scholarly journals Soil organic matter is essential for colony growth in subterranean termites

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aaron Mullins ◽  
Thomas Chouvenc ◽  
Nan-Yao Su

AbstractIntrinsic dinitrogen (N2) fixation by diazotrophic bacteria in termite hindguts has been considered an important pathway for nitrogen acquisition in termites. However, studies that supported this claim focused on measuring instant N2 fixation rates and failed to address their relationship with termite colony growth and reproduction over time. We here argue that not all wood-feeding termites rely on symbiotic diazotrophic bacteria for colony growth. The present study looks at dietary nitrogen acquisition in a subterranean termite (Rhinotermitidae, Coptotermes). Young termite colonies reared with wood and nitrogen-rich organic soil developed faster, compared to those reared on wood and inorganic sand. More critically, further colony development was arrested if access to organic soil was removed. In addition, no difference of relative nitrogenase expression rates was found when comparing the hindguts of termites reared between the two conditions. We therefore propose that subterranean termite (Rhinotermitidae) colony growth is no longer restricted to metabolically expensive intrinsic N2 fixation, as the relationship between diazotrophic bacteria and subterranean termites may primarily be trophic rather than symbiotic. Such reliance of Rhinotermitidae on soil microbial decomposition activity for optimal colony growth may also have had a critical mechanistic role in the initial emergence of Termitidae.

2020 ◽  
Vol 66 (1) ◽  
Author(s):  
Yusuf Sudo Hadi ◽  
Muh Yusram Massijaya ◽  
Dodi Nandika ◽  
Wa Ode Muliastuty Arsyad ◽  
Imam Busyra Abdillah ◽  
...  

Abstract Smoke treatment can be used to enhance wood resistance to subterranean termite attack. In this study, kesambi (Schleichera oleosa) wood was pyrolyzed to produce charcoal. The smoke produced as a by-product of pyrolysis was used to treat sengon (Falcataria moluccana), jabon (Anthocephalus cadamba), mangium (Acacia mangium), and pine (Pinus merkusii) wood samples for 1, 2, or 3 weeks. Following the smoke treatment, the wood specimens were exposed to subterranean termites (Coptotermes curvignathus Holmgren) according to the Indonesian standard 7207-2014 in a laboratory. The color change caused by smoke treatment was observed, and chemical analysis of smoke was also done. The results showed that chemical compounds of kesambi smoke predominantly consisted of acetic acid, phenol, ketones, amines, and benzene. The color of smoked wood became darker, less yellow, and a little redder, while a longer smoking period produced a darker color which was more resistant to termite attack. Smoke treatment enhanced the resistance of wood to subterranean termite attack, and the resistance levels were not significantly different based on the duration of the smoke treatment.


el–Hayah ◽  
2012 ◽  
Vol 1 (4) ◽  
Author(s):  
Prihastuti Prihastuti

<p>Soils are made up of organic and an organic material. The organic soil component contains all the living creatures in the soil and the dead ones in various stages of decomposition.  Biological activity in soil helps to recycle nutrients, decompose organic matter making nutrient available for plant uptake, stabilize humus, and form soil particles.<br />The extent of the diversity of microbial in soil is seen to be critical to the maintenance of soil health and quality, as a wide range of microbial is involved in important soil functions.  That ecologically managed soils have a greater quantity and diversity of soil microbial. The two main drivers of soil microbial community structure, i.e., plant type and soil type, are thought to exert their function in a complex manner. The fact that in some situations the soil and in others the plant type is the key factor determining soil microbial diversity is related to their complexity of the microbial interactions in soil, including interactions between microbial and soil and microbial and plants. <br />The basic premise of organic soil stewardship is that all plant nutrients are present in the soil by maintaining a biologically active soil environment. The diversity of microbial communities has on ecological function and resilience to disturbances in soil ecosystems. Relationships are often observed between the extent of microbial diversity in soil, soil and plant quality and ecosystem sustainability. Agricultural management can be directed toward maximizing the quality of the soil microbial community in terms of disease suppression, if it is possible to shift soil microbial communities.</p><p>Keywords: structure, microbial, implication, sustainable agriculture<br /><br /></p>


Author(s):  
Wahyu Purbalisa ◽  
Ina Zulaehah ◽  
Dolty Melyga W. Paputri ◽  
Sri Wahyuni

Carbon and microbes in the soil fluctuated from time to time due to various things. This study aims to determine the dynamics of carbon and microbes in the soil in the treatment of biochar-compost. In addition to the use of biochar-compost, this research also uses nano biochar and enrichment with microbial consortia. The study was conducted at the screen house using a complete randomized design with three replications with following treatments: control / without organic fertilizer (P0), compost (P1), biochar-compost 1: 4 (P2), nano-biochar-compost 1: 4 (P3 ), biochar-compost + microbial consortia (P4), compost + microbial consortia (P5) and biochar-compost + microbial consortia (P6) with a dose of 2.5 tons/ha respectively. Biochar comes from corncobs. Compost biochar plus application was made before planting.  Parameters observed were soil carbon (C-organic), soil acidity (pH) at 7 DAA, 37 DAA and after harvest, and the total soil microbial population at 2 DAA and after harvest. Soil carbon was measured using Walkey and Black method measured by spectrophotometer, soil pH using a soil: water ratio = 1: 5 and measured by a pH meter, the total microbial population using Total Plate Counting (TPC) method. The results showed carbon and soil microbial populations decreased over time, except for microbial communities in a single compost treatment.


