Streptomyces lunalinharesii 235 prevents the formation of a sulfate-reducing bacterial biofilm

ABSTRACT Streptomyces lunalinharesii strain 235 produces an antimicrobial substance that is active against sulfate reducing bacteria, the major bacterial group responsible for biofilm formation and biocorrosion in petroleum reservoirs. The use of this antimicrobial substance for sulfate reducing bacteria control is therefore a promising alternative to chemical biocides. In this study the antimicrobial substance did not interfere with the biofilm stability, but the sulfate reducing bacteria biofilm formation was six-fold smaller in carbon steel coupons treated with the antimicrobial substance when compared to the untreated control. A reduction in the most probable number counts of planktonic cells of sulfate reducing bacteria was observed after treatments with the sub-minimal inhibitory concentration, minimal inhibitory concentration, and supra-minimal inhibitory concentration of the antimicrobial substance. Additionally, when the treated coupons were analyzed by scanning electron microscopy, the biofilm formation was found to be substantially reduced when the supra-minimal inhibitory concentration of the antimicrobial substance was used. The coupons used for the biofilm formation had a small weight loss after antimicrobial substance treatment, but corrosion damage was not observed by scanning electron microscopy. The absence of the dsrA gene fragment in the scraped cell suspension after treatment with the supra-minimal inhibitory concentration of the antimicrobial substance suggests that Desulfovibrio alaskensis was not able to adhere to the coupons. This is the first report on an antimicrobial substance produced by Streptomyces active against sulfate reducing bacteria biofilm formation. The application of antimicrobial substance as a potential biocide for sulfate reducing bacteria growth control could be of great interest to the petroleum industry.

Enhancing Bio-Available Phosphorous in Soil Through Sulfur Oxidation by Thiobacilli.

Aims: The objectives were to evaluate the phosphate solubilization efficiency of different Thiobacilli strains and to find out the best combination of sulfur and Thiobacilli for enhancing bio-available P in soil. Study Design: An experimental study. Place and Duration of Study: Microbiology and Soil Fertility Labs, Department of Soil Science and Soil and Water Conservation, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi, Pakistan and Microbiology and Soil Chemistry Labs, Auriga Research Center, Lahore, Pakistan, between May 2011 and November 2012. Methodology: Fifty Thiobacilli strains were isolated from ten different ecologies. Then an incubation study of soil was performed wherein the most efficient four Thiobacilli strains were inoculated in combination with three different levels of elemental sulfur to determine pH, water soluble sulfur, sequential P fractions and bio-available phosphorous contents in the incubated soil. Results: All the four Thiobacillus strains (IW16, SW2, IW1 and IW14) dropped pH of the incubated soil along with three doses of S° (50, 75 and 100 kg ha-1). However, Thiobacillus strains IW16 and SW2 reduced soil pH quite sharply from 7.90 to 7.12 (net reduction of 0.78 points) and 7.28 (net reduction of 0.62 points) respectively where inoculated with S° @ 100 kg ha-1. The best P solubilizer was Thiobacillus strain IW16 and the best dose of S° was @ 100 kg ha-1 and their combination enhanced maximum quantity of P (22.26 mg kg-1) in the soil by solubilizing already present insoluble calcium bounded P fractions like octacalcium phosphate (Ca8-P) and apatite (Ca10-P). Conclusion: The present study suggests the use of Thiobacilli along with elemental sulfur for the dissolution and enhancement of bio-available P in alkaline and calcareous soils.

Biofilm formation for organic matter and sulphate removal in gas-lift reactors

A start-up strategy was presented and evaluated to obtain a well-established biofilm in a gas lift-reactor capable both for the removal of organic matter and sulphate. Pumice stone was used as material support. The influence of shear forces, given by the biogas recirculation, the effect of the COD/SO4-2 ratio and the OLRs increase were evaluated on the reactor performance. From the first stages, cell colonization was observed along with the presence of extracellular polymeric substances. The COD and sulphate removal was over 70 percent, for all conditions. The increase of gas flow did not have an adverse effect on biofilm development even though there was some detachment. Specific methanogenic activity of the biofilm increased along the experiments. Operational parameters as alkalinity and alkalinity ratio were within the recommended values for the operation with sulphate-rich wastewater. For gas-lift reactors operation it becomes fundamental to have a suitable start-up strategy that takes into account the initial biofilm development from a non-acclimatized biomass.

