Polysaccharides of <Emphasis Type="Italic">Ganoderma lucidum</Emphasis>: Factors affecting their production

The conditions of polysaccharide production by the fungus Ganoderma lucidum were optimized. The maximal yield of endopolysaccharides and exopolysaccharides was observed at 25–30°C, initial pH of culture medium 4.0–6.0, and at a C:N ratio of 18:1 and 25:1, respectively. The greatest yield of mycelium was reached at a more intensive aeration, and the maximal yield of polysaccharides was observed at a less intensive aeration. The optimal ratio between fungus growth and polysaccharide production was observed at 100 rpm and an aeration of 1.0– 1.5 1/1 medium·min.Translated from Prikladnaya Biokhimiya i Mikrobiologiya, Vol. 41, No. 2, 2005, pp. 194–199.Original Russian Text Copyright © 2005 by Babitskaya, Shcherba, Puchkova, Smirnov.     

Optimization of culture conditions for production of antimalarial menisporopsin A by the seed fungus Menisporopsis theobromae BCC 4162

AIMS: The aim of this work was to optimize the production of a novel antimaralial menisporopsin A by the seed fungus Menisporopsis theobromae BCC 4162. METHODS AND RESULTS: Fungal cultures were grown in shake flasks at 25 degrees C in the basal medium with varying carbon and nitrogen sources, aeration rates and initial pH levels. The optimal carbon and nitrogen sources that improved the production of menisporopsin A were 1% fructose and 2.5% meat extract respectively. The production was further enhanced when the culture incubated on a shaker at 200 rev min(-1) with an initial pH of 8. The yield of menisporopsin A cultured under the optimized conditions was increased from 348.30 (obtained from basal medium) to 889.02 mg l(-1), and the cultivation time was reduced from 28 to only 4 days. As a result, the productivity of menisporopsin A was greatly enhanced to 222.26 mg l(-1) day(-1) which is 18-fold higher than that of basal conditions. Larger scale production in a fermenter was also achieved, yielding menisporopsin A at a maximal level of 594.32 mg l(-1) in 4 days. CONCLUSIONS: The optimized culture conditions for menisporopsin A production by M. theobromae BCC 4162 was the cultivation under shaking or agitation at 25 degrees C in fructose-meat extract medium with an initial pH of 8. SIGNIFICANCE AND IMPACT OF THE STUDY: The production of menisporopsin A in a fermenter with a relatively short incubation period could be valuable for further utilization for chemical structure modification and derivatization.     

Effect of culture medium composition on the activity of extracellular lectins of Lentinus edodes

The time course of lectin production in culture liquid of the basidial fungus Lentinus edodes strain F-249 in different media under the conditions of submerged culture was studied. The activity of agglutinins depended on the ratio between carbon and nitrogen sources and pH of culture medium. The activity of lectin in culture medium was maximal when the fungus was grown in a medium containing L-arabinose as a source of carbon and L-asparagine as a source of nitrogen (C : N ratio, (9.5-12): 1)) on the day 15-18 of culturing at pH 8-9.     

The Biology of the Acaropathogenic Fungus Hirsutella kirchneri

The acaropathogenic fungus Hirsutella kirchneri (Rostrup) Minter , Brady and Hall grew best and produced most mycelia on a medium containing yeast extract , dextrose and agar; conidial production , however , was maximal or potato dextrose agar (PDA) . The best growth on both media was at 25 C and conidial germination was high within a wide range of temperatures (10 - 35 C) . Colony growth , mycelial mass production and conidial yield were best under alternating dark and light regimes . Maximal germination occurred under dark conditions . When grown in continuous light the fungus produced synnemata (compacted conidiophores) which remained viable for 22 weeks . Of six species of phytophagous mites assayed , three spider mites and a rust mite became infected by the fungus , as did , to a limited degree , a parasitic mite . Another four mites , including two pests , a scavenger and a predator , were unaffected . The fungus grew on and sporulated from heat - killed cadavers of a dead mealybug (Homoptera) . Conidial germination and penetration into live mites , under saturation condi tions , were affected little by temperatures . Intra - host growth was temperature dependent , with mite death beginning on the second or third day post - infection . Maximal sporulation from infected mites took place at 25 C . Mortality was quickest at 25 C when mites were held under saturation conditions , but some death also occurred at lower relative humidities . These data are discussed with a view to using H. kirchneri in the biological control of plant mites .     

