Population density of Trichoderma fungi in natural environments and agrosystems of a Cerrado area / Densidade populacional de fungos do gênero Trichoderma em ambientais naturais e agrossistemas de uma área de Cerrado

Abstract: Soil microorganisms present a great diversity, involving taxonomically distinct groups that play a role in the decomposition of organic matter, nutrient cycling, soil aggregation, among others. In this diversity, the fungi of the genus Trichoderma have been successful plant pathogen biocontrol agents, as plant growth promoters and as inducers of plant resistance to diseases. In addition, they are important in the sustainability of natural ecosystems. Aiming to verify the population density of Trichoderma fungi in natural environments and agroecosystems, in Cerrado area, samples of soils and roots from native vegetation and agroecological production system were collected in the Federal District, Brazil. The collection points were randomly selected, and each soil or root sample was individually wrapped. The soil adhered to the roots was removed for evaluations. Serial sample dilutions and number of Colony Forming Units (CFUs) of Trichoderma isolates were performed. The results showed that the number of CFU varied depending on the plant and location evaluated. The replacement of native vegetation by organic farming systems did not result in a significant reduction in this number.

Resumo: Os microrganismos de solo apresentam uma grande diversidade, envolvendo grupos taxonomicamente distintos que desempenham papel na decomposição da matéria orgânica, ciclagem de nutrientes, agregação dos solos, dentre outros. Nesta diversidade, os fungos do gênero Trichoderma tem apresentado sucesso como agentes de biocontrole de fitopatógenos, como promotores de crescimento de plantas e, ainda, como indutores de resistência de plantas a doenças. Além disso, são importantes na sustentabilidade dos ecossistemas naturais. Com o objetivo de verificar a densidade populacional de fungos do gênero Trichoderma em ambientes naturais e agroecossistemas, em área de Cerrado, amostras de solos e raízes oriundas de vegetação nativa e de sistema de produção agroecológica foram coletadas na região do Distrito Federal, Brasil. Os pontos de coleta foram selecionados aleatoriamente, e cada amostra de solo ou raiz foi acondicionada individualmente. O solo aderido às raízes foi removido para as avaliações. Foram realizadas diluições seriadas das amostras e contagem do número de Unidades Formadoras de Colônias (UFCs) de isolados de Trichoderma. Os resultados mostraram que o número de UFC variou dependendo da planta e da localidade avaliada. A substituição da vegetação nativa por sistemas de cultivo orgânicos não resultou em importante redução neste número.

Identification of Bacterial Population of Activated Sludge Process and Their Potentials in Pharmaceutical Effluent Treatment.

Aims/objectives: The cognition about microbial population of activated sludge and their treatment potential will be very useful for industrial wastewater treatment plant operation. Methodology: In this study microbial population of activated sludge process that was used for pharmaceutical wastewater has been investigated. Sampling was done from return sludge line and after serial dilution 1500 plates were studied. Methods for separating the bacteria from wastewater was pour plate method. All bacterial samples were purified using nutrient Agar and Macconkey Agar culture. Bacteria were separated from return sludge line and classified into 3 groups after biochemical tests and morphological analysis, These include positive bacteria of Bacillus genus, Pseudomonas aeruginosa and Flavobacterium. Results: The biodegradability study on pharmaceutical effluent using identified cultures in laboratory scale showed that Bacillus spp. are the most efficient bacteria for organic matter degradation. Conclusion: Results of this study showed that providing a microbial bank of these spp. can be useful for resistant operation of activated sludge.

