• Journal of Hydrogen and New Energy
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• 제19권1호
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• pp.41-48
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• 2008

Fermentative $H_2$ production was studied using microbial consortia isolated from heat-treated ($90{\circ}C$, 20 min) sewage sludge. Important parameters investigated were carbon(C) and nitrogen(N)-sources, C/N ratio, phosphate concentration, pH and temperature during anaerobic cultivation in serum bottles. Starch, ribose, sucrose and glucose were good C-sources for the culture growth and $H_2$ production. Yeast extract was better N-source than $(NH_4)_2SO_4$ or peptone when individually added to the synthetic media, however the combination of above three N-sources exhibited the additional effect for cell growth and $H_2$ evolution. Addition of 100 mM phosphate as a buffering agent prevented the rapid pH drop during the cultivation. The optimum initial pH for the cell growth was at 7.0, whereas $H_2$ production was observed at pH 5.5. Optimum temperature for the cell growth and $H_2$ production was $37{\circ}C$. Initial C/N ratio of 1.22 in the media using glucose and yeast extract as the C- and N-sources, respectively, showed the $H_2$ yield 1.0 mol $H_2$/mol glucose.

• Advances in Energy Research
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• 제2권1호
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• pp.1-9
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• 2014

The green microalgae Chlamydomonas reinhardtti is well-known specie in the terms of $H_2$ production by photo fermentation and has been studying for a long time. Although the $H_2$ production yield is promising; there are some bottlenecks to enhance the yield and efficiency to focus on a well-designed, sustainable production and also scaling up for further studies. D1 protein of photosystem II (PSII) plays an important role in photosystem damage repair and related to $H_2$ production. Because Chlamydomonas is the model algae and the genetic basis is well-studied; metabolic engineering tools are intended to use for enhanced production. Mutations are focused on D1 protein which aims long-lasting hydrogen production by blocking the PSII repair system thus $O_2$ sensitive hydrogenases catalysis hydrogen production for a longer period of time under anaerobic and sulfur deprived conditions. Chlamydomonas CC124 as control strain and D1 mutant strains(D240, D239-40 and D240-41)are cultured photomixotrophically at $80{\mu}mol\;photons\;m^{-2}s^{-1}$, by two sides. Cells are grown in TAP medium as aerobic stage for culture growth; in logarithmic phase cells are transferred from aerobic to an anaerobic and sulfur deprived TAP- S medium and 12 mg/L initial chlorophyll content for $H_2$ production which is monitored by the water columns and later detected by Gas Chromatography. Total produced hydrogen was $82{\pm}10$, $180{\pm}20$, $196{\pm}20$, $290{\pm}30mL$ for CC124, D240, D239-40, D240-41, respectively. $H_2$ production rates for mutant strains was $1.3{\pm}0.5mL/L.h$ meanwhile CC124 showed 2-3 fold lower rate as $0.57{\pm}0.2mL/L.h$. Hydrogen production period was $5{\pm}2days$ for CC124 and mutants showed a longer production time for $9{\pm}2days$. It is seen from the results that $H_2$ productions for mutant strains have a significant effect in terms of productivity, yield and production time.

• Asian-Australasian Journal of Animal Sciences
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• 제14권8호
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• pp.1110-1117
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• 2001

Responses of the rumen fungus, Neocallimastix frontalis RE1, to long chain fatty acid (LCFA) were evaluated by measuring gas production, filter paper (FP) cellulose digestion and polysaccharidase enzyme activities. LCFA (stearic acid, $C_{18:0}$; oleic acid, $C_{18:1}$; linoleic acid, $C_{18:2}$ and linolenic acid, $C_{18:3}$) were emulsitied by ultrasonication under anaerobic condition, and added to the medium. When N frontalis RE1 was grown in culture with stearic, oleic and linoleic acid, the cumulative gas production, gas pool size, FP cellulose digestion and enzymes activities significantly (p<0.05) increased at some incubation times(especially, exponential phases of fungal growth, 48~120 h of incubation) relative to that for control cultures. However, the addition of linolenic acid strongly inhibited all of the investigated parameters up to 120 h incubation, but not after 168 and 216 h of incubation. These results indicated that stearic, oleic and linoleic acids tended to have great stimulatory effects on fungal cellulolysis, whereas linolenic acid caused a significant (p<0.05) inhibitory effects on the cellulolysis by the rumen fungus. These results are the first report of the effect of LCFAs on the ruminal fungi. Further research is needed to identify the mode of action of LCFAs on fungal strains and to verify whether or not ruminal fungi have ability to hydrate unsaturated LCFAs to saturated FAs. There was high correlation between cumulative in vitro gas production and fungal growth (94.78%), FP cellulose degradation (96.34%), CMCase activity(90.86%) or xylanase activity (87.67%). Thus measuring of cumulative gas production could be a useful tool for evaluating fungal growth and/or enzyme production by ruminal fungi.

