Vermiremediation of dyeing sludge from textile mill with the help of exotic earthworm Eisenia fetida Savigny

The aim of present study was for the vermiremediation of dyeing sludge from textile mill into nutrient-rich vermicompost using earthworm Eisenia fetida. The dyeing sludge was mixed with cattle dung in different ratios, i.e., 0:100 (D₀), 25:75 (D₂₅), 50:50 (D₅₀), 75:25 (D₇₅), and 100:0 (D₁₀₀) with earthworms, and 0:100 (S₀), 25:75 (S₂₅), 50:50 (S₅₀), 75:25 (S₇₅), and 100:0 (S₁₀₀) without earthworms. Minimum mortality and maximum population build-up were observed in a 25:75 mixture. Nitrogen, phosphorus, sodium, and pH increased from the initial to the final products with earthworms, while electrical conductivity, C/N ratio, organic carbon, and potassium declined in all the feed mixtures. Vermicomposting with E. fetida was better for composting to change this sludge into nutrient-rich manure.     

Nutrient and enzymatic changes of hydrolysed tannery solid waste treated with epigeic earthworm Eudrilus eugeniae and phytotoxicity assessment on selected commercial crops

Animal fleshing (ANFL) is the predominant proteinaceous solid waste generated during processing of leather and it is confronting disposal problems. The aim of this study was to assess the potential of epigeic earthworm Eudrilus eugeniae to utilize and transform the fermented ANFL in the solid state (SSF) and submerged state (SmF) into a value added product along a low residence period (25 days). A total of six treatment units containing different waste mixture compositions were established. Fifty healthy and non-clitellated earthworms were introduced in three different treatment containers: control, SSF, and SmF (+worm). Another set of treatment mixtures (control, SSF, SmF) was established without earthworms (?worm) to compare the results. The products were characterized for physico-chemical, enzymatic analysis and seedling growth parameters to compare the differences in the process with and without earthworms. The changes observed in the analytical parameters were in the following order: SSF > SmF > control mixtures (p?<?0.05). The vermicompost showed a significant reduction in heavy metals, total organic carbon and an increase in total Kjeldhal nitrogen as compared to the product untreated by earthworms. The maximum enzymatic activities were observed after 21 days of vermicomposting. The relative seed germination of vermicompost extracts were in the order of tomato (Lycopersicon esculentum) > green gram (Vigna radiata) > cucumber (Cucumis sativus) > bottle gourd (Lagenaria siceraria (Mol.) Standl.) and showed no phytotoxicity effects. The results indicated that the combination of both ANFL hydrolysis through fermentation and vermicomposting is a good alternative to the management of this kind of waste.     

Effect of vermicast generated from an allelopathic weed lantana (Lantana camara) on seed germination,plant growth,and yield of cluster bean (Cyamopsis tetragonoloba)

In perhaps the first-ever study of its kind, the effect of vermicompost, derived solely from an allelopathic weed, on the germination, growth, and yield of a botanical species, has been carried out. In test plots, the soil was treated with the vermicompost of lantana (Lantana camara) at the rates of 5, 7.5, and 10 t ha^?1, and cluster bean (Cyamopsis tetragonoloba) was grown on it. The performance of these systems was compared with the systems in which the soil was fortified with inorganic fertilizers (IFs) in concentrations equivalent to those present in the respective vermicompost (VC) treatments. Additionally, a set of control was studied in which the soil was used without fortification by either VC or IF. It was seen that up to 51.5 % greater germination success occurred in the VC treatments compared to controls. VC also supported better plant growth in terms of stem diameter, shoot length, shoot mass, number of leaves, and leaf pigments. The positive impact extended up to fruit yield. In addition, vermicast application enhanced root nodule formation, reduced disease incidence, and allowed for a smaller number of stunted plants. The results indicate that allelopathic ingredients of lantana seem to have been totally eliminated during the course of its vermicomposting and that lantana vermicompost has the potential to support germination, growth, and fruit yield better than equivalent quantities of IFs.     

