Studies on the bacteria isolated anaerobically from paddy field soil IV. Model experiments on the production of branched-chain fatty acids

Based on the fact that the clostridia isolated from paddy field soil were mostlyproteolytic and that they produced some branched-chain volatile fatty acids on peptone media, the occurrence and the substrates for the production of such acids in paddy soil were investigated. The results obtained are as follows:

• 1) It was revealed that two branched-chain volatile fatty acids, iso-valeric and iso-butyric acids, were detected In fresh paddy field soil.

• 2) The paddy soil supplemented with peptone solution produced significant amounts of branched-chain volatile fatty acids-iso-butyric and iso-valeric acidsin addition to straight-chain volatile fatty acids-acetic, propionic, and butyric acids. When glucose was added instead of peptone, not branched-chain fatty and propionic acids were detected but only acetic and butyric acids. These facts indicate that the branched-chain fatty acids may originate from amino acids.

• 3) When a pair of amino acids, such as proline and leucine or proline-and valine, were supplemented in addition to peptone, the production of iso-valeric or iso-butyric acids was increased, respectively. Even In the case of glucose, the supplementation of a pair of amino acids supported the production of branched-chain fatty acids. These facts indicate that the Stickland reaction may take place in paddy field soil.

• 4) All the strains of strict anaerobes isolated from the soil and supplemented with peptone formed iso-valeric and iso-butyric acids in addition to two or three kinds of volatile fatty acids when they were cultured in medium containing peptone. All of them were classified as belonging to genus Clostridium. No strains of facultative anaerobes isolated from the same soil produced any branched-chain fatty acids, but produced only acetic acid.

• 5) In conclusion, these results reveal that the branched-chain fatty acid in paddy field soil is produced only by clostridia through the Stickland reaction.

     

Studies on controlled potassium fertilizers I. Relative effectiveness of various hardly soluble potassium compounds as source of slow-release

Relative effectiveness of various hardly soluble K materials as sources of slow availability for plants was compared by uptake of K in Brassica seedlings grown in quartz sand-nutrient medium with occasional leaching, and by the release pattern of K.

Material characteristics exert a great influence on K availability. Water solubility is not a dominant factor for controlling the availability of K to the plants, but particle sizes and the reaction of K in fertilizers with nutrient ions in the medium play a significant role in the release pattern of K. Moreover, the plant roots have an ability to accelerate K release from such hardly soluble aources as fused potassium phosphate, KMgPO₄, and K₂CaP₂O₇.

According to the results obtained, that is, total dry matter production, pattern of K uptake through four successive croppings and loss of K by leaching the examined materials appear to be divided into the following three groups:

• a) Materials having a high degree of slow availability-KMgPO₄ (+3 mesh), fused potassium phosphate (+28 mesh and -65 mesh), K₂CaP₂O₇ (+3 mesh), and calcined potassium phosphate (-7+14 mesh).

• b) Materials having a mid degree of slow availability- KCaPO₄ (+3 mesh), liparite potassium. Sulphur coated KCl, calcined potassium phosphate (-32 mesh), K₂CaP₂O₇ (-32 mesh), KMgPO₄ (-32 mesh), and KPO₃ (+3 mesh).

• c) Materials having a low degree of slow availability-KCaPO, ( -32 mesh), KPO, (-32 mesh).

     

Evaluation of Several Indices of Potentially Mineralizable Soil Nitrogen

Abstract

A routine soil test that accurately predicts soil nitrogen (N) mineralization has long eluded researchers. Soil incubations, which are not practical for routine soil testing, are the only methods that have proven successful. Although several quick analytical methods have been proposed, no one method has correlated consistently enough to be implemented into a soil‐testing program. The objective of this study was to compare proposed quick analytical procedures with the amount of ammonium (NH₄)‐N mineralized after a 14‐d anaerobic incubation. The analytical methods of interest were

1. applying a mild acid oxidation to the soil using acidified permanganate;

2. analyzing a 1 M potassium chloride (KCl) soil extract in the ultraviolet (UV) spectrophotometric range before and after nitrate (NO₃) removal with Devarda's alloy; and

3. quantifying soil amino sugar‐N content using the Illinois soil N test (ISNT) diffusion method.

