Showing papers on "Bioconversion published in 1985"
TL;DR: The best mode of fermentation was a semicontinuous fed‐batch fermentation where one‐half of the fermented material was removed at three‐day intervals and replaced by fresh substrate, and protein production was 20% higher than in batch mode, protein productivity was maintained over 12 days, and sporulation was prevented.
Abstract: Optimal conditions for solid substrate fermentation of wheat straw with Chaetomium cellulolyticum in laboratory-scale stationary layer fermenters were developed. The best pretreatment for wheat straw was ammonia freeze explosion, followed by steam treatment, alkali treatment, and simple autoclaving. The optimal fermentation conditions were 80% (w/w) moisture content; incubation temperature of 37°C; 2% (w/w) unwashed mycelial inoculum; aeration at 0.12 L/h/g; substrate thickness of 1 to 2 cm; and duration of three days. Technical parameters for this optimized fermentation were: degree of substance utilization, 27.2%; protein yield/substrate, 0.09 g; biomass yield/bioconverted substrate, 0.40 g; degree of bioconversion of total available sugars in the substrate, 60.5%; specific efficiency of bioconversion, 70.8%; and overall efficiency of biomass production from substrate, 42.7%. Mixed culturing of Candida utilis further increased biomass production by 20%. The best mode of fermentation was a semicontinuous fed-batch fermentation where one-half of the fermented material was removed at three-day intervals and replaced by fresh substrate. In this mode, protein production was 20% higher than in batch mode, protein productivity was maintained over 12 days, and sporulation was prevented.
93 citations
TL;DR: Examination of the metabolism of pentoses by these microorganisms, reveals major differences in both the initial reactions of sugar breakdown and the nature of the resultant endproducts.
Abstract: Hemicellulose carbohydrates comprise a significant proportion of available biomass resources such as agricultural residues and wood wastes. These sugars, of which D-xylose is the most abundant, can be converted to valuable fuels and chemical feedstocks by bacteria, yeasts and mycelial fungi. Examination of the metabolism of pentoses by these microorganisms, reveals major differences in both the initial reactions of sugar breakdown and the nature of the resultant endproducts. Wide variability exists in the ability of microbes to utilize D-xylose and its ketose isomer, D-xylulose. Methods for recovery of hemicellulose sugars include autohydrolysis, alkaline or dilute acid extraction and enzymatic hydrolysis. Processes indicating the feasibility of ethanol manufacture from corn stover, wheat straw and wood have been studied.
79 citations
TL;DR: Derivatives having solution stability exceeding 2 years at 25 degrees C with a faster bioconversion rate and an overall bioavailability equal to or higher than that of the succinate ester have been identified and relative bioavailability appears to be highly sensitive to the charge of the solubilizing pro-moiety and pro-Moiety chain length.
27 citations
TL;DR: The bioconversion of cellulose and hemicellulose substrates to 2,3-butanediol by a sequential coculture approach was investigated with the cellulolytic fungus Trichoderma harzianum E58 and the fermentative bacterium Klebsiella pneumoniae, indicating that the inhibitory effect on solvent production under such conditions was due to the indirect result of growth inhibition of the bacterial cells.
Abstract: The bioconversion of cellulose and hemicellulose substrates to 2,3-butanediol by a sequential coculture approach was investigated with the cellulolytic fungus Trichoderma harzianum E58 and the fermentative bacterium Klebsiella pneumoniae. Vogel medium optimal for the production of the cellulolytic and xylanolytic enzymes of the fungus was found to be inhibitory to butanediol fermentation. This inhibition appeared to be due to a synergistic effect of various ingredients, particularly the salts, present in the fungal medium. The removal or replacement of such ingredients from Vogel medium led to the relief of fermentation inhibition, but the treatments also resulted in a significant decrease in fungal enzyme production. Resting cells of K. pneumoniae could be used for butanediol production in the fungal medium, indicating that the inhibitory effect on solvent production under such conditions was due to the indirect result of growth inhibition of the bacterial cells. The resting-cell approach could be combined with a fed-batch system for the direct conversion of 8 to 10% (wt/vol) of Solka-Floc or aspenwood xylan to butanediol at over 30% of the theoretical conversion efficiencies.
27 citations
TL;DR: A new method for solid‐state ethanol fermentation (the SSEF system) was experimented on for the ethanol production from solid starchy materials, where a packedbed‐type fermentor was used and both cultivation of Aspergillus saitoi and enrichment of a saccharifying enzyme were effective for hydrolysis of the starch.
Abstract: A new method for solid-state ethanol fermentation (the SSEF system) was experimented on for the ethanol production from solid starchy materials, where a packedbed-type fermentor was used. Both cultivation of Aspergillus saitoi and enrichment of a saccharifying enzyme were effective for hydrolysis of the starch. Ethanol production was set in by a form of parallel fermentation using a respiration-deficient mutant of Saccharomyces cerevisiae. Produced ethanol was simultaneously stripped by circulating inert gas and separated in a condenser. Average ethanol concentration in the condensate was over 200 g/L, and over 90% of produced ethanol was recovered from the packed bed during 15 or 16 days of stripping. The fermentation efficiency was about 80%, which was evaluated much higher than those of conventional solid-state fermentations. The residue had lesser volume and a higher solids content compared with the distillery wastewaters of conventional liquid-state fermentations. This means an advantage for the treatment and the effective conversion of the residue into fetilizers or animal feeds.