In vitro plant regeneration system for common bean (Phaseolus vulgaris): effect of N6-benzylaminopurine and adenine sulphate / Sistema de regeneración de plantas in vitro para el frijol común (Phaseolus vulgaris): efecto del frl sulfato N6-bencilaminopurina y adenina

A method for regeneration of the commercially important common bean (Phaseolus vulgaris ) using N6-benzylaminopurine(BAP) and adenine sulphate (AS) was established. Embryogenic axes of the Costa Rican common bean cultivars Bribrí, Brunca, Guaymí, Huetar and Telire were cultured on Murashige and Skoog medium supplemented with 100 mgl-1 myo-inositol, 1 mgl-1 thiamine, 30 gl-1 sucrose, BAP (0, 5 and 10 mgl-1), AS (0, 20 and 40 mgl-1) and 8 gl-1 agar. Regardless of the concentration of BAP and AS in the induction medium, the number of shoots and leaves differed significantly among the common bean cultivars evaluated. The higher average of shoots was obtained for Brunca > Telire > Bribrí > Guaymí > Huetar. Moreover, independently of the cultivar, the induction medium supplemented with 5 mgl-1 BAP and 20 or 40 mgl-1 AS resulted in the higher average of shoots formation. Culture of Bribrí, Brunca, Guaymí, Huetar and Telire embryogenic axes on induction medium supplemented with different BAP and AS resulted in a differential response. Successful acclimatization of common bean in vitro plants were achieved in the greenhouse, and plants appeared morphologically normal. The regeneration system developed in this investigation for this important crop could be a useful tool for the genetic modification through mutagenesis or genetic transformation.

Las dietas hiperproteicas y sus consecuencias metabólicas / Hiperproteicas diets and metabolic consequences

El consumo excesivo de proteínas produce un incremento en la excreción neta de ácidos, lo cual a su vez aumenta la excreción urinaria de calcio. Los efectos de la dieta sobre la excreción urinaria de ácidos y de calcio no sólo dependen de la cantidad de proteínas, sino que también pueden ser modificados por otros constituyentes de la alimentación, tales como el potasio y los equivalentes alcalinos de bicarbonato contenidos en las frutas y hortalizas. La deficiencia de estas bases de potasio en la dieta aumenta la carga ácida sistémica producida por las proteínas. En consecuencia, el resultado de una ingesta elevada en proteínas o bien deficiente en frutas y hortalizas es la generación de acidosis metabólica crónica, la cual, aún siendo de bajo grado, tiene efectos deletéreos sobre el organismo, incluyendo retardo del crecimiento en niños, disminución de la masa ósea y muscular en adultos, y formación de cálculos renales. En la presente revisión se resumen las evidencias actuales en relación a los efectos de las dietas hiperproteicas sobre distintos órganos y sistemas incluyendo el metabolismo hidroelectrolítico y ácido base, el metabolismo óseo, la función renal y la función endocrina. Asimismo se mencionan los aspectos particulares que influyen de un modo especial en los gupos de las edades extremas de la vida, los niños y los ancianos.

High protein intake produces an increase in net acid excretion, which in turn leads to an increase in urinary calcium. Effects of diet in urinary acid and calcium excretion depend not only on the protein content, but also may be modified by other constituents such as potassium and alkali equivalents of bicarbonate present in fruits and vegetables. Diets deficient in these potassium bases increase the acid load imposed by proteins. In consequence, diets with a high protein intake or poor in fruits and vegetables produce a low-grade systemic metabolic acidosis which exerts deleterious effects on the body, including growth retardation in children, decreased muscle and bone mass in adults, and kidney stone formation. This review intends to summarize the present evidence in relation to the effects of high protein diets in different organs and systems including hydroelectrolytic and acid base metabolism, bone metabolism, renal and endocrine function. Particular aspects that may exert a special influence in life extremes as childhood and old age are also addressed.

Effect of ambient air sulphur dioxide on sulphate accumulation in plants.

Present study deals with the relationship between ambient air sulphurdioxide and sulphate content in leaf of selected tropical plant species, Ficus religiosa. The study reveals a positive correlation between ambient air sulphur dioxide and sulphate in the leaves. Two way ANOVA finds the obtained values to be highly significant (p < 0.001). Amount of sulphate in leaves shows positive correlation with sulphur dioxide in air (p < 0.001) during most part of the study A marked reduction of sulphate content in leaf was found during October when reduction in ambient air sulphur dioxide was recorded.

