The Internet journal of microbiology最新文献

{"title":"Neutrophiles: Acid Challenge and Comparison with Acidophiles","authors":"P. Jain, Sarika Sinha","doi":"10.5580/1ee7","DOIUrl":"https://doi.org/10.5580/1ee7","url":null,"abstract":"When neutrophiles like Escherichia coli are exposed to low pH environments mechanisms are required, within the cell, to alleviate the effects of lowered cytoplasmic pH. They do undergo acid adaptation wherein there is an induction of glutamate decarboxylases, arginine decarboxylases and RpoS-dependent oxidative systems etc. After rapid acid treatment neutrophiles show a change in the expression of three different classes of genes. This review discusses the mechanisms adopted by neutrophiles to be able to survive and grow in the extreme acid conditions and a compares these mechanisms with those that are exclusively present in acidophiles.","PeriodicalId":22514,"journal":{"name":"The Internet journal of microbiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85663222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Comparison of Measures of the Bilateral Limb Deficit During Short and Long Time Isometric Knee Extensions","authors":"U. Kuruganti, P. Parker, M. Tingley, G. Sleivert","doi":"10.5580/1090","DOIUrl":"https://doi.org/10.5580/1090","url":null,"abstract":"Aim: To investigate the presence of the Bilateral Limb Deficit (BLD) during isometric knee extensions and the differences in voluntary activation and muscle fatigue during bilateral and unilateral contractions. Methods: Twelve subjects (6 female, 6 male, (mean ± standard deviation) age = 27.6 ± 6.9 years) completed a series of short (5-second) and long (30-second) isometric knee extensions during which force, myoelectric signal (MES) amplitude and voluntary activation were measured.Results: No BLD was detected during the isometric contractions and voluntary activation (estimated using the twitch interpolation technique) did not differ between unilateral and bilateral conditions The mean voluntary activation levels were significantly higher (p<.05) during the short (5-second) contractions (91% activation) than the first five seconds of the long (30-second) contractions (80% activation). Unilateral and bilateral contractions resulted in similar decreases in fatigue (measured as a decline in mean frequency). Significant differences were detected in the mean frequency (14 – 17 Hz) between short and long contractions (p < 0.001). Finally, it was found that the current used to elicit the maximal twitch force differed between unilateral and bilateral contractions suggesting that there are differences in the twitch response that may contribute to the BLD.Conclusion: These data showed that the BLD is not present during isometric knee extensions and that voluntary activation and neuromuscular fatigue are similar for bilateral and unilateral conditions. Differences were detected in voluntary activation between short and long contractions and between the current required to elicit a supramaximal twitch during bilateral and unilateral contractions.","PeriodicalId":22514,"journal":{"name":"The Internet journal of microbiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77049152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Importance of catalase in adaptive response and resistance to hydrogen peroxide in Haloferax IRU1","authors":"H. Amirkhani, E. Asgarani, Mahvash Khodabanode","doi":"10.5580/18b2","DOIUrl":"https://doi.org/10.5580/18b2","url":null,"abstract":"Haloferax IRU1 is an extremely halophilic Archaeon, which is highly resistant to the lethal effects of hydrogen peroxide. To investigate the role of catalase in the tolerance of Haloferax IRU1 to hydrogen peroxide stress, theexpression and activity of catalase by this archaeon was studied. When cells were treated with several levels of hydrogen peroxide, activity and expression of catalase increased, in comparison to that of untreated cells. This suggests that catalase is an important factor in the tolerance of Haloferax IRU1 to hydrogen peroxide stress.To investigate the adaptive response to the lethal effects of hydrogen peroxide in Haloferax IRU1, cultures when pretreated with sub-lethal levels of hydrogen peroxide, became more resistant to its lethal effects and exhibited higher levels of catalase than those of un-pretreated cultures. This indicates that catalase is induced during the adaptive response of this strain to hydrogen peroxide stress.","PeriodicalId":22514,"journal":{"name":"The Internet journal of microbiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88457657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Protein fingerprinting may serve as a complementary tool for the phylogenetic classification of heterocystous (Nostoc, Anabaena, Cylindrospermum, Aulosira and Tolypothrix) Cyanobacteria","authors":"S. Mishra, P. Bhargava, R. Rai, Y. Mishra, T. Zotta, E. Parente, L. Rai","doi":"10.5580/46b","DOIUrl":"https://doi.org/10.5580/46b","url":null,"abstract":"A combination of morphology, SDS-PAGE, 16S rRNA gene and the fuzzy approach has been used for the first time to attest the phylogenetic affiliation of the cyanobacterial species such as