Total Phosphate Content Research Articles

Bacterial community structure and function in soils from tidal freshwater wetlands in a Chinese delta: Potential impacts of salinity and nutrient

Microorganisms in tidal freshwater wetlands affect biogeochemical cycling of nutrients, but the structures and functions of the wetland communities change due to natural and anthropogenic stresses. Soil samples were collected along a 350-m sampling belt in typical tidal freshwater wetlands of Yellow River Delta to investigate nutrient distributions, bacterial community structures and potential metabolic functions under tide and runoff stress by high-throughput sequencing and PICRUSt analysis. The total nitrogen (TN) contents varied greatly while total phosphorous (TP) contents were relatively stable. The bacterial community structures and predicted functions varied along a 350-m sampling belt. Some sulfate-reducing bacteria, nitrifying bacteria, Marmoricola, unclassified_f_Salinisphaeraceae and Oceanococcus exhibited a decreased trend with increasing distances far away from the river bank (B-0m). However, Salinisphaera was more dominant far away from the river bank (B-350m), indicating the stronger tolerance degree under salt stress. Marinobacterium and Marinobacter could be widely detected from B-0m to B-350m, demonstrating that those bacteria could tolerate a broad range of salinity and have its exceptional adaptation capacities. Redundancy analysis (RDA) indicated that nutrient and salinity played an important role in shaping bacterial community composition. NH4+-N and AP were the key factors in explaining the variance of the genus level. Predicted by PICRUSt analysis, nitrogen fixation (NF), nitrogen mineralization (NM), denitrification and dissimilatory nitrate reduction to ammonium (DNRA) might be the dominant processes of nitrogen metabolism and related genes abundance were abundant in tidal freshwater wetland soils. These findings could provide new insights into the prevention and control of potential nutrient pollution in tidal freshwater wetlands under the dual stress of tide and runoff.

Soil ciliates of the Indian Delhi Region: Their community characteristics with emphasis on their ecological implications as sensitive bio-indicators for soil quality.

The present investigation aims to study the diversity of ciliates from different habitats in and around Delhi, India, and the correlation of this diversity with soil quality {agricultural lands (site 1 and 2), dump yards (site 3 and 4), sewage treatment plant (site 5), residential land (site 6), landfill (site 7) and barren land (site 8)}. Various physicochemical parameters of the different soil samples were studied and analysed for soil texture, interstitial water, pH, conductivity, total organic carbon, total organic matter, total nitrogen and phosphorous content, using standard protocols. Seventeen ciliate taxa belonging to four classes, seven orders, ten families, and 17 genera were recorded, with the maximum number of species (eleven) belonging to the class Spirotrichea. Ciliate diversity was highest at sites 5 and 6 and lowest at sites 1 and 2. Spathidium sp. was the dominant species in the conditioned land (site 8), while the ciliate Colpoda sp. was present in all the sites examined, showing the highest population density in the sewage treatment plant site (site 5). Statistical analysis showed that ciliate diversity was positively correlated to physicochemical parameters such as interstitial water, total organic matter and organic carbon, total nitrogen and total phosphorous content. Analyses of spirotrichs/colpodids (S/C) ratio and diversity indices implied that the habitat conditions of sites 1, 2, 3 and 8 are relatively unfavourable for soil ciliates to flourish; while sites 4, 5, 6 and 7 provided more favourable conditions. The ubiquity of ciliate distribution suggests their important role in the soil food webs and nutrient cycling, and their community structure and specific characteristics appear to be of major importance for soil formation. A full understanding of soil ciliate diversity and physicochemical parameters helps to inform best practice for improving soil quality as well as conservation practices for sustainable development and management of farms and cultivated lands. In conclusion, ciliate diversity serves as an important and sensitive bio-indicator for soil quality.

