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Fermentative production of spiramycins by Streptomyces ambofaciens has been performed using fermentation media of different chemical compositions. Medium I was selected from nine media as the best for production of high titres of spiramycins. Biochemical changes which occurred during fermentative production of spiramycins revealed that adjustment of the initial pH value of the medium was very important. The initial pH value of the fermentation medium which allowed the organism to produce a good yield of antibiotic was 6.5. The fermentation period affected the formation of spiramycins, and the maximum incubation period required for the fermentation process was 120 h. The role of inoculum on spiramycin yield showed that it was better to inoculate the fermentation medium with vegetative cells of Streptomyces ambofaciens rather with spores. The carbon source influenced spiramycin biosynthesis: dextrin was the best carbon source and stimulated the organism to form high titres of antibiotics. The best concentrations of dextrin and glucose for increased antibiotic yields were 25 and 15 gl?1, respectively. Organic sources in the fermentation medium were more efficient than inorganic nitrogen sources for spiramycin formation. Fodder yeast was the best organic nitrogen source in fermentative production of spiramycins. The maximal concentrations of fodder yeast, soybean meal, peptone, Ca(NO3)2 and NH4NO3 for increased antibiotic yield were 6.5, 6.0, 4.0, 10.0 and 4.0 gl?1, respectively. 相似文献
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Dürre P 《Current opinion in biotechnology》2011,22(3):331-336
As mobility is a major pillar of World's economic system and burning fuels from fossil resources leads to a dramatic increase in greenhouse gas emissions, the production and use of appropriate biofuels offer at least a partial solution to this problem. Butanol represents a biofuel extender or replacement with properties clearly superior to ethanol (higher mileage, not hygroscopic, usable without engine modifications, not corrosive). In addition, it is a valuable feedstock for the chemical industry. Scientific challenges for an economically competitive fermentation process include employment of cheap carbon sources, not competing with nutrition, a detailed understanding of the metabolic reactions of the biological process, development of appropriately engineered construction strains, and adaption of process technology to modern standards. 相似文献
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Fermentative biohydrogen production systems integration 总被引:2,自引:0,他引:2
Guwy AJ Dinsdale RM Kim JR Massanet-Nicolau J Premier G 《Bioresource technology》2011,102(18):8534-8542
Acidogenic fermentation can be used to produce hydrogen from a range of biomass sources. The effluent from this process can be utilised in a number of biological processes enabling further recovery of energy from the biomass. In this review a number of candidate technologies are assessed including conventional methanogenic anaerobic digestion, dark fermentative hydrogen production, photo-fermentation, and bioelectrochemical systems. The principles, benefits and challenges associated with integrating these technologies are discussed, with particular emphasis on integration with fermentative hydrogen production, and the current state of integrative development is presented. The various system configurations for potential integrations presented here may simultaneously permit an increase in the conversion efficiency of biomass to energy, improved adaptability to varying operating conditions, and improved stability. Such integration, while increasing system complexity, may mean that these bioprocesses could be deployed in a wider range of scenarios and be used with a greater range of substrates. 相似文献
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Fermentative butanol production by Clostridia 总被引:1,自引:0,他引:1
Lee SY Park JH Jang SH Nielsen LK Kim J Jung KS 《Biotechnology and bioengineering》2008,101(2):209-228
Butanol is an aliphatic saturated alcohol having the molecular formula of C(4)H(9)OH. Butanol can be used as an intermediate in chemical synthesis and as a solvent for a wide variety of chemical and textile industry applications. Moreover, butanol has been considered as a potential fuel or fuel additive. Biological production of butanol (with acetone and ethanol) was one of the largest industrial fermentation processes early in the 20th century. However, fermentative production of butanol had lost its competitiveness by 1960s due to increasing substrate costs and the advent of more efficient petrochemical processes. Recently, increasing demand for the use of renewable resources as feedstock for the production of chemicals combined with advances in biotechnology through omics, systems biology, metabolic engineering and innovative process developments is generating a renewed interest in fermentative butanol production. This article reviews biotechnological production of butanol by clostridia and some relevant fermentation and downstream processes. The strategies for strain improvement by metabolic engineering and further requirements to make fermentative butanol production a successful industrial process are also discussed. 相似文献
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Fermentative production of butanol--the industrial perspective 总被引:1,自引:0,他引:1
Green EM 《Current opinion in biotechnology》2011,22(3):337-343
