Exploring the Characterization of biodegradable plastic “polyhyroxybutrate” (PHB) from Bacillus siamensis PHB 01 (MW440618) isolated from termite mound soil of Western Ghats of Coimbatore, Tamil Nadu.

The present study was aimed to explore the characterization of polyhydroxy butrate extracted from the bacterial strain under optimized conditions for the production of bioplastic. Under optimized fermentation conditions, Polyhydroxy butrate (PHB) was extracted and subjected to examine their properties via Thin Layer Chromotogram (TLC), Gas Chromotogram- Mass Spectrometer (GC-MS), Fourier Transform Infrared spectrum (FTIR). The presence of a brown spot in the TLC plate indicates the presence of hydroxylgroup which is similar to the polymer group. GC-MS analysis of extracted PHB shows peaks at the retention time of 3.8, 11.6 which is corresponding to octadecanoic acid, hexadecanoic acid, butyl -2-ethylester confirms the presence of polymeric nature in the extracted PHB. The absorption bands of FTIR at 1719–1720 cm −1 indicate the presence of C=O group of PHB. The absorption peaks at wave numbers 500-1000 cm -1 , 1055 cm -1 and 1230 cm -1 denotes (OH) group, (C–O) stretch and (C=O) ester group. From these results, it was confirmed that the extracted PHB is having the potential to replace petroleum plastic.

Influence of leachates on geotehnical and geochemical properties of termite mound soils

This study investigated the influence of leachate prepared from Telfairia occidentalis on the geotechnical and geochemical properties of termite mound soil obtained from the premises of the federal university of agriculture, Abeokuta, south-western Nigeria. The termite mound soil samples were collected from three different locations and each sample collected was contaminated by mixing with leachates in percentage increments of 0% 10%, 15% and 20% of dry weight of the air-dried soil. The soil samples were subjected to Atterberg limits and hydraulic conductivity tests for geotechnical observation and X-ray fluorescence tests for geochemical tests. The range of values for the geotechnical analyses were obtained as; plastic limit (9.1% – 14.2%), liquid limit (28.6 % – 61%), plasticity index ((18.2% – 49.5%) and hydraulic conductivity (1.85 – 4.1 x 10-8) cm/sec) with a resultant reduction in the plastic limit, liquid limit and plasticity index values but an increase in the hydraulic conductivity of the samples as the leachate concentration increased. The results from X-ray fluorescence analyses after 20% leachate contamination showed that the major elemental chemical composition for the three samples were comprised of SiO2 (56.25 – 56.5%), Al2O3 (28.42 – 28.50%), Fe2O3 (4.46 – 6.5%), TiO2 (1.08 – 1.23%), CaO (1.45 – 1.60%), P2O5 (0 – 0.04%), K2O (0.9 – 6.1%) and MnO (0.02 – 4.7%). There was a marginal alteration of the indices with the values inferring the presence of a minimum composition of feldspar and a major composition of quartz-rich minerals and thus lending more credence to the presence of silicates as shown from the X-ray fluorescence results. It also infers that the termite mounds are predominantly made from sand materials. The termite soil samples obtained from the aforementioned locations may not be suitable for engineering works unless stabilization procedure is adopted.

The Potential of Termite Mound Spreading for Soil Fertility Management under Low Input Subsistence Agriculture

Termites can play a localized prominent role in soil nutrient availability and cycling because mound materials are often enriched in nutrients relative to surrounding soil. Mound materials may thus prove to be useful amendments, though evidently mound spatial arrangement needs to be considered as well. Furthermore, it is not known if gradients of soil properties exist from termite mound to interspace sites. Studying both aspects would be required to decide whether spreading of mounds or spatially differentiated management of surrounding crop to accommodate soil fertility gradients would be valid nutrient-management strategies. Mound abundance and mass were estimated at 9 and 4 mounds ha−1, representing 38.9 and 6.3 t ha−1 on Nitisols and Vertisols, respectively. Soil physical and chemical properties were measured on samples collected from internal and external parts of mounds and adjacent soils at 0.5, 1 and 10 m away from mounds. In general, termite mounds were enriched in plant nutrients and SOC on Vertisols but not on Nitisols. Termite mounds constituted only 0.3 to 1.3% of the 0–15 cm SOM stock on a per ha basis but nevertheless the immediate vicinity of termite mounds was a relative fertile hotspot. Hence, under the studied condition, we suggest spatial arrangement of crop around termite mounds according to soil fertility gradient and spatially differentiated nutrient management strategies. Our result suggests recommendation of termite mound spreading for soil nutrient amendment has to consider plant nutrient stock in termite mounds on per ha basis besides their nutrient enrichment. Interesting topics for future investigation would be growth experiment for different crops with mound materials treatment. It would also be interesting to study the effect mound building termite on soil properties under different soil conditions, slope class and land use.