Phospholipid distributions in purple phototrophic bacteria and LH1-RC core complexes

In contrast to plants, algae and cyanobacteria that contain glycolipids as the major lipid components in their photosynthetic membranes, phospholipids are the dominant lipids in the membranes of anoxygenic purple phototrophic bacteria. Although the phospholipid compositions in whole cells or membranes are known for a limited number of the purple bacteria, little is known about the phospholipids associated with individual photosynthetic complexes. In this study, we investigated the phospholipid distributions in both membranes and the light-harvesting 1-reaction center (LH1-RC) complexes purified from several purple sulfur and nonsulfur bacteria. 31P NMR was used for determining the phospholipid compositions and inductively coupled plasma atomic emission spectroscopy was used for measuring the total phosphorous contents. Combining these two techniques, we could determine the numbers of specific phospholipids in the purified LH1-RC complexes. A total of approximate 20–30 phospholipids per LH1-RC were detected as the tightly bound lipids in all species. The results revealed that while cardiolipin (CL) exists as a minor component in the membranes, it became the most abundant phospholipid in the purified core complexes and the sum of CL and phosphatidylglycerol accounted for more than two thirds of the total phospholipids for most species. Preferential association of these anionic phospholipids with the LH1-RC is discussed in the context of the recent high-resolution structure of this complex from Thermochromatium (Tch.) tepidum. The detergent lauryldimethylamine N-oxide was demonstrated to selectively remove phosphatidylethanolamine from the membrane of Tch. tepidum.

Modification of Cassava Root Starch Phosphorylation Enhances Starch Functional Properties.

Cassava (Manihot esculenta Crantz) is a root crop used as a foodstuff and as a starch source in industry. Starch functional properties are influenced by many structural features including the relative amounts of the two glucan polymers amylopectin and amylose, the branched structure of amylopectin, starch granule size and the presence of covalent modifications. Starch phosphorylation, where phosphates are linked either to the C3 or C6 carbon atoms of amylopectin glucosyl residues, is a naturally occurring modification known to be important for starch remobilization. The degree of phosphorylation has been altered in several crops using biotechnological approaches to change expression of the starch-phosphorylating enzyme GLUCAN WATER DIKINASE (GWD). Interestingly, this frequently alters other structural features of starch beside its phosphate content. Here, we aimed to alter starch phosphorylation in cassava storage roots either by manipulating the expression of the starch phosphorylating or dephosphorylating enzymes. Therefore, we generated transgenic plants in which either the wild-type potato GWD (StGWD) or a redox-insensitive version of it were overexpressed. Further plants were created in which we used RNAi to silence each of the endogenous phosphoglucan phosphatase genes STARCH EXCESS 4 (MeSEX4) and LIKE SEX4 2 (MeLSF), previously discovered by analyzing leaf starch metabolism in the model species Arabidopsis thaliana. Overexpressing the potato GWD gene (StGWD), which specifically phosphorylates the C6 position, increased the total starch-bound phosphate content at both the C6 and the C3 positions. Silencing endogenous LSF2 gene (MeLSF2), which specifically dephosphorylates the C3 position, increased the ratio of C3:C6 phosphorylation, showing that its function is conserved in storage tissues. In both cases, other structural features of starch (amylopectin structure, amylose content and starch granule size) were unaltered. This allowed us to directly relate the physicochemical properties of the starch to its phosphate content or phosphorylation pattern. Starch swelling power and paste clarity were specifically influenced by total phosphate content. However, phosphate position did not significantly influence starch functional properties. In conclusion, biotechnological manipulation of starch phosphorylation can specifically alter certain cassava storage root starch properties, potentially increasing its value in food and non-food industries.

