Bio-hydrogen production from a marine brown algae and its bacterial diversity

이재화,Dong-Geun Lee,Jae-Il Park,Ji-Youn Kim 한국화학공학회 2010 Korean Journal of Chemical Engineering Vol.27 No.1

The aim of this study was to determine how bio-hydrogen production was related to the composition of the bacterial community in a dark fermentation fed with marine brown algae (Laminaria japonica). The bacterial diversity was ascertained by 16S rDNA PCR-sequencing. A total of 444 mL of bio-hydrogen was produced from 10 g/L of dry algae in a 100 mL of culture fluid for 62 h. The pH varied from 8.74 to 7.05. Active bio-hydrogen production was observed from 24 to 48 h, and maximum bio-hydrogen production was 106 mL over 1 L gas. The bacterial community of the activated sludge consisted of 6 phyla, where H2 producing and consuming bacteria coexisted. The only detectable bacterial phylum after bio-hydrogen generation with heat-treated (65 oC, 20 min) seeding was Firmicutes. Clostridium and Bacillus species constituted 54% and 46%, respectively, of the bacterial mixture and the most abundant species was Clostridium beijierinckii (34%). These results may provide a better understanding of how different biohydrogen communities affect hydrogen production and aid in the optimization of bio-hydrogen production.

Fermentative Bio-Hydrogen Production of Food Waste in the Presence of Different Concentrations of Salt (Na⁺) and Nitrogen

( Pul-eip Lee ),( Yuhoon Hwang ),( Tae-jin Lee ) 한국미생물 · 생명공학회 2019 Journal of microbiology and biotechnology Vol.29 No.2

Fermentation of food waste in the presence of different concentrations of salt (Na⁺) and ammonia was conducted to investigate the interrelation of Na⁺ and ammonia content in biohydrogen production. Analysis of the experimental results showed that peak hydrogen production differed according to the ammonia and Na⁺ concentration. The peak hydrogen production levels achieved were (97.60, 91.94, and 49.31) ml/g COD at (291.41, 768.75, and 1,037.89) mg-N/L of ammonia and (600, 1,000, and 4,000) mg-Na⁺/L of salt concentration, respectively. At peak hydrogen production, the ammonia concentration increased along with increasing salt concentration in the medium. This means that for peak hydrogen production, the C/N ratio decreased with increasing salt content in the medium. The butyrate/acetate (B/A) ratio was higher in proportion to the bio-hydrogen production (r-square: 0.71, p-value: 0.0006). Different concentrations of Na⁺ and ammonia in the medium also produced diverse microbial communities. Klebsiella sp., Enterobacter sp., and Clostridium sp. were predominant with high bio-hydrogen production, while Lactococcus sp. was found with low bio-hydrogen production.

Enhancement of hydrogen production and power density in a bio-reformed formic acid fuel cell (BrFAFC) using genetically modified Enterobacter asburiae SNU-1

Lee, J.,Jung, N.,Shin, J.H.,Park, J.H.,Sung, Y.E.,Park, T.H. Pergamon Press ; Elsevier Science Ltd 2014 International journal of hydrogen energy Vol.39 No.22

The objective of this research was to enhance hydrogen production and power density of a bio-reformed fuel cell (BrFAFC) in the fermentative hydrogen-producing bacterium, Enterobacter asburiae SNU-1, by genetic manipulation and treatment for cell stability. At certain formate concentrations and pHs, formate hydrogen lyase (FHL) decomposes formate to hydrogen and CO<SUB>2</SUB>. FHL is expressed by the FhlA transcription activator. Consequently, over-expressing the fhlA gene will increase FHL activity. We tested hydrogen productivity in peptone-yeast extract-glucose (PYG) growth medium and in formate production medium using fhlA over-expressed E. asburiae SNU-1 and found that specific hydrogen production was enhanced by 36.89% and 56.28%, respectively. Using a 25 mM optimized concentration of MgSO<SUB>4</SUB>, cell autolysis, which impedes hydrogen production in formic acid media, decreased; therefore, hydrogen production increased by 18%. A BrFAFC performance test was conducted in 300 mM formic acid containing 25 mM MgSO<SUB>4</SUB>. The BrFAFC using fhlA over-expressed SNU-1 as a cell catalyst for hydrogen production showed similar fuel cell performance up to 0.6 V compared to that of a proton exchange membrane fuel cell supplying pure H<SUB>2</SUB> gas, and also generated a two-fold maximum power density than that using the SNU-1wild type.

