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PubMed2003

[Effects of light on morphological plasticity and biomass allocation of Momordica charantia].

The growth dynamics, morphological characteristics and biomass allocation of climbing plant Momordica charantia were studied under shading. The results showed that the growth of Momordica charantia had a significant difference under different levels of shading. Under weak light, the plants decreased the chance to increase their modular numbers and accumulate biomass, and had fewer shoots, thinner laminas, longer and thinner petioles, and more slender stems. The plants showed a stronger morphological plasticity under weak light than under strong light, and had a stronger morphological plasticity at early growth stage than at later growth stage. The laminas and stem biomass allocation increased, while branch biomass allocation decreased with decreasing light illumination. Light intensity had little effect on biomass allocation to shoot stems. External support is not necessary for the growth of Momordica charantia under strong light.

Biomass↗

PubMed2003

Nutrient removal and plant biomass in a subsurface flow constructed wetland in Brisbane, Australia.

Four native plant species (Baumea articulata, Carex fascicularis, Philydrum lanuginosum and Schoenoplectus mucronatus) are being investigated for their suitability in subsurface flow wetlands. The pilot scale Oxley Wetland, Brisbane, consists of 4 cells with different sized gravel (5 mm and 20 mm). The project aims to investigate nutrient removal rates and removal efficiency; nutrient storage in plant biomass; effect of cropping on plant regrowth, and the effect of gravel size on both water treatment and plant growth. Average daily mass removal rates ranged from 7.3 Kgha(-1)d(-1) NH4-N in Cell D to 4.6 Kgha(-1)d(-1) in Cell C i.e. 37%-22% removal efficiency respectively; 5.2 Kgha(-1)d(-1) NOx-N in Cell C to 1.3 Kgha(-1)d(-1) in Cell A (i.e. 75%-22% removal efficiency) and 0.8 Kgha(-1)d(-1) PO4-P in Cell A to 0.1 Kgha(-1)d(-1) in Cell C (i.e. 10%-1% removal efficiency). Cell A was the youngest wetland with new 5 mm gravel. Plant biomass was highest for Baumea and Carex. Gravel size does not appear to have affected biomass and recovery following cropping. Carex consistently had the highest harvested above ground biomass with high re-growth following cropping. Cropping appears to have retarded growth of the other three species with Schoenoplectus consistently having slowest regrowth. Plant biomass and nutrient storage was highest in Cell A and accounted for 11% of nitrogen removal and 3% of phosphorus removal.

Australia↗

PubMed2003

[Effect of straw pretreatment on soil microbial biomass and respiration activity].

Winter wheat straw particles (0.5 ~ 2.0mm) were soaked with 8.0 g.L-1 H202(pH11.0), 12.5 g.L-1 Na0H or H2S04 solution for 8 h and dried at 80 degreeC. Soils amended with the pretreated straw and inorganic N were incubated aerobically at 25 degreeC for 60 days. The C02 emission rate and soil microbial biomass C and N were measured at different time. The results showed that during the earlier stage of incubation, the pretreatments of straw increased soil microbial biomass C by 1.0 ~ 1.4 folds, but decreased soil microbial respiration activity. During the later stage of incubation, the Na0H and H2S04 pretreated straw decreased soil microbial biomass carbon by 28% and 42%, respectively, while increased the soil microbial respiration activity. The straw pretreated by H202 increased soil microbial biomass nitrogen by 90% after the 15th day of incubation. The pretreatments of straw increased the fungi/bacteria ratio at different special time. It could be concluded that soil microbial biomass and respiration activity could be changed after the pretreated straw was added into the soil.

Biomass↗

PubMed2001

Biomass, productivity and density of the seagrass Thalassia testudinum at three sites in Cahuita National Park, Costa Rica.

The basic ecology of seagrass beds was investigated by comparing biomass, productivity and density of Thalassia testudinum (turtle grass) at three sites: Puerto Vargas, Punta Cahuita and Rio Perezoso, in Cahuita National Park, Limón, Costa Rica, over a two month period (March-April 1999). Above ground biomass, density, and productivity were highest in the Puerto Vargas site while Punta Cahuita had the least non-green above ground biomass was significantly lower in total biomass than Puerto Vargas. Punta Cahuita was distinguished by the largest grain size, a very hard substrate, and shallower water. Rio Perezoso, on the other hand, had extremely fine sediment and lower salinity, while Puerto Vargas was intermediate both in sediment size and environmental conditions. It appears, therefore, that higher biomass and productivity result from a combination of moderate environmental characteristics and an intermediate sediment size.

