Corchorus olitorius aqueous extract attenuates quorum sensing-regulated virulence factor production and biofilm formation

Objective:To investigate the effect of Corchorus olitorius aqueous fraction (COAF) on quorum sensing (QS)-regulated virulence factors and biofilm formation in Pseudomonas aeruginosa (PAO1). Methods:The preliminary screening of the anti-QS effect of COAF was performed by evaluating the anti-pathogenic activity against Chromobacterium violaceum CV026 biosensor strain. Next, the inhibitory effects of COAF on QS-regulated pyocyanin production, proteolytic and elastolytic activities, swarming motility, and biofilm formation were evaluated in PAO1.Results:The results showed that the treatment of COAF significantly decreased the biofilm biomass, attenuated virulence factors, and inhibited swarming motility of PAO1 without affecting the growth of the bacteria in a dose-dependent manner. COAF at 2000 μg/mL significantly decreased Las B elastase activity in PAO1 culture, exopolysaccharide production, swarming motility, pyocyanin level, and biomass of PAO1 by 55％ (P<0.05), 60％ (P<0.01), 61％ (P<0.01), 65％(P<0.01) and 73％ (P<0.01), respectively. In addition, the production of violacein was decreased by 62％ (P<0.01) with the treatment of a high dose of COAF. Conclusions:These findings indicate that COAF can be a potential source of anti-QS agents.

Isolation and Characterization of Chromobacterium sp. from Lake Water at Manipal International University

@#Introduction: The violet-pigmented Chromobacterium spp. are vastly located in soil and surface water of subtropical regions. Majority of the species have been identified as highly potential in bio-industries; however, the bacterial pathogenicity is largely understudied. These bacteria are resistant to multiple-drugs and infections may cause sepsis and liver abscissions. Thus, this study aimed to characterize the violet-pigmented bacteria isolated from the lake in Manipal International University and further examine its antibiotic susceptibility. Methods: The isolated violet bacteria (Dyh27s2016) were subjected to the morphology, physiology, biochemical and antibiotic susceptibility tests. Also, the species were scrutinized via the 16S rRNA and phylogenetic analysis. In addition, the lake water physicochemical properties were examined to understand the bacterial adaptability in this region. Results: Dyh27s2016 strain was found to exhibit similar morphology and physiology characteristics to Chromobacterium spp. and be closely related to Chromobacterium amazonense (98% sequence-homology). However, the biochemical analysis indicated that this strain was capable of indole production; contrarily, Chromobacterium spp. were found mostly indole negative. On top of that, this strain also tested resistant to most β-lactam and aminoglycoside antibiotics. The adaptability of the Dyh27s2016 strain in this region might be supported by the satisfactory physiochemical properties of the lake water and mainly by the low dissolve oxygen concentration. Conclusion: The morphology, physiology, biochemical and molecular characterizations of Dyh27s2016 isolate show high similarity to Chromobacterium spp. and the multi-drug resistance of this strain can potentially harbour a threat to public health if contacted by humans or animals via food or water.

Septicemia por Chromobacterium Violaceum en pediatría / Septicemia due to Chromobacterium Violaceum in pediatrics

Chromobacterium violaceum es una bacteria gram negativa anaerobia facultativa, que se encuentra ampliamente distribuida en el agua y el suelo en regiones tropicales y subtropicales, que se asocia con infecciones respiratorias, gastrointestinales, abscesos hepáticos, meningitis, endocarditis, síndrome hemofagocítico y sepsis fulminante. Se presentan 2 casos en niños: el primero es un varón de 8 años con lesiones en piel, fiebre y adenitis inguinal, que ingresó con un cuadro de sepsis severa, síndrome de distrés respiratorio agudo (SDRA) y falleció a las 3 h del ingreso. De los hemocultivos se aisló Chromobacterium violaceum. El segundo caso, es una niña de 12 años con antecedente de fiebre y adenopatía inguinal secundaria a herida cortopunzante en el pie homolateral, que ingresó con un cuadro de sepsis, con desarrollo de abscesos múltiples profundos. De la colección obtenida de piel y partes blandas y de un aspirado traqueal se aisló Chromobacterium violaceum. Recibió tratamiento antibiótico adecuado y posteriormente fue dada de alta. Se realizó una revisión bibliográfica de esta infección en niños y se encontraron 44 casos en todo el mundo. Algunos de éstos, se relacionaron con inmunodeficiencia de base, como la enfermedad granulomatosa crónica. La infección por esta bacteria es rara y se presenta como un cuadro grave que no responde a antibióticos habituales de uso empírico y tiene una alta tasa de mortalidad (AU)

