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固定化红曲葡萄糖母液流加发酵红曲色素的研究 总被引:4,自引:1,他引:4
对固定化红曲(Monascus purpureus),在生物反应器中流加葡萄糖母液发酵生产红曲色素进行了研究,建立了简单的数学模型控制流加。结果表明:当总葡萄糖母液浓度为150g/L时,以90g/L初始葡萄糖母液开始发酵,当流加因子K=0.0013时,变速流加发酵组的色素浓度比非流加发酵组的色价提高32%。 相似文献
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Kuwae S Ohda T Tamashima H Miki H Kobayashi K 《Journal of Bioscience and Bioengineering》2005,100(5):502-510
Antithrombin is a serine protease inhibitor that inactivates several coagulation proteases, primarily thrombin and factor Xa. The Chinese hamster ovary (CHO) cell line transfected with a vector expressing recombinant human antithrombin (rAT) and a selectable marker, glutamine synthetase (GS), was cultivated in a 2-l fed-batch culture process using serum-free, glutamine-free medium. To maximize the rAT yield, effects of culture pH, balanced amino acid feeding, and an increased glutamate concentration on cell metabolism and rAT production were investigated. When cells were grown at pH values of 6.6, 6.8, 7.0, and 7.2, the maximum cell density and maximum lactate concentration decreased with decreasing pH. The highest production level of rAT was obtained at culture pH 6.8 due to the extended culture lifetime. Compared to the imbalanced amino acid feeding at culture pH 6.8, the balanced amino acid feeding increased the amount of rAT activity by 30% as a result of an increased viable cell number. A decrease in the specific glucose consumption rate (q(Glc)) with increasing culture time was observed in all the above-mentioned experiments, while the glucose concentration was maintained above 0.7 g l(-1). In addition, a decrease in the specific rAT production rate (q(rAT)) was observed after the depletion of lactate in the late cultivation stage. Taken together, these results suggest that the reduced availability of cellular energy caused by the decrease in q(Glc) and depletion of lactate led to the decrease in q(rAT). This decrease in q(rAT) was partially prevented by increasing the residual glutamate concentration from 1 mM to 7 mM, thus resulting in an additional 30% increase in the amount of rAT activity. The optimized fed-batch culture process yielded 1.0 g l(-1) rAT at 287 h of cultivation. 相似文献
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研究了不同初始酒精浓度对醋酸发酵的影响及分批补料对贝壳钙源发酵的影响.醋酸茵在初始酒精浓度为6%vol时的产酸速率、菌体生长速率都较快,且其发酵周期适中.在此基础上,研究了分批补料发酵过程中菌体生长、产物及副产物的合成规律.结果表明:分批补料发酵通过改善发酵的环境条件,进而提高钙离子的转化率.与分批发酵相比,发酵中钙离子的转化率由18.08%提高到了37.33%,钙离子的总浓度由16.96mg/mL提高到了33.99mg/mL.因此,分批补料发酵可显著提高代谢产物的产量,促进贝壳钙源的生物转化率. 相似文献
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流加法发酵生产较高酒精度蜂蜜酒 总被引:1,自引:0,他引:1
为生产较高酒精度的纯发酵蜂蜜酒,对流加法发酵蜂蜜酒的工艺进行了研究。以市售天然纯蜂蜜为主要原料,经稀释、巴氏灭菌、调整发酵液成分后,采用活性干酵母混合发酵,得到了酒精度较高,口感、色泽、风味都较好的纯发酵蜂蜜酒。通过正交试验确定其最佳工艺参数为:酵母菌接种量1.2‰,分别在发酵第5d、6d共流加蜂蜜20mL,发酵14d得到16.8%vol以上的蜂蜜酒。 相似文献
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以酿酒酵母为发酵菌种,使用自主优化筛选配制的糖蜜培养基,分别采用残糖反馈分批补料和连续流加补料方式,优化发酵工艺条件以提高发酵液中菌体密度。残糖反馈分批补料,拟设定3个梯度,分别控制对数期发酵液中残糖含量在0.5%~1.5%,1.0%~2.0%,1.5%~2.5%。三次试验结果分别为,试验1菌体培养32 h时达到最大生物量,为28.88 g/L;试验2菌体培养52 h时达到最大生物量,为27.43 g/L;试验3菌体培养24 h时达到最大生物量,为22.06 g/L。通过连续流加补料培养菌体,结果培养30 h时达到最大生物量,为29.29 g/L。 相似文献
