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21.
The effect of overall oxygen mass transfer coefficient (kLa) on the conversion of xylose to xylitol by Candida guilliermondii FTI 20037 was investigated in batch experiments. Rice straw hemicellulose hydrolysate obtained by acid hydrolysis was employed as a xylose-rich medium. The results showed that this bioconversion strongly depended on the aeration rate. The maximum volumetric productivity (0.52 g/l hу) and the highest xylitol yield (0.73 g/g) were achieved at an overall oxygen mass transfer coefficient of 15 hу. Under these conditions 80% efficiency in relation to theoretical yield was attained. 相似文献
22.
Electron microscopy of ultrathin sections of leaves of symptomless Himalaya Giant blackberry and of the virus indicator species, Rubus macraei, showing severe leaf curl symptoms following graft inoculation with scions from this blackberry, detected highly flexuous virus‐like particles with an unusual ‘beaded’ structure. Such particles were restricted to a few vascular cells and were distinct from P‐protein common in some such cells. This virus, provisionally named Hawaiian rubus leaf curl virus (HRLCV), symptomlessly infected a wide range of Rubus species and cultivars. Badnavirus‐like bacilliform particles were observed in some cells of a single R. macraei plant showing leaf curl symptoms following graft inoculation with the causal agent of this disease symptom from Himalaya Giant blackberry after passage through red raspberry, but not in any other material. PCR with primer sets for the badnaviruses Rubus yellow net virus and Gooseberry veinbanding associated virus, showed that no Rubus sources studied contained these viruses. However, using a sequence‐specific primer set designed from the sequence of the product generated with a badnavirus degenerate primer set, a specific product was amplified from healthy plants of all of 16 raspberry cultivars and two Rubus species, but not from 16 blackberry cultivars (including cv. Himalaya Giant). All of these sources were free from viruses known to occur in Rubus. Sequence analysis of this product showed no homology with any known badnavirus, or with any other published sequences. It seems most likely therefore that a region of the raspberry genome has been amplified using the degenerate badnavirus primer set and that it is absent from the blackberry genome. 相似文献
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Sabine JM de Brouwer Floris W Kraaimaat Fred CGJ Sweep Marjonne CW Creemers Timothy RDJ Radstake Antoinette IM van Laarhoven Piet LCM van Riel Andrea WM Evers 《Arthritis research & therapy》2010,12(3):R89
Introduction
Stressful events are thought to contribute to the aetiology, maintenance and exacerbation of rheumatic diseases. Given the growing interest in acute stress responses and disease, this review investigates the impact of real-life experimental psychosocial, cognitive, exercise and sensory stressors on autonomic, neuroendocrine and immune function in patients with inflammatory rheumatic diseases. 相似文献25.
I. C. Roberto S. Sato I. M. de Mancilha M.E. S. Taqueda 《Biotechnology letters》1995,17(11):1223-1228
Summary The bioconversion of xylose to xylitol by the yeast Candida guilliermondii FTI 20037 was evaluated under different nutritional conditions using rice straw hemicellulose hydrolysate. Statistical designs were used to determine the fermentation medium composition. Ammonium sulfate and rice bran have been identified as required nutrients in the hydrolysate since there was a significant interaction between them. In the presence of both nutrients, the xylitol yield factor (Yp/s) and volumetric productivities (Qp) were 0.68 g/g and 0.54 g/L.h, respectively. 相似文献
26.
Walter Carvalho Julio C. Santos Larissa Canilha Joo B. Almeida e Silva Maria G.A. Felipe Ismael M. Mancilha Silvio S. Silva 《Process Biochemistry》2004,39(12):2135-2141
Candida guilliermondii FTI 20037 cells were entrapped in Ca-alginate beads and used for xylitol production from sugarcane bagasse hemicellulosic hydrolysate in a stirred tank reactor (STR). Screening design and response surface methodologies were used to determine adequate cultivation conditions for this fermentation system. Quadratic models were fitted to the experimental data by regression analysis, considering the yield (YP/S) and the productivity (QP) of the xylose-to-xylitol bioconversion as dependent variables. Using a five-fold concentrated hydrolysate, air flowrate of 1.30 l/min, agitation speed of 300 rpm, initial cell concentration of 1.4 g/l and value 6.0 for the initial pH of the fermentation medium resulted in a xylitol production of 47.5 g/l after 120 h of fermentation, corresponding to a YP/S of 0.81 g/g and to a QP of 0.40 g/l h. 相似文献
27.
