SOIL MICROBIAL BIOMASS AND ENZYME ACTIVITIES RESPONSE TO COPPER AND MOLYBDENUM POLLUTION IN THE VICINITY OF ZANGEZUR COPPER AND MOLYBDENUM COMBINE, ARMENIA

The aim of this study was to define a relationship between heavy metal (Cu, Mo) pollution of soil and various extracellular enzyme activities. Six enzymatic activities involved in cycles of carbon, nitrogen, phosphorus and sulfur (β-glucosidase, chitinase, leucine-aminopeptidase, acid phosphomonoesterase, alkaline phosphomonoesterase, and arylsulphatase) as well as microbial biomass were determined in soil samples collected in the surroundings of Zangezur Copper and Molybdenum Combine. The investigations showed that pollution of soil with copper and molybdenum led to a decrease in microbial biomass and soil enzymatic activity, which in turn had a negative impact on cycles of chemical elements, in particular C, P, N and S. This gives reason to conclude that the changes in soil microbial biomass and enzymatic activity may act as indicators of soil biological activity and quality.

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Effects of Mixing Feldspathic Sandstone and Sand on Soil Microbial Biomass and Extracellular Enzyme Activities—A Case Study in Mu Us Sandy Land in China

Applied Sciences ◽

10.3390/app9193963 ◽

2019 ◽

Vol 9 (19) ◽

pp. 3963

Author(s):

Xiuxiu Feng ◽

Lu Zhang ◽

Fazhu Zhao ◽

Hongying Bai ◽

Russell Doughty

Keyword(s):

Enzyme Activity ◽

Microbial Biomass ◽

Microbial Activity ◽

Soil Quality ◽

Enzyme Activities ◽

Soil Microbial Biomass ◽

Extracellular Enzyme ◽

Soil Microbial Activity ◽

Soil Microbial ◽

Feldspathic Sandstone

Microbial biomass, extracellular enzyme activity, and their stoichiometry in soil play an important role in ecosystem dynamics and functioning. To better understand the improvement of sand soil quality and the limitation of soil nutrients after adding feldspathic sandstone, we investigated changes in soil microbial activity after 10 months of mixing feldspathic sandstone and sand, and compared the dynamics with soil properties. We used fumigation extraction to determine soil microbial biomass carbon (MBC), nitrogen (MBN), phosphorus (MBP), and microplate fluorometric techniques to measure soil β-1,4-glucosidase (BG), β-1,4-xylosidase (BX), β-D-cellobiohydrolase (CBH), N-acetyl-β-glucosaminidase (NAG), and Alkaline phosphatase (AKP). We also measured soil organic carbon (SOC), pH, electrical conductivity (EC), soil inorganic carbon (SIC), and soil water content (SWC). Our results showed that the soil microbial biomass C, N, P, and individual extracellular enzyme activities significantly increased in mixed soil. Similarly, the soil microbial biomass C:N, C:P, N:P, MBC:SOC, and BG:NAG significantly increased by 54.3%, 106.3%, 33.1%, 23.0%, and 65.4%, respectively. However, BG:AKP and NAG:AKP decreased by 19.0% and 50.3%, respectively. Additionally, redundancy analysis (RDA) and Pearson’s correlation analysis showed that SWC, SOC, porosity and field capacity were significantly associated with soil microbial biomass indices (i.e., C, N, P, C:N, C:P, N:P in microbial biomass, and MBC:SOC) and extracellular enzyme activity metrics (i.e., individual enzyme activity, ecoenzymatic stoichiometry, and vector characteristics of enzyme activity), while pH, EC, and SIC had no correlation with these indices and metrics. These results indicated that mixing feldspathic sandstone and sand is highly susceptible to changes in soil microbial activity, and the soil N limitation decreased while P became more limited. In summary, our research showed that adding feldspathic sandstone into sand can significantly improve soil quality and provide a theoretical basis for the development of desertified land resources.

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Understory vegetation plays the key role in sustaining soil microbial biomass and extracellular enzyme activities

Biogeosciences ◽

10.5194/bg-15-4481-2018 ◽

2018 ◽

Vol 15 (14) ◽

pp. 4481-4494 ◽

Cited By ~ 4

Author(s):

Yang Yang ◽

Xinyu Zhang ◽

Chuang Zhang ◽

Huimin Wang ◽

Xiaoli Fu ◽

...

