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1.
We tested the hypothesis that avocado idioblast oil cells play a defensive role against herbivorous insects. Toxicities of the intact avocado idioblast oil cells and the extracted idioblast oil were compared for three insect herbivores. Spodoptera exigua (Hübner) larvae are generalists that do not feed on avocados. By contrast, Sabulodes aegrotata (Guenée) and Pseudoplusia includens (Walker) larvae are generalist herbivores that readily feed on avocados. All bioassays were performed at a naturally occurring concentration of idioblast oil cells (2% w/w). Choice experiments showed that S. exigua larvae avoided diet treated with avocado idioblast oil cells and consume more control than treated diet. In contrast, idioblast oil cells had no significant antifeedant effects on the adapted S. aegrotata and P. includens larvae. Subsequent experiments designed to assess resistance mechanisms separated pre-ingestive (behavioral) and post-ingestive (physiological) effects of the avocado idioblast oil cells, and the extracted idioblast oil, on the two adapted herbivores. Post-ingestive adaptation was the mechanism that allows feeding. Because the impact of the avocado idioblast oil cells was greatest on the performance of non-adapted S. exigua, additional experiments determined that larvae fed diet containing the oil cells had higher mortality and reduced larval growth compared to controls. Developmental times were significantly prolonged for the survivors. Thus, increased mortality, reduced developmental rates, and antifeedant activity in the non-adapted insect indicate that defense against non-adapted herbivores may be an important function of idioblast cells in avocados. 相似文献
2.
Use of starter culture of Lactobacillus plantarum BP04 in the preservation of dining-hall food waste
Zhi-Long Ye Yan Zheng Ya-Hong Li Wei-Min Cai 《World journal of microbiology & biotechnology》2008,24(10):2249-2256
In this work, Lactobacillus plantarum BP04 was employed as starter culture in dining-hall food waste storage with different inoculant levels at 0, 2 and 10% (v/w)
to suppress the outgrowth of pathogenic and spoilage bacteria. Inoculation by Lactobacillus plantarum BP04 was effective in accelerating pH drop and reducing the growth period of enterobacteria to 9, 7 and 2 days, corresponding
to inoculant levels at 0, 2 and 10% (v/w). Increasing inoculum levels were found to inhibit the growth of Lactobacillus brevis and Leuconostoc lactis. HPLC analysis revealed that lactic acid was the predominant organic acid during the treatment of dining-hall food waste.
Its concentration varied among the fermented processes reflecting variations of microbial activity in the fermented media. 相似文献
3.
A. Cristina Figueiredo M. Salomé S. Pais Johannes J. C. Scheffer 《Plant Cell, Tissue and Organ Culture》1995,40(2):113-118
The composition of the essential oil isolated from Achillea millefolium L. ssp. millefolium cell suspension cultures was analysed by GC and GC-MS. The yield of the oil obtained by hydrodistillation or a simultaneous distillation -extraction of these cultures, harvested at days 8–10 (end of exponential phase), was 0.001 % (w/w). The analysis of the volatiles showed the presence of thirteen components; monoterpenes amounted to 5%, sesquiterpene hydrocarbons attained 40%, while eugenol, demethoxyencecalin and two unidentified compounds amounted to 45% of the total oil. Several methods were tested in an attempt to increase the essential oil production by the cultures: growth on solid medium, growth in light, use of a different culture medium, elicitation with cellulase or yeast extract, and growth in a two-phase system. Of the different methods tested, the growth in B5+ medium with Miglyol 812 led to the highest essential oil yield (0.002%, w/w), and resulted in a more diverse oil composition. 相似文献
4.