Studies on Akamu, a traditional fermented maize food / Estudios en Akamu, una comida tradicional de maiz fermentado

Microbiological and some physicochemical properties of akamu, a fermented maize food were studied. Microbial population, pH, titratable acidity, protein, sugar and starch were measured during the fermentation. The initial microflora consisted ofa heterogenous mixture of microorganisms namely Lactobacillus delbrueckii, Lactobacillus plantarum, Lactobacillus fermentum, Lactobacillus amylovorus, Pseudomonas aeruginosa, Pseudomonas alkaligenes, Bacillus cereus, Bacillus licheniformis, Bacillus subtilis, Candida utilis, Candida tropicalis, Saccharomyces cerevisiae, Aspergillus oryzae, Aspergillus niger, Penicillium citrinum, Rhizopus micros-porus and Rhizopus oligosporus. Within 24 h, lactobacilli and aerobic mesophilic bacteria accounted for a major portion of the total microflora. The lactobacilli numbers increased from 1.6 x107 cfu/g after24 h to 7.1 x108 cfu/g after 72 h. Total aerobic mesophilic bacteria increased from 2.5 x109 cfu/g after 24 h to 4.2 x108 cfu/g after 72 h. Enterobacteriaceae count decreased from 6.3 x 103 cfu/g after 24 h to 2.5x102 cfu/g after 72 h, although this level remained significantly high for a finished food product. Yeasts increased steadily and reached 6.8 x105 cfu/g after 72 h. Mould counts decreased from 6.3 x103 cfu/g after 24 h to 1.3 x102 cfu/g after 72 h. Moulds were largely responsible for amylolytic activity in pure culture. Fermentation caused a general decrease in pH from 6.6 to 3.9 after 72 h and titratable acidity increased from 0.48 to 0.79 after 72 h. Starch concentration decreased from 68 g/100 g to 37.4 g/100g. Protein and reducing sugar concentrations increased from 12.8 g/100 g to 18.5 g/100 g and from 5.3 g/100 g to 17.6 g/100 g, respectively. The types and numbers of microorganisms isolated from akamu could pose a health risk to consumers especially where this food product is used as a weaning product for infants.

Se estudiaron las propiedades microbiológicas y fisicoquímicas del akamu, un alimento fermentado a base de maíz. Se midió la población microbiológica, el pH, la acidez por titulación, azúcar y almidón durante la fermentación. La microflora inicial consistía en una mezcla heterógenea de microrganismos denominados Lactobacillus delbruecki, Lactobacillus plantarum, Lactobacillus fermentum, Lactoba-cillus amylovorus, Pseudonomas aeruginosa, Pseudomonas alkaligenes, Bacillus cereus, Bacillus licheniformis, Bacillus subtilis, Candida utilis, Candida tropicvallis, Saccharomyces cerevisiae,Aspergillus oryzae, Aspergillus niger, Penicillium citrinum, Rhizopus microsporus y Rhizopus oligosporus. Al cabo de 24 horas, las bacterias lactobacillus y mesofílicas aeróbicas formaron una parte importante de la microflora total. Las bacterias lactobacilli aumentaron a 1.6 x107 cfu/g a las 24 horas y al cabo de 72 horas a 7.1 x 10 8 cfu/g. El total de bacterias mesofílicas aeróbicas aumentaron desde 2.5 x 109 en 24 horas y a 4.2 x 10 8 a las 72 horas. El recuento de enterobacterias disminuyó de 6.3 x 103 en 24 horas a 2.5x 102 cfu/g a las 72 horas, aunque este nivel permaneció significativamente alto para un producto alimentario final. Las levaduras aumentaron en forma significativa y alcanzaron un rango de 6.8 x 105 a las 72 horas. Los recuentos de hongos disminuyeron desde 6.3 x 103 cfu/g a las 24 horas a un rango de 1.3 x 102 cfu/g a las 72 horas. Los hongos fueron responsables de la actividad amilolitica en el cultivo puro. La fermentación provocó una disminución general en el pH desde 6.6 a 3.9 a las 72 horas y la acidez por titulación aumentó a 0.48 a 0.79 a las 72 horas. La concentración de almidón disminuyó desde 68 g/100 g a 37.4 g/100 g. Las concentraciones de proteínas y azúcar reducida aumentaron desde 12.8 g/100 g a 18.5 g/100 g y desde 5.3 g/100 g a 17.6 g/100 g respectivamente. Los tipos y cantidades de microrganismos aislados del akamu suponen un riesgo sanitario para los consumidores especialmente dado que este producto es utilizado como una formula láctea para lactantes.

