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• EPS production from Weissella confusa MD1 is optimized, purified and characterized. • This is the first reports of Mannan EPS production from Weissella confusa. • The average molecular weight of EPS was 2.909 KDa. • The EPS was thermally stable and showed degradation temperature around 267.74 °C. • The EPS showed promising antioxidant activity and antibiofilm activity. The present study focused on production, optimization and characterization of exopolysaccharide (EPS) from Weissella confusa MD1. The purified EPS MD1 was also evaluated for in vitro biological activities. The maximum yield of EPS (10.07 ± 0.32 g/L) was obtained with optimized culture conditions of 35 °C at pH 6.5 for 36 h with 4% (w/v) galactose and 1% (w/v) ammonium nitrate supplemented in MRS broth. The crude EPS was purified with diethylamino ethanol-Sepharose Fast Flow column and Sephadex-G 75 column. The physicochemical and functional characterization of the EPS was done by high-performance thin-layer chromatography (HPTLC), high-performance gel permeation chromatography (HPGPC), fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR), thermo gravimetric and differential scanning calorimetric (TG-DSC) analysis, x-ray diffraction (XRD) and scanning electron microscopy (SEM). HPGPC analysis showed molecular weight of purified EPS MD1 as 2.909 KDa. Monosaccharide analysis showed that EPS was a novel mannan with mannose as the only monomeric unit present, suggesting EPS to be a homopolysaccharide containing → 6) α-Man p (1 → linkages. Microstructure studies by SEM showed MD1 EPS has globular and porous structure. The purified EPS MD1 exhibited higher thermal stability having degradation temperature around 267.74 °C with melting enthalpy value (Δ H) of 337.7 J/g. The EPS showed promising antioxidant activities with excellent antibiofilm activity against Staphylococcus aureus , Listeria monocytogenes , Salmonella enterica and Salmonella typhi. These striking physicochemical characteristics features and bioactivities of EPS would serve as potential candidate in food processing industry to be used as food adjunct in foods with health benefits. This is the first study reporting a mannan homopolysaccharide from Weissella sp. to be structurally characterized. [ABSTRACT FROM AUTHOR]

The present study reports the biosynthesis of silver nanoparticles (IH-AgNPs) using aqueous leaf extract of Indigofera hisruta L. The biosynthesized IH-AgNPs were found to be FCC crystals, 5-10 nm in size, spherical in shape and stable. The biosynthesized IH-AgNPs showed dose-dependant cytotoxicity against prostate cancer (PC3) (IC50 = 68.5 μg/mL), colon cancer (COLO205) (IC50 = 85.2 μg/mL), and mouse melanoma (B16F10) (IC50 = 80.9 μg/mL). IH-AgNPs were found to be nontoxic towards normal CHO (Chinese hamster ovary) cells. The biosynthesized IH-AgNPs showed effective in vitro antioxidant activity against DPPH (IC50 = 63.43 μg/mL) and H2O2 (IC50 = 89.93 μg/mL) radicals. IH-AgNPs exhibited effective antibacterial activity against both Gram+ve and Gram-ve bacteria. MIC values of IH-AgNPs against S. aureus, B. subtilis, P. aeruginosa and E. coli were found to be 7.8 μg/mL, 3.9 μg/mL, 15.6 μg/mL and 15.6 μg/mL respectively. IH-AgNPs also showed inhibitory activity against fungal pathogens including C. albicans, C. nonalbicans and C. tropicalis. Considering the results together, we demonstrate that IH-AgNPs exhibits three different bioactivities (3-in-1 system) and they could be employed as future antimicrobial, antioxidant and anticancer agents/drug delivery vehicles in the field of biomedicine. [ABSTRACT FROM AUTHOR]

