共查询到20条相似文献,搜索用时 15 毫秒
1.
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
2.
Magda A. El-Bendary 《World journal of microbiology & biotechnology》2010,26(1):153-159
In this study, Bacillus sphaericus NRC 69 was grown in culture media, in which 12 agricultural wastes were tested as the main carbon, nitrogen and energy sources
under solid state fermentation. Of the 12 tested agricultural by-products, wheat bran was the most efficient substrate for
the production of B. sphaericus mosquitocidal toxins against larvae of Culex pipiens (LC50 1.2 ppm). Mixtures of tested agricultural wastes separately with wheat bran enhanced the produced toxicity several folds
and decreased LC50 between 3.7- and 50-fold in comparison with that of agricultural wastes without mixing. The toxicity of B. sphaericus grown in wheat bran/rice hull at 8/2 (g/g) and wheat bran/barley straw at 1/4 (g/g) showed the same toxicity as that in wheat
bran medium (LC50 decreased 17- and 16-fold, in comparison with that in rice hull or barely straw media, respectively). In wheat bran medium,
the maximum toxicity of the tested organism obtained at 50% moisture content, inoculum size 84 × 106 CFU/g wheat bran and incubation for 6 days at 30°C. Addition of cheese whey permeate at 10% to wheat bran medium enhanced
the toxicity of B. sphaericus NRC 69 about 46%. 相似文献
3.
This study describes the release of antioxidant ferulic acid from wheat and triticale brans by mixtures of extracellular enzymes
produced in culture by a strain FC007 of Alternaria alternata, a dark mold originally isolated from Canadian wood log. The genus of the mold was confirmed as Alternaria by 18S ribosomal DNA characterization. Enzyme activities for feruloyl esterase (FAE) and polysaccharide hydrolyzing enzymes
were measured, and conditions for release of ferulic acid and reducing sugars from the mentioned brans were evaluated. The
highest level of FAE activity (89 ± 7 mU ml−1 fermentation culture) was obtained on the fifth day of fermentation on wheat bran as growth substrate. Depending on biomass
and processing condition, up to 91.2 or 72.3% of the ferulic acid was released from wheat bran and triticale bran, respectively,
indicating the proficiency of A. alternata extracellular enzymes in plant cell wall deconstruction. The apparent high extraction of ferulic acid from wheat and triticale
brans represents a potential advantage of using a whole fungal cell enzyme complement over yields reported previously through
an artificial assembly of cloned FAE with a particular xylanase in a cocktail format. 相似文献
4.
Facchini FD Vici AC Reis VR Jorge JA Terenzi HF Reis RA Polizeli Mde L 《Bioprocess and biosystems engineering》2011,34(3):347-355
Solid-state fermentation obtained from different and low-cost carbon sources was evaluated to endocellulases and endoxylanases
production by Aspergillus japonicus C03. Regarding the enzymatic production the highest levels were observed at 30 °C, using soy bran added to crushed corncob
or wheat bran added to sugarcane bagasse, humidified with salt solutions, and incubated for 3 days (xylanase) or 6 days (cellulase)
with 70% relative humidity. Peptone improved the xylanase and cellulase activities in 12 and 29%, respectively. The optimum
temperature corresponded to 60 °C and 50–55 °C for xylanase and cellulase, respectively, both having 4.0 as optimum pH. Xylanase
was fully stable up to 40 °C, which is close to the rumen temperature. The enzymes were stable in pH 4.0–7.0. Cu++ and Mn++ increased xylanase and cellulase activities by 10 and 64%, respectively. A. japonicus C03 xylanase was greatly stable in goat rumen fluid for 4 h during in vivo and in vitro experiments. 相似文献
5.
Basil J. Macris 《Applied microbiology and biotechnology》1981,13(3):161-164
Summary A strain ofFusarium moniliforme, previously used for microbial protein production, excreted lactase (-D-galactosidase, EC.3.2.1 23) when cultivated either in a whey liquid medium or on a wheat bran solid medium. The enzyme produced in both media had pH and temperature optima of 4–5 and 50–60°C respectively and was particularly suitable for processing acid whey.In the whey culture, maximum lactase yield was observed after 95 h of growth at 30°C and whey lactose concentration of 9%. The addition of ammonium, potassium and sodium ions to the growth medium considerably enhanced lactase production. A maximum enzyme yield corresponding to hydrolysis of 3 nmoles o-nitrophenyl--D-galactopyranoside sec–1 ml–1 of growth medium, at pH 5 and 60°C, was obtained.In the wheat bran culture, the maximum enzyme yield was obtained after 140 h of growth at 28–30°C. A marked increase in the enzyme production was observed when nitrate or phosphate was added to the growth medium. Also, the addition of certain agricultural by-products (molasses, whey) enhanced lactase production. The observed maximum yield corresponding to the hydrolysis of 182 nmoles of ONPG sec–1 g–1 of wheat bran, at pH 5 and 60°C, is comparable to that reported for certain microorganisms used commercially for lactase production. 相似文献
6.
