An economical biorefinery process for propionic acid production from glycerol and potato juice using high cell density fermentation.

An economically sustainable process was developed for propionic acid production by fermentation of glycerol using Propionibacterium acidipropionici and potato juice, a by-product of starch processing, as a nitrogen/vitamin source. The fermentation was done as high-cell-density sequential batches with cell recycle. Propionic acid production and glycerol consumption rates were dependent on initial biomass concentration, and reached a maximum of 1.42 and 2.30gL(-1)h(-1), respectively, from 50gL(-1) glycerol at initial cell density of 23.7g(CDW)L(-1). Halving the concentration of nitrogen/vitamin source resulted in reduction of acetic and succinic acids yields by ∼39% each. At glycerol concentrations of 85 and 120gL(-1), respectively, 43.8 and 50.8gL(-1) propionic acid were obtained at a rate of 0.88 and 0.29gL(-1)h(-1) and yield of 84 and 78mol%. Succinic acid was 13g% of propionic acid and could represent a potential co-product covering the cost of nitrogen/vitamin source

Production of glycidyl ethers by chemo-enzymatic epoxidation of allyl ethers

Production of glycidyl ethers is industrially carried Out by reacting alcohols with epichlorhydrin, a potentially carcinogenic compound. This paper investigates a less hazardous alternative-that of a chemo-enzymatic process in which Candida antarctica lipase B catalysed generation of peracid from a carboxylic acid is followed by a Prileshajev epoxidation of the corresponding allyl ether. Trimethylolpropane monoallyl ether (TMPME) was used as a model substrate. A maximal epoxide product yield of 77% was achieved through the optimization of temperature. acid concentration and hydrogen peroxide concentration. Peracid formation was considerably faster than the subsequent epoxidation step, and accumulation of the peracid was Found to be important to drive the epoxidation forward. (C) 2008 Elsevier B.V. All rights reserved

Bioremediation of industrial dyes: black reactive 5 and methylene blue by white rot fungus

The aim of the presence research work is to discover the degree of dye decolourization by novel white rot fungi isolated from soil at three different sites; agriculture, virgin forest soil and composting in Johore. Initial experiment was performed with 29 white rot fungus isolates and 3 standard strains, namely Phanerochaete chrysosporium (DSM 6909), Bkerjandera adusta (DSM 4710) and Phlebia radiata (DSM 2111). Soil characteristics; pH, moisture, total viable count, total fungi as well as fungal cell morphology were performed during analysis. White rot fungi were isolated and cultivated on solid medium containing indicator compounds that enabled the detection of enzymes peroxidase as specific colour reactions using guaicol. Selected isolates then were performed in solid medium containing 0.2% dyes (Methylene blue and Reactive Black 5) and incubated up to 10 days at 30 °C before the decolourization rate was observed. The screening work resulted in isolation of 26 positive fungal strains. Liquid cultivations of positive strains confirmed that 24 out of 26 dye degrader were found in the screening. Methylene blue was found to be the most decolorized by white rot fungi with 68.52±3.88% compared to Reactive Black 5, 59.91±3.42 %, respectively. There was significance difference in decolorizing for both dyes responded by soil isolates from different locations. But, in comparison among standard strains, non-significance was observed. P. chrysosporium present the best degrader among the other standard strains for both dyes. Analysis of variance for different locations showed that isolates from virgin forest soil was found to be the most significance in decolourization of methylene blue while composting site for decolourization of Reactive Black 5 dye. This study also suggests that plate-test screening based on polymeric dye compound; guaiacol is an efficient way to screening novel white rot fungus. Further identification and ability to degrade various biological products such as lignin and halo-cellulose should be done as essential to find local and efficient white rot fungus to further develop these industrial applications

Improved propionic acid production from glycerol: combining cyclic batch-and sequential batch fermentations with optimal nutrient composition

Propionic acid was produced from glycerol using Propionibacterium acidipropionici. In this study, the impact of the concentrations of carbon and nitrogen sources, and of different modes of high cell density fermentations on process kinetics and -efficiency was investigated. Three-way ANOVA analysis and batch cultivations at varying C/N ratios at pH 6.5 revealed that propionic acid production rate is significantly influenced by yeast extract concentration. Glycerol to yeast extract ratio (w w−1) of 3:1 was required for complete glycerol consumption, while maintaining the volumetric productivity. Using this optimum C/N ratio for propionic acid production in cyclic batch fermentation gave propionate yield up to 93 mol% and productivity of 0.53 g L−1 h−1. Moreover, sequential batch fermentation with cell recycling resulted in production rates exceeding 1 g L−1 h−1 at initial glycerol up to 120 g L−1, and a maximum of 1.63 g L−1 h−1 from 90 g L−1 glycerol