Fifty agricultural soils with different physical and chemical properties were utilized in this study. All methods displayed significant relationships with the anaerobic incubation procedure; however, some methods displayed higher, more acceptable, coefficients of determination. The ISNT and UV spectrophotometry measurement at 210 nm after NO₃ removal failed to accurately estimate N mineralization (R²=0.45 and 0.31, respectively). The acid oxidation procedure and UV measurement at 260 nm of soil extracts before NO₃ removal produced better results with coefficients of determination of 0.58 and 0.56, respectively. We suspect the ability of some methods to predict N mineralization was hindered because of the wide variety of geographic locations from which the soils were collected. Additional analyses were conducted on a subset of 16 silt‐loam soils from Arkansas. The coefficient of determinations increased for each method: acid oxidation procedure increased to 0.83, the ISNT increased to 0.71, and the UV method (at 260 nm before NO₃ removal) increased to 0.63. If anaerobic incubation is a true indication of N mineralization in the field, the aforementioned methods display promise to correlate with N uptake by field‐grown plant studies when adapted to a specific geographic location and/or soil series.     

Untersuchungen zur physiologischen Bedeutung von Chlorophyllb,eine Literaturübersicht

Значение хлорофилла Ъ обсуждается в литер атуре со следующих точек зрен ия:

1. Улучшение абсорбции света зелеными расте ниями.
2. Полимеризация фотос интетически возникш их моносахаридов до кра хмала.
3. Стабилизация фотоси нтетического аппара та.
4. Первичная фотосинте тическая реакция как таковая.
5. Накопление и перенос энергии на фотосинте тически действующие молекул ы хлорофилла a.

     

The response of specific conductance to environmental conditions in the everglades National Park,Florida

The specific conductance of surface delivery waters to the Shark River Slough (Everglades National Park, Florida) has increased significantly since the completion of Levee 29 (L-29) and the S-12 water delivery system in the early 1960's. In order to document the response of specific conductance in the slough to changing environmental conditions, it was monitored continuously for a period of 12 mo at a location in central Shark approximately 17 km south of the water delivery site. In addition, variability in isoconductivity patterns throughout the slough was assessed by conducting biweekly surveys at 97 locations. Specific conductance was found to respond to a variety of natural and manmade environmental changes and proved to be an important management tool serving as an early indicator of potentially broad changes in water quality. Factors important in determining overall isoconductivity patterns in Shark Slough include:

1. the ionic composition of surface delivered to Shark Slough via the S-12 delivery structures.
2. the quantitative relationship between the amount of surface water delivered to the slough and the amount of precipitation falling directly upon the slough.
3. the effects of evapotranspiration and concentration of biological organisms during seasonal periods of extreme drawdown.

     

Calibration of collection procedures for the determination of precipitation chemistry

Precipitation is currently collected by several methods, including several different designs of collection apparatus. We are investigating these differing methods and designs to determine which gives the most representative sample of precipitation for the analysis of some 25 chemical parameters. The experimental site, located in Ithaca, New York, has 22 collectors of 10 different designs. The designs include bulk (wet and dry deposition collected together), wet only (only rain and snow) and wet/dry (collects wet and dry deposition separately). In every sampling period, which varies from 1 day to 1 mo, depending on the time variable being tested, the following chemical parameters are determined: conductivity, pH, Ca, Mg, Na, K, NH₄, N0₃, N_total Si0₄, PO₄, P_total, Cl, SO₄, DOC, Zn, Cu, Mn, Fe, Al, Ni, Cd, Pb, Ag, DDT, DDE, Dieldrin and PCB's. The results of the investigation lead us to conclude that:

1. Precipitation samples must exclude dry deposition if accurate information on the chemical content of precipitation is required.
2. Substantial contamination results when glass and plastic collectors are used to sample precipitation for inorganic and organic components, respectively.
3. The inorganic components of precipitation samples of low pH (3.5 to 4.5), with the exception of P0₄ and Cl, exhibited no significant change in concentration when stored at 4\dgC for a period of 8 mo. We believe this is due to the stabilizing influence of a large concentration of H ions.
4. If quantitative information on the chemical composition is required, precipitation samples should be collected at no longer than weekly intervals if immediate collection is not possible.