Interactions between sewage sludge-amended soil and earthworms—comparison between <Emphasis Type="Italic">Eisenia fetida</Emphasis> and <Emphasis Type="Italic">Eisenia andrei</Emphasis> composting species

Vermicomposting is an eco-friendly technology, where earthworms are introduced in the waste, inter alia sewage sludge, to cooperate with microorganisms and enhance decomposition of organic matter. The main aims of the present study was to determine the influence of two different earthworm species, Eisenia fetida and Eisenia andrei, on the changes of selected metallic trace elements content in substratum during vermicomposting process using three different sewage sludge mainly differentiated by their metal contents. Final vermicompost has shown a slight reduction in Cd, Cu, Ni, and Pb, while the Zn concentration tends to increase. Accumulation of particular heavy metals in earthworms’ bodies was assessed. Both species revealed high tendency to accumulate Cd and Zn, but not Cu, Ni, and Pb, but E. andrei has higher capabilities to accumulate some metals. Riboflavin content, which content varies depending on metal pollution in several earthworms species, was measured supravitaly in extruded coelomocytes. Riboflavin content decreased slightly during the first 6 weeks of exposure and subsequently restored till the end of the 9-week experiment. Selected agronomic parameters have also been measured in the final product (vermicompost) to assess the influence of earthworms on substratum.     

Management of fresh water weeds (macrophytes) by vermicomposting using Eisenia fetida

In the present study, potential of Eisenia fetida to recycle the different types of fresh water weeds (macrophytes) used as substrate in different reactors (Azolla pinnata reactor, Trapa natans reactor, Ceratophyllum demersum reactor, free-floating macrophytes mixture reactor, and submerged macrophytes mixture reactor) during 2 months experiment is investigated. E. fetida showed significant variation in number and weight among the reactors and during the different fortnights (P <0.05) with maximum in A. pinnata reactor (number 343.3?±?10.23 %; weight 98.62?±?4.23 % ) and minimum in submerged macrophytes mixture reactor (number 105?±?5.77 %; weight 41.07?±?3.97 % ). ANOVA showed significant variation in cocoon production (F₄?=?15.67, P <0.05) and mean body weight (F₄?=?13.49, P <0.05) among different reactors whereas growth rate (F₃?=?23.62, P <0.05) and relative growth rate (F₃?=?4.91, P <0.05) exhibited significant variation during different fortnights. Reactors showed significant variation (P <0.05) in pH, Electrical conductivity (EC), Organic carbon (OC), Organic nitrogen (ON), and C/N ratio during different fortnights with increase in pH, EC, N, and K whereas decrease in OC and C/N ratio. Hierarchical cluster analysis grouped five substrates (weeds) into three clusters—poor vermicompost substrates, moderate vermicompost substrate, and excellent vermicompost substrate. Two principal components (PCs) have been identified by factor analysis with a cumulative variance of 90.43 %. PC1 accounts for 47.17 % of the total variance represents “reproduction factor” and PC2 explaining 43.26 % variance representing “growth factor.” Thus, the nature of macrophyte affects the growth and reproduction pattern of E. fetida among the different reactors, further the addition of A. pinnata in other macrophytes reactors can improve their recycling by E. fetida.     

Distinctive effects of nano-sized permethrin in the environment

Pesticides are an essential tool in integrated pest management. Nanopermethrin was prepared by solvent evaporation from an oil-in-water volatile microemulsion. The efficacy of the formulated nanopermethrin was tested against Aedes aegypti and the results compared to those of regular, microparticular permethrin. The 24 h LC₅₀ for nanopermethrin and permethrin was found to be 0.0063 and 0.0199 mg/L, respectively. The formulated nanopermethrin was tested for toxicity against non-target organisms. Nanopermethrin did not show antibacterial activity against Escherichia coli (ATCC 13534 and 25922) or against Bacillus subtilis. Phytotoxicity studies of nanopermethrin to the seeds of Lycopersicum esculentum, Cucumis sativus, and Zea mays showed no restraint in root length and germination percentage. In the Allium cepa test, regular microparticular permethrin treatment of 0.13 mg/L showed a mitotic index (MI) of 46.8 % and chromosomal aberration of 0.6 %, which was statistically significant (p?<?0.05) compared to control. No significant differences were observed in 0.13 mg/L nanopermethrin exposure as compared to control (MI of 52.0 and 55.03 % and chromosomal aberration of 0.2 and 0 %, respectively). It was concluded that formulated nanopermethrin can be used as a safe and effectual alternative to commercially available permethrin formulation in agricultural practices.     