Effect of carbon source and aeration rate on broth rheology and fungal morphology during red pigment production by Paecilomyces sinclairii in a batch bioreactor

The influence of carbon source and aeration rate on fermentation broth rheology, mycelial morphology and red pigment production of Paecilomyces sinclairii was investigated in a 5-l stirred-tank bioreactor. The characteristics of P. sinclairii grown on starch and on sucrose medium were comparatively studied: the specific growth rate in sucrose medium (0.04 h(-1)) was higher than that in starch medium, whereas the specific production rate of red pigments (0.04 gg(-1)d(-1)) was favorable in starch medium. P. sinclairii grown in sucrose medium were highly branched and showed longer hyphal lengths than that in starch medium. The consistency index (K) in sucrose medium was markedly higher than that in starch medium due to higher cell mass, while the higher values of flow behavior index (n) were indicated at the late stationary phase in starch medium. The aeration rate was varied within the ranges from 0.5 to 3.5 vvm while running the fermentation at mild agitation of 150 rpm using sucrose as the carbon source. The maximum biomass concentration of P. sinclairii was about 33 gl(-1) with an aeration rate of 1.5 vvm, whereas the maximum yield of red pigment production (4.73 gl(-1)) was achieved with 3.5 vvm. The highly branched cell morphology appeared at 1.5 vvm and the highly vacuolated cell morphology was observed in a high aeration rate (3.5 vvm). There was no significant variance in rheological parameters (K and n) between culture broths from different aeration conditions.     

Production of exopolysaccharides by submerged mycelial culture of a mushroom Tremella fuciformis

The optimization of submerged culture conditions for mycelial growth and exopolysaccharide (EPS) production in an edible mushroom Tremella fuciformis was studied in shake flasks and bioreactors. The temperature of 28 degrees C and pH 8 in the beginning of fermentation in agitated flasks was the most efficient condition to obtain maximum mycelial biomass and EPS. The optimal medium constituents were as follows (gL(-1)): glucose 20, tryptone 2, KH(2)PO(4) 0.46, K(2)HPO(4) 1 and MgSO(4).7H(2)O 0.5. The fungus was cultivated under various agitation and aeration conditions in a 5L stirred-tank bioreactor. The maximum cell mass and EPS production were obtained at a relatively high agitation speed of 200 rpm and at an aeration rate of 2 vvm. The flow behavior of the fermentation broth was Newtonian and the maximum apparent viscosity (35 cP) was observed at a highly aerated condition (2 vvm). The EPS productivity in an airlift reactor was higher than that in the stirred-tank reactor. The morphological study revealed that the fungus grows in mainly three different yeast-like forms: ovoid, elongated, and double yeast forms. The high population of the elongated yeast has a very close relationship to high EPS production. The EPS were protein-bound polysaccharides consisted of mainly mannose, xylose, and fucose. The molecular weights of EPS were determined to be (1.3-1.5)x10(6).     

Optimization of culture conditions for production of the anti-tubercular alkaloid hirsutellone A by Trichoderma gelatinosum BCC 7579

AIMS: This work aimed to optimize the culture conditions for production of a novel and potent anti-tubercular alkaloid, hirsutellone A, by the saprophytic soil fungus Trichoderma gelatinosum BCC 7579. METHODS AND RESULTS: The fungus was initially cultured in shake flasks at 25 degrees C in the potato dextrose broth (PDB) supplemented with various carbon and nitrogen sources and mineral salts to select suitable medium for mycelial growth and hirsutellone A production. Cultivation conditions were further optimized by adjusting initial pH and changing temperature levels to maximize the production of hirsutellone A. The optimal condition that increased the production of hirsutellone A from 19.04 mg l(-1), obtained from basal condition, to 610.55 mg l(-1) and reduced the cultivation time from 40 to 6 days was to cultivate in a shaker at 200 rev min(-1) at 25 degrees C in PDB plus 20 g l(-1) soluble starch, 10 g l(-1) peptone and 2.5% (v/v) salt solution with initial pH of 7. Production of hirsutellone A in larger-scale using a 5-l batch fermenter was also completed yielding 958 mg l(-1) of hirsutellone A within 6 days. CONCLUSIONS: The suitable culture conditions for hirsutellone A production by T. gelatinosum BCC 7579 was the cultivation in 5-l fermenter at 25 degrees C in PDB plus 20 g l(-1) soluble starch, 10 g l(-1) peptone and 2.5% (v/v) salt solution with an initial pH of 7. SIGNIFICANCE AND IMPACT OF THE STUDY: The production of hirsutellone A in a fermenter to obtain a high yield and reduce an incubation period will become very useful in anti-tubercular drug development process in the future.     

