Biosurfactants synthesized by endophytic Bacillus strains as control of Moniliophthora perniciosa and Moniliophthora roreri

ABSTRACT: Ecuador is responsible for up to 70 % of the worlds production of fine flavor cocoa. Although fungal diseases have reduced cocoa production, ecofriendly alternatives have been implemented to control the spread of phytopathogens. This study aimed to explore the potential of endophytic strains isolated from fine flavor Nacional cocoa trees to synthetize compounds with antimicrobial and surface active properties. It was determined that under in vitro conditions, seven strains (DS03, DS07, DS18, DS23, DS31, DS34 and DS50) exhibited antifungal activity that inhibited the mycelial growth of Moniliophthora roreri and Moniliophthora perniciosa. The strains were identified based on their morphological (pattern forming Bacilli) and genetic characteristics using the 16S SSU rRNA gene sequences. Furthermore, we determined that the endophytic strains contained genes that encoded the lipopeptides Fengycin (fenA, fenB, fenC, fenE), Iturin (ituB, ituC, ituD), and Bacyllomicin D (bamC, bamD). The production of biosurfactant compounds was determined by a reduction in surface tension in the mineral medium. Additionally, the biosurfactant crude extract (BCE) was tested for its inhibitory activity against M. perniciosa and M. roreri. The minimal inhibitory concentration (MIC) was determined to be 0.07 and 0.035 mg mL1, respectively, in both cases in a fungistatic action mode. The swelling granulation and fragmentation of both phytopathogens hyphae were observed using the BCE treatment. These results suggested the biocontrol capacity of the endophytic strains, which under in vitro conditions, have the ability to synthesize antifungal and surface active compounds that might be used as an ecological alternative in cocoa plants to prevent infection by phytopathogens.

Biosurfactants synthesized by endophytic Bacillus strains as control of Moniliophthora perniciosa and Moniliophthora roreri

Ecuador is responsible for up to 70 % of the world’s production of fine flavor cocoa. Although fungal diseases have reduced cocoa production, eco–friendly alternatives have been implemented to control the spread of phytopathogens. This study aimed to explore the potential of endophytic strains isolated from fine flavor Nacional cocoa trees to synthetize compounds with antimicrobial and surface active properties. It was determined that under in vitro conditions, seven strains (DS03, DS07, DS18, DS23, DS31, DS34 and DS50) exhibited antifungal activity that inhibited the mycelial growth of Moniliophthora roreri and Moniliophthora perniciosa. The strains were identified based on their morphological (pattern forming Bacilli) and genetic characteristics using the 16S SSU rRNA gene sequences. Furthermore, we determined that the endophytic strains contained genes that encoded the lipopeptides Fengycin (fenA, fenB, fenC, fenE), Iturin (ituB, ituC, ituD), and Bacyllomicin D (bamC, bamD). The production of biosurfactant compounds was determined by a reduction in surface tension in the mineral medium. Additionally, the biosurfactant crude extract (BCE) was tested for its inhibitory activity against M. perniciosa and M. roreri. The minimal inhibitory concentration (MIC) was determined to be 0.07 and 0.035 mg mL−1, respectively, in both cases in a fungistatic action mode. The swelling granulation and fragmentation of both phytopathogens’ hyphae were observed using the BCE treatment. These results suggested the biocontrol capacity of the endophytic strains, which under in vitro conditions, have the ability to synthesize antifungal and surface active compounds that might be used as an ecological alternative in cocoa plants to prevent infection by phytopathogens.