Biomass↗

PubMed2004

[Distribution of lichens biomass and its affecting factors during restoration process of Inner Mongolia steppe].

An experiment was installed in the typical steppe area of Central Inner Mongolia to study the distribution characteristics of lichen biomass in the restoration process. The experimental areas were continuously grazed for ten years (1989 to 1998) under different stocking rate, and stopped grazing since 1999. Two years (2001 to 2002) monitoring on the distribution of lichen biomass and its affecting factors showed that no significant difference was found between different stocking rate treatments (P < 0.05). There existed positive correlations between lichen biomass and plant species diversity and between soil water content and soil organic matter content (P < 0.05), and negative correlations between lichen biomass and soil bulk density, and between Gramineae plant functional group and plant community coverage and biomass (P < 0.05).

Animal Husbandry↗

PubMed2004

[Biomass and yield of Betula platyphylla population in Mila Mount of Tibet].

Mila Mount in Southeast Tibet is the west boundary of the horizontal distribution of Betula platyphylla. It is also the highest altitude area in China and the world, where Betula platyphylla is distributed. Based on the investigation of regional sample plots and the analysis of analytic trees, this paper compared the biomass and yield of Betula platyphylla population at different slope orientation and different altitude. The results showed that the growth of Betula platyphylla was greatly interfered by human activities. The yearly productivity of Betula platyphylla grown in Mila Mount was 363.1-2,072.94 kg x hm(-2), and the biomass was 7,625.00-33,167.00 kg x hm(-2), indicating that the biomass of Betula platyphylla was quite different for different population. The productivity and biomass of Betula platyphylla coppice after cutting were lower than those of seedling forest, and there existed youth broken-down in the coppice. The zonal changes of water resources had no significant effect on the water allocation and the biomass of Betula platyphylla.

Altitude↗

PubMed2004

[Biomass distribution patterns of Alnus hirsuta and Betula platyphylla-swamp ecotone communities in Changbai Mountains].

In order to reveal the growth patterns of dominant tree species and the distribution patterns of community biomass along the horizontal environmental gradients or among the vertical layers of communities in Changbai Mountains, this paper studied the biomass distribution patterns of Alnus hirsuta-swamp and Betula platyphylla-swamp ecotone communities. The results showed that there were some differences in growth rate and in adaptability to habitats between A. hirsuta and B. platyphylla. In the wetland habitats of the ecotone, A. hirsuta grew 1-2 times faster than B. platyphylla, but along the gradient from swamp to forest, it grew slowly, while B. platyphylla grew fast. Therefore, A. hirsuta was a favorite tree species in wetland habitats. The distribution pattern of organ biomass was similar between A. hirsute and B. platyphylla, the trunk being 1/2, tree root 1/4, branch 1/10, bark 1.5/20, and leaf 1/20. The vertical distribution pattern of biomass was also similar between A. hirsute-swamp and B. platyphylla-swamp ecotone communities, the tree, shrub, and herbage layer accounted for 87%-90%, 7%-9%, and 2%-3%, respectively in the whole ecotone communities. The community biomass increased linearly from swamp to forest with the change of environment factors.

Alnus↗

PubMed2004

Root biomass and carbon storage in oriental spruce and beech stands in Artvin, Turkey.

In this study, influence of slope position (south-facing vs. north-facing), species type and sampling time on fine (0-2 mm), small (2-5 mm) and coarse (5-10 mm) root biomass and carbon storage of oriental spruce (Picea orientalis) and oriental beech (Fagus orientalis) were investigated. Mean total root biomass of oriental spruce was 20160 kg ha(-1) in south-facing slopes and 17140 kg ha(-1) in north-facing slopes. Mean total belowground C storage of oriental spruce was 7861 kg ha(-1) in south-facing slopes and 6840 kg ha(-1) in north-facing slopes. Similarly, biomass and C storage of oriental beech were 17190 and 6690 kg ha(-1) in south-facing slopes, and 13260 and 5200 kg ha(-1) in north-facing slopes, respectively. Oriental spruce had significantly higher fine root biomass than did oriental beech in south-facing slopes. Fine root biomass was significantly higher in fall than in spring in south-facing slopes.

