• Title/Summary/Keyword: SSF

Search Result 165, Processing Time 0.038 seconds

Production of Acetic Acid from Cellulosic Biomass (섬유성 바이오매스를 이용한 Acetic Acid 생산)

  • 우창호;박준호;윤현희
    • KSBB Journal
    • /
    • v.15 no.5
    • /
    • pp.458-463
    • /
    • 2000
  • Production of acetic acid from cellulosic biomass by Simultaneous Saccharification and Extractive Fermentation (SSEF) was investigated. The homoacetate organism used in this study was a strain of Clostridium thermoaceticum, ATCC # 49707. A batch operation of Simultaneous Saccharification and Fermentation(SSF) using ${\alpha}$-cellulose at pH 5.5 and 55$^{\circ}C$ yielded 40% conversion of cellulose to acetic acid, while a fed-batch SSF operation produced a maximum acetic acid concentration of 25 g/L, with 50% overall yield. In-situ extractive fermentation to reduce the end-product inhibition on both bacteria and enzyme was carried out. in a batch SSEF using 200 g/L IRA-400 resin, acetic acid concentration reached to 23.9 g/L and acetic acid yield and productivity were observed to be 48% and 0.20 g/L-hr, respectively.

  • PDF

A Design of Optical Internet Simulator using SSF (SSF를 이용한 광인터넷 시뮬레이터 설계)

  • 윤성현;조기성
    • Proceedings of the Korean Information Science Society Conference
    • /
    • 2003.04d
    • /
    • pp.472-474
    • /
    • 2003
  • 최근의 인터넷은 트래픽과 서비스 품질에 대한 요구사항이 지속적으로 중대함에 따라 이를 원활히 수용할 수 있는 광인터넷으로 급속히 전환되고 있으며, 향후의 광인터넷 환경에서 사용하기 위한 광인터넷 관련 요소 기술들이 개발 중에 있다. 그러나 광인터넷에 적용될 각 개발 요소 기술들은 단계적으로 개발되고 있고, 기존 네트워크 서비스와의 연동을 고려해야 하므로 각 요소 시스템들이 지닌 기능 및 성능을 검증하기 위해서는 광인터넷을 모델링하고 분석 할 수 있는 광인터넷 시뮬레이터가 필요하게 된다. 이 논문에서는 확장성이 뛰어난 시뮬레이션 엔진인 SSF(Scalable Simulation Framework)를 이용하여, 용이한 광인터넷 모델의 구성과 시뮬레이션 수행 결과에 대한 분석을 제공할 수 있는 광인터넷 시뮬레이터를 설계한다.

  • PDF

Ethanol Production by Synchronous Saccharification and Fermentation using Food Wastes (음식물 쓰레기 동시당화 발효에 의한 에탄올 생산)

  • Han, Hyo-Jung;Li, Hong-xian;Kim, Seong-Jun
    • KSBB Journal
    • /
    • v.21 no.6 s.101
    • /
    • pp.474-478
    • /
    • 2006
  • For the economically feasible production of ethanol, utilization of SFW (saccharified food wastes) as substrate for synchronous saccharification and fermentation (SSF) process was developed in this study. When 200 g of food wastes and 40 mL of enzyme ($amylase activity,\;3.0\;U/m{\ell}$) were reacted, production rate of reducing sugar was $5.84\;g/{\ell}{\cdot}h$, and consumption rate was $-3.88\;g/{\ell}{\cdot}h\;at\;35^{\circ}C$ So suitable condition of SSF was concluded at temperature of $35^{\circ}C$. Also, optimal enzyme concentration of SSF was concluded in $2.0\;U/m{\ell}$, at this condition, the production rate of reducing sugar was $4.80\;g/{\ell}{\cdot}h$ At SSF process, when 50 g of food wastes was supplied in 12 h interval, $64\;g/{\ell}$ of ethanol and 0.45 g-ethanol/g-reducing sugar in yield were obtained in 120 h fermentation. Thus, the technology of high yield of ethanol production using food wastes was confirmed. And semi-continuos SSF system for cutting off cost of enzymatic saccharification was developed in this study.

