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51.
Noomen Hmidet Nedra El Hadj Ali Nahed Zouari-Fakhfakh Anissa Haddar Moncef Nasri Alya Sellemi-Kamoun 《Journal of industrial microbiology & biotechnology》2010,37(9):983-990
This study is concerned with the co-production of alkaline proteases and thermostable α-amylase by some feather-degrading
Bacillus strains: B. mojavensis A21, B. licheniformis NH1, B. subtilis A26, B. amyloliquefaciens An6 and B. pumilus A1. All strains produced both enzymes, except B. pumilus A1, which did not exhibit amylolytic activity. The best enzyme co-production was obtained by the NH1 strain when chicken
feathers were used as nitrogen and carbon sources in the fermentation medium. The higher co-production of both enzymes by
B. licheniformis NH1 strain was achieved in the presence of 7.5 g/l chicken feathers and 1 g/l yeast extract. Strong catabolic repression
on protease and α-amylase production was observed with glucose. Addition of 0.5% glucose to the feather medium suppressed
enzyme production by B. licheniformis NH1. The growth of B. licheniformis NH1 using chicken feathers as nitrogen and carbon sources resulted in its complete degradation after 24 h of incubation at
37°C. However, maximum protease and amylase activities were attained after 30 h and 48 h, respectively. Proteolytic activity
profiles of NH1 enzymatic preparation grown on chicken feather or casein-based medium are different. As far as we know, this
is the first contribution towards the co-production of α-amylase and proteases using keratinous waste. Strain NH1 shows potential
use for biotechnological processes involving keratin hydrolysis and industrial α-amylase and proteases co-production. Thus,
the utilization of chicken feathers may result in a cost-effective process suitable for large-scale production. 相似文献
52.
All trans retinal was attached to both the primary face and the secondary face of beta-cyclodextrin via a Schiff base linkage, analogous to that in rhodopsin. The new models were evaluated and compared with n-butylamine retinylidene Schiff base for their rates of hydrolysis, and factors that influence such rates. Competition studies using adamantane carboxylate demonstrated the kinetic trap theory by diminishing the binding of retinal in the cyclodextrin, thereby augmenting the rate of hydrolysis. NMR experiments indicate that the retinylidene is most probably bound in the form of a dimer. 相似文献
53.
球孢白僵菌Beauveria bassiana (Balsamo) Vuillemin是最重要的昆虫病原真菌, 广泛用于防治世界各地的多种害虫。本研究评价了球孢白僵菌9个菌株对赤拟谷盗Tribolium castaneum (Herbst)成虫的致病性。将15头赤拟谷盗成虫浸入到4个浓度 (1×106, 1×107, 1×108 和 1×109 个分生孢子/mL)的白僵菌菌株中 20 s, 14 d内每日记录成虫的死亡率。结果表明: IRAN 440C菌株对赤拟谷盗成虫的LC50最低 (5.04×107 个分生孢子/mL), IRAN 187C菌株的最高(5.05×108 个分生孢子/mL); DEBI 005菌株对赤拟谷盗成虫的LT50最短(2.88 d), DEBI 014菌株的最长(4.96 d)。根据LC50, LT50和死亡率结果得出IRAN 440C是防治这一害虫的理想菌株。 相似文献
54.
Tohidi M Ghasemi A Hadaegh F Arbabi S Hosseini Isfahani F 《Biological trace element research》2011,143(2):835-843
This study aims at determining the association between markers of hepatic injury and serum, urinary, and intra-erythrocyte
magnesium concentrations and dietary magnesium intake in obese children and adolescents. In a case–control study, 42 obese
children and adolescents (8–18 years) and 42 sex- and puberty-matched controls were studied. Serum, urinary, and intra-erythrocyte
magnesium levels, indices of insulin sensitivity, and liver enzymes were measured. Dietary magnesium intake was assessed using
a food frequency questionnaire. Obese children and adolescents exhibited insulin resistance as determined by a higher fasting
insulin and the HOMA-IR (p < 0.001) and lower QUICKI indices (p = 0.001); in addition these subjects had significantly higher intra-erythrocyte magnesium (IEM) concentrations, than non-obese
ones (3.99 ± 1.05 vs. 3.35 ± 1.26 mg/dL of packed cell; p = 0.015). Among liver enzymes, only gamma-glutamyl transferase (GGT) was significantly higher in obese than in non-obese
subjects (22.7 ± 9.4 vs. 17.1 ± 7.9 U/l; p = 0.002). A positive association was found between GGT and IEM in both groups; however in multivariate analysis, in obese
subjects, only GGT (p = 0.026) and, in non-obese subjects, only age (p = 0.006) remained as significant predictors of IEM. In conclusion, increased IEM concentration was seen in insulin-resistant
obese children and adolescents; furthermore, serum GGT was associated with IEM, independently of body mass index and HOMA-IR. 相似文献
55.