The present study reports a simple and eco-friendly synthesis of silver nanoparticles (AgNPs) using leaf extract of Rhynchosia suaveolens. UV-Vis analysis of R. suaveolens synthesized AgNPs (RS-AgNPs) showed surface plasmon resonance (SPR) peak at 426 nm. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis revealed that RS-AgNPs were 10-30 nm in size with spherical shape. X-ray diffraction (XRD) analysis of RS-AgNPs confirmed the crystalline nature with face-centered cubic (FCC) lattice. Fourier transform infrared (FTIR) interprets that polyphenols and proteins take part in bioreduction and capping of RS-AgNPs. RS-AgNPs exhibited dose-dependent inhibition of proliferation of different cancer cells including DU145 and PC-3(human prostate carcinoma cell lines), SKOV3 (human ovarian carcinoma) and A549 (human lung adenocarcinoma)with IC50 values of 4.35, 7.72, 4.2 and 24.7 μg/mL, respectively. The plausible reasons behind anticancer activity of RS-AgNPs were explained using different assays on the most susceptible SKOV3 cells. RS-AgNPs induced oxidative stress in SKOV3 cells by generating reactive oxygen species (ROS), enhancing lipid peroxidation (LPO) levels and decreasing glutathione (GSH) levels. RS-AgNPs induced the apoptosis of SKOV3 cells by up regulating the caspase-3, caspase -8, caspase -9, p53 and BAX and down regulating the antiapoptotic protein Bcl-2. Further, RS-AgNPs showed elevation of caspase 3/7 activity and also exhibited antimigratory effect by inhibiting the migration of SKOV3 cells into the wounded area. The findings suggested that biogenic RS-AgNPs provide an alternative approach to overcome several limitations of chemotherapy. [ABSTRACT FROM AUTHOR]

The present work is carried out to determine the biodegradation potential of n -hexadecane by bacterial strain P. aeruginosa PU1 isolated from soil polluted with transformer oil. The bacteria showed its ability to grow in n -hexadecane containing medium and its utilization was revealed by a 2, 6-dichlorophenol indophenol assay, where complete decolorization of the medium occurred on the 5th day, at 35 °C. During the n -hexadecane degradation, maximum alkane hydroxylase (147 μmol min−1 mg−1) and alcohol dehydrogenase (113 μmol min−1 mg−1) activities were noticed at 3rd day of incubation. The production of such enzymes is important in the degradation of long-chain alkanes. On 10 days of incubation, P. aeruginosa PU1 degraded 100% n -hexadecane as performed by gravimetric analysis. The formation of P. aeruginosa PU1 biofilm in n -hexadecane containing medium was observed by the Scanning electron microscope (SEM) and intracellular accumulation of n -hexadecane was confirmed by Transmission electron microscope (TEM). Further, studies on ex-situ biodegradation results obtained from the Fourier transform infrared (FT-IR) and Gas Chromatography-Mass Spectrometer (GC-MS) analysis were interrelated with data obtained from Zeta Potential (ZP), Contact Angle (CA) measurement, and Gravimetric Analysis (GA) which showed the hydrophilic nature of the medium due to the production of acids and alcohol on the degradation of n -hexadecane. The biodegradation of the n -hexadecane resulted in the formation of products such as 3-pentyn-1-ol (C 5 H 8 O), n-hexyl formate (C 7 H 14 O 2), cyclopentane propanoic acid (C 8 H 14 O 2), and 2-ethylbutyl acrylate (C 9 H 16 O 2). Based on morphological changes and end products formation upon degradation of n -hexadecane implies that the P. aeruginosa PU1 is a effective and robust model in degradation of n -hexadecane and strain can be utilized for reclamation of sites polluted with petroleum sources. • n -hexadecane degradation by P. aeruginosa PU1 was monitored in BH broth. • The uptake of n -hexadecane by P. aeruginosa PU1 was observed by SEM and TEM. • The amount of alkane hydroxylase and alcohol dehydrogenase enzymes were evaluated. • The impact of biosurfactants on cell surface hydrophobicity was analyzed. • Biodegradation of n -hexadecane was confirmed by DCPIP, Gravimetric, FT-IR, and GC-MS analysis. [ABSTRACT FROM AUTHOR]

