scholarly journals Effects of pH and Lactate on Hydrogen Sulfide Production by Oral Veillonella spp.

2014 ◽  
Vol 80 (14) ◽  
pp. 4184-4188 ◽  
Author(s):  
Jumpei Washio ◽  
Yuko Shimada ◽  
Masakazu Yamada ◽  
Ryouichi Sakamaki ◽  
Nobuhiro Takahashi

ABSTRACTIndigenous oral bacteria in the tongue coating such asVeillonellahave been identified as the main producers of hydrogen sulfide (H2S), one of the major components of oral malodor. However, there is little information on the physiological properties of H2S production by oralVeillonellasuch as metabolic activity and oral environmental factors which may affect H2S production. Thus, in the present study, the H2S-producing activity of growing cells, resting cells, and cell extracts of oralVeillonellaspecies and the effects of oral environmental factors, including pH and lactate, were investigated. Type strains ofVeillonella atypica,Veillonella dispar, andVeillonella parvulawere used. TheseVeillonellaspecies produced H2S during growth in the presence ofl-cysteine. Resting cells of these bacteria produced H2S froml-cysteine, and the cell extracts showed enzymatic activity to convertl-cysteine to H2S. H2S production by resting cells was higher at pH 6 to 7 and lower at pH 5. The presence of lactate markedly increased H2S production by resting cells (4.5- to 23.7-fold), while lactate had no effect on enzymatic activity in cell extracts. In addition to H2S, ammonia was produced in cell extracts of all the strains, indicating that H2S was produced by the catalysis of cystathionine γ-lyase (EC 4.4.1.1). Serine was also produced in cell extracts ofV. atypicaandV. parvula, suggesting the involvement of cystathionine β-synthase lyase (EC 4.2.1.22) in these strains. This study indicates thatVeillonellaproduce H2S froml-cysteine and that their H2S production can be regulated by oral environmental factors, namely, pH and lactate.

2014 ◽  
Vol 64 (Pt_5) ◽  
pp. 1501-1506 ◽  
Author(s):  
Bacem Mnasri ◽  
Tian Yan Liu ◽  
Sabrine Saidi ◽  
Wen Feng Chen ◽  
Wen Xin Chen ◽  
...  

Three microbial strains isolated from common beans, 23C2T (Tunisia), Gr42 (Spain) and IE4868 (Mexico), which have been identified previously as representing a genomic group closely related to Rhizobium gallicum , are further studied here. Their 16S rRNA genes showed 98.5–99 % similarity with Rhizobium loessense CCBAU 7190BT, R. gallicum R602spT, Rhizobium mongolense USDA 1844T and Rhizobium yanglingense CCBAU 71623T. Phylogenetic analysis based on recA, atpD, dnaK and thrC sequences showed that the novel strains were closely related and could be distinguished from the four type strains of the closely related species. Strains 23C2T, Gr42 and IE4868 could be also differentiated from their closest phylogenetic neighbours by their phenotypic and physiological properties and their fatty acid contents. All three strains harboured symbiotic genes specific to biovar gallicum. Levels of DNA–DNA relatedness between strain 23C2T and the type strains of R. loessense , R. mongolense , R. gallicum and R. yanglingense ranged from 58.1 to 61.5 %. The DNA G+C content of the genomic DNA of strain 23C2T was 59.52 %. On the basis of these data, strains 23C2T, Gr42 and IE4868 were considered to represent a novel species of the genus Rhizobium for which the name Rhizobium azibense is proposed. Strain 23C2T ( = CCBAU 101087T = HAMBI3541T) was designated as the type strain.


2013 ◽  
Vol 63 (Pt_2) ◽  
pp. 593-598 ◽  
Author(s):  
Bruno Mayeux ◽  
Marie-Laure Fardeau ◽  
Manon Bartoli-Joseph ◽  
Laurie Casalot ◽  
Agnès Vinsot ◽  
...  

A novel anaerobic, Gram-positive, spore-forming, curved rod-shaped, mesophilic and sulfate-reducing bacterium was isolated from pore water collected in a borehole at −490 m in Bure (France). This strain, designated BSREI1T, grew at temperatures between 5 °C and 30 °C (optimum 25 °C) and at a pH between 6 and 8 (optimum 7). It did not require NaCl for growth, but tolerated it up to 1.5 % NaCl. Sulfate, thiosulfate and elemental sulfur were used as terminal electron acceptors. Strain BSREI1T used crotonate, formate, lactate, pyruvate, fructose, glycerol and yeast extract as electron donors in the presence of sulfate. The sole quinone was MK-7. The G+C content of the genomic DNA was 43.3 mol%. Strain BSREI1T had the type strains of Desulfosporosinus lacus (16S rRNA gene sequence similarity of 96.83 %), Desulfosporosinus meridiei (96.31 %) and Desulfosporosinus hippei (96.16 %) as its closest phylogenetic relatives. On the basis of phylogenetic and physiological properties, strain BSREI1T is proposed as a representative of a novel species of the genus Desulfosporosinus , Desulfosporosinus burensis sp. nov.; the type strain is BSREI1T ( = DSM 24089T = JCM 17380T).


