• Journal of Species Research
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• v.6 no.spc
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• pp.227-246
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• 2017

A study of the Cladocera (Crustacea: Branchiopoda) from the Korean Peninsula resulted in the checklist of Jeong et al. (2014). Several sampling campaigns conducted by our team since 2014, with the framework of the programs supported by the National Institute of Biological Resources (NIBR), have resulted in a considerable increase in the number of water bodies studied in South Korea. In this report, seven new records for the Korean Peninsula are provided: (1) Macrothrix vietnamensis Silva-Briano, Dieu and Dumont, 1999; (2) Disparalona chappuisi (Brehm, 1931); (3) Pleuroxus(Picripleuroxus) quasidenticulatus (Smirnov, 1996); (4) Acroperus africanus Neretina and Kotov, 2015; (5) Alona ossiani herricki Sinev, 2013; (6) Coronatella trachystriata (Chen, Zhang and Liu, 1994); (7) Leydigia louisi Jenkin, 1934. Most of these taxa belong to the southern thermophilic complex. In addition several populations of Pleuroxus (Picripleuroxus) denticulatus Birge, 1879 and Pseudochydorus globosus (Baird, 1843) were re-studied, and their presence in Korea is confirmed. Through increased collection efforts and the application of molecular methods we are confident that more new records of Korean fauna will be published in the near future.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.5
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• pp.539-545
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• 2009

A feasibility of a pilot scale two-phase anaerobic digestion with ultra filtration system treating garbage leachate were evaluated. The treatment system consisted of a thermophilic acidogenic reactor, a mesophilic methanogenic reactor, and an UF membrane. The average COD removal efficiency of the treatment system was 95% up to the OLR of 3.1 g COD/L/d. The higher COD removal efficiency with membrane unit resulted from the removal of some portion of soluble organics by membrane as well as particulate materials. When the membrane unit was in operation, bulk liquid in acidogenic and methanogenic reactors was partially interchanged, which maintained the acidogenic reactor pH over 5.0 without external chemical addition. Also, with the production of methane in the acidogenic reactor, the organic loading rate of the methanogenic reactor reduced. The initial flux of the membrane unit was $50{\sim}60L/m^2/hr$, but decreased to $5 L/m^2/hr$ after 95 days of operation due to clogging caused by particulate materials such as fibrous materials in garbage leachate. To prevent clogging caused by particulate materials, a pretreatment system such as screening is required. With the improvement with membrane unit operation, the two-phase anaerobic digestion with ultra filtration system is expected to have the possibility of treating garbage leachate.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.4
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• pp.59-67
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• 1988

Anaerobic digestion at the temperature of $35-55^{\circ}C$ was conducted using an artificial sludge of uniform composition. The hydraulic retention time of 5 days was chosen because the temperature effect was effectively shown at a high loading. Inhibition of the methane fermentation decreased as the temperature increased. Acid fermentation was prevalent at the mesophilic and intermediate temperatures, while active methane fermentation took place at $55^{\circ}C$. Temperature not only affects activity of the microorganisms, but also affects physical and chemical properties of the sludge, Digestion inhibition was much reduced when the feed sludge was diluted, and active methane fermentation was possible at all temperatures. The digestion efficiency was governed by the organic loading rate as well as the hydraulic 10ading rate. No reduction of the digestion efficiency at $40-45^{\circ}C$, which had been referred to a critical temperature range, was observed. The digestion efficiency increased monotonically from mesophilic to thermophilic range. Improved settling properties of digested sludge was also recorded at higher temperatures.

• BMB Reports
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• v.35 no.6
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• pp.568-575
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• 2002

An $\alpha$-amylase (EC 3.2.1.1) was purified that catalyses the production of a high level of maltose from starch without the attendant production of glucose. The enzyme was produced extracellularly by thermophilic Streptomyces sp. that was isolated from Thailand's soil. Purification was achieved by alcohol precipiation, DEAE-Cellulose, and Gel filtration chromatographies. The purified enzyme exhibited maximum activity at pH 6-7 and $60^{\circ}C$. It had a relative molecular mass of 45 kDa, as determined by SDS-PAGE. The hydrolysis products from starch had $\alpha$-anomeric forms, as determined by $^1H$-NMR. This maltose-forming $\alpha$-amylase completely hydrolyzed the soluble starch to produce a high level of maltose, representing up to 90%. It hydrolyzed maltotetrose and maltotriose to primarily produce maltose (82% and 62%, repectively) without the attendant production of glucose. The high maltose level as a final end-product from starch and maltooligosaccharides, and the unique action pattern of this enzyme, indicate an unusual maltose-forming system. After the addition of the enzyme in the bread-baking process, the bread's volume increased and kept its softness longer than when the bread had no enzyme.

