共查询到20条相似文献,搜索用时 15 毫秒
1.
本文以玉米浆和木薯为原料,用机械搅拌式发酵罐制备细菌纤维素(BC),对发酵过程的纤维素产量、还原糖消耗、溶氧变化和茵浓变化进行了监测,并以葡萄糖一蛋白胨-酵母粉培养基为对照进行了比较。实验得出玉米浆作氮源时不溶BC的产量为9.2g/L,而氮源成本只是对照组的15%;木薯水解液作碳源时的不溶BC产量达到11.7g/L,比对照组(10.8g/L)高8%;而用玉米浆搭配木薯水解液发酵生产BC,产量也达到10.1g/L,验证了这两种天然原料的廉价高效性,用于工业生产细菌纤维素具有良好的前景。 相似文献
2.
The production of water-soluble single-sugar glucuronic acid-based oligosaccharides (WSOS) by a cellulose producing strain
Gluconacetobacter hansenii PJK was studied in a periodically recycled and fed-batch cultivations using glucose/ethanol or glucose only. Fermentations
were carried out in a 2 L jar fermenter equipped with a turbine impeller with 6 flat blades. WSOS were produced constantly
but the bacterial cellulose (BC) production stopped at 48 h of cultivation in a periodically recycled culture using the exhausted
medium supplemented with glucose and ethanol. Tremendous quantities of WSOS were obtained in fed-batch cultivations using
glucose/ethanol (35.6 g/L at 132 h of cultivation) or glucose only (86 g/L after 240 h of cultivation) as the nutritional
source. However, the BC production yield under these nutritional conditions decreased significantly in comparison to previous
studies about the BC production by the same strain. The overall results revealed that G. hansenii is capable of producing enormous quantities of WSOS compared to those reported previously for compounds of a related chemical
nature. Moreover, the WSOS production was found to be dependent on the pH of the culture broth. 相似文献
3.
Nhu-Ngoc Nguyen Thi Tuong Vi Tran Quoc-Duy Nguyen Tran-Phong Nguyen Tuyet-Ngan Lien 《Biotechnology progress》2023,39(4):e3344
Bacterial cellulose (BC) is a biopolymer with applications in numerous industries such as food and pharmaceutical sectors. In this study, various hydrocolloids including modified starches (oxidized starch—1404 and hydroxypropyl starch—1440), locust bean gum, xanthan gum (XG), guar gum, and carboxymethyl cellulose were added to the Hestrin-Schramm medium to improve the production performance and microstructure of BC by Gluconacetobacter entanii isolated from coconut water. After 14-day fermentation, medium supplemented with 0.1% carboxymethyl cellulose and 0.1% XG resulted in the highest BC yield with dry BC content of 9.82 and 6.06 g/L, respectively. In addition, scanning electron microscopy showed that all modified films have the characteristic three-dimensional network of cellulose nanofibers with dense structure and low porosity as well as larger fiber size compared to control. X-ray diffraction indicated that BC fortified with carboxymethyl cellulose exhibited lower crystallinity while Fourier infrared spectroscopy showed characteristic peaks of both control and modified BC films. 相似文献
4.
Zhigang Lu Yanyan Zhang Yujie Chi Ning Xu Wanying Yao Bo Sun 《World journal of microbiology & biotechnology》2011,27(10):2281-2285
To improve the yield of cellulose production in bacteria, we investigated the stimulatory effects of six different alcohols
during fermentation of Acetobacter xylinum 186. Our study showed that after static fermentation at 30°C for 6 days, bacterial culture with 1.0% (v/v) of methanol added
in the medium produced the highest bacterial cellulose (BC) yield at 103.5 mg/100 ml, which was 21.8% higher than the control
group. Addition of 0.5% of ethylene glycol in the culture yielded 105.5 mg/100 ml BC, 24.1% higher than the control group.
