• Asian-Australasian Journal of Animal Sciences
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• v.30 no.7
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• pp.950-956
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• 2017

Objective: Effects of newly isolated Lactobacillus plantarum on the fermentation and chemical composition of fresh rice straw silage was evaluated in this study. Methods: Lactic acid bacteria (LAB) from good crop silage were screened by growing them in MRS broth and a minimal medium with low carbohydrate content. Selected LAB (LAB 1821) were Gram-positive, rods, catalase negative, and were identified to be Lactobacillus plantarum based on their biochemical characteristics and a 16S rRNA analysis. Fresh rice straw was ensiled with two isolated LAB (1821 and 1841), two commercial inoculants (HM/F and P1132) and no additive as a control. Results: After 2 months of storage at ambient temperature, rice straw silages treated with additives were well-preserved, the pH values and butyric and acetic acid contents were lower, and the lactic acid content and lactic/acetic acid ratio were higher than those in the control (p<0.05). Acidity (pH) was lowest, and lactic acid highest, in 1821-treated silage (p<0.05). The $NH_3-N$ content decreased significantly in inoculant-treated silage (p<0.05) and the $NH_3-N$ content in 1821-treated silage was lowest among the treatments. The dry matter (DM) content of the control silage was lower than that of fresh rice straw (p<0.05), while that of the 1841- and p1174-inoculant-treated silages was significantly higher than that of HM/F-treated silage. Microbial additives did not have any significant (p>0.05) effect on acid detergent fiber or neutral detergent fiber contents. Crude protein (CP) content and in vitro DM digestibility (IVDMD) increased after inoculation of LAB 1821 (p<0.05). Conclusion: LAB 1821 increased the CP, IVDMD, lactic acid content and ratio of lactic acid to acetic acid in rice straw silage and decreased the pH, acetic acid, $NH_3-N$, and butyric acid contents. Therefore, adding LAB 1821 improved the fermentation quality and feed value of rice straw silage.

• New & Renewable Energy
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• v.18 no.2
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• pp.9-17
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• 2022

In this study, we used the Flux Balance Analysis (FBA) program to examine the behavior of hydrogen and organic acids according to seasonal changes in food wastewater collected from D city. The results showed that average hydrogen conversion rates in spring, summer, autumn, and winter were 1.06, 0.71, 1.21, and 1.13 mol H₂/mol of hexose_added, respectively, indicating a significantly lower hydrogen conversion rate in summer than in other seasons. This phenomenon is believed to occur because the carbohydrate concentration of the incoming food wastewater is low. In addition, Lactobacillus, the lactic acid-producing bacterium, was 21.3% in spring, 27.2% in summer, 17.5% in autumn, and 22.6% in winter. The most distinctive feature of the microbial community in summer was that 15.3% of the Ilyobacter was analyzed. It was confirmed that Ilyobacter, which is involved in the production of acetic acid and propionic acid, is closely associated with the tendency of increasing acetic acid and propionic acid and thus contributes to organic acid change. Clostridium, a hydrogen-producing bacterium, was 76.2%, 50.8%, 78.3%, and 74%, in spring, summer, autumn, and winter, respectively. It was confirmed that Clostridium dominates the microbial community by approximately 70% or more in all seasons except summer.

• Food Science of Animal Resources
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• v.44 no.2
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• pp.372-389
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• 2024

This study investigated the efficacy of ultraviolet-C (UV-C) irradiation in enhancing the quality of raw bovine milk by targeting microbial populations and lipid peroxidation, both of which are key factors in milk spoilage. We categorized the raw milk samples into three groups based on initial bacterial load: low (<3 Log 10 CFU/mL), medium (3-4 Log 10 CFU/mL), and high (>4 Log 10 CFU/mL). Using a 144 W thin-film UV-C reactor, we treated the milk with a flow rate of 3 L/min. We measured the bacterial count including standard plate count, coliform count, coagulase-negative staphylococci count, and lactic acid bacteria count and lipid peroxidation (via thiobarbituric acid reactive substances assay) pre- and post-treatment. Our results show that UV-C treatment significantly reduced bacterial counts, with the most notable reductions observed in high and medium initial load samples (>4 and 3-4 Log 10 CFU/mL, respectively). The treatment was particularly effective against coliforms, showing higher reduction efficiency compared to coagulase-negative staphylococci and lactic acid bacteria. Notably, lipid peroxidation in UV-C treated milk was significantly lower than in pasteurized or untreated milk, even after 72 hours. These findings demonstrate the potential of UV-C irradiation as a pre-treatment method for raw milk, offering substantial reduction in microbial content and prevention of lipid peroxidation, thereby enhancing milk quality.

