Résumé
@#Objective To isolate and identify Lactobacillus paracasei and Bacillus subtilis from feces of northern white geese.Methods Lactobacillus paracasei and Bacillus subtilis,numbered S00834-8 and IS00439-2 respectively,were isolated from feces of 30 52-week-old northern white geese and cultured in specific medium,and identified by 16S DNA sequencing. The two strains were cultured for different time duration(0,2,4,6,8,10,12,14,16,18,20,22,24,36 and 48 h),at different temperature(34,36,37,38 and 40 ℃)and pH(5. 5,6. 0,6. 5,7. 0,7. 5 and 8. 0). The growth characteristics of the strains were evaluated according to the A600values measured by UV-Vis spectrophotometer. At the same time,the acid and bile salt tolerance(pH 2. 0,2. 5,3. 0,3. 5 and 7. 0,bile salt concentration 0,0. 3%,0. 5%,1. 0% and 1. 5%)and the antibiotic tolerance were tested. Results The strains S00834-8 and IS00439-2 were Lactobacillus paracasei subspecies tolerance H and Bacillus subtilis KA9,respectively. The strain S00834-8 cultured under the optimum condition of the culture medium with pH 6. 0,at 37 ℃,for 12 h,had good bile resistance and gastric acid resistance,which was moderately susceptible to piperacillin,norfloxacin,amikacin,gentamicin and tetracycline,and susceptible to levofloxacin,streptomycin and chloramphenicol. The strain IS00439-2 best cultured in the culture medium with pH 7. 5,at 36 ℃,for 8 h,showed good bile resistance and gastric acid resistance,which was moderately sensitive to levofloxacin and tetracycline,while sensitive to piperacillin,norfloxacin,streptomycin and chloramphenicol. Conclusion Goose-derived Lactobacillus paracasei subspecies tolerance H and Bacillus subtilis KA9 have good acid resistance and bile salt resistance,which are expected to be candidate strains for goose-derived microecological preparations.
Résumé
Functional membrane microdomains (FMMs) that are mainly composed of scaffold proteins and polyisoprenoids play important roles in diverse cellular physiological processes in bacteria. The aim of this study was to identify the correlation between MK-7 and FMMs and then regulate the MK-7 biosynthesis through FMMs. Firstly, the relationship between FMMs and MK-7 on the cell membrane was determined by fluorescent labeling. Secondly, we demonstrated that MK-7 is a key polyisoprenoid component of FMMs by analyzing the changes in the content of MK-7 on cell membrane and the changes in the membrane order before and after destroying the integrity of FMMs. Subsequently, the subcellular localization of some key enzymes in MK-7 synthesis was explored by visual analysis, and the intracellular free pathway enzymes Fni, IspA, HepT and YuxO were localized to FMMs through FloA to achieve the compartmentalization of MK-7 synthesis pathway. Finally, a high MK-7 production strain BS3AT was successfully obtained. The production of MK-7 reached 300.3 mg/L in shake flask and 464.2 mg/L in 3 L fermenter.
Sujets)
Bacillus subtilis/métabolisme , Vitamine K2/métabolisme , Bioréacteurs/microbiologie , Microdomaines membranaires/métabolismeRésumé
Bacillus subtilis is recognized as a generally-regarded-as-safe strain, and has been widely used in the biosynthesis of high value-added products, including N-acetylneuraminic acid (NeuAc) which is widely used as a nutraceutical and a pharmaceutical intermediate. Biosensors responding to target products are widely used in dynamic regulation and high-throughput screening in metabolic engineering to improve the efficiency of biosynthesis. However, B. subtilis lacks biosensors that can efficiently respond to NeuAc. This study first tested and optimized the transport capacity of NeuAc transporters, and obtained a series of strains with different transport capacities for testing NeuAc-responsive biosensors. Subsequently, the binding site sequence of Bbr_NanR responding to NeuAc was inserted into different sites of the constitutive promoter of B. subtilis, and active hybrid promoters were obtained. Next, by introducing and optimizing the expression of Bbr_NanR in B. subtilis with NeuAc transport capacity, we obtained an NeuAc-responsive biosensor with wide dynamic range and higher activation fold. Among them, P535-N2 can sensitively respond to changes in intracellular NeuAc concentration, with the largest dynamic range (180-20 245) AU/OD. P566-N2 shows a 122-fold of activation, which is 2 times of the reported NeuAc-responsive biosensor in B. subtilis. The NeuAc-responsive biosensor developed in this study can be used to screen enzyme mutants and B. subtilis strains with high NeuAc production efficiency, providing an efficient and sensitive analysis and regulation tool for biosynthesis of NeuAc in B. subtilis.
