• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.4
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• pp.264-269
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• 2022

The present study investigated effects of microbial additives on the floor of Hanwoo steer manure in barn. The treatment following: without additives (CON); additives (AMA). Each treatment used 3 barns as replication and each barn contained 5 Hanwoos. The Hanwoo steer manure in barns was sub-sampled from 5 sides of pen at 0, 4 and 12 weeks. The sub-samples were used for analyses of chemical compositions, microbial counts, gas emissions and compost maturity. The concentrations of moisture, organic matter, total nitrogen and carbon-to-nitrogen (C/N ratio) of Hanwoo steer manure before the microbial additives were each 59.1%, 83.2%, 1.78% and 50.0%, respectively. The counts of lactic acid bacteria, Yeast, Bacillus subtilis, and Escherichia coli (E. coli) were each 5.94, 6.83, 7,28 and 5.52 cfu/g, but Salmonella was not detected. The ammonia-N gas was 4.67 ppm, but hydrogen sulfide gas was not detected. After 4 weeks, moisture, organic matter, total nitrogen, pH and yeast count were lowest (p<0.05). The lactic acid bacteria, yeast, Escherichia coli (E. coli) and ammonia-N gas were not effects of microbial additives. All treatments was not detected at Salmonella count and hydrogen sulfide emission, and compost maturity was completed. After 12 weeks, the lactic acid bacteria and Bacillus subtilis were highest in AMA, while moisture, yeast and E. coli were lowest (p<0.05). The ammonia-N gas was not effect by microbial additive. Salmonella and hydrogen sulfide emission were not detected in all treatments, and compost maturity was completed. Therefore, in present study, the microbial additive did not affect of gas and compost maturity, but the pathogenic microorganism such as E. coli, were inhibited by microbial additives.

• Microbiology and Biotechnology Letters
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• v.39 no.3
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• pp.301-307
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• 2011

Oil pollution was world-wide prevalent treat to the environment, and the physic-chemical remediation technology of the TPH (total petroleum hydrocarbon) contaminated soil had the weakness that its rate was very slow and not economical. Bioremediation of the contaminated soil is a useful method if the concentrations are moderate and non-biological techniques are not economical. The aim of this research is to investigate the influence of additives on TPH degradation in a diesel contaminated soil environment. Six experimental conditions were conduced; (i) diesel contaminated soil, (ii) diesel contaminated soil treated with microbial additives, (iii) diesel contaminated soil treated with microbial additives and the mixture was titrated to the end point of pH 7 with NaOH, (iv) diesel contaminated soil treated with microbial additives and accelerating agents and (v) diesel contaminated soil treated with microbial additives and accelerating agents, and the mixture was titrated to the end point of pH 7 with NaOH. After 10 days, significant TPH degradation (67%) was observed in the DSP-1 soil sample. The removal of TPH in the soil sample where microbial additives were supplemented was 38% higher than the control soil sample during the first ten days. The microbial additives were effective in both the initial removal rate and relative removal efficiency of TPH compared with the control group. However, various environmental factors, such as pH and temperature, also affected the activities of microbes lived in the additives, so the pH calibration of the oil-contaminated soil would help the initial reduction efficiency in the early periods.

• Journal of environmental and Sanitary engineering
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• v.16 no.2
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• pp.79-90
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• 2001

Commercial liquid seeds are used for supplying active microbial flora to organic wastewater treatment plants of high feed-to-microorganism ratio and to maintain optimal microbial condition during unsteady state operation of the biological wastewater treatment plant. In addition to bacterial cells, the liquid weeds contain various additives for special purposes as well as organic substrates for energy supply. The additives give physical stability for the maintenance of microbial decomposition activity and ability to control the overgrowth of seed strains. In this work, the effects of addition of two kinds of typical substrate additives, poly aluminum chloride(PAC) and poly aluminum sulfate(PAS) on the consitutional total cell counts(CFU/ml) of four kinds of reorganization liquid seeds(RLS I, RLS II, RLS III and RLS IV) were studied experimentally. The addition of PAC and PAS gave negative effect on TCC constitution for the four seeds studied.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.15 no.3
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• pp.270-276
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• 2005

This study was conducted to examine whether a specific synthetic metalworking fluid (MWF), "A", in use for 10 months without replacement, displayed microbial resistance and to identify the additives associated with the control of microbial growth. Three synthetic MWF products ("A", "B", and "C") were studied every week for two months. Microbial deterioration of the fluids was assessed through evaluation by endotoxin, bacteria and fungi levels in the MWFs. In addition, formaldehyde, boron, ethanolamine, and copper levels were also studied to determine whether they influence microbial growth in water-based MWFs. Throughout the entire study in the sump where MWF "A" was used, bacteria counts were lower than 103 CFU/mL, and endotoxins never exceeded 103 EU/mL. These levels were significantly lower than levels observed in sumps badly deteriorated with microbes. Boron levels in MWF "A" ranged from 91.7 to 129.6 ppm, which was significantly higher than boron levels found in other MWF products. The total level of ethanolamine (EA) in MWF "A" ranged from 35,595 to 57,857 ppm (average 40,903 ppm), which was over ten times higher than that found in other MWFs. Monoethanolamine (MEA), diethanolamine (DEA) and triethanolamine (TEA) concentrations in MWF "A" were also significantly higher than seen in other MWFs. However, although EA and boron might improve anti-microbial performance, their abuse can pose a serious risk to workers who handle MWFs. From an industrial hygiene perspective, our study results stress that the positive synergistic effect of boron and EA in reducing microbial activity in MWF must be balanced with the potentially negative health effects of such additives. Our study also addresses the disadvantage of failing to comprehensively report MWF additives on Material Safety Data Sheets (MSDS). Future research in MWF formulation is needed to find the best level of EA and boron for achieving optimal synergistic anti-microbial effects while minimizing employee health hazards.