• Journal of Life Science
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• v.13 no.5
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• pp.618-625
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• 2003

Investigations were carried out to optimize the culture conditions for the production of xylanase by Paenibacillus sp. DG-22, a moderately thermophilic bacterium isolated from timber yard soil. Xylanase production showed a cell growth associated profile. Xylanase activity was found only in the culture supernatant, while $\beta-xylosidase$ activity was mainly associated with the cells. The formation of xylanase activity was induced by xylan and repressed by glucose and xylose. The production profile of xylanase was examined with various commercial xylan and maximum yield was achieved with 0.1∼ 0.5% birchwood xylan. Among various nitrogen sources tested, yeast extract was optimal for the production of xylanase. The xylanase activity was inhibited by $Co^{2+},\; Cu^{2+},\; Fe^{3+},\; Hg^{2+}\;$ and$\;Mn^{2+}$ ions while $Ca^{2+},\; Mg^{2+},\; Ni^{2+},\; Zn^{2+}$ions and DTT stimulated xylanase activity Mercury (II) ion at 5 mM concentration abolished all the xylanase activity. The predominant products of xylan-hydrolysate were xylobiose, xylotriose, and higher xylooligo-saccharides, indicating that the enzyme was an endoxylanase.

• Journal of Dairy Science and Biotechnology
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• v.35 no.2
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• pp.121-133
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• 2017

A small amount of milk is sold as 'untreated' or raw in the US; the two most commonly used heat-treatments for milk sold in retail markets are pasteurization (LTLT, low-temperature long time; HTST, high-temperature short time) and sterilization (UHT, ultra-high temperature). These treatments extend the shelf life of milk. The main purpose of heat treatment is to reduce pathogenic and perishable microbial populations, inactivate enzymes, and minimize chemical reactions and physical changes. Milk UHT processing combined with aseptic packaging has been introduced to produce shelf-stable products with less chemical damage than sterile milk in containers. Two basic principles of UHT treatment distinguish this method from in-container sterilization. First, for the same germicidal effect, HTST treatments (as in UHT) use less chemicals than cold-long treatment (as in in-container sterilization). This is because Q10, the relative change in the reaction rate with a temperature change of $10^{\circ}C$, is lower than the chemical change during bacterial killing. Based on Q10 values of 3 and 10, the chemical change at $145^{\circ}C$ for the same germicidal effect is only 2.7% at $115^{\circ}C$. The second principle is that the need to inactivate thermophilic bacterial spores (Bacillus cereus and Clostridium perfringens, etc.) determines the minimum time and temperature, while determining the maximum time and temperature at which undesirable chemical changes such as undesirable flavors, color changes, and vitamin breakdown should be minimized.

• Korean Journal of Veterinary Research
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• v.28 no.2
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• pp.345-353
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• 1988

The present study was carried out to investigate the incidence of C jejuni and C coli in chicken. Also were examined the pathogenicity of the isolates in chick by experimental inoculation. Thermophilic Campylobacter were isolated from 34(45.9%) of the 74 specimens, and classified as 21.6% C jejuni, and 24.3% C coli. In the biotyping of 16 stranis of C jejuni isolates, 37.5% of the strains were grouped as biotype I, 62.5% as biotype II. In the case of 18 strains of C coli isolates, 49.9% of isolates were grouped as biotype I, 55.6% as biotype II. n oral inoculation with $10^4cfu$ of Campylobacter isolates into infant chicks(1 to 3 days-old), 17 days-old and 34 days-old chicks, 32.5% of the chicks developed diarrhea on day 1, 52.5% on day 3, 70.0% on day 5, and 27.5% on day 7, and the peak incidence of diarrhea was reached on day 5. The organisms were found to be discharged in feces one day afterwards. C jejuni and C coli strains were detected from the feces in 87.5% of the chicks on day 5. The organisms were multiplied from $10^4$ to $10^6cfu/gm$ in feces 5 to 7 days after inoculation. C jejuni and C coli recovered from 100% of the cecum, 64.3% of the duodenum, 50.0% of the spleen, 42.9% of the livers, and from 21.4% of gallbladders 7 days after inoculation.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.11
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• pp.1591-1598
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• 2004