Sujets)
Acide N-acétyl-neuraminique/métabolisme , Bacillus subtilis/métabolisme , Régions promotrices (génétique)/génétique , Sites de fixation , Techniques de biocapteurRésumé
Isla Arena is located in the coordinate 20° 70´ N - 90° 45´ W, from Campeche, Mexico. In these estuaries, the ocean mixes with fresh water, and ecosystems are concentrated where petenes and pink flamingos proliferate. Crustaceans and mollusks abound in the sea. Despite its enormous marine wealth, there are no studies carried out on which halophilic microorganisms are present in these waters. In this work, the diversity and structure of the microbial community was investigated through a metagenomics approach and corroborated for sequencing of 16S rRNA genes. It was found that the phylum Fimicutes predominates with more than 50%, in almost the same proportion of the class Bacilli and with almost 41% of relative abundance of the order Bacillales. The sequencing results showed that one of the samples presented a high percentage of similarity (99.75%) using the Nucleotide BLAST program with a peculiar microorganism: Bacillus subtilis. This microorganism is one of the best characterized bacteria among the gram-positive ones. Our results demonstrate that B. subtilis can be an efficient source of proteases, lipases and cellulases, from halophilic microbial communities located in poorly explored areas.
Isla Arena está localizada na coordenada 20°70N - 90°45W, de Campeche, México. Nesses estuários, o oceano se mistura com a água doce e os ecossistemas se concentram onde proliferam petenos e flamingos rosa. Crustáceos e moluscos abundam no mar. Apesar de sua enorme riqueza marinha, não há estudos realizados sobre a presença de microrganismos halofílicos nessas águas. Neste trabalho, a diversidade e estrutura da comunidade microbiana foram investigadas através de uma abordagem metagenômica e corroboradas para o sequenciamento de genes 16S rRNA. Verificou-se que o filo Fimicutes predomina com mais de 50%, quase na mesma proporção da classe Bacilli e com quase 41% de abundância relativa da ordem Bacillales. Os resultados do sequenciamento mostraram que uma das amostras apresentou alto percentual de similaridade (99,75%) pelo programa Nucleotide BLAST com um microrganismo peculiar: Bacillus subtilis. Nossos resultados demonstram que B. subtilis pode ser uma fonte eficiente de proteases, lipases e celulases, provenientes de comunidades microbianas halofílicas localizadas em áreas pouco exploradas.
Sujets)
Animaux , Bacillales/isolement et purification , Bacillus subtilis/croissance et développement , Écosystème , Microbiote/génétique , /analyseRésumé
Abstract Endophytic bacteria serve key roles in the maintenance of plant health and growth. Few studies to date, however, have explored the antagonistic and plant growth-promoting (PGP) properties of Prunus cerasifera endophytes. To that end, we isolated endophytic bacteria from P. cerasifera tissue samples and used a dual culture plate assay to screen these microbes for antagonistic activity against Verticillium dahliae, Botryosphaeria dothidea, Fusarium oxysporum, F. graminearum, and F. moniliforme. Of the 36 strains of isolated bacteria, four (strains P1, P10, P16, and P20) exhibited antagonistic effects against all five model pathogens, and the P10 strain exhibited the strongest antagonistic to five pathogens. This P10 strain was then characterized in-depth via phenotypic assessments, physiological analyses, and 16s rDNA sequencing, revealing it to be a strain of Bacillus subtilis. Application of a P10 cell suspension (1×108 CFU/mL) significantly enhanced the seed germination and seedling growth of tomato in a greenhouse setting. This P10 strain further significantly suppressed tomato Verticillium wilt with much lower disease incidence and disease index scores being observed following P10 treatment relative to untreated plants in pot-based experiments. Tomato plants that had been treated with strain P10 also enhanced defense-related enzymes, peroxidase, superoxide dismutase, and catalase activity upon V. dahliae challenge relative to plants that had not been treated with this endophytic bacterium. The results revealed that the P10 bacterial strain has potential value as a biocontrol agent for use in the prevention of tomato Verticillium wilt.
Resumo As bactérias endofíticas desempenham papel fundamental na manutenção da saúde e do crescimento das plantas. Poucos estudos até o momento, no entanto, exploraram as propriedades antagônicas e promotoras de crescimento de plantas (PGP) de endófitos de Prunus cerasifera. Para esse fim, isolamos bactérias endofíticas de amostras de tecido de P. cerasifera e usamos um ensaio de placa de cultura dupla para rastrear esses micróbios quanto à atividade antagonista contra Verticillium dahliae, Botryosphaeria dothidea, Fusarium oxysporum, F. graminearum e F. moniliforme. Das 36 cepas de bactérias isoladas, quatro (cepas P1, P10, P16 e P20) exibiram efeitos antagônicos contra todos os cinco patógenos modelo, e a cepa P10 exibiu o antagonista mais forte para cinco patógenos. Essa cepa P10 foi então caracterizada em profundidade por meio de avaliações fenotípicas, análises fisiológicas e sequenciamento de rDNA 16s, revelando ser uma cepa de Bacillus subtilis. A aplicação de uma suspensão de células P10 (1 × 108 UFC / mL) aumentou significativamente a germinação das sementes e o crescimento das mudas de tomate em casa de vegetação. Essa cepa P10 suprimiu ainda mais a murcha de Verticillium do tomate com incidência de doença muito menor e pontuações de índice de doença sendo observadas após o tratamento com P10 em relação a plantas não tratadas em experimentos baseados em vasos. As plantas de tomate que foram tratadas com a cepa P10 também aumentaram as enzimas relacionadas à defesa, peroxidase, superóxido dismutase e atividade da catalase após o desafio de V. dahliae em relação às plantas que não foram tratadas com essa bactéria endofítica. Os resultados revelaram que a cepa bacteriana P10 tem valor potencial como agente de biocontrole para uso na prevenção da murcha de Verticillium em tomate.