Biosurfactants synthesized by endophytic Bacillus strains as control of Moniliophthora perniciosa and Moniliophthora roreri

Ecuador is responsible for up to 70 % of the worlds production of fine flavor cocoa. Although fungal diseases have reduced cocoa production, eco–friendly alternatives have been implemented to control the spread of phytopathogens. This study aimed to explore the potential of endophytic strains isolated from fine flavor Nacional cocoa trees to synthetize compounds with antimicrobial and surface active properties. It was determined that under in vitro conditions, seven strains (DS03, DS07, DS18, DS23, DS31, DS34 and DS50) exhibited antifungal activity that inhibited the mycelial growth of Moniliophthora roreri and Moniliophthora perniciosa. The strains were identified based on their morphological (pattern forming Bacilli) and genetic characteristics using the 16S SSU rRNA gene sequences. Furthermore, we determined that the endophytic strains contained genes that encoded the lipopeptides Fengycin (fenA, fenB, fenC, fenE), Iturin (ituB, ituC, ituD), and Bacyllomicin D (bamC, bamD). The production of biosurfactant compounds was determined by a reduction in surface tension in the mineral medium. Additionally, the biosurfactant crude extract (BCE) was tested for its inhibitory activity against M. perniciosa and M. roreri. The minimal inhibitory concentration (MIC) was determined to be 0.07 and 0.035 mg mL−1, respectively, in both cases in a fungistatic action mode. The swelling granulation and fragmentation of both phytopathogens hyphae were observed using the BCE treatment. These results suggested the biocontrol capacity of the endophytic strains, which under in vitro conditions, have the ability to synthesize antifungal and surface active compounds that might be used as an ecological alternative in cocoa plants to prevent infection by phytopathogens.(AU)

Isolation and characterization of hydrocarbon-degrading bacteria from gas station leaking-contaminated groundwater in the Southern Amazon, Brazil / Isolamento e caracterização de bactérias degradadoras de hidrocarbonetos de água subterrânea contaminada por vazamentos em posto de combustível no sul da Amazônia, Brasil

Twenty-three hydrocarbon-degrading bacteria strains were isolated from gas station leaking-contaminated groundwater located in the Southern Amazon, Brazil. Based on hydrocarbon (diesel, hexadecane, benzene, toluene and xylene) degradation ability, two strains were selected for further study. The amplification and sequencing of the 16S rRNA gene showed that these two strains belonged to the genus Bacillus (Bacillus sp. L26 and Bacillus sp. L30). GC-MS analysis showed that strain L30 was the most effective in degrading n-alkane (C10-C27) from diesel after 7 days of cultivation in mineral medium. Both strains produced biosurfactants and showed emulsification activity, specially the strain L30. Alkane hydroxylase gene (group III), which is important for alkane biodegradation, was present in strains. As a result, this study indicated that these bacteria could have promising applications in hydrocarbon bioremediation.(AU)

Vinte e três linhagens bacterianas degradadoras de hidrocarbonetos foram isoladas de água subterrânea contaminada por vazamento em posto de combustível no sul da Amazônia, Brasil. Com base na habilidade de degradar hidrocarbonetos (diesel, hexadecano, benzeno, tolueno e xileno), duas linhagens foram selecionadas para estudos posteriores. A amplificação e sequenciamento do gene 16S rRNA demonstrou que essas linhagens pertencem ao gênero Bacillus (Bacillus sp. L26 and Bacillus sp. L30). Análises de GC-MS mostraram que a linhagem L30 foi mais eficiente em degradar n-alcanos (C10-C27) presentes no diesel, após 7 dias de cultivo em meio mineral. Ambas as linhagens produziram biossurfactantes e apresentaram atividade emulsificante, especialmente a linhagem L30. O gene alcano hidroxilase (grupo III), o qual é importante para degradação de alcanos, foram detectados nas linhagens. Como resultado, este estudo indicou que essas linhagens bacterianas podem ser promissoras se aplicadas em processos de biorremediação.(AU)

Isolation and characterization of hydrocarbon-degrading bacteria from gas station leaking-contaminated groundwater in the Southern Amazon, Brazil

Abstract Twenty-three hydrocarbon-degrading bacteria strains were isolated from gas station leaking-contaminated groundwater located in the Southern Amazon, Brazil. Based on hydrocarbon (diesel, hexadecane, benzene, toluene and xylene) degradation ability, two strains were selected for further study. The amplification and sequencing of the 16S rRNA gene showed that these two strains belonged to the genus Bacillus (Bacillus sp. L26 and Bacillus sp. L30). GC-MS analysis showed that strain L30 was the most effective in degrading n-alkane (C10-C27) from diesel after 7 days of cultivation in mineral medium. Both strains produced biosurfactants and showed emulsification activity, specially the strain L30. Alkane hydroxylase gene (group III), which is important for alkane biodegradation, was present in strains. As a result, this study indicated that these bacteria could have promising applications in hydrocarbon bioremediation.

