Estimation of plant leaf chlorophyll is critical for assessment of overall health condition of plants. The existing detection methods demand relatively expensive and bulky instruments, thus ...restricting its use for onsite investigations. Present work demonstrates a low-cost, compact fluorescence-based sensor using a smartphone to estimate the chlorophyll content in plant leaves. The extracted plant chlorophyll samples have been optically excited by using an external LED with peak emission wavelength of 475 nm, and the corresponding emitted fluorescence signals at 679 nm have been recorded by the ambient light sensor of the phone. A 3D printed compact set-up has been designed to couple it with the phone to record the emitted fluorescence signal intensity from the sample. Chlorophyll concentrations in the range of 1-12 mg/g prepared from fresh tea leaves have been accurately estimated with a sensitivity of 0.068 AU g/mg and Limit of Detection (LoD) of 0.618 μg/L. The performance of the proposed smartphone sensor has been assessed by comparing the data with the commercial chlorophyll meter.
This article demonstrates a cost-effective, compact, and handheld smartphone-based sensing tool for accurate estimation of pH values of agricultural farmlands. We develop a spectrometric tool with a ...resolution ability of 0.22 nm/pixel by utilizing 3D printing technology, regular optical components, a Digital Versatile Disc (DVD) as a grating element, and the rear camera of the phone. The sensor responses for standard pH samples within the pH range 4 to 10 are observed to be linear yet yield a sensitivity of 0.129 per pH unit. The resolution of the proposed sensor for the considered samples is observed to be 0.09 pH units. The results obtained from the designed tool while measuring the pH values of six field-collected soil samples are found to be accurate. The designed sensor's performance has been evaluated by comparing the experimental data with the commercial-grade pH sensing tool. With the advantages of being a low-weight and data-sharing ability, we envision that the proposed sensing scheme could emerge as a promising alternative platform for in-field estimation of pH values of soil and water resources of our environment.
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•Vermicomposting removed ~50–70% toxic metals from cotton textile sludge (CTS)•Budget equations were evolved to assess metal apportionments during biocomposting.•Eudrilus eugeniae ...promoted transition of toxic Cr6+ to benign Cr3+.•Humic acid and humin formation strongly induced Cr transition in vermibeds.•Nutrients and pH were remarkably stabilized in CTS + CD vermibeds.
Information on prospective metal remediation by Eudrilus eugeniae during vermicomposting of cotton textile sludge (CTS) is rather scarce. This investigation, therefore, evaluates the sanitization efficiency of this species in CTS and CTS + cow-dung (CD) based feedstocks against aerobic composting. Accordingly, reduction in Pb, Cd, Cr, and Zn concentrations was between 50 and 70% under vermicomposting. Budget equations substantiated that humic compound mediated chelation was the dominant route of metal removal, against nominal bioaccumulation by earthworms. Correlation statistics revealed that formation of humic compounds (humic acid, fulvic acid, and humin) greatly influenced the transition of toxic Cr6+ to benign Cr3+ during vermicomposting. Moreover, increase in total N content and P availability was significantly greater under vermicomposting than composting. Thus, E. eugeniae efficiently stabilized the feedstocks by reducing pH, Ca, S, and organic C and CTS + CD(2:1) was the most favorable feedstock for E. eugeniae vermicomposting in respect of metal detoxification and nutrient stabilization.
Residual pollutants including polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), and carbon (aceous) nanoparticles are inevitably generated during the pyrolysis of waste ...biomass and remain on the solid coproduct called biochar. Such pollutants could have adverse effects on the plant growth as well as microbial community in soil. Although biochar has been proposed as a ‘carbon negative strategy’ to mitigate the greenhouse gas emissions, the impacts of its application with respect to long‐term persistence and bioavailability of hazardous components are not clear. Moreover, the co‐occurrence of low molecular weight VOCs with PAHs in biochar may exert further phytotoxic effects. This review describes the basic need to unravel key mechanisms driving the storage vs. emission of these organics and the dynamics between the sorbent (biochar) and soil microbes. Moreover, there is an urgent need for standardized methods for quantitative analysis of PAHs and VOCs in biochar under environmentally relevant conditions. This review is also extended to cover current research gaps including the influence of biochar application on the short‐ and long‐term fate of PAHs and VOCs and the proper control tactics for biochar quality and associated risk.