Effect of calcium, phosphate and nitrogen on cell growth and biosynthesis of cell wall polysaccharides by Silene vulgaris cell culture

Medium nutrients such as calcium, phosphorus, nitrogen and nitrate to ammonium ratio have significant influence on the growth, biosynthetic and biochemical characteristics of polysaccharides produced by Silene vulgaris (M.) G. cell culture. Cell growth and production of polysaccharides was limited by an absence of any of these components in the medium. Optimal growth of the callus and production of arabinogalactan were achieved at 1.5-4.5 microM calcium while the optimal production of pectin named silenan was observed at 3.0-4.5 microM. The phosphate contents in the medium in the range of 0.63-3.75 microM were favorable for callus growth. Production of silenan was maximal at 1.25-3.75 microM phosphate. Optimal growth of the callus was achieved at 30-90 microM nitrogen. Maximal production of silenan was observed at 60 microM nitrogen while the optimal production of arabinogalactan was at 90 microM nitrogen (at ratio of NH(4)(+):NO(3)(-) as 1:2). A presence both of nitrate and ammonium is needed for the silenan biosynthesis (the NH(4)(+):NO(3)(-) ratio as 1:1 and 1:2). Yields and volumetric production of arabinogalactan were maximal at deletion of ammonium from the nutrient medium (ratio 0:1). Absence of calcium or nitrogen in the medium leads to a decrease of the galacturonic acid residues in silenan. The galactose residues contents in arabinogalactan were decreased in the absence of nitrogen and calcium in the medium.     

Effects of temperature, incubation period and substrate on production of fusaproliferin by Fusarium subglutinans ITEM 2404

The kinetics of the production of fusaproliferin by Fusarium subglutinans ITEM 2404 in maize and rice cultures was investigated at various incubation temperatures. The growth rate of F. subglutinans was highest at 20 degrees C and 25 degrees C in maize cultures and at 15 degrees C in rice cultures. Although the growth rate was higher in rice than in maize, the maximal production of fusaproliferin was obtained in maize cultures, with a maximum yield (4309 microg g(-1)) at 20 degrees C for 6 weeks. In rice cultures the optimal incubation regimen was at 15 degrees C for 6 weeks, with a fusaproliferin level of 1557 microg g(-1). The production of fusaproliferin at 25 degrees C and 30 degrees C in both substrates was very low, with maximal yield at 25 degrees C of 979 microg g(-1) after 2 weeks and 143 microg g(-1) after 3 weeks in maize and rice cultures, respectively.     

Optimization of lipid production in the oleaginous yeastApiotrichum curvatum in wheypermeate

Summary Lipid production of the oleaginous yeastApiotrichum curvatum was studied in wheypermeate to determine optimum operation conditions in this medium. Studies on the influence of the carbon to nitrogen ratio (C/N-ratio) of the growth medium on lipid production in continuous cultures demonstrated that cellular lipid content in wheypermeate remained constant at 22% of the cell dry weight up to a C/N-ratio of about 25. The maximal dilution rate at which all lactose is consumed in wheypermeate with excess nitrogen was found to be 0.073 h^-1. At C/N-ratios higher than 25–30 lipid content gradually increased to nearly 50% at C/N=70 and the maximal obtainable dilution rate decreased to 0.02 h^-1 at C/N=70. From these studies it could be derived that maximal lipid production rates can be obtained at C/N-ratios of 30–35 in wheypermeate. Since the C/N-ratio of wheypermeate normally has a value between 70 and 101, some additional nitrogen is required to optimize the lipid production rate. Lipid production rates ofA. curvatum in wheypermeate were compared in four different culture modes: batch, fed-batch, continuous and partial recycling cultures. Highest lipid production rates were achieved in culture modes with high cell densities. A lipid production rate of nearly 1 g/l/h was reached in a partial recycling culture. It was calculated that by using this cultivation technique lipid production rates of even 2.9 g/l/h may be reached when the supply of oxygen can be optimized.Nomenclature C/N-ratio carbon to nitrogen ratio of the growth medium (g/g) - C/N_crit C/N-ratio at which there is just enough nitrogen to allow all carbon source to be converted to biomass - D dilution rate=volume of incoming medium per unit time/volume of medium in the culture vessel (h^-1) - D_max maximum dilution rate (h^-1) - DW cell dry weight - L lipid yield (g storage lipid/g carbon source) - specific growth rate (h^-1) - _max maximum specific growth rate (h^-1) - Q_L lipid production rate (g/l/h) - Y_i molecular fraction of carbon substrate that is converted to storage carbohydrate (C-mol/C-mol) - Y_ls maximal amount of storage lipid that can be produced per mol carbon source (C-mol/C-mol)     