Resumo Vinte e três linhagens bacterianas degradadoras de hidrocarbonetos foram isoladas de água subterrânea contaminada por vazamento em posto de combustível no sul da Amazônia, Brasil. Com base na habilidade de degradar hidrocarbonetos (diesel, hexadecano, benzeno, tolueno e xileno), duas linhagens foram selecionadas para estudos posteriores. A amplificação e sequenciamento do gene 16S rRNA demonstrou que essas linhagens pertencem ao gênero Bacillus (Bacillus sp. L26 and Bacillus sp. L30). Análises de GC-MS mostraram que a linhagem L30 foi mais eficiente em degradar n-alcanos (C10-C27) presentes no diesel, após 7 dias de cultivo em meio mineral. Ambas as linhagens produziram biossurfactantes e apresentaram atividade emulsificante, especialmente a linhagem L30. O gene alcano hidroxilase (grupo III), o qual é importante para degradação de alcanos, foram detectados nas linhagens. Como resultado, este estudo indicou que essas linhagens bacterianas podem ser promissoras se aplicadas em processos de biorremediação.

Characterization of dioxygenases and biosurfactants produced by crude oil degrading soil bacteria

ABSTRACT Role of microbes in bioremediation of oil spills has become inevitable owing to their eco friendly nature. This study focused on the isolation and characterization of bacterial strains with superior oil degrading potential from crude-oil contaminated soil. Three such bacterial strains were selected and subsequently identified by 16S rRNA gene sequence analysis as Corynebacterium aurimucosum, Acinetobacter baumannii and Microbacterium hydrocarbonoxydans respectively. The specific activity of catechol 1,2 dioxygenase (C12O) and catechol 2,3 dioxygenase (C23O) was determined in these three strains wherein the activity of C12O was more than that of C23O. Among the three strains, Microbacterium hydrocarbonoxydans exhibited superior crude oil degrading ability as evidenced by its superior growth rate in crude oil enriched medium and enhanced activity of dioxygenases. Also degradation of total petroleum hydrocarbon (TPH) in crude oil was higher with Microbacterium hydrocarbonoxydans. The three strains also produced biosurfactants of glycolipid nature as indicated d by biochemical, FTIR and GCMS analysis. These findings emphasize that such bacterial strains with superior oil degrading capacity may find their potential application in bioremediation of oil spills and conservation of marine and soil ecosystem.(AU)

Isolation and characterization of hydrocarbon-degrading bacteria from gas station leaking-contaminated groundwater in the Southern Amazon, Brazil

Abstract Twenty-three hydrocarbon-degrading bacteria strains were isolated from gas station leaking-contaminated groundwater located in the Southern Amazon, Brazil. Based on hydrocarbon (diesel, hexadecane, benzene, toluene and xylene) degradation ability, two strains were selected for further study. The amplification and sequencing of the 16S rRNA gene showed that these two strains belonged to the genus Bacillus (Bacillus sp. L26 and Bacillus sp. L30). GC-MS analysis showed that strain L30 was the most effective in degrading n-alkane (C10-C27) from diesel after 7 days of cultivation in mineral medium. Both strains produced biosurfactants and showed emulsification activity, specially the strain L30. Alkane hydroxylase gene (group III), which is important for alkane biodegradation, was present in strains. As a result, this study indicated that these bacteria could have promising applications in hydrocarbon bioremediation.

