Single cell oil (SCO) production by Mortierella isabellina grown on high-sugar content media

Mortierella isabellina cultivated in nitrogen-limited media presented remarkable cell growth (up to 35.9 g/l) and high glucose uptake even with high initial sugar concentrations (e.g. 100 g/l) in media. After nitrogen depletion, significant fat quantities were accumulated inside the fungal mycelia (50-55%, wt/wt oil in dry biomass), resulting in a notable single cell oil production of 18.1 g/l of culture medium. Total dry biomass and lipid yields presented greatly increased values (0.34 and 0.17 g respectively per gram of glucose consumed). The microbial lipid produced contained gamma-linolenic acid (GLA) at a concentration of 3.5+/-1.0%, wt/wt, which corresponded to 16-19 mg GLA per gram of dry microbial mass and a maximum concentration of 0.801 g GLA per liter of culture medium.     

Submergence(Fermentation)Culture of Anisodus acutanguhts Cells and Identification of Hyoscyamine and Scopolamine in the Cultured Ceils

The growth rate of Anisodus acutangulus cells in the submergence culture was 1.5 g dry wt/l/day, a rate 3 times as that in the suspension culture and more than 10 times over that of the solid static culture: However, the contents of hyoscyamine (0.203 mg/g dry wt) and scopolamine (0.178 mg/g dry. wt) in submergence culture were only slightly higher than those in the two other cultures. But when the 12-day-old submergence culture was supplemented with phenylalanine (5m mol/l) and kinetin (0.1mg/l), it was observed that not only the cell growth rate was increased but also the cellular content of hyoscyamine was raised to a level of 0.217 mg/g dry wt., and that scopolamine to 0.412 mg/g dry wt. The contents of these two alkaloids represented 1.1 and 2.3 times respectively the value of the culture without phenylalanine and kinetin supplements. The optimum date for harvesting the A. acutangulus culture Was on the 14th day of the culture. The monomers of hyoscyamine and scopolamine isolated from the cultured cells were purified and recrystalized, and then identifited as the two compounds in question by the thin-layer chromatography, melting point determination, and ultraviolet, infra-red and nuclear magnetic resonance spectra. In this paper, we also summarize and discuss the results of A. acutangulus culture experiments performed in the past 8 years. Our finding seems to inclieate that following a pilot production trial, the tissue culture method could well be employed to produce hyoscyamine and scopolamine from A. acutangulus cells on an industrial scale.     

Silver tolerance and silver accumulation of microorganisms from soil materials of a silver mine

Summary Silver-tolerant microoganisms were isolated from soil materials of a silver mine. The bacterial count decreased approximately linearly with increasing silver concentration. The fungal count, however, remained almost constant in all flasks, up to a concentration of 1 mM silver. At 10 mM Ag⁺ (about 1 g/l) and more, neither bacterial nor fungal growth could be observed.All silver-tolerant isolates were tested for silver accumulation capacity. Bacteria accumulated a mean 23 mg Ag⁺/g dry weight, hyphomycetes 6.7 mg/g dry wt. and yeasts 0.46 mg/g dry wt. The accumulation process of the hyphomycete with the highest accumulation capacity (20 mg/g dry wt.) was shown to be completed after about 30 min. Between 4°C and 80°C the process was nearly independent of temperature; as to the optimum pH, a slight preference for the neutral range was observed. Mycelium destroyed by formaldehyde solution showed the same accumulation pattern. These results would indicate a binding of silver to the surface of the cell.     

Salicylic acid-induced taxol production and isopentenyl pyrophosphate biosynthesis in suspension cultures of Taxus chinensis var. mairei

The influences of salicylic acid (SA) on taxol production and isopentenyl pyrophosphate (IPP) biosynthesis pathways in suspension cultures of Taxus chinensis var. mairei were investigated by adding SA and mevastatin (MVS), a highly specific inhibitor of 3-hydroxy-3-methylglutaryl-CoA reductase in the mevalonate pathway for IPP biosynthesis, into the culture systems. The cell death and taxol production were induced upon the introduction of SA, and 20mg/l was proved to be the optimal SA concentration in terms of the less damage to Taxus cells and marked activation of phenylalanine ammonia lyase (PAL). In the coexistence of SA (20mg/l) and MVS (100 nmol/l), the taxol content (1.626 mg/g dry wt) was higher than that (0.252 mg/g dry wt) of the MVS-treated system but almost equal to that (1.581 mg/g dry wt) of the SA-treated system. It is thus inferred that the activated non-mevalonate pathway should be responsible for the formation of IPP in taxol biosynthesis in the presence of SA.     

