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Bacterium Isolated (bacterium + isolated)
Selected AbstractsModelling the growth of Weissella cibaria as a function of fermentation conditionsJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2009A. Ricciardi Abstract Aims:, To investigate the effect of pH, water activity (aw) and temperature on the growth of Weissella cibaria DBPZ1006, a lactic acid bacterium isolated from sourdoughs. Methods and Results:, The kinetics of growth of W. cibaria DBPZ1006 was investigated during batch fermentations as a function of pH (4·0,8·0), aw (0·935,0·994) and temperature (10,45°C) in a rich medium. The growth curve parameters (lag time, growth rate and asymptote) were estimated using the dynamic model of Baranyi and Roberts (1994. A dynamic approach to predicting bacterial growth in food. Int J Food Microbiol23, 277,294). The effect of pH, aw and temperature on maximum specific growth rate (,max) were estimated by fitting a cardinal model. ,max under optimal conditions (pH = 6·6, aw = 0·994, T = 36·3°C) was estimated to be 0·93 h,1. Minimum and maximum estimated pH and temperature for growth were 3·6 and 8·15, and 9·0°C and 47·8°C, respectively, while minimum aw was 0·918 (equivalent to 12·2% w/v NaCl). Conclusions:,Weissella cibaria DBPZ1006 is a fast-growing heterofermentative strain, which could be used in a mixed starter culture for making bread. Significance and Impact of the Study:, This is the first study reporting the modelling of the growth of W. cibaria, a species that is increasingly being used as a starter in sourdough and vegetable fermentations. [source] The copper-resistant bacterium ACU isolated from the rhizosphere of Eichhornia crassipes (Mart.) increased the endurance of Potamogeton crispus L. to copper toxicityJOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2008L. Zhang Abstract Aims:, This study aimed to develop endurance to copper stress in Potamogeton crispus L. by inoculation with the anti-copper strain ACU , a novel Enterobacteriaceae bacterium isolated from the rhizosphere of Eichhornia crassipes with high copper-removal ability. Methods and Results:, A spherical copper-resistant bacterium, namely ACU, was isolated from the rhizosphere of E. crassipes. It was demonstrated to have substantial copper-removing capability, even at copper concentrations as high as 69 mg l,1. The 16S rRNA gene sequence of ACU suggested it to be a novel Enterobacteriaceae bacterium most closely related to Providencia sp. With increasing copper concentrations, the growth rate of ACU gradually decreased with a delay in the logarithmic growth phase. ACU demonstrated high copper-removal ability at the lag phase when cultivated in media with high copper concentrations. A 48-kDa extracellular copper-binding protein was detected in ACU. When P. crispus was inoculated with ACU, the growth ability of P. crispus significantly improved at all the tested copper concentrations, and the lethal time for 10 mg l,1 was delayed. Further study revealed that while ACU cells were rarely detected in the culture solution, they were associated with the surface of P. crispus. These findings indicated that ACU grew by anchoring itself on the surface of P. crispus and could increase the ability of P. crispus to resist copper toxicity. Conclusion:, To the best of our knowledge, the Enterobacteriaceae bacterium ACU is a novel nonpathogenic bacterium with high copper-removing ability from water. Significance and Impact of the Study:, This study demonstrated that the Enterobacteriaceae bacterium ACU has potential applicability for use in copper removal and in the protection of aquatic plants in copper-polluted water. [source] Isolation and characterization of a biphenyl-utilizing psychrotrophic bacterium, Hydrogenophaga taeniospiralis IA3-A, that cometabolize dichlorobiphenyls and polychlorinated biphenyl congeners in Aroclor 1221JOURNAL OF BASIC MICROBIOLOGY, Issue 2 2006Adewale J. Lambo A psychrotrophic bacterium isolated from polychlorinated biphenyls (PCBs)-contaminated soil grew on biphenyl as sole carbon and energy source, and actively cometabolized PCBs at low temperature. Analysis of cellular fatty acids indicate that the bacterium is most closely related to Hydrogenophaga taeniospiralis . Resting cells incubated with 10 ppm of Aroclor 1221 at 5 or 30 °C for 48 h removed all mono-, most di-, and several trichlorobiphenyls. At 5 °C, removal of MCBs (monochlorobiphenyls) was between 63 to 89%, DCBs (dichlorobiphenyls) was between 30 to 78%, and TCBs (trichlorobiphenyls) was between 30 to 75%. At 30 °C, removal of MCBs was 100%, DCBs was between 30 to 100%, and TCBs was between 27 to 59%. Congeners with two or more ortho chlorine were generally resistant to