• Journal of Microbiology and Biotechnology
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• 제34권8호
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• pp.1727-1737
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• 2024

The quality of tobacco is directly affected by macromolecular content, fermentation is an effective method to improve biochemical properties. In this study, we utilized CBHA (cellobiohydrolase A) glycosylase, which was expressed by Pichia pastoris, as an additive for fermentation. The contents of main chemical components of tobacco leaves after fermentation were determined, and the changes of microbial community structure and abundance in tobacco leaves during fermentation were analyzed. The relationship between chemical composition and changes in microbial composition was investigated, and the function of bacteria and fungi in fermentation was predicted to identify possible metabolic pathways. After 48 h of CBHA fermentation, the contents of starch, cellulose and total nitrogen in tobacco leaf decreased by 17.60%, 28.91% and 16.05%, respectively. The microbial community structure changed significantly, with Aspergillus abundance decreasing significantly, while Filobasidum, Cladosporium, Bullera, Komagataella, etc., increased in CBHA treated group. Soluble sugar was most affected by microbial community in tobacco leaves, which was negatively correlated with starch, cellulose and total nitrogen. During the fermentation process, the relative abundance of metabolism-related functional genes increased, and the expressions of cellulase and endopeptidase also increased. The results showed that the changes of bacterial community and dominant microbial community on tobacco leaves affected the content of chemical components in tobacco leaves, and adding CBHA for fermentation had a positive effect on improving the quality of tobacco leaves.

• KSBB Journal
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• 제7권2호
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• pp.102-106
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• 1992

본 연구에서는 C. bombiocola에서 생성되는 미생물 계면활성제인 Sophorolipid의 생산관여인자 중, 질소원의 종류에 따른 영향과 C/N비율에 따른 생성량의 변화를 관찰하였다. 유기질소원이 비교적 놓은 생성량을 보였으며 그 중 pepton의 경우가 80g/L에 해당하는 높은 생성량을 보였다. C/N의 비율의 변화에 의한 Sophorolipid의 생성량의 변화 양상이 질소원의 종류에 따라 각기 다르게 나타났다. 또한 탄소원의 50%을 배양 이틀후 공급하는 방법으로 Sophorolipid가 약 30% 증가됨을 알 수 있다.

• 한국토양비료학회지
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• 제45권3호
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• pp.377-384
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• 2012

온도조건이 유기물의 질소무기화율, 인지질 지방산유래 미생물 분포와 군집구조에 미치는 영향을 평가하고자 수행하였다. 비화산회토양 30 g에 입상유기질비료, 음식물퇴비, 돈분퇴비를 각각 2 g씩 잘 혼합한 후 $10^{\circ}C$, $20^{\circ}C$, $30^{\circ}C$에서 항온배양을 하면서 질소 무기화량과 인지질 지방산 함량을 분석하였다. 질소 무기화율은 온도와 비례하여 증가하였으며 음식물퇴비>입상유기질비료>돈분퇴비 순으로 질소무기화율이 높았다. 지방산 유래 미생물 그룹의 분포는 온도, 유기물종류에 따라 차이를 보였으며 시간이 경과 할수록 미생물의 밀도는 감소하는 경향을 나타냈다. G-/G+, F/B, Unsat/sat비는 온도가 올라가면서 감소하였다. 인지질 지방산 함량을 이용하여 주성분 분석을 한 결과 270일에 온도에 따라 입상유기질비료는 뚜렷한 미생물군집구조를 보였다. 결론적으로 미생물 활성은 온도, 유기물 종류에 따라 상대적인 민감도와 시기별로 차이를 보였다.

• 한국토양비료학회지
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• 제45권4호
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• pp.467-474
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• 2012

본 연구는 토양과 온도조건이 질소무기화율, 인지질 지방산유래 미생물 분포와 군집구조에 미치는 영향을 평가하고자 수행하였다. 화산회토양 30 g에 입상유기질비료, 음식물퇴비, 돈분퇴비를 각각 2 g씩 잘 혼합한 후 $10^{\circ}C$, $20^{\circ}C$, $30^{\circ}C$에서 항온배양을 하면서 질소 무기화율과 인지질 지방산 함량을 분석하였다. 질소 무기화율은 온도와 비례하여 증가하였으며 음식물퇴비>입상유기질비료>돈분퇴비 순으로 질소무기화율이 높았다. 지방산 유래 미생물 그룹의 분포는 온도, 유기물종류에 따라 차이를 보였으며 시간이 경과 할수록 미생물의 밀도는 감소하는 경향을 나타냈다. G-/G+, F/B, Unsat/sat 비는 온도가 $10^{\circ}C$씩 올라갈수록 감소하였고 cy19:0/$18:1{\omega}7c$비는 음식물퇴비와 돈분퇴비에서 증가하였다. PLFA 함량을 이용한 주성분 분석 결과 초기 (75일)는 $10^{\circ}C$, 후기 (270일)는 $30^{\circ}C$에서 온도요인에 따라 뚜렷하게 미생물 군집을 보였으며 시간이 경과 할수록 군집이동이 나타냈다.

