Ambiental , Reatores Biológicos/microbiologia , Bovinos , Gorduras/análise , Resíduos Industriais/análise , Modelos Biológicos , Poluentes da Água/química , Purificação da Água/métodosRESUMO
The aerobic fat biodegradation potential and growth characteristics of a commercial and a native inoculum (activated sludge from a dairy wastewater treatment pond), were evaluated. Batch tests were conducted with a medium based on butter oil, as the sole source of carbon, and mineral salts. Residual fat, biomass and CO(2) production were measured. Overall fat removal values were above 78% for both inocula. The growth kinetics of the commercial and native inocula followed Haldane and Monod models respectively. Both inocula showed a similar behaviour when butter oil concentration was under 360 mg/l; at higher values, the difference between the growth rates increased as a consequence of the inhibition exhibited by the commercial inoculum. The selection of an inoculum for bioaugmentation of bioreactors in the wastewater treatment requires a comprehensive knowledge of their degradation ability and tolerance to fluctuating compounds and of the operational conditions that will be utilized.