Resumo Vinte e três linhagens bacterianas degradadoras de hidrocarbonetos foram isoladas de água subterrânea contaminada por vazamento em posto de combustível no sul da Amazônia, Brasil. Com base na habilidade de degradar hidrocarbonetos (diesel, hexadecano, benzeno, tolueno e xileno), duas linhagens foram selecionadas para estudos posteriores. A amplificação e sequenciamento do gene 16S rRNA demonstrou que essas linhagens pertencem ao gênero Bacillus (Bacillus sp. L26 and Bacillus sp. L30). Análises de GC-MS mostraram que a linhagem L30 foi mais eficiente em degradar n-alcanos (C10-C27) presentes no diesel, após 7 dias de cultivo em meio mineral. Ambas as linhagens produziram biossurfactantes e apresentaram atividade emulsificante, especialmente a linhagem L30. O gene alcano hidroxilase (grupo III), o qual é importante para degradação de alcanos, foram detectados nas linhagens. Como resultado, este estudo indicou que essas linhagens bacterianas podem ser promissoras se aplicadas em processos de biorremediação.

Lipopeptide production by Bacillus subtilis R1 and its possible applications

The possible application of a bacterial strain - Bacillus subtilis R1, isolated from an oil contaminated desert site in India, as biocontrol agent and its biosurfactant in microbial enhanced oil recovery are discussed. The biosurfactant production in minimal medium was carried out at different temperatures and salt concentrations, where it produced an efficient biosurfactant at 30-45 °C and in presence of up to 7% salt. It significantly reduced the surface tension from 66 ± 1.25 mN/m to 29 ± 0.85 mN/m within 24 h. In order to enhance the biosurfactant production, random mutagenesis of B. subtilis R1 was performed using chemical mutagen - ethyl methanesulfonate. Majority of the isolated 42 mutants showed biosurfactant production, but the difference was statistically insignificant as compared with parent strain R1. Therefore none of the mutants were selected for further study, and only parent strain R1 was studied. The biosurfactant was quite stable under harsh conditions for up to 10 days. The biosurfactant was extracted and characterized as similar to the lipopeptide group - surfactins and fengycin. The crude oil displacement experiments using biosurfactant broth in sand pack glass columns showed 33 ± 1.25% additional oil recovery. The strain also showed inhibition of various plant pathogenic fungi on potato dextrose agar medium.(AU)

Biosurfactant production by Pseudomonas aeruginosa in kefir and fish meal

The aim of this study was to increase rhamnolipid production by formulating media using kefir and fish meal for Pseudomonas aeruginosa strains isolated from different environmental resources. The strains, named as H1, SY1, and ST1, capable of rhamnolipid production were isolated from soil contaminated with wastes originating from olive and fish oil factories. Additionally, P. aeruginosa ATCC 9027 strain, which is known as rhamnolipid producer, was included in the study. Initially, rhamnolipid production by the strains was determined in Mineral Salt Medium (MSM) and then in media prepared by using kefir and fish meal. The obtained rhamnolipids were purified and quantified according to Dubois et al. (1956). The quantity of rhamnolipids of ATCC, H1 and SY1 strains in kefir media were determined as 11.7 g/L, 10.8 g/L and 3.2 g/L, respectively, and in fish meal media as 12.3 g/L, 9.3 g/L and 10.3 g/L, respectively. In addition, effect of UV light exposure on rhamnolipid production was also investigated but contrary a decrease was observed. The results indicate that P. aeruginosa strains isolated from various environmental resources used in this study can be important due to their rhamnolipid yield, and fish meal, which is obtained from waste of fish, can be an alternative source in low cost rhamnolipid production..(AU)

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.

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. (AU)

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. (AU)

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.

