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Conversion of corn stover alkaline pre-treatment waste streams into biodiesel via Rhodococci

Author:
Le, Rosemary K., Wells Jr., Tyrone, Das, Parthapratim, Meng, Xianzhi, Stoklosa, Ryan J., Bhalla, Aditya, Hodge, David B., Yuan, Joshua S., Ragauskas, Arthur J.
Source:
RSC advances 2017 v.7 no.7 pp. 4108-4115
ISSN:
2046-2069
Subject:
Rhodococcus jostii, Rhodococcus opacus, bacteria, biodiesel, bioethanol, biorefining, biotransformation, corn stover, feedstocks, fermentation, glucose, lignin, lipids, molecular weight, oils, solubilization, viability
Abstract:
The bioconversion of second-generation cellulosic ethanol waste streams into biodiesel via oleaginous bacteria is a novel optimization strategy for biorefineries with substantial potential for rapid development. In this study, one- and two-stage alkali/alkali-peroxide pretreatment waste streams of corn stover were separately implemented as feedstocks in 96 h batch reactor fermentations with wild-type Rhodococcus opacus PD 630, R. opacus DSM 1069, and R. jostii DSM 44719ᵀ. Here we show using ³¹P-NMR, HPAEC-PAD, and SEC analyses, that the more rigorous and chemically-efficient two-stage chemical pretreatment effluent provided higher concentrations of solubilized glucose and lower molecular weight (∼70–300 g mol⁻¹) lignin degradation products thereby enabling improved cellular density, viability, and oleaginicity in each respective strain. The most significant yields were by R. opacus PD 630, which converted 6.2% of organic content with a maximal total lipid production of 1.3 g L⁻¹ and accumulated 42.1% in oils based on cell dry weight after 48 h.
Agid:
6415001