• Food Science and Biotechnology
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• v.16 no.6
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• pp.948-953
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• 2007

The powdered cereal sunsik is a partially thermal-processed product that required safety evaluations for food-borne pathogens. Thirty-six sunsik products from Korean markets were collected and analyzed for contamination by total viable cell counts, coliforms, Escherichia coli, and the spore-forming Clostridium perfringens and Bacillus cereus. Enterobacter sakazakii, as a newly emerging pathogen, was also analyzed. Approximately 28% of sunsik were contaminated at 5 log CFU/g for total viable counts. Coliforms and E. coli were detected in 33 and 4% of the samples, respectively. The spore-forming B. cereus was found in 42% of the samples at a maximal level of 3 log CFU/g on average. About 6% the samples were contaminated with Cl. perfringens at an average level of 15 CFU/g. Forty-five % of sunsik contained E. sakazakii, at levels from 0.007 to over 1.1 cell/g by MPN method. In addition, one sunsik product for infants and children showed over 3 log CFU/g for both B. cereus and E. sakazaki. Therefore, concern should be placed on controlling for microbial hazards such as B. cereus and E. sakazakii in sunsik, particularly for the products fed to infants under 6 months of age.

• Korean Journal of Food Science and Technology
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• v.16 no.3
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• pp.267-272
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• 1984

${\beta}-Fructofuranosidase$ was immobilized covalently on the oxidized microbial wall of a Penicillium spp. 'PS-8', which is totally different from the conventional whole cell immobilization in concept. The immobilization of ${\beta}-fructofuranosidase$ by a series of treatments; oxidation of microbial cells with sodium metaperiodate, enzyme loading on the oxidized cells, extrusion, and crosslinking induced by glutaradehyde, were carried out. The final product had a good mechanical strength and showed 26% of the applied enzyme activity. The specific activity was 750 units per g of the dry cell product. The immobilized enzyme showed the kinetic parameters as follows; optimum pH at 5, optimum temperature at $55^{\circ}C$, activation energy of 19 kJ $mol^{-1}$, and apparent Km of 55 mM.

• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.670-677
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• 2010

An alkaline pectate lyase, Bsp165PelA, was purified to homogeneity from the culture broth of alkaliphilic Bacillus sp. N16-5. The enzyme showed a specific activity as high as 1,000 U/mg and had optimum activity at pH 11.5 and $50^{\circ}C$. It was composed of a single polypeptide chain with a molecular mass of 42 kDa deduced from SDS-PAGE, and its isoelectric point was around pH 6.0. It could efficiently depolymerize polygalacturonate and pectin. Characterization of product formation revealed unsaturated digalacturonate and trigalacturonate as the main products. The pectate lyase gene (pelA) contained an open reading frame (ORF) of 1,089 bp, encoding a 36-amino acids signal peptide and a mature protein of 326 amino acids with a calculated molecular mass of 35.943 Da. The deduced amino acid sequence from the pelA ORF exhibited significant homology to those of known pectate lyases in polysaccharide lyase family 1. Some conserved active-site amino acids were found in the deduced amino acid sequence of Bsp165PelA. $Ca^{2+}$ was not required for activity on pectic substrates.

• Journal of Microbiology and Biotechnology
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• v.23 no.12
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• pp.1717-1725
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• 2013

Traditional soybean paste from Shandong Liangshan and Tianyuan Jiangyuan commercial soybean paste were chosen for analysis and comparison of their bacterial and fungal dynamics using denaturing gel gradient electrophoresis and 16S rRNA gene clone libraries. The bacterial diversity results showed that more than 20 types of bacteria were present in traditional Shandong soybean paste during its fermentation process, whereas only six types of bacteria were present in the commercial soybean paste. The predominant bacteria in the Shandong soybean paste were most closely related to Leuconostoc spp., an uncultured bacterium, Lactococcus lactis, Bacillus licheniformis, Bacillus spp., and Citrobacter freundii. The predominant bacteria in the Tianyuan Jiangyuan soybean paste were most closely related to an uncultured bacterium, Bacillus licheniformis, and an uncultured Leuconostoc spp. The fungal diversity results showed that 10 types of fungi were present in the Shandong soybean paste during the fermentation process, with the predominant fungi being most closely related to Geotrichum spp., an uncultured fungal clone, Aspergillus oryzae, and yeast species. The predominant fungus in the commercial soybean paste was Aspergillus oryzae.

• Food Science of Animal Resources
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• v.36 no.5
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• pp.617-625
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• 2016

Pastırma, a dry-cured meat product, is produced from the whole muscle and/or muscles obtained from certain parts of beef and water buffalo carcasses. The purpose of this study was to determine the effects of different levels of sodium nitrite on changes in the physicochemical and microbial quality during the production of pastırma. The changes in residual nitrite, salt, pH, moisture, thiobarbutiric acid reactive substances (TBARS), colour (L*, a*, b*), total aerobic mesophilic bacteria (TAMB), lactic acid bacteria (LAB), Micrococcus/Staphylococcus (M/S), mould-yeast (M-Y), and Enterobacteriaceae counts of pastırma with 0, 50, 100 and 150 ppm sodium nitrite were determined during the production. The nitrite levels and the production stages had significant effects (p<0.01) on residual nitrite, TBARS, pH, salt, and colour values. The TBARS values of the pastırma with nitrite were significantly lower (p<0.05) than the control. The final TAMB, LAB, M/S, and M-Y counts of pastırma with 150 ppm nitrite were significantly (p<0.05) lower than the control. Also, the a* (relative redness) values of control pastırma were significantly lower (p<0.05) than the pastırma with nitrite. The production stages had a significant effect (p<0.01) on the moisture.

