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1.
The lactone 6-pentyl-α-pyrone has a characteristic coconut aroma and is produced by Trichoderma species. A study on the fermentative production of 6-pentyl-α-pyrone in both surface and submerged conditions by Trichoderma harzianum was carried out. Maximum concentrations of 455 mg/l and 167 mg/l after 96 h and 48 h of fermentation in surface and submerged
conditions, respectively, were obtained without using any additional recovery operations. The resultant yields are higher
than those previously reported in the literature, which may be attributable to strain characteristics in combination with
the choice of fermentation conditions employed in the present study. Enough scope exists for further improvement in the yields
by optimizing the cultural and nutritional parameters.
Received: 13 July 1999 / Received revision: 19 November 1999 / Accepted: 19 November 1999 相似文献
2.
Succinoglycan was produced by cultivating Agrobacterium tumefaciens on various solid substrates, including agar medium, spent malt grains, ivory nut shavings, and grated carrots, impregnated
with a nutrient solution. Fermentations were performed on a laboratory scale, both under static conditions and with agitation,
using bottles and a prototype horizontal bioreactor. Several fermentation parameters were examined and optimized, including
carbon and nitrogen composition, water content and layer thickness of the substrate. The yields and rheological properties
of the polymers obtained under different fermentation conditions were compared. The highest succinoglycan yield was achieved
in static cultivation, reaching 42 g/l of impregnating solution, corresponding to 30 g/kg of wet substrate. The polymer production
in the horizontal bioreactor was faster, but the final yield was lower (29 g/l of impregnating solution).
Received: 26 January 1999 / Received revision: 20 April 1999 / Accepted: 23 April 1999 相似文献
3.
Biotechnology of succinic acid production and markets for derived industrial products 总被引:29,自引:4,他引:25
Succinic acid, derived from fermentation of agricultural carbohydrates, has a specialty chemical market in industries producing
food and pharmaceutical products, surfactants and detergents, green solvents and biodegradable plastics, and ingredients to
stimulate animal and plant growth. As a carbon-intermediate chemical, fermentation-derived succinate has the potential to
supply over 2.7 × 108 kg industrial products/year including: 1,4-butanediol, tetrahydrofuran, γ-butyrolactone, adipic acid, n-methylpyrrolidone and linear aliphatic esters. Succinate yields as high as 110 g/l have been achieved from glucose by the
newly discovered rumen organism Actinobacillus succinogenes. Succinate fermentation is a novel process because the greenhouse gas CO2 is fixed into succinate during glucose fermentation. New developments in end-product recovery technology, including water-splitting
electrodialysis and liquid/liquid extraction have lowered the cost of succinic acid production to U.S. $ 0.55/kg at the 75 000
tonne/year level and to $ 2.20/kg at the 5000 tonne/year level. Research directions aimed at further improving the succinate
fermentation economics are discussed.
Received: 27 October 1998 / Received revision: 22 January 1999 / Accepted: 22 January 1999 相似文献
4.
J Lin D Panigraphy L B Trinh J Folkman J Shiloach 《Journal of industrial microbiology & biotechnology》2000,24(1):31-35
A pilot-scale production method of recombinant human angiostatin, a 38-kD fragment of plasminogen which has been reported
to have antiangiogenic activity, has been successfully established by expressing the protein in the methylotrophic yeast Pichia pastoris. The secreted protein inhibited cultured endothelial cell proliferation in vitro and Lewis lung carcinoma growth in mice. The fermentation process was carried out using an on-line methanol controller, administering
methanol to the growing culture and keeping its concentration under 2 g L−1. The fermentation lasted 90 h, of which 70 h were growth on methanol. During growth on methanol the culture volume increased
64%, from 7 L to 11.5 L, producing 200 mg angiostatin and 5 kg of biomass. Journal of Industrial Microbiology & Biotechnology (2000) 24, 31–35.
Received 12 May 1999/ Accepted in revised form 06 September 1999 相似文献
5.
