共查询到20条相似文献,搜索用时 15 毫秒
1.
Hadeer Lazim Houda Mankai Nedra Slama Insaf Barkallah Ferid Limam 《Journal of industrial microbiology & biotechnology》2009,36(4):531-537
The purpose of the present research is to study the production of thermophilic alkaline protease by a local isolate, Streptomyces sp. CN902, under solid state fermentation (SSF). Optimum SSF parameters for enzyme production have been determined. Various
locally available agro-industrial residues have been screened individually or as mixtures for alkaline protease production
in SSF. The combination of wheat bran (WB) with chopped date stones (CDS) (5:5) proved to be an efficient mixture for protease
production as it gave the highest enzyme activity (90.50 U g−1) when compared to individual WB (74.50 U g−1) or CDS (69.50 U g−1) substrates. This mixed solid substrate was used for the production of protease from Streptomyces sp. CN902 under SSF. Maximal protease production (220.50 U g−1) was obtained with an initial moisture content of 60%, an inoculum level of 1 × 108 (spore g−1 substrate) when incubated at 45°C for 5 days. Supplementation of WB and CDS mixtures with yeast extract as a nitrogen source
further increased protease production to 245.50 U g−1 under SSF. Our data demonstrated the usefulness of solid-state fermentation in the production of alkaline protease using
WB and CDS mixtures as substrate. Moreover, this approach offered significant benefits due to abundant agro-industrial substrate
availability and cheaper cost. 相似文献
2.
Kameshnee Naidoo Manimaran Ayyachamy Kugen Permaul Suren Singh 《Bioprocess and biosystems engineering》2009,32(5):689-695
Xanthomonas campestris pv phaseoli produced an extracellular endoinulinase (9.24 ± 0.03 U mL−1) in an optimized medium comprising of 3% sucrose and 2.5% tryptone. X. campestris pv. phaseoli was further subjected to ethylmethanesulfonate mutagenesis and the resulting mutant, X. campestris pv. phaseoli KM 24 demonstrated inulinase production of 22.09 ± 0.03 U mL−1 after 18 h, which was 2.4-fold higher than that of the wild type. Inulinase production by this mutant was scaled up using
sucrose as a carbon source in a 5-L fermenter yielding maximum volumetric (21,865 U L−1 h−1) and specific (119,025 U g−1 h−1) productivities of inulinase after 18 h with an inulinase/invertase ratio of 2.6. A maximum FOS production of 11.9 g L−1 h−1 and specific productivity of 72 g g−1 h−1 FOS from inulin were observed in a fermenter, when the mutant was grown on medium containing 3% inulin and 2.5% tryptone.
The detection of mono- and oligosaccharides in inulin hydrolysates by TLC analysis indicated the presence of an endoinulinase.
This mutant has potential for large-scale production of inulinase and fructooligosaccharides. 相似文献
3.
Vladimir Elisashvili Eva Kachlishvili Nino Tsiklauri Eka Metreveli Tamar Khardziani Spiros N. Agathos 《World journal of microbiology & biotechnology》2009,25(2):331-339
The production of lignocellulolytic enzymes by eleven basidiomycetes species isolated from two ecosystems of Georgia was investigated
for the first time under submerged (SF) and solid-state fermentation (SSF) of lignocellulosic by-products. Notable intergeneric
and intrageneric differences were revealed with regard to the extent of hydrolase and oxidase activity. Several fungi produced
laccase along with hydrolases in parallel with growth during the trophophase, showing that the synthesis of this enzyme is
not connected with secondary metabolism. The lignocellulosic substrate type had the greatest impact on enzyme secretion. Some
of the substrates significantly stimulated lignocellulolytic enzyme synthesis without supplementation of the culture medium
with specific inducers. Exceptionally high carboxymethyl cellulase (CMCase, 122 U ml−1) and xylanase (195 U ml−1) activities were revealed in SF of mandarin peelings by Pseudotremella gibbosa IBB 22 and of residue after ethanol production (REP) by Fomes fomentarius IBB 38, respectively. The SSF of REP by T. pubescens IBB 11 ensured the highest level of laccase activity (24,690 U l−1), whereas the SSF of wheat bran and SF of mandarin peels provided the highest manganese peroxidase activity (570–620 U l−1) of Trichaptum biforme IBB 117. Moreover, the variation of lignocellulosic growth substrate provides an opportunity to obtain enzyme preparations
containing different ratios of individual enzymes. 相似文献
4.