Removal of hydrocarbon from refinery tank bottom sludge employing microbial culture

Accumulation of oily sludge is becoming a serious environmental threat, and there has not been much work reported for the removal of hydrocarbon from refinery tank bottom sludge. Effort has been made in this study to investigate the removal of hydrocarbon from refinery sludge by isolated biosurfactant-producing Pseudomonas aeruginosa RS29 strain and explore the biosurfactant for its composition and stability. Laboratory investigation was carried out with this strain to observe its efficacy of removing hydrocarbon from refinery sludge employing whole bacterial culture and culture supernatant to various concentrations of sand–sludge mixture. Removal of hydrocarbon was recorded after 20 days. Analysis of the produced biosurfactant was carried out to get the idea about its stability and composition. The strain could remove up to 85?±?3 and 55?±?4.5 % of hydrocarbon from refinery sludge when whole bacterial culture and culture supernatant were used, respectively. Maximum surface tension reduction (26.3 mN m^?1) was achieved with the strain in just 24 h of time. Emulsification index (E24) was recorded as 100 and 80 % with crude oil and n-hexadecane, respectively. The biosurfactant was confirmed as rhamnolipid containing C₈ and C₁₀ fatty acid components and having more mono-rhamnolipid congeners than the di-rhamnolipid ones. The biosurfactant was stable up to 121 °C, pH 2–10, and up to a salinity value of 2–10 % w/v. To our knowledge, this is the first report showing the potentiality of a native strain from the northeast region of India for the efficient removal of hydrocarbon from refinery sludge.     

Bio-optimization of the carbon-to-nitrogen ratio for efficient vermicomposting of chicken manure and waste paper using <Emphasis Type="Italic">Eisenia fetida</Emphasis>

The main objective of the present study was to determine the optimum C/N ratio for converting waste paper and chicken manure to nutrient-rich manure with minimum toxicity. Six treatments of C/N ratio 20, 30, 40, 50, 60, and 70 (T1, T2, T3, T4, T5, and T6, respectively) achieved by mixing chicken manure with shredded paper were used. The study involved a composting stage for 20 days followed by vermicomposting with Eisenia fetida for 7 weeks. The results revealed that 20 days of composting considerably degraded the organic waste mixtures from all treatments and a further 7 weeks of vermiculture significantly improved the bioconversion and nutrient value of all treatments. The C/N ratio of 40 (T3) resulted in the best quality vermicompost compared to the other treatments. Earthworm biomass was highest at T3 and T4 possibly due to a greater reduction of toxic substances in these waste mixtures. The total N, total P, and total K concentrations increased with time while total carbon, C/N ratio, electrical conductivity (EC), and heavy metal content gradually decreased with time during the vermicomposting process. Scanning electron microscopy (SEM) revealed the intrastructural degradation of the chicken manure and shredded paper matrix which confirmed the extent of biodegradation of treatment mixtures as result of the composting and vermicomposting processes. Phytotoxicity evaluation of final vermicomposts using tomato (Lycopersicon esculentum), radish (Raphanus sativus), carrot (Daucus carota), and onion (Allium cepa) as test crops showed the non-phytotoxicity of the vermicomposts to be in the order T3 > T4 > T2 > T1 > T5 > T6. Generally, the results indicated that the combination of composting and vermicomposting processes is a good strategy for the management of chicken manure/paper waste mixtures and that the ideal C/N ratio of the waste mixture is 40 (T3).     

