Lentilactobacillus farraginis FSI (3): a whole cell biocatalyst for the synthesis of kojic acid derivative under aquatic condition.

Kojic acid derivatives are useful in the cosmetics and pharmaceutical industries. The current investigation focuses on the search for a safe and environmentally friendly newer whole-cell biocatalyst for the synthesis of kojic acid derivative especially 2-amino-6-(hydroxymethyl)-8-oxo-4-phenyl-4,8-dihydropyrano[3,2-b]pyran-3-carbonitrile (APhCN). In this context, a total of six cultures were isolated from fecal samples of infants and subjected to probiotic characterization followed by screening as whole cell biocatalyst (WCB). In this multicomponent reaction, benzaldehyde, malononitrile, and kojic acid were used to synthesize APhCN at room temperature under aqueous conditions. The screening of potent whole cell biocatalyst (WCB) from isolated cultures was done by comparing reaction time and percent yield. The potent WCB gave a good yield of 95% within 15 h of time and hence further characterized biochemically and identified as Lentilactobacillus farraginis by using 16S rRNA gene sequencing. Lactobacilli having GRAS (generally regarded as safe) status and being able to carry out this transformation under moderate reaction conditions with easy recovery of both product and biocatalyst, it has the potential to replace some of the chemical catalytic methods.

Lipase-mediated multicomponent synthesis of 1H-Pyrazolo[1,2-b]phthalazine-5,10-dione derivatives in a binary solvent medium.

A new method for the synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives via lipase from the Aspergillus niger-catalyzed multicomponent reaction of aldehydes, malononitrile, and phthalhydrazide is reported herein for the first time. This novel method holds several advantages, including its efficiency, environmental friendliness, simple workup procedure, and good yield (70-86%). The effects of temperature, organic solvents, and water content were investigated. This protocol has the potential to replace traditional chemical synthesis routes for the synthesis of nitrogen-containing heterocyclic compounds.

Effect of Lactobacillus helveticus CD6 on serum lipid profile and indicators of liver function in high-fat diet fed Swiss albino mice.

In this study, we have investigated the effect of Lactobacillus helveticus CD6 on weight gain, lipid profile, liver function biomarkers (ALT: alanine aminotransferase; and AST: aspartate aminotransferase) and liver histopathology in high-fat diet fed Swiss albino mice. Twenty-four healthy male Swiss albino mice with an average body weight of 25.94 ± 0.33 g (35 days old) were acclimatized and equally distributed into four groups treated with different diets. The treatment groups were control (control diet), HFD (high-fat diet), HFD + LH (high-fat diet + L. helveticus CD6), and HFD + Gemf (high-fat diet + Gemfibrozil). After 12 weeks, L. helveticus CD6 treatment significantly reduced HFD-induced weight gain, the levels of serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), ALT and AST, and elevated serum high-density lipoprotein (HDL) levels. In addition, L. helveticus CD6 treatment maintained satiety and normal liver histology as compared to HFD group. Besides this, the results observed with L. helveticus CD6 treatment were comparable with lipid lowering drug gemfibrozil, except TG levels and body weight gain. In conclusion, it was found that L. helveticus CD6 could effectively reduce HFD-induced hyperlipidemia and weight gain and maintained normal liver histology. Moreover, the strain could be used to develop functional foods for individuals with dyslipidemia after appropriate human studies.

A halotolerant hyaluronidase from newly isolated Brevibacterium halotolerans DC1: Purification and characterization.