2021 ◽  
Author(s):  
Jussi Heinonsalo ◽  
Anna-Reetta Salonen ◽  
Rashmi Shrestha ◽  
Subin Kalu ◽  
Outi-Maaria Sietiö ◽  
...  

&lt;p&gt;Soil C sequestration through improved agricultural management practices has been suggested to be a cost-efficient tool to mitigate climate change as increased soil C storage removes CO&lt;sub&gt;2&lt;/sub&gt; from the atmosphere. In addition, improved soil organic carbon (SOC) content has positive impacts on farming though better soil structure and resilience against climate extremes through e.g. better water holding capacity. In some parts of the world, low SOC content is highly critical problem for overall cultivability of soils because under certain threshold levels of SOC, soil loses its ability to maintain essential ecosystem services for plant production. Soil organic amendments may increase soil C stocks, improve soil structure and boost soil microbial activities with potential benefits in plant growth and soil C sequestration. Additional organic substrates may stimulate microbial diversity that has been connected to higher SOC content and healthy soils.&lt;/p&gt;&lt;p&gt;We performed a two-year field experiment where the aim was to investigate whether different organic soil amendments have an impact on soil microbial parameters, soil structure and C sequestration.&lt;/p&gt;&lt;p&gt;The experiment was performed in Parainen in southern Finland on a clay field where oat (Avena sativa) was the cultivated crop. Four different organic soil amendments were used (two wood-based fiber products that were leftover side streams of pulp and paper industry; and two different wood-based biochars). Soil amendments were applied in 2016. Soil C/N analysis was performed in the autumns 2016-2018 and soil aggregate in the summer and autumn 2018, as well as measures to estimate soil microbial activity: microbial biomass, soil respiration, enzymatic assays, microbial community analysis with Biolog &amp;#174;&amp;#160; EcoPlates and litter bag decomposition experiment. The relative share of bacteria and fungi was determined using qPCR from soil samples taken in the autumns 2016, 2017 and 2018.&lt;/p&gt;&lt;p&gt;Data on how the studied organic soil amendments influence soil structure and C content, as well as soil microbial parameters will be presented and discussed.&lt;/p&gt;


2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Jukka Intosalmi ◽  
Adrian C. Scott ◽  
Michelle Hays ◽  
Nicholas Flann ◽  
Olli Yli-Harja ◽  
...  

Abstract Background Multicellular entities like mammalian tissues or microbial biofilms typically exhibit complex spatial arrangements that are adapted to their specific functions or environments. These structures result from intercellular signaling as well as from the interaction with the environment that allow cells of the same genotype to differentiate into well-organized communities of diversified cells. Despite its importance, our understanding how this cell–cell and metabolic coupling lead to functionally optimized structures is still limited. Results Here, we present a data-driven spatial framework to computationally investigate the development of yeast colonies as such a multicellular structure in dependence on metabolic capacity. For this purpose, we first developed and parameterized a dynamic cell state and growth model for yeast based on on experimental data from homogeneous liquid media conditions. The inferred model is subsequently used in a spatially coarse-grained model for colony development to investigate the effect of metabolic coupling by calibrating spatial parameters from experimental time-course data of colony growth using state-of-the-art statistical techniques for model uncertainty and parameter estimations. The model is finally validated by independent experimental data of an alternative yeast strain with distinct metabolic characteristics and illustrates the impact of metabolic coupling for structure formation. Conclusions We introduce a novel model for yeast colony formation, present a statistical methodology for model calibration in a data-driven manner, and demonstrate how the established model can be used to generate predictions across scales by validation against independent measurements of genetically distinct yeast strains.