Fate and effects of cadmium in an experimental marine ecosystem

Two recirculated marine seawater systems (capacities: 150 and 300 l) were used for the study on cadmium accumulation of biological filter sludge, by the musselMytilus edulis and the plaicePleuronectes platessa for a period of up to 300 days. In the contaminated system Cd concentrations varied from 2.5 to 7.0 g/l with a mean of 4.6±1.15 g/l (control: 1.04±0.46 g/l). Accumulation of Cd by the filter sludge from the control system as well as from the contaminated system was significant. Mean concentrations of control-and contaminated sludge over the experimental period were 2.01±0.86 ng Cd/mg dry wt and 9.98±3.55 ng Cd/mg dry wt respectively. Accumulation of Cd byM. edulis both in the control and in the contaminated system was considerable. After 163 days of exposure the whole body burden of mussels rose from 0.3 ng Cd/mg dry wt to around 10 ng Cd/mg dry wt in the controls and to 70 ng Cd/mg dry wt in the contaminated systems. Accumulation of Cd byP. platessa was analysed in backbone, fins, gills, liver, muscle (fillet), otolith and skin (dorsal and ventral) over a period of 280 days. Elevated Cd contents of livers from control specimens were noticed after 200 days and reached 1.75 ng Cd/mg dry wt in liver. There was considerable accumulation in the liver (maximum values: 3.0 ng Cd/mg dry wt) and gills (6.0 ng Cd/mg dry wt) of specimens from the contaminated system, Cd contents of plaice exposed for identical periods of time were very variable. Growth of plaice living in the contaminated system was at times significantly slower than that of the control group. Of the three biological objects tested-filter sludge,M. edulis, P. platessa—the mussel seemed to be the most sensitive indicator of elevated Cd-concentrations, while the reaction of the plaice was slow and less distinct.     

Growth and fatty acid composition of Nannochloropsis sp. grown mixotrophically in fed-batch culture

The cell growth and eicosapentaenoic acid (EPA) yields of Nannochloropsis sp. were enhanced in the fed-batch cultures. With feeding glucose solution, the biomass reached 1.1 g dry wt l(-1) after 10 days' culture, which was 40% higher than that obtained in the batch culture (0.8 g dry wt l(-1)). With supplement of nitrate solution, the biomass reached 1 g dry wt l(-1), and reached the stationary phase 2 days earlier than the others. The maximum of biomass (1.2 g dry wt l(-1)) was obtained with the supplement of the mixture of glucose and nitrate solution. The EPA yields of Nannochloropsis sp. after 10 days' growth in the fed-batch cultures were 52 mg l(-1), 43 mg l(-1) and 56 mg l(-1) with, respectively, addition of nitrate, glucose and both together. In batch culture only 35 mg EPA l(-1) was obtained.     

Growth and rutin production in hairy root cultures of buckwheat (Fagopyrum esculentum M.)

Buckwheat (Fagopyrum esculentum Moench.) is a potentially important source of rutin, a natural flavonoid with antihyperglycemic, antihypertensive, and antioxidative properties. To examine in vitro production of rutin, we established a hairy root culture of buckwheat by infecting leaf explants with Agrobacterium rhizogenes R1000, and tested the growth conditions and rutin production rates of these cultures. Ten hairy root clones were established; their growth and rutin production rates ranged from 233 to 312 (mg dry wt per 30 mL flask, and 0.8 to 1.2 (mg/g dry wt), respectively. Clone H8, which had high growth and rutin production rates (312 mg dry wt per 30 mL flask and 1.2 mg/g dry wt, respectively), was selected for further experiments. H8 showed maximal growth and rutin content at 30 days in culture in MS medium. Of four tested culture media, half-strength MS medium was found to induce the highest levels of growth (378 mg dry wt per 30 mL flask) and rutin production (1.4 mg/g dry wt) by clone H8. In contrast, supplementation with auxins (0.1-1 mg/l IAA, IBA and NAA) increased the growth rate, but had no significant effect on rutin production by H8. Collectively, these findings indicate that hairy root cultures of buckwheat culture could be a valuable alternative approach for rutin production.     

