共查询到20条相似文献,搜索用时 781 毫秒
1.
Ashwani Sanghi Neelam Garg Jitender Sharma Kalika Kuhar Ramesh C. Kuhad Vijay K. Gupta 《World journal of microbiology & biotechnology》2008,24(5):633-640
Alkalophilic Bacillus subtilis ASH produced high levels of xylanase using easily available inexpensive agricultural waste residues such as wheat bran, wheat
straw, rice husk, sawdust, gram bran, groundnut and maize bran in solid-state fermentation (SSF). Among these, wheat bran
was found to be best substrate. Xylanase production was highest after 72 h of incubation at 37 °C and at a substrate to moisture
ratio of 1:2 (w/v). The inoculum level of 15% resulted in maximum production of xylanase. The enzyme production was stimulated
by the addition of nutrients such as yeast extract, peptone and beef extract. In contrast, addition of glucose and xylose
repressed the production of xylanase. The extent of repression by glucose (10%, w/v) was 81% and it was concentration-dependent.
Supplementation of the medium with 4% xylose caused 59% repression. Under optimized conditions, xylanase production in SSF
(8,964 U of xylanase/g dry wheat bran) was about twofold greater than in submerged fermentation. Thus, B. subtilis produced a very high level of xylanase in SSF using inexpensive agro-residues, a level which is much higher than that reported
by any other bacterial isolate. Furthermore, the enzyme was produced at room temperature and with tap water without the addition
of any mineral salt in SSF, leading to a marked decrease in the cost of xylanase production, which enhances its industrial
potential. 相似文献
2.
Prof. Zübeyde Baysal Fikret Uyar Mehmet Doğru Hüseyin Alkan 《Preparative biochemistry & biotechnology》2013,43(2):184-190
Abstract Production of alkaline α‐amylase employing our laboratory isolate, Bacillus sp., under solid state fermentation, was optimized. The effect of wheat bran and lentil husk was examined. Lentil husk exhibited the highest enzyme production. The appropriate incubation time, inoculum size, moisture level, and buffer solution level were determined. Maximum yields of 216,000 and 172,800 U/g were achieved by employing lentil husk and wheat bran as substrates in 0.1 M carbonate/bicarbonate buffer at pH 10.0 with 30% initial moisture level at 24 h. Inoculum size and buffer solution level were found to be 20% and 1:0.5 for two solid substrates. 相似文献
3.
Dasagrandhi Chakradhar Saleem Javeed Avinash P. Sattur 《Journal of industrial microbiology & biotechnology》2009,36(9):1179-1187
Nigerloxin, a new and potent lipoxygenase inhibitor, was discovered in our laboratory through solid-state fermentation of
wheat bran by Aspergillus niger V. Teigh (MTCC-5166). The aim of this study is to investigate the possibility of using different agro-industrial residues
as nutritional supplements along with wheat bran to enhance the production of nigerloxin. Nigerloxin produced by SSF was quantified
spectrophotometrically at 292 nm. The results indicate that the inhibitor production was influenced by the type of solid substrate
supplemented, moisture content, pH and size of the inoculum. Individually optimized supplements were tested in different combinations
to determine their effects on nigerloxin production. A twofold increase in the production of nigerloxin (4.9 ± 0.3 mg gds−1) was achieved by supplementing wheat bran with 10% w/w sweet lemon peel and 5% v/w methanol at optimized process parameters,
that is, an initial moisture content of 65% v/w and incubation period of 6 days with an initial inoculum size of 2 ml (8 × 105 spores gds−1). Nigerloxin production was stable between pH of 4 and 5. 相似文献
4.
