Metabolic design of
Corynebacterium glutamicum
by CRISPR-MAD7
for lycopene production using glucose from straw
Demographic and Agricultural Context
China, home to over 1.43 billion residents in 2023,
houses a quarter of the world's population. With 14% of
its citizens aged 65 or older, the nation mirrors a
global demographic shift where countries with aging
populations have grown from 23.5% to 44% between 1950
and 2015. Concurrently, China's agricultural dominance
is evident in its leadership in GDP, producing 133
million tons of wheat and significantly contributing to
worldwide corn and rice outputs. However, the challenge
of managing unused crop residues emerges, posing both
environmental and economic concerns.
Global Challenges
The United Nations emphasizes the overarching issue of
the global aging population, which impacts sectors like
labor, finance, housing, and social security. There's an
imperative need to amplify senior health initiatives and
promote effective anti-aging medications. Alongside, the
annual yield of three billion tons of food worldwide
brings forth considerable agricultural waste. The
conventional practice of burning residues, particularly
straw, harms the environment and entails economic
inefficiencies. Thus, innovative, eco-friendly, and
economical solutions are paramount for environmental
conservation and energy repurposing.
Lycopene as a Solution
In the quest for anti-aging solutions, antioxidants play
a pivotal role. However, many synthetic antioxidants are
riddled with challenges such as potential organ harm,
inadequate heat stability, and diminished
efficacy—sometimes just a sixth of their natural
counterparts. Lycopene, a naturally occurring
antioxidant known for vision protection, emerges as a
promising solution. Its potency lies in its robust
antioxidant activity, capabilities to reduce lipid
oxidation, enhance immune cells, safeguard against
oxidative damage, and foster lymphocyte growth, thereby
bolstering overall immunity.
Innovative Extraction Method
Currently, lycopene extraction relies on plant
extraction, chemical synthesis, and biosynthesis. Plant
extraction, despite being natural, can compromise purity
due to low lycopene content and heavy reliance on
organic solvents, leading to environmental degradation.
Chemical synthesis, on the other hand, can introduce
toxicity and carcinogenicity, posing safety risks. Our
aim is to pivot to a biosynthetic approach, utilizing
Corynebacterium glutamicum. By harnessing its
straw decomposition products as a carbon source and
deploying the CRISPR-MAD7(Cas12a) system, we anticipate
a high-yield lycopene output. This method not only
addresses the environmental issues stemming from straw
burning but also offers a potent antioxidant solution to
combat aging-related challenges.