Improved parameters of Pinus greggii seedling growth and health after inoculation with ectomycorrhizal fungi

Pinus greggii Engelm. ex Parl. is an endemic pine of Mexico with notorious adaptability to eroded, shallow and poor soils. It is widely used in reforestation programmes worldwide. The purpose of the present study is to develop an ectomycorrhizal fungi (ECM) treatment with different native ectomycorrhizal fungal species (collected in P. greggii and Abies vejarii stands) to improve seedling survival of P. greggii. Four-month-old P. greggii var. greggii seedlings were inoculated with ground fruiting bodies of the ECM species Astraeus spp., Boletus barrowsii, Geastrum minimum, Lactarius deliciosus var. deterrimus, Russula cf. atroglauca, Russula spp., Suillus caerulescens, as well as a mixture of three species (Russula sp., R. lutea and L. deliciosus) and soil litter with mycelium from the base of a fruiting body of L. deliciosus. Agronomic variables, and total phosphorous and glucosamine contents were measured in P. greggii seedlings. Inoculated treatments with B. barrowsii, Geastrum minimum and S. caerulescens showed increases in seedling height and basal diameter as well as dry shoot biomass compared with those of the control plants. Geastrum minimum, B. barrowsii and R. xerampelina significantly increased values of dry weight compared with that of the control. Inoculation of soil litter from the base of a fruiting body of L. deliciosus induced the maximum glucosamine response (40.2 mg g−1 of dry root biomass). Geastrum minimum, a fungus collected in P. greggii stands, enhanced basal diameter of pine seedlings in the nursery. Fungal species B. barrowsii, Suillus caerulescens, Russula cf. atroglauca and Russula spp. from the Abies forest improved plant quality in terms of the Dickson quality index and root and shoot biomass, compared with those of the control.

Aplikasi Pupuk N, P, K dan Konsorsium Pupuk Hayati terhadap Retensi Hara, Serapan, dan Hasil Kedelai (Glycine max (L.)) pada Inceptisol

Inceptisol is a widespread soil order with low fertility. Hence it is necessary to improve its quality status through the application of chemical and biological fertilizers. The main objecttive of this study is to determine the effect of NPK fertilizer and biofertlizer consortia (BC) combinations in Inceptisols towards N and P availability in soil and uptake by soybean (Glycine max L.). Experiments were carried out from April to August 2016 at Ciparanje Experimental Farm, Faculty of Agriculture, Universitas Padjadjaran, Jatinangor, Sumedang at the approximate altitude of 720 meters above the sea level. Randomized Block Design experimental design consisted of ten treatments and three replications was used in this study. Treatments consisted of control (no treatment), Recommended NPK dosage, 0 NPK + 1 BC, ¼ NPK + 1 BC, ½ NPK + 1 BC, ¾ NPK + 1 BC, 1 NPK + 1 BC, ¾ NPK + ¼ BC, ¾ NPK + ½ BC and also ¾ NPK + ¾ BC. Experimental results showed that the combination of NPK fertilizer and soybean-spesific biofertilizer consortium increased soil total phosphate content, nitrogen uptake by plant, and soyben yield significantly. Keywords: Biofertilizer, Soybean, total-N, Uptake of N, Inceptisols

Growth and potential purification ability of Nitzschia sp. benthic diatoms in sea cucumber aquaculture wastewater

The growth patterns and water treatment capacity of Nitzschia sp. benthic diatoms in different concentrations of sea cucumber aquaculture wastewater (0%, 10%, 30%, 50%, 80% and 100%) and f/2 medium were studied. Nitzschia sp. grew in different concentrations of aquaculture wastewater and showed remarkable differences in their rate of growth among the treatment groups. Nitzschia sp. grew most quickly (0.83 ind/day) and showed the greatest total chlorophyll-a content in 30% wastewater. The total chlorophyll-a content and growth rate of Nitzschia sp. were strongly correlated (R2 > 0.98). The total lipid (TL), total protein, exopolysaccharide (EPS) and intracellular polysaccharide (IPS) contents of the diatoms were highest in 100% wastewater and showed significant differences among the experimental groups (p < 0.05). Total nitrogen (TN), ammonium-nitrogen (NH4-N) (AN), nitrate nitrogen (NO3-N) (NN), nitrite nitrogen (NO2-N) (NIN) and total phosphate (TP) contents were significantly reduced after cultivation. TN uptake peaked at 54.58% in 30% wastewater. AN uptake exceeded 95% in 30% wastewater and 100% wastewater. NN uptake peaked at 56.42% in 80% wastewater, whereas TP uptake ranged from 16.80% to 27.69%. These results suggest that Nitzschia sp. biomass can be enhanced via cultivation in low-concentration (30%) wastewater, after which their cultivation may be continued in high-concentration (100%) wastewater, increasing their nutritional value and aiding in the removal of surplus nitrogen and phosphorus in sea cucumber aquaculture wastewater. Application of Nitzschia sp. using the recirculating wastewater-treatment methods described has the potential to reduce environmental harm caused by sea cucumber cultivation and thus achieve sustainable aquaculture.

