Ammonium assimilation in Proteus vulgaris,Bacillus pasteurii,and Sporosarcina ureae

No active uptake of ammonium was detected in Proteus vulgaris, Bacillus pasteurii, and Sporosarcina ureae, which indicates that these bacteria depend on the passive diffusion of ammonia across the cell membrane. In P. vulgaris the glutamine synthetase-glutamate synthase (GS-GOGAT) pathway and glutamate dehydrogenase (GDH) were present, and these enzymes exhibited high affinities for ammonium. In B. pasteurii and S. ureae, however, no GS activity was detected, and GOGAT activity was only present in S. ureae. GDH enzymes were present in these two organisms, but showed only low affinity for ammonium, with apparent K _m-values of 55.2 mM in B. pasteurii and 36.7 mM in S. ureae, repectively. These observations explain why P. vulgaris is able to grow at neutral pH and low ammonium concentration (2 mM), while B. pasteurii and S. ureae require high ammonium concentration (40 mM) and alkaline pH for growth.Non-standard abbreviations GS glutamine synthetase - GOGAT glutamate synthase - GDH glutamate dehydrogenase - GT glutamyl transferase - MA methylammonium - NB nutrient broth - YE yeast extract - NA nocotinic acid     

Characterization of urease from Sporosarcina ureae

Alkaline stable (pH 7.75–12.5) urease from Sporosarcina ureae was purified over 400-fold by ion exchange and hydrophobic interaction chromatography. The cytoplasmic enzyme was remarkably active with a specific activity of greater than 9300 μmol urea degraded min^-1 mg protein^-1 at pH 7.5, where it has optimal activity. Although S. ureae is closely related to Bacillus pasteurii, known to posses a homopolymeric urease containing 1 nickel per subunit [M _r=65000], the S. ureae enzyme is comprised of three subunits [apparent M _r=63100 (α), 14500 (β), and 8500 (γ)] in an estimated ∝βγ stoichiometry and contains 2.1±0.6 nickel ions per ∝βγ unit as measured by atomic absorption spectrometry. Stationary phase cultures sometimes possessed low levels of urease activity, but the specific activity of cell extracts of partially purified urease preparations from such cultures could be elevated by heat treatment, dilution, or dialysis to values comparable to those observed in samples from exponentially grown cells.     

Comparison of the production of intracellular l-phenylalanine dehydrogenase by Rhodococcus species M4 and Sporosarcina ureae at 50 liter scale

Summary The production of l-phenylalanine dehydrogenase by Rhodococcus spec. M4 (DSM 3041) and Sporosarcina urea (DSM 317) at 50 1 scale was compared. Also at 50 1 scale Rhodococcus spec. M4 (DSM 3041) turns out to be a superior producer: max. 3×10⁴ U/l. Sporosarcina ureae (DSM 317) produces l-phenylalanine dehydrogenase at lower but still very acceptable level: max. 3.7×10³ U/l and 26.4% of the production capacity of Rhodococcus spec. M4 (DSM 3041) based on dry cell matter.     

Comparison of microbially induced calcium carbonate precipitation eligibility using sporosarcina pasteurii and bacillus licheniformis on two different sands

The use of biological means for ground improvement have become popular, which generally works through the process called microbially-induced calcium carbonate precipitation (MICP). Many studies indicate successful application of MICP based improvement with multiple bacteria and on several soils. Given the proven performance of MICP, this study aims to examine the MICP process by comparing the calcium carbonate precipitation ability of widely studied bacteria, i.e., Sporosarcina pasteurii and relatively under-recognized bacteria, i.e., Bacillus licheniformis to outline the formation success. For this purpose, two different sands were tested for observing precipitation behavior using a series of syringe tests. Furthermore, the effect of concentration and inclusion of calcium chloride for nutrition of bacteria, saturation with water, and hybrid use of two bacteria were investigated in some tests for diversification. X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive x-ray spectroscopy (EDS) were used for the interpretation of results. Results indicated that Sporosarcina pasteurii had performed superior over Bacillus licheniformis when achieving calcium carbonate precipitation in tests for both sands. In addition, many intriguing SEM images contributed to the literature of MICP monitoring, highlighting the effects of the variables investigated.     

巴氏芽孢杆菌矿化作用机理及应用研究进展

本文介绍了具有诱导碳酸钙矿化功能的巴氏芽孢杆菌及其矿化核心酶脲酶的结构与功能,较为系统地综述了巴氏芽孢杆菌矿化作用的生物机制,简要介绍了国内外多领域关于巴氏芽孢杆菌矿化应用的研究现状及典型应用案例,并探讨了相应微生物矿化技术在特定环境下的应用前景及在未来应用中可能存在的不足之处,相关分析论述对进一步推进微生物矿化技术的应用具有较为重要的意义.     