Chromobacterium violaceum is a facultative anaerobic Gramnegative bacillus, widely distributed in water and soil in tropical and subtropical regions and associated with respiratory and gastrointestinal infections, liver abscesses, meningitis, endocarditis, hemophagocytic syndrome, and fulminant sepsis. Here two pediatric cases are presented: The first was an 8-year-old boy with skin lesions, fever, and inguinal adenitis, who was admitted with severe sepsis, acute respiratory distress syndrome (ARDS) and died three hours after. Chromobacterium violaceum was isolated from blood cultures. The second case was a 12-year-old girl with a history of fever and inguinal adenopathy secondary to a wound in the homolateral foot, who was admitted because of sepsis and multiple deep abscesses. From samples collected from the skin and soft tissues as well as tracheal aspirate Chromobacterium violaceum was isolated. Adequate antibiotic treatment was started and the patient was subsequently discharged. In a review of the literature, 44 cases worldwide were identified. Some of these cases were related to underlying immunodeficiency, such as chronic granulomatous disease. Infection with this bacterium is rare and presents with severe manifestations that do not respond to the common empirical antibiotics and are associated with a high mortality rate (AU)

Romipeptides A and B, two new romidepsin derivatives isolated from Chromobacterium violaceum No.968 and their antitumor activities in vitro / 中国天然药物

Romipeptides A and B (1 and 2), two new romidepsin derivatives, and three known compounds, chromopeptide A (3), romidepsin (4) and valine-leucine dipeptide (5) were isolated from the fermentation broth of Chromobacterium violaceum No. 968. Their structures were elucidated by interpretation of their UV, HR-ESI-MS and NMR spectra. The absolute configuration of compound 1 and 2 were established by single crystal X-ray diffraction analysis. Compounds 1-5 were evaluated for their anti-proliferative activities against three human cancer cell lines, SW620, HL60, and A549. The results showed most of these compounds exhibited antitumor activities in vitro, in which compound 2 displayed potent cytotoxicity to SW620, HL60 and A549 cell lines, with IC of 12.5, 6.7 and 5.7 nmol·L, respectively.

Anti-Candida and anti-quorum sensing activity of airborne microorganisms detected by a rapid method

Abstract INTRODUCTION: Introducing new antibiotics to the clinic is critical. METHODS: We adapted a plate method described by Kawaguchi and coworkers in 20131 for detecting inhibitory airborne microorganisms. RESULTS: We obtained 51 microbial colonies antagonist to Chromobacterium violaceum, purified and retested them, and of these, 39 (76.5%) were confirmed. They comprised 24 bacteria, 13 fungi, and 2 yeasts. Among the fungi, eight (61.5%) produced active extracts. Among the bacterial, yeast, and fungal strains, 17 (44.7%) and 12 (31.6%) were active against Candida albicans and Candida parapsilosis, respectively. CONCLUSIONS: The proposed screening method is a rapid strategy for discovering potential antibiotic producers.