K. Hofvendahl E. W. J. van Niel B. Hahn-Hägerdal 《Applied microbiology and biotechnology》1999,51(5):669-672
Lactococcus lactis ssp. lactis ATCC 19435 is known to produce mixed acids when grown on maltose. A change in fermentation conditions only, elevated temperatures
(up to 37 °C) and reduced pH values (down to 5.0) resulted in a shift towards homolactic product formation. This was accompanied
by decreased growth rate and cell yield. The results are discussed in terms of redox balance and maintenance, and the regulation
of lactate dehydrogenase and pyruvate formate-lyase.
Received: 14 December 1998 / Received revision: 12 January 1999 / Accepted: 22 January 1999 相似文献
6.
Enterobacter cloacae NRRL B-23289 was isolated from local decaying wood/corn soil samples while screening for microorganisms for conversion of
l-arabinose to fuel ethanol. The major product of fermentation by the bacterium was meso-2,3-butanediol (2,3-BD). In a typical
fermentation, a BD yield of 0.4 g/g arabinose was obtained with a corresponding productivity of 0.63 g/l per hour at an initial
arabinose concentration of 50 g/l. The effects of initial arabinose concentration, temperature, pH, agitation, various monosaccharides,
and multiple sugar mixtures on 2,3-BD production were investigated. BD productivity, yield, and byproduct formation were influenced
significantly within these parameters. The bacterium utilized sugars from acid plus enzyme saccharified corn fiber and produced
BD (0.35 g/g available sugars). It also produced BD from dilute acid pretreated corn fiber by simultaneous saccharification
and fermentation (0.34 g/g theoretical sugars).
Received: 17 December 1998 / Revision received: 9 March 1999 / Accepted: 20 March 1999 相似文献
7.
Riboflavin production is significantly determined by the type and initial concentration of the carbon and nitrogen sources
and also by other flavinogenic stimulants. Using an optimum carbon and nitrogen concentration, an industrial fermentation
medium has been designed with molasses as the carbon source and peanut seed cake as the nitrogen source. In addition the stimulatory
effect of some of the low-cost agro-industrial by-products on riboflavin yield was investigated.
Received: 10 March 1996 / Received revision: 25 June 1996 / Accepted: 14 July 1996 相似文献
8.
Batch and continuous cultivation of Anaerobiospirillum succiniciproducens for the production of succinic acid from whey 总被引:3,自引:0,他引:3
Batch and continuous cultivation of Anaerobiospirillum succiniciproducens were systematically studied for the production of succinic acid from whey. Addition of 2.5 g l−1 yeast extract and 2.5 g l−1 polypeptone per 10 g l−1 whey was most effective for succinic acid production from both treated and nontreated whey. When 20 g l−1 nontreated whey and 7 g l−1 glucose were used as cosubstrates, the yield and productivity of succinic acid reached at the end of fermentation were 95%
and 0.46 g (l h)−1, respectively. These values were higher than those obtained using nontreated whey alone [93% and 0.24 g (l h)−1 for 20 g l−1 whey]. Continuous fermentation of A. succiniciproducens at an optimal dilution rate resulted in the production of succinic acid with high productivity [1.35 g (l h)−1], high conversion yield (93%), and higher ratio of succinic acid to acetic acid (5.1:1) from nontreated whey.
Received: 23 July 1999 / Received revision: 17 November 1999 / Accepted: 24 December 1999 相似文献
9.
A Gram-negative bacterium producing a heat-stable nitrilase highly active on aliphatic dinitriles 总被引:8,自引:0,他引:8
J. E. Gavagan R. DiCosimo A. Eisenberg S. K. Fager P. W. Folsom E. C. Hann K. J. Schneider R. D. Fallon 《Applied microbiology and biotechnology》1999,52(5):654-659
A Gram-negative bacterial strain, identified as Acidovorax facilis strain 72W, has been isolated from soil by enrichment using 2-ethylsuccinonitrile as the sole nitrogen source. This strain
grows on a variety of aliphatic mono- and dinitriles. Experiments using various heating regimes indicate that nitrile hydratase,
amidase and nitrilase activities are present. The nitrilase is efficient at hydrolyzing aliphatic dinitriles to cyanoacid
intermediates. It has a strong bias for C3–C6 dinitriles over mononitriles of the same chain length. Whole, resting cell hydrolysis of 2-methylglutaronitrile results in
4-cyanopentanoic acid and 2-methylglutaric acid as the major products. Heating, at least 20 min at 50 °C, eliminates nitrile
hydratase and amidase activities, resulting in greater than 97% selectivity to 4-cyanopentanoic acid. The nitrilase activity
has good heat stability, showing a half-life of 22.7 h at 50 °C and a temperature optimum of at least 65 °C for activity.
