• Journal of Life Science
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• v.29 no.1
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• pp.29-36
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• 2019

We investigated the fermentation conditions for extracts of leave/branches and sap from Korean Dendropanax morbifera (D. morbifera) using Lactobacillus plantarum (L. plantarum) ilchiwhangchil 1785 and L. plantarum ilchiwhangchil 2020. Log growth phase cultured L. plantarum ilchiwhangchil 1785 and L. plantarum ilchiwhangchil 2020 were used for fermentation. The pH and growth of the microorganisms in broth were monitored during the fermentation period. The results revealed that the optimum fermentation conditions for 20 wt% of leave/branches extracts and 1 wt% of sap extract was 2 days incubation at $37^{\circ}C$. The minimum inhibitory concentration (MIC) method and a disk diffusion assay were used to evaluate the antimicrobial activity of the fermented extracts of the leave/branches and sap against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The antimicrobial activity increased in all three strains grown on the medium containing fermented extracts of the leave/branches and sap as compared with that of the strains grown on medium containing non fermented extracts. Furthermore, the antimicrobial activity increased in proportion to the contents of the fermented extracts. Our data suggest that fermented extracts of leave/branches and sap of D. morbifera have applications as natural bio functional materials, such as preservatives, cosmetic materials, and natural packaging materials.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.7
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• pp.996-1006
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• 2019

Objective: This study aimed to gain deeper insights into the dynamic changes in spoilage fungi populations during fermentation and the influence of traditional additives on silage quality. Methods: Elephant grass (Pennisetum purpureum) was prepared without any additive (control), and with the addition of 0.5% salt, and 0.5% salt-0.2% sugar mixture. The fungal community was then determined using a classic culturing method and high-throughput sequencing at 0, 5, 15, and 60 days after ensiling. Results: The results showed that the fungal community of elephant grass silage varied significantly between the natural fermentation without any additive and the two additive groups. The diversity and relative abundance of spoilage molds in the control group were much higher than those in the two treatment groups (p<0.05). Three species of yeasts (Candida sp., Pichia sp., Trichosporon sp.) and four spoilage molds (Fusarium sp., Aspergillus sp., Muco sp. and Penicillin sp.) were the predominant fungi in elephant grass during natural fermentation from 0 to 60 days, which were found to be significantly decreased in salt and sugar additive groups (p<0.05). Meanwhile, the diversity and relative abundance of undesirable molds in the 0.5%-salt additive group were the lowest among all groups. Conclusion: Adding salt and sugar, particularly 0.5% salt, is a promising effective approach to reduce the amount of undesirable fungi thus, improving the silage quality of elephant grass in northern Vietnam.

• Korean Journal of Microbiology
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• v.45 no.4
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• pp.391-396
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• 2009

This study was carried out to investigate the changes in yeast cell number, organic acid and total acid during the fermentation and distribution processes for enhancement of preservation of Makgeolli. Organic acids, including lactic acid, succinic acid, malic acid and citric acid, were increased with fermentation time, while oxalic acid, phosphoric acid and acetic acid were not detected, respectively. Production of organic acids leaded to pH reduction in Makgeolli. In case of Makgeolli kept at $4^{\circ}C$, there was no change in organic acids until 20 days. On the other hand, when observing the change in organic acid of Makgeolli kept at $25^{\circ}C$, concentration of lactic acid was decreased, while citric acid was not detected from the beginning of storage. However, acetic acid was detected from 10th day and rapidly increased at the 25th day. Therefore, it is suggested that the current expiration date (10 days in a cooler) could be extended.

• Microbiology and Biotechnology Letters
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• v.43 no.3
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• pp.241-248
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• 2015

Tuak is a traditional alcoholic beverage, one of the most widely known in the North Sumateran region of Indonesia. It is produced by a spontaneous fermentation process through the application of one or more several kinds of wood bark or root, called raru (Xylocorpus wood bark or a variety of forest mangosteen), into the sap water of sugar palm (Arenga pinnata) for 2−3 days. In this research, yeast that are potentially useful for ethanol production was isolated from Tuak and identified. Based on analysis of D1/D2 domain sequence of LSU (large subunit) rRNA genes, those isolated yeast strains, HT4, HT5, and HT10 were identified as Candida tropicalis. Fermentation test of these C. tropicalis isolates displayed an ability to produce 6.55% (v/v) and 4.58% ethanol at 30℃ and 42℃, respectively. These results indicated C. tropicalis isolates more rapidly utilize glucose and obtain higher levels of the production of ethanol at the higher temperature of 42℃ than S. cerevisiae, a common yeast used for bioethanol fermentation.

• Microbiology and Biotechnology Letters
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• v.28 no.6
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• pp.349-354
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• 2000

Culture conditions and nitrogen sources were optimized for production of erythritol, a natural sweetener, by Candida magnoliae M26. The optimal culture conditions were found to be culture temperature of $28^{\circ}C$, initial pH of 7, aeration of 1 vvm and agitation speed of 500 rpm in a 2.5 1 jar-fermentor. Glucose was chosen as the best carbon cource bsed on cell growth and erythritol productivity. Kight steep water(LSW) and corn steep liquor (CSL) which are by-products in starch processing from corn were tested as a nitrogen source substitute for yeast extract. The use of either LSW or CSL did not change the fermentation performance. The experimental results using LSW and CSL showed 1.5 times higher in cell growth and almost the same value in erythritol productivity com-pared with the control fermentation using yeast extract as a nitrogen source. These results suggested that either LSW of CSL could be used as a nitrogen source in a large-scale fermentation for erythritol production.