Solid-state fermentation for gluconic acid production from sugarcane molasses by Aspergillus niger ARNU-4 employing tea waste as the novel solid support

Solid-state fermentation (SSF) was evaluated to produce gluconic acid by metal resistant Aspergillus niger (ARNU-4) strain using tea waste as solid support and with molasses based fermentation medium. Various crucial parameters such as moisture content, temperature, aeration and inoculum size were derived; 70% moisture level, 30 degrees C temperature, 3% inoculum size and an aeration volume of 2.5l min(-1) was suited for maximal (76.3 gl(-1)) gluconic acid production. Non-clarified molasses based fermentation media was utilized by strain ARNU-4 and maximum gluconic acid production was observed following 8-12 days of fermentation cycle. Different concentrations of additives viz. oil cake, soya oil, jaggary, yeast extract, cheese whey and mustard oil were supplemented for further enhancement of the production ability of microorganism. Addition of yeast extract (0.5%) was observed inducive for enhanced (82.2 gl(-1)) gluconic acid production.     

Staphylococcal Enterotoxin B and Nuclease Production Under Controlled Dissolved Oxygen Conditions

Enterotoxin B, nuclease, and total exoprotein production by Staphylococcus aureus strain S-6 was studied in a 0.5-liter fermentor system. While these extracellular products were elaborated over a wide range of aeration rates, maximal production occurred within the very narrow range of 125 to 150 cm(3) of air per min. The levels attained at the optimal aeration rate were not increased by maintaining a constant pH, although yield of enterotoxin:cell mass was highest at a constant pH of 7.0. During the growth cycle of the cultures, when aeration rate alone or aeration rate and pH were held constant, the dissolved oxygen (DO) levels, initially set at 100% of saturation, decreased to 5 to 10% 4 to 5 h after inoculation. The oxygen demand of the culture then maintained this level for an additional 4 to 6 h. This interval of low DO was characterized by maximal growth and exoprotein production. When the DO was controlled at a constant value throughout growth (by increasing or decreasing the airflow rate as appropriate), the culture demonstrated different optima for maximal growth and exoprotein production. A constant DO of 100% stimulated growth to extremely high densities, but the accumulation of toxin and nuclease was not observed. On the other hand, maintaining constant DO levels at 50 or 10% raised exoprotein levels higher than those achieved in a culture grown at the optimal aeration rate. Compared to the optimal aeration rate culture, the 10% DO culture yielded 20% more nuclease, 25% more toxin, and 40 to 50% more total exoprotein. These results indicate that it is the DO and not the aeration rate, per se, that is influential in controlling growth, toxin, nuclease, and total exoprotein production.     

<Emphasis Type="Italic">Brettanomyces bruxellensis</Emphasis>: effect of oxygen on growth and acetic acid production

The influence of the oxygen supply on the growth, acetic acid and ethanol production by Brettanomyces bruxellensis in a glucose medium was investigated with different air flow rates in the range 0-300 l h(-1 ) x (0-0.5 vvm). This study shows that growth of this yeast is stimulated by moderate aeration. The optimal oxygen supply for cellular synthesis was an oxygen transfer rate (OTR) of 43 mg O(2) l(-1) x h(-1). In this case, there was an air flow rate of 60 l h(-1) (0.1 vvm). Above this value, the maximum biomass concentration decreased. Ethanol and acetic acid production was also dependent on the level of aeration: the higher the oxygen supply, the greater the acetic acid production and the lower the ethanol production. At the highest aeration rates, we observed a strong inhibition of the ethanol yield. Over 180 l h(-1) x (0.3 vvm, OTR =105 mg O(2) l(-1) x h(-1)), glucose consumption was inhibited and a high concentration of acetic acid (6.0 g x l(-1)) was produced. The ratio of "ethanol + acetic acid" produced per mole of consumed glucose using carbon balance calculations was analyzed. It was shown that this ratio remained constant in all cases. This makes it possible to establish a stoichiometric equation between oxygen supply and metabolite production.     