The strain has been deposited as ATCC 55746.
Received: 26 January 1999 / Received revision: 10 June 1999 / Accepted: 27 June 1999 相似文献
10.
Y. Zhu A. Rinzema J. Tramper E. de Bruin J. Bol 《Applied microbiology and biotechnology》1998,49(3):251-257
In the later stages of a batch fermentation for microbial transglutaminase production by Streptoverticillium mobaraense the availability of a nitrogen source accessible to the microorganism becomes critical. Fed-batch fermentation is investigated
with the aim of avoiding this substrate limitation. When peptone is used as a nitrogen source in the feed, no significant
improvement of growth and transglutaminase production is observed. This is probably due to crosslinking of the nitrogen source
by the transglutaminase produced. Using an inorganic nitrogen source alone does not give satisfactory growth and production.
A fed-batch fermentation method has thus been developed to deal with this problem. In the batch phase of the fermentation,
an initial medium containing peptone, designed on the basis of the stoichiometric requirements of the microorganism, is used
to ensure optimal growth. In the feeding phase, ammonium sulphate is used instead to avoid the crosslinking effect. The feed
composition, mainly the amount of nitrogen and carbon source, is also based on the stoichiometric requirements of the organism,
taking into account the replacement of peptone by ammonium sulphate. By using this fed-batch fermentation technique, cell-mass
dry weight and transglutaminase production could be increased by 33% and 80% respectively, compared to those in a batch fermentation.
Received: 10 July 1997 / Received revision: 24 October 1997 / Accepted: 24 October 1997 相似文献
11.
5-Hydroxypyrazine-2-carboxylic acid, a versatile building block for the synthesis of new antituberculous agents, was prepared
by whole-cell biotransformation from 2-cyanopyrazine via pyrazinecarboxylic acid using Agrobacterium sp. DSM 6336. By developing a fermentation process for this two-enzyme-step bioconversion, a product concentration of 286 mM
(40 g/l) was obtained. After the isolation method had been optimized the total yield was 80%.
Received: 28 February 1997 / Received revision: 28 April 1997 / Accepted: 4 May 1997 相似文献
12.
Ashkenazy R Yannai S Rahman R Rabinovitz E Gottlieb L 《Applied microbiology and biotechnology》1999,52(4):608-611
Spent Saccharomyces cerevisiae cells from a beer fermentation process were evaluated for lead cation sorption. The crude biomass was washed with water and
acetone prior to any other treatment. Although the washed biomass showed substantial lead ion sorption it was susceptible
to microbial spoilage. Different aldehydes were tested as chemical fixation agents; however, most of them caused drastic lowering
of the metal uptake capacity. However, benzaldehyde was not only an excellent fixation agent, but the biomass treated with
it also retained its original lead sorption capacity. A mechanism for the fixation process is suggested.
Received: 11 January 1999 / Received revision: 26 April 1999 / Accepted: 1 May 1999 相似文献
13.
L. Escalante I. Ramos I. Imriskova E. Langley S. Sanchez 《Applied microbiology and biotechnology》1999,52(4):572-578
The effect of glucose on growth and anthracycline production by Streptomyces peucetius var. caesius was examined in a chemically defined medium. Glucose concentrations above 100 mM inhibited anthracycline synthesis in the
original strain without causing significant change in growth and final pH values. This effect was observed when the carbohydrate
was added initially or after 24 h fermentation, but not when added during the stationary growth phase. When the microorganism
was pregrown in 100 mM glucose and then transferred to a resting cell system with 444 mM glucose, no significant differences
in antibiotic production were observed compared to the control without glucose. The negative effect of glucose on antibiotic
synthesis was not observed in a mutant (2-dogR–21) resistant to growth inhibition by 2-deoxyglucose. Glucose consumption by this mutant was approximately 30% of that utilized
by the original strain. Compared to the original strain, the mutant 2-dogR–21 exhibited a reduction of 50% in glucose transport and an 85% decrease in glucose kinase activity. The experimental evidence
obtained suggests that glucose represses anthracycline formation in a transitory manner and that this effect is related to
glucose transport and phosphorylation.
