• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.971-971
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• 2005

• Journal of Microbiology and Biotechnology
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• 제6권6호
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• pp.482-486
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• 1996

Batch fermentations of lactic acid were performed with Lactobacillus casei to investigate the effect of pH on cell growth and production of lactic acid and by-products. Maximum productivity of lactic acid increased with increasing pH from 5.0 to 6.5, and the extent of D-lactate production was different at each pH. Acetate and D-lactate concentrations increased even after the complete consumption of glucose in the medium. While a pH range of 6.0-6.5 was optimal for cell growth and lactic acid production, superior results were achieved at pH 6.0 when both maximum lactic acid productivity and minimum by-product formation were considered.

• Journal of Microbiology and Biotechnology
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• 제27권1호
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• pp.1-8
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• 2017

The production of high-value chemicals from natural resources as an alternative for petroleum-based products is currently expanding in parallel with biorefinery. The use of lignocellulosic biomass as raw material is promising to achieve economic and environmental sustainability. Filamentous fungi, particularly Aspergillus species, are already used industrially to produce organic acid as well as many enzymes. The production of lignocellulose-degrading enzymes opens the possibility for direct fungal fermentation towards organic acids such as itaconic acid (IA) and fumaric acid (FA). These acids have wide-range applications and potentially addressable markets as platform chemicals. However, current technologies for the production of these compounds are mostly based on submerged fermentation. This work showed the capacity of two Aspergillus species (A. terreus and A. oryzae) to yield both acids by solid-state fermentation and simultaneous saccharification and fermentation. FA was optimally produced at by A. oryzae in simultaneous saccharification and fermentation (0.54 mg/g wheat bran). The yield of 0.11 mg IA/g biomass by A. oryzae is the highest reported in the literature for simultaneous solid-state fermentation without sugar supplements.

• Journal of Microbiology and Biotechnology
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• 제7권6호
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• pp.417-422
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• 1997

Recombinant Bacillus subtilis LKS88[pASA240] containing the amylase gene from Streptomyces albus KSM-35 was exploited in fed-batch cultivation for mass production of maltotetraose-producing amylase. The effects of dissolved oxygen, additional organic nutrients (peptone and yeast extract) and mixed carbon sources (glucose plus soluble starch) on amylase production were examined in fed-batch operations in an effort to determine the optimum conditions for a maximum amylase productivity. Under the optimum conditions, maximum amylase activity was about 4.2 times higher than that obtained in batch cultivations, indicating that mass production of maltotetraose-producing amylase could be accomplished in fed-batch cultivation of the recombinant B. subtilis strain.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
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• pp.300-306
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• 2000

This paper introduces a new concept of automation for bio-production with tele-operative system. The proposed system showed practical and feasible way of automation for the volatile bio-production process. Based on the proposition, recognition of the job environment with object identification was performed using computer vision system. A man-machine interactive hybrid decision-making, which utilized a concept of tele-operation was proposed to overcome limitations of the capability of computer in image processing and feature extraction from the complex environment image. Identifying watermelons from the outdoor scene of the cultivation field was selected to realize the proposed concept. Identifying watermelon from the camera image of the outdoor cultivation field is very difficult because of the ambiguity among stems, leaves, shades, and especially fruits covered partly by leaves or stems. The analog signal of the outdoor image was captured and transmitted wireless to the host computer by R.F module. The localized window was formed from the outdoor image by pointing to the touch screen. And then a sequence of algorithms to identify the location and size of the watermelon was performed with the local window image. The effect of the light reflectance of fruits, stems, ground, and leaves were also investigated.

• Journal of Biosystems Engineering
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• 제40권3호
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• pp.159-164
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• 2015

Purpose: Recently, environmental pollution and safety problems in agricultural production have become important issues. Initially, bio-production machines focused on high production efficiency rather than workers' safety and comfort, but this trend slowly has changed as time went on. Methods: This study was carried out to identify sound efficiently and reliably for noise reduction by using a combine cabin model. Ethylene propylene diene monomer (M-class) rubber (EPDM) was applied to improve noise reduction performance from parts connected directly to the front, rear, left side, and bottom side of the cabin. Results: As a result, an average noise reduction of 1.85 dB was achieved in the normal hearing range between 500 Hz to 2 kHz. Conclusions: Reducing the cabin noise levels can reduce a worker's fatigue, improve working environment, and contribute to future low-noise and high-quality cabin environment.

