• Asian-Australasian Journal of Animal Sciences
• /
• v.26 no.6
• /
• pp.856-863
• /
• 2013

An in vitro gas production technique was used in this study to elucidate the effect of two strains of active live yeast on methane ($CH_4$) production in the large intestinal content of pigs to provide an insight to whether active live yeast could suppress $CH_4$ production in the hindgut of pigs. Treatments used in this study include blank (no substrate and no live yeast cells), control (no live yeast cells) and yeast (YST) supplementation groups (supplemented with live yeast cells, YST1 or YST2). The yeast cultures contained $1.8{\times}10^{10}$ cells per g, which were added at the rates of 0.2 mg and 0.4 mg per ml of the fermented inoculum. Large intestinal contents were collected from 2 Duroc${\times}$Landrace${\times}$Yorkshire pigs, mixed with a phosphate buffer (1:2), and incubated anaerobically at $39^{\circ}C$ for 24 h using 500 mg substrate (dry matter (DM) basis). Total gas and $CH_4$ production decreased (p<0.05) with supplementation of yeast. The methane production reduction potential (MRP) was calculated by assuming net methane concentration for the control as 100%. The MRP of yeast 2 was more than 25%. Compared with the control group, in vitro DM digestibility (IVDMD) and total volatile fatty acids (VFA) concentration increased (p<0.05) in 0.4 mg/ml YST1 and 0.2 mg/ml YST2 supplementation groups. Proportion of propionate, butyrate and valerate increased (p<0.05), but that of acetate decreased (p<0.05), which led to a decreased (p<0.05) acetate: propionate (A: P) ratio in the both YST2 treatments and the 0.4 mg/ml YST 1 supplementation groups. Hydrogen recovery decreased (p<0.05) with yeast supplementation. Quantity of methanogenic archaea per milliliter of inoculum decreased (p<0.05) with yeast supplementation after 24 h of incubation. Our results suggest that live yeast cells suppressed in vitro $CH_4$ production when inoculated into the large intestinal contents of pigs and shifted the fermentation pattern to favor propionate production together with an increased population of acetogenic bacteria, both of which serve as a competitive pathway for the available H2 resulting in the reduction of methanogenic archaea.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.26 no.1
• /
• pp.54-59
• /
• 1997

After extracting Caridina denticulata denticulata, the raw material of salt-fermented Toha, with the use of water, ether, acetone and methanol in order, we had the antimicrobial activity test for nine strains of bacteria which are harmful to the human body and food. It is as follows; solvent extract yield of the powder of vacuum freeze dried Caridina denticulata denticulata was 52% of water fraction, 7.4% of ether fraction, 1.0% of acetone fraction and 0.8% of methanol fraction. The result of solvent extract antimicrobial search of Caridina denticulata denticulata said that with the sample of 20$\mu\textrm{g}$/disk, ether fraction resulted in clear one of 8~12mm, acetone fraction 8~12mm, methanol fraction 7~9mm and water fraction didn't have antimicrobial effect. The minimal inhibitory concentration of solvent extract of Caridina denticulata denticulata per area was that ether fraction was 250~500$\mu\textrm{g}$/$m\ell$, acetone fraction 125~500$\mu\textrm{g}$/$m\ell$ and methanol fraction 250~500$\mu\textrm{g}$/$m\ell$. The minimal bactericidal concentration of solvent extract per area of Caridina denticulata denticulata showed that ether fraction was 2, 500~10, 000$\mu\textrm{g}$/$m\ell$, acetone fraction 1, 250~10, 000$\mu\textrm{g}$/$m\ell$ and methanol fraction 5, 000~10, 000$\mu\textrm{g}$/$m\ell$.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.6
• /
• pp.754-760
• /
• 2006

This study was conducted to examine the quality characteristics of canned kimchi prepared by minimal thermal processing. Korean cabbage kimchi was fermented at $20^{\circ}C$ for several days up to acidity $0.5{\pm}0.1%$, was packaged in cylindrical can of 115 mL and pasteurized at low temperature. Thermal processing times based on $F_{60}$ value at geometrical center of the can were determined as 23.1, 17.7 and 12.7 min at 65, 70 and $80^{\circ}C$, respectively. The quality changes of the processed kimchi were measured during storage at $20^{\circ}C$. The pH of pasteurized kimchi was higher than that of unpasteurized control. The number of lactic acid bacteria was reduced to about $10^{2}{\sim}10^{3}$ (CFU/mL). The pasteurized kimchi product showed better texture and color values compared to the control, while resulting in the lower carotenoid and ascorbic acid contents. Kimchi preparation by minimal thermal processing had a positive effect for reduction of sour taste and sour flavor in sensory quality, but gave adverse effect in acceptability because of off-taste and off-flavor.