• Journal of Microbiology and Biotechnology
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• v.20 no.5
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• pp.853-861
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• 2010

High substrate costs decrease the profitability of polyhydroxyalkanoates (PHAs) production, and thus low-cost carbon substrates coming from agricultural and industrial residuals are tested for the production of these biopolymers. Among them, crude glycerol, formed as a by-product during biodiesel production, seems to be the most promising source of carbon. The object of this study was to characterize the mixed population responsible for the conversion of crude glycerol into PHAs by cultivation-dependent and -independent methods. Enrichment of the microbial community was monitored by applying the Ribosomal Intergenic Spacer Analysis (RISA), and the identification of community members was based on 16S rRNA gene sequencing of cultivable species. Molecular analysis revealed that mixed populations consisted of microorganisms affiliated with four bacterial lineages: ${\alpha}$, ${\gamma}$-Proteobacteria, Actinobacteria, and Bacteroides. Among these, three Pseudomonas strains and Rhodobacter sp. possessed genes coding for polyhydroxyalkanoates synthase. Comparative analysis revealed that most of the microorganisms detected by direct molecular analysis were obtained by the traditional culturing method.

• Journal of Dairy Science and Biotechnology
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• v.29 no.2
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• pp.51-57
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• 2011

Milk and dairy products are nutritionally one of the most important food in human health and the quality of raw milk is significantly important to ensure safety of dairy products. However, milk and dairy products are commonly related with chemical and microbial contaminations. Therefore, rapid and reliable detection of hazardous (e.g. pathogenic bacteria, pesticides, antibiotics, microbial toxins) in milk and dairy products is essential to ensure human health and food safety. Conventional methods for detection of food hazardous are mostly time-consuming to yield a results. Recently, biosensors have been focused as its rapidity and high sensitivity to analyse chemical and microbial hazardous from a variety of foods and environments. This study reviewed the recent trends and applications of biosensors as rapid detection method of hazardous in milk and dairy products.

• Food Science of Animal Resources
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• v.44 no.2
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• pp.309-325
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• 2024

The consumption of meat has been increasing, leading to a dynamic meat and meat processing industry. To maintain the quality and safety of meat products, various technologies have been explored, including intense pulsed light (IPL) technology. Several factors affect the inactivation of microorganisms by IPL treatment, including light intensity (fluence), treatment duration, pulse frequency, and the distance between the lamp and the samples. Meat products have been studied for IPL treatment, resulting in microbial reductions of approximately 0.4-2.4 Log. There are also impacts on color, sensory attributes, and physico-chemical quality, depending on treatment conditions. Processed meat products like sausages and ham have shown microbial reductions of around 0.1-4 Log with IPL treatment. IPL treatment has minimal impact on color and lipid oxidation in these products. Egg products and dairy items can also benefit from IPL treatment, achieving microbial reductions of around 1-7.8 Log. The effect on product quality varies depending on the treatment conditions. IPL technology has shown promise in enhancing the safety and quality of various food products, including meat, processed meat, egg products, and dairy items. However, the research results on animal-based food are not diverse and fragmentary, this study discusses the future research direction and industrial application through a review of these researches.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.10
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• pp.1464-1469
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• 2016

This study was carried out to investigate the effect of dietary supplementation of red ginseng by-product (RGB) on the laying performance, blood biochemistry, and microbial population in laying hens. A total of 120 Hy-Line Brown laying hens (75 weeks old) were randomly allotted to 1 of 3 dietary treatments with 4 replicates per treatment. A commercial-type basal diet was prepared, and 2 additional diets were prepared by supplementing 5.0 or 10.0 g/kg of RGB to the basal diet at the expense of corn. The diets were fed to hens on an ad libitum basis for 4 weeks. There were no differences in feed intake, egg weight, and feed conversion ratio during 4 weeks of the feeding trial. However, hen-day egg production was significantly greater (p<0.05) for the RGB treatment groups than that for the basal treatment group. There were no differences in triglyceride, aspartate aminotransferase, and alanine aminotransferase during the 4-week feeding trial. However, RGB supplementation increased (p<0.05) the serum immunoglobulin G (IgG) and IgM content compared with basal treatment group. The total cholesterol was lower (p<0.05) in the RGB treatments groups than that in the basal treatment group. The intestinal Lactobacillus population was greater (p<0.05) for the RGB treatments groups than that for the basal treatment group. However, the numbers of Salmonella and Escherichia coli were not different among dietary treatments. During the entire experiment, there was no significant difference in egg quality among all the treatments. In conclusion, in addition to improving hen-day production, there were positive effects of dietary RGB supplementation on serum immunoglobulin and cholesterol levels in laying hens.

• Journal of Microbiology and Biotechnology
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• v.25 no.2
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• pp.178-184
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• 2015

This work aims to utilize wastes from the potato starch industry to produce single-cell protein (SCP) with high lysine content as animal feed. In this work, S-(2-aminoethyl)-_L-cysteine hydrochloride-resistant Bacillus pumilus E1 was used to produce SCP with high lysine content, whereas Aspergillus niger was used to degrade cellulose biomass and Candida utilis was used to improve the smell and palatability of the feed. An orthogonal design was used to optimize the process of fermentation for maximal lysine content. The optimum fermentation conditions were as follows: temperature of 40℃, substrate concentration of 3%, and natural pH of about 7.0. For unsterilized potato starch wastes, the microbial communities in the fermentation process were determined by terminal restriction fragment length polymorphism analysis of bacterial 16S rRNA genes. Results showed that the dominant population was Bacillus sp. The protein quality as well as the amino acid profile of the final product was found to be significantly higher compared with the untreated waste product at day 0. Additionally, acute toxicity test showed that the SCP product was non-toxic, indicating that it can be used for commercial processing.