Presence Of Bacterial Strains Research Articles

Synthesis and Characterization of Zinc Oxide Nanoparticles Using Thermophilic Bacteria Isolated from Arid Region of Rajasthan

AbstractFour bacterial strains were used for biosynthesis of zinc oxide (ZnO) nanoparticles (NPs), namely Bacillus tropicus SHJP5, Bacillus tropicus LKJP6, Aeribacillus composti SJP25, and Aeribacillus pallidus SJP28. The synthesized nanoparticles were characterized using UV‐Visible spectroscopy (UV‐Vis), Fourier transform infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), Photoluminescence spectroscopy (PL), Thermogravimetric analysis (TGA), and X‐ray diffraction (XRD). The XRD pattern of NPs (bio‐synthesized) shows the polycrystalline hexagonal wurtzite structure with the three major planes (100), (002), and (001). The average crystallite size determined by the Debye‐Scherrer equation is between 8–54 nm. A reduction in crystallite size of as‐prepared nanoparticles was observed in the presence of bacterial strains. The FTIR analysis reveals the amide, carboxyl, and hydroxyl groups found on the surface of biosynthesized ZnO NPs. These groups behave as reducing and stabilizing agents. The UV‐Vis spectra reveal the absorption bands for control, SHJP5, LKJP6, SJP25, and SJP28 at 373, 363, 382, 358, and 380 nm respectively. The corresponding energy band gap was found to be 3.324, 3.415, 3.246, 3.463, and 3.263 eV respectively, with the decreasing size of the nanoparticles produced by bacterial strains. The FESEM analysis confirms the hexagonal structure of bio‐synthesized ZnO NPs. The nanoparticles have a uniform distribution of spherical shape except for the strain Aeribacillus pallidus LKJP6 which exhibits uniform and thin nanorods. Minimum inhibitory concentration (MIC) tests against E. coli (7.1 mg/ml) and S. aureus (3.2 mg/ml) verified the antibacterial activity of produced ZnO NPs. The use of isolated strains for the extracellular manufacture of ZnO NPs is encouraged in this work. To the best of our knowledge, this might be the first study that has been presented that shows the structural, optical, and surface morphology of a thermophilic bacterium, Bacillus tropicus SHJP5, Bacillus tropicus LKJP6, Aeribacillus composti SJP25, and Aeribacillus pallidus SJP28 for the biosynthesis of ZnO NPs in particular.

Prevalence of Urinary bacterial colonisation in women seeking Obstetrical and Gynecological support at a secondary care centre in South India

Asymptomatic bacteriuria is the presence of bacterial strains in urine samples obtained from a person without revelation of any symptoms of urinary infections. During pregnancy, women are prone to suffer from urinary tract infection at much higher rates due to certain physiological alterations. Thus, the awareness amongst women to protect themselves from asymptomatic bacteriuria and its risk factors are much required. The aim of this study was to determine the predominant uropathogens and their antibiotic susceptibility pattern isolated from women attending the outpatient department in Sri Narayani Hospital and Research Centre. Group of 350 patients were routinely checked. Urine samples of the patients were routinely collected and checked for presence of pathogenic bacteria. The microbes obtained were studied thoroughly to determine their pathogenicity. Antibiotic susceptibility ability of the organisms was studied to detect the resistance of the strains against the drugs used for the treatment. Escherichia coli and Klebsiella sp. were the two most predominantly found pathogens in the urine samples of patients suffering from asymptomatic bacteriuria.

Zoonotic potential of oral microbiota of capuchins monkeys (sapajus libidinosus)

Sapajus libidinosus is a species of primates, popularly known as capuchin monkey. The oral cavity of the monkeys may have pathogenic microbiota for human. Therefore, the study of the microbiota of these species is of great interest in unique health. The objective of the present article was to carry out a survey of the oral microbiota of Sapajus libidinosus, kept in captivity, in the Zoobotanical Park of Teresina (PI, Brazil). Ten chemically immobilized primates were used. Samples were collected from the oral mucosa along the maxillary muco-gingival transition, and these samples were sent to culture and microbiological identification. Most of the microorganisms found were Gram negative and E.coli was the most frequent, followed by Enterobacter spp, Klebsiella spp, Proteus mirabilis, Citrobacter spp.,Morganella morganii, as well as Gram positive bacteria of the type Staphylococcus spp. The data obtained demonstrated the presence of bacterial strains with potential risk of transmission to other animals kept in the park as well as humans in contact with these animals.