• Korean journal of food and cookery science
• /
• v.21 no.4 s.88
• /
• pp.440-446
• /
• 2005

To determine the shelf-life of low salted Myungran-jeot (low salted and fermented Alaska pollack roe), various chemical, microbiological and sensory analyses were carried out with Myungran-jeot stored at 10 days. The lactic acid content was slowly increased in the early stage of storage but then was rapidly increased with lengthening storage period, while pH was decreased during storage. The $NH_2-N$ content was steady at 10 days and peaked at 17 days. The production of VBN was increased to over $30mg\%$ at 19 days. In microbiological tests, the viable cell count and halotolerant bacteria were $1.5\times10^3\;and\;5.5\times10^3CFU/g$, respectively, at the initial state, but they slowly increased to $10^7 CFU/g$ at 17 days. Yeast or fungi did not appear on the surface of Myungran-jeot. Sensory evaluation showed that the original torture of Myungran-jeot in the mouth was a very important indicator for acceptability. Sensory characters and acceptability of Myungran-jeot at 17 days were not significantly different from those of the initial state. From these results, the estimated shelf-life of Myungran-jeot whom sealed with aluminum coated paper, was about 18 days in this study.

• Korean Journal of Microbiology
• /
• v.51 no.2
• /
• pp.133-140
• /
• 2015

We have examined the correlation between the physicochemical and microbiological environment variables for the different layers of oak forest soil in Mt. Gyeryong, Korea. The result shows that there is a high correlation in the environment variables between the soil parameters of the fermented (F) layer and humus (H) layer. In particular, the pH level in the F layer shows a high correlation with C and N, while the various organic acids of the H layer turns out to be closely correlated with soil bacteria density. As we evaluated phylogenetic characteristics of bacterial populations by DGGE analysis with DNA extracted. Total of 175 bands including 43 bands from litter (L) layer, 42 bands from F layer, 43 bands from H layer and 47 bands from rhizosphere (A) layer were selected as the major DGGE band of oak forest soil. Based on the 16S rRNA gene sequences, 175 DGGE bands were classified into 32 orders in 7 phylum. The heat map was analyzed in order to compare the quantity of the base sequences of each order and based on the clustering of the different layers of oak forest soil, the result confirms that the F layer and H layer belong to a different cluster from that of L layer and A layer. Furthermore, it also showed that approximately 50% of the total microbial population in different layers is ${\alpha}$-proteobacteria, which indicates that they belong to the dominant system group. In particular, Rhizobiales, Burkholderiales and Actinobacteriales were observed in all the seasons and layers of oak forest soil, which confirms that they are the indigenous soil bacterial community in oak forest soil.

• Korean Journal of Food Science and Technology
• /
• v.45 no.4
• /
• pp.515-520
• /
• 2013

Bacterial communities derived from cheonggukjang and raw rice straw collected from a Mireuksan farm and a Heungup cheonggukjang in Gangwon province were investigated using both culture-based method and denaturing gradient gel electrophoresis (DGGE) analysis. Pure cultures, which were isolated from raw rice straw and cheonggukjang and cultured on tryptic soy agar plates (53-76 colonies per plate), were identified by analysis of 16S rRNA sequences. The traditional culture-based method and analysis of PCR-amplified 16S rRNA by DGGE revealed that for samples collected from the Mireuksan farm, Pantoea agglomerans and Bacillus subtilis were the predominant species in the raw rice-straw and cheonggukjang, respectively. For samples collected from the Heungup cheonggukjang, Bacillus amyloliquefaciens was the predominant species in both raw rice straw and cheonggukjang. Other microorganisms, including members of Pantoea, Bacillus, Enterococcus, Enterobacter, Pseudomonas, Rhodococcus, and Acinetobacter, were also present in the raw rice-straw and cheonggukjang, as were bacteria that could not be cultured.

• The Korean Journal of Food And Nutrition
• /
• v.15 no.3
• /
• pp.241-249
• /
• 2002

In this research, we targeted to see if there was difference of shelf$.$lives of two different species cucumber. We pickled domestic and exporting cucumber to make comparison while they were fermented and stored. As for the domestic cucumber we choose CHICHEONG and for the exporting cucumber we choose special BAEKSEONG and SHARP 1. We blanched them and soaked them into hot saline water for 8 hours. Two kinds of Cucumber Kimchi were at room temperature for first day and 5'c from 2nd to 28th day. It was found, from the results, that all of samples of pH reached at 3.5 $\pm$ 0.1 on the 14th day of fermentation. The titratable acidity of the control increased on 14th day of fermentation, which was bit late than change of others. The reducing sugar contents of the control did not decrease until 7th day of fermentation while reducing sugar contents of others decreased gradually from the beginning. The patterns of Microfloral changes of two kinds of Cucumber Kimchi were similar during fermentation period. The number of total cell increased up to 14th day, similary the numbers of lactic acid bacteria increased up to 14th day then barely decreased. The hardness of the control was bit higher than others when it was measured on 14th day of fermentation. The sensory evaluation of Cucumber Kimchi with different species showed that both species had siginificant high negative scores in green color and crispness when those were compared between fermentation time and samples.