An enzyme hyaluronidase (hyase) producing halotolerant bacterium was isolated from dental caries and identified as Brevibacterium halotolerans DC1. Higher growth and hyase production were observed in nutrient broth fortified with hyaluronic acid at pH 7.0, temperature 37 °C, 120 rpm upon 48 h of incubation. Hyase was purified using salt precipitation, DEAE cellulose ion exchange, and Sephadex G-100 gel filtration chromatography. The enzyme was purified to 13-fold with 67.19% recovery of activity and 26.37 U/mg of specific activity. SDS-PAGE and zymography revealed it to be near to homogeneity showing a relative molecular weight of about 43 kDa that was confirmed by MALDI-TOF MS. This hyase was very active and stable at pH 7.0 and temperature 40 °C. The presence of metal ions Ca2+ and Mg2+ increased its activity while Zn2+ and Cu2+ severely inhibited it. Being stable at 2 M NaCl, hyase exhibited its halotolerant nature. This enzyme showed wide substrate specificity where hyaluronic acid (HA) was the best substrate. The kinetic studies revealed that Km and Vmax were 91.3 µg/mL and 306.2 µg/mL/min respectively. This is the first report of hyaluronidase from a halotolerant Brevibacterium spp. which can find applications under high salinity.

Bioprocess optimization of laccase production through solid substrate fermentation using Perenniporia tephropora-L168 and its application in bioremediation of triaryl-methane dye.

Laccases are multi copper oxidases that can oxidize both phenolic and nonphenolic lignin related compounds. Consequently, there has been continuous demand for laccases for the oxidative degradation of phenolic dyes in effluents. In view of this, the present work was focused on laccase production by solid substrate fermentation using a newly isolated fungus Perenniporia tephropora-L168. To intensify the laccase production, the process parameters pH, nitrogen, inducer, and substrate: water ratio were optimized by using statistical model. A set of optimal conditions noted were pH 3, nitrogen 0.001 g/L; inducer 0.5% and substrate: water ratio (1:10), which yielded laccase 1,160 U/g. The crude laccase exhibited noteworthy potential to degrade a triaryl-methane dye especially Malachite green. Also, during bioremediation studies, the statistical process optimization could achieve 81% decolourization within 180 min. The laccase treatment brought chemical transformation in malachite green as evident from UV-Visible spectra, FTIR, HPLC while toxicity against bacteria and fungi was also reduced. During phytotoxicity study, effect of treated and untreated dye on germination of seed was analyzed. Interestingly, the germination index for Vigna aconitifolia and Vigna radiata was increased by two and fourfold, respectively. Overall, this work demonstrates optimized production of laccase using Perenniporia tephropora-L168 and its efficient bioremediation potential for triaryl-methane dye.

Instant green synthesis of silver-based herbo-metallic colloidal nanosuspension in Terminalia bellirica fruit aqueous extract for catalytic and antibacterial applications.

In the present study, microwave-assisted, optimized, instant, Terminalia bellirica fruit extract-mediated green synthesis of colloidal silver nanoparticles (AgNPs) has been reported. The synthesized AgNPs were characterized by UV-Vis spectroscopy, FTIR, Zetasizer, FESEM, EDX and XRD. The characteristic surface plasmon peak of reaction mixture at 406 nm confirmed the synthesis of AgNPs. The FTIR studies confirmed phytoconstituents were responsible for the synthesis and stability of AgNPs. The FESEM, EDX and XRD analysis revealed the presence of spherical silver nanoparticles of mean diameter ≤20.6 nm with face-centered cubic crystalline structure. These AgNPs showed notable catalytic activity in reduction of 4-nitrophenol to 4-aminophenol in the presence of NaBH4. The synthesized AgNPs showed potential antibacterial and antibiofilm activity against bacterial pathogens like Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. Thus, these synthesized AgNPs can open avenues for the development of AgNP-based efficient nanocatalyst and potent nanomedicine in future.

Bio-therapeutic Potential and Cytotoxicity Assessment of Pectin-Mediated Synthesized Nanostructured Cerium Oxide.

