• Journal of Microbiology and Biotechnology
• /
• 제20권4호
• /
• pp.763-766
• /
• 2010

An efficient and simple fermentation process was developed for the production of ${\gamma}$-aminobutyric acid (GABA) by Lactobacillus sakei B2-16. When the L. sakei B2-16 was cultivated in the rice bran extracts medium containing 4% sucrose, 1% yeast extract, and 12% monosodium glutamate, the maximum GABA concentration reached 660.0 mM with 100% conversion yield, showing the 2.4- fold higher GABA concentration compared with the modified MRS medium without the rice bran extracts. The GABA production was scaled-up from a laboratory scale (5 l) to a pilot (300 l) and a plant (5,000 l) scale to investigate the application possibility of GABA production to industrial fields. The production yields at the pilot and plant scales were similar to the laboratory scale using rice bran extracts medium, which could be effective for the low-cost production of GABA.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2022년도 추계학술대회
• /
• pp.106-106
• /
• 2022

An appropriate amount of nitrogen fertilizer input during rice cultivation is essential for rice growth, quality control, and reduction of greenhouse gases in paddy fields. Therefore, it is necessary to develop a technology that can check whether an appropriate amount of fertilizer is applied in paddy fields. In this study, we tried to derive a method for diagnosing nitrogen fertilization level using spectroscopic diagnosis, physiological analysis, and molecular indicator genes. Nitrogen fertilization treatment was performed in a greenhouse by dividing into five treatment conditions: no fertilization (N0), low fertilization (N0.5), standard fertilization (N1.0), excessive fertilization (N1.5), and double fertilization (N2.0), respectively. Growth characteristics analysis was investigated by nitrogen fertilization conditions and growth stages, and the height of the canopy was analyzed using a laser scanner. Physiological and spectroscopic analyses were performed by analyzing chlorophyll and sugar contents and measuring SPAD and leaf spectrometer on rice leaves. In addition, real-time PCR experiment was performed to check the relative expression levels of several known nitrogen metabolism related genes. These results suggest that spectroscopic techniques can be helpful in diagnosing the level of nitrogen fertilization in rice paddy fields.

• 한국식품영양학회지
• /
• 제6권4호
• /
• pp.294-300
• /
• 1993

This study was carried out to investigate the influences of cultural conditions of koji on the production of saccharogenic amylase during rice-koji making by Aspergillus awamori var. kawachii which is now widely used as koji-mold in brewing Tikju and Yakju in Korea. The optimum cultural temperature for the production of saccharogenic amylase by this mold was 36$^{\circ}C$, and at this temperature it needed 40 hours of cultivation for maximum production of this enzyme. It was favorable for high production of both organic acid and saccharogenic amylase to shift the cultural temperature form initial 36$^{\circ}C$ to 32$^{\circ}C$ after 20~25 hours of cultivation. The production of saccharogenic amylase was low when the water content of steamed rice was below 35%, but its production was high at 40~60% of water content. When the quantity of conidial inoculation was too small, the production of saccharogenic amylase was low in initial phase, but it was retrived after 40 hours of cultivation. When koji-thickness was over 3cm, the production of saccharogenic amylase was markedly restricted. The saccharogenic amylase of this koji was stable at pH 2~7, and showed high activity at pH 2~5.

• 한국식품영양학회지
• /
• 제6권4호
• /
• pp.287-293
• /
• 1993

This study was carried out to investigate the influences of cultural conditions of koji on the production of organic acid during rice-koji making by Aspergillus awamori var. kawachii which is now widely used as koji-mold in brewing Takju and Yakju in Korea. The optimum temperature for the germination of the conidia of the mold was 35'8, and the time required for germination at this temperature was 8 hours. Rapid germination occurred when the water content of steamed rice was above 40%, but germination retardation occurred markedly below 35%. The optimum cultural temperature for the production of organic acid was 32$^{\circ}C$, and the production of organic acid was markedly restricted at 36$^{\circ}C$ and 4$0^{\circ}C$. It was effective for the high production of both saccharogenic amylase and organic acid to shift the cultural temperature from initial 36$^{\circ}C$ to 32$^{\circ}C$ after 20~25 hours of cultivation. Initial water content suitable to the production of organic acid was 40% in steamed rice, but its production was markedly restricted below 30% of water content. When the quantity of conidial inoculation was too small, the production of organic acid was low in initial phase, but it was retrived at later period. Acid production was markedly restricted together with the increase in koji thickness.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2022년도 추계학술대회
• /
• pp.104-104
• /
• 2022