Studies on the Microbial Utilization of Agricultural Wastes (Part 12) Comparisions of Cellulolytic Methods for Ethanol Production from Cellulosic Material (농산폐자원의 미생물학적 이용에 관한 연구 (제12보) Ethanol 생산을 위한 Cellulose 함유물의 당화법비교)

  • Kim, Byung-Hong;Lee, Jung-Yoon;Bae, Moo;Kim, Sung-Ki
    • Microbiology and Biotechnology Letters
    • /
    • v.9 no.2
    • /
    • pp.65-69
    • /
    • 1981
  • As a process to utilize agricultural residues, simultaneous hydrolysis-fermentation (SSF) was compared with fermentation of enzymic hydrolyzate using koji cultures of Trichoderma sp. KI 7-2 and a thermotolerant yeast Saccharomyces cerevisiae NCYC 716. Cellobiose was not detected in SSF broth whilst 15 mg/$m\ell$ of the disaccharide was found in enzymic hydrolysate of rice straw using the same enzyme source. It was found that converting glucose to ethanol in SSF process reactivated the cellobiase activity, which is inhibited by the accumulation of glucose in enzymic hydrolysis process. Cutting milled rice straw was fermented as effectively as ball milled one in SSF process. From tile results discussions are made on the product inhibition mechanism of cllulolytic enzyme system.

  • PDF

Optimization of Simultaneous Saccharification and Fermentation of Rice Straw to Produce Butanol (Butanol 생산을 위한 동시 당화 발효법의 최적화)

  • Jun, Young-Sook;Kwon, Gi-Seok;Kim, Byung-Hong
    • Microbiology and Biotechnology Letters
    • /
    • v.16 no.3
    • /
    • pp.213-218
    • /
    • 1988
  • Studies were made to optimize the simultaneous saccharification and fermentation (SSF) of rice straw to produce butanol using Clostridium acetobutylicum KCTC 1037 and a cellulolytic enzyme preparation from Trichoderma viride. The fermentation was inhibited when the liquid enzyme preparation from Novo was used, whilst a successful fermentation was achieved in the SSF using the enzyme manufactured by Pacific Chemical Co. The minimum cellulase concentration for the successful fermentation of pure cellulose was found to be 4 IU/g of substrate used. Alkaline treatment was better method for the fermentation of rice straw by the system. SSF using 25% alkaline treated rice straw produced 150 mM butanol, 90 mM acetone. On the other hand, fermentation of ball milled rice straw was mainly acidogenic producing 98 mM acetate and 64 mM butyrate with less than 20 mM butanol. These results show that rice straw contains (a) specific inhibitor(s) for solventogenesis which is destroyed or soluble in alkali.

  • PDF

Application and Analysis of Rhizopus oryzae Mycelia Extending Characteristic in Solid-state Fermentation for Producing Glucoamylase

  • Tang, Xianghua;Luo, Tianbao;Li, Xue;Yang, Huanhuan;Yang, Yunjuan;Li, Junjun;Xu, Bo;Huang, Zunxi
    • Journal of Microbiology and Biotechnology
    • /
    • v.28 no.11
    • /
    • pp.1865-1875
    • /
    • 2018
  • Enhanced application of solid-state fermentation (SSF) in industrial production and the influence of SSF of Rhizopus K1 on glucoamylase productivity were analyzed using the flat band method. A growth model was implemented through SSF of Rhizopus K1 in this experiment, and spectrophotometric method was used to determine glucoamylase activity. Results showed that in bran and potato culture medium with 70% moisture in a loose state, ${\mu}$ of mycelium reached to $0.15h^{-1}$ after 45 h of culture in a thermostatic water bath incubator at $30^{\circ}C$. Under a low-magnification microscope, mycelial cells appeared uniform, bulky with numerous branches, and were not easily ruptured. The generated glucoamylase activity reached to 55 U/g (dry basis). This study has good utilization value for glucoamylase production by Rhizopus in SSF.