To isolate the $\beta$-galactosidase producing thermophilic bacteria, samples of mud and water were collected from hot springs of avolcanic area near Golden Springs in New Zealand. Among eleven isolated strains, the strain of KNOUC112 produced the highest amounts of $\beta$-galactosidase at 40 h incubation time (0.013 unit). This strain was aerobic, asporogenic bacilli, immobile, gram negative, catalase positive, oxidase positive, and pigment producing. Optimum growth was at 70-72$^{\circ}C$, pH 7.0-7.2, and it could grow in the presence of 3% NaCl. The main fatty acids of cell components were iso-15:0 (30.26%), and iso-17:0 (31.31%). Based on morphological and biochemical properties and fatty acid composition, the strain could be identified as genus Thermus, and finally as Thermus thermophilus by phylogenetic analysis based on 16S rRNA sequence. So the strain is designated as Thermus thermophilus KNOUC112. A gene from Thermus thermophilus KNOUC112 encoding $\beta$-galactosidase was amplified by PCR using redundancy primers prepared based on the structure of $\beta$-galactosidase gene of Thermus sp. A4 and Thermus sp. strain T2, cloned and expressed in E. coli JM109 DE3. The gene of Thermus thermophilus KNOUC112 $\beta$-galactosidase(KNOUC112$\beta$-gal) consisted of a 1,938 bp open reading frame, encoding a protein of 73 kDa that was composed of 645 amino acids. KNOUC112$\beta$-gal was expressed as dimer and trimer in E. coli JM109 (DE3) via pET-5b.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.12
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• pp.1769-1774
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• 2001

Bacillus licheniformis strains L-25 and PWD-1 are two thermophilic feather-degrading bacteria. Despite isolated from different environmental conditions, they were both capable of breaking down chicken feathers and growing in a medium in which feather was the only source of carbon and nitrogen. A 1.46-kb keratinase gene (ker B) was isolated from strain L-25 by a polymerase chain reaction (PCR) using L-25 genomic DNA as templates. Sequencing results reveal that ker B shares great sequence identity with a previously published keratinase gene of B. licheniformis PWD-1 (ker A). Only two amino acids differences were found in the deduced amino acid sequence between the keratinases from L-25 and PWD-1. However several nucleotide changes were found upstream of the putative promoter region. Protease inhibition studies indicated that neutral protease activity accounted for approximate 25 to 30% of total extracellular proteolytic activity produced by strain L-25 in the feather medium. In contrast, no measurable neutral protease activity was produced by strain PWD-1 in the feather medium. When glucose (1%), a common catabolic repressor, was added into the feather medium, L-25 was still able to grow and produce keratinase. Strain PWD-1 produced no neutral protease activity and its growth was severely inhibited in the feather medium containing glucose. L-25 produced an enhanced level of keratinase in the feather medium in comparison with PWD-1.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.1
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• pp.129-137
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• 2018

Objective: The objective of this research was to evaluate the physico-chemical, microbiological and sensorial qualities of restructured steaks processed from beef trimmings (grade I and II) and frozen beef (fresh beef as control and frozen beef). Methods: Beef trimmings from commercial butcher were collected, designated into 4 treatments differing in beef trimmings grade and freezing, processed into restructured steaks with 1% microbial transglutaminase and then analyzed for product quality. Results: The results showed that all meat from different groups could be tightly bound together via cross-linking of myosin heavy chain and actin as observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Microbial counts of psychrotrophic and mesophilic bacteria were not affected by treatments (p>0.05), and no detectable of thermophilic bacteria were found. Regarding effect of beef trimmings grade, steaks made from beef trimmings grade II (16.03% fat) showed some superior sensorial qualities including higher tenderness score (p<0.05) and tendency for higher scores of juiciness and overall acceptability (p<0.07) than those made from beef trimmings grade I (2.15% fat). Moreover, a hardness value from texture profile analysis was lower in steaks processed from beef trimmings grade II than those made from grade I (p<0.05). Although some inferior qualities in terms of cooking loss and discoloration after cooking were higher in steaks made from beef trimmings grade II than those made from beef trimmings grade I (p<0.05), these differences did not affect the sensory evaluation. Frozen beef improved the soft texture and resulted in effective meat binding as considered by higher cohesiveness and springiness of the raw restructured product as compared to fresh beef (p<0.05). Conclusion: The results indicated the most suitable raw beef for producing restructured steaks without detrimental effect on product quality was beef trimmings grade II containing up to 17% fat which positively affected the sensory quality and that frozen beef trimmings increased tenderness and meat binding of restructured beef steaks.