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首页> 外文期刊>Biotechnology Progress >Effects of pH Strategy on endo- and exo-Metabolome Profiles and Sodium Potassium Hydrogen Ports of beta-Lactamase-Producing Bacillus licheniformis
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Effects of pH Strategy on endo- and exo-Metabolome Profiles and Sodium Potassium Hydrogen Ports of beta-Lactamase-Producing Bacillus licheniformis

机译：pH策略对产β-内酰胺酶的地衣芽孢杆菌内外代谢组谱和钾钾氢端口的影响

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The effects of pH strategy on endo- and exo-metabolome profiling of beta-lactamase-producing Bacillus licheniformis were investigated at controlled-pH (pH_C=6.5,6.75,7.0,7.25,7.5) and uncontrolled-pH (pH_(UC)=7.5) values using a glucose-based defined medium.The cell concentration profiles were not affected by the pH considerably within the investigated range.The highest enzyme activities were obtained as A=54 U cm~(-3) at pH_C=6.75 among the controlled-pH operations and as A=57 U cm~(-3) at the uncontrolled-pH pHuc=7.5.At all conditions,oxygen transfer resistances were more effective,whereas the limitation increased in the beta-lactamase production phase.Total intracellular amino acid concentrations ranged between 0.142 and 6.766 kg m~(-3) (0.0058-0.277 g g_(cell)~(-1)),and their concentrations in terms of kg m~(-3) were,at most,580-fold higher than the extracellular concentrations.Methionine/cysteine concentrations were generally higher than the other intracellular amino acids,whereas asparagine concentration was the highest in the fermentation broth.From Na~+,K~+,and H~+ ion profiles,Na~+-K~+ antiport and Na~+-H~+ symport were found to be present within the system,and a correlation was found between organic acid transport and Na~+-H~+ symport.Intracellular organic acid concentrations in terms of kg m~(-3) were,at most,20-fold higher than that of the extracellular,and with the increase in pH,extracellular acetic acid concentration increased and lactic acid concentration decreased.Average permeability coefficient values of organic acids were found to be in the range from 4.10 x 10~(-7) to 4.32 x 10~(-6) cm s~(-1) for the growth phase (0 < t < 6 h) and decreased at least 3-fold in the beta-lactamase production phase (8 < t < 15 h),indicating the considerable structural change of the lipid membrane during the fermentation.
机译：在控制pH（pH_C = 6.5,6.75,7.0,7.25,7.5）和非控制pH（pH_（UC）= 7.5）值使用葡萄糖基定义的培养基。在研究范围内，pH值对细胞浓度分布的影响不明显。在pH_C = 6.75时，酶的最高活性为A = 54 U cm〜（-3）。在pH值为7.5的非控制条件下，pH值控制为A = 57 U cm〜（-3）。在所有条件下，抗氧转移性更有效，而在β-内酰胺酶生产阶段的限制增加了。氨基酸浓度范围为0.142至6.766 kg m〜（-3）（0.0058-0.277 g g_（cell）〜（-1）），以kg m〜（-3）计的最大浓度为580 -蛋氨酸/半胱氨酸浓度通常高于其他细胞内氨基酸在发酵液中天冬酰胺的浓度最高。从Na〜+，K〜+和H〜+离子分布图可以看出，Na〜+ -K〜+反向转运和Na〜+ -H〜+共转运。在系统中，有机酸的运输与Na〜+ -H〜+的共迁移有相关性。以kg m〜（-3）计，细胞内有机酸的浓度最多比细胞外的高20倍，有机酸的平均渗透系数值在4.10 x 10〜（-7）到4.32 x 10〜（-6）的范围内，随着pH的增加，细胞外乙酸的浓度增加而乳酸的浓度降低。 cm s〜（-1）处于生长期（0

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