Lactobacillus acidophilus-derived biosurfactant effect on gtfB and gtfC expression level in Streptococcus mutans biofilm cells

Streptococcus mutans (S. mutans), harboring biofilm formation, considered as a main aetiological factor of dental caries. Gtf genes play an important role in S. mutans biofilm formation. The purpose of this study was to investigate the effect of Lactobacillus acidophilus-derived biosurfactant on S. mutans biofilm formation and gtfB/C expression level (S. mutans standard strain ATCC35668 and isolated S. mutans strain (22) from dental plaque). The Lactobacillus acidophilus (L. acidophilus) DSM 20079 was selected as a probiotic strain to produce biosurfactant. The FTIR analysis of its biosurfactant showed that it appears to have a protein-like component. Due to the release of such biosurfactants, L. acidophilus was able to interfere in the adhesion and biofilm formation of the S. mutans to glass slide. It also could make streptococcal chains shorter. Using realtime RT-PCR quantitation method made it clear that gtfB and gtfC gene expression were decreased in the presence of L. acidophilus-derived biosurfactant fraction. Several properties of S. mutans cells (the surface properties, biofilm formation, adhesion ability and gene expression) were changed after L. acidophilus-derived biosurfactant treatment. It is also concluded that biosurfacant treatment can provide an optional way to control biofilm development. On the basis of our findings, we can suggest that the prepared biosurfactant may interfere with adhesion processes of S. mutans to teeth surfaces, provided additional evaluation produce satisfactory results.

Biosurfactant production by Rhodococcus erythropolis and its application to oil removal

The influence of different nutrients on biosurfactant production by Rhodococcus erythropolis was investigated. Increasing the concentration of phosphate buffer from 30 up through 150 mmol/L stimulated an increase in biosurfactant production, which reached a maximum concentration of 285 mg/L in shaken flasks. Statistical analysis showed that glycerol, NaNO3,MgSO4 and yeast extract had significant effects on production. The results were confirmed in a batchwise bioreactor, and semi-growth-associated production was detected. Reduction in the surface tension, which indicates the presence of biosurfactant, reached a value of 38 mN/m at the end of 35 hours. Use of the produced biosurfactant for washing crude oil-contaminated soil showed that 2 and 4 times the critical micellar concentration (CMC) were able to remove 97 and 99% of the oil, respectively, after 1 month of impregnation.

Evaluation of a lipopeptide biosurfactant from Bacillus natto TK-1 as a potential source of anti-adhesive, antimicrobial and antitumor activities

A lipopeptide biosurfactant produced by Bacillus natto TK-1 has a strong surface activity. The biosurfactant was found to be an anti-adhesive agent against several bacterial strains, and also showed a broad spectrum of antimicrobial activity. The biosurfactant induced a significant reduction in tumor cells viability in a dose- dependent manner.

Um lipopeptídio biosurfactante produzido por Bacillus natto TK-1 apresenta intensa atividade de superfície. Verificou-se que o biosurfactante apresentou atividade antiadesiva contra várias cepas bacterianas, e também atividade antimicrobiana de amplo espectro. O biosurfactante causou uma redução significativa na viabilidade de células tumorais, de forma dose-dependente.

Mass spectrometry analysis of surface tension reducing substances produced by a pah-degrading Pseudomonas citronellolis strain

In this work we investigated the structure of the iron-stimulated surface tension reducing substances produced by P. citronellolis 222A isolated from a 17-years old landfarming used for sludge treatment in petrochemical industries and oil refinery. Its mass spectrum differs from P. aeruginosa spectrum, indicating that the surface tension reducing substances produced by P. citronellolis can be a new kind of biosurfactant.

Neste trabalho é apresentado um estudo a respeito da análise da estrutura de substâncias redutoras de tensão superficial produzidas por Pseudomonas citronellolis 222A estimulado pela presença de ferro. Esta bactéria foi isolada de um solo que há 17 anos vem sendo utilizado para o tratamento de borra oleosa proveniente da indústria petroquímica e de refinaria de petróleo. O espectro de massa difere do espectro de P. aeruginosa, indicando que as substâncias redutoras de tensão superficial produzidas por P. citronellolis podem ser um novo tipo de biosurfactante.