• Journal of Applied Biological Chemistry
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• v.54 no.1
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• pp.51-55
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• 2011

To develop a health-aid preparation of Dioscorea batatas (DB), lactic acid fermentation was attempted using a mixed starter comprising of Lactobacillus acidophilus, Lactobacillus plantarum, Bifidobacterium longum. The anaerobic fermentation of a 10% DB flour suspension gave a uniform suspension of pH 3.65, containing $8{\times}10^6$ CFU/mL lactic acid bacteria. During the administration of the lactic acid fermented DB (FDB) and DB to trinitrobenzene sulfonic acid (TNBS)-induced colitis mouse model, histological lesions, morphological damage, and myeloperoxidase acitivity were significantly reduced at a dosage of 200 and 400 mg/kg/day. Dose-response (200 and 400 mg/kg/day) studies revealed that FDB pre-treatment of mice significantly ameliorated the appearance of diarrhoea and the disruption of colonic architecture. In FDB-pretreated mice, there was a significant reduction in the degree of both neutrophil infiltration (measured as decrease in myeloperoxidase activity) and weight loss rates. Theses findings suggest that FDB exerts beneficial effects in experimental colitis and may be useful in the treatment of inflammatory bowel disease.

• Korean Journal of Food Science and Technology
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• v.23 no.6
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• pp.689-694
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• 1991

Jangsu, a Korean ancient non-alcoholic beverage made by lactic acid fermentation of cooked rice, was prepared and the microbial characteristics were investigated. The periodic removal of fermented product and the addition of newly made cooked rice and cold water as new substrate enhanced the growth of lactic acid forming bacteria but supressed the growth of proteolytic bacteria. The important microorganisms in jangsu were Lactobacillus, Lactococcus, Pediococccus and Leuconostoc species. Lactococcus thermophilus, Lactobacillus coryniformis and Leuconostoc mesenteroides were identified. The isolated strains were cultivated and used as starter culture of jangsu. Some useful strains were selected which were able to produce acceptable flavor and sufficient amount of acid lowering the pH to near 4.0.

• Journal of Environmental Science International
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• v.30 no.8
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• pp.703-708
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• 2021

To improve the environmental management and resources, in this study, we aimed to investigate the effect of adding oyster shell powder to Hanwoo manure on its characteristics and microbial composition during the storage period. Additives were deposited on top of the manure surface at the rate of 0, 0.5, and 1% of oyster shell powder per 200 g of Hanwoo manure in a plastic container with three replicates; however, untreated manure litter served as the control. Manure characteristics (dry matter, organic matter and crude ash) and microbial composition (lactic acid bacteria, yeast, Bacillus subtilis, Salmonella, and E.coli) were evaluated at day 0, 2, 4, and 8. Manure characteristics exhibited an effect on dry matter, organic matter, and crude ash at day 2 and 8 (p<0.05), and not for day 0 and 4 (p>0.05). With the exception of yeast content at day 4 of storage, lactic acid bacteria, yeast, Bacillus subtilis, Salmonella, and E.coli exhibited no significant differences in all conditions during the storage period. Conclusively, addition of 1% oyster shell powder to Hanwoo manure resulted in slightly better manure characteristics; however, its microbial composition remained unchanged.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1358-1364
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• 2000

A mixed culture of bacteriocin-producing lactic acid bacteria and yeast was used to prepare unique fermented fruit and vegetable beverage which contains bacteriocin. Fruit and vegetable broth fermented by Lactococcus lactis 11454 showed inhibitory activity against foodborne pathogens such as Listeria monocytogens and Staphylococcus aureus, and Streptococcus mutans which is a major causative agent for dental caries. Bacteriocin was detected at the end of fermentation of fruit and vegetables and its antimicrobial activity was stable for 5 weeks during storage at $4^{\circ}C$. These results suggest that the presence of bacteriocin in beverages during fermentation and storage will provide a safeguard against foodborne pathogens and spoilage bacteria. To improve flavor of the fermented broth, post-fermentation of the fermented broth was carried out at $4^{\circ}C$ by using yeast isolated from raw material mixture. Total acidity of the post-fermented broth was slightly decreased, but significant increase in the concentration of succinic acid was observed in the post-fermented broth. It was also observed that bitter and disagreeable taste compounds such as phthalates were decreased, and mild acidic and fruity flavor esters and alcohols were increased by the post-fermentation of the fermented broth with yeast.

