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1.
Dialister pneumosintes has been indicated as a potentially new periodontopathic species. This study evaluated the prevalence of this microorganism in saliva and subgingival biofilm from subjects with different periodontal conditions. Subgingival biofilm and saliva samples from 48 subjects with periodontal health (PH) and 116 patients with chronic periodontitis (CP) were obtained. DNA was extracted from the samples and the presence of D. pneumosintes was determined by PCR. Differences in clinical parameters and frequency of D. pneumosintes between groups were sought by Mann-Whitney, Chi-square and Fisher's exact tests. Overall, D. pneumosintes was detected in 47.8% of the biofilm samples, but only in 3% of saliva samples. CP patients presented a significantly greater mean prevalence of this species in sites with periodontal health and periodontal infection (43.5+/-7.4% and 62.1+/-6.4%, respectively) than PH subjects (29.4+/-7.9%) (Mann-Whitney; p<0.01). Moreover, significant associations between the prevalence of D. pneumosintes and pocket depth (p=0.001), attachment loss (p=0.001) and bleeding on probing (GLM, p=0.014) were observed after adjusting for age and gender. These findings corroborate the association of D. pneumosintes with periodontitis. 相似文献
2.
Nishiyama SA Nakano V Velásquez-Melendez G Avila-Campos MJ 《Canadian journal of microbiology》2008,54(4):326-330
Viral and bacterial associations appear to be implicated in the development of periodontal infections. Little information is available describing the periodontopathic agents in root canals with necrotic pulp. In this study, the occurrence and the combinations among herpes simplex virus type 1 (HSV-1) and Dialister pneumosintes, Tannerella forsythia, and Treponema denticola in patients with chronic periodontitis and necrotic pulp were evaluated. Clinical samples from healthy subjects and patients with periodontal or pulp infections were analyzed using a nested polymerase chain reaction PCR to detect HSV and PCR to detect the 3 periodontal bacteria. The presence of Tannerella forsythia and Treponema denticola was observed in healthy, periodontitis, and necrotic pulp patients. HSV was observed in periodontitis and necrotic pulp patients, and no healthy subject harbored D. pneumosintes or HSV. The occurrence of Tannerella forsythia was not statistically significant in patients with necrotic pulp (P = 0.704). Periodontal bacteria were observed varying from 10.3% to 20.7% in periodontitis and necrotic pulp patients. The presence of Treponema denticola - HSV association was predominant in patients showing necrotic pulp (24.1%); however, HSV alone was observed in one patient with periodontitis and in another patient with necrotic pulp. The presence of double association among bacteria or bacteria - HSV could indicate a role in both periodontitis and necrotic pulp, and Tannerella forsythia - Treponema denticola - HSV and Tannerella forsythia - D. pneumosintes - Treponema denticola - HSV associations might be important in periodontitis. 相似文献
3.
Anther culture response was examined in five Solanum genotypes. Large genotypic differences exist in response to culture and liquid culture media were found to be superior to agar solidified media systems. Pre-treatment effects on embryoid induction were also investigated and two of the genotypes displayed differential response to temperature stress pretreatment. In general the beneficial effect of charcoal in the media was confirmed. Successful embryoid production and plantlet regeneration was obtained from the wild potato species, Solanum papita. The influence of sucrose concentration on embryoid production was also investigated. Large genotype by sucrose interactions were detected and this was mainly due to the differential response of the tuberosum clones to increasing sucrose concentration when compared with S. papita. Embryoids were produced from this species in media containing 15% sucrose although the optimum concentration of sucrose for embryoid production was 9%. The possible role of anther culture techniques in gene introgression and potato improvement is discussed. 相似文献
4.
Giovanni Mita Carmela Gerardi Antonio Miceli Roberto Bollini Pietro De Leo 《Plant cell reports》1994,13(7):406-410
Summary An in vitro culture of Alkanna tinctoria Tausch cells was set up in order to investigate the possibility of producing alkannin, a red naphthoquinone naturally present in the root bark of this plant. Furthermore, an in vitro culture of callusderived roots was established and the production of alkannin evaluated. In the different experimental conditions investigated, differences in the production of alkannin derivatives as well as in the type of pigments produced, were observed. The potential use of this technology is discussed. 相似文献
5.