Palm kernel oil, palm olein, crude palm oil and palm acid oil were used for the synthesis of poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(3HB-co-3HHx)] by a mutant strain of Wautersia eutropha (formerly Ralstonia eutropha) harboring the Aeromonas caviae polyhydroxyalkanoate (PHA) synthase gene. Palm kernel oil was an excellent carbon source for the production of cell biomass
and P(3HB-co-3HHx). About 87% (w/w) of the cell dry weight as P(3HB-co-3HHx) was obtained using 5 g palm kernel oil/l. Gravimetric and microscopic analyses further confirmed the high PHA content
in the recombinant cells. The molar fraction of 3HHx remained constant at 5 mol % regardless of the type and concentration
of palm oil products used. The small amount of 3HHx units was confirmed by 13C NMR analysis. The number average molecular weight (Mn) of the PHA copolymer produced from the various palm oil products ranged from 27 0000 to 46 0000 Da. The polydispersity was
in the range of 2.6–3.9. 相似文献
5.
Production of α-amylase from local isolate, Penicillium chrysogenum, under solid-state fermentation (SSF) was carried out in this study. Different agricultural by-products, such as wheat bran
(WB), sunflower oil meal (SOM), and sugar beet oil cake (SBOC), were used as individual substrate for the enzyme production.
WB showed the highest enzyme activity (750 U/gds). Combination of WB, SOM, and SBOC (1:3:1 w/w/w) resulted in a higher enzyme
yield (845 U/gds) in comparison with the use of the individual substrate. This combination was used as mixed solid substrate
for the production of α-amylase from P. chrysogenum by SSF. Fermentation conditions were optimized. Maximum enzyme yield (891 U/gds) was obtained when SSF was carried out using
WB + SOM + SBOC (1:3:1 w/w/w), having initial moisture of 75%, inoculum level of 20%, incubation period of 7 days at 30°C.
Galactose (1% w/w), urea and peptone (1% w/w), as additives, caused increase in the enzyme activity. 相似文献
6.
Teresa Lopes da Silva Carla Amarelo Santos Alberto Reis 《Biotechnology and Bioprocess Engineering》2009,14(3):330-337
Multi-parameter flow cytometry was used to monitor cell intrinsic light scatter, viability, and lipid content of Chlorella protothecoides cells grown in shake flasks. Changes in the right angle light scatter (RALS) and forward angle light scatter (FALS) were
detected during the microalgal growth, which were attributed to the different microalgal cell cycle stages. The proportion
of cells not stained with PI (cells with intact cytoplasmic membrane) was high (> 90%) during the microalgal growth, even
in the latter stationary phase, suggesting that the microalgal cells built-up storage materials which allowed them to survive
under nutrient starvation, maintaining their cytoplasmic membranes intact. A high correlation between the Nile Red fluorescence
intensity measured by flow cytometry and total lipid content assayed by the traditional lipid extraction method was found
for this microalga, making this method a suitable and quick technique for the screening of microalgal strains for lipid production,
optimization of biofuel production bioprocesses, and scale-up studies. The highest oil content (∼28% w/w dry cell weight,
estimated by flow cytometry) was observed in the latter stationary phase. In addition, C. protothecoides oil also depicted the adequate fatty acid methyl ester composition for biodiesel purposes at this growth phase, suggesting
that the microalgal oil produced during the latter stationary phase could be an adequate substitute for diesel fuel. Medium
growth optimization for enhancement of microalgal oil production is now in progress, using the multi-parameter approach. 相似文献
7.
Improved biodesulfurization of hydrodesulfurized diesel oil using Rhodococcus
erythropolis and Gordonia sp. 总被引:1,自引:0,他引:1
Substituted benzothiophenes (BTs) and dibenzothiophenes (DBTs) remain in diesel oil following conventional desulfurization
by hydrodesulfurization. A mixture of washed cells (13.6 g dry cell wt l−1) of Rhodococcus erythropolis DS-3 and Gordonia sp. C-6 were employed to desulfurize hydrodesulfurized diesel oil; its sulfur content was reduced from 1.26 g l−1 to 180 mg l−1, approx 86% (w/w) of the total sulfur was removed from diesel oil after three cycles of biodesulfurization. The average desulfurization
rate was 0.22 mg sulfur (g dry cell wt)−1 h−1. A bacterial mixture is therefore efficient for the practical biodesulfurization of diesel oil. 相似文献
8.