Diversity and seasonal fluctuation of predominant microbial communities in Bhitarkanika, a tropical mangrove ecosystem in India

Different groups of microorganisms are present in mangrove areas, and they perform complex interactions for nutrient and ecological balances. Since little is known about microbial populations in mangroves, this study analyzed the microbial community structure and function in relation to soil physico-chemical properties in Bhitarkanika, a tropical mangrove ecosystem in India. Spatial and seasonal fluctuations of thirteen important groups of microorganisms were evaluated from the mangrove forest sediments during different seasons, along with soil physico-chemical parameters. The overall microbial load (x10(5)cfu/g soil) in soil declined in the order of heterotrophic, free living N2 fixing, Gram-negative nitrifying, sulphur oxidizing, Gram-positive, spore forming, denitrifying, anaerobic, phosphate solubilizing, cellulose degrading bacteria, fungi and actinomycetes. Populations of the heterotrophic, phosphate solubilizing, sulphur oxidizing bacteria and fungi were more represented in the rainy season, while, Gram-negative, Gram-positive, nitrifying, denitrifying, cellulose decomposing bacteria and actinomycetes in the winter season. The pool size of most of other microbes either declined or maintained throughout the season. Soil nutrients such as N, P, K (Kg/ha) and total C (%) contents were higher in the rainy season and they did not follow any common trend of changes throughout the study period. Soil pH and salinity (mS/cm) varied from 6-8 and 6.4-19.5, respectively, and they normally affected the microbial population dynamics. Determination of bacterial diversity in Bhitarkanika mangrove soil by culture method showed the predominance of bacterial genera such as Bacillus, Pseudomonas, Desulfotomaculum, Desulfovibrio, Desulfomonas, Methylococcus, Vibrio, Micrococcus, Klebsiella and Azotobacter. Principal component analysis (PCA) revealed a correlation among local environmental variables with the sampling locations on the microbial community in the mangrove soil. Rev. Biol. Trop. 60 (2): 909-924. Epub 2012 June 01.

En las zonas de manglares están presentes diferentes grupos de microorganismos, los cuales presentan complejas interacciones que afectan los balances ecológicos y de nutrientes. Debido a que se sabe poco sobre las poblaciones microbianas en los manglares, este estudio analiza la estructura y función de la comunidad microbiana según las propiedades físico-químicas del suelo en Bhitarkanika, un ecosistema de manglares tropicales en la India. Se evaluaron las fluctuaciones espaciales y temporales de 13 grupos de microorganismos importantes en el sedimento de los manglares durante diferentes temporadas y parámetros físico-químicos del suelo. La carga microbiana total (x10(5)cfu/g de suelo) en el suelo se redujo en la categoría de las heterotróficas, de las bacterias libres fijadoras de N2, Gram-negativas nitrificantes, oxidativas de azufre, Gram-positivas, formadoras de esporas, desnitrificantes, anaeróbicas, las solubilizadoras de fosfato, bacterias degradadoras de celulosa, hongos y actinomicetos. Las poblaciones de heterótrofos, solubilizadoras de fosfato, oxidativas de azufre y los hongos estuvieron más representadas en la temporada lluviosa, mientras que, las Gram-negativas y Gram-positivas, nitrificantes, desnitrificantes, descomponedoras de celulosa y los actinomicetos, en la temporada de invierno. El tamaño poblacional de otros microorganismos disminuyó o se mantuvo durante toda la temporada. Los nutrientes del suelo, tales como N, P, K (Kg/ha) y el contenido total de C (%) fueron mayores en la temporada de lluvias, y no siguieron ninguna tendencia común de cambio a través del período de estudio. El pH del suelo y la salinidad (mS/cm) variaron de 6-8 y 6.4-19.5, respectivamente, lo que afectó significativamente la dinámica de la población microbiana. La determinación de la diversidad de bacterias en el suelo del manglar Bhitarkanika por el método de cultivo mostró el predominio de los géneros de bacterias como Bacillus, Pseudomonas, Desulfotomaculum, Desulfovibrio, Desulfomonas, Methylococcus, Vibrio, Micrococcus, Klebsiella y Azotobacter. El análisis de componentes principales (ACP) reveló una correlación entre las variables locales del ambiente y los sitios de muestreo en la comunidad microbiana en el suelo del manglar.