Colletotrichum acutatum has become an increasingly important plant pathogen worldwide. With this background, a study was carried out to characterize
the toxicity of liquid culture media from different isolates and to identify some properties of the toxic principles. Liquid
culture media from all isolates were toxic to rubber leaves and induced the anthracnose symptoms. Toxicity of the culture
filtrate was not host specific and toxic substances were thermostable. Acetone soluble fraction of the culture filtrates retained
the toxic activity and it was effective even at a concentration of 700 μg dry mycelium mass/ml.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
6.
Long Liu Guocheng Du Jian Chen Miao Wang Jun Sun 《Biotechnology and Bioprocess Engineering》2008,13(3):269-273
The principal objective of this study was to assess the effects of culture modes including batch culture, pulse fed-batch
culture, constant feeding rate fed-batch culture, and exponential fed-batch culture on the production of hyaluronic acid (HA)
by Streptococcus zooepidemicus. Batch cultures had the highest levels of HA productivity, whereas fed-batch cultures were more favorable with regard to
cell growth, and exponential fed-batch cultures evidenced the highest cell concentrations. A two-step culture model was proposed
to enhance HA production: an exponential fed-batch culture was conducted prior to 8 h and then sucrose supplementation was
applied for 8 h to start the batch fermentation of S. zooepidemicus. HA production and productivity were increased by 36 and 37% in the proposed two-step culture process as compared with that
observed in the batch culture, respectively. The proposed two-step culture model can be applied in the production of secondary
metabolites, and particularly of the exopolysaccharides. 相似文献
7.
Mycelium of shiitake (Lentinula edodes) was cultured continuously in liquid medium. The liquid culture was carried out for the production of liquid spawn in the
cultivation of this mushroom on synthetic sawdust substrate, and its performance was compared with that of the solid spawn.
The initial colonization in culture bags was faster with the solid spawn than with the liquid spawn, but after this stage
CO2 production was higher with the liquid spawn than with the solid spawn. For harvesting sufficient amount of good quality mushrooms,
120 d of incubation in bags was needed with the solid spawn, but this was reduced to 90 d for the sawdust blocks using liquid
spawn of less than 50 d old. If continuous culture of the liquid spawn was prolonged over 50 d, immature fruit-bodies or their
initials formed during the period of bag incubation. The solid subcultures of the liquid spawns retained the fruiting characteristics
acquired in the liquid culture. Liquid culture could be a useful tool for breeding of mushrooms. 相似文献
8.
Aydoğan H Basustaoğlu A Yildiran ST Küçükkaraaslan A Yavuz Sanisoğlu S Kubar A 《Microbiological research》2006,161(1):55-58
The purpose of this in vitro study was to determine the ability of seeded and not-seeded commercial pediatric blood culture bottles to support the growth of the most frequently responsible microorganisms for bacterial meningitides (Neisseria meningitidis, and Haemophilus influenzae). Tests have been carried out with an automated colorimetric pediatric blood culture system, BacTAlert, Organon Teknika. Bottles were inoculated with X-V factors and serial dilutions of the each bacterium in six times (10(1)-10(6) colony forming unit [CFU]/ml). The bottles, which were supplemented with X-V factors, proved to be effective and time to detection (TTD) was shorter than the un-seeded bottles (p0.05). Time difference between seeded and not-seeded bottles was getting greater at high dilutions of both bacteria. We consider that in presence of a few bacteria, the seeding of bottles with X-V factors is very critical obtaining N. meningitidis, and H. influenzae as the causative agents of meningitidis. The recovery rate of the microorganisms, which were isolated from cerebrospinal fluid by using the X-V factor-seeded blood culture bottles, is therefore higher than with the conventional culture methods. 相似文献
9.
Summary. This paper reports an efficient protoplast culture technique, the “extra thin alginate film” technique. The development of
this improved method of protoplast culture was an outcome of an assessment of the efficiency and shortcomings of various protoplast
culture techniques. The efficiency of this technique was evaluated with two model plant systems, viz., Nicotiana tabacum and Lotus corniculatus, and a comparison was made with the “thin alginate layer” technique, another efficient protoplast culture system. Results
indicate that the culture technique with extra thin alginate film is as efficient as the technique with thin alginate layer,
with many additional advantages. The present innovation overcomes most of the limitations of protoplast culture techniques
described so far and can now be applied to a wide variety of crops to check its general applicability.