degradation. However, removal of di- ortho plus para -substituted congeners at 30 °C and not at 5 °C, suggest that the presence of a para -chlorine enhanced the cometabolism of these congeners at 30 °C. Furthermore, after 72 h, resting cells removed 68 and 83% of 500 ,m of 2,4,-dichlorobiphenyl (2,4,-DCB) and, 35 and 44% of 500 ,m of 2,3-dichlorobiphenyl (2,3-DCB) at 5 and 30 °C, respectively. Analysis of metabolites by GC-MS indicates that the cometabolized 2,3-DCB was completely recovered as 2,3-chlorobenzoic acid (2,3-CBA), while the cometabolized 2,4,-DCB was not completely recovered as chlorobenzoic acid. To our knowledge, it is the first strain of Hydrogenophaga taeniospiralis found to degrade an organic pollutant, and also the first psychrotrophic strain of a member of the genus Hydrogenophaga to grow on biphenyl or cometabolize PCBs at low temperature. Results suggest that the bacterium has potential use in the bioremediation of PCB-contaminated sites in cold regions. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] ANTIOXIDANT ACTIVITY OF FERMENTED BERRY JUICES AND THEIR EFFECTS ON NITRIC OXIDE AND TUMOR NECROSIS FACTOR-ALPHA PRODUCTION IN MACROPHAGES 264.7 GAMMA NO(,) CELL LINEJOURNAL OF FOOD BIOCHEMISTRY, Issue 3 2006TRI VUONG ABSTRACT Serratia vaccinii, a novel bacterium isolated from blueberry microflora, increased the phenolic content of berry juices, and thus increased antioxidant activities. The fermentation capacity of Serratia was investigated with Saskatoon berries, cranberries, strawberries and grapes in both aerobic and anaerobic conditions. It was shown to be compatible with wine yeast in anaerobic fermentations, producing wine with high antioxidant activity. The effects of fermented berry juices were tested on lipopolysaccharide/inferon-gamma-activated macrophages 264.7 NO(,). Data indicated that fermented berry juices strongly inhibited activated-macrophage NO production but induced tumor necrosis factor-alpha production. [source] Some new aspects of the pathology, pathogenesis, and aetiology of disseminated lung lesions in slaughter pigsAPMIS, Issue 5 2003CAMILLA H. LILJEGREN From 40 pigs rejected for human consumption at slaughter due to an apparent presence of pyemic lung lesions (defined as disseminated processes containing pus and/or necrotic material), the lungs, spleen, liver, and kidneys were subjected to an extended macroscopic examination. Several lung lesions were sampled from each animal for histological and bacteriological examination. Samples from the kidneys and spleens were also subjected to bacteriological examination. At gross level, four groups of lung lesions were identified: 1) disseminated foci with contents of pus and/or necrotic material (n=26); 2) disseminated or multifocally located ecchymoses with a central area of fibroplasia (n=9); 3) non-pneumonic lesions, i.e., disseminated areas of atelectasis (n=1) or haemorrhagic areas developing due to the process of slaughter (n=1); and 4) suppurative lesions without a disseminated distribution pattern (n=3). Histologically, the disseminated suppurative/necrotic foci were identified as: A) abscesses (n=10); B) necrotic lesions (n=6); and C) ectatic or ectatic-like bronchioles with contents of pus and necrotic material (n=10). The macroscopic observation of disseminated centres of fibroplasia with peripheral ecchymoses (n=9) was confirmed histopathologically. The livers of five pigs contained multiple areas of chronic interstitial fibrosis related to migration of Ascaris suum larvae ("milk spotted liver"). Such hepatic lesions were significantly (p<0.01) related to the simultaneous occurrence of disseminated pulmonary ecchymoses with a central area of fibroplasia. Generally, all lung lesions of each individual animal contained identical monocultures of bacteria following this pattern: Staphylococcus aureus (abscesses); Actinomyces hyovaginalis (necroses); S. aureus, A. hyovaginalis, and Arcanobacterium pyogenes (ectatic and ectatic-like bronchioles). Areas with fibrosis were sterile or contained bacteria considered to be a result of contamination. Apart from one kidney, from which S. aureus was cultured, all other organs were sterile. It is concluded that difficulties exist in differentiating pulmonary pyemic lesions from non-pyemic lesions at the gross level. Thus, it was not possible to distinguish between abscesses/necroses and ectatic bronchioles, the pathogenesis of the latter being uncertain. However, the chronic non-pyemic lesions related to the migration of A. suum larvae should be identified by the absence of pus/necrosis. S. aureus was predominantly isolated from abscesses, whereas, and most surprisingly, A. hyovaginalis was the dominant bacterium isolated from the pulmonary necroses. [source] | ||||||||||