Strain improvement of <Emphasis Type="Italic">Sporosarcina pasteurii</Emphasis> for enhanced urease and calcite production

Phenotypic mutants of Sporosarcina pasteurii (previously known as Bacillus pasteurii) (MTCC 1761) were developed by UV irradiation to test their ability to enhance urease activity and calcite production. Among the mutants, Bp M-3 was found to be more efficient compared to other mutants and wild-type strain. It produced the highest urease activity and calcite production compared to other isolates. The production of extracellular polymeric substances and biofilm was also higher in this mutant than other isolates. Microbial sand plugging results showed the highest calcite precipitation by Bp M-3 mutant. Scanning electron micrography, energy-dispersive X-ray and X-ray diffraction analyses evidenced the direct involvement of bacteria in CaCO₃ precipitation. This study suggests that calcite production by the mutant through biomineralization processes is highly effective and may provide a useful strategy as a sealing agent for filling the gaps or cracks and fissures in any construction structures.     

A Novel Approach to Enhance the Urease Activity of Sporosarcina pasteurii and its Application on Microbial-Induced Calcium Carbonate Precipitation for Sand

Abstract

Urease is involved in the formation of carbonate sediments by microbial-induced calcium carbonate precipitation (MICP), and Sporosarcina pasteurii used extensively in this technique owing to its high urease production. In this study, a simple two-step culture method with the appropriate medium was developed to enhance the urease activity of S. pasteurii. Urea played an important role in the culture process, particularly during the pre-cultivation step and the newly developed method improved both urease activity and specific urease activity. Furthermore, the increase in urease activity by MICP resulted in increased production of calcium carbonate and better strength of bio-cemented sand.     

Pasteurella strains isolated from human sputum

Summary In four years ten strains ofPasteurella were isolated from the sputum of eight patients. Six strains proved to bePasteurella multocida (with two lactose-positive variants); the other strains were classified asPasteurella haemolytica var.ureae. (Henriksen andJyssum, 1960) orPasteurella ureae (Jones, 1962).     

Evidence for urea cycle activity in Sporosarcina ureae

Sporosarcina ureae BS 860, a motile, sporeforming coccus, possesses the enzymes required for a functioning urea (ornithine) cycle. This is only the second known example of urea cycle activity in a prokaryote. Specific activities are reported for ornithine carbamoyltransferase, argininosuccinase, arginase, and urease. Although argininosuccinate synthetase activity could not be detected directly in crude cell extracts, indirect evidence from radiocarbon tracing data for arginine synthesis from the substrate, l-[1-¹⁴C]-ornithine, strongly suggest the presence of this or other similar enzyme activity. Furthermore, good growth in defined media containing either 1.0% glutamine, ornithine, or citrulline as sole carbon sources suggests argininosuccinate synthetase activity is necessary for arginine synthesis. The effect of varying pH on arginase and urease activities indicate that these two enzymes may function within the context of the urea cycle to generate ammonia for amino acid synthesis, as well as for raising the pH of the growth micro-environment.     

Classification of the genus Humicola Traaen: II. The DNA base composition of some strains within the genus

The base composition of DNA (GC content) of 25 strains, morphologically referred to the genusHumicola Traaen, is studied. The range of GC% variation is about 23 % (from 28,5 % to 51,6). Two prominent groups of strains with similar GC content may be distinguished: one ranging from 28 % to 37 % and the other ranging from 40 % to 49 %. The aleuriospore size is not related to the DNA base composition, but a group of strains with prevalently coloured hyphae, with aleuriospores of similar size and with high GC content is recognized. Several previous literature reports on the taxonomy ofHumicola are discussed.     

Lactose mother liquor as an alternative nutrient source for microbial concrete production by <Emphasis Type="Italic">Sporosarcina pasteurii</Emphasis>

Microbiologically induced calcite precipitation by the bacterium Sporosarcina pasteurii (NCIM 2477) using the industrial effluent of the dairy industry, lactose mother liquor (LML) as growth medium was demonstrated for the first time in this study. The urease activity and the calcite precipitation by the bacterium was tested in LML and compared with the standard media like nutrient media and yeast extract media. Calcite constituted 24.0% of the total weight of the sand samples plugged by S. pasteurii and urease production was found to be 353 U/ml in LML medium. The compressive strength of cement mortar was increased by S. pasteurii in all the media used compared to control. No significant difference in the growth, urease production and compressive strength of mortar among the media suggesting LML as an alternative source for standard media. This study demonstrates that microbial calcite acts as a sealing agent for filling the gaps or cracks and fissures in constructed facilities and natural formations alike.     

