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A continuous research is attempted to fulfil the highest industrial demands of natural amylases presenting special properties. New α-amylases extracted from stems and leaves of Pergularia tomentosa, which is widespread and growing spontaneously in Tunisia, were studied by the means of their activities optimization and purification. Some similarities were recorded for the two identified enzymes: (i) the highest amylase activity showed a promoted thermal stability at 50°C; (ii) the starch substrate at 1% enhanced the enzyme activity; (iii) the two α-amylases seem to be calcium-independent; (iv) Zn2+, Cu2+, and Ag2+ were considered as important inhibitors of the enzyme activity. Following the increased gradient of elution on Mono Q-Sepharose column, an increase in the specific activity of 11.82-fold and 10.92-fold was recorded, respectively, for leaves and stems with the presence of different peaks on the purification profiles. Pergularia amylases activities were stable and compatible with the tested commercial detergents. The combination of plant amylase and detergent allowed us to enhance the wash performance with an increase of 35.24 and 42.56%, respectively, for stems and leaves amylases. Characterized amylases were reported to have a promoted potential for their implication notably in detergent industry as well as biotechnological sector. [ABSTRACT FROM AUTHOR]

Background: Nutritional fact study has prime importance to make the species edible and commercially viable to the food consumers. This is the first report that indicates the chemical characterization, functional, antioxidant and antihypertensive properties of Cymodocea nodosa to evaluate its nutritional status. Methods: Physico-chemical determination was determined by colorimetric and spectroscopic analysis. The functional and texture properties were evaluated since a desirable texture should be retained. Bioactive substances were determined by liquid chromatography-high resolution electrospray ionization mass spectrometry HPLC-DAD-ESI/MS2 analysis. Health benefit of this plant was highlighting by the antioxidant and antihypertensive potentials. Results: Results showed that the seagrass powder was characterized by a high content of fibers (56.4%), the fatty acids profile was dominated by the oleic acid, which represents about 62.0% of the total fatty acids and the functional properties proved important values of swelling capacity (6.71 ± 0.2) and water holding capacity (12.26 ± 0.25), that were comparable to those of some foodstuffs. Finally, the physico-chemical analysis shows the wealth in phenolic compounds, that could be explained by the high antioxidant and antihypertensive ability which was concentration dependent. Conclusion: The results from this study suggested that this marine plant could be utilized as a healthy food item for human consumption. [ABSTRACT FROM AUTHOR]

In the present study, we investigated a potent extracellular β-glucosidases secreted by the thermophilic fungal strain AX4 ofTalaromyces thermophilus, isolated from Tunisian soil samples. This strain was selected referring to the highest thermostability of its β-glucosidases compared to the other fungal isolates. The β-glucosidase production was investigated by submerged fermentation. The optimal temperature and initial pH for maximum β-glucosidase production were 50°C and 7.0, respectively. Several carbon sources were assayed for their effects on β-glucosidase production, significant yields were obtained in media containing lactose 1% (3.0 ± 0.36 U/ml) and wheat bran 2% (4.0 ± 0.4 U/ml). The combination of wheat bran at 2% and lactose at 0.8% as carbon source enhanced β-glucosidase production, which reached 8.5 ± 0.28 U/ml. Furthermore, the β-glucosidase-rich enzymatic juice ofT. thermophilusexhibited significant synergism withTrichoderma reesei(Rut C30) cellulases for pretreated waste paper (PWP) hydrolysis. Interestingly, the use of this optimal enzymatic cocktail increased 4.23 fold the glucose yield after saccharification of waste paper. A maximum sugar yield (94%) was reached when using low substrate (2%) and enzyme loading (EC1). [ABSTRACT FROM PUBLISHER]

Crude extracts from a medicinal Tunisian plant, Pergularia tomentosa L., were the investigated natural material. Butanolic extract of roots analyzed with IR spectra revealed the presence of hydroxyl, alcoholic, and carboxylic groups and sugars units. Analysis of some secondary metabolites, total phenolic, flavonoids, flavonols, and procyanidins, was performed using different solvents following the increased gradient of polarity. Fruits and leaves contained the highest amounts of all these compounds. Antioxidant properties were evaluated by the determination of free radical scavenging activity and the reducing power of methanolic extracts. Fruits and leaf extracts were the most powerful antioxidants for the two-assay in vitro system. Stems and fruits extracts exhibit an antifungal activity against Fusarium oxysporum f. sp. lycopersici which could become an alternative to synthetic fungicide to control Solanum species fungal diseases. [ABSTRACT FROM AUTHOR]