Identification of Chromobacterium violaceum by MALDI-TOF mass spectrometry in blood culture

Report of Chromobacterium violaceum isolation from blood culture. Identification by MALDI-TOF mass spectrometry. Relevant report due to the site affected, infection severity, and importance of correct and rapid identification for a successful treatment and lower risk of morbidity and mortality. (AU)

Efecto de inoculantes bacterianos edáficos mixtos en el desarrollo temprano de cultivares mejorados de cacao (Theobroma cacao L.) en un sistema agroforestal tradicional del norte de Oaxaca, México / Effect of mixed edaphic bacterial inoculants in the early development of improved cocoa cultivars (Theobroma cacao L.) in a traditional agroforestry system of Oaxaca, Mexico

El cacao (Theobroma cacao L.) es nativo de América del Sur y representa uno de los recursos «bioculturales¼ más significativos de Mesoamérica, ya que es una región donde se domesticó y tuvo relevancia como bebida ritual y como moneda en muchas culturas prehispánicas hasta la llegada de los españoles, quienes difundieron su uso en el mundo y lo convirtieron en una de las mercancías «commodity¼ más consumidas. Mediante este trabajo se propone una alternativa para atender la problemática de las plantaciones a través de la introducción de una diversidad amplia de cultivares de cacao en sistemas agroforestales tradicionales, en sinergia con la inoculación de bacterias edáficas fijadoras de nitrógeno y solubilizadoras de fósforo insoluble. En una parcela agroforestal tradicional se introdujeron plantas de cacao injertadas de cuatro cultivares y se dispusieron 3 tratamientos: aplicación de biofertilizante, aplicación de fertilizante químico y testigo. Se registraron la altura, el diámetro basal, el número de hojas y el número de ramas a los 2 y 12 meses, y se caracterizó la población de microorganismos asociada alrededor del tallo bajo la copa de las plantas. Los resultados de crecimiento muestran un buen potencial para los 4 cultivares estudiados y se observó que la biofertilización generó efectos significativos en algunos de los indicadores de crecimiento de las plantas de cacao. Así, las asociaciones vegetales en un sistema agroforestal podrían ser favorables para potenciar el desarrollo de frutos y resistencia a plagas y enfermedades.

Cocoa plant (Theobroma cacao L.) is native from South America and it represents one of the most significant "bio-cultural" resources of Mesoamerica, since it is a region where it was domesticated and had a relevance as ritual drink and as currency in many pre-hispanic cultures until the arrival of the Spaniards who spread its use worldwide, and became it one of the most consumed commodity goods. Through this research, an alternative is proposed to address the problem of cultivars through the introduction of a wide variety of cocoa plants in traditional agroforestry systems, in synergy with the inoculation of nitrogen-fixing and insoluble phosphor solubilizing edaphic bacterial consortia. Four cultivars of improved grafted cocoa plants were introduced in a traditional agroforestry plot and three fertilization treatments were applied: application of biofertilizer, application of chemical fertilizer and control. Measurements of height, stem diameter, number of leaves and branches were recorded at 2 and 12 months after planting and rhizosphere microbial populations were characterized. Growth results showed good potential for all studied cultivars and it was observed that biofertilization foresees significant effects in some of the growth indicators of cocoa plant. Thereby, plant associations in an agroforestry system could be favorable to promote fruit development and resistance to pests and diseases.

Reporte de dos casos de inusual infección no letal por Chromobacterium violaceum. Revisión literaria / Report two cases non lethal infectious diseases for Chromobacterium violaceum. Review of the literature

Chromobacterium violaceum es una bacteria gramnegativa anaeróbica facultativa, que habita en el suelo y el agua de las áreas tropicales y subtropicales. La infección en seres humanos es rara. A continuación se presentan dos casos; una lactante mayor, indígena, quien posterior a baño de inmersión en aguas estancadas comienza a presentar fiebre con aumento de volumen y limitación funcional y gonalgia izquierda, se realiza lavado articular, se toma muestra para cultivo con crecimiento para Chromobacterium violaceum. Un escolar masculino de 7 años de edad con antecedente de Leucemia Linfoblastica Aguda con recaída en sistema nervioso central, cumpliendo esquema de altas dosis de metotrexate; quien comienza a presentar fiebre y signos de flogosis en sitio de colocación de cáteter de vía central, el cual es retirado y cultivado con crecimiento para Chromobacterium violaceum. Esta infección en humanos es una enfermedad grave y sistémica con una alta tasa de mortalidad.