Résumé
Abstract Isla Arena is located in the coordinate 20° 70´ N - 90° 45´ W, from Campeche, Mexico. In these estuaries, the ocean mixes with fresh water, and ecosystems are concentrated where petenes and pink flamingos proliferate. Crustaceans and mollusks abound in the sea. Despite its enormous marine wealth, there are no studies carried out on which halophilic microorganisms are present in these waters. In this work, the diversity and structure of the microbial community was investigated through a metagenomics approach and corroborated for sequencing of 16S rRNA genes. It was found that the phylum Fimicutes predominates with more than 50%, in almost the same proportion of the class Bacilli and with almost 41% of relative abundance of the order Bacillales. The sequencing results showed that one of the samples presented a high percentage of similarity (99.75%) using the Nucleotide BLAST program with a peculiar microorganism: Bacillus subtilis. This microorganism is one of the best characterized bacteria among the gram-positive ones. Our results demonstrate that B. subtilis can be an efficient source of proteases, lipases and cellulases, from halophilic microbial communities located in poorly explored areas.
Resumo Isla Arena está localizada na coordenada 20°70N - 90°45W, de Campeche, México. Nesses estuários, o oceano se mistura com a água doce e os ecossistemas se concentram onde proliferam petenos e flamingos rosa. Crustáceos e moluscos abundam no mar. Apesar de sua enorme riqueza marinha, não há estudos realizados sobre a presença de microrganismos halofílicos nessas águas. Neste trabalho, a diversidade e estrutura da comunidade microbiana foram investigadas através de uma abordagem metagenômica e corroboradas para o sequenciamento de genes 16S rRNA. Verificou-se que o filo Fimicutes predomina com mais de 50%, quase na mesma proporção da classe Bacilli e com quase 41% de abundância relativa da ordem Bacillales. Os resultados do sequenciamento mostraram que uma das amostras apresentou alto percentual de similaridade (99,75%) pelo programa Nucleotide BLAST com um microrganismo peculiar: Bacillus subtilis. Nossos resultados demonstram que B. subtilis pode ser uma fonte eficiente de proteases, lipases e celulases, provenientes de comunidades microbianas halofílicas localizadas em áreas pouco exploradas.
Résumé
Abstract Isla Arena is located in the coordinate 20° 70´ N - 90° 45´ W, from Campeche, Mexico. In these estuaries, the ocean mixes with fresh water, and ecosystems are concentrated where petenes and pink flamingos proliferate. Crustaceans and mollusks abound in the sea. Despite its enormous marine wealth, there are no studies carried out on which halophilic microorganisms are present in these waters. In this work, the diversity and structure of the microbial community was investigated through a metagenomics approach and corroborated for sequencing of 16S rRNA genes. It was found that the phylum Fimicutes predominates with more than 50%, in almost the same proportion of the class Bacilli and with almost 41% of relative abundance of the order Bacillales. The sequencing results showed that one of the samples presented a high percentage of similarity (99.75%) using the Nucleotide BLAST program with a peculiar microorganism: Bacillus subtilis. This microorganism is one of the best characterized bacteria among the gram-positive ones. Our results demonstrate that B. subtilis can be an efficient source of proteases, lipases and cellulases, from halophilic microbial communities located in poorly explored areas.
Resumo Isla Arena está localizada na coordenada 20°70'N - 90°45'W, de Campeche, México. Nesses estuários, o oceano se mistura com a água doce e os ecossistemas se concentram onde proliferam petenos e flamingos rosa. Crustáceos e moluscos abundam no mar. Apesar de sua enorme riqueza marinha, não há estudos realizados sobre a presença de microrganismos halofílicos nessas águas. Neste trabalho, a diversidade e estrutura da comunidade microbiana foram investigadas através de uma abordagem metagenômica e corroboradas para o sequenciamento de genes 16S rRNA. Verificou-se que o filo Fimicutes predomina com mais de 50%, quase na mesma proporção da classe Bacilli e com quase 41% de abundância relativa da ordem Bacillales. Os resultados do sequenciamento mostraram que uma das amostras apresentou alto percentual de similaridade (99,75%) pelo programa Nucleotide BLAST com um microrganismo peculiar: Bacillus subtilis. Nossos resultados demonstram que B. subtilis pode ser uma fonte eficiente de proteases, lipases e celulases, provenientes de comunidades microbianas halofílicas localizadas em áreas pouco exploradas.