Kinetics of ethanol production by immobilized Kluyveromyces marxianus cells at varying sugar concentrations of Jerusalem artichoke juice

Summary Kinetics of ethanol fermentation at varying sugar concentrations of Jerusalem artichoke tuber extract has been studied using Kluyveromyces marxianus cells immobilized in calcium alginate gel beads. A maximum ethanol concentration of 111 g/l was achieved at an initial sugar concentration of 260 g/l in 20 hours, when the immobilized cell concentration in the calcium alginate beads was 53.3 g dry wt./l bead volume. Ethanol yield remained almost unaffected by initial sugar concentration up to 250 g/l and was found to be about 88% of the theoretical. Maximum rate of ethanol production decreased from 22.5 g ethanol/l/h to 10.5 g ethanol/l/h while the maximum rate of total sugars utilization decreased from 74.9 g sugars/l/h to 28.5 g sugars/l/h as the initial substrate concentration was increased from 100 to 300 g/l. The concentration of free cells in the fermentation broth was low.     

以环氧乙烷为活性基的多孔颗粒状固定化青霉素酰化酶的制备

报道了用以环氧乙烷为活性基的多孔颗粒状载体（Eupergit-C）制备固定由巨大芽孢杆菌（B．megaterium）产生的青霉素酰化酶的研究。用已二胺,赖氨酸对载体进行化学修饰后制备固定化酶,获得了较好的固定结果。用未修饰的载体制备固化酶,经24h固定反应,酶活力达176．5IU／g（wet）,酶活力总叫率达53．7％,酶蛋白的固定量为19＝7mg/g（dr）,酶蛋白的固定效率达87．5％。游离酶的酶浓度对制备固定化酶的活力无显影响。当加酶量从312IU/g（dry）上升到6250IU／g（dry）时,固定化酶活力从89IU／g(wet）上升到475IU／g（wet）,总收率和固定化效率分别从99％和99％下降到26．5％和32．5％,酶蛋白的固定量从6．9mg/g（dry）上升到112mg/g（dry）,酶蛋白的固定效率从99％下降至80．5％。以酶活力为155IU/g(wet）,酶蛋白固定量为22mg/g(dry）的固定化酶水解青霉素G钾盐,经过20批循环水解后,剩余酶活力为92．5％。     

Population dynamics and production of Daphnia hyalina in a eutrophic reservoir

The population dynamics and production of Daphnia hyaiina^ the dominant cladoceran i n Eglwys Nynydd, a shallow eutrophic reservoir in South Wales, were studied for 2 years against a background of limnological measurements. The appearance and development of successive generations from egg to adult could be followed from changing numbers in arbitrarily defined size classes. Seasonal variations in mean length, mean brood-size and proportion of gravid adults were recorded and mean brood-size was related to changing food and temperature conditions. Egg-development times for D. hyaiina were determined in culture and the population parameters finite birth (S), instantaneous birth (b′), instantaneous population change (r′), instantaneous death (d′) and finite death rates (D) were estimated from field data. Turnover and production estimates were calculated from finite death rates and biomass. The calculated potential rate of increase (b′) was nearly always greater than the observed rate of increase (r′): seasonal changes in death rate (d′) generally parallel changes in birth rate (b′) but remain somewhat out of phase. Population oscillations are probably due t o a delay in the expression of the effects of population density upon birth and death rates. The mean biomass of Daphnia in 1970 was 0-57 mg dry wt/l (0-88 g C/m²) and in 1971 0-32 mg dry wt/l (0.49 g C/m²). Annual production for Daphnia was 11-8 mg dry wt/l (18-2 g C/m²) in 1970 and 8-30 mg dry wt/l (12 8 g C/m²) in 1971. Information available on primary production in the reservoir suggests that the production of Daphnia accounts for less than 2% of gross primary production. However, the pattern of population growth of Daphnia in Eglwys Nynydd almost certainly reflects a food limited system. In summer, blue-green algae may be abundant but serve as a poor food source: throughout the blue-green bloom egg production remains low, at times remaining below 0-5 eggs/adult.     

Increased taxane accumulation in callus cultures of Taxus cuspidata and Taxus × media by some elicitors and precursors

In Taxus cuspidata callus, vanadyl sulfate (10 mg l^–1) induced a high (146 g g^–1 dry wt) production of 10-deacetylbaccatin III in comparison to 7 g g^–1 dry wt of the control. The content of paclitaxel in this species increased from 16 g g^–1 to 74 g g^–1 dry wt when 20 mg phenylalanine l^–1 was used. In T. media, p-aminobenzoic acid induced the highest content of 10-deacetylbaccatin III (481 g g^–1 dry wt) versus 181 g g^–1 in the control. Paclitaxel increased from 89 to 139 g g^–1 dry wt after adding chitosan (20 mg l^–1) to the cultures.     

