Backgrounds: Activation of silent biosynthetic gene clusters (BGCs) in marine-derived actinomycete strains is a feasible strategy to discover bioactive natural products. Actinoalloteichus sp. AHMU CJ021, isolated from the seashore, was shown to contain an intact but silent caerulomycin A (CRM A) BGC- cam in its genome. Thus, a genome mining work was preformed to activate the strain’s production of CRM A, an immunosuppressive drug lead with diverse bioactivities.
Results: To well activate the expression of cam , ribosome engineering was adopted to treat the wild type Actinoalloteichus sp. AHMU CJ021. The initial mutant strain XC-11G with gentamycin resistance and CRM A production titer of 42.51 ± 4.22 mg/L was selected from all generated mutant strains by gene expression comparison of the essential biosynthetic gene-camE. The titer of CRM A production was then improved by two strain breeding methods via UV mutagenesis and cofactor engineering-directed increase of intracellular riboflavin, which finally generated the optimal mutant strain XC-11GUR with a CRM A production titer of 113.91 ± 7.58 mg/L. Subsequently, this titer of strain XC-11GUR was improved to 618.61 ± 16.29 mg/L through medium optimization together with further adjustment derived from response surface methodology. In terms of this 14.6 folds increase in the titer of CRM A compared to the initial value, strain XC-GUR could be a well alternative strain for CRM A development.
Conclusions: Our results have constructed an ideal CRM A producer. More importantly, our efforts also have demonstrated the effectiveness of abovementioned combinatorial strategies, which is applicable to the genome mining of bioactive natural products from abundant actinomycetes strains.
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Posted 30 Jul, 2020
On 06 Aug, 2020
On 28 Jul, 2020
On 26 Jul, 2020
Received 26 Jul, 2020
On 24 Jul, 2020
Invitations sent on 24 Jul, 2020
On 23 Jul, 2020
On 23 Jul, 2020
On 20 Jul, 2020
Received 19 Jul, 2020
Received 17 Jul, 2020
On 12 Jul, 2020
On 11 Jul, 2020
Received 08 Jul, 2020
On 07 Jul, 2020
Invitations sent on 07 Jul, 2020
On 07 Jul, 2020
On 06 Jul, 2020
On 06 Jul, 2020
On 29 May, 2020
Received 22 May, 2020
Received 20 May, 2020
Received 18 May, 2020
On 12 May, 2020
On 12 May, 2020
On 11 May, 2020
On 08 May, 2020
Invitations sent on 07 May, 2020
On 04 May, 2020
On 03 May, 2020
On 03 May, 2020
On 03 May, 2020
Posted 30 Jul, 2020
On 06 Aug, 2020
On 28 Jul, 2020
On 26 Jul, 2020
Received 26 Jul, 2020
On 24 Jul, 2020
Invitations sent on 24 Jul, 2020
On 23 Jul, 2020
On 23 Jul, 2020
On 20 Jul, 2020
Received 19 Jul, 2020
Received 17 Jul, 2020
On 12 Jul, 2020
On 11 Jul, 2020
Received 08 Jul, 2020
On 07 Jul, 2020
Invitations sent on 07 Jul, 2020
On 07 Jul, 2020
On 06 Jul, 2020
On 06 Jul, 2020
On 29 May, 2020
Received 22 May, 2020
Received 20 May, 2020
Received 18 May, 2020
On 12 May, 2020
On 12 May, 2020
On 11 May, 2020
On 08 May, 2020
Invitations sent on 07 May, 2020
On 04 May, 2020
On 03 May, 2020
On 03 May, 2020
On 03 May, 2020
Backgrounds: Activation of silent biosynthetic gene clusters (BGCs) in marine-derived actinomycete strains is a feasible strategy to discover bioactive natural products. Actinoalloteichus sp. AHMU CJ021, isolated from the seashore, was shown to contain an intact but silent caerulomycin A (CRM A) BGC- cam in its genome. Thus, a genome mining work was preformed to activate the strain’s production of CRM A, an immunosuppressive drug lead with diverse bioactivities.
Results: To well activate the expression of cam , ribosome engineering was adopted to treat the wild type Actinoalloteichus sp. AHMU CJ021. The initial mutant strain XC-11G with gentamycin resistance and CRM A production titer of 42.51 ± 4.22 mg/L was selected from all generated mutant strains by gene expression comparison of the essential biosynthetic gene-camE. The titer of CRM A production was then improved by two strain breeding methods via UV mutagenesis and cofactor engineering-directed increase of intracellular riboflavin, which finally generated the optimal mutant strain XC-11GUR with a CRM A production titer of 113.91 ± 7.58 mg/L. Subsequently, this titer of strain XC-11GUR was improved to 618.61 ± 16.29 mg/L through medium optimization together with further adjustment derived from response surface methodology. In terms of this 14.6 folds increase in the titer of CRM A compared to the initial value, strain XC-GUR could be a well alternative strain for CRM A development.
Conclusions: Our results have constructed an ideal CRM A producer. More importantly, our efforts also have demonstrated the effectiveness of abovementioned combinatorial strategies, which is applicable to the genome mining of bioactive natural products from abundant actinomycetes strains.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
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