Physiological changes and growth promotion induced in poplar seedlings by the plant growth-promoting rhizobacteria Bacillus subtilis JS

This study aimed to determine the effects of plant growth-promoting rhizobacteria Bacillus subtilis JS on the growth and physiological changes of Populus euramericana and Populus deltoides × P. nigra. Poplar seedlings were treated with B. subtilis JS and their growth was monitored for up to 120 d. Three different types of treatments [control, B1 (B. subtilis:double-distilled water, 1:100, v/v), and B2 (1:50)] were established. B. subtilis JS enhanced seedling height by 62% and total biomass by 37% after 120 d. Physiologically, the photosynthetic rate increased by 54%, and the total chlorophyll (Chl) content, foliage nitrogen and phosphate content were significantly higher after treatment with B2 than that of the control. These results suggest that the total Chl content is directly related to not only the photosynthetic capacity of the foliage but also to the nitrogen content, indicating that the strain JS may promote the growth of poplar.

Spatial and seasonal distribution of carbon, nitrogen, phosphorus, and sulfur and their ecological stoichiometry in wetland soils along a water and salt gradient in the Yellow River Delta, China

Top soils (0–10 cm) were collected in three sampling belts during four seasons in 2014, including bare land (HN1), Calamagrostis epigeios (HN2), Typha orientalis (HN3), Phragmites australis (HN4), Tamarix chinensis (HN5) and Suaeda salsa (HN6) along a water and salinity gradient in the Yellow River Delta, China. Soil organic carbon (SOC), total nitrogen (TN), total phosphorous (TP), total sulfur (TS) and their ecological stoichiometry were measured to investigate their seasonal and horizontal distribution patterns, as well as their important influencing factors such as electric conductivity (EC) and water content (WC). Our results showed that the contents of SOC and TN exhibited similar changing tendency along the water and salinity gradient. The TP contents followed the order HN5 ≈ HN2 > HN3 ≈ HN6 > HN4 > HN1. TS levels generally increased with increasing salinity from HN1 to HN6. The higher levels of SOC and TP were mostly observed in October and August, respectively, while the seasonal variations in TN were heterogeneous under different plant covers. TS contents were lower in August compared with other sampling periods except for HN4. The mean values of the C/N, C/P and C/S ratios along a water-salinity gradient ranged from 26 to 72, 20 to 74, and 61 to 292, respectively. Generally, higher C/P ratios were observed in sampling sites with plant covers in October expect for HN1, whereas they were lower in January or August. SOC, TN and TP were significantly positively correlated with soil organic matter (SOM), silt, WC and cation exchange capacity (CEC) (p < 0.05), whereas TS showed a positive correlation with EC and cations content (p > 0.05). Bulk density (BD) had a great influence on C/N ratio, C/P ratio were mainly effected by SOM, EC and silt, while C/S ratio showed a significant negative correlation with BD, EC, K+, Na+, and Mg2+ (p < 0.05).

