Abstract
Abstract
Background
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 had constructed an ideal CRM A producer. More importantly, our efforts also had demonstrated the effectiveness of abovementioned combinatorial strategies, which is applicable to the genome mining of bioactive natural products from abundant actinomycetes strains.
Funder
National Natural Science Foundation of China
Provincial Natural Science Research Project of Anhui Colleges and Universities
Open Project Program of Guangdong Key Laboratory of Marine Materia Medica & Key Laboratory of Tropical Marine Bio-resources and Ecology, SCSIO, CAS
Open Project Program of Key Laboratory of Functional Small Organic Molecule, Ministry of Education, Jiangxi Normal University
Guangdong Provincial Key Laboratory of Genome Read and Write
Shenzhen Engineering Laboratory for Innovative Molecular Diagnostics
Guangdong Provincial Academician Workstation of BGI Synthetic Genomics
Publisher
Springer Science and Business Media LLC
Subject
Applied Microbiology and Biotechnology,Bioengineering,Biotechnology
Cited by
6 articles.
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