In the present studies, renewable and nontoxic biopolymer, pectin, was extracted from Indian red pomelo fruit peels and used for the synthesis of cerium oxide nanoparticles (CeO2-NPs) having bio-therapeutic potential. The structural information of extracted pectin was investigated by FTIR and NMR spectroscopic techniques. Physicochemical characteristics of this pectin suggested its application in the synthesis of metal oxide nanoparticles. Using this pectin as a template, CeO2-NPs were synthesized by simple, one step and eco-friendly approach. The UV-Vis spectrum of synthesized CeO2-NPs exhibited a characteristic absorption peak at wavelength 345 nm, which can be assigned to its intrinsic band gap (3.59 eV) absorption. Photoluminescence measurements of CeO2-NPs revealed that the broad emission was composed of seven different bands. FTIR analysis ensured involvement of pectin in the formation and stabilization of CeO2-NPs. FT-Raman spectra showed a sharp Raman active mode peak at 461.8 cm-1 due to a symmetrical stretching mode of Ce-O vibration. DLS, FESEM, EDX, and XRD analysis showed that the CeO2-NPs prepared were polydispersed, spherical shaped with a cubic fluorite structure and average particle size ≤40 nm. These CeO2-NPs displayed broad spectrum antimicrobial activity, antioxidant potential, and non-cytotoxic nature.

Selective ciprofloxacin antibiotic detection by fluorescent siderophore pyoverdin.

Fluorescent siderophore pyoverdin (PVD) was produced from a soil isolate Pseudomonas monteilii strain MKP 213. The PVD was purified near to homogeneity and applied for the fluorescent chemosensing of various antibiotics in aqueous solution (pH=7.0). Upon addition of ciprofloxacin, PVD showed new UV-vis absorption bands at 252 and 321nm due to an internal charge transfer mechanism. Also, the addition of ciprofloxacin induced a highly selective fluorescence enhancement of PVD with a 13nm blue shift from 458 to 445nm. The combination of a long peptide chain along with the chromophore unit of PVD generates a converging cleft for ciprofloxacin recognition with LOD and LOQ of 7.13µM and 21.6µM, respectively without interference from other studied antibiotics. The association constant (Ka) of PVD with ciprofloxacin was calculated to be as low as 1.40×10(5)M(-1) using Benesi-Hildebrand plot depicting its significance in detection. The pharmaceutical tablet analysis measures the sensing with negligible matrix effect and quantitative recovery.

Cholesterol assimilation and biotransformation by Lactobacillus helveticus.

Lactobacillus helveticus, grown at 37°C in MRS medium supplemented with 3 mM cholesterol, assimilated all the cholesterol in 42 h having 68 U mg(-1) of intracellular cholesterol oxidase activity. The strain transformed 1 g cholesterol to 0.05 g of androsta-1, 4-diene-3, 17-dione and 0.04 g of androst-4-ene-3, 17 dione within 48 h at 37°C with extracellular cholesterol oxidase activity at 12 U mg(-1) and intracellular oxidase at 0.5 U mg(-1).

Production, Purification of Exo-Polygalacturonase from Soil Isolate Paecilomyces variotii NFCCI 1769 and Its Application.

The aim of the present study was to produce exo-polygalacturonase from potent soil isolate by submerged fermentation and its application for fruit juice treatment. Pectinase producing strains were selectively isolated from pectin industry waste. A selected isolate C2 was found to produce significant amount of exo-polygalacturonase. The isolate was identified as Paecilomyces variotii on the basis of morphological characteristics and 18S rRNA gene sequence analysis. The exo-polygalacturonase produced by the isolate was purified by ammonium sulphate precipitation, size exclusion chromatography and ion exchange chromatography. The purified enzyme had MW of 39.4 kD based on SDS PAGE. Under partially optimized conditions, purified exo-polygalacturonase showed specific activity of 98.49 U/mg protein at pH 6.0 and 30°C. The enzyme was comparatively stable from 10 to 30°C and the activity decreased with increasing temperature. Purified enzyme brought about considerable reduction in viscosity of fruit juice samples.

Production of hyaluronic acid from Streptococcus zooepidemicus MTCC 3523 and its wound healing activity.

Exopolysaccharide produced and purified from Streptococcus zooepidemicus MTCC 3523 was identified as hyaluronic acid (HA) based on IR and NMR spectroscopy while its Mw was found to be 5.38 × 10(5)Da. HA produced passed bacterial endotoxin test and showed significant wound healing activity in Wistar rats on 12th and 16th day.