Adding 0.5% of n-propanol yielded 96.4 mg/100 ml BC, 13.4% higher; 3.0% of glycerol yielded 108.3 mg/100 ml BC, 27.4% higher; 0.5% of n-butanol yielded 132.6 mg/100 ml BC, 56.0% higher; and 4.0% of mannitol in the culture yielded 125.2 mg/100 ml BC, 47.3% higher,
respectively. The rate of bacterial cellulose production increased with the growth rate of the bacteria. The stimulatory effects
of these alcohols that we observed were significant in the later stage of fermentation, which was considered to be important
for the biosynthesis of bacterial cellulose. 相似文献
5.
Mu-Tan Luo Xue-Fang Chen Qian-Lin Huang Hai-Long Li Xin-De Chen 《Indian journal of microbiology》2017,57(4):393-399
Durian is one important tropical fruit with high nutritional value, but its shell is usually useless and considered as waste. To explore the efficient and high-value utilization of this agricultural and food waste, in this study, durian shell was simply hydrolyzed by dilute sulfuric acid, and the durian shell hydrolysate after detoxification was used for bacterial cellulose (BC) production by Gluconacetobacter xylinus for the first time. BC was synthesized in static culture for 10 days and the highest BC yield (2.67 g/L) was obtained at the 8th day. The typical carbon sources in the substrate including glucose, xylose, formic acid, acetic acid, etc. can be utilized by G. xylinus. The highest chemical oxygen demand (COD) removal (16.40%) was obtained at the 8th day. The highest BC yield on COD consumption and the highest BC yield on sugar consumption were 93.51% and 22.98% (w/w), respectively, suggesting this is one efficient bioconversion for BC production. Durian shell hydrolysate showed small influence on the BC structure by comparison with the structure of BC generated in traditional Hestrin–Schramm medium detected by FE-SEM, FTIR, and XRD. Overall, this technology can both solve the issue of waste durian shell and produce valuable bio-polymer (BC). 相似文献
6.
不同培养方式对细菌纤维素产量和结构性质的影响 总被引:9,自引:0,他引:9
考察了自行筛选的Acetobacter xylinum NUST4.2在静置培养和发酵罐培养获得的细菌纤维素(BC)的产量、基本结构和性能的差异。结果表明:静置培养时产纤维素7.5g/L,产率为0.052g/L/h,在机械搅拌发酵罐中培养3d产量达3.13g/L,产率达0.043g/L/h;SEM分析显示静置培养和发酵罐培养得到的纤维素均具有网状结构,但静置获得的纤维素丝带相互缠绕且层状重叠,更加致密,丝带更细;FT-IR分析知搅拌不改变纤维素的化学结构,但能减弱分子间氢键,和XRD结合分析可知静置培养的纤维素具有更高结晶指数,更高Iα含量和更大晶粒尺寸,但不改变晶型,仍为纤维素I型,说明搅拌会干扰纤维素初始纤丝的结晶,有利于形成更小的晶粒和较Iα稳定的Iβ。与棉纤维素相比,静置培养获得的纤维素的热稳定性更好,而发酵罐培养获得的纤维素则阻燃性更好。 相似文献
7.
Acetobacter xylinum BPR2001 produces water-insoluble bacterial cellulose (BC) and a water-soluble polysaccharide called acetan in corn steep liquor-fructose medium. Acetobacter xylinum EP1, which is incapable of acetan production was derived by disrupting the aceA gene of BPR2001. The BC production by EP1 (2.88 g/L) was lower than that by BPR2001 (4.6 g/L) in baffled-flask culture. When purified acetan or agar was added to the medium from the start of cultivation, the BC production by EP1 was enhanced and the final BC yield of EP1 was almost the same as that of BPR2001. A similar improvement of BC production by EP1 by the addition of agar was also confirmed by cultivation in a 50-L airlift reactor. From these results, the role of acetan in BC production is associated with the increase in the viscosity of the culture medium which may hinder coagulation of BC and cells in the culture, thereby accelerating the growth of BPR2001 and BC production by BPR2001. 相似文献
8.