Biomass↗

PubMed2005

Biomass concentration and biofilm characteristics in high-performance fluidized-bed biofilm reactors.

Two laboratory scale fluidized-bed biofilm reactors (FBBRs) were used to investigate the biomass concentration and the biofilm characteristics in a high performance FBBR used for the denitrification of exceptionally high-nitrate wastewater (1000 mg-N/L). Reported correlations by other workers for predicting the biomass concentration in FBBR were examined for their validity in comparison with the experimental results of this study and the best set of applicable correlations was recommended. The effects of the two main operational parameters, the superficial velocity and nitrogen loading rate on the biomass concentration in the FBBR were also studied. Correlations for the drag coefficient and the expansion index from the literature, together with the biofilm dry density correlation produced from this study were found to produce the best prediction of the FBBR biomass concentration compared to other reported correlations. The average biomass concentration in the FBBR decreased with the increase of the superficial velocity in the range of 45 to 65 m/h at all the applied nitrogen loadings (i.e. 6, 8, 12 and 16 kg-N/m3(bed).d).

Biofilms↗

PubMed1996

Bronchial responsiveness of non-smoking women exposed to environmental tobacco smoke or biomass fuel combustion.

We studied bronchial responsiveness (BR) in three groups of housewives with or without history of exposure to tobacco smoke or combustion of biomass fuels. Methacholine bronchoprovocation test was used to study BR. The group I subjects (60), who served as controls, were nonsmokers and had no chronic exposure to passive smoking or environmental tobacco smoke (ETS) or biomass fuels. Three of these women showed a 20 per cent FEV1 fall with a cumulative methacholine dose of 72.5 mg or less. Of 60 women in group II (ETS-exposure) and 52 in group III (biomass exposure), 26 (43.3%) and 10 (19.2%) respectively showed bronchial hyper-responsiveness (BHR). The odds ratios for BHR in groups II and III were 14.53 and 4.52 respectively. The number of hyper-responders was significantly more and the mean PD20 less in the exposed than the non-exposed groups. The occurrence of BHR in the ETS exposed group was more (P < 0.05) than the biomass combustion group. There were more hyper-responders (both groups II and III) amongst those who had an exposure index (EI) of 50 or more compared to those with EI of less than 50. We conclude that chronic cumulative exposure to both ETS and biomass combustion produces significant BHR. Further, BHR developed more often on ETS exposure, and when the exposure was present for a longer period.

Adult↗

PubMed1999

Characteristics of Aluminum Biosorption by Sargassum fluitans Biomass.

: Biomass of nonliving brown seaweed Sargassum fluitans pretreated by different methods is capable of taking up more than 10% (11 mEq/g) of its dry weight in aluminum at pH 4.5. There are indications that the biomass hydroxyl groups were involved in sequestering the aluminum in the form of polynuclear aluminum species. Aluminum-alginate complex (like cotton candy) was formed in the aluminum sorption solution as alginate was partially released from the biomass. Aluminum uptake of S. fluitans biomass was independent of residual alginate content in the biomass. Sodium ion added for pH adjustment was not adsorbed at all in the presence of aluminum ion.

Journal Article↗

PubMed1996

Vitality fertilization of Scots pine stands growing along a gradient of heavy metal pollution: short-term effects on microbial biomass and respiration rate of the humus layer.

