Ultrasound assisted extraction of β-carotene from Spirulina platensis

Cell growth kinetics of Chlorella sorokiniana and nutritional values of its biomass

The present study investigates the effects of different physico-chemical parameters for the growth of Chlorella sorokiniana and subsequently determination of nutritional values of its biomass. Most suitable temperature, light intensity, pH, and acetic acid concentration were 30°C, 100 μmol m(-2)s(-1), pH 7.5, and 34.8mM, respectively for the growth of this microorganism. Arrhenius growth activation energy, Ea was calculated as 7.08 kJ mol(-1). Monod kinetics constants: maximum specific growth rate (μ max) and substrate (acetic acid) affinity coefficient (Ks) were determined as 0.1 ± 0.01 h(-1) and 76 ± 8 mg L(-1), respectively. Stoichiometric analysis revealed the capture of 1.83 g CO2 and release of 1.9 g O2 for 1g algal biomass synthesis. Algal biomass of C. sorokiniana was found rich in protein and several important minerals such as Mg, Ca, and Fe. Astaxanthin and β-carotene were extracted and quantified using high performance liquid chromatography.

Ultrasound-assisted extraction of polysaccharide from Nephelium lappaceum L. fruit peel

In this study, ultrasound-assisted extraction technology was employed to investigate and optimize the crude polysaccharide extraction from Nephelium lappaceum L. fruit peel using three levels, four factors (LS ratio, ultrasonic power, extraction temperature and extraction time) Box-Behnken response surface design. The results showed that highest polysaccharide yield of 8.31% was obtained with an LS ratio of 32:1 ml:g, ultrasonic power of 110 W, extraction temperature of 53°C and extraction time of 41 min. The experimental yield of polysaccharide (8.29±0.03%) at optimal condition was well agreed with the predicted value. Fourier transform infrared spectroscopy (FTIR) was used for the identification of functional groups present in the extracted polysaccharide. The results suggest that ultrasound-assisted extraction could be a good alternative for the extraction of polysaccharide from N. lappaceum L. fruit peel at industrial level.

Ultrasound assisted enzymatic pre-treatment of high fat content dairy wastewater

This paper illustrates the application of ultrasound in a dairy waste water treatment for the removal of fat using enzyme as a catalyst. Lipase Z was used to perform the enzymatic pre-hydrolysis of a synthetic dairy wastewater containing around 2000 mg/L of fat content coupled with ultrasound irradiation. Different process parameters like effect of enzyme loading, temperature, ultrasound power, frequency, duty cycle and speed of agitation are optimized. The maximum hydrolysis of 78% is achieved at 0.2% enzyme loading (w/v), 30°C temperature, 165 W of ultrasonication power at 25 kHz and 66% duty cycle. It was observed that the enzymatic pre-hydrolysis under the influence of ultrasound drastically reduces the reaction time from 24h to 40 min as compared to conventional stirring with improved yield.

High-throughput extraction of β-carotene from Blakeslea trispora based on a newly developed setup

Rapid and efficient extraction of bioactive compounds from biomass for sample analysis presents one of the major challenges in high-productive strain screening and bioprocess development. In this work, a high-throughput method based on a new setup was developed for the extraction of β-carotene from Blakeslea trispora. After the cell was completely disrupted by high-throughput machinery grinding, β-carotene was completely extracted by chloroform and dimethylsulfoxide (1:1, v/v). According to the experimental results, the newly developed high-throughput extraction (HTPE) method could simultaneously process 96 samples within 30 Min, and only 5-mL solvent was used for each sample. The sufficient extraction of β-carotene by the HTPE method, which was confirmed by the conventional reference extraction method, further demonstrated that the newly developed HTPE method was more efficient and economical than the methods developed previously for the extraction of β-carotene.

Ultrasound assisted three phase partitioning of a fibrinolytic enzyme

The present investigation is aimed at ultrasound assisted three phase partitioning (UATPP) of a fibrinolytic enzyme from Bacillus sphaericus MTCC 3672. Three phase partitioning integrates the concentration and partial purification step of downstream processing of a biomolecule. Three phase system is formed with simultaneous addition of ammonium sulfate to crude broth and followed by t-butanol. UATPP of a fibrinolytic enzyme was studied by varying different process parameters such as ammonium sulfate saturation concentration, pH, broth to t-butanol ratio, temperature, ultrasound frequency, ultrasonication power, and duty cycle. The optimized parameters yielding maximum purity of 16.15-fold of fibrinolytic enzyme with 65% recovery comprised of 80% ammonium sulfate saturation, pH 9, temperature 30 °C, broth to t-butanol ratio 0.5 (v/v), at 25 kHz frequency and 150 W ultrasonication power with 40% duty cycle for 5 min irradiation time. SDS PAGE analysis of partitioned enzyme shows partial purification with a molecular weight in the range of 55-70 kDa. Enhanced mass transfer of UATPP resulted in higher fold purity of fibrinolytic enzyme with reduced time of operation from 1 h to 5 min as compared to conventional TPP. Outcome of our findings highlighted the use of UATPP as an efficient biosepartion technique.

Ultrasound stimulated production of a fibrinolytic enzyme

The present study is aimed at enhanced production of a fibrinolytic enzyme from Bacillus sphaericus MTCC 3672 under ultrasonic stimulation. Various process parameters viz; irradiation at different growth phases, ultrasonication power, irradiation duration, duty cycle and multiple irradiation were studied for enhancement of fibrinolytic enzyme productivity. The optimum conditions were found as follows, irradiation of ultrasonic waves to fermentation broth at 12 h of growth phase with 25 kHz frequency, 160 W ultrasound power, 20% duty cycle for 5 min. The productivity of fibrinolytic enzyme was increased 1.82-fold from 110 to 201 U/mL compared with the non sonicated control fermentation. Drop in glucose concentration from 0.41% to 0.12% w/v in ultrasonicated batch implies that, ultrasonication increases the cell permeability, improves substrate intake and progresses metabolism of microbial cell. Microscopic images before and after ultrasonic stimulation clearly signifies the impact of duty cycle on decreasing biomass concentration. However, environmental scanning electron micrograph does not show any cell lysis at optimum ultrasonic irradiation. Offshoots of our results will contribute to fulfill the demand of enhancement of microbial therapeutic enzyme productivity, through ultrasonication stimulation.

Ultrasound extraction optimization of Acanthopanax senticosus polysaccharides and its antioxidant activity

In this study, effects of several experimental parameters, including ultrasonic time, ratio of water to material, extraction temperature and ultrasonic power on the extraction yield of polysaccharides from Acanthopanax senticosus stem (ASS) were investigated by single factor experiment and an orthogonal test design (L9(3)(4)) was used to optimize the ultrasound extraction conditions. The polysaccharides from Acanthopanax senticosus stem (ASSP) and fruit (ASFP) were further fractionated by stepwise ethanol precipitation and the anti-oxidation activities of those fractions were evaluated by hydroxyl, superoxide anion and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. Under the optimal conditions (ultrasonic time 75min, ratio of water to material 50ml/g, extraction temperature 80°C and ultrasonic power 100W), the yield was 10.9mg/g. All fractions of ASP possessed considerable antioxidant activity. The results indicated that the ultrasound extraction was a very useful method for the extraction of ASP and the polysaccharides could be explored as a potential antioxidant agent for use in medicine or functional food.