Optimization of alkaline amylase production by thermophilic Bacillus stearothermophilus AN 002

Bacillus stearothermophilus AN 002 secreted thermostable alkaline amylase into a liquid growth medium containing 2 g/l starch. Amylase activity was highest at early stationary phase of growth. Among the various carbohydrates tested maximum amylase production was obtained with starch. When starch was replaced by other carbon sources, amylase production was reduced. Peptone and corn steep liquor (CSL) were the ideal nitrogen sources for amylase production by this strain. Of the phosphate sources tested, (NH₄)₂HPO₄ showed best restults. Amylase production was highest in a laboratory fermenter at a initial pH of 6.5 and at a constant pH of 7.0. The optimum aeration and agitation for amylase production were 0.66 v/v/m and 400 rev/min, respectively. Maximum growth was obtained at 55 °C and maximum amylase was produced at 50 °C. The amylase was found to be stable between pH 6.0 to 11.0.     

Modulation of Gut Microbiota and Neuroprotective Effect of a Yeast-Enriched Beer

Beer is the most consumed alcoholic beverage worldwide. It is rich in nutrients, and with its microbial component it could play a role in gut microbiota modulation. Conflicting data are currently available regarding the consequences of alcohol and alcohol-containing beverages on dementia and age-associated disorders including Alzheimer’s disease (AD), a neurodegeneration characterized by protein aggregation, inflammatory processes and alterations of components of the gut–brain axis. The effects of an unfiltered and unpasteurized craft beer on AD molecular hallmarks, levels of gut hormones and composition of micro/mycobiota were dissected using 3xTg-AD mice. In addition, to better assess the role of yeasts, beer was enriched with the same Saccharomyces cerevisiae strain used for brewing. The treatment with the yeast-enriched beer ameliorated cognition and favored the reduction of Aβ(1-42) and pro-inflammatory molecules, also contributing to an increase in the concentration of anti-inflammatory cytokines. A significant improvement in the richness and presence of beneficial taxa in the gut bacterial population of the 3xTg-AD animals was observed. In addition, the fungal order, Sordariomycetes, associated with gut inflammatory conditions, noticeably decreased with beer treatments. These data demonstrate, for the first time, the beneficial effects of a yeast-enriched beer on AD signs, suggesting gut microbiota modulation as a mechanism of action.     

Boosting nitrogen fertilization by a slow releasing nitrate-intercalated biocompatible layered double hydroxide–hydrogel composite loaded with Azospirillum brasilense

Indiscriminate use of chemical fertilizers leads to soil environmental disbalance and therefore, preparation and application of environment-friendly slow-release multifunctional fertilizers are of paramount importance for sustainable crop production in the present scenario. In this study, we propose a slow-release multifunctional composite nitrogen (N) fertilizer, which possesses the ability to supply plant accessible N in the form of ammonium (NH₄⁺) and nitrate (NO₃⁻) to improve nitrate assimilation coupled with zinc (Zn, a major micronutrient for plants in the soil) after its degradation. For this purpose, NO₃⁻-intercalated zinc–aluminum (Zn–Al) layered double hydroxide (LDH) was synthesized using a co-precipitation protocol. The prepared LDH was added as 25.45% of total polymer weight to a sodium carboxymethyl cellulose/hydroxyethyl cellulose citric acid (NaCMC/HEC-CA) biodegradable hydrogel. A. brasilense, commonly used nitrogen-fixing bacteria in soils, was added to the LDH–hydrogel composite along with LDH alone to augment the availability of NH₄⁺ and NO₃⁻. Adjusting the pH under acidic (pH 5.25) and neutral (pH 7) conditions, the release pattern of NO₃⁻ from LDH and the composite was monitored for 30 days at normal temperature. The pH was selected based on the soil analysis data of North East India. The LDH-composite released 90% (w/w) and 85.45% (w/w) of intercalated NO₃⁻ at pH 5.25 and 7.00 respectively in 30 days. However, 100% (w/w) and 87% (w/w) of intercalated NO₃⁻ at pH 5.25 and 7.00 respectively were released in 30 days when only LDH was applied, which indicated the lower performance of LDH alone in comparison to the LDH-composite for the nitrate holding pattern. The pH of the bacteria-loaded system was observed to be acidic (pH = 5–6) during the study of nitrate assimilation and Zn²⁺ release. A. brasilense improved nitrate assimilation and increased the NH₄⁺ ion concentration in the studied system. A significant increase in Zn²⁺ release was observed from day 5 in the presence of A. brasilense in the LDH-composite compared with that in the absence of A. brasilense. In conclusion, the prepared LDH–hydrogel–A. brasilense composite fertilizer system increases the availability of plant accessible N form (both NO₃⁻ and NH₄⁺) and can potentially improve soil fertility with the addition of Zn and bacteria to the soil in the extended course.

Indiscriminate use of chemical fertilizers leads to soil environmental disbalance, therefore, use of environment-friendly slow-release multifunctional fertilizers are of paramount importance for sustainable crop production in the present scenario.     

Multifunctional D2/D3 Agonist D-520 with High in Vivo Efficacy: Modulator of Toxicity of Alpha-Synuclein Aggregates

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Synthesis,Docking, In Vitro and In Vivo Antimalarial Activity of Hybrid 4‐aminoquinoline–1,3,5‐triazine Derivatives Against Wild and Mutant Malaria Parasites

A new series of hybrid 4‐aminoquinoline–1,3,5‐triazine derivatives was synthesized by a four‐step reaction. Target compounds were screened for in vitro antimalarial activity against chloroquine‐sensitive (3D‐7) and chloroquine‐resistant (RKL‐2) strains of Plasmodium falciparum. Compounds exhibited, by and large, good antimalarial activity against the resistant strain, while two of them, that is 8g and 8a, displayed higher activity against both the strains of P. falciparum. Additionally, docking study was performed on both wild (1J3I.pdb) and quadruple mutant (N51I, C59R, S108 N, I164L, 3QG2.pdb) type pf‐DHFR‐TS to highlight the structural features of hybrid molecules.