• Journal of Microbiology and Biotechnology
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• 제2권2호
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• pp.85-91
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• 1992

The intestinal microflora of humans is an extraordinarily complex mixture of microorganisms, the majority of which are anaerobic microorganisms. The distribution of amylolytic microorganisms in the human large intestinal tract was investigated in various individuals of differing ages using anaerobic culture techniques. A large percentage of the amylolytic microorganisms present belonged to the Genus Bifidobacteria. The number of Bifidobacteria increased significantly at two years of age. Adults and children above 2 years old carried about $0.8{\times}10^9-2.0{\times}10^{10}$ colony forming units (CFU/gram) of amylolytic Bifidobacteria. Among these amylolytic Bifidobacteria, Int-57 was chosen for further studies. Between 65% and 85% of the amylase produced was secreted and the remaining amylase was bound to the cell wall facing the outside. Amylase production could be induced by starch in a stable form. When cells were grown on maltose or glucose, amylase production was much lower than on starch and amylase activity disappeared after 24 hours growth on these media. Partially purified enzymes showed optimum activity at a temperature of $50^{\circ}C$ and at an optimum pH of 5.5, respectively. Heat treatment at $70^{\circ}C$ for 30 minutes almost completely inactivated amylase. The hydrolysis products of starch were mainly maltose and maltotriose. Soluble starch, amylose, amylopectin, and $\gamma$-cyclodextrin($\gamma$-CD) were easily hydrolyzed. The rate of hydrolysis of $\alpha$-CD and $\beta$-CD was slower than that of $\gamma$-CD. Carboxymethyl cellulose, $\beta$-1, 3-glucan and inulin were not hydrolyzed.

• Microbiology and Biotechnology Letters
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• 제13권3호
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• pp.257-263
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• 1985

Rhodopseudomonas sp. KCTC 1437 evolved molecular hydrogen efficiently under light illuminated anaerobic culture condition in the presence of organic acids and various sugars. especially glucose when low concentration of NH$_4$ + or L-glutamate was added to cultures. It was revealed that hydrogen formation from Rhodopseudomonas sp. KCTC 1437 was mediated by two different enzyme systems. Under the nitrogen limiting condition, hydrogen evolution from glucose was catalyzed by nitrogenase. For the nitrogenase activation in vivo, the precultured cells drown on limiting concentration of NH$_4$$^{+}$ as a sole nitrogen source showed more capacity of hydrogen evolution from glucose in the presence of L-glutamate than any other cells .frown on sufficient concentration of NH$_4$$^{+}$, L-glutamate, NH$_4$$^{+}$, or both of L-glutamate and $N_2$. A significant volume of molecular hydrogen was evolved from glucose even in the presence of excess NH$_4$$^{+}$ either in the light or dark anaerobic condition, presumably due to the mediation of hydrogen evolution by fromic hydrogenlyase.enlyase.

• Korean Journal of Microbiology
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• 제25권4호
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• pp.293-303
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• 1987

A $C_{1}$ enriched cellulase fraction was separated from culture filtrate of anaerobic Clostridium thermocellum by hydroxyapatite column chromatography. The separated fraction showed strong synergistic action with $C_{x}$ component (endo-$\beta$-1, 4-glucanase) in digestion of crystalline cellulose, similar to the other aerobic cellulolytic microorganisms. Unlike the $C_{x}$ component the $C_{1}$ enriched fraction was rapidly inactivated by oxidation at the atmospheric condition. The enzyme activity was significantly enhanced by the addition of reducing agents, especially $\beta$-mercaptoethanol, which indicates that a $C_{1}$ component has a lot of sulfhydryl groups essential for the enzyme activity. The effect of metal ions on $C_{1}$ activity was also investigated. The $C_{1}$ fraction was found to be thermally stable compare to endo-$\beta$-1,4-glucanase. Optimal temperature and pH were found to be $60^{\circ}C$ and 6.0, respectively.

