Effect of Natural Vegetation Strips and Herbicides on Enzyme Activities and Bacterial Diversity in Olive-Orchard Systems

AbstractGolden apple snails (GAS) have become a serious pest for agricultural production in Asia. A sustainable method for managing GAS is urgently needed, including potentially using them to produce commercial products. In this study, we evaluate the effects of GAS residues (shell and meat) on soil pH, bacterial diversity, enzyme activities, and other soil characteristics. Results showed that the amendment of GAS residues significantly elevated soil pH (to near-neutral), total organic carbon (TOC) (by 10-134%), NO3-N (by 46-912%), NH4-N (by 18-168%) and total nitrogen (TN) (by 12-132%). Bacterial diversity increased 13% at low levels of amendment and decreased 5% at high levels, because low-levels of GAS residues increased soil pH to near-neutral, while high-levels of amendment substantially increased soil nutrients and subsequently suppressed bacterial diversity. The dominant phyla of bacteria were: Proteobacteria (about 22%), Firmicutes (15-35%), Chloroflexi (12%-22%), Actinobacteria (8%-20%) Acidobacteria, Gemmatimonadetes, Cyanobacteria and Bacterioidetes. The amendment of GAS residues significantly increased the relative abundance of Firmicutes, Gemmatimonadetes, Bacterioidetes and Deinococcus-Thermus, but significantly decreased the relative abundance of Chloroflexi, Actinobacteria, Acidobacteria, Cyanobacteria and Planctomycetes. Our results suggest that GAS residues treatment induces a near-neutral and nutrient-rich soil. In this soil, soil pH may not be the best predictor of bacterial community composition or diversity; rather soil nutrients (ie., NH4-N and NO3-N) and soil TOC showed stronger correlations with bacterial community composition. Overall, GAS residues could replace lime for remediation of acidic and degraded soils, not only to remediate physical soil properties, but also microbial communities.ImportanceThe wide spreading golden apple snail (GAS) is a harmful pest to crop productions and could result in soil and air pollutions after death. In the previous study, we developed a biocontrol method: adding GAS residues to acidic soil to mitigate the living GAS invasion and spread, improve soil quality, and reduce soil and air pollution. However, the effects of GAS residues amendment on bacterial diversity and community still remain unclear. This study provided insights into bacterial diversity and community compositions to facilitate the evaluation of GAS residues application.

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The Effects of Organic and Mineral Fertilization on Soil Enzyme Activities and Bacterial Community in the Below- and Above-Ground Parts of Wheat

Agronomy ◽

10.3390/agronomy10101452 ◽

2020 ◽

Vol 10 (10) ◽

pp. 1452

Author(s):

Abdoulaye Amadou ◽

Alin Song ◽

Zhi-Xi Tang ◽

Yanling Li ◽

En-Zhao Wang ◽

...

Keyword(s):

Bacterial Community ◽

Bacterial Diversity ◽

Enzyme Activities ◽

Organic Amendment ◽

Mineral Fertilizer ◽

Soil Enzyme ◽

Community Diversity ◽

Bulk Soil ◽

Soil Enzyme Activities ◽

Soil Rhizosphere

Bacterial community and soil enzymatic activity depend on soil and management conditions. Fertilization is an important approach to maintain and enhance enzyme activities and microbial community diversity. Although the effects of fertilizer application on soil microbial community and related parameters are explored, the effects on the soil microbiome associated with those of wheat plant organs, including those associated with roots and spikelets, are not well-known. Therefore, in this study, by using a sequencing approach, we assessed the effects of inorganic fertilizers, manure, and biochar on soil enzyme activities, bacterial community diversity and structure in the bulk soil, rhizosphere, roots, and spikelet of wheat (Triticumaestivum L.). For this, different treatment biochar (BC), manure (OM), low mineral fertilizer (HL), high mineral fertilizer (HF), and no fertilizer (FO) were used for the enzyme activities and bacterial community structure diversity tested. The result showed that organic amendment application increased total nitrogen, soil available phosphorus, and potassium compared to inorganic fertilizer and control, especially in the rhizosphere. Enzyme activities were generally higher in the rhizosphere than in the bulk soil and organic amendments increased activities of acid phosphatase (AcP), β-1,4-N-acetyl-glucosaminidase (NAG), and phenol oxydase (PhOx). Compared with soil and rhizosphere, bacterial diversity was lower in wheat roots and evenlower in the spikelet. From the bulk soil, rhizosphere to roots, the fertilization regimes maintained bacterial diversity, while organic amendment increased bacterial diversity in the spikelet. Fertilization regimes significantly influenced the relative abundances of 74 genera across 12 phyla in the four compartments. Interestingly, the relative abundance of Proteobacteria (Citrobacter, Pantoea, Pseudomonas, and unclassified Enterobacteriaceae) in the spikelet was decreased by increasing inorganic fertilizer and further by manure and biochar, whereas those of Actinobacteria (Microbacterium and an unclassified Microbacteriaceae) and Bacteroidetes (Hymenobacter and Chitinophagaceae) were increased. The results suggest that potential bacterial functions of both roots and above-ground parts of wheat would be changed by different organic amendment regimes (manure and biochar).

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Conversion of cropland to natural vegetation boosts microbial and enzyme activities in soil

The Science of The Total Environment ◽

10.1016/j.scitotenv.2020.140829 ◽

2020 ◽

Vol 743 ◽

pp. 140829

Author(s):

Lilit Ovsepyan ◽

Irina Kurganova ◽

Valentin Lopes de Gerenyu ◽

Yakov Kuzyakov

Keyword(s):

Enzyme Activities ◽

Natural Vegetation

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Impact of Water Stress on Microbial Community and Activity in Sandy and Loamy Soils

Agronomy ◽

10.3390/agronomy10091429 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1429 ◽

Cited By ~ 1

Author(s):

Sylwia Siebielec ◽

Grzegorz Siebielec ◽

Agnieszka Klimkowicz-Pawlas ◽

Anna Gałązka ◽

Jarosław Grządziel ◽

...