N. Dahiya R. Tewari R. P. Tiwari G. S. Hoondal 《World journal of microbiology & biotechnology》2005,21(8-9):1611-1616
Summary In this study flake chitin, crab shell chitin, mushroom stalk, fungal cell wall, wheat bran and rice bran were used as substrate
for chitinase production by Enterobacter sp. NRG4 under submerged and solid state fermentation (SSF) conditions. Enterobacter sp. NRG4 produced 72 and 49.7 U/ml of chitinase in presence of cell walls of Candida albicans and Fusarium moniliforme in submerged fermentation. Under SSF, maximum chitinase production was 965 U/g solid substrate with flake chitin and wheat
bran (1:3 ratio) at 75% moisture level after 144 h. The purified chitinase inhibited hyphal extension of Fusarium moniliforme, Aspergillus niger, Mucor rouxi and Rhizopus nigricans. The chitinase was effective in release of protoplasts from Trichoderma ressei, Pleurotus florida, Agaricus bisporus and Aspergillus niger. Protoplasts yield was maximum with 60 mg of 24 h old fungal mycelium incubated with 60 U of chitinase and 60 U of cellulase. 相似文献
5.
Evaluation of solid substrates for enzyme production by Coriolus versicolor, for use in bioremediation of chlorophenols in aqueous effluents 总被引:1,自引:0,他引:1
In the development of a system for the removal of chlorophenols from aqueous effluents, a range of solid substrates for the
growth of Coriolus versicolor were investigated. Substrates included wood chips, cereal grain, wheat husk and wheat bran. Suitability for transformation
of chlorophenols depended on laccase production by the fungus. The greatest amount of laccase (<25 Units g−1 substrate) was produced on wheat husk and wheat bran over 30 days colonisation. Aqueous extracts of laccase from wheat husk
and wheat bran cultures removed 100% of 2,4-dichlorophenol (50 ppm) from solution within 5 h and 75–80% of pentachlorophenol
(50 ppm) within 24 h. Wheat bran was formulated into pellets with biscuit flour to provide a compact substrate for fungal
immobilisation. Addition of 8–12% yeast extract to the pellets increased laccase production five-fold. Colonised pellets were
added to chlorophenol solutions in 200–4000-ml bioreactors, resulting in >90% removal of chlorophenols within 100 min.
Received: 10 April 2000 / Received revision: 4 July 2000 / Accepted: 10 July 2000 相似文献
6.
Production of alkaline alpha-amylase employing our laboratory isolate, Bacillus sp., under solid state fermentation, was optimized. The effect of wheat bran and lentil husk was examined. Lentil husk exhibited the highest enzyme production. The appropriate incubation time, inoculum size, moisture level, and buffer solution level were determined. Maximum yields of 216,000 and 172,800 U/g were achieved by employing lentil husk and wheat bran as substrates in 0.1 M carbonate/bicarbonate buffer at pH 10.0 with 30% initial moisture level at 24 h. Inoculum size and buffer solution level were found to be 20% and 1:0.5 for two solid substrates. 相似文献
7.
Gupta Saurabh Kuhad R.C. Bhushan Bharat Hoondal G.S. 《World journal of microbiology & biotechnology》2001,17(1):5-8
The production of an alkali-stable xylanase, with dual pH optima, from haloalkalophilic Staphylococcus sp. SG-13 has been enhanced using agro-residues in submerged fermentation and a biphasic growth system. The agro-residues such as wheat bran, sugarcane bagasse, corncobs and poplar wood when used as sole carbon source, improved the xylanase yield by five-fold as compared to xylose and xylan. Staphylococcus sp. SG-13 also produced equally good amounts of xylanase when grown simply in deionized water (pH 8.0) supplemented with agro-residues as sole carbon source. In the biphasic growth system (lower layer containing agricultural residue set in agar medium with liquid medium above it), the prime substrate, wheat bran (1% w/v), resulted in maximum xylanase production of 4525 U l–1 (pH 7.5) and 4540 U l–1 (pH 9.2) at an agar: broth ratio of 4.0 after 48 h of incubation at 37 °C under static conditions. In general, the cost-effective agro-residues were found to be more suitable inducers for xylanase production over expensive substrates like xylan. 相似文献
8.
The optimization of process parameters for high inulinase production by the marine yeast strain Cryptococcus aureus G7a in solid-state fermentation (SSF) was carried out using central composite design (CCD), one of the response surface methodologies
(RSMs). We found that moisture, inoculation size, the amount ratio of wheat bran to rice husk, temperature and pH had great
influence on inulinase production by strain G7a. Therefore, the CCD was used to evaluate the influence of the five factors
on the inulinase production by strain G7a. Then, five levels of the five factors above were further optimized using the CCD.
