Inhibition of AckA and Pta Genes Using Two Specific Antisense RNAs Reduced Acetate Accumulation in Batch Fermentation of E. coli BL21 (DE3)
نویسندگان: ثبت نشده
چکیده مقاله:
Expression of foreign proteins in E. coli is normally inhibited by exogenous production of acetate. To overcomethis problem, various strategies have been proposed and tested to reduce the extent of acetate accumulation.Although these strategies can improve the outcome, the implementation of their proposed techniquesis not practical. Because to achieve optimal results, it requires extremely tight control conditionsand the actual cost is very high. Furthermore, a simple knockout mutation of the target metabolic pathwaywould not be appropriate because the acetate pathway plays an important physiological role in E. coli. In thisstudy, we employed an antisense RNA strategy as an elaborated metabolic engineering tool to partially blockbiosynthesis of two major acetate pathway enzymes, acetate kinase (ACK) and phosphotransacetylase(PTA). The fragments of antisense cassette were cloned sequentially in pBluescriptsk+ and completedcassette subcloned in pLT10T3. The function of this cassette was evaluated with RT-PCR and ACK andPTA assay. The effect of cassette on cell physiology was monitored by determination of optical density, glucose consumption and acetate production. We found that the antisense method partially reduced mRNA levels of the target genes, lowered the concentration of acetate in culture media and increased growth rateand final cell density in antisense-regulated strain. This strategy could provide us with a useful, inexpensiveand practical tool to achieve a large-scale protein production system.
منابع مشابه
Down Regulation of ackA-pta Pathway in Escherichia coli BL21 (DE3): A Step Toward Optimized Recombinant Protein Expression System
BACKGROUND One of the most important problems in production of recombinant protein is to attain over-expression of the target gene and high cell density. In such conditions, the secondary metabolites of bacteria become toxic for the medium and cause cells to die. One of these aforementioned metabolites is acetate, which enormously accumulated in the medium, so that both cell and protein yields ...
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Introduction: Escherichia coli (E.coli) is one of the most widely used hosts for the production of recombinant proteins. The main problem in getting high product yields and productivity is the accumulation of acetic acid (acetate) as an unwanted metabolic by-product. In this study, an antisense-based strategy as a metabolic engineering approach was employed to hamper the acetate excretion probl...
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down regulation of acka-pta pathway in escherichia coli bl21 (de3): a step toward optimized recombinant protein expression system
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عنوان ژورنال
دوره 8 شماره 4
صفحات 243- 251
تاریخ انتشار 2010-10-01
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