• Journal of Microbiology and Biotechnology
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• v.24 no.12
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• pp.1690-1698
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• 2014

Partial purification of glucoamylase from solid-state fermentation culture was, firstly, investigated by reverse micellar extraction (RME). To avoid back extraction problems, the glucoamylase was kept in the original aqueous phase, while the other undesired proteins/enzymes were moved to the reverse micellar organic phase. The individual and interaction effects of main factors (i.e., pH and NaCl concentration in the aqueous phase, and concentration of sodium bis-2-ethyl-hexyl-sulfosuccinate (AOT) in the organic phase) were studied using response surface methodology. The optimum conditions for the maximum recovery of the enzyme were pH 2.75, 100 mM NaCl, and 200 mM AOT. Furthermore, the optimum organic to aqueous volume ratio ($V_{org}/V_{aq}$) and appropriate number of sequential extraction stages were 2 and 3, respectively. Finally, 60% of the undesired enzymes including proteases and xylanases were removed from the aqueous phase, while 140% of glucoamylase activity was recovered in the aqueous phase and the purification factor of glucoamylase was found to be 3.0-fold.

• Food Science and Biotechnology
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• v.15 no.6
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• pp.884-888
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• 2006

In this study, we have attempted to characterize the effects of encapsulated mustard oil with regard to the extension of the shelf life of kimchi. The quantity of mustard oil or encapsulated mustard oil added to the brined cabbage in this study was 0.05%(w/w). Overall, the fermentation processes in the encapsulated mustard oil-added kimchi (EMO) and mustard oil-added kimchi (MO) occurred at a slower rate than in the controls. The periods during which the MO and EMO kimchi samples were edible were prolonged for more than two weeks, according to measurements of pH, total acidity, and microbial changes. The overall acceptability of EMO was superior to MO throughout the entirety of the fermentation period. Sensory evaluation verified that EMO yielded a more favorable product than the MO and control varieties. Encapsulated mustard oil can be employed as a natural food additive to prolong the shelf life of kimchi, via an induced delay of the fermentation process.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.6
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• pp.593-598
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• 1997

The changes of tissue structure in timothy and alfalfa during ensiling process with silage additives; lactic acid bacteria, cellulase and formic acid, were observed with a video microscope. Stem samples were obtained from the second internode, and cut to divide into 2 pieces. One piece was for observation of ensiled material and the other was for silage. The latter piece was put into a nylon cloth bag, and ensiled with grass for 50 days in a small experimental silo Lignification of the plant tissues was checked by acid phloroglucinol. Natural silage fermentation resulted in some degradation of less lignified parenchyma in both plant species. However, lignified sclerenchyma and vascular bundles remained intact. The cellulase enhanced the degradation of parenchyma tissue, while the formic acid suppressed the degradation. The effect of lactobacillus was small. The percentage of remained cross sectional area of stem and the loss of NDF and ADF by silage fermentation confirmed the observation. High negative correlations were obtained between the remained area and loss of fibrous components during silage fermentation in both plants, and between the loss of fibrous components and in vitro dry matter digestibility in timothy but not in alfalfa.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.4
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• pp.516-522
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• 2016

We investigated the effects of the predominant lactic acid bacteria (LAB) on the fermentation characteristics and aerobic stability of total mixed ration (TMR) silage containing soybean curd residue (SC-TMR silage). The SC-TMR materials were ensiled in laboratory silos for 14 or 56 days. LAB predominant in SC-TMR silage were identified (Exp. 1). Lactobacillus fermentum (L. fermentum) and Streptococcus bovis (S. bovis) were found in the untreated materials, Leuconostoc pseudomesenteroides (L. pseudomesenteroides) in 14-day silage and Lactobacillus plantarum (L. plantarum) in all silages. Pediococcus acidilactici (P. acidilactici), Lactobacillus paracasei (L. paracasei), and Lactobacillus brevis (L. brevis) formed more than 90% of the isolates in 56- day silage. Italian ryegrass and whole crop maize were inoculated with P. acidilactici and L. brevis isolates and the fermentation and aerobic stability determined (Exp. 2). Inoculation with P. acidilactici and L. brevis alone or combined improved the fermentation products in ryegrass silage and markedly enhanced its aerobic stability. In maize silage, P. acidilactici and L. brevis inoculation caused no changes and suppressed deterioration when combined with increases in acetic acid content. The results indicate that P. acidilactici and L. brevis may produce a synergistic effect to inhibit SC-TMR silage deterioration. Further studies are needed to identify the inhibitory substances, which may be useful for developing potential antifungal agents.

• Journal of Life Science
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• v.20 no.7
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• pp.999-1004
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• 2010

Investigations were carried out on a $\beta$-glucosidase produced by Aspergillus niger under solid-state fermentation conditions as a model of enzyme recovery from fermented wheat bran. The leaching efficiency of distilled water to recover the enzyme from the fermented bran was higher than acetate buffer, citrate buffer, citrate-phosphate buffer and 5% methanol; thus, the conditions were further optimized with distilled water as the extracting agent. After fermented bran was washed three times with distilled water for 1.5 hr each under shaking conditions at 1:5 solid to solvent ratio, a maximum recovery of 0.025 U/g of wheat bran was obtained.