• 한국생물공학회:학술대회논문집
• /
• 2002.04a
• /
• pp.211-214
• /
• 2002

The optimal condition for the production of DXAMase, containing the both characteristics of dextranase and amylase, was studied based on different levels of pH, temperature, and aeration rate. Response surface methodology was applied to find the optimatic condition showing the relationship between the fermentation response(dextranase and amylase activity of DXAMase) and the fermentation variables(pH, temperature, and agitation rate). In case of dextranase activity, the condition of pH 4.06, $28.08^{\circ}C$, and 235.14 rpm showed the highest activity, 2.26 U/ml, and for amylase activity, the condition of pH 4.01, $27.96^{\circ}C$, and 212.01 rpm showed the highest activity, 3.52 U/ml. For the production of DXAMase, dextranase and amylase, the optimum condition was pH 4.06, $28.08^{\circ}C$, and 234.80 rpm.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.99-99
• /
• 2022

This study was carried out to select the excellent silage maize varieties customized for paddy cultivation that is vulnerable to lodging and waterlogging in the central and region. Ten varieties (Kwangpyeongok, P3394, etc.) were sown with 3 replicates in Suwon, Gyeonggi-do. It was sown twice in April and June of each year in 2020-2021 and harvested during the yellow ripe stage suitable for silage. The number of days to flowering stage in lowland condition increased up to 11 days compared to that in upland condition. In April seedling, varieties that showed a relatively small decrease in biomass production and total digestible nutrients (TDN) under lowland condition compared to upland condition were Gangdaok and Kwangpyeongok in 2020, and Dacheongok, Gangdaok and Kwangpyeongok in 2021. Kwangpyeongok, Gangdaok, and Sinhwangok showed relatively higher biomass production and TDN than the other varieties under lowland compared to upland in both 2020 and 2021. Our results suggest that Kwangpyeongok and Gangdaok are suitable silage maize varieties for lowland cultivation in the central region of Korea.

• Korean Journal of Veterinary Service
• /
• v.24 no.3
• /
• pp.279-285
• /
• 2001

The change of the body condition score(BCS) and milk production graph as days in milk by lactation number show that the productivity of cow is on the increase as increase the lactation number, but the health condition is much worse because of the inappropriate nutrition intake. Metabolic profiles test(MPT) results indicate that the early-lactation for directly after the parturition to the peak production of milk during the total lactation period is the time of the more likely to be exposed to lack of energy, protein, minerals. To solve this problem, the early-lactation cows should be sufficiently supplied the required nutrients and should maximum intake the supplied nutrients not to be suddenly decline body weight and BCS from postparturition to the peak production of milk. To maximize the dry matter intake of a cow, there is have got to improve the management of body weight for heifer's skeletal development and in the dry period which is carelessly deal by mostly farms. This study presents that the use of measurement of body weight, graph of body condition score, distribution of milk production, metabolic profiles test in the monitoring for dairy herd health management is very valuable.

• Journal of Biosystems Engineering
• /
• v.43 no.2
• /
• pp.110-118
• /
• 2018

Purpose: In this study, the potential for biogas production, degradation rates, and lag-phase of diauxic growth of carbohydrate-based material, which is one of the proximate compositions, were investigated. Methods: This study was conducted using starch as a carbohydrate-based material. In experimental condition 1, the biogas potential of carbohydrate-based material was measured. In experimental condition 2, the effect of feed to microorganism ratio (F/M ratio) on lag-phase of diauxic growth from carbohydrate-based material was tested. Biochemical methane potential tests were performed at five different feed to microorganism ratios (0.2, 0.4, 0.6, 0.8, and 1.0) under mesophilic conditions. The biogas production patterns, lag-phase, total volatile fatty acids to total alkalinity ratio (TVFA/TA ratio), and time required for 90 percent biogas production were used to evaluate biogas production based on the biochemical methane potential tests. Results: In experimental condition 1, unlike previous studies, biogas was produced in the TVFA/TA ratio ranging from 1.131 to 2.029 (approximately 13-19 days). The methane content in the biogas produced from the digesters was 7% on day 9 and increased rapidly until approximately day 27 (approximately 72%). In experimental condition 2, biogas yield was improved when the feed to microorganism ratio exceeded 0.6, with an initial lag-phase. Conclusions: Even if the TVFA/TA ratio was greater than 1.0, the biogas production was processed continuously, and the $CO_2$ content of the biogas production was as high as 60%. The biogas yield was improved when the F/M ratio was increased more than 0.6, but the lag-phase of carbohydrate-based material digestion became longer starting with high organic loading rate. To clarify the problem of the initial lag-phase, our future study will examine the microbial mechanisms during anaerobic digestion.