Dietary acidifiers in weanling pig diets: a review / Acidificantes dietarios para cerdos recién destetados: revisión / Dietas acidificadas em suínos desmamados: uma revisão

The objective of the present review is to provide an overview on the effects of the addition of acidifiers to nursery pig diets. Researchers have proposed that dietary acidifiers decrease pH in the stomach and the lower gastrointestinal tract (GIT) of weanling pigs, and thus, protect the host from pathogenic invasion and proliferation and improve nutrient digestion. These benefits may subsequently result in improved growth performance of weanling pigs. In experiments on nursery pigs, dietary acidifiers decreased stomach pH at least to a small extent, but had little influence on the pH of the lower GIT. Studies found no observable changes in microbial populations upon providing weanling pigs with dietary acidifiers, but they found a slight reduction in lactobacilli or lactic acid-producing bacteria throughout the GIT. Dietary acidifiers improved protein digestion in many cases despite variable results regarding the digestibility of amino acids and improved growth performance. Such positive responses were more apparent during the first or second week of experiments than the later stages. However, growth responses were inconsistent among different sources and varying inclusion rates of acidifiers. Information on the dietary acidifiers’ mode of action is quite limited, and large variations exist in results regarding the effects of dietary acidifiers. Based on the present review, the benefit of dietary acidifiers for nursery pigs is not entirely convincing. Further research is required to clarify the acidifiers’ mode of action and its association with subsequent growth performance in weanling pigs.

El objetivo de esta revisión es ofrecer una visión general sobre los efectos de la adición de acidificantes orgánicos en la dieta de cerdos destetos. Se ha propuesto que los acidificantes dietarios reducen el pH en el estómago y tracto gastrointestinal (TGI) de los cerdos recién destetados, y por lo tanto protegen al huésped de la invasión y proliferación de patógenos, al tiempo que mejoran la digestión de nutrientes. Estos beneficios podrían resultar en una mejora del crecimiento de dichos animales. En experimentos con cerdos destetados, los acidificantes dietarios han mostrado que pueden disminuir el pH del estómago, al menos en pequeña medida, pero han tenido poca influencia en el pH del tracto gastrointestinal posterior. Algunos estudios no encontraron cambios observables en las poblaciones microbianas al ofrecer acidificantes en la dieta a estos animales, pero se reporta una ligera reducción de los lactobacilos o bacterias lácticas productoras de ácido en todo el tracto gastrointestinal. En muchos casos, los acidificantes parecen mejorar la digestión proteica, a pesar de ofrecer resultados variables con respecto a la digestibilidad de los aminoácidos y mejora del crecimiento. Tales respuestas positivas parecen ser más evidentes durante la primera o segunda semana de los experimentos que en etapas posteriores. Sin embargo, la respuesta en crecimiento ha sido inconsistente respecto a diferentes fuentes y niveles de inclusión de acidificantes. La información sobre el modo de acción de los acidificantes dietarios es bastante limitada y existen grandes variaciones en los resultados respecto a sus efectos. De acuerdo con esta revisión, el beneficio potencial de los acidificantes dietarios en cerdos destetados no está del todo justificado. Se requiere investigación adicional para aclarar su modo de acción y su relación con el crecimiento de los cerdos recién destetados.