• Journal of the Korean Society of Food Culture
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• v.34 no.2
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• pp.217-223
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• 2019

This study aimed to evaluate the characteristic differential between whole cabbage kimchi (pogi kimchi) and sliced cabbage kimchi (mat kimchi) during kimchi fermentation at $6^{\circ}C$. The difference of microbial and physicochemical properties was investigated until 6 weeks. For the changes in the microbial flora, both kimchi samples exhibited a continuous increase in total aerobic bacteria and lactic acid bacteria (LAB) population size up to 2 weeks followed by a stationary phase until 5 weeks. Interestingly, the number of LAB of mat kimchi was overall higher than that of pogi kimchi during kimchi fermentation. We speculate that mat kimchi has in a more advantageous growth condition than pogi kimchi for microbial growth because small kimchi cabbage size appropriately derives nutritional supply in order to increase the LAB growth. During lactic fermentation at $6^{\circ}C$, physicochemical changes in the pH, salinity, and titratable acidity was observed to be no significant differences between two types of kimchi. Furthermore the contents of organic acids such as oxalic acid, citric acid, malic acid, lactic acid, fumaric acid, and acetic acid was not significantly different (p>0.05) between both kimchi samples as well as the contents of total free amino acid.

• Journal of Microbiology and Biotechnology
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• v.22 no.8
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• pp.1101-1106
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• 2012

Market fresh makgeolli was stored at different temperatures of $4^{\circ}C$ and $25^{\circ}C$ to assess the change of the microbial diversity according to the storage temperature and period. Yeast counts increased until day 3 of storage and decreased thereafter. General and lactic acid bacterial counts continuously increased during storage. The data indicated that the control of growth of microorganisms, particularly general bacteria and lactic acid bacteria (LAB), is essential. Total acid levels started to decrease in the makgeolli stored at $4^{\circ}C$, and increased from day 6 of storage in the makgeolli stored at $25^{\circ}C$. The increase of total acid in the non-refrigerated condition greatly affected the quality of makgeolli. In both the fresh makgeolli samples stored at $4^{\circ}C$ and $25^{\circ}C$, yeast (Saccharomyces cerevisiae) and molds (Aspergillus tubingensis, Candida glaebosa, and Aspergillus niger) were noted. Denaturing gradient gel electrophoresis (DGGE) band patterns were almost constant regardless of the storage period. As for bacteria, Lactobacillus crustorum, L. brevis, and Microlaena stipoides were found in the makgeolli stored at $4^{\circ}C$, and L. crustorum, Lactobacillus sp., L. plantarum, L. brevis, L. rhamnosus, and L. similis were found in the makgeolli stored at $25^{\circ}C$. In particular, in the makgeolli stored at $25^{\circ}C$, L. crustorum and L. plantarum presented dark bands and were identified as the primary microorganisms that affected spoilage of fresh makgeolli.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.5
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• pp.616-622
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• 2011

This study evaluated the fermentation characteristics and protein degradation dynamics of wet green tea grounds (WGTG) silage. The WGTG was ensiled with distilled water (control), or lactic acid bacteria (LAB), enzyme (E), formic acid (FA) and formaldehyde (FD) prior to ensiling. Three bag silos for each treatment were randomly opened at 0, 3, 7, 14, 28 and 60 days after anaerobic storage. For all the treatments, except for FA, there was a rapid decline in pH during the first 7 days of ensiling. LAB treatment had higher lactic acid content, lower ammonia-N ($NH_3$-N) and free-amino nitrogen (FAA-N) contents than other treatments (p<0.05). E treatment had higher lactic acid, water-soluble carbohydrates (WSC) and non-protein nitrogen (NPN) content than the control (p<0.05). FA treatment had higher $NH_3$-N and FAA-N content than the control (p<0.05). FD treatment had lower NPN and FAA-N content than the control, but it did not significantly inhibit the protein degradation when compared to LAB treatment (p>0.05). Results indicate that LAB treatment had the best effect on the fermentation characteristics and protein degradation of WGTG silage.