Effect of the carbon source and aeration conditions on homoserine lysine biosynthesis in the threonine-dependent mutant Brevibacterium flavum 2T

The effect of two carbon sources (sucrose and acetate), aeration conditions and threonine concentration on the homoserine and lysine biosynthesis by the threonine-dependent mutant Brevibacterium flavum 2T was examined. It was demonstrated that acetate provided the predominant synthesis of homoserine to a far greater extent than sucrose (with the weight/weight ratio of homoserine : lysine being 2.5-5.0 and 0.8-1,2, respectively). The maximal level of homoserine and lysine was 18-21 and 3-7 g/l on the acetate containing medium and 18-22 and 12-16 g/l on the sucrose containing medium, respectively. On sucrose the total amount of amino acids and the total yield of products as related to the consumed substrate were greater than on acetate. Using the sucrose medium, the effect of aeration conditions and threonine concentration on the biosynthesis of both compounds was investigated. With an aeration increase from 1.3 to 4.6 g O2/l.hr the optimal concentration of threonine in the medium grow. The biosynthesis of homoserine was less sensitive to the inhibitory effect of excessive threonine than that of lysine. With an increase of the threonine concentration in the medium from 0.25 to 3.0 g/l the ratio homoserine : lysine grew from 1.03 to 5.20 (with the sulphite number being 4.6 g O2/l.hr). This effect was independent of the aeration conditions.     

Production of fuel ethanol at high temperature from sugar cane juice by a newly isolated Kluyveromyces marxianus

Kluyveromyces marxianus DMKU 3-1042, isolated by an enrichment technique in a sugar cane juice medium supplemented with 4% (w/v) ethanol at 35 degrees C, produced high concentrations of ethanol at both 40 and 45 degrees C. Ethanol production by this strain in shaking flask cultivation in sugar cane juice media at 37 degrees C was highest in a medium containing 22% total sugars, 0.05% (NH(4))(2)SO(4), 0.05% KH(2)PO(4), and 0.15% MgSO(4).7H(2)O and having a pH of 5.0; the ethanol concentration reached 8.7% (w/v), productivity 1.45 g/l/h and yield 77.5% of theoretical yield. At 40 degrees C, a maximal ethanol concentration of 6.78% (w/v), a productivity of 1.13 and a yield 60.4% of theoretical yield were obtained from the same medium, except that the pH was adjusted to 5.5. In a study on ethanol production in a 5l jar fermenter with an agitation speed of 300 rpm and an aeration rate of 0.2 vvm throughout the fermentation, K. marxianus DMKU 3-1042 yielded a final ethanol concentration of 6.43% (w/v), a productivity of 1.3g/l/h and a yield of 57.1% of theoretical yield.     

Lipase from marine Aspergillus awamori BTMFW032: production, partial purification and application in oil effluent treatment

Marine fungus BTMFW032, isolated from seawater and identified as Aspergillus awamori, was observed to produce an extracellular lipase, which could reduce 92% fat and oil content in the effluent laden with oil. In this study, medium for lipase production under submerged fermentation was optimized statistically employing response surface method toward maximal enzyme production. Medium with soyabean meal-0.77% (w/v); (NH(4))(2)SO(4)-0.1m; KH(2)PO(4)-0.05 m; rice bran oil-2% (v/v); CaCl(2)-0.05 m; PEG 6000-0.05% (w/v); NaCl-1% (w/v); inoculum-1% (v/v); pH 3.0; incubation temperature 35°C and incubation period-five days were identified as optimal conditions for maximal lipase production. The time course experiment under optimized condition, after statistical modeling, indicated that enzyme production commenced after 36 hours of incubation and reached a maximum after 96 hours (495.0 U/ml), whereas maximal specific activity of enzyme was recorded at 108 hours (1164.63 U/mg protein). After optimization an overall 4.6-fold increase in lipase production was achieved. Partial purification by (NH(4))(2)SO(4) precipitation and ion exchange chromatography resulted in 33.7% final yield. The lipase was noted to have a molecular mass of 90 kDa and optimal activity at pH 7 and 40°C. Results indicated the scope for potential application of this marine fungal lipase in bioremediation.     