An artificial fusion protein of Arthrobacter oxydans dextranase and Klebsiella pneumoniae α-amylase was constructed and expressed in Escherichia coli. Most of the expressed protein existed as an insoluble fraction, which was solubilized with urea. The purified fusion enzyme
electrophoretically migrated as a single protein band; M = 137 kDa, and exhibited activities of both dextranase (10.8 U mg−1) and amylase (7.1 U mg−1), which were lower than that of reference dextranase (13.3 U mg−1) and α-amylase (103 U mg−1). The fusion enzyme displayed bifunctional enzyme activity at pH 5–7 at 37°C. These attributes potentially make the fusion
enzyme more convenient for use in sugar processing than a two-enzyme system. 相似文献
5.
Claucia Fernanda Volken de Souza Júlio Xandro Heck Marco Antônio Záchia Ayub 《Journal of industrial microbiology & biotechnology》2008,35(12):1677-1685
In this work, we investigated the production of transglutaminase (TGase) by an Amazonian isolated strain of Bacillus circulans by solid-state cultivation (SSC). Several agro-industrial residues, such as untreated corn grits, milled brewers rice, industrial
fibrous soy residue, soy hull, and malt bagasse, were used as substrates for microbial growth and enzyme production. Growth
on industrial fibrous soy residue, which is rich in protein and hemicellulose, produced the highest TGase activity (0.74 U g−1 of dried substrate after 48 h of incubation). A 23 central composite design was applied to determine the optimal conditions of aeration, cultivation temperature and inoculum
cell concentration to TGase production. The best culture conditions were determined as being 0.6 L air min−1, 33 °C and 10 log 10 CFU g−1 of dried substrate, respectively. Under the proposed optimized conditions, the model predicted an enzyme production of 1.16 U g−1 of dried substrate, closely matching the experimental activity of 1.25 U g−1. Results presented in this work point to the use of this newly isolated B. circulans strain as a potential alternative of microbial source for TGase production by SSC, using inexpensive culture media. 相似文献
6.
Christiane Liers Caroline Bobeth Marek Pecyna René Ullrich Martin Hofrichter 《Applied microbiology and biotechnology》2010,85(6):1869-1879
The jelly fungus Auricularia auricula-judae produced an enzyme with manganese-independent peroxidase activity during growth on beech wood (∼300 U l−1). The same enzymatic activity was detected and produced at larger scale in agitated cultures comprising of liquid, plant-based
media (e.g. tomato juice suspensions) at levels up to 8,000 U l−1. Two pure peroxidase forms (A. auricula-judae peroxidase (AjP I and AjP II) could be obtained from respective culture liquids by three chromatographic steps. Spectroscopic
and electrophoretic analyses of the purified proteins revealed their heme and peroxidase nature. The N-terminal amino acid
sequence of AjP matched well with sequences of fungal enzymes known as “dye-decolorizing peroxidases”. Homology was found
to the N-termini of peroxidases from Marasmius scorodonius (up to 86%), Thanatephorus cucumeris (60%), and Termitomyces albuminosus (60%). Both enzyme forms catalyzed not only the conversion of typical peroxidase substrates such as 2,6-dimethoxyphenol and
2,2′-azino-bis(3-ethylthiazoline-6-sulfonate) but also the decolorization of the high-redox potential dyes Reactive Blue 5
and Reactive Black 5, whereas manganese(II) ions (Mn2+) were not oxidized. Most remarkable, however, is the finding that both AjPs oxidized nonphenolic lignin model compounds (veratryl
alcohol; adlerol, a nonphenolic β-O-4 lignin model dimer) at low pH (maximum activity at pH 1.4), which indicates a certain ligninolytic activity of dye-decolorizing
peroxidases. 相似文献
7.