Interaction of soil water storage and stoichiometrical characteristics in the long-term natural vegetation restoration on the Loess Plateau

Knowledge of the soil water and stoichiometrical characteristics (SC) during long-term natural vegetation restoration is essential for managing the restoration of vegetation. To evaluate the response of soil water storage (SWS), soil organic carbon (SOC), total nitrogen content (TN) and total phosphorous content (TP) to long-term natural vegetation restoration (∼160 a), we examined the soil moisture and SC in areas with different restoration ages located in the central part of the Loess Plateau, China. Our results showed that the SWS decreased significantly with vegetation restoration and that the C:P ratio, N:P ratio, TN and TP increased significantly. The SWS increased gradually, whereas the SOC, C:P ratio, N:P ratio, TN and TP in each restoration stage decreased significantly with increasing soil depth in the 0–60 cm soil layer. These parameters tended to be stable in the soil layer below 60 cm. Vegetation acts as a link between SWS and soil SC, and they interact with each other indirectly. SWS and SWC showed an significant positive relationship (P < 0.01), whereas SWS and SOC, TN, TP, C:P ratio, and N:P ratio showed significant negative relationships (P < 0.01), thus, SOC, TN and TP are the key chemical factors affecting SWS.. These results could help estimating the productivity and sustainability of semiarid ecosystems and improve future eco-environmental reconstructions.

Microcystin-LR Contamination Status and Physico-Chemical Water Quality Parameters of Five Selected Recreational Water Bodies in Sri Lanka

Microcystin-LR (MC-LR) is the most toxic and commonly encountered cyanotoxin variant in aquatic systems. MC-LR is a hepatotoxin, but evidences suggest that it might also induce kidney injury. There is an increasing trend in mortality due to chronic kidney disease (CKD) in Sri Lanka where the underlying cause of CKD remains complicated. Cyanobacterial toxins is considered as one of the possible reasons implicated in the aetiology of CKDu in Sri Lanka. A significant source of cyanobacterial toxin exposure is recreational use of contaminated freshwater bodies. Therefore, it was a timely need to assess MC-LR contamination status. Thus, in the present study, freshwater bodies of Beira, Boralesgamuwa, Kandy, Kurunegala and Hot water springs in Kinniya were sampled. Triplicate surface water samples were collected from each water body. Surface water temperature, pH, conductivity and dissolved oxygen (DO) were measured at the site itself and chemical analyses of nitrate, total phosphate and chlorophyll-a were carried out. Analysis of MC-LR contamination was done by Enzyme Link Immuno Sorbent Assay (ELISA). In this study, cyanotoxin MC-LR was not reported from Boralesgamuwa whereas all the other water bodies showed MC-LR contamination. The concentrations of MC-LR from the highest to the lowest were reported respectively from Beira lake (2198 ppb), Kandy lake (103 ppb), Kurunegala lake (75.6 ppb) and the Hot water springs (0.34 ppb). Results of the present study revealed that pH, nitrate, total phosphate and chlorophyll-a contents showed significant positive correlation with the MC-LR concentration of each water body (p<0.05) while surface water temperature, DO and conductivity did not show significant correlation to MC-LR contamination.

English

This study was conducted in Arsi Negelle woreda of West Arsi Zone, Oromia regional state. The main objective of the study was to investigate the impacts of soil bund on soil physical and chemical properties in Arsi Negelle woreda. The soil data was collected from sites namely: lowland, midland and highland and from soil bunds aged >4 years, 4years) at both soil sampling depths. Aged soil bunds (treated plots) showed a significant changes on soil physical and chemical properties than control plots. The mean of total nitrogen (TN), available phosphorous (AP) and organic carbon contents were recorded significantly higher (p≤ 0.05) in lowland than highland at both soil sampling depths. In generally, ages of soil bunds and sites had significant effect on many soil physical and chemical properties. The sites and ages interaction had significant effect on bulk density (BD) at both depths at P ≤ 0.05. In conclusion, this study showed that soil bunds had significant effect on many physical and chemical properties of soil in the study area. Key words: Soil bund, bulk density, saturated hydraulic conductivity, electrical conductivity, total nitrogen, organic carbon.