Effects of Engineered Saccharomyces cerevisiae Fermenting Cellobiose through Low-Energy-Consuming Phosphorolytic Pathway in Simultaneous Saccharification and Fermentation

  • Choi, Hyo-Jin;Jin, Yong-Su;Lee, Won-Heong
    • Journal of Microbiology and Biotechnology
    • /
    • v.32 no.1
    • /
    • pp.117-125
    • /
    • 2022
  • Until recently, four types of cellobiose-fermenting Saccharomyces cerevisiae strains have been developed by introduction of a cellobiose metabolic pathway based on either intracellular β-glucosidase (GH1-1) or cellobiose phosphorylase (CBP), along with either an energy-consuming active cellodextrin transporter (CDT-1) or a non-energy-consuming passive cellodextrin facilitator (CDT-2). In this study, the ethanol production performance of two cellobiose-fermenting S. cerevisiae strains expressing mutant CDT-2 (N306I) with GH1-1 or CBP were compared with two cellobiose-fermenting S. cerevisiae strains expressing mutant CDT-1 (F213L) with GH1-1 or CBP in the simultaneous saccharification and fermentation (SSF) of cellulose under various conditions. It was found that, regardless of the SSF conditions, the phosphorolytic cellobiose-fermenting S. cerevisiae expressing mutant CDT-2 with CBP showed the best ethanol production among the four strains. In addition, during SSF contaminated by lactic acid bacteria, the phosphorolytic cellobiose-fermenting S. cerevisiae expressing mutant CDT-2 with CBP showed the highest ethanol production and the lowest lactate formation compared with those of other strains, such as the hydrolytic cellobiose-fermenting S. cerevisiae expressing mutant CDT-1 with GH1-1, and the glucose-fermenting S. cerevisiae with extracellular β-glucosidase. These results suggest that the cellobiose-fermenting yeast strain exhibiting low energy consumption can enhance the efficiency of the SSF of cellulosic biomass.

Evaluation of Multi-microbial Probiotics Produced by Submerged Liquid and Solid Substrate Fermentation Methods in Broilers

  • Shim, Y.H.;Shinde, P.L.;Choi, J.Y.;Kim, J.S.;Seo, D.K.;Pak, J.I.;Chae, B.J.;Kwon, I.K.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.23 no.4
    • /
    • pp.521-529
    • /
    • 2010
  • Two experiments were conducted to evaluate multi-microbe submerged liquid (SLF) and solid substrate (SSF) fermented probiotic products in broilers. The SLF and SSF probiotics were comprised of Lactobacillus acidophilus ($1.1{\times}10^9$ and $4{\times}10^8$ cfu/g), Bacillus subtilis ($1.1{\times}10^9$ and $4{\times}10^9$ cfu/g), Saccharomyces cerevisiae ($1.5{\times}10^7$ and $1.0{\times}10^4$ cfu/g) and Aspergillus oryzae ($2.6{\times}10^7$ and $4.3{\times}10^7$ cfu/g), respectively. In Exp. 1, 640 day-old Ross chicks were allotted to 4 treatments, each comprising 4 replicates (40 chicks/replicate). The basal diet was prepared without any antimicrobials (negative control, NC), and 20 mg/kg avilamycin (positive control, PC), 0.3% SLF and 0.3% SSF probiotics were added to the basal diets as treatments. Birds fed PC and SSF diets showed improved (p<0.001) overall weight gain and F/G than birds fed NC and SLF diets; whereas, birds fed SLF diet had better weight gain and F/G than birds fed NC diet. Retention of CP was higher (p<0.05) in birds fed the SSF diet than birds fed PC, SLF and NC diets. Birds fed the SLF diet tended to have higher (p<0.10) cecal total anaerobic bacteria than birds fed PC and NC diets; whereas, lesser cecal coliforms were noticed in birds fed PC, SLF and SSF diets than birds fed the NC diet. In Exp. 2, 640 day-old Ross chicks were randomly allotted to 4 treatments in a $2{\times}2$ factorial arrangement. Each treatment had 4 replicates (40 chicks/replicate). Two different multi-microbe probiotic products (0.3% SLF or SSF) each with two different antibiotics (10 mg/kg colistin, or 20 mg/kg avilamycin) were used as dietary treatments. Birds fed the SSF diet had greater weight gain (p<0.001), better F/G (p<0.05), greater retention of energy (p<0.001) and protein (p<0.05), and lesser cecal Clostridium (d 35) than birds fed SLF diet. Birds fed the colistin-supplemented diet had less (p<0.01) cecal coliforms when compared with birds fed the avilamycin diet. Additionally, birds fed the avilamycin diet had greater energy retention (p<0.05) than birds fed the colistin diet. Thus, the results of this study suggest the multi-microbe probiotic product prepared by a solid substrate fermentation method to be superior to the probiotic product prepared by submerged liquid fermentation; moreover, feeding of probiotics with different antibiotics did not elicit any interaction effect between probiotic and antibiotic.

