Phytoliths: Persistence & Release of Silicon in Soil and Plants – A Review

Phytoliths are formed from silica carried up from groundwater and some plants. The weathering of silicate minerals at the Earth’s surface provides large amounts of soluble silica, some of which is absorbed by growing plants. In solution, silica exists as mono silicic acid Si (OH4) with pH values of 2–9. It is carried upward in the vascular system and becomes concentrated during transpiration around the leaf stomata. The supersaturated solution begins to polymerize or gel then solidifies and forms solid opaline silica (SiO2:nH2O) bodies (phytoliths) within and between some of the plant cells. Phytoliths were extracted from the 7.4 meter loess core and analyzed morphologically and isotopically from the occluded carbon. Rates of isotopic fractionation between plant and phytolith were determined by measurements from many modern tree, fern, and grass species. The use of phytolith biochar as a Si fertilizer offers the undeniable potential to mitigate desilication and to enhance Si ecological services due to soil weathering and biomass removal. Silicon is accumulated at levels equal to or greater than essential nutrients in plant species belonging to the families Poaceae, Equisetaceae, and Cyperaceae. However, the abundance of silicon in soils is not an indication that sufficient supplies of soluble silicon are available for plant uptake.

Physiochemical Changes to TTCF Ensilication Investigated Using Time-Resolved SAXS

Successful eradication or control of prevailing infectious diseases is linked to vaccine efficacy, stability, and distribution. The majority of protein-based vaccines are transported at fridge (2–8 °C) temperatures, cold chain, to retain potency. However, this has been shown to be problematic. Proteins are inherently susceptible to thermal fluctuations, occurring during transportation, causing them to denature. This leads to ineffective vaccines and an increase in vaccine-preventable diseases, especially in low-income countries. Our research utilises silica to preserve vaccines at room temperature, removing the need for cold chain logistics. The methodology is based upon sol–gel chemistry in which soluble silica is employed to encapsulate and ensilicate vaccine proteins. This yields a protein-loaded silica nanoparticle powder which is stored at room temperature and subsequently released using a fast chemical process. We have previously shown that tetanus toxin C fragment (TTCF) ensilication is a diffusion-limited cluster aggregation (DLCA)-based process using time-resolved small-angle x-ray scattering (SAXS). Here, we present our expanded investigation on the modularity of this system to further the understanding of ensilication via time-resolved SAXS. Our results show that variations in the ensilication process could prove useful in the transition from batch to in-flow manufacturing of ensilicated nanoparticles.

Effect of soluble silica fertiliser on total sugar, protein, starch content along with amylase and cellulase activity in banana

Fertilisers have become an important factor used by farmers to increase yield and improve product quality. Earth’s crust carries a large amount of elemental silicon. However, silicon is not considered an essential element for plant growth therefore is not included in fertilisers. Silicon has shown to enhance the growth and productivity of various crops. The present study aimed to explore the potential of soluble silica in improving the biochemical parameters of banana (Grand naine variety). The field experiment was conducted at Ropni Vasaad village, Burhanpur District of Madhya Pradesh from August 2017 to September 2018. Silica was supplied as potassium silicate in the liquid form under the trade name AgriboosterTM. Doses were administered at the interval of one month starting from planting the tissue culture explants till harvesting the final crop. Eight treatments were designed which included three different concentration of soluble silica applied alone and with combination with compound fertilisers. Control was without any treatment. A significant increase in fresh and dry weight was observed with all the treatments. All the combinations of soluble silica resulted in significant increase in starch and total sugar content. The protein content showed significant increase with treatments consisting of soluble silica and compound fertiliser. Cellulase and amylase activity declined on treatment with soluble silica. The present study reveals that if soluble silica is either applied alone or with compound fertiliser, it can enhance the biochemical parameters and can indirectly delay ripening of banana by altering activity of cellulase and amylase.

Soluble Pozzolanic Materials from Coal Bottom Ash as Cement Replacement Material

Nowadays, intensive research in production of highly reactive pozzolanic materials from industrial waste to replace cement is crucial. This action expected to increase industrial waste recycling rate and at the same time reduce extraction of non-renewable resources of limestone. Unique characteristics of coal bottom ash as one of the industrial based pozzolan gained less popularity because of its low reactivity and heavy metal leaching due to conventional method used for disposal. Therefore, an alternative approach was deliberated in this research to utilize coal bottom ash into soluble form and enhance the quality of bottom ash as pozzolanic material. Coal bottom ash after the acid washing with optimum parameter was then undergoes solution-gelification process with various alkali based solution for 2 hours soaking durations. The conversion of coal bottom ash into soluble silica in this study demonstrates good pozzolanic performance in a state of siliceous gel pozzolan compared to the raw ones. 5% of cement replacement by soluble silica from CBA shows good strength development from early and later age. The physical dispersion effect is the cumulative effect of enhancement cement hydration due to the availability of increased the nucleation sites on soluble silica particles.

A facile approach to prepare silica hybrid, spin-crossover water-soluble nanoparticles as a potential platform for thermally responsive MRI agents

A reverse micelle method was used for the synthesis of water soluble silica hybrid, spin-crossover (SCO) nanoparticles (NPs). MRI experiments provided thermally responsive T2 values indicating their potential usage as...

Beneficial Role of Soluble Silica in Enhancing Chlorophyll Content in Onion Leaves

Silicon which is not considered essential element, improves growth and development in onion. The present study was designed to investigate beneficial role of soluble silica in increasing chlorophyll content in onion leaves. Soluble silica under tradename AgriboosterTM was used to alleviate environmental stress. Eight treatments were given at the interval of 15 days after one month of sowing in randomised block design as follows: T1- without fertilizer and soluble silica (Control), T2, T3, T4- foliar spray of soluble silica viz, 7.5, 10 and 12.5 ml/ lit respectively,T5- only fertilizer,T6, T7, T8- fertilizer + foliar spray of soluble silica viz, 7.5, 10 and 12.5 ml/ lit respectively. Chlorophyll a, b and carotenoid content were determined. Malondialdehyde was estimated in leaves to determine level of stress. Malondialdehyde content was found to be significantly higher in control and only fertilizer treated leaves of onion indicating stress in plants which significantly decreased level of chlorophyll a as well as chlorophyll b. This negative effect of stress in chlorophyll content was counteracted by soluble silica. Soluble silica could be used to increase chlorophyll content which will improve photosynthesis.