Fungalβ-glucosidases were extensively studied regarding their various potential biotechnology applications. Here, we report the selection ofFusarium solanistrain producing high yield ofβ-glucosidase activity. The effect of some factors onβ-glucosidase production was studied including: Initial pH, medium composition, concentration of carbon and nitrogen sources, and particle size of raw substrates. The optimal enzyme production was obtained with 4 units of pH. The highestβ-glucosidase activity was produced on 4% wheat bran (WB) as raw carbon sources, reaching 5 U/mL. A positive correlation between WB particle size and theβ-glucosidase production level was settled. The last one was enhanced to 13.60 U/mL in the presence of 0.5% (w/v) of ammonium sulfate. Interestingly, the activated charcoal was used as an inexpensive reagent enabling a rapid and efficient purification prior step that improved the enzyme-specific activity. Eventually,F. solaniβ-glucosidase acts efficiently during the bioconversion process of oleuropein. Indeed, 82.5% of oleuropein was deglycosylated after 1 hr at 40°C. Altogether, our data showed that theβ-glucosidase ofF. solanihas a potential application to convert oleuropein to ameliorate food quality. [ABSTRACT FROM PUBLISHER]

The present study investigated the effect of theCystoseira crinitasulfated polysaccharide (CCSP) on key enzymes activities related to diabetesin vitroand in diabetic rats. We found that CCSP inhibited pancreatic α-amylase with IC50= 39.16 μg/ml and angiotensin I-converting enzyme (ACE) activity with IC50 = 58.35 μg/mlin vitro. In diabetic rats, the administration of CCSP reduced the activity of α-amylase in serum, pancreas, and intestine by 23%, 44.38%, and 45%, respectively as compared to untreated diabetic rats. Moreover, the administration of CCSP to surviving diabetic rats protects pancreas β cells from death and damage, which leads to insulin levels. The decrease in α-amylase and the increase in insulin level lead to a decrease in glucose rate by 56% as compared to untreated diabetic rats. The inhibitory action of α-amylase activity and hypoglycemic effect of CCSP were confirmed by oral glucose tolerance test (OGTT). In addition, the administration of CCSP to surviving diabetic rats normalizes lipid profile, stimulates antioxidant capacity, and prevents liver–kidney toxicities, evidenced by decrease in serum indices of liver and kidney toxicity and confirmed by histological analysis. The overall findings presented in this study demonstrate that the administration of CCSP to diabetic rats can make it a potentially strong candidate for industrial application as a pharmacological agent for the treatment of hyperglycemia, hyperlipidemia, and liver–kidney dysfunctions. [ABSTRACT FROM AUTHOR]

We report here the enhanced hemicellulase production by a Talaromyces thermophilus strain in a fed-batch fermentation using 3.6-1itre laboratory-controlled bioreactor. When grown on wheat bran, this fungus produces a wide spectrum of polysaccharide-hydrolysing enzymes, mainly endo-(3-l,4-xylanase (27 U/mL), P-xylosidase (1.4 U/mL), α-L-arabinofura-nosidase (1.05 U/mL) and (3-D-mannosidase (0.78 U/mL). The β-xylosidase was purified and shown to hydrolyse xylobiose and short xylooligosaccharides, but it was inactive on xylan. It released xylose from xylooligosaccharides with a degree of polymerisation ranging from 2 to 5. Talaromyces thermophilus β-xylosidase activity was unaffected by high glucose or arabinose concentration (0.5 M) and retained 75 % of its original activity in the presence of 133 mM xylose. Chitosan-immobilised β-xylosidase was used in a continuous process of conversion of wheat bran hydrolysate to xylose in a packed bed reactor. Xylose production of 18.6 mg/g was reached after six hours in the bioreactor and was twofold higher than that produced by the free enzyme. The produced xylose was further converted into xylitol using the crude intracellular enzyme of Talaromyces thermophilus. [ABSTRACT FROM AUTHOR]

The data presented in this article are related to the research article titled "Immobilization nd topochemical mechanism of a new β-amylase extracted from Pergularia tomentosa" (Lahmar et al., 2017) [1]. This article documented information on the determination of the molecular weight of the β-amylase, the method of its immobilization and a comparison of the kinetic mechanism between the free and the immobilized forms by a mathematical method. Fresh Pergularia tomentosa was collected from Tunisia and a special method for β-amylase extraction was followed (Yotova et al., 2000) [2]. Public dissemination of this dataset will allow further analyses of the data.

A newly isolated thermophilic fungal strain from Tunisian soil samples was identified as Talaromyces thermophilus and was selected for its ability to produce extracellular hemicellulases when grown on various lignocellulosic substrates. Following the optimization of carbon source, nitrogen source, and initial pH of the growth medium in submerged liquid cultures, yields as high as 10.00 +/- 0.15 and 0.21 +/- 0.02 U/ml were obtained for xylanase and beta-xylosidase, respectively. In fact, wheat bran was found to be a good inducer of hemicellulase enzymes, mainly beta-xylosidase. The optimal temperature and pH of the xylanase activity were 75 degrees C and 8.0, respectively. This enzyme exhibited a remarkable stability and retained 100% of its original activity at 50 degrees C for 7 days at pH 7.0-8.0. The half-lives of the enzyme were 4 h at 80 degrees C, 2 h at 90 degrees C, and 1 h at 100 degrees C. T. thermophilus could therefore be considered as a satisfactory and promising producer of thermostable xylanases. Crude enzyme of T. thermophilus rich in xylanase and beta-xylosidase was established for the hydrolysis of lignocellulosic materials as wheat bran.