• Journal of Life Science
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• v.33 no.10
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• pp.808-819
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• 2023

This study was conducted to develop a selection marker for the identification of the Bacillus licheniformis K12 strain in microbial communities. The strain not only demonstrates good growth at moderate temperatures but also contains enzymes that catalyze the decomposition of various polymer materials, such as proteases, amylases, cellulases, lipases, and xylanases. To identify molecular markers appropriate for use in a microbial community, a search was conducted to identify variable gene regions that show considerable genetic mutations, such as recombinase, integration, and transposase sites, as well as phase-related genes. As a result, five areas were identified that have potential as selection markers. The candidate markers were two recombinase sites (BLK1 and BLK2), two integration sites (BLK3 and BLK4), and one phase-related site (BLK5). A PCR analysis performed with different Bacillus species (e.g., B. licheniformis, Bacillus velezensis, Bacillus subtilis, and Bacillus cereus) confirmed that PCR products appeared at specific locations in B. licheniformis: BLK1 in recombinase, BLK2 in recombinase family protein, and BLK3 and BLK4 as site-specific integrations. In addition, BLK1 and BLK3 were identified as good candidate markers via a PCR analysis performed on subspecies of standard B. licheniformis strains. Therefore, the findings suggest that BLK1 can be used as a selection marker for B. licheniformis species and subspecies in the microbiome.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.4
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• pp.550-556
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• 2014

Rice bran contains both excellent nutritional value and functional advantages. Its utilization is limited due to reducing texture and low storage. To satisfy various tastes, Bacillus spp. having high amylase and protease activities were selected. Using the strains, we made whole grain soybean Meju with a reduced manufacturing period by increasing the concentration of total nitrogen. We made soy sauces with mashing ratios of soy bean and rice bran at 10:0, 9:1, 7:3, and 5:5, and then compared their physiochemical properties. After 2 weeks of fermentation, the sugar content increased from 21~22% to 30~32%. However, pH and salinity showed no differences. At a ratio of 9:1, total nitrogen, amino nitrogen content, and total free amino acid contents were the highest at 1.62%, 652.52 mg%, and 8,804.03 mg/kg, respectively, compared to other mashing ratios of soy bean and rice bran. Especially, the contents of aspartic and glutamic acid, which increase delicate flavoring, were higher in our soy sauce compared to those of general traditional soy sauce and brewed soy sauce, which were 504.25 and 1,262.25 mg/kg, respectively. Serine and alanine, which are related to sweet taste, were present at 49.50 and 518.75 mg/kg, respectively, which were the highest among all mixing ratios, at a ratio of 9:1. Compared to general traditional soy sauce and brewed soy sauce, the contents of histamine and tyramine among biogenic amines decreased to 35.85 and 41.04 mg/kg, respectively. Finally, a soy bean and rice bran mixing ratio of 9:1 was determined to be the optimal mixing ratio in the sensory evaluation.

• Applied Biological Chemistry
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• v.11
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• pp.1-27
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• 1969