     

Effects of straw amendment and moisture on microbial communities in Chinese fluvo-aquic soil

Purpose

Returning crop straw into fields is a typical agricultural practice to resolve an oversupply of straw and improve soil fertility. Soil microorganisms, especially eukaryotic microorganisms, play a critical role in straw decomposition. To date, microbial communities in response to straw amendment at different moisture levels in Chinese fluvo-aquic soil are poorly understood. The aim of this study was to explore the effects of straw amendment and moisture on microbial communities in Chinese fluvo-aquic soil.

Materials and methods

Two soils (one was applied with organic manure, and the other was not applied with any fertilizer) from a long-term field experiment in the North China Plain were collected. Soils with and without straw amendment at 25 and 55 % of the average water-holding capacities of the two soils were incubated at 25 °C for 80 days. All treatments were sampled 20 and 80 days after the start of incubation. Microbial biomass and community structure were analyzed by phospholipid fatty acids (PLFA) assay, and the eukaryotic diversity and community composition were assessed via barcoded pyrosequencing of the 18S ribosomal RNA (rRNA) gene amplicons.

Results and discussion

PLFA analysis showed that straw amendment increased the biomass of Gram-positive bacteria, Gram-negative bacteria, actinobacteria, and fungi and shifted microbial community structure. The varied straw availability resulted in a large variation in microbial community structure. In the presence of straw, actinobacterial and fungal biomass both decreased under high moisture content. 18S rRNA gene pyrosequencing indicated that straw amendment decreased eukaryotic diversity and richness and probably restructured the eukaryotic community. Under identical moisture content, long-term organic manure-fertilized soil had higher eukaryotic diversity and richness than the unfertilized soil. In the amended soils under high moisture content, the relative abundance of dominant fungal taxa (Dikarya subkingdom, Ascomycota phylum, and Pezizomycotina subphylum) decreased.

Conclusions

Straw amendment increases microbial biomass, shifts microbial community structure, and decreases eukaryotic diversity and richness. High moisture content probably has a negative effect on fungal growth in the amended soils. In conclusion, microbial communities in Chinese fluvo-aquic soil are significantly affected by straw amendment at different moisture levels.     

Fundamental roles of biological barriers in mercury accumulation and transfer in freshwater ecosystems (analysis at organism,organ, cell and molecular levels)

In the framework of an ecotoxicological approach to the processes of bioaccumulation and transfer of Hg in freshwater systems, we present a synthesis of our experimental studies concerning the interactions between inorganic Hg and MeHg and biological barriers

- at organism and organ levels : three biological models are selected: fish (Salmo gairdneri), burrowing mayfly nymphs (Hexagenia rigida) and rooted macrophytes (Elodea densa, Ludwigia natans). Results show strong specificities of the biological barriers (gills, intestine, roots, ...) towards metal fixation and absorption, closely related to the chemical form of the metal, the contamination sources (water, sediments or food) and the physico-chemical characteristics of the medium ;

- at cell and molecular levels : biophysical study of Hg fixation on membrane reveals a new binding site on the phospholipids, the primary amine group on serine and ethanolamine polar heads, jointly with the SH groups of proteins ; Hg(II) induces a strong rigidification of the phospholipidic bilayers. Inorganic Hg and MeHg transports through model membranes (BLM) are essentially due to diffusion of neutral chloride species. These interactions between Hg compounds and membranes are strongly dependent on Hg chemical speciation (pH and pCl effects).

     

Plant growth promoting bacteria increases biomass,effective constituent,and modifies rhizosphere bacterial communities of Panax ginseng

Purpose: The main aim of this study was to introduce and explore plant growth-promoting bacteria (PGPB) indigenous to ginseng, and to evaluate their ability to improve production and quality, and effect on rhizosphere niche in ginseng.