• 한국토양비료학회지
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• 제34권1호
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• pp.8-16
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• 2001

미생물제 비료시용이 배추의 생육과 토양의 화학성 변화 및 미생물상에 미치는 영향을 포장시험으로 실시하였다. 대조구에 비하여 TLB미생물제 비료를 시용함으로써 배추의 생육은 양호하였으며, 배추수량에 있어서도 유의성 있는 증수 효과를 보였다. 그러나 TLB미생물제 비료를 시용하더라도 배추생육시 요소비료의 추비량 및 퇴비 시용량을 줄일 경우에는 대조구에 비하여 수량이 다소 감소하는 경향을 보였다. 토양의 화학적 성질에 미치는 TLB 미생물제 비료 시용의 효과는 대조구에 비하여 수확기의 토양유기물 함량의 감소가 가장 큰 것으로 나타났고, 토양중 전질소 함량은 0.76~1.44% 범위로 대조구보다 오히려 미생물제 비료 시용구가 감소하는 경향을 보였다. 토양중 유효인산 함량은 시험전 토양의 559ppm에 비하여 배추의 수확기에 대조구 755ppm 그리고 미생물제 시용구 653ppm으로 대조구와 비교하여 미생물제 시용으로 인하여 다소 낮은 편이었다. 한편 배추 수확 후 배추의 화학적 성분은 전 질소 2.62~2.94%, 인산 1.48~1.55%, 칼리 3.60~4.38%범위이었으며, 각 처리간에 함량의 뚜렷한 차이는 없었다. 토양 미생물상중 전세균수는 대조구보다 미생물제 시용으로 다소 감소하였으나, 배추수확기 토양에서 Pseudomonas속이 3배 이상 높은 군락을 보였다. 그러나 방선균은 큰 차이를 보이지 않았지만, 사상균수는 수확기 토양에서 미생물제 비료 시용으로 현저히 높은 군락을 형성하였다.

• 한국환경복원기술학회지
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• 제26권2호
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• pp.13-24
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• 2023

Sewage sludge has been widely used as an organic fertilizer in agriculture. However, sewage sludge can cause serious malodor problems resulting from the decomposition of organic compounds in anaerobic conditions. The malodor of sewage sludge mainly occurs due to a low carbon to nitrogen ratio (C/N), high moisture, and low temperature, which are ideal conditions for ammonia emissions. Therefore, in this study, we investigated the reduction of the odor-causing ammonia nitrogen (NH₃-N) in sewage sludge by co-application of microbes and methanol (MeOH). The physico-chemical properties of the municipal sewage sludge showed that the odor was mainly caused by a higher NH₃-N content (2932.2 mg L^-1). Supplementation with MeOH (20%) as a carbon source in the sewage sludge significantly reduced the NH₃-N up to 34.2% by increasing C/N ratio. Furthermore, the sewage sludge was treated with the NH₃-N reducing and plant growth promoting (PGP) bacteria Stenotrophomonas rhizophila SRCM 116907. The treatment with S. rhizophila SRCM 116907 significantly increased the seedling vigor index of Lolium perenne (10.3%) and Chrysanthemum burbankii (42.4%). The findings demonstrate that supplementing sewage sludge with methanol significantly reduces ammonia emissions, thereby mitigating malodor problems. Overall, the study highlights the potential of using a microbial and methanol approach to improve the quality of sewage sludge as an organic fertilizer and promote sustainable agriculture.

• Journal of the korean society of oceanography
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• 제37권1호
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• pp.35-44
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• 2002

To assess the relative contribution of bacterial and phytoplankton biomasses to particulate organic matter (POM) in the water column, microbial abundance and biomass were from two transects in the western channel of the Korea Strait in 1996. Bacterial abundance had a mean value of $5.9{\times}10^5$ cells/ml and chlorophyll-a averaged 0.14 ${\mu}g/l$. Bacterial abundance in the Korea Strait showed a positive relationship with chlorophyll-a concentration, while the distribution of POM did not covary with chlorophyll-a. Particulate organic carbon (POC) and nitrogen (PON) concentrations were greater in August than in October. Bacterial carbon (POC) and nitrogen (PON) concentrations were greater in August than in October. Bacterial carbon and nitrogen biomasses were 7.29 ${\mu}gC/l$ and 1.24 ${\mu}gN/l$, respectively, during the study periods. Bacterial biomass was larger in October than in August due to the autumn phytoplankton bloom. Phytoplankton biomass based on chlorophyll-a was 7.67 ${\mu}gC/l$ for carbon and 1.10${\mu}gN/l$l for nitrogen. The ratio of bacterial carbon (BC) to phytoplankton carbon (Cp) averaged 0.95 in the Korea Strait in 1996. Bacteria may play a more significant role in the dynamics of POM than phytoplankton do in August, with BC/Cp ratio of 1.26. The ratio of BC to Cp increased with a decrease in chlorophyll-a concentration. Averaged over all the samples in both cruises, the contribution of microbial biomass to POC and PON was about 43% and 51%, respectively. Bacterial assemblage constituted a significant fraction of POC (21%) and PON (27%). Phytoplankton accounted for 22% of POC and 24% of PON. Microbial biomass played a more important role in the dynamics of POC and PON in October than in August due to a significant increase in microbial biomass in the southern transect (transect-B) in October by the autumn phytoplankton bloom. This study showed that marine microbes may constitute a significant part in the reservoir of POM in the Korea Strait.