Bacterial cellulose (BC) has unique properties, such as high crystallinity, a high degree of polymerisation, high tensile strength and high purity, compared with native cellulose. In this study, a previously determined BC production medium was improved in static culture, and the production cost was evaluated and compared with molasses and with other defined media, such as Hestrin–Schramm, Zhou, Yamanaka and Park, using Gluconacetobacter xylinus. In addition to this analysis, because the surface area/volume ratio is an important parameter in static culture, different surface area/volume ratios were analysed in the range of 0.2–1.46. The defined medium (M1A05P5) and culture type contained glucose (10 g/L), yeast extract (10 g/L), peptone (7 g/L), acetic acid (1.5 ml/L), and ethanol (5 ml/L), and the pH was adjusted to 5.0 in static culture. The highest productivity was observed in the M1A05P5 medium that was 5-fold higher than either molasses or Park's medium. Although the molasses medium was proposed as a cost-effective medium, the production price of BC was the lowest in the M1A05P5 medium. Therefore, the newly developed medium and strategy were highly promising candidates for the industrial-scale production of BC. 相似文献
9.
Statistical optimization of culture conditions for bacterial cellulose production using Box-Behnken design 总被引:2,自引:0,他引:2
Culture conditions in a jar fermentor for bacterial cellulose (BC) production from A. xylinum BPR2001 were optimized by statistical analysis using Box-Behnken design. Response surface methodology was used to predict the levels of the factors, fructose (X1), corn steep liquor (CSL) (X2), dissolved oxygen (DO) (X3), and agar concentration (X4). Total 27 experimental runs by combination of each factor were carried out in a 10-L jar fermentor, and a three-dimensional response surface was generated to determine the effect of the factors and to find out the optimum concentration of each factor for maximum BC production and BC yield. The fructose and agar concentration highly influenced the BC production and BC yield. However, the optimum conditions according to changes in CSL and DO concentrations were predicted at almost central values of tested ranges. The predicted results showed that BC production was 14.3 g/L under the condition of 4.99% fructose, 2.85% CSL, 28.33% DO, and 0.38% agar concentration. On the other hand, BC yield was predicted in 0.34 g/g under the condition of 3.63% fructose, 2.90% CSL, 31.14% DO, and 0.42% agar concentration. Under optimized culture conditions, improvement of BC production and BC yield were experimentally confirmed, which increased 76% and 57%, respectively, compared to BC production and BC yield before optimizing the culture conditions. 相似文献
10.
Seung-Hyeon Moon Ji-Min Park Hwa-Young Chun Seong-Jun Kim 《Biotechnology and Bioprocess Engineering》2006,11(1):26-31
The saccharogenic liquid (SFW) obtained by the enzymatic saccharification of food wastes was used as a medium for production
of bacterial cellulose (BC). The enzymatic saccharification of food wastes was carried out by the cultivation supernatant
ofTrichoderma harziaum FJ1 culture.Acetobacter xylinum KJ1 was employed for the BC production culture. The physical properties, such as polymerization, crystallinity, Young's modulus,
and tensile strength, of BCs produced by three culture methods: the static cultures using HS (Hestrin-Schramm) as a reference
medium (A) or the SFW medium (B), the shaking culture (C) or the air circulation culture (D) using the SFW medium, were investigated.
The degrees of polymerization of BCs produced under the different culture conditions (A∼D) showed 11000, 9500, 8500, and 9200,
respectively. Young's modulus was 4.15, 5.0, 4.0, and 4.6 GPa, respectively. Tensile strength was 124, 200, 80, and 184 MPa,
respectively. All of the BC had a form of cellulose I representing pure cellulose. In the case of the shaking culture, the
degree of crystallinity was 51.2%, the lowest degree. Under the other culturing conditions, the trend should remain in the
range of 89.7–84%. Overall, the physical properties of BC produced from SFW were similar to those of BC from HS medium, a
commercial complex medium, and BC production by the air circulation culture mode brought more favorable results in terms of
the physical properties and its ease of scale-up. Therefore, it is expected that a new BC production method, like air circulation
culture using SFW, would contribute greatly to BC-related manufacturing. 相似文献
11.