Sujets)
Archéobactéries , Microbiote , Phylogenèse , Bactéries/génétique , ARN ribosomique 16S/génétique , MexiqueRésumé
Abstract Endophytic bacteria serve key roles in the maintenance of plant health and growth. Few studies to date, however, have explored the antagonistic and plant growth-promoting (PGP) properties of Prunus cerasifera endophytes. To that end, we isolated endophytic bacteria from P. cerasifera tissue samples and used a dual culture plate assay to screen these microbes for antagonistic activity against Verticillium dahliae, Botryosphaeria dothidea, Fusarium oxysporum, F. graminearum, and F. moniliforme. Of the 36 strains of isolated bacteria, four (strains P1, P10, P16, and P20) exhibited antagonistic effects against all five model pathogens, and the P10 strain exhibited the strongest antagonistic to five pathogens. This P10 strain was then characterized in-depth via phenotypic assessments, physiological analyses, and 16s rDNA sequencing, revealing it to be a strain of Bacillus subtilis. Application of a P10 cell suspension (1×108 CFU/mL) significantly enhanced the seed germination and seedling growth of tomato in a greenhouse setting. This P10 strain further significantly suppressed tomato Verticillium wilt with much lower disease incidence and disease index scores being observed following P10 treatment relative to untreated plants in pot-based experiments. Tomato plants that had been treated with strain P10 also enhanced defense-related enzymes, peroxidase, superoxide dismutase, and catalase activity upon V. dahliae challenge relative to plants that had not been treated with this endophytic bacterium. The results revealed that the P10 bacterial strain has potential value as a biocontrol agent for use in the prevention of tomato Verticillium wilt.
Resumo As bactérias endofíticas desempenham papel fundamental na manutenção da saúde e do crescimento das plantas. Poucos estudos até o momento, no entanto, exploraram as propriedades antagônicas e promotoras de crescimento de plantas (PGP) de endófitos de Prunus cerasifera. Para esse fim, isolamos bactérias endofíticas de amostras de tecido de P. cerasifera e usamos um ensaio de placa de cultura dupla para rastrear esses micróbios quanto à atividade antagonista contra Verticillium dahliae, Botryosphaeria dothidea, Fusarium oxysporum, F. graminearum e F. moniliforme. Das 36 cepas de bactérias isoladas, quatro (cepas P1, P10, P16 e P20) exibiram efeitos antagônicos contra todos os cinco patógenos modelo, e a cepa P10 exibiu o antagonista mais forte para cinco patógenos. Essa cepa P10 foi então caracterizada em profundidade por meio de avaliações fenotípicas, análises fisiológicas e sequenciamento de rDNA 16s, revelando ser uma cepa de Bacillus subtilis. A aplicação de uma suspensão de células P10 (1 × 108 UFC / mL) aumentou significativamente a germinação das sementes e o crescimento das mudas de tomate em casa de vegetação. Essa cepa P10 suprimiu ainda mais a murcha de Verticillium do tomate com incidência de doença muito menor e pontuações de índice de doença sendo observadas após o tratamento com P10 em relação a plantas não tratadas em experimentos baseados em vasos. As plantas de tomate que foram tratadas com a cepa P10 também aumentaram as enzimas relacionadas à defesa, peroxidase, superóxido dismutase e atividade da catalase após o desafio de V. dahliae em relação às plantas que não foram tratadas com essa bactéria endofítica. Os resultados revelaram que a cepa bacteriana P10 tem valor potencial como agente de biocontrole para uso na prevenção da murcha de Verticillium em tomate.
Sujets)
Solanum lycopersicum , Verticillium , Prunus domestica , Maladies des plantes/prévention et contrôle , Ascomycota , Bacillus subtilis , FusariumRésumé
Endophytic bacteria serve key roles in the maintenance of plant health and growth. Few studies to date, however, have explored the antagonistic and plant growth-promoting (PGP) properties of Prunus cerasifera endophytes. To that end, we isolated endophytic bacteria from P. cerasifera tissue samples and used a dual culture plate assay to screen these microbes for antagonistic activity against Verticillium dahliae, Botryosphaeria dothidea, Fusarium oxysporum, F. graminearum, and F. moniliforme. Of the 36 strains of isolated bacteria, four (strains P1, P10, P16, and P20) exhibited antagonistic effects against all five model pathogens, and the P10 strain exhibited the strongest antagonistic to five pathogens. This P10 strain was then characterized in-depth via phenotypic assessments, physiological analyses, and 16s rDNA sequencing, revealing it to be a strain of Bacillus subtilis. Application of a P10 cell suspension (1×108 CFU/mL) significantly enhanced the seed germination and seedling growth of tomato in a greenhouse setting. This P10 strain further significantly suppressed tomato Verticillium wilt with much lower disease incidence and disease index scores being observed following P10 treatment relative to untreated plants in pot-based experiments. Tomato plants that had been treated with strain P10 also enhanced defense-related enzymes, peroxidase, superoxide dismutase, and catalase activity upon V. dahliae challenge relative to plants that had not been treated with this endophytic bacterium. The results revealed that the P10 bacterial strain has potential value as a biocontrol agent for use in the prevention of tomato Verticillium wilt.