Anaerobic bio-hydrogen production from ethanol fermentation: the role of pH

Hwang, Moon H.,Jang, Nam J.,Hyun, Seung H.,Kim, In S. Elsevier 2004 Journal of biotechnology Vol.111 No.3

<P><B>Abstract</B></P><P>Hydrogen was produced by an ethanol–acetate fermentation at pH of 5.0 ± 0.2 and HRT of 3 days. The yield of hydrogen was 100–200mlgGlu<SUP>−1</SUP> with a hydrogen content of 25–40%. This fluctuation in the hydrogen yield was attributed to the formation of propionate and the activity of hydrogen utilizing methanogens. The change in the operational pH for the inhibition of this methanogenic activity induced a change in the main fermentation pathway. In this study, the main products were butyrate, ethanol and propionate, in the pH ranges 4.0–4.5, 4.5–5.0 and 5.0–6.0, respectively. However, the activity of all the microorganisms was inhibited below pH 4.0. Therefore, pH 4.0 was regarded as the operational limit for the anaerobic bio-hydrogen production process. These results indicate that the pH plays an important role in determining the type of anaerobic fermentation pathway in anaerobic bio-hydrogen processes.</P>

바이오 수소 생산 탐구실험을 위한 홍색비황세균 균주 분리 및 생장조건

안경준,김흥태 한국현장과학교육학회 2016 현장과학교육 Vol.10 No.3

Researches about the development of alternative energy have been actively conducted. Bio-hydrogen production experiment by anaerobic photosynthetic bacteria that can be easily isolated from the surrounding environment is useful for realizing the advancement and application of modern biology and understanding the biology-related concepts. The present study suggested that bio-hydrogen production experiment by utilizing phototrophic metabolism of purple non-sulfur bacteria. The experimental procedures for the isolation, pure cultivation, and cold preservation of purple non-sulfur bacteria from the surrounding environment were addressed with the methods for light environmental condition for the culture growth and bio-hydrogen production responding to substrate in the media. Bio-hydrogen production experiment developed in the present study can be helpful for increasing students' interest to renewable energy and improving their understanding microbial metabolism. 현재 미생물의 다양한 대사작용을 활용한 대체에너지 개발 연구가 활발하다. 주변에서 쉽게 얻을 수 있는 혐기성 광합성 세균을 활용하여 바이오 수소를 생산하는 실험은 현대 생명과학의 발달 및 응용, 관련 생명과학 개념을 이해하는 데 도움이 된다. 본 연구에서는 홍색비황세균의 광영양 대사를 활용한 바이오 가스 생산 실험방법을 제안하기 위해, 주변 환경으로부터 홍색비황세균을 분리하여 순수 배양하고 장기 보존하는 방법 및 적정한 배양을 위한 빛 환경 조건 설정 실험과 함께, 배지 조건에 따른 수소 생산 확인 실험을 제시하였다. 본 연구는 미생물을 활용한 재생에너지 개발에 대한 관심 유도를 통해 미생물의 주요 대사작용에 대한 이해를 높일 수 있는 광합성 미생물 활용 실험 교육용 자료를 제안한다.

Physical Properties of Agro-Flour Filled Aliphatic Thermoplastic Polyester Bio-Composites

Young Geun Eom,Hee Soo Kim,Han Seung Yang,Hyun Joong Kim 한국목재공학회 2004 목재공학 Vol.32 No.3

생물학적 수소 발효를 통한 수처리 시스템

이정열 ( Jung Yeol Lee ),( Xue Jiao Chen ),민경석 ( Kyung Sok Min ) 한국물환경학회 2011 한국물환경학회지 Vol.27 No.6

Among various techniques for hydrogen production from organic wastewater, a dark fermentation is considered to be the most feasible process due to the rapid hydrogen production rate. However, the main drawback of it is the low hydrogen production yield due to intermediate products such as organic acids. To improve the hydrogen production yield, a co-culture system of dark and photo fermentation bacteria was applied to this research. The maximum specific growth rate of R. sphaeroides was determined to be 2.93 h-1 when acetic acid was used as a carbon source. It was quite high compared to that of using a mixture of volatile fatty acids (VFAs). Acetic acid was the most attractive to the cell growth of R. sphaeroides, however, not less efficient in the hydrogen production. In the co-culture system with glucose, hydrogen could be steadily produced without any lag-phase. There were distinguishable inflection points in the accumulation of hydrogen production graph that resulted from the dynamic production of VFAs or consumption of it by the interaction between the dark and photo fermentation bacteria. Lastly, the hydrogen production rate of a repeated fed-batch run was 15.9 mL-H2/L/h, which was achievable in the sustainable hydrogen production.