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•Thin earthworm stocking promotes degradation of lignocellulosic vermibeds.•5–7 earthworm/kg stocking improved fecundity, humification, and NPK availability.•Thin Eisenia stocking and ...dense Eudrilus stocking enriched microbial-PLFA profiles.•Metal removal efficacy of Eisenia fetida enhanced by thin initial stocking density.•Microbial-PLFA strongly regulated metal availability in lignocellulosic vermibeds.
Earthworm-induced microbial enrichment is the key to success in vermitechnology, yet the influence of initial earthworm stocking density on microbial community profiles in vermibeds is unknown. Therefore, vermicomposting of lignocellulosic feedstock was performed with different stocking densities of two earthworms (Eisenia fetida and Eudrilus eugeniae) compared with composting. Eventually, earthworm growth, microbial (activity and community profiles), and physicochemical dynamics were assessed. The earthworm population significantly increased under low stocking, while denser stocking (15/kg) was stressful. The XRD-based crystallinity assessment revealed that comminuting efficiency of Eisenia and Eudrilus was prudent at 7 and 10 worm/kg stockings, respectively. Moreover, the 5 and 7 worm/kg stockings effectively mobilized microbial activity, promoting NPK-mineralization and C-humification balance. Correlation statistics indicated that earthworm stocking density-driven microbial community shift and fatty acid profiles strongly influenced metal removal in vermibeds. Hence, the findings implied that 5–7 worm/kg stockings of earthworms produced high-quality sanitized vermicompost.
•Metal-rich textile sludge induced oxidative stress and DNA-damage in earthworms.•Earthworms restore genetic integrity through epigenetic regulations in vermibeds.•Cotton sludge induced greater ...toxicity than silk processing sludge to earthworms.•Eisenia was a healthier choice than Eudrilus for valorization of textile sludge.•Proportion of cow dung in the feedstock is vital for vermiremediation of sludge.
Genotoxicity-based assessments of vermitechnology for textile-sludge valorization have rarely been attempted. Therefore, waste sanitization and epigenetic stress-regulation efficiency of Eisenia fetida and Eudrilus eugeniae were evaluated in silk (DSPS) and cotton (CPWS) processing sludge-based vermibeds. Vermicomposting resulted in greater C, N, and P recovery than composting. Earthworm population reduced by 6–50% in DSPS/CPWS, while it significantly increased in cow dung (CD) mixed DSPS/CPWS. The Cr, Cd, Pb, and Zn accumulation efficiency of earthworms was higher in DSPS-based feedstocks than CPWS. However, metal-rich sludge elevated oxidative stress, causing greater inhibition of cell viability and DNA damage in Eudrilus than in Eisenia. Although histo-architecture of chloragogenous tissues was perturbed, earthworms combatted metal-induced lipid peroxidation via the activation of catalase, superoxide-dismutase, and reduced-glutathione. Correlation statistics revealed that genetic integrity in earthworms was restored through DNA-methyltransferase activity, especially in DSPS/CPWS + CD vermibeds. Overall, Eisenia was a healthier choice than Eudrilus for sustainable valorization of textile-sludge.
The impacts of Municipal solid wastes (MSW) vermicompost (VC) on soil-crop interface have rarely been studied. Hence, the influence of vermicompost on soil health and soil organic C (SOC) dynamics ...was assessed under intensive rice-rice cropping system. A 20-40% of the recommended N-fertilization was substituted by MSW-vermicompost for the crop. SOC storage, degree of humification, humic acid C, and fulvic acid C in soil gradually increased by 55-60% under NPK
60
+ VC and NPK
80
+ VC treatments in 2 years. The improvement in N-mineralization was spectacular in NPK
60
+ VC (2.79 folds) and NPK
80
+ VC (2.25 folds) treated soil. The carbon pool management index in soil was greatest under NPK
60
+ VC (2.1) treatment followed by NPK
100
+ VC (1.96) and NPK
80
+ VC (1.87) treatments. Moreover, the crop biomass and grain yield increased under VC treatments. The correlation and regression statistics revealed that rice production was enhanced due to improvement of SOC pool and humified carbon fractions in soil. Finally, we recorded highest benefit-cost ratio under NPK
60
+ VC (benefit/cost 5.55) followed by NPK
80
+ VC (benefit/cost 5.44). The study indicated that MSW-vermicompost sustained soil microbial health and SOC balance, which significantly correlated with rice production.