O objetivo desta revisão é fornecer uma visão geral dos efeitos da adição de acidificantes orgânicos na dieta de leitões desmamados. Tem sido proposto que a dieta acidificante reduz o pH do estômago e do trato gastrointestinal (TGI) de leitões desmamados, e assim proteger o hospedeiro da invasão e proliferação de patogênicos, melhorando a digestão dos nutrientes. Estes podem resultar em um maior crescimento destes animais. Em experimentos com suínos desmamados, a acidificação da dieta têm sido mostrados para diminuir o pH do estômago, pelo menos em pequena medida, mas tiveram pouca influência sobre o pH do trato gastrointestinal posterior. Alguns estudos não encontraram alterações observáveis em populações microbianas ao oferecer acidificantes na dieta, mas tem-se reportado uma ligeira redução de lactobacilos ou bactérias lácticas produtoras de ácido em tudo o trato gastrointestinal. Em muitos casos, os acidificantes parecem melhorar a digestão de proteínas, apesar de oferecer resultados variáveis com respeito à digestibilidade dos aminoácidos e melhora o crescimento. ais respostas positivas parecem ser mais evidentes durante a primeira ou segunda. No entanto, a resposta de crescimento tem sido inconsistente com relação a diferentes fontes e níveis de inclusão de acidificantes. A Informação sobre o modo de ação dos acidificantes na dieta é bastante limitado e existem grandes variações nos resultados sobre seus efeitos. De acordo com essa análise, o benefício potencial de alimentar leitões desmamados com acidificantes não é inteiramente justificado. Mais pesquisas são necessárias para esclarecer seu modo de ação e sua relação com o crescimento de leitões desmamados.

Genetic diversity analysis on rhizosphere soil microbial population of Panax ginseng and Panax quinque folium by RAPD / 中草药

Objective: To study rhizosphere and non-rhizosphere soil microbial population genetic diversity of Panax ginseng and P. quinquefolium with different growing years. Methods: Eighteen P. ginseng and P. quinquefolium rhizosphere and non-rhizosphere soil samples were collected from Fusong county of Jilin Province, and genetic diversity of microbial population construction were analyzed by RAPD. Results: Cultivation times have great influence on microbial population construction of rhizosphere and non-rhizosphere soil. Also we found that there were differences between soil microbial population construction of P. ginseng and P. quinquefolium. Furthermore, rhizosphere effect of plants on soil microbial population construction was also found. Conclusion: Directional selection pressure that root secretions of P. ginseng and P. quinquefolium to soil microorganisms is one of the main drives that resulted in the change of microbial population genetic diversity, and microbial population construction change in P. ginseng and P. quinquefolium cultivated soil is the key factor for soil ecological function turbulence and the development of continuously cropping obstacle.

Pathogen Distribution after Incision of Trachea and Correlation Factors / 中华医院感染学杂志

0.0125) incision of trachea,and oral and pharyngeal portion,but no correlation with hands of nurse and external environment(P

Effect of various rotation systems on yield of Angelica sinensis and microbial populations in its rhizosphere / 中草药

Objective To study the effects of four rotation system on the soil microbial populations in rhizosphere,yield,and recovery rate of Ditylenchus destructor of Angelica sinensis.Methods In rhizosphere soil,the microbe amount of various rotation system was determined with the flat dilution,the bacteria were counted with the culture medium of beef-cream and peptone,the fungi were counted with the Martin culture medium,the actinomyces was counted with the improved Gao 1 culture medium.Results Compared with the rotation cropping,the bacterium amount of companion,continuous,and 3a cropping was decreased by 15.76%,30.67%,and 34.24%,respectively;The fungi amount was increased by 24.73%,119.28%,and 135.77%;The diversity indexes of microbe were decreased by 47.90%,78.84%,and 80.63%,and the yields of A.sinensis were decreased by 10.59%,29.52%,and 57.85%;The recovery rate of D.destructor was 1.37,2.52,and 4.12 times.Conclusion The total microbes,which could be cultured in soil,will be decreased.The amount of bacterium,actinomycetes,diversity index and yields,recovery rate of the first grade of A.sinensis were decreased,while fungi and recovery rate of the third grade and substandard of A.sinensis,recovery rate of D.destructor increased with the continuous cropping increasing.