• Journal of Veterinary Clinics
• /
• v.17 no.2
• /
• pp.299-304
• /
• 2000

The activated immune systems with lipopolysaccharide(LPS) were evaluates by ${\gamma}$- globulin levels in domestic cats. Especially, cats were in a stress condition, which was unfamiliar environmental change. Effect of continuous unfamiliar environmental stressor was a diminution of production of serum total globulin auld ${\gamma}$- globulin on feline infectious peritonitis(FIP) vaccination. The ${\gamma}$-globulin production on FIP vaccination more increased in LPS treated 77ups than non-LPS treated group. Also. the ${\gamma}$-globulin production on FIP vaccination was maintained in LPS treated group under stress condition. These results imply that that the ${\gamma}$-globulin can be produced under a stress condition by mitogen like as LPS.

• Korean Journal of Microbiology
• /
• v.40 no.3
• /
• pp.217-220
• /
• 2004

The effect of media composition and culture condition on mycelial growth and cordycepin (3'-deoxyadenosine) production was determined using Cordyceps spp. Among the strains of C. militaris and C. sinensis tested, C. militaris KCTC 6862, C. militaris DGUM 32003 and C. militaris KCTC 16932 were excellent for the production of cordycepin. The optimal temperature and pH for production of cordycepin were $24^{\circ}C$ and pH ranged from 6.0 to 10, respectively. Among various sources of carbon and nitrogen tested, glucose and tryptone were very excellent for the production of cordycepin, respectively. After 5days cultivation with 1% of tryptone with nitrogen source, 39mg/l of cordycepin was produced. However, addition of phosphorus sources reduced the production of cordycepin.

• Smart Media Journal
• /
• v.12 no.10
• /
• pp.29-37
• /
• 2023

Human lifestyle is affected by the agricultural development in the last 12,000 years ago. The development of agriculture is one of the reasons that global population surged. To ensure sufficient food production for supporting human life, pesticides as a more effective and economical tools, are extensively used to enhance the yield quality and boost crop production. This study investigated the factors that affect crop production and whether the factors of pesticide usage are the most important factors in crop production using the dataset from Kaggle that provides information based on crops harvested by various farmers. Logistic regression is used to investigate the relationship between various factors and crop production. However, the logistic regression is unable to deal with predictors that are related to each other and identifying the greatest impact factor. Therefore, causal discovery is applied to address the above limitations. The result of causal discovery showed that crop condition is greatly impacted by the estimated insects count, where estimated insects count is affected by the factors of pesticide usage. This study enhances our understanding of the influence of pesticide usage on crop production and contributes to the progress of agricultural practices.

• Journal of Environmental Science International
• /
• v.21 no.10
• /
• pp.1255-1263
• /
• 2012

Batch cultivations were performed to evaluate the influences of the initial pH condition on mesophilic and thermophilic acidogenic fermentation with food waste recycling wastewater. In both conditions of mesophilic and thermophilic fermentation, TVFAs production rates were maximized at the initial pH 7 condition as 0.15 and 0.23 g TVFAs/L hr, respectively. And pH was also maintained stably between 6 and 7 during 72hr acidogenic cultivation at both conditions. However, predominant VFA components were different according to reaction temperature conditions. In mesophilic condition, propionic acid which has low conversion efficiency to methane was accumulated up to 1,348 mg/L while acetic and butyric acid were predominant in thermophilic condition. Therefore, thermophilic acidogenic fermentation was superior for the effective VFAs production than mesophilic condition. From the DGGE analysis, the band patterns were different according to the initial pH conditions but the correlations of the each band were increased in similar pH conditions. These results mean that microbial communities were certainly affected by the initial pH condition. Consequently, the adjustment of the initial pH to neutral region and thermophilic operation are needed to enhance acidogenic fermentation of food waste recycling wastewater.

• 한국생물공학회:학술대회논문집
• /
• 2000.11a
• /
• pp.295-296
• /
• 2000

Effect of light intensity on ALA production was, investigated. The culture condition and medium optimization were also examined for the biosynthesis of ALA using Rhodobacter sphaeroides, non-sulfur bacteria, and investigated for enhancement of the production of ALA. In the dark condition, extracellular ALA formation and cell growth were not observed. Optimum light intensity for cell growth and ALA production were 4 kLux and 5 kLux, respectively.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2020.11a
• /
• pp.11-11
• /
• 2020