• 한국미생물·생명공학회지
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• 제42권1호
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• pp.41-50
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• 2014

수소생산 유효세균을 유지하기 위해 열처리한 혐기소화슬러지를 접종원으로 하여 PVA 담체를 활용한 고정화와 비고정화 방법에 의한 수소생산능 및 세균 군집을 비교분석 하였다. 고정화에 의한 수소생산성은 비고정화 방법과 비교하여 수소생산성에 영향을 미치지 않았다. 그러나 고정화 방법은 유기물 분해결과 발생하는 유기산 축적 및 pH 강하 등의 환경변화에 있어 세균의 성장과 활성에 안정적 환경을 제공할 수 있는 가능성을 나타내었다. DGGE 분석에 의한 세균군집분석에서는 비고정화와 고정화 반응조간에 형성된 세균군집이 차이가 있는 것으로 나타났으며, 상대적으로 고정화 반응조내의 유효 수소생산 세균 군집이 좀 더 안정적으로 유지되는 것으로 확인되었다. Droplet digital PCR에 의한 6종의 유효한 수소생산 세균 절대정량 분석결과, encapsulation에 관계없이 두 반응기에서의 우점세균수는 유사하였다. Firmicutes, Clostridium, Enterobacter, Ruminococcus 및 Escherichia가 $1{\times}10^5-1{\times}10^6$ copy number of ml-sample 수준에서 존재하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권6호
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• pp.808-814
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• 2019

Objective: The objective of this study was to investigate the effects of essential oil mixture (EOM) supplementation on rumen fermentation characteristics and microbial changes in an in vitro. Methods: Three experimental treatments were used: control (CON, no additive), EOM 0.1 (supplementation of 1 g EOM/kg of substrate), and EOM 0.2 (supplementation of 2 g EOM/kg of substrate). An in vitro fermentation experiment was carried out using strained rumen fluid for 12 and 24 h incubation periods. At each time point, in vitro dry matter digestibility (IVDMD), neutral detergent fiber digestibility (IVNDFD), pH, ammonia nitrogen ($NH_3-N$), and volatile fatty acid (VFA) concentrations, and relative microbial diversity were estimated. Results: After 24 h incubation, treatments involving EOM supplementation led to significantly higher IVDMD (treatments and quadratic effect; p = 0.019 and 0.008) and IVNDFD (linear effect; p = 0.068) than did the CON treatment. The EOM 0.2 supplementation group had the highest $NH_3-N$ concentration (treatments; p = 0.032). Both EOM supplementations did not affect total VFA concentration and the proportion of individual VFAs; however, total VFA tended to increase in EOM supplementation groups, after 12 h incubation (linear; p = 0.071). Relative protozoa abundance significantly increased following EOM supplementation (treatments, p<0.001). Selenomonas ruminantium and Ruminococcus albus (treatments; p<0.001 and p = 0.005), abundance was higher in the EOM 0.1 treatment group than in CON. The abundance of Butyrivibrio fibrisolvens, fungi and Ruminococcus flavefaciens (treatments; p<0.001, p<0.001, and p = 0.005) was higher following EOM 0.2 treatment. Conclusion: The addition of newly developed EOM increased IVDMD, IVNDFD, and tended to increase total VFA indicating that it may be used as a feed additive to improve rumen fermentation by modulating rumen microbial communities. Further studies would be required to investigate the detailed metabolic mechanism underlying the effects of EOM supplementation.

• Asian-Australasian Journal of Animal Sciences
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• 제12권5호
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• pp.708-714
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• 1999

Fermentation of legume fodder tree leaves by rumen microorganisms was evaluated. The substrates were sun-dried, ground leaves. Gas and volatile fatty acid (VFAs) production were estimated. Using gas production as an index of fermentation at 12 h, the leaves tested ranked as follows; Chamaecytisus palmensis>Gliricidia sepium>Sebania sesban>Tephrosia bracteolate>Leucaena pallida>Vernonia amygdalina>Acacia sieberiana>Sesbania goetzei>Acacia angustissima. Using VFA production, the ranking was a follows; G. sepium>S. sesban>S. goetzei>L. pallida>C. palmensis/V. amygdalina>T. bracteolate> A. sieberiana>A. angustissima. Absolute gas or VFA production rates, were also used to rank the leaves. Extracts (70% acetone) of A. angustissima inhibited the growth of Ruminococcus albus 8, R. flavefaciens FD-1, Prevotella ruminicola D3ID and Streptococcus bovis JBI while the trowth of Selenomonas ruminantium D was depressed when 0.6 ml exracts were added. C. palmensis water extracts enhanced cellulose hydrolysis by R. flavefaciens FD-1. All extracts reduced celluloysis by R. albus 8. R. flavefaciens FD-1 hydrolyzed more (p<0.001) cellulose than R. albus 8.

