From Natural Microbe Screening to Sustained Chitinase Activity in Exogenous Hosts

Area of Science:

• Synthetic biology
• Biotechnology
• Enzyme engineering

Background:

• Chitinase is crucial for breaking down chitin, the second most abundant biopolymer.
• Achieving sustained chitinase activity in heterologous hosts is challenging due to toxicity and environmental condition mismatches.

Purpose of the Study:

• To discover and characterize new chitinase genes from environmental microbes.
• To achieve stable, long-term chitinase expression and activity in heterologous hosts for industrial applications.

Main Methods:

• Screening ocean water samples for chitinase activity.
• Whole genome sequencing, gene selection, and optimization of heterologous expression.
• Engineering ribosome binding sites and identifying a novel promoter for inducible expression.

Main Results:

• Identified and expressed a functional chitinase gene in standard (Escherichia coli) and nonstandard (Roseobacter denitrificans) hosts.
• Achieved sustained chitinase activity for over 21 days in engineered hosts.
• Developed a pipeline extendable to other functions and identified naturally occurring microbes for direct use.

Conclusions:

• The study successfully engineered stable chitinase activity in heterologous hosts, overcoming previous limitations.
• The developed pipeline offers a versatile platform for synthetic biology and enzyme applications.
• This work contributes novel genetic parts and methods for enhanced biocatalysis.