Valuation of characteristics of water purity. I. Estimation of the usefulness of some microbiological and hydrobiological characteristics.

The titres of physiological processes in bacteria (hydrolysis of urea, nitrification), total number of bacteria and photosynthesis were found to show high correlation with standard characteristics: BOD5 and saprobic index. The classificatory values of BOD5 and saprobic index depend on the pollution of waters (with BOD5 less than 3 mg O2/l more information on the extent of pollution is given by the saprobic index whereas with higher values BOD5 is better). The content of NH3-N and titres of ammonification and H2S production depend on the type of pollution and should not be used for determination of water purity without additional studies. Of increasing importance as a measure of pollution is the BOD5/BOD2 quotient.     

Valuation of characteristics of water purity. II. The use of numerical methods for the taxonomic appreciation of selected characteristics of water purity.

Numerical methods have been employed to determine the taxonomic value of a number of microbiological, hydrobiological and chemical characteristics of water purity either in current use or proposed. Numerical methods have at the same time served to evaluate the usefulness and correlation coefficients of these characteristics in classification of the degree of pollution in different stretches (sites) of rivers.     

Valuation of characteristics of water purity. III. The use of numerical methods for qualitative and quantitative evaluation of the degree of pollution.

The taxonometric methods of centrifugal correlation and principal components were used to classify sites along the investigated river with respect to quantity and quality of pollution. The degree of pollution was determined with the use of a collection of microbiological, hydrobiological and chemical characteristics selected by statistical methods.     

Storage of oil field-produced waters alters their chemical and microbiological characteristics

Many oil fields are in remote locations, and the time required for shipment of produced water samples for microbiological examination may be lengthy. No studies have reported on how storage of oil field waters can change their characteristics. Produced water samples from three Alberta oil fields were collected in sterile, industry-approved 4-l epoxy-lined steel cans, sealed with minimal headspace and stored under anoxic conditions for 14 days at either 4°C or room temperature (ca. 21°C). Storage resulted in significant changes in water chemistry, microbial number estimates and/or community response to amendment with nitrate. During room-temperature storage, activity and growth of sulfate-reducing bacteria (and, to a lesser extent, fermenters and methanogens) in the samples led to significant changes in sulfide, acetate and propionate concentrations as well as a significant increase in most probable number estimates, particularly of sulfate-reducing bacteria. Sulfide production during room-temperature storage was likely to be responsible for the altered response to nitrate amendment observed in microcosms containing sulfidogenic samples. Refrigerated storage suppressed sulfate reduction and growth of sulfate-reducing bacteria. However, declines in sulfide concentrations were observed in two of the three samples stored at 4°C, suggesting abiotic losses of sulfide. In one of the samples stored at room temperature, nitrate amendment led to ammonification. These results demonstrate that storage of oil field water samples for 14 days, such as might occur because of lengthy transport times or delays before analysis in the laboratory, can affect microbial numbers and activity as well as water sample chemistry.     

Some physical,chemical, and microbiological characteristics of two beaches of anglesey

Observations during 1971 and 1972 of some of the physical, chemical, and microbiological characteristics of contrasting Anglesey beaches, Newborough and Llanddona, are reported. The fine sandy beach at Newborough was observed to be very unstable and topographical changes were recorded. In particular, the movement of a sand wave across the intertidal zone from low water to extinction at the foot of the dune system was observed. The more extensive fine sandy beach at Llanddona had greater stability.Chemically, each beach was variable both spatially and temporally, with ill-defined patterns of concentration changes. Sand from Newborough beach was low in organic carbon (0.07–0.40 mg C/g dry sand) and well aerated, and the soluble inorganic nitrogen in the ground water (up to 30 μg-at. N/l) was dominated by nitrate form (up to 22 μg NO₃-N/l). By contrast, Llanddona sand had a more variable organic carbon content (0.22–2.25 mg C/g dry sand), was wetter, and poorly aerated with consequent sulphide lenses; its dissolved inorganic nitrogen (over 70 μg-at. N/l) was completely dominated by the ammonium form.Microbiologically, the beaches possessed dissimilar bacterial floras, and sediment from Llanddona gave higher bacterial counts than that from Newborough. For both beaches it is shown that estimated bacterial numbers decreased with depth as well as down the intertidal zone.     