Sustainable reuse of rice residues as feedstocks in vermicomposting for organic fertilizer production

Over the past decade, rice (Oryza sativa or Oryza glaberrima) cultivation has increased in many rice-growing countries due to the increasing export demand and population growth and led to a copious amount of rice residues, consisting mainly of rice straw (RS) and rice husk (RH), being generated during and after harvesting. In this study, Eudrilus eugeniae was used to decompose rice residues alone and rice residues amended with cow dung (CD) for bio-transformation of wastes into organic fertilizer. Generally, the final vermicomposts showed increases in macronutrients, namely, calcium (11.4–34.2 %), magnesium (1.3–40.8 %), phosphorus (1.2–57.3 %), and potassium (1.1–345.6 %) and a decrease in C/N ratio (26.8–80.0 %) as well as increases in heavy metal content for iron (17–108 %), copper (14–120 %), and manganese (6–60 %) after 60 days of vermicomposting. RS as a feedstock was observed to support healthier growth and reproduction of earthworms as compared to RH, with maximum adult worm biomass of 0.66 g/worm (RS) at 60 days, 31 cocoons (1RS:2CD), and 23 hatchlings (1RS:1CD). Vermicomposting of RS yielded better results than RH among all of the treatments investigated. RS that was mixed with two parts of CD (1RS:2CD) showed the best combination of nutrient results as well as the growth of E. eugeniae. In conclusion, vermicomposting could be used as a green technology to bio-convert rice residues into nutrient-rich organic fertilizers if the residues are mixed with CD in the appropriate ratio.     

Optimization of animal manure vermicomposting based on biomass production of earthworms and higher plants

The goal of this study was to optimize the mixture of swine manure (SM) and cattle manure (CM) used in the vermicomposting process, seeking to increase the manure biodegradation rate and enhance the biomass production of both earthworms and higher plants. To achieve this goal, physico-chemical parameters were determined to assess the final compost quality after 50 days of vermicomposting. The different manure ratios used to produce the composts (C) were as follows (SM:CM, % m/m basis): C1 100:0, C2 (75:25), C3 (50:50), C4 (25:75), and C5 (0:100). In addition, the earthworm biomass and the phytoproductivity of lettuce (Lactuca sativa L.) plants grown in mixtures (1:1) of natural soil and the most viable vermicomposts were investigated. The C1 and C2 compost compositions were associated with high earthworm mortality rates. The C3 compost provided the highest mineral concentrations and C5 showed the highest lettuce yield (wet biomass). The results verify that stabilized cattle manure is an excellent substrate for the vermicomposting process and that fresh swine manure must be mixed with pre-stabilized cattle manure to ensure an optimized vermicomposting process, which must be controlled in terms of temperature and ammonia levels. It is concluded that small livestock farmers could add value to swine manure by applying the vermicomposting process, without the need for high investments and with a minimal requirement for management of the biodegradation process. These are important technical aspects to be considered when circular economy principles are applied to small farms.     

Feasibility of vermicomposting dairy biosolids using a modified system to avoid earthworm mortality

Abstract

A laboratory study was conducted to examine the feasibility of vermicomposting dairy biosolids (dairy sludge), either alone or with either of the bulking agents ‐ cereal straw or wood shavings, using the epigeic earthworm ‐ Eisinea andrei. Earthworms added directly to these three substrates died within 48 hours. A system was developed to overcome the toxic effect of unprocessed dairy biosolids. The substrates were placed over a layer of vermicomposted sheep manure into which the earthworms were inoculated. Within two weeks, all earthworms were within the upper layer of substrate. Compared to sheep manure which is a favourable substrate for vermicomposting, the three substrates containing dairy biosolids were more effective in supporting earthworm growth and reproduction. The final products obtained after 63 days of vermicomposting had 39–53% less organic carbon than the initial substrates. Organic fractionation indicated that vermicomposting increased the stability of the materials to biological decomposition. The vermicomposts obtained from the three substrates with dairy biosolids had low heavy metal contents and electrical conductivities, and did not inhibit plant growth when compared with a commercial vermicompost in a bioassay.     

Genotoxic effects of Bismuth (III) oxide nanoparticles by Allium and Comet assay

Genotoxic effects of Bismuth (III) oxide nanoparticles (BONPs) were investigated on the root cells of Allium cepa by Allium and Comet assay. A. cepa roots were treated with the aqueous dispersions of BONPs at five different concentrations (12.5, 25, 50, 75, and 100 ppm) for 4 h. Exposure of BONPs significantly increased mitotic index (MI) except 12.5 ppm, total chromosomal aberrations (CAs) in Allium test. While stickiness chromosome laggards, disturbed anaphase–telophase and anaphase bridges were observed in anaphase–telophase cells, pro-metaphase and c-metaphase in other cells. A significant increase in DNA damage was also observed at all concentrations of BONPs except 12.5 ppm by Comet assay. The results were also analyzed statistically by using SPSS for Windows; Duncan’s multiple range test was performed. These results indicate that BONPs exhibit genotoxic activity in A. cepa root meristematic cells.     