Nostoc, Anabaena, Cylindrospermum, Tolypothrix and Aulosira. The idea was to ascertain as how far SDS-PAGE analysis and morphological taxonomy work coherently and serve as a reliable tool, compatible with 16S rRNA gene based classification of cyanobacteria. Intermingling of Nostoc and Anabaena species in SDS-PAGE and 16S rRNA gene indicates that the two taxa are not clearly separated at the genetic level and may be polyphyletic in origin. In contrast to this, clustering of Tolypothrix and Aulosira species in the same clade attests the taxonomic coherence of these species. However, Cylindrospermum showed greater phylogenetic relatedness with Anabaena strain in all phylogenetic analyses. Despite a few minor incongruities, protein fingerprint depicted greater similarity with 16S rRNA gene as compared to morphological taxonomy. Thus protein fingerprinting developed using fuzzy approach appears to be more compatible with 16S rRNA gene analysis than morphological taxonomy in discriminating cyanobacteria up to the species level.","PeriodicalId":22514,"journal":{"name":"The Internet journal of microbiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74898382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Production of Commercially Important Glucansucrase from a Newly Isolated Strain of Leuconostoc mesenteroides AA1","authors":"Afsheen Aman, S. A. Qader, Saeeda Bano, S. Iqbal, A. Azhar","doi":"10.5580/232","DOIUrl":"https://doi.org/10.5580/232","url":null,"abstract":"Glucansucrase is an industrially important extracellular enzyme produced by Leuconostoc mesenteroides. This glucansucrase is widely used for glucan production. Both the product and the enzyme have received increased attention because of their wide range of applications. Due to this, isolation of new strains of L. mesenteroides for glucansucrase production is of great interest. In this work eleven different strains of Leuconostoc mesenteroides were screened and isolated from locally available fruits and vegetables. A new glucansucrase producing strain of Leuconostoc mesenteroides AA1 have been isolated from Brassica oleracea var Capitata L. and was selected on the basis of high enzyme productivity. Various experimental conditions and aspects regarding glucansucrase production were studied. This newly isolated strain optimally produces maximum glucansucrase enzyme after 8 hours of incubation in a new medium designed for enzyme production. Maximum glucansucrase was produced at a sucrose concentration of 2.5% when incubated at 25°C and pH 7.5. Under these conditions 53.0DSU/ml/hr units were produced. This new strain Leuconostoc mesenteroides AA1 could be used for the commercial production of glucansucrase and can also facilitate glucan production on large scale.","PeriodicalId":22514,"journal":{"name":"The Internet journal of microbiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74437940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isolation of Crude Oil Degrading Marine Bacteria and Assessment for Biosurfactant Production","authors":"Kritika Sakalle, S. Rajkumar","doi":"10.5580/1d0e","DOIUrl":"https://doi.org/10.5580/1d0e","url":null,"abstract":"Ten bacterial isolates recovered from the crude oil contaminated sea water samples from a ship yard in Alang coast, Gujarat showed optimum growth in presence of crude oil. The crude oil degrading isolates were identified as species of genera Acinetobacter, Marinococcus, Micrococcus, Planococcus, Methylobacterium, Rhodococcus and Noccardia. All the ten isolates degraded 1% crude oil in Bushnell Haas broth. Highest biodegradation of crude oil was found to be 70% by the isolate M2 which belonged to genus Marinococcus. Other isolates showed biodegradation in the range of 55-30%. On addition of 1% Tween 80 biodegradation reduced in majority of cases. 70% of the bacterial isolates scored positive for biosurfactant production and emulsified toluene however emulsion stability varied drastically among the isolates. None of the biosurfactant producing bacterial isolates was hemolytic.","PeriodicalId":22514,"journal":{"name":"The Internet journal of microbiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83098333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Purified Dextransucrase from Leuconostoc mesenteroides NRRL B-640 Exists as Single Homogeneous Protein: Analysis by Non-denaturing Native-PAGE","authors":"R. K. Purama, A. Goyal","doi":"10.5580/1b1d","DOIUrl":"https://doi.org/10.5580/1b1d","url":null,"abstract":"The extracellular dextransucrase from Leuconostoc mesenteroides NRRL B-640 was purified using polyethylene glycol (PEG-400) fractionation. A 25% (v/v) PEG-400 concentration gave dextransucrase with maximum specific activity of 9.2 U/mg with 16 fold purification in a single step. The purified enzyme by PEG-400 showed multiple protein bands on SDS-PAGE with one prominent band corresponding to the size 180 kDa (12). However, the same PEG-$00 fractionated dextransucrase samples showed single, intact and homogeneous band when analyzed on non-denaturing native-PAGE. This showed that dextransucrase remains in single molecular form in the native state and shows multiple forms only under denaturing conditions when it is heated before