Molybdenum status of laminae as determined by bioassay and chemical methods

Summary 1. Seedlings ofHevea brasiliensis were grown in sand culture under conditions of varied mineral status; the laminae were analysed for molybdenum by a bioassay and by a chemical method.2. Both the bioassay and chemical methods indicated that sulphur-deficient laminae possessed a much higher concentration of molybdenum than those of normal plants.3. The interpretation of the effects of some of the treatments on the accumulation of molybdenum in laminae depended on the method of molybdenum estimation; it was suggested that some laminae, even after wet digestion, contained constituents which interfered with the bioassay method of estimation.     

Classification of central amazon lakes on the basis of their microbiological and physico-chemical characteristics

Twenty-four Central Amazonian Várzea and Ria lakes, lateral to the Rio Negro and the Rio Solimões, were studied for a year and are classified here in terms of physical, chemical and microbiological characteristics. White water (W), mixed water (M) and black water (B) lakes are ranked according to bacterial densities, electrical conductivity, pH, DO, POC, Fe, Si0₂ and PO₄ consumption in the following order W > M > B. The range of V_max decreased as net primary production increased. Further differentiation among the three lake types is made on the basis of dominant algal species and species diversity.     

Classification of staphylococci based on chemical and biochemical properties

Summary In the present work the chemical cell wall composition and some other biochemical characteristics were studied in staphylococci with the intention of utilizing the data obtained in their classification.According to the cell wall peptidoglycans and teichoic acids, the 130 strains of staphylococci studied are divided into 10 major groups. This division of staphylococci into groups is in good agreement with their present classification only in some cases. All of the 47Staphylococcus aureus strains contain a cell wall peptidoglycan of thel-Lys-Gly_5–6 type and ribitol teichoic acid. Coagulase-negative staphylococci are more heterogeneous and are divided according to their cell wall composition into 9 major groups. 21 strains of them are classified asS. epidermidis sensu stricto. They form a natural group and are distinguished by the occurrence of thel-Lys-Gly_4–5,l-Ser_0.5–1.8 peptidoglycan type, glycerol teichoic acid and anl-lactate dehydrogenase which is activated by fructose-1,6-diphosphate. 8 strains with peptidoglycan of thel-Lys-Gly_4–5,l-Ser_0.5–1.8 type and ribitol teichoic acid are labeled asS. saprophyticus. The remaining groups have not been given species names and require further extensive comparative study.     

Influence of climatypes of Scots pine on certain chemical and microbiological characteristics of soils

By using multivariate statistical analysis, the influence of Scots pine climatypes on a set of chemical and microbiological properties of soil, i.e., soil C/N, C_mic/C_org, and C_mic/N_mic, was revealed in a series of long-term (ca. 30 years) field experiments, which were carried out according to the same scheme under contrasting environmental and soil conditions of Siberian forestries.     

Feasibility of methods based on nucleic acid amplification techniques to fulfil the requirements for microbiological analysis of water quality