•Bioconversion of tea factory and paper mill coal ash is a novel effort.•Solubility of Cr and Ni in coal ashes is reduced due to vermiconversion.•Vermicomposted coal ashes improve soil ...health.•Vermicomposted tea factory coal ash enhances crop yield.
Considerable amount of bottom ash (BA) is produced by tea and paper factories in Northeast India. This significantly deteriorates soil and surface water quality through rapid acidification, releasing sulfur compounds and heavy metals. The present investigation endeavoured to convert this waste to organic manure through vermicomposting by Eisenia fetida. Substantial increment in bioavailability of N, P, K, Fe, Mn and Zn along with remarkable decline in toxic metal like Cr due to vermicomposting was noteworthy. Furthermore, vermicomposted mixtures of Tea Factory BA (TFBA) or Paper Mill BA (PMBA) with organic matter (OM) attributed profuse pod yield of French Bean (Phaseolus vulgaris L.). Hence, bioconversion of TFBA and PMBA is highly feasible through vermicomposting and the converted materials can be utilized as potential organic fertilizer.
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•SMS degradation greatly varies depending on earthworm species during vermicomposting.•Biomass degradability of earthworms was first assessed via XRD-crystallinity index.•PLFA assay ...revealed greater microbial diversity in Perionyx vermibeds than others.•Vermicomposted SMS was effective enough to greatly boost seed germination and vigor.
Spent mushroom substrate (SMS) is a recalcitrant lignocellulosic waste. Recycling of SMS through composting has been reported; however, the process is lengthy due to its complex biochemical composition. Although vermitechnology is known for its high efficiency, it has rarely been applied to recycle SMS. In this study, the qualitative value of vermicomposted SMS mediated by three earthworm species (i.e., Eisenia fetida, Eudrilus eugeniae, and Perionyx excavatus) was evaluated on the basis of nutrient availability, microbial activity, phospholipid fatty acid (PLFA) profiles, and seed germination assays. Degradation profiles of the lignocellulosic substrate in the vermireactors were assessed by monitoring the changes in crystallinity and distribution of functional groups using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy, respectively. Total organic carbon decreased by 1.4–3.5 folds with approximately 2.1–2.4 folds increase in nitrogen and phosphorus availability in all vermibeds. Interestingly, pH declined in the Eisenia and Eudrilus systems but increased in the Perionyx-vermibeds. XRD-derived crystallinity index was reduced significantly by 1.37 folds in Perionyx-vermicompost with concurrent microbial enrichment. Further, profuse abundance of vital functional groups (CO, NH, and OH) was clearly observed in the vermicompost with Perionyx followed by that with Eisenia. Moreover, PLFA illustrated significant variations in fatty acid distributions and microbial communities of the three vermicomposting systems. The seed germination assay showed that the germination index and relative root-shoot vigor of Perionyx-vermicompost treated seeds were 1.05–1.30 times greater than those of Eisenia and Eudrilus vermicompost treated ones. The results suggest that SMS degradability was affected by the growth of a healthy microbial community through vermicomposting.
Antibiotic treatment plays an essential role in preventing
Shigella
infection. However, incidences of global rise in antibiotic resistance create a major challenge to treat bacterial infection. In ...this context, there is an urgent need for newer approaches to reduce
S. flexneri
burden. This study largely focuses on the role of the herbal compound capsaicin (Caps) in inhibiting
S. flexneri
growth and evaluating the molecular mechanism behind bacterial clearance. Here, we show for the first time that Caps inhibits intracellular
S. flexneri
growth by inducing autophagy. Activation of autophagy by Caps is mediated through transcription factor TFEB, a master regulator of autophagosome biogenesis. Caps induced the nuclear localization of TFEB. Activation of TFEB further induces the gene transcription of autophagosomal genes. Our findings revealed that the inhibition of autophagy by silencing TFEB and Atg5 induces bacterial growth. Hence, Caps-induced autophagy is one of the key factors responsible for bacterial clearance. Moreover, Caps restricted the intracellular proliferation of
S. flexneri
-resistant strain. The efficacy of Caps in reducing
S. flexneri
growth was confirmed by an animal model. This study showed for the first time that
S. flexneri
infection can be inhibited by inducing autophagy. Overall observations suggest that Caps activates TFEB to induce autophagy and thereby combat
S. flexneri
infection.
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