As bactérias endofíticas desempenham papel fundamental na manutenção da saúde e do crescimento das plantas. Poucos estudos até o momento, no entanto, exploraram as propriedades antagônicas e promotoras de crescimento de plantas (PGP) de endófitos de Prunus cerasifera. Para esse fim, isolamos bactérias endofíticas de amostras de tecido de P. cerasifera e usamos um ensaio de placa de cultura dupla para rastrear esses micróbios quanto à atividade antagonista contra Verticillium dahliae, Botryosphaeria dothidea, Fusarium oxysporum, F. graminearum e F. moniliforme. Das 36 cepas de bactérias isoladas, quatro (cepas P1, P10, P16 e P20) exibiram efeitos antagônicos contra todos os cinco patógenos modelo, e a cepa P10 exibiu o antagonista mais forte para cinco patógenos. Essa cepa P10 foi então caracterizada em profundidade por meio de avaliações fenotípicas, análises fisiológicas e sequenciamento de rDNA 16s, revelando ser uma cepa de Bacillus subtilis. A aplicação de uma suspensão de células P10 (1 × 108 UFC / mL) aumentou significativamente a germinação das sementes e o crescimento das mudas de tomate em casa de vegetação. Essa cepa P10 suprimiu ainda mais a murcha de Verticillium do tomate com incidência de doença muito menor e pontuações de índice de doença sendo observadas após o tratamento com P10 em relação a plantas não tratadas em experimentos baseados em vasos. As plantas de tomate que foram tratadas com a cepa P10 também aumentaram as enzimas relacionadas à defesa, peroxidase, superóxido dismutase e atividade da catalase após o desafio de V. dahliae em relação às plantas que não foram tratadas com essa bactéria endofítica. Os resultados revelaram que a cepa bacteriana P10 tem valor potencial como agente de biocontrole para uso na prevenção da murcha de Verticillium em tomate.
Sujets)
Bacillus subtilis/physiologie , Bacillus subtilis/génétique , Endophytes/isolement et purification , Fusarium/pathogénicité , Prunus/microbiologie , Verticillium/pathogénicitéRésumé
Introduction: Bacillus species are used as biological controllers for phytopathogenic fungi, and the mechanisms to produce controllers include biosynthesis of lipopeptide biosurfactants with antifungal activity. Objective: To evaluate the antifungal potential of the biosurfactants produced by Bacillus strains, selected by molecular screening, on Fusarium oxysporum. Methods: We selected four molecular markers, related to the biosynthesis of surfactin, fengicin, and lichenysin (srfA, spf, fenB, LichAA) in nine Bacillus strains. We used two mineral media with several culture conditions, for biosurfactant production, and a well diffusion test for antifungal potential. Results: Only the biosurfactant produced by UFAB25 inhibits the mycelial growth of F. oxysporum (44 % ± 13): this biosurfactant was positive for srfA, spf, and fenB genes involved in the synthesis of surfactin and fengicine. Antifungal activity depends on culture conditions and the strain. Conclusions: Genetic markers are useful to detect strains with antifungal potential, facilitating the selection of bio-controllers. The biosurfactant profile is influenced by the strain and by culture conditions.
Introducción: Especies de Bacillus han sido empleadas como controladores biológicos contra hongos fitopatógenos. Entre los mecanismos utilizados se destaca la biosíntesis de biosurfactantes lipopeptídicos con actividad antifúngica. Objetivo: Evaluar el potencial antifúngico de los biosurfactantes producidos por cepas Bacillus nativas, previamente seleccionadas mediante tamizaje molecular, sobre Fusarium oxysporum. Métodos: Se utilizaron cuatro marcadores moleculares, relacionados con la biosíntesis de surfactina, fengicina y liquenisina (srfA, spf, fenB, LichAA) sobre nueve cepas de Bacillus. Se utilizaron dos medios minerales con diferentes condiciones de cultivo para la producción del biosurfactante. Se evaluó el potencial antifúngico de los biosurfactantes mediante la prueba de difusión en pozos. Resultados: Se determinó que solo el biosurfactante producido por UFAB25 actúa como inhibidor del crecimiento micelial de Fusarium oxysporum (43.6 % ± 13), esta cepa es positiva para los genes srfA, spf y fenB, involucrados en la síntesis de surfactina y fengicina. La actividad antifúngica depende de las condiciones de cultivo y la cepa. Conclusiones: Los marcadores genéticos ayudan a detectar cepas con potencial antifúngico, facilitando la selección de biocontroladores. El perfil del biosurfactante está influenciado no solo por la cepa, sino también por las condiciones del cultivo.
