top of page

Photo from Skovran and Martinez-Gomez, Science, 2015.  Methylotrophic bacteria are often found on leaf surfaces and can grow into colonies when pressed onto methanol medium lacking (left) or containing (right) lanthanides.  Addition of lanthanides may allow the laboratory cultivation of previously uncultivatable species. Leaf prints by Vanessa Jimenez and Sang Phan.  Photo by Walter Carlson.

The Skovran laboratory focuses on understanding the metabolism and physiology of methylotrophic bacteria to advance our engineering efforts in the biomining and biorecycling of lanthanide elements (rare earths) and the production of biodegradable plastics.

Methyltrophs and lanthanides

Methylotrophic bacteria are important for global carbon cycling and are capable of growing on single-carbon compounds like methane, methanol and methylated amines.  Recently, methylotrophs gained recognition for being the only KNOWN forms of life that inherently use lanthanides for growth.  Lanthanides are important for our modern lifestyles and technologies.  They are found in our computers, cell phones, cars, wind turbines, and military weaponry just to name a few.  Currently the U.S. imports most of its lanthanides because lanthanide mining is environmentally destructive.  Mining often involves roasting the ores in acid, followed by solvent extractions which release radioactive byproducts.  Cost and demand for lanthanides continue to rise while suitable ore deposits continue to decline.   Our lab has shown that Methylobacterium extorquens AM1, a model organism for the study of methylotrophy, is capable of acquiring and using lanthanides from computer hard drive magnets and different mining ores for growth.  Our current efforts are focused on understanding how lanthanides are acquired and transported into the cell, the enzymes that use lanthanides as cofactors, and how genes encoding lanthanide transport systems and lanthanide-dependent enzymes are regulated.  Additionally, we are focused on metal homeostasis and the cross-regulation that may occur between different metal uptake systems.

Methylobacterium extorquens AM1 can use computer hard drive magnets for growth. Images by Huong Vu.

Methyltrophs and biodegradable plastics

Plastics are both a benefit and a detriment to society.  They are moldable, durable substances that do not break down.  The problem is, THEY DO NOT BREAK DOWN.  As a result, plastics accumulate in our environment and end up harming our wildlife.  Did you know that there is a garbage patch in the ocean called the Pacific Gyre which is 1-2 times the size of Texas?  Many birds and sea animals think the plastics are food and end up starving to death because their stomachs fill with plastic which does not leave room for actual food.  Additionally, plastics get wrapped around the bodies of animals causing disfigurements as they grow.  There are many scientific efforts toward finding plastic alternatives.  Some bacteria like M. extorquens AM1 naturally produce biodegradable plastic in the form of carbon storage products such as poly-hydroxybutyrate or PHB.  We are interested in understanding the cellular signals that promote PHB accumulation, and engineering alternative metabolic pathways and mutations  to reroute carbon to PHB without significant detriment to cell growth.

Fluorescent PHB stain of wild type (left) and a mutant strain that overproduces PHB (right).  Image by Charuamathi Raghuraman.

Student training

The Skovran lab consistently has a dedicated, enthusiastic, vibrant group of students that enjoy solving metabolic and molecular puzzles.  Students receive training in classical and molecular genetics.  Additionally, students may learn biochemical and systems level approaches along with techniques involving microscale thermophoresis, confocal microscopy, flow cytometry and RNAseq.  Students develop and implement creative thinking skills to unravel the intricate and integrative nature of metabolism and to develop the applications that metabolic engineering permits. 

Interested in joining our lab?  E-mail transcripts or student ID, and a paragraph explaining your career goals, why you want to join the Skovran lab and how much time you have remaining at SJSU to Elizabeth.skovran@sjsu.edu.  

bottom of page