Bacillus pumilus strain NMSN-1d isolated from polyurethane-contaminated water was found to grow in high salt concentration (NaCl 10%, w/v)
and degrade Impranil-DLN, water-dispersible polyurethane. The genetic relatedness of the isolate has been established by standard
molecular biological techniques and the enzyme(s) involved in polyurethane degradation were also studied. A total of nine
bacterial strains were isolated from polyurethane-polluted sites and characterized by conventional, microbiological and biochemical
methods. These isolates were subjected to 16S ribosomal RNA gene amplification by PCR using specific primers. The genetic
relatedness of the isolates was also ascertained by ribotyping and BLAST analysis of the 16S ribosomal RNA gene sequences.
The bacterial isolates were grown in yeast extract-salts minimal broth medium supplemented with water-dispersible polyurethane
(Impranil DLN) as a sole source of carbon. The promising isolate utilizing polyurethane and producing lipase was identified
as Bacillus pumilus NMSN-1d. The polyurethane degradation has been studied in polyurethane-Rhodamine-B and Luria-Bertani-polyurethane plate assays.
The activity of hydrolytic enzymes such as lipase and esterase was confirmed on 2xYT-olive oil and tributyrin-Tween 20 plate
assay. The newly isolated Bacillus pumilus appears promising in the management of polyurethane waste and in production of industrially important enzymes. 相似文献
9.
Fatty acid composition in lipid fractions lengthwise the mycelium of Mortierella isabellina and lipid production by solid state fermentation 总被引:1,自引:0,他引:1
Stylianos Fakas Anna Makri Maria Mavromati Maria Tselepi George Aggelis 《Bioresource technology》2009,100(23):6118-6120
This paper investigates the correlation between mycelial age and fatty acid biosynthesis. The correlation was investigated by analyzing the lipid composition lengthwise the mycelium of the oleaginous fungus Mortierella isabellina, a potential producer of γ-linolenic acid (GLA). Young mycelia were rich in polar lipids (glycolipids plus sphingolipids and phospholipids), while neutral lipid content increased in aged mycelia. In young mycelia, each polar lipid fraction contained almost 40% (w/w) polyunsaturated fatty acids (PUFAs), but this content decreased to less than 30% (w/w) in aged mycelia. On the other hand, PUFA content in neutral lipids fluctuated slightly with age. These results indicate that PUFA biosynthesis is favored in young, fast growing mycelia, while it decreases significantly in aged mycelia. This trend was also observed when we grew M. isabellina on pear pomace, an agro-industrial waste. Pear pomace cultures yielded significant amounts of lipid, which reached 12% (w/w) in dry fermented mass. The produced lipid was rich in GLA and the maximum GLA content in dry fermented mass was 2.9 mg/g. 相似文献
10.
H. Rahmat R. A. Hodge G. J. Manderson P. L. Yu 《World journal of microbiology & biotechnology》1995,11(2):168-170
Apple pomace was used in solid-substrate fermentation with the yeastsKloeckera apiculata orCandida utilis Y15. A total crude protein content of 7.5% (w/w) was achieved after 72 h for each yeast. The concentration of essential amino acids in the modified apple pomace was more than twice that in the control, enhancing its nutritive value as a stock-feed supplement. The fermentation of pomace as described can be used to reprocess this waste material into a useful value-added product for the agricultural sector.H. Rahmat was and R.A. Hodge, G.J. Manderson and P.L. Yu are with the Biotechnology Group, Department of Process and Environmental Technology, Massey University, Palmerston North, New Zealand; H. Rahmat is now with the Department of Chemical Engineering, Queen's University of Belfast, Belfast BT9 5AG, Northern Ireland, UK. 相似文献
11.
