Recombinant Penicillium oxalicum 16 ß-Glucosidase 1 Displays Comprehensive Inhibitory Resistance to Several Lignocellulose Pretreatment Products, Ethanol, and Salt.

ß-Glucosidase (BGL) is a rate-limiting enzyme of lignocellulose hydrolysis for second-generation bioethanol production, but its inhibition by lignocellulose pretreatment products, ethanol, and salt is apparent. Here, the recombinant Penicillium oxalicum 16 BGL 1 (rPO16BGL1) from Pichia pastoris GS115 kept complete activity at 0.2-1.4 mg/mL furan derivatives and phenolic compounds, 50 mg/mL sodium chloride (potassium chloride), or 100 mg/mL ethanol at 40 °C. rPO16BGL1 retained above 50% residual activity at 30 mg/mL organic acid sodium, and 60% residual activity at 40 °C with 300 mg/mL ethanol. Sodium chloride and potassium chloride had a complicated effect on rPO16BGL1, which resulted in activation or inhibition. The inhibition kinetics of the enzyme reaction demonstrated that organic acids and organic acid sodium were non-competitive inhibitors and that ethanol was a competitive inhibitor at < 1.5 mg/mL salicin. Moreover, substrate inhibition of the enzyme was found at > 2 mg/mL salicin, and the Km/KI and Km/KSI average values revealed that the inhibitory strength was ranked as salicin-organic acids > organic acids > salicin-organic acid sodium salt > organic acid sodium salt > salicin > salicin-KCl > salicin-NaCl > salicin-ethanol > ethanol.

[Biological activity of selenorganic compounds at heavy metal salts intoxication].

Possible mechanisms of the antitoxic action of organoselenium compounds in heavy metal poisoning have been considered. Heavy metal toxicity associated with intensification of free radical oxidation, suppression of the antioxidant system, damage to macromolecules, mitochondria and the genetic material can cause apoptotic cell death or the development of carcinogenesis. Organic selenium compounds are effective antioxidants during heavy metal poisoning; they exhibit higher bioavailability in mammals than inorganic ones and they are able to activate antioxidant defense, bind heavy metal ions and reactive oxygen species formed during metal-induced oxidative stress. One of promising organoselenium compounds is diacetophenonyl selenide (DAPS-25), which is characterized by antioxidant and antitoxic activity, under conditions including heavy metal intoxication.

STRUCTURAL CHANGES IN SUBMANDIBULAR SALIVARY GLAND, CAUSED BY HEAVY METAL SALTS, AND THEIR CORRECTION WITH DIALIPON (EXPERIMENTAL STUDY).

Setting of possibilities of structural changes correction in submandibular salivary gland with a Dialipone drug, caused by adverse effect of heavy metals salts on an organisms of different age group rats. Structural changes and their correction were studied on the histological preparations basis painted by hematoxylin-eozin, Van-Gizon, PAS reaction, investigated and photographed by means of the digital image display system "SEO Scan". In comparison to the results of submandibular salivary gland tissue histological research of animals without any correction of microelementosis, animals that took Dialipone are marked with a better glandular epithelium saving, less widespreading of dystrophic and dyscirculatory changes, sclerotization processes in stroma. When comparing of Dialipone restoration possibilities, it was set, that different age group animals show different application efficiency of the corrector. The rats of young and mature age have more complete renewal of structural changes. The rats of advanced age show worse reparative capabilities, less complete and effective renewal of structural changes.