共查询到20条相似文献,搜索用时 2 毫秒
1.
Thompson David N. Fox Sandra L. Bala Gregory A. 《Applied biochemistry and biotechnology》2001,91(1-9):487-501
Pretreatments of low-solids potato process effluent were tested for their potential to increase surfactin yield. Pretreatments
included heat, removal of starch particulates, and acid hydrolysis. Elimination of contaminating vegetative cells was necessary
for surfactin production. After autoclaving, 0.40 g/L of surfactin was produced from the effluent in 72 h, vs 0.24 g/L in
the purified potato starch control. However, surfactin yields per carbon consumed were 76% lower from process effluent. Removal
of starch particulates had little effect on the culture. Acid hydrolysis decreased growth and surfactant production, except
0.5 wt% acid, which increased the yield by 25% over untreated effluent. 相似文献
2.
Karl S. Noah Debby F. Bruhn Gregory A. Bala 《Applied biochemistry and biotechnology》2005,122(1-3):465-473
The biosurfactant surfactin has potential to aid in the recovery of energy resources (oil recovery) or subsurface organic
contaminants (environmental remediation). However, high medium and purification costs limit its use in these high-volume applications.
In previous work, we showed that surfactin could be produced from an inexpensive low-solids potato process effluent with minimal
amendments or pretreatments. Previous research has also shown that surfactin can be both produced in Bacillus subtilis cultures and recovered by foam fractionation in an airlift reactor. Results using both purified potato starch and unamended
low-solids potato process effluent as substrates for surfactin production indicate that the process is oxygen limited and
that recalcitrant indigenous bacteria in the potato process effluent hamper continuous surfactin production. The research
reported here features the use of a chemostat operated in batch mode for producing surfactin with concomitant use of antifoam
to prevent surfactant loss. The antifoam did not interfere with surfactin recovery by acid precipitation or its efficacy.
Initial trials took about 48 h to produce 0.9 g/L of surfactin from potato process effluent. Increasing the oxygen mass transfer
by increasing the stirring speed and adding a baffle decreased production time to 12–24 h and produced about 0.6 g/L of surfactin
from two different potato-processing facilities. 相似文献
3.
Kastli D. Schaller Sandra L. Fox Debby F. Bruhn Karl S. Noah Gregory A. Bala 《Applied biochemistry and biotechnology》2004,115(1-3):827-836
Surfactin produced by Bacillus subtilis (ATCC 21332) was used to examine the effect of altering salt concentration, pH, and temperature on surfactin activity (as
measured by reductions in surface tension). These parameters are some of the conditions that define oil reservoir characteristics
and can affect the application of surfactants. The Biotechnology for Oilfield Operations research program at the Idaho National
Engineering and Environmental Laboratory (INEEL) has successfully produced surfactin from potato process effluents for possible
use as an economical alternative to chemical surfactants for improved oil recovery. Surfactants enhance the recovery of oil
through a reduction of the interfacial tension between the oil and water interfaces, or by mediating changes in the wettability
index of the system. We investigated changes in surfactin activity under a range of conditions by measuring surface tension.
Surface tension was determined using video image analysis of inverted pendant drops. Experimental variables included NaCl
(0–10%), pH (3.0–10.0), and temperature (21–70°C). Each of these parameters, as well as selected combinations, resulted in
discrete changes in surfactin activity. It is therefore important to consider the exploration of the studied surfactin as
an enhanced oil recovery agent. 相似文献
4.
A cassava flour-processing effluent (manipueira) was evaluated as a substrate for surfactant production by two Bacillus subtilis strains. B. subtilis ATCC 21332 reduced the surface tension of the medium to 25.9 mN/m, producing a crude biosurfactant concentration of 2.2 g/L.
The wild-type strain, B. subtilis LB5a, reduced the surface tension of the medium to 26.6 mN/m, giving a crude biosurfactant concentration of 3.0 g/L. A decrease
in surfactant concentration observed for B. subtilis ATCC 21332 seemed to be related to an increase in protease activity. The biosurfactant produced on cassava effluent medium
by B. subtilis LB5a was similar to surfactin. 相似文献
5.