More than thirty kinds of sea food pickles have been eaten in Korea. Out of these salted yellow tail pickle, salted clam pickle, salted oyster pickle, and salted cuttlefish pickle were employed for the analysis of their components, identification of main fermenting microbes, and determination of enzyme characteristics concerned. Also studied was the effect of enzymic action of microbes, which are concerned with the fermenting of pickles, on the production of flavorous 5'-mononucleotides and amino acids. The results are summarized as follows: 1. Microflora observed in the pickles are: (a) Total count of viable cells after 1-2 months of pickling was found to be $10^7$ and that after 6 months decreased to $10^4$. (b) Microbial occurence in the early stage of pickling was observed to be 10-20% Micrococcus spp., 10-20% Brevibacterium spp., 0-30% Sarcina spp., 20-30% Leuconostoc spp., ca 30% Bacillus spp., 0-10% Pseudomonas spp., 0-10% Flavobacterium spp., and 0-20% yeast. (c) Following the early stage of pickling, mainly halophilic bacteria such as Bacillus subtilis, Leuconostoc mesenteroides, Pediococcus halophilus and Sarcina litoralis, were found to exhibit an effect on the fermentation of pickle and their enzyme activities were in direct concern in fermentation of pickles. (d) Among the bacteria participating in the fermentation, Sarcina litoralis 8-14 and 8-16 strains were in need of high nutritional requirement and the former was grown only in the presence of purine, pyrimidine and cystine and the latter purine, pyrimidine and glutamic acid. 2. Enzyme characteristics studied in relation to the raw materials and the concerned microbes isolated are as follows: (a) A small amount of protease was found in the raw materials and 30-60% decrease in protease activity was demonstrated at 7% salt concentration. (b) Protease activity of halophilic bacteria, Bacillus subtilis 7-6, 11-1, 3-6 and 9-4 strains, in the complete media decreased by 10-30% at the 7% salt concentration and that of Sarcina litoralis 8-14 and 8-16 strains decreased by 10-20%. (c) Proteins in the raw materials were found to be hydrolyzed to yield free amino acids by protease in the fermenting microbes. (d) No accumulation of flavorous 5'-mononucleotides was demonstrated because RNA-depolymerase in the raw materials and the pickles tended to decompose RNA into nucleoside and phosphoric acid. (e) The enzyme produced in Bacillus subtilis 3-6 strain isolated from the salted clam pickles, was ascertained to be 5'-phosphodiesterase because of its ability to decompose RNA and thus accumulating 5'-mononucleotide. (f) It was demonstrated that the activity of phosphodiesterase in Bacillus subtilis 3-6 strain was enhanced by some components in the corn steep liquor and salted clam pickle. The enzyme activity was found to decrease by 10-30% and 40-60% at the salt concentration of 10% and 20%, respectively. 3. Quantitative data for free amino acids in the pickles are as follows: (a) Amounts of acidic amino acids such as glutamic and aspartic acids in salted clam pickle, were observed to be 2-10 times other pickles and it is considered that the abundance in these amino acids may contribute significantly to the specific flavor of this food. (b) Large amounts of basic amino acids such as arginine and histidine were found to occur in salted yellow tail pickle. (c) It is much interesting that in the salted cuttlefish pickle the contents of sulfur-containing amino acids were exceedingly high compared with those of others: cystine was found to be 17-130 times and methionine, 7-19 times. (d) In the salted oyster pickle a high content of some essential amino acids such as lysine, threonine, isoleucine and leucine, was demonstrated and a specific flavor of the pickle was ascribed to the sweet amino acids. Contents of alanine and glycine in the salted oyster pickle were 4 and 3-14 times as much as those of the others respectively. 4. Analytical data for 5'-mononucleotides in the pickles are as follows: (a) 5'-Adenylic acid and 3'-adenylic acid were found in large amounts in the salted yellow tail pickle and 5'-inosinic acid in lesser amount. (b) 5'-Adenylic acid, especially 3'-adenylic acid predominated in amount in the salted oyster pickle over that in the other pickles. (c) The salted cuttlefish pickle was found to contain only 5'-adenylic acid and 3'-adenylic acid. It has become evident from the above fact that clam and the invertebrate lack of adenylic deaminase and contain high content of adenylic acid. Thus, they were demonstrated to be the AMP-type. (d) 5'-Inosinic acid was contained in the salted yellow tail pickle in a significant concentration, and it might be considered to be IMP-type. 5. Comparative data for flavor with regard to the flavorous amino acids and the contents of 5'-mononucleotides are: (a) A specific flavor of salted yellow tail pickle was ascribed to the abundance in glutamic acid and aspartic acid, and to the existence of a small amount of flavorous 5'-inosinic acid. The combined effect of these components was belived to exhibit a synergistic action in producing a specific fiavor to the pickle. (b) A specific flavor of salted clam pickle has been demonstrated to be attributable to the richness in glutamic acid and aspartic acid rather than to that of 5'-mononucleotides.