Sujets)
Bacillus/composition chimique , Antifongiques/analyseRésumé
Background and Objective: The majority of liquid waste generated by the tofu industry in Semarang exceeds the recommended limit. This condition disturbs the ecology of the surrounding environment. so a solution is needed to manage it. The use of bacteria in bioremediation technology has been proven to reduce pollutants produced by the tofu industry. The purpose of this study was to identify specific bacteria and test their ability to bioremediate pollutants from tofu wastewater using the Chemical Oxygen Demand (COD) parameter. Methodology: Methodology: The study was exploratory and experimental in nature, with the variable ability of degradative bacteria degrading tofu industrial wastewater based on COD parameters. Bacterial identification was performed using the 16S-rRNA Gene Analysis method, genomic DNA extraction with the Quick-DNA Bacterial Miniprep Kit, PCR amplification, and bi-directional sequencing. Results: The results of the identification of the selected bacteria show that they are molecules of the type nucleic acid with a query length of 1394. with a lineage report and a 93% phylogenetic tree as Bacillus subtilis, Bioremediation test shows that tofu waste can be degraded. The degradation percentage is 17%. Conclusion: Bacillus subtillis, a bacterium that degrades tofu industrial wastewater, was found as an indigenous bacteria.
Résumé
La regulación en el uso de antibióticos promotores de crecimiento en la alimentación animal requiere de la búsqueda de alternativas nutricionales seguras, que mejoren la salud intestinal y el rendimiento productivo en los animales, mientras protegen la salud del consumidor. La investigación tuvo como objetivo evaluar el efecto de Bacillus subtilis sobre el desarrollo de órganos digestivos, la morfología del intestino y el rendimiento productivo, en pollos de engorde.192 pollos Cobb 500 de un día de edad fueron asignados aleatoriamente a una de tres dietas: basal libre de antibióticos (D1), basal adicionada con 10 ppm de avilamicina (D2) o basal adicionada con 50 ppm de esporas de B. subtilis (D3), durante 42 días. Los días 21 y 42 de edad, se determinó la conversión alimenticia (CA), la ganancia acumulada de peso (GAP) y se evaluó el desarrollo de los principales órganos digestivos y la histomorfología de cada segmento del intestino delgado, mediante el sacrificio de 48 aves (8 aves/dieta/día). El uso de B. subtilis incrementó significativamente la CA y la GAP. Por otra parte, B. subtilis aumentó la alométria del intestino en comparación con el uso de antibióticos, aunque no se evidenciaron diferencias significativas para el peso de órganos digestivos, entre ambos tratamientos; B. subtilis mejoró la altura de las vellosidades y disminuyó la profundidad de las criptas, significativamente. B. subtilis favorece el desempeño productivo en pollos de engorde, mejora el desarrollo de órganos digestivos y la histomorfología del intestino delgado.
Regulation in the use of growth promoters antibiotics in animal feed has led to the search for safe nutritional alternatives that improve intestinal health and growth performance in animal, while protecting consumer health. The aim was to assess the effect of Bacillus subtilis on the digestive organs development, intestinal morphology and growth performance in broilers. A total of 192 one-day old Cobb 500 chicks, were randomized and assigned to one of three diets: basal diet free of antibiotics (D1) or basal diet added with 10ppm of avilamicyn (D2) or basal diet added with 50ppm of B. subtilis's spores (D3) for 42 days. On days 21 and 42 the feed conversion ratio (FCR) and average body weight (ABW) were determined; also, eight birds per treatment were euthanized to assess the development of digestive organs and the histomorphology in the different sections of the small intestine. The use of B. subtilis significantly increased FCR and ABW. On the other hand, B. subtilis significantly small intestine length compared to antibiotic growth promoter, but there was no differences in the weight of the digestive organs between B. subtilis and antibiotic diet, in addition B. subtilis improve villus height and decreased crypt depth significantly. In conclusion, the use of B. subtilis improve growth performance, digestive organs development and small intestine histomorphology in broilers.
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The menace of drug resistant pathogens is increasing and their level of evading conventional antimicrobials is rising. It is therefore important to discover new antimicrobials to counter the current challenges. Our preliminary investigation identified Bacillus subtilis subsp. subtilis 168 isolated from soil sample sourced from a river bank in Abuja, Nigeria, as the most potent antibiotic-producing bacteria among the other identified producers. The current study screened for the antimicrobial activity of the extract and fractions of the isolate by broth microdilution method. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and the ratio of the MBC/MIC were determined. All the tested pathogens were susceptible to the ethyl-acetate extract (MIC between 28.70 mg/ml and 57.40 mg/ml). The extract displayed bactericidal activity against all tested pathogens (MBC/MIC between 1.00 and 2.00) while Proteus mirabilis was least susceptible. The extract was purified by vacuum liquid chromatography and the fractions challenged with pathogenic strains. The fraction E was the most potent (MIC between 0.09 mg/ml and 0.75 mg/ml) and also bactericidal against all the test microbes (MBC/MIC between 2.00 and 2.11). GC-MS analysis of the purified sub fraction obtained from fraction E identified 13 compounds with different Retention time and peak areas. Among these were three major compounds which include: (i) bis(2-ethylhexyl) phthalate (ii) 1,4-epoxynaphthalene-1(2H)-methanol, 4,5,7-tris(1,1-dimethylethyl)-3,4-dihydro- (iii) D:B-Friedo-B':A'-neogammacer-5-en-3-ol, (3.beta.)-. Our findings suggest that Bacillus subtilis subsp. subtilis 168 isolated locally could serve as a valuable source of lead compounds for pharmaceutical and biotechnological purposes.