Growth and sporulation of Verticillium lecanii on inert and organic carriers (sugar-cane bagasse, corncob, rice straw, polyurethane foam and activated carbon) in a solid-state
fermentation process was studied. Sugar-cane bagasse and polyurethane foam produced 1010 spores g−1 dry carrier whereas corncob, rice straw, and activated carbon yielded, respectively 8 × 109, 4 × 109, and 3 × 108 spores g−1. Chitinase activity of the conidia was in the following order: sugar-cane bagasse (3.3 U mg−1) > wheat bran (3.0 U mg−1) > polyurethane foam (2.7 U mg−1). There was no significant difference (2.5–2.7 U mg−1) in the proteinase activity among the conidia from the three cultures. Scanning electron microscopy shows that aerial mycelium
freely penetrated into the internal area of polyurethane foam. Sugar-cane bagasse provided enough area for vegetative hyphae
to attach. Of the carriers analyzed, polyurethane foams and sugar-cane bagasse were the best carriers for V. lecanii growth and spore production. 相似文献
8.
Ya-Ping Xue Sai-Zhen Xu Zhi-Qiang Liu Yu-Guo Zheng Yin-Chu Shen 《Journal of industrial microbiology & biotechnology》2011,38(2):337-345
(R)-(−)-Mandelic acid (R-MA) is an important intermediate with broad uses. Recently, R-MA production using nitrilase has been gaining more and more attention due to its higher productivity and enantioselectivity.
In this work, a new bacterium WT10, which exhibited favorable nitrilase activity and excellent enantioselectivity for production
of R-MA by enantioselective biocatalytic hydrolysis of (R,S)-mandelonitrile, was isolated and identified as a strain of Alcaligenes faecalis. In order to improve its nitrilase activity for industrial application, the wild-type strain WT10 was further subjected to
mutagenesis using a combined LiCl–ultraviolet irradiation and low energy N+ ion beams implantation technique. A valuable mutant strain A. faecalis ZJUTB10 was obtained. The nitrilase specific activity of the mutant strain was greatly improved up to 350.8 U g−1, in comparison with wild-type strain WT10 of 53.09 U g−1. The reaction conditions for R-MA production by mutant strain A. faecalis ZJUTB10 were also optimized. Nitrilase activity in mutant strain showed a broad pH optimum at pH 7.7–8.5. The optimal temperature
was 35°C. The highest production rate reached 9.3 mmol h−1 g−1. The results showed that mutant strain A. faecalis ZJUTB10 was a new candidate for efficient R-MA production from (R,S)-mandelonitrile and could potentially be used in industrial production. 相似文献
9.
In vitro transgenic hairy root cultures provide a rapid system for physiological, biochemical studies and screening of plants
for their phytoremediation potential. The hairy root cultures of Brassica juncea L. showed 92% decolorization of Methyl orange within 4 days. Out of the different redox mediators that were used to achieve
enhanced decolorization, 2, 2′-Azinobis, 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) was found to be the most efficient.
Laccase activity of 4.5 U mg−1 of protein was observed in hairy root cultures of Brassica juncea L., after the decolorization of Methyl orange. Intracellular laccase produced by B. juncea root cultures grown in MS basal medium was purified up to 2.0 fold with 6.62 U mg−1 specific activity using anion-exchange chromatography. Molecular weight of the purified laccase was estimated to be 148 kDa
by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The purified enzyme efficiently oxidized ABTS which was also
required for oxidation of the other tested substrates. The pH and temperature optimum for laccase activity were 4.0 and 40°C,
respectively. The purified enzyme was stable up to 50°C and was stable in the pH range of 4.0–6.0. Laccase activity was strongly
inhibited by sodium azide, EDTA, dithiothreitol and l-cysteine. The purified enzyme decolorized various textile dyes in the presence of ABTS as an efficient redox mediator. These
findings contribute to a better understanding of the enzymatic process involved in phytoremediation of textile dyes by using
hairy roots. 相似文献
10.
Effect of growth substrate,method of fermentation,and nitrogen source on lignocellulose-degrading enzymes production by white-rot basidiomycetes 总被引:2,自引:0,他引:2
Elisashvili V Kachlishvili E Penninckx M 《Journal of industrial microbiology & biotechnology》2008,35(11):1531-1538
The exploration of seven physiologically different white rot fungi potential to produce cellulase, xylanase, laccase, and
manganese peroxidase (MnP) showed that the enzyme yield and their ratio in enzyme preparations significantly depends on the
fungus species, lignocellulosic growth substrate, and cultivation method. The fruit residues were appropriate growth substrates
for the production of hydrolytic enzymes and laccase. The highest endoglucanase (111 U ml−1) and xylanase (135 U ml−1) activities were revealed in submerged fermentation (SF) of banana peels by Pycnoporus coccineus. In the same cultivation conditions Cerrena maxima accumulated the highest level of laccase activity (7,620 U l−1). The lignified materials (wheat straw and tree leaves) appeared to be appropriate for the MnP secretion by majority basidiomycetes.