Keyword(s):

Water Stress ◽

Microbial Communities ◽

Bacterial Diversity ◽

Water Deficit ◽

Enzyme Activities ◽

Soil Microbial Communities ◽

Stress Conditions ◽

Drought Period ◽

Soil Microbial ◽

Level 2

Prolonged drought and extreme precipitation can have a significant impact on the activity and structure of soil microbial communities. The aim of the study was to assess the impact of drought length on the dynamics of mineral nitrogen, enzyme activities and bacterial diversity in two soils of different texture (sand and silt loam, according to USDA classification). An additional objective was to evaluate the effect of compost on the alleviation of soil microbial responses to stress conditions, i.e. alternating periods of drought and excessive soil moisture. The pot study was carried out in a greenhouse under controlled conditions. Compost was added at an amount equal to 3% of soil to the sandy soil, which was characterised by a significantly lower water retention capacity. Specific levels of water stress conditions were created through application of drought and soil watering periods. For each soil, four levels of moisture regimes were set-up, including optimal conditions kept at 60% of field water holding capacity, and three levels of water stress: The low level—2 week period without watering; the medium level—1 month drought period followed by watering to full but short-term soil saturation with water; and the high level—2 month drought period followed by full and long-term saturation with the same total amount of water, as in other variants. The soil water regime strongly modified the activities of dehydrogenases and acid and alkaline phosphatase, as well as the bacterial diversity. Loamy soil exhibited greater resistance to the inhibition of soil enzymatic activity. After irrigation, following both a 1 month and 2 month drought, the enzyme activities and nitrification largely recovered in soil with a loamy texture. Drought induced substantial shifts in the functional diversity of bacterial communities. The use of such C substrates, as carboxylic and acetic acids, was strongly inhibited by water deficit. Water deficit induced changes in the relative abundances of particular phyla, for example, an increase in Acidobacteria or a decrease in Verrucomicrobia. The study clearly proves the greater susceptibility of microbial communities to drought in sandy soils and the important role of exogenous organic matter in protecting microbial activity in drought periods.

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High time resolution enzyme cytochemistry of rod outer segment

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100161953 ◽

1990 ◽

Vol 48 (3) ◽

pp. 878-879

Author(s):

Takuma Saito ◽

Toshihiro Takizawa

Keyword(s):

Enzyme Activities ◽

Outer Segment ◽

Rapid Change ◽

High Time Resolution ◽

Visual Cell ◽

Enzyme Cytochemistry ◽

Activation Effect ◽

Rod Outer Segment ◽

Enzymatic Cascades ◽

Rapid Drop

Cells and tissues live on a number of dynamic metabolic pathways, which are made up of sequential enzymatic cascades.Recent biochemical and physiological studies of vision research showed the importance of cGMP metabolism in the rod outer segment of visual cell, indicat ing that the photon activated rhodopsin exerts activation effect on the GTP binding protein, transducin, and this act ivated transducin further activates phosphodiesterase (PDEase) to result in a rapid drop in cGMP concentration in the cytoplasm of rod outer segment. This rapid drop of cGMP concentration exerts to close the ion channel on the plasma membrane and to stop of inward current brings hyperpolarization and evokes an action potential.These sequential change of enzyme activities, known as cGMP cascade, proceeds quite rapidly within msec order. Such a rapid change of enzyme activities, such as PDEase in rod outer segment, was not a matter of conventional histochemical invest igations.

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Tryptophan-Niacin Metabolism in Rat with Puromycin Aminonucleoside-Induced Nephrosis

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831.76.1.28 ◽

2006 ◽

Vol 76 (1) ◽

pp. 28-33 ◽

Cited By ~ 7

Author(s):

Yukari Egashira ◽

Shin Nagaki ◽

Hiroo Sanada

Keyword(s):

Body Weight ◽

Urinary Excretion ◽

Enzyme Activities ◽

Treated Group ◽

Control Group ◽

Puromycin Aminonucleoside ◽

Low Level ◽

Key Enzyme

We investigated the change of tryptophan-niacin metabolism in rats with puromycin aminonucleoside PAN-induced nephrosis, the mechanisms responsible for their change of urinary excretion of nicotinamide and its metabolites, and the role of the kidney in tryptophan-niacin conversion. PAN-treated rats were intraperitoneally injected once with a 1.0% (w/v) solution of PAN at a dose of 100 mg/kg body weight. The collection of 24-hour urine was conducted 8 days after PAN injection. Daily urinary excretion of nicotinamide and its metabolites, liver and blood NAD, and key enzyme activities of tryptophan-niacin metabolism were determined. In PAN-treated rats, the sum of urinary excretion of nicotinamide and its metabolites was significantly lower compared with controls. The kidneyα-amino-β-carboxymuconate-ε-semialdehyde decarboxylase (ACMSD) activity in the PAN-treated group was significantly decreased by 50%, compared with the control group. Although kidney ACMSD activity was reduced, the conversion of tryptophan to niacin tended to be lower in the PAN-treated rats. A decrease in urinary excretion of niacin and the conversion of tryptophan to niacin in nephrotic rats may contribute to a low level of blood tryptophan. The role of kidney ACMSD activity may be minimal concerning tryptophan-niacin conversion under this experimental condition.

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