Concept of Nuruk on Brewing Technology

Nuruk is a traditional Korean fermentation starter that is used to produce starch-based alcoholic beverages using various cereals as raw material. As a determinant factor for flavor, taste, and color of alcoholic beverages, Nuruk is an indispensable ingredient for brewing alcoholic beverages in Korea. Nuruk shows significant variation in the shape, and in the brewing and fermentation methods, which are dependent on the unique climate in each area. Therefore, it is worthy to note that the characteristics of Korean traditional Nuruk are based on its diversity. Thus, this chapter is aimed to scientifically identify the characteristics of traditional Nuruk on brewing technology. In this chapter, the concept of Nuruk will be discussed in terms of its history, production, microorganism diversity, and enzymatic function

Investigation of bacterial predators for the prevention of membrane biofouling

Environmental Science and EngineeringA flux decrease because of membrane biofouling is a crucial problem restricting membrane applications in conventional water treatment. Several investigations have been investigated to alleviate the biofouling problems; improving feed water qualities through coagulation, chlorine treatment, etc. Even though these methods improve the membrane performance, they are not sustainable due to the dosed chemicals. This is because the chemicals lead to the production of harmful disinfection by-products such as trihalomethanes, aldehydes, etc. In this study, the bacterial predators, BALOs (Bdellovibrio-and-like-organisms), were investigated, as an alternative treatment to alleviate biofouling and its consequent performance decrease. Dead-end microfiltration (MF) tests were conducted on Escherichia coli (E.coli) and BALOs co-culture feed solutions. Predation of E.coli was represented by the multiplicity of infection (MOI), which is explained as the proportion of predator to prey cell. The tested conditions of predation were both high MOI (high predator, HP) and low MOI (low predator, LP), and the total number of viable E.coli prey and predators were counted over 48 hr. The membrane performance of cultures such as NP (no predation), LP and HP was evaluated using a resistance-in-series model. In the performance experiments with a microbial solution containing predator bacterium, its total resistance became lower than the control (NP culture) over 48 hr. However, the LP culture showed an increase of irreversible fouling of the membranes. This was most likely due to prey cell debris produced by predation. In contrast, previous investigations of other research groups showed that coagulation using alum can mitigate membrane biofouling. Additionally, several studies found that lysing the microorganisms utilizing ultrasonication can enhance the membrane performance with alum coagulation. It was hypothesized that the predation impact may be comparable with that of the ultrasonication. This is because both predation and ultrasonication have an effect on the lysis of the bacteria leading to membrane fouling. Thus, it was predicted that a combined pre-treatment of bacterial predation and alum coagulation could improve the membrane performance. From this hypothesis, the goal of another investigation was to evaluate a combined pre-treatment using both bacterial predation and alum coagulation in order to reduce membrane biofouling, specifically, the irreversible fouling from the LP culture. Dead-end microfiltration (MF) tests were conducted on co-culture feed solutions using Escherichia coli and B. bacteriovorus after coagulation with diverse concentrations of alum. The results represented that when 10 ppm of alum was utilized, the membrane fouling got worse for both NP and LP cultures, as compared to no alum addition, because the irreversible resistance of the membrane was a lot higher. Conversely, using alum at 100 ppm reduced the total resistance similarly in both NP and LP cultures noticeably. In addition, for using 100ppm of alum, the LP culture led to both a lower total and irreversible resistance compared to the NP culture. This was because the LP culture with alum coagulation was well aggregated. These results indicate that combined treatments of both B. bacteriovorus predation and a suitable concentration of alum can be an effective pretreatment method for improving membrane performance. Powdered activated carbon (PAC) was used as alum coagulation, for the NP and LP cultures in order to decrease membrane biofouling caused by prey cell debris of the LP culture. Dead-end microfiltration (MF) tests were conducted on both NP and LP cultures, after treatment with various concentrations of PAC. The results showed that when 10 ppm or 100ppm of PAC were added, the performance of the membrane was better for both cultures as compared to no PAC addition. This was because using PAC could have effects on the reduction of reversible resistance. This finding concurs with another previous study that the application of PAC was related to decrease of reversible resistance. Furthermore, for the LP culture, 100ppm of PAC led to a decrease of irreversible resistance compared to 0ppm of PAC. In addition, when 10 ppm or 100ppm of PAC were added, the LP culture caused less total resistance of the membrane compared to the NP culture. These results also show that combined pre-treatments of bacterial predation and PAC treatment can be an effective method for enhancing membrane performance. In conclusion, this study showed that using bacterial predators at a suitably high concentration was useful at mitigating microbial fouling of the membrane. Also, even though using bacterial predators at a low concentration led to an increase of irreversible resistance of the membrane, either a proper alum concentration or PAC treatment, in combination with bacterial predation, can be a beneficial pretreatment method for reducing membrane biofouling.ope