A potential probiotic culture ST2 produces siderophore 2,3-dihydroxybenzoylserine under intestinal conditions.

The aim of this study was to characterise siderophores of a culture bearing better probiotic qualities of human origin. In this direction, bacterial strain ST2 was isolated from faecal sample of 6-month-old healthy infant, which showed close similarity with Escherichia coli based on 16S r-RNA gene sequence analysis and biochemical characteristics. It was tested for siderophore production under in vitro iron limiting intestinal conditions. The siderophore produced was catecholate type of 2,3-dihydroxybenzoylserine on the basis of FTIR, NMR and mass spectra analysis. The strain obeyed probiotic properties as per WHO and FAO guidelines. It showed excellent tolerance in partially simulated gastro-intestinal tract conditions, non-haemolytic nature, susceptibility to many antibiotics tested and antimicrobial activity against enteric pathogens like Salmonella typhimurium, Streptococcus pyogenes, and Staphylococcus aureus. Hence, this culture could be a possible probiotic candidate in iron nutrition, but only after conducting proper animal and human trials.

Cholesterol biotransformation to androsta-1,4-diene-3,17-dione by growing cells of Chryseobacterium gleum.

Cholesterol oxidase activity was studied during biotransformation of cholesterol to androsta-1,4-diene-3,17-dione (ADD) by Chryseobacterium gleum. Spent LB media, containing cholesterol (3 mM approximately = 1 g l(-1)) where the bacterium was grown for 24 h, at 30 degrees C with constant shaking at 120 rpm, had the highest enzyme activity (167 U mg(-1)). The growing cells produced 0.076 g ADD from 1 g cholesterol l(-1).

Evaluation of probiotic characteristics of siderophoregenic Bacillus spp. isolated from dairy waste.

Siderophoregenic Bacillus strain DET9 has been selectively isolated from dairy waste. It was evaluated for probiotic characteristics and susceptibility pattern against antibiotics. Its spores showed excellent tolerance to simulated gastrointestinal tract conditions and exhibited antimicrobial activity against organisms such as Escherichia coli, Micrococcus flavus, and Staphylococcus aureus. Its susceptibility to antibiotics reduces the prospect to donate resistance determinants if administered in the form of probiotic preparations. It was observed to produce approximately 60 mg/l catecholate type of siderophore under iron stressed conditions, identified as a 2,3-dihydroxy benzoic acid by high-performance liquid chromatography, infrared spectroscopy, nuclear magnetic resonance, and mass spectral analysis. Partial 16S-rRNA gene sequencing analysis shows that the isolate exhibited homology with Bacillus thuringiensis and Bacillus weihenstephanensis, whereas biochemical characterization revealed its novelty. DET9 exhibited no mortality of fishes in a 60-day trial, when fishes (surfi tetra) were challenged up to 100 ppm cell concentration, with their daily diet.

Production, purification and chemical characterization of the catecholate siderophore from potent probiotic strains of Bacillus spp.

The aim of the present study was to characterize the probiotic qualities of Bacillus isolates and study their siderophore prior to possible siderophoregenic probiotic application for iron nutrition in animals and humans. Bacillus strains were selectively isolated from dairy waste and mango pulp waste. Best two siderophore positive isolates, JHT3 and DET6 showed high homology with Bacillus megaterium (98%) and B. subtilis (99%), respectively, using partial 16S-rRNA sequencing and biochemical characterization. These isolates produced catecholate type of siderophore under iron stressed conditions and were screened for probiotic properties as per WHO and FAO guidelines. Spores of these strains showed excellent tolerance in partially simulated gastrointestinal tract conditions and exhibited antimicrobial activity against organisms such as Staphylococcus aureus, Micrococcus flavus and Escherichia coli. Importantly, these isolates were susceptible to the most of the antibiotics tested, in conflict that they would not donate resistance determinants if administered in the form of probiotic preparations.