Physiological, biochemical and molecular characterization of potential bacteriocin producing strain isolated from fermented berseem

Lactic acid bacteria in fermented foods help in the improvement of flavour, preservation of the nutritive values of the raw material, and inhibition of growth or killing of food spoilage and pathogenic bacteria. Beside other metabolites, the produced bacteriocin, which is a ribosomally synthesized antimicrobial peptide, is the major metabolite involved in the killing of food spoilage microorganisms and acts as a biopreservative. In search of a bacteriocin having specific inhibitory activity against food pathogenic bacteria, isolation of bacteriocin producing lactic acid bacteria from various food items was carried out. Based on maximum production of the bacteriocin, strain BS13 was characterized and was further identified as Enterococcus faecium BS13 on the basis of physicochemical properties and 16S rRNA analysis. In MRS medium this isolate presented the maximum production of bacteriocin (27 306 AU ml−1) after 18 h of incubation period. BS13 bacteriocin showed antimicrobial activity against a wide range of bacteria, including Bacillus subtilis, Staphylococcus sp., Pediococcus sp., Listeria monocytogenes and Lactobacillus sp

Parametric Optimization of Lactic Acid Extraction from Aqueous Solution in a Mixed Flow Reactor using Emulsion Liquid Membrane by Response Surface Methodology

A statistical programme using Box-Behnken design, which applies a response optimization algorithm, was used to calculate and optimize simultaneously the lactic acid extraction by emulsion liquid membrane (ELM) in a mixed flow reactor. A 3-level Box-Behnken design with seven variables i.e. lactic acid concentration, internal reagent concentration, Alamine 336 fraction in oleyl alcohol, stirring speed, fraction of acceptor phase containing internal reagent in emulsion feed: emulsion ratio and residence time was used to identify a significant correlation between the effect of these variables on lactic acid extraction from aqueous phase since the conventional practice of single factor optimization by maintaining other factors at an unspecified constant level does not depict the combined effect of all the factors involved. The experimental values were found to be in good agreement with predicted values. The analysis of the variance (ANOVA) shows that all the extraction process parameters significantly affect the performance and also shows that there are some interactions between the extraction parameters. The contribution of feed: emulsion ratio and stirring speed on extraction efficiency was more than other factors and the fraction of acceptor phase in emulsion has minimum contribution. The optimum value of the process quantities for the maximization of extraction of lactic acid from aqueous phase using ELM in MFR by the application of Box-Behnken design has been found. The recommended optimal conditions have been verified by conducting confirmation experiments. It can be concluded that the Box-Behnken experimental design provides a suitable means of optimizing and testing the robustness of lactic acid extraction in a MFR using emulsion liquid membrane and 100 % lactic acid extraction in MFR using ELM from aqueous feed can be achieved in few minutes within the specified range of independent process parameters

Parametric Optimization of Lactic Acid Extraction from Aqueous Solution in a Mixed Flow Reactor using Emulsion Liquid Membrane by Response Surface Methodology

A statistical programme using Box-Behnken design, which applies a response optimization algorithm, was used to calculate and optimize simultaneously the lactic acid extraction by emulsion liquid membrane (ELM) in a mixed flow reactor. A 3-level Box-Behnken design with seven variables i.e. lactic acid concentration, internal reagent concentration, Alamine 336 fraction in oleyl alcohol, stirring speed, fraction of acceptor phase containing internal reagent in emulsion feed: emulsion ratio and residence time was used to identify a significant correlation between the effect of these variables on lactic acid extraction from aqueous phase since the conventional practice of single factor optimization by maintaining other factors at an unspecified constant level does not depict the combined effect of all the factors involved. The experimental values were found to be in good agreement with predicted values. The analysis of the variance (ANOVA) shows that all the extraction process parameters significantly affect the performance and also shows that there are some interactions between the extraction parameters. The contribution of feed: emulsion ratio and stirring speed on extraction efficiency was more than other factors and the fraction of acceptor phase in emulsion has minimum contribution. The optimum value of the process quantities for the maximization of extraction of lactic acid from aqueous phase using ELM in MFR by the application of Box-Behnken design has been found. The recommended optimal conditions have been verified by conducting confirmation experiments. It can be concluded that the Box-Behnken experimental design provides a suitable means of optimizing and testing the robustness of lactic acid extraction in a MFR using emulsion liquid membrane and 100 % lactic acid extraction in MFR using ELM from aqueous feed can be achieved in few minutes within the specified range of independent process parameters