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The objective was to determine the effects of linoleic acid and different isomers of conjugated linoleic acid (CLA) at different concentrations on hepatic lipid and glucose metabolism in the bovine. Monolayer cultures of hepatocytes obtained from 7- to 10-d-old Holstein bull calves were exposed to treatments from 16 to 64 h after plating. The treatments included 1.0 mM palmitic acid plus either 0.1 or 1.0 mM of cis-9, cis-12 linoleic acid, cis-9, trans-11 CLA, or trans-10, cis-12 CLA. Metabolism of palmitic acid to cellular triacylglycerol (TAG) was decreased when media contained cis-9, trans-11 compared with trans-10, cis-12 CLA. Total cellular TAG content was increased for the CLA isomers compared to cis-9, cis-12 linoleic acid. Both CLA isomers increased palmitic acid incorporation into phospholipids, cholesterol, and media triacylglycerol compared with cis-9, cis-12 linoleic acid at a concentration of 1.0 mM. Increasing the concentration of treatment fatty acids from 0.1 to 1.0 mM decreased oxidation of palmitic acid to acid-soluble products, but no effects of fatty acids were observed. There was no treatment effect on rates of gluconeogenesis from propionic acid. Overall, CLA isomers elicited changes in palmitic acid metabolism to cellular and media triacylglycerol, and cellular phospholipids and cholesterol, but had little or no effect on other measured pathways of lipid metabolism or gluconeogenesis in bovine hepatocytes. 相似文献
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The present paper reports the study of the optimal conditions for grape (Vitis vinifera cv. Barbera) cell suspensions in batch and fed-batch bioreactor cultures, in order to specifically improve the production of mono-glucosylated stilbenes, which are resveratrol derivatives. These compounds are physiologically as active as free resveratrol in cardio- and chemoprotection, but are more stable and bioavailable after ingestion through diet. In fed-batch conditions the production of mono-glucosides was considerably increased together with that of free resveratrol. For the first time, an elicitor (chitosan) was tested in a bioreactor system, demonstrating its efficacy in inducing the production of stilbenes. The bioreactor culture conditions also allowed the accumulation of other polyphenols, such as catechins. The vast majority of the produced compounds was released into the culture media, which represents a relevant advantage for the recovery of specific molecules or of polyphenol-enriched mixtures. These results represent a further step toward the employment of grape cells in fed-batch cultures, as a promising alternative to whole plant extraction for the industrial production of plant polyphenols, considering the necessity for developing sustainable processes. 相似文献
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为了提高红曲菌(Monascus purpureus)FM-4000的红色素色价,采用优化种龄和接种量的方法,探索了分批补料发酵基质对红色素色价的影响。结果表明,最佳种龄为6 h二级种子液,接种量10%(V/V),在发酵48 h时补加20 g/L黄豆粉,在发酵84 h时补加0.5 mol/L氨水,在发酵96 h时补加60 g/L米粉。在此工艺条件下,摇瓶发酵红曲菌FM-4000的红色素色价达到135.61 U/mL,相对初始摇瓶红曲菌FM-4000的红色素色价提高了37.25%;在5 L发酵罐中对红曲菌FM-4000进行分批补料发酵培养,红色素色价可达145 U/mL。 相似文献
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Inflammation of ruminal epithelium may occur during ruminal acidosis as a result of translocation and interaction of ruminal epithelial cells (REC) with molecules such as lipopolysaccharide (LPS). Such inflammation has been reported to alter cellular processes such as nutrient absorption, metabolic regulation, and energy substrate utilization in other cell types but has not been investigated for REC. The objectives of this study were to investigate the effects of LPS on metabolism of short-chain fatty acids by primary REC, as well as investigating the effects of media containing short-chain fatty acids on the proinflammatory response. Ruminal papillae from 9 yearling Speckle Park beef heifers were used to isolate and culture primary