loading and when it contained SDS or 2-mercaptoethanol.","PeriodicalId":22514,"journal":{"name":"The Internet journal of microbiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83431759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Surface bone remodeling induced by the Distance-running and medial tibial stress syndrome (shin splints)","authors":"M. Tsili","doi":"10.5580/59e","DOIUrl":"https://doi.org/10.5580/59e","url":null,"abstract":"We based on the theory of Cowin and Firoozbakhsh,(1981) and qualitatively studied the surface remodeling of tibia,induced by the distance -running. We showed that its periosteal and endosteal surfaces will move outwards and inwards respectively. The result predicts “Medial Tibial Stress Syndrome” ( M.T.S.S) or “Shin Splints”, an overuse injury of tibia (Hester, 2006; Romansky and Erfle, 2003; Magnusson et., al., 2003; Couture and Karlson, 2002; Walker, 1999; Bouche, 1999; Amendola et., al.,1999; Beck, 1998; Kaplan et., al.,1997; Monaco et., al.,1997)characterizing by a periosteal inflammation and decreased bone marrow density. M.T.S.S. occurs commonly in runners and due: i)to suddenly increase of the intensity or /and of the duration of training, ii) participation to a new activity, iii) poor footwear and iv) training to hard surfaces ( Hester,2006; Romansky and Karlson, 2003; Bennet, 2001; Kaplan et., al.,1997; Monaco et., al.,1997; Walker, 1999; Bouche, 1999; Amendola, 1999, Cook et., al.,1985). INTRODUCTION Living bone is continually undergoing processes of growth, reinforcement and resorption termed collectively “remodeling”. Accordingly to Frost (1964) there are two kinds of bone remodeling : internal and surface. Many theories of surface bone remodeling have been proposed (Gjelsvik,1973a and 1973b; Cowin and Van-Buskik,1979; Cowin and Firoozbakhsh,1981; Hart et., al.,1982; Hart et., al., 1984; Cowin et.,al., 1985). The purpose of this work is to qualitative study the surface remodeling of tibia, induced by the distance running. For that reason, we will use the propo-sed theory of Cowin –Firoozbakhsh (1981). BIOMECHANICAL ANALYSIS OF THE DISTANCE-RUNNING A person starts distancerunning and suppose that he (she) continues to be training with the same way, for a long time period. Initially the athlete was following a normal lifestyle, by walking with constant velocity vo. Consequently his (her) tibia was in a state at which no remodeling occurred, subjected only to a constant compressive load Go, due to the vertical component of ground reaction force, at late stance phase during walking. Accounting the data from Andriacchi et. al.,(1977); Rohrle et., al., (1984), neglecting the weight of the foot because is small (Harless,1860) and using a linear regression analysis, it is possible to obtain:","PeriodicalId":22514,"journal":{"name":"The Internet journal of microbiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86606422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plasmid Analysis and Prevalence of Multidrug Resistant Staphylococcus aureus Reservoirs in Chennai City, India","authors":"S. Jayaraman, M. Manoharan, Seethalakshmi Illanchezian, Ridhiba Roshini Sekher, Preethy Sathyamurthi","doi":"10.5580/545","DOIUrl":"https://doi.org/10.5580/545","url":null,"abstract":"The present study was designed to investigate the prevalence of multidrug resistant Staphylococcus aureus carriers in Chennai, India. A total of 40 clinical samples comprising of 20 urine and 20 serum samples, collected from healthy individuals of both sex between the age group of 25-50 years in Chennai city were used in this study. About 57.5 % of samples were positive for S. aureus and all of them exhibited b-haemolysis on blood agar. All the isolates were resistant to methicillin, bacitracin, novobiocin and sensitive to norfloxacin. None of the isolates were susceptible to all the antibiotics tested. The MAR index of the isolates ranged between 0.18 and 0.63. All the isolates harboured a 23 kb plasmid.","PeriodicalId":22514,"journal":{"name":"The Internet journal of microbiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88888566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antibacterial And Antifungal Activity Of Buckinghamia Celsissima Leaf Extracts","authors":"I. Cock","doi":"10.5580/56c","DOIUrl":"https://doi.org/10.5580/56c","url":null,"abstract":"The antimicrobial activity of a methanolic extract of Buckinghamia celsissima leaves was investigated by disc diffusion assay against a panel of bacteria and fungi. B. celsissima leaf extractinhibited the growth of 5 of the 14 bacteria tested (36%). Grampositive and Gram-negative bacteria were both affected by B. celsissima extract although Gram-positive bacteria were more susceptible. 3 of 11 Gram-negative (27%) and 2 of the 3 Gram-positive bacteria tested (67%) had their growth inhibited by B. celsissima extract. B. celsissima leaf extractdisplayed antifungal activity towards Candida albicans when tested by disc diffusion assay and inhibited the growth of the","PeriodicalId":22514,"journal":{"name":"The Internet journal of microbiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90595258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}