• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.1
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• pp.90-98
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• 2001

The slow degradation rate of sewage sludge in anaerobic digesters is due to the rate limiting step of sludge hydrolysis. Therefore, the pre-treatment process had been carried out using acidic(pH 1.5, 3, 4, 5) and alkaline(pH9, 10, 13), thermal(50, 100, 150, $200^{\circ}C$) and ultrasonic treatment(400W, 20kHz, 15, 20, 25, 30, 35, 40, 50, 60min). In the best conditions of each treatment, the SCOD ratio(%) of treated/untreared samples were increased 102% in acid(pH5), 986% in alkali(pH13), 959% in thermal($200^{\circ}C$) and 1123% in ultrasonic(35min) treatment. As the result, the ultrasonic treatment was most effective, followed by alkali, thermal, acidic treatment. In the effects of total gas productivity, the thermal($200^{\circ}C$) pretreatment was the highest, followed by thermal($150^{\circ}C$), ultrasonic(90min), alkaline(pH9) and ultrasonic(50min).

• Microbiology and Biotechnology Letters
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• v.26 no.2
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• pp.173-178
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• 1998

This study presents the influence of ammonium-nitrogen on microorganisms in swine wastewater. For the anaerobic batch fermentation, two different methods were used. One is the dilution of wastewater with water. The other method is the elimination of ammonium-nitrogen from the wastewater. By addition of MgO into wastewater, non-soluble crystall was formed under alkaline condition as MgNH$_4$PO$_4$6$H_2O$ (MAP). The master culture was adapted in swine wastewater for more than 3 months, in water-dilution method, the dilution of wastewater with 25% water gave us the best result in efficiency of COD removal. Two hundred hours later MAP-treated wastewater showed the efficiency of the COD removal more than 80%. Under same condition obtained none MAP-treated wastewater about 50%. MAP treatment carried out the very effective anaerobic digestion with swine wastewater. The important result in this study is that the low ratio of C:N influenced on anaerobic microorganisms more than high concentration of ammonium nitrogen in swine wastewater. The struvite for the crystallforming has no toxic effect on methanogenic bacteria.

• Applied Chemistry for Engineering
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• v.23 no.6
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• pp.594-598
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• 2012

In the present study, biogas was produced from the anaerobic digestion of marine macroalgae (Laminaria japonica) biomass. The optimal anaerobic condition for producing the sludge was the freeze treatment at $-70^{\circ}C$ for 20 min. Total amounts of hydrogen and methane gas produced were 667.28 mL/L and 3420.24 mL/L, respectively, which were 2.7 and 3.4 times greater than that in the control group. Freeze treatment of sludge produced the maximum biogas under an initial optimum pH of 7.0 and the maximum biomass at an initial optimum pH of 8.0. We confirmed that biogas production was greatly reduced under acidic conditions compared to that under alkaline conditions. Sludge was freeze treated, and the biomass and sludge production was optimal the total amounts of hydrogen and methane gas produced were 643.73 mL/L and 4291.6 mL/L, respectively, which were 2.6 and 4.3 times greater than in the control group. Also the results showed that under optimal conditions in a 5-L bioreactor, a maximum of 1605.03 mL/L of hydrogen and 4593.71 mL/L of methane gas could be produced by the substrate contained in the marine macroalgae biomass.

• Journal of fish pathology
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• v.27 no.1
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• pp.25-33
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• 2014

Hydrolase activities of excretory-secretory products (ESP) and somatic extracts (SE) from Anisakis simplex sensu stricto (s.s.) and Anisakis pegreffii larvae were investigated by using API ZYM kit. In esterase group, acid phosphatase showed high activity from both of A. simplex (s.s.) and A. pegreffii. Esterase (C4) showed activity only from SE and A. simplex (s.s.) showed higher activity than A. pegreffii. Alkaline phosphatase, acid phosphatase and naphthol-AS-BI-phosphohydrolase showed higher activity in 3rd stage larvae than in 4th stage larvae of both species. In aminopeptidase group, only leucine arylamidase showed remarkable activity in SE of both anisakid species, and A. simplex (s.s.) SE showed higher activity than A. pegreffii SE. In glycosidase group, N-acetyl-${\beta}$-glucosaminidase, ${\alpha}$-mannosidase, ${\alpha}$-fucosidase showed higher activity in A. simplex (s.s.) than A. pegreffii, and 4th larvae showed higher activity than 3rd larvae. These differences in hydrolase activity of anisakid nematodes larvae are thought to be due to different metabolism such as growth, moulting, digestion and feeding.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.3
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• pp.355-365
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• 2004