Evaluación del molibdato y nitrato sobre bacterias sulfato-reductoras asociadas a procesos de corrosión en sistemas industriales / Evaluation of molybdate and nitrate on sulphate-reducing bacteria related to corrosion processes in industrial systems

Se estudió la cinética de crecimiento de bacterias sulfato-reductoras (BSR) y la biotransformación de sulfato a sulfuro de hidrógeno bajo condiciones de laboratorio, para establecer el efecto inhibitorio de sales de molibdato y nitrato de sodio. Los microorganismos estudiados fueron aislados del agua de producción contenida en un sistema de transporte de gas natural, donde se encontraban relacionados con procesos de corrosión influenciada microbiológicamente. Con 5 mM de molibdato se obtuvo una reducción de células libres a niveles no detectables y de seis órdenes de magnitud en las biopelículas, con una disminución del sulfuro de alrededor del 100%. Con 75 mM de nitrato se observó una reducción de cuatro y dos órdenes de magnitud en las células libres y en las adheridas en forma de biopelículas, respectivamente, con una disminución del sulfuro de alrededor del 80%. La reducción de la tasa de corrosión observada sustenta la posibilidad de emplear estas sales como biocidas no convencionales no contaminantes del medio ambiente, para el control y mitigación efectiva de los procesos de biocorrosión interna de tanques de almacenamiento y de líneas de transporte en sistemas industriales de gas natural y petróleo.

The sulfate-reducing bacteria growth kinetics and the biotransformation of sulfate into hydrogen sulfide were studied under laboratory conditions, using batch and continuous assays to determine the effect of molybdate and nitrate as metabolic inhibitors. The microorganisms were isolated from water coming from a natural gas dehydration plant, where they were associated with Microbiologically Influenced Corrosion (MIC) processes, and later cultured in planktonic and sessile states. The addition of 5 mM molybdate showed a growth reduction to levels of non - detectable floating cells and a six order of magnitude reduction in biofilms, concomitant with a sulfide decrease of around 100% in all cultures inhibited by this compound. The addition of 75 mM nitrate showed a four order of magnitude reduction in free bacterial cells and a two order of magnitude reduction in adhered bacterial cells, respectively, as well as a sulfide decrease of around 80%. The decreased corrosion rate detected suggests that these inorganic salts could be nonconventional biocides for an effective and environmentally non contaminant way of controlling and mitigating internal biocorrosion processes in storage tanks and pipelines in natural gas and petroleum industrial systems.

Activity test for biological sulfate reduction.

Biofilm reactors with turbulent agitation are often the best choice for sulfate reduction using hydrogen as electron donor for treatment of metal sulfate wastewater. In this paper, a simple activity set-up with self aspiration of gas into liquid is described for determining the sulphidogenic activity of biofilms on polystyrene beads. Sulfate reducing bacteria attached to the beads of size 1-2 mm and 2 mm were found helpful for 0.058 g SO4(2-) reduction per g of dry beads per day and 0.33 g SO4(2-) reduction per g of dry beads respectively. Also it is observed that zinc has no impact on this activity at the concentration of 680 mg/L.

The specificity of interactions between proteins and sulfated polysaccharides

Os polissacarídeos sulfatados são capazes de se ligar às proteínas com diferentes níveis de especificidade. São macromoléculas altamente ácidas que podem se ligar de forma inespecífica a qualquer domínio básico da superfície de uma proteína em soluções com baixa força iônica, contudo tais interações não parecem ser fisiologicamente significativas. Por outro lado, foram identificados vários sistemas nos quais componentes estruturais muito específicos dos polissacarídeos sulfatados conferem alta afinidade para algumas proteínas. O exemplo mais conhecido é o pentassacarídeo da heparina com alta afinidade pela antitrombina. Outros exemplos podem ser observados no estudo de invertebrados marinhos, tais como a importância da estrutura fina do dermatam sulfato para sua interação com o cofator II da heparina e o envolvimento defucanas sulfatadas encontradas no gel que envolve osóvulos dos ouriços-do-mar na espécie especificidade da fertilização. Um terceiro exemplo de interação específica é aquele descrito para o glicosaminoglicano heparam sulfato encontrado na superfície celular. Neste caso, o padrão de sulfatação pode determinar diferentes afinidades do carboidrato por citoquinas, fatores de crescimento e outras proteínas encontradas na superfície celular e na matriz extracelular. Estas interações complexas entre proteínas e carboidratos são capazes de influenciar a difusão das proteínas através dos tecidos, assim como modelar a resposta celular a estas moléculas.