Antimicrobial activity of surfactants produced by Bacillus subtilis R14 against multidrug-resistant bacteria

Lipopeptides represent a class of microbial surfactants with increasing scientific, therapeutic and biotechnological interests. The genus Bacillus is a producer of these active compounds, and among them B. subtilis produces surfactin, the most potent biosurfactant known. These compounds can act as antibiotics, antivirals, antitumorals, immunomodulators and enzyme inhibitors. In this work, the antimicrobial activity of biosurfactants obtained by cultivation of B. subtilis R14 was investigated against multidrug-resistant bacteria. During cultivation in defined medium, the surface tension of the medium was reduced from 54 mN/m in the beginning of the microbial growth to 30 mN/m after 20 hours. A crude surfactant concentration of 2.0 g/L was obtained after 40 hours of cultivation. A preliminary characterization suggested that two surfactants were produced. The evaluation of the antimicrobial activity of these compounds was carried out against 29 bacteria. Enterococcus faecalis (11 strains), Staphylococcus aureus (6 strains) and Pseudomonas aeruginosa (7 strains) and Escherichia coli CI 18 (1 strain) displayed a profile of well defined drug resistance. All strains were sensitive to the surfactants, in particular Enterococcus faecalis. The results demonstrated that lipopeptides have a broad spectrum of action, including antimicrobial activity against microorganisms with multidrug-resistant profiles.

Os lipopeptídeos representam uma classe de surfactantes microbiológicos com crescente interesse científico, terapêutico e biotecnológico. O gênero Bacillus é um dos maiores produtores destes compostos ativos. Dentre as espécies produtoras de biossurfactante, B. subtilis produz surfactina um dos mais conhecidos. Estes compostos atuam como antibióticos, antivirais, agente antitumorais, imunomoduladores e inibidores enzimáticos. O objetivo deste trabalho foi determinar a atividade antimicrobiana de biossurfactantes, obtidos pelo cultivo de B. subtilis R14, frente a bactérias multidroga-resistentes. Durante o cultivo em meio quimicamente definido, a tensão superficial do meio foi reduzida de 54 mN/m no início do crescimento microbiano para 30 mN/m depois de 20 h. Uma concentração de surfactante bruto de 2 g/L foi obtida depois de 40h de cultivo. Uma caracterização preliminar sugeriu que dois surfactantes foram produzidos. A avaliação antimicrobiana destes compostos foi realizada frente a vinte e nove bactérias. O perfil de multidroga-resistência foi previamente definido para Enterococcus faecalis (11 cepas) Staphylococcus aureus (6 cepas), Pseudomonas aeruginosa (7 cepas) e Escherichia coli IC18. Todas as cepas foram sensíveis aos surfactantes, em particular Enterococcus faecalis. Os resultados demonstraram que os lipopeptídios têm um amplo espectro de ação, incluindo microrganismos multidroga-resistentes.

Selection of microorganisms for biosurfactant production using agroindustrial wastes

Biosurfactant production by some bacterial isolates using molasses, milk whey and cassava flour wastewater (manipueira) as substrates was evaluated and compared with the production in conventional medium. Isolates growing in manipueira medium decreased the surface tension around 42%, the highest reduction among all the substrates tested. From the eleven isolates tested, eight were able to decrease the surface tension to levels below 30 mN/m using manipueira as substrate. The isolates LB5a, LB2a, LB262, LBB and LB1a that gave surface tension about 26 mN/m were identified as Bacillus sp. Natural manipueira (high solids content) and decanted manipueira (no solids) were investigated as culture media for biosurfactant production by selected microorganisms. Natural manipueira medium showed minimum surface tension of 28 mN/m (LB5a isolate) whereas for decanted manipueira the lowest value was 26 mN/m (isolate LB2a). Average diameter of growth on manipueira agar was 7.2 cm for isolate LB5a suggesting a high growth capacity on this substrate. Manipueira comprises a potential alternative culture medium for biosurfactant production by the selected isolates.