• Asian-Australasian Journal of Animal Sciences
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• 제5권3호
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• pp.511-517
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• 1992

Ethanol was utilized by mixed rumen microbes, but addition of pentachlorophenol (25 mg/l), a methanogen inhibitor, suppressed the utilization of ethanol. Carbon monoxide (50% of the gas phase), a hydrogenase inhibitor, more strongly suppressed the utilization of ethanol, propanol, and butanol. These results suggest that the major ethanol utilizers are $H_2$ producers. Ethanol utilization was depressed at low pH (below 6.0). Since methanogens were shown to be relatively resistant to low pH, it appears that ethanol utilizers are particularly sensitive to low pH. Ruminococcus albus and R. flavefaciens in mono-culture produced ethanol from carbohydrate (glucose and cellobiose), even when a high level (170 mM) of ethanol was present. Ethanol was not utilized even in the absence of carbohydrate, but the co-culture of these bacteria with methanogens resulted in the utilization of ethanol, i.e., when $H_2$ was rapidly converted to $CH_4$, R. albus and R. flavefaciens utilized ethanol. These results suggest that ethanol is utilized when the electrons liberated by the oxidation of ethanol are rapidly removed, and ready electron disposal in ethanol-utilizing, $H_2$-producing bacteria is accomplished by the interspecies transfer of $H_2$.

• Journal of Microbiology and Biotechnology
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• 제32권3호
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• pp.324-332
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• 2022

The incidence of stress-related type 2 diabetes (stress-T2D), which is aggravated by physiological stress, is increasing annually. The effects of Lactobacillus, a key component of probiotics, have been widely studied in diabetes; however, studies on the effects of postbiotics are still limited. Here, we aimed to examine the mechanism through which heat-killed Lactiplantibacillus plantarum LRCC5314 (HK-LRCC5314) alleviates stress-T2D in a cold-induced stress-T2D C57BL/6 mouse model. HK-LRCC5314 markedly decreased body weight gain, adipose tissue (neck, subcutaneous, and epididymal) weight, and fasting glucose levels. In the adipose tissue, mRNA expression levels of stress-T2D associated factors (NPY, Y2R, GLUT4, adiponectin, and leptin) and pro-inflammatory factors (TNF-α, IL-6, and CCL-2) were also altered. Furthermore, HK-LRCC5314 increased the abundance of Barnesiella, Alistipes, and butyrate-producing bacteria, including Akkermansia, in feces and decreased the abundance of Ruminococcus, Dorea, and Clostridium. Thus, these findings suggest that HK-LRCC5314 exerts protective effects against stress-T2D via gut microbiome modulation, suggesting its potential as a supplement for managing stress-T2D.

• Journal of Applied Biological Chemistry
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• 제65권1호
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• pp.63-74
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• 2022

Microbial dysbiosis in the gut is associated with human diseases, and variations in mucus alter gut microbiota. Therefore, we explored the effects of mucin on the gut microbiota using a community of 19 synthetic gut microbial species. Cultivation of these species in modified Gifu anaerobic medium (GAM) supplemented with mucin before synthetic community assembly facilitated substantial growth of the Bacteroides, Akkermansia, and Clostridium genera. The results of 16S rRNA microbial relative abundance profiling revealed more of the beneficial microbes Collinsella, Bifidobacterium, Ruminococcus, and Lactobacillus. This increased acetate levels in the community cultivated with, rather than without (control), mucin. We identified differences in predicted cell function and metabolism between microbes cultivated in GAM with and without mucin. Mucin not only changed the composition of the gut microbial community, but also modulated metabolic functions, indicating that it could help to modulate microbial changes associated with human diseases.

• IMMUNE NETWORK
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• 제21권2호
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• pp.15.1-15.10
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• 2021

Abnormal inflammatory responses are closely associated with intestinal microbial dysbiosis. Oral administration of Qmatrix-diabetes-mellitus complex (QDMC), an Aloe gel-based formula, has been reported to improve inflammation in type 2 diabetic mice; however, the role of the gut microbiota in ameliorating efficacy of QDMC remains unclear. We investigated the effect of QDMC on the gut microbiota in a type 2 diabetic aged mouse model that was administered a high-fat diet. Proinflammatory (TNF-α and IL-6) and anti-inflammatory (IL-4 and IL-10) cytokine levels in the fat were normalized via oral administration of QDMC, and relative abundances of Bacteroides, Butyricimonas, Ruminococcus, and Mucispirillum were simultaneously significantly increased. The abundance of these bacteria was correlated to the expression levels of cytokines. Our findings suggest that the immunomodulatory activity of QDMC is partly mediated by the altered gut microbiota composition.