Proteoglycans production by aortic vascular smooth muscle cells from hypertensive rats

Remodeling of large and small arteries contributes to the development and complications of hypertension. Artery structural changes in chronic sustained hypertension include vascular smooth muscle cells (VSMC) proliferation and extracellular matrix (ECM) modifications. Extracellular constituents such as proteoglycans (PGs), may modulate vascular stiffness and VSMC growth and differentiation. We examined the effect of growth factors on secreted and membrane-bound PGs synthesis by cultured aortic smooth muscle cells (SMC) from 12- to 14- week-old spontaneously hypertensive rats (SHR) and age-matched Wistar rats. After stimulation with platelet-derived growth factor (PDGF-BB), 10% fetal calf serum (FCS) or 0.1% FCS as control, PGs synthesis (dpm/ng DNA) was evaluated in the medium (M-ECM) and in the cell layer (P-ECM) by a double-isotopic label method using both [3H]-glucosamine and [35S]-sodium sulfate which are incorporated into all complex carbohydrates or only into sulfated dysaccharides, respectively. Data are presented as percent of the control (0.1% FCS). SHR VSMC displayed a significantly greater synthesis of M-ECM [3H]-PGs than Wistar rat cells, with both treatments, but no differences in M-ECM [35S] uptake were found in any case. In the P-ECM, both PDGF-BB and 10% FCS produced a greater effect on [3H]-PGs and sulfated PGs synthesis in VSMC from SHR. An important change seen in SHR cells was a significant decreased sulfation, assessed by [35S]/[3H] ratio, in basal and stimulation conditions. Present results indicate the existence of changes in PGS synthesis and modulation in VSMC from a conduit-artery of SHR and support the pathophysiological role proposed for matrix proteoglycans in the vascular wall changes associated to hypertension and related vascular diseases as atherosclerosis.

Astroglial cells derived from lateral and medial midbrain sectors differ in their synthesis and secretion of sulfated glycosaminoglycans

Astroglial cells derived from lateral and medial midbrain sectors differ in their abilities to support neuritic growth of midbrain neurons in cocultures. These different properties of the two types of cells may be related to the composition of their extracellular matrix. We have studied the synthesis and secretion of sulfated glycosaminoglycans (GAGs) by the two cell types under control conditions and ß-D-xyloside-stimulated conditions, that stimulate the ability to synthesize and release GAGs. We have confirmed that both cell types synthesize and secrete heparan sulfate and chondroitin sulfate. Only slight differences were observed between the proportions of the two GAGs produced by the two types of cells after a 24-h labeling period. However, a marked difference was observed between the GAGs produced by the astroglial cells derived from lateral and medial midbrain sectors. The medial cells, which contain derivatives of the tectal and tegmental midline radial glia, synthesized and secreted ~2.3 times more chondroitin sulfate than lateral cells. The synthesis of heparan sulfate was only slightly modified by the addition of ß-D-xyloside. Overall, these results indicate that astroglial cells derived from the two midbrain sectors have marked differences in their capacity to synthesize chondroitin sulfate. Under in vivo conditions or a long period of in vitro culture, they may produce extracellular matrix at concentrations which may differentially affect neuritic growth

Chronic myelogenous leukemia: alterations in red cell membrane band 3 and increased IgG binding.

Chronic myelogenous leukemia (CML) is a hematologic malignancy arising from an abnormal hemopoietic stem cell. Our earlier studies have identified defects in spectrin tetramer formation and organization of cytoskeletal proteins (Basu et al., Biochim. Biophys. Acta 1988, 121-126); and decreased ankyrin binding to ankyrin-depleted vesicles in CML patients. These may lead to clustering of band 3 and increased binding of autologous IgG. This has now been explored by studying the binding of 125I-protein A to normal and CML erythrocytes. There is increased binding of 125I-protein A in CML erythrocytes compared to normal erythrocytes. Since binding of autologous IgG is responsible for removal of erythrocytes from the circulation, the above findings suggest that CML erythrocytes are likely to be prematurely removed from the circulation, accounting for anemia.