Scaling of soil carbon, nitrogen, phosphorus and C:N:P ratio patterns in peatlands of China

Inspired by the importance of Redfield-type C:N:P ratios in global soils, we looked for analogous patterns in peatlands and aimed at deciphering the potential affecting factors. By analyzing a suite of peatlands soil data (n = 1031), mean soil organic carbon (SOC), total nitrogen (TN) and total phosphorous (TP) contents were 50.51%, 1.45% and 0.13%, respectively, while average C:N, C:P and N:P ratios were 26.72, 1186.00 and 46.58, respectively. C:N ratios showed smaller variations across different vegetation coverage and had less spatial heterogeneity than C:P and N:P ratios. No consistent C:N:P ratio, though with a general value of 1245:47:1, was found for entire peatland soils in China. The Northeast China, Tibet, Zoige Plateau and parts of Xinjiang had high soil SOC, TN, TP, and C:P ratio. Qinghai, parts of the lower reaches of the Yangtze River, and the coast zones have low TP and N:P ratio. Significant differences for SOC, TN, TP, C:N, C:P and N:P ratios were observed across groups categorized by predominant vegetation. Moisture, temperature and precipitation all closely related to SOC, TN, TP and their pairwise ratios. The hydrothermal coefficient (RH), defined as annual average precipitation divided by temperature, positively and significantly related to C:N, C:P and N:P ratios, implying that ongoing climate change may prejudice peatlands as carbon sinks during the past 50 years in China.

Effect of polyphosphates on the quality of frozen light salted cod (Gadus morhua L.) fillets

Frozen light salted fillets have been subject to discussion concerning their definition as foodstuff. EU has recently placed these products in the frozen category. The aim was to investigate how a commercial polyphosphate blend affected the quality of light salted fillets. Fresh and previously frozen fillets of cod were injected with a brine containing 0, 4.5, 9 or 18 g/L of Carnal 2110. Quality, chemical characteristics and phosphate residues were analyzed in fillets. Compared to previously frozen, light salted fillets from fresh raw materials had a whither and less yellow color while significantly lower yields and oxidation levels were registered. No differences were found in drip loss during thawing. Addition of polyphosphate contributed to increased whiteness of both frozen and thawed fillets from both raw material groups, while no effects on yields or drip loss were detected. Polyphosphate reduced oxidation only in the frozen raw material group. Total phosphate contents were higher in fillets from fresh than frozen raw materials and residues were mainly detected as monophosphate. The choice of raw material will affect the end quality and yields and results suggest that polyphosphate can improve light salted fillet quality and therefor may be defined as a food additive.

Reduced sludge production in a membrane bioreactor by uncoupling metabolism and its effect on phosphorus accumulation in the biomass

ABSTRACTDue to its limited recycling or reuse, treatment and disposal of excess waste activated sludge has been a major challenge. As a preemptive method, therefore, uncoupling metabolism for reduced sludge production has been investigated recently. In this study, we operated a pilot-scale A2O-membrane bioreactor (MBR) system incorporating an anaerobic sludge holding tank (SHT) in a sludge recycling line to induce uncoupling metabolism, and investigated sludge production and treatment efficiency. After operation for ≥1 year, the Yobs value was estimated to be 0.041 g mixed liquor suspended solid (MLSS)/g chemical oxygen demand with 198.7 days of solids retention time (SRT). This Yobs value was markedly lower than those reported previously. Since MBR can be operated with a relatively high MLSS and prolonged SRT, the greatest reduction was achieved by combination with uncoupling metabolism. Phosphate fractionation experiments of the MLSS from the pilot MBR suggested the total phosphate content of microorganisms was 47.0 mg P/g mixed liquor volatile suspended solid; 83% higher than that of the activated sludge process and 49% higher than that of the conventional A2O process. Of the increased phosphate contents, that of the acid-insoluble polyphosphate (AISP) fraction was greatest, suggesting that growth inhibition by uncoupling metabolism stimulates AISP synthesis, which can be utilized under growth-limiting conditions.Abbreviations: AISP: acid-insoluble polyphosphate; ASP: acid-soluble polyphosphate; BNR: biological nutrients removal; EPS: extracellular polymeric substance; LMH: L/m2 h; MBR: membrane bioreactor; OST: oxic-settling-anaerobic; PAO: phosphate accumulation organism; PCA: perchloric acid; SBR: sequencing batch reactor; SHT: sludge holding tank; SRT: solids retention time; TN: total nitrogen; TP: total phosphate; WAS: waste activated sludge

Management of food and vegetable processing waste spiked with buffalo waste using earthworms (Eisenia fetida).