23 citations
TL;DR: The hydrolysis of lignocellulose using mycelial biomass of P. funiculosum cultivated on cellulose and its reuse potential is reported, which shows promise for producing unlimited quantities of fermentable feedstocks and liquid fuels.
Abstract: Cellulose bioconversion has great promise for producing unlimited quantities of fermentable feedstocks and liquid fuels. Extensive studies on the production of extracellular cellulase and on the saccharification of various cellulosic substrates using cellulases have been reported. Use of mycelial biomass having cell bound cellulase for saccharification of cellulose was studied in Aspergillus terreus by Miller and Srinivasan. Extracellular cellulase production by P. funiculosum and its application for cellulose hydrolysis have been reported earlier by the authors. The present communication reports the hydrolysis of lignocellulose using mycelial biomass of P. funiculosum cultivated on cellulose and its reuse potential. 10 references.
18 citations
TL;DR: Dissociation of cell growth and metabolite production allows the creation of continuous reactors where conversion yields of carbon to product are very high, especially for products such as xanthans, where physical parameters change rapidly, especially viscosity.
18 citations
TL;DR: A mutant of Aspergillus ochraceus has been developed, which converts progesterone to 11α-hydroxyprogesterone in high yields (∼90%) and the formation of 6β, 11 α-dihydroxy compound is minimal at high substrate concentrations.
Abstract: A mutant of Aspergillus ochraceus has been developed, which converts progesterone (substrate concentration 40 g/l) to 11α-hydroxyprogesterone in high yields (∼90%). The formation of 6β, 11α-dihydroxy compound is minimal at high substrate concentrations. The bioconversion rate is also much higher. The various parameters for optimal conversion have been standardised.
17 citations
Patent•
6 Feb 1985TL;DR: Amino acids eg phenylalanine are produced by transamination at a temperature equal to or greater than 40 DEG C, between an amine donor and keto acid precursor of the amino acid in the presence of an aminotransferase obtained from a microorganism which has been genetically modified to overproduce the AMINOTransferases as discussed by the authors.
Abstract: of EP0152275Amino acids eg phenylalanine are produced by transamination at a temperature equal to or greater than 40 DEG C, between an amine donor and keto acid precursor of the amino acid in the presence of an aminotransferase obtained from a microorganism which has been genetically modified to overproduce the aminotransferase
Patent•
26 Jul 1985TL;DR: In this article, a process for the bioconversion of a non-growth aromatic feed to an accumulated quantity of a picolinic acid product with reduced accumulation of 2-hydroxymuconic semialdehyde, and conducted in the presence of ammonium or a primary amine, is described.
Abstract: This invention provides a process for the bioconversion of a non-growth aromatic feed to an accumulated quantity of a picolinic acid product with reduced accumulation of 2-hydroxymuconic semialdehyde, and conducted in the presence of ammonium or a primary amine, which acid subsequently can be converted by chemical means to a pyridine product.
TL;DR: Addition of α,α′-dipyridyl and sodium arsenite as metabolic inhibitors in the culture medium enhanced the accumulation of a 17-ketosteroid which acts as precursor of steroidal drugs and hormones.
Abstract: Arthrobacter globiformis isolated from garden soil was cultured on phosphate salt medium containing phytosterols extracted from sulphitation pressmud, a sugar industry waste, as sole source of carbon. The bacterium grew well on sterols and transformed them into precursors of steroidal drugs and hormones. Addition of α,α′-dipyridyl and sodium arsenite as metabolic inhibitors in the culture medium enhanced the accumulation of a 17-ketosteroid which acts as precursor of steroidal drugs. The optimum temperature and pH conditions for its maximum accumulation were found to be 32 ± 0.5dC and 7.2. Spectroscopic analyses by u.v., i.r., p.m.r. and mass spectra of the 17-ketosteroid formed by microbial activity in the medium confirmed it to be androsta-1,4-diene-3,17-dione (ADD). The bioconversion of sugar-cane sterols into 17-ketosteroid in varying culture condition is discussed.
TL;DR: Bioconversion experiments using washed mycelia of Penicillium aculeatum revealed that penitricin was biosynthesized from trans-2-butene-1,4-diol via 4-hydroxycrotonaldehyde.
Abstract: Bioconversion experiments using washed mycelia of Penicillium aculeatum NR 5165 and NR 6216 revealed that penitricin (Ro 09-0804, hydroxymethylcyclopropenone) was biosynthesized from trans-2-butene-1,4-diol via 4-hydroxycrotonaldehyde.