Finally, the optimal parameters obtained with the RSM were the initial moisture 61.5%, inoculum 2.75%, the amount ratio of
wheat bran to rice husk 0.42, temperature 29 °C, pH 5.5. Under the optimized conditions, 420.9 U g−1 of dry substrate of inulinase activity was reached in the solid-state fermentation culture of strain G7a within 120 h whereas
the predicted maximum inulinase activity of 436.2 U g−1 of inulinase activity of 436.2 U g−1 of dry weight was derived from the RSM regression. This is the highest inulinase activity produced by the yeast strain reported
so far. A large amount of monosaccharides and oligosaccharides were detected after inulin hydrolysis by the crude inulinase. 相似文献
9.
Production of alkaline protease employing the laboratory isolate, Bacillus sp. under solid state fermentation (SSF) was optimized. The effect of wheat bran and lentil husk was examined. Wheat bran showed highest enzyme production. The appropriate incubation time, inoculum size, moisture level and buffer solution level were determined. Maximum yields of 429.041 and 168.640 U g−1 were achieved by employing wheat bran and lentil husk as substrates in 0.1 M carbonate/bicarbonate buffer at pH 10 with 30 and 40% initial moisture level at 24 h. Inoculum size and buffer solution level were found to be 20 and 25% and 0.5:1 for wheat bran and lentil husk, respectively. 相似文献
10.
Aims: Utilization of cheap and readily available agricultural residues as cheap carbon sources for poly(3‐hydroxybutyrate) (PHB) production by Halomonas boliviensis. Methods and Results: Wheat bran was hydrolysed by a crude enzyme preparation from Aspergillus oryzae NM1 to provide a mixture of reducing sugars composed mainly of glucose, mannose, xylose and arabinose. Growth of H. boliviensis using a mixture of glucose (0·75% w/v) and xylose (0·25% w/v) in the medium led to a PHB content and concentration of 45 wt% and 1 g l?1, respectively, after 30 h. A similar PHB concentration was attained when H. boliviensis was grown on wheat bran hydrolysate but with a lower PHB content, 34 wt%. In a batch cultivation mode in a fermentor, using 1·8% (w/v) reducing sugars, the maximum PHB accumulation by H. boliviensis was attained in 20 h, but was reduced to about 30 wt%. By adding butyric acid (0·8% v/v), sodium acetate (0·8% w/v) and decreasing the reducing sugars concentration to 1·0% w/v in the medium, PHB accumulation and concentration were increased to 50 wt% and 4 g l?1, respectively, after 20 h. Butyric acid and sodium acetate for PHB production could also be provided by anaerobic digestion of solid potato waste. Conclusions: Cheap and readily available agricultural residues can be used as substrates to produce PHB. The production of PHB by H. boliviensis using wheat bran hydrolysate as source of carbon is expected to reduce the production cost and motivates further studies. Significance and Impact of the Study: Large‐scale commercial utilization of PHB is mainly hampered by its high production cost. Carbon source for PHB production accounts up to 50% of the total production costs. Thus, the use of waste agricultural residues can substantially reduce the substrate cost (and in turn even provide value to the waste), and can downsize the production costs. This improves the market competitiveness. Studies on PHB production by moderate halophiles were recently initiated with H. boliviensis and findings show that it has potential for commercial exploitation. PHB production by H. boliviensis using wheat bran and potato waste is hence interesting. 相似文献
11.
The present work was aimed to investigate the impact of the solid substrates mixture on Fructosyltransferases (FTase) and Fructo-oligosaccharides (FOS) production. An augmented simplex lattice design was used to optimize a three component mixture for FTase production. Among selected substrates corn cobs has highest impact on FTase production followed by wheat bran and rice bran. All two substrates and three substrate combinations showed the highest enzyme production than their individual levels. Among the tested various models quadratic model was found to be the best suitable model to explain mixture design. Corncobs, wheat bran and rice bran in a ratio of approximately 45:29:26 is best suitable for the FTase production by isolated Aspergillus awamori GHRTS. This study signifies mixture design could be effective utilize for selection of best combination of multi substrate for improved production of high value products under solid state fermentation. 相似文献
12.