Removal of Cr(VI) from ground water by Saccharomyces cerevisiae

Chromium can be removed from ground water by the unicellular yeast, Saccharomyces cerevisiae. Local ground water maintains chromium as CrO₄ ^2- because of bicarbonate buffering and pH and E _h conditions (8.2 and +343 mV, respectively). In laboratory studies, we used commercially available, nonpathogenic S. cerevisiae to remove hexavalent chromium [Cr(VI)] from ground water. The influence of parameters such as temperature, pH, and glucose concentration on Cr(VI) removal by yeast were also examined. S. cerevisiae removed Cr(VI) under aerobic and anaerobic conditions, with a slightly greater rate occurring under anaerobic conditions. Our kinetic studies reveal a reaction rate (V_max) of 0.227 mg h^-1 (g dry wt biomass)^-1 and a Michaelis constant (Km) of 145 mg/l in natural ground water using mature S. cerevisiae cultures. We found a rapid (within 2 minutes) initial removal of Cr(VI) with freshly hydrated cells [55–67 mg h^-1 (g dry wt biomass)^-1] followed by a much slower uptake [0.6–1.1 mg h^-1 (g dry wt biomass)^-1] that diminished with time. A materials-balance for a batch reactor over 24 hours resulted in an overall shift in redox potential from +321 to +90 mV, an increase in the bicarbonate concentration (150–3400 mg/l) and a decrease in the Cr(VI) concentration in the effluent (1.9-0 mg/l).     

Thermophilic Fermentation of Pig Faeces and Straw by Actinomycetes

The ability of Thermomonospora fusca, Thermomonospora curvata and Pseudonorcardia thermophila to grow on and hydrolyse pig faeces and straw was studied in a 6 d batch culture at 55°C. T. fusca produced the highest levels of cellulase activity (3·3 mg/ml/h) and the greatest cellulose reduction (from 25 to 6% dry wt) in a pig faeces medium (10 g/l). Replacing half the pig faeces with grass straw reduced the cellulose breakdown (29 to 18% dry wt). Increasing the concentration of pig faeces to 30 and 50 g/l caused a decrease in cellulose breakdown. To achieve similar cellulose reductions in straws required NaOH pretreatment. All fermentations resulted in significant increases in digestible protein. The celluloses produced by the strains growing on pig faeces exhibited greatest activity in the pH range 5·9–6·4.     

Enhanced plumbagin production from in vitro cultures of <Emphasis Type="Italic">Drosera burmanii</Emphasis> using elicitation

Methyl jasmonate, 50 μM, 0.5 mg yeast extract/l and 100 mg chitosan/l stimulated plumbagin production in Drosera burmanii whole plant cultures after 6 days of elicitation. Yeast extract (0.5 mg/l) was the most efficient enhancing plumbagin production in roots of D. burmanii to 8.8 ± 0.5 mg/g dry wt that was 3.5-fold higher than control plants.     

Oxygen uptake in developing eggs and larvae of the cod, Gadus morhua L.

Unfertilised cod eggs showed a mean oxygen uptake rate at 5°C of 0.089 μl O₂, dry wt.⁻¹ h⁻¹; this gradually rose to 0.768 μl O₂ mg dry wt.⁻¹ h⁻¹ in eggs about to hatch. From hatching to complete yolk absorption larvae respired at 1.6 μl O₂, mg dry wt.⁻¹ h⁻¹. During starvation following yolk absorption, uptake fell significantly to 1.1 μl O₂, mg dry ⁻¹ h⁻¹. Much of this decrease in oxygen consumption was shown to be caused by reduction in activity. Loss of weight during the embryo and larval phases could not easily be reconciled with total oxygen consumption; it is suggested that cod embryos and larvae may not rely solely upon endogenous energy reserves during development.     

Effects of sowing time and plant age on critical nitrogen concentrations in canola (Brassica napus L.)