Gopinath V Meiswinkel TM Wendisch VF Nampoothiri KM 《Applied microbiology and biotechnology》2011,92(5):985-996
Corynebacterium glutamicum wild type lacks the ability to utilize the pentose fractions of lignocellulosic hydrolysates, but it is known that recombinants
expressing the araBAD operon and/or the xylA gene from Escherichia coli are able to grow with the pentoses xylose and arabinose as sole carbon sources. Recombinant pentose-utilizing strains derived
from C. glutamicum wild type or from the l-lysine-producing C. glutamicum strain DM1729 utilized arabinose and/or xylose when these were added as pure chemicals to glucose-based minimal medium or
when they were present in acid hydrolysates of rice straw or wheat bran. The recombinants grew to higher biomass concentrations
and produced more l-glutamate and l-lysine, respectively, than the empty vector control strains, which utilized the glucose fraction. Typically, arabinose and
xylose were co-utilized by the recombinant strains along with glucose either when acid rice straw and wheat bran hydrolysates
were used or when blends of pure arabinose, xylose, and glucose were used. With acid hydrolysates growth, amino acid production
and sugar consumption were delayed and slower as compared to media with blends of pure arabinose, xylose, and glucose. The
ethambutol-triggered production of up to 93 ± 4 mM l-glutamate by the wild type-derived pentose-utilizing recombinant and the production of up to 42 ± 2 mM l-lysine by the recombinant pentose-utilizing lysine producer on media containing acid rice straw or wheat bran hydrolysate
as carbon and energy source revealed that acid hydrolysates of agricultural waste materials may provide an alternative feedstock
for large-scale amino acid production. 相似文献
7.
Damage to the ozone layer has led to increased levels of ultraviolet radiation at the earth’s surface. Increased ultraviolet
radiation can affect macroalgae in many important ways, including reduced growth rate, changes in cell biology and ultrastructure.
Kappaphycus alvarezii is a red macroalga of economic interest due to its production of kappa carrageenan. In this study, we examined two strains
of K. alvarezii (green and red) exposed to ultraviolet B radiation (UVBR) for 3 h per day during 28 days of cultivation in vitro. UVBR caused
changes in the ultrastructure of cortical and subcortical cells, which included increased thickness of the cell wall and plastoglobuli,
reduced intracellular spaces, changes in the cell contour, and destruction of chloroplast internal organization. While the
green strain exposed to photosynthetically active radiation (PAR) showed growth rates of 6.75% day−1, the red strain grew only 6.35% day−1. Upon exposure to PAR + UV-B, a decreasing trend in growth rates was observed for both strains, with the green strain growing
3.0% day−1 and the red strain growing 2.77% day−1. Significant differences in growth rates between control and UV-B-exposed algae were also found in both strains. Furthermore,
compared with control algae, phycobiliprotein contents (phycoerythrin, phycocyanin, and allophycocyanin) were observed to
decrease in both strains after PAR + UV-B exposure. However, while the chlorophyll a levels increased in both strains, the green strain showed no significant differences in chlorophyll a levels. Taken together, these findings strongly suggested that UVBR negatively affects the ultrastructure, growth rates,
and photosynthetic pigments of intertidal macroalgae and, in the long term, their economic viability. 相似文献
8.
Hitoshi Kusakabe Kenjiro Kodama Akira Kuninaka Hiroshi Yoshino Kenji Soda 《Bioscience, biotechnology, and biochemistry》2013,77(12):2531-2535
A mold strain Y244-2 capable of producing l-lysine α-oxidase, a new enzyme catalyzing the α-oxidative deamination of l-lysine, was identified as Trichoderma viride. Among strains belonging to the genus Trichoderma tested, only Trichoderma viride Y244-2 produced the enzyme in wheat bran culture. The maximum enzyme production by the mold grown on wheat bran was observed after 10 and 14 days incubation with and without NaN03, respectively. Addition of NaN03, NH4N03, adenine, purine nucleosides, l-histidine, glycine or l-glutamine to wheat bran stimulated the production of the enzyme. In the liquid culture, the enzyme was produced extracellulary under the aerobic conditions, although the production was much lower than that in the wheat bran culture. 相似文献
9.
