초록 ▼

○ 연구결과
국내 환경으로부터 신규 당화효소(셀룰라아제, 자일라나아제, 글루코시다아제, 자일로시다아제 등)를 발굴 및 개량하였다. 또한 xylanase(KRICT PX1) 및 신규 당화효소 고정화 담체 선발 및 활용 핵심기술 개발(glucan, xylan), 이온성 액체적용을 통한 당화효율 최적화 기술개발, 당화효소 고정화 담체 제작 및 고정화를 수행하였다. C6/C5 동시 이용성, 당화/발효 대사공학적 개량, C6/C5 동시 당화/발효 Z. mobilis 균주개량 및 산성/젖산 생산성 증진을 위한 대사공학적 개량, xylA,

○ 연구결과
국내 환경으로부터 신규 당화효소(셀룰라아제, 자일라나아제, 글루코시다아제, 자일로시다아제 등)를 발굴 및 개량하였다. 또한 xylanase(KRICT PX1) 및 신규 당화효소 고정화 담체 선발 및 활용 핵심기술 개발(glucan, xylan), 이온성 액체적용을 통한 당화효율 최적화 기술개발, 당화효소 고정화 담체 제작 및 고정화를 수행하였다. C6/C5 동시 이용성, 당화/발효 대사공학적 개량, C6/C5 동시 당화/발효 Z. mobilis 균주개량 및 산성/젖산 생산성 증진을 위한 대사공학적 개량, xylA, xylB, tktA 및 talB 유전자 도입, D-형 젖산 선택적 생산 균주 개발 등을 수행하였다.

Abstract ▼

Ⅰ. Title
Development of C5-SSF technology for lactic acid production from xylan in hemicellulose
Ⅱ. Purpose and Necessity of R&D
- Purpose of R&D
To establish the core biorefinery technology to overcome the increasing cereal cost, and prepare alternatives for petroleum-origin chemicals,