Patent•
18 Jun 1985
TL;DR: In this paper, a process for the bioconversion of Lascorbic acid (Vitamin C) to microorganisms (e.g., Candida Norvegensis MF-56, ATCC 20686 and Candida N. MF-78, atCC 20732) is described.
Abstract: Processes for the bioconversion production of L-ascorbic acid (Vitamin C), and to microorganisms (e.g., Candida Norvegensis MF-56, ATCC 20686 and Candida Norvegensis MF-78, ATCC 20732) and bioconversion media which are specifically adapted for such bioconversion.
1 Jan 1985
TL;DR: Experiments were conducted to study the effects of gamma-ray irradiation, alkaline-hydrogen perioxide pretreatment, and moderate ( 100/sup 0/C) temperature alkaline pretreatment of wheat straw prior to anaerobic fermentation to methane.
Abstract: Experiments were conducted to study the effects of ..gamma..-ray irradiation, alkaline-hydrogen perioxide pretreatment, and moderate ( 100/sup 0/C) temperature alkaline pretreatment of wheat straw prior to anaerobic fermentation to methane.
Book•
1 Jan 1985
TL;DR: Modeling, optimization and control of semi-batch bioreactors for adaptive control of single cell protein processes in tower loop biOREactors are studied.
Abstract: Industrial processing and products from the Jerusalem artichoke.- The utilization of cheese whey and its components.- Bioconversion of hemicellulosics.- Mathematical modelling, parameter identification and adaptive control of single cell protein processes in tower loop bioreactors.- Modeling, optimization and control of semi-batch bioreactors.
Patent•
12 Aug 1985TL;DR: In this paper, a process for the bioconversion of a non-growth aromatic feed to an accumulated quantity of 2-hydroxymuconic semialdehyde metabolite is described.
Abstract: This invention provides a process for the bioconversion of a non-growth aromatic feed to an accumulated quantity of 2-hydroxymuconic semialdehyde metabolite. 2-Hydroxysemialdehyde is a useful intermediate for subsequent conversions to picolinic acid and pyridine.
TL;DR: In this paper, the authors performed chemical characterization of blanching effluent and bioconversion by Hansenula anamola and found that the effluent contained 27,000 mg/L biochemical oxygen demand (BOD) and 31,000mg/L total solids including 49.5% starch and 23.6% protein.
Abstract: Chemical characterization of blanching effluent and bioconversion by Hansenula anamola was performed. The effluent contained 27,000 mg/L BOD and 31,000 mg/L total solids including 49.5% starch and 23.6% protein (dry basis). A high biochemical oxygen demand (BOD): chemical oxygen demand (COD) ratio (0.95) indicated a waste easily and completely degradable, with nitrogen and phosphorus levels above those necessary for unimpeded microbial growth. Batch fermentations of raw effluent produced 12g dry cells/L, containing 53% protein, with a corresponding 84% reduction in BOD. Great Northern bean blanching effluent was demonstrated to be a suitable growth medium for H. anomala.
TL;DR: On the basis of 1H and 13C NMR spectra, the conformation of a bioconversion product of grisorixin is elucidated in this paper, where the authors show that the product can be expressed as
Dissertation•
1 Jan 1985
TL;DR: Tomatines are bioconverted by Nocardia restricta to less polar products by conjugation with l (+)‐lactic acid, depending on the length of the sugar‐chain.
Abstract: Tomatines are bioconverted by Nocardia restricta to less polar products by conjugation with l (+)-lactic acid. The yields of these bioconversions decrease from 50% with α-tomatine to 5% with δ-tomatine, depending on the length of the sugar-chain.
Patent•
8 Apr 1985TL;DR: In this paper, an improved microbial bioconversion to produce 1,2-dehydro steroids from their corresponding 1, 2-saturated derivatives is described, which is claimed to be the state-of-the-art.
Abstract: Disclosed and claimed is an improved microbial bioconversion to produce 1,2-dehydro steroids from their corresponding 1,2-saturated derivatives.
TL;DR: In this article, a feasibility study was undertaken to evaluate the bioconversion of draff, a residue from the industrial conversion of malt in brewery, into a valuable fuel, and an overall yield of 35 m3 gas/dry ton substrate were observed at ambient temperature.
TL;DR: In this article, the sugar content of pretreated wheat straw and sunflower stalks was investigated and it was found that pretreatment with peracetic acid enhanced the enzymatic hydrolysis and the yields of sugars (glucose and xylose) were higher than those from untreated wheat straw.
Patent•
17 Apr 1985TL;DR: In this article, an improved microbial bioconversion to produce 1,2-dehydro steroids from their corresponding 1, 2-saturated derivatives by use of a water-immiscible solvent comprising an aromatic hydrocarbon in the reaction procedure is described.
Abstract: Disclosed and claimed is an improved microbial bioconversion to produce 1,2-dehydro steroids from their corresponding 1,2-saturated derivatives by use of a water-immiscible solvent comprising an aromatic hydrocarbon in the reaction procedure.