Vaidyanatha Lyer Thankamani Raghavan Nair Giridhar 《Biotechnology and Bioprocess Engineering》2004,9(6):435-439
ThreeBacillus strains were isolated from soil samples. Morphological and physiological characterization indicated that the isolated strains
wereB. mycoides, B. licheniformis andB. brevis. White pepper was produced from black pepper by the fermentative method using the isolates in shake flaks as well as in a
large-scale fermenter. Volatile oil and piperine contents of the product were 3.2% (v/w) and 4% (v/w) respectively. The moisture
content was 15%. The microbial contamination was less than 10 per 100 g. The product also exhibited excellent storage stability. 相似文献
12.
Jia Liu Xiang-Feng Huang Li-Jun Lu Jing-Cheng Xu Yue Wen Dian-Hai Yang Qi Zhou 《Bioresource technology》2009,100(24):6481-6487
In order to lower the production cost, waste frying oils were used in the biosynthesis of demulsifier by Dietzia sp. S-JS-1, which was isolated from petroleum contaminated soil. After 7 days of cultivation, the biomass concentration of the most suitable waste frying oil (WFO II) culture reached 3.78 g/L, which was 2.4 times the concentration of paraffin culture. The biodemulsifier produced with WFO II culture broke the emulsions more efficiently than that produced with paraffin culture, given the same volume ratio of carbon source in the culture medium and the same cultivation conditions. It achieved 88.3% of oil separation ratio in W/O emulsion and 76.4% of water separation ratio in O/W emulsion within 5 h. With the aid of thin layer chromatography (TLC) and Fourier transform infrared (FTIR) spectrometry, biodemulsifiers produced from both paraffin and WFO II were identified as a mixture of lipopeptide homologues. The subtle variation in the distribution of these homologues and high biomass concentration of WFO II cultures may account for the afore-mentioned good demulsification performance. 相似文献
13.
Honda K Yamashita S Nakagawa H Sameshima Y Omasa T Kato J Ohtake H 《Applied microbiology and biotechnology》2008,78(5):767-773
Rhodococcus opacus B-4, which has recently been isolated as an organic solvent-tolerant bacterium, stabilized water-in-oil (w/o) emulsions by
inhibition of droplet coalescence when the cells were dispersed in 90% (v/v) organic solvents. Confocal microscopy revealed that many bacterial cells assembled at the interface between oil and water
droplets, though free cells were also detectable at the inside of water droplets. Bacterial cells in the w/o emulsion were
capable of utilizing both a water-soluble (glucose) and an oil-soluble substrate (oleic acid) as an energy source. Availability
of the w/o emulsion as an immobilized cell system in organic solvents was demonstrated using production of indigo from indole
and production of o-cresol from toluene as model conversions. When glucose and oleic acid were simultaneously supplied as energy sources, the
w/o emulsion culture of R. opacus B-4 produced indigo and o-cresol at levels of 0.217 and 2.12 mg ml−1, respectively, by 12 h. 相似文献
14.
Heba El Bialy Ola M. Gomaa Khaled Shaaban Azab 《World journal of microbiology & biotechnology》2011,27(12):2791-2798
Oil waste poses a highly dangerous threat to the environment, mainly because it is considered a high energy demanding degradation
process. Oleaginous yeast utilizing oil waste to produce microbial fatty acids is considered an innovative method for oil
waste elimination. In the present study, fifteen yeast isolates were screened for their lipid content, three of which were
chosen for their high lipid content as compared to the standard strain Phaffia rhodozyma NRRL-Y-10921. The three selected isolates were further screened for their fatty acid profile. Yeast isolate (NC-I), identified
as Yarrowia lipolytica, was chosen because it exceeded the lipid production of the standard strain by 21%, it also produced the highest C 14:0 (myristic
acid), C 18:1 (oleic acid) and C18:2 (linoleic acid), compared to the other two isolates. Growth on different oil wastes resulted
in an increase in total lipid content which reached its maximum when oil waste of frying vegetables was added to the media
(57.89%). A variation in the fatty acid profile was detected when different types of oil waste were used before and after
fermentation. The addition of different glucose concentrations to the vegetable oil waste media resulted in the appearance
of C 22:0 (behenic acid) which was not present when the basal medium was used. Scanning Electron Microscopy indicated morphologic
changes when the yeast was grown in high glucose concentration as compared to those grown in oil waste media. The activity
of malate dehydrogenase (MDH) enzyme exhibited a correlative relationship with the lipid content under various glucose concentrations.