Biosurfactants from potato process effluents 总被引:1,自引:0,他引:1
Thompson David N. Fox Sandra L. Bala Gregory A. 《Applied biochemistry and biotechnology》2000,84(1-9):917-930
High-solids (HS) and low-solids (LS) potato process effluents were tested as substrates for surfactin production. Tests used
effluents diluted 1∶10, unamended and amended with trace minerals or corn steep liquor. Heat pretreatment was necessary for
surfactin production from effluents due to indigenous bacteria, whose spores remained after autoclaving. Surfactin production
from LS surpassed HS in all cases. Surfactin yields from LS were 66% lower than from a pure culture in an optimized potatostarch
medium. LS could potentially be used without sterilization for surfactin production for low-value applications such as environmental
remediation or oil recovery. 相似文献
6.
Philippe Jacques Choukai Hbid Jacqueline Destain Hary Razafindralambo Michel Paquot Edwin De Pauw Philippe Thonart 《Applied biochemistry and biotechnology》1999,77(1-3):223-233
Bacillus subtilis S499 is well-known for its ability to produce two families of surfactant lipopeptides: Iturin A and Surfactin S1. Fermentation
optimization for this strain was performed to amplify the surfactant production. Ten active variables were analyzed by two
successive Plackett-Burman designs, consisting respectively of 12 and 16 experiments to give an optimized medium. The amount
of biosurfactant lipopeptides in the supernatant of a culture carried out in this optimized medium was about five times higher
than that obtained in nonoptimized rich medium. The analysis of the surfactant molecules produced in such optimized conditions
has revealed the presence of a third family of lipopeptides: the fengycins.
The time-dependent production of these three families of molecules in bioreactors showed that surfactin S1 is produced during
the exponential phase and iturin A and fengycins during the stationary phase. 相似文献
7.
Fabíula A. S. L. Reis Eliana Flavia C. Sérvulo Francisca P. De França 《Applied biochemistry and biotechnology》2004,115(1-3):899-912
The production of biosurfactant by Bacillus subtilis ATCC 6633 was investigated using commercial sugar, sugarcane juice and cane molasses, sugarcane juice alcohol stillage, glycerol,
mannitol, and soybean oil. Commercial sugar generated the minimum values of surface tension, with the best results (28.7 mN/m,
(relative critical micelle concentration [CMC−1] of 78.6) being achieved with 10 g of substrate/L in 48 h. At a pH between 7.0 and 8.0, a higher production of surface-active
compounds and a greater emulsifier activity was also observed. Enrichment of the culture medium with trace minerals and EDTA
showed maximum yields, whereas supplementation with yeast extract stimulated only cell growth. The kinetic studies revealed
that biosurfactant production is a cell growth-associated process; surface tension, CMC, and emulsification index values of
29.6 dyn/cm, 82.3, and 57%, respectively, were achieved, thus indicating that it is feasible to produce biosurfactants from
a renewable and low-cost carbon source. 相似文献
8.
Akpa Eric Jacques Philippe Wathelet Bernard Paquot Michel Fuchs Regine Budzikiewicz Herbert Thonart Philippe 《Applied biochemistry and biotechnology》2001,91(1-9):551-561
Bacillus subtilis produces various families of lipopeptides with different homologous compounds. To produce “new molecules” with improved activities
and to select strains that produced a reduced number of homologs or isomers, we studied the effects of different media on
the nature of the synthesis of fatty acid chains for each lipopeptide family. This study focused on two B. subtilis strains cultivated in flasks. Optimized medium for lipopeptide production and Landymedium modified by replacing glutamic
acid with other α-amino acids were used. We found that the intensity of production of homologous compounds depends on the
strain and the culture medium. Analysis of these lipopeptides by high-performance liquid chromatography showed that the strain
B. subtilis NT02 yielded various homologous compounds when cultivated in Landy medium (L-Glu), but primarily one homologous product in
high relative amounts when cultivated in the optimized medium. Mass spectrometric analysis and determination of the amino
acid composition of this molecule enabled us to identify it as Bacillomycine L c15. 相似文献
9.