Изучение свойств штаммов бактерий рода Рaenibacillus, выделенных с семян нута

A necessary condition for the creation of effective biological preparations with a complex effect is the presence of bacterial strains that have several mechanisms of a positive effect on the plant. Preference is given to those microorganisms that are able to survive in adverse environmental conditions. The aim of the study was to search for new bacterial strains characterized by antagonism towards phytopathogenic microflora and exhibiting tolerance to soil contamination by lead ions and chloride ions. As a result of the screening, bacterial strains were isolated from the surface of chickpea seeds that were identified as Paenibacillus peoriae ANT 13 and Paenibacillus jamilae ANT 14 based on cultural-morphological and physiological-biochemical properties, as well as a comparative analysis of the nucleotide sequences of the gene 16S rRNA. The strains P. peoriae ANT 13 and P. jamilae ANT 14 exhibit antagonistic activity against phytopathogenic micromycetes. The strain P. jamilae ANT 14 is resistant to NaCl (content in the medium is up to 7 %), the strain P. peoriae ANT 13 is able to grow in the presence of Pb2 + ions in an amount up to 3150 mg/l. The use of isolated isolates for presowing treatment of wheat seeds (Triticum aestivum L.) helped to reduce the spread of root rot of seedlings and increase the length of shoots. Inoculation of seeds of alfalfa changeable (Medicago varia Mart.) of P. peoriae ANT 13 and P. jamilae ANT 14 increased the activity of nodulation and contributed to the growth of the root system of the plant, bacterization of chickpea seeds (Cicer arietinum L.) affected the increase in the mass of shoots and roots of this culture. The research results allow us to consider strains of P. peoriae ANT 13 and P. jamilae ANT 14 as promising objects of agricultural biotechnology.

Oralne bolesti kod bolesnika sa hroničnom bubrežnom insuficijencijom

Objective: In the available literature data, there is not much information about problems of patients with end stage kidney disease in relation to oral health. Our objective was to show the importance of oral diseases for patients on hemodialysis. Data sources: In this review article, the sources of data are review articles and scientific articles in the English language published in MEDLINE database. The choice of studies was based on keywords: Chronic kidney disease, Hemodialysis, Oral health, Periodontal diseases. Results: It is assumed that almost 90% patients with chronic kidney disease manifest some symptoms of oral disease. Therefore, it is important to determine the impact of periodontal disease on the progression of kidney failure in these individuals, to evaluate inflammatory parameters in this patient population, to assess the degree of bone loss and periodontal disease index, to determine the presence of bacterial strains, paradontopathy of gingival fluid and antibody titers, to examine correlations of proinflammatory cytokines in the gingival sulcus and serum, as well as to determine the relationship between periodontal tissue and inflammatory mediators. Periodontal diseases can increase the possibility of developing chronic kidney disease by 1.5 to 2 times. These oral diseases include gingival hyperplasia, periodontitis, xerostomia, unpleasant breath, changes in the oral mucosa, malignancies, oral infections, dental abnormalities and bone lesions. Conclusion: This requires serious cooperation between nephrologists and dentists to make proper communication possible, in order to provide quality dental care for this growing patient population in accordance with new treatment strategies.

Degradation kinetics and mechanistic study on herbicide bioremediation using hyper butachlor-tolerant Pseudomonas putida G3

The present study reports a new bacterial isolate identified as Pseudomonas putida strain G3 that can be used for the efficient biodegradation of butachlor, a systemic selective herbicide. Reports suggests butachlor to be a persistent pollutant, a suspected carcinogen and mutagen which poses threat to the environment. Batch biodegradation of the herbicides over a concentration ranging from 100 to 1000 mg/L by the bacterial strain has been studied after process parameter optimization. The bacterial strain is able to degrade up to 700 mg/L of butachlor completely within 360 h. However, increasing the concentration of the herbicide resulted in substrate inhibition in the efficiency of the microbial strain G3. Thus, to determine the bio-kinetic parameters, various inhibition models were fitted to the results obtained during batch biodegradation study. The maximum estimated specific degradation rate was found to be 2.74 mg/L/h. To enhance the bioremediation efficiency of the bacterial strain in presence of higher concentration of the herbicide, the microbial cells were immobilized on Ca-alginate beads and the efficiencies of free and immobilized bacterial cultures were evaluated. The ESI-MS analysis indicated that butachlor biodegradation took place with 2-chloro-N-(2,6-diethylphenyl)-N-hydroxymethylacetamide, 2-chloro-N-(2,6-diethylphenyl) acetamide and 2,6-diethylaniline as intermediate metabolites and a degradation pathway has been proposed. The bacterial strain is able to degrade up to 500 mg/L and 1000 mg/L of other herbicides such as Alachlor and Glyphosate efficiently proposing its wide substrate specificity. The study serves as an important basis that should help to design future bioremediation technology that would be expedient for the treatment of various herbicides.