With few exceptions, SF favored to hydrolases and laccase production by fungi tested whereas SSF was appropriate for the MnP
accumulation. Thus, the Coriolopsis polyzona hydrolases activity increased more than threefold, while laccase yield increased 15-fold when tree leaves were undergone
to SF instead SSF. The supplementation of nitrogen to the control medium seemed to have a negative effect on all enzyme production
in SSF of wheat straw and tree leaves by Pleurotus ostreatus. In SF peptone and ammonium containing salts significantly increased C. polyzona and Trametes versicolor hydrolases and laccase yields. However, in most cases the supplementation of media with additional nitrogen lowered the fungi
specific enzyme activities. Especially strong repression of T. versicolor MnP production was revealed. 相似文献
11.
White-rot fungi are extensively used in various submerged biotechnology processes to produce ligninolytic enzymes. Transfer
of the process from the laboratory to the industrial level requires optimization of the cultivation conditions on the laboratory
scale. An interesting area of optimization is pellet growth since this morphological form solves problems such as the decreased
oxygen concentration, limited heat, and nutrient transport, which usually occur in dispersed mycelium cultures. Many submerged
fermentations with basidiomycetes in pellet form were done with Phanerochaete, Trametes, and Bjerkandera species, among others. In our study, another promising basidiomycete, D. squalens, was used for ligninolytic enzyme production. With the addition of wood particles (sawdust) as a natural inducer and optimization
of mixing and aeration conditions in laboratory stirred tank (STR) and bubble column (BCR) reactors on pellet growth and morphology,
the secretion of laccase and the manganese-dependent peroxidase into the medium was substantially enhanced. The maximum mean
pellet radius was achieved after 10 days in the BCR (5.1 mm) where pellets were fluffy and 5 days in the STR (3.5 mm) where
they were round and smooth. The maximum Lac activity (1,882 U l−1) was obtained after 12 days in the STR, while maximum MnP activity (449.8 U l−1) occurred after 18 days in the BCR. The pellet size and morphology depended on the agitation and aeration conditions and
consequently influenced a particular enzyme synthesis. The enzyme activities were high and comparable with the activities
found for other investigations in reactors with basidiomycetes in the form of pellets. 相似文献
12.
13.
Sharma Sampriya Mandhan Rishi Pal Sharma Jitender 《World journal of microbiology & biotechnology》2011,27(11):2697-2701
A cellulase free, alkaline, thermo-tolerant pectinase was produced by a novel yeast strain Pseudozyma sp. SPJ using citrus peel as inexpensive carbon source. The crude enzyme showed good prospects in degumming of flax fibers
for textile industry. An optimum pectinase dose of 80 U g−1 resulted in reduction of 15 ± 1.92% dry weight of the fibers, releasing maximum galacturonic acid (10825.5 ± 34.2 μg g−1 dry fiber) after the incubation of 6 h. The yeast culture could grow on the flax fibers (as sole carbon source) without addition
of any other nutrient and produce good enzyme yield (9235.5 ± 21.51 U g−1 dry fiber). After 12 h incubation of the fibers with the isolated yeast strain, 4471 ± 19.5 μg g−1 dry fiber galacturonic acid was achieved with maximum weight loss of 11 ± 1.2%. This process reduced the amount of chemicals
and energy used in conventional methods. It also contributed to enhance fineness and overall quality of the fiber strands.
This study is relevant to the textile industry as it provided a fast, economical and eco-friendly method for degumming of
flax fibers. 相似文献
14.