Tomasz Janek Eduardo J. Gudia Xymena Poomska Piotr Biniarz Dominika Jama Lígia R. Rodrigues Waldemar Rymowicz Zbigniew Lazar 《Molecules (Basel, Switzerland)》2021,26(12)
Most biosurfactants are obtained using costly culture media and purification processes, which limits their wider industrial use. Sustainability of their production processes can be achieved, in part, by using cheap substrates found among agricultural and food wastes or byproducts. In the present study, crude glycerol, a raw material obtained from several industrial processes, was evaluated as a potential low-cost carbon source to reduce the costs of surfactin production by Bacillus subtilis #309. The culture medium containing soap-derived waste glycerol led to the best surfactin production, reaching about 2.8 g/L. To the best of our knowledge, this is the first report describing surfactin production by B. subtilis using stearin and soap wastes as carbon sources. A complete chemical characterization of surfactin analogs produced from the different waste glycerol samples was performed by liquid chromatography–mass spectrometry (LC-MS) and Fourier transform infrared spectroscopy (FTIR). Furthermore, the surfactin produced in the study exhibited good stability in a wide range of pH, salinity and temperatures, suggesting its potential for several applications in biotechnology. 相似文献
10.
E. C. Azevedo E. M. Rios K. Fukushima G. M. Campos-Takaki 《Applied biochemistry and biotechnology》1993,42(1):1-7
A new strain ofBacillus subtilis C 126 was isolated from sugar cane fermentation and produced an antibiotic that inhibited the growth ofMicrococcus flavus. The production of the antibiotic in culture medium followed to extraction withn-butanol, thin layer chromatography, and microbiological tests indicated that a polypeptide antibiotic was produced. The fraction
obtained by Sephadex G-25 column and analyzed by HPLC indicated that bacitracin complex was produced. 相似文献
11.
Yujie Wang Lifang Ruan Wai-Hung Lo Hong Chua Hoi-Fu Yu 《Applied biochemistry and biotechnology》2006,132(1-3):1015-1022
Polyhydroxyalkanoates (PHAs) are polyesters of hydroxyalkanoates synthesized by numerous bacteria as intracellular carbon
and energy storage compounds and accumulated as granules in the cytoplasm of cells. In this work, we constructed two recombinant
plasmids, pBE2C1, and pBE2C1AB, containing one or two PHA synthse, genes, respectively. The two plasmids were inserted into
Bacillus subtilis DB104 to generate modified strains, B. subtilis/pBE2C1 and B. subtilis/pBE2C1AB. The two recombinants strains were subjected to fermentation and showed PHA accumulation, the first reported example
of mcl-PHA production in B. subtilis. Gas Chromatography analysis identified the compound produced by B. subtilis/pBE2C1 to be a hydroxydecanoate-co-hydroxydodecanoate (HD-co-HDD) polymer whereas that produced by B. subtilis/pBE2C1AB was a hydroxybutyrate-co-hydroxyde-canoate-co-hydroxydodecanoate (HB-HD-HDD) polymer. 相似文献
12.
Valeria F. Soares Leda R. Castilho Elba P. S. Bon Denise M. G. Freire 《Applied biochemistry and biotechnology》2005,121(1-3):311-319
A Bacillus subtilis isolate was shown to be able to produce extracellular protease in solid-state fermentations (SSF) using soy cake as culture
medium. A significant effect of inoculum concentration and physiological age on protease production was observed. Maximum
activities were obtained for inocula consisting of exponentially growing cells at inoculum concentrations in the range of
0.7–2.0 mg g−1. A comparative study on the influence of cultivation temperature and initial medium pH on protease production in SSF and
in submerged fermentation (SF) revealed that in SSF a broader pH range (5–10), but the same optimum temperature (37°C), is
obtained when compared to SF. A kinetic study showed that enzyme production is associated with bacterial growth and that enzyme
inactivation begins before biomass reaches a maximum level for both SF and SSF. Maximum protease activity and productivity
were 960 U g−1 and 15.4 U g−1 h−1 for SSF, and 12 U mL−1 and 1.3 U mL−1 h−1 for SF. When SSF protease activity was expressed by volume of enzyme extract, the enzyme level was 10-fold higher and the
enzyme productivity 45% higher than in SF. These results indicate that this bacterial strain shows a high biotechnological
potential for protease production in solid-state fermentation. 相似文献
13.
