Methane-to-feed company to increase aquafeed sustainability

String Bio has built a deep technology platform for producing a protein ingredient from greenhouse gases that is scalable and competitive in terms of quality and price, the company told us in a recent interview.

007 - STRING BIO - Vinod and Ezhil
Ezhil Subbian, co-founder and CEO and Vinod Kumar, co-founder and managing director
August 17, 2022

String Bio has built a deep technology platform for producing high-quality ingredients from greenhouse gases, mainly methane. “Using deep technology to enable sustainable food systems that are climate resilient is the primary driver behind the work at String. The company’s focus has been to make sustainability market-relevant by redefining manufacturing,” Ezhil Subbian, co-founder and CEO, told in a recent interview.

After playing critical roles in bio-based product innovation at different startups/early-stage companies in the Silicon Valley ecosystem, the founding team built on their experience over the past 20 years in bio-based product commercialization and market growth. “We aim to leverage the technology process of the west and the manufacturing capabilities of the east to develop innovations that can have a global impact,” said Subbian.

The process

String Bio’s gas-based fermentation process produces high-quality protein ingredients from methane using a proprietary platform called String Integrated Methane Platform (SIMP). The key USPs for the technology are scalability, modularity and efficiency. Apart from animal nutrition, the String platform enables next-generation ingredients for agriculture, human nutrition and personal care sectors, all manufactured using methane as the raw material.

PRO-DG is the company’s high-quality protein with an optimal nutritional profile for animal nutrition and is free of antibiotics, pesticides and mycotoxins. “It provides traceability, significantly optimizes land and water use, and provides sustainability to the feed value chain,” said Subbian. PRO-DG has been validated in research institutes for use in animal nutrition through successful trials in aquaculture species and poultry.

Trial results

The company has tested the protein in aquaculture species such as shrimp, yellowtail, barramundi and trout.

In a trial on rainbow trout performed at ICAR, India, results suggested that the novel methanotroph bacteria meal can replace 12.5% of fishmeal in rainbow trout feeds, without compromising feed utilization, nutrient digestibility and balance, growth, tissue integrity and fish welfare. Moreover, it significantly reduced phosphorus loss, with substantial implications for lowering the eutrophic potential of aquafeeds.

After this trial, the company has improved its protein meal through optimization in production and processing. Further investigations with the improved variants were performed to increase palatability and benefits.

String protein was also tested in Pacific white shrimp by the Aquaculture and Fisheries Group, Wageningen University, the Netherlands, and compared to other protein sources, such as fishmeal and soybean meal. Results showed that String protein is an optimal protein source for shrimp aquafeeds.

The company found that some of the critical performance and physiological parameters from both trials confirm the advantages of using PRO-DG as a feed ingredient for animal nutrition, such as improved ROI, easy digestibility, improved animal health and welfare, feed intake reduction, clean and sustainable protein source free from mycotoxins, and consistent and long shelf life.

The company is currently testing the protein on large-scale farms in partnership with feed companies.

Future prospects

“The technology developed by String Bio is robust and scalable and the protein ingredient is competitive in terms of quality and price,” said Subbian.

String Bio raised a few investments to scale up the production. “These investments will be leveraged to establish a larger capacity manufacturing facility. As seen from the growth and demand in the sector, there is a critical gap in the market for high-quality, clean, and sustainable protein ingredients. We are working with key partners on both the supply and market sides to scale and address this gap. We aim to partner with more global companies this year,” Subbian concluded.