Mineral and carbon usage of two synthetic pyrethroid degrading bacterial isolates

AIMS: To investigate the biodegrading ability and cometabolism of synthetic pyrethroid (SP) utilizing bacteria in cultures with various minerals and carbon sources. METHODS AND RESULTS: Previously isolated SP-degrading Pseudomonas sp. and Serratia sp. were used in cultures containing either flumethrin SP or cypermethrin SP formulations. The culture media consisted of either (i) water only, (ii) water and sucrose, (iii) mineral broth or (iv) mineral broth and sucrose. The growth of both organisms was greatest in the mineral broth and sucrose medium, but the growth-limiting factor for Pseudomonas sp. strain Circle was the mineral content whereas for Serratia sp. strain White it was the carbon substrate. CONCLUSION: The greatest extent of degradation of both SP-based compounds occurred with Pseudomonas sp. strain Circle but was dependant on the medium. SIGNIFICANCE AND IMPACT OF THE STUDY: This investigation could lead to the development of a relatively inexpensive medium supplement to enhance the microbial biodegradation of undesirable compounds, either in situ or ex situ. In this particular case, for the biodegradation of SPs used in sheep dip.     

Conditions affecting growth and enterotoxin production by Staphylococcus aureus on temperature-abused chicken meat

Growth of Staphylococcus aureus at 15°C, with and without addition of representative spoilage bacteria, was studied in cooked, whole chicken meat and chicken broth. In the absence of competitors, the organism grew better in broth culture than on whole meat, but multiplied more slowly in broth when other organisms were present, even from twice the previous level of inoculum. The presence of competitors had no marked effect on the growth of Staph. aureus on whole meat. Enterotoxin A was not produced at 15°C on either whole meat or in broth, and occurred at 20°C only in pure culture. At 30° and 37°C, toxin was produced whether or not competitors were present. Toxin production by Staph. aureus appeared to be influenced more by growth temperature than by bacterial competition.     

Effect of glucose and sucrose on the survival in batch culture of Streptococcus mutans C67-1 and a non-cariogenic mutant C67-25. Morphological studies.

This study comprised an ultrastructural examination of a cariogenic strain of Streptococcus mutans, C67-1, and a non-cariogenic mutant of that strain, C67-25. The aim of the work was to define more clearly the relationship between S. mutans and dental caries and, more specifically, to elicit ultrastructural evidence for the conclusion from a previous investigation that the greater survival of the parent strain in sucrose broth at uncontrolled pH was related partly to the production in this medium of abundant extracellular polysaccharide (EPS). The strains were grown as previously in 5% (w/v) glucose or sucrose broths, the pH being either allowed to fall or maintained above 6.0, and processed by the thiosemicarbazide technique for election microscopy. It was confirmed that EPS was most abundant in the sucrose broth culture of the parent strain at uncontrolled pH. While the presence of abundant EPS relates to the greater survival of the parent strain in sucrose broth at uncontrolled pH, this organism possesses at least one other mechanism of survival in acid media, possibly dependent on cell wall properties, in view of its greater cell wall thickness and increased survival in pH-uncontrolled glucose broth in the absence of detectable EPS production. It is postulated that intracellular and extracellular polysaccharide formation, cell wall thickening and reduced viability were indicators of unfavourable growth conditions in the test media. Cariogenic strains of S. mutans appear to be able to survive better under such conditions and hence the prevalence of this and other polysaccharide-producing organisms in stagnant sites in natural dental plaques.     

The Influence of Sodium-Free Solutions on the Membrane Potential of Frog Muscle Fibers

The membrane potential of frog sartorius muscle fibers in a Cl- and Na-free Ringer's solution when sucrose replaces NaCl is about the same as that in normal Ringer's solution. The K⁺ efflux is also about the same in the two solutions but muscles lose K and PO₄ in sucrose Ringer's solutions. The membrane potential in sucrose Ringer's solution is equal to that given by the Nernst equation for a K⁺ electrode, when corrections are made for the activity coefficients for K⁺ inside and outside the fiber. For a muscle in normal Ringer's solution, the measured membrane potential is within a few millivolts of E_K. This finding is incompatible with a 1:1 coupled Na-K pump. It is consistent with either no coupling of Na efflux to K influx, or a coupling ratio of 3 or greater.     

