Title : Mixed Culture Fermentation (MCF) for Sustainable Lactic Acid Production for Polylactic Acid (PLA)
Abstract:
This abstract outline an innovative approach to producing lactic acid for polylactic acid (PLA), addressing the limitations of conventional methods that rely on food-based feedstocks and create environmental burdens. Developed by Nature’s Principles.
Mixed Culture Fermentation (MCF) offers a flexible, decentralized alternative that can use both first- and second-generation (1G and 2G) unrefined feedstocks, such as agro-industrial residues and brewers’ spent grain. This method bypasses the issues of food competition and high costs associated with traditional production.
A key challenge is the downstream processing (DSP) of the complex fermentation broth, which contains variable concentrations of salts, colorants, and other organic acids. An inefficient DSP process risks negating the economic gains of low-cost fermentation. The success of this technology hinges on developing a cost-effective, sustainable, and scalable DSP that can consistently produce polymer-grade lactic acid.
This approach offers significant environmental and economic benefits:
Climate Impact: By utilizing its patented MCF technology, lactic acid production can reduce CO? emissions by ~50% (0.5 kg CO?/ton) compared to conventional methods. This technology offers a significant climate advantage over fossil-based plastics like PET and PP, potentially saving 1.6-2.1 kg of CO? per kilogram of plastic produced. Over the next decade, two to three new lactic acid facilities in India could save an estimated 59,000 metric tons of CO? annually.
Resource Efficiency and Circularity: MCF's feedstock flexibility enables the valorization of low-grade agricultural waste streams that would otherwise be used for ethanol production. This supports a more circular and resilient bio-based economy by reducing reliance on high-grade refined sugars. The process also avoidsthe use of GMO strains and energy-intensive sterilization. Any gypsum produced as a byproduct is of high quality and suitable for reuse in building and agricultural industries. The final PLA product is biodegradable, decomposing within 6–24 months under industrial composting conditions, which helps to improve soil structure and reduce water contamination risks.
Economic and Societal Benefits: By using alternative biomass sources, the technology can make domestic lactic acid production in India profitably, reducing reliance on sugary feedstocks. This strengthens India’s bio-based sovereignty and creates value from underutilized streams. The project also has the potential to create new revenue streams for operating companies and support job creation in the circular
economy.
From Linear to Circular Value Chains: Our technology introduces a circular value chain for PLA where:
• Bio-based (2G) raw materials are used in production.
• CO? emissions are reduced to 99% L-lactic acid.
• Production and distribution chains are localized through integration.
The PLA and bioplastics market are rapidly growing addressable market that Nature’s Principles is targeting with its MCF technology. Production of lactic acid based on Nature’s Principles technology is estimated to reach 250 kilotons of lactic acid per year by 2035. With an output ratio of ~1 ton of PLA per 1.2 tons of lactic acid, the annual potential for PLA production is 200 kton of PLA, resulting in the reduction of more than 100 kton of CO2 emissions when compared to the production of fossil-based plastics and conventional plastics.