In 1992 forest vitality fertilization experiments were established on a heavy metal deposition gradient with four treatments in three replications at distances of 0.5, 4 and 8 km from a Cu-Ni smelter in order to estimate their impact on the disturbed forest ecosystem. The increase in Cu concentration in the humus (F/H) layer of the Calluna site type Scots pine (Pinus sylvestris) stands from ca. 300 to 8000 mg kg(-1) d.m. (dry matter) along the 8 km long transect towards the smelter resulted in declining soil microbial biomass and soil respiration activity. Three independent measurements of microbial biomass: C(mic)-FE (fumigation extraction), C(mic)-SIR (substrate induced respiration), and ATP have been used together with an indicator of fungal biomass (ergosterol) and microbial activity (soil respiration). Within this Cu pollution range, all the measured microbial biomass levels declined to 10%-28% of the control plot values and activity assessed by respiration was lowered to 16%. Liming has increased the C(mic)-SIR and respiration rate. Treatments with test fertilizer, made from grounded apatite, did not result in different microbial biomass and respiration rate values compared to the respective controls along the whole gradient. Nitrogen + lime treatments resulted in similar changes to lime alone. No changes, as compared to the respective control, could be detected with nitrogen fertilization at the less polluted end of the gradient.

Journal Article↗

PubMed2026

Integration of domestic wastewater and native Tetradesmus obliquus for bioremediation and production of biomass rich in protein and polyunsaturated fatty acids.

The large-scale deployment of microalgae-based bioprocesses is often limited by high freshwater and nutrient demands. Domestic wastewater represents a sustainable alternative, enabling simultaneous pollutant removal and biomass production. In this study, a native strain of Tetradesmus obliquus, isolated in southern Brazil, was cultivated in raw domestic wastewater (RDW) and primary-treated domestic wastewater (TDW) at three initial inoculum densities (10%, 20%, and 30% v/v) for 14 days. Tetradesmus obliquus in TDW inoculated at 10% (v/v) removed 62.46% of ammonium and 98.56% of phosphate, simultaneously exhibiting the highest specific growth rate (0.16 d⁻1) and the highest biomass productivity (42.54 mg L⁻1 d⁻1). Iron and manganese concentrations decreased significantly with a native strain in TDW, indicating effective removal of them under the evaluated conditions. RDW was associated with higher carbohydrate accumulation (32.68%) and pigment production, whereas TDW was associated with higher protein content (45.83%) and a lipid fraction with a high relative proportion of polyunsaturated fatty acids (72.70-78.90%), primarily represented by α-linolenic and linoleic acids. The combined assessment of wastewater condition and initial inoculum density revealed distinct effects on the cultivation system. These aspects influence the biochemical composition of biomass, initial inoculum density, nutrient removal, specific growth rate, and biomass productivity. Thus, the present study supports the potential to integrate domestic wastewater treatment with the cultivation of a native Tetradesmus obliquus strain and indicates that, under the evaluated conditions, both the wastewater treatment conditions and the initial inoculum density influenced bioremediation performance and the biochemical composition of biomass.

Biochemical composition↗

PubMed1992

On-line biomass monitoring by capacitance measurement.

An in-situ, steam-sterilizable capacitance probe was used to follow the biomass concentration on-line, in bioreactors from 20 to 2000 l total volume. Microbial cultures of Saccharomyces cerevisiae, Pichia pastoris and Streptomyces virginiae were grown in batch and fed-batch culture in both defined and complex media in order to demonstrate the wide dynamic operating range of the instrument. A linear correlation was found between the on-line capacitance measurement and the off-line measurements (optical density, OD620; packed mycelial volume, PMV; biomass concentration X, and colony forming units, CFU ml-1) for biomass concentrations (dry cell weight) up to 30 g l-1 (St. virginiae), 106 g l-1 (S. cerevisiae) and 89 g l-1 (P. pastoris). The on-line capacitance measurement was slightly influenced by variations in agitation speed and strong extraneous radio frequencies. A specific capacitance constant (Cs) was defined for all microbial cells which was dependent on cell viability and cell size. The Cs was easy to calculate using the on-line capacitance measurement and an off-line estimation of biomass concentration. The Biomass Monitor proved suitable for precise on-line monitoring of both homogeneous (uni-cellular) and heterogeneous (mycelial) cultures in bioreactors.

Biotechnology↗

PubMed1995

Measurements of sulfur, phosphorus and other ions in microbial biomass: influence on correct determination of elemental composition and degree of reduction.