A low molecular weight polysaccharide, the AMLP was isolated from the leaves of Avicennia marina and sequentially purified using DEAE-Sepharose fast flow and size exclusion chromatography. Monosaccharide analysis suggested that AMLP is mainly composed of fucose (38.34 %), galactose (30.16 %), mannose (13.32 %), and rhamnose (18.18 %). IR spectroscopy and High-performance size-exclusion chromatography (HPSEC) analysis revealed that AMLP was a sulfated homogenous heteropolysaccharide, and their molecular weight observed was 1.31 kDa. The Spectroscopic analysis of AMLP comprised of (1,2)- α-L-Fuc p , (1,6)-β-D-linked galactan, α-rhamnose, and (1,4)-β-D mannose residues. AMLP has a loosely arranged granular bead-like appearance present on the surface and also with the presence of some porous structures. The rheological properties of AMLP exhibited pseudoplastic properties with shear-thinning flow behavior. Congo red test and X-ray diffraction (XRD) results indicated the semi-crystalline nature of AMLP with a triple-helical structure. Thermogravimetric and Differential scanning calorimetry (TGA-DSC) analysis of AMLP found was thermally stable and its degradation temperature observed was 280 °C. Furthermore, AMLP exhibited potential antibacterial and antibiofilm properties against bacterial pathogens such as Listeria monocytogenes, Escherichia coli , Klebsiella pneumonia , Salmonella typhimurium, and Staphylococcus aureus. The In vitro antioxidant activities such as DPPH scavenging, Superoxide radical scavenging, OH radical scavenging, and reducing power activities of AMLP were evaluated and the results revealed that the tested antioxidant activities of AMLP were significantly (P < 0.05) increased with increasing the concentrations. Overall, these findings suggested that AMLP could be used as a potential candidate in pharmaceutical, cosmetics, and food industry applications. [Display omitted] • AMLP (polysaccharide) from the leaves of Avicennia marina mangrove plant was characterized. • The backbone of AMLP contains (1,2)-α-L-Fuc p , (1,6)-β-D-linked galactan, α-rhamnose and (1,4)-β-D mannose residues. • It shows pseudoplastic flow properties with shear thinning behavior in solution. • AMLP showed triple-helix conformation and high thermal stability with degradation temperature of 280 °C. • It showed promising antioxidant activity and antibiofilm activity against several pathogens. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate the probiotic potential of Weissella confusa MD1 and Weissella cibaria MD2 isolated from a fermented batter. They possessed characters like high survivability in gastrointestinal conditions, tolerance towards lysozyme and phenol. Both strains exhibited strong auto-aggregation property and co-aggregation with Listeria monocytogenes. The adhesion behavior towards intestinal epithelial cells (HT-29 cells) was observed by scanning electron microscopy (SEM). Both strains MD1 and MD2 exhibited antimicrobial activity against foodborne pathogens like Escherichia coli , Salmonella enterica , Listeria monocytogenes , Salmonella typhi and Staphyloccocus aureus. They also showed high bile salt hydrolase activity towards sodium taurocholate and bile salt mixture. Strain MD1 and MD2 demonstrated a tremendous reduction in the cholesterol by 67.11% and 78%, respectively. The intact cells of both strains showed strong antioxidant activity by scavenging 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical and inhibition of linoleic acid peroxidation. The formation of biofilm was demonstrated by using atomic force microscopy (AFM) on the glass cover. Both strains showed sensitivity towards conventionally used antibiotics and no hemolytic activity. The results from the study suggested that Weissella confusa MD1 and Weissella cibaria MD2 have exemplary technological properties that can be implemented in the pharmaceutical and food industry. • Probiotic properties of W. confusa MD1 and W. cibaria MD2 were evaluated. • SEM images revealed phenomenal adhesion behavior towards HT-29 cells. • Both strains showed antimicrobial activity against foodborne pathogens. • Intact cells of both strains possess high antioxidant property. • Both strains were regarded safe after safety evaluation. [ABSTRACT FROM AUTHOR]

Biosurfactant-producing bacteria were isolated from transformer oil-contaminated soil. The strain was identified as Pseudomonas aeruginosa PU1 based on its molecular characterization by 16S rRNA gene sequencing. The extraction of biosurfactant was done by acid precipitation method using 2 N hydrochloric acid and further purified by silica-gel column chromatography. The highest rhamnolipid biosurfactant production (8.92 ± 0.08 g/L) was obtained using molasses (6%, w/v) and ammonium nitrate (5%, w/v). The purified biosurfactant showed a reduction of surface tension of water from 70.23 mN/m to 29.77 mN/m at a concentration of 30 mg/L. The functional groups were characterized by fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance ( 1 H NMR). The liquid chromatography-mass spectrometry (LC-MS) analysis showed six different rhamnolipid congeners with psuedomolecular ions (m/z) of 305, 361, 451, 505, 532 and 621. X-ray diffraction (XRD) analysis and the thermal analysis showed crystalline nature and thermal stability of the biosurfactant. The stability study of the biosurfactant reveals that the emulsifying activity was much stable at various ranges of temperature (4-120 °C), pH (2-12), and NaCl concentration (2-10%, w/v) even on the 7 th day. The purified biosurfactant PU1 was found to be effective in oil recovery and showed 68.53 ± 3.07% of oil recovery in the sand pack column under saline condition, which was higher than anionic surfactant sodium dodecyl sulphate (SDS). The physico-chemical properties and the stability studies of the biosurfactant suggested that it has enormous potential in oil recovery in the soil contaminated with the oils.