담수조류 그물말로부터 당 용액의 효율적 제조를 위한 가수분해 방법 = Hydrolysis Methods for the Efficient Manufacture of Sugar Solutions from the Freshwater Alga Water-net (Hydrodictyon reticulatum)

다국어 초록 (Multilingual Abstract)

To explore hydrolysis methods for the efficient manufacture of sugar solutions from the freshwater alga Water-net (Hydrodictyon reticulatum, HR), acid hydrolysis, enzymatic hydrolysis, and combined hydrolysis (acid followed by enzymatic hydrolysis) were investigated. In the one-step acid hydrolysis, the reaction of 8% solids content using 2% sulfuric acid at 120oC for 1 hour was desirable. In this case, glucose 27.44 g 100 g DM-1 could be obtained from the HR-d13 samples. In the two-step acid hydrolysis, the primary hydrolysis (HR powder : 72% sulfuric acid = 1 g : 1.5 mL) was carried out for 1 hour at 60oC, and then the secondary hydrolysis was done for 1 hour at 120oC after addition of distilled water 23.5 mL. In this case, glucose 35.11 g/100 g DM could be obtained from the HR-d13 samples. In the combined hydrolysis, 25% solids content using 2% hydrochloric acid were reacted for 1 hour at 120oC, and then citrate buffer and hydrolysis enzyme complexes (E1 1.0 mL+E2 0.2 mL g-1 dried matter) were added and reacted for 1 – 2 days at 50oC. In this case, glucose 33.5 g 100 g DM-1could be obtained from the HR-d23+26 samples. In conclusion, combined hydrolysis was likely to be more useful saccharification method of HR biomass at a practical level, considering the glucose productivity, generation of fermentation-inhibiting substances(hydroxyl methyl furfural, furfural), and limited use of strong acid.

국문 초록 (Abstract)

담수조류인 그물말 (Hydrodictyon reticulatum, HR)의 실용적 당화조건 확립을 위해 산 가수분해 방법으로서 onestepacid hydrolysis과 two-step acid hydrolysis, 그리고 산가수분해 후 효소가수분해를 병행하는 combined hydrolysis를 검토하였다. One-step acid hydrolysis의 경우, 120oC에서 HR 4% 고형분을 2% 황산 용액에 넣어 1시간 동안 반응시킬 경우가 적정하였다. Two-step acid hydrolysis의 적정조건은 1차 가수분해시 HR 건조중: 72% 황산을 1 g : 1.5mL로 하여 60oC에서 1시간 반응시킨 다음, 증류수 23.5 mL를첨가하고 120oC에서 1시간 가수분해시키는 것이었다.
Combined hydrolysis의 경우, 2% 염산에 25%의 HR 고형분을 넣고 120oC에서 1시간 반응시킨 후, citrate buffer로4% 고형분 함량이 되도록 희석하고 E1+E2 효소를 각각1+0.2 mL g DM-1 수준으로 첨가하여 50oC에서 1~2일 동안 반응시키는 것이 바람직하였다. Glucose 생성량, 발효억제물질(HMF, furfural) 생성량, 강산 사용제한 등을 종합적으로 감안할 때, combined hydolysis가 보다 유용할 것으로 판단되었다.

참고문헌 (Reference)

1 김슬기, "발효 당용액 생산자원으로서 담수조류 그물말의 유용성" 한국잡초학회 32 (32): 85-97, 2012

2 윤병태, "구멍갈파래의 알칼리 과산화수소 전처리 및 효소 가수분해 특성" 한국공업화학회 22 (22): 336-339, 2011

3 Jeong, T. S., "Two-stage acid saccharification of fractionated Gelidium amansii minimizing the sugar decomposition" 102 : 10529-10534, 2011

4 Ge, L., "Study on saccharification techniques of seaweed wastes for the transformation of ethanol" 36 : 84-89, 2011

5 이성목, "Saccharomyces cerevisiae에 의한 Agar로부터 바이오 에탄올 생산" 한국공업화학회 20 (20): 290-295, 2009

6 Daroch, M., "Recent advances in liquid biofuel production from algal feedstocks" 102 : 1371-1381, 2013

7 Jang, S. S., "Production of mono sugar from acid hydrolysis of seaweed" 11 : 1953-1963, 2012

8 Nguyen, C. M., "Production of L-lactic acid from a green microalga, Hydrodictyon reticulum, by Lactobacillus paracasei LA104 isolated from the traditional Korean food, Makgeolli" 110 : 552-559, 2012

9 Alvira, P., "Pretreatment technologies for an efficient bioethanol production process based on enzymatic hydrolysis : A review" 101 : 4851-4861, 2010

10 Miranda, J. R., "Pretreatment optimization of Scenedesmus obliquus microalga for bioethanol production" 104 : 342-348, 2012

11 Isa, A., "Preliminary study on ethanol production by using macro green algae" 88 : 912-917, 2009

12 Mata, T. M., "Microalgae for biodiesel production and other applications : A review" 14 : 217-232, 2010

13 John, R. P., "Micro and macroalgal biomass : A renewable source for bioethanol" 102 : 186-193, 2011

14 Matrai, T., "Invertase production of common storage moulds in food and feed grains as a possibility for rapid detection of Aspergillus flavus group and Aspergillus fumigatus" 61 : 187-191, 2000

15 Zhou, N., "Hydrolysis of Chlorella biomass for fermentable sugars in the presence of HCl and MgCl2" 102 : 10158-10161, 2011

16 Adams, J. M., "Fermentation study on Saccharina latissima for bioethanol production considering variable pre-treatments" 21 : 569-574, 2009

17 Mosier, N., "Features of promising technologies for pretreatment of lignocellulosic biomass" 96 : 673-686, 2005

18 Harun, R., "Exploring alkaline pre-treatment of microalgal biomass for bioethanol production" 88 : 3464-3467, 2011

19 Ueno, Y., "Ethanol production by dark fermentation in the marine green alga, Chlorococcum littorale" 86 : 38-43, 1998

20 Choi, S. P., "Enzymatic pretreatment of Chlamydomonas reinhardtii biomass for ethanol production" 101 : 5330-5336, 2010

21 Wingren, A., "Effect of reduction in yeast and enzyme concentrations in a simultaneous saccharification and fermentation-based bioethanol process : technical and economic evaluation" 121 : 485-499, 2005

22 NREL., "Chemical analysis and testing standard procedure" National Renewable Energy Labs 2010

23 Harun, R., "Bioprocess engineering of microalgae to produce a variety of consumer products" 14 : 1037-1047, 2010

24 Brennan, J., "Biofuels from microalgae—A review of technologies for production, processing, and extractions of biofuels and co-products" 14 : 557-577, 2010

25 Scott, S. A., "Biodiesel from algae : challenges and prospects" 21 : 277-286, 2010

26 Qian, X., "Acidic sugar degradation pathways" 124 : 989-997, 2005