Alguns isolados bacterianos foram avaliados quanto à capacidade de produção de biossurfatantes a partir de melaço, soro de leite e manipueira como substratos. A produção nestes meios alternativos foi comparada com a produção em meio de cultura convencional. Dentre os meios testados, a manipueira demonstrou a maior percentagem de redução na tensão superficial atingindo valores ao redor de 42%. Dos onze isolados testados, oito foram capazes de diminuir a tensão superficial para níveis inferiores à 30mN/m utilizando manipueira como substrato. Os isolados LB 5a, LB2a, LB262, LBB e LB1a apresentaram tensão superficial em torno de 26 mN/m sendo selecionados e posteriormente identificados como pertencentes ao gênero Bacillus sp. A manipueira natural (alto teor de sólidos) e a manipueira decantada (ausência de sólidos) foram investigadas como meios de cultivo para produção de biossurfatantes pelos microrganismos selecionados. O meio de manipueira natural apresentou tensão superficial minima de 28 mN/m (isolado LB5a) enquanto que o meio de manipueira decantada apresentou tensão superficial mínima de 26 mN/m (isolado LB2a). O diâmetro de crescimento médio do isolado LB5a em ágar manipueira foi de 7.2 cm sugerindo maior capacidade de crescimento neste substrato. A manipueira demonstrou potencial como meio de cultura alternativo para a produção de biossurfatantes pelos isolados selecionados.

Selection of microorganisms for biosurfactant production using agroindustrial wastes

Biosurfactant production by some bacterial isolates using molasses, milk whey and cassava flour wastewater (manipueira) as substrates was evaluated and compared with the production in conventional medium. Isolates growing in manipueira medium decreased the surface tension around 42%, the highest reduction among all the substrates tested. From the eleven isolates tested, eight were able to decrease the surface tension to levels below 30 mN/m using manipueira as substrate. The isolates LB5a, LB2a, LB262, LBB and LB1a that gave surface tension about 26 mN/m were identified as Bacillus sp. Natural manipueira (high solids content) and decanted manipueira (no solids) were investigated as culture media for biosurfactant production by selected microorganisms. Natural manipueira medium showed minimum surface tension of 28 mN/m (LB5a isolate) whereas for decanted manipueira the lowest value was 26 mN/m (isolate LB2a). Average diameter of growth on manipueira agar was 7.2 cm for isolate LB5a suggesting a high growth capacity on this substrate. Manipueira comprises a potential alternative culture medium for biosurfactant production by the selected isolates.

Alguns isolados bacterianos foram avaliados quanto à capacidade de produção de biossurfatantes a partir de melaço, soro de leite e manipueira como substratos. A produção nestes meios alternativos foi comparada com a produção em meio de cultura convencional. Dentre os meios testados, a manipueira demonstrou a maior percentagem de redução na tensão superficial atingindo valores ao redor de 42%. Dos onze isolados testados, oito foram capazes de diminuir a tensão superficial para níveis inferiores à 30mN/m utilizando manipueira como substrato. Os isolados LB 5a, LB2a, LB262, LBB e LB1a apresentaram tensão superficial em torno de 26 mN/m sendo selecionados e posteriormente identificados como pertencentes ao gênero Bacillus sp. A manipueira natural (alto teor de sólidos) e a manipueira decantada (ausência de sólidos) foram investigadas como meios de cultivo para produção de biossurfatantes pelos microrganismos selecionados. O meio de manipueira natural apresentou tensão superficial minima de 28 mN/m (isolado LB5a) enquanto que o meio de manipueira decantada apresentou tensão superficial mínima de 26 mN/m (isolado LB2a). O diâmetro de crescimento médio do isolado LB5a em ágar manipueira foi de 7.2 cm sugerindo maior capacidade de crescimento neste substrato. A manipueira demonstrou potencial como meio de cultura alternativo para a produção de biossurfatantes pelos isolados selecionados.