Root-associated n(2) fixation (acetylene reduction) by enterobacteriaceae and azospirillum strains in cold-climate spodosols

N(2) fixation by bacteria in associative symbiosis with washed roots of 13 Poaceae and 8 other noncultivated plant species in Finland was demonstrated by the acetylene reduction method. The roots most active in C(2)H(2) reduction were those of Agrostis stolonifera, Calamagrostis lanceolata, Elytrigia repens, and Phalaris arundinacea, which produced 538 to 1,510 nmol of C(2)H(4).g (dry weight). h when incubated at pO(2) 0.04 with sucrose (pH 6.5), and 70 to 269 nmol of C(2)H(4). g (dry weight).h without an added energy source and unbuffered. Azospirillum lipferum, Enterobacter agglomerans, Klebsiella pneumoniae, and a Pseudomonas sp. were the acetylene-reducing organisms isolated. The results demonstrate the presence of N(2)-fixing organisms in associative symbiosis with plant roots found in a northern climatic region in acidic soils ranging down to pH 4.0.     

Bacteriophage resistance of attached organisms as a factor in the survival of plasmid-bearing strains of Escherichia coli

Unattached organisms of plasmid-free and plasmid-bearing strains of Escherichia coli showed marked sensitivity to phages T4, Tula and K3 on incubation in broth at 37°C but organisms attached to glass beads or sand were resistant. Phage T4 sensitivity of free organisms and resistance of glass bead-attached ones were also observed when incubation was in broth at 15° or 20°C or anaerobically at 37°C. In contrast, free and attached organisms were resistant at 37°C or lower temperature when incubation was in poor media. It seems likely that the presence of phage will be a major factor reducing survival in the intestine and in sewage and that attachment (which is more significant for strains bearing certain plasmids) will protect. In contrast, survival of either free or attached organisms in polluted water will probably not be significantly influenced by the presence of phage.     

Role of haemagglutinins in adhesion of Erwinia carotovora to potato tissue

The adhesion of two strains each of Erwinia carotovora subsp. carotovora and Erwinia carotovora subsp. atroseptica to potato tuber discs, leaflets and tuber cell cultures was examined and found to occur independently of the presence of either mannose-sensitive (MSHA) or mannose-resistant (MRHA) haemagglutinins. Adhesion was generally greater when bacteria were grown in nutrient broth than on phosphate-buffered agar. The specific MSHA inhibitor α-methyl mannoside reduced the adhesion of two strains to tuber discs and leaflets and the specific MRHA inhibitor, asialofetuin inhibited strains only on leaflets. A reduction in adhesion of a MSHA-producing strain by α-methyl mannoside was observed by scanning electron microscopy which found that adhesion was localized at intercellular junctions.     

Influence of phagotrophic processes on the regeneration of nutrients in two-stage continuous culture systems

Regeneration of nutrients in aquatic ecosystems may be affected by autolysis, bacterial degradation, and activities of phagotrophic organisms. To examine the relative importance of these processes, mineralization of carbon, nitrogen, and phosphorus was studied in a two-stage continuous culture system. In the first stage (production compartment), aChlorella sp. was grown either axenically or in the presence of bacteria under P-limited conditions. In the presence of bacteria, the biomass of algae decreased due to efficient competition for P by bacteria. In the second stage (remineralization compartment), which was kept continuously in the dark, the nutrients incorporated by the organisms in the first stage were remineralized only slightly (0–25%) irrespective of the presence or absence of bacteria. However, remineralization of all nutrients tested was strongly increased (60–80%) after addition of zooflagellates, which grazed on algae and bacteria. These observations suggest that a net regeneration of nutrients was provided by phagotrophic organisms, whereas nutrients were trapped rather than released by bacteria. It is concluded that nutrient cycling could probably not proceed at the high velocities observed in the field without the participation of phagotrophic organisms.     

Protein-mediated adhesion of Lactobacillus fermentum strain 737 to mouse stomach squamous epithelium

The mechanism of adhesion of Lactobacillus fermentum strain 737 to mouse stomach squamous epithelium was investigated. Adhesion inhibition tests involving chelators, monosaccharides, periodate and concanavalin A and the use of bacteria grown in the presence of tunicamycin failed to clarify the adhesive mechanism. Washed bacterial cells had reduced adhesive capacity, except in the presence of spent broth culture supernatant fraction or cell washings. Spent culture supernatant fractions of erythrosine-supplemented broth did not enhance adhesion of washed cells. The adhesion-promoting factor(s) in the spent broth culture supernatant fractions and cell washings bound to both bacterial and epithelial cell surfaces, but did not promote adhesion of two other Lactobacillus strains which were not of mouse origin, thereby indicating host specificity for the adhesion-promoting activity. Chemical characteristics of the adhesion-promoting factor were determined by pretreatment of the dialysis retentate of spent broth culture supernatant fractions with proteolytic enzymes, concanavalin A-Sepharose or periodate before the adhesion assay. The adhesin was non-dialysable, pronase-sensitive, heat sensitive at 100 degrees C, had no affinity for concanavalin A-Sepharose and contained no carbohydrate groups active in the adhesion process. The protein profiles of dialysis retentates of spent broth culture supernatant fractions after bacterial growth in the absence and presence of erythrosine were determined by 2-dimensional SDS-PAGE. Gel filtration by HPLC was used for purification of an adhesion-promoting fraction. The host-specific adhesion of L. fermentum strain 737 was mediated by a protein, with an Mr of 12-13000, that was not detectable in cells grown in the presence of erythrosine. A model for the mode of binding of the adhesin to host epithelia and bacterial surfaces is proposed.     