• Asian-Australasian Journal of Animal Sciences
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• 제31권10호
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• pp.1627-1634
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• 2018

Objective: The study aimed to evaluate the effect of replacing wheat bran for cactus cladodes plus urea (0%, 25%, 50%, 75%, and 100%) on the intake of nutrients, nitrogen balance, microbial protein synthesis, and rumen fermentation for steers. Methods: Five crossbred steers (1/2 Holstein-Zebu), with rumen cannula and an average body weight of $180{\pm}5.3kg$, were assigned to a $5{\times}5$ Latin square design. Dietary treatments consisted of the replacement of the total of wheat bran in basal diet by cactus cladodes using the following proportions: 0% for basal diet, 25%, 50%, 75%, and 100% cactus cladodes replacing wheat bran. Urea was added to the diets to adjust the crude protein (CP) content to 130 g/kg dry matter. Results: Maximum dry matter intake (5.73 kg/d) and maximum nitrogen balance (103 g/d) were estimated for 54.6% and 70.8% replacement levels of wheat bran. The maximum microbial protein production (44.6 g/d) was obtained at a replacement level of 49.7%, and a medium value (125 g CP mic/kg total digestible nutrients) of microbial protein efficiency was observed. The rumen pH increased linearly according to cactus cladodes inclusion, while the ammonia nitrogen medium value was 24.5 mg/dL. Conclusion: The replacement of 55% wheat bran for cactus cladodes plus urea in the diet of crossbred steers is recommended.

• 한국가금학회지
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• 제27권1호
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• pp.19-23
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• 2000

The effects of microbial phutase on laying performance and phosphorus utilization were examined at different levels of dietary nonphosphorus(NPP) in 320 23-week-old Hy-line brown hens for 12weeks. Diets were formulated 0.275%(T1), 0.220%(T2), 0.165%(T3) of NPP levels, and supplemental microbial phytase was 300DPU/kg diet constantly. Conventional diet(C) was formulated 0.275% NPP level without microbial phytase. Egg production and egg mass were higher in T2 than the others (p<0.05), and average egg weight was higher in T1 than the other (p<0.05). Egg productivity was tended to increase with supplemental phytase compared to conventional diet. Daily feed intake a hen also increased in T2 (p<0.05). Feed conversion ratio was improved slightly without significant difference. Eggshell breaking strength and thickness were not different significantly among the treatments. Haugh unit and yolk color were also not different. Calcium and phosphorus retention in body increased in T2 (p<0.05), but dry matter and nitrogen retention were not different significantly. Differences in nitrogen and calcium excretions were not found among the treatments. But phosphorus excretion decreased in order of dietary phosphorus levels with supplement phytase compared to C (p<0.05). Tibial ash, calcium and phosphorus were similar among the treatments. In conclusion, supplemental microbial phytase in laying diet may help to utilize phytase phosphorus, and could decrease NPP intake.

• 한국수산과학회지
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• 제54권5호
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• pp.751-760
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• 2021

This study investigated the changes in water quality parameters and microbial colonies when ozone was applied to a semi-recirculating aquaculture system (semi-RAS) for the olive flounder Paralichthys olivaceus (500 g in average weight). Concentrations of ozone-produced oxidants (OPO) in rearing tanks were maintained at 0, 0.014, 0.025 mg/L as Cl₂ for 26 days. Except total ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, phosphate phosphorus, chemical oxygen demand, and total suspended solids decreased significantly with increasing OPO concentration in daily and weekly monitoring (P<0.05). Colony forming unit (CFU) counts of heterotrophic marine bacteria decreased in an OPO concentration-dependent manner. Overall reduction rates of microbial colonies in the treatments were 80% higher than those of the control (P<0.05). During the experiment, the OPO concentration-driven ozonation was reliably practiced without any adverse effects on the animals cultured in semi-RAS. Considering the biohazard, operating cost, and stability of ozonation, an OPO concentration of 0.014 mg/L would be sufficient to control water quality parameters and microbial colonies in a semi-RAS.