2014 ◽  
Vol 3 (3) ◽  
pp. 50
Author(s):  
Habib Kato ◽  
Robert Mulebeke ◽  
Felix Budara Bareeba ◽  
Elly Nyambobo Sabiiti

<p>Soil organic carbon (C) and nitrogen (N) decomposition in fecal manure of cattle fed browses of Calliandra (<em>Calliandra calothyrsus</em>), Gliricidia (<em>Gliricidia sepium</em>) and Leucaena (<em>Leucaena leucocephala</em>) browse/maize silage mixtures and maize (<em>Zea mays</em>) silage alone when applied to the soil were investigated in a pot experiment in comparison to the corresponding silages fed. Maize silage alone had the lowest N and a larger C: N ratio, making it a poor quality compost when applied to the soil, but compared to the browse/maize silage mixtures it had the highest level of soluble N as non-protein nitrogen (NPN) which makes much of its N available for soil microbial decomposition of its organic C. Calliandra browse/maize silage mixture had the highest level of fiber-bound N (ADFN), which reduces N availability for soil microbial decomposition of its organic C in spite of its high N content and a narrower C: N ratio. Fecal manure from maize silage alone had a lower level of N and a wider C: N ratio than fecal manure from the other silages fed which would affect its decomposition in the soil, but it had the lowest level of ADFN and much of its N is made available for soil microbial decomposition of its organic C. Soil samples after 12 weeks of the experiment showed that Calliandra browse/maize silage mixture maintained the highest level of C in the soil, while maize silage alone maintained the lowest level. Also soils treated with fecal manure from the other browse/maize silage mixtures maintained higher levels of C than fecal manure from maize silage alone. Organic C levels were lowest at 8 weeks of the experiment for all treatments and rose to the original levels at 12 weeks which could have been as a result of biotic and hydrologic factors coupled with soil aggregation. Decomposition of organic N followed a similar trend as organic C. The two elements are linked in both plant inputs in the soil and in the eventual soil humic substances. The soils treated with browse/maize silage mixtures maintained C: N ratios that were similar to that of the control soil and higher than those of the fecal manure treatments. Thus, in spite of the added silage materials to the soil, rapid decomposition of organic C could not occur to reflect benefits of adding the silage materials to the soil. Thus, fecal manure, particularly from feeding animals on browse/forage diets is more beneficial in the soil as it would decompose more readily releasing the plant nutrients they contain.</p>


1967 ◽  
Vol 125 (4) ◽  
pp. 703-720 ◽  
Author(s):  
J. L. Curry ◽  
J, J. Trentin ◽  
N. Wolf

The polycythemic repression of erythropoiesis and the restoration of erythropoiesis by specific stimulation were studied in the spleen colony system in irradiated mice. 1. A 5 day period of erythropoietin stimulation (exogenous erythropoietin) or repression (polycythemia) of the bone marrow donor only, does not significantly alter the number or type of colonies formed by the transplanted marrow cells. 2. Erythropoietin stimulation did not alter the number or type of endogenous colonies formed in mice receiving 580 R. Erythropoietin repression (polycythemia) markedly reduced the growth but not the number of erythroid colonies, while not affecting the other types of colonies formed endogenously. 3. Erythropoietin stimulation of the irradiated recipient during colony growth did not alter the number or type of spleen colonies formed by transplanted marrow. Erythropoietin repression by polycythemia during colony growth completely suppressed the appearance of morphologically erythroid colonies without significantly altering the incidence of the other colony types. This effect of polycythemia was completely prevented by exogenous erythropoietin. Irradiated mice are therefore presumed to be secreting sufficient erythropoietin for maximal erythroid colony development. 4. The erythroid colonies suppressed by polycythemia were recognizable as microscopic foci of undifferentiated cells. Exposure of these foci to erythropoietin stimulation at different periods in their development was manifested by different degrees of growth and differentiation, from which it is apparent that erythropoietin stimulates not only morphological differentiation but also rapid mitosis. Retransplantation of either erythroid or of neutrophilic primary spleen colonies gave rise to both erythroid and neutrophilic secondary spleen colonies. The percentage of erythroid secondary colonies was slightly but significantly higher among the progeny of transplanted erythroid primary colonies than among the progeny of transplanted neutrophilic primary colonies. On the basis of these and other results, a working hypothesis is proposed for factors controlling the growth and differentiation of spleen colonies from transplanted bone marrow. It is postulated that most but perhaps not all spleen colony-forming units are pluripotent hemopoietic stem cells. It is further postulated that hemopoietic-inductive microenvironments (HIM) of different kinds exist in both the spleen and the bone marrow, and that these determine the differentiation of pluripotent stem cells into each of the lines of hemopoietic differentiation. Erythropoietin therefore may "induce" erythroid differentiation of only those stem cells under the influence of an erythroid HIM. Alternatively erythropoietin may act only as a growth and function stimulant of those stem cells that have been "induced" by an erythroid HIM into a state of erythropoietin responsiveness. In the latter case morphological differentiation presumably results from the functional activity stimulated by ESF.


2013 ◽  
Vol 75 (1) ◽  
pp. 41-45
Author(s):  
D. Parks Collins

Populations of the Eastern subterranean termite, Reticulitermes flavipes, are widespread throughout most of the eastern United States. Subterranean termites have the ability to survive flooding conditions by lowering their metabolism. This lesson investigates the connection between the ability of termites to lower their metabolism to survive floods and their feeding behavior. Using an incubator, Petri dishes, and different types of mulch, termite consumption can be measured and compared. These results can be analyzed with a simple statistical test to look for significance.


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