Lactococcus lactis A32 Strain for High-Yield Nisin Production

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Solution Overview

Problem

There is a lack of bacterial strains with high nisin yield, which is a concern for the food and medical industries seeking efficient and safe preservatives, as conventional preservatives raise safety and health concerns.

Innovation Solution

The development of Lactococcus lactis subsp. Lactis A32, a genetically stable strain with a high nisin yield, obtained through atmospheric room temperature plasma and compound mutation, which produces nisin at levels over 5066.58 IU/mL, significantly higher than initial strains, and is resistant to nisin at 15000 IU/mL.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional preservatives are used, then preservation effectiveness is achieved, but safety and health concerns increase

Engineering Contradiction:

Improvepreservation effectivenessVSAvoidsafety and health concerns

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful effect of conventional preservatives on health into a benefit by using nisin, a natural antimicrobial peptide produced by Lactococcus lactis subsp. lactis A32. This biological preservative maintains preservation effectiveness while eliminating the safety concerns associated with conventional chemical preservatives, thus converting a harmful situation into a beneficial one

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Productivity

If bacterial strains with high nisin yield are used, then nisin production efficiency is improved, but such strains are currently lacking in literature

Engineering Contradiction:

Improvenisin yieldVSAvoidavailability of suitable strains

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent applies parameter changes by optimizing cultivation conditions including temperature (28-32°C), pH (6.8-7.2), and medium composition (CM1 medium with specific carbon and nitrogen sources) to maximize nisin production. These parameter optimizations enable the Lactococcus lactis subsp. lactis A32 strain to achieve high nisin yields of over 5066.58 IU/mL, addressing the scarcity of high-yield strains

Inventive Principle:

Principle #35Parameter changes

3Productivity

If nisin production is increased, then preservation capability is enhanced, but genetic stability of the strain must be maintained

Engineering Contradiction:

Improvenisin titreVSAvoidgenetic stability

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The patent implements feedback control by monitoring nisin production levels and strain performance across multiple generations. The Lactococcus lactis subsp. lactis A32 strain demonstrates stable nisin production over 20 generations with consistent titres, indicating that feedback mechanisms are in place to maintain both high productivity and genetic stability simultaneously

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS11746368B1<i>Lactococcus lactis </i>subsp. <i>lactis </i>A32, derived product and use thereof

Publication Date: 2023.09.05 QILU UNIVERSITY OF TECHNOLOGY (SHANDONG ACADEMY OF SCIENCES)

AI summary

The present invention provides a Lactococcus lactis subsp. lactis A32, derived product and use thereof, the present invention falls in the technical field of microorganisms. In the present invention, the Lactococcus lactis subsp. lactis A32 is obtainable by compound mutation on the basis of the original strain L. lactis lxl. Experiments showed that, compared with nisin titre of the original strain L. lactis lxl, the Lactococcus lactis subsp. lactis A32 has high nisin yield, and the nisin titre has been improved for 3˜4 times (over 5066.58 IU/mL); in the meanwhile, the growth curve of the Lactococcus lactis subsp. lactis A32 is slightly longer than the original strain L. lactis lxl and biomass peaks of them are basically consistent. The present invention has laid a foundation for large scale production of nisin.