Extraction and characterization of exopolysaccharides from Lactiplantibacillus plantarum strain PRK7 and PRK 11, and evaluation of their antioxidant, emulsion, and antibiofilm activities

Exopolysaccharides (EPS) are produced by probiotic bacteria Lactiplantibacillus plantarum PRK7 and L. plantarum PRK11. The structure of EPS-7 and EPS-11 was characterized by Fourier-transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), gas chromatography-mass spectroscopy (GCMS), and thermogravimetric analysis (TGA). Further, in in vitro studies antioxidant, emulsion, and antibiofilm activity were investigated. The FTIR spectrum confirmed the presence of polysaccharides in EPS-7 and EPS-11, with absorbance at 1654.93 and 1655.33 cm^-1, respectively. H¹ NMR further confirmed the presence of glucose, galactose, xylose, and mannose. Sugar derivatives in EPS-7 and EPS-11 were further confirmed with GCMS. The SEM analysis revealed that EPS-7 had a weblike structure and EPS-11 had a smooth porous layer. The result of the TGA revealed that EPS-7 and EPS-11 had greater thermal stability at 319.1 and 300.1 °C, respectively. Furthermore, EPS-7 and EPS-11 showed a good percentage of free radical scavenging in DPPH (89.77 % and 93.1 %), ABTS (57.65 % and 58.63 %), hydroxyl radical scavenging (44.46 % and 40.308 %), and reducing power assay. The emulsion activity was confirmed with edible oils such as coconut oil, sesame oil, almond oil, castor oil, and neem oil. The highest emulsion activity for EPS-7 and EPS-11 was found be with coconut and castor oil. In addition, the antibiofilm activity against pathogens revealed that EPS possess can prevent biofilm formation. Thus, it was found that EPS-7 and EPS-11 possess good structural characteristics and their biological activity makes them ideal for applications in the food and pharmaceutical industry.

IN-VITRO ASSESSMENT OF PROBIOTIC PROPERTIES OF LACTIC ACID BACTERIA ISOLATED FROM NATURALLY FERMENTED RICE GRUEL OF SOUTH INDIA

Fermented foods prepared traditionally involves natural fermentation by numerous beneficial bacteria. The scientific evidence for the presence of specific probiotic strains in fermented rice gruel is lacking. The objective of our study is to identify the lactic acid bacteria involved in the fermentation of rice gruel and to evaluate their probiotic characteristics. From the fermented rice gruel, Pediococcus pentosaceus strain PRK1 (MT019527) and Lactobacillus plantarum strain PRK7 (MT022517) and Lactobacillus plantarum strain PRK11 (MT022576) were identified by 16s rRNA gene sequencing and their sequence was submitted to NCBI. The invitro probiotic characterization methods like autoaggregation, co-aggregation, tolerance to acidic pH, bile, Nacl, antibacterial activity, antibiotic susceptibility and safety assessment were analyzed in this study. The evaluated invitro probiotic properties of the isolates were tolerance to pH 2; autoaggregation is 91%, 83 %, and 89%; co-aggregation is 36.1%, 37.1%, and 42.5%; the percentage of suppression at 0.3% of bile is 88%, 86.5%, and 81.3% and tolerance to 4% of NaCl. The isolates exhibited antibacterial activity against the clinical pathogens E. coli, P. aeroginosa, Proteus sp., K. pneumoniae, Salmonella sp., S. aureus, Staphylococcus haemolyticus, Enterococcus faecium, and S. epidermidis. The safety assessment of the isolates exhibits no hemolytic activity and it is also sensitive to most of the tested antibiotics. Further, nutrition profiling of fermented rice gruel shows increase in micronutrients and the presence of vitamin B9 and B12. Hence, this study provides evidence for the presence of lactic acid bacteria in the fermented rice gruel an indigenous food  which can be developed as functional food in future.

Green synthesis of stable antioxidant, anticancer and photocatalytic activity of zinc oxide nanorods from Leea asiatica leaf

The present work reveals zinc oxide nanorods (ZnO NRs) obtained via green synthesis approach utilizing phytochemicals present in the Leea asiatica plant. The synthesized ZnO NRs was confirmed by various characterization methods like X-ray diffraction, FTIR, SEM-EDX, UV-vis, TEM and Raman spectra analysis. The obtained nanorods show less particle size with a distinctive high surface area. The photodegradation activity of obtained ZnO NRs shows 81.3 % of dye degradation at high concentration whereas 42.9 % in low concentration and also antioxidant test shows a better result for free radical scavenging. To understand the safety of the ZnO NRs zebrafish embryos was utilized as a model and found to be less toxic after assessment. Furthermore, to understand the anticancer activity of ZnO NRs it was assessed against breast cancer cell line through MTT, XTT, NRU, and LDH assay. The ZnO NRs exposed against breast cancer cell line (MCF-7) had resulted in necrosis and apoptosis which was further confirmed by genotoxicity assay. Also, the molecular mechanisms behind the necrosis and apoptosis are also discussed to show the involvement of ZnO NRs towards breast cancer cells (MCF-7). The present study on ZnO NRs gives a wide spectrum understanding of using ZnO NRs as a potential drug for human breast cancer by showing its physiological pathways as well as a novel way to synthesize ZnO NRs using Leea asiatica plant extract.

A novel minimum cost maximum power algorithm for future smart home energy management

With the latest development of smart grid technology, the energy management system can be efficiently implemented at consumer premises. In this paper, an energy management system with wireless communication and smart meter are designed for scheduling the electric home appliances efficiently with an aim of reducing the cost and peak demand. For an efficient scheduling scheme, the appliances are classified into two types: uninterruptible and interruptible appliances. The problem formulation was constructed based on the practical constraints that make the proposed algorithm cope up with the real-time situation. The formulated problem was identified as Mixed Integer Linear Programming (MILP) problem, so this problem was solved by a step-wise approach. This paper proposes a novel Minimum Cost Maximum Power (MCMP) algorithm to solve the formulated problem. The proposed algorithm was simulated with input data available in the existing method. For validating the proposed MCMP algorithm, results were compared with the existing method. The compared results prove that the proposed algorithm efficiently reduces the consumer electricity consumption cost and peak demand to optimum level with 100% task completion without sacrificing the consumer comfort.