Reduction of bioavailability and leachability of heavy metals during vermicomposting of water hyacinth

Vermicomposting of water hyacinth is a good alternative for the treatment of water hyacinth (Eichhornia crassipes) and subsequentially, beneficial for agriculture purposes. The bioavailability and leachability of heavy metals (Zn, Cu, Mn, Fe, Ni, Pb, Cd, and Cr) were evaluated during vermicomposting of E. crassipes employing Eisenia fetida earthworm. Five different proportions (trials 1, 2, 3, 4, and 5) of cattle manure, water hyacinth, and sawdust were prepared for the vermicomposting process. Results show that very poor biomass growth of earthworms was observed in the highest proportion of water hyacinth (trial 1). The water soluble, diethylenetriaminepentaacetic acid (DTPA) extractable, and leachable heavy metals concentration (percentage of total heavy metals) were reduced significantly in all trials except trial 1. The total concentration of some metals was low but its water soluble and DTPA extractable fractions were similar or more than other metals which were present in higher concentration. This study revealed that the toxicity of metals depends on bioavailable fraction rather than total metal concentration. Bioavailable fraction of metals may be toxic for plants and soil microorganisms. The vermicomposting of water hyacinth by E. fetida was very effective for reduction of bioavailability and leachability of selected heavy metals. Leachability test confirmed that prepared vermicompost is not hazardous for soil, plants, and human health. The feasibility of earthworms to mitigate the metal toxicity and to enhance the nutrient profile in water hyacinth vermicompost might be useful in sustainable land renovation practices at low-input basis.     

Levels, compositions, and inventory of polybrominated diphenyl ethers in sewage sludge of Guangdong Province, South China

Polybrominated diphenyl ethers (PBDEs) were measured in sewage sludge samples collected from major wastewater treatment plants in Guangdong Province, South China. Concentrations of ∑₃₉PBDE (all 39 compounds including tri- to hepta- PBDE congeners except for BDE-209) ranged from 3.6 to 428 ng/g dw with a mean value of 67.4 ng/g dw and a median value of 25.9 ng/g dw, and those of BDE-209 ranged from 9.9 to 5,010 ng/g dw (mean 1,024 ng/g dw and median 824 ng/g dw). The PBDE mixtures detected were mainly comprised of penta-, octa-, and deca-BDEs, with deca-BDE as the dominant constituent. The most abundant congeners, excluding BDE-209, were BDE-47, BDE-99, and BDE-183. Good correlations were found among the concentrations of BDE-47, BDE-99, BDE-100, BDE-138, and BDE-154 (r?>?0.8). However, poor correlations were found between the concentrations of BDE-209 and all other congeners (r?<?0.3). This fact suggests that most tri- to hepta-BDEs detected did not originate from decomposition of deca-BDE. The estimated annual emission of ∑_allPBDEs, ∑₃₉PBDEs, penta-BDE, octa-BDE, and deca-BDE to the Pearl River Delta environment (PRD), based on the sludge samples analyzed, amounts to 232, 20.2, 5.5, 1.7, and 212 kg per year, implicating sewage sludge as a significant source of PBDEs to the PRD environment.     

Harnessing dark fermentative hydrogen from pretreated mixture of food waste and sewage sludge under sequencing batch mode

Food waste and sewage sludge are the most abundant and problematic organic wastes in any society. Mixture of these two wastes may provide appropriate substrate condition for dark fermentative biohydrogen production based on synergistic mutual benefits. This work evaluates continuous hydrogen production from the cosubstrate of food waste and sewage sludge to verify mechanisms of performance improvement in anaerobic sequencing batch reactors. Volatile solid concentration and mixing ratio of food waste and sludge were adjusted to 5 % and 80:20, respectively. Five different hydraulic retention times (HRT) of 36, 42, 48, 72, and 108 h were tested using anaerobic sequencing batch reactors to find out optimal operating condition. Results show that the best performance was achieved at HRT 72 h, where the hydrogen yield, the hydrogen production rate, and hydrogen content were 62.0 mL H₂/g VS, 1.0 L H₂/L/day, and ~50 %, respectively. Sufficient solid retention time (143 h) and proper loading rate (8.2 g COD/L/day as carbohydrate) at HRT 72h led to the enhanced performance with better hydrogen production showing appropriate n-butyrate/acetate (B/A) ratio of 2.6. Analytical result of terminal-restriction fragment length polymorphism revealed that specific peaks associated with Clostridium sp. and Bacillus sp. were strongly related to enhanced hydrogen production from the cosubstrate of food waste and sewage sludge.     