The elemental composition of microorganisms varies widely with respect to the N, S, P and ash content as well as many trace elements depending on microorganism and growth conditions. As a consequence, the mass of 1 C-mol of biomass can differ considerably from one microorganism to another. Experimental results show that sulfur is completely volatilized during combustion, so that the calculation of the mass fraction of oxygen is affected when S is not measured. However, its neglect does not seriously affect the elemental composition and the degree of reduction of biomass. Phosphorus is found in ash after combustion at the same degree of reduction as in biomass. Therefore, oxygen bound to it should be included in the elemental formula, so that the degree of reduction of biomass remains unchanged by inclusion of P into elemental formula. No external oxygen is incorporated into biomass during combustion and thus the measured ash fraction is correct.

DNA↗

PubMed2006

Ni(II) removal from aqueous solutions using cone biomass of Thuja orientalis.

The biomass of terrestrial-plant materials has high removal capacities for a number of heavy metal ions. The Ni(II) biosorption capacity of the cone biomass of Thuja orientalis was studied in the batch mode. The biosorption equilibrium level was determined as a function of contact time, pH, temperature, agitation speed at several initial metal ion and adsorbent concentrations. The removal of Ni(II) from aqueous solutions increased with adsorbent concentration, temperature and agitation speed of the solution were increased. The biosorption process was very fast; 90% of biosorption occurred within 3 min and equilibrium was reached at around 7 min. It is found that the biosorption of Ni(II) on the cone biomass was correlated well (R2 > 0.99) with the Langmuir equation as compared to Freundlich, BET Temkin and D-R isotherm equation under the concentration range studied. According to Langmuir isotherm, the monolayer saturation capacity (Q(o)) is 12.42 mg g(-1). The pseudo-first-order, pseudo-second-order and intraparticle diffusion kinetic models were applied to test the experimental data for initial Ni(II) and cone biomass concentrations. The pseudo-second-order kinetic model provided the best correlation of the used experimental data compared to the pseudo-first-order and intraparticle diffusion kinetic models. The activation energy of biosorption (E(a)) was determined as 36.85 kJ mol(-1) using the Arrhenius equation. This study indicated that the cone biomass of T. orientalis can be used as an effective and environmentally friendly adsorbent for the treatment of Ni(II) containing aqueous solutions.

Adsorption↗

PubMed2000

Heterotrophic production of biomass and lutein by Chlorella protothecoides on various nitrogen sources.

The effects of nitrate, ammonium, and urea as nitrogen sources on the heterotrophic growth of Chlorella protothecoides were investigated using flask cultures. No appreciable inhibitory effect on the algal growth was observed over a nitrogen concentration range of 0.85-1.7 g l(-)(1). In contrast, differences in specific growth rate and biomass production were found among the cultures with the various nitrogen compounds. The influence of different nitrogen sources at a concentration equivalent to 1.7 g l(-)(1) nitrogen on the heterotrophic production of biomass and lutein by C. protothecoides was investigated using the culture medium containing 40 g l(-)(1) glucose as the sole carbon and energy source in fermentors. The maximum biomass concentrations in the three cultures with nitrate, ammonium, and urea were 18.4, 18.9, and 19.6 g l(-)(1) dry cells, respectively. The maximum lutein yields in these cultures were between 68.42 and 83.81 mg l(-)(1). The highest yields of both biomass and lutein were achieved in the culture with urea. It was therefore concluded that urea was the best nitrogen source for the production of biomass and lutein. Based on the experimental results, a group of kinetic models describing cell growth, lutein production, and glucose and nitrogen consumption were proposed and a satisfactory fit was found between the experimental results and predicted values. Dynamic analysis of models demonstrated that enhancing initial nitrogen concentration in fermentor cultures, which correspondingly enhances cell growth and lutein formation, may shorten the fermentation cycle by 25-46%.

Journal Article↗

PubMed2003

Recovery of microalgal biomass and metabolites: process options and economics.

Commercial production of intracellular microalgal metabolites requires the following: (1) large-scale monoseptic production of the appropriate microalgal biomass; (2) recovery of the biomass from a relatively dilute broth; (3) extraction of the metabolite from the biomass; and (4) purification of the crude extract. This review examines the options available for recovery of the biomass and the intracellular metabolites from the biomass. Economics of monoseptic production of microalgae in photobioreactors and the downstream recovery of metabolites are discussed using eicosapentaenoic acid (EPA) recovery as a representative case study.

Journal Article↗