• Journal of Microbiology and Biotechnology
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• v.31 no.8
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• pp.1163-1174
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• 2021

Casein-derived antioxidant peptides by using microbial proteases have gained increasing attention. Combination of two microbial proteases, Protin SD-NY10 and Protease A "Amano" 2SD, was employed to hydrolyze casein to obtain potential antioxidant peptides that were identified by LC-MS/MS, chemically synthesized and characterized in a oxidatively damaged HepG2 cell model. Four peptides, YQLD, FSDIPNPIGSEN, FSDIPNPIGSE, YFYP were found to possess high 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging ability. Evaluation with HepG2 cells showed that the 4 peptides at low concentrations (< 1.0 mg/ml) protected the cells against oxidative damage. The 4 peptides exhibited different levels of antioxidant activity by stimulating mRNA and protein expression of the antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px), as well as nuclear factor erythroid-2-related factor 2 (Nrf2), but decreasing the mRNA expression of Kelch-like ECH-associated protein 1 (Keap1). Furthermore, these peptides decreased production of reactive oxygen species (ROS) and malondialdehyde (MDA), but increased glutathione (GSH) production in HepG2 cells. Therefore, the 4 casein-derived peptides obtained by using microbial proteases exhibited different antioxidant activity by activating the Keap1-Nrf2 signaling pathway, and they could serve as potential antioxidant agents in functional foods or pharmaceutic preparation.

• Korean Journal of Veterinary Service
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• v.45 no.3
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• pp.155-164
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• 2022

This study was conducted for safety evaluation on 130 pet food products, which are distributed in Gwangju, South Korea. The microbial contamination part and the usage of food additives part were mainly investigated. The five microorganisms that we tested were total viable cell counts (TVC), Coliforms, Salmonella spp., Campylobacter spp., pathogenic Escherichia coli and there were 15 products that exceed the microbial criteria or detected food poisoning bacteria. Specifically, Coliforms (13 products, 10%), TVC (9 products, 6.9%), Salmonella spp. (2 products, 1.5%), and E. coli (2 products, 1.5%) were followed. On the other hand, food additives such as preservatives, antioxidants and sodium nitrite were detected in 61 products. Among the preservatives, sorbic acid and benzoic acid were detected in 58 (44.6%) products. In antioxidants, Butylated hydroxytoluene (BHT) was detected in 3 (2.3%) products. In addition, preservatives and antioxidants were detected in 8 of 20 products labeled as 'additive-free'. Microbial contamination tended to occur mainly in small-scale individual homemade feed stores, while food additives were all detected in pet shops and supermarkets. Currently, the criteria for microorganisms and food additives for pet foods are insufficient in Korea. So, it is necessary to establish detailed feed standards and specifications for companion animals.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.2
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• pp.96-102
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• 2022

The present study investigated effects of microbial additives and silo density on chemical compositions, fermentation indices, and aerobic stability of whole crop rice (WCR) silage. The WCR ("Youngwoo") was harvested at 49.7% dry matter (DM), and ensiled into 500 kg bale silo with two different compaction pressures at 430 kgf (kilogram-force)/cm² (LOW) and 760 kgf/cm² (HIGH) densities. All WCR forage were applied distilled water (CON) or mixed inoculants (Lactobacillus brevis 5M2 and Lactobacillus buchneri 6M1) with 1:1 ratio at 1x105 colony forming unit/g (INO). The concentrations of DM, crude protein, ether extract, crude ash, neutral detergent fiber, and acid detergent fiber of whole crop rice before ensiling were 49.7, 9.59, 2.85, 6.74, 39.7, and 21.9%, respectively. Microbial additives and silo density did not affect the chemical compositions of WCR silage (p>0.05). The INO silages had lower lactate (p<0.001), but higher propionate (p<0.001). The LOW silages had higher lactate (p=0.004). The INO silages had higher yeast count (p<0.001) and aerobic stability (p<0.001). However, microbial counts and aerobic stability were not affected by silo density. Therefore, this study concluded that fermentation quality of WCR silage improved by microbial additives, but no effects by silo density.

• Advances in concrete construction
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• v.4 no.3
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• pp.195-206
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• 2016

Today, application of additives to replace cement in order to improve concrete mixes is widely promoted. Micro-silica is among the best pozzolanic additives which can desirably contribute to the concrete characteristics provided it is used properly. In this paper, the effects of AP2RC and P1RB micro-silica gels on strength characteristics of normal concrete are investigated. Obtained results indicated that the application of these additives not only provided proper workability during construction, but also led to increased tensile, compressive and flexural strength values for the concrete during early ages as well as ultimate ones with the resulting reduction in the porosity lowering permeability of the micro-silica concrete. Furthermore, evaluation of microbial contamination of the mentioned gels showed the resultant contamination level to be within the permitted range.

• Korean Journal of Poultry Science
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• v.22 no.2
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• pp.105-115
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• 1995

The balance of microbial populations in the gastrointestinal (GI) tract of all warm-blooded animals is critical to the maintenance of health and resistance to disease. The composition of the populations can be altered by diet and environment, making the host animal susceptible to disease, and reducing growth rate and feed efficiency. Some feed additives including antimicrobial agents, prohiotics or yucca extract have been used to promote growth and feed utilization. There is evidence that part of growth-promoting effect of those feed additives results from the suppression of microbial urease activity or ammonia production in the GI contents of animals. Over 200 microbial species have been known to produce urease and the product of urea hydrolysis, ammonia, is toxic to animals. Carefully tested probiotics or other urease-suppressing agents can be a possible alternative to antimicrobial agents including antibiotics as growth promotants used for animals feeds.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.1015-1016
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• 2005