Kinetics of phenol biodegradation at high concentration by a metabolically versatile isolated yeast Candida tropicalis PHB5

A highly tolerant phenol-degrading yeast strain PHB5 was isolated from wastewater effluent of a coke oven plant and identified as Candida tropicalis based on phylogenetic analysis. Biodegradation experiments with C. tropicalis PHB5 showed that the strain was able to utilize 99.4 % of 2,400 mg l^?1 phenol as sole source of carbon and energy within 48 h. Strain PHB5 was also observed to grow on 18 various aromatic hydrocarbons. Haldane model was used to fit the exponential growth data and the following kinetic parameters were obtained: μ _max?=?0.3407 h^?1, K _S?=?15.81 mg l^?1, K _i?=?169.0 mg l^?1 (R ²?=?0.9886). The true specific growth rate, calculated from μ _max, was 0.2113. A volumetric phenol degradation rate (V _max) was calculated by fitting the phenol consumption data with Gompertz model and specific degradation rate (q) was calculated from V _max. The q values were fitted with Haldane model, yielding following parameters: q _max?=?0.2766 g g^?1 h^?1, K _S ′?=?2.819 mg l^?1, K _i ′?=?2,093 (R ²?=?0.8176). The yield factor (Y _X/S ) varied between 0.185 to 0.96 g g^?1 for different initial phenol concentrations. Phenol degradation by the strain proceeded through a pathway involving production of intermediates such as catechol and cis,cis-muconic acid which were identified by enzymatic assays and HPLC analysis.     

The impact of sewage sludge compost on tree peony growth and soil microbiological,and biochemical properties

In order to assess the suitability of sludge compost application for tree peony (Paeonia suffruticosa)–soil ecosystems, we determined soil microbial biomass C (C_mic), basal respiration (R_mic), enzyme activities, and tree peony growth parameters at 0–75% sludge compost amendment dosage. Soil C_mic, R_mic, C_mic as a percent of soil organic C, enzyme (invertase, urease, proteinase, phosphatase, polyphenoloxidase) activities, and plant height, flower diameter, and flower numbers per plant of tree peony significantly increased after sludge compost amendment; however, with the increasing sludge compost amendment dosage, a decreasing trend above 45% sludge compost amendment became apparent although soil organic C, total Kjeldahl N, and total P always increased with the sludge compost amendment. Soil metabolic quotient first showed a decreasing trend with the increasing sludge compost application in the range of 15–45%, and then an increasing trend from compost application of 45–75%, with the minimum found at compost application of 45%. As for the diseased plants, 50% of tree peony under the treatment without sludge compost amendment suffered from yellow leaf disease of tree peony, while no any disease was observed under the treatments with sludge compost application of 30–75%, which showed sludge compost application had significant suppressive effect on the yellow leaf disease of tree peony. This result convincingly demonstrated that ?45% sludge compost application dosage can take advantage of beneficial effect on tree peony growth and tree peony–soil ecosystems.     

Natural deep eutectic solvent mediated pretreatment of rice straw: bioanalytical characterization of lignin extract and enzymatic hydrolysis of pretreated biomass residue

