Bacillus subtilis mutant strains for enzyme secretion

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Solution Overview

Problem

Current Bacillus subtilis mutant strains have insufficient productivity of proteins such as cellulase and protease, and there is a lack of effective methods for improving their secretory productivity.

Innovation Solution

Development of novel Bacillus subtilis mutant strains through extensive analysis and deletion of large regions of the Bacillus subtilis genome, specifically targeting regions for improved secretory productivity of target proteins like cellulase and protease, by introducing genes with secretion signals and using deletion techniques such as SOE-PCR and LP transformation methods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional Bacillus subtilis strains or single-gene disrupted strains are used, then the strain can be easily manufactured, but the secretory productivity of cellulase and protease remains insufficient

Engineering Contradiction:
Improvesecretory productivity of cellulase and proteaseVSAvoidgenomic structure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The genome of Bacillus subtilis is divided into multiple functional regions, and specific regions are deleted to improve protein secretion. The patent identifies and removes particular genomic segments that hinder secretory productivity, thereby enhancing enzyme production without requiring complete genome redesign.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Specific genomic regions that negatively affect secretory productivity are extracted and removed from the Bacillus subtilis genome. By taking out these inhibitory regions, the patent achieves improved productivity of cellulase and protease while maintaining the overall bacterial structure and essential functions.

Inventive Principle:
Principle #2Taking out (Extraction)

2Productivity

If large regions of the genome are deleted to improve productivity, then secretory productivity increases, but the difficulty of strain construction increases

Engineering Contradiction:
Improvesecretory productivity of target proteinsVSAvoidease of strain construction
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent employs preliminary identification and characterization of genomic regions that affect secretory productivity before performing deletions. By pre-mapping functional regions and their impact on protein secretion, the strain construction process is streamlined, reducing the difficulty of manipulating large genomic regions.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent systematically varies the extent and location of genomic deletions to optimize secretory productivity. By changing parameters such as deletion size, position, and combination of deleted regions, the patent identifies optimal strain configurations that balance productivity improvement with construction feasibility.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP1944365B1Novel bacillus subtilis mutant strain
Publication Date: 2012.03.14 KAO CORP
  • EP1944365B1 patent drawingFigure 1
  • EP1944365B1 patent drawingFigure 2
  • EP1944365B1 patent drawingFigure 3

AI summary

Novel Bacillus subtilis mutant strains having good productivity of various enzymes are provided through extensive analysis of strains that are derived from Bacillus subtilis via gene disruption. The Bacillus subtilis mutant strains according to the present invention have genomic structures prepared by deletion of regions listed in the columns for deficient regions. Each of these Bacillus subtilis mutant strains exerts significantly improved secretory productivity of a protein when a gene encoding such a secretory target protein is introduced so that it can be expressed, compared with a case in which the same gene is introduced into a wild-type strain.