A cellulose-producing strain isolated from rotten apples was identified asGluconace-tobacter hansenii based on its physiological properties and the 16S rDNA complete sequencing method, and specifically namedGluconacetobacter hansenii PJK. The amount of bacterial cellulose (BC) produced byG. hansenii PJK in a shaking incubator was 1.5 times higher than that produced in a static culture. The addition of ethanol to the medium
during cultivation enhanced the productivity of bacterial cellulose, plus the supplementation of 1% ethanol into the culture
medium made the produced BC aggregate into a big lump and thus protected the bacterial-cellulose-producingG. hansenii PJK cells in the shear stress field from being converted into noncellulose-producing (Cel) mutants. Cells subcultured three times in a medium containing ethanol retained their ability to produce BC without any loss
in the production yield. 相似文献
12.
Zhou LL Sun DP Hu LY Li YW Yang JZ 《Journal of industrial microbiology & biotechnology》2007,34(7):483-489
Bacterial cellulose (BC) production by Acetobacter xylinum NUST4.1 was carried out in the shake flask and in a stirred-tank reactor by means of adding sodium alginate (NaAlg) into
the medium. When 0.04% (w/v) NaAlg was added in the shake flask, BC production reached 6.0 g/l and the terminal yield of the
cellulose was 27% of the total sugar initially added, compared with 3.7 g/l and 24% in the control, respectively. The variation
between replicates in all determinations was less than 5%. During the cultivation in the stirred-tank reactor, the addition
of NaAlg changed the morphology of cellulose from the irregular clumps and fibrous masses entangled in the internals to discrete
masses dispersing into the broth, which indicates that NaAlg hinders formation of large clumps of BC, and enhances cellulose
yield. Because the structure of cellulose is changed depending on the culture condition such as additives, structural characteristics
of BC produced in the NaAlg-free and NaAlg medium are compared using scanning electron microscopy (SEM), fourier transform
infrared spectroscopy (FT-IR), X-ray diffraction (XRD). SEM photographs show some differences in reticulated structures and
ribbon width and FT-IR spectra indicate that there is the hydrogen bonding interaction between BC and NaAlg, then X-ray diffraction
(XRD) analysis reveals that BC produced with NaAlg-added has a lower crystallinity and a smaller crystalline size. The results
show that enhanced yields and modification of cellulose structure occur in the presence of NaAlg. 相似文献
13.
细菌纤维素发酵培养基的优化及超微观结构分析 总被引:1,自引:0,他引:1
为了提高细菌纤维素的产量, 本研究对一株氧化葡糖杆菌菌株J2液体发酵生产细菌纤维素的培养基进行了优化, 并对其代谢的细菌纤维的超微观结构进行了观察。运用Plackett-Burman试验设计法对8个相关影响因素的效应进行了评价, 筛选出了有显著效应的3个因素: 酵母膏、ZnSO4、无水乙醇, 其他5个因素的影响未达到显著水平(P>0.05)。然后采用Box-Behnken的中心组合试验设计和响应面分析方法(RSM)确定了上述三个因素的最佳浓度, 并且以棉纤维为对照, 运用扫描电镜观察了细菌纤维素的超微观结构, 结果表明: 菌株J2利用优化后的发酵培养基生产细菌纤维素的产量为11.52 g/100 mL, 是优化前的1.35倍, 电镜照片显示细菌纤维素微纤维丝直径<0.1 mm, 比棉纤维细很多, NaOH处理可以除去纤维网络结构中的菌体。 相似文献
14.