A sustainable bacterial fermentation route to produce biobutanol is poised for re-commercialization. Today, biobutanol can compete with synthetic butanol in the chemical market. Biobutanol is also a superior biofuel and, in longer term, can make an important contribution towards the demand for next generation biofuels. There is scope to improve the conventional fermentation process with solventogenic clostridia and drive down the production cost of 1-butanol by deploying recent advances in biotechnology and engineering. This review describes re-commercialization efforts and highlights developments in feedstock utilization, microbial strain development and fermentation process development, all of which significantly impact production costs. 相似文献
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Ahmed H. S. Hassan Thorsten Mietzel Ruth Brunstermann Sebastian Schmuck Jens Schoth Marco Küppers Renatus Widmann 《World journal of microbiology & biotechnology》2018,34(12):176
Hydrogen is a promising energy source that is believed to replace the conventional energy sources e.g. fossil fuels over years. Hydrogen production methods can be divided into conventional production methods which depend mainly on fossil fuels and alternative production methods including electrolysis of water, biophotolysis and fermentation hydrogen production from organic waste materials. Compared to the conventional methods, the alternative hydrogen production methods are less energy intensive and negative-value substrates i.e. waste materials can be used to produce hydrogen. Among the alternative methods, fermentation process including dark and photo-fermentation has gained more attention because these processes are simple, waste materials can be utilized, and high hydrogen yields can be achieved. The fermentation process is affected by several parameters such as type of inoculum, pH, temperature, substrate type and concentration, hydraulic retention time, etc. In order to achieve optimum hydrogen yields and maximum substrate degradation, the operating conditions of the fermentation process must be optimized. In this review, two routes for biohydrogen production as dark and photo-fermentation are discussed. Dark/photo-fermentation technology is a new approach that can be used to increase the hydrogen yield and improve the energy recovery from organic wastes. 相似文献
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Fermentative production of ethanol from carbon monoxide 总被引:1,自引:0,他引:1
'Too much Carbon Monoxide for me to bear…' are the opening lyrics of the CAKE song Carbon Monoxide (from their 2004 album Pressure Chief), and while this may be the case for most living organisms, several species of bacteria both thrive on this otherwise toxic gas, and metabolize it for the production of fuels and chemicals. Indeed CO fermentation offers the opportunity to sustainably produce fuels and chemicals without impacting the availability of food resources or even farm land. Mounting commercial interest in the potential of this process has in turn triggered greater scrutiny of the molecular and genetic basis for CO metabolism, as well as the challenges associated with the implementation and operation of gas fermentation at scale. 相似文献
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Maya P. Singh Margaret M. Leighton Laurel R. Barbieri Deborah M. Roll Susan E. Urbance Linda Hoshan Leonard A. McDonald 《Journal of industrial microbiology & biotechnology》2010,37(4):335-340
Fungi are well known for their vast diversity of secondary metabolites that include many life-saving drugs and highly toxic mycotoxins. In general, fungal cultures producing such metabolites are immune to their toxic effects. However, some are known to produce self-toxic compounds that can pose production optimization challenges if the metabolites are needed in large amounts for chemical modification. One such culture, LV-2841, was identified as the lead for one of our exploratory projects. This culture was found to be a slow grower that produced trace amounts of a known metabolite, cercosporamide, under the standard flask fermentation conditions, and extensive medium optimization studies failed to yield higher titers. Poor growth of the culture in liquid media was attributed to the self-toxicity of cercosporamide to the producing organism, and the minimum inhibitory concentration (MIC) of cercosporamide was estimated to be in the range of 8–16 μg/ml. Fermentations carried out in media containing Diaion® HP20 resin afforded significantly higher titers of the desired compound. While several examples of resin-based fermentations of soil streptomyces have been published, this approach has rarely been used for fungal fermentations. Over a 100-fold increase in the production titer of cercosporamide, a self-toxic secondary metabolite, was achieved by supplementing the production medium with a commercially available neutral adsorbent resin. 相似文献
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Fermentative biohydrogen production: trends and perspectives 总被引:1,自引:1,他引:0
Gustavo Davila-Vazquez Sonia Arriaga Felipe Alatriste-Mondragón Antonio de León-Rodríguez Luis Manuel Rosales-Colunga Elías Razo-Flores 《Reviews in Environmental Science and Biotechnology》2008,7(1):27-45
Biologically produced hydrogen (biohydrogen) is a valuable gas that is seen as a future energy carrier, since its utilization
via combustion or fuel cells produces pure water. Heterotrophic fermentations for biohydrogen production are driven by a wide
variety of microorganisms such as strict anaerobes, facultative anaerobes and aerobes kept under anoxic conditions. Substrates
such as simple sugars, starch, cellulose, as well as diverse organic waste materials can be used for biohydrogen production.