Trehalose and sucrose protect both membranes and proteins in intact bacteria during drying.

The microorganisms Escherichia coli DH5 alpha and Bacillus thuringiensis HD-1 show an increased tolerance to freeze-drying when dried in the presence of the disaccharides trehalose and sucrose. When the bacteria were dried with 100 mM trehalose, 70% of the E. coli and 57% of the B. thuringiensis organisms survived, compared with 56 and 44%, respectively, when they were dried with sucrose. Only 8% of the E. coli and 14% of the B. thuringiensis organisms survived drying without the sugars. Fourier transform infrared spectroscopy was used to investigate the role of membrane phase transitions in the survival of the organisms during drying and rehydration. Both E. coli and B. thuringiensis showed an increase of 30 to 40 degrees C in the temperature of their phospholipid phase transition when dried without the sugars, while phase transition temperatures of those dried with the sugars remained near those of the hydrated cells. A Fourier transform infrared spectroscopy microscope made it possible to investigate the effects of drying on the protein structure in the intact cells. The amide II peak shifts from 1,543 cm-1 in the hydrated cells to about 1,533 cm-1 in the cells dried without sugar. There is no shift in the amide II peak when the cells are dried with trehalose or sucrose. We attribute the increased survival to the sugars' ability to lower the membrane phase transition temperature and to protect protein structure in the dry state.(ABSTRACT TRUNCATED AT 250 WORDS)     

Selection of Media for the Isolation of Common Bacterial L-Phase Organisms from a Clinical Specimen

The L-phase of 13 bacteria commonly associated with disease were induced by penicillin and inoculated into various solid and broth media; their growth was recorded for a period of 14 days. Plates containing highly purified agar and sucrose as the stabilizing agent and those incubated under aerobic conditions gave the best results. Magnesium seems to be necessary for growth in broth media on primary isolation, although it may not be necessary on multiple transfers after a more stable state has been reached. Growth in broth media is much more difficult to achieve. Reversion is aided by using a higher concentration of agar in plates, by decreasing the sucrose concentration, and by omitting the antibiotics and horse serum. A procedure has been outlined for the routine culture and identification of L-phase organisms from a clinical specimen.     

Adhesion of cellulolytic ruminal bacteria to barley straw

Adhesion of the cellulolytic ruminal bacteria Ruminococcus flavefaciens and Fibrobacter succinogenes to barley straw was measured by incubating bacterial suspensions with hammer-milled straw for 30 min, filtering the mixtures through sintered glass filters, and measuring the optical densities of the filtrates. Maximum adhesion of both species occurred at pH 6.0 and during mid- to late-exponential phase. Adhesion was saturable at 33 and 23 mg (dry weight) g of straw for R. flavefaciens and F. succinogenes, respectively. Methyl cellulose and carboxymethyl cellulose inhibited adhesion by 24 to 33%. Competition between species was determined by measuring characteristic cell-associated enzyme activities in filtrates of mixtures incubated with straw; p-nitrophenyl-beta-d-lactopyranoside hydrolysis was used as a marker for F. succinogenes, while either beta-xylosidase or carboxymethyl cellulase was used for R. flavefaciens, depending on the other species present. R. flavefaciens had no influence on F. succinogenes adhesion, and F. succinogenes had only a minor (<20%) effect on R. flavefaciens adhesion. The noncellulolytic ruminal bacteria Bacteroides ruminicola and Selenomonas ruminantium had no influence on adhesion of either cellulolytic species, although these organisms also adhered to the straw. We concluded that R. flavefaciens and F. succinogenes have separate, specific adhesion sites on barley straw that are not obscured by competition with non-cellulolytic species.     