• Mycobiology
• /
• 제42권4호
• /
• pp.346-352
• /
• 2014

Recently, the Q biotype of tobacco whitefly has been recognized as the most hazardous strain of Bemisia tabaci worldwide, because of its increased resistance to some insecticide groups. As an alternative control agent, we selected an Isaria javanica isolate as a candidate for the development of a mycopesticide against the Q biotype of sweet potato whitefly. To select optimal mass production media for solid-state fermentation, we compared the production yield and virulence of conidia between 2 substrates (barley and brown rice), and we also compared the effects of various additives on conidia production and virulence. Barley was a better substrate for conidia production, producing $3.43{\times}10^{10}$ conidia/g, compared with $3.05{\times}10^{10}$ conidia/g for brown rice. The addition of 2% $CaCO_3+2%$ $CaSO_4$ to barley significantly increased conidia production. Addition of yeast extract, casein, or gluten also improved conidia production on barley. Gluten addition (3% and 1.32%) to brown rice improved conidia production by 14 and 6 times, respectively, relative to brown rice without additives. Conidia cultivated on barley produced a mortality rate of 62% in the sweet potato whitefly after 4-day treatment, compared with 53% for conidia cultivated on brown rice. The amendment of solid substrate cultivation with additives changed the virulence of the conidia produced; the median lethal time ($LT_{50}$) was shorter for conidia produced on barley and brown rice with added yeast extract (1.32% and 3%, respectively), $KNO_3$ (0.6% and 1%), or gluten (1.32% and 3%) compared with conidia produced on substrates without additives.

• Journal of Microbiology and Biotechnology
• /
• 제16권12호
• /
• pp.1856-1861
• /
• 2006

A Bacillus sp. A-6 strain that produced xylanase was isolated from rice bran. The optimal temperature and pH for xylanase activity of the culture supernatant of Bacillus sp. A-6 were 40$^{\circ}C$ and pH 7, respectively. The optimal temperature and pH for xylanase production in the xylan medium were 30$^{\circ}C$ and pH 9, respectively. The optimal concentrations of oat spelt xylan and peptone for xylanase production were 0.5% and 1.5%, respectively. The best nitrogen sources for xylanase production was beef extract, but xylanase production was also supported comparably by tryptone and peptone. The bacterial growth in the optimal xylan medium reached stationary growth phase after 12 h of incubation. The xylanase production in the culture supernatant increased dramatically during the initial 12 h exponential growth phase and then remained constant at 23.8-24.5 unit/ml during the stationary growth phase. The pH of the culture medium decreased from 8.8 to 6.7 during the exponential growth phase and subsequently increased to 8.1 during the stationary growth phase. Rice bran, sorghum bran, and wheat bran as well as oat spelt xylan induced xylanase production. The xylanase production was repressed when glucose was added to the xylan-containing medium.

• 생명과학회지
• /
• 제21권8호
• /
• pp.1083-1093
• /
• 2011

왕겨를 기질로 사용하여 carboxymethylcellualse (CMCase)를 생산하는 미생물을 해수에서 분리하였으며 16S rDNA의 염기서열을 분석하여 동정한 결과, Bacillus lichemiformis로 확인되었다. CMCase를 생산하기 위한 최적의 탄소원과 질소원은 왕겨와 암모니움 나이트레이트이었다. 통계학적인 방법인 response surface method (RSM)을 사용하여 CMCase를 생산하기 위한 조건을 최적화하였다. 통계학적인 분석 결과, 왕겨가 균체의 생육에 미치는 영향이 가장 높았으며, 왕겨와 배지의 초기 pH가 CMCase 생산에 미치는 영향이 높았다. Design Expert Software를 사용하여 결과를 분석한 결과, 균체의 생장에 최적인 조건은 48.7 g/l 왕겨, 1.8 g/l 암모니움 나이트레이트, 배지의 초기 pH 6.8 및 배양온도 35.7$^{\circ}C$이었으나, CMCase의 생산에 최적인 조건은 43.2 g/l 왕겨, 1.1 g/l 암모니움 나이트레이트, 배지의 초기 pH 6.8 및 배양온도 35.7$^{\circ}C$이었다. 최적화된 조건에서 왕겨를 기질로 사용하여 B. lincheniformis LBH-52가 생산하는 CMCase는 79.6 U/ml이었다. 본 연구를 통하여 왕겨와 암모니움 나이트레이트를 CMCase를 생산하는 기질로 개발하였으며, 해수에서 분리한 미생물을 사용하여 생산기간을 3일로 단축하였다.