Materials and methods: Endophytic bacteria were isolated from root, stem, and leaf of ginseng from different sites and genotype in China and Korea, screened based on their beneficial properties as PGPB. Nine bacterial isolates were selected according to their plant growth properties including soluble phosphate and potassium, ammonia, auxin and siderophore producing, ACC deaminase, and antagonistic pathogen as well. Changes in ginseng after PGPB inoculation were evaluated with respect to the non-inoculated control.

Results and Conclusions: The PGPB isolates were identified as genera Bacillus, Lysinibacillus, Rhizobium, Stenotrophomonas, Erwinia, Ochrobactrum, Enterobacter and Pantoea based on 16S rRNA sequences. Inoculation of G209 and G119 increased not only plant height, root length, fresh weight, and dry weight, but also root activity and the amount of ginsenosides significantly. In particular, using the Illumina Miseq platform, the native bacterial community of rhizospheric soil maintained high community diversity and increased abundance of specific bacteria. Therefore, they may be play a crucial role in sustainable ginseng cultivating in farmland.     

Effects of combined sewer overflows and storm water drains on metal bioavailability in small urban streams (Prague metropolitan area,Czech Republic)

Purpose

The aims of the study were to evaluate the effect of combined sewer overflows (CSO) and storm water drains (SWD) on metal bioavailability in small urban streams in Prague and to evaluate levels of metals in water, sediment, and macroinvertebrates. The following working hypotheses were adopted: (a) sites dominantly affected by SWD are less polluted by metals, and (b) sites dominantly affected by SWD have higher bioavailability of metals.

Materials and methods

Physical and chemical parameters (pH, conductivity, NO₃-N, NH₄-N, COD, alkalinity, and water hardness) and concentrations of the metals Cu, Zn, Pb, Ni, and Cr were determined in samples of water and sediment at five to six sites on four target streams—Záti?ský Creek, Ko?íkovský Creek, Boti? Creek, and Rokytka Creek—three to five times per year during the period 2002–2004. The sites from all studied creeks were categorized into five groups according to the prevailing type of urban drainage impact. Macroinvertebrates were sampled and analyzed for metals at each site for a period of 1 month. The concentration patterns of metals were interpreted by partition coefficient (Kd), hazard quotient (HQ), cumulative criterion unit (CCU), and biota sediment accumulation factor (BSAF).

Results and discussion

Concentrations of metals in water as well as in sediment at sites receiving water from SWD were lower than at sites where creeks receive water from CSO, except for Pb. Concentrations of Cu, Zn, and Pb in sediment were higher at sites affected by CSO. Concentrations of metals in aquatic macroinvertebrates, expressed as BSAF, indicated higher values at sites affected by SWD. Frequencies of high BSAF (>1) were lower in CSO compared to SWD. This finding was explained by (a) a decrease of pH on SWD sites compared to the increase of pH on CSO sites during rain events, (b) a greater resuspension of sediment at SWD sites during rain events, and (c) an abundance of organic matter in CSO available for sorption of metals and a corresponding reduction of their bioavailability.

Conclusions

In the study area, the type of urban drainage affects the bioavailability of metals—while SWD increase metal bioavailability, CSO cause its decrease. The sediments in SWD sites do not indicate risk to the benthic community according to the applied environmental quality standards. Water and sediment in creeks affected by SWD are less polluted by metals. Both working hypotheses were therefore supported.

     

A two-dimensional quantification of soil ped shape

Quantification of soil ped shape is discussed from three viewpoints:

• 1 The theoretical reasons why quantification of ped shape should be useful (objective classification of shape, improved understanding of ped/pore relationships, soil genesis and ped development and as a measure of soil heterogeneity);
• 2 The theoretical division of irregular shape into three components (circularity, angularity and surface roughness) and how circularity and surface roughness can be quantified using Cox's R-statistic and the Fractal dimension (D). Angularity remains unquantified;
• 3 The testing of a computer program written to quantify ped shape against six criteria that were presented (Clark, 1981) to allow an assessment of shape quantification methods and the calibration of the program using Pettijohn's (1 957) standard shape chart.

It is concluded that R and D are able quantifiers of irregular particle shape.     

