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611.
The culturability of a strictly anaerobic, extremely thermophilic archaeon, Thermococcus peptonophilus (optimal growth temperature: 85° C), was studied during survival stages at various temperatures (98, 85, 70, and 4° C).
Total cell number (determined by DAPI staining), active cells (rhodamine-stained cells), and culturable cells (using most-probable-number)
were counted over time. The number of culturable cells decreased under each condition tested. The total number of cells significantly
decreased only at temperatures close to the maximum for growth (98° C); at this temperature, the cells spontaneously lysed.
Our results suggested that survival at 4° C in oxygenated waters might be a mechanism for the dispersion of extreme thermophiles
in the ocean. In addition, we proved the existence of T. peptonophilus cells in several physiological states: culturable cells, active non-culturable cells, inactive non-culturable cells, and
dead cells. Cell death was caused by cellular lysis.
Received: 5 February 1996 / Accepted: 16 April 1996 相似文献
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The gene coding for the class A beta-lactamase of Citrobacter diversus has been cloned and sequenced. It contains the information for a 294-amino-acid precursor protein, including a 27-residue N-terminal signal peptide. The deduced sequence of the N-terminal portion of the mature protein is in excellent agreement with that determined by microsequencing of the protein and readily explains the pI differences observed between the naturally occurring forms I and II of the enzyme. The sequence of the mature protein exhibits a very high degree of similarity with that of the Klebsiella oxytoca class A beta-lactamase. 相似文献
615.
Predrag Sikiric Sven Seiwerth Gorana Aralica Darko Perovic Mario Staresinic Tomislav Anic Miroslav Gjurasin Ingrid Prkacin Jadranka Separovic Dinko Stancic-Rokotov Martina Lovric-Bencic Darko Mikus Branko Turkovic Ivo Rotkvic Stjepan Mise Rudolf Rucman Marijan Petek Tihomil Ziger Bozidar Sebecic Zoran Ivasovic Vjekoslav Jagic Ljiljana Komericki Ivan Balen Alenka Boban-Blagaic Ivo Sjekavica 《Journal of Physiology》2001,95(1-6):283-288
After demonstration that cysteamine induced duodenal lesions in gastrectomized rats, while a number of antiulcer drugs mitigated these lesions, it was shown that one single intrarectal (i.r.) cysteamine application produced severe colon lesions in acute studies in rats. Thus, the further focus was on the protracted effect of cysteamine challenge (400 mg/kg b.w. i.r.) and therapy influence in chronic experiments in female rats. Regularly, cysteamine colon lesions were markedly mitigated by ranitidine (10), omeprazole (10), atropine (10), methylprednisolone (1), sulphasalazine (50; mg/kg), pentadecapeptide BPC 157 (PL-10, PLD-116; 10 microg or 10 ng/kg). Specifically, after 1 or 3 months following initial challenge (cysteamine 400 mg/kg i.r.) in female rat, the therapy [BPC 157 (PL-10, PLD-116 (10.0 microg or 10.0 ng/kg; i.g., i.p., i.r.), ranitidine, omeprazole, atropine, methylprednisolone, sulphasalazine (i.p.)] reversed the protracted cysteamine colon injury: the 1 week-regimen (once daily application) started after 1 month post-cysteamine, as well as the 2 weeks-regimen (once daily application), which started after 3 months. The effect on recidive lesion was also tested. These cysteamine lesions may reappear after stopping therapy (after stopping therapy for 3 weeks at the end of 2-weeks regimen started in 3 months-cysteamine female rats) in sulphasalazine group, while this reappearance is markedly antagonized in pentadecapeptide BPC 157 (PL-10, PLD-116)-rats (cysteamine-colon lesion still substantially low). 相似文献