Combined bead milling and enzymatic hydrolysis for efficient fractionation of lipids, proteins, and carbohydrates of Chlorella vulgaris microalgae

A combined bead milling and enzymatic hydrolysis process was developed for fractionation of the major valuable biomass components, i.e., proteins, carbohydrates, and lipids from the microalgae Chlorella vulgaris. The cells were treated by bead milling followed by hydrolysis with different hydrolytic enzymes, including lipase, phospholipase, protease, and cellulase. Without enzymatic hydrolysis, the recovery yield of lipids, carbohydrates, and proteins for bead milled biomass was 75%, 31%, and 40%, respectively, while by applying enzymatic treatments these results were improved significantly. The maximum recovery yield for all components was obtained after enzymatic hydrolysis of bead milled biomass by lipase at 37 degrees C and pH 7.4 for 24 h, yielding 88% lipids in the solid phase while 74% carbohydrate and 68% protein were separated in the liquid phase. The recovery yield of components after enzymatic hydrolysis of biomass without bead milling was 44% lower than that of the milled biomass.publishedVersionPaid Open Acces

An integrated and optimized process for cleaner production of ethanol and biodiesel from corn stover by Mucor indicus

A two-stage process was successfully developed for biodiesel and ethanol production from corn stover using zygomycetes fungus Mucor indicus. Dilute-acid pretreatment followed by enzymatic saccharification was applied to release the maximum amount of sugars (glucose and xylose) from the lignocellulosic structure of corn stover. Dilute-acid hydrolysis was optimized by a response surface design. Under the optimal reaction conditions (i.e., 1.8% v/v H2SO4, 121 °C for 22 min), the hydrolysis resulted in the production of 270 g glucose per kg of dry corn stover (57.8% theoretical yield) and 100 g xylose per kg of dry corn stover (84.0% theoretical yield). Validation of the model exhibited proper fit between predicted and observed values of glucose and xylose concentrations: 91.4% regression adjustment for xylose and 98.2% for glucose. In the first stage, cells fermented the enzymatic hydrolysate to the maximum amount of 74.5% (0.38 g g−1) ethanol as the main product. In the second stage, the dilute-acid hydrolysate was used for lipid accumulation in the fungal cells of the first stage fermentation. The hydrolysates were used without detoxification since the fungus is among the most resistant microorganisms to the inhibitors available in the acid hydrolysates. Effects of addition of different nutrient sources, including fungal extract and yeast extract along with mineral salts, were also investigated to maximize lipid yield. Overall, 21.4 g ethanol and 2.2 g biodiesel (obtained from 4.00 g accumulated lipid) were produced from 100 g dry corn stover.</p

An integrated and optimized process for cleaner production of ethanol and biodiesel from corn stover by Mucor indicus

A two-stage process was successfully developed for biodiesel and ethanol production from corn stover using zygomycetes fungus Mucor indicus. Dilute-acid pretreatment followed by enzymatic saccharification was applied to release the maximum amount of sugars (glucose and xylose) from the lignocellulosic structure of corn stover. Dilute-acid hydrolysis was optimized by a response surface design. Under the optimal reaction conditions (i.e., 1.8% v/v H2SO4, 121 °C for 22 min), the hydrolysis resulted in the production of 270 g glucose per kg of dry corn stover (57.8% theoretical yield) and 100 g xylose per kg of dry corn stover (84.0% theoretical yield). Validation of the model exhibited proper fit between predicted and observed values of glucose and xylose concentrations: 91.4% regression adjustment for xylose and 98.2% for glucose. In the first stage, cells fermented the enzymatic hydrolysate to the maximum amount of 74.5% (0.38 g g−1) ethanol as the main product. In the second stage, the dilute-acid hydrolysate was used for lipid accumulation in the fungal cells of the first stage fermentation. The hydrolysates were used without detoxification since the fungus is among the most resistant microorganisms to the inhibitors available in the acid hydrolysates. Effects of addition of different nutrient sources, including fungal extract and yeast extract along with mineral salts, were also investigated to maximize lipid yield. Overall, 21.4 g ethanol and 2.2 g biodiesel (obtained from 4.00 g accumulated lipid) were produced from 100 g dry corn stover.</p