Potentialities of Six Plant Species on Phytoremediation Attempts of Fuel Oil-Contaminated Soils

A field experiment investigating the phytoremediation potential of six plant species—Goosegrass (Eleusine indica), Bermuda grass (Cynodon dactylon), Sessile joyweed (Alternanthera sessilis), Benghal dayflower (Commelina benghalensis), Lovanga (Cleome ciliata), and Chinese violet (Asystasia gangetica)—on soil contaminated with fuel oil (82.5 ml/kg of soil) have been conducted from March to August 2016. The experiments consider three modalities—Tn: unpolluted planted soils, To: unplanted polluted soils, and Tp: polluted planted soil—randomized arranged. Only three (E. indica, C. dactylon, and A. sessilis) of the six species survived while the others died 1 month after the beginning of experimentations. The relative growth indexes showed a strong similarity between the growth parameters of E. indica and C. dactylon, each on polluted and control soils, unlike A. sessilis. Total petroleum hydrocarbons (TPHs) removal efficiency were 82.56, 80.69, and 77% on soil planted with E. indica, C. dactylon, and A. sessilis, respectively; and 57.25% on non-planted soil. According to the bioconcentration and translocation factors, E. indica and A. sessilis are involved on rhizodegradation and phytoextraction of hydrocarbons whereas C. dactylon is only involved into rhizodegradation. Overall, E. indica and C. dactylon out-yielded A. sessilis in the phytoremediation capacity of fuel oil-contaminated soils.     

Sulfur nutrition effects on dinitrogen fixation of seedling alfalfa

Greenhouse experiments with alfalfa (Medicago sativa L. cv. ‘Apollo') were performed to evaluate the effect of varied nutrient solution concentrations of S on the yield, nodulation, dinitrogen fixation, N and S concentration, and the partitioning of N and S into shoots and roots.

Sulfur treatments consisted of four levels (0, 1, 2.5, and 25 mg S/L) of added S. The experimental design was a randomized complete block, with three replications. Seeds were inoculated with commercial inoculum, planted in plastic containers of acid‐washed sand, and irrigated with nutrient solution for one minute, at 2 h intervals.

Sulfur application increased the yield of all treatments. The results demonstrated that the addition of 2.5 mg S/L to the nutrient solution, besides providing the highest total dry matter yield (12 g/72 plants), showed the highest percent yield increase (19%), acetylene reduction rate (0.426 umole ethylene/mg nodule dry wt/h), total N content (306 mg/72 plants), percent recovery of S (3.8%), and percent increase in N due to dinitrogen fixation (32%).

N:S ratios obtained were different for shoots and roots, with S application decreasing the N:S ratios. The N:S ratios of 16:1 (shoots), and 9:1 (roots) obtained in the 2.5 mg S/L treatment were found to be adequate for normal growth and development.

These data indicated that the 2.5 mg S/L treatment (2.7 mg total S/L) was optimal for alfalfa seedling development.     

Genetic diversity of a <Emphasis Type="Italic">Coffea</Emphasis> Germplasm Collection assessed by RAPD markers

Genetic diversity and relationships within and among nine species of Coffea, one species of Psilanthus and the Piatã hybrid from the Coffee Germplasm Collection of Instituto Agronômico de Campinas (IAC), Brazil were assessed using RAPD markers. Genetic diversity and relationships were evaluated by proportion of polymorphic loci (P), Shannon’s genetic index (H′ and G′_ST) and clustering analysis. The overall RAPD variation among all accessions was mostly partitioned between rather than within species. However, C. canephora and C. liberica showed a high genetic diversity within the species (\({\underline{\hbox{H}'}} \) _sp = 0.414 and \({\underline{\hbox{H}'}} \) _sp = 0.380, respectively) and this was highly structured (high \({\underline{\hbox{G}'}} \) _ST). Genetic diversity from C. congensis and C. arabica was also structured, but with lower levels of genetic diversity (\({\underline{\hbox{H}'}} \) _sp = 0.218 and \({\underline{\hbox{H}'}} \) _sp = 0.126, respectively). The results were consistent with agronomic and molecular studies and demonstrated that the IAC Coffea Collection is representative of the phylogenetic structure observed in the genera. This study devises sampling strategies for coffee germplasm collections and provides genetic diversity parameters for future comparisons among them.     