• Journal of Animal Science and Technology
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• v.44 no.5
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• pp.549-560
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• 2002

This study, including two in vitro experiments and an in vivo experiment were conducted to evaluate effects of Passtein$^{(R)}$ on crude protein degradability, ruminal fermentation characteristics and nutrient digestibility. In in vitro experiment protein degradability was examined using borate-phosphate buffer and neutral detergent, and using protease from Stroptomyces griseus at 39$^{\circ}C$ for 0, 2, 4, 8, 12, and 48 h. In addition, an in vivo experiment was conducted in a switch back design and ruminal fermentation and nutrient digestibility were determined. Four ruminal-fistulated Holstein cows weighing 300kg in mean body weight randomly allotted to 2 treatments (control and Passtein$^{(R)}$ supplementation). Although there was no significant difference on protein fraction between treatments, it appears that Passtein$^{(R)}$ supplementation decreased buffer soluble protein fraction compared to control. Protein degradability was not affected by Passtein$^{(R)}$ from 0 h to 4 h, but decreased at 12 h and 48 h compared to control. Degradation of immediately degradable fraction was higher in Passtein$^{(R)}$ treatment, but degradation of fermentable fraction was lower in Passtein$^{(R)}$ treatment compared to control. The pH and $NH_3$-N concentration tended to increase in Passtein$^{(R)}$ treatment, but VFA production, microbial counts and enzyme activity tended to decrease in Passtein$^{(R)}$ treatment compared to control. In addition, nutrient digestibility in the total tract tended to increase in Passtein$^{(R)}$ treatment compared to control.

• Microbiology and Biotechnology Letters
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• v.42 no.3
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• pp.267-274
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• 2014

High pressure processing (HPP) is a non-thermal method used to prevent bacterial growth in the food industry. Currently, pasteurization is the most common method in use for most milk processing, but this has the disadvantage that it leads to changes in the milk's nutritional and chemical properties. Therefore, the effects of HPP treatment on the microbiological and chemical properties of milk were investigated in this study. With the treatment of HPP at 600 MPa and $15^{\circ}C$ for 3 min, the quantity of microorganisms and lactic acid bacteria were reduced to the level of 2-3 log CFU/ml, and coliforms were not detected during a storage period of 15 d at $4^{\circ}C$. An analysis of milk proteins, such as ${\alpha}$-casein, ${\beta}$-casein, ${\kappa}$-casein, ${\alpha}$-lactalbumin, ${\beta}$-lactoglobulin by on-chip electorophoresis revealed that the electrophoretic pattern of the proteins from HPP-treated milk was different from that of conventionally treated commercial milk. While the quantities of vitamins and minerals in HPP-treated milk were seen to be comparable to amounts found in raw milk, the enzyme activity of lipase, protease and alkaline phosphatase after HPP treatment was reduced. These results suggest that HPP treatment is a viable method for the control of undesirable microorganisms in milk, allowing for minimal nutritional and chemical changes in the milk during the process.

• Journal of Animal Environmental Science
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• v.18 no.sup
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• pp.47-54
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• 2012

Effect of commercial Direct Fed Microbials (DFM) or protease treated feed (PTF) supplementation on growth rate and biogenic substances such as BUN, glucose, IgG, GOT, GPT and Vitamin A, C, E from Holstein steers was studied for 7 months. Thirty two steers aged 2~3 months were separated with 4 groups for control, DFM (PS), protease (ES) and their mix (PS + ES) supplementally fed 0, 100, 100 and 50 + 50 g/day respectively. Weight gain was averagely higher in PS than any others, although there were no differences significantly. All treatments enhanced to 3~8% of control in dry matter, crude protein and total digestible nutrient (P>0.05). Metabolic diseases with veterinary cure had not shown in this study. Plasma GOT and GPT were lower in the PS and ES than control. Plasma glucose concentration was also lower in PS than the others. Total cholesterol of ES was higher than the others but that of PS is the lowest. Plasma vitamin C was higher in PS than the others. It was shown that dietary PS affected change from glucose to vitamin C with not overloading liver. Conclusionally, PS and ES were shown to enhance metabolic health of steers during growing period.