Complete nucleotide sequences of bovine alpha S2- and beta-casein cDNAs: comparisons with related sequences in other species 总被引:2,自引:0,他引:2
Stewart AF; Bonsing J; Beattie CW; Shah F; Willis IM; Mackinlay AG 《Molecular biology and evolution》1987,4(3):231-241
The nucleotide sequences corresponding to bovine alpha S2- and beta- casein
mRNAs have been determined by cDNA analysis. Both sequences appear to be
complete at their 5' ends. The nucleotide sequence of alpha S2-casein, when
compared with the corresponding cavine A sequence, helps to define the
boundaries of a large amino acid repeat (approximately 80 residues) whereas
comparisons with the nucleotide sequences of rat gamma- and mouse
epsilon-casein mRNAs also reveal extensive sequence similarities. An
alignment of these four sequences shows that the divergence of their
translated regions has been characterized by the duplication and deletion
of discrete segments of sequence that probably correspond to exons. A high
degree of nucleotide substitution is also found when the four sequences are
compared, except for well-conserved leader-peptide and phosphorylation-site
sequences and, to a lesser extent, the 5'-untranslated regions. Similar
comparison of the bovine and rat beta-caseins shows that their divergence
has involved a high rate of nucleotide substitution but that no major
insertions or deletions of sequence have occurred. The several splice sites
that have veen defined in the rat beta-casein gene are likely to have been
conserved in the bovine. The contrasting evolutionary histories of the
alpha- and beta-casein coding sequences correlate with the distinctive
functions of these proteins in the casein micelle system in milk.
相似文献
28.
I C Roberto S Sato I M de Mancilha 《Journal of industrial microbiology & biotechnology》1996,16(6):348-350
The effect of inoculum level on xylitol production byCandida guilliermondii was evaluated in a rice straw hemicellulose hydrolysate. High initial cell density did not show a positive effect in this bioconversion since increasing the initial cell density from 0.67 g L–1 to 2.41 g L–1 decreased both the rate of xylose utilization and xylitol accumulation. The maximum xylitol yield (0.71 g g–1) and volumetric productivity (0.56 g L–1 h–1) were reached with an inoculum level of 0.9 g L–1. These results show that under appropriate inoculum conditions rice straw hemicellulose hydrolysate can be converted into xylitol by the yeastC. guilliermondii with efficiency values as high as 77% of the theoretical maximum. 相似文献
29.
The xylose conversion into by Candida guilliermondii was evaluated in sugar cane bagasse hemicellulosic hydrolysate. The effect of air flow rates of 0.4, 0.6 and 0.8 vvm cn xylitol formation was studied. In addition, inoculum previously adapted to the hydrolysate was also tested in the fermentation carried out at 0.6 vvm. The results showed that xylitol production depends markedly on the aeration rate and on the previous adaptation of the yeast to the hydrolysate. When the highest productivity of xylitol was 0.39 g/l × h. However, during the fermentation carried out at an air flow rate of 0.6 vvm with adapted inoculum, the productivity increased to 0.65 g/l × h. Furthermore, the adapted cells performed quite well in the presencel of acetic concentrations of about 4.5 g/l in the medium. 相似文献
30.
ABEL TRUJILLO-OCAMPO HYUN-WOO CHO AMANDA C. HERRMANN WILFREDO RUIZ-VAZQUEZ ANDREW B. THORNTON HONG HE DAN LI MARIAM A. QAZILBASH QING MA STEVEN A. PORCELLI ELIZABETH J. SHPALL JEFFREY MOLLDREM JIN S. IM 《Cytotherapy》2018,20(8):1089-1101