Purification and properties of a heat-stable and cold-labile NAD-specific glutamate dehydrogenase from Sporosarcina ureae

NAD-specific glutamate dehydrogenase (NAD-GluDH; EC 1.4.1.2) was purified to homogeneity from Sporosarcina ureae DSM 320; the native enzyme (M _r 250,000±25,000) is composed of subunits identical in molecular mass (M _r 42,000±3,000), suggesting a hexameric structure. In cell-free extracts and in its purified form, the enzyme was heat-stable, retaining 50% activity after 15 min incubation at temperatures up to 82°C. When exposed to low temperatures at pH values between 7.0 and 9.0. cell-free extracts and purified preparations lost enzyme activity rapidly and irreversibly. The addition of substrates, glycerol, or sodium chloride improved the stability of the enzyme with respect to cold lability and heat stability.Abbreviation NAD-GluDH nicotinamide-adenine-dinucleotide-specific glutamate dehydrogenase     

Enzyme inhibition and radical scavenging activities of aerial parts of Paeonia emodi Wall. (Paeoniaceae)

The ethanolic extract derived from aerial parts of an indigenous medicinal plant Paeonia emodi was screened for enzyme inhibition activities against Urease (jack bean and Bacillus pasteurii) and α-Chymotrypsin. The extract was also investigated for its radical scavenging activity using DPPH assay. The crude extract was found to possess significant enzyme inhibition activities against jack bean (74%) and Bacillus pasteurii (80%) urease and a moderate activity (54%) against α-Chymotrypsin. The extract also displayed excellent (83%) radical scavenging activity. On the basis of these results, the crude extract was subsequently fractionated into n-hexane, chloroform, ethyl acetate, n-butanol and water fractions and tested independently for the aforesaid activities. Significant inhibitory activity against urease enzyme was observed for the ethyl acetate, n-butanol and water fractions while the n-hexane and chloroform fractions were devoid of any such activity. In the α-Chymotrypsin enzyme inhibition studies the activity was concentrated into the ethyl acetate fraction. All the fractions displayed potent radical scavenging activity. The crude extract and fractions thereof were also subjected to total phenolic content determination. A correlation between radical scavenging capacities of extracts and total phenolic content was observed in the majority of cases.     

Mercury detoxifying enzymes within endospores of a broad-spectrum mercury resistantBacillus pasteurii strain DR2

Bacillus pasteurii DR₂, a broad-spectrum Hg-resistant bacterial strain, exhibited delayed sporulation and less mercury volatilization in the presence of mercury compounds. However, Hg-sensitiveBacillus subtilis sporulated quickly in the presence of HgCl₂ and volatilized no mercury. Levels of Hg²⁺-reductase and organomercurial lyase in the endospores ofBacillus pasteurii DR₂ were lower than those in vegetative cells     

L'appareil ectadenial de Hydrous piceus L.

Résumé Une étude sur l'appareil ectadenial du mâle de Hydrous piceus a démontré la nature lipo-protéique de la sécrétion; la fraction lipidique se rapporte aux céphalines et la fraction protéique montre une haute téneur en proline et aminoacides dicarboxyliques. La sécrétion est député à la formation du bouchon vaginal (Begattungszeichen) de la femelle. Les observations précédentes sur la présence de DNA dans la sécrétion n'ont pas été confirmées.

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Ectadenic glands of Hydrous piceus L.

Summary The secretory products of the ectadenic system of the male coleopterus Hydrous piceus is composed of lipoprotein. The lipid fraction consists of cephalins; in the proteic fraction a high content of proline and dicarhoxylic aminoacids was found. The secretion of the ectadenic system constitutes the vaginal plug (Begattungszeichen) of the female. Previous observations on the presence of DNA in the secretory product are not confirmed.

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Les Auteurs remercient vivement Mme. Dr. Silvia Caravita pour sa contribution dans la partie ultrastructurelle du travail et le Prof. R. Zito pour ses conseils dans l'interprétation des données biochimiques.     

