Transition Metal Solutions has closed an oversubscribed $6 million seed round to commercialize a bio-enabled approach aimed at boosting copper recovery from existing mines and waste streams, as copper demand continues to climb faster than new supply can be brought online.
The financing was led by Transition Ventures, with participation from climate and deeptech investors across the U.S., Europe, and Australia. The company said proceeds will be used to advance its technology from lab-scale results to industrial pilot conditions, with 3-meter column trials targeted to begin in the first half of 2026.
Founded in 2023 and formerly known as Transition Biomining, the Berkeley-based startup rebranded as Transition Metal Solutions to better reflect what it describes as a chemical approach to enhancing biological systems. The company is headquartered at UC Berkeley’s Bakar Labs for Energy & Materials.
Transition Metal Solutions’ platform focuses on the microbial communities already present in an orebody. Instead of introducing lab-grown organisms, the company analyzes the “wild” biology operating inside heap leach environments and then predicts, tests, and formulates chemical additives designed to optimize the activity of those microbes and increase copper output. The idea emerged after work at a major copper mine where certain heaps consistently produced more copper than expected. According to the company, subsequent analysis found that the overperformance correlated with unusually diverse microbial populations in the ore, the majority of which had never been isolated or sequenced.
The company says its approach is intended to address longstanding skepticism around biomining performance by avoiding additional infrastructure and minimizing operational disruption. Rather than requiring new plants or extensive retrofits, Transition positions its additives as a drop-in enhancement to existing leaching processes, aiming to improve recovery from low-grade and complex ores that are increasingly common as higher-grade deposits decline.
In laboratory testing on low-grade primary sulfide ore, Transition Metal Solutions reported copper recovery increasing from 60% to 90%. The company also said experiments on ores with challenging mineralogy, including refractory high-carbonate ore, achieved in situ acid generation and metal leaching three times faster than industry standard.
The round comes as miners and governments elevate copper’s strategic importance. Copper demand is being pulled by electrification trends across the energy transition, including renewables and electric vehicles, as well as by growing electricity and infrastructure requirements associated with AI data centers. Transition Metal Solutions cited expectations that global copper demand will rise by 50% by 2040, even as richer deposits become harder to find and bring to production—raising the stakes for technologies that can unlock more metal from existing operations.
Transition said it plans to use the seed capital to validate performance under industrial pilot conditions and to build a path toward broader adoption at mine sites. Over the longer term, the company intends to extend the platform beyond copper into other critical metals, including nickel, cobalt, gold, and zinc.
The startup’s leadership team is led by founder and CEO Dr. Sasha Milshteyn, who the company says has more than 20 years of experience spanning biophysics, metagenomics, and synthetic biology. Co-founder and COO Alexandra Shiluk is focused on execution and market adoption. The company’s R&D is led by Dr. Suzan Yilmaz, supported by Dr. Diana Bojanova and Jeremy Wei. Go-to-market efforts are led by Chief Commercial Officer Vania Grandi, and independent board director Dr. Peter Kondos brings decades of mining and metallurgical leadership experience, including roles at Barrick Gold, Inco (Vale), and Noranda (Glencore).
In addition to Transition Ventures, the seed round included participation from prior investors SOSV, Dolby Family Ventures, Astor Management AG, Juniper VC, and Climate Capital, as well as new investors Possible Ventures, Understorey Ventures, New Climate Ventures, Essential Capital, and Kayak Ventures.
KEY QUOTES
“We just need to identify what’s limiting the microbial communities from doing what they naturally evolved to do.”
Dr. Sasha Milshteyn, Founder and CEO, Transition Metal Solutions
“We listened to dozens of miners and industry experts who have been disappointed by the performance of past biomining efforts. Our solution does not require lab-grown microbes or additional capital investments, making it cheaper, faster, and easier to adopt and scale.”
Alexandra Shiluk, Co-Founder and COO, Transition Metal Solutions
“Transition Metal Solutions has developed a scalable, low-emission alternative to smelting. This drop-in solution to leaching low-grade ores is transforming the industry and addressing a critical gap in the energy transition worth billions.”
Clara Ricard, Partner, Transition Ventures
“We evaluated dozens of new mining start-ups and urged Sasha to start the company because his unique scientific insight draws a straight line to scaled cash flows for his customers by tapping into what mining companies are already doing — without any overhead.”
Pae Wu, General Partner, SOSV