Received: 15 January 1999 / Received revision: 7 April 1999 / Accepted: 1 May 1999 相似文献
14.
M. C. de O. Souza I. C. Roberto A. M. F. Milagres 《Applied microbiology and biotechnology》1999,52(6):768-772
We investigated xylanase production by Thermoascus aurantiacus using semisolid fermentation. Multivariant statistical approaches were employed to evaluate the effects of several variables
(initial moisture in the medium, cultivation time, inoculum level, and bagasse mass) on xylanase production. The initial moisture
content and bagasse mass were the most important factors affecting xylanase activity. The xylanase activity produced by the
fungus under the optimized conditions (81% moisture content and 17 g bagasse) was found to be 2700 U per gram of initial dry
matter, whereas its value predicted by a polynomial model was 2400 U per gram of initial dry matter.
Received: 4 December 1998 / Received revision: 15 March 1999 / Accepted: 16 May 1999 相似文献
15.
K. Hofvendahl C. Åkerberg G. Zacchi B. Hahn-Hägerdal 《Applied microbiology and biotechnology》1999,52(2):163-169
Simultaneous saccharification of starch from whole-wheat flour and fermentation to lactic acid (SSF) was investigated. For
saccharification the commercial enzyme mixture SAN Super 240 L, having α-amylase, amyloglucosidase and protease activity,
was used, and Lactococcus lactis ssp. lactis ATCC 19435 was used for the fermentation. SSF was studied at flour concentrations corresponding to starch concentrations
of 90 g/l and 180 g/l and SAN Super concentrations between 3 μl/g and 8 μl/g starch. Kinetic models, developed for the saccharification
and fermentation, respectively, were used for simulation and data from SSF experiments were used for model verification. The
model simulated SSF when sufficient amounts of nutrients were available during fermentation. This was achieved with high wheat
flour concentrations or with addition of yeast extract or amino acids. Nutrient release was dependent on the level of enzyme
activity.
Received: 26 January 1999 / Accepted: 20 February 1999 相似文献
16.
A two-phase organic/aqueous reactor configuration was developed for use in the biodegradation of benzene, toluene and p-xylene, and tested with toluene. An immiscible organic phase was systematically selected on the basis of predicted and experimentally
determined properties, such as high boiling points, low solubilities in the aqueous phase, good phase stability, biocompatibility,
and good predicted partition coefficients for benzene, toluene and p-xylene. An industrial grade of oleyl alcohol was ultimately selected for use in the two-phase partitioning bioreactor. In
order to examine the behavior of the system, a single-component fermentation of toluene was conducted with Pseudomonas sp. ATCC 55595. A 0.5-l sample of Adol 85 NF was loaded with 10.4 g toluene, which partitioned into the cell containing 1 l
aqueous medium at a concentration of approximately 50 mg/l. In consuming the toluene to completion, the organisms were able
to achieve a volumetric degradation rate of 0.115 g l−1 h−1. This system is self-regulating with respect to toluene delivery to the aqueous phase, and requires only feedback control
of temperature and pH.
Received: 16 November 1998 / Received revision: 28 March 1999 / Accepted: 9 April 1999 相似文献
17.
Microbial production of 1,3-propanediol 总被引:79,自引:2,他引:77
H. Biebl K. Menzel A.-P. Zeng W.-D. Deckwer 《Applied microbiology and biotechnology》1999,52(3):289-297
1,3-Propanediol (1,3-PD) production by fermentation of glycerol was described in 1881 but little attention was paid to this
microbial route for over a century. Glycerol conversion to 1,3-PD can be carried out by Clostridia as well as Enterobacteriaceae.