Screening of media components and process parameters for production of L(+) lactic acid from potato waste liquid using amylolytic Rhizopus oryzae

The utilization of potato waste liquid instead of synthetic substrates for lactic acid production cannot only reduce the production cost but also makes the process environment effective. Unlike many lactic acid bacteria, lactic acid producing Rhizopus strains generates L(+) lactic acid as a sole isomer of lactic acid. Furthermore, some Rhizopus spp. are amylolytic in nature and can produce lactic acid from starchy substrates without prior saccharification. This study aimed at the utilization of potato waste liquid for the production of L(+) lactic acid using amylolytic Rhizopus oryzae MTCC 8784. The effect of media components and process parameters on simultaneous saccharification and fermentation of potato waste liquid by fungal strain has been studied to maximize the production of L(+) lactic acid. The results revealed that highest lactic acid production (15.5 g l–1) was obtained with potato waste liquid containing 30 g l–1 starch supplemented with soya okara hydrolysate (1.5%, v/v), calcium carbonate (1.5%, w/v), and salts. In terms of process parameters, the maximum L(+) lactic acid (18.15 g l–1) production was obtained at pH 6 with temperature 30 °C, agitation of 150 r.p.m., after incubation period of 48 h

Utilization of agro-industrial residues for the production of β-Galactosidase using fungal isolate under solid state fermentation conditions

β-Galactosidase is an enzyme of commercial importance owing to its multiple benefits. Among all microbial sources, fungal species are of great interest for the production of this enzyme. Thus, the aim of this present work was to optimize the media as well as process parameters to achieve maximum β-Galactosidase production by solid state fermentation using the fungal isolate Rhizomucor pusillus. Various agro-industrial residues were tested for carbon as well as for nitrogen sources. The different process parameters were also studied to observe their effects on β-galactosidase production. Among all screened agro-industrial residues, wheat bran and corn steep liquor had the potential to be used as carbon and nitrogen sources, respectively; whereas MgSO4 was found to be a suitable salt supplement. The optimal process parameters included particle size of 1000 microns, 50% moisture content, pH 5.5, 50 ºC temperature, and 7 days of fermentation

On the structure and evolution of a polar crown prominence/filament system

Polar crown prominences are made of chromospheric plasma partially circling the Suns poles between 60 and 70 degree latitude. We aim to diagnose the 3D dynamics of a polar crown prominence using high cadence EUV images from the Solar Dynamics Observatory (SDO)/AIA at 304 and 171A and the Ahead spacecraft of the Solar Terrestrial Relations Observatory (STEREO-A)/EUVI at 195A. Using time series across specific structures we compare flows across the disk in 195A with the prominence dynamics seen on the limb. The densest prominence material forms vertical columns which are separated by many tens of Mm and connected by dynamic bridges of plasma that are clearly visible in 304/171A two-color images. We also observe intermittent but repetitious flows with velocity 15 km/s in the prominence that appear to be associated with EUV bright points on the solar disk. The boundary between the prominence and the overlying cavity appears as a sharp edge. We discuss the structure of the coronal cavity seen both above and around the prominence. SDO/HMI and GONG magnetograms are used to infer the underlying magnetic topology. The evolution and structure of the prominence with respect to the magnetic field seems to agree with the filament linkage model.Comment: 24 pages, 14 figures, Accepted for publication in Solar Physics Journal, Movies can be found at http://www2.mps.mpg.de/data/outgoing/panesar

