• Journal of Plant Biology
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• 제13권1호
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• pp.1-12
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• 1970

The Nongkwang variety was sown directly in the field by the three methods of dibbling, drill seeding and broad-casting in non-, low- and high-salty areas, and compared with the growth of transplanted rice in each areas. The yield of rough rice was increased remarkably by direct sowing when compared with that produced by transplanting inboth salty areas, but in non-salty area, the former was decreased significantly. There was no significant difference in the yields of rough rice resulting from three seedling methods of direct sowing in each area. The direct sowing method was predominated in number of panicle, weight of panicle, ratio of matured grains, milling recovery percentage, and straw weight in both salty areas, and dicreased in panicle weight and ratio of matured grain in nonsalty area.

• Mycobiology
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• 제33권2호
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• pp.84-89
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• 2005

Five types of agricultural wastes were used for the production of xylanolytic enzyme by Aspergillus flavus K-03. All wastes materials supported high levels of xylanase and ${\beta}-xylosidase$ production. A high level of proteolytic activity was observed in barley and rice bran cultures, while only a weak proteolytic activity was detected in corn cob, barley and rice straw cultures. Maximum production of xylanase was achieved in basal liquid medium containing rice barn as carbon source for 5 days of culture at pH 6.5 and $25^{\circ}C$. The xylanolytic enzyme of A. flavus K-03 showed low thermostability. The times required for 50% reduction of the initial enzyme activity were 90 min at $40^{\circ}C$, 13 min at $50^{\circ}C$, and 3 min at $60^{\circ}C$. Xylanolytic activity showed the highest level at pH $5.5{\sim}10.5$ and more than 70% of the original activity was retained at pH 6.5 and 7.0. The higher stability of xylanolytic enzymes in the broad range of alkaline pH is useful for utilization of the enzymes in industrial process requiring in alkaline conditions. Moreover, the highest production of xylanolytic enzyme was obtained when 0.5% of rice bran was supplied in basal liquid medium. SDS-PAGE analysis revealed a single xylanase band of approximately 28.5 kDa from the culture filtrates.

• Mycobiology
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• 제43권3호
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• pp.258-265
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• 2015

The fungi on Meju are known to play an important role as degrader of macromolecule of soybeans. In order to elucidate the origin of fungi on traditional Meju, mycobiota of the air both inside and outside traditional Meju fermentation rooms was examined. From 11 samples of air collected from inside and outside of 7 Meju fermentation rooms, 37 genera and 90 species of fungi were identified. In outside air of the fermentation room, Cladosporium sp. and Cladosporium cladosporioides were the dominant species, followed by Cladosporium tenuissimum, Eurotium sp., Phoma sp., Sistotrema brinkmannii, Alternaria sp., Aspergillus fumigatus, Schizophyllum commune, and Penicillium glabrum. In inside air of the fermentation room, Cladosporium sp., Aspergillus oryzae, Penicillium chrysogenum, Asp. nidulans, Aspergillus sp., Cla. cladosporioides, Eurotium sp., Penicillium sp., Cla. tenuissimum, Asp. niger, Eur. herbariorum, Asp. sydowii, and Eur. repens were collected with high frequency. The concentrations of the genera Aspergillus, Eurotium, and Penicillium were significantly higher in inside air than outside air. From this result and those of previous reports, the origin of fungi present on Meju was inferred. Of the dominant fungal species present on Meju, Lichtheimia ramosa, Mucor circinelloides, Mucor racemosus, and Scopulariopsis brevicaulis are thought to be originated from outside air, because these species are not or are rarely isolated from rice straw and soybean; however, they were detected outside air of fermentation room and are species commonly found in indoor environments. However, Asp. oryzae, Pen. polonicum, Eur. repens, Pen. solitum, and Eur. chevalieri, which are frequently found on Meju, are common in rice straw and could be transferred from rice straw to Meju. The fungi grow and produce abundant spores during Meju fermentation, and after the spores accumulate in the air of fermentation room, they could influence mycobiota of Meju fermentation in the following year. This could explain why concentrations of the genera Aspergillus, Eurotium, and Penicillium are much higher inside than outside of the fermentation rooms.

• 한국미생물·생명공학회지
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• 제43권4호
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• pp.401-404
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• 2015

Bacillus coagulans는 프로바이오틱스 및 내열성 생물소재의 생산에 활용 가능성이 높은 미생물로 주목받고 있지만, 우리나라에서는 관심의 대상이 되지 못하고 있으며 상용화된 바 없다. 따라서 기능연구를 통한 산업화 대상 균주가 국내에는 충분히 확보되지 못한 상태에 있다. 본 연구자들은 미래 활용을 위한 B. coagulans의 확보를 위하여 볏짚으로부터 B. coagulans의 빠른 분리법을 개발하였다. $50^{\circ}C$에서의 집적배양, 산 생성 확인을 통한 Bacillus 속 균주의 제거, 선택배지를 이용한 enterococci 균주의 제거는 B. coagulans 선발을 위한 빠르고 정확한 방법이 될 수 있는 것으로 확인되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권6호
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• pp.776-782
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• 2019