Molecular methods based on nucleic acid recognition and amplification are valuable tools to complement and support water management decisions. At present, these decisions are mostly supported by the principle of end‐point monitoring for indicators and a small number of selected measured by traditional methods. Nucleic acid methods show enormous potential for identifying isolates from conventional culture methods, providing data on cultivable and noncultivable micro‐organisms, informing on the presence of pathogens in waters, determining the causes of waterborne outbreaks, and, in some cases, detecting emerging pathogens. However, some features of water microbiology affect the performance of nucleic acid‐based molecular techniques and thus challenge their suitability for routine water quality control. These features include the variable composition of target water samples, the generally low numbers of target micro‐organisms, the variable water quality required for different uses and the physiological status or condition of such micro‐organisms. The standardization of these molecular techniques is also an important challenge for its routine use in terms of accuracy (trueness and precision) and robustness (reproducibility and reliability during normal usage). Most of national and international water regulations recommend the application of standard methods, and any new technique must be validated respect to established methods and procedures. Moreover, molecular methods show a high cost‐effectiveness value that limits its practicability on some microbial water analyses. However, new molecular techniques could contribute with new information or at least to supplement the limitation of traditional culture‐based methods. Undoubtedly, challenges for these nucleic acid‐based methods need to be identified and solved to improve their feasibility for routine microbial water monitoring.     

Physical, chemical, and microbiological characteristics of microbial mats (kopara) in the South Pacific atolls of French Polynesia.

Microbial mats that develop in shallow brackish and hyposaline ponds in the rims of two French polynesian atolls (Rangiroa and Tetiaroa) were intensively investigated during the past three years. Comparative assessment of these mats (called kopara in polynesian language) showed remarkable similarities in their composition and structure. Due to the lack of iron, the color of the cyanobacterial pigments produced remained visible through the entire depth of the mats (20-40 cm depth), with alternate green, purple, and pink layers. Profiles of oxygen, sulfide, pH, and redox showed the anoxia of all mats from a depth of 2-3 mm. Analyses of bacterial pigments and bacterial lipids showed that all mats consisted of stratified layers of cyanobacteria (mainly Phormidium, Schizothrix, Scytonema) and purple and green phototrophic bacteria. The purple and green phototrophic bacteria cohabit with sulfate reducers (Desulfovibrio and Desulfobacter) and other heterotrophic bacteria. The microscopic bacterial determination emphasized the influence of salinity on the bacterial diversity, with higher diversity at low salinity, mainly for purple nonsulfur bacteria. Analyses of organic material and of exopolymers were also undertaken. Difference and similarities between mats from geomorphological, microbiological, and chemical points of view are discussed to provide multicriteria of classification of mats.     

Phototoxic potential of mequitazine, a phenothiazine derivative, as determined by the photosensitized action on microbiological systems

In order to determine phototoxic potential of mequitazine (MQZ), a phenothiazine derivative, in vitro tests were attempted using microbiological systems. When Escherichia coli was irradiated with ultraviolet-A light in the presence of MQZ, the surviving fraction was decreased with increasing fluence. Irradiation of bacteriophage lambda in the presence of the drug decreased the surviving fraction as well. Possible targets for the photosensitized action in these systems were discussed.     

Spatial organization of template polynucleotides on the ribosome determined by fluorescence methods.

The spatial organization of template polynucleotides on the ribosome and the dynamics of their interaction with 30 S subunits have been studied by fluorescence spectroscopy. The topography of the mRNA in the ribosome has been determined using singlet-singlet energy transfer. This method has allowed us to estimate distances between donors and acceptors of energy which have been linked to the terminal residues of template polynucleotides (poly- and oligo(U) and oligo(A] and 16 S RNA or to SH-groups of ribosomal proteins S1 and S8. The dynamics of mRNA-ribosome interaction have been investigated by the fluorescence stopped-flow technique. It has been shown that the binding to the 30 S subunit of poly(U) with length much shorter (16 nucleotides) than that covered by the ribosome is greatly enhanced by protein S1. However, the final position of oligo(U)16 on the 30 S subunit, which probably includes the ribosomal decoding site, proves to be quite different from that occupied by oligo(U)16 on a free protein S1. Interaction of oligo- and poly(U) with the 30 S subunit occurs in at least two steps: the first one is as fast as the interaction of poly(U) with free S1, whereas the second step represents a first-order reaction. Therefore, the second step may reflect some rearrangement of the template in the ribosome after its primary binding. It is suggested that protein S1 in some cases may fulfill the role of a transient binding site for mRNA in the course of its interaction with the ribosome. The general shape of the template in the mRNA binding region of the ribosome has been studied using various synthetic ribopolynucleotides and has been shown to be similar. It can be represented by a loop(s) or "U-turn(s)". On the basis of estimation of distances from the ends of poly(U) to some well-localized points on the 30 S ribosomal surface, a tentative model of mRNA path through the ribosome is proposed.     