The obtained results indicate that vegetable oil waste is suitable for microbial fatty acid production and that the fatty
acid profile could be maneuvered through the manipulation of the fermentation media. 相似文献
15.
Polystyrene, which is one of the most utilized thermoplastics, is highly durable and is considered to be non-biodegradable.
Hence, polystyrene waste accumulates in the environment posing an increasing ecological threat. In a previous study we have
isolated a biofilm-producing strain (C208) of the actinomycete Rhodococcus ruber that degraded polyethylene films. Formation of biofilm, by C208, improved the biodegradation of polyethylene. Consequently,
the present study aimed at monitoring the kinetics of biofilm formation by C208 on polystyrene, determining the physiological
activity of the biofilm and analyzing its capacity to degrade polystyrene. Quantification of the biofilm biomass was performed
using a modified crystal violet (CV) staining or by monitoring the protein content in the biofilm. When cultured on polystyrene
flakes, most of the bacterial cells adhered to the polystyrene surface within few hours, forming a biofilm. The growth of
the on polystyrene showed a pattern similar to that of a planktonic culture. Furthermore, the respiration rate, of the biofilm,
exhibited a pattern similar to that of the biofilm growth. In contrast, the respiration activity of the planktonic population
showed a constant decline with time. Addition of mineral oil (0.005% w/v), but not non-ionic surfactants, increased the biofilm
biomass. Extended incubation of the biofilm for up to 8 weeks resulted in a small reduction in the polystyrene weight (0.8%
of gravimetric weight loss). This study demonstrates the high affinity of C208 to polystyrene which lead to biofilm formation
and, presumably, induced partial biodegradation. 相似文献
16.
Ariel Shabtay Yitzhak Hadar Harel Eitam Arieh Brosh Alla Orlov Yaakov Tadmor Ido Izhaki Zohar Kerem 《Bioresource technology》2009,100(24):6457-6464
The aims of the current study were to follow: (1) the capability of the edible mushroom Pleurotus ostreatus to degrade cell wall components and soluble phenols of the olive mill solid waste (OMSW), and improve it for ruminant nutrition (2) the fate of oil and the lipid-soluble compounds tocopherols, squalene and β-sitosterol in the fermented OMSW. A significant decrease in oil and lipid-soluble compounds with a concomitant shift in the fatty acid profile and degradation of soluble phenols took place already after 14 d. The utilization of lipids by the fungus shifted the degradation of the structural carbohydrates to a later stage, and significantly reduced the metabolizable energy of the OMSW. We propose that edible fungi with reduced lipase activity would preserve the energy and health promoting ingredients of the oil, and force the fungus to degrade structural carbohydrates, thus improving its digestibility. 相似文献
17.
Camargo-de-Morais M.M. Ramos S.A.F. Pimentel M.C.B. de Morais Jr M.A. Lima Filho J.L. 《World journal of microbiology & biotechnology》2003,19(2):191-194
Penicillium citrinum produced a glycolipid with emulsifier properties during cultivation on mineral medium with 1% (v/v) olive oil as carbon source. The emulsifier production was growth-associated and reached maximal activity at 60 h of cultivation. The production yield (Y
p/s) was 0.54 and the best emulsifying activity was observed for xylene and diesel oil when compared to other carbohydrates tested. The emulsifier was shown to be stable to a wide range of pH and temperature values and was shown to contain D-galactose, D-glucose and D-xylose (8.2:1.0:5.3) with a total carbohydrate content of 43%. The presence of salts stimulated the emulsification activity, suggesting potential for its application in industrial waste or marine remediation. 相似文献
18.