Increased Mg release rates and related Mg isotopic signatures during bacteria-phlogopite interactions

Phlogopite weathering experiments were carried out under aerobic conditions in a closed system to study Mg isotopic fractionation during the dissolution and processes involved in the presence of bacterial strains. Four different bacterial strains with different metabolisms were chosen. Biotic experiments were performed in batch reactors at 24 °C for 12 days. In parallel, abiotic phlogopite weathering experiments were also performed using organic and nitric acids. Citric and gluconic acids were used to model the effects of chelating agents produced by bacteria, and nitric acid was used to model the effects of acidifying agents. The results indicate that both decreases in pH and the production of metabolites during heterotrophic bacterial activities significantly accelerate the release of Mg and Si in solution. Also, at a given pH, the fraction of elements released in solution is greater in the presence of bacteria or citric acid compared to that released in the presence of nitric and gluconic acids. Magnesium isotopic analyses indicate that the solutions obtained using nitric acid and acidifying bacterial strains display, on average, δ26Mg values that are close to or slightly heavier (by 0.4‰) than those of fresh phlogopite (−1.2‰ ± 0.08). In contrast, in experiments performed with citric acid, the Mg leached into solution is slightly enriched in light isotopes by −0.3‰ relative to the initial phlogopite, while its binding to organics is expected to be related to its preferential enrichment in heavy isotopes. Despite its small range of variations, the δ26Mg values of solutions vary inversely with pH, thus suggesting that secondary phases preferentially enriched in 26Mg at the highest pH values may play a key role.

Risk of chlamydia linked to presence of bacterial strain

Risk of chlamydia linked to presence of bacterial strain

Neem extract as a green inhibitor for microbiologically influenced corrosion of carbon steel API 5LX in a hypersaline environments

In this study, the efficiency of neem extract to inhibit the corrosion of carbon steel API 5LX in the presence of different bacterial strains (Bacillus subtilis A1, Streptomyces parvus B7, Pseudomonas stutzeri NA3 and Acinetobacter baumannii MN3) were evaluated. 150ppm of Azadirachta indica leave extract (AILE) was identified as minimal inhibitory concentration for the bacterial strains B. subtilis A1, S. parvus B7, P. stutzeri NA3 and A. baumannii MN3. Weight loss, electrochemical studies including potential measurements, potentiodynamic polarization and impedance and surface analysis includes Fourier transform infrared spectroscopy (FT-IR) were used to examine the corrosion inhibition efficiency (IE) of AILE on carbon steel API 5LX. The individual bacterial strains and mixed consortium had showed severe corrosion of carbon steel API 5LX in hypersaline environment. In contrast with AILE, the IE of abiotic control and mixed consortia were about 81% and 72% respectively. The corrosion rate was observed as increased trends in presence of all bacterial strains (0.179mm/y) when compared to abiotic system with AILE system (0.012mm/y). X-ray diffraction spectroscopy (XRD) confirms that all bacterial strains has accelerates the corrosion by the production of higher intensity peaks of corrosion products when compared to AILE systems. FT-IR data reveals that AILE extracts consists of azadirachtin and other phytochemical compound which was play a key role in control of bacterial biofilm on metal surface and thus leads to inhibit corrosion process. This is the first report on the application of AILE as a natural, eco-friendly corrosion inhibitor with antibacterial activities to control microbiologically influenced corrosion in hypersaline environment of oil reservoir.

Synergistic influence of Vetiveria zizanioides and selected rhizospheric microbial strains on remediation of endosulfan contaminated soil.

Application of endosulfan tolerant rhizospheric bacterial strain isolated from pesticide contaminated area, Ghaziabad in combination with V. zizanioides for the remediation of endosulfan is described herein. The dissipation of endosulfan from soil was considerably enhanced in the presence of bacterial strain and Vetiveria zizanioides together when compared to the dissipation in presence of either of them alone. Four strains- EAG-EC-12 (M1), EAG-EC-13(M2), EAG-EC-14(M3) and EAG-EC-15(M4) are used for this purpose. V. zizanioides was grown in garden soil spiked with 1500µgg(-1) of endosulfan and inoculated with 100ml of microbial culture of above motioned strains. Effect of microbial inoculation on plant growth, endosulfan uptake and endosulfan removal efficiency were analyzed. The microbial inoculation significantly enhances the growth of test plant and endosulfan dissipation from soil (p<0.05). The addition of bacterial strain M1, M2, M3 and M4 in treated pots showed enhanced root length by 13, 33 35, 20.2 and 4.3%, above ground plant length by 16.38, 35.56, 24.92 and 9.8% and biomass by 33.69, 49.63, 39.24 and 17.09% respectively when compared with endosulfan treated plants. After 135days of exposure, a decline in endosulfan concentration by 59.12, 64.56, 62.69 and 56.39% was obtained in the spiked soil inoculated with bacterial strains M1, M2, M3 and M4 respectively whereas, decrease in endosulfan concentration by 72.78, 85.25, 76.91 and 65.44% in the vegetative spiked soil inoculated with same strains was observed during same exposure period. After 135days of growth period, enhanced removal of endosulfan from experimental soil by 13.66, 20.69, 14.22 and 9.05% was found in vegetative experiment inoculated with same strains when compared with non vegetative experiment. Result of the study showed that use of toletant plant and tolerant bacterial strains could be the better strategy for the remediation of endosulfan contaminated soil.