• The Korean Journal of Food And Nutrition
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• v.33 no.4
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• pp.381-389
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• 2020

The purpose of this study was to evaluate the appearance, physicochemical, physical, and fermentation properties of the fermented soybean produced by manufacturing with inoculation the different types of microbial strains. The strains were inoculated by the NSI (natural strains inoculation), and the SSI (selective strain inoculation) were treatments. The appearance showed differences in color, viscous substance, and hardness depending on strains inoculation and fermentation duration. The pH, and total acidity were 6.40~7.26%, and 0.10~0.39% respectively with differences depending on the samples. The moisture content as the fermentation duration increased, the NSI (56.03~57.66%) decreased and the SSI (56.71~58.63%) increased. The physical characteristics of the hardness increased as the fermentation duration increased for the NSI and the SSI decreased. The color values for the L, a, and b values were 47.64~58.56, 7.15~9.08, and 12.41~17.30, respectively. The α-amylase and protease activities of the SSI were the highest among all treatments. The total viable cell counts of the fermented soybean products by strains were 5.02 to 9.77 log CFU/g, and SSI (fermentation, 48 hours) was the highest. The amino-type nitrogen contents of all samples were 301.62~746.97 mg% and the SSI showed the highest content. The amino acid had the highest glutamic acid content.

• Korean Journal of Food Science and Technology
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• v.37 no.3
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• pp.449-455
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• 2005

To reduce saft content of kochujang, various combinations of sub-materials such as ethanol mustard and chitosan were added to kochujang, and their effects on microbial characteristics, enzyme activities, and physicochemical characteristics of kochujang were investigated after 12 weeks of fermentation. Activities of ${\beta}$-amylase and pretense were low in ethanol-mustard-chitosan-added kochujang, whereas no significant difference was observed in ${\alpha$-amylase activity among all groups. Number of viable yeast cells decreased remarkably in mustard-added kochujang during late aging period, and anaerobic bacterial counts decreased in sub-material-added groups. Consistency of kochujang increased by addition of sub-materials, and oxidation-reduction potential was low in chitosan-added group. Mustard-chitosan-added kochujang showed lowest increase in total color difference(${\Dalta}E$) and decrease in water activity. PH of kochujang wns highest in mustard-chitosan-added kochujang, resulting in significantly increased titratable acidity. Addition of sub-material increased reducing sugar contents of kochujang, whereas ethanol production was significantly repressed in mustard-chitosan-added kochujang. Amino nitrogen content was Highest in mustard-chitosan-added kochujang during late aging period, whereas ammonia nitrogen content was lower in ethanol-mustard-added kochujang. Results of sensory evaluation indicated ethanol-mustard-added kochujang was more acceptable than other groups in taste and overall acceptability.

• Korean Journal of Food Science and Technology
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• v.37 no.3
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• pp.463-467
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• 2005

To reduce salt content in Korean traditional kochujang, horseradish powder (1.2%, w/w) was added to kochujang with 4-10% salt, and its microbial characteristics, enzyme activities, and gas formation in kochujang were evaluated during fermentation far 120 days at $25^{\circ}C$. All treatments of kochujang had no effects on total viable bacterial numbers, which kept constant level, during fermentation (7.32-8.765 log CFU/g). Yeast numbers did not change under all treatments up to 90 days of fermentation, then decreased thereafter, ${\alpha}$-Amylase and ${\beta}$-amylase, and neutral- and acid-pretense activities of kochujang added with horseradish powder were higher than those of control group. ${\beta}$-Amylase activity of kochujang increased in proportion to salt concentration. Total accumulative volume of gas produced during fermentation of kochujang without horseradish powder was 5,892 mL/pack then decreased to 121-347mL/pack with low-salted kochujang (salt 4%, 6%) added with horseradish powder, Major gas produced was $CO_{2}(74-80%)$. Results indicate salt contents of kochujang could be lowered up to 6% by addition of horseradish powder without gas formation and quality alteration.

• Microbiology and Biotechnology Letters
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• v.6 no.1
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• pp.41-46
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• 1978

Piscicidal substance produced by Streptomyces sp. isolated from soil was toxic against various kinds of fish. After extraction with CH$Cl_3$ from the culture medium, the substance was purified by avicel column chromatography. In order to test toxicity, various kinds of fish were subjected to the acqueous solution of 100 us of the substance per liter of water. Generally, the substance was toxic to most fish, but Macropodus chinenes and Misgurnus mizolepis are resistant to the substance than Gobius similis and Pseudorasbora parva. The substance was stable at pH range, 3.0 to 7.0, but labile at alkaline pH, and to heat as well. Succinic dehydrogenase on most of tissue cell of Cyprinus carpio was inhibited by this substance strongly, but spinal cord was not inhibited. By addition of Cu and Pb salts to the culture medium, piscicidal substance producibility was activated.