Bacillus halodurans was cultivated on wheat bran as a solid-state substrate and produced haloduracin, a bacteriocin, at about 245 AU per wheat
bran. Supplementation of the bran with Lauria-Bertani broth decreased haloduracin production. However, production was stimulated by addition of Mg2SO4 and K2HPO4. The highest production was achieved at a wheat bran/moisture ratio of 1:1.8 and in the presence of 10% (w/w) Na2CO3. Under optimum conditions, the organism produced about 3,000 AU per gram dry bran. 相似文献
13.
Yin Li Zhiqiang Liu Fengjie Cui Yingying Xu Hui Zhao 《World journal of microbiology & biotechnology》2007,23(6):837-843
A new strain of Penicillium sp. ZH-30 that produces xylanase was isolated from soil. According to the morphology and comparison of internal transcribed
spacer (ITS) rDNA gene sequence, the strain Penicillium sp. ZH-30 was identified as a strain of Penicillium oxalicum. When xylan or wheat bran was used as substrate at 30°C for 3 days under submerged cultivation, xylanase production was 5.3
and 13.3 U ml−1, respectively. The temperature and pH for optimum activity were 50°C and 5.0–6.0, respectively. 相似文献
14.
B. Zentgraf 《Engineering in Life Science》1992,12(5):377-382
The most frequently used sources of more stable enzymes are thermophilic bacteria, e.g. Bacillus, Closrridium, and Therrnus strains, occurring in natural as well as man-made habitats. They grow from 55 to 88°C with a specific growth rate of up to 2.6 h? and a yield coefficient of up to 0.4 gram of dry cell weight per gram of carbohydrate consumed. Several thermophilic strains, e.g. Bacillus sp. TP32, rapidly and effectively produce enzymes having a higher thermal stability and resistance to chemical denaturants in comparison to their mesophilic counterparts. Therefore, thermostable enzymes are of importance for bioorganic syntheses. For the further optimization of enzyme production, genetic engineering is applied. 相似文献
15.
Aims: To improve the α‐amylase production in solid‐state fermentation (SSF) condition utilizing a new bioreactor (NB) system. Methods and Results: In NB system, 20 g of wheat bran moistened with liquid medium in 1 : 1 ratio (w/v) was taken on the tray present inside the upper vessel and an additional 80 ml medium was supplemented into the lower vessel. Oxygen uptake rate was improved by supplying compressed air that lifted the liquid medium into the upper vessel and touched the substrate bed. This condition probably facilitated the heat transfer to liquid medium, reduce water loss and catabolite repression. With 1% glucose supplementation, maximum α‐amylase activity of 22 317 Ugds?1 was produced by Aspergillus oryzae IFO 30103 within a very short incubation period (48 h) at 2‐cm bed height with air flow rate of 0·1 l min?1 g?1 wheat bran at 32°C and initial medium pH of 6. Conclusions: Within a short incubation period, significantly high α‐amylase activity was obtained and it is higher than those reported to date at bioreactor scale operating with a fungal strain. Significance and Impact of the Study: The reactor is novel and can overcome some of the major problems associated with SSF process. A. oryzae IFO 30103 is reported as the best fungal source for α‐amylase production. 相似文献
16.
Isolation and characterization of Aspergillus sp. for the production of extracellular polysaccharides by response surface methodology 总被引:1,自引:0,他引:1
Balamuralikrishnan Balasubramanian Soundharrajan Ilavenil Paul Agastian Ki Choon Choi 《Saudi Journal of Biological Sciences》2019,26(3):449-454
In this study, Aspergillus sp. was isolated for the production of extracellular polysaccharide. The process parameters were initially optimized by traditional methods. The cheap substrate, wheat bran was used for the production of extracellular polysaccharide in solid state fermentation. Supplementation of (1%, w/w) maltose, gelatin enhanced EPS production (5.36?mg/g). The salts such as, Cu2+ (4.9?mg/g), Ca2+ (3.5?mg/g), Zn2+ (2.9?mg/g), Mn2+ (3.4?mg/g) and Mg2+ (1.8?mg/g) stimulated EPS production. In two level full factorial experimental designs, the EPS yield varied from 3.18 to 11.65?mg/g wheat bran substrate with various combinations of the components supplemented with wheat bran substrate. Among these selected factors in central composite design, maltose significantly influenced on extracellular polysaccharide production. 相似文献
17.