Some physiochemical properties of termite mound soil and its effect on yield and yield components of maize (Zea mays L.) Under Greenhouse condition at Nekemte, western Ethiopia

Termite mound soil amends soil fertility and utilized as an alternative to npk fertilizers by smallholder farmers in Africa. Experiment was conducted in western Ethiopia to compare selected physical and chemical properties of mound soil (ms), Adjacent soil (as) and non-mound soil (nms) and the effect of these soils on maize plant growth and yield in the Greenhouse. In Limu district, Fitbako kebele, cultivated land was purposively selected for sampling. In the cultivated land, a plot of 100m x100m was delineated and three mounds within the plot were also purposively selected to collect composite soil sample for soil analysis and Greenhouse pot experiment. From each mound, 10kg soil each from bottom, middle and top (total= 30 kg) were collected and mixed to obtain working sample of 10 kg. About 30kg of adjacent soil 5m away from mound soils and Non-mound soil at the distance of 20 m away from mound soil at the depth of 0-30cm were collected and thoroughly mixed to make working sample of 10kg from each soil type. Three kilograms of mound soil, adjacent soil and non-mound soil each was put in separate plastic bucket for greenhouse pot experiment. About 100 gm of each soil type was used for selected physical and chemical properties analyses. The result obtained demonstrated that termite mound soil was significantly (P<0.05) high in bulk density (bd), moisture contents (mc), porosity (P), Soil pH, percent organic carbon (% oc) and percent organic matter (% om). Total Nitrogen (tn), average (av.) P, av. K, Exch. Ca and Exch. Mg were also significantly (P<0.05) higher in mound soil in comparison with adjacent soil and non-mound soil. Maize plant growth traits and yield were significantly (P<0.05) high in mound soil. From the current study, it can be concluded that the use of npk fertilizer on plots having termite mound is not recommended. However, further research is needed on how to use mound soil on large plot of land

The role of termite CH₄ emissions on the ecosystem scale: a case study in the Amazon rainforest

The magnitude of termite methane (CH4) emissions is still an uncertain part of the global CH4 budget and current emission estimates are based on limited field studies. We present in situ CH4 emission measurements of termite mounds and termite mound subsamples performed in the Amazon rainforest. Emissions from five termite mounds of the species Neocapritermes brasiliensis were measured by use of a large flux chamber connected to a portable gas analyser measuring CH4 and CO2. In addition, the emissions of mound subsamples were measured, after which the termites were counted so that a termite CH4 and CO2 emission factor could be determined. Mound emissions were found to range between 17.0 and 34.8 nmol mound−1 s−1 for CH4 and between 1.1 and 13.0 µmol mound−1 s−1 for CO2. A termite emission factor of 0.35 µmol CH4 gtermite-1 h−1 was found, which is almost twice as high as the only other reported value for the Amazon. By combining mound emission measurements with the termite emission factor, colony sizes could be estimated, which were found to range between 55–125 thousand individuals. Estimates were similar to literature values, and we therefore propose that this method can be used as a quick non-intrusive method to estimate termite colony size in the field. The role of termites in the ecosystem's CH4 budget was evaluated by use of two approaches. Termite mound emission values were combined with local mound density numbers, leading to an estimate of 0.15–0.71 nmol CH4 m−2 s−1, on average, emitted by termite mounds. In addition, the termite CH4 emission factor from this study was combined with termite biomass numbers, resulting in an estimate of termite-emitted CH4 of ∼1.0 nmol m−2 s−1. Considering the relatively low net CH4 emissions previously measured at this ecosystem, we expect that termites play an important role in the CH4 budget of this terra firme ecosystem.

Termite Mound Soils for Sustainable Production of Bricks

The article presents the alternative use of termite mound soils (TMSs) as full replacement for clay soils in brick production. TMSs from two localities, Jawaj and Sene, in Ethiopia were investigated for bricks production. The TMSs samples contained high SiO2 and Al2O3. The TMSs bricks were fired at different temperatures from 500 to 1,000°C. The obtained mean compressive strengths (σ), 18 and 14 MPa, were observed for bricks made from TMSs from Jawaj and Sene, respectively, at the optimum firing temperature of 700°C. The σ of TMSs bricks decreased as the firing temperature increased above 700°C, while for conventional clay soil brick, the σ increased with temperature beyond 700°C. The water absorptions and saturation coefficients of fired TMSs bricks decreased with increased firing temperature. The TMSs bricks meet the standard specification of dimension tolerance only along the height. All the TMSs bricks made from the two localities were not efflorescent. TMSs from Jawaj and Sene sites can be used as a raw material to replace the long-used clay soils for bricks production as a construction material for houses construction in rural and urban areas.