The production of extracellular xylanase by a locally isolated strain of Aspergillus tubingensis JP-1 was studied under solid-state fermentation. Among the various agro residues used wheat straw was found to be the best
for high yield of xylanase with poor cellulase production. The influence of various parameters such as initial pH, moisture,
moistening agents, nitrogen sources, additives, surfactants and pretreatment of substrates were investigated. The production
of the xylanase reached a peak in 8 days using untreated wheat straw with modified MS medium, pH 6.0 at 1:5 moisture level
at 30 °C. Under optimized conditions yield as high as 6,887 ± 16 U/g of untreated wheat straw was achieved. Crude xylanase
was used for enzymatic saccharification of agro-residues like wheat straw, rice bran, wheat bran, sugarcane bagasse and industrial
paper pulp. Dilute alkali (1 N NaOH) and acid (1 N H2SO4) pretreatment were found to be beneficial for the efficient enzymatic hydrolysis of wheat straw. Dilute alkali and acid-pretreated
wheat straw yielded 688 and 543 mg/g reducing sugar, respectively. Yield of 726 mg/g reducing sugar was obtained from paper
pulp after 48 h of incubation. 相似文献
10.
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
11.
Rodríguez MA Cabrera G Gozzo FC Eberlin MN Godeas A 《Journal of applied microbiology》2011,110(5):1177-1186
Aims: To establish the modes of action of the antagonistic fungal strain Clonostachys rosea BAFC3874 isolated from suppressive soils against Sclerotinia sclerotiorum and to determine its potential as a biocontrol agent. Methods and Results: The antagonistic activity of C. rosea BAFC3874 was determined in vitro by dual cultures. The strain effectively antagonized S. sclerotiorum in pot‐grown lettuce and soybean plants. Antifungal activity assays of C. rosea BAFC3874 grown in culture established that the strain produced antifungal compounds against S. sclerotiorum associated with secondary metabolism. High mycelial growth inhibition coincided with sclerotia production inhibition. The C. rosea strain produced a microheterogeneous mixture of peptides belonging to the peptaibiotic family. Moreover, mycoparasitism activity was observed in the dual culture. Conclusions: Clonostachys rosea strain BAFC3874 was proved to be an effective antagonist against the aggressive soil‐borne pathogen S. sclerotiorum in greenhouse experiments. The main mechanisms involve peptaibiotic metabolite production and mycoparasitism activity. Significance and Impact of the Study: Clonostachys rosea BAFC3874 may be a good fungal biological control agent against S. sclerotiorum. In addition, we were also able to isolate and identify peptaibols, an unusual family of compounds in this genus of fungi. 相似文献
12.
Ning Guo Fang Gong Zhenming Chi Jun Sheng Jing Li 《Journal of industrial microbiology & biotechnology》2009,36(4):499-507
In order to isolate inulinase overproducers of the marine yeast Pichia guilliermondii, strain 1, cells were mutated by using UV light and LiCl2. One mutant (M-30) with enhanced inulinase production was obtained. Response surface methodology (RSM) was used to optimize
the medium compositions and cultivation conditions for inulinase production by the mutant in solid-state fermentation. The
initial moisture, inoculum, the amount ratio of wheat bran to rice bran, temperature, pH for the maximum inulinase production
by the mutant M-30 were found to be 60.5%, 2.5%, 0.42, 30°C and 6.50, respectively. Under the optimized conditions, 455.9 U/grams
of dry substrate (gds) of inulinase activity was reached in the solid state fermentation culture of the mutant M-30 whereas
the predicted maximum inulinase activity of 459.2 U/gds was derived from RSM regression. Under the same conditions, its parent
strain only produced 291.0 U/gds of inulinase activity. This is the highest inulinase activity produced by the yeast strains
reported so far. 相似文献
13.
A. Philippoussis P. Diamantopoulou K. Papadopoulou H. Lakhtar S. Roussos G. Parissopoulos S. Papanikolaou 《World journal of microbiology & biotechnology》2011,27(2):285-297
Mycelium growth rates, biomass concentration (estimated as glucosamine content) and laccase and endoglucanase secretion were
monitored during solid state fermentation (SSF) of wheat straw (WS), reed grass (RG) and bean stalk (BS) residues by Lentinula edodes strains 119, 121, and 122. In a first experiment, these strains were subjected to screening regarding their growth rates
and biomass yield, where strain 121 proved to be the fastest colonizer. However, the greater biomass yield at the end of colonization
was demonstrated by strain 122 on BS (465.93 mg g−1 d.w.). In a second experiment, growth characters, as well as endoglucanase and laccase production patterns of the selected
strains 121 and 122 were monitored at three intervals i.e., at 33, 66, and 100% of substrate colonization. BS furnished the
highest endoglucanase production for strain 121, while RG for strain 122. A strain and substrate-dependent behaviour of the
enzyme secretion was detected, with strain 122 presenting maximal endoglucanase activity in all substrates at the initial
(33%) and final (100%) stages of colonization (0.64–0.90 and 0.79–0.97 U g−1, respectively). However, in strain 121 the peak of endoglucanase production was detected in the early stages of colonization
(at 33% on WS and at 66% on RG and BS). Laccase activity showed increased values (maxima on WS, 353.68 and 548.67 U g−1 by strains 121 and 122, respectively) at 66% of colonization. Correlation analysis of growth data demonstrated negative relations
between growth rate and biomass yield and between laccase and endoglucanase activities on WS and RG substrates fermented by
strain 122. Finally, possible relations of growth parameters with nutritional constituents of the substrates were investigated. 相似文献
14.