Specific Features of Table Wine Production Technology

Humans have been making and consuming wine from the time immemorial. Most of the wines produced in the world are undoubtedly made from grapes and the technique of winemaking has developed by hit and trial until the fundamental of microbiology, biochemistry, food science especially sensory science could be developed and applied. Fruits other than grapes are also used to make wine. This chapter focuses on the specific features of making table wine from non-grape fruits, viz., pome fruits, stone fruits, berries, citrus fruits, and tropical fruits. The pome fruits include apple, pear, quince, cotoneaster, hawthorn, loquat, medlar, Pyracantha, toyon, rowan, and whitebeam while apricots, plums, peaches, and cherries are the major stone fruits. Among the colorful fruits, are the berries such as blackberry (Rubus sp.), black raspberry (Rubus occidentalis), blueberry (Vaccinium corymbosum), cranberry (Vaccinium macrocarpon), red raspberry (Rubus idaeus), strawberry (Fragaria. ananassa), etc. Citrus fruits include orange, lime, lemon, and kinnow, among others, whereas there are hundreds of edible tropical fruits. All these fruits are nutritious, tasty, and flavorful; are very good sources of anthocyanins/carotenoids, minerals like K, Na, Ca, Mg, and Fe, and vitamins, especially vitamin C; are juicy/pulpy in nature; and have appealing color; but their sugar and acid contents vary. In addition, many fruits are good sources of polyphenols that contribute to their antioxidant activities. Being highly perishable, these fruits have to be either consumed immediately or preserved in one or another form, and conversion of such fruits into wine of acceptable quality could save these precious resources from postharvest losses to a greater extent. Consequently, the production of wine from these fruits is receiving a lot of attention these days, with the added advantage that they contain antioxidants, considered useful in preventing cardiovascular diseases.This chapter describes in detail the methods used to produce wines and low-alcoholic beverages from pome fruits, stone fruits, berries, citrus fruits, and tropical fruits. The process of alcoholic fermentation to make wines from these fruits is basically the same as that for grapes, but there are some major differences in the techniques of production of wines from these fruits because of the difficulty in extracting the sugar from the pulp of some of the fruits, and their composition is especially high in acidity, and thus amelioration of the must or blending is needed to make the wine palatable. Biological deacidification in fruits using the yeast like Schizosaccharomyces pombe has been attempted and hold promise in future. In fruit wine production, the selection of good variety; amelioration, especially for sugar content; pectinase enzyme treatment (to increase the yield of juice) and later clarification of wines produced; inclusion of other additives, especially a nitrogen source; and, consequently, ethanol production are very important. Research and development efforts have been made quite extensively in the preparation of apple wine, apple cider, plum wine, apricot wine, strawberry wine, jamun wine, passion fruits wine, peach wine, berries wine and perry and accordingly, some of these products are produced commercially. Because almost all the stone fruits are low in sugar, have high acidity, and are pulpy in nature, to make wine of acceptable quality from these fruits is not easy, and accordingly, modifications are needed. Methods to prepare various berry wines, viz., strawberry, cherry, raspberry, sea buckthorn, and lychee, are well investigated, but wines from fruits like papaya, pumpkin, persimmon, passion fruit, etc., are still being standardized. Citrus wines, which are produced in a specific wine style, may demand unique conditions compared to grapes and other fruits. Specific mention can be made of problems of bitterness in citrus fruits and to overcome the same efforts have been made with encouraging results. These wines undergo different biological and chemical processes that affect their chemical composition and their volatile, phenolic, and sensory properties distinctively. Orange and mandarin winemaking techniques have been well documented and are described in this chapter. Wines from many tropical fruits like mango, banana, pineapple, papaya, guava, custard apple, lychee, watermelon, coconut, sapota, and jamun have also been prepared and evaluated for their acceptability, especially that from mango (Mangifera indica L), as reviewed in this chapter. For mango wine, optimization of the fermentation conditions, production profiles of higher alcohols and other volatile compounds during wine fermentation, total volatile composition, and identification of compounds having fruity aroma characters have been carried out. Similarly, a very interesting line of research is focusing on the antimicrobial and antioxidant activities of fruit wines and the components responsible for the same. Extensive research has been reported on various aspects of wine production including the study of the effects on maturation of these wines using wood chips from various trees.Compared to the quantity of grape wine produced and consumed in the world, the quantity of wine produced from nongrape fruits is insignificant, except for cider and perry, which are produced and consumed in significant quantities throughout the world. But research on the preparation of wines from other pome fruits is at the preliminary stage, so it could certainly be a fruitful area of research, especially in those countries and regions where these fruits are cultivated on a commercial scale. Despite the efforts made and described here for the preparation of berry wines, there are a large number of research gaps for more elaboration in future. But by and large, more concerted and in-depth research is required to make the technology for the commercial production of wines from these fruits a successful commercial venture. © 2017 Elsevier Inc. All rights reserved