Various bioreactor types have been used and operated under batch and continuous conditions; substantial increases in hydrogen
yields have been achieved through optimum design of the bioreactor and fermentation conditions. This review explores the research
work carried out in fermentative hydrogen production using organic compounds as substrates. The review also presents the state
of the art in novel molecular strategies to improve the hydrogen production. 相似文献
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四乙酰基植物鞘氨醇(tetraacetyl phytosphingosine, TAPS)是一种性能卓越的天然护肤品原料,经去乙酰化后生成的植物鞘氨醇可作为前体合成保湿护肤品神经酰胺,因此广泛应用于护肤化妆品行业。非常规酵母威克汉姆西弗酵母(Wickerhamomyces ciferrii)是已知的唯一可天然分泌四乙酰基植物鞘氨醇的微生物,目前已成为四乙酰基植物鞘氨醇工业生产的宿主。本文介绍了四乙酰基植物鞘氨醇的发现、功能及其生物合成途径,综述了近年来利用单倍体筛选、诱变育种和代谢工程改造威克汉姆西弗酵母高产四乙酰基植物鞘氨醇的研究进展,并展望了实现四乙酰基植物鞘氨醇工业生产的未来发展方向。 相似文献
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Micrococcus sodonensis KY 3765 and Arthrobacter citreus KY 3155 were found capable of accumulating IMP in media supplemented with hypoxanthine as a precursor. High concentrations of phosphate and magnesium salts were required for high yields of IMP. Manganese deficiency in the media was also essential. Excessive Mn2+ effects were also seen in the IMP fermentation carried out with an adenineless mutant, of Cornynebacterium glutamicum. In M. sodonensis, R5P-like substances, 5-phosphoribose pyrophosphokinase and IMP pyrophosphorylase, were leaked out, of the cells grown in suboptimal Mn2+ levels. This excretion was inhibited by high levels of Mn2+. Such a phenomenon was not noted in A. citreus. An adenineless mutant (KY 7208) of Brevibacterium ammoniagenes was found to accumulate an appreciable amount of IMP. The chemical changes in this fermentation showed that, hypoxanthine was first produced de novo, excreted, and then reconverted into IMP by a salvage pathway. When hypoxanthine was added to 7208 culture, IMP yield was increased appreciably. In fact exogenous 14C-hypoxanthine was incorporated into 14C-IMP. Subsequent experiments showed that indeed Br. ammoniagenes ATCC 6872, a parent culture of KY 7208, was able to produce IMP, GMP, and AMP, in good yield from hypoxanthine, guanine, and adenine, respectively. 相似文献
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Jagurti Jadhav Sruba Dutta Sandeep Kale 《Preparative biochemistry & biotechnology》2018,48(3):234-241
Glycolipids are one of the major classes of biosurfactants in which the rhamnolipids are best studied. The present work investigates the optimization of inoculum age and batch time for maximizing the yield of rhamnolipid from Pseudomonas aeruginosa (MTCC 2453). The yield and titer of rhamnolipids were maximum in the fermentation batch with an inoculum age of 24?hr. Batch time studies were performed on biomass production, rhamnolipid production, and sunflower oil utilization. The maximum yield of rhamnolipid was achieved at 96?hr when the culture cells were in the late exponential/early stationary phase. At optimum substrate concentration, maximum yield of 10.8?g/L was achieved. Further, downstream processing of crude rhamnolipid from broth using organic solvent extraction and subsequent purification using adsorption chromatography was done. In this study, chromatographic method was developed for purification of rhamnolipid by adsorption phenomena with more than 88.7% purity and 86.5% recovery. The present study provides new perspective on concepts involving separation by adsorption. Further antimicrobial properties and surfactant properties were studied for rhamnolipid production. 相似文献
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AbstractIn recent years, there have been many studies on producing acetoin by microbial fermentation, while only a few studies have focused on chiral acetoin biosynthesis. The weight assignment method was first applied to balance the chiral purity (expressed as the enantiomeric excess value) and the titer of acetoin. Bacillus sp. H-18W, a thermophile, was selected from seven Bacillus strains for chiral acetoin production. To lower the cost of the fermentation medium, soybean meal was used as a feedstock. Four kinds of frequently used commercial proteinases with different active sites were tested for the hydrolyzation of the soybean meal, and the combination of the acidic proteinase and the neutral proteinase showed the best results. In a fermentation medium containing 100?g L?1 glucose and 200?g L?1 hydrolysate, Bacillus sp. H-18W produced 21.84?g L?1 acetoin with an ee value of 96.25% at 60?h. This is the first report of using a thermophilic strain to produce chiral acetoin by microbial fermentation. Thermophilic fermentation can reduce the risk of bacterial contamination and can save cooling water. Using soybean meal hydrolysate and glucose as feedstocks, this work provides an economical and alternative method for the production of chiral pure acetoin. 相似文献
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Vaidyanatha Lyer Thankamani Raghavan Nair Giridhar 《Biotechnology and Bioprocess Engineering》2004,9(6):435-439
ThreeBacillus strains were isolated from soil samples. Morphological and physiological characterization indicated that the isolated strains
wereB. mycoides, B. licheniformis andB. brevis. White pepper was produced from black pepper by the fermentative method using the isolates in shake flaks as well as in a
large-scale fermenter. Volatile oil and piperine contents of the product were 3.2% (v/w) and 4% (v/w) respectively. The moisture
content was 15%. The microbial contamination was less than 10 per 100 g. The product also exhibited excellent storage stability. 相似文献