Penna Thereza Christina Vessoni Marques Marcelo Machoshvili Irena A. Ishii Marina 《Applied biochemistry and biotechnology》2002,98(1-9):539-551
Large-volume parenteral solutions were submitted to heat treatments after being inoculated with Bacillus stearothermophilus ATCC 7953 (T
r
=121°C) and Bacillus subtilis ATCC 9372 (T
r
=104.5°C) spores. The average decimal reduction time for B. stearothermophilus ranged from a D
121°C value of 1.31 to 3.14 min, in glucophysiologic and Ringer’s solutions respectively. For B. subtilis, D
104.5°C value increased from 0.69 to 1.37 min, in Ringer’s (pH=5.91) and 50% glucose (pH 3.05) solutions respectively. The z value ranged from 7.95°C (20% mannitol solution) to 13.14°C (50% glucose solution), corresponding to an activation energy
(Ea) of 81.48 and 49.30 kcal/mol, respectively. 相似文献
14.
The effect of the shear rate on pullulan production from beet molasses by Aureobasidium pullulans P56 in an airlift reactor was investigated. A maximum polysaccharide concentration (18.5 g/L), biomass dry weight (14.0 g/L),
polysaccharide yield (38.5%), and sugar utilization (96%) was achieved at a shear rate of 42 s−1. A. pullulans grown on beet molasses produced a mixture of pullulan and other polysaccharides. The highest value of pullulan proportion
(30% of total polysaccharide) was obtained at a low shear rate (42 s−1). The apparent viscosity of the fermentation broth increased as the shear rate increased up to 42 s−1 and then decreased. On the other hand, the dissolved oxygen concentration and the volumetric mass transfer coefficient increased
with the increase of the shear rate from 21 to 84 s−1. The external addition of L-glutamic acid, olive oil, and Tween-80 improved significantly the production of crude polysaccharide (27.0 g/L), but the
pullulan content of the polysaccharide was low (20%). 相似文献
15.
Oleinikova G. K. Kuznetsova T. A. Huth F. Laatsch H. Isakov V. V. Shevchenko L. S. Elyakov G. B. 《Russian Chemical Bulletin》2001,50(11):2231-2235
A mixture of cyclic lipopeptides with fungicidal activity was extracted from the sea isolate of the bacterium Bacillus subtilis (KMM 457). HPLC separation gave two main individual peptides of this mixture (M = 1030 and 1044 Da). According to amino acid analysis and 1H and 13C NMR data, they belong to iturin antibiotics and are cyclic systems composed of the same seven -amino acids (2 Asn, Glu, Tyr, Pro, Thr, and Ser) and one -amino acid (3-aminotetradecanoic or 3-amino-13-methyltetradecanoic acid, respectively). The sequence of amino acids in these peptides was determined for the first time using tandem electrospray ionization mass spectrometry. 相似文献
16.
Singh BR Dwivedi S Al-Khedhairy AA Musarrat J 《Colloids and surfaces. B, Biointerfaces》2011,85(2):128-213
In this study, a surfactin was extracted from a novel surfactant producing bacterial strain Bacillus amyloliquifaciens KSU-109, isolated from rhizosphere of date palm (Phoenix dactylifera), and characterized based on 16Sr RNA and sfp genes using Blastn, Blastx and phylogenetic analyses. The study was performed to obtain a renewable bioresource for surfactin production, and its application in nanotechnology as a non-hazardous and environmentally compatible nanoparticle (NP) stabilizer. The strain KSU-109 produced the surfactin with an average yield of 160 mg/L with strong surfactant activity, reducing the surface tension of the medium from 72 mN/m to 29.3 mN/m. The surfactin preparation was used for synthesizing the cadmium sulfide nanoparticles (CdS-NPs) by mixing 0.005% surfactin with 1mM Cd(NO(3))(2) in 1:1 ratio (v/v) and 10mM Na(2)S solution at pH 7.2 and ambient temperature, which were stable up to 120 days. The surfactin stabilized CdS-NPs were characterized using XRD, TEM, and spectroscopic techniques. The data revealed a significant role of surfactin as a stabilizer and capping agent, which also causes phase transition to yield the cubic/hexagonal CdS-NPs of average size of 3-4 nm. The results elucidated the significance of biocompatible and biodegradable surfactin as an effective and inexpensive stabilizing agent for developing stable CdS nanoparticles. 相似文献
17.