Reddampalli V. Sreedhar Lakshmanan Venkatachalam Bhagyalakshmi Neelwarne 《Journal of Plant Growth Regulation》2009,28(1):46-57
Shoot cultures of vanilla (Vanilla planifolia) showed a progressive change toward hyperhydricity syndrome (HHS) leading to the necrosis of shoot buds when transferred
to liquid medium of shake-flask type from solid (gelled) medium (S). HHS was also associated with severe damage at cellular
and subcellular levels, an increase in free polyamines (PAs) and accumulation of water, a decrease in quantities of chlorophyll
and protein, and drastic changes in reducing and nonreducing sugars. Spermine was by far the major polyamine in all the analyzed
cultures. The progression toward and onset of HHS showed higher activities of antioxidant enzymes, indicative of the shoots’
defensive efforts against oxidative stress. The specific enzyme activities of normal and H2 stages were 342.6 and 350.35 U mg−1 protein for peroxidase (POD, EC 1.11.1.11), 38.4 and 30.38 U mg−1 protein for superoxide dismutase (SOD, EC 1.15.1.1), and 71.3 and 82.75 U mg−1 protein for catalase (CAT, EC 1.11.1.6), respectively. The kinetic parameters of the culture medium suggested that nutrient
utilization was normal in HHS and that the severe biochemical alterations and cellular damage were mainly due to oxidative
stress. 相似文献
15.
α-Amylase activities of Aspergillus oryzae grown on dextrin or indigestible dextrin were 7·8 and 27·7 U ml−1, respectively. Glucoamylase activities of the cultures grown on dextrin or indigestible dextrin were 5·4 and 301 mU ml−1, respectively. The specific glucoamylase production rate in indigestible dextrin batch culture reached 1·35 U g DW−1 h−1. In contrast, biomass concentration of A. oryzae in indigestible dextrin culture was 35% of that in dextrin culture. Thus, the culture method using indigestible dextrin has
the potential to improve amylolytic enzyme production and fungal fermentation broth rheology. 相似文献
16.
M. Bustamante M. E. González A. Cartes M. C. Diez 《Journal of industrial microbiology & biotechnology》2011,38(1):189-197
The present work optimized the initial pH of the medium and the incubation temperature for ligninolytic enzymes produced by
the white-rot fungus Anthracophyllum discolor. Additionally, the effect of soya lecithin on mycelial growth and the production of ligninolytic enzymes in static batch
cultures were evaluated. The critical micelle concentration of soya lecithin was also studied by conductivity. The effects
of the initial pH (3, 4, and 5) and incubation temperature (20, 25, and 30°C) on different enzymatic activities revealed that
the optimum conditions to maximize ligninolytic activity were 26°C and pH 5.5 for laccase and manganese peroxidase (MnP) and
30°C and pH 5.5 for manganese-independent peroxidase (MiP). Under these culture conditions, the maximum enzyme production
was 10.16, 484.46, and 112.50 U L−1 for laccase, MnP, and manganese-independent peroxidase MiP, respectively. During the study of the effect of soya lecithin
on A. discolor, we found that the increase in soya lecithin concentration from 0 to 10 g L−1 caused an increase in mycelial growth. On the other hand, in the presence of soya lecithin, A. discolor produced mainly MnP, which reached a maximum concentration of 30.64 ± 4.61 U L−1 after 25 days of incubation with 1 g L−1 of the surfactant. The other enzymes were produced but to a lesser extent. The enzymatic activity of A. discolor was decreased when Tween 80 was used as a surfactant. The critical micelle concentration of soya lecithin calculated in our
study was 0.61 g L−1. 相似文献
17.
Hong Lu Jiti Zhou Jing Wang Guangfei Liu Lihong Zhao 《World journal of microbiology & biotechnology》2008,24(7):1147-1152
Sphingomonas xenophaga QYY from sludge samples could effectively decolorize 1-aminoanthraquinone-2-sulfonic acid (ASA-2), one kind of anthraquinone
dye intermediate, under aerobic conditions. More than 98% of ASA-2 could be removed within 120 h at the dye concentration
from 200 mg l−1 to 1,000 mg l−1 due to oxidative degradation. The strain converted ASA-2 to 2-(2′-hydroxy-3′-amino-4′-sulfo-benzoyl)-benzoic acid, 2-(2′-amino-3′-sulfo-6′-hydroxy-benzoyl)-benzoic
acid, o-phthalic acid and 2-amino-3-hydroxy-benzenesulfonic acid, which were identified using HPLC-MS and NMR. A possible
initial decolorization pathway was proposed according to these metabolites. The decolorization of ASA-2 by cells in the basal
salt medium was induced by ASA-2, and was due to soluble cytosolic enzymes. Combined initial decolorization pathway and the
analysis of decolorization enzyme(s), the major enzyme responsible for ASA-2 decolorization was a NADH-dependent oxygenase. 相似文献
18.