Application of Stereolithographic Custom Models for Studying the Impact of Biofilms and Mineral Precipitation on Fluid Flow

Here we introduce the use of transparent experimental models fabricated by stereolithography for studying the impacts of biomass accumulation, minerals precipitation, and physical configuration of flow paths on liquid flow in fracture apertures. The internal configuration of the models ranged in complexity from simple geometric shapes to those that incorporate replicated surfaces of natural fractures and computationally derived fracture surfaces. High-resolution digital time-lapse imaging was employed to qualitatively observe the migration of colloidal and soluble dyes through the flow models. In this study, a Sphingomonas sp. and Sporosarcina (Bacillus) pasteurii influenced the fluid dynamics by physically altering flow paths. Microbial colonization and calcite deposition enhanced the stagnant regions adjacent to solid boundaries. Microbial growth and calcite precipitation occurred to a greater extent in areas behind the fabricated obstacles and less in high-velocity orifices.     

Endospores of Sporosarcina halophila: characteristics and ultrastructure

Sporosarcina halophila forms endospores. Electron micrographs revealed ultrastructural similarity to spores of S. ureae. Spore germination indicated by loss of refractility, darkening, swelling and formation of new vegetative cells was followed by phase contrast light microscopy. To induce spore germination, the endospores needed to be heat avtivated. After activation, they were inoculated into nutrient broth medium supplemented with sea-water. Double concentrated sea-water was found to be optimal for germination. Similar to other bacterial endospores, the spores were found to be resistant to heat and ethanol. An ultraviolet absorbing substance was isolated from suspensions of free spores; it was identified to be pyridine-2,6-dicarboxylic acid (DPA) usually present in bacterial spores. DPA was detected in amounts ranging from 5–7% of the spore dry weight; it was not detected in extracts of vegetative cells.Abbreviation DPA 2,6-pyridine-dicarboxylic acid     

A Modified PCR System for Amplifying <Emphasis Type="Italic">β</Emphasis>-ketoacyl-ACP Synthase Gene Fragments with DNA from <Emphasis Type="Italic">Streptomyces luteogriseus</Emphasis>

Streptomyces luteogriseus strain 099, producing a new type of macrolide antibiotic with anti-coxB6 virus and anti-HIV protease activities, was isolated from soil. PCR was optimized to amplify β-ketoacyl-ACP synthase (KS) genes. The system was optimized around the use of higher concentrations of DMSO (15% vs. 10% v/v) and dNTP (500 μM vs. 50–200 μM) and a lower annealing temperature (55 °C vs. 60–70 °C) than the normal PCR method used to amplify high GC content DNA.     

Parameters Effects Evaluation of Microbial Strengthening of Sandy Soils in Mixing Experiments Using Taguchi Methodology

The effects of experimental parameters including soil type, curing duration, inoculum size, and biomass and nutrients concentration on soil strengthening due to calcite precipitation by Sporosarcina pasteurii PTCC 1645 were investigated. The laboratory-scale mixing experiments on remolded samples were designed by the Taguchi method. Soil type proved to be the most incorporating factor, followed by curing time and nutrient concentration. The main effect and the interactions of the parameters were presented and the optimal conditions were obtained. This suggests the importance of local conditions including soil type on any future large-scale, in situ application.     

Pattern and process in a New Zealand subalpine plant community

Summary Two dynamic patterns found in subalpine herbaceous communities of the North Island of New Zealand are described. These show remarkable similarities with patterns in comparable areas of the northern hemisphere described by Watt (1957) and Burges (1951) as eroded Rhacomitrietum. While the genera, except for Rhacomitrium are distinctive, the families represented by other basic zone formers in this pattern are in related families in both hemispheres. The place of Empetrum (Ericaceae) is taken by Dracophyllum (Epacridaceae) in New Zealand. Vaccinium has its equivalent in Gaultheria (both Ericaceae). It is suggested that when further information is obtained, some interesting comparisons and generalisations will be possible.

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Résumé L'auteur a étudié deux configurations dynamiques trouvées dans des groupements sub-alpins du North Island de la Nouvelle-Zélande. On note des ressemblances remarquables avec les configurations de régions comparables de l'hémisphère boréal, dénommées par Watt (1947) et Burges (1951) eroded Rhacomitrietum. Tandis que les genres sont distincts, excepté Rhacomitrium, les familles représentées par les principaux formateurs de zone des deux hémisphères sont affines.A la Nouvelle-Zélande Dracophyllum (Epacridaceae) prend la place d'Empetrum (Ericaceae), et Gaultheria équivaut à Vaccinium (tout deux Ericaceae).Une étude plus détaillée de ces communautés australes permettra sans doute de faire des comparaisons et des généralisations significatives.