Microbial Variants from Iron Ore Slimes: Mineral Specificity and pH Tolerance

This paper describes the isolation of the native bacterial strains from the iron ore mines slime pond and its extremophilic characteristics. The two microbial isolates designated as CNIOS-1 and CNIOS-2 were grown in selective silicate broth at pH 7.0 and the organisms were tested for their selective adhesion on silicate and alumina minerals. The silicate bacteria with their exopolymers are very potent to grow over aluminosilicates. It was established that CNIOS-1 grew preferentially in the presence of silicate mineral compared to CNIOS-2 which grew in the presence of alumina. The organisms were tested for growth at various pH and trials were carried to define their efficacy for eventual applications to remove gangue minerals of silica and alumina from the raw material.

Electronic supplementary material

The online version of this article (doi:10.1007/s12088-015-0544-6) contains supplementary material, which is available to authorized users.     

Effect of Osmotic Stabilizers on 14CO2 Production by Bacteria and Blood

Evolution of (14)CO(2) by whole blood as well as by Diplococcus pneumoniae, Haemophilus sp., Pseudomonas aeruginosa, Pseudomonas diminuta, and Streptococcus pyogenes was examined by using the BACTEC system. The control medium was JLI no. 6A culture vial containing 30 ml of enriched tryptic soy broth and 1.5 muCi of (14)C-substrate. Hypertonic media consisted of control medium with either 1 or 3% NaCl, 10% sucrose, and 5%, 10%, or 15% dextran. The most deleterious treatment to bacteria was 3% NaCl since it not only retarded (14)CO(2) production, but also prevented growth of D. pneumoniae, Haemophilus, and P. diminuta. The 10% sucrose treatment diminished (14)CO(2) output, although it did not retard growth of test organisms. This effect was probably due to (14)C-substrate dilution rather than to osmotic effects. Dextran had slight effect on (14)CO(2) production and slightly acidified the medium. Of the treatments tested, only 10% sucrose reduced normal output of (14)CO(2) by whole blood. This also is probably due to (14)C-substrate dilution. It appears that 10% sucrose is potentially the most useful osmotic agent for radiometric techniques since, although bacterial (14)CO(2) production is lowered, blood (14)CO(2) is lowered also.     

Role of Bacteriocin During Plaque Formation by Streptococcus salivarius and Streptococcus sanguis on a Tooth in an Artificial Mouth

Bacteriocinogenic strains of Streptococcus salivarius antagonized Strep. sanguis on blood agar and in Todd-Hewitt broth with, but not without, sucrose. Each organism produced plaque in vitro but, after a mixed inoculum with both organisms, the numbers of Strep. sanguis rapidly fell to <0.01% plaque organisms. A non-bacterio-cinogenic mutant of Strep. salivarius was itself inhibited by Strep. sanguis in the plaque-producing system; derivatives of Strep. sanguis partially resistant to bacteriocin in the plate test nevertheless failed to co-habit plaque with bacteriocinogenic Strep. salivarius. The latter could suppress Strep. sanguis in established monoculture plaque but only if sucrose were continuously supplied. It was concluded that the effect of bacteriocin in plaque formation by these streptococci is linked to other as yet unknown properties which may account for the absence of Strep. salivarius from plaque in vivo .     

Contraction and Action Potentials of Frog Heart Muscles Soaked in Sucrose Solution

Isolated auricles or ventricles from the frog continue to contract, either spontaneously or when stimulated, for from 2 to 4 hours after they are placed in isotonic sucrose solution. After the muscles stop contracting in sucrose solution, contractility is partially restored when the muscles are placed in chloride Ringer's. However, contractility is usually not restored if the muscles are placed in sulfate Ringer's. Ventricles soaked in sucrose solution at 4–7°C continue to contract for 12 to 24 hours and during the first few hours in sucrose solution the contractions often are enhanced. Several types of experiment indicate that the sucrose solution does replace the Ringer's in the extracellular space. Auricles and ventricles also continue to conduct action potentials, with an overshoot, for from 30 to 360 minutes after being placed in sucrose solution. Muscles soaked in sucrose until they are inexcitable rapidly recover in chloride Ringer's but often fail to recover in sulfate Ringer's. The results are discussed in relation to theories about the generation of the action potential in cardiac muscle, and the role of the extracellular fluid in contraction.     