Correspondence and reprints: Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar 143 005,
India. 相似文献
10.
The aim of this study was to culture sponge juveniles from larvae. Starting from larvae we expected to enhance the survival
and growth, and to decrease the variation in these parameters during the sponge cultures. First, settlement success, morphological
changes during metamorphosis, and survival of Dysidea avara, Ircinia oros, Hippospongia communis, under the same culture conditions, were compared. In a second step, we tested the effects of flow and food on survival and
growth of juveniles from Dysidea avara and Crambe crambe. Finally, in a third experiment, we monitored survival and growth of juveniles of D. avara and C. crambe transplanted to the sea to compare laboratory and field results. The results altogether indicated that sponge culture from
larvae is a promising method for sponge supply and that laboratory culture under controlled conditions is preferred over sea
cultures in order to prevent biomass losses during these early life stages. 相似文献
11.
Muhannad I. Massadeh Wan Mohtar Wan Yusoff Othman Omar Jalil Kader 《Biotechnology letters》2001,23(21):1771-1774
Sugar cane bagasse was subjected to a mixed culture, solid substrate fermentation with Trichoderma reesei QM9414 and Aspergillus terreus SUK-1 to produce cellulase and reducing sugars. The highest cellulase activity and reducing sugar amount were obtained in mixed culture. The percentage of substrate degradation achieved employing mixed culture was 26% compared to 50% using separate cultures of the two molds. This suggests that the synergism of enzymes in mixed culture solid substrate fermentation have lower synergism than in pure culture. 相似文献
12.
Kee-Yoeup Paek Eun-Joo Hahn Sung-Ho Son 《In vitro cellular & developmental biology. Plant》2001,37(2):149-157
Summary The application of bioreactor culture techniques for plant micropropagation is regarded as one of the ways to reduce production
cost by scaling-up and automation. Recent experiments are restricted to a small number of species that, however, demonstrate
the feasibility of this technology. Periodic immersion liquid culture using ebb and flood system and column-type bubble bioreactors
equipped with a raft support system to maintain plant tissues at the air and liquid interface were found to be suitable for
micropropagation of plants via the organogenic pathway. Balloon-type bubble bioreactors proved to be fit for micropropagation
via somatic embryogenesis with less shear stress on cultured cells. Several cultivars of Lilium were successfully propagated using a two-stage culture method in one bioreactor. A large number of small-scale segments were
cultured for 4 wk with periodic immersion liquid culture to induce multiple bulblets from each segment, then the bulblet induction
medium was changed into bulblet growth medium by employing a submerged liquid bioreactor system. This culture method resulted
in a nearly 10-fold increase in bulblet growth compared to conventional culture with solid medium. About 20 000 cuttings of
virus-free potato could be obtained from 120 singlenode explants in a 20-liter balloon-type bubble bioreactor after 8 wk of
culture. The percentage of ex vitro survival and root induction of the cuttings was more than 95%. Other successful results were obtained from the micropropagation
and transplant production of chrysanthemum, sweetpotato, Chinese foxglove. Propagation systems via somatic embryogenesis in
Acanthopanax koreanum and thornless Aralia elata were established using a liquid suspension of embryogenic determined cells. More than 500 000 somatic embryos in different
stages were harvested from a 10-liter balloon-type bubble bioreactor after a 6-wk culture. Further development of these embryos
in solid medium and eventually in the field was successful. The bioreactor system could reduce initial and operational cost
for micropropagation, but further development of sophisticated technology might be needed to apply this system to plant micropropagation
industries. 相似文献
13.
B. M. R. Harvey G. Bowden C. Reavey C. Selby 《Plant Cell, Tissue and Organ Culture》1994,37(3):271-276
Fluridone, an inhibitor of abscisic acid (ABA) biosynthesis, strongly stimulated rooting of nodal stem segments of potato (Solanum tuberosum L.) cultivar Arran Banner cultured in darkness on tuberisation medium. Inclusion of 10-6 M ABA in the culture medium prevented this rooting response, indicating that root proliferation in the presence of fluridone could be due to inhibition of ABA synthesis. The rooting response to fluridone (increased total root number and root fresh weight) was obtained only at high sucrose concentrations (0.175 and 0.234 M) and was demonstrated with two potato cultivars and two culture media; one which favoured tuberisation and one which did not. Shoot numbers were also increased, but to a lesser extent than root numbers, and total fresh weight of plant material per culture was greatly increased by inclusion of both fluridone (10-6 or 10-5 M) and 0.234 M sucrose in the culture medium. The role of sucrose was not simply osmotic because when the osmolarity of fluridone medium was increased using mixtures of mannitol and sucrose, no root proliferation occurred unless sucrose predominated in the mixture. 相似文献
14.