Chromobacterium violaceum is a Gram-negative facultative anaerobic bacterium, which lives in the soil and water of subtropical and tropical areas. Infection in humans is rare. Here we present two cases. One was in one indigenous newborn, who after one immersion in stagnant waters presented fever and increase in the volume of testicle and limitation in movility of the left limb. After arthrocentesis of left knee and culture of the sinovial liquid, growth of Cromabacterium violaceum was reported. Another case was a male school of 7 years old with a history of acute lymphoblastic leukemia relapse in the central nervous system, that completed his high dose methotexate scheme. Some days after he presented fever and edema at the site of central venous catheterization. The catheter was retired and it was obtained growth of Chromobacterium violaceum. Human infection with Chromobacterium violaceum is a severe and systemic disease with a high mortality rate.

Recent research advances on Chromobacterium violaceum

Chromobacterium violaceum is a gram-negative bacterium, which has been used widely in microbiology labs involved in quorum sensing (QS) research. Among the QS-regulated traits of this bacterium, violacein production has received the maximum attention. Violacein production in this organism, however is not under sole control of QS machinery, and other QS-regulated traits of this bacterium also need to be investigated in better detail. Though not often involved in human infections, this bacterium is being viewed as an emerging pathogen. This review attempts to highlight the recent research advances on C. violaceum, with respect to violacein biosynthesis, development of various applications of this bacterium and its bioactive metabolite violacein, and its pathogenicity.

Antagonistic Evaluation of Chromobacterium sp. JH7 for Biological Control of Ginseng Root Rot Caused by Cylindrocarpon destructans

Cylindrocarpon destructans is an ascomycete soil-borne pathogen that causes ginseng root rot. To identify effective biocontrol agents, we isolated several bacteria from ginseng cultivation soil and evaluated their antifungal activity. Among the isolated bacteria, one isolate (named JH7) was selected for its high antibiotic activity and was further examined for antagonism against fungal pathogens. Strain JH7 was identified as a Chromobacterium sp. using phylogenetic analysis based on 16S rRNA gene sequences. This strain was shown to produce antimicrobial molecules, including chitinases and proteases, but not cellulases. Additionally, the ability of JH7 to produce siderophore and solubilize insoluble phosphate supports its antagonistic and beneficial traits for plant growth. The JH7 strain suppressed the conidiation, conidial germination, and chlamydospore formation of C. destructans. Furthermore, the JH7 strain inhibited other plant pathogenic fungi. Thus, it provides a basis for developing a biocontrol agent for ginseng cultivation.

Recent research advances on Chromobacterium violaceum

Chromobacterium violaceum is a gram-negative bacterium, which has been used widely in microbiology labs involved in quorum sensing (QS) research. Among the QS-regulated traits of this bacterium, violacein production has received the maximum attention. Violacein production in this organism, however is not under sole control of QS machinery, and other QS-regulated traits of this bacterium also need to be investigated in better detail. Though not often involved in human infections, this bacterium is being viewed as an emerging pathogen. This review attempts to highlight the recent research advances on C. violaceum, with respect to violacein biosynthesis, development of various applications of this bacterium and its bioactive metabolite violacein, and its pathogenicity.