Effect of low pH on the activity of hydrogen utilizing methanogen in bio-hydrogen process

Kim, In S.,Hwang, Moon H.,Jang, Nam J.,Hyun, Seong H.,Lee, S.T. Elsevier 2004 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY - Vol.29 No.11

<P><B>Abstract</B></P><P>The pH is one of the most important parameters for producing hydrogen in biological processes. The major effect of low pH is the inhibition of the methanogenic activity in anaerobic biological processes for the production of hydrogen and, in general, it is considered that a pH below 5 can inhibit the methanogenic activity. In a semi-continuous reactor for the production of hydrogen, the pH was maintained at 4.5±0.2 by fixing the influent alkalinity to 1000mg/l as CaCO<SUB>3</SUB>. The primary fermentation product in this pH range was butyrate. The rate of hydrogen production stabilized at 35±5ml/g Glu-day after 35 days. The yield efficiency of hydrogen was relatively low due to the methanogenic activity. The methanogenic activity originated from the hydrogen utilizing methanogen, and was inhibited by the addition of nitrate. At pH 4.3, the butyrate type of fermentation was changed to the butanol type and, simultaneously, the production of hydrogen stopped.</P>

산업배열 및 부산물을 활용한 1톤급 바이오수소 생산 시뮬레이터 동적 열설계

김혜준(Hyejun Kim),김석연(Seokyeon Kim),안준(Joon Ahn) 대한설비공학회 2017 설비공학 논문집 Vol.29 No.5

This paper proposes a hydrogen-based social economy derived from fuel cells capable of replacing fossil fuels and resolving global warming, It thus provides an entry for developing economically feasible social configurations to make use of bio-hydrogen production systems. Bio-hydrogen production works from the principle that microorganisms decompose water in the process of converting CO to CO2, thereby producing hydrogen. This study parts from an analysis of an existing 157-ton class NA1 bio-hydrogen reactor that identifies the state of feedstock and reactor conditions. Based on this analysis, we designed a 1-ton class bio-hydrogen reactor process simulator. We carried out thermal analyses of biological heat reactions, sensible heat, and heat radiation in order to calculate the thermal load of each system element. The reactor temperature changes were determined by modeling the feed mixing tank capacity, heat exchange, and heat storage tank. An analysis was carried out to confirm the condition of the feed mixing tank, heat exchanger, heat storage tank capacity as well as the operating conditions of the system so as to maintain the target reactor temperature.

바이오 수소를 이용한 이산화탄소의 메탄 전환 연구

이준철(Jun Cheol Lee),김재형(Jae Hyung Kim),최광근(Kwang Keun Choi),박대원(Dae Won Pak) 大韓環境工學會 2008 대한환경공학회지 Vol.30 No.9

유기성 폐기물을 이용하여 생산된 수소를 환원제로 활용하여 이산화탄소를 유용한 에너지원인 메탄으로 전환시키고자 하였다. 3개월 동안 혐기성 미생물을 이산화탄소와 수소만을 이용하여 배양하였으며, 그 결과 acetogenotrophs의 영향에 의한 메탄의 생성은 없었고, 이산화탄소를 8 mL/min으로 주입하였을 때 이산화탄소와 수소의 주입비가 1:5에서 메탄의 생성량이 2.2 m3/m3day로 가장 많았으며, 이때의 이산환탄소 저감률 또한 92%로 가장 우수하였다. 회분형태로 수소 생산과 메탄발효조와의 연계실험을 통하여, 연속적으로 수소를 생산하면서 이산화탄소를 같이 메탄발효조에 주입하여, 이산화탄소의 메탄으로의 전환을 확인하였다. In the present study, carbon dioxide was converted to methane, using bio-hydrogen. Here, the bio-hydrogen was produced from organic waste. The anaerobic microorganism was cultured using only carbon dioxide and hydrogen for duration of 3 months. Therefore methane was not produced with acetogenotrophs. During methane production, carbon dioxide and hydrogen are taken in different ratios; among which 1:5 ratio has shown the highest methane yield. Carbon dioxide and hydrogen were introduced into the reactor at the rate of 8 mL/min and 40 mL/min, respectively. In this case, 92% of carbon dioxide was reduced and 2.2 m3/m3 day amount of methane was produced. Thus, the process has been successful in conversion of carbon dioxide into methane by purging it into methane fermentation reactor with bio-hydrogen using batch process.