Adenoid Vegetations - Reservoir of Bacteria for Chronic Otitis Media with Effusion and Chronic Rhinosinusitis.

Otitis media and rhinosinusitis are commonly encountered illnesses in pediatric population. Literature reports have documented the association between the occurrence of these two conditions and even their almost identical microbiological findings. Until recently, the key factor in the association of these two conditions was considered to be the hypertrophic adenoid tissue, but within the past few years there have been evidences in the literature about the presence of bacterial biofilms on the adenoids suggesting biofilms to be also responsible for both conditions, chronic otitis media with effusion and chronic rhinosinusitis. The aim of this study was to make a microbiological analysis of the adenoid tissue specimens taken from patients with chronic otitis media with effusion and chronic or recurrent rhinosinusitis and to determine their potential for biofilms formation. After the surgical intervention, adenoidectomy, microbiological evaluation and analysis of the adenoid tissue specimens taken from 20 patients were made. Having in mind the disease history, chronic otitis media with effusion was diagnosed in all 20 patients and chronic rhinosinusitis in 9 patients. The results obtained from the microbiological analyses showed many potentially pathogenic bacteria in the adenoids that were almost identical with the most common organisms incorporated in the etiopathogenesis of both conditions, in chronic otitis media with effusion and in chronic rhinosinusitis. In 7 (35%) patients Haemophylus influenzae was isolated, in 6 (30%) Streptococcus pneumoniae, in 4 (20%) Moraxella catаrrhalis, in 2 (10%) patients Staphylococcus aureus and in 1 (5%) patient Streptococcus pyogenes - group A was isolated. One bacterium was isolated from all adenoid vegetations, except in one case when two bacteria (Haemophylus influenzae and Staphylococcus aureus) were concurrently isolated. Our results have shown that the key role in adenoid vegetations in chronic otitis media with effusion and chronic rhinosinusitis is not only the mechanism of rhinopharyngeal obstruction, but also the presence of bacterial strains with a large potential for formation of biofilms adhered to their surface, especially in cases with symptoms of chronic otitis media with effusion and chronic rhinosinusitis that were resistant to antibiotic therapy.

Arsenic accumulating and transforming bacteria isolated from contaminated soil for potential use in bioremediation

Arsenic (As) is a metalloid and considered harmful due to its toxic and carcinogenic effects. Removal of arsenic is of great importance for human welfare. The main objective of this study was to isolate arsenic-resistant bacteria that are capable of removing arsenic from the environment. Soil samples were collected from an arsenic-affected area of West Bengal, India and 10 different bacterial strains were isolated. The minimum inhibitory concentration (MIC) values of the isolates varied widely in the range 50–125 mM (As) as arsenate and 10–100 mM (As) as arsenite. TEM and EDAX analysis were done to confirm intracellular accumulation of arsenic. The 16s RNA and phylogenetic analysis showed that seven isolates belonged to γ-proteobacterium, two isolates belonged to Firmicutes and one was identified as Kocuria genera. Some of these bacteria could oxidize arsenite to arsenate and all others could reduce arsenate to arsenite. The growth pattern of the bacterial strains in presence and absence of arsenic was also observed. All the 10 isolates exhibited multiple heavy metal (like Ni, Zn, Cu, Pb, Co, etc.) tolerances. Thus, these new bacterial strains could conveniently be used for bioremediation of soil and effluents and the enzymes produced by them may be used for commercial exploitation.