Mutuswamy Shanmugaprakash Vaidyanathan Vinoth Kumar Manickavassham Hemalatha Vargese Melbia Pothiyappan Karthik 《Engineering in Life Science》2011,11(3):322-325
Aspergillus niger produced high levels of naringinase using easily available, inexpensive industrial waste residues such as rice bran, wheat bran, sugar cane bagasse, citrus peel, and press mud in solid‐state fermentation (SSF). Among these, rice bran was found to be the best substrate. Naringinase production was highest after 96 h of incubation at 27°C and at a substrate‐to‐moisture ratio of 1:1 w/v. Supplementation of the medium with 10% naringin caused maximum induction. An inoculum age of 72 h and an inoculum level of 15% resulted in maximum production of naringinase. Enzyme production was stimulated by the addition of nutrients such as naringin and peptone. Thus, A. niger produced a very high level of naringinase within a short time in solid‐state fermentation using inexpensive agro‐residues, a level that is much higher than reported for any other microbes. 相似文献
18.
Several fungal endophytes of the Egyptian marine sponge Latrunculia corticata were isolated, including strains Trichoderma sp. Merv6, Penicillium sp. Merv2 and Aspergillus sp. Merv70. These fungi exhibited high cellulase activity using different lignocellulosic substrates in solid state fermentations
(SSF). By applying mutagenesis and intergeneric protoplast fusion, we have obtained a recombinant strain (Tahrir-25) that
overproduced cellulases (exo-β-1,4-glucanase, endo-β-1,4-glucanase and β-1,4-glucosidase) that facilitated complete cellulolysis
of agricultural residues. The process parameters for cellulase production by strain Tahrir-25 were optimized in SSF. The highest
cellulase recovery from fermentation slurries was achieved with 0.2% Tween 80 as leaching agent. Enzyme production was optimized
under the following conditions: initial moisture content of 60% (v/w), inoculum size of 106 spores ml−1, average substrate particle size of 1.0 mm, mixture of sugarcane bagasse and corncob (2:1) as the carbon source supplemented
with carboxymethyl cellulose (CMC) and corn steep solids, fermentation time of 7 days, medium pH of 5.5 at 30°C. These optimized
conditions yielded 450, 191, and 225 units/gram dry substrate (U gds−1) of carboxylmethyl cellulase, filter-paperase (FPase), and β-glucosidase, respectively. Subsequent fermentation by the yeast,
Saccharomyces cerevisiae NRC2, using lignocellulose hydrolysates obtained from the optimized cellulase process produced the highest amount of ethanol
(58 g l−1). This study has revealed the potential of exploiting marine fungi for cost-effective production of cellulases for second
generation bioethanol processes. 相似文献
19.
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
20.
An alkali-tolerant cellulase-free xylanase producer, WLI-11, was screened from soil samples collected from a pulp and paper mill in China. It was subsequently identified as a Pseudomonas sp. A mutant, WLUN024, was selected by consecutive mutagenesis by u.v. irradiation and NTG treatment using Pseudomonas sp. WLI-11 as parent strain. Pseudomonas sp. WLUN024 produced xylanase when grown on xylosidic materials, such as hemicellulose, xylan, xylose, and wheat bran. Effects of various nutritional factors on xylanase production by Pseudomonas sp. WLUN024 with wheat bran as the main substrate were investigated. A batch culture of Pseudomonas sp. WLUN024 was conducted under suitable fermentation conditions, where the maximum activity of xylanase reached 1245 U ml−1 after incubating at 37 °C for 24 h. Xylanase produced by Pseudomonas sp. WLUN024 was purified and the molecular weight was estimated as 25.4 kDa. Primary studies on the characteristics of the purified xylanase revealed that this xylanase was alkali-tolerant (optimum pH 7.2–8.0) and cellulase-free. In addition, the xylanase was also capable of producing high quality xylo-oligosaccharides, which indicated its application potential in not only pulp bio-bleaching processes but also in the nutraceutical industry. 相似文献