Jay keasling , research leader , has extensively re-engineered yeast changing several genes and biological pathways to produce artemisinin , the most effective treatment for malaria , in a microbial fermenter .

研究领导人杰伊凯斯林（jaykeasling）对酵母菌进行了大量再造改变了数个基因和生物学通路以便在微生物发酵筒中生产治疗疟疾的特效药青蒿素。

During fermentation , the rising carbon dioxide bubbles stick to the residual grain fibers and carry them to the top of the fermenter and form a cap which can be 6 or more inches thick , depending on selection of grains .

发酵时产生的二氧化碳带着发酵后余下的谷物纤维到达瓶口，形成可厚达六英寸（15cm）的瓶盖，此厚度与谷物种类有关。