In this work we show how three types of cucumber in vitro cultures – leaf callus culture, cytokinin dependent cell suspension and liquid culture of meristematic clumps – influence the metabolite profiles of plants in the first generative progeny. Based on this study we conclude that there exists a specific and inheritable metabolic fingerprint reflecting the history of previous generations, probably related to specific stress factors accompanying the passage through different types of culture. The leaf callus culture generated the highest heritable differences in metabolite content and was the most distinctly separated cluster in PCA analysis. The smallest number of variable metabolites characterizes the plants regenerated from cytokinin dependent cell suspension whereas the liquid culture of meristematic clumps induced slightly more changes. Changes induced by these two culture types were not as pronounced as in the case of leaf callus culture. However the plants after these types of culture were well separated from the control on PCA diagram. The highest changes were over 2-fold increases in cystin and galactose-6-P and over 2-fold decreases in aspartate, myo-inositol, hydroxylamine, phosphate and putrescine. These changes concerned the plants, which were one generation after the leaf callus culture. The possible nature of observed heritable changes is discussed. 相似文献
15.
Jeong-Jin Park Sung-Yong H. Yoon Hwa Young Cho Seok Young Son Hong Soon Rhee Jong Moon Park 《Plant Cell, Tissue and Organ Culture》2006,86(2):257-269
The optimal timing of elicitation was determined for the production of benzophenanthridine alkaloids (BPAs) by Eschscholtzia californica cell culture. Upon elicitation, 7-day old cells produced more alkaloids than 14-day old cells (5.1 times for sanguinarine and 2.7 times for dihydrosanguinarine). We presumed that these alkaloids are growth-rate-associated secondary metabolites in E. californica cell culture. Although the specific productivity of alkaloids were higher in 7-day old culture, the total cell mass of 7-day old culture was about half that of 14-day old culture. In order to increase the overall productivity, sucrose was added to the 14-day old culture before the addition of elicitor. By this way, cells in the stationary phase (14-day old culture) could be switched to the cells in the logarithmic growth phase (similar to 7-day old culture). Total production of alkaloids was increased by adding sucrose; especially the production of sanguinarine was increased as high as 5.7 times of the control. To find out the protein level changed by the elicitation, proteins extracted from whole cell were separated by using two-dimensional gel electrophoresis. The patterns of the gels were different and little correlation among the proteins could be observed. And Western blotting was employed to check the expression level of selected five enzymes, these enzymes believed to be involved in BPAs production, resulting in up-regulated with elicitor addition. 相似文献
16.
Kyung-Min Choi Young-Kwon Seo Hee-Hoon Yoon Kye-Yong Song Soon-Yong Kwon Hwa-Sung Lee Jung-Keug Park 《Biotechnology and Bioprocess Engineering》2007,12(6):601-609
To support and enhance thein vitro growth and activity of mesenchymal stem cells (MSCs), the cell culture medium may be supplemented with various proteins and
factors to mimic the physiological environment in which the cells optimally proliferate and differentiate. In this study,
the effects of mechanical factors on cellular metabolic responses were investigated experimentally using a bioreactor. The
effects of various chemical factors, such as growth factors, cytokines, and hormones, were also investigated. Based on previous
reports demonstrating the important roles of mechanical factors in the growth and activity of MSCs, we sought to evaluate
the effects of mechanical stimuli on the proliferation of bone marrow-derived MSCs using a cell training bioreactor that imposed
cyclic mechanical stretch, with parameters of 240 min/day, 0.03 Hz, and 5–15% strain. The application of cyclic stretch (5–15%
strain) to the MSCs enhanced their proliferation during the early stage (3 days), but not the late stage (14 days), of batch
culture. Mechanical stretch did not increase the release of lactate dehydrogenase (LDH) from the MSCs during culture. Appropriate
levels of mechanical stretch (5–10% strain) increased collagen synthesis, but did not alter MSC surface antigen expression.