The present investigation demonstrated pretreatment of lignocellulosic biomass rice straw using natural deep eutectic solvents (NADESs), and separation of high-quality lignin and holocellulose in a single step. Qualitative analysis of the NADES extract showed that the extracted lignin was of high purity (>90 %), and quantitative analysis showed that nearly 60?±?5 % (w/w) of total lignin was separated from the lignocellulosic biomass. Addition of 5.0 % (v/v) water during pretreatment significantly enhanced the total lignin extraction, and nearly 22?±?3 % more lignin was released from the residual biomass into the NADES extract. X-ray diffraction studies of the untreated and pretreated rice straw biomass showed that the crystallinity index ratio was marginally decreased from 46.4 to 44.3 %, indicating subtle structural alterations in the crystalline and amorphous regions of the cellulosic fractions. Thermogravimetric analysis of the pretreated biomass residue revealed a slightly higher T _dcp (295 °C) compared to the T _dcp (285 °C) of untreated biomass. Among the tested NADES reagents, lactic acid/choline chloride at molar ratio of 5:1 extracted maximum lignin of 68?±?4 mg g^?1 from the rice straw biomass, and subsequent enzymatic hydrolysis of the residual holocellulose enriched biomass showed maximum reducing sugars of 333?±?11 mg g^?1 with a saccharification efficiency of 36.0?±?3.2 % in 24 h at 10 % solids loading.     

Start-up of sequencing batch reactor with <Emphasis Type="Italic">Thiosphaera pantotropha</Emphasis> for treatment of high-strength nitrogenous wastewater and sludge characterization

Biological treatment of high-strength nitrogenous wastewater is challenging due to low growth rate of autotrophic nitrifiers. This study reports bioaugmentation of Thiosphaera pantotropha capable of simultaneously performing heterotrophic nitrification and aerobic denitrification (SND) in sequencing batch reactors (SBRs). SBRs fed with 1:1 organic-nitrogen (N) and NH₄ ⁺-N were started up with activated sludge and T. pantotropha by gradual increase in N concentration. Sludge bulking problems initially observed could be overcome through improved aeration and mixing and change in carbon source. N removal decreased with increase in initial nitrogen concentration, and only 50–60 % removal could be achieved at the highest N concentration of 1000 mg L^?1 at 12-h cycle time. SND accounted for 28 % nitrogen loss. Reducing the settling time to 5–10 min and addition of divalent metal ions gradually improved the settling characteristics of sludge. Sludge aggregates of 0.05–0.2 mm diameter, much smaller than typical aerobic granules, were formed and progressive increase in settling velocity, specific gravity, Ca²⁺, Mg²⁺, protein, and polysaccharides was observed over time. Granulation facilitated total nitrogen (TN) removal at a constant rate over the entire 12-h cycle and thus increased TN removal up to 70 %. Concentrations of NO₂ ^?-N and NO₃ ^?-N were consistently low indicating effective denitrification. Nitrogen removal was possibly limited by urea hydrolysis/nitrification. Presence of T. pantotropha in the SBRs was confirmed through biochemical tests and 16S rDNA analysis.     

Protective effect of Syzygium cumini against pesticide-induced cardiotoxicity

Pesticide-induced toxicity is a serious issue which has resulted in plethora of diseases all over the world. The organophosphate pesticide malathion has caused many incidents of poisoning such as cardiac manifestations. The present study was designed to evaluate the effect of Syzygium cumini on malathion-induced cardiotoxicity. Dose optimization of malathion and polyphenols such as curcumin, (?)-epicatechin, gallic acid, butylated hydroxyl toluene, etc. was done by MTT cell proliferation assay. Nuclear deformities, ROS production, and integrity of extra cellular matrix components were analyzed by different techniques. S. cumini methanolic pulp extract (MPE), a naturally derived gallic acid-enriched antioxidant was taken to study its effect on malathion-induced toxicity. Nuclear deformities, ROS production, and integrity of extra cellular matrix components were also analyzed. Twenty micrograms per milliliter LD50 dose of malathion was found to cause stress-mediated responses in H9C2 cell line. Among all the polyphenols, gallic acid showed the most significant protection against stress. Gallic acid-enriched methanolic S. cumini pulp extract (MPE) showed 59.76 %?±?0.05, 81.61 %?±?1.37, 73.33 %?±?1.33, 77.19 %?±?2.38 and 64.19 %?±?1.43 maximum inhibition for DPPH, ABTS, NO, H₂O₂ and superoxide ion, respectively, as compared to ethanolic pulp extract and aqueous pulp extract. Our study suggests that S. cumini MPE has the ability to protect against the malathion-mediated oxidative stress in cardiac myocytes.