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Background & objectives: Bacillus subtilis subsp. subtilis (VCRC B471) and Pseudomonas fluorescens (B426) produce mosquitocidal biosurfactant, surfactin and di-rhamnolipid. The objective of the study was to carry out a small-scale field evaluation of the two biosurfactants to determine the efficacy, application dosage, residual activity and frequency of application against Anopheles stephensi immatures in selected sites in Goa, India. Methods: Surfactin (VCRC B471) and di-rhamnolipid (VCRC B426) were formulated as aqueous suspensions (5% AS), and were applied at the dosages of 34, 51 and 68 mL/m2 and 27, 41 and 54 mL/m2 respectively. Two experiments were carried out with the two formulations. Results: Surfactin (VCRC B471) formulation was effective at all the dosages and there was sustained reduction (>80%) in immature density in the treated sites up to 18 days in experiment 1 and up to 15 days in experiment 2. No pupae were found in the treated sites throughout the study. Di-rhamnolipid (VCRC B426) formulation was also found to reduce the immature density in the treated sites up to 14 days in experiment 1 and up to 15 days in experiment 2. Interpretation & conclusion: For VCRC B471, the optimum application dosage determined was 51 mL/m2 and for VCRC B426, 27mL/m2 . The formulations are to be applied fortnightly for effective control of Anopheles. The application dosage determined in the present study can be used for large scale field evaluation to assess their suitability for use in public health programmes for the control of Anopheles mosquitoes vectoring malaria
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@#To investigate the effect of nucleoside diphosphate kinase (NDK) on the synthesis of hyaluronic acid, nucleoside diphosphate kinase gene (ndk) was overexpressed along with the hyaluronic acid-producing genes in recombinant B.subtilis. Two engineered strains named Hp8tg and Pn8tg were constructed.Uniform hyaluronic acid (HA) could be obtained from both engineered strains.HA produced by both recombinant strains was confirmed by monosaccharide composition analysis, Fourier transform infrared spectometry and nuclear magnetic resonance spectroscopy.Inducing conditions of HA fermentation were optimized by response surface methodology.Overexpression of ndk could increase the production and molecular weight of HA by 1.3-fold and 1.1-fold, respectively. This study revealed for the first time that overexpression of ndk could relieve the inhibition effect of uridine diphosphate (UDP) on Class II HA synthase and increase the production and molecular weight of HA, which proves to be an efficient strategy for the production of HA, and the preparation of other polysaccharides.
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Background: Dysregulation of intestinal flora is a key risk factor for colorectal cancer (CRC). In recent years, traditional Chinese medicine preparations and probiotics have been increasingly applied in the prevention of CRC. Aims: To investigate the preventive effect of Panax notoginseng saponins (PNS) combined with Bacillus subtilis on CRC. Methods: Thirty female BALB/c mice were randomly divided into normal control group (NC group), model group, PNS group, Bacillus subtilis group and PNS combined with Bacillus subtilis group (PaB group). CRC mice model was constructed by azoxymethane (AOM)/dextran sulfate sodium (DSS) method. During the experiment, the mice were weighed, and disease activity index (DAI) score was evaluated. The length of colorectum and tumor number were measured. Serum interleukin (IL) - 6 and IL - 10 contents were determined by ELISA. 16S rRNA sequencing was used to analyze the composition of intestinal flora. Results: Compared with model group, DAI score was significantly decreased (P<0.001), colorectal length was significantly increased (P<0.001), number of tumor was significantly decreased (P<0.001), tumor volume was significantly decreased (P<0.01), serum IL-6 content was significantly decreased (P<0.000 1), and serum IL-10 content was significantly increased in PaB group (P<0.000 1). The results of intestinal flora sequencing showed that Simpson index was significantly decreased in PaB group than in model group (P<0.05), Shannon index and Chao index were significantly increased (P<0.05), abundance of Bacteroidota was significantly increased (P<0.01), abundances of Firmicutes, Helicobacter and Oscillibacter were significantly decreased (P all <0.05), abundance of Lactococcus was significantly increased (P<0.05). Conclusions: The combination of PNS and Bacillus subtilis can effectively alleviate the occurrence of CRC caused by AOM/DSS, and its mechanism may be related to the improvement of composition of intestinal microbial community.
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Bacillus spp. are probiotics and can secrete a variety of natural antimicrobiol active substances, of which lipopeptides are an important class. Up to now, about 90 lipopeptides have been identified, and most of them are cyclic lipopeptides. surfactin, iturin, fengycin, bacillomycin and polymyxins are widely studied, and the first three have huge potential for application due to their properties of surfactants and anti-fungal, anti-bacterial, anti-viral, anti-tumor and anti-inflammatory functions. In this paper, the research progress in the structure, function, synthesis regulation, separation, purification and production of surfactin, iturin and fengycin was reviewed. Synthetic biology is a vital means to increase the yield of lipopeptides, and in the future, lipopeptides can be used in crop cultivation, animal farming, food, medicine and petroleum industries as well as environmental protection. Future research should be strengthened on the discovery of new lipopeptides, synthesis of high-activity lipopeptides, economical production of lipopeptides on a large scale and their safety evaluation.