Pedro A.G. Santos A. Cristina Figueiredo Pedro M.L. Lourenço José G. Barroso Luis G. Pedro M. Margarida Oliveira Jan Schripsema Stanley G. Deans Johannes J.C. Scheffer 《Biotechnology letters》2002,24(12):1031-1036
Transformed root cultures of Anethum graveolens were induced by inoculation of aseptically grown seedlings with Agrobacterium rhizogenes carrying plasmid pRi 1855. The main component of the essential oils from the fruits and from the roots of the parent plant was carvone, whereas -phellandrene and apiole were dominant in the oil from, respectively, the aerial parts and the hairy roots. The essential oils from the fruits, aerial parts and roots of the parent plant were at 2%, 0.3% and 0.06% (v/w), respectively, but only 0.02% (v/w) in the hairy root cultures. Growth of the hairy root cultures reached 600 mg dry wt/50 ml medium after 50 days. The essential oil composition did not change significantly during their growth. 相似文献
19.
Enzyme Activities and Chemical Changes in Wet Olive Cake after Treatment with Pleurotus ostreatus or Eisenia fetida 总被引:1,自引:0,他引:1
A laboratory experiment was conducted to evaluate the enzyme activities and chemical changes recorded in a recalcitrant phenolic-rich
waste after treatment with Pleurotus ostreatus or Eisenia fetida. The waste used was wet olive cake (alperujo in Spanish), a waste produced in huge amounts by the olive oil industry. Both P. ostreatus and E. fetida were very effective in removing phenolic compounds, the initial concentration in the wet olive cake being reduced in both
cases by around 90%. Laccase and manganese peroxidase activities were measured in the growth medium of P. ostreatus, and catechol 2,3 dioxygenase activity was only detected in the waste treated with Eisenia; these could be the main factors responsible for the oxidation of phenolic compounds. Increases of dehydrogenase and β-glucosidase
activities were detected in the degraded wet olive cake by fungi or earthworms. In comparison with the natural wet olive cake,
the degraded products had lower total organic carbon and humic acid contents but were rich in nitrogen and other nutrients,
having lower C:N ratios. In addition, the toxicity of the wet olive cake against the seeds of Lepidium sativum significantly decreased after degradation. The low toxicity as well as moderate stability and maturity recorded in the wet
olive cake treated with P. ostreatus or E. fetida imply that these products could be used as soil amendments. 相似文献
20.
Siddhartha G. V. A. O. Costa François Lépine Sylvain Milot Eric Déziel Marcia Nitschke Jonas Contiero 《Journal of industrial microbiology & biotechnology》2009,36(8):1063-1072
Glycerol, cassava wastewater (CW), waste cooking oil and CW with waste frying oils were evaluated as alternative low-cost
carbon substrates for the production of rhamnolipids and polyhydroxyalkanoates (PHAs) by various Pseudomonas aeruginosa strains. The polymers and surfactants produced were characterized by gas chromatography–mass spectrophotometry (MS) and by
high-performance liquid chromatography–MS, and their composition was found to vary with the carbon source and the strain used
in the fermentation. The best overall production of rhamnolipids and PHAs was obtained with CW with frying oil as the carbon
source, with PHA production corresponding to 39% of the cell dry weight and rhamnolipid production being 660 mg l−1. Under these conditions, the surface tension of the culture decreased to 30 mN m−1, and the critical micelle concentration was 26.5 mg l−1. It would appear that CW with frying oil has the highest potential as an alternative substrate, and its use may contribute
to a reduction in the overall environmental impact generated by discarding such residues. 相似文献