Two experiments were conducted to determine the effect of alkaline hydrogen peroxide (AHP) treatment (1% NaOH+1.5% $H_2O_2$; 1 AHPMS, 2% NaOH+1.5% $H_2O_2$; 2AHPMS) on rate and extent of degradation of mustard straw (MS) in sacco in sheep, and its in vivo digestion and ruminal fermentation characteristics when fed to sheep with concentrate (200 g per sheep daily). The treatment of straw with 1 and 2% AHP increased its sodium content by 148 and 296% to that of untreated straw (UMS). There was significant decrease in NDF and hemicellulose contents of AHP treated straw and increase in cellulose and lignin contents. Phenolic acids like ferrulic, $\rho$-coumaric and o-coumaric significantly (p<0.001) reduced by AHP treatment of mustard straw. In first experiment the in sacco degradation of DM, OM and NDF was significantly (p<0.01) greater for 2 AHPMS than for UMS at all incubation periods. The disappearance of nutrient from 1 AHPMS and 2 AHPMS treated straws continue to increase up to 96 h whereas in UMS the peak disappearance was found at 48 h. By using the equation {(y=a+b) ($1-e^{-ct}$)} the degradation rates (c) for DM, OM, and NDF were significantly higher for UMS than AHP treated straws. Level of alkali (1 and 2%) had significant effect on degradation characteristics (a, b, c and $P_{0.05}$) of DM and NDF fraction of MS. However, the effect was not pronounced on OM fraction of MS. In feeding experiment, the intake of nutrients for DM, OM, cell wall constituents and energy was higher on 2 AHPMS, whereas no effect on the digestibility of these nutrients was observed. The apparent nitrogen retention was higher (p<0.05) both in 1 and 2 AHPMS groups. Water intake by animals was significantly increased due to AHP treated mustard straw feeding. Rumen liquor pH was higher in 2 AHPMS fed animals. The $NH_3-N$ of rumen liquor was not affected by feeding of AHP treated MS based diets. Total VFA concentration was significantly (p<0.01) higher in UMS fed group. The fractional out flow rate of DM was higher (p<0.05) in animals fed on 2 AHPMS diets compared to UMS and lAHPMS fed groups. The population of large holotrichs was higher (p<0.05) on AHP treated MS fed diets compared to UMS. The study indicated that treatment of mustard straw with AHP changed its chemical composition towards a better feed. The nutritive value of 2% AHP treated mustard straw was better in terms of dry matter intake and apparent nitrogen retention. The higher in sacco DM, OM and NDF disappearance however, was not confirmed by in vivo data in this study.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.2
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• pp.239-245
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• 2011

This study was conducted to determine the effects of excess vitamin A on alkaline phosphatase (ALP) activity, contents of calcium-binding protein (CaBP), bone gla-protein (BGP) in culture medium and CaBP mRNA expression in chicken osteoblasts in vitro. Osteoblastic cells in the tibia from 1-day-old Arbor Acre broiler chickens were isolated using enzyme digestion. The subconfluenced cells were divided into eight treatments with six replicates in each treatment and cultured in a medium containing either vehicle or different levels of vitamin A (0, 0.2, 0.6, 1.0, 2.0, 5.0, 10.0 and $20.0\;{\mu}g$/ml), and the control received an equivalent volume of ethanol. The incubation lasted 48 h. The results showed that vitamin A down-regulated ALP activity in the culture medium as well as CaBP mRNA expression of osteoblasts in a linear dose-dependent manner (p = 0.124 and p<0.10, respectively), and suppressed the contents of BGP and CaBP in the culture medium in a quadratic dose-dependent manner (p<0.05 and p<0.10, respectively) with increasing addition of vitamin A. The addition of 0-$0.2\;{\mu}g$/ml vitamin A to the culture medium increased ALP activity, BGP and CaBP contents as well as CaBP mRNA expression compared with other groups, but positive effects of vitamin A tended to be suppressed when vitamin A was increased to $1.0\;{\mu}g$/ml, and adverse effects occurred when vitamin A was increased to 10.0-$20.0\;{\mu}g$/ml. These results implied that there was a threshold level of vitamin A inclusion beyond which inhibitory effects occurred, and the mechanism by which overdose of vitamin A reduced bone growth in chickens was probably reduced osteoblastic cell activity, and inhibited expression of CaBP mRNA and CaBP secretion.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.5
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• pp.620-631
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• 2015