High resolution visualization and exo‐proteomics reveal the physiological role of XlnR and AraR in plant biomass colonization and degradation by Aspergillus niger 下载免费PDF全文
Joanna E. Kowalczyk Claire Khosravi Samuel Purvine Alice Dohnalkova William B. Chrisler Galya Orr Errol Robinson Erika Zink Ad Wiebenga Mao Peng Evy Battaglia Scott Baker Ronald P. de Vries 《Environmental microbiology》2017,19(11):4587-4598
15.
Kurutahalli S. Vishwanatha A. G. Appu Rao Sridevi Annapurna Singh 《Applied microbiology and biotechnology》2010,85(6):1849-1859
Microbial milk-clotting enzymes are valued as calf rennet substitutes in the cheese industry. Aspergillus oryzae MTCC 5341 was identified to produce the highest milk-clotting activity during screening of 16 fungal strains. Solid state
fermentation using wheat bran along with 4% defatted soy flour and 2% skim milk powder as substrate was optimal for growth
of A. oryzae and production of the enzyme. Nearly 40,000 U/g bran of milk-clotting activity was present at the end of 120 h. The enzyme
could be recovered by percolating the bran with 0.1 M sodium chloride for 60 min at 4°C. The decolorized enzyme preparation
had high ratio of milk clotting to proteolytic activity. Affinity precipitation with alginate and subsequent elution with
0.5 M sodium chloride containing 0.2 M CaCl2 resulted in an enzyme preparation with specific activity of 3,500 U/mg and 72% yield. Optimum pH and temperature for activity
of the enzyme were characterized as 6.3 and 55°C, respectively. Milk-clotting enzyme showed differential degree of hydrolysis
on casein components. High ratio of milk clotting to proteolytic activity coupled with low thermal stability strengthens the
potential usefulness of milk-clotting enzyme of A. oryzae MTCC 5341 as a substitute for calf rennet in cheese manufacturing. 相似文献
16.
The present study reports the economic production of thermostable chitinase production from Oerskovia xanthineolytica NCIM 2839 by solid-state fermentation (SSF) technique and its application in fungal protoplasts formation. The Oerskovia xanthineolytica NCIM 2839 was found to produce thermostable chitinase 148 U g−1 of solid substrate in SSF using wheat bran with colloidal chitin as base. Protoplasts of A. niger were formed by using crude chitinase produced in SSF and formed protoplasts were confirmed by using scanning electron microscopy.
This is the simple and economical method for protoplast formation which makes it possible applications in strain improvement
of various fungi by protoplasts fusion in Biotechnological industries. 相似文献
17.
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
18.
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
19.
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
20.
Po Teen Lim Chui Pin Leaw Shigeru Sato Chu Van Thuoc Atsushi Kobiyama Takehiko Ogata 《Journal of applied phycology》2011,23(5):857-864
A clonal culture of a Vietnamese strain of Alexandrium minutum, AlexSp17, was subjected to different salinity treatments to determine the growth and toxin production of this strain that
produces a novel toxin analogue, deoxy GTX4-12ol. The experiment was carried out in batch cultures without pre-acclimatization
at seven salinity treatments from 5 to 35 psu, under constant temperature of 25°C, illumination of 140 μmol photon m−2 s−1, and 12:12 light/dark photoperiod. The strain grew in all salinity treatments, with optimum growth at 10–15 psu. However,
the specific growth rate (0.2 day−1) was lower than those reported in Malaysian strains and other strains from different geographical areas. The optimum range
of salinity for the growth of this species agreed with field observations of the locality of origin. No significant change
in toxin profiles was observed at different salinities. The cellular toxin quota, Qt, was not affected by the salinity-dependent
growth rate. The toxin GTX4-12ol is presumed to be a transformation product of GTX4 from specific cellular reductase enzymes.
Further investigation at the molecular level of toxin biosynthesis and subcellular enzyme activities is needed to provide
insight in the production of this unique toxin analogue. 相似文献