Improving the antioxidant and anticancer potential of Cinnamomum cassia via fermentation with Lactobacillus plantarum

This study designed to investigate effect of fermentation by Lactobacillus plantarum on antioxidant and anticancer properties of Cinnamomum cassia aqueous solution. The optimum condition to produce high antioxidant activity was 10⁷ CFU L. plantarum/10 g cinnamon at pH6 after 3 days of incubation at 35 °C. Fermented cinnamon showed an increase in ABTS, DPPH and H₂O₂ by 24.63, 58.31 and 60.27%, respectively over the control. Also, the total phenolic and flavonoid contents were increased, 8.15 to 11.40 mg GAE/g and 0.43 to 2.61 mg QE/g, respectively. The gallic acid, p-hydroxybenzoic acid, catechin and chlorogenic acid were increased by 37, 404, 11 and 98%, respectively. Also, anticancer activity was developed after fermentation. The increased antioxidant activity of fermented cinnamon could be attributed to the increase of some phenolics and flavonoids. Hence, cinnamon fermentation using L. plantarum is able to enhance its antioxidant and anticancer activities without producing toxic substances.

An updated review on advancement in fermentative production strategies for biobutanol using Clostridium spp

A significant concern of our fuel-dependent era is the unceasing exhaustion of petroleum fuel supplies. In parallel to this, environmental issues such as the greenhouse effect, change in global climate, and increasing global temperature must be addressed on a priority basis. Biobutanol, which has fuel characteristics comparable to gasoline, has attracted global attention as a viable green fuel alternative among the many biofuel alternatives. Renewable biomass could be used for the sustainable production of biobutanol by the acetone-butanol-ethanol (ABE) pathway. Non-extinguishable resources, such as algal and lignocellulosic biomass, and starch are some of the most commonly used feedstock for fermentative production of biobutanol, and each has its particular set of advantages. Clostridium, a gram-positive endospore-forming bacterium that can produce a range of compounds, along with n-butanol is traditionally known for its biobutanol production capabilities. Clostridium fermentation produces biobased n-butanol through ABE fermentation. However, low butanol titer, a lack of suitable feedstock, and product inhibition are the primary difficulties in biobutanol synthesis. Critical issues that are essential for sustainable production of biobutanol include (i) developing high butanol titer producing strains utilizing genetic and metabolic engineering approaches, (ii) renewable biomass that could be used for biobutanol production at a larger scale, and (iii) addressing the limits of traditional batch fermentation by integrated bioprocessing technologies with effective product recovery procedures that have increased the efficiency of biobutanol synthesis. Our paper reviews the current progress in all three aspects of butanol production and presents recent data on current practices in fermentative biobutanol production technology.

Development of bioactive solid support for immobilized Lactobacillus casei biofilms and the production of lactic acid

Polypropylene was modified to contain chitosan and evaluate its ability to generate Lactobacillus casei biofilms and their lactic acid production. Biofilm formation was carried out in either rich or minimal media. The chitosan-modified polypropylene harbored ~ 37% more cells than the control polypropylene. The biofilms from the chitosan-modified polypropylene grown in rich medium produced ~ 2 times more lactic acid after 72 h of incubation than the control suspended cells. There was no significant difference in the production of lactic acid after 72 h by L. casei biofilms on the chitosan-modified polypropylene grown in minimal media as compared with cells in suspension after 48 h and 72 h of incubation. Infrared spectroscopy confirmed higher deposition of nutrients and biomass on the chitosan-modified polypropylene as compared to the chitosan-free polypropylene. Electron and atomic force microscopy confirmed thicker biofilms when rich media were used to grow them as compared to minimal medium.

Model-based optimization and scale-up of multi-feed simultaneous saccharification and co-fermentation of steam pre-treated lignocellulose enables high gravity ethanol production

BACKGROUND

High content of water-insoluble solids (WIS) is required for simultaneous saccharification and co-fermentation (SSCF) operations to reach the high ethanol concentrations that meet the techno-economic requirements of industrial-scale production. The fundamental challenges of such processes are related to the high viscosity and inhibitor contents of the medium. Poor mass transfer and inhibition of the yeast lead to decreased ethanol yield, titre and productivity. In the present work, high-solid SSCF of pre-treated wheat straw was carried out by multi-feed SSCF which is a fed-batch process with additions of substrate, enzymes and cells, integrated with yeast propagation and adaptation on the pre-treatment liquor. The combined feeding strategies were systematically compared and optimized using experiments and simulations.

RESULTS

For high-solid SSCF process of SO2-catalyzed steam pre-treated wheat straw, the boosted solubilisation of WIS achieved by having all enzyme loaded at the beginning of the process is crucial for increased rates of both enzymatic hydrolysis and SSCF. A kinetic model was adapted to simulate the release of sugars during separate hydrolysis as well as during SSCF. Feeding of solid substrate to reach the instantaneous WIS content of 13 % (w/w) was carried out when 60 % of the cellulose was hydrolysed, according to simulation results. With this approach, accumulated WIS additions reached more than 20 % (w/w) without encountering mixing problems in a standard bioreactor. Feeding fresh cells to the SSCF reactor maintained the fermentation activity, which otherwise ceased when the ethanol concentration reached 40-45 g L(-1). In lab scale, the optimized multi-feed SSCF produced 57 g L(-1) ethanol in 72 h. The process was reproducible and resulted in 52 g L(-1) ethanol in 10 m(3) scale at the SP Biorefinery Demo Plant.

CONCLUSIONS

SSCF of WIS content up to 22 % (w/w) is reproducible and scalable with the multi-feed SSCF configuration and model-aided process design. For simultaneous saccharification and fermentation, the overall efficiency relies on balanced rates of substrate feeding and conversion. Multi-feed SSCF provides the possibilities to balance interdependent rates by systematic optimization of the feeding strategies. The optimization routine presented in this work can easily be adapted for optimization of other lignocellulose-based fermentation systems.