Phosphorus Fertility Assessment of Intensively Farmed Areas of Catchments Draining to the Great Barrier Reef World Heritage Area; 1: Soil Phosphorus Status

Abstract

Australia's reef water quality protection plan has a key objective: “reduce the load of pollutants from diffuse sources in the water entering the Reef.” This article reports on a survey to assess the contemporary phosphorus (P) status of fertilized cropping soils across 21 catchments in coastal Queensland, Australia. The survey focused on surface soils from cane farms, vegetable and subtropical/tropical fruit tree sites. There were sampling depth effects on P levels in sugar and fruit tree sites (lower with depth). Importantly, 84% of 105 sugarcane sites were excessively fertile and only 3% rated low (P deficient). Some 75% of 16 vegetable sites and 38% of 8 fruit tree sites had excess ratings for extractable soil P fertility. Highest total P levels (0–10 cm) occurred in fruit tree sites, followed by vegetable and sugarcane soils. There are regional differences in P soil fertility, and the recycling of mill by‐products needs attention. Part 2 (Bloesch and Rayment 2006 Bloesch, P. M. and Rayment, G. E. 2006. “Phosphorus fertility assessment of intensively farmed areas of catchments draining to the Great Barrier Reef World Heritage Area, 2: Potential of soils to release soluble phosphorus”. In Communications in Soil Science and Plant Analysis 37 [Google Scholar]) examines the potential of these soils to release soluble P in a nutrient‐sensitive area.     

Characteristics of bacterial community in the water and surface sediment of the Yellow River,China, the largest turbid river in the world

Purpose

Few studies have described the bacterial community structures of turbid rivers. In this paper, the characteristics of the bacterial community in the water and surface sediment of the Yellow River, China, the largest turbid river in the world, were studied.

Materials and methods

Water and sediment samples were collected from six sites along the river. Bacterial community composition was determined using the 16S ribosomal RNA (rRNA) gene clone library technique. The relationship between environmental parameters and bacterial diversity was analyzed.

Results and discussion

A total of 1,131 gene sequences were obtained and clustered into 639 operational taxonomic units (at the 97 % identity level), with Proteobacteria as the predominant phylum. The Shannon index for water samples ranged from 3.39 to 4.40 and was generally higher than that in other rivers; this was probably due to the high suspended particulate sediment (SPS) concentration in the Yellow River, which can provide more habitats for both aerobic and anaerobic bacteria. Also, the bacterial diversity of the water samples was slightly higher than that of the surface sediment samples. The bacterial diversity of water increased along the river in the downstream direction, while there was no trend for the sediment. Redundancy analysis indicated that pH, dissolved organic carbon (DOC), and SPS were the main factors controlling the water bacterial community in the Yellow River, and pH, nitrate–nitrogen, and water content were the main factors for the surface sediment bacterial community.

Conclusions

This study indicated that the bacterial diversity of the Yellow River is generally higher than that in other rivers, suggesting that SPS plays an important role in regulating bacterial diversity and community structure in aquatic environments.     

CO2-mitigation by agroforestry

Agroforestry is a very important option for C-fixation in the tropics because of the large area suitable for this practice. The amount of C directly sequestered by trees within the different agroforestry systems normally ranges from 3 to 25 t · ha^?1 and in some cases up to 60 t · ha^?1. Additional CO₂-mitigating effects can achieve more than 20 times this quantity. Such effects are:

the protection of existing forests.

the conservation of soil productivity.

the reduction of fossil energy consumption by use of timber instead of more energyintensive raw materials and

the substitution of fossil fuel by wood as an energy source.

     

DELPHI - Ein Modell zur Langzeitprognose der Verlagerung von Stoffen in Böden

DELPHI - a leaching model for long term simulation

• ? the integration of a cascade model for the simulation of water movement

• ? the determination of typical monthly rates of decomposition due to soil temperature

• ? an iterative solution of convective-dispersive solute transport equation and

• ? the possibility to consider the spatial variability of pore water velocity

the model is proper for long term simulations A new model for the behaviour of chemicals in soil is described. Because of