Objective: Fasting may lead to changes in the microbiota and activity in the rumen. In the present study, the effects of fasting on rumen microbiota and the impact of fasting on in vitro rumen fermentation were evaluated using molecular culture-independent methods. Methods: Three ruminally cannulated Holstein steers were fed rice straw and concentrates. The ruminal fluids were obtained from the same steers 2 h after the morning feeding (control) and 24 h after fasting (fasting). The ruminal fluid was filtrated through four layers of muslin, collected for a culture-independent microbial analysis, and used to determine the in vitro rumen fermentation characteristics. Total DNA was extracted from both control and fasting ruminal fluids. The rumen microbiota was assessed using denaturing gradient gel electrophoresis (DGGE) and quantitative polymerase chain reaction. Microbial activity was evaluated in control and fasting steers at various intervals using in vitro batch culture with rice straw and concentrate at a ratio of 60:40. Results: Fasting for 24 h slightly affected the microbiota structure in the rumen as determined by DGGE. Additionally, several microorganisms, including Anaerovibrio lipolytica, Eubacterium ruminantium, Prevotella albensis, Prevotella ruminicola, and Ruminobacter amylophilus, decreased in number after fasting. In addition, using the ruminal fluid as the inoculum after 24 h of fasting, the fermentation characteristics differed from those obtained using non-fasted ruminal fluid. Compared with the control, the fasting showed higher total gas production, ammonia, and microbial protein production (p<0.05). No significant differences, however, was observed in pH and dry matter digestibility. Conclusion: When in vitro techniques are used to evaluate feed, the use of the ruminal fluid from fasted animals should be used with caution.

• 한국균학회지
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• 제45권1호
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• pp.43-53
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• 2017

본 연구는 양송이 배지의 관행적인 발효기술 개선에 대한 기초자료를 제공하기 위하여 배지 발효에 중요한 역할을 하는 다양한 미생물에 대한 밀도변화 및 분류학적인 특징을 밝혔고, 이들 미생물이 분비하는 세포벽 분해 관련 효소활성 변화를 조사하였다. 양송이 배지 발효와 밀접한 관련이 있는 미생물의 밀도 변화를 분석한 결과 고온성 세균, 방선균, 형광성 Pseudomonas spp., 사상균 등 다양한 미생물들이 분포하였으며, 고온성 발효가 진행됨에 유해균은 사멸되는 경향을 보였다. 야외발효 과정에서는 Psychrobacter속, Pseudomonas속, Bacillus속, Pseudoxanthomonas속이 가장 많이 분포하였고, 후발효 완료 배지에서는 Bacillus속, Psychrobacillus속이 우점하였다. 이러한 볏짚 발효 과정 중 분리한 미생물의 효소활성은 발효 초기에 cellulose 분해효소가 먼저 배지에 작용하여 탄소원을 분해한 후 hemicellulose 분해효소가 부차적으로 작용하는 양상을 보였고, 이들 효소를 분비하는 미생물들은 2차와 3차 뒤집기에서 많이 분포하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제12권5호
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• pp.752-757
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• 1999

Studies were made of digestion of timothy (Pheleum pretense) hay, tall fescue (Festuca elatior) hay, and rice (Oryza sativa) straw in pure cultures of rumen anaerobic fungus, Neocallimastix frontails MCH3. The fungus was inoculated on ground forages (1%, w/v) in an anaerobic medium and incubated at $39^{\circ}C$. Incubation was continued for 24, 48, 72 and 96 h. The losses of dry matter, xylose and glucose of forage during incubation were determined at the end of these incubation periods. Xylose and glucose were considered to be released from xylan and cellulose, respectively. The digested xylan to digested cellulose (X/C) ratios of the substrate were calculated. Xylanase and carboxymethyl cellulose (CMCase) of culture supernatant and residual substrate was measured at the same time. The X/C ratios in the cultures on timothy hay and rice straw were greater than 0.5 in the first 24-h incubation period. The values were smaller than 0.3 in tall fesque. The ratio of xylanase activity to that of CMCase in the first 24-h incubation period correlated well with the traits in X/C ratio. However xylanase activity was still superior to CMCase in the following incubation period (48 to 96 h), although the glucose (designated as cellulose) was more intensively digested than xylose (designated as xylan). The production of these polysaccharidases appeared to correlate with substrate cell-wall sugar composition, xylose to glucose ratios, at the beginning of fast growing period.