• The Korea Journal of Herbology
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• 제29권5호
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• pp.45-53
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• 2014

Objectives : The purpose of the study is to test the antibacterial, anti-inflammatory and antioxidant effects of BPH, which is composed of Pini Densiflorae Nodi Lignum and Querci Acutissimae Fructus, Angelicae Gigantis Radix, Cnidii Rhizoma, Angelicae Dahuricae Radix, Angelicae Tenuissimae Radix. Method : Antibacterial and anti-inflammatory effects of BPH on Propionibacterium acnes, one of anaerobic bacteria species were evaluated by measuring the levels of 2,2-diphenyl-1-picrylhydrazyl (DPPH) elimination and lipid peroxidation. Result : When BPH was applied to CCD-986sk (Human normal fibroblast) to confirm the level of cytokine(tumor necrosis factor-alpha, interleukin-8), its level increased in proportion to that of BPH's concentration, which indicated dose-dependent relationship. Using the Disk diffusion to measure the bacterial growth inhibition zone varying BPH concentration, it was found that the antibacterial effect of BPH was less than that of erythromycin, the control group, but was higher than that of saline, and it increased with higher concentrations. In a liquid culture medium containing BPH, the growth rate of Propionibacterium acnes was decreased by more than 10% at 25% BPH. After adding P. acnes to THP-1 monocyte, and treated it with BPH, and measuring the concentration of TNF-a and IL-8, it was observed that the amount of TNF-alpha and IL-8 significantly decreased depending on the level of BPH concentration. The ability to eliminate DPPH increased with higher BPH concentration. The inhibition of lipid peroxidation was increased by BHT treatment in a dose-dependent manner. Conclusion : Using Propionibacterium acnes, an anaerobic bacteria, we confirmed that BPH has antibacterial, anti-inflammatory and antioxidant effects.

• Pediatric Infection and Vaccine
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• 제29권3호
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• pp.173-178
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• 2022

Streptococcus intermedius is a small, non-motile, Gram-positive, non-sporeforming, and aerotolerant anaerobic coccus. It is a part of the normal microflora in the oral cavity and upper respiratory, gastrointestinal and female urogenital tracts. It is an opportunistic pathogen that causes serious infections in patients with immunocompromised states or cardiac diseases as a result of trauma or invasive procedures. We describe a case of septic arthritis of the hip caused by S. intermedius in an immunocompetent healthy 7-year-old boy without a history of periodontal disease or invasive procedures. He had hip joint pain three weeks ago, and the fever began on the day of the visit. He had been healthy and had not undergone any invasive procedures recently. Septic arthritis of the hip was indicated in the magnetic resonance imaging of the hip. S. intermedius was identified in the hip joint fluid aspiration and blood culture. He was successfully treated with surgical intervention and antibiotic therapy with ceftriaxone followed by amoxicillin for five weeks.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권6호
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• pp.519-522
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• 2004

In the course of anaerobic storage of excess sludge, odors due to chemicals such as hydrogen sulfide are produced. These odors cause many problems. Many methods have been developed to eliminate odors, but all current methods are not only costly, but also largely inef­fective. In this paper, we investigate the process of transformation of sludge microorganism cul­tures through intense aeration under nutrient-poor conditions, in terms of the selective adjust­ment and control of microorganism culture. The aerated sludge is subsequently returned to the adjusting pool, where the microorganisms inhibit odors, thus the excess sludge itself will act as an odor inhibitor. The process can be verified in terms of viability, in that the degradation capac­ity of the sludge was maintained after the intensely-aerated sludge was returned to the treat­ment system.

• Journal of Microbiology and Biotechnology
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• 제4권2호
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• pp.151-154
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• 1994

Lactobacillus acidophilus KFRI 233, a strain isolated from human, was selected as a candidate for probiotics due to its excellent growth in MRS broth where no special anaerobic condition is required. Both simultaneous and deferred agar diffusion assays exhibited Lb. acidophilus KFRI 233 to possess an antagonistic effect against Clostridium perfringens. Its antagonistic effect was pH dependent Associative culture of KFRI 233 and Cl. perfringens in broth resulted in maximum 94.04% inhibition of Cl. perfringens. $\beta$-Galactosidase activity of KFRI 233 was higher than other tested strains that are sold as commercial probiotics. Survival of KFRI 233 in pasteurized skim milk (4$^{\circ}C$) and Sherbet mix (-15$^{\circ}C$) after 7 days of storage were 71.9 and 105.5%, respectively.