It is thought that the appropriate level of mechanical stretch was able to serve as a potent positive modulator of MSC proliferation
during the initial stages of culture. 相似文献
17.
H. A. Pedrozo Z. Schwartz H. Nakaya J. L. Harrison D. D. Dean M. L. Wiederhold B. D. Boyan 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1995,177(4):415-425
A novel organ culture system has been developed to study the regulation of statoconia production in the gravity sensing organ in Aplysia californica. Statocysts were cultured in Leibovitz (L15) medium supplemented with salts and Aplysia haemolymph for four days at 17°C. The viability of the system was evaluated by examining four parameters: statocyst morphology, the activity of the mechanosensory cilia in the statocyst, production of new statoconia during culture and change in statoconia volume after culture. There were no morphological differences in statocysts before and after culture when ciliary beating was maintained. There was a 29% increase in the number of statoconia after four days in culture. Mean statocyst, statolith and statoconia volumes were not affected by culture conditions. The presence of carbonic anhydrase in the statocysts was shown using immunohistochemistry. When statocysts were cultured in the presence of 4.0 × 10–4
M acetazolamide to inhibit the enzyme activity, there was a decrease in statoconia production and statoconia volume, indicating a role for this enzyme in statoconia homeostasis, potentially via pH regulation. These studies are the first to report a novel system for the culture of statocysts and show that carbonic anhydrase is involved in the regulation of statoconia volume and production. 相似文献
18.
M. Shirzadegan M. Christey E. D. Earle J. D. Palmer 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1989,77(1):17-25
Summary We compared Brassica campestris mitochondrial and chloroplast DNAs from whole plants and from a 2-year-old cell culture. No differences were observed in the chloroplast DNAs (cpDNAs), whereas the culture mitochondrial DNA (mtDNA) was extensively altered. Hybridization analysis revealed that the alterations are due entirely to rearrangement. At least two inversions and one large duplication are found in the culture mtDNA. The duplication element is shown to have the usual properties of a plant mtDNA high frequency recombination repeat. The culture mtDNA exists as a complex heterogeneous population of rearranged and unrearranged molecules. Some of the culture-associated rearranged molecules are present in low levels in native plant tissue and appear to have sorted out and amplified in the culture. Other mtDNA rearrangements may have occurred de novo. In addition to alterations of the main mitochondrial genome, an 11.3 kb linear mtDNA plasmid present in whole plants is absent from the culture. Contrary to findings in cultured cells of other plants, small circular mtDNA molecules were not detected in the B. campestris cell culture. 相似文献
19.
Anandan D Marmer WN Dudley RL 《Journal of industrial microbiology & biotechnology》2007,34(5):339-347
Aspergillus tamarii expresses an extracellular alkaline protease that we show to be effective in removing hair from cattle hide. Large quantities
of the enzyme will be required for the optimization of the enzymatic dehairing process so the growth conditions for maximum
protease expression by A. tamarii were optimized for both solid-state culture on wheat bran and for broth culture. Optimal protease expression occurred, for
both cultural media, at initial pH 9; the culture was incubated at 30 °C for 96 h using a 5% inoculum. The crude enzyme was
isolated, purified and characterized using MALDI TOF TOF. The alkaline protease was homologous to the alkaline protease expressed
by Aspergillus viridinutans.
Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information
and does not imply recommendation or endorsement by the U.S. Department of Agriculture. 相似文献
20.
The objective of this study is to improve cephalosporin C (CPC) production by optimization of medium and culture conditions.
A statistical method was introduced to optimize the main culture medium. The main medium for CPC production was optimized
using a statistical method. Glucose and corn steep liquor (CSL) were found to be the most effective factors for CPC production.
Glucose and CSL were optimized to 2.84 and 6.68%, respectively. CPC production was improved 50% by feeding of 5% rice oil
at day 3rd and 5th day during the shake flask culture ofC. acremonium M25. The effect of agitation speeds on CPC production in a 2.5-L bioreactor was also investigated with fed-batch mode. The
maximum cell mass (54.5 g/L) was obtained at 600 rpm. However, the maximum CPC production (0.98 g/L) was obtained at 500 rpm.
At this condition, the maximum CPC production was improved about 132% compared to the result with batch flask culture. 相似文献