• 한국작물학회지
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• 제41권5호
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• pp.505-513
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• 1996

보리 입모중 벼 직파재배에 있어서 콤바인 수확에 따른 보리짚 피복량의 불균일에 의한 표면수의 화학성분 변화와 그 표면수가 벼 품종의 발아율 및 초기 유묘신장에 미치는 영향을 검토하였던 바, 그 결과를 요약하면 다음과 같다. 1. pH는 보리짚 무피복에 비하여 피복구가 낮았으며, 피복량이 많을수록 낮았으나 15일 이후에는 처리간 차이가 없었다. 2. 용존산소는 무피복에 비하여 피복량이 많을수록 낮았으나, 시일이 경과할수록 증가경향을 보였으나, EC는 용존산소와는 반대로 피복량이 많을수록 높았으며, 처리간 차이가 컸고 15 일에 가장 높았으며, 이후 감소하는 경향을 보였다. 3. N $H_4$-N는 처리 초기(5일)에 높고 피복량이 많을수록 높았으나, 급격히 감소되어 10일 이후에는 처리간의 차이를 보이지 않았다. N $O_3$-N는 N $H_4$-N와는 반대로 10일과 15일까지는 증가 경향을 보인 후 감소하였다. 그러나 피복량간에는 N $H_4$-N와 같이 기복량이 많을수록 높게 나타났다. 인산(P $O_4$$^{3-}$ ) 및 양이온( $K^{+}$,C $a^{2+}$ $Mg^{2+}$)함량 들은 무피복에 비하여 피복양이 많을수록 높았으며, 10일과 15일에 최고수준을 보인 후 감소하였다. 4. 보리짚 피복량별 논물이 벼 품종의 발아에 미치는 영향은, 피복량이 많을수록 발아율은 현격히 떨어졌으며, 생태형간에는 중만생종이 가장 높았고 중생종, 조생종 순이었다. 품종별로 보면 전량 환원구에서는 금오벼, 간척벼, 일품벼, 동진벼 및 계화벼가 우수하였던 바, 이러한 경향은 피복량간에도 같았다. 5. 치상 11일의 유묘신장은 무처리 대비 피복량이 많을수록 유묘의 신장률은 떨어졌으며, 전량 환원피복에서는 일품벼가 가장 우수하였고, 농안벼와 신운봉벼 는 50% 이하의 낮은 신장률을 보였으며, 2배 피복에서는 신운봉벼, 운장벼, 농안벼, 동진벼 등이 신장률이 낮게 나타났다.

• 한국유기농업학회지
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• 제19권spc호
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• pp.190-193
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• 2011

Organic and chemical fertilizer amendments are an important agricultural practice for increasing crop yields. In order to maintain the soil sustainability, it is important to monitor the effects of fertilizer applications on the shift of soil microorganism, which control the cycling of many nutrients in the soils. Here, culture-dependent and culture-independent approaches were used to analyze the soil microorganism and community structure under six fertilization treatments, including green manure, rice straw compost, rapeseed cake, pig mature compost, NPK +pig mature compost, NPK and control. Both organic and chemical fertilizers caused a shift of the cultural microorganism CFUs after treatments. Bacterial CFUs of the organic fertilization treatments were significantly higher than that of chemical fertilization treatments. The DGGE profiles of the bacterial communities of the samples showed that the green manure treatment was a distinct difference in bacterial community, with a greater complexity of the band pattern than other treatments. Cluster analyses based on the DGGE profile showed that rice straw compost and pig mature compost had a similar banding pattern and clustered together firstly. Rapeseed cake, NPK, NPK +pig manure compost and control clustered together in other sub-cluster and clearly distinguished from green manure.

• 한국초지조사료학회지
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• 제33권3호
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• pp.197-205
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• 2013

An in vitro study was conducted to determine the effects of defaunation (removal of protozoa) and forage sources (rice straw, ryegrass and tall fescue) on ruminal fermentation characteristics, methane ($CH_4$) production and degradation by rumen microbes. Sodium lauryl sulfate, as a defaunation reagent, was added into the mixed culture solution to remove ruminal protozoa at a concentration of 0.375 mg/ml. Pure cellulose (0.64 g, Sigma, C8002) and three forage sources were incubated in the bottle of culture solution of mixed rumen microbes (faunation) or defaunation for up to 24 h. The concentration of ammonia-N was high under condition of defaunation compared to that from faunation in all incubations (p<0.001). Total VFA concentration was increased at 3, 6 and 12 h (p<0.05~p<0.01) but was decreased at 24 h incubation (p<0.001) under condition of defaunation. Defaunation decreased acetate (p<0.001) and butyrate (p<0.001) proportions at 6, 12 and 24 h incubation times, but increased propionate (p<0.001) proportion at all incubation times for forages. Effective degradability of dry matter was decreased by defaunation (p<0.001). Defaunation not only decreased total gas (p<0.001) and $CO_2$ (p<0.01~0.001) production at 12 and 24 h incubations, but reduced $CH_4$ production (p<0.001) at all incubation times for all forages. The $CH_4$ production, regardless of defaunation, in order of forage sources were rice straw > tall fescue > ryegrass > cellulose (p<0.001) up to 24 h incubation.