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Antibactériens , Anti-infectieux/pharmacologie , Bacillus , Bacillus subtilis , Lipopeptides/pharmacologie , Peptides cycliques/pharmacologieRésumé
Aims@#Thermophilic proteases are important industrial enzymes because they can be used at high temperatures in various bioprocessing schemes. The bacterial population of the Cholistan desert was explored for thermophilic proteases and their industrial applications.@*Methodology and results@#Three bacterial isolates K1, K5 and K7 were found promising protease producers. These isolates were preliminary identified as Bacillus based on morphological characteristics and biochemical tests (positive for catalase, oxidase and citrate tests, and negative for indole and urease tests). The isolates K1, K5 and K7 were further identified as Priestia endophytica, Lysinibacillus cresolivorans and Bacillus subtilis, respectively by phylogenetic analysis. The isolates grew best at 50 °C and P. endophytica (K1), L. cresolivorans (K5) and B. subtilis (K7) produced larger zones of hydrolysis at 37 °C, 45 °C and 50 °C at pH 7, respectively. The optimum temperature where protease activity was maximum was 65 °C for P. endophytica and L. cresolivorans and 55 °C for B. subtilis, and the optimum pH was 9.@*Conclusion, significance and impact of study@#The proteases produced by these isolates were found active at high temperatures (45 °C to 85 °C) and high pH (9-12), which make them industrially important thermoalkaliphilic proteases. These proteases successfully de-haired cow’s skin and de-stained blood from cotton cloth pieces, which are rarely tested applications of these proteases.
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Désert , Peptide hydrolasesRésumé
Abstract Bacillus species are promising producers of various compounds that have pronounced antimicrobial, antiviral and antitumor activities. Due to its GRAS status, Bacillus subtilis represents an excellent candidate for the usage in plant pathogens biocontrol. In this research, evaluation of antifungal metabolites biosynthesis by Bacillus subtilis ATCC 6633 and optimization of glycerol-based medium composition, using response surface methodology, for the production of compounds effective against Neurospora crassa were investigated. The results of disc-diffusion method indicate that applied Bacillus strain produces compounds with antifungal activity against tested fungus. In order to find optimal cultivation medium composition, the experiments were carried out in accordance with Box-Behnken design, and optimization was performed using the concept of desirability function combined with previously defined mathematical equation, which describes examined bioprocess. The optimization model predicts that maximum inhibition zone diameter against Neurospora crassa of 32.24 mm is achieved when initial content of glycerol, NaNO2 and K2HPO4 were 49.68 g/L, 2.90 g/L and 6.49 g/L, respectively. Additionally, the second optimization set was made to minimize the consumption of medium components and costs of medium preparation. The obtained results are the basis for further research aimed to develop medium appropriate for economically justified production of bioactive compounds at industrial scale.
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Bacillus subtilis/métabolisme , Optimisation du Processus , Glycérol/analogues et dérivés , Antiviraux/administration et posologie , Coûts et analyse des coûts/classification , Méthodologie , Études d'évaluation comme sujetRésumé
BACKGROUND The extracellular expression of enzymes in a secretion host such as Bacillus subtilis is a useful strategy in reducing the cost of downstream processing of industrial enzymes. Here, we present the first report of the successful extracellular expression in Bacillus subtilis WB800 of Geobacillus stearothermophilus lipase (T1.2RQ), a novel industriallydesirable thermostable lipolytic enzyme which has an excellent hydrolytic and transesterification activity. Signal peptides of a-amylase, extracellular protease, and lipase A, as well as two different promoters, were used in the secretion and expression of lipase T1.2RQ. RESULTS Lipase activity assay using p-nitrophenyl laurate showed that all three signal peptides directed the secretion of lipase T1.2RQ into the extracellular medium. The signal peptide of lipase A, resulted in the highest extracellular yield of 5.6 U/ml, which corresponds to a 6-fold increase over the parent Bacillus subtilis WB800 strain. SDS-PAGE and zymogram analysis confirmed that lipase T1.2RQ was correctly processed and secreted in its original size of 44 kDa. A comparison of the expression levels of lipase T1.2RQ in rich medium and minimal media showed that the enzyme was better expressed in rich media, with up to an 8-fold higher yield over minimal media. An attempt to further increase the lipase expression level by promoter optimization showed that, contrary to expectation, the optimized promoter exhibited similar expression levels as the original one, suggesting the need for the optimization of downstream factors. CONCLUSIONS The successful extracellular secretion of lipase T1.2RQ in Bacillus subtilis represents a remarkable feat in the industrial-scale production of this enzyme