Efeito da violaceína sobre formas evolutivas de trypanosoma cruzi

A Organização Mundial de Saúde estima que aproximadamente 7 a 8 milhões de pessoas encontram-se infectadas pelo Trypanosoma cruzi no mundo. O tratamento da doença de Chagas apresenta eficácia limitada e efeitos colaterais que limitam a tolerabilidade e a adesão dos pacientes. A busca de novas alternativas terapêuticas a partir de substâncias bioativas cresceu bastante nos últimos anos. A violaceína (VIO), um pigmento bacteriano produzido por Chromobacterium violace um tem mostrado diversas ações biológicas, dentre elas, ações antiulcerogênica, antitumoral, antiviral e antiparasitária. No presente trabalho, estudamos os efeitos da VIO sobre as formas evolutivas doTrypanosoma cruzi. As formas epimastigotas foram cultivadas em meio LIT, a 28°C, na presença deVIO (0,97; 1,9; 3,9; 7,8; 15,62; 31,25; 62,5; 125; 250; 500; 1000μM) por 24, 48 e 72h. As formas tripomastigotas, foram obtidas após infecção em células LLC-MK2, ressuspensas em meio DMEM2% de SBF e incubadas com VIO (0,97; 1,9; 3,9; 7,8; 15,62; 31,25μM) por 24h. Formas amastigotas foram cultivadas em lamínulas circulares no interior de placas de cultura contendo células LLC-MK2e tratadas com violaceína (4,97 e 9,94 μM)...

The World Health Organization estimates that approximately 7 to 8 million individuals areinfected with Trypanosoma cruzi worldwide. The treatment of Chagas disease has limited efficacy andside effects that limit patient tolerability and compliance. The search for new therapeutic alternativesbased on bioactive substances has increased significantly in recent years. Violacein (VIO), a bacterialpigment produced by Chromobacterium violaceum, has shown several biological actions and amongthem, antiulcer, antitumor, antiviral, and antiparasitic action. In this study, we assessed the effects ofVIO on the evolutionary forms of Trypanosoma cruzi. Epimastigotes were cultured in liver infusiontryptose (LIT) medium at 28 °C in the presence of VIO (0.97; 1.9; 3.9; 7.8; 15.62; 31.25; 62.5; 125;250 ; 500; 1000μM) for 24, 48 and 72 hours. Trypomastigotes were obtained after infection in LLCMK2cells resuspended in 2% DMEM medium of FBS and incubated with VIO (0.97; 1.9; 3.9; 7.8;15.62; 31.25μM ) for 24h. Amastigotes were cultured on circular glass slides within culture platescontaining LLC-MK2 cells and treated with violacein (4.97 and 9.94 μM)...

Fatal Wound Infection by Chromobacterium violaceum after Open Ankle Fracture Surgery / 계명의대학술지

Chromobacterium violaceum (C. violaceum) is a gram negative, facultative anaerobe widely distributed in natural aquatic environments and is sensitive to temperature. Its infection has a predilection to tropical or subtropical regions that between latitude 35degrees N and 35degrees S. Infection due to C. violaceum is rare. But human infection with this organism can result in severe, systemic disease with a high fatality rate. C. violaceum infection may rapidly progress to sepsis with multiple organ abscesses, predominantly in lungs, liver, and spleen. The organism is usually resistant to most antibiotics commonly prescribed for gram-negative bacterial infection like aminoglycosides, extended spectrum beta-lactam antibiotics etc. In Korea, two cases of C. violaceum infections were reported in patients injured in a Guam airplane accident, and one case was reported local C. violaceum infection. Here, we report a case of fatal C. violaceum postoperative wound infection in Korea.

Chromopeptide A, a highly cytotoxic depsipeptide from the marine sediment-derived bacterium Chromobacterium sp. HS-13-94

A bicyclic depsipeptide, chromopeptide A (1), was isolated from a deep-sea-derived bacterium Chromobacterium sp. HS-13-94. Its structure was determined by extensive spectroscopic analysis and by comparison with a related known compound. The absolute configuration of chromopeptide A was established by X-ray diffraction analysis employing graphite monochromated Mo K α radiation (λ=0.71073 Å) with small Flack parameter 0.03. Chromopeptide A suppressed the proliferation of HL-60, K-562, and Ramos cells with average IC50 values of 7.7, 7.0, and 16.5 nmol/L, respectively.