1970 ◽  
Vol 24 (1) ◽  
pp. 38-41
Author(s):  
Taslima Taher Lina ◽  
Mohammad Ilias

The in vivo production of soluble inorganic pyrophosphatases (PPases) was investigated in two strains, namely, Vibrio cholerae EM 004 (environmental strain) and Vibrio cholerae O1 757 (ATCC strain). V. cholerae is known to contain both family I and family II PPase coding sequences. The production of family I and family II PPases were determined by measuring the enzyme activity in cell extracts. The effects of pH, temperature, salinity of the growth medium on the production of soluble PPases were studied. In case of family I PPase, V. cholerae EM 004 gave the highest specific activity at pH 9.0, with 2% NaCl + 0.011% NaF and at 37°C. The strain V. cholerae O1 757 gave the highest specific activity at pH 9.0, with media containing 0% NaCl and at 37°C. On the other hand, under all the conditions family II PPase did not give any significant specific activity, suggesting that the family II PPase was not produced in vivo in either strains of V. cholerae under different experimental conditions. Keywords: Vibrio cholerae, Pyrophosphatases (PPases), Specific activityDOI: http://dx.doi.org/10.3329/bjm.v24i1.1235 Bangladesh J Microbiol, Volume 24, Number 1, June 2007, pp 38-41


BIO-PROTOCOL ◽  
2014 ◽  
Vol 4 (23) ◽  
Author(s):  
Melike Çağlayan ◽  
Samuel Wilson

2012 ◽  
Vol 78 (15) ◽  
pp. 5238-5246 ◽  
Author(s):  
Dongfei Han ◽  
Ji-Young Ryu ◽  
Robert A. Kanaly ◽  
Hor-Gil Hur

ABSTRACTA plasmid, pTA163, inEscherichia colicontained an approximately 34-kb gene fragment fromPseudomonas putidaJYR-1 that included the genes responsible for the metabolism oftrans-anethole to protocatechuic acid. Three Tn5-disrupted open reading frame 10 (ORF 10) mutants of plasmid pTA163 lost their abilities to catalyzetrans-anethole. Heterologously expressed ORF 10 (1,047 nucleotides [nt]) under a T7 promoter inE. colicatalyzed oxidative cleavage of a propenyl group oftrans-anethole to an aldehyde group, resulting in the production ofpara-anisaldehyde, and this gene was designatedtao(trans-anetholeoxygenase). The deduced amino acid sequence of TAO had the highest identity (34%) to a hypothetical protein ofAgrobacterium vitisS4 and likely contained a flavin-binding site. Preferred incorporation of an oxygen molecule from water intop-anisaldehyde using18O-labeling experiments indicated stereo preference of TAO for hydrolysis of the epoxide group. Interestingly, unlike the narrow substrate range of isoeugenol monooxygenase fromPseudomonas putidaIE27 andPseudomonas nitroreducensJin1, TAO fromP. putidaJYR-1 catalyzed isoeugenol,O-methyl isoeugenol, and isosafrole, all of which contain the 2-propenyl functional group on the aromatic ring structure. Addition of NAD(P)H to the ultrafiltered cell extracts ofE. coli(pTA163) increased the activity of TAO. Due to the relaxed substrate range of TAO, it may be utilized for the production of various fragrance compounds from plant phenylpropanoids in the future.


2014 ◽  
Vol 64 (Pt_12) ◽  
pp. 4068-4072 ◽  
Author(s):  
Young-Ok Kim ◽  
Sooyeon Park ◽  
Doo Nam Kim ◽  
Bo-Hye Nam ◽  
Sung-Min Won ◽  
...  