A total of 59 lactic acid bacteria (LAB) strains were isolated from corn stover silage. According to phenotypic and chemotaxonomic characteristics, 16S ribosomal DNA (rDNA) sequences and recA gene polymerase chain reaction amplification, these LAB isolates were identified as five species: Lactobacillus (L.) plantarum subsp. plantarum, Pediococcus pentosaceus, Enterococcus mundtii, Weissella cibaria and Leuconostoc pseudomesenteroides, respectively. Those strains were also screened for antimicrobial activity using a dual-culture agar plate assay. Based on excluding the effects of organic acids and hydrogen peroxide, two L. plantarum subsp. plantarum strains ZZU 203 and 204, which strongly inhibited Salmonella enterica ATCC $43971^T$, Micrococcus luteus ATCC $4698^T$ and Escherichia coli ATCC $11775^T$ were selected for further research on sensitivity of the antimicrobial substance to heat, pH and protease. Cell-free culture supernatants of the two strains exhibited strong heat stability (60 min at $100^{\circ}C$), but the antimicrobial activity was eliminated after treatment at $121^{\circ}C$ for 15 min. The antimicrobial substance remained active under acidic condition (pH 2.0 to 6.0), but became inactive under neutral and alkaline condition (pH 7.0 to 9.0). In addition, the antimicrobial activities of these two strains decreased remarkably after digestion by protease K. These results preliminarily suggest that the desirable antimicrobial activity of strains ZZU 203 and 204 is the result of the production of a bacteriocin-like substance, and these two strains with antimicrobial activity could be used as silage additives to inhibit proliferation of unwanted microorganism during ensiling and preserve nutrients of silage. The nature of the antimicrobial substances is being investigated in our laboratory.

• Journal of Energy Engineering
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• v.21 no.2
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• pp.194-201
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• 2012

In this research, a sewage sludge solubilization study using electrolysis was performed as a pre-treatment for anaerobic digestion efficiency improvement. SCOD potency increased as the treatment time and electric current density increased with sludge electrolysis treatment while SCOD, TN, and TP especially showed the highest increase of 7.4 times, 1.9 times, and 1.3 times respectively at the 60 minute point of treatment. Solubilization was high at the strong acidic and alkaline status for the sewage sludge electrolysis treatment results along early stage pH, and especially, a high solubilization percentage of 32.9% was seen at pH 12. The above result shows that there was an increase of organic matter able to be used by microorganisms from sludge floc and the destruction of EPS structure due to direct and indirect oxidation following electrolysis.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.632-635
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• 2003

For the disposal of low-level radwaste from nuclear power plant need the determination of levels of radio nuclides in radwaste. These nuclides include the difficult-to-measure nuclides, so indirect methodology for the determination of the difficult-to-measure nuclides have to be developed. In this work, for the determination of $^129I(t_{1/2}=1.57{\times}10^7 years)$ in low-level radwaste from nuclear power plant is investigated. Recovery of Iodide in simulated waste($UO_2$ pellet) as a soluble and radwaste(resin, woolen fabric)as a insoluble samples are measured. After pretreatment of sample, $I_2$ are extracted from aqueous solution with $CCl_4$. Then I are extracted from $CCl_4$ with 0.1M $NaHSO_3$ aqueous solution. iodide in aqueous solution are determined by ion chromatography. The overall recovery yield is 76.7 (RSD 1.7%) for mixed-acid digestion method. Incase of woolen fabrics, overall recovery yield is 74.3 (RSD 2.2%) and recovery of iodide in resin 56.5(RSD 5.6%) for alkaline fusion method.

• Food Science of Animal Resources
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• v.34 no.3
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• pp.362-371
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• 2014

This study utilized commercially available proteolytic enzymes to prepare egg-white protein hydrolysates (EPHs) with different degrees of hydrolysis. The antioxidant effect and functionalities of the resultant products were then investigated. Treatment with Neutrase yielded the most ${\alpha}$-amino groups (6.52 mg/mL). Alcalase, Flavourzyme, Protamex, and Ficin showed similar degrees of ${\alpha}$-amino group liberation (3.19-3.62 mg/mL). Neutrase treatment also resulted in the highest degree of hydrolysis (23.4%). Alcalase and Ficin treatment resulted in similar degrees of hydrolysis. All hydrolysates, except for the Flavourzyme hydrolysate, had greater radical scavenging activity than the control. The Neutrase hydrolysate showed the highest 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity ($IC_{50}=3.6mg/mL$). Therefore, Neutrase was identified as the optimal enzyme for hydrolyzing egg-white protein to yield antioxidant peptides. During Neutrase hydrolysis, the reaction rate was rapid over the first 4 h, and then subsequently declined. The $IC_{50}$ value was lowest after the first hour (2.99 mg/mL). The emulsifying activity index (EAI) of EPH treated with Neutrase decreased, as the pH decreased. The EPH foaming capacity was maximal at pH 3.6, and decreased at an alkaline pH. Digestion resulted in significantly higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ABTS radical scavenging activity. The active peptides released from egg-white protein showed antioxidative activities on ABTS and DHHP radical. Thus, this approach may be useful for the preparation of potent antioxidant products.