Pyoverdine Production in Pseudomonas Fluorescens UTPF5 and its Association with Suppression of Common Bean Damping off Caused by Rhizoctonia Solani (Kühn)

Siderophore production is an important mechanism of biological control by a number of strains of plant growth-promoting rhizobacteria. Pseudomonas fluorescens UTPF5 was originally obtained from onion field. Biochemical and physiological characteristics of this strain refer to biovar 3 of P. fluorescens. Strain UTPF5 is an effective bacterium against several phytopathogenic fungi. Pyover- dine type siderophore of this strain was isolated using XAD amberlite column. The plant growth promotion and antifungal proper- ties of bacteria were demonstrated under greenhouse conditions in combination with Fe-EDTA, Fe-EDDHA and Zn as modulators of pyoverdine production. Amendment with zinc, Fe-EDTA and Fe-EDDHA suppressed the disease inhibition when partially used with UTPF5. 7NSK 2 and its pyoverdine mutant, MPFM1, were used as reference strains the inhibition percent of which was not affect by soil amendment. Iron chelates, especially Fe-EDDHA, increased growth and chlorophyll production by plants. This effect was improved in the presence of bacterial strains. The siderophore mutant MPFM1 did not exhibit satisfactory disease inhibition and growth promotion activity. In vitro experiments showed that purified pyoverdine could decrease the fungal growth to the same extent as pyoverdine-producing strain.

Comparative study on the bioleaching of zinc sulphides

Bioleaching processes of three zinc sulphides (marmatite, sphalerite and ZnS synthetically prepared) with Acidithiobacillus ferrooxidans and a moderately thermoacidophilic iron-oxidizing bacterium (MLY) were investigated by leaching experiments and electrochemical methods. Experimental results showed that marmatite had the highest dissolution rate in the presence of bacterial strains among the three zinc sulphides due to the difference of physicochemical property. Compared with synthetic ZnS, the part iron existed as pyrite contained in two concentrates and the dissolution of zinc sulphides was accelerated for galvanic cell effect. More Fe existed in the crystal lattice of marmatite solid solution were released to liquid phase and oxidized into Fe 3+ ions by bacterial strains to accelerate the dissolution of marmatite during the bioleaching process. The bacterial leaching of zinc sulphides could become diffusion controlled when insufficient bacterial oxidation of the sulphur layer occurred, especially in the more rapid marmatite leaching reaction. The zinc sulphides bioleaching was significantly affected by mineralogical properties and leach solutions, which was supported by electrochemical measurements based on the working electrode of zinc sulphides–carbon paste electrode. The marmatite concentrate was more suitable for the extraction of zinc by the microbial leaching, when compared with the sphalerite and synthetic ZnS.

Electrochemistry of marmatite – carbon paste electrode in the presence of bacterial strains

The electrochemical behaviors of a marmatite – carbon paste electrode with the chemical leaching of Fe 3+ ions, or the microbial leaching using Acidithiobacillus ferrooxidans, were compared. The cyclic voltammograms of the electrode in the presence and absence of bacterial strains showed that the leaching process of marmatite was carried out by the different reactions occurring in the interface of the marmatite electrode — leach liquid. The polarization currents of the electrode under the differently applied potentials suggested that the microbial leaching of marmatite could be accelerated by the applied potential. The SEM observations indicated that the corrosion pits formed in the electrode surface were similar to the attached bacterial cells in shape and size, other than that by the chemical leaching of Fe 3+ ions. The contact leaching of the attached cells on the mineral substrate played an important role on the dissolution of marmatite in addition to the chemical leaching of Fe 3+ ions.

Bioleaching of marmatite flotation concentrate by Acidithiobacillus ferrooxidans

Bioleaching of a marmatite flotation concentrate by Acidithiobacillus ferrooxidans was carried out at 35 °C and an initial pH of 2.0 on an orbital shaker at 160 min −1. Experimental results indicated that the adapted strains markedly increased the dissolution rate of marmatite when compared with the sterile control and the original strains. The fact that Fe 3+ ions played a key role in the dissolution of marmatite was demonstrated by the chemical leaching of the concentrate with different concentrations of Fe 3+ ions. The main role of the microorganisms was to oxidize Fe 2+ ions into Fe 3+ ions during the bioleaching process. S.E.M. observations showed the morphological features of the mineral sample and leach residues. The cross-section image of residue particles revealed two different regions, a periphery consisting of reaction products and an undissolved core. It was shown by X-ray diffraction and EDX analysis that the leach residues were composed of elemental sulfur, precipitate of jarosite and undissolved mineral impurities. These facts suggested that the elemental sulfur formed was not completely oxidized and dissolved only partially in the marmatite bioleaching even in the presence of bacterial strains. The sulfur product coated the residue particles and negatively affected the dissolution of marmatite. The marmatite was dissolved preferentially during the bioleaching process by Acidithiobacillus ferrooxidans, as compared with other sulfide minerals such as pyrite and galena in the concentrate.