• Environmental Engineering Research
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• 제24권2호
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• pp.202-210
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• 2019

In order to maximize the utilization of sewage sludge, a waste from wastewater treatment facility, the residual sewage sludge generated after lipid and carbohydrate extraction for biodiesel and bioethanol production was used to produce bio-oil by pyrolysis. Thermogravimetric analysis showed that sludge pyrolysis mainly occurred between 200 and $550^{\circ}C$ (with peaks formed around 337.0 and $379.3^{\circ}C$) with the decomposition of the main components (carbohydrate, lipid, and protein). Bio-oil was produced using a micro-tubing reactor, and its yield (wt%, g-bio-oil/g-residual sewage sludge) increased with an increase in the reaction temperature and time. The maximum bio-oil yield of 33.3% was obtained after pyrolysis at $390^{\circ}C$ for 5 min, where the largest amount of energy was introduced into the reactor to break the bonds of organic compounds in the sludge. The main components of bio-oil were found to be trans-2-pentenoic acid and 2-methyl-2-pentenoic acid with the highest selectivity of 28.4% and 12.3%, respectively. The kinetic rate constants indicated that the predominant reaction pathway was sewage sludge to bio-oil ($0.1054min^{-1}$), and subsequently to gas ($0.0541min^{-1}$), rather than the direct conversion of sewage sludge to gas ($0.0318min^{-1}$).

• 한국유기농업학회지
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• 제17권1호
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• pp.1-17
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• 2009

The production of bio-energy crops is a major research project in the emphasizing the "low carbon green growth" strategy. For this, the possibility of the introduction of the new energy crops improve the agricultural income from fanning must be diagnosed. This study describes the level of agricultural income per unit area by cropping system based on the income of crops in the field. Especially, we have chosen the southern part attracting the attention in the possible area of the bio-energy crop production. This study consists of five chapters. Chapter I is the introduction. Chapter II is on the status of the southern part cropping system and the analysis of the economic value. Chapter III is on the economic value analysis introducing new bio-energy crops. Chapter IV is on the comparative analysis for the economic value of the croping system introducing new bio-energy crops. Chapter V is the conclusion.

• BMB Reports
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• 제46권5호
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• pp.244-251
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• 2013

Lignocellulosic materials are commonly used in bio-$H_2$ production for the sustainable energy resource development as they are abundant, cheap, renewable and highly biodegradable. In the process of the bio-$H_2$ production, the pretreated lignocellulosic materials are firstly converted to monosaccharides by enzymolysis and then to $H_2$ by fermentation. Since the structures of lignocellulosic materials are rather complex, the hydrolysates vary with the used materials. Even using the same lignocellulosic materials, the hydrolysates also change with different pretreatment methods. It has been shown that the appropriate hydrolysate compositions can dramatically improve the biological activities and bio-$H_2$ production performances. Over the past decades, hydrolysis with respect to different lignocellulosic materials and pretreatments has been widely investigated. Besides, effects of the hydrolysates on the biohydrogen yields have also been examined. In this review, recent studies on hydrolysis as well as their effects on the biohydrogen production performance are summarized.

• Journal of Biosystems Engineering
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• 제36권6호
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• pp.461-466
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• 2011

The purpose of this study is basically for the use of simulations to enhance productivity. In this paper, the optimal number of allocation in a small and medium industry which produces eleutherococcus senticosus sap, is performed using simulations. The simulation model was developed under considerations of production layout, process & operation, process time, total work time, work in process (WIP), utilization, failure rate, and operation efficient as inputs, and was validated with careful comparisons between real behaviors and outputs of the production line. Therefore, we can evaluate effects and changes in productivity when some strategies and/or crucial factors are changed. Although too many workers and machines could decrease productivity, the eleutherococcus senticosus sap production line in this paper has been maintained many machines. To solve this problem, we determined the optimal number of workers and machines that could not cause any interrupt in productions using simulations. This simulation model considers diverse input variables which could influence productivity, and it is very useful not only for the production line of Eleutherococcus Senticosus Sap, but also for other production lines with various purposes, especially, in the small and medium industries.