Microbial oil produced from the fermentation of microwave-depolymerised rapeseed meal

Dark fermentation production of volatile fatty acids from glucose with biochar amended biological consortium

Effects of adding biochars on dark fermentation production of volatile fatty acids (VFAs) from glucose were investigated. Nine biochars were synthesized and applied, together with an activated carbon, as the testing amendment to enhance preferable fermentation. Biochars were porous materials with internal pores and excess surface functional groups, which would lead to enrichment of acetate over butyrate in the VFA production. Biochar coconut and biochar longan shell showed excess functional groups and high bulk internal crystallinity, presented 109.6% and 71.8% enrichments of acetate production, respectively. The syntrophic growth of fermentative bacteria and homoacetogens on biochar surfaces via direct interspecies electron transfer mechanism was assumed to interpret the noted enhanced acetate production. The excess functional groups on biochar surface to facilitate biofilm development and the high crystallinity of biochar bulk to ease electron transfer favored the production of acetate.

Glucose fermentation with biochar amended consortium: Sequential fermentations

The aim of this work was to study sequential batch fermentation of glucose with a biological consortium amended with nine different biochars or with an activated carbon. The glucose fermentation was enhanced by carbon amendment, with activated carbon being more effective than biochars as cell carriers and electron conductors between functional species. The volatile fatty acid distributions were shifted in the consumption of the produced H₂ and CO₂. The types of biochars were irrelevant to glucose glycolysis and the subsequent H₂ and CO₂ consumption reactions. Biofilm growth affects the detailed mechanisms occurred in fermentation broth to the yielded volatile fatty acid distributions.

Orange peel waste-based liquid medium for biodiesel production by oleaginous yeasts

Orange peel waste (OPW), the primary byproduct of the juice extraction process, is annually generated in massive amounts (21 Mton), and its aqueous extraction in biorefining operations yields a liquid fraction, referred to as orange peel extract (OPE). Although OPE contains significant amounts of easily assimilable carbohydrates, such as fructose, glucose, and sucrose, no investigations have been conducted yet to assess its possible use in biodiesel production by oleaginous yeasts. Consequently, the objective of the present study was to assess whether OPE might act as the basis of a liquid medium for microbial lipid production. A screening conducted with 18 strains of oleaginous yeasts in shaken flask on the OPE-based medium showed that Rhodosporidium toruloides NRRL 1091 and Cryptococcus laurentii UCD 68-201 gave the best results in terms of lipid production (5.8 and 4.5 g L^-1, respectively) and accumulation (77 and 47% on a dry matter basis, respectively). The subsequent scale transfer of the process to a 3-L STR operated in batch mode halved the time required to reach the lipid peak with the ensuing increase in volumetric productivities in R. toruloides NRRL 1091 (3646 mg L^-1 day^-1) and C. laurentii UCD 68-201 (2970.7 mg L^-1 day^-1). The biodiesel yields from the lipids of the former and the latter strain were 36.9 and 31.9%, respectively. Based on multivariate analysis of fatty acid methyl ester compositions, the lipids from the former and the latter strain were highly resembling those of Jatropha and palm oils, two commonly used feedstocks for biodiesel manufacturing.