Bacteria as food had no effect on fecundity during domestication of the fruit fly,Bactrocera tryoni

Adult Bactrocera tryoni from different generations of domestication were given various diets to determine whether either or both the bacteria Klebsiella oxytoca and Klebsiella pneumoniae could provide a source of proteinaceous material sufficient to allow the female flies to produce mature oocytes and eggs or alternatively, whether the bacteria could act as a beneficial supplementary food when given in addition to the usual laboratory proteinaceous food that consisted of a paste of sucrose and yeast autolysate. Overall, there was no evidence from any generation studied that female flies could produce eggs or mature oocytes on a bacterial diet above the levels attained with access to culture medium without bacteria. Similarly, there was no evidence that bacterial supplementation to a diet that included a paste of sucrose and yeast autolysate was more beneficial than when the paste was the sole source of proteinaceous food. There was an increase in mature oocytes per female with the number of generations of culture but the extent of increase was greater when sugar/yeast paste was included in the diet. There was no evidence that mixtures of either bacterium species in nutrient broth or the broth itself was attractive to female B. tryoni over a distance of a few centimetres when the tested flies were caged at low density but flies of later generations did feed when offered either type of food at very close range.     

Characteristics of aerobic,solid substrate fermentation of swine waste-corn mixtures

Summary Aerobic fermentation of swine waste combined with corn produced differences in microbial and biochemical patterns dependent on use of fresh or stored excrement. Lactic acid fermentation and odor control resulted with either waste. Homofermentative lactic acid bacteria were present initially at 10⁷ organisms/dry g with stored waste-corn cultures and total microflora amounted to 10⁸ organisms/dry g. Fresh waste-corn fermentations initially yielded heterofermentative lactic acid bacteria at 10⁷ organisms/dry g and total viable population was 10⁹ organisms/dry g. These respective groups of lactic acid bacteria dominated from 12 through 144 h in cultures with either waste, and acid production (0.2 meq/dry g) decreased pH by 2 units to 4.5. The major acid component with stored waste-corn was lactic acid, whereas fresh waste-corn fermentation produced both lactic and homologous fatty acids from acetic through valeric acid. Coliform bacteria present initially at 10⁵ organisms/dry g in stored waste-corn cultures were not detected after 36 h; coliform bacteria in fresh waste-corn fermentations persisted at 10⁶ organisms/dry g. A silage-like fermentation product resulted which may have use in animal feed formulations.     

Bacterial Adhesion to Soil Contaminants in the Presence of Surfactants

It has been proposed that addition of surfactants to contaminated soil enhances the solubility of target compounds; however, surfactants may simultaneously reduce the adhesion of bacteria to hydrophobic surfaces. If the latter mechanism is important for the biodegradation of virtually insoluble contaminants, then the use of surfactants may not be beneficial. The adhesion of a Mycobacterium strain and a Pseudomonas strain, isolated from a creosote-contaminated soil, to the surfaces of highly viscous non-aqueous-phase liquids (NAPLs) was measured. The NAPLs were organic material extracted from soils from two creosote-contaminated sites and two petroleum-contaminated sites. Cells suspended in media with and without surfactant were placed in test tubes coated with an NAPL, and the percentages of cells that adhered to the surface of the NAPL in the presence and absence of surfactant were compared by measuring optical density. Test tubes without NAPLs were used as controls. The presence of either Triton X-100 or Dowfax 8390 at a concentration that was one-half the critical micelle concentration (CMC) inhibited adhesion of both species of bacteria to the NAPLs. Both surfactants, when added at concentrations that were one-half the CMCs to test tubes containing previously adhered bacteria, also promoted the removal of the cells from the surfaces of the NAPL-coated test tubes. Neither surfactant was toxic to the bacteria. Further investigation showed that a low concentration of surfactant also inhibited the growth of both species on anthracene, indicating that the presence of a surfactant resulted in a reduction in the uptake of the solid carbon source.     

Effect of Conditioning, Betaine, and Sucrose on Survival of Rhizobacteria in Powder Formulations

To assess the feasibility of simplified dry formulations of beneficial rhizobacteria with improved shelf life, strains of Pseudomonas and members of the family Enterobacteriaceae were conditioned by either aging, exposure to osmotica, or growth on media amended with sucrose or betaine. Strains thus treated were formulated in 1% methylcellulose and talc, and survival was assessed over 10 to 12 months. Survival of 24-h-old cultures of the same strains suspended in 20% xanthan gum and talc over the same interval was used as the standard of comparison. The survival of strains treated with sucrose, with or without betaine, and formulated in methylcellulose and talc was equal to or greater than that of 24-h-old cultures suspended in 20% xanthan gum and talc. Aging of strains on unamended King's medium B, growth of strains on KCl-amended media, and addition of betaine to KCl-amended King's medium B, whether or not strains were suspended in buffer or a diluent isosmotic to culture conditions, failed to improve survival of the strains tested. The practicality of specific amendments, such as sucrose or other disaccharides, for promoting survival of beneficial bacteria in simplified dry formulations was thus demonstrated.