REC. Cells were grown in minimum essential medium (MEM) for 12 d before use and then reseeded in 24-well culture plates. The study was conducted as a 2 × 2 factorial, where cells were grown in unaltered MEM (REG) or medium containing 2 mM butyrate and 5 mM propionate (SCFA) with (50,000 EU/mL; +LPS) or without LPS (?LPS) for 24 h. Supernatant samples were collected for analysis of glucose and SCFA consumption. Cells were collected to determine the expression of mRNA for genes associated with inflammation (TNF, IL1B, CXCL2, CXCL8, PTGS2, and TLR4), purinergic signaling (P2RX7, ADORAB2, and CD73), nutrient transport [SLC16A1 (MCT1), SLC16A3 (MCT4), SLC5A8, and MCU], and cell metabolism [ACAT1, SLC2A1 (GLUT1), IGFBP3, and IGFBP5]. Protein expression of TLR4 and ketogenic enzymes (BDH1 and HMGCS1) were also analyzed using flow cytometry. Statistical analysis was conducted with the MIXED model of SAS version 9.4 (SAS Institute Inc., Cary, NC) with medium, LPS exposure, and medium × LPS interaction as fixed effects and animal within plate as a random effect. Cells tended to consume more glucose when exposed to LPS as opposed to no LPS exposure (31.8 vs. 28.7 ± 2.7), but consumption of propionate and butyrate was not influenced by LPS. Expression of TNF and IL1B was upregulated when exposed to LPS, and expression of CXCL2 and CXCL8 increased following LPS exposure with SCFA (medium × LPS). For cells exposed to LPS, we found a downregulation of ACAT1 and IGFBP5 and an upregulation of SLC2A1, SLC16A3, MCU, and IGFBP3. Medium with SCFA led to greater expression of MCU. SLC16A1 was upregulated in cells incubated with SCFA and without LPS compared with the other groups. Protein expression of ketogenic enzymes was not affected; however, BDH1 mean fluorescence intensity (MFI) expression tended to be less in cells exposed to LPS. These data are interpreted to indicate that when REC are exposed to LPS, they may increase glucose metabolism. Moreover, transport of solutes was affected by SCFA in the medium and by exposure to LPS. Overall, the results suggest that metabolic function of REC in vitro is altered by a proinflammatory response, which may lead to a greater glucose requirement. 相似文献
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Chemostat cultures of NS0 cell lines were carried out at dilution rates ranging from 0.8 d(-1) to 0.2 d(-1). Compared with the control, the viable cell density of the Bcl-2 cell line was approximately 10% higher at 0.8 d(-1) and increased to 55% when the dilution rate was reduced to 0.2 d(-1). As the dilution rate was reduced, the viability of the two cultures diverged reaching a difference of 43% at 0.2 d(-1). The specific growth rate of the control cells was the same as the dilution rate down to a value of 0.6 d(-1). By contrast, the specific growth rate of Bcl-2 cells was parallel to the dilution rate down to a value as low as 0.3 d(-1). For both NS0 cell lines, the G1 cell population decreased, while the S and G2/M cell populations increased as the dilution rate was reduced. The antibody titer of the control cells increased from 7 to 21 microg.ml(-1) as the dilution rate was reduced from 0.8 to 0.2 d(-1). With an initial increase from 2 to 15 microg.ml(-1) as the dilution rate was reduced from 0.8 to 0.4 d(-1), the antibody titer of the Bcl-2 cells remained constant as the dilution rate was further reduced to 0.2 d(-1). A good correlation between specific antibody production rate and the percentage of G2/M cells was observed. 相似文献
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