Ⅰ. Title
Development of C5-SSF technology for lactic acid production from xylan in hemicellulose
Ⅱ. Purpose and Necessity of R&D
- Purpose of R&D
To establish the core biorefinery technology to overcome the increasing cereal cost, and prepare alternatives for petroleum-origin chemicals, this project is aimed to develope the acid-tolerant bacterial strain for the effective fermentative bio-transformation of the substrates to lactic acid. using C6/C5 substrates (glucose/xylose) produced by saccharification using cheap biomass such as agricultural by-products available in Korea.
- Necessity of R&D
The development of biorefinery technology is a mega-trend for the continuous growth of chemical industry in confront of various problems such as rising oil price, depletion of oil resources, carbon dioxide emissions by the use of fossil fuels, and global worming. In order to develop alternative sources of fossil fuels, many researches are focused to the main targets such as solar, wind, hydro, nuclear, and biomass etc., but biomass is the only carbon-based resource capable to produce alternative chemicals for petrochemicals with fully developed biorefinery technology in the near future. In other words, from commodities to various energy, chemical, plastics, food and feed, pharmaceuticals, etc. biotechnology are applied to a wide variety of technology industries, the impact to the future economy is expected to be very large.
Accordingly, programs to establish an institutional framework among industry, academia, research institutions, and a strong policy of technical cooperation are being planned. Therefore, the future market structure will be replaced by bio-chemical market demand, and secure and stable supply of biomass utilization technologies for the development of appropriate resources in South Korea, a the comprehensive biorefinery including pre-treatment technology development, saccharification system development, and fermentation technology should be addressed as essential. Biorefinery technology that collectively produces chemical feedstocks from biomass technology, is sub-classified as the type and composition of the biomass to various sectors. Notably, sugar biomass (glucose, fructose, sugar producing crops, sugar cane and sugar beet, etc.), starch biomass (starch from corn, wheat, potatoes, etc.), lignocellulosic biomass (variety of plants), crops, and raw material waste can be used. Lactic acid production technology with sugar and glucose have already reached completion, but using non-food biomass resources, lignocellulosic biomass utilization technology is still in an early stage in many developed countries. In general, the composition of lignocellulosic biomass is consisted of cellulose 38-50%, hemicellulose 23-32% , and lignin 15-25%. Thus, 61-82% saccharification including both cellulose and hemicellulose would be a very efficient biomass utilization. Utilization of lignocellulosic biomass has two technical barriers as follows: techniques ① for efficient degradation and separation of biomass consisting of cellulose, hemicellulose, and lignin to fermentable sugars, ② bacterial strain improvement technology capable to ferment a variety of biomass sugars consisting of glucose, xylose, and arabinose. Currently, production cost of lactic acid is dependent on the cost of raw material, so for the competitiveness of low-cost raw materials, especially the production of lactic acid derived from xylose generated from hemicellulose should be able to overcome the improving rate governing process. Because saccharification process of lignocellulosic resources with development of new enzymes and mass production is not complete, fermentation technique using both glucose (hexose) and xylose (pentose) generated from saccharification process or continuous process of saccharification and fermentation process should be developed as a future fundamental technology.
Ⅲ. Accomplishment Contents and Result of R&D Project
- Result of R&D Project
Core technologies for biorefinery include many unit processes of various biomass pretreatment methods, enzyme engineering, metabolic engineering, biological/chemical conversion technology, biochemical/physicochemical conversion process technology, fermentation process optimization, separation and purification, monomer production and polymerization technologies, application technology, and commercialized marketing. Therefore, value chain of biorefinery is completed with step 1: biomass saccharification technology, step 2: sugar fermentation technology, step 3:intermediates purification technology, step 4: Use development of the produced intermediate, step:5 final product developing technology. Among these unit processes of a continuous process, this project is aiming to develop the step 1: enzymatic saccharification of biomass resources and the step 2: development of the bacterial strain producing lactic acid. To fulfill these objectives, this project consists of pentose production technology from hemicellulose using fused bio-nano technology and selective D-lactic acid production technology with C6/C5 of Macrogen's Zymomonas mobilis improved by metabolic-engineering technique.
- Accomplishment Contents
Research scope of this project can be classified broadly into two areas. The first aspect is the development and utilization of enzymatic saccharification, and the second is the development of lactic acid bacteria with improved productivity. Specifically, xylose production with renewable lignocellulosic biomass saccharification enzyme (xylanase production 10 IU/ml by batch, or 20~25 IU/ml by fed-batch) and strain system producing lactic acid (lactic acid production 0.6 g/l/h, pH 5.0 or more) is to develop. The scope of development of saccharification enzyme includes bio-nano fusion technology, improvement and immobilization of saccharification enzyme, dissolution (optimization) technology of insoluble fiber using ionic liquid catalyst at room temperature, and in the area of fermentation strain development includes the bacterial strain improvement by metabolic engineering of Macrogen's Zymomonas mobilis for simultaneous use of C6/C5 sugars.
Ⅳ. Achievement of R&D Goals
- New saccharification enzymes (cellulase, xylanase, glucosidase) were discovered from the domestic environment and improved. In addition, for the selection and utilization of immobilized carrier and core application technology (glucan, xylan) with xylanase (KRICT PX1) and new saccharification enzyme, optimization of saccharification efficiency through the application of ionic liquids technology, production of immobilizing carrie and saccharification enzyme immobilization were carried out. For simultaneous utilization of C6/C5, metabolic engineering improvement of saccharification/fermentation, Z. mobilis strain improvement for C6/C5 simultaneous saccharification/fermentation, metabolic engineering improvement for increasing acid-tolerant lactic acid productivity, xylA, xylB, tktA and talB transgenic, bacteria development for the selective production of D-type lactic acid were carried out.
Ⅴ. Application Plan of R&D Result
R&D results are classified to the core technology (hemicellulose solubilizing catalysts, enzymatic saccharification, lactic acid producing strains), process platform (integrated dissolution/saccharification process and lactic acid fermentation process), products (lactic acid and PLA intermediates), etc., and first technology licensing and commercialization after 2012, joint venture promotion, factory establishment in 2014, and the full-scale production is planned since 2017.
The promotion to establish joint venture companies with demanding companies or petrochemical companies, export market driving after replacing domestic import volume are targeted, and the initial production volume will increase from 500 to 50,000 tons, and the estimated sales of 1.5~30 billion won with 40 billion won investment (facility, land, and operations) is expected.
(1) If aligning the pretreatment technology development and standardization of pre-renewable resources, the development of new environment-friendly technologies switching agro- and forest resources to new basic feedstock for chemical industry will contribute to solve the concurrent difficulties faced in both chemical and agriculture industry
(2) Due to the use of renewable biomass, the oil substitution effects (replacing 4-10% crude oil imports in 2016 and increase in industrial biotechnology production from 800 million USD in 2005 to 135 billion USD in 2016 ) will be achieved

목차 Contents

• 표지 ... 1
• 제출문 ... 2
• 보고서 요약서 ... 3
• 요약문 ... 6
• SUMMARY ... 7
• CONTENTS ... 10
• 목차 ... 11
• 그림 목차 ... 12
• 표 목차 ... 16
• 제 1장 연구개발 과제의 개요 ... 17
• 1. 연구개발의 목적 ... 17
• 2. 연구개발의 필요성 ... 17
• 3. 연구개발의 범위 ... 21
• 제 2장 국내외 기술개발 현황 ... 22
• 1. 국내ㆍ외 기술개발현황 ... 22
• 2. 기술개발의 차별성 ... 38
• 제 3장 연구개발 수행 내용 및 결과 ... 43
• 제1절 이론적, 실험적 접근방법 ... 43
• 제2절 연구내용 및 연구결과 ... 48
• 제 4장 목표달성도 및 관련분야에의 기여도 ... 172
• 1. 연구개발목표의 달성도 ... 172
• 2. 관련분야의 기술발전에의 기여도 ... 174
• 제 5장 연구개발 성과 및 성과활용 계획 ... 176
• 제 6장 연구개발과정에서 수집한 해외과학기술정보 ... 181
• 1. 출장목적 ... 181
• 2. 세부내용 ... 181
• 3. 주요업무수행사항 및 관련정보 자료의 분석내용 ... 184
• 4. 수집정보자료 및 참고문헌 ... 196
• 제 7장 참고문헌 ... 210
• 끝페이지 ... 213