Ayse Gerze Didem Omay Yuksel Guvenilir 《Applied biochemistry and biotechnology》2005,121(1-3):335-345
Bacteria of genus Bacillus are active producers of extracellular proteases, and characteristics of enzyme production by Bacillus species have been well studied. The aim of this experimental study is isolation and partial purification of protease enzyme
from the Bacillus subtilis megatherium bacteria species. Protease enzyme is obtained by inducing spore genesis of bacteria from Bacillus species on suitable media. The partial purification was reali-zed by applying successively ammonium sulfate precipitation,
dialysis, DEAE-cellulose ion exchange chromatography to the supernatant. In this study, the effect of substrate concentration,
reaction time, the effect of inhibitor and activator on the optimum pH, optimum temperature, pH stability, and temperature
stability was determined. Molecular weight of the obtained enzyme was investigated by SDS-PAGE. In this study, the specific
activity of the supernatant, which was partially purified from Bacillus subtilis megatherium bacteria, was 10.4 U/mg, specific activity of supernatant was 13.5 U/mg after 80% ammonium sulfate fractionation. The final
enzyme preparation was 1.1-fold purer than the crude homogenate. Molecular weight of the protease was determined, and it was
found that the weight of enzyme was 45 kDa by using SDS-PAGE. 相似文献
18.
Summary The application of capillary zone electrophoresis to the study of interactions betweenBacillus subtilis tryptophanyl-tRNA synthetase (TrpRS) and tRNATrp is described. Significant changes in peak shape of tRNATrp incubated with TrpRS indicated the occurrence of interactions between TrpRS and tRNATrp in pH 8.0 Tris-HCl buffer containing 0.1 mmol L−1 EDTA and 1 mmol L−1−5 mmol L−1 mgCl2. Addition of Mg2+ decreased the electrophoretic mobility of tRNATrp, which illustrated that conformation of tRNATrp depended on Mg2+. The dissociation constant of the TrpRS-tRNATrp complex was estimated to be 0.63 μmol L−1 at 25°C in buffer solution. 相似文献
19.
Pinotti Laura M. Silva Rosineide G. Giordano Roberto C. Giordano Raquel L. C. 《Applied biochemistry and biotechnology》2002,98(1-9):679-686
This article reports studies concerning the production of penicillin G acylase (PGA) by Bacillus megaterium. This enzyme has industrial use in the hydrolysis of penicillin G to obtain 6-aminopenicillanic acid, an essential intermediate
for the production of semisynthetic β-lactam antibiotics. Although most microorganisms produce the enzyme intracellularly,
B. megaterium provides extracellular PGA. The enzyme production by microorganisms involves several steps, resulting in a many operational
variables to be studied. The study of the inoculum is an important step to be accomplished, before addressing other issues
such as culture optimization and downstream processing. In this study, using a standard inoculum as reference, several runs
were performed aiming at the definition of operational conditions in the PGA production. Cell concentration and PGA activity
in the production medium were measured after 24, 48, and 72 h of the beginning of the production phase. This study encompasses
the duration of the inoculum germination phase and the concentration of cells used to startup the germination. Based on these
results, PGA productivity during the production phase was maximized. The selected values for these variables were 1.5 × 107 spores/mL of germination medium, germination during 24 h, and 72 h for the production phase. 相似文献
20.
Lienhardt Jason Schripsema Justin Qureshi Nasib Blaschek Hans P. 《Applied biochemistry and biotechnology》2002,98(1-9):591-598
Acetone butanol ethanol was produced in a continuous immobilized cell (biofilm) plug-flow reactor inoculated with Clostridium beijerinckii BA101. To achieve high reactor productivity, C. beijerinckii BA101 cells were immobilized by adsorption onto clay brick. The continuous plug-flow reactor offers high productivities owing
to reduced butanol inhibition and increased cell concentration. Although high productivity was achieved, it was at the expense
of low sugar utilization (30.3%). To increase sugar utilization, the reactor effluent was recycled. However, this approach
is complicated by butanol toxicity. The effluent was recycled after removal of butanol by pervaporation to reduce butanol
toxicity in the reactor. Recycling of butanolfree effluent resulted in a sugar utilization of 100.7% in addition to high productivity
of 10.2g/(L·h) at a dilution rate of 1.5 h−1. A dilution rate of 2.0h−1 resulted in a reactor productivity of 16.2g/(L·h) and sugar utilization of 101.4%. It is anticipated that this reactor-recovery
system would be economical for butanol production when using C. beijerinckii BA101. 相似文献