Tumor Margin Infiltration in Soft Tissue Sarcomas: Prediction Using 3T MRI Texture Analysis (연조직 육종의 종양 가장자리 침윤: 3T 자기공명영상 텍스처 분석을 통한 예측)

  • Minji Kim;Won-Hee Jee;Youngjun Lee;Ji Hyun Hong;Chan Kwon Jung;Yang-Guk Chung;So-Yeon Lee
    • Journal of the Korean Society of Radiology
    • /
    • v.83 no.1
    • /
    • pp.112-126
    • /
    • 2022
  • Purpose To determine the value of 3 Tesla (T) MRI texture analysis for predicting tumor margin infiltration in soft tissue sarcomas. Materials and Methods Thirty-one patients who underwent 3T MRI and had a pathologically confirmed diagnosis of soft tissue sarcoma were included in this study. Margin infiltration on pathology was used as the gold standard. Texture analysis of soft tissue sarcomas was performed on axial T1-weighted images (WI) and T2WI, fat-suppressed contrast-enhanced (CE) T1WI, diffusion-weighted images (DWI) with b-value of 800 s/mm2, and apparent diffusion coefficient (ADC) was mapped. Quantitative parameters were compared between sarcomas with infiltrative margins and those with circumscribed margins. Results Among the 31 patients with soft tissue sarcomas, 23 showed tumor margin infiltration on pathology. There were significant differences in kurtosis with the spatial scaling factor (SSF) of 0 and 6 on T1WI, kurtosis (SSF, 0) on CE-T1WI, skewness (SSF, 0) on DWI, and skewness (SSF, 2, 4) on ADC between sarcomas with infiltrative margins and those with circumscribed margins (p ≤ 0.046). The area under the receiver operating characteristic curve based on MR texture features for identification of infiltrative tumor margins was 0.951 (p < 0.001). Conclusion MR texture analysis is reliable and accurate for the prediction of infiltrative margins of soft tissue sarcomas.

The effect of forging process conditions of semi-solid aluminum material on mechanical properties (반용융 알루미늄재료의 단조공정조건이 기계적 성질에 미치는 영향)

  • Gang, Chung-Gil;Gang, Dong-U
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.21 no.9
    • /
    • pp.1400-1413
    • /
    • 1997
  • Semi-solid forging(SSF) process of A356 aluminium alloy has been studied to assess the effect of process variables on the component integrity. Semi-solid material(SSM) was fabricated by mechanical and electro-magnetic stirring process. The fabricated SSM by using mechanical stirring process has been carried out on cooling rate of 0.022.deg. C/sec 0.0094.deg. C/sec and stirring speed n=600, 1000 rpm, respectively. The fabricated SSM by using electro-magnetic stirring process is supplied by Pechiney. The holding time and temperature in the semi-solid state before forging also affects the globular microstructure of alloy. Therefore, the influence of these two parameters is discussed in terms of the microstructure of alloy. The SSF process has been conducted with three different die temperatures($T_{die}$=250.deg. C, 300.deg. C, 350.deg. C) and two kinds of gate types(straight gate and orifice gate). This paper is to investigate the influence of gate shapes of die on filling phenomena in SSF process more deeply. The mechanical properties of forged components were also investigated for variation of process conditions such as die temperature, gate shape and SSM.