为了提高细菌纤维素的产量, 本研究对一株氧化葡糖杆菌菌株J2液体发酵生产细菌纤维素的培养基进行了优化, 并对其代谢的细菌纤维的超微观结构进行了观察。运用Plackett-Burman试验设计法对8个相关影响因素的效应进行了评价, 筛选出了有显著效应的3个因素: 酵母膏、ZnSO4、无水乙醇, 其他5个因素的影响未达到显著水平(P>0.05)。然后采用Box-Behnken的中心组合试验设计和响应面分析方法(RSM)确定了上述三个因素的最佳浓度, 并且以棉纤维为对照, 运用扫描电镜观察了细菌纤维素的超微观结构, 结果表明: 菌株J2利用优化后的发酵培养基生产细菌纤维素的产量为11.52 g/100 mL, 是优化前的1.35倍, 电镜照片显示细菌纤维素微纤维丝直径<0.1 mm, 比棉纤维细很多, NaOH处理可以除去纤维网络结构中的菌体。 相似文献
15.
Nasrullah Shah Jung Hwan Ha Joong Kon Park 《Biotechnology and Bioprocess Engineering》2010,15(1):110-118
The effect of agar plates on the bacterial cellulose (BC) production in a static culture was investigated in order to find
the role of agar component as a surface modifying agent. Two types of surface modified reactors (SMRs: SMRD and SMRB) were
prepared by coating the bottom of the reactors with agar dissolved in distilled water and basal medium, respectively. The
SMRs were used for BC and water soluble oligosaccharides (WSOS) production. Control was done by the same procedure using reactors
without agar plate. In both types of SMRs, the maximum production rate was observed after the second day of cultivation compared
to third day of cultivation in the case of the control. The maximum productions of BC 5.308 and 5.472 g/L were observed at
the first batch using SMRs prepared with agar dissolved in distilled water (SMRDs) and SMRs prepared with agar dissolved in
a basal medium (SMRBs), respectively. Similarly, in the daily-culture and successive batch strategy experiments the maximum
amount of WSOS produced in the SMRs was almost double that of the control. The highest water holding capacity value 92.21
g/g was observed for BC formed in the SMRs prepared with 3.0% of agar. FTIR and XRD analyses were carried out to study the
structural features of the prepared BC. 相似文献
16.
Carreira P Mendes JA Trovatti E Serafim LS Freire CS Silvestre AJ Neto CP 《Bioresource technology》2011,102(15):7354-7360
Bacterial cellulose (BC), a very peculiar form of cellulose, is gaining considerable importance due to its unique properties. In this study, several residues, from agro-forestry industries, namely grape skins aqueous extract, cheese whey, crude glycerol and sulfite pulping liquor were evaluated as economic carbon and nutrient sources for the production of BC. The most relevant BC amounts attained with the residues from the wine and pulp industries were 0.6 and 0.3 g/L, respectively, followed by biodiesel crude residue and cheese whey with productions of about, 0.1 g/L after 96 h of incubation. Preliminary results on the addition of other nutrient sources (yeast extract, nitrogen and phosphate) to the residues-based culture media indicated that, in general, these BC productions could be increased by ∼200% and ∼100% for the crude glycerol and grape skins, respectively, after the addition organic or inorganic nitrogen. 相似文献
17.
Hyperosmotic stress (OS, created with 50 g/L sorbitol) and a yeast elicitor (YE, polysaccharide fraction of yeast extract)
applied to Salvia miltiorrhiza hairy root cultures had a synergistic effect on the diterpenoid tanshinone production. With a single OS+YE treatment and
nutrient feeding, the total tanshinone content of roots was increased by sevenfold (from 0.2 to 1.6 mg/g dry weight (dw))
and the volumetric yield by 13-fold (from 1.95 to 27.4 mg/L) compared to the batch control culture. With repeated feeding
of OS and nutrient medium in an extended fed-batch culture process (i.e., 10 mL fresh medium with 50 g/L sorbitol 25 mg/L
YE, every 5 days from day 21 to day 60), the total tanshinone content of roots was increased to 18.1 mg/g dw (or 1.8 wt.%)
and the volumetric tanshinone yield to 145 mg/L, which were about 100-fold and 70-fold of those, respectively, in the batch
control. Another interesting finding was the presence of root fragments (fine particles) with extremely high tanshinone content
in the OS+YE treated cultures. It was also possible to reuse the sorbitol medium for the hairy root growth and tanshinone
production to reduce the medium expenses. 相似文献
18.