• The Korean Journal of Food And Nutrition
• /
• v.28 no.6
• /
• pp.1026-1032
• /
• 2015

This study attempted to find an efficient method for the preparation of high-purity galactooligosaccharides (HP-GOS) using ${\beta}$-galactosidase and yeast fermentation. GOS prepared using Lactozym 3000L showed the greatest enhancement in total GOS of the six ${\beta}$-galatosidases tested. GOS alone achieved 51% conversion of initial lactose. GOS production was enhanced by fermentation with commercial yeast (Saccharomyces cerevisiae); its concentration reached 71% after 36h fermentation with 8% yeast. Component sugar analysis with HPLC indicated that HP-GOS fermented with S. cerevisiae showed significantly increased levels of 4'/6'-galactosyllactose and total GOS as well as a significantly decreased glucose level. HP-GOS facilitated the growth of Lactobacillus sp. (L. acidophilus and L. casei) and Bifidobacterium sp. (B. longum and B. bifidum). In sum, high-purity GOS has been successfully produced through both an enzymatic process and yeast fermentation. GOS encourages the growth of bacteria such as Lactobacillus and Bifidobacterium that may be beneficial to human gastrointestinal health.

• Korean Journal of Food Science and Technology
• /
• v.31 no.2
• /
• pp.495-501
• /
• 1999

Lactobacillus acidophilus KY 2104 was isolated from 41 healthy korean ($2{\sim}35\;age$, 26 man, 15 woman) feces to use as a probiotic lactic acid bacteria for functional foods, fermented milk and pharmaceutical products. L. acidophilus KY 2104 survived in the presence of acid and bile, and inhibited pathogens. It survived almost 100% in pH 3.0 phosphate buffer for 2 hr, and more than $10^4\;cfu/mL$ in pH 2.0 phosphate buffer when inoculated by $10^7\;cfu/mL$. It was also found to grow in MRS medium containing 0.5% oxgall. L. acidophilus KY 2104 exerted inhibitory effect against enteric pathogens such as Escherichia coli, Shigella dysenteriae, Staphylococcus aureus and Salmonella typhimurium, when grown with each in associative cultures for 16 hr. As a result of acute toxicity of L. acidophilus KY 2104 in rats, there was no observation on motality, clinical signs, body weights and gross findings in the oral administration.

• Asian-Australasian Journal of Animal Sciences
• /
• v.33 no.8
• /
• pp.1292-1300
• /
• 2020

Objective: To explore feed resources capable of replacing regular poor-quality fodder, this study was conducted to evaluate the effects of additives on the fermentation quality, in vitro digestibility and aerobic stability of mulberry leaves silage. Methods: The mulberry leaves were ensiled either untreated (control) or treated with 1×10⁶ cfu/g fresh matter Lactobacillus plantarum (L), 1% glucose (G), 3% molasses (M), a combination of 1% glucose and Lactobacillus plantarum (L+G), and a combination of 3% molasses and Lactobacillus plantarum (L+M). The fermentation quality and chemical composition were analyzed after 7, 14, 30, and 60 d, respectively. The 60-d silages were subjected to an aerobic stability test and fermented with buffered rumen fluid to measure the digestibility. Results: Inoculating lactic acid bacteria (LAB) resulted in more rapid increase in lactic acid concentrations and decline in pH of mulberry leaves silage as compared control. Higher acetic acid and lower ethanol and ammonia nitrogen concentrations (p<0.05) were observed in the LAB-inoculated silages as opposed to control during ensiling. The LAB-inoculated silages contained lower water-soluble carbohydrates compared with control during the first 14 d of ensiling, and lower neutral detergent fibre (p<0.05) concentrations as compared with non-LAB inoculated silages. Adding molasses alone increased (p<0.05) the digestibility of dry matter (DM). The aerobic stability of mulberry leaves silage was increased by LAB inoculation, whereas decreased by adding glucose or molasses. Conclusion: The LAB inoculation improved fermentation quality and aerobic stability of mulberry leaves silage, while adding glucose or molasses failed to affect the fermentation and impaired the aerobic stability. Inoculating LAB alone is recommended for mulberry leaves especially when ensiled at a relatively high DM.