Critical concentrations of NO₃-N in fresh petiole tissue and total N in the dried lamina were determined for the youngest mature leaf (YML) of field-grown canola. For dry matter yield of canola sown on 4 May, critical NO₃-N concentration in the YML petiole at the rosette stage (RS) was 1.46 mg/g fresh wt. At the flower-buds-visible stage (BV) it was 0.45 mg/g fresh wt. For seed yield the values were 1.72 and 0.53 mg/g fresh wt. Critical total N concentration in the YML lamina for dry matter yield were 69 mg/g dry wt. at RS and 57 at BV. For seed yield they were 71 and 59 mg/g dry wt. Critical NO₃-N concentrations in the YML petiole of canola sown on 30 May were reduced by 50%; critical total-N concentrations in the YML lamina were not reduced to the same extent. Despite the reductions in critical N concentrations in the YML, critical N fertilizer rates for vegetative growth and seed yield were unaffected by sowing date or plant growth stage.     

Biochemical values of blood serum in the female silvered leaf-monkey,Presbytis cristatus

Thirteen days after capture, the blood serum of eight anesthetized female leaf-monkeys,Presbytis cristatus (3.86 kg of mean body weight), were analyzed for hematocrit (35.6±6.7 %), total protein (6.7±0.8 g/dl), albumin (3.61±0.77 g/dl), α-1 globulin (0.13±0.04 g/dl), α-2 globulin (0.73±0.18 g/dl), β globulin (0.87±0.27 g/dl), γ globulin (1.36±0.55 g/dl), A/G ratio (1.23±0.38), Na (161±6.14 mEq/l), K (5.61±0.74 mEq/l), LDH (575±257 IU/l), GOT (93±67 IU/l), GPT (34±33 IU/l), CPK (250±200 IU/l), ALP (613±633 IU/l), LAP (115±68 IU/l), γ-GTP (28±30 IU/l), TG (47±24 mg/dl), T-Cho (141±31 mg/dl), BUN (29.0±5.7 mg/dl), T-bil (0.21±0.07 mg/dl), and IP (3.4±2.0 mg/dl).     

High-cell-density cultivation of Schizochytrium sp. in an ammonium/pH-auxostat fed-batch system

Thraustochytrids, in particular Schizochytrium spp., are used for the production of the valuable polyunsaturated fatty acid, docosahexaenoic acid (DHA; 22:6 n-3). Growth of Schizochytrium sp. G13/2S in a defined medium was initially made in shake-flask cultures to determine the optimum concentrations of glucose (100-200 g l(-1)) and ammonia ( approximately 300 mg l(-1)) that could be used by this microorganism. In subsequent fermenter cultures, a pH-auxostat method was used to maintain NH(3) from 200-300 mg l(-1). During the first 49 h of fermentation, 150 g glucose l(-1) produced 63 g cell dry wt l(-1). Although growth was not limited by the supply of nitrogen, total fatty acids were at 25% cell dry wt which is more than half the final lipid content of commercially-grown Schizochytrium biomass which uses N-limited medium in the final stages for maximum lipid accumulation. This strategy is therefore useful for the cultivation of Schizochytrium to a high cell density up to the point when lipid accumulation can be triggered by N exhaustion.     

Astragaloside IV and polysaccharide production by hairy roots of Astragalus membranaceus in bioreactors

Hairy roots of Astragalus membranaceus were grown in bioreactors up to 30 l for 20 d. Cultures from a 30 l airlift bioreactor gave 11.5 g l dry wt with 1.4 mg g^–1 astragaloside IV, similar to cultures from 250 ml and 1 l flasks, but greater than yields from a 10 l bioreactor (dry wt 9.4 g l^–1, astragaloside IV 0.9 mg g^–1). Polysaccharide yields were similar amongst the different bioreactors (range 25–32 mg g^–1). The active constituent content of the cells approached that of plant extracts, indicating that large scale hairy root cultures of A. membranaceus has the potential to provide an alternative to plant crops without compromising yield or pharmacological potential.     

Growth and Pigment Production by Hairy Root Cultures of Beta Vulgaris L. in a Bubble Column Reactor

Beet hairy root cultures established from red and yellow varieties were grown in a 2 L bubble column reactor. The yellow clone showed profuse root hairs and a predominance of betaxanthin pigment with the red clone showed fewer root hairs and both betaxanthin and betacyanin pigments. The cultures displayed different ionic and sugar yields: 2.1 mg dry wt / mS.mL and 0.361 g dry wt / g sugar for the yellow clone and 2.3 mg dry wt / mS.mL and 0.375 g dry wt / g sugar for the red one. Both cultures grew at the same specific growth rate of 0.22 d^-1in the bubble column, as compared to 0.32 d^-1in shake flasks, indicating mass transfer limitations for growth in reactors.