Aref Mohammadi Seyed Abbas Shojaosadati Hajar Jamshidian Tehrani Seyed Mohammad Mousavi Tayebeh Saleh Alireza Chackoshian Khorasani 《Annals of microbiology》2018,68(1):47-62
Schizophyllan (SPG) is a commercially attractive biopolymer produced by Schizophyllum commune. An investigation on the potential for SPG production by Iranian native S. commune was conducted based on culture medium, fermentation conditions and bioreactor type, . Nine native fungal strains were isolated from the northern forest of Iran at different times. Based on growth rate and SPG production, one strain was selected for further study. Optimal medium composition and inoculum size for maximizing SPG production and minimizing biomass were determined using central composite design by setting sucrose, yeast extract, inoculum size, carboxymethyl cellulose and oleic acid in the ranges of 50–200 g/L, 1–4 g/L, 2–10%, 2–12 g/L and 0.032–0.222%, respectively. The results showed that optimal results were obtained at 93.47 g/L sucrose, 1.87 g/L yeast extract, 7.68% inoculum size, 9.07 g/L carboxymethyl cellulose and 0.13% oleic acid, with maximum SPG production of 9.97 g/L and minimum biomass of 35.18 g/L. Under these optimal conditions, the production of SPG was studied in stirred tank and bubble column bioreactors. The results revealed greater production in the stirred tank because of better mixing of the culture medium. The SPG produced was characterized using rheometery, Fourier transform infrared spectroscopy, nuclear magnetic resonance), scanning electron microscopy and gel permeation chromatography. The results of these characterizations demonstrated the similarity of the SPG produced by S. commune IBRC-M 30213 to commercial SPG. Thus, the SPG produced shows good potential as a polysaccharide for use in various industries. 相似文献
19.
Factors affecting the yield and properties of bacterial cellulose 总被引:12,自引:0,他引:12
Krystynowicz A Czaja W Wiktorowska-Jezierska A Gonçalves-Miśkiewicz M Turkiewicz M Bielecki S 《Journal of industrial microbiology & biotechnology》2002,29(4):189-195
Acetobacter xylinum E25 has been applied in our studies in order to find optimal culture conditions for effective bacterial cellulose (BC) production.
The strain displays significantly higher stability in BC production under stationary culture conditions. In contrast, intensive
agitation and aeration appear to drastically reduce cellulose synthesis since such conditions induced formation of spontaneous
cellulose nonproducing mutants (Cel−), which dominated in the culture. Mutation frequency strictly depends on the medium composition in agitated cultures. Enrichment
of the standard SH and Yamanaka media with 1% ethanol significantly enhanced BC production in stationary cultures. Horizontal
fermentors equipped with rotating discs or rollers were successfully applied in order to improve culture conditions. Relatively
slow rotation velocity (4 rpm) and large surface area enabling effective cell attachment are optimal parameters for cellulose
production. Physical properties of BC samples synthesized either in stationary cultures or in a horizontal fermentor revealed
that cellulose from stationary cultures demonstrated a much higher value of Young's modulus, but a much lower value of water-holding
capacity. Journal of Industrial Microbiology & Biotechnology (2002) 29, 189–195 doi:10.1038/sj.jim.7000303
Received 01 March 2002/ Accepted in revised form 18 July 2002 相似文献
20.
Vitreoscilla hemoglobin (VHb) was constitutively expressed in Acetobacter xylinum to enhance bacterial cellulose (BC) production. A pronounced enhancement of BC production in static culture was observed. Reducing O(2) tension in gaseous phase of the culture by tightly sealing the culture tube could also enhance BC production by 70%. O(2) tension in gaseous phase reduced from 21 to 15% in the sealed and static culture of VHb-expressing A. xylinum after 7 days cultivation, while 7.36g/l of BC with yield of 0.44 were obtained. BC pellicle production by VHb-expressing A. xylinum was successfully scaled-up in a sealed 4l disposable zip lock plastic bag with BC yield of 0.38 and concentration of 6.73g/l. 相似文献