Calcium Supplementation Abates the Inhibition Effects of Acetic Acid on Saccharomyces cerevisiae.

The toxic level of acetic acid could be released during the pretreatment of lignocellulosic biomass, and an economical method was reported to minimize the acidic stress on the fermentation of Saccharomyces cerevisiae by cation supplementation. A dose-dependent protection of Ca2+ was monitored, and the optimal concentration of Ca2+ was 8 mM under 4.5 g/L acetic acid stress. The activities of catalase and superoxide dismutase of yeast cells supplemented with optimal Ca2+ increased by 18.6 and 27.3 %, respectively, coupling with an obvious decrease of reactive oxygen species content. Cell viability also performed a significant increase from 52.4 % (without Ca2+ addition) to 73.56 % (with 8 mM Ca2+ addition). No significant improvements were found in the bioethanol yields by Ca2+ supplementation; however, the fermentation time was shortened by about 8 h obviously. Our results illustrated that the Ca2+ supplementation could be an economical method to make the bioethanol production more efficient and cost-effective.

Analysis of Mogroside V in Siraitia grosvenorii with micelle-mediated cloud-point extraction.

INTRODUCTION: Mogroside V is the main effective ingredient of Siraitia grosvenorii used as a natural sweet food as well as a traditional Chinese medicine. The sample pre-treatment prior to chromatographic analysis requires large amounts of toxic organic solvents and is time consuming. OBJECTIVE: To develop an effective and simple method for extracting and determining mogroside V of Siraitia grosvenorii. METHODS: Mogroside V was extracted and preconcentrated by micelle-mediated cloud-point extraction with nonionic surfactant isotridecyl poly (ethylene glycol) ether (Genapol® X-080). The obtained solutions containing mogroside V were analysed by high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection. The chromatographic separation was performed on a C18 -column using gradient elution with acetonitrile and water at 203 nm. RESULTS: The cloud-point extraction yield was 80.7% while the pre-concentration factor was about 10.8. The limit of detection was 0.75 µg/mL and the limit of quantification was 2 µg/mL. The relative standard deviations for intra- and interday precisions of mogroside V were less than 8.68% and 5.78%, respectively, and the recoveries were between 85.1% and 103.6%. CONCLUSION: The HPLC-UV method based on micelle-mediated cloud-point extraction for determination mogroside V in Siraitia grosvenorii was environmentally friendly, simple and sensitive.

Production of fibrinolytic enzyme from Bacillus amyloliquefaciens by fermentation of chickpeas, with the evaluation of the anticoagulant and antioxidant properties of chickpeas.

To develop safe and cheap thrombolytic agents, a fibrinolytic enzyme productive strain of LSSE-62 was isolated from Chinese soybean paste. This strain was identified as Bacillus amyloliquefaciens by 16S rDNA sequence analysis. Nucleotide and amino acid sequence analysis showed that this fibrinolytic enzyme was identical to subtilisin DJ-4. Chickpeas were used as the substrate for fibrinolytic enzyme production from B. amyloliquefaciens in solid-state fermentation. Under the optimized conditions (34 °C and 50% initial moisture content), the fibrinolytic activity of fermented chickpeas reached 39.28 fibrin degradation units (FU)/g. Additionally, the fermented chickpeas showed anticoagulant activity, and the purified anticoagulant component showed higher anticoagulant activity than heparin sodium. After fermentation, the total phenolic and total flavonoid contents increased by 222 and 71%, respectively, and then the antioxidant activities were improved significantly. This study provided a novel method for the preparation of multifunctional food of chickpeas or raw materials for the preparation of functional food additives and potential drugs.

Application of non-ionic surfactant in the microwave-assisted extraction of alkaloids from Rhizoma Coptidis.

The feasibility of employing non-ionic surfactant oligoethylene glycol monoalkyl ether (Genapol X-080) as an alternative and effective solvent for the microwave-assisted extraction of alkaloids from Rhizoma Coptidis was demonstrated. When compared with commonly used solvents, 5% Genapol X-080 enhanced the extraction efficiency. Under optimal conditions, i.e. 5% acidified Genapol X-080 (v/v), microwave-assisted extraction for 10 min at 100 degrees C, the extraction recovery of alkaloids reached 92.8% in a one-step extraction. The efficiency of cloud-point preconcentration of three alkaloids was in the range 93.6-94.7% with relative standard deviation lower than 3.3% by the proposed procedure. Furthermore, the combination of microwave-assisted extraction and cloud-point extraction was shown to be a green, rapid and effective approach for alkaloids preconcentration of Rhizoma Coptidis samples.

Analysis of glycyrrhizic acid and liquiritin in liquorice root with microwave-assisted micellar extraction and pre-concentration.

The feasibility of employing a non-ionic surfactant (Triton X-100) as an alternative and effective solvent for the microwave-assisted extraction of glycyrrhizic acid and liquiritin from liquorice root has been demonstrated. When compared with commonly used solvents, 5% Triton X-100 yielded higher extraction efficiency than aqueous solutions of ethanol or methanol. Under optimal conditions, i.e. 5% Triton X-100 (v/v) and microwave-assisted extraction for 3-5 min at 100 degrees C, the percentage extraction of active ingredients reached the highest value. The pre-concentration factor for the glycyrrhizic acid and liquiritin was about 13, and the cloud-point extraction recoveries for the two ingredients were 98.4 and 96.1%, respectively. The results showed that the coupling of microwave-assisted extraction and cloud-point extraction could be employed as a new and effective approach for the rapid extraction and pre-concentration of pharmacologically active ingredients from liquorice root without disturbing the subsequent chromatographic analysis.