The present investigation was focused on the vermicomposting of food and vegetable processing waste (VW) mixed with buffalo dung (BW) under laboratory condition employing Eisenia fetida earthworm species. Four different proportions of VW and BW were prepared and subjected to vermicomposting after 3weeks of pre-composting. After vermicomposting, nitrogen (7.82-20.73g/kg), total available phosphate (4.80-11.74g/kg) and total potassium (7.43-12.75g/kg) content increased significantly as compared to initial feed stocks. Significant reduction was observed in pH (7.56 to 6.55), total organic carbon (48.25-23.54%) and organic matter (83.18-40.68%). Metal content (Fe, Cu, Zn and Ni) was higher in all the vermicomposts than feedstocks. Data on growth and reproduction of earthworm revealed that the highest biomass gain and fecundity of worms were attained in 100% BW followed by [BW75%+VW25%]>[BW50%+VW50%]>[BW25%+VW75%] feedstocks. Results evidenced the suitability of VW (up to 50%) spiked with BW for increasing earthworm population and in providing potent organic manure for agricultural applications.

Land-use change on Mount Gede, Indonesia, reduced native earthworm populations and diversity

The conversion of natural forest to agroforestry plantations and annual cropping systems alters the soil habitat and food resources for biota, including earthworms. Native earthworm species may disappear whereas exotic species with greater tolerance of disturbance and less niche specialisation may thrive. The objective of the study was to compare the earthworm diversity in managed forest and agroforestry systems, which were cultivated for mixed plantation and annual crop production on Mount Gede, Indonesia. All the habitats in the study area were impacted by humans. The forest habitat was a managed forest, with a permanent tree cover, whereas mixed plantation had a partial shrub cover. Meanwhile, homogenous plantation was cultivated with annual crops. Among 3787 individuals collected during July–October 2012, five Oriental earthworm species were identified in the soil communities of Mount Gede: Drawida nepalensis, Notoscolex javanica, Pheretima pura-group, Polypheretima moelleri, and Polypheretima sempolensis. Also, 18 species were found that are reported to be non-Oriental in origin. Anthropogenic disturbance of forests on Mount Gede, due to conversion into plantations, alters the earthworm environment by increasing soil water content, temperature and total phosphorous content, while decreasing organic carbon. N. javanica was the only native species to survive this deforestation, while the exotic Ocnerodrilus occidentalis and Pontoscolex corethrurus thrived, becoming the eudominant species. From the forest area to the mixed and homogenous plantations, the predicted decreasing diversity is evidenced by the lowering trend of Shannon’s diversity index. In conclusion, the land-use change into mixed plantations and annual croplands has reduced earthworm diversity in this region of Mount Gede, Indonesia.

Modelling of phosphate enrichment and trophic status of Sipin Lake Jambi using TSI Carlson method

Floating fishery net (keramba) activity in Sipin Lake Jambi has increased significantly in the last decade. This intensive fishery results in enrichment of phosphate due to the application of fish feeding and induces eutrophication. The objectives of this study are to determine phosphate enrichment, the trophic status using TSI Carlson method and to propose a model of phosphate enrichment in the lake water. TSI Carlson is a method to determine the trophic status condition in the water body. Composite water samples were collected at up-, downstream and middle of the lake. Total phosphate content, chlorophyl-a, and brightness were measured. The results show that the average of total phosphate, chlorophyl-a, and brightness of the lake water are 0.0505 mg/L, 5.86 μg/L and 58 cm, respectively. These figures indicate that fishery net activity has induced eutrophication with phosphate enrichment of 9.65 T/yr. A proposed TSI Carlson model estimates the TSI value would be 61.79 within next ten years with phosphate enrichment of 12.04 T/yr. Application of double fishery nettings (keramba) would be expected to reduce these figures and the risk of eutrophication in the lake.