56.
Samira Riabi Rafik Harrath Imed Gaaloul Lamjed Bouslama Dorsaf Nasri Mahjoub Aouni Sylvie Pillet Bruno Pozzetto 《Journal of biomedical science》2014,21(1):50
Background
Decay Accelerating Factor (DAF) and Coxsackievirus-Adenovirus Receptor (CAR) have been identified as cellular receptors for Coxsackie B viruses (CV-B). The aim of this study is to elucidate the different binding properties of CV-B serotypes and to find out if there are any amino acid changes that could be associated to the different phenotypes.Twenty clinical CV-B isolates were tested on CaCo-2 cell line using anti-DAF (BRIC216) and anti-CAR (RmcB) antibodies. CV-B3 Nancy prototype strain and a recombinant strain (Rec, CV-B3/B4) were tested in parallel. The P1 genomic region of 12 CV-B isolates from different serotypes was sequenced and the Trans-Epithelial Electrical Resistance (TEER) along with the virus growth cycle was measured.Results
Infectivity assays revealed clear differences between CV-B isolates with regard to their interactions with DAF and CAR. All tested CV-B isolates showed an absolute requirement for CAR but varied in their binding to DAF. We also reported that for some isolates of CV-B, DAF attachment was not adapted. Genetic analysis of the P1 region detected multiple differences in the deduced amino acid sequences.Conclusion
Within a given serotype, variations exist in the capacity of virus isolates to bind to specific receptors, and variants with different additional ligands may arise during infection in humans as well as in tissue culture. 相似文献57.
André Dautigny Ellen M. Prager Danièle Pham-Dinh Jacqueline Jollès Farzad Pakdel Bjørn Grinde Pierre Jollès 《Journal of molecular evolution》1991,32(2):187-198
Summary The complete 129-amino-acid sequences of two rainbow trout lysozymes (I and II) isolated from kidney were established using
protein chemistry microtechniques. The two sequences differ only at position 86, I having aspartic acid and II having alanine.
A cDNA clone coding for rainbow trout lysozyme was isolated from a cDNA library made from liver mRNA. Sequencing of the cloned
cDNA insert, which was 1 kb in length, revealed a 432-bp open reading frame encoding an amino-terminal peptide of 15 amino
acids and a mature enzyme of 129 amino acids identical in sequence to II. Forms I and II from kidney and liver were also analyzed
using enzymatic amplification via PCR and direct sequencing; both organs contain mRNA encoding the two lysozymes. Evolutionary
trees relating DNA sequences coding for lysozymesc and α-lactalbumins provide evidence that the gene duplication giving rise to conventional vertebrate lysozymesc and to lactalbumin preceded the divergence of fishes and tetrapods about 400 Myr ago. Evolutionary analysis also suggests
that amino acid replacements may have accumulated more slowly on the lineage leading to fish lysozyme than on those leading
to mammal and bird lysozymes. 相似文献
58.
Jalili F Khavazi K Pazira E Nejati A Rahmani HA Sadaghiani HR Miransari M 《Journal of plant physiology》2009,166(6):667-674
Salinity stress is of great importance in arid and semi-arid areas of the world due to its impact in reducing crop yield. Under salinity stress, the amount of 1-aminocyclopropane-1-carboxylate (ACC), a precursor for ethylene production in plants, increases. Here, we conducted research under the hypothesis that isolated ACC deaminase-producing Pseudomonas fluorescens and Pseudomonas putida can alleviate the stressful effects of salinity on canola (Brassica napus L.) growth. The experiments were conducted in the Soil and Water Research Institute, Tehran, Iran. Seven experimental stages were conducted to isolate and characterize ACC deaminase-producing Pseudomonas fluorescens strains and to determine factors enhancing their growth and, consequently, their effects on the germination of canola seeds. Under salinity stress, in 14% of the isolates, ACC deaminase activity was observed, indicating that they were able to utilize ACC as the sole N-source. Bacterial strains differed in their ability to synthesize auxin and hydrogen cyanide compounds, as well as in their ACC deaminase activity. Under salinity stress, the rate of germinating seeds inoculated with the strains of ACC deaminase-producing Pseudomonas fluorescens and Pseudomonas putida, and seedling growth was significantly higher. These results indicate the significance of soil biological activities, including the activities of plant growth-promoting bacteria, in the alleviation of soil stresses such as salinity on plant growth. 相似文献
59.
60.