Production of red pigments by the insect pathogenic fungus Cordyceps unilateralis BCC 1869

Production of red pigments (naphthoquinones) by the insect pathogenic fungus Cordyceps unilateralis BCC 1869 was investigated in this study. Cultivation conditions, including temperature, intitial pH of medium, and aeration, were optimised to improve the yield of total naphthoquinones in shake-flask culture of C. unilateralis. The highest yield of total naphthoquinones (3 g L^–1) was obtained from a 28-day culture grown in potato dextrose broth with an initial pH of 7.0, at 28°C with shaking-induced aeration at 200 rpm. An extraction process for isolation of the targeted naphthoquinone, 3,5,8-trihydroxy-6-methoxy-2-(5-oxohexa-1,3-dienyl)-1,4-naphthoquinone (3,5,8-TMON), from a culture of C. unilateralis, was also developed. The yield of 3,5,8-TMON obtained was about 1.2 g L^–1 or 40% of total naphthoquinones. The stability of 3,5,8-TMON was very high, even upon exposure to strong sunlight (70,000 lx), high temperature up to 200°C, and acid and alkali solutions at concentrations of 0.1 M     

Production of red pigment by submerged culture of Paecilomyces sinclairii

AIMS: From a survey of submerged culture of edible mushrooms, a high pigment-producing fungus Paecilomyces sinclairii was selected and its optimal culture conditions investigated. METHODS AND RESULTS: The optimal culture conditions for pigment production were as follows: inoculum age, 3 d; temperature, 25 degrees C; initial pH, 6.0; carbon source, 1.5% (w/v) soluble starch; nitrogen source, 1.5% (w/v) meat peptone. Although addition of 10 mmol l(-1) CaCl2 to the culture medium slightly increased pigment production, most of the bio-elements examined had no notable or detrimental effect on pigment production. CONCLUSIONS: Under the optimal conditions obtained in the flask culture tested, a ninefold increase in pigment production (4.4 g l(-1)) was achieved using a 5(-l) batch fermenter. Paecilomyces sinclairii secreted water-soluble red pigment into the culture medium. The pigment colour was strongly dependent on the pH of the solution: red at pH 3-4, violet at pH 5-9 and pink at pH 10-12. SIGNIFICANCE AND IMPACT OF THE STUDY: The high concentration of pigment (4.4 g l(-1)) produced by P. sinclairii demonstrates the possibility of commercial production of pigment by this strain, considering its relatively high production yield and light stability.     

Laccase production by Phanerochaete chrysosporium– an artefact caused by Mn(III)?

AIMS: The possibility of laccase production by Phanerochaete chrysosporium was studied. METHODS AND RESULTS: A relatively high initial Mn(II) concentration (1-4 mM) in the growth medium leads to the development of reddish-brown coloration and intensive oxidation of 2.2'-azino-bis(3-etilbenz-tiazolin-6-sulfonate) (ABTS). The peak of ABTS oxidation was obtained approximately 1 day after the peak of MnP activity. CONCLUSION: ABTS oxidation was not caused by manganese peroxidase (MnP) nor by laccase but was the consequence of the action of Mn(III) which was stabilised in the growth medium. Decomposition of the complex took place after the biomass was removed from the growth medium and especially after the aeration of the culture was interrupted. Significance and Impact of the Study: Mn(III) seems to be the cause of false positive laccase reactions. More reliable data on MnP activity can be obtained if the complex is decomposed by the fungus before MnP activity is measured in the medium.     

Effect of culture medium composition on the activity of extracellular lectins of <Emphasis Type="Italic">Lentinus edodes</Emphasis>

The time course of lectin production in culture liquid of the basidial fungus Lentinus edodes strain F-249 in different media under submerged culture conditions was studied. The activity of agglutinins depended on the ratio between carbon and nitrogen sources and the pH of the culture medium. The lectin activity in culture medium was maximal when the fungus was grown in a medium containing L-arabinose as a source of carbon and L-asparagine as a source of nitrogen (C:N ratio, (9.5–12):1) on day 15–18 of culturing at pH 8.0–9.0.Translated from Prikladnaya Biokhimiya i Mikrobiologiya, Vol. 41, No. 2, 2005, pp. 200–203.Original Russian Text Copyright © 2005 by Tsivileva, Nikitina, Garibova.