• Asian-Australasian Journal of Animal Sciences
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• 제27권2호
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• pp.179-186
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• 2014

This study aimed to investigate the diversity of the Butyrivibrio group bacteria in goat rumen and its response to garlic oil (GO) supplementation as revealed by molecular analysis of cloned 16S rRNA genes. Six wethers fitted with ruminal fistulas were assigned to two groups for a cross-over design with 28-d experimental period and 14-d interval. Goats were fed a basal diet without (control) or with GO ruminal infusion (0.8 g/d). Ruminal contents were used for DNA extraction collected before morning feeding on d 28. A total bacterial clone library was firstly constructed by nearly full-length 16S rRNA gene cloned sequences using universal primers. The resulting plasmids selected by Butyrivibrio-specific primers were used to construct a Butyrivibrio group-specific bacterial clone library. Butyrivibrio group represented 12.98% and 10.95% of total bacteria in control and GO group, respectively. In libraries, clones were classified to the genus Pseudobutyrivibrio, Butyrivibrio and others within the family Lachnospiraceae. Additionally, some specific clones were observed in GO group, being classified to the genus Ruminococcus and others within the family Ruminococcaceae. Based on the criterion that the similarity was 97% or greater with database sequences, there were 29.73% and 18.42% of clones identified as known isolates (i.e. B. proteoclasticus and Ps. ruminis) in control and GO groups, respectively. Further clones identified as B. fibrisolvens (5.41%) and R. flavefaciens (7.89%) were specifically found in control and GO groups, respectively. The majority of clones resembled Ps. ruminis (98% to 99% similarity), except for Lachnospiraceae bacteria (87% to 92% similarity) in the two libraries. The two clone libraries also appeared different in Shannon diversity index (control 2.47 and GO group 2.91). Our results indicated that the Butyrivibrio group bacteria had a complex community with considerable unknown species in the goat rumen.

• Asian-Australasian Journal of Animal Sciences
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• 제21권4호
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• pp.603-615
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• 2008

Dietary fiber is an inevitable component in pig diets. In non-ruminants, it may influence many physiological processes in the gastrointestinal tract (GIT) such as transit time as well as nutrient digestion and absorption. Moreover, dietary fiber is also the main substrate of intestinal bacteria. The bacterial community structure is largely susceptible to changes in the fiber content of a pig's diet. Indeed, bacterial composition in the lower GIT will adapt to the supply of high levels of dietary fiber by increased growth of bacteria with cellulolytic, pectinolytic and hemicellulolytic activities such as Ruminococcus spp., Bacteroides spp. and Clostridium spp. Furthermore, there is growing evidence for growth promotion of beneficial bacteria, such as lactobacilli and bifidobacteria, by certain types of dietary fiber in the small intestine of pigs. Studies in rats have shown that both phosphorus (P) and calcium (Ca) play an important role in the fermentative activity and growth of the intestinal microbiota. This can be attributed to the significance of P for the bacterial cell metabolism and to the buffering functions of Ca-phosphate in intestinal digesta. Moreover, under P deficient conditions, ruminal NDF degradation as well as VFA and bacterial ATP production are reduced. Similar studies in pigs are scarce but there is some evidence that dietary fiber may influence the ileal and fecal P digestibility as well as P disappearance in the large intestine, probably due to microbial P requirement for fermentation. On the other hand, fermentation of dietary fiber may improve the availability of minerals such as P and Ca which can be subsequently absorbed and/or utilized by the microbiota of the pig's large intestine.

• Asian-Australasian Journal of Animal Sciences
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• 제24권6호
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• pp.810-817
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• 2011

A feeding trial was conducted to study the effect of tannin rich Pakar (Ficus infectoria) leaves on microbial profile, rumen fermentation and nutrient utilization in goats. Eight goats divided in two groups were fed pakar leaves (experimental group) and green oats (control group) as sole roughage source along with a fixed quantity of concentrate mixture for a period of 3 months. Two metabolic trials of six days duration were conducted after 30 and 90 days of experimental feeding. The dry matter intake was significantly higher (p<0.05) and digestibility's of DM, OM, CP, EE, NDF and ADF were reduced in experimental as compared with the control group. The TDN intake was similar (236.52 vs. 240.39 g/d) in both the groups. All the animals were in positive nitrogen balance. The concentration of ammonia nitrogen, TVFA, lactic acid and activities of xylanase and protease were reduced in pakar leaves fed goats. The rumen microbial profile as obtained by MPN technique showed no change in total bacterial population but total fungi and cellulolytic bacteria were reduced (p<0.05), whereas, tannin degrading/tolerant bacteria increased with the feeding of pakar leaves. Real time PCR data revealed a decrease in Ruminococcus flavefaciens, an increase in methanogens and no change in the Fibrobacter succinogenes population by feeding of pakar leaves.