A Gram-stain-negative, aerobic, non-spore-forming, non-flagellated and rod-shaped or ovoid bacterial strain, designated RA1T, was isolated from faeces collected from Beluga whale (Delphinapterus leucas) in Yeosu aquarium, South Korea. Strain RA1T grew optimally at 25 °C, at pH 7.0–8.0 and in the presence of 2.0 % (w/v) NaCl. Neighbour-joining, maximum-likelihood and maximum-parsimony phylogenetic trees based on 16S rRNA gene sequences revealed that strain RA1T joins the cluster comprising the type strains of three species of the genus Amphritea , with which it exhibited 95.8–96.0 % sequence similarity. Sequence similarities to the type strains of other recognized species were less than 94.3 %. Strain RA1T contained Q-8 as the predominant ubiquinone and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C18 : 1ω7c and C16 : 0 as the major fatty acids. The major polar lipids of strain RA1T were phosphatidylethanolamine, phosphatidylglycerol, two unidentified lipids and one unidentified aminolipid. The DNA G+C content of strain RA1T was 47.4 mol%. The differential phenotypic properties, together with the phylogenetic distinctiveness, revealed that strain RA1T is separated from other species of the genus Amphritea . On the basis of the data presented, strain RA1T is considered to represent a novel species of the genus Amphritea , for which the name Amphritea ceti sp. nov. is proposed. The type strain is RA1T ( = KCTC 42154T = NBRC 110551T).


2012 ◽  
Vol 56 (8) ◽  
pp. 4146-4153 ◽  
Author(s):  
Zaid Al-Nakeeb ◽  
Ajay Sudan ◽  
Adam R. Jeans ◽  
Lea Gregson ◽  
Joanne Goodwin ◽  
...  

ABSTRACTItraconazole is used for the prevention and treatment of infections caused byAspergillus fumigatus. An understanding of the pharmacodynamics of itraconazole against wild-type and triazole-resistant strains provides a basis for innovative therapeutic strategies for treatment of infections. Anin vitromodel of the human alveolus was used to define the pharmacodynamics of itraconazole. Galactomannan was used as a biomarker. The effect of systemic and airway administration of itraconazole was assessed, as was a combination of itraconazole administered to the airway and systemically administered 5FC. Systemically administered itraconazole against the wild type induced a concentration-dependent decline in galactomannan in the alveolar and endothelial compartments. No exposure-response relationships were apparent for the L98H, M220T, or G138C mutant. The administration of itraconazole to the airway resulted in comparable exposure-response relationships to those observed with systemic therapy. This was achieved without detectable concentrations of drug within the endothelial compartment. The airway administration of itraconazole resulted in a definite but submaximal effect in the endothelial compartment against the L98H mutant. The administration of 5FC resulted in a concentration-dependent decline in galactomannan in both the alveolar and endothelial compartments. The combination of airway administration of itraconazole and systemically administered 5FC was additive. Systemic administration of itraconazole is ineffective against Cyp51 mutants. The airway administration of itraconazole is effective for the treatment of wild-type strains and appears to have some activity against the L98H mutants. Combination with other agents, such as 5FC, may enable the attainment of near-maximal antifungal activity.


2014 ◽  
Vol 64 (Pt_11) ◽  
pp. 3862-3866 ◽  
Author(s):  
Shi Peng ◽  
Dong Dan Hong ◽  
Yang Bing Xin ◽  
Li Ming Jun ◽  
Wei Ge Hong

A Gram-staining-negative, non-motile, catalase- and oxidase-positive strain, designated CCNWSP36-1T, was isolated from the nodule surface of soybean [Glycine max (L.) Merrill] cultivar Zhonghuang 13. The 16S rRNA gene sequence analysis clearly showed that the isolate represented a member of the genus Sphingobacterium . On the basis of pairwise comparisons of 16S rRNA gene sequences, strain CCNWSP36-1T showed 96.8 % similarity to Sphingobacterium nematocida CCTCC AB 2010390T and less than 95.2 % similarity to other members of the genus Sphingobacterium . Growth of strain CCNWSP36-1T occurred at 10–40 °C and at pH 5.0–9.0. The NaCl range (w/v) for growth was 0–4 %. The predominant isoprenoid quinone was MK-7. The polar lipids were phosphatidylethanolamine and several unidentified polar lipids. Sphingolipid was present. The major fatty acids were iso-C15 : 0 and summed feature 3 (comprising C16 : 1ω6c and/or C16 : 1ω7c). The G+C content of the genomic DNA was 41.1 mol%. As the physiological and biochemical characteristics of strain CCNWSP36-1T and the type strains of its closest phylogenetic neighbours showed clear differences, a novel species, Sphingobacterium yanglingense, is proposed. The type strain is CCNWSP36-1T ( = ACCC 19328T = JCM 30166T).


Sign in / Sign up

Export Citation Format

Share Document