Diagnosis of tuberculous lymphadenitis by FNAC, microbiological methods and PCR: a comparative study

Despite its usefulness in the diagnosis of tuberculous lymphadenitis, fine needle aspiration cytology (FNAC) faces several limitations, and its sensitivity and specificity are not well established. The diagnostic accuracy and limitations of FNAC were studied in comparison with conventional microbiological methods and polymerase chain reaction (PCR). Sixty patients with lymphadenopathy and a clinical diagnosis of tuberculous lymphadenitis were subjected to FNA. The aspirate was used for cytological examination, Ziehl-Neelsen staining, mycobacterial culture and PCR. PCR was performed using two sets of oligonucleotide primers for Mycobacterium tuberculosis and a single primer for M. bovis species. The results of FNAC, microbiological methods and PCR correlated with the clinical outcome after follow-up for an average period of 24 months. Twenty-five cases (41.6%) were treated and responded well to anti-tuberculosis therapy, among them 17 were correctly diagnosed by FNAC (68%), eight by microbiological methods (32%) and 24 by PCR (96%). When PCR is considered the gold standard, FNAC predicted the correct diagnosis in 62% of cases with a high false negative rate (38%) due to the absence of granuloma/necrosis in smears from cases of early tuberculosis. In the latter group PCR proved to be the most valuable and a diagnostic success of 100% was achieved when FNAC and PCR were combined. In addition, PCR allowed immediate characterization of M. tuberculosis in the vast majority (96.2%) of cases in the study population.     

Comparative study of the quantitative determination of kanamycin sulfate in ophthalmic films with a collagen base by microbiological and chemical methods

The results of the comparative study on microbiological and chemical quantitative determination of kanamycin sulfate in the ophthalmic films with the collagen base are presented. The intraocular films prepared with the use of 1 per cent collagen solution contain dexamethasone and kanamycin. The agar diffusion method with Bacillus pumilus NCTC 8241 as the test microbe and the photocolorimetric method based on estimation of the optical density of the colored compound formed after acid hydrolysis of kanamycin with orcinol and ferric chloride were used for the quantitative determination of kanamycin. The results of the quantitative determinations of kanamycin in the films with the two methods did not differ significantly. However, the error of the microbiological method was +/- 3,75 per cent, whereas that of the chemical method was +/- 1.23 per cent or approximately 3 times lower. The time of the analysis decreased from 24 to 1.5-2 h. Moreover, the chemical method is simple and readily reproducible.     

絮凝剂与复合菌综合处理养殖水体污染研究

为净化水产养殖水体 ,减少鱼病发生和污水排放 ,通过试验比较PFS、PDMDAAC、EM和PFS +PDMDAAC与PFS +PDMDAAC +EM各种净水方法净化鳖池水体的效果 .据此建立了各种净水方法影响水体水质的最佳数学模型 .结果表明 ,联合使用 30mg·L-1的PFS、0 5mg·L-1的PDMDAAC和 30ml·m-3的EM菌 ,效果最好 ,絮凝率达 98%以上 ,CODcr去除率达 95 %以上 ,池水和排污口水体BOD5/CODcr分别由 0 6 1、0 5 1降至 0 2 4和 0 2 9左右 ,说明水体中可生物降解物质被有效去除 .水质各项指标均符合特种水产养殖水质标准 ,水质稳定 ,池水与排污口水体水质基本一致 ,达到了无污染排放 ,实现生态平衡养殖 .