Whole-cell catalytic system and applications thereof

1. A method of activating gene expression, comprising a step of contacting a recombinant microbial cell with a medium-chain or long-chain alkane or a medium-chain or long-chain fatty acid methyl ester;

wherein the recombinant microbial cell expresses a protein having 90% or more sequence identity to SEQ ID NO:45 and comprises a gene for activated expression;

wherein the recombinant microbial cell further expresses an alkane transporter and an alkane monooxygenase;

wherein the alkane monooxygenase is a cytochrome P450, the cytochrome P450 consists of a CYP153A, a ferredoxin, and a ferredoxin reductase;

wherein the CYP153A, the ferredoxin, and the ferredoxin reductase are derived from Marinobacter aquaeoli VT8, the CYP153A is reconstructed to exclude a transposon at a position corresponding to an amino terminus of the ferredoxin; and

wherein the alkane transporter is an AlkL protein derived from Pseudomonas putida , and the gene expression is activated without adding isopropyl β-D-1-thiogalactopyranoside (IPTG) or dicyclopropylketone (DCPK) as an inducer.

2. The method of claim 1 , wherein the medium-chain or long-chain alkane is a straight-chain alkane having a carbon chain length of C8 or greater.

3. The method of claim 1 , wherein the medium-chain or long-chain fatty acid methyl ester is a straight-chain saturated fatty acid methyl ester having a carbon chain length of C8 or greater.

4. The method of claim 3 , wherein the straight-chain saturated fatty acid methyl ester is methyl laurate.

5. The method of claim 1 , wherein the gene encodes a cytochrome P450.

6. A whole-cell catalytic system regulated by a medium-chain or long-chain alkane or a medium-chain or long-chain fatty acid methyl ester, comprising a recombinant microbial cell expressing a protein having 90% or more sequence identity to SEQ ID NO:45 and an alkane monooxygenase;

wherein the recombinant microbial cell further expresses an alkane transporter, the alkane transporter is an AlkL protein derived from Pseudomonas putida , and the whole-cell catalytic system is regulated without adding isopropyl β-D-1-thiogalactopyranoside (IPTG) or dicyclopropylketone (DCPK) as an inducer; and

wherein the alkane monooxygenase is a cytochrome P450, the cytochrome P450 consists of a CYP153A, a ferredoxin, and a ferredoxin reductase, the CYP153A, the ferredoxin, and the ferredoxin reductase are derived from Marinobacter aquaeoli VT8, and the CYP153A is reconstructed to exclude a transposon at a position corresponding to an amino terminus of the ferredoxin.

7. A method of preparing a medium-chain or long-chain alkane terminal oxidation product, comprising the following steps of:

(a) providing a recombinant microorganism, comprising a first gene encoding an alkane monooxygenase, and a second gene encoding a protein having 90% or more sequence identity to SEQ ID NO:45;

(b) incubating the recombinant microorganism in a culture medium containing a carbon source; and

(c) adding a medium-chain or long-chain alkane or a medium-chain or long-chain fatty acid methyl ester to the culture medium for a predetermined period of time to obtain the medium-chain or long-chain alkane terminal oxidation product, wherein the recombinant microorganism further comprises a gene encoding an alkane transporter, the alkane transporter is an AlkL protein derived from Pseudomonas putida , and the medium-chain or long-chain alkane terminal oxidation product is prepared without adding isopropyl β-D-1-thiogalactopyranoside (IPTG) or dicyclopropylketone (DCPK) as an inducer;

wherein the alkane monooxygenase is a cytochrome P450, the cytochrome P450 consists of a CYP153A, a ferredoxin, and a ferredoxin reductase, the CYP153A, the ferredoxin, and the ferredoxin reductase are derived from Marinobacter aquaeoli VT8, and the CYP153A is reconstructed to exclude a transposon at a position corresponding to an amino terminus of the ferredoxin.

8. The method of claim 7 , wherein the medium-chain or long-chain alkane is a straight-chain alkane having a carbon chain length of C8 or greater.

9. The method of claim 7 , wherein the medium-chain or long-chain fatty acid methyl ester is a straight-chain saturated fatty acid methyl ester having a carbon chain length of C8 or greater.

10. The method of claim 9 , wherein the straight-chain saturated fatty acid methyl ester having a carbon chain length is methyl laurate.

11. The method of claim 7 , wherein the medium-chain or long-chain alkane terminal oxidation product is an alkanol, an alkanediol, an alkanoic acid, an alkane dioic acid, a dicarboxylic acid methyl ester, an alcohol acid, or an alcohol amine having a carbon chain length of C8 or greater.

12. The method of claim 7 , wherein the expression of the alkane transporter is regulated by rhamnose.