Differences in Breast Milk Composition of HIV-Infected and HIV-Uninfected Mothers of Premature Infants: Effects of Antiretroviral Therapy.

A key strategy to prevent mother-to-child transmission of the human immunodeficiency virus (HIV) and to reduce infant morbidity and mortality includes providing the HIV-exposed premature infant with breast milk accompanied by dual anti-retroviral therapy (ART). The effects of HIV and ART on premature breast milk composition are largely unknown. The aim of the study was to assess and compare the breast milk composition of HIV-infected mothers receiving ART and HIV-uninfected mothers who gave birth to premature infants. Lactating HIV-infected women receiving ART (n = 38) and HIV-uninfected women (n = 36) with premature infants provided two breast milk samples on days 7 and 9, respectively, of lactation. Breast milk samples were analyzed for total energy, protein, carbohydrates, fat, phosphate, iron, zinc, and copper content. Breast milk of HIV-infected women contained higher protein (1.95 versus 1.78 g/100 g; p = 0.04), fat (4.42 versus 3.49 g/100 g; p = 0.01), and copper (0.64 versus 0.56 mg/L; p = 0.02) levels; whereas carbohydrate (5.37 versus 6.67 g/100 g; p = 0.002) and zinc (5.26 versus 5.78 mg/L; p = 0.04) levels were lower compared with those of HIV-uninfected women. Zinc levels were significantly lower in HIV-infected women with early gestation periods, and the lowest levels were observed in women who received ART for ≤4 weeks (0.58 mg/L; p = 0.03). Total energy (78.22 versus 61.48 kCal/100 mL) and fat levels (5.39 versus 3.00 g/100 mL) were significantly higher in the late gestation period HIV-infected women. Copper levels (0.61 mg/L) were higher in the late gestation period women who received >4 weeks of ART exposure (p = 0.05). Differences existed in the breast milk composition of HIV-infected women on ART compared with HIV-uninfected women. ART exposure period may influence breast milk composition.

Effects of soil nutrients and climate factors on belowground biomass in an alpine meadow in the source region of the Yangtze-Yellow rivers, Tibetan Plateau of China

Improving our knowledge of the effects of environmental factors (e.g. soil conditions, precipitation and temperature) on belowground biomass in an alpine grassland is essential for understanding the consequences of carbon storage in this biome. The object of this study is to investigate the relative importance of soil nutrients and climate factors on belowground biomass in an alpine meadow in the source region of the Yangtze and Yellow rivers, Tibetan Plateau. Soil organic carbon (SOC), total nitrogen (TN) and total phosphorous (TP) contents and belowground biomass were measured at 22 sampling sites across an alpine meadow on the Tibetan Plateau. We analyzed the data by using the redundancy analysis to determine the main environmental factors affecting the belowground biomass and the contribution of each factor. The results showed that SOC, TN and TP were the main factors that influenced belowground biomass, and the contribution of SOC, TN and TP on biomass was in the range of 47.87%–72.06% at soil depths of 0–30 cm. Moreover, the combined contribution of annual mean temperature (AMT) and mean annual precipitation (MAP) on belowground biomass ranged from 0.92% to 4.10%. A potential mechanism for the differences in belowground biomass was caused by the variations in soil nitrogen and phosphorous, which were coupled with SOC. A significant correlation was observed between MAP and soil nutrients (SOC, TN and TP) at the soil depth of 0–10 cm (P<0.05). We concluded that precipitation is an important driving force in regulating ecosystem functioning as reflected in variations of soil nutrients (SOC, TN and TP) and dynamics of belowground biomass in alpine grassland ecosystems.