Mahesh Chandra Alok Kalra Pradeep K. Sharma Rajender S. Sangwan 《Journal of industrial microbiology & biotechnology》2009,36(4):605-609
Capabilities of cellulase production, using delignified bioprocessings of medicinal and aromatic plants, viz. citronella (Cymbopogon winterianus) and Artemisia annua (known as marc of Artemisia) and garden waste (chiefly containing Cynodon dactylon), by the six species of Trichoderma were comparatively evaluated. Among the members of Trichoderma studied, T. citrinoviride was found to be the most efficient producer of cellulases along with a high level of β- glucosidase (produced 102.4 IU g−1 on marc of Artemisia; 101.33 IU g−1 on garden waste; 81.86 IU g−1 on distillation waste of citronella and 94.77 IU g−1 on pure cellulose). Although T. virens was noticed to be the minimal enzyme producer fungus, it interestingly could not produce complete cellulase enzyme complex
on any test waste or pure cellulose, except on marc of Artemisia, where it produced all three enzymes of the complex. Immediate reduction in pH was also noticed during fermentation in the
case of pure polymer (cellulose) by all tested fungi, while it was delayed with delignified agrowastes. The pH profile varied
with the substrate used as well as with individual species of Trichoderma. On the other hand, no alteration in pH with any species of Trichoderma was noticed when grown on marc of A. annua, which might be due to the buffering capacity of this marc. 相似文献
19.
Arsenic content of cyanobacterial biomass, soil and water samples from arsenic-contaminated area of eastern India were estimated.
It was found that arsenic content in cyanobacterial biomass (276.9 μg g−1) was more than soil (19.01 μg g−1) or water sample (244.13 μg L−1). Shallow tube well water showed more arsenic (244.13 μg L−1) than deep tube well water (146.13 μg L−1). Arsenic resistant genera recorded from the contaminated area were Oscillatoria princeps, Oscillatoria limosa, Anabaena sp. and Phormidium laminosum. Among these, P. laminosum was isolated and exposed to different concentration of Arsenic in vitro (0.1–100 ppm) to study the toxicity level of arsenic.
Modulation in stress enzymes and stress-related compounds were studied in relation to lipid peroxidase, catalase, super oxide
dismutase (SOD), ascorbate peroxidase (APX), reduced glutathione and carotenoids in arsenic exposed biomass to understand
the resistance mechanism of the genus both in laboratory condition as well as in natural condition. Arsenic content of cyanobacterial
biomass from contaminated area was more (276.9 μg g−1) than laboratory exposed sample (37.17 μg g−1), indicating bioconcentration of arsenic in long-term-exposed natural biomass. Overall, more activity of catalase was recorded
in cyanobacterial biomass of natural condition whereas SOD and APX were at higher level in laboratory culture. 相似文献
20.
Sharma NN Sharma M Bhalla TC 《Journal of industrial microbiology & biotechnology》2011,38(9):1235-1243
Nitrilase of Nocardia globerula NHB-2 was induced by short-chain aliphatic nitriles (valeronitrile > isobutyronitrile > butyronitrile > propionitrile) and
exhibited activity towards aromatic nitriles (benzonitrile > 3-cyanopyridine > 4-cyanopyridine > m-tolunitrile > p-tolunitrile). Hyperinduction of nitrilase (6.67 U mgDCW−1, 18.7 U mL−1) was achieved in short incubation time (30 h, 30°C) through multiple feeding of isobutyronitrile in the growth medium. The
nitrilase of this organism exhibits both substrate and product inhibition effects. In a fed batch reaction at 1 L scale using
hyperinduced resting cells corresponding to 10 U mL−1 nitrilase activity (1.5 mgDCW mL−1), a total of 123.11 g nicotinic acid was produced at a rate of 24 g h−1 gDCW−1. 相似文献