thats what i got from the article.
" In the lab, the scientists demonstrated the accumulation of significant amounts of chemically complex, persistent soil organic matter from microbial materials, in the absence of any plant inputs. Microbes unexpectedly produced soil organic matter that was almost identical to natural, field-derived soil organic matter when fed nothing but table sugar. Further, soil organic matter accumulation is greatest when more–not less–active microbial biomass is formed. This is especially true when that biomass is produced more efficiently, meaning more of the substrate is converted to biomass rather than carbon dioxide.

"Cynthia showed that the amount of organic matter formed depends heavily on the characteristics and physiology of the microbial community," Grandy said. "Challenging another long-held view, Cynthia also found that the characteristics of the microbial community are even more important for soil organic matter formation than soil type."