Mixed cultures of Kimchi lactic acid bacteria show increased cell density and lactate productivity

This study was carried out to determine the characteristics of cell growth, lactate production and amino acid secretion among four kimchi lactic acid bacteria (Leuconostoc mesenteroides JEI, Leuconostoc kimchi 132, Lactobacillus sakei 171, and Weissella koreensis 521) alone and in selected mixtures. In solo culture, L. sakei 171 was superior in cell growth, lactate production and the release of amino acids to the extracellular medium. In contrast, W. koreensis 521 showed the least cell growth, lactate production and amino acid release among the tested bacteria. W. koreensis 521 consumed essential amino acids for growth, whereas L. sakei 171 released several of the essential amino acids important for the growth of W. koreensis 521. When we mixed L. sakei 171 and W. koreensis 521 at optimal concentrations, the obtained cell growth and lactic acid production were higher than those seen with either strain alone, presumably reflecting mutual effects between the two strains. Mixed culture of two kimchi lactobacilli on batch fermentation increased the cell density and lactic acid production with low nutrients consumption. These results suggest that mixed culturing of kimchi lactobacilli may be more effective than single culturing of kimchi lactic acid bacteria for improving lactic acid production.Keywords: Kimchi lactic acid bacteria, amino acid utilization, nutrients consumption.African Journal of BiotechnologyVol. 12(25), pp. 4000-400

The Spitzer C2D Survey of Nearby Dense Cores: Jet and Molecular Outflow Associated With A Young Stellar Object in Core A of L1251

A long infrared jet has been discovered by the Spitzer c2d Legacy Program in core A of L1251. It is associated with a very embedded Class 0 object with an accretion luminosity of about 0.9 L(circle dot) derived by radiative transfer model fitting to the observed spectral energy distribution. Comparing the observed Infrared Array Camera colors along the infrared jet with those calculated from a model of an admixture of gas with a power-law temperature distribution indicates that the jet is possibly created by a paraboloidal bow shock propagating into the ambient medium of n(H(2)) = 10(5) cm(-3). In addition, the variation of the power-law index along the jet suggests that the portion of hot gas decreases with distance from the jet engine. The molecular outflow in this region has been mapped for the first time using CO data. From the calculated outflow momentum flux, a very strong lower limit to the average accretion luminosity is 3.6 sin i/cos(3) i L(circle dot), indicative of a decrease in the accretion rate with time.Korean government (MEST) 2009-0062865NRF R01-2007-000-20336-0NASA 1407, 1224608Astronom

Development of Eco-VE Function for Construction

AbstractRecently accepted “Paris Agreement” has restricted the Earth temperature increase to be below 1.5 degrees Celsius contrast to previous industrialization. To follow this agreement, there should be efforts such as carbon emission reduction and eco design etc. One of these efforts is development of eco-VE function that applied eco-friendly concept on VE which is commonly used at design phase. Concept of this model includes carbon productivity concept and potential environment pollution index that reflects eco-VE function on original VE. The carbon productivity concept is a cause of production increase that offset production decrease factor depending on green-house gas reduction. The potential environment pollution index presents the possibility of environment pollution through construction phase. The carbon productivity is ‘Construction cost/Carbon emission’. The construction costs are consisted of material, equipment, labour cost and indirect expenses. Carbon emissions are calculated by emission for material production and equipment fuel consumption. The potential environment pollution index is composed of environmental pollution and conservation cost. The environmental pollution cost includes environmental damage and destruction cost. The environmental conservation cost includes environmental pollution prevention cost, waste treatment cost, environmental pollution compensation, environmental pollution test research funds and law cost