Fenpyroximate resistance in Iranian populations of the European red mite Panonychus ulmi (Acari: Tetranychidae)

The European red mite, Panonychus ulmi (Koch), is one of the most important apple orchard pests worldwide. Fenpyroximate, a mitochondrial electron transport inhibitor of complex I (METI-I), is a commonly used acaricide to control this pest. In this study, we determined fenpyroximate resistance levels for 11 P. ulmi populations from Iran and a spirodiclofen-resistant strain from Germany (PSR-TK). The LC50 values ranged between 121.8 and 5713.9 mg a.i. L-1 and the highest resistance ratio (RR) was 47-fold for the Padena population. PBO, TPP and DEM synergist ratios (SRs) were the highest for the PSR-TK (SR = 6.7), Shahin Dej (SR = 6.1) and Semirom3 (SR = 3.6) populations, respectively. In vitro enzyme activity measurements also showed that there was a higher glutathione S-transferases (GSTs) activity in the PSR-TK and Shahin Dej population compared to the most susceptible populations, whereas the esterase and P450 monooxygenase activity were not significantly higher in the resistant populations. Last, we screened all populations for the presence of two mutations previously associated with METI-I resistance in spider mites but none of these mutations could be detected. To conclude, moderate to high levels of fenpyroximate resistance were observed in P. ulmi populations from Iran, with increased detoxification most likely underlying fenpyroximate resistance

Biorefining of corn stover for efficient production of bioethanol, biodiesel, biomethane, and value-added byproducts

info:eu-repo/semantics/publishe

Combined bead milling and enzymatic hydrolysis for efficient fractionation of lipids, proteins, and carbohydrates of Chlorella vulgaris microalgae

A combined bead milling and enzymatic hydrolysis process was developed for fractionation of the major valuable biomass components, i.e., proteins, carbohydrates, and lipids from the microalgae Chlorella vulgaris. The cells were treated by bead milling followed by hydrolysis with different hydrolytic enzymes, including lipase, phospholipase, protease, and cellulase. Without enzymatic hydrolysis, the recovery yield of lipids, carbohydrates, and proteins for bead milled biomass was 75%, 31%, and 40%, respectively, while by applying enzymatic treatments these results were improved significantly. The maximum recovery yield for all components was obtained after enzymatic hydrolysis of bead milled biomass by lipase at 37 degrees C and pH 7.4 for 24 h, yielding 88% lipids in the solid phase while 74% carbohydrate and 68% protein were separated in the liquid phase. The recovery yield of components after enzymatic hydrolysis of biomass without bead milling was 44% lower than that of the milled biomass

Combined bead milling and enzymatic hydrolysis for efficient fractionation of lipids, proteins, and carbohydrates of Chlorella vulgaris microalgae

A combined bead milling and enzymatic hydrolysis process was developed for fractionation of the major valuable biomass components, i.e., proteins, carbohydrates, and lipids from the microalgae Chlorella vulgaris. The cells were treated by bead milling followed by hydrolysis with different hydrolytic enzymes, including lipase, phospholipase, protease, and cellulase. Without enzymatic hydrolysis, the recovery yield of lipids, carbohydrates, and proteins for bead milled biomass was 75%, 31%, and 40%, respectively, while by applying enzymatic treatments these results were improved significantly. The maximum recovery yield for all components was obtained after enzymatic hydrolysis of bead milled biomass by lipase at 37 °C and pH 7.4 for 24 h, yielding 88% lipids in the solid phase while 74% carbohydrate and 68% protein were separated in the liquid phase. The recovery yield of components after enzymatic hydrolysis of biomass without bead milling was 44% lower than that of the milled biomass.</p