• 한국토양비료학회지
• /
• 제45권6호
• /
• pp.1157-1163
• /
• 2012

2011년 전북 군산과 익산 지역의 관행농, 무농약, 유기농 농가를 대상으로 영농방법별로 쌀 생산 과정 중 투입 배출되는 물질 목록을 면접조사하여 전과정평가를 수행하고 쌀 생산체계에 대한 영농방법별 환경영향을 평가하고 탄소배출량을 비교 분석하였다. 전과정 목록분석 결과 $CO_2$ 배출은 화학비료 생산과 벼 재배단계에서 가장 많았고, $CH_4$과 $N_2O$ 배출은 대부분 벼 재배 중에 발생되었다. 쌀 (조곡) 1 kg 생산을 기준으로 하는 탄소성적은 관행농이 1.01E+00 $CO_2$-eq. $kg^{-1}$로 가장 높았고, 무농약이 5.37E-01 $CO_2$-eq. $kg^{-1}$, 유기농법이 6.58E-01 $CO_2$-eq. $kg^{-1}$였다. 농자재 투입량이 가장 적었던 무농약 쌀 생산에서 탄소성적이 가장 낮았고, 생산량은 가장 적었지만 복비투입이 없었던 유기농이 관행농보다 탄소성적이 낮았다. 관행농과 무농약 쌀 생산체계에서 온실가스 배출 주요 요인은 복비생산과 벼 재배 중 $CH_4$ 발생이었고, 유기농에서는 벼 재배 중 농기계 연료사용과 논토양 $CH_4$ 발생이었다. 그러므로 온실가스 감축을 위한 영농방법 활용으로 복합비료 적정량 사용을 위한 맞춤형 비료의 권장 및 벼논 물관리에 의한 메탄발생 저감방법 등을 제안하며, 더불어 유기농법에서는 수확량 향상을 위한 생산 효율성 증대와, 벼 재배 단계에서 농기계 연료 효율성 증대 활용에 관한 연구가 요구되었다.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
• /
• pp.235-238
• /
• 2008

We examined butanol fermentation by Clostridium beijerinckii NCIMB 8052 using various hydrolyzates obtained from rice bran which is one of the most abundant agricultural by-products in Korea and Japan. In order to increase the amount of fermentable sugars in the hydrolyzates of rice bran, various hydrolysis procedures were applied. Total eight different hydrolyzates were prepared using rice bran (RB) and defatted rice bran (DRB) with enzyme or acid treatment and both. Each hydrolyzate was evaluated in terms of total sugar concentration and butanol production after fermentation by C. beijerinckii NCIMB 8052. Acid treatment yielded more sugar than enzyme treatment and combined treatment with enzyme and acid yielded even more sugars as compared to single treatment with enzyme or acid. As a result, the highest sugar concentration (33 g/L) was observed from the hydrolyzate from DRB (100 g/L) with combined treatment using enzyme and acid. Prior to perform fermentation of the hydrolyzates, we examined the effect of P2 solution containing yeast extract, buffer, minerals, and vitamins on production of butanol during the fermentation. Fermentation of the hydrolyzates with or without additionof P2 was performed using C. beijerinckii NCIMB 8052 in a 1 L anaerobic bioreactor. Although the hydrolyzates RB were able to support growth and butanol production, addition of P2 solution into the hydrolyzates significantly improved cell growth and butanol production. Highest butanol production (12.24 g/L) was observed from the hydrolyzate of DRB with acid and enzyme treatment after supplementation of P2 solution.