Keyword(s):

Microbial Biomass ◽

Organic Carbon ◽

Enzyme Activities ◽

Soil Microbial Biomass ◽

Extracellular Enzyme ◽

Chinese Fir ◽

Understory Vegetation ◽

Soil C ◽

Extracellular Enzyme Activities ◽

Soil Microbial

Abstract. While we know that understory vegetation affects the soil microbial biomass and extracellular enzyme activities in subtropical Chinese fir (Cunninghamia lanceolata) forests, we are less certain about the degree of its influence. We determined the degree to which the soil abiotic and biotic properties, such as PLFAs and extracellular enzyme activities, were controlled by understory vegetation. We established a paired treatment in a subtropical Chinese fir plantation, which comprised one plot from which the understory vegetation and litter were removed (None) and another from which the litter was removed but the understory vegetation was left intact (Understory). We evaluated how the understory vegetation influenced the soil abiotic properties, the bacterial, fungal, and actinobacterial PLFAs, and the activities of five hydrolases and two oxidative enzymes. The dissolved organic carbon (DOC), particulate organic carbon, soil organic carbon, ammonia nitrogen (NH4+–N), and total nitrogen contents and soil moisture were 18 %, 25 %, 12 %, 34 %, 8 %, and 4 % lower in the None treatments than in the Understory treatments, respectively (P<0.05). Soil bacterial, fungal, and total PLFAs, and the potential activities of β-1,4-glucosidase (βG), β-1,4-N-acetylglucosaminidase, phenol oxidase, and peroxidase, were as much as 24 % lower in None treatments than in Understory treatments (P<0.05). The specific activities of C-acquiring enzymes were as much as 41 % higher (P<0.05), and the ratio of C- to N-acquiring enzymes was also higher in the None treatments than in the Understory treatments. This suggests that in the absence of understory vegetation microbes invested more in C acquisition than N acquisition because the carbon (C) inputs were less labile. The negative relationship between DOC and AP shows that DOC is consumed when P-acquiring enzymes are produced. The positive correlation between NH4+–N and βG suggested the increased availability of N promoted the decomposition of C. More extracellular enzymes that degrade soil organic matter are produced when there is understory vegetation, which leads to losses of soil C. On the other hand, the soil C sink is maintained by increased inputs of C. We can therefore conclude that understory vegetation contributes to C sequestration in Chinese fir forests and suggest that understory should be maintained to sustain soil quality in subtropical Chinese fir plantations.

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Characteristics of soil microbial biomass carbon, nitrogen and enzyme activities in Picea asperata plantations with different ages in subalpine of western Sichuan, China

Acta Ecologica Sinica ◽

10.5846/stxb202008192158 ◽

2021 ◽

Vol 41 (14) ◽

Author(s):

罗明霞，胡宗达，刘兴良，李亚非，胡璟，欧定华，吴德勇 LUO Mingxia

Keyword(s):

Microbial Biomass ◽

Enzyme Activities ◽

Soil Microbial Biomass ◽

Microbial Biomass Carbon ◽

Biomass Carbon ◽

Western Sichuan ◽

Soil Microbial ◽

Soil Microbial Biomass Carbon ◽

Picea Asperata ◽

Different Ages

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Age and Species of Eucalyptus Plantations Affect Soil Microbial Biomass and Enzymatic Activities

Microorganisms ◽

10.3390/microorganisms8060811 ◽

2020 ◽

Vol 8 (6) ◽

pp. 811 ◽

Cited By ~ 1

Author(s):

Jie Xu ◽

Bing Liu ◽

Zhao-lei Qu ◽

Yang Ma ◽

Hui Sun

Keyword(s):

Microbial Biomass ◽

Enzyme Activities ◽

Fungal Biomass ◽

Soil Microbial Biomass ◽

Extracellular Enzymes ◽

Eucalyptus Species ◽

Eucalyptus Plantation ◽

Soil Microbial ◽

Eucalyptus Plantations ◽

Plantation Age

Soil microorganisms and extracellular enzymes play important roles in soil nutrient cycling. Currently, China has the second-largest area of eucalyptus plantations in the world. Information on the effects of eucalyptus age and species of trees on soil microbial biomass and enzyme activities, however, is limited. In this paper, the soil microbial biomass and enzyme activities were studied in eucalyptus plantations with different ages (1 and 5+ years) and species of trees (E. urophylla×E. grandis, E. camaldulens and E. pellita) in South China. The results showed that both plantation age and eucalyptus species could affect the total microbial biomass and fungal biomass, whereas the bacterial biomass was affected only by plantation age. The fungal biomass and the fungi-to-bacteria ratio significantly increased along with increasing plantation age. Similarly, the plantation age and eucalyptus species significantly affected the enzyme activities associated with carbon cycling (β-xylosidase, β-d-glucuronidase, β-cellobiosidase and β-glucosidase). The activities of β-d-glucuronidase and β-glucosidase were significantly higher in the E. camaldulens plantation. The enzymes involved in nitrogen (N-acetyl-glucosamidase) and sulfur (sulfatase) cycling were only affected by the eucalyptus plantation age and species, respectively. The results highlight the importance of the age and species of eucalyptus plantations on soil microbial activities.

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