The main intermediate of the oxidative pathway is pyruvate, the further utilization of which produces CO2, H2, acetate, butyrate, ethanol, butanol and 2,3-butanediol. In addition, lactate and succinate are generated. The yield of 1,3-PD
per glycerol is determined by the availability of NADH2, which is mainly affected by the product distribution (of the oxidative pathway) and depends first of all on the microorganism
used but also on the process conditions (type of fermentation, substrate excess, various inhibitions). In the past decade,
research to produce 1,3-PD microbially was considerably expanded as the diol can be used for various polycondensates. In particular,
polyesters with useful properties can be manufactured. A prerequisite for making a “green” polyester is a more cost-effective
production of 1,3-PD, which, in practical terms, can only be achieved by using an alternative substrate, such as glucose instead
of glycerol. Therefore, great efforts are now being made to combine the pathway from glucose to glycerol successfully with
the bacterial route from glycerol to 1,3-PD. Thus, 1,3-PD may become the first bulk chemical produced by a genetically engineered
microorganism.
Received: 12 January 1999 / Received revision: 9 March 1999 / Accepted: 14 March 1999 相似文献
18.
Simultaneous bioconversion of glucose and xylose to ethanol by Saccharomyces cerevisiae in the presence of xylose isomerase 总被引:3,自引:0,他引:3
Simultaneous isomerisation and fermentation (SIF) of xylose and simultaneous isomerisation and cofermentation (SICF) of a
glucose/xylose mixture was carried out by Saccharomyces cerevisiae in the presence of xylose isomerase. The SIF of 50 g l−1 xylose gave an ethanol concentration and metabolic yield of 7.5 g l−1 and 0.36 g (g xylose consumed)−1. These parameters improved to 13.4 g l−1 and 0.40 respectively, when borate was added to the medium. The SICF of a mixture of 50 g l−1 glucose and 50 g l−1 xylose gave an ethanol concentration and metabolic yield of 29.8 g l−1 and 0.42 respectively, in the presence of borate. Temperature modulation from 30 °C to 35 °C during fermentation further
enhanced the above parameters to 39 g l−1 and 0.45 respectively. The approach was extended to the bioconversion of sugars present in a real lignocellulose hydrolysate
(peanut-shell hydrolysate) to ethanol, with a fairly good yield.
Received: 14 May 1999 / Received revision: 27 September 1999 / Accepted: 2 October 1999 相似文献
19.
A comparative study was carried out in anaerobic batch cultures on 20 g/l of either glycerol or glucose using two propionibacteria
strains, Propionibacterium acidipropionici and Propionibacterium freudenreichii ssp. shermanii. In all cases, fermentation end-products were the same and consisted of propionic acid as the major product, acetic acid
as the main by-product and two minor metabolites, n-propanol and succinic acid. Evidence was provided that greater production of propionic acid by propionibacteria was obtained
with glycerol as carbon and energy sources. P. acidipropionici showed higher efficiency in glycerol conversion to propionic acid with a faster substrate consumption (0.64 g l−1 h−1) and a higher propionic acid production (0.42 g l−1 h−1 and 0.79 mol/mol). The almost exclusive production of propionic acid from glycerol by this bacterium suggested an homopropionic
tendency of this fermentation. Acetic acid final concentration was two times lower on glycerol (2 g/l) than on glucose (4 g/l)
for both micro-organisms. P. freudenreichii ssp. shermanii exhibited a glycerol fermentation pattern typical of non-associated glycerol-consumption-product formation. This could indicate
a particular metabolism for P. freudenreichii ssp. shermanii oriented towards the production of other specific components. These results tend to show that glycerol could be an excellent
alternative to conventional carbon sources such as carbohydrates for propionic acid production.
Received: 21 May 1999 / Accepted: 1 November 1999 相似文献
20.
Fernández MJ Adrio JL Piret JM Wolfe S Ro S Demain AL 《Applied microbiology and biotechnology》1999,52(4):484-488
Growth of Streptomyces clavuligerus NP1 in the presence of methanol or ethanol resulted in a marked increase in production of cephalosporin(s) from penicillin
G by resting cells. The mycelium produced in alcohol-supplemented medium was fragmented and dispersed as compared with growth
in control medium. HPLC analysis showed that at least two products were present in the biotransformation supernatant fluid
after 1 h incubation. One of them has been identified as deacetoxycephalosporin G (DAOG).
Received: 9 December 1998 / Received revision: 29 March 1999 / Accepted: 16 April 1999 相似文献