Composition, anti-quorum sensing and antimicrobial activity of essential oils from Lippia alba

Many Gram-negative pathogens have the ability to produce N-acylhomoserine lactones (AHLs) as signal molecules for quorum sensing (QS). This cell-cell communication system allows them to coordinate gene expression and regulate virulence. Strategies to inhibit QS are promising for the control of infectious diseases or antibiotic resistant bacterial pathogens. The aim of the present study was to evaluate the anti-quorum sensing (anti-QS) and antibacterial potential of five essential oils isolated from Lippia alba on the Tn-5 mutant of Chromobacterium violaceum CV026, and on the growth of the gram-positive bacteria S. aureus ATCC 25923. The anti-QS activity was detected through the inhibition of the QS-controlled violacein pigment production by the sensor bacteria. Results showed that two essential oils from L. alba, one containing the greatest geranial:neral and the other the highest limonene:carvone concentrations, were the most effective QS inhibitors. Both oils also had small effects on cell growth. Moreover, the geranial/neral chemotype oil also produced the maximum zone of growth inhibition against S. aureus ATCC 25923. These data suggest essential oils from L. alba have promising properties as QS modulators, and present antibacterial activity on S. aureus.

Chromobacterium violaceum: um caso fatal no nordeste do Brasil / Chromobacterium violaceum: a fatal case in the northeast of the Brazil

Chromobacterium violaceum is a rare pathogen that can potentially cause fatal infections in humans. An 8-year-old child from Natal, northeast of Brazil, presented history of fever, sore throat, and abdominal pain, during 5 days before admission, and died 4 hours after hospitalization. Chromobacterium violaceum was isolated from oropharynx scrapings and was resistant to ampicillin, cefotaxime, cefalotin, ceftazidime, and ceftriaxone...

Chromobacterium violaceum é um patógeno raro que potencialmente pode causar infecções fatais em humanos. Relatamos o caso de uma criança de 8 anos de idade, moradora da cidade de Natal, nordeste do Brasil, que apresentou história de febre, dor na garganta e no abdome durante os cinco dias anteriores à internação, e veio a falecer após 4 horas de hospitalização. A bactéria Chromobacterium violaceum foi isolada da orofaringe e apresentou resistência a ampicilina, cefotaxima, cefalotina, ceftazidima e ceftriaxona...

In vitro and in vivo antitumor activity of crude extracts obtained from Brazilian Chromobacterium sp isolates

Natural products produced by microorganisms have been an important source of new substances and lead compounds for the pharmaceutical industry. Chromobacterium violaceum is a Gram-negative β-proteobacterium, abundant in water and soil in tropical and subtropical regions and it produces violacein, a pigment that has shown great pharmaceutical potential. Crude extracts of five Brazilian isolates of Chromobacterium sp (0.25, 2.5, 25, and 250 µg/mL) were evaluated in an in vitro antitumor activity assay with nine human tumor cells. Secondary metabolic profiles were analyzed by liquid chromatography and electrospray ionization mass spectrometry resulting in the identification of violacein in all extracts, whereas FK228 was detected only in EtCE 308 and EtCE 592 extracts. AcCE and EtCE 310 extracts showed selectivity for NCI/ADR-RES cells in the in vitro assay and were evaluated in vivo in the solid Ehrlich tumor model, resulting in 50.3 and 54.6% growth inhibition, respectively. The crude extracts of Chromobacterium sp isolates showed potential and selective antitumor activities for certain human tumor cells, making them a potential source of lead compounds. Furthermore, the results suggest that other compounds, in addition to violacein, deoxyviolacein and FK228, may be involved in the antitumor effect observed.

Biosynthesis of P(3HB-co-3HV-co-3HHp) terpolymer by Cupriavidus necator PHB4 transformant harboring the highly active PHA synthase gene of Chromobacterium sp. USM2

Aims: This study evaluates potentials of Cupriavidus necator PHB4 transformant harboring the highly active polyhydroxyalkanoate synthase gene (phaC) of a locally isolated Chromobacterium sp. USM2 for its ability to incorporate 3-hydroxyheptanoate (3HHp) monomer. Methodology and results: A mixture of fructose and sodium heptanoate fed to the culture gave rise to poly(3- hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyheptanoate), [P(3HB-co-3HV-co-3HHp)] terpolymer synthesis, with traces of 3HHp monomers confirmed through gas chromatography (GC), proton (1H) and carbon (13C) NMR spectra. Conclusion, significance and impact of study: This study has revealed that the PHA synthase of Chromobacterium sp. USM2 has a broad range of substrate specificity. The synthase is able to polymerize 3-hydroxyalkanoate monomers having 4–7 carbon atoms.

Inhibition of quorum sensing in Chromobacterium violaceum by Syzygium cumini L. and Pimenta dioica L

Objective: To investigated into the anti-quorum sensing (QS) activity of Syzygium cumini L. (S. cumini) and Pimenta dioica L. (P. dioica) using Chromobacterium violaceum (C. violaceum) strains. Methods:In this study, anti-QS activity of ethanol extract of Syzygium cumini L. and Pimenta dioica L. were screened using C. violaceum CV026 biosensor bioassay. By bioassay guided fractionation of S. cumini and P. dioica, ethyl acetate fraction (EAF) with strong anti-QS activity was separated. Inhibition of QS regulated violacein production in C. violaceum ATCC12472 by EAF was assessed at different concentrations. The effect of EAF on the synthesis of autoinducer like N-acyl homoserine lactone (AHL) was studied in C. violaceum ATCC31532 using its mutant C. violaceum CV026 by standard methods. Results: EAF inhibited violacein production in C. violaceum ATCC12472 in a concentration dependent manner without significant reduction in bacterial growth. Complete inhibition of violacein production was evidenced in 0.75-1.0 mg/mL concentration of EAF without inhibiting the synthesis of the AHL. TLC biosensor overlay profile of EAF revealed two translucent spots in S. cumini and P. dioica that inhibited C6-AHL mediated violacein production in C. violaceum CV026. Conclusions:This study indicates the anti-QS activity of the tested medicinal plants against C. violaceum.

Biosurfactant production by Chr omobacterium violaceum ATCC 12472 using corn steep liquor and corn post-frying oil as nutrients / Produção de biossurfactante por Chromobacterium violaceum ATCC 12472 utilizando milhocina e óleo de milho pós-fritura como nutrientes

The interest in microbial surfactants has been increased considerably in the recent years. Environmental concern among consumers, combined with new laws control of the environment, the demand for natural surfactants, to replace petrochemicals. The microbial surfactants have been tested in many industrial and environmental applications, such as in bioremediation, oil dispersion and oil recovery, replacing chemical surfactants. Furthermore, they can also be used in the food, cosmetic, detergent and agriculture. However, increased environmental concern among consumers to new legislation combined control of the environment has led to demand for natural surfactants as alternatives to existing products. This work aimed to produce biosurfactant by Chromobacterium violaceum ATCC 12472, using low nutrient value. The surface tension of the biosurfactant produced by C. violaceum ATCC 12472 had values between 29 and 40 mN/m. The best result was observed on the assay 8 (8.0% of corn steep liquor, 1.0% of lactose and corn oil post-frying 7.5%) factorial design, within 72 hours of fermentation, lowering the surface tension of water from 71 to 29 mN/m. The best results of the index (E24) and emulsification activity (UEA) were observed in the central point, and using the both methods and corn post-frying oil